Search

Chestnut [Castanea dentata (Marsh.) Borkh.] was a dominant tree of the upland forests of eastern North America until its elimination by the blight fungus, Endothia parasitica Anders. The blight originated in New York City in 1904, and within 50 years, it spread throughout the entire range of Castanea dentata. The chestnut destruction is documented in lake sediments by a corresponding decline of chestnut pollen as illustrated in examples from Lakes Ontario and Erie, and Woodcliff Lake, New Jersey. According to the data from Woodcliff Lake, the decline can be assigned an age equivalent to the time of the chestnut die-out for the area. Thus, dates of 1930 A.D. and 1935 A.D. are taken to represent times of the chestnut pollen decline in Lakes Ontario and Erie, respectively. The Castanea pollen decline provides an excellent and very recent time horizon (above the Ambrosia pollen boundary) for determining sedimentation trends since the time of European settlement as well as recent sedimentation rates.

Existing edaphic factors on two lowland study sites at Dunbar Forest have resulted in a rich and characteristic flora of about 100 species. Alnusrugosa (Du Roi) Spreng. dominates the better drained very fine sandy loam site. The poorly drained silty clay loam site is in a transitional stage of succession from alder to a mixed alder-ash (Fraxinusnigra Marsh) community.A drainage ditch constructed 6 years earlier across both sites has had little effect on water table fluctuation. However, of the two areas the poorly drained site was more influenced by the drainage. The ditch did not greatly change species composition, but resulted in a distribution shift among herbaceons species.

The behaviour and ecology of Franklin's gull were studied at Agassiz National Wildlife Refuge in northwestern Minnesota to determine the adaptations of the species for nesting in marshes. Two factors seemed to be important in colony site selection: cattail dispersion pattern and cattail density. Franklin's gulls prefer to nest in cattail areas closest to open water. The number of nests per unit area decreased as cattail density increased. Nest site selection is dependent on aggression and visibility. Visibility from nest level is the result of cattail placement and height. The distance between nests was directly correlated with visibility. Aggression by gulls on nests was lowered experimentally by decreasing visibility and raised by increasing visibility. Nest platforms were constructed of cattail material, and were attached to cattail stems. Nest material was added to the nests throughout the incubation and brooding period. Material was usually added following nest relief. The egg laying period was from 6 to 28 May. There was more synchrony of egg laying in sub-areas of the colony than in the colony as a whole. Successive eggs in clutches were laid at 24- to 48-hr intervals. The distance between nests decreased during the season as pairs filled in areas that were not defended. Territorial pairs defended an area up to 10 m from their stations prior to egg laying, but defended only the area within 3 m of their nests during incubation. Both members of pairs incubated the eggs and cared for the young. The incubation period was 24 days. The primary predators on adults and young were marsh hawk, great horned owl and mink. Franklin's gulls do not eat eggs or young of gulls. Adults fed on earthworms, insects and grain. Most marked adults fed within 16 km of the colony. Chicks were fed primarily on earthworms. The hatching period was from 30 May to 21 June. Chicks of all ages tested on a visual cliff apparatus were able to perceive the drop. Chicks tested on a 30-degree incline apparatus walked up it when 6 days old and younger, and walked down at 12 days of age and older. Brood mobility was less than in ground nesting species of gulls. In an undisturbed colony the chicks remained on the nest platforms until they were 25 to 30 days old although they were capable of swimming shortly after hatching. Individual recognition between parents and chicks appeared later in this species than in ground-nesting gulls. Adults accepted alien chicks (experimentally exchanged) that were younger than about 14 days old until their own chicks were over that age. Adults accepted larger and older broods than their own, as well as broods of mixed ages. Chicks began to react differently to strange adults at about 16 days of age. The breeding chronology of Franklin's gull is compressed when compared to that of other gulls. Possible selection pressures affecting this synchrony are discussed. The behaviour of the marsh-nesting Franklin's gull is compared with that of typical ground-and cliffnesting gulls; the possibility that the ancestral gull may have been a marsh nester is discussed.

The ergot fungus Claviceps purpurea was found on Spartina alterniflora throughout Gulf and Atlantic coastal marshes. Spartina patens and Spartina cynosuroides were also collected bearing sclerotia of C. purpurea. Observations on the intensity of infection are reported, with notably heavy infection apparent in regions of spoil deposits Conditions for germination of sclerotia are given along with some details of stromal morphology. Implications of C. purpurea in salt marsh ecosystems are discussed.

1974 marks the centenary of the birth of an important Proven~al author, Joseph D'Arbaud, who not only wrote in Proven9al but himself 'translated' his own work into Modem French (which he also spoke and wrote as a native tongue). Like Mistral, who wrote a foreword in 1913 to D'Arbaud's volume of verse Le Laurier d'Arles, D'Arbaud lived and wrote all his life in terms of Proven~al values: he was a 'Majoral' of the Felibrige, son of a well-known Proven~al poetess, Marie D' Arbaud, and editor, with Emile Sicard, of a long-lived local review, Le Fleu. What is even more interesting, and quite characteristic of the man, is that, though born in the sunny Durance valley at Meyrargues and educated at A vignon and Aix-en-Provence, he deliberately turned his back on conventional city living to go and settle, for quite a number of years, as a manadier or cattle ranch owner, near Fos, in the Camargue, the vast, flat, salty reach of country that makes up the Rhone delta. And it is the Camargue that is the basic inspiration of his work. Today's Camargue is on the way to becoming a rice-bowl. In D' Arb aud's time, not so very long ago, it remained, and in the western reaches still is, a blistered, wind-scorched tract, a home for herds of horses and bulls, a haunt of flamingoes and herons and sea-gulls. Landscape here is a long horizon of reeds, tamarisks and stunted trees, topped by a huge architecture of scudding clouds driven by the unceasing winds. For this area is the homeland of the winds: there is nothing to stop them. They rage in from the Rhone valley or the Atlantic or Mediterranean, whip the great etangs into spindrift, flatten the reeds and thickets into prostrate obedience and parch the cracked soil into salty barrenness. The herdsmen's cabanes, thatched and squat, present their rounded roofs to the blast and weather the storms. The birds have the shelter of marsh grasses and stunted shrubs, or of canal banks, but the stallions and bulls, come wind, come weather, seem to be quite hardened to the wildest of wild elements, and to be themselves just as wild. They roam and pasture freely over a far-extending, unfenced wilderness, and their only restraint is the periodical round-up by the herdsmen or gardians, armed with their tridents and mounted on the fast, white horses, tireless and alert, which are the special glory of the Camargue. It is no country for weaklings

Benjamin C. Marsh, a vigorous young social worker in the early years of the twentieth century, attacked the extreme congestion of poor people in the nation's largest cities. In his analysis of the causes of congestion, Marsh identified the basic dynamics of large-scale crowding and offered some of the most radical solutions of taxation, land-use, and planning proposed during his day. As an early leader against the overcrowding of land, the author of the first book devoted entirely to city planning, and the founder of the first National Conference on City Planning, Marsh's career points up the diversity of style and ideology that characterized the pioneers of the planning profession.

Collections of hybrid poplars made in the Roseisle area of Manitoba appear to have resulted from hybridization of introduced P. × petrowskyana Schneid. with native P. deltoides Marsh. var. occidentalis Rydb. and P. balsamifera L. This interpretation was supported by morphology of an open-pollinated seedling population of P. × petrowskyana and by chromatographic analyses. Gas chromatographic results were effective in distinguishing the three parent species; however, the hybrid nature of P. × petrowskyana made chromatographic documentation of hybridization very difficult. High fertility, indicated by abundant production of sound seed, was noted for several mature P. × petrowskyana × P. deltoides var. occidentalis female trees. No barriers were found that would prevent a three species complex of all three hybridizing species.

Gross primary production of edaphic algae was estimated for five areas in a high salinity tidal marsh near Lewcs, Delaware. Salt pan and bare bank (free of angiosperms) algal production did not vary significantly from one part of the year to another. Algal productivity in the tall Spartina alterniflora and Distichlis spicata areas was greatest from midJanuary to mid-May. In the short S. alterniflora area algal productivity did not decrease in the warmest part of the year as it did in the two other grass areas. Annual cycles of light, tcmpcrature, and salinity were measured. Gross algal production was about a third of the angiosperm net production. Since much of the algal production occurs when angiosperms are dormant, it complements the pattern of angiosperm energy fixation. Primary production in the salt marsh has three components: angiosperms, planktonic algae, and attached algae. Many investigators have examined aerial angiosperm production (e.g. Keefe 1972). Phytoplankton productivity in the major stream channels of a Georgia marsh system was measured by Ragotzkic (1959) and Pomeroy ( 1959) examined the edaphic algal productivity in the same marsh. Production of the soil algae was greatest at low tide in winter and highest at high tide in summer, but total daily production (high and low tide values combined) was not significantly different at different seasons. WC believed that edaphic algal production in a more northern salt marsh would differ from that in Georgia. In addition to affecting algal activities directly, the differcnt climatic conditions would indirectly affect the algae through their influence on the angiosperms. This study was undertaken to measure the algal primary produc1 Part of a thesis submitted for the degree of Ph.D. at the University of Dclawarc. This rcscarch was supported in part by Pittman-Robertson funds made available to the State of Delaware’s Division of Fish and Wildlife, Department of Natural Resources and Environmental Control. 2 Present address : Marine Institute, The University of Georgia, Sapelo Island 31327. tion in a Delaware salt marsh and to examine the potential relationships between the algae and some environmental factors. Materials and rmthods Algal communities associated with five areas in Canary Creek near Lewes, Delaware, wcrc studied for a year. The areas were: a tall (ca. 145 cm) Spartina alterniflora Loisel. stand along a creek, a short (ca. 25 cm) S. alterniflora stand in the higher marsh, a bare bank between the two S. alterniflora stands, a Distichlis spicata L. Greene stand, and a salt pan. Randomly selected samples of the edaphic marsh communities were taken from each area 15 times during the year, and data on illuminance, temperature, salinity (surface and interstitial water ) , surface water pH, and the height of spcrmatophytc cover were collected using standard equipment. Soil for interstitial water salinity samples was obtained by coring with plastic tubing. Water movement during transport was not significant since the average water pcrcolation rates for these saturated soils (57% water) was 0.37 ml hr-l cm-2 (SE = 0.08). Evaporation was reduced by lightly stoppering the coring tubes. Interstitial water samples were obtained by wrapping soil in LIMNOLOGY AND OCEANOGRAPHY 390 MAY 1974, V. 19(3) Marsh edaphic algal production 391

Growth in Mercenaria mercenaria and Crassostrea virginica , bivalves found in tidal creeks in salt marshes on the coast of the NW Atlantic, was not affected by experimental additions of metal-containing sewage sludge and urea fertilisers to salt marsh plots. Modiolus demissus , a mussel inhabiting the marsh surface itself, did grow better under the same fertiliser treatments. All three species of shellfish showed no increases in lead or zinc contents, but all showed increased cadmium contents related to the sludge fertiliser treatments. Increases in zinc, and particularly in cadmium, but not lead, were detected in the creek bottom detritus downstream from the plots. The surface sediment of the marsh plots shows significant accumulations of all three metals. The calculation of input-output budgets shows that lead was trapped in the sediments with virtually no losses to deeper waters. Zinc and cadmium also accumulated in the sediments but there is some transport away from the salt marsh surface, especially in the case of cadmium.

ABILITY to establish and maintain self-sustaining breeding colonies of captive Red-winged Blackbirds (Agelaius phoeniceus) would facilitate long-term studies designed to develop methods for alleviating blackbird depredations as well as provide basic life history data. To be most useful, the colonies should be established in pens near laboratory facilities; this frequently involves putting colonies in unnatural nesting habitat. This paper describes a 5-year effort at Gainesville, Florida, to induce captive Red-wings, most of them taken from the wild as nestlings and then handreared in our laboratory, to breed regularly under such conditions. Except for an undocumented report of two young fully reared at the London Zoo in 1913 (Prestwick per. comm.), captive Red-wings have not been induced to breed successfully under avicultural conditions. In 1969, captive Red-wings, wild-trapped as adults, were induced to breed and to rear young successfully in large pens over normal marsh and hayfield nesting habitat in Ohio (Jackson pers. comm.). Earlier, a pair of Redwings that had been caught as adults and kept together for a year hatched two young in a 40X 20X 6-foot cage in Massachusetts (Wetherbee 1960, Wilson Bull. 74: 90), but the nestlings died soon after hatching.

Mineral exploitation directly affects organisms through both physical and chemical modification of their environment, and indirectly in a variety of ways. Excavation alters landform, drainage and soil conditions, while waste disposal has parallel effects and, along with processing, may cause pollution problems elsewhere. The effects on nature conservation interest vary according to the type and quality of habitat, vegetation and animal communities concerned, but mineral extraction can create new habitats of considerable value as well as causing damage. Adverse effects include direct habitat destruction, e. g. quarrying of important limestone areas and mining of ironstone; and production of chemical conditions unfavourable to both terrestrial and aquatic plants and animals, e. g. lead mining in Wales. Benefits are mainly the creation of new or more varied habitats, including lakes and marshes (flooded gravel pits and salt-mine subsidence); cliffs, screes and waste ground (quarries and mine tips); and old access routes, walls and buildings. Lead-mine spoil has greatly increased the populations of certain local plant species. In the past the gains to nature conservation interest have probably outweighed the losses, but the future scale and methods of mineral extraction may pose more serious problems, as through opencast working for ball clay and copper, removal of important coastal shingle beaches, and final exhaustion of the Magnesian limestone. Conservation in the broadest sense requires that ecological knowledge be employed to restore all derelict land to productive use, but this should include nature conservation as well as other uses such as agriculture. Nature conservationists have the knowledge to advise where mineral extraction would cause serious damage, and to indicate how operations elsewhere might be conducted with advantage to their interests. It is, however, important that their information and views be made as early as possible in the planning process controlling future extraction.

An occurrence of the Cretaceous toothed bird Hesperornis Marsh is recorded from a tarsometatarsus found in the middle Campanian Foremost Formation, Alberta. The discovery may be the geologically youngest record of Hesperornis known and provides the only well documented nonmarine occurrence of the genus.

The depth distributions of dissolved CH4, total CO2, Cl− and SO42− in interstitial waters are reported from three subenvironments in the coastal marsh sediments of south Louisiana. Dissolved CH4 ranged from 8.0 × 10−3 to 7.2 ml/l, with each core demonstrating a slight increase in concentration with depth. The highest concentrations of methane were observed in the northern subenvironment of the marsh, which was low in salinity. Extraction under vacuum of methane from whole sediment samples indicated that a significant amount of gas is present as bubbles. Total CO2 ranges from 110 to 410 ml/l. Carbon dioxide, extracted under vacuum, yielded δ13CPDB values of −18.9 and −22.5‰ for the southern and northern areas, respectively. The ∑CO2 concentration in two areas was greater than or equal to that predicted by the depletion of dissolved SO42− from microbial reduction processes. In one core, however, the ∑CO2 concentration was less than could be accounted for by the SO42− deficit. In general, where SO42− reduction was active or where the dissolved SO42− concentration was low, the concentration of CH4 increased. Relatively small vertical gradients of dissolved CH4 and ∑CO2, the low hydrostatic head above the sediment column and the high degree of unconsolidation suggest that gas is migrating upward through the sediment column. Coastal marshes may be an important source of methane to the atmosphere and waters of coastal environments.

During the period 14 June to 4 October 1973, nitrogen, phosphorus and biomass determinations were carried out twice weekly in the waters of Cootes Paradise, Dundas, Ontario. In the western end of the marsh, biomass values (as chlorophyll a) were as high as 3900 mg/m3 with an average of 700 mg/m3. Total inorganic phosphorus was always in abundant supply ranging in concentrations of 1.2 ppm to 25.00 ppm. There was indication of mining of PO4, ‒P from the sediments of the Desjardins Canal under anoxic conditions. An inverse relationship was found between biomass and total inorganic phosphorus while there was no correlation between biomass and No3 ‒N overall. Average N:P ratios were low, generally less than 0.5. Nitrification of effluent ammonia was shown to be the major source of nitrogen. A periodicity in the effluent ammonia concentration preceeded increases in biomass. Biomass was dominated by Scenedesmus sp. Wind stress was found to have a significant influence on the changes in biomass. Average net production estimates were 1.65 gm O2/m2/hr with a maximum of 3.17 gm O2/m2/hr. The Dundas sewage plant effluent is the prime source of nutrients, both from the current effluent and from previously settled solids. Biological activity in the marsh is directly related to these periodic nutrient inputs. The west end of the marsh removes 80% of the PO4 before the water reaches the main area and therefore has a vital role to play in controlling the overall water quality of the marsh.

A quantitative study was made of the littoral microcrustaceans in a bog pond and an acid marsh located on the Avalon Peninsula, Newfoundland, from May, 1972 to May, 1973. A total of 17 species of Cladocera and 7 species of Copepoda were found in La Manche Marsh, while 21 species of Cladocera and 5 species of Copepoda were collected in Round Pond. The maximum standing stocks were similar in the two localities. The dominant forms in the summer and fall in La Manche Marsh were Cladocera: Acantholeberis curvirostris, Biapertura intermedia, Chydorus sphaericus, and Ilyocryptus spinifer. In the winter the copepod, Macrocyclops albidus, was dominant, while Cyclops varicans rubellus was the most abundant species in the spring. Round Pond also was dominated by Cladocera in the summer and fall; namely, Acroperus alonoides, Alona rustica, Alonella excisa, Chydorus sphaericus, and Sida crystallina. The copepods, Eucyclops agilis and Macrocyclops albidus, were dominant in the winter and early spring.

Most of the usual methods for studying fish populations have been ineffective when applied in the shallow, freshwater marshes of southern Florida. Exceptions are devices which trap fish by rapidly enclosing a known area of marsh. Of these, pull-up traps are best suited for sampling large areas for relatively large or widely dispersed fish, whereas drop traps with bottom nets are the most efficient for studies of small species at permanent sampling sites. Each produces comparable but consistently biased results due to habitat disturbance. The most precise data on shallow water fish communities are obtained by use of bottomless drop traps which are moved to new sites for each sample.

SummaryThe excavation of the Sweet track at two sites in the Somerset Levels has yielded unique material of the late fourth millennium bc. The track was built across a reed marsh, and the builders used a variety of timber obtained from both nearby fen-wood and from the dry land of the Burtle sand and the Poldens. Pollen analyses indicate that certain areas of the Levels were particularly favourable for forest clearance and cultivation, and the debris from the track shows a range of woodwork so far unique to the British Neolithic.

Anthills made by Lasius flavus F. in a saltmarsh have significantly different vegetation from that of the surrounding marsh. One species, Frankenia laevis L., is differentially distributed with aspect on the mounds. The reasons for these differences and the problems of survival of anthills on a saltmarsh are discussed.

Nitrogen fixation as estimated by acetylene reduction takes place in intertidal sand and mud in salt marshes and is inhibited by additions of nitrogenous compounds such as sewage sludge or urea. Fixers on the marsh use combined nitrogen available from other sources in preference to nitrogen fixation. Marshes can remove substantial amounts of nitrogen from eutrophic waters by this shift in the nitrogen cycle.

THE Laridae breed in a variety of habitats throughout the world. Of the 44 species of gulls (genus Larus), 19 nest exclusively on the ground and 19 others often or sometimes nest on flat ground. Many of the latter species also nest on cliffs and ledges. The adaptations of gulls for nesting on cliffs have been studied in some detail (cf. Cullen 1957; Emlen 1964; Hailman 1965, 1968; Smith 1966). Beer (1966) studied the breeding adaptations of the Black-billed Gull (Larus bulleri) for nesting on unstable river beds. I examined the behavioral and ecological adaptations in Franklin's Gull (L. pipixcan) for breeding in marshes (Burger 1972a). The Brown-hooded Gull (L. maculipennis) is the ecological counterpart of Franklin's Gull in South America (Weller 1967) where it usually nests in the pampa marshes of Argentina and Uruguay although it infrequently nests on dry ground (Wetmore 1926, Olrog 1959, Meyer de Schauensee 1970). Only very general descriptions of the breeding biology of the Brown-hooded Gull are available (MacDonagh 1944, Plotnick 1951, Moynihan 1962). I studied the behavior and ecology of nesting Brown-hooded Gulls in Argentina, placing emphasis on colony and nest site selection, coloniality, synchrony, and interspecific relationships.

The modification by man of his environment, particularly for large‐scale irrigation and ricefield extension, often results in increased incidence of mosquito‐borne disease in associated human populations. Habitat modification leads to changes in the species composition of mosquitoes and thus the variety of disease agents to which man is exposed. Increased acreage of water attracts birds which act as hosts of arboviruses while a raised water table leads to marginal marshy areas and humid peripheral vegetation. These two aspects of the environment favour extended breeding and survival respectively. Higher atmospheric humidity enhances mosquito survival and the transmission of disease. Associated urban resettlement encourages domestic mosquito species and effects the distribution and abundance of vertebrates which may act as hosts of disease agents.

The Flandrian (Pleistocene) stratigraphy and the intermittent character of the Flandrian transgression in the Cancale area (Ille-et-Vilaine, France) are established on the basis of information from a series of borings in a sand bar in the Duguesclin bay. The present topography is an exact reflection of the Flandrian topography; the sand bar and the marsh behind it have retreated inland, however.

At Nazeing, Essex, in the valley of the River Lea, a series of deposits has been investigated which extends back in time from the Post-Glacial climatic optimum to Late-Glacial times in the widest sense of that term. They are of special importance as bridging the time gap between the well-known ‘Arctic Plant Bed’ of the Ponder’s End stage (which occurs also at Nazeing), and the established Post-Glacial vegetational and climatic sequence. Pollen analysis of the main organic beds has permitted a general dating to be given to the various stages of formation of the deposits and this has been supplemented by a radio-carbon assay. Through the gravel sheet of the Ponder’s End stage a wide channel was cut which persisted with vicissitudes until Boreal time. At first this channel and the surrounding gravel plain were covered with organic muds and marls of a shallow lake containing stunted Mollusca of close affinity with those of Ponder’s End, and pollen indicative of rich herbaceous vegetation and an unwooded countryside. The channel was re-cut and the mere drained, and in the bed of the new channel, above an infilling of gravel, there began deposition of organic muds and then peats, a process which continued without interruption until, after a third short phase of erosion and drying in MidBoreal time (zone VI), the whole valley of the Lea was converted to fen. The later Boreal and succeeding Atlantic peats (zone VII) are sealed in by river flood clay. The Mollusca (whose determination is largely that of the late Santer Kennard) retain the general character of the Ponder’s End aggregate through the mere deposits, and the channel deposits up to the third erosion stage. The progress of drying of the mere is shown by the increasing proportion of land- to fresh-water shells. From the base of the channel which is referred to zone III, the close of the Late-Glacial period, the calcareous muds have yielded an extensive collection of plant remains, chiefly fruits and seeds belonging to ‘arctic-alpine’, ‘marsh’ and ‘ruderal’ species. Some of the species recognized have hitherto been regarded as weeds and introductions by man to the British flora; others have now a very restricted range. The pollen analyses of both the mere and channel-bottom deposits show great abundance and range of pollen of herbaceous plants, including many familiar already as Late-Glacial species and some, such asPolemonium coeruleum, newly recognized as such. It is apparent that conditions of the Late-Glacial period greatly favoured the spread of certain categories of plants, and that knowledge of this period is of the utmost importance in establishing the history of the British Flora. In the calcareous muds of the channel (zone III) and in the earlier muds beneath the lake marl the remains have been identified of four mammals of late Pleistocene character (including two species of lemming). At the close of zone III the calcareous muds yielded abundant bones ofBufoandRanatogether withLacerta vivipara. At the Early Boreal drying surface (Mx) of the channel there are also abundant land shells, and at this stage the molluscan fauna has a new and characteristic Holocene stamp, although small mammals of Late Pleistocene type survive, notablyOchotona spelaea(pika) andMicrotus anglicus. A general correlation is attempted for all the phenomena described, geological, floristic and faunistic, and they are tentatively related to corresponding phenomena in Britain and north-western Europe.

The aestuarial marsh, locally known as the Jones Salt Marsh, upon which our studies were made, lies at the head of the Inner Harbor at Cold Spring Harbor, Long Island, New York. A detailed belt transect of this marsh was made in i9io-ii by the senior author.' The tension zone between salt and fresh water has since been found to fluctuate in such a way that it gives sequence to some very interesting plant successions. A resurvey of the same transect made in 1922 2 indicated that fresh water vegetation had advanced while saline vegetation had retreated seaward, due to seepage of fresh water and perhaps to the excessive precipitation during the years immediately preceding the survey. The causeway thrown across the south (inner) end of the marsh in I904 for a highway has been a potent factor, seriously affecting the changes in the vegetation on the landward side of the marsh since that time, by setting up a barrier to the advance of salt water and by changing the course and amount of fresh water seepage in the southeast corner of the marsh. Probably the changes still in progress are adjustments to these artificial changes in the habitat. The partial resurvey reported herein was made by the junior author in the summer of I928 to note what further changes had taken place since I922, where succession is going on most markedly, and to check up on conclusions drawn at that time. Some careful notes made by the senior author in I927 have also been used. Old and permanent landmarks, such as a stump of Prunus serotine which was a living tree in i9io, were used to locate the boundaries of the transect. At 437S and I iooE we found an old stake of a previous survey which helped to establish the fact that our lines approximately coincided with those of former years. Not every plant in the transect was plotted on the chart. Particular attention was given to the boundaries of definite zones of vegetation to compare advances and changes with the former surveys.

Twelve species of sawflies are common on white birch (Betula papyrifera Marsh.) in the forested areas of Manitoba and Saskatchewan. They also occur in Fastern Canada and the United States. A key is presented at the end of the paper by which the late instars of these twelve species can be identified. The immature forms of these species were described by Dyar (1893, 1895a, 1895b, 1895c), Middleton (1915, 1922) and Riley (1890). Unfortunately these descriptions are scattered in several publications, and in most cases the names of the genera or species in the original descriptions have been changed (Ross 1951). This paper brings together the current nomenclature and some biological information on these species.

The Federal Government of Nigeria is constructing a dam across the River Niger at Kainji (9°51′N, 4°37′E). When complete approximately 130,000 hectares will be inundated. An account of the climate, hydrology, geology, pedology, land-usage and vegetation of the reservoir site is given. The terrestrial plant communities are described in outline. The aquatic and marsh plant communities are described in more detail using the floristic-ecological method.

Six types of habitat in papyrus (Cyperus papyrus) swamps in Uganda were studied with regard to the production of mosquito larvae. A classification, of the types is given, which was largely based on the lapse of time since temporary clearing by cutting or burning had been carried out.Altogether a total of 5,781 larvae belonging to 17 species was studied. Culex (Culex) guiarti Blanch., C. (C.) univittatus Theo. and C. (Neoculex) rubinotus Theo. were the dominant species, comprising together 78 per cent. of the total number of larvae. Anopheles gambiae Giles was not recorded. Samples of larvae were taken at intervals between mid-January and early April 1957. The sampling method used was unsuitable for those species of which the larvae obtain air from roots or stems of submerged vegetation, and these were excluded from the present study.There was considerable variation in species and numbers of larvae and in their frequency in the different types of habitat.It is concluded that (a) peripheral zones, especially in natural untouched swamps, are much more productive than the interior, (b) where swamps have been altered by cutting and by burning of papyrus and other vegetation, burnt habitats, whether recently or after the lapse of up to four or five months, have a very low productivity, (c) of the six chemical factors investigated (pH, K, Na, absorbed oxygen, free and saline ammonia and albuminoid ammonia) only the quantity of soluble organic matter, indicated by absorbed oxygen, and albuminoid ammonia, showed any relation to productivity, the least productive habitats containing the smallest quantity of organic matter.Other possible factors in swamp water, which were not investigated, are mentioned. These are (a) the nature of soluble oxidisable organic matter, (b) conductivity, (c) ferruginous surface films and (d) iron in solution.

The Southeast Saline Everglades is a distinct geographical area, lying entirely in Dade County, Florida, bounded on the north and northwest by pineland, on the east and south by the ocean and its mangroves, and on the west by aquatic vegetation on land permanently submerged. This is a low flat wet region, partaking collectively of certain characteristics of river, swamp, fen, marsh, tidal-marsh, lake, and even upland. By referring to this area as “saline” is it not implied that the region is continuously saline or that the marl was formed under saline conditions. The term is used to indicate that the vegetation is in adjustment with sporadic hurricane floods of ocean waters, which not only serve as dissemination agents for certain kinds of plants, but which affect the presence and distribution of other plants according to their tolerance to salinity. In respect to this sporadic saline factor, the region can be segregated from the rest of the Florida Everglades. (As a nomenclatural term, “Saline Everglades” is thus analogous to various “hurricane forests” and “fire types”, named with reference to historic events and not the continuing environment.) The vegetation of this area is an endless prairie, dotted with dense tree hammocks, developed on a thin layer of Recent freshwater marl, overlying a calcareous oolite, in a tropical climate. The present complex vegetation appears to be a “fossil” phenomenon, developed under past conditions of higher water tables and Indian fires, and now rapidly disappearing. This vegetation has supported large populations of wildlife, especially the larger birds. The bird-supporting plant communities however are to a certain extent no longer self-perpetuating, and the management of these lands will require some unprecedented manipulation of the water, fire and other factors. Construction of highways and railroads and agricultural practices have interfered with surface drainage, and directly changed large areas of the natural vegetation. Agricultural values have been in part nullified by encroaching subsoil salinity. Casuarina equisetifolia, a naturalized tree of increasing economic value, is producing a new self-perpetuating forest. The Saline Everglades and vicinity can be described in terms of seven belts, each with its own aggregate of past present and future communities, its own contemporary vegetation-change, and its own possibilities of management. Description of many of these communities is in terms of quadrat data and sample plots. These belts apparently represent a normal sequence for tropical vegetation passing from upland through winter-dry swamp, to shallow ocean shores. Lowered water tables appear to be effecting a mass seaward shift of Belts 1 and 2. Rising sea level would effect a landward shift of Belts 4, 5, 6 and 7, with the seaward side of Belt 7 possibly exhibiting a lag due to organic and inorganic deposition related to the mangrove. Belt 3, the major belt of the area, becomes narrower as a result of this encroachment from both sides.

During the course of three years' estate medical work in British North Borneo, ample opportunity was found for studying the local mosquitos, and I publish the few following notes in the hope that they may be of use to other workers in Borneo.

At 13h02m, June 16, 1964, a severe earthquake occurred with its epicenter near Awa, Island, 70km to NE of Niigata City. Damages were caused by the earthquake in Niigata and Yamagata Prefectures. Especially, in Niigata City, the damages were severe. Large amount of sand and water jetted out from silt and sand layers about -3--9 m from the surface and as its result many concrete buildings were slanted in various degrees. Tsunami raided into the area near the mouth of the Shinano, so that many houses and factories were flooded and areas near the river course were inundated. Some agricultural land and rural settlements were destroyed. But the damages were limited in old river courses and reclaimed lands of back marshes.

I. Introduction. The present paper is supplementary to that brought before this Society three years ago. The broader problems of correlation, and the general conclusions with regard to the climatic evidence furnished by these deposits, have been entered into in the previously published paper. At the present time, I have little modification of importance to suggest. There are, however, additional sections which seem to deserve description. The geographical range of these deposits has now been extended to a distance of 6 1/2 miles along the course of the Lea, that is, roughly speaking, from Ponder9s End to Stratford. In the opposite direction, at right angles to the course of the river, they have been traced for 2 1/4 miles, from Lower Edmonton to the Tottenham Marshes: that is, nearly across the whole range of the Low Terrace Drift. Thus the Arctic deposits are seen to be an integral part of the Low Terrace River-Drift, and not an accidental fragment of some earlier deposit. Doubtless, their range will be extended still farther as favourable sections are opened up. The position of the various sites is indicated on the accompanying map (fig. 1, p. 166) as follows:—A, Pickett9s Lock Pit, Ponder9s End; B, the Angel Road pit; C, the Southgate District Council pit, with Arctic plant-beds; D, the eastern pit in Hedge Lane in the Low Terrace; E, the pit in the Middle Terrace on the south side of Hedge Lane; F, the approximate position of

Bionomics of 4 common Tabanidae (Diptera) was studied by use of emergence traps, Manitoba fly traps, and insect sweep-net collections. Emergence locations and sex ratios are presented. Female Tabanus nigrovittatus Macquart predominated on a New Jersey salt marsh near an upland area, apparently being concentrated by southeast breezes. The tall, dense, marsh-upland border vegetation apparently presented a geographical barrier to flight farther inland and formed an environmental trap at some locations. Aggregation to geographically pronounced locations occurred on the marsh. Many female Chrysops atlanticus Pechuman sought a blood meal on the marsh during the period of adult emergence, but those seeking blood shifted entirely from the marsh to the upland, about 150 yards from the marsh edge soon after adults had ceased emerging.

Such great emphasis was attached to the “salubriousness” of California during the nineteenth century that attention seems to have been diverted from the fact that not all of the state was viewed as outstandingly healthful. Indeed, during the first fifty years or so of American occupance a substantial section of California, mainly the Central Valley, was regarded as inherently insalubrious. Perception of this insalubrity mainly involved malaria together with certain other diseases with which malaria was diagnostically confused. During the nineteenth century malaria was one of the most common diseases of North America and reached a peak of endemicity in California about 1880. The governing doctrine among medical practitioners was that malaria was caused by “bad air” or miasma. According to this doctrine, miasma was believed to be produced by decaying organic matter and was most abundant in marshes or in areas of newly disturbed soil. In California, the region of highest malarial endemicity was the ...

A program of field tests was conducted with the Marsh Screw Amphibian to evaluate its performance on a range of soil conditions. Performance was expressed in term of ability to travel 50 passes in the same path, manoeuvrability, speed, drawbar pull, ans slope-climbing ability. Soil conditions were described in terms of soil type, moisture content, density and cone index. Relations between vehicle performance and soil condition are presented.

AMONG the many Selachian and Cetacean fossils found in the cliffs bordering Chesapeake Bay in Calvert County, Maryland, there have been a few fragments of fossil birds, a number surprisingly small when the scrutiny to which these deposits have been subjected during the past sixty years is considered. Sometime ago the type of Puffinu conradi Marsh, and other avian types of similar nature from the Academy of Natural Sciences in Philadelphia, were sent to the U. S. National Museum that they might be cast in plaster. The writer took advantage of this opportunity to make a careful study of these type specimens in connection with two other fragments of recent acquisition. The results have proved of sufficient interest to warrant assembling for publication.

THE Blue-winged Teal (Anas discors) was the subject of one of the first publications dealing with the breeding biology of a species of North American waterfowl (Bennett, 1938). Recent studies of the nesting chronology, clutch size, and incubation period of this species include the works of Hochbaum (1944), Sowls (1955), and Glover (1956). The present paper supplements information on these aspects of breeding biology. Field work was done during the summers of 1961, 1962, and 1963 at the Delta Waterfowl Research Station (15 miles north of Portage la Prairie, Manitoba) which is adjacent to the Delta marsh at the south edge of Lake Manitoba. The climate in the area is subhumid. The mean annual temperature is 45.3?F and the annual precipitation is 20.1 inches at Winnipeg (60 miles ESE of Delta). The spring warming trend is variable and influences the time of spring arrival and the start of nesting of waterfowl (Sowls, 1955) and, as will be shown, the temperature may also influence the nesting chronology once a species has begun to nest. The daily mean temperatures and the daily lows at Winnipeg for the springs of 1962 and 1963 are graphed in Figures 1 and 2. Daily records kept by Nan Mulder at Delta show that the temperatures there are similar to those at Winnipeg.

Larvae of the marsh fly, Sepedon tenuicornis Cresson, were used to determine (1) number and approximate volume of snails killed before pupation, (2) time required to make the first kill as a function of distance and snail density, and (3) vulnerability of snails of different sizes to larvae of different sizes.Results1. Mean number of snails killed (by 34 larvae): 8.1 ± 2.5, (S.E.) Volume: 544 ± 256 mm3.2. Regression line relating time required to kill as a function of snail density: T (minutes) = 65.3–111.6 × (snail density).Regression line relating time to kill and snail densities of 0.6 and 1.2 snails/cm as a function of distance from snails: T = 0.79–0.33 × (distance).Data from a snail density of 0.3/cm could not be pooled because of high day-to-day variation in larvae.3. Vulnerability of snails can be expressed for each larva length by the equation: Fraction of snails killed = a + b × (snail size).Values of a and b are as follows

From the sap of the sugar maple (Acersaccharum Marsh) two trisaccharides have been isolated by column and paper chromatography. One was identified as O-β-D-fructofuranosyl-(2 → 6)α-D-glucopyranosyl(1 → 2)β-D-fructofuranoside (6G-fructosylsucrose), the other was tentatively established as either 6F-fructosylsucrose or 1F-fructosylsucrose. These trisaccharides are not related in either composition or structure to the polysaccharides present in the sap and wood.