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This is the second of two papers dealing with pollen morphology and evolution within the tribe Embothrieae. The present paper examines pollen of the subtribe Embothriinae, Embothrium (1 sp.), Oreocallis (6 spp.), Telopea (4 spp.)) in the light microscope and scanning and transmission electron microscopes. Pollen is large-sized, oblate to suboblate to oblate-spheroidal, foveolate to microreticulate to spinulate with a predominantly granular exine and simple aperture morphology. The Embothriinae are palynologically heterogeneous with both Oreocallis and Telopea each exhibiting two distinct pollen types. Pollen of New World Oreocallis (O. grandiflora, O. mucronala) and the Old World O. pinnata are closer to the Old World Telopea (excluding T. speciosissima) than to other Old World Oreocallis (O. sp. nov. O. brachycarpa, O. wickhamii). Within this complex, O. pinnata occupies an intermediate position between Oreocallis and Telopea. Despite the uniformly biporate condition in Embothrium, other pollen characters support its inclusion in Embothriinae with close ties to Oreocallis. Analysis of pollen trends within the tribe reveal: (1) an increase in pollen size; (2) a trend towards more spheroidal pollen; (3) the independent developments of biporate pollen in Embothrium, Oreocallis and Lomatia; (4) independent developments of recticulate and spinulate sculpturing from a tectate-perforate exine; (5) loss of columellae; and 6) independent developments of complex modified postvestibulate and simple thickened-lamellate aperture morphologies.

This is the first of two papers detailing pollen morphology and evolution with the tribe Embothrieae comprising eight genera and ca. 56 spp. The present paper examines pollen of subtribes Buckinghaminae (Buckinghamia; 2 spp., Opislhiolepis; 1 sp.), Stenocarpinae (Strangea; 3 spp.), Stenocarpus (ca. 27 spp.) and Lomatiinae (Lomatia; ca. 12 spp.) in the light microscope and scanning and transmission electron microscopes. Pollen is medium-sized, oblate, foveolate to microreticulate to reticulate, and predominantly columellate with a complex modified postvestibulate aperture morphology. Pollen data indicate ties between Lomatia and Stenocarpus on the one hand and Stenocarpus and Strangea on the other. Though Buckinghamia and Opislhiolepis have been placed in the same subtribe, the unique combination of pollen features in each suggests only a remote relationship to each other as well as to remaining Embothrieae. Comparisons to the remaining genera of Embothriae (Embothrium, Oreocallis, Telopea) and overall analysis of pollen evolution within the tribe are detailed in the subsequent paper.

Fungal spores and pollens can be dispersed in a number of ways: by animals and insects; by water; by wind or by rain. This paper concentrates on the effects of wind on the dispersal of spores and pollen grains and the effects of rain on spore dispersal. For dispersal to be successful particles must complete three phases: removal, dispersal through the air and deposition. The biology of the organism and its environment can affect all three phases, however, once released the fate of all airborne particles largely depends on the laws of physics which govern the motion of the air. Many types of spore are actively ejected into the air while others are simply blown from the host surface. Particle size and shape affects dispersal and deposition phases. Local environmental factors such as temperature, humidity and light, as well as wind or rain, can play a key role in the removal of spores. Wind speed and turbulence or rainfall, largely determine spore dispersal, but, the size and shape of the particle, the nature of the plant canopy and the way the particles are released into the air may also be important. Particle deposition depends on both environmental and biological factors. This paper briefly considers these processes using examples and how they can be modelled.

In an earlier paper, which includes pollen descriptions for 93 genera and approximately 430 species of the large, tropical family Annonaceae, the author laid the foundation for a generic reclassification and natural phylogeny of the family based largely on comparative palynology. The present paper includes generic pollen descriptions for an additional 18 genera and 21 species of Annonaceae

Although pressure-sensitive adhesive tapes appear to offer many advantages over traditional adhesives in sampling with a Hirst-type spore trap, their particle capturing efficiency has never been documented. In this paper, the particle capture efficiency of four pressure-sensitive adhesive tapes was compared to the standard vaseline adhesive in the Burkard 7-day volumetric spore trap. The capture efficiency was assessed at flow rates of 8 and 101 min-1 over a 16 week period with each tape run alongside the standard. Image analysis was used to count and measure the surface area of individual inorganic and organic particles collected onto each tape. Approximately 230,000 individual particles were analysed, the majority of particles collected on both standard and pressure-sensitive adhesive tapes had a surface area less than 150 μm2 (approximately diameter 14 μm). Capture efficiency was expressed as a percentage of the counts on the standard and classified by particle size and flow rate. For particles < 1000 μm2(<36 μm in diameter), the best adhesive tape captured 247.6% at 81 min-1 and 132.5% at 101 min-1. For particles > 1000 μm2, the best adhesive tape captured 86.9% at 81 min-1 and 69.8% at 101 min-1. In addition to image analysis, manual counts of pollen grains and Alternaria-like spore were performed over a four day period for each adhesive and parallel standard at the flow rate of 101 min-1. On the adhesive tapes, pollen grains <20 μm, and pollen grains >20 μm with heavy ornamentation and/or free standing exine elements were captured best. For the best adhesive tape, the capturing efficiency compared to the standard vaseline was 83% for all pollen grains and 60% for Alternaria-like spores.

It is difficult to reliably distinguish Betula species solely on pollen morphological criteria. Size differences between the pollen of different Betula species have proved to provide a basis for their separation.Pollen grain size is affected by both sedimentary environment and laboratory treatment. Only grains from similar sediment lithologies that have had identical laboratory treatment can be considered comparable in size with each other. A simple size comparison between modern and fossil pollen is not advisable.In this paper previous methods for the separation of birch pollen types are reviewed and some new measurements of the Finnish birch species are presented and discussed.

There are at present 25 species and 26 infraspecific taxa recognized in the resurrected genus Baccharoides. Of these, 17 species and 16 infraspecific taxa are new combinations made in this paper. Full descriptions of the pollen characters of the genus as well as the floral microcharacters, synonymy and distribution are provided. Remarks on diagnostic features are also given for most taxa in a taxonomic note.

This paper presents, for the first time, new information obtained from a research programme on the biopolymer organization of the sporoderm. The results are as follows: 1. In the TEM photographs of the partially degraded exine of Pinus griffithii McClell., 3.0 Å diameter molecular units were observed with fivefold symmetry. Using the modified Markham rotation method, secondary points of symmetry were also observed indicating that the quasi-crystalloid organization is at the molecular level. 2. In the partially degraded and fragmented wall of Botryococcus braunii Kutz., obtained from fossil colonies extracted from the Hungarian Oil Shale, two kinds of biopolymer structures were observed in the same fragment. One type was a quasi-equivalent globular unit with a diameter of 50-75 Å, whereas the other type consisted of peculiar quasi-crystalloid pentagonal polygons with a diameter of 20-30 Å. Symmetry operations involving the points of the biopolymer structured wall of the fossil Botryococcus algae were made for the first time. A quasi-crystalloid skeleton was also demonstrated as present in this cell wall. 3. A three dimensional model of the sporoderm quasi-crystalloid skeleton was established. A complete model of the Penrose-II type biopolymer structure is presented here. This model contains one central unit, surrounded by two types of Penrose-I units. Eight units can be directly attached to the central unit. An additional six units may be attached to the previous ones by asymmetrical connections. The „large frustrations“, sensu Nelson 1986, are also asymmetrical with a peculiar asymmetry which can be observed in this large biopolymer model.

In many, mostly temperate regions of the world, crops are cultivated in completely or partly closed environments. Problems concerning the dissemination of fungal spores or bacterial cells in these systems are comparable to those in open systems, but there are many supplementary problems, which have hardly been investigated up to now.Now the application of chemicals in agriculture is strongly discussed worldwide, it will be of the utmost importance to know more about the aerobiological principles of spore dissemination in closed, more or less conditioned environments, to be able to create better disease management programs for plant diseases on crops cultivated in those conditioned environments.In this paper problems concerning the dissemination phase of the fungal infection cycle developing in “closed” spaces will be discussed.

Numbers of airborne microorganisms, fungi, Gram-negative bacteria, thermophilic microorganisms, endotoxins and dust have been monitored in resource recovery plants and composting plants. The work is still in progress, so this paper decribes only preliminary results. Only low levels (< 15 ng m-3) of endotoxins were found at all locations. Levels of microorganisms, fungi, Gram-negative bacteria and dust changed with quality of waste, activity in the plant etc. Levels of airborne microorganisms, endotoxins and dust could be considerably decreased in resource recovery plants if only waste of good quality, e.g. presorted materials, is handled. For composting plants the highest levels of airborne microorganisms were found during aeration, especially by indoor composting where levels of 8.3 × 105 CFU of mesophilic microorganisms were found.

Cette etude est la premiere d'une serie concernant les associations sporo-polliniques prequaternaires de l'Egypte. Dans cet article les spores, les pollens des Gymnospermes et les Breviaxes des Angiospermes sont presentes. Dix especes de forme nouvelle sont decrites. Vue la composition des sporomorphes presentes, les formes monoporees et periporees sont riches en especes. L'interpretation detaillee prendra place dans la deuxieme partie, apres la fin de la partie taxonomique des couches Neogenes du Wadi el Fharigh et du Wadi el Natrun.This study is the first of a series of publications concerning the spore-pollen assemblages of the Egyptian Prequaternary. In this article the spores, the gymnosperm pollen grains, and the Brevaxones of the Angiospermae are presented Ten new form-species are described. As regards the composition of ths sporomorphs presented in this paper, monoporate and polyporate pollen grains are abundant in species. Evaluation and discussion of the forms described herein will be published in the second part after completion of the taxonomic part on the Neogene deposits of Wadi el Fharigh and Wadi el Natrun.

The paper reviews some widely used pollen morphological concepts which are slightly vague and ambiguous. To meet the needs of palynological descriptions, the terminology has to be precise and, as far as possible, numerically defined. The terms oncus, verruca, annulus, prolate and oblate are discussed and redefined. The words sculpture and structure are discusssed, delimited and defined, and it is proposed that they be accepted as terms. A new term, pseudo-annulus has been proposed.

Optimal conditions for in vitro germination and tube growth of Limonium perezii (Plumbaginaceae) pollen were established. Boric acid, calcium nitrate, casein hydrolysate and sucrose were all important medium components. A dialysis tubing & filter paper support combined with using polyethylene glycol as an osmoticum in the medium provided appropriate physical conditions for L. perezii pollen germination. An in vitro pollen germination rate of about 40% was achieved. The longest pollen tube observed was four times the pollen grain diameter.While prehydration did not improve L. perezii pollen germination percentage nor the final pollen tube length, temperature influenced both of these factors. The optimum temperature range for germination was between 15°C and 35°C but the optimum temperature for pollen tube length was in the range 20°C-25°C.

Aerobiological modelling and pollen forecasting have already been attempted with some success, notably for grasses in Europe, and ragweed in North America. But there has been no proposition for a general model of pollen curve morphology. In this paper, a methodology is suggested that allows a rationalisation of the number of aerobiological model needed to classify pollen curves and thus optimize pollen forecasting. By using descriptive parameters (of central tendency, dispersion, skewness and kurtosis) similarity coefficients were calculated for 13 taxa (chosen for their constancy, representativity and allergenicity). A cluster analysis was then undertaken that allowed the determination of inter- and intra-annual, and inter- and intra-taxonomic ratios. These ratios permit the estimation of “morphological constancy coefficients”. The most constant taxa were ragweed, mugwort, plantain and Chenopodiaceae-Amaranthaceae. The similarity of pollen curves allows the clustering of all pollen curves in three major types for each of the past four years. However, only ragweed exhibits the same model (or type) from year to year. It is not clear, at this stage, whether the types selected arc the result of a filtering of the environmental factors over the years (thus enlighting the “biological order”), or the result of their accumulation (thus masking the “biological order”).

Pollen concentrations recorded during three years sampling in north-central London have shown distinctive diurnal variations. This paper identifies these patterns for three pollen taxa and attempts to account for the variations observed. The diurnal variations identified are interpreted in relation to meteorological conditions, pollen source area and phenological patterns of pollen release. A hypothesis of pollen dispersal to the sampling site is suggested.

In botany tentative attempts have been made to classify species, based not on the plant as a whole, but on a particular character, for example pollen characteristics. Pollen, which is involved in the transmission of male genetic information during sexual reproduction, is of particular interest in distinguishing plants and their relationships.These characters, observed in photon- and scanning electron- microscopy are symmetry, form, number and position of germinating areas. Being genetically stable for a given species, they identify a plant.Recently, a novel character has been added: the concentration of elements in the exine, determined by electron probe micro-X-ray analysis. It is interesting to follow relationship of plant species, based on the mineral composition of their pollen as a whole, taking into account both plastic and oligoelements, obtained via an inductive coupled plasma spectrometer. Samples of pollen from different plant species, at distinct taxonomic levels, were analyzed; the results were submitted to a normalisation procedure and the standard patterns obtained were investigated by means of a number of numerical techniques (clustering and factor analysis). The aim was to establish if elements could be considered as chemical markers in plant cladistics. The mineral composition in a given species appeared quite stable and this furnished a convenient identification-critorion.This approach further allows a chemo-taxonomy of species, in as much as organization of families, and perhaps orders, would conform to the phylogenetic proximity-criterion. Hence, we found clusters including pollen of Gramineae, Coniferae, Betulaceae…This methodology, that should be completed and corroborated on a wider range of samples would provide an original responsee to the problems of identification and classification encountered in a pollen bank. It follows that:Hence, the working hypothesis that the chemical markers and, in particular, oligo-elements, complete pollen typologies based on morphological and structural characters, appears quite reasonable.In conclusion, this paper brings a complement to the mineral composition of the exine.En botanique, des tentatives ont ete faites pour classer les especes non plus a partir d'individus pris dans leur integralite, mais sur la base d'une de leurs particularites, par exemple a partir des caracteristiques offertes par les pollens. Ainsi, le pollen, dont le role est de transmettre l'information genetique male de la plante au moment de la reproduction sexuee, presente des caracteres de premier ordre utilisables pour distinguer les differentes plantes et pour situer leur parente et leur filiation.Ces caracteres, que l'on observe en microscopies photonique et electronique a balayage sont la symetrie, la forme, le nombre et la position des zones germinatives. Pour une espece genetiquement stable, ils constituent la carte d'identite de la plante.Il est interessant de continuer a explorer la voie de la structuration des especes vegetales basee sur la connaissance chimique du pollen en determinant sa composition en oligo-elements par l'utilisation d'un spectrometre a plasma a couplage inductif. Ainsi, des echantillons de pollens appartenant a diverses especes vegetales situees a differents niveaux taxinomiques ont ete analyses et les resultats normalises sous forme de profils standard ont ete soumis a differentes techniques d'analyse statistique mathematique (classification automatique et analyse factorielle). Le but de cette approche est d'apprecier l'aptitude des elements mineraux a etre des marqueurs chimiques en cladistique vegetale.Les resultats obtenus ont permis de constater la relative stabilite du profil en composition minerale au sein d'une meme espece vegetale, ce qui donne acces a un critere d'identification commode.Cette approche permet d'autre part une chimiotaxinomie des plantes etudiees.Cette approche methodologique semble susceptible d'apporter une reponse originale aux problemes de conservation. Les pollens conserves doivent avoir la meme composition minerale que les pollens frais.— the pattern of pollen composition of oligo-elements, calcium and magnesium is a marker in plant cladistics. Since a typology depending on proximity is found between plant species, families and orders.— an unknown pollen sample may be located, tentatively, on the base of a described model of pollen relation (shortest connexion network — Prim algorithm — and pollen of Bactris-oil palm and Phoenix dactylifera).

The principles of aerosol sampling involve both a) the scientific factors which govern the way in which particles are transported from the air outside the sampler to a filter or sensing region inside it, and b) recognition of particle size-selective criteria which relate the act of sampling to the reason it is being carried out (e.g., assessment of health risk associated with inhalation). This paper reviews the state-of-the-art in both these areas, and goes on to mention some recent technical developments concerning practical sampling instruments.

In Japan, the problems of Sugi (Cryptomeria japonica)-pollinosis have been much discussed in recent papers and journals. The author made an investigation on the airborne pollen grains from a scientific standpoint in connection with the incidence of pollinosis. By using the Cascade Impactor the author collected 600 liters of air sample a day, at the roof of the Pharmaceutical Science Building, Toho University, Funabashi, Chiba, Japan. Each air sampling for 2 hrs was repeated three times a week since 1969. The airborne pollen grains in each sample were counted under the microscope to identify the pollen types. The pollen grains were classified into six types according to the classification of pollen grains in Japan established by lkuse. The accumulated number of pollen of each species was analysed statistically by circular plot, Weibull plot, Edwards plot and semi-logarithmic plot. In this report mainly 3B type of pollen grains (Cryptomeria, Chamaecyparis), collected in the last three years are described. The total number of pollen grains in 1988 (2820 grains) was doubled in quantity as compared with that in 1987 (1177 grains) and in 1989 (1121 grains). The 3B type of pollen grains in 1988 (1450 grains) was 3.4 times as many as in 1987 (397 grains), and 12.9 times as in 1989 (112 grains). The 3B type of pollen grains represented the major portion of total pollen, and influenced the annual amount and the dispersal period.

This paper reports on pollen analyses carried out in the course of a ten-year investigation, on many thousands of cytological smears coming from various organs and systems of the human body, and prepared for diagnostic purposes. The frequency and the significance of the pollen records vary according to the specific cytological field taken into account. In the urinary sediment smears, nipple secretions, and needle aspirations the polliniferous smears are very few, and the pollen number per smear is low (max 14 pollen grains, belonging always or mostly to anemophilous species). In these cases, the pollen records evidence the airborne contamination during medical procedures, the same happens with most of cervico-vaginal smears. In some cervico-vaginal smears, the high frequency of pollen grains belonging to pharmaceutical taxa suggests that lavages with vegetable components were used by the patients before undergoing the test. In nasal, bronchial and conjunctival cytology greater amounts of polliniferous slides were recorded (in bronchial/nasal cytology also a higher number of pollen grains per smears, up to 114-428 respectively) and pollen spectra reflected the vegetational environment of the patients' living sites. In these cases, most pollen grains are thought to be really present on mucosae when the samples were taken. In these cytological fields pollen analysis may be useful for diagnostic purposes, above all in case of allergic pathology to detect the pollen grains causing the disease.

This paper describes a pollen survey from Turin based on 25 taxa of interest. The survey took place between 1981 to 1988 recording pollen types and amounts.Pollen was collected using a Hirst spore trap. A pollen calendar was constructed using 10 day means: aerosporological data were then compared to the urban vegetation and flora. Pollen distribution was analysed in relation to temperature, calculated as the taxon's yearly specific temperature sum.The situation in Turin was then compared to other central European and Mediterranean stations: results were found to be more comparable with the former.

The present paper deals with the results of continuous aeropalynological survey of the atmosphere at Bangalore carried out for the past six years. The aeropalynological survey was conducted by trapping airborne bioparticles such as pollen and fungal spores by operating vertical cylinder pollen traps. The traps were installed at different ecogeographical sites in Bangalore City. The results of qualitative and quantitative analysis of the atmospheric biopollutants are correlated with the meteorological parameters such as temperature, relative humidity, wind speed and cloud cover. It is seen that generally the higher temperature and lower relative humidity enhance the liberation and distribution of pollen in the atmosphere; whereas the higher humidity and lower temperatures trigger the liberation and distribution of fungal spores in the atmosphere. Atmospheric pollen count is drastically reduced during the rainfall.

Science citation index in its various cumulations for 1955 through 1986 has 1909 citations of Gunnar Erdtman's palynological works. His 1952 book, including its 1966 and 1971 reprints and its 1956 Russian translation, received 653 citations. Next are his 1943 pollen analysis book, including its 1954 reprint, with 172 citations, and his 1969 palynology handbook, with 146 citations. Volumes 2-4 of An introduction to palynology have collectively 150 citations, whereas the two volumes on the Scandinavian pollen flora have collectively 129 citations. Erdtman's most cited article is his 1960 paper on the acetolysis method, with 158 citations. All his other 223 books and articles (1920-73) have only a handful of citations each, collectively 501 citations for 1955-86 citing works. In the literature there are various bibliographic inaccuracies involving Erdtman's works. The 1952 book was cited 131 times as 1966 or 1971, usually without mention that a 1952-vintage book had been reprinted. In addition, “G. Erdtman” has been misspelled 11 different ways in 64 citations.

This paper begins a systematic SEM and LM study of the pollen grains of the Rosaceae in Western Canada with genera Agrimonia, Alchemilla, Amelanchier, Aruncus, Chamaerhodos, and Crataegus. The above genera have tricolporate-tectate pollen grains in monads. Agrimonia gryposepala and A. striata have distinct striate sculpturing perpendicular to the colpus. Alchemilla occidentalis pollen is psilate except in the colpus area which is microechinate. The exine is thickened in the intercolpium. Aruncus Sylvester pollen is very small and exhibits a coarsely striate sculpture. Chamaerhodos erecta pollen has a characteristic protruding pore area with a fusiform operculum over the aperture. The sculpturing consists of patches of short ridges. Crataegus and Amelanchier pollen have pores with a characteristic equatorial bridge or flaps when open. Dimensions of the grains vary with degree of distension. Amelanchier alnifolia pollen exhibits geographic variability. Native North American Crataegus species: C. douglasii, C. rotundifolia and C. succulenta have pollen which exhibits morphological variability and requires more study. In the survey so far, surface sculpturing is the most distinctive feature and, in combination with characteristics of the pore area, seems to distinguish the types. A table of characters permits the pollen of most taxa studied to be identified using LM and SEM

A new method has been experimented in order to identify more easily allergenic spores and pollen grains from Northern Europe described in the Atlas of Nilsson et al. (1977). It is a knowledge base system named XPER. This system based upon an automatic elaboration of a data matrix, includes for this contribution, 74 individuals (or taxa, objects) 40 variables (or characters, features) and 199 modalities (or character states). It is an on-line program type of identification (monothetic and multi-access key) working on several types of microcomputers. Four main subunits are available in this program (1) an editor to create, consult and modify the data arrangement of either taxa or characters or states; (2) a determiner to identify an unknown taxon by a step-by-step identification with possible return and several options; (3) a reorganizer to modify drastically the data and to connect several bases and (4) a printer to give as options, either only on the video display unit or simultaneously on paper listing: list of taxa, characters, states, data-matrix and complete descriptions of each taxon.

This paper aims to assess to what degree and in what way the brood chamber affects the pollen content of the honey. Twenty-nine pieces of comb containing only honey were cut from different frames of hives. The percentage of cells in each frame occupied by the brood chamber and the distance between these cells and the cut piece were recorded. A honey sample was extracted from each comb piece, avoiding any contamination with pollen, its sediment examined under the microscope and its botanical constituents identified and counted. The results show that the pollen content of honey was higher in samples from frames containing brood or pollen cells; in these samples the pollen content was positively correlated with the amount of these cells in the frame and the proximity of the honey to them. The proportion of pollen grains from principally nectariferous plants was lower in honeys with a high pollen content.

Asthma and allergic alveolitis account for about one third of the total number (2000 plus) of cases of work-related respiratory disease reported annually in the U.K. The majority of cases of occupational asthma are caused by chemical agents, but a significant number of the remainder result from inhalation of biological agents, such as those encountered in agriculture. A wide range of activities can result in exposure to organic dusts and associated microorganisms. These include handling mouldy hay and grains, fruit and vegetables, processing wastes, including compost making for mushroom growing and tending animals in confined facilities. To determine the incidence of occupational respiratory allergy in agriculture, to study aetiology and risk factors and, ultimately, to establish dose response relationships, requires input from a wide range of disciplines including clinicians, immunologists, microbiologists and aerobiologists. The link between what a farm worker breathes in and development of disease needs to be established. This paper reviews the role of microorganisms in the aetiology of disease with examples of typical exposures in agriculture and outlines the role that aerobiology can play in risk assessment.

Recent studies to determine whether long-distance dispersal of the pathogens causing Yellow and Black Sigatoka diseases in banana and plantain plays a significant role in the epidemiology of these diseases are inconclusive. This paper reviews current knowledge and identifies areas where further studies are needed to establish the relative roles of wind transport and transfer of diseased material in disease spread.

Annual variations in the ambient concentrations of Betula pollen monitored by volumetric sampling at sites in London and also at a site to the South of the city between the years 1961-1990 are analysed in relation to the main meteorological parameters. Attention is focussed on variations in the start and duration of the seasons and on the annual patterns of pollen abundance. Consideration is given also to the variation in the severity of seasons. The paper examines possible rhythms in the annual production of Betula pollen and develops empirical regression models from the analyses of the trends to predict the main characteristics of the seasons.

The paper records the occurrence of indigenous oaks (Quercus semecarpifolia and Q. dilatata) in the Kashmir valley, which have hitherto been reported as absent there. It also gives an outline history of the oaks in the Kashmir valley since the beginning of the Pleistocene and discusses the historical status of the modern oaks in the valley.

Records of air-borne pollen and spores were made during a six month period in the Stockholm area in 1972. This paper presents phenological data and volumetric measurements obtained by means of a Burkard trap. Attention was paid to both arboreal pollen and non-arboreal pollen and spores, identified to family, genus or species level. Spores of certain common Pteridophytes were also included in the investigation, but not Bryophytes or fungal spores.

The taxonomic basis of a paper by K. Mitra, M. Mondal & S. Saha on “The pollen morphology of Burseraceae” (Grana 16: 75-79, 1977) is criticized. Apparently, there has been no cooperation with a specialized taxonomist, no use has been made of the many recent revisions, especially of SE. Asian Burseraceae, and the voucher specimens have been cited in such a way that checking with these revisions is impossible. Among the specific names mentioned many are incorrect, and some are completely unknown in taxonomy. It is to be regretted that this in itself careful and detailed work has lost much of its value by having been done on such a shaky taxonomic basis.

The possibility to apply diffusiophoresis and the Stefan flow effects in a new type of sampler was investigated. The advantages of the later are significant compared with other sampler desingns, since it gives representative samples that can subsequently analysed by the methods of optic and electron microscopy. The low particle deposition velocity keeps microorganisms intact, on the other hand, the small depence of the particles' deposition velocity upon their sizes makes the separation of the analyzed aerobiological objects impossible. As a result, the representativness of samples is secured. In this paper the sampler design is described and its working conditions (heat, hydrodynamic) are analyzed.