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Temporal changes in spatial distribution patterns of aphids infesting winter strawberries in coastal California were determined using Green's Coefficient, Cx, Iwao's regression of mean crowding on the mean, and Lloyd's “Patchiness Index.” Both C, and the Patchiness Index indicated the aphids were initially overdispersed, but became random as populations increased. Distribution remained random following population collapse, suggesting that density-independent mortality factors suppressed populations. Iwao's regression method provided analogous results when populations were temporarily stratified

Utilization of patchy habitats by adult populations of threePieris butterflies,P. rapae, P. melete andP. napi was studied throughout the flight season in an area of their coexistence, about 3×1.5 km, in a farm village in the mountains in Inabu, Aichi Prefecture. Field study was by the mark-recapture method. Results were analyzed by dispersal distances and recapture duration decay curves for adults of different age-classes estimated on the basis of physical condition of their wings, together with supplementary information of daliy egg-laying rate of females, obtained in field cages.

Die Verteilung des Wurzelsystems von Mais wurde im Hinblick auf die Wurzelkonkurrenz um Makronahrstoffe unter Feldbedingungen mit Hilfe der radioautographischen Methode untersucht. Die groste Wurzeldichte wurde stets in den obersten 20 cm Boden direkt unter der Pflanze ermittelt. Es fanden sich bis zu 130 radioaktive Schwarzungen pro 33 cm2 Bodenquerschnittsflache, was einer errechneten Wurzeldichte von ca. 8 cm/cm3 Boden entspricht. Im ubrigen Wurzelraum liesen sich dagegen nur Werte von ≧ 2 cm/cm3 nachweisen. Diese raumliche Verteilung des Wurzelsystems von Maispflanzen war im wesentlichen unabhangig von der Bestandsdichte (1 Pflanze bzw. 9 Pflanzen pro 0.84 m2) und dem Pflanzenalter (Stadium des Schossens und der Blute). Das raumliche Verteilungsmuster des Wurzelsystems zeigte niemals eine statistisch abgesicherte aquidistante Anordnung der Wurzeln. Vielmehr waren die Wurzeln uberwiegend zufallig im Boden verteilt. Es traten aber innerhalb der untersuchten Bodenzylinder in speziellen “Microsites” Wurzelaggregationen auf. Aufgrund der gefundenen Wurzeldichten und -verteilungsmuster einerseits und der fur den ungedungten Versuchsboden (lehmiger Sand, 8% Ton) ermittelten Einzugsbereiche der Einzelwurzel fur P und K andererseits, konnten bis zu 40% der Wurzeln einer Maispflanze um P und bis zu 75% um K konkurrieren. Dagegen konnte fur die mit verschiedenen Radioisotopen (32P bzw. 35S) markierten Wurzelsysteme zweier benachbart wachsender Maispflanzen (Abstand 50 cm) im Stadium der Rispenblute nur eine geringfugige Durchdringung festgestellt werden. Die ermittelten in-situ Abstande der 32P und 35S markierten Wurzeln lassen keine Wurzelkonkurrenz der beiden Pflanzen um P und K erwarten. Distribution of the root system of maize with respect to competition for macronutrients The distribution of the root system of maize was studied with respect to root competition for macronutrients in the field by means of the radioautographic method. The greatest root density was always measured in the uppermost 20 cm soil layer directly below the plant. Up to 130 radioactive spots per 33 cm2 soil cross section could be found, which corresponds to a calculated root density of approximately 8 cm/cm3 soil. In contrast, values of only ≧ 2 cm/cm3 could be determined in the residual root space. This aspect of the spatial distribution of the root system of maize plants was found to be essentially independent of the plant density (1 plant und 9 plants per 0.842, respectively) and the plant age (late preflowering stage, flowering stage, respectively). The spatial distribution pattern of the root system never indicated a statistically significant regular arrangement of the roots. On the contrary, the roots were randomly distributed in most cases. However, the roots formed aggregations at special “microsites” within the investigated soil cylinders. As a result of the root densities and the root distribution patterns observed, on the one hand, and the depletion zones of P and Kin the vicinity of single roots determined for the unfertilized soil used in our investigations (loamy sandy soil, 8 % clay), on the other hand, up to 40 % of the roots of one maize plant could compete for P and nearly 75 % for K. However, only a weak interpenetration of the root systems of two adjacently grown maize plants at the tasselling stage (separated from each other by a distance of 5Ocm), having been labelled with different radioisotopes (32P and 35S, respectively), could be observed. The determined in-situ separation distances of the 32P and 35S labelled roots from one another do not indicate that any competition between the roots of the two plants for P and K would have taken place.

無防除のトウモロコシ畑で,その重要害虫であるアブラムシ類の個体数変動と空間分布構造を3年間調査した。1) 毎年ムギクビレアブラムシ,トウモロコシアブラムシ,ムギヒゲナガアブラムシの3種が見られたが,それらの個体群密度は常にきわめて低く,小さなコロニーが部分的に形成されたにすぎない。また,毎年6月下旬には急激な減少を示し,7月上旬にはほとんど0となった。秋季の個体群も高密度に達しないまま,青刈りが行なわれた。ほ場全体としてみても,アブラムシによる実害は全く認められなかった。2) これら3種のアブラムシの分布様式は,有翅虫では区(20株),株,葉といういずれの空間単位でも,ランダムないし一様分布であった。しかし,これら有翅虫に由来する無翅虫(幼虫も含む)は,いずれの空間単位でも著しい集中分布を示した。3) 有翅虫,無翅虫とも特定の部位の葉(やや下位)に集中して寄生する傾向を示した。しかし,3種間の葉位によるすみ分けは認められなかった。4) このような分布様式はアブラムシの低密度個体群の特色で,その意義について考察した。

The changes in spatial distribution pattern during larval stage of the fall webworm,Hyphantria cunea were quantitatively investigated in the field experimental populations. The female adult deposits eggs as a cluster and the hatchlings make a compact colonial-web. In this period, the all-or-none type mortality which is characteristic in gregarious insect species was occasionary recognized before spinning a compact colonial-web. Once making a compact colonial-web, the larvae feed the leaves in the colonial-web up to about 5th instar. In this period, the movement of larvae occurred due to the local food shortage in a colonial-web and the expansion of colonial-web. As the larvae developed, the colonial-web was separated into several small groups. These larvae began to disperse about 5th instar. In this period, the local food shortage seems to be an important trigger for the larval dispersal. The mean concentration of larvae on leaves abruptly decreased, and finally the larvae became solitary at the 6th or 7th instars. The dispersal process in later larval stage is not necessarily due to the complete food shortage. The dispersal prior to the occurrence of food shortage may be a safety mechanism to protect the larvae from the food shortage.

Seston size distribution was determined with a Coulter Counter to investigate seston interaction and its effects on phytoplankton production. Spatial distribution patterns of the non-productive component of the seston were as complex as those commonly associated with algae. Seston might interact influencing production by changes in optical depth, abrasive actions and nutrient adsorption.

Pelosina cf. arborescens appeared in high numbers in sediments placed in a mesocosm system. Analyses of spatial patterns showed that the species was in general aggregated, but at low abundances the distributions were regular or random. Where aggregated at low abundances patch sizes were 50 cm2, 200 cm2, and 800 cm2, at medium abundances at 50 cm2 and 400 cm2, and at high abundances at 100 cm2 and larger than 3200 cm2.

The spatial pattern of Hypera postica (Gyllenhal) in Kentucky alfalfa fields was investigated using Taylor's and Iwao's distribution functions as statistical models. Field counts of the insect in 2 contiguous plots where the populations were relatively low conformed to an overdispersed pattern. However, at a 3rd plot where the density was high, numerous population aggregates were formed and they dispersed in the direction of randomness. Randomness also increased with development of the larvae, partially owing to mortality caused by the 2 parasitic Bathyplectes spp. For all stages the variance was proportional to a fractional power of the mean. Taylor's power function b varied with environment. Use of one-quarter square foot samples for estimating egg populations had little effect on the skewness of the distribution. Two transformations are offered for stabilizing the variance of overdispersed field counts. However, only the square root transformation stabilized the variance of counts in the plot where the populations were randomly dispersed.

Plots of sound-source direction from 4-hydrophone array data for underwater sperm whale (Physeter catodon) sounds indicated a consistent scatter in both horizontal and vertical bearings to different animals. During each dive the whales routinely appeared to be distributed 100 m or more apart throughout a large volume of water, both in depth and plan, but they usually regrouped to surface together for breathing. A plot of acoustic bearings to 19 sperm whales in one group shows their underwater distribution scattered over 100° horizontally and 30° vertically. Underwater distributions and surfacing patterns were analyzed from eight groups of sperm whales during August and September 1972, 1974, and 1975 in the western North Atlantic from 300 km east of New Jersey to 100 km south of Sable Island. It is suggested that the whales probably maintain contact with each other acoustically, and that their underwater spatial distribution patterns could be designed for foraging.

The functional roles of the mucous secretions from the frontal organ and epidermal glands of the acoel turbellarian Convoluta sp. VOrsted were investigated. Experiments that tested choice of the animals between sand previously exposed to Convoluta sp. (natural sand) and acid-cleaned sand resulted in the preferential choice of Convoluta sp. for natural sand (Z = 2.45; P < 0.05). Since the animals were distributed gregariously in their natural environment (Morisita index, Iδ = 2.36; F = 20.19; P < 0.05), it is proposed that mucus is involved in this observed spatial distribution pattern by acting as an attractive signal to conspecifics. It was further found that these mucous secretions agglutinate sediment particles into an interstitial system of tunnels and trails, thus promoting the stabilization of the sediment. Secreted mucus significantly enhanced the growth rate of at least one of the acoel's food items, the diatom Nitzschiacurvilineata Hustedt (U = 25; P < 0.05).

Between 1982 and 1985, Nigerian cassava fields were periodically sampled through three crop growing seasons to analyze the within and between‐plant distribution of CM as affected by weather (dry and rainy season) using the mean crowding statistics and Taylor's power law. Enumerative and binomial sampling plans were developed which take into consideration the seasonal changes in the spatial distribution patterns of CM. The costs of the two procedures were compared to select the most cost‐efficient sampling plan.

The author summarises the results of his studies of Central and West African rare-metal pegmatites and supplements them by the newest datas obtained by H. Adam in Ivory Coast. He compares then the classification of African rare-metal pegmatites with the classifications obtained in U.S.S.R., in U.S.A. and in Canada for the same kind of pegmatites. The author's conclusions may be summarised as follows: (a) The rare-metal pegmatite types succeed each other in a more or less defined order which is independent from the ages of the orogenies as well as from the nature and from the degree of metamorphism of enclosing rocks. (b) The spatial distribution of the rare-metal pegmatite types in or around the granitic intrusions depends from the depth at which the parent granites are crystallizing. — When the granites are crystallizing at relatively shallow depths, the rare-metal pegmatites and partially the quartz veins and the associated mineralizations are located in the granitic bodies them selves. When the granites are crystallizing at more and more greather depths, the rare-metal pegmatites, the quartz veins and the associated mineralizations as well as the secondary phenomena such as albitization and greisenization are no more restricted to the granitic intrusions, but with the increasing depth of their crystallization are more and more penetrating in the roofs of the granitic cupolas. In addition it must be underlined that in granites crystallizing at shallow depths, the dimensions of the individual pegmatites are small and have no economic value; the rare-metal pegmatites associated with granitic intrusions cyrstallizing at greather depths may reach gigantic dimensions and certain types may be mined for tin, niobium, tantalum, beryl and lithium minerals; (c) In the same metallogenic province may co-exist granitic intrusions having crystallized at diffrent depths or at diffrent geological ages. To each depth of crystallization of the granitic intrusions corresponds a specific spatial distribution pattern of rare-metal pegmatites characterized by the distance of different pegmatite types to the granitic contacts as well as by the dimensions of the pegmatite types and by the size of their minerals. This may outline a special zonation within a metallogenic province. — At the end of the paper, the author gives a comparison of Central and West African rare-metal pegmatite type classification with similar classifications obtained in U.S.S.R., in U.S.A. and in Canada. From this comparison it results that the evolution of the pegmatitic process remains the same throughout geological epochs and is independent of the nature of the enclosing rocks. The magnitude and the fullness of this process are depending from the depth of crystallization of the granitic intrusions.

Adults and nymphs of Lygus hesperus Knight and L. elisus Van Duzee were found to be distributed in cotton fields in clumped, nonrandom patterns. The nymphs showed more clustering than the adults. The adults and nymphs were consistent in their degree of clumping between 8 AM and 6 PM. The observed distribution patterns were fitted by several contagious mathematical models. Statistical analyses indicate the feasibility of using theoretical distributions to describe samples based on adult-plus-nymph or adult-plus-twice-nymphs counts.

The performance of Holgate's mean ratio and correlation tests was intensively evaluated on five 48-acre forest tracts and four computer-redistributed populations with specified spatial distribution patterns generated from each tract. These two test statistics were calculated for all possible combinations of distances to the sth and tth (s

Deeply buried, high-grade oreshoots in carbonate-quartz veins are found in the Silver Belt of the Coeur d9Alene district by the application of various geologic criteria. Exploration is costly, and additional indications of the proximity of ore are highly desirable. The purpose of this study is to examine significant mineralogical features of the district in an attempt to develop additional helpful criteria.A search is made for indicator minerals; i.e., minerals, the spatial distribution of which may be indicative of the position of ore. In this respect, spatial distribution patterns of most of the vein and country-rock minerals are discussed, and the genesis and time relationships of the minerals are interpreted as an aid in the evaluation of these patterns.Arsenopyrite is believed to be an indicator, apparently forming envelopes around oreshoots. Similarly, late hydrothermal chlorite is considered to be an indicator. Sericite and carbonates of pre-hydrothermal-vein origin have a negative significance as indicators; i.e., little ore has been found in areas where these minerals are concentrated. Since beds rich in detrital quartz are the best ore horizons, such quartz is considered to be an indicator of limited practicability.An attempt is made to clarify the genetic classification of the various minerals, and within genetic types a few minerals not previously described in the district are listed. Six genetic types of chlorite are defined.The hydrothermal-vein history of the district is divided into three stages. In chronological order these are: (1) the bleaching alteration stage, (2) the carbonate-quartz stage, and (3) the sulfide stage. The hydrothermal bleaching alteration of large areas of the country-rock is largely the destruction of the rock pigments, and no strong sericitization is involved as previously thought.

ミカンハモグリガ幼虫個体群のほ場における分布構造を明らかにすると共に,分布形成過程や死亡過程の解析を通じて,本種個体群の空間的な動態の特性を検討した。1) 幼虫分布の基本単位は個体ではなく,ルーズなclumpであり,これは雌成虫による産卵が,1本の新梢に続けて行なわれることに由来していると思われる。このようなclumpがほ場内では集中的な分布をしているが,これは雌成虫の産卵活動の集中性と共に,樹あたり新梢数の変異など,環境の異質性に影響されるためであろう。2) 1本の樹の中での葉あたり卵の分布は,密度が低いと一様的で,密度が高くなると集中的となる。これは雌成虫が既産卵葉をさけて産卵する性質をもっていることと,それぞれの葉に異質性があることの複合された結果であると思われる。葉あたり幼虫分布はポアソン分布に近い形となったが,産下卵の分布様式に対して個体単位にランダムな死亡が起こった後,幼虫がふ化したことからも説明される。3) 幼虫後半期と蛹期に起こった死亡過程は,ほ場全体の個体群密度に関しては密度依存的な傾向をもっている。これに対し,局所的(樹,梢,葉単位)な個体群に関しては,幼虫期,蛹期ともそれぞれの密度にあまり関係なく,またall-or-none的傾向を示しており,個体群密度の局所的な変異を増加させている。

Documento originalmente apresentado em International workshop “Uranium, Environment and Public Health”, UrEnv 2013. Submitted by Maria Eduarda Pereira Rodrigues (erodrigues@ipcb.pt) on 2015-11-18T15:11:27Z No. of bitstreams: 1 Antunes et al_Procedia Earth and Planetary Sciences.pdf: 625807 bytes, checksum: 837dadde9db3b626968bd290fa3ee459 (MD5) Approved for entry into archive by Maria Eduarda Pereira Rodrigues (erodrigues@ipcb.pt) on 2015-11-20T12:48:54Z (GMT) No. of bitstreams: 1 Antunes et al_Procedia Earth and Planetary Sciences.pdf: 625807 bytes, checksum: 837dadde9db3b626968bd290fa3ee459 (MD5) Made available in DSpace on 2015-11-20T12:49:13Z (GMT). No. of bitstreams: 1 Antunes et al_Procedia Earth and Planetary Sciences.pdf: 625807 bytes, checksum: 837dadde9db3b626968bd290fa3ee459 (MD5) Previous issue date: 2014

A greenhouse study was conducted to develop time-activity budgets for third-instar tobacco budworm, Heliothis virescens (F.), and to determine its spatial distribution patterns on chlordimeform-treated cotton plants. Compared with untreated plants, chlordimeform 1) reduced plant-feeding by larvae, 2) increased movement by larvae over plant surfaces, especially over leaves and stems, and 3) increased abandonment of plants by larvae. We hypothesize that under field conditions, insecticide synergism by chlordimeform against Heliothis spp. larvae may be partly due to chlordimeform-induced modification of this pest’s behavior.

Data of the Multistate Atmospheric Power Production Pollution Study (MAP3S) and the National Atmospheric Deposition Program (NADP) were utilized to develop wet deposition spatial distribution patterns for the eastern United States for 1979. The ions of SO4 =, NO3 −, H+, and NH4 + were selected for study since they are the most prominent ones found in precipitation.

Protozoological and physicochemical analyses were performed in a waste stabilization pond at Sto. Tomas Atzingo, a small town near Mexico City, in order to discern the internal dynamics of the pond water through the study of the spatial distribution pattern of flagellates and the parallel water volume distribution pattern of some selected physicochemical determined parameters. The statistical method applied to the data obtained was by cluster analysis. The results showed a slight trend to heterogeneity in the system, when it was evaluated through the physicochemically determined parameters. On the other hand, the spatial distribution pattern of the flagellates pointed out a remarkable heterogeneity in the pond. In systems like the one studied where the main feature is an organic matter overload, such a difference in findings indicates a low correlation between the biological parameters, in this case the flagellates, and the physicochemical variables, that should be considered when evaluating the water quality of such systems, either through the physicochemical, the biological or both scopes.

The small lamellibranch Macoma balthica (L.) has been extensively studied in recent years. Many authors have investigated the spatial distribution pattern of Macoma and its growth and production, among them Anderson (1972), Beukema et al. (1977), Chambers and Milne (1975), McLusky and Allan (1976), Reading (1979) and Tunnicliffe and Risk (1977). However, causal relationships have seldom been demonstrated, and gaps have emerged in our knowledge of the factors influencing the distribution and mortality of the animal, particularly during its early life.

14 páginas, 5 tablas, 2 figuras, The problem of spatial distribution pattern of Octopus vulgaris in the northwest coast of Africa is investigated. The influence of growth, reproduction and behaviour on the distributional pattern is discussed.

Despite the simple structure of male conifer cones, there is an enormous variability in cone properties observed upon more careful examination. The diversity ranges from simple cones to compound cones. Moreover, cones can be distinguished according to different spatial distributions on the tree. Simple cones are distributed either as solitary cones or as fascicular or clustered aggregations, while compound cones only exhibit fascicular or clustered aggregations. Here, we demonstrate that these different spatial distribution patterns correlate with distinct leaf types and variable branching frequencies. Furthermore, we provide new insights into the evolution of the sporangiophore, particularly in Taxaceae. Two notably important and fast-evolving characters of conifers are the number of sporangia per sporangiophore and the number of sporangiophores per cone. We demonstrate, across many species and types of cones, how these characters are able to adjust according to the optimal amount of pollen.

A class of intractable bio accumulative halogenated compounds polybrominated diphenyl ethers (PBDEs) was studied. Specifically, PBDEs and dechloran plus (DP) contamination in wheat and the assaulted environment—agricultural soil and dust—from metropolitan cities of Pakistan was the focus. The exposure of brominated flame retardants (BFRs) to humans, their probable toxicological impact on health, source apportionment, and the spatial tendency of BFRs were studied. Chromatographic analysis was performed, and concentrations (ng g−1) of ΣPBDE and ΣDP in soil, dust, and cereal crops were estimated in a range from 0.63 to 31.70 n.d. to 6.32 and n.d. to 3.47, respectively, and 0.11 to 7.05, n.d. to 4.56 and 0.05 to 4.95, respectively. Data analysis of source apportionment reflected that the existence of solid and e-waste sites, long-range transport, urban and industrial fraction can be the potential source of PBDE and DP pollution. Moreover, potential hazardous risks to human health across the study area via the dietary intake of cereal foods were deemed trifling, and were gauged on the basis of existing toxicological data.

Archaeoentomological research at the precontact site of Nunalleq (sixteenth and seventeenth centuries AD), Southwest Alaska, has identified hundreds of lice and fleas that infested both the human inhabitants of the site and their canine companions. As lice are host specific, staying attached to the host’s hair or fur during the totality of their lifecycle, they are generally considered excellent indicators of activity areas. Fleas, however, are relatively less common in archaeological contexts and, since they are mobile and able to infest several different host species, their potential use in the spatial reconstruction of activities is more limited. At Nunalleq, the study of insects from the most recent archaeological contexts produced very different spatial distribution patterns for human lice, fleas, and dog lice. This article compares these archaeoentomological data with other datasets available for the site (carrion-feeding flies, human hair, fur, coprolites, projectile points, and pieces of clothing) with the aim of establishing the phenomena that produced the distinct spatial distributions observed., À Nunalleq, un site yup’ik précontact (XVIe et XVIIe siècles après J.C.) du sud-ouest de l’Alaska, des centaines de poux et de puces ayant infesté les habitants du site ainsi que leurs chiens ont pu être identifiés. Puisque les poux sont spécifiques à leur hôte, demeurant attachés aux poils ou à la fourrure de celui-ci pendant la totalité de leur cycle de vie, ils sont généralement considérés comme d’excellents indicateurs d’aires d’activités. Les puces sont relativement plus rares en contexte archéologique. Mobiles et capables d’infester plusieurs espèces-hôtes différentes, leur potentiel dans la reconstitution spatiale des activités semble, a priori, plus limité. Or, à Nunalleq, les résultats de l’étude des insectes provenant des contextes archéologiques les plus récents ont produit des schémas de distribution spatiale très différents entre les poux et les puces de l’Homme et également les poux du chien. Cet article compare ces données archéoentomologiques avec d’autres corpus de données disponibles à Nunalleq (mouches nécrophages, cheveux humains, fourrure, coprolithes, pointes lithiques, pièces vestimentaires) dans l’objectif de reconstituer les phénomènes à l’origine de ces distributions spatiales distinctes.

Se analizo la abundancia y distribucion batimetrica de juveniles de Lutjanus peru en la plataforma continental de Jalisco y Colima, Mexico. Las muestras fueron recolectadas con redes de arrastre tipo camaronero durante tres cruceros. Se capturo un total de 641 individuos, juveniles, cuya longitud total oscila entre 3.7 y 21.9 cm y su peso entre 0.6 y 153.3 g. Los juveniles presentaron una disposicion espacial de tipo agregada. Se determinaron diferencias significativas en la distribucion batimetrica de los organismos, limitandose su presencia a las profundidades de 20 y 40 m. Se encontraron dos grupos de tallas durante los cruceros de mayo a junio (DEM I) y marzo (DEM III), mientras que solo es posible distinguir un grupo en el de noviembre a diciembre (DEM II). De acuerdo con el modelo de crecimiento propuesto por otros autores, los grupos encontrados tendrian 1 y 1.5 anos, respectivamente. Se encontraron diferencias significativas en tallas y pesos individuales entre sitios durante DEM I y DEM III, mientras que durante DEM II las tallas y pesos promedios fueron homogeneos entre sitios. Los juveniles presentaron un crecimiento de tipo isometrico en el intervalo de tallas analizado. The abundance and bathymetric distribution of juveniles of Lutjanus peru on the continental shelf of Jalisco and Colima, Mexico, were analyzed. Shrimp trawl samples were taken from three expeditions during one year. A total of 641 juveniles of L. peru were caught, ranging in total length from 3.7 to 21.9 cm and in weight from 0.6 to 153 g. The juveniles exhibited an aggregate spatial distribution pattern. Significant differences were observed in the bathymetric distribution of the organisms, since their occurrence was limited to shallow waters between 20 and 40 m depth. Two size classes were identified during the May-June cruise (DEM I) and the March cruise (DEM III), but only one class was found in the November-December cruise (DEM II). According to the growth model known for the species, the two size classes found could be of 1 and 1.5 years, respectively. Significant differences were observed in the individual sizes and weights among sites during DEM I and DEM III, whereas the average sizes and weights of DEM II were homogeneous among sites. The juveniles presented isometric growth in the size ranges analyzed.

EXAMINATIONS have been made of the distribution of multiple-allelomorphic mating-type factors (m.t.f.) carried by basidiospores and produced by adjacent carpophores of higher fungi. The spatial distribution patterns found have been interpreted to provide evidence concerning the disposition of the mycelium giving rise to the sporophores and its genetieal homogeneity or heterogeneity1.