摘要:

Salient features of microanatomy ofPyramimonas tetrarhynchus, type species of the genus, are described and illustrated. The species is shown to possess a flagellar scale reservoir comparable to that previously described for a marine species(P. amylifera)though somewhat simpler. The body scales are shown to arise directly from Golgi eisternae as inP. amylifera.Other features discussed include the flagellar roots and certain aspects of the mode of liberation of scales to the exterior. Participation by endoplasmic reticulum in the latter process is shown to be probable but there is no precise explanation forthcoming for the elaborate scale arrangement encountered both on the flagella and on the cell. Participation by cytoplasmic tubules is nevertheless effectively excluded for the latter.

ISSN:0370-0461    

DOI:10.1111/j.1095-8312.1968.tb00974.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

In this paper the recorded distributions of butterfly, bird and bat taxa in the Indo‐Australian area are subjected to various kinds of numerical analysis. Numerical methods are used to assign primary areas to zoogeographic regions and to assign taxa to faunal elements. An attempt is made to relate these classifications to the past geographical history of the area, and hence to infer something about past trends of spread and speciation in each grou

ISSN:0370-0461    

DOI:10.1111/j.1095-8312.1968.tb00975.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

Among the Solomon Islands' insects two distribution patterns are important, a distinctive fauna on S. Cristoval, and a similarity between the islsnds of Bougainville, Choiseul and S. Ysabel. These result from the island area‐fauna size relation, and the expansion of immigrants or island endemics which takes place most easily across the narrower water gaps, although different insects vary in their ability to cross them. The distributions of species in three heteropteran genera are interpreted as stages in a process of expansion, differentiation and replacement. Peculiarities of the S. Cristoval fauna are related to the island's isolation in terms of distance from major sources, rather than any conjectural geological history. However the Bougainville‐S. Ysabel affinity coincides with a possible late Pleistocene land connex

ISSN:0370-0461    

DOI:10.1111/j.1095-8312.1968.tb00976.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

The life history of a new species of the ChytridialesRhizophydium nobileis described. It occurs in the autumn on resting spores of the algaCeratium hirundinellaO.F.M. in Blelham Tarn, Windermere and Esthwaite Water, lakes in the English Lake District. The sporangium develops from the zoospore and possesses a branched rhizoidal system. The zoospores are fully formed in the sporangium. On dehiscence part of the sporangium content flows out surrounded by a vesicle which eventually bursts and liberates the zoospores. Only a few resting spores were seen associated with the sporangial stage. They were small spherical thick‐walled bodies containing several globules. Further observations need to be made upon this stag

ISSN:0370-0461    

DOI:10.1111/j.1095-8312.1968.tb00977.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

Apart from ciliates, there are other protozoans which can form an important element in the herbivorous zooplankton of lakes.The protozoans discussed in this paper feed on colonial algae. They can greatly reduce the numbers of certain Chlorophyta in Windermere, Esthwaite Water and Blelham Tarn, lakes in the English Lake District.A very short period, often 7–14 days, can suffice for the destruction of more than 99% of an algal population.Experiments with a species ofPseudosporashowed that it would only ingest one out of six green algal species, although, in nature,Pseudosporaewhich are morphologically similar to this species have been observed in all these algae.The importance of such protozoans, and of parasitic fungi, has been underrated or neglected in studies of the quantitative relationships between primary and secondary production in the plankto

ISSN:0370-0461    

DOI:10.1111/j.1095-8312.1968.tb00978.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

School subdivision of animals is the subdivision into classes according to similarities; while in nature animals are subdivided into stems (Stämme) according to kinships determined by generation. The former classification supplies a school‐system for the sake of memorising; the latter a natural system for comprehension; the former has for its purpose only to bring creatures under a system of labelling; but the latter seeks to bring them under a system of law. I. Kant, 1775.On different human ra

ISSN:0370-0461    

DOI:10.1111/j.1095-8312.1968.tb00979.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

The taxonomy of the Southern Hemisphere lampreys,QeotriaandMordacia, is reviewed. Many invalid species have been created within these genera due to a lack of knowledge of the great morphological changes that take place during development. The sequence of changes in the dentition ofMordaciais described in detail.Geotriais now considered to be monotypic, containing onlyQ. australisGray, which is found in Australia, New Zealand, and South America.Caragolais regarded as a synonym ofMordacia, and thus the exclusively South AmericanC. lapicidabecomesM. lapicida(Gray). The otherMordaciaspecies,M. mordax(Richardson) andM. praecoxPotter, are found only in Australia. All these species are anadromous and parasitic, exceptM. praecox, which is nonparasitic and never leaves fresh‐water.A comparison of anatomical features indicates that living lampreys (Petromyzonidae) are best separated into three subfamilies: Petromyzoninae to contain all Northern Hemisphere genera, Geotriinae forGeotria, and Mordaciinae forMordacia.A record of the Australian rivers in which lampreys have been found, shows that both genera are sympatric in South Australia, western Victoria, and Tasmania, and that onlyQeotriais found in Western Australia, and onlyMordaciain south‐eastern Austra

ISSN:0370-0461    

DOI:10.1111/j.1095-8312.1968.tb00980.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

(i) The experiment described in this paper was designed to investigate Sheppard's (1951) results which showed that thrushes predated individuals ofG. nemoralisselectively, and further that the relative disadvantage of the yellow morph changed with the changing colour of the background.(ii) Because of the scarcity of thrushes only a relatively few individuals were predated. The predation was much later in the year than in Sheppard's experiment, probably because of the differences in weather conditions.(iii) The results of the experiment indicate that yellows are at a disadvantage during the summer months in the area under investigation, probably because there is a dense and tall growth of herbs in the area and this gives rise to a dark background near the ground.(iv) These results are similar to those obtained by Wolda (1963) who could not explain them in terms of the colour of the background. It seems likely that the present explanation could account for his results.(v) A comparison of the yellow morph‐frequencies of predated samples removed from the area before the present experiment was begun, with those in the predated sample from the original natural population found by Sheppard 12 years previously show very little difference although the addition of Sheppard's experimental population changed the frequency of this morph considerably. It is therefore suggested that systematic processes play a large part in determining the population geneti

ISSN:0370-0461    

DOI:10.1111/j.1095-8312.1968.tb00981.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

ISSN:0370-0461    

DOI:10.1111/j.1095-8312.1968.tb00982.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

ISSN:0370-0461    

DOI:10.1111/j.1095-8312.1968.tb00983.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY