摘要:

After analyzing the musculature of annelids and their locomotive mechanisms, the author goes back to the probable origin of the various muscle groups in these animals and reconstructs an archetype.

ISSN:0373-4137    

DOI:10.1080/11250008109439338

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

An experiment was performed on five inbred strains ofDrosophila melanogasterto find out the kind of developmental variations that occur from changes in environmental temperature. Dimensional traits representative of three units (compartments) of development from the same imaginal wing disc (mesonotum, anterior and posterior wing regions) have been considered.

ISSN:0373-4137    

DOI:10.1080/11250008109439339

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

In the buccal ganglia ofAplysia depilansandA. fasciata, the small S1cells were found to affect synaptically not only the A, B, and C cells, as already reported, but also the middle-sized and large neurones which are placed in a central position in the caudal face of the ganglion, and which are labelled “D cells” here.

ISSN:0373-4137    

DOI:10.1080/11250008109439340

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The ultrastructure of gamonts in syzygy, of gametes and zygotes inApolocystissp. was examined. The gamonts looked globular (Ø 50 μm), surrounded by a wall (gamontocyst) 150 nm thick. The gamont cytoplasm was covered only by the plasmalemma but at some points there were traces of the trimembrane pellicle; the endoplasm was filled with large oval granules of amylopectin. Gametocysts with gametes in formation had thinner walls (c. 50 nm) and a dense band had become detached and followed the contours of the inner material. Some gametes were attached to the surface of the gamont cytoplasmic mass by a peduncle; other gametes were contained in large vesicles which split the endoplasm into lobes. In more aged gametocysts, gametes looked free in the space between the wall and the residual cytoplasm. This cytoplasm, reduced by the confluence of large vesicles, showed in the outer part bundles of fibrils and microtubules and in the inner part clusters of big nuclei; amylopectin granules did not pass into the gametes. Gametes formed by two sexually complementary partners were identical (isogametes), roundish (Ø 4 μm) and surrounded by the plasmalemma which formed some micropores. From a dense polar cap radiated a cone of microtubules, some of which ran tangent to the nuclear envelope wrapping the nucleus near the cell surface. Zygotes, protected by a thin wall, 20 nm, corresponding to the inner layer of the oocyst wall, were oval (6 [μm X 4 μm) with a very dense cytoplasm in which were large lipid inclusions and small granules of amylopectin.

ISSN:0373-4137    

DOI:10.1080/11250008109439341

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The evaluation of DNA content in Australian marsupials (Martin & Hayman, 1967; Bick & Jackson, 1967) together with the morphological analysis of the karyotype (which shows a strong variability: 2n between 10 and 32 with modes at 14 and 22) has yielded useful information for the phylogenetic analysis of this order.

ISSN:0373-4137    

DOI:10.1080/11250008109439342

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Elaphoidella moreaen. sp.,Parapseudoleptomesochra hellenican. sp. andNitocrella achaiaen. sp. are described from phreatic subterranean waters of Greece. Moreover, new localities are reported for the speciesElaphoidella karamaniChappuis,Elaphoidella elaphoides(Chappuis),Attheyella (Brehmiella) dentata(Poggenpol),Attheyella (Attheyella) crassa(Sars),Nitocrella skirensisPesce,Nitocra spinipesBoeck,Bryocamptus (Bryocamptus) minutus(Claus), andCanthocamptus staphylinus(Jurine).

ISSN:0373-4137    

DOI:10.1080/11250008109439343

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Each of the two adrenal glands ofRhacophorusconsists of a strip lying along the lateral edge of the ventral surface of the ipsilateral kidney. The gland is composed of Interrenal, Stilling and Chromaffin cells. The Chromaffin cells, according to their granule content, may be divided into Adrenaline-, Noradrenaline-, and Small Granule Containing-Cells. The structure of the gland is compared with that in other amphibians; its peculiar affinity with the adrenal gland ofRanais discussed.

ISSN:0373-4137    

DOI:10.1080/11250008109439344

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

InKalotermes flavicollisFabr. (Isoptera, Kalotermitidae) the tryptophan metabolites were determined by paper chromatography.

ISSN:0373-4137    

DOI:10.1080/11250008109439345

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Three different strains ofOphryotrocha labronicawere used for all the possible reciprocal crosses. The results substantiate Bacci's thesis (1978), according to whichOphryotrocha labronicawould consist of sexual races with different valences in geographically distinct populations, and indicate a reproductive isolation on ethological bases. A close correlation has been found between the occurrence of sexual races and the difference in the degree of courtship activity according to strains.

ISSN:0373-4137    

DOI:10.1080/11250008109439346

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The results of a year's research on the benthic community in the Acquarella area of Lake Bracciano are reported. Fifty-three taxa of benthic invertebrates were collected. The fauna is mainly represented by gastropods (in the littoral), chironomids and oligochaetes (especially in the sublittoral and profundal zones). There are numerous other taxa, particularly in the littoral. The diversity indices (Shannon's diversity and evenness) were also calculated. The results suggest that the area investigated still exhibits unpolluted environmental conditions.

ISSN:0373-4137    

DOI:10.1080/11250008109439347

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor