38 SUMMARY OF CURRENT RESEARCHES RELATING TO 



with normally retired forms showed no marked contrast in the muscular 

 tissue. The significance of these results is discussed. 



b. Histology. 



The Histology of the Cell.* — E. Rohde discusses very fully the 

 insufficiency of present cell theory, the independence of the nucleus, 

 the relation of the nucleus and cell body of the Metazoa (and Infusoria) 

 to the central body (Biitschli) of bacteria, and other cell problems. A 

 brief enumeration of some of his points on the first head may be given. 

 Embryonic syncytia occur and frequently play a great part in histo- 

 genesis. Especially instructive in the genesis of different tissue is the 

 fact that cells clearly formed but undifferentiated blend into a syncytium 

 from which diverse tissues are developed. An illustration of this is 

 found in the development of the oesophagus of Ascuris. The (esophagus 

 consists of a thoroughly uniform fundamental substance wdiich simul- 

 taneously generates first a thick cuticle ; secondly, powerful supporting 

 fibres of different systems ; thirdly, well developed muscle fibrils, which 

 are said to be diagonally striped. Proof of another kind is found in 

 the fact that many formations regarded as cells are the product of 

 several quite different cells, e.g. Tubularian egg-cells, according to 

 Doflein. Labbe regarded the ovum in this case as a plasmodium, which 

 arose by the blending of several oocytes. Schneider observed the same 

 in Synapta. 



Relations between Nucleus and Cytoplasm.f — Stanislas Maziarski 

 describes three kinds of more or less pseudopodium-like processes which 

 extend towards the base of the cell from the nucleus into the cytoplasm 

 in the hepato-pancreatic tubules of various marine Isopods {Hymothoa, 

 Nerocile, Anilocra). The prolongations may absorb substances from 

 the cytoplasm, or may conduct products from the nucleoplasm to the 

 cytoplasm. In any case, they point to close inter-relations between 

 the two. 



Comparative Histology of Ducts and Accessory Glands of Male 

 Gonads.:}: — R. Disselhorst is the author of the fourth part of Oppel's 

 treatise on the comparative histology of Vertebrates. He deals with 

 the minute structure of the ducts and accessory glands of the male 

 reproductive system. Fifteen sections deal with these in fishes, am- 

 phibians, reptiles, birds, and the chief orders of mammals. Two final 

 sections sum up results, and give a short sketch of the history of the 

 subjects. Then there are some physiological notes. This part main- 

 tains the high standard of its predecessors, for which the editor was 

 responsible. 



Epithelium of the Epididymis.§ — Zenon Jeleniewski has studied' 

 this in cat, dog, mouse, rat, guinea-pig, and hedgehog. The epithelium 



* Zeitschr. wiss. Zool. Ixxviii. (1904) pp. 1-148 (7 pis.). 



+ Bull. Internal Acad. Sci. Craeovie, 1-904, pp. 345-66 (2 pis.). 



* Lehrbueh der vergleicbenden mikroskopiscb.cn Anatumie der "Wirbeltiere. 

 Herausgegeben von Prof. Albert Oppel. Vierter Teil. Ausfiihrapparat und Anhangs- 

 driisen tier in'annlichen Ge.schlecbtsorgane. Prof. K. Disselborst. Jena (1904) 

 x. and 432 pp., 435 figs, and 7 pis. 



§ Anat. Anzeig. xxiv. (1904) pp. 630-40 (8 figs.). 





