614 SUMMARY OF CURRENT RESEARCHES RELATING TO 



gera the number of segments ranges from 40 to 100, the body is 

 enveloped in clear mucus, the gills are in two tufts, the surface is 

 covered with papillae which show a basal piece, a long stalk, and a 

 terminal thickening. Glinther gives a detailed histological account of 

 all the organs in the body. 



New Branchiate Leech.* — Asajiro Oka describes Ozobranchus 

 jantseaiius sp. n., a small leech from China, found at Wutschang on the 

 Yantsekiang, on a river turtle. The other species of Ozobranchus are 

 marine. Tlie animal has eleven pairs of uniform gills, forming a fringe 

 on each side of the body. In this respect, and in the number of the 

 gills, the new form approaches BranchelUon. 



Nematohelmintlies 



Spermatogenesis of Ascaris megalocephala.f — E. Faure-Fremiet 

 calls attention to some debated points in regard to the spermatogenesis 

 of this thread-worm. The rodlets in the centre of the " brilliant 

 granules " in the cytoplasm of the spermatocytes of the first order have 

 no relation to the mitochondria. It is possible to demonstrate the 

 presence of glycogen in the spermatids, but not in the cytophore. It 

 seems probable that Van Beneden was right in concluding that the 

 spermatids do not become mature until they are transferred to the 

 female. 



Fertilization in Ascaris megalocephala.J — H. Held brings forward 

 evidence to show (1) that the plasmosomes of the gametes are important 

 and persistent ; (2) that there is a mingling of paternal and maternal 

 plasmosomes in fertilization ; and (3) that the plasmosomes function as 

 vehicles of inheritance. 



Fertilization in Ascaris megalocephala.§ — Hans Held has been 

 al)le to trace the plasmosomes or macrosomes of the spermatozoon within 

 the ovum where they go through a definite process, which must have 

 some physiological importance. There is an intimate mixing of paternal 

 and maternal plasmosomes, which must be of importance as vehicles of 

 inheritance as well as the chromosomes. 



Disease of Ascaris megalocephala. |1 — M. Weinberg and Mile. 

 Keilin describe a kind of dermo-myositis in this thread-worm. Minute 

 roundish lesions occur here and there on the skin. Below each there is 

 evidence of an inflammatoiy process which seems to begin in the sub- 

 cutaneous layer, and spreads to the cuticle on the one side, and the 

 muscular layer on the other. In one case large cocci were found at the 

 level of one of the lesions and in the peri-enteric fluid, but this was 



* Ann. Zool. Japon, viii. (1912) pp. 1-4 (1 fig.) 



+ C.R. Soc. Biol. Paris, Ixxiii. (1912) pp. 271-2. 



1 Anat Anzeig., xll. (1912) Ergiinzungsheft, pp. 242-8. 



§ Ber. k. Sachs. Ges. Wiss. Leipzig, ii. (1912) pp. 29-34. 



i; C.R. Soc. Biol. Paris, Ixxiii. (1912) pp. 260-2 (7 figs.). 



