604 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Cells of Giant Tadpoles.* — A. Hahn has made a histological study 

 of giant tadpoles of Rana esculenta. He associates the gigantism and 

 the early differentiation of the ovaries (suggestive of neotgenic forms) 

 with hypertrophy of the hypophysis. In many organs, especially in the 

 kidneys, there are degenerative changes and signs of abnormal develop- 

 ment. As Levi pointed out, epithelial-cells and gland-cells in the giant 

 tadpoles have the normal size, but ganglion-cells are larger than the 

 normal. 



Seminal Vesicles of Frog-.f — M. Nussbanm gives an account of the 

 minute structure and cyclical changes in the seminal vesicles of Rana 

 fusca. The series of progressive and retrogressive changes undergone 

 at each breeding season is carefully described. 



Giant Cells in Intestine of Fasting Teleosts.:}: — Anna Drzewina 

 finds that peculiar giant cells appear in the intestinal mucous membrane 

 of Lahrus hergyUa and Crenilabrus melops which have been kept fasting 

 for two weeks to two months. These giant cells differ greatly in size 

 and in the number of nuclei (3-30). It seems as if they arose from the 

 coalescence of several contiguous epithelial cells. But the contained 

 nuclei are not like those of the epitlielium. They are more like those of 

 small leucocytes whicli occur abundantly at the bases of the epithelial 

 cells. Perhaps the giant cell engulfs these ; perhaps there is immigra- 

 tion into the giant cell. 



Sub-Pial Layer of Spinal Cord in Fishes.§ — Anton Nemiloff finds 

 in various Selachians and Teleosts distinct evidence of a sub-pial layer 

 on the periphery of the spinal cord. It is homologous with the sub-pial 

 layer in Mammals. It is a peripheral layer of grey matter, and is 

 distinct from the thick feltwork which is formed from the dendrites of 

 the cells of the grey matter (the circum-medullary or peri-medullary 

 feltwork). 



Vibratile Fin of Rockling.H —J. Stuart Thomson gives an account 

 of the minute structure of the dorsal vibratile fin in Motella, which he 

 regards as a localized and specially efficient taste-organ or food-locating 

 organ. The vibratile fin is a modified part of the ordinary dorsal fin. 

 It is innervated partly by the ramus lateralis accessorius, and partly by 

 branches of the dorso-spinal nerves. The epidermis in the groove 

 bordering the fin is particularly noteworthy because of its abundant 

 taste-buds, which project slightly on the surface. They are bulb-like 

 organs containing long sensory cells. The vibrations of the rays keep 

 the skin on either side, on which the taste-buds are situated, clear of 

 sand-particles and the like, and bring currents of water to the receptor 

 area. 



* Arch. Mikr. Anat., Ixxx. (1912) pp. 1-38 (3 pis. and 13 figs.). 

 t Arch. Mikr. Anat., Ixxx. (1912) Heft 1, Abt. ii., pp. 1-59 (2 pis.). 

 X C.R. Soc. Biol. Paris, Ixxxii. (1912) pp. 18-19. 

 § Arch. Mikr. Anat., Ixxx. (1912) pp. 587-608 (1 pi. and 1 fig.). 

 Ii Quart. Journ. Micr. Sci., Iviii. (1912) pp. 241-56 (1 pi.). 



