ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 7 



true glandular organs. From the beginning of their existence, even 

 before sexual differentiation, they elaborate chemical secretions with the 

 same microchemical characters as the supra-renals and Wolffian bodies. 

 In adult life they become definitely glandular. The internal secretion 

 of the ovary, the cells of the ovary and of the corpus luteum, are 

 described in the paper. 



Interstitial Testicular Gland of Horse.* — P. Bouin and P. Ancel 

 have made a careful study of the minute structure of the interstitial 

 glands in the testis of the horse. The matter is somewhat complicated, 

 for there appear to be three successive and distinct interstitial glands. 



1. There is a fetal interstitial gland, strongly developed, but dis- 

 appearing towards the end of gestation. 



2. There is an interstitial gland during the juvenile immature life, 

 but it is slightly developed, and is composed of xanthochrome cells. 



3. There is an adult interstitial gland, whose presence coincides 

 with the period of spermatogenesis. 



Accessory Sex Glands in Insectivora and Rodents.f — S. Grosz 

 finds in these a variety of forms, both as regards the morphological 

 relation of their excurrent ducts to the urogenital tract, and the 

 histology of the secreting region. Individual forms show remarkable 

 differences in the development of those glands which do not serve the 

 sexual act directly, but which probably function as a means of attraction 

 between the sexes. Such glands are perineal, inguinal, anal, and 

 perhaps also preputial. 



Regeneration in Testes.} — M. Nussbaum discusses the various ways 

 in which reproductive organs form new germ-cells after liberating what 

 they have produced. In the testicular canals of Teleosts, Reptiles, Birds, 

 and Mammals, it was shown by von la Valette St. George that sperma- 

 togonia remain inactive until the next sexual period, when they begin 

 again to divide. In Elasmobranchs, it was shown by Semper that quite 

 new ampullae are formed from a special region of the gonad ( Vorkeim- 

 falte) after the previously active ampulla? have been exhausted. Nuss- 

 baum finds that Anura illustrate the first mode of regeneration ; there 

 are resting spermatogonia. But in Urodela {Salamandra maculata and 

 Triton cristatus) the old ampullae and most of the testis undergo 

 degeneration, and there is a new formation from the oval apex of the 

 testes which corresponds to the Vorkeimfalte of Elasmobranchs. 



Formation of Eye Vesicle in Vertebrates.§ —A. Froriep describes 

 certain peculiarities of growth in the eye vesicle of Selachians, Reptiles, 

 Birds, and Mammals, showing that it does not arise by the invagination 

 of a previously formed hollow ball. It never has a symmetrical ball-like 

 form ; its development into the double-walled eye-cup is by a gradual 

 change from its original formation as a lateral outgrowth of the brain 

 tube. 



* Arch. Zool. Exper., xxxiii. (1905) pp. 391-433 (3 pis.). 

 + Arch. Mikr. Anat., lxvi. (1905) pp. 567-608 (1 pi.), 

 t SB. Med. Ges. Bonn, 1905, pp. 18-20. 

 § Arch. Mikr. Anat., lxvi. (1905) pp. 1-11 (1 pi.). 



