448 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Structure and Function of Corpus Luteum.*— N. Niskoubina, 

 working with the rabbit, finds that the glandular activity of the corpus 

 luteum ceases abruptly towards the fifteenth day, that is, about the 

 middle of the gestation. It has a preparatory action on the uterus 

 during the first half of the gestation. Thereafter, and somewhat 

 abruptly, the corpus luteum begins to show signs of a progressive 

 atrophy. 



Corpus Luteum and Mammary Gland.f — P. Ancel and P. Bouin 

 find that there is a close correlation between the corpus luteum and 

 the development of the mammary gland. The gland grows for 14 

 days, and then begins to retrogress ; the corpus luteum develops for 

 14 days, and then begins to retrogress. It seems as if the corpus 

 luteum conditioned the development of the gland. 



In the course of gestation the mammary gland passes first through 

 a " kinetic phase," characterised by numerous mitoses, which prepare 

 all the cellular material of the future gland ; and, second, through a 

 "glandular phase," characterised essentially by cytological changes, 

 which transform the epithelial elements into glandular elements. It is 

 the first of these two periods that is determined by the internal secre- 

 tion of the corpus luteum. 



Two Ova together in Rabbit.J— CI. Regaud and G. Dubreuil 

 report finding two cases where two ova were contained within a common 

 envelope of albumen. One of the pairs was in the uterus, the other in 

 the oviduct. Follicles with two ova are well known, but what the 

 authors describe is different. Each ovum has its proper envelope, and 

 then both are wrapped up together. 



Interstitial Cells of Testis in Frog.§— Christian Champy has 

 studied these cells in Rana esculenta. They undergo a measure of 

 involution in July, when the spermatogenesis is at its maximum. The 

 nutritive substances formed go to sustain previously formed spermatozoa. 

 There is probably some internal secretion, as the perivascular disposition 

 of the interstitial cells suggests. 



Interstitial Gland in Ovary of Rabbit.||— G. Dubreuil and CI. 

 Regaud describe two extreme types of interstitial gland, macroscopically 

 distinguishable. There is a slightly developed gland, which is very 

 transparent, owing to the abundance of lipoid bodies in the young cells. 

 There is a greatly developed gland, the opacity and milky whiteness of 

 which are due to the abundance of fat in the adult cells. Many inter- 

 mediate stages occur. 



Interstitial Cells of Mole's Testis.^— A. Lecaillon finds that these 

 elements are very abundant in the non-active testis. They are not of 

 uniform structure, and they do not differ essentially from interstitial 

 cells in ovaries or in active testes. Some of the cells degenerate and 



* C.R. Soc. Biol. Paris, lxvi. (1909) pp. 767-71. 



t Tom. cit., pp 605-7. 



% Comptes Rendus, cxlviii. (1909) pp. 1279-81 (1 fig.). 



§ C.R. Soc. Biol. Paris, lxiv. (1908) pp. 895-6. 



|| Tom. cit., pp. 901-3. f Op. cit. lxvi. (1909) pp. 599-601. 



