160 SUMMARY OF CURRENT RESEARCHES RELATING TO 



control ovary. This iudicates that changes in the total number of ova 

 do not cause the hypertrophy of the surviving ovary. This is due to a 

 greater abundance of well-developed normal and degenerate follicles, as 

 well as by an excess of corpora lutea. This indicates an increased 

 activity of the surviving ovary due to some unknown stimulus. Changes 

 in the ovarian stroma influence but slightly, if at all, these results. 

 Semispayed females produce litters with nearly as many young as the 

 controls. The time of the first ovulation in the surviving ovary is 

 normal. Young females separated from the males show a slightly 

 slower growth and maturing of the ovary than do the females kept 

 with the males. J. A. T. 



Degenerative Changes of the Pancreas during Pregnancy. — 

 M. Aron {Comptes Rendm Soc. Biol., 1920, 83, 1122-5). Autolytic 

 processes on the surface of the small pancreatic lobules are seen in 

 pregnant bats and in some other cases, including man. Aron thinks 

 the phenomena may be due to a toxic fluid in the peritoneal serosa. 



J. A. T. 



Development of Supra-renal Body of Hedgehog.— A. Celestino 

 DA Costa {Comptes Rendus Soc. Biol., 1920, 83, <s78-9). The primordia 

 of the cortical portion are first seen in an embryo of 6 mm. Thickened 

 zones of coelomic epithelium grow into the mesenchyme, on the two sides 

 of the origin of the mesentery, a little in front of the emergence of the 

 coeliac artery. Besides this inter-renal primordium there is a distinct 

 genital primordium, and the relations between the two are very clear in 

 the hedgehog. Into the inter-renal primordium there is, in the 8 mm. 

 stage, a penetration of sympathetic elements. J. A. T. 



Haematopoietic Processes in Gonads of the Fowl. — Jose F. 

 NoNiDEZ {Amer. Journ. Anaf., 1920, 28, 81-113, o pis.). In the 

 gonads of the fowl, both in the embryo and mature bird, there is a 

 widespread tendency towards the formation of blood-cells which usually 

 appear as small lymphocytes grouped in lymphogranulopoietic foci. 

 Similar groups occur in other organs and in the general mesenchyme. 

 The granule-laden cells could be traced to h?emocytoblasts or large 

 lymphocytes, which arise as a differentiation in the mesenchyme cells. 

 The hgemocytoblasts become granulocytoblasts (= myeloblasts) after 

 deposition of acidophile granules in their cytoplasm. The granulo- 

 cytoblasts eventually become eosinophile leucocytes which degenerate. 

 The small lymphocytes referred to above are endowed with seveial 

 potentialities. Besides becoming granular leucocytes of smaller size, 

 they give rise to large wandering cells which agree in their characteristics 

 with cells hitherto regarded as interstitial. But they may be quite 

 absent, and it does not seem probable that they have an endocrine 

 function. The granule-laden interstitial cells in the ovary and testis 

 described by Boring and Pearl are granulocytoblasts. The mature 

 cock-feathered-male lacks a specific interstitial tissue influencing the 

 secondary sex-characters. J. A. T. 



Anterior End of Notochord in Embryos of Reptiles. — A. Webee 

 {Comptes Rendm Soc. Biol., 1920, 83," 1056-8). In the earliest 



