702 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Development of Kidney in Teleosteans.* — L. Roule and I. Audige 

 have studied various Teleosteans, e.g., Cepoia rtibcsceiis, and find that 

 the kidney includes pronephros, mesonephros, and metanephros, or, 

 rather, that this distinction is not valid, the series of tubules being 

 really continuous both as regards space and time. 



Development of Notochord in Fishes.f — Louis Roule has studied 

 this in the perch. He finds that the notochord arises directly from the 

 archenteron as a compact cellular axis, whereas in Tunicates it is due 

 to a diverticulum of the archenteron, possibly comparable to the post- 

 anal gut in higher Chordata. In fact, the notochord of Tunicates 

 is not strictly homologous with the notochord of Fishes. 



Embryonic Circulation in Goldfish.} — P. Wintrebert has studied 

 the transparent embryos of Garassius auratus, and finds that the blood 

 from the caudal artery passes forwards by a median trunk vein, 

 posterior cardinal veins, and the ducts of Cuvier. Between these and 

 the auricle there is, in place of the sinus venosus, a very large lacuna, 

 which spreads over the whole surface of the vitellus. There is no 

 sub-intestinal vein. The first vitelline circulation is thus entirely 

 venous, but subsequently there is a secondary arterial circulation. 



Hybrid between Bream and Rudd.§ — C. Tate Regan describes 

 from Lough Erne what seem to be hybrids between bream and rudd 

 (Abramis brama x Leuciscus erythrophthahnus), and compares them 

 with hybrids between bream-flat (A. blicca) and rudd. 



b. Histology. 



Minute Structure of Mammalian Pituitary Body.|j— P. T. Herring 

 has studied this in cat, dog, and monkey. The pituitary body may be 

 divided into two parts, which show structural differences probably in- 

 dicative of distinct functions. The anterior lobe, consisting of large 

 granular cells and numerous blood-vessels, is a gland of internal secretion 

 of undetermined function, but which may influence growth. The 

 posterior lobe consists of two structures. The part developed from the 

 brain, and consisting of neuroglia and epeudyma cells and fibres, acts as 

 a framework. It is more or less surrounded and invaded by epithelium, 

 which is probably the active part. There is histological evidence of a 

 secretion produced by the epithelial cells, which apparently passes into 

 lymph-vessels, and is destined to enter the ventricles of the brain. The 

 posterior lobe is a brain-gland, not by virtue of tissue of brain origin, 

 but by the growth into it of epithelial cells of ectodermic origin. 

 Extracts produce marked effects on cardiac and plain muscle-fibres, 

 comparable in some respects to the action of the medulla of the supra- 

 renal capsule ; they have a selective action on the kidney, causing 

 dilatation of the renal blood-vessels and diuresis. Disturbances of the 

 posterior lobe of the pituitary are probably responsible for the occur- 



* Comptes Rendus, cxlvii. (1908) pp. 275-7. 



t Op. cit., cxlvi. (1908) pp. 1423-5. 



X Comptes Rendus, cxlvii. (1108) pp. 85-7. 



§ Aim. Nat. Hist., ii. (1908) pp. 162-5 (2 pis.). 



H Quart. Journ. Exp. Physiol., i. (1908) pp. 121-59 (16 figs.). 



