282 SUMiMAIlY OF CURRENT RESEARCHES RELATING TO 



ventral to the cephalic end of the fore-gut. By the growth of the fore- 

 brain and the sharpness of the cervical flexure, this endodermal bud 

 comes into contact with the growing hypophyseal sac and fuses with it. 

 The fusion occurs at about the time the oral membrane ruptures. The 

 fused bud soon loses its connexion with the endoderm. It remains fused 

 with the dorsal wall of Ratke's pocket, however, and contributes a small 

 mass of cells to the hypophysis-primordium. The notochord still shows 

 indications of an attachment to tbe fused bud. Thus the attachment of 

 the notochord (which is gradually becoming less and less a definite 

 attachment) is transferred from Seessel's pouch to Ratke's pocket. The 

 relation of the notochord to this small endodermal increment of the 

 hypophysis, and the fact that no lumen is to be found, tend to show that 

 the endodermal contribution to the hypophysis is unimportant and 

 accidental. 



Hermaphroditism of Gilthead,* — E. J. Bounhiol and L, Pron 

 describe the occurrence of double gonads and ducts in Glirysophrys 

 aurata, well-known to be a hermaphrodite fish. The organs on the 

 left are most strongly developed — an asymmetry common in fishes. 

 The important point, however, is that the ovaries and testes were both 

 mature. The hermaphroditism is thoroughgoing and simultaneous, 

 not protandrous. The authors do not refer to previous statements as to 

 the hermaphroditism of this fish. 



Somatic Sterility .f — Maynie R. Curtis and Raymond Pearl use 

 the term " somatic sterility " to distinguish obstructions to egg-laying 

 (in fowls) due to accident or disease affecting the individual, and not 

 inherited from her ancestors. Sterility due to these causes, which may 

 include not only actual obstructive lesions of the genital organs, but also 

 a general lowering of the physiological tonus of the individual to such 

 an extent that it does not form yolk, is distinguished from sterility due 

 to a lack of the genes for egg production. 



It was found that three of four birds which belonged to high-laying 

 strains, and which did not fulfil the expectation based on a knowledge 

 of their genetic constitution, failed because of the impossibility of 

 a yolk entering the oviduct. Two other birds belonging to segregating 

 families (one of these had proved herself a high producer by her own 

 winter record) showed the same reason for not laying. It was found 

 that birds which ovulate, or return partly formed eggs, into the body 

 cavity usually show the nesting instinct. The nesting records show 

 a rhythm similar to egg records of normal birds, and it seems probable 

 that they are the normal resultant of the ovulation. 



Confirmation was obtained of the following conclusions previously 

 readied : — In case of stoppage of the duct at any level, the duct on 

 both sides of the point of stoppage passes through the same cyclic 

 changes, co-ordinated with the cyclic changes in the ovary, as a normal 

 unobstructed duct ; the duct functions only as far as it receives the 

 stimulus of tbe advancing egg ; absence of pressure from the funnel 



* Comptes Rendus, clxii. (1916) pp. 273-6. 

 t Journ. Exper. Zool., xix. (1915) pp. 45-59. 



