294 SUMMARY OF CURRENT RESEARCHES RELATING TO 



remarkable histolytic process. Over a considerable area there was dis- 

 solution and degeneration of the epithelial cells, which formed a mass of 

 detritus in the tubules. The fundus portion of the vesicle showed a 

 double stratum of epitbelial cells, which is regarded as the normal 

 lining; towards the efferent duct there was a single layer of cubical 

 cells, apparently the result of regeneration ; between these was the area 

 of dissolution. It is evident that more specimens must be studied 

 before a secure statement can be made, but there was no sign of disease. 



Influence of Diet on Egg-laying in the Fowl.* — F. Houssay- 

 found that two bens fed with grain laid, in a given period, 127 -f 67 

 eggs, while two others of similar races, fed with raw flesh, laid 176 -f- 121. 

 The total for the first two is 194, for the other two 297. There was 

 also a superiority as to weight in favour of the eggs laid by the carni- 

 vorous fowls, their average being 58 grm. as against 55 grm. for the 

 vegetarians. 



Early Stages in Development of Duck and Tern.f — Prof. P.. 

 Mitrophanow finds that these resemble in general the corresponding 

 stages in the fowl. The beginning of morphological differentiation is in 

 the formation of the median ectodermal thickening, which in the above- 

 named aquatic birds is shunted distinctly backwards. The very distinot 

 Primitivknoten — the antecedent of the primitive streak — is probably a 

 palingenetic feature ; it occurs as a very rare deviation from the norm 

 in the fowl. From the middle of the ectodermal thickening, or from 

 the Primitivknoten, the primitive streak begins to grow in the direction 

 of the tail. The primitive groove follows the same path. The anterior 

 end of these structures, which appears first, and is always more pro- 

 nounced than the posterior end, corresponds to the blastopore of reptiles,, 

 and sometimes shows a similar form. 



Maternal Impression in a Mare.| — Le Hello notes that a racing 

 mare, Mascarade, by Mask and Shepherd's Bush, hurt the left side of 

 her head by galloping against a tree. After the wound healed there was 

 left a marked hollow at the level of the lachrymal, and a certain de- 

 pression of tbe orbital apophysis. The nutrition of the eye was seriously 

 affected, and the globe is now much atrophied. 



More than a month before the accident, Mascarade had been success- 

 fully served by Nicham II., and the foal — La Courtille — born in due 

 course, shows on the left side of her head lesions closely resembling 

 those of the mother. The lachrymal depression is less marked ; the 

 orbital arcade is even more suppressed; the little cavity called the 

 salihe is virtually absent, and the eye is not bigger than a lentil.. 

 JLe Hello regards it as a clear case of maternal impression. 



Heredity Studied in Mice.§ — Prof. L. Cuenot has verified in mice 

 the law which Gregor Mendel stated in 1865 in regard to peas. If a 

 common grey mouse — male or female — be. paired with a white mouse — 

 female or male — the result is, without exception, that grey mice are 

 produced. The pigmented form is, as regards pigmentation, invariably 

 prepotent over the unpigmented form. 



* Coroptes Eendus, oxxxiv. (1902) pp. 432-3. 



t Ztitschr. f. wisa. Zool., lxxi. (1902) pp. 189-210 (2 pis.). 



% Comptes Eendus, cxxxiv. (1902) pp. 201-2. § Tom. cit., pp. 779-81. 



