128 SUMMAEY OF CURRENT RESEARCHES RELATING TO 



Inbreeding and Body Weight in Albino Rats. — Helen Dean King 

 {Journ. Exper. Zool, 1918, 26, 1-54, 14 charts). The general course 

 of the growth in body weight of inbred rats is similar to that of stock 

 animals. For the first six generations there was malnutrition, and the 

 b.ody weights were under the normal. Many had defective teeth, and 

 the majority of the females were sterile. When nutritive conditions 

 were improved the animals quickly regained their normal body size, and 

 the tendency to sterility and malformation was checked. J. A. T. 



Inbreeding and Fertility in Albino Rats. — Helen Dean King 

 (Journ. Exper. Zool., 1918, 26, 335-78, 2 charts). Two series of albino 

 rats were inbred, brother and sister, for twenty-five generations. The 

 two series combined comprise a total of 3408 litters, which contained 

 25,452 individuals. The inbreeding did not decrease the produc- 

 tiveness. The constitutional vigour did not seem to be impaired. The 

 span of life in both sexes was increased. The results obtained do not 

 accord with the general view regarding the effects of inbreeding, since 

 they indicate that inbreeding per se is not necessarily inimical either to 

 fertility or to vigour. Success or failure in any series of inbreeding 

 experiments would seem to depend on the character of the stock that is 

 inbred, on the manner in which breeding animals are selected, and on 

 the environmental conditions under which the animals are reared. 



J. A. T. 



Feeding Sudan to Young.Albino Rats.— S. Hatai [Journ. Exper. 

 Zool., 1918, 26, 101-117,' 3 charts). Albino rats, 27 to 33 days old, 

 were fed with Sudan III. mixed in olive oil. In all cases the normal 

 rate of growth was retarded to a considerable extent. Liver and pan- 

 creas show a steady increase in weight ; the thymus, testes and ovaries 

 show a striking diminution. There was a high degree of antemia. The 

 composition of the organs is more or less altered, there is an increase of 

 water content in the blood, lungs and pancreas, while a reduction occurs 

 in the liver, spleen, kidneys, heart and brain. In the last the reduction 

 is small, but quite uniform, and in every specimen. J. A. T. 



Suckling and Rate of Embryonic Development in Mice. — W. B. 

 > KiRKHAM {Journ. Exper. Zool., 1918, 27, 49-55). In mice simul- 

 taneously suckling and pregnant, the removal of all but one of the 

 suckling young at any time during the first six days after the birth of 

 the suckling litter leads in some instances to implantation of the embryos 

 as soon as they reach the uterus, but in other cases the implantation is 

 more or less delayed. If the same removal takes place at any time from 

 seven to fourteen days after the birth of the suckling litter the result is 

 delayed implantation. The full activity of the mammary glands seems 

 to be the chief cause of delayed implantation in the case of mice which 

 are suckling young, but this influence is subject to marked individual 

 variation. J. A. T. 



Effect of Alcohol on Guinea-pigs. — Charles R. Stock ard and 

 George N. Papanicolaou {Journ. Exper. Zool., 1918, 26, ] 19-226, 

 9 tables, 9 figs.). This communication presents the results obtained 



