8G4 EXPERIMEiSTT STATION KECOED. [W.L 41 



rate which the normal group would have exhibited had the distribution of 

 litter sizes been the same as in the group under consideration. 



That a high proportion i>f unsuccessful matiugs (indicative of early death 

 of embryos or low fertility or both), a small sized litter, and a low litter weight 

 are characteristic of both the matings with a treated male and those with 

 alcoholic male ancestors is held to "prove the hereditary transmission of the 

 defects arising from the treatment of the male animals." The general 

 similarity of the two groups of young derived from alcoholized females indi- 

 cates that "the treatment of female individuals also induces effects that are 

 transmitted to later generations through the germ cells." The liigh mortality 

 of the offspring of an alcoholized mother is attributed in part to the direct 

 influence of the treatment. The authors consider the results secured by Cole 

 and Davisi (who found that spermatozoa of treated rabbits were liandicapped 

 in a direct competition with normal si^rmatozoa ) , and by Arlitt and Wells 

 (noted above) to be of significance in explaining the intensity and the racial 

 persistence of the effects of alcoholizing male guinea pigs. 



Tlie ratio of males to females was 109.2 : 100 in young with fathers or other 

 male ancestors treated, S6.5 : 100 in those with only female ancestors treated, 

 and 123.6 : 100 when ancestors of both sexes had been treated. The ratio in 

 the normal line was 113.2 : 100. These wide differences are discussed, but inas- 

 much as the normals showed an unusualiy high proportion of males no certain 

 conclusions are drawn, although the possibility of higher prenatal mortality 

 on the part of the females of alcoholic stock is pointed out. 



About 2.52 per cent of the noninbred young of alcoholic stock and 3.31 per 

 cent of the inbred alcoholics were conspicuously malformed in some particular 

 (abnormally small eye on one side, cataract, opaque lenses, deformed limbs, 

 etc.) or showed paralysis, gross tremors, and the like. In none of the un- 

 treated stock, inbred or not, were such defects noted. 



In attempting to reconcile tlieir results with those of Pearl on the domestic 

 fown (E. S. R., 40, p. 470), the authors are inclined to hold that many of 

 the " infertile " eggs in Pearl's experiments contained embryos tliat died in 

 early cleavage stages. 



Studies on inbreeding.— I-IV, H. D. King {Jour. Expt. Zool., 26 {1918), 

 Nos. 1, pp. 1-54, fws. Ih; 2, pp. 3S5-37S, figs. 2; 21 {1918), No. 1, pp. 1-35, fig. 1; 

 29 {1919), No. 1, pp. 71-111, figs. 8). — The observations reported in these four 

 papers cover 25 generations of inbred white rats reared at the Wistar Institute. 

 The experiments were started with a litter consisting of two males and two 

 females born in May, 1909. One of the females was called A and the other B ; 

 their inbred descendants are respectively designated the A and the B series. 

 The plan required that A and B and every other female used for breeding 

 should be mated twice with a brother from the same litter and then twice with 

 an unrelated stock male. Young from the latter matings were not used to carry 

 on the inbred line. 



During the first six generations the diet consisted mostly of milk, bread, and 

 corn, and many of the rats remained undersized, developed deformed teeth and 

 other malformations, and produced small sized litters. These defects are not 

 attributed to inbreeding, as they were also abundantly manifested by the rest 

 of the rat colony. The diet was then changed to selected table refuse supple- 

 mented by ear corn or dog biscuit, and all evidence of malnutrition disappeared. 

 Less marked nutritive disturbances were, however, again met with during the 



^ Tho Effpct of Alcohol on the Male Germ Cells studied by means of Double Matings, 

 L. .1. Cole and C. L. Davis. Abs. in Science n. ser., 30 (1914), No. 1004, pp. 476, 477. 



