164 CHARLES R. STOCKARD AND GEORGE N, PAPANICOLAOU 



A greater percentage of individuals survived than in any of the 

 preceding groups except the control. 



The proportion of prenatal to postnatal mortality shows the 

 arrangement characteristic of the alcoholic groups. As a matter 

 of fact, the prenatal mortality is really unusually high, and this 

 is probably due to the high percentage of large litters, as among 

 these the prenatal mortality is most frequent. It is as though 

 the animals of this group had produced almost as high a pro- 

 portion of large litters as the control animals and still they were 

 not sufficiently good quality as compared with the control to 

 keep down the prenatal mortality in these high litters. 



The total mortality when corrected on the normal rate for the 

 litter sizes and expressed on the basis of 100 for the control 

 becomes 145. This is a decided improvement over the other 

 alcoholic groups, although poor in the light of the control. 



From a survey of this column it may be concluded that ani- 

 mals as far as three generations removed from the direct alcohol 

 treatment are still differentiated as a group from the control in 

 regard to the weight of the litters in which they are born, the 

 tendency of the matings to result in failure, the high proportion 

 of prenatal mortality over postnatal, and the total mortality 

 which is one and one-half times higher than the normal. All 

 of these differences exist in spite of the fact that more and more 

 normal germ plasm has been introduced during each generation 

 until some of these animals may have had as many as six or 

 seven normal great-grandparents against one or two treated or 

 alcoholic great-grandparents, though the average of course had 

 somewhat more treated ancestry than this. 



One of the F3 individuals, descended from treated great- 

 grandparents, is shown in figure 7. The animal on the left was 

 a non-inbred female. No. 803, with six of its eight great-grand- 

 parents treated with alcohol and only two, on the paternal side, 

 were normal. Its great-grandparents may be written thus: A 

 indicating alcoholic and N normal, the 9 on the left, in the 

 formulae: [(AxA) (AxA)l [(NxA) (AxN)]. The animal on the 

 right is an ordinary normal guinea-pig born on the same day 

 as the small degenerate specimen which weighed only one-third 



