MODIFICATION OF THE GERM-CELLS IN MAMMALS 177 



In table 4, on the other hand, the groups with only male 

 ancestors treated owe their modified conditions, if such exist, 

 entirely to the effects of the treatment on male animals, though 

 the individual being considered may have inherited this alco- 

 holic effect through its mother. Thus animals in the columns 

 with only male ancestors treated were not necessarily derived 

 from alcoholic fathers, but may have been produced by alco- 

 holic mothers which, however, owe their alcoholic condition 

 to one or more treated male ancestors. The table permits a 

 comparison of the action of the treatment on the male germ cells 

 and the transmission of the effects with the action of the alcohol 

 treatment on the female germ cells and the effects transmitted 

 to the different generations. While the last table permitted a 

 comparison of the animals derived from males of alcoholic stock 

 with others derived from females of alcoholic stock. The two 

 tables serve to analyze very completely the problem of the 

 parts played by the sexes in the acquisition and transmission 

 of the effects of the alcohol treatments. 



The three columns in the first group of table 4 are the same 

 as those of the first group of table 3, being the records of Fi 

 animals derived from treated fathers, which have only one male 

 ancestor treated according to the table 4 arrangement, and Fi 

 animals derived from treated mothers or from only the one 

 female ancestor treated. This group was discussed in review- 

 ing the third table. The points of chief interest in the present 

 connection are the decidedly inferior conditions of the off- 

 spring from the treated females as compared with those from the 

 treated males, in so far as their measured mortality records and 

 birth weights per litter are concerned. On the other hand, the 

 records from treated males suffer as regards the 'early prenatal 

 mortality' indicated by the small average-size litter and the 

 high percentage of mating failures, while the records of the 

 treated females in regard to these conditions are equally as 

 good as those of the control animals. 



The next three columns of table 4 are highl}^ important, since 

 they contain the results of matings when, first, only male an- 

 cestors are treated; second, when only female ancestors are 



THE JOURNAL OF EXPERIMENTAL ZOOLOGY, VOL. 26, NO. 1 



