250 RAYMOND PEARL 



Other workers have noted adverse effects of poisons upon 

 production of offspring. Stockard and Papanicolaou (38"*, p. 172) 

 report with guinea pigs about 15 per cent more successful mat- 

 ings with normal than with alcoholic parents. They also found 

 a higher proportion of still-born young in the matings of alco- 

 holic parents than in controls. Weller (42 p. 292) finds that 

 chronic lead poisoning in guinea pigs leads in some cases to ste- 

 rility of the male without loss of sexual activity, and in case the 

 female is poisoned, to an increase in the number of still-births. 

 Cole and Bachhuber (3, p. 27) present some evidence regarding 

 the effect of lead poisoning of the parents upon the fertility and 

 hatching quality of eggs. In their experiments the percentage 

 of fertile eggs from the control, untreated male is abnormally 

 low, so that it is impossible to say whether the percentage given 

 by the treated male (73 per cent fertile) is to be regarded as 

 above or below the normal average fertility of untreated males 

 for that .particular season and strain of birds. Probably it was 

 below, thus agreeing with the data here presented. On the 

 other hand, the percentage of fertile eggs hatched was nearly 

 twice as high in the case of the normal untreated sire as in the 

 case of the sire poisoned with lead acetate. Lead appears to 

 have a different action on fowls, in this respect, than do the 

 substances used in the present experiments, alcohol and ether. 



III. TOTAL BREEDING CAPACITY 



In the preceding section the quantitative results concerning 

 the production of offspring by alcoholized parents have been 

 treated in detail. From these detailed figures it is somewhat 

 difficult to form a general comprehensive idea of the reproductive 

 capacity of these birds taking all the pertinent factors into 

 account together. One question for which we want an answer 

 is this: What relation, if any, is there between the total germ 

 dosage index for each mating and the total reproductive capacity 

 of that mating? 



* Throughout this paper the references to literature are by number and refer 

 to the bibliography printed at the end of I. By this method space is saved over 

 what would be involved in reprinting the entire bibliography here. 



