292 EAYMOND PEARL 



On this hypothesis it might be supposed that with larger 

 administration to the fowls (higher germ dosage) or more years 

 of drinking behind them in the case of Elderton and Pearson's 

 workingmen, the conditions shown in figure 7 would gradually 

 pass over into those shown in figure 5. Possibly this. is so, but 

 there is no evidence as yet that it is. The germ dosage index 

 of this paper is a time index. It takes no account of the inten- 

 sity factor in dosage because the intensity factor is a constant 

 in these experiments. It is represented by th,e time spent in 

 the tank in the saturated atmosphere each day. This intensity 

 factor is the same in my experiments as in Stockard's, and in 

 both cases it represents according to his experience and mine 

 practically a maximum value of P. Fowls can not be left 

 much longer than one hour at a time in an atmosphere saturated 

 with alcohol vapor. Now in view of the facts (a) that alcohol 

 is rapidly eliminated from the system and not accumulated 

 therein and (b) that large and repeated doses immediately 

 affect the germ cells very markedly as shown by Todde (40), it 

 seems to me probable that when alcohol is administered by the 

 inhalation method the factor which determines the width of the 

 h' zone relative to a' is the length of time the animal stays in 

 the tank per day, and not the number of days it is treated. It 

 may well be that the longer the treatment is continued the 

 greater will A' become. But all the evidence now available 

 seems to indicate that this is at the expense of a' alone and 

 that h' is simply pushed along or may even be narrowed. 



On the hypothesis here advanced we see why the percentage 

 of infertile eggs is higher for alcoholic than control matings. 

 This merely is the expression of the transference of the ai, ai 



ah germ cells over into the A' group. Thej'' are germ 



cells which before treatment were of rather low grade but still 

 good enough to take part effectively in zygote formation. Alco- 

 hol treatment put them definitely over the line into the A' 

 class. In this connection it is of interest to note that we have 

 for the correlation between per cent of infertile eggs and germ 

 dosage index 



r = + 0.316 ± 0.136 



