EXPERIMENTS WITH ALCOHOL 161 



one of the parents only is treated and matings in which both the 

 parents are treated. 



Table 6 gives in order the germinal dosage index for each of 

 the Fi matings which produced offspring in these experiments. 

 The matings are arranged in ascending order of total germ dosage 

 index. 



From this table it is seen that the total germ dosage index for 

 the Fi progeny in these experiments ranges from 130 days to 

 354 days with the matings for the different substances used well 

 scattered oyer the range. The facts are represented graphically 

 in figure 1 of paper No. Ill in this series. 



G. Scope of present reports 



It is the purpose of the present paper and the two next fol- 

 lowing in this series to present and discuss the data which have 

 accumula.ted in this investigation from September, 1914 up to 

 February 1, 1916, This includes the Fi generation of progeny 

 only. The experiment is of course being continued and later 

 reports will be given on further generations of progeny and 

 others matters of interest not taken up in the present reports. 



III. SUMMARY 



This paper is the first of a series of studies having to do with 

 attempts, in the first place, to modify hereditary factors or 

 determinants in a definite and specific way, and in the second 

 place, to observe and analyze the hereditary behavior following 

 such modification. The results here reported followed attempts 

 to modify the germ cells by treating the individual domestic 

 fowl with one or another of three poisons, viz., ethyl alcohol, 

 methyl alcohol, and ether. 



Summarily stated the chief points brought out in the paper 

 are: 



1. The males used in the experiments were pure bred Black 

 Hamburgs. The females were pure bred Barred Plymouth 

 Rocks. There are shown to be numerous advantages in hav- 

 ing the progeny of treated parents Fi crossbreds rather than 

 pure. 



THE JODBNAL OF EXPERIMENTAXi ZOOLOGY, VOL. 22, NO. 1 



