No. 541] EFFECTS OF ALCOHOL IX II YD AT IN A 43 



organs of the animal are subjected to whatever dialyzable 

 chemical substance there may be in the solution. 



The young females grow to maturity very rapidly and 

 lay eggs which develop and hatch within a few hours. 

 This extremely short life-cycle, from egg to egg in forty- 

 eight hours, more or less, makes this animal a very favor- 

 able form with which to work. Many generations can he 

 reared in a short time and as much information gained in 

 a few weeks as it would require years to obtain from 

 some of the other forms. 



Kxperiments were first carried out to determine what 

 influence a \ percent.. ! per cent. an. 1 1 per cent, alcoholic 

 solution had upon the race when it was subjected to it 



that the temperature was always uniform for each genera- 

 tion. The same amount of food culture from the same 

 jar was always mixed with the same amount of water or 

 with the same amounts of the various alcoholic solutions 

 thus making the proportion of food culture to the mixture 

 always alike. This mixture was then poured out into 



glass. & At the end of fortv-eight hours the young female 

 had matured, laved eggs some of which had hatched, and 

 young daughter-females would be found swimming in the 

 dish. One of these daughter-females was isolated to start 



ori-inallv isolated. This was continued for twenty-eight 

 consecutive generations. The twenty young females 

 which were isolated to form the first generation were the 

 grandchildren of the same grandmother, thus making the 

 control, and the other three strains or groups all start 

 originallv from one female of one race. This was a very 

 vigorous* race hatched from a winter egg which was taken 

 from a general mixed culture jar in the early spring. 

 Table I shows the detailed and summarized data of the 



