\ 



Ethanol, Caffeine and Nicotine. 241 



exconjugant line with that attained by its parent line during 

 the first 15 days after the former's origin gives the following 

 results. Forty-two exconjugant lines produced more genera- 

 tions, eight produced less generations and two produced essentially 

 the same number of generations as their respective parent lines. 

 The various cases in which the parent line did not survive the 

 first fifteen days after the exconjugant line was derived from it 

 are not comprised in these data. If such cases were included it 

 obviously would increase the number of plus cases of exconjugant 

 lines. 



Analysis of the data thus far obtained inevitably leads to 

 the conclusion that the exconjugant lines of this pedigree culture 

 of Spathidium, under the conditions of the experiment, exhibit, 

 in the great majority of cases, a higher division rate for the first 

 fifteen days after conjugation than the parent lines. 



The evidence to date also indicates that exconjugant lines 

 which are derived from old parent lines {i.e. from lines which have 

 undergone many generations since conjugation) show a relatively 

 greater increase in the division rate, during the first fifteen days, 

 as compared with the parent lines, than do exconjugant lines 

 which are derived from young parent lines {i.e., from lines which 

 have more recently conjugated). 



The complete paper will appear in the Journal of Experimental 

 Zoology. 



120 (1702) 



Comparative study of ethanol, caffeine and nicotine on the de- 

 velopment of frogs' larvae. 



By D. I. MACHT and WM. BLOOM. 



[From the Pharmacological Laboratory, Johns Hopkins University.] 



The effects of ethanol, caffeine (alkaloid) and nicotine (al- 

 kaloid) solutions were studied on the growth and development 

 of the larvae of two species of frogs, viz., Rana sylvatica and Rana 

 palustris. The study of the larvae was begun immediately after 

 hatching from the eggs and continued on tadpoles of older ages. 

 Tadpoles of the same species and ages were placed in solutions of 

 the above drugs of various concentrations and the effect of the 

 poisons was noted. 



