304 



Scientific Proceedings (116). 



4. By analysis of the data from an entirely different angle 

 the same general conclusion is apparent. The total number of 

 generations attained before the F x generation appeared, plus those 

 from the Fi to the origin of the F 2 , and so on to the F 5 generation, 

 amounts to date to from 450 to 550 generations, according to the 

 series followed. The first line reached 234 generations without 

 conjugation, therefore by conjugation it thus far has been possible 

 more than to double the number of fissions obtainable without 

 conjugation. 



In brief, all the data thus far secured indicate that in this 

 pedigree culture, under the conditions of the experiment, the 

 survival value of conjugation in the majority of cases is marked — 

 the exconjugant lines exhibiting a higher division rate and out- 

 living the non-conjugant lines. 



The complete paper will appear in the Journal of Experi- 

 mental Zoology. 



157 (1739) 



The precipitation of botulinus toxin with alcohol. 



By J. BRONFENBRENNER and M. J. SCHLESINGER. 



[From The Department of Preventive Medicine and Hygiene, 

 Harvard Medical School, Boston, Mass.] 



While attempting to purify botulinus toxin by precipitation 

 with ethyl alcohol, we found that the alcohol causes destruction 

 of this toxin. Even a weak solution (20-30 per cent.) of ethyl 

 alcohol is capable of quickly destroying many thousand lethal doses 

 of botulinus toxin in vitro. This destruction takes only five to 

 ten minutes if the mixture is kept at 37 0 C. On the other hand 

 the toxins of tetanus and diphtheria are much more resistant to 

 the destructive effects of alcohol. 



It had been observed in several outbreaks of botulism that 

 those who had partaken freely of alcoholic beverages while eating 

 the incriminated food were not severely affected or remained en- 

 tirely well, whereas others eating as much or even less of the same 

 food were severely and sometimes fatally poisoned. 



