Experiments with B. enteritidis (murium). 



7i 



lot. Genetically they have higher litter-producing powers than 

 the controls; when alcohol is given to them it causes a reduction 

 in the number of their litters, but this reduction is half as great as 

 the reduction caused by the treatment of their parents which were 

 genetically equal to the controls. The alcohol has sorted out 

 differences already present. 



This is a very different result from that given by litter size, 

 which demands the assumption of alcohol modifications. It is to 

 be concluded, then, that alcohol works upon the size of litters and 

 the number of litters through different channels. This leads to 

 two generalizations: first, that fertility is a complicated character 

 whose different measures are not all manifestations of the same 

 factors; second, that the action of alcohol upon animals is very 

 complicated; it may act through different channels and in differ- 

 ent ways, so that the end results in any special case are due to the 

 interaction of different tendencies. Students of experimental 

 alcoholism must recognize the complex nature of their problem, 

 and, leaving behind the familiar method of generalizing from end 

 results, focus attention upon the problem of the channels through 

 which alcohol may work. 



37 (1784) 



Experiments with B. enteritidis (murium) 1 on normal 

 and immune mice. 



By LESLIE T. WEBSTER. 



[From the Laboratories of the Rockefeller Institute for 

 Medical Research, New York City.] 



These experiments were undertaken to ascertain varieties and 

 degrees of resistance of normal and immune mice to fixed doses of 

 B. enteritidis {murium). 



1. If live cultures of this organism are injected intrapleurally 

 or intraperitoneally into normal mice, there occurs an initial lag in 

 the rate of bacterial multiplication lasting a few hours followed by 

 a rapid and continued acceleration of growth until the death of 

 the animal. 



If live cultures of this organism are given per os to normal mice, 

 there occurs an incubation period of 5-6 days, after which the 



1 A serological and cultural description of this organism will appear in the 

 Journal of Experimental Medicine. 



