THE VITAMINES IN THE ANIMAL KINGDOM 



119 



The difference in the mode of action of both vitamines was explained 

 by the supposition that there is only a small reserve supply of the 

 antiberiberi vitamine in the body, and hence a lack of it is almost 

 immediately noticeable; on the other hand, the reserve of antirachitic 

 vitamine was thought to be greater. This observation may naturally 

 be explained in another way, namely, that vitamine B is of greater 

 significance in metabolic processes and growth, and hence larger 

 amounts are necessary. In accordance with this, is the fact that 

 grown rats require less vitamine A than young rats, whereas vitamine 

 B is necessary throughout the course of life. When there is a lack 

 of vitamine B, symptoms arise which have been likened to those of 

 beriberi by Funk and Macallum. Be that as it may, these symptoms 



Diet without vitamine B 

 Complete diet 



Diet without vitamines A and B 



x x x x Diet without vitamine B 



may be obviated just as in avian beriberi. Whether it really is 

 beriberi remains to be demonstrated. A paresis of the legs is no 

 rare occurrence in these rats. Voegtlin and Lake (334) observed 

 that rats are much more resistant to beriberi than are cats and dogs. 

 Since beriberi is not an infectious disease, we cannot speak of a 

 resistance ; rather must we say that the lack of vitamine B in rats is 

 not followed by characteristic symptoms. It is interesting to follow 

 the influence of an addition of vitamine B upon the food intake, as is 

 shown in an experiment by Osborne and Mendel (335). Osborne is 

 of the opinion that a daily addition of 0.2 gram yeast is quite suffi- 

 cient to provide for the vitamine B requirement of rats. Osborne 

 and Mendel (336) rightly maintain that the effect of vitamine B 



