56 Miss H, Chick and Miss E. M. Hume. The Substance, the 



polished rice. In order to cure pigeons suffering from acute polyneuritis 

 (1914, II), he used autolysed yeast, and found it necessary to administer the 

 equivalent of 3-6 grm. of the original pressed yeast; on a second occasion 

 the equivalent of 1-2 grm. was sufficient. There are no other good 

 instances available, because curative experiments have almost universally 

 been made with material which has been extracted with alcohol to 

 concentrate the vitamine, while, for the preventive experiments, the natural 

 foodstuffs have been used. As pointed out above, there is a great loss of 

 anti-neuritic material in the extraction process as usually carried out. 

 Hence the stated amounts required for the cure of animals show an 

 exaggerated size when reckoned on the original foodstuffs. 



That the preventive and curative doses are of the same order of magnitude 

 is perplexing, and demands further investigation. In order to obtain some 

 light upon this point we are making a series of preventive experiments in 

 which the total amount of vitamine is kept constant, but the dosage, i.e., 

 size and periodicity of the dose, is varied. These experiments are not yet 

 completed, but the only interpretation which the facts seem capable of 

 carrying at present is that : 



(1) There is an urgent daily need for a small quantity of this vital sub- 

 stance to maintain the metabolism of the nerve tissue ; 



(2) In the normal condition a considerable store is available somewhere 

 in the animal body upon which to draw ; and 



(3) This store becomes suddenly exhausted, but can be temporarily 

 restored by the administration of a small quantity from outside. 



Influence of a Small Regular Ration of Whcat-Emhryo in Maintaining the 

 Weight of Birds Feci on Polished Rice. 



It has been shown by numerous observers that birds fed exclusively on 

 polished rice lose consistently in weight. In our experience, the average loss 

 of weight under these conditions varied from 11 to 22 per cent, over a mean 

 period varying from 17 to 22 days (see control experiments. Tables I-IV). 

 "When a ration of wheat was given insufficient to prevent the onset of poly- 

 neiiritis {i.e., from 0'5 to 1'5 grm. every second day), this loss in weight 

 was not exceeded, although the mean period of the experiment lasted from 

 22 to 35 days (see Tables I and II). 



When the wheat ration was adequate for protection against polyneuritis 

 {i.e., 3 grm. every second day), in one instance (Expt. 4, Table I) the average 

 loss of weight was negligible, viz., —4 per cent., and in a second (Expt. 3 , 

 Table II) a gain in weight was observed, viz., + 8 per cent. The total weight 



