Deficiency of which causes Beri-heri in Man. 



59 



Sitmmary and Conclusions. 



1. The foregoing experiments deal with , the distribution of " anti-neuritic 

 (anti-beri-beri) vitamines " in the various contituents of the wheat, maize, and 

 rice grains. By " anti-neuritic vitamine " is meant the substance whose 

 deficiency in a diet causes polyneuritis in pigeons and beri-beri in man. 



2. Wheat-endosperm, after removal of the aleurone-layer in the ordinary 

 milling processes, constitutes white flour. It is deficient in this vitamine, and 

 if used as an exclusive diet will induce polyneuritis in pigeons (or beri-beri 

 in man) in a manner identical with polished rice. 



3. In both the rice and wheat grain, the anti-neuritic vitamine is concen- 

 trated mainly in the germ or embryo ; it is also present to a less degree in the 

 bran (pericarp and aleurone-layer), probably in the aleurone-layer. 



4. In case of maize grain, the embryo also possesses marked anti-neuritic 

 properties. Here the scutellum can be separated from the " plantlet " and 

 separately investigated. Both these constituents of the embryo were found to 

 contain anti-neuritic vitamine. 



5. The practical results given under 2 and 3 show the importance of 

 including germ in the flour from which wheaten bread or biscuit is made, 

 especially when the diet may consist largely of preserved foods, e.g. tinned 

 meats and vegetables, which are deficient in anti-beri-beri vitamines. 



6. The daily ration of wheat-germ that must be added to a diet of polished 

 rice in order to prevent the onset of polyneuritis is of the same order of 

 magnitude as the amount which, administered by the mouth, will cure a 

 pigeon acutely ill with polyneuritis, brought on by an exclusive diet of 

 polished rice. This relation is not peculiar to wheat-germ but applies to other 

 foodstuffs containing anti-neuritic vitamines, e.g. yeast. 



7. The addition of wheat-germ to a diet of polished rice in quantity (3 grm. 

 every second day) sufficient to prevent polyneuritis, also maintained the 

 weight and general health of the bird. Eations in excess of this (2 grm. every 

 day to 3 grm. every day) led to great increase in body-weight and in general 

 well being and vitality of the birds, which, after a short period of this diet, 

 became in remarkably fine condition. 



In conclusion, our best thanks are due to Messrs. Steele and Co. (rice 

 millers), to The Hovis Milling Co., and to Messrs. J. and H. Eobinson (wheat 

 millers), for kindness in supplying us with material for experirfient, and 

 especially to Mr. E. G. Ellis, of the last-named firm, for much valuable advice 

 and assistance. We are also much indebted to Professor A. Harden, F.E.S., 

 for kindly preparing one of the extracts mentioned in Table V, to Captain 

 A. H. Osman, of the Home Forces Pigeon Service, for a generous supply of 



VOL. XC. — B, G 



