288 THE CHEMISTRY OF GROWTH AND REPAIR 



Whatever the deficiency in diet may be, pellagra seems to develop 

 most often in persons whose diet is preponderatingly maize seed 

 products. Only in countries where maize is the chief dietary staple 

 does pellagra occur with any great frequency, and in those countries 

 where part of the population lives chiefly on maize, and other groups 

 live on other foods, pellagra occurs chiefly or only in the former group. 

 I have had the opportunity to observe much pellagra in Roumania 

 during a period of protracted and serious food shortage, and this 

 relation to maize was most striking and convincing. The peasants 

 of this country have for their cliief food a thick mush of boiled, coarsely 

 ground corn meal, called mamaliga, supplemented by such other foods 

 as they can secure. Dwellers in the towns rely on bread from wheat 

 flour as their chief carbohydrate supply, and have a much more abun- 

 dant and varied list of accessory foods. Pellagra is prevalent in Rou- 

 mania, but restricted to the maize-eating peasants, and in very definite 

 relation to their inability to secure accessory food stuffs. While 

 Roumanian physicians seem generally inclined to accept the theory 

 that spoiled maize is responsible, my own observations would indicate 

 that the chief difficulty is lack of accessory foods. The relation of 

 maize to pellagra becomes particularly striking if we compare Rou- 

 mania with a country where maize is not a staple food, such as Korea. 

 Here for centuries a large part of the population has existed on the 

 verge of starvation, the chief food being rice. Although here beriberi 

 is common enough, especially among those who can afford the luxury 

 of polished rice, pellagra is not observed, despite a much greater 

 deficiency in total food supply, both as regards calories and acces- 

 sories, than prevails in Roumania. 



Despite the abundant evidence of the relation of dietary deficiency 

 there are those who interpret existing evidence as establishing or 

 making probable that pellagra is nevertheless essentially an infectious 

 disease. ^^ The compromise view that pellagra is an infectious disease 

 which can only manifest itself among those suffering from dietary 

 deficiency has also been supported, especially by INIcCollum.''^ 



Rickets. — Mellanby^^ holds that this disease results from a defi- 

 ciency in fat-soluble vitamine, although admitting that the efficiency 

 of malt extracts and lean meat in preventing experimental rickets is 

 not in harmony with this hypothesis. As the total growth of rachitic 

 puppies on a diet poor in fat-soluble A is about normal, he suggests 

 that this agent is not necessary for growth, but merely for making 

 growth normal. Without "A" the development of teeth is much 

 interfered with. The recognized value of cod liver oil in rickets is in 

 support of this view. Hess, McCollum and others do not accept the 

 hypothesis that rickets is solely the result of lack of fat-soluble A. 



" See Jobling and Peterson, Jour. Infect. Dis., 191G (IS), 501. 



" Proc. Amer. Philos. Soc, 1919 (58), 41. 



«' Jour. Physiol., 1919 (.52), liii; Lancet, 1919 (19G), 407. 



