866 MICROBIOLOGY OF DISEASES OF MAN AND DOMESTIC ANIMALS 



eating maize (Indian corn) ; according to the other, pellagra is a specific 

 infectious disease not necessarily associated with the ingestion of corn. 

 None of the theories concerning causation is supported by conclusive 

 evidence. The evidence against the corn theory marshalled by Sambon 

 and others has greatly weakened the almost general belief in this 

 theory which formerly obtained. Some prominent zeists have recently 

 shown a tendency to ascribe pellagra not essentially to the use of maize 

 but to a supposed deficiency or lack of a necessary something in the 

 diet. This change of opinion has been caused in part by the failure 

 of the maize theory when put to the test of actual observation and in 

 part by an eager application to pellagra of the facts learned in the 

 study of another disease, namely, beriberi. To the writer it seems 

 very improbable that this new phase of the dietary theory will survive 

 as long as has the maize theory proper, although it has received 

 enthusiastic support from the U. S. Public Health Service. 



According to the second theory, pellagra is a specific infectious dis- 

 ease, in which poor nutrition is one of the important predisposing factors. 

 The epidemiological study of pellagra, as it has developed and spread 

 in certain parts of the southern United States, has brought to light evi- 

 dence of its infectious nature which, to the writer, seems very convinc- 

 ing. The same investigations have also strongly suggested that the 

 infection is intestinal and transmitted in much the same way as is 

 typhoid fever. A specific microbic cause of pellagra has not been 

 identified. 



The final decision in regard to the essential nature of pellagra must 

 therefore await further research. Certain facts in regard to the disease 

 are, however, well established. In the first place modern students agree 

 that the ingestion of maize is not essential for the production of pella- 

 gra. It occurs in persons who have not eaten this food. The preval- 

 ence of pellagra, especially in institutions, bears a very definite relation 

 to the deficiency of animal protein in the diet, as was first pointed out 

 in this country by the Illinois State Pellagra Commission. This com- 

 mission observed that pellagra diminished in the Peoria and Dunning 

 institutions coincidently with an increase in meat supply, while at the 

 Elgin Hospital the number of pellagrins increased with a decrease in 

 the amount of meat provided per capita. This commission made a 

 specific recommendation to the Governor of Illinois that "as a prophy- 

 lactic measure the animal protein content of the State Hospital dietaries 



