916 E. V. McCOLLTJM 



symmetry of the skin lesions can best be accounted for on the assumption 

 that they have their origin in damage to certain centers in the cord. 



Vedder further points to the similarity of the symptomatology of pel- 

 lagra and of scurvy on the one hand, in that diarrhea, enteritis, ulceration 

 of the intestine and hemorrhage into the mucous membranes are observed 

 in both conditions. He also emphasizes that there are similar nervous 

 symptoms in pellagra and scurvy. 



On the other hand Vedder calls attention "to the similarities in the 

 lesions in the nervous system and in the symptomatology referable to the 

 nervous system in pellagra and beri-beri. After discussing this point he 

 concludes: "Now if we compare this picture with the changes found in 

 the cord in beri-beri, we find that pellagra is characterized by the same 

 scattered degeneration of the fibers and similar changes in the cells of 

 the cord." 



Modern studies in nutrition have made it clear that it will rarely if 

 ever happen in everyday life, that the diet of man will be of such a 

 nature as to induce one of the deficiency diseases without complications 

 arising from dietary deficiencies of kinds not related to the specific symp- 

 toms which predominate and decide the nature of the diagnosis. It has 

 certainly been true that no case of beri-beri has ever developed which was 

 not also at least a borderline case of scurvy as well. Without doubt defi- 

 ciency diseases tend to occur together, either as well marked conditions or 

 as superimposed borderline complexes forming syndromes which vary to 

 some extent in individuals and lead to confusion.' 



In conclusion it may be said that pellagra can at present be viewed 

 either as an infection transmitted by some agency such as an insect, or as 

 due to specific starvation for some one or more dietary essential. The first 

 view is supported especially by the epidemiological studies of the Thomp- 

 son Pellagra Commission, and Jobling and Peterson ; the latter by almost 

 all other investigators, notably Goldberger, Wilson, Voegtlin and others. 

 It is not possible to decide with certainty from the experimental data at 

 present available which theory is correct, but the evidence seems prepon- 

 derating that faulty diet is the underlying causative agent, either inducing 

 the disease in a manner analogous to the recognized deficiency diseases, 

 beri-beri, scurvy, and ophthalmia of dietary origin, or in a more compli- 

 cated way as rickets is now known to be caused by poorly constituted diets, 

 or by preparing the body for the reception of some infective agent owing 

 to the breaking down of the natural barriers of resistance. The remedy in 

 either case is entirely clear. It consists in the establishment of a more 

 satisfactory dietary regimen in those regions where the disease prevails. 



