_The Zeistic Views._—The idea which was at one time entertained that maize, whether good or bad, brought on pellagra has now been generally abandoned, owing to investigations, which proved that corn possessed a fair nutritive value and was easily assimilable, together with evidence to show that where care was taken in the maturing of the grain and the prevention of decomposition by moulds or bacteria, pellagra was either nonexistent or diminished in a district where such measures were instituted. The statement is frequently seen that pellagra did not make its appearance in Europe until after the introduction of maize, subsequent to the discovery of the New World. There are authors who think Casal was suspicious of a maize dietary. The zeistic views now incorporate some additional factor with the basic one of a rather exclusive maize dietary. 1. The verderame theory of Ballardini. From noting on the corn grains a covering with a greenish mould, Ballardini in 1845 advanced the view that pellagra was due to this mould and from this time on we have the so-called zeitoxic views, which hold that pellagra is caused by spoiled corn. Ceni and Fossati regard a toxin elaborated by various moulds as causative. The fungi toward which attention has been chiefly directed are _Aspergillus fumigatus_ and _A. flavescens_ as well as certain species of _Penicillium_ and _Mucor_. 2. The Lombroso view that as a result of the action of moulds or bacteria, toxins are elaborated which, when ingested, give rise to the disease. 3. That the toxins have origin in the action of various organisms, especially _B. coli_, on the ingested corn, while in the intestines. 4. Recently views have been brought forward that pellagra is an anaphylactic phenomenon connected with sensitization to the maize proteins. 5. Rabitschek has brought forward a photodynamic theory which is that pellagra is due to a preponderating maize or possibly other cereal dietary which results in certain photodynamic substances being introduced into the circulation. These substances become toxic under the influence of sunlight. Hirschfelder has failed to find any fluorescent body in the serum of five patients suffering with severe pellagra. Among arguments in favor of the maize etiology of pellagra may be mentioned the following: (_a_) Among the natives of Upper Egypt, where millet instead of maize is the staple cereal, pellagra is rare, while in Lower Egypt where much maize is eaten the disease is far more prevalent. (_b_) While the natives of Corfu, prior to 1857, grew their own maize and ate only sound grains there was no pellagra but later, when the corn crop was less profitable, and the grain was imported from Roumania, much spoiled maize was brought in and pellagra made its appearance.