The relative frequency of intestinal disorders in tropical countries, the multiplicity of microörganisms to which a causal relation has been attributed, the uncertainty prevailing about the distribution and significance of such bacteria as the Morgan bacillus and various Salmonella types and the general lack of knowledge about the etiology of tropical intestinal disease combine to give to even fragmentary observations some degree of value in guiding further research. In the course of various studies on other matters in Puerto Rico and in the Panama Canal Zone, we have gathered a few data upon intestinal flora which it seems worth while to place on record.
Enteritis and diarrhea are common in Puerto Rico. On this island in 1930 (January to March), 144 fecal specimens were examined by the poured plate method; these specimens were derived from 81 persons. They were distributed as follows.