Klite, P. D. (Middle America Research Unit, Balboa Heights, Canal Zone). Intestinal bacterial flora and transit time of three neotropical bat species. J. Bacteriol. 90:375-379. 1965.-Quantitative studies on the intestinal bacterial flora of three neotropical bat species revealed the following average bacterial populations: Molossus major, 10(4.8) bacteria per intestinal contents; Carollia perspicillata, 10(3.3); Chilonycteris rubiginosa, 10(3.9). In comparison, laboratory mice had an average of 10(9.7) bacteria per intestinal contents. Of 236 bacterial isolates obtained from 60 bats, bacteria of the Klebsiella-Aerobacter-Serratia group were found most frequently, followed by enterococci and Proteus spp. Bacteria of eight other groups were less frequently recovered. A large intestine, cecum, or appendix was absent in all three bat species, and the intestinal length was one-third to one-fifth of that in a mouse of comparable weight. The transit time through the short bat intestine was 15 min. The possible relationship of these unusual anatomical and physiological phenomena to the ability of Histoplasma capsulatum to survive in bat feces is discussed.