Abstract
1. The bacteria commonly found in freshly collected fowl semen are coliform bacilli, staphylococci, diphtheroid bacilli and haemolytic streptococci. These organisms are probably derived from the cloaca, which usually has the same flora as the expressed semen, while the sperm mass from the vas deferens is sterile.2. In diluted or undiluted semen stored for 24 hr. at room temperature, or 48 hr. at 2°C, there is a great increase in the bacterial population, especially of coliform bacilli.3. Although the presence of egg white did not diminish the growth of bacteria in stored diluted semen it improved the motility of the spermatozoa.4. Sulphathiazole in the concentrations used proved toxic to the spermatozoa, and unreliable for bacteriostasis.