Spermatozoan cytoplasmic droplets have been noted in a variety of animal species. Although their function and chemical nature is as yet undetermined, Noble and Weber (1) suggested that droplets in plethodontid salamanders are useless vestiges retained on the mature spermatozoa, while Murphy et al. (2) have suggested that the cytoplasmic droplets may play some role in sperm maturation. The object of the present study is to determine the morphology and chemical nature of these droplets at the light and electron microscopy level.In our studies of spermatozoan cytoplasmic droplets, we used the sperm from Plethodon jordani and Desmognathus ochrophaeus (Caudata, Plethodontidae). The droplets were observed in testicular material of both species and from spermatozoa taken from the vas deferens of Desmognathus ochrophaeus, and were most often found associated with the middle piece of the spermatozoa. The droplets were limited by a single membrane and located on the side of the axial rod opposite the undulating membrane and flagellum (Fig. 1 and 2).
