The XIIth North American Testis Workshop was held in Tampa, Florida, April 13 to 16, 1993. The program consisted of 23 invited lectures and 120 poster presentations. In keeping with the tradition of the Testis Workshop, every attempt was made to emphasize recent develop ments in the study of endocrine and gametogenic functions of the male gonad. Although the main emphasis, reflected in the title of the pro ceedings, was on the function and control of somatic cells in the testis, one session was devoted to germ cells and one to the studies of male reproductive development and function. The...