Abstract
Forty-three males were divided into three experimental groups and ligatures placed unilaterally as follows: (1) on the ductus deferens, (2) on the ductus deferens and corpus epididymidis, and (3) on the ductus deferens, corpus epididymidis and ductuli efferentes. Semen was collected six times a week from all males before ligation and for as long as 12 weeks thereafter.