at 35 , 45 , 55 and 65 d of age in normally-fed animals , and at 45 and 55 d of age in undernourished animals , blood testosterone levels were determined by radioimmunoassay , epididymidal tissue examined for the presence of spermatozoa and testes sectioned for rating of spermatogenesis using light microscopy .
C0037868
spermatozoa
C0037864
spermatogenesis