Abstract
17 immature male and female rabbits were injd. intramusc. with 5 mg. of testosterone propionate in oily soln. 3 times a week from the beginning of the 2d week of life to an avg. age of 53 days (min. 47 days, max. 67 days.). At the end of the expt. the body wt., the length of femur and tibia, and the histological appearance of the distal femoral epiphyseal cartilage were compared with those of 17 untreated litter-mate controls. The only significant difference found, was a slight inhibition of the growth of the femur. The development of the ossification centers was studied in 12 rabbits treated during the first few weeks of life with varying doses of testosterone propionate (min. 18 mg. over 16 days, max. 125 mg. over 14 days), 18 litter-mates serving as untreated controls. No difference was observed.