Investigations on the postnatal morphological development of genital organs and accessory glands in the male rabbits

39 SUMMARY In this study, morphological changes of genital organs and descent of testes to scrotum at postnatal period were examined in 60 male rabbits. Rabbits were allocated into equally 8 groups considering 0-4, 4-8, 8-12, 12-16, 16-20, 20- 24, 24-28 and 28-52 week ages of periods Testes that were located in the lumbal area behind the kidneys, descended scrotum on the 13. tn day. The right testis was found to be heavier 8-12 and 28-52 week old groups, longer 4-8 and 28-52 week old groups, wider 4-8 and 8-12 week old groups and thicker 8-1 2 week old groups than the left testis. These parameters were found to be totaly different for others groups. The fastest increase in the measurement values of testes until maturation were observed in the length.largeness and thickness, respectively. The proportion of testes to body weight reached to the highest value in the 24-28 week old group. There was perfect correlation among testes, body weight and accessory sex organs. Histologically, Leydig cells in the interstitial area and spermatogoniums in tubules were determined in the 0-4 week old group. In the 4-8 week old group, spermatogoniums and primary spermatocytes were found in tubules. The sole finding in the 8-12 week old group was the enlargement in the tubules diameters. In the 12-16 week old group, the increase in the tubular diameter was very slow and first spermatozoon was found in the 15 week old rabbits. Mucosal curls and secretion glands in ampulla (distal) ductus deferens appeared first in the 4-8 week old group. The greatest increase in the weight of gl. vesicularis was seen in the 16-20 week old group. However, the greatest increase in the length, largeness and thickness of gl. vesicularis was observed in the 24-28 week old group.40 While the greatest increase in the largeness and thickness occurred in the 4-8 week old group, the greatest increase in the weight and length of proprostata was obtained in the 16-20 and 24-28 week old groups, The greatest increase in the weight, length, largeness and thickness of the prostata was seen in the 4-8 week old group. The greatest increase in the weight and length of gl. bulbourethralis was obtained in the 24-28 week old group. The greatest increase in the largeness and thickness was seen respectively in the 12-16 and 20-24 week old groups.