Abstract
Fine structure, postnatal development and reaction to efferent duct ligation of the loose connective tissue of the rat rete testis were studied by light and electron microscopy. The loose connective tissue of adult rats consists of elongate fibroblasts in a homogenous ground substance, together with some Leydig cells, lymphocytes, macrophages and mast cells. During postnatal development this tissue increases in amount, while the interstitial areolar tissue decreases. The “looseness” of the tissue becomes more evident between days 22 and 27, and may reflect an increase in hydration. Efferent duct ligation for 15 min to five days has no effect on the histological appearance of the tissue.