[Comparative histological investigations on the teats of sheep and goats].

In the present study the teats of the goat and the sheep were investigated light microscopically. In both species, smooth muscle elements condense towards the streak canal, and abundant arteries occur with thick tunica media and various valve structures. The apocrine sweat gland have a wide acinous element, which are regarded as a part of the excretory duct. Additional alveolar secretory tissue is present in the wall of the lactiferous sinus, which tubuloalveoli are probably of two varying types in the sheep and empty directly into the lumen of the lactiferous sinus in the goat. The histologic features of the teat in the goat differ mainly in the smaller and less coiled apocrine sweat glands, the thin stratum granulosum of the teat canal epithelium and the occurrence of supplementary canals (frequently two) in the initial part of the teat canal. The ovine teat shows a partly extremely thin epidermis, solid coiled apocrine sweat glands, and a pigmented epithelium of the teat canal equipped with a considerably thicker stratum granulosum.