Distribution and comparative anatomy of cutaneous glands in certain Marsupials.

Abstract

An account is given of the histological structure of the cutaneous glands of the four species of marsupials, Trichosurus vulpecula, Dromicia concinna, Isoodon obesulus, and Sminthopsis crassicaudata. The types of glands described comprise the eccrine sweat glands of non-hairy skin and the apocrine sweat and sebaceous glands usually associated with hairs. Also included in the survey are the more specialized glands of the sternal and interscapular regions as well as the apocrine and sebaceous glands present in the skin lining the marsupium. The histology of the nipples is also given but, as the mammary glands of marsupials are regarded as being similar to those of other mammals, no account of them has been presented. The glands of Harder and, in marsupials, the less frequently occuring lacrimal gland are described with other glands of the ocular region. The cerumen-producing glands of the external auditory meatus include apocrine tubules and large compound sebaceous glands; the histology of both types is given. The less well-known glands of the cloacal region are described in some detail. These glands comprise two main varieties: a holocrine sebaceous type (which produces an oily secretion) and another structure, somewhat similar histologically, which liberates cells into the glandular lumen.