Studies on the poll glands of the one-humped camel in relation to reproductive activity. II. Ultrastructural observations.

An alveolus of an active poll gland is lined with cells in various stages of secretory activity. The cells are generally tall and characterised by the presence of a spherical nucleus, a massive Golgi complex, numerous mitochondria, granular endoplasmic reticulum, many ribosomes and secretory granules; these are features which constitute evidence of high metabolic and secretory activities. An alveolus of a resting gland, on the other hand, is lined with low inactive cells possessing an infolded nucleus, an inconspicuous Golgi complex and a few other organelles; secretory granules are virtually absent. The alveolar cells undergo a cyclic merocrine secretory activity yielding a proteinaceous product. It is suggested also that the gland may be a steroid-dependent organ accumulating or possibly synthesising steroids and releasing them through a mechanism as yet unknown.