Observations on odoriferous and other glands in the Australian wild rabbit, Oryctolagus cuniculus (L.), and the hare, Lepus europaeus P. I. The Anal gland

Abstract

The histology and weight relationships of the anal glands from wild rabbits, Oryctolagus cuniculus (L.), and hares, Lepus europaeus P., have been studied. In the rabbit the anal glands are larger in males than in females; sexual dimorphism appears with sexual maturity. The size of the gland is correlated with sexual activity (social status). In hares the differences between sexes are not so obvious. Weight and secretory activity of the anal gland were highest during the breeding season and lowest during the non-breeding season in both the rabbit and the hare. Castration during early life inhibited the growth of the anal glands in male rabbits but not in females. Secretion was inhibited in castrated males but was not affected to the same extent in castrated females. The height of the secretory epithelium, the diameter of tubules and the occurrence of cytoplasmic blebs and processes on the secretory margin were all greater in intensively secreting glands than in lightly secreting ones, but lipid was more copious in less active glands. Lipid seems to be a precursor of the final secretory product which is not distinctively stained by Sudan stains. No changes were seen in the glands from a small sample of pseudopregnant females killed at different intervals after oestrus. The functioning of the anal gland for the purpose of territorial marking is suggested.