Geissmann T., 1986: Sternal gland in the siamang, Hylobates syndactylus. Primate Report 14: 22-23 (Abstract only).

Sternal gland in the siamang, Hylobates syndactylus

T. Geissmann

Anthropological Institute, University Zürich-Irchel

Sternal glands occur in many species of strepsirhine primates and New World monkeys but are known only from few species of Old World monkeys. In hominoids, the only evidence of a sternal gland so far provided has been for the orang-utan. This report presents the first description and histological sections of a sternal gland of the siamang (Hylobates syndactylus). The gland occurs in males and females. Observations of several groups of captive siamang failed to reveal any kind of marking behaviour, and no such behaviour is known from feral siamang. This is in contrast to other primates and mammals with a sternal gland. Possible parallel functions to the axillary organ of man and the African apes are considered.