Newport (1844) was the first worker to recognise that the forcipules of centipedes, which he termed the mandibles, contained a poison gland. Despite this, many nineteenth-century workers confused the poison glands with other head glands (Duboscq, 1898): their true nature was recognised by MacLeod (1878). He examined Scutigera coleoptrata, Lithobius forficatus, Cryptops savignyi and various Scolopendra species and geophilomorphs noting the gland duct and pore. He demonstrated that whereas a bite from the poison claws of L. forficatus produces almost instantaneous death in flies, extracts of the ‘salivary glands’, when injected, did not.

Structure of the gland and discharge of poison in Scolopendra

The structure of the poison glands has been described for Scolopendra subspinipes by MacLeod (1878), for S. cingulata by Duboscq (1898), for S. morsitans by Pawlowsky (1913) and Dass & Jangi (1978), and for S. viridicornis by Barth (1967). Cornwall (1916) described the poison gland in Ethmostigmus platycephalus spinosus and Bücherl (1946) described the gland of a number of scolopendrids.

The gland is situated in the distal part of the trochantero-prefemur and extends into the poison claw on which its duct opens subterminally. It is innervated by a nerve from the suboesophageal ganglion and is well supplied with tracheae. In S. cingulata it is bluish white in colour. Transverse sections show a central duct surrounded for three-quarters of its circumference by elongated gland cells which open into the duct by pores (Fig. 121a).