THE CHILOPODS. 



153 



curved, tapering joint, terminated by a sharp, perforated claw, through which the poison secreted by 

 a gland can be poured into the wounds inflicted by the point. The whole of this apparatus lies flat 

 upon the under surface of the head, usually closing the mouth from beneath entirely. 



The segments behind the head, which vary in number between sixteen and over a hundred, are 

 formed by separate horny dorsal and ventral plates, joined at the sides by a membranous part in which 

 the stigmata are usually situated. Each of these plates more or less overlies the one behind it, and in 

 some forms the alternate dorsal plates are so large as to cover those between them, causing the number 

 of segments to appear only half what it really is. In these cases, however, the ventral plates indicate 

 the true number of seg- 

 ments. The rudimen- 

 tary condition of the 

 dorsal plates of the 

 first or first and second 

 segments has already 

 been mentioned ; and 

 these, and the third 

 segment, are to be 

 regarded as constitut- 

 ing a thoracic region 

 homologous with that 

 of insects. Each seg- 

 ment of the body, 

 from the third on- 

 wards, bears a pair of 

 jointed legs, which 

 spring from the borders 

 of the ventral plates 

 and stand out from 

 the sides of the body. 

 They are usually of 

 moderate length, but 

 sometimes very long. 

 The legs attached to 

 the last segment are 



generally much longer and stronger than the rest, and differ from them also in being directed back- 

 wards nearly in a line with the body. The antennae are long, composed of many joints, and tapering 

 in form. The stigmata are usually placed on the alternate segments, and lead into a system of tracheae 

 closely resembling the type seen in insects. The organs of reproduction open at the posterior ex- 

 tremity of the body, and the impregnation of the females is said to be effected by the agency of sper- 

 matophores, which the males attach to irregular webs which they spin close to the ground. 



The Chilopods are spread over all parts of the earth, but the species of temperate countries are 

 mere pygmies when compared with some inhabitants of the tropics. They are all shannon of light, 

 retiring during the day to hiding-places in the ground, under stones and the bark of trees, and in 

 the crevices of rocks, buildings, &c., and coming forth at night in search of their food, which consists 

 of insects, worms, and other small animals. When disturbed, most of them run with considerable 

 rapidity, and with an undulating, more or less snake-like, movement of the body ; and if seized or 

 otherwise interfered with they have no scruples about making use of the formidable nippers formed 

 by the second pair of limbs. The poisonous secretion which, as already stated, is poured forth through 

 the perforated point of these organs, renders the bite of the larger species very formidable ; but even 

 the small British species, such as Litkobius forficatus, will attempt to bite the fingers of their captor 

 in a most savage manner. The order may be divided into two families, the first of which includes 

 only a comparatively small number of curious forms, while the second comprises the great majority 

 of the species, which vary considerably in character. 

 258 



SCOLOl'EXDHA CIXGULATA. 



