CENTIPEDES AND MILLIPEDES 371 



regard as " vermin " all and sundry forms even remotely resem- 

 bling those actually known to be objectionable. 



Centipedes and Millipedes have fallen under this ban, and as 

 a . result our knowledge of them is comparatively scanty, and 

 mainly due to a few enterprising investigators. The structure 

 of these creatures is of very great interest, throwing light as it 

 does upon the origin of Insects, and that the habits deserve 

 investigation may be judged from the following accounts which 

 Sinclair gives (in The Cambridge Natural History) of two well- 

 known British species, the Thirty- Foot (Litkobius forficatus), 

 one of our commonest Centipedes (see vol. i, p. 394), and the 

 Earth Snake-Millipede {Julus terrestris)^ which is even more 

 abundant. 



Sinclair speaks as follows of the Thirty-Foot: "The female 

 Lithobius is furnished with two small movable hooks at the end 

 of the under surface of the body close to the opening of the 

 oviduct. These small hooks have been observed by many 

 naturalists, but their use has, so far as I know, never been 

 described before. They play an important part in the proceed- 

 ings following the laying of the egg. The time of breeding in 

 Lithobius .... begins about June and continues till August. 

 There are first of all some convulsive movements of the last 

 segments of the body, and then in about ten minutes the egg 

 appears at the entrance of the oviduct. The egg is a small 

 sphere (about the size of a number-five shot) rather larger than 

 that of Juhis, and is covered with a sticky slime secreted by 

 the large glands inside the body, usually called the accessory 

 glands. When the egg falls out it is received by the little 

 hooks, and is firmly clasped by them. This is the critical 

 moment in the existence of the Lithobius into which the egg is 

 destined to develop. If a male Lithobius sees the egg he makes 

 a rush at the female, seizes the egg, and at once devours it. 

 All the subsequent proceedings of the female seem to be directed 

 to the frustration of this act of cannibalism. As soon as the egg 

 is firmly clasped in the little hooks she rushes off to a convenient 

 place away from the male, and uses her hooks to roll the egg 

 round and round until it is completely covered by earth, which 

 sticks to it owing to the viscous material with which it is 

 coated; she also employs her hind-legs, which have glands on 

 the thighs, to effect her purpose. When the operation is com- 



