36 THE BOOK OF NATURE STUDY 



is very slender and relatively long ; indeed, it might be mistaken 

 for a worm. The light which the creature emits is like that of a 

 glow-worm, though feebler ; and it persists for a short time as 

 a luminous trail upon the ground, being evidently due to some 

 substance emitted. The phenomenon is probably associated 

 with the breeding season, but we need more exact observations 

 on this point. 



The most familiar member of this division is the ordinary 

 red centipede, Lithobius forficatus, a swift, active creature that 

 may be seen hurrying away into safety when a large stone, log, 

 or any similar object that has been lying for some time upon 

 the ground is uplifted. The animal has fifteen pairs of legs 

 and possesses eyes. Its food consists of earth-worms, blue- 

 bottle-flies, and many other small animals which are captured 

 alive. Earthworms are pursued, as rabbits by a ferret, along 

 their burrows. This species may be kept in captivity, but is 

 rather shy of observation. Dr. D. Sharp has, however, suc- 

 ceeded in determining the following facts regarding its habits. 

 The breeding season begins in June and goes on till August. The 

 eggs pass from the body singly, and as each arrives at the genital 

 opening it is grasped by two small hooks on the ventral surface 

 of the body of the female, and by these organs it is quickly rolled 

 round and round on the earth until it is covered with soil adhering 

 to the slime with which the spherical egg-shell is covered ; the 

 hind-legs also take part in this operation. The purpose of this 

 manoeuvre is to conceal the egg from the male, who will, if poss- 

 ible, seize it from the female at its first appearance and devour 

 it. The female frequently has to run hastily away from the 

 greedy male, holding the egg in the special hooks until she can 

 find a quiet spot free from his molestations, and there convert 

 the appearance of the egg into that of a pellet of mud. 



The millipedes are of very different shape and habits. Their 

 body is, in the commonest species, cylindrical, but in others 

 flattened and with lateral projections from the segments ; only 

 the first few anterior segments possess but one pair of legs each, 

 the remainder carry two pairs each, and thus give the appearance 

 whence the popular name is derived ; the bases of the legs are 

 close together, near the mid- ventral line ; the reproductive 



