HABITS, BREEDING 37 



prussic acid, and has a very iinpleasant odour. Most of the 

 Millepedes are provided with these glands ; but in the cave 

 Myriapods mentioned before, the animals have not to contend 

 against so many adversaries, and these glands almost disappear. 

 Other Myriapods defend themselves by means of the long and 

 stiff bristles %Yith which they are pro- 

 vided, e.g. the little Polyxenus. This 

 means of defence seems to have been 

 more common among the fossil Myria- 

 pods than among those still living. 

 Variations in the shape and size of the 

 limbs are numerous.as might beexpected Fig.18.— Po/l/.^•enJ«%«™s (From 



? , 'i „ C. L. Koch, Die Jfi/riajjoden). 



m so large a class 01 anmials. One ot 



the most curious of such variations is found in a Centipede of the 

 Scolopendra tribe, called Eucoryhas, in which the last limbs are 

 flattened out and provided with paddle-shaped lobes. The use 

 of these is unknown, but it is probable that they are concerned 

 in some way with the breeding habits of the animal. The 

 habits of the Jlyriapods connected with their breeding are most 

 interesting,' but have been very insufficiently investigated. There 

 is no doubt that a full incxuiry into all such habits would be of 

 great interest, and would help to answer some of the problems 

 which are still unsolved in these forms. My own observations 

 refer to two forms — Julus terrestris among the Millepedes, and 

 Lithohius forficat'us among the Centipedes. Jidus terrestris is 

 one of the most common of the English IMillepedes, and can be 

 easily obtained. I kept them in large shallow glass vessels with 

 a layer of earth at the bottom, and thus was able easily to 

 watch the whole process. They breed in the months of May, 

 June, and July. The female JuJus when about to lay her eggs 

 sets to work to form a kind of nest or receptacle for her eggs. 

 She burrows down into the earth, and at some distance below 

 the sm-face begins the work. She moistens small bits of earth 

 with the sticky fluid secreted by her salivary glands, which 

 become extraordinarily active in the spring. She works up 

 these bits of earth with her jaws and front legs till they are of 

 a convenient size and shape, and places them together. When 

 complete, the nest is shaped like a hollow sphere, the inside 

 being smooth and even, while the outside is rough and shows 

 the shape of the small knobs of earth of which it is composed. 



