HABITS, BREEDING 37 



prussic acid, and has a very unpleasant 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 with w^hich 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 be expected 'Pio^-^. Polyxenus lagurus (From 



, , p 1 7x r. C. L. Koch, Die Myriapoden). 



m SO large a class 01 anmials. One of 



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 w^ay with the breeding habits of the animal. The 

 habits of the Myriapods connected with their breeding are most 

 interesting, but have been very insufficiently investigated. There 

 is no doubt that a full inquiry 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 

 LitJiohius forficatus among the Centipedes. Julus terrestris is 

 one of the most common of the English Millepedes, 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 Julus when about to lay her eggs 

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

 She burrow^s down into the earth, and at some distance below 

 the surface 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. 



