62 B. GRASSI AND A. SANDIAS. 



to avoid the dryness of that part. They do not dig in order 

 to bury themselves, but make use of natural cracks caused by 

 drought. 



In order to gain a clearer idea of the galleries and of the 

 mode of life of these animals, I kept a certain number in 

 a corked glass jar a third full of earth and vegetable rubbish, 

 and in this they flourished for several months. 



They constructed galleries in the middle of the contents'or 

 between them and the inner surface of the jar, most of which 

 below the level of rubbish was spun over with threads or small 

 webs of silk, with occasional galleries. They generally remain 

 motionless in these, and probably emerge only for pairing, 

 feeding, defsecation, or to escape their enemies. 



If an Embia is put into a glass jar with a little earth it 

 runs about in search of a suitable situation, either in a corner 

 or against a lump of earth ; then in two or three minutes it 

 begins to cast out silk threads in order to make its gallery. 

 This is sketched out in about a quarter of an hour, but takes 

 from twelve to fifteen hours to complete. The Embia clearly 

 accomplishes the task with its fore-legs,standing still 

 on the chosen spot and moving them in the most 

 varied directions, downwards, sideways, forwards, 

 and backwards, always with great rapidity. Fre- 

 quently it alternates the work of one leg with that 

 of the other, but at times both work together with 

 intervals of rest. 



The silk produced is seen under the microscope to consist 

 of a network of subcylindrical fibres, which appears to the 

 naked eye as a thin semi-opaque white membrane. 



Here and there are scattered silk threads of variable length 

 and thickness, which serve to fix it in position. These threads 

 can often be seen to merge gradually into the network, of 

 which they are clearly a modified form ; under the microscope 

 they are found to be composed entirely of fibres. The com- 

 ponent fibres of the silk are more or less slender, and vary 

 from extremely fine fibrils scarcely visible with a high power 

 to fibres readily distinguishable with low magnification. A 



