152 THE WONDERS OF INSTINCT 



On this foundation, which acts as a protection from 

 the sand, the Lycosa fashions a round mat, the size of a 

 two-franc piece and made of superb white silk. With 

 a gentle, uniform movement, which might be regulated 

 by the wheels of a delicate piece of clockwork, the tip 

 of the abdomen rises and falls, each time touching the 

 supporting base a little farther away, until the extreme 

 scope of the mechanism is attained. 



Then, without the Spider's moving her position, the 

 oscillation is resumed in the opposite direction. By 

 means of this alternate motion, interspersed with numer- 

 ous contacts, a segment of the sheet is obtained, of a very 

 accurate texture. When this is done, the Spider moves 

 a little along a circular line and the loom works in the 

 same manner on another segment. 



The silk disk, a sort of hardy concave paten, now no 

 longer receives anything from the spinnerets in its center ; 

 the marginal belt alone increases in thickness. The piece 

 thus becomes a bowl-shaped porringer, surrounded by a 

 wide, flat edge. 



The time for the laying has come. With one quick 

 emission, the viscous, pale-yellow eggs are laid in the 

 basin, where they heap together in the shape of a globe 

 which projects largely outside the cavity. The spinner- 

 ets are once more set going. With short movements, as 

 the tip of the abdomen rises and falls to weave the round 

 mat, they cover up the exposed hemisphere. The result 

 is a pill set in the middle of a circular carpet. 



The legs, hitherto idle, are now working. They take 

 up and break off one by one the threads that keep the 



