REPRODUCTION AND HEREDITY 



273 



similar phenomenon is observed in the mole, in whose run, 

 especially in winter time, large heaps of living earth-worms 

 are found which the mole has paralyzed by a bite in the cephalic 

 lappet. This method secures the victim as safely as if it had 

 been killed, and has the additional advantage that the food- 

 supply remains always fresh. 



Numerous weevils make really touching provision for their 

 offspring. The so-called leaf-rollers cut with their proboscis 

 deep into the leaves of the host-plant and by means of their legs 

 skilfully roll the section up. Having hidden a few eggs in this 

 roll, they fold the open ends down and firmly seal them with 

 a viscid fluid secreted through the anus. Untiringly the abdomen 

 moves up and down until the minutest hole has been closed. 

 The inner parts of the leaf afterwards serve as food for the young 

 larvae (fig. 65). 



Still greater pre- 

 cautions are taken 

 for the safety of its 

 offspring by the nut- 

 weevil. In default 

 of an ovipositor it 

 bores with its long, 

 thin proboscis a little 

 circular hole into the 

 soft nutshell and 

 pushes, also with its 

 proboscis, into each 

 nut one egg. By the 

 beginning of October 

 the larva has mostly 

 consumed the kernel 



and now cuts with its sharp mandibles a way through the nut- 

 shell, which in the meantime has become hard, in order to pass 

 its development deep down in the earth. 



Equally remarkable is the behaviour of the so-called grave- 

 diggers which are not content, like numerous other carrion- 

 beetles, simply to deposit their eggs on the carcases, but first bury 

 the corpse by joint labour. Most celebrated is doubtless the 

 Sacred Pill-beetle (Sisiphus sacer), which was in ancient times 

 18 



FIG. 65. (1) Rhynchites populi, WITH LEAF-BOLL. 

 (2) LEAF-ROLLS OF Rhynchites betulce. 



