THE CICADA 



round holes about the size of a man's thumb. Through 

 these holes the Cicada-grubs come up from the under- 

 ground to be transformed into full-grown Cicadae on the 

 surface. Their favourite places are the driest and 

 sunniest; for these grubs are provided with such powerful 

 tools that they can bore through baked earth or sandstone. 

 When I examine their deserted burrows I have to use 

 my pickaxe. 



The first thing one notices is that the holes, which 

 measure nearly an inch across, have absolutely no rubbish 

 round them. There is no mound of earth thrown up 

 outside. Most of the digging insects, such as the Dor- 

 beetles for instance, make a mole-hill above their 

 burrows. The reason for this difference lies in their 

 manner of working. The Dorbeetle begins his work at 

 the mouth of the hole, so he can heap up on the surface the 

 material he digs out: but the Cicada-grub comes up 

 from below. The last thing he does is to make the door- 

 way, and he cannot heap rubbish on a threshold that does 

 not yet exist. 



The Cicada's tunnel runs to a depth of fifteen or six- 

 teen inches. It is quite open the whole way. It ends 

 in a rather wider space, but is completely closed at the 

 bottom. What has become of the earth removed to make 

 this tunnel? And why do not the walls crumble? One 

 would expect that the grub, climbing up and down with 



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