THE FAUNA OF THE MOOR 127 



with great rapidity and sometimes fly. They are Tiger 

 Beetles (Cicindela campestris}, about three-quarters of 

 an inch long, with white and yellow spots on the wing 

 covers. They prey upon other insects, including some 

 which are injurious to pasture. They are extra- 

 ordinarily beautiful, like living jewels. The brilliance 

 is due to thin films of almost metal-like material. 



The behaviour of the grubs is very remarkable. 

 They are hatched in the soil, from eggs which the 

 mother beetle has buried there, and they soon set to 

 work to make vertical or sloping burrows, which are 

 sometimes deepened to about a foot. To begin with, 

 a rough burrow is made by pushing the sand to the 

 side with feet and jaws ; the miner works head down- 

 wards and brings some material to the surface. But 

 soon a more intricate behaviour commences. The 

 larva loads its head and turns a quick somersault in 

 the shaft; it reaches the entrance head up, and with a 

 backward toss of its head it presses the material 

 against the margin. It rights itself and goes head 

 downwards down the shaft to repeat the performance. 

 As the shaft deepens, the material is not brought to 

 the entrance but is pressed into the wall lower down. 

 But there is a continuance of the shovelling, the load- 

 ing of the head, the rapid somersaulting, the backward 

 tossing, and the pressing of the material into the wall 

 of the shaft. All this has been very carefully watched 

 by Dr. Robert Stager, a Swiss naturalist, who got the 

 Tiger grubs to do their mining in a glass vessel filled 

 with sand. 



We can understand why the shafts are sunk in 

 places where there is vegetation of the kind we men- 

 tioned, for the presence of the plants ensures some 



