MOLE-CRICKET 



333 



tion is the same as in the Locustidae, rapid vibration of the 

 tegmina causing the edge of one of them to act on the tile of the 

 other. 



The mole-cricket, Gryllotalpa vulgaris the Werre of the 

 Germans, Court ilidre of the French is placed with a few 

 allies in a special group, Gryllotalpides, characterised by the 

 dilated front legs, which are admirably adapted for working- 

 underground. Like the mole, this Insect has a subterranean 

 existence. It travels in burrows of its own formation, and it also 

 forms beneath the surface a habitation for its eggs and family. 

 Its habits have been alluded to by Gilbert White, 1 who tells us 

 that " a gardener at a house where I was on a visit, happening 

 to be mowing, on the 6th of May, by the side of a canal, his 

 scythe struck too deep, pared off a large piece of turf, and laid 

 open to view a curious scene of domestic economy : there were 

 many caverns and winding passages leading to a kind of chamber, 

 neatly smoothed and rounded, and about the size of a moderate 

 snuff-box. Within this secret nursery were deposited near a 

 hundred eggs of a dirty yellow colour, and enveloped in a tough 

 skin, but too lately excluded to contain any rudiments of young, 

 being full of a viscous substance. The eggs lay but shallow, and 

 within the influence of the sun, 

 just under a little heap of fresh 

 moved mould like that which is 

 raised by ants." 



The front legs are remark- 

 able structures (Fig. 206), being 

 beautifully adapted for burrow- 

 ing ; the tibiae and tarsi are 

 arranged so as to act as shears 

 when it may be necessary to 

 sever a root. The shear - like 

 action of the tarsus and tibia is 

 very remarkable : the first and 

 second joints of the former are 

 furnished with hard processes, 

 which, when the tarsus is moved, pass over the edges of the 

 tibial teeth in such a way as to be more effective than a 

 pair of shears. In consequence of its habit of cutting roots, 



1 Xatural History of Selborne, Letter xc. 



FIG. 206. Front leg of the mole-cricket. 

 A, outer ; B, iuiier aspect : e, ear-slit. 



