94 CORFID.E. 



these, and probably many others equally injurious to vegeta- 

 tion, are searched for and devoured with avidity, forming a 

 very large proportion of the food of this most numerous spe- 

 cies. Early in the morning Rooks visit meadow land while 

 the grass is yet wet with dew, to break their fast on worms 

 and slugs, which the moisture of that period induces to crawl 

 forth. Later in the day, they may be seen either searching 

 newly ploughed ground for the various insects there exposed, 

 or again visiting pastures for other purposes. There they 

 are accused of destroying the grass by pulling it np by the 

 roots ; " but it has been stated, and I believe truly, that 

 this is an error arising out of the following circumstance : — 

 In searching for grubs which are concealed in the earth, and 

 supported by eating the roots of the grass, the Rook pulls at 

 the blade of grass with its bill, and when the grass comes up 

 readily, the bird knows that there are under it insects which 

 have destroyed its roots, and in this way detects them ; but if 

 the blade of grass is firm, the Rook goes to another part of the 

 ground. In a field where grubs are very abundant, the Rooks 

 scatter the grass everywhere, so as to give the appearance of 

 having rooted it up, while they have only exposed the depreda- 

 tions of the insects by which the roots have been destroyed." 

 The author of the Journal of a Naturalist, speaking of the 

 readiness with which Rooks detect the places where grubs 

 are sure to be found, says, " I have often observed them 

 alight on a pasture of uniform verdure, and exhibiting no 

 sensible appearance of feathering or decay, and immediately 

 commence stocking up the ground. Upon investigating the 

 object of their operations, I have found many heads of plan- 

 tains, the little autumnal dandelions, and other plants, drawn 

 out of the ground, and scattered about, their roots having 

 been eaten off by a grub, leaving only a crown of leaves upon 

 the surface." It may readily be supposed that extensive 

 injury at the root of a plant cannot exist long without some 



