A Plea for the Rooks. 571 



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 every- 

 where, so as to give the appearance of having rooted it up, while 

 they have only exposed the depredations of the insects by which 

 the roots have been destroyed/ The author of the c 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 ex- 

 hibiting no sensible appearance of feathering or decay, and imme- 

 diately commence stocking up the ground. Upon investigating 

 the object of their operations, I have found many heads of plain- 

 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 alteration in the appearance 

 of the leaves, or other parts, above ground, and the Rooks seem to 

 have learned by experience hew to select those plants which are 

 the most likely to afford them some recompense for the trouble 

 they take in grubbing them up. Jesse,* in his instructive 'Glean- 

 ings,' says : ' A gentleman once showed me a field which had all 

 the appearance of having been scorched, as if by a burning sun in 

 dry hot weather : the turf peeled from the ground as if it had 

 been cut with a turfing spade, and we then discovered that the 

 roots of the grass had been eaten away by the larvae of the cock- 

 chafer, which were found in countless numbers at various depths 

 in the soil. This field was visited by a great quantity of Rooks 

 (though there was no rookery within many miles of the neighbour- 

 hood), who turned up, and appeared to devour the grubs with 

 Jesse's * Gleanings in Natural History,' p. 30. 



