146 ON THE CLASSIFICATION OF BIRDS. 
(lucecl by claws which both terminate in remarkably 
acute points, appears at first exceedingly perplexing, 
and may well claim our attention. The explanation 
appears to be this : 1. the claw of the sparrow-hawk, in- 
dependent of its acute point, has two sharp cutting 
edges beneath, one on each side, which are continued 
to the tip ; by this structure it becomes a three-sided 
weapon, and enters the flesh immediately upon the least 
force being applietl ; 2. the claw reaches its termin- 
ation very gradually, so that its power of penetration is 
doubly augmented. No such characters belong to the 
claw of the Jiujihaga ; it has no lateral cutting edges, 
although the sides (occasioned by the flatness of its 
under part) are bluntly angulated ; added to which the 
termination is remarkably abrupt, so that the extreme 
point would act as a little hook, without penetrating 
farther. This, in fact, is established by the experiment 
just alluded to, and which it is in the power of any one, 
having skins of the birds in question, to verify. It is 
quite obvious that if the claws of the liuphaga would 
not excite pain upon the human hand, it would have 
no such effect upon the thick hide of an ox, but rather 
excite an agreeable irritation, like that which is felt on 
scratching an inflamed part of the human body. The 
large Acari of tropical countries are well known to 
create sores, and the gentle irritation round these parts, 
according to every principle of analogy, would have the 
same effect upon the skin of the ox, as upon that of 
the human species. On attentively considering all these 
circumstances, we feel persuaded that the linjihnga not 
only seeks its chief food from the Acari and other 
parasitic insects infecting cattle, but that it actually 
climbs about their bodies for that purpose, in all direc- 
tions ; this latter belief being sanctioned by the great 
development of the hind claw, and its very rigid, 
although not pointed, tail. 
(126.) There is only one other modification of foot 
which seems also belonging to the scansorial type ; this 
