168 Zoological Collections. Veitebrata. 



middle claw is pectinated, and, from the circumstance of its being frequently 

 found with small portions of down adhering to the teeth, is probably employed 

 as a comb, to rid the plumage of its head of vermin, this being the principal 

 and almost the only part so infested in all birds.' * 



" Of another species, called chuck- will's -widow ( C. Carolinensis,) he says, 

 -*• their mouths are capable of prodigious expansion, to seize with more cer- 

 tainty, and furnished with long hairs or bristles, serving as palisades to secure 

 what comes between them. Reposing much during the heat of the day, 

 they are much infested with vermin, particularly about the head, and are 

 provided with a comb on the inner edge of the middle claw, with which they 

 are often employed in ridding themselves of these pests, at least when in a 

 state of captivity.' f Considering the utility of such an instrument, we may 

 wonder, perhaps, that, besides the herons (Ardece,) no other birds are similarly 

 provided for attacking those troublesome insects ^ (Homaloptera, Macleay, 

 Nirmidce, Leach, &c.) which often seriously injure the vigour and health of 

 the animal infested, and sometimes even occasion death. On going to visit 

 the ruins of Brougham Castle, in Cumberland, I was struck by the unusual 

 tameness of a swallow (Hirundo rustica,) which I found sitting on the para- 

 pet wall of the bridge which crosses the Emont, on the road from Penrith. 

 Swallows are, indeed, far from being generally shy, trusting, perhaps, to 

 their rapidity of flight, should danger threaten ; but this poor swallow allowed 

 itself to be approached, without offering to escape. It seemed, in fact, 

 instinctively courting human aid, at least I was inclined so to interpret its 

 pitiful looks. On taking hold of it, I found the feathers swarming with an 

 insect (Craterina Hirundinis, Olfers,) somewhat larger in size than the com- 

 mon house-bug (Cimex lectularius.) I took the poor bird immediately to 

 the river ; and, on being freed from its tormentors, it flew off joyfully to 

 Join its companions. Had it been furnished with a comb, like the night- 

 jars, it would not probably have needed my assistance." 



In the second number of the same Journal, p. 261, it is remarked by Mr 

 Ainsworth, as a fact not generally known, that the claws of most birds are 

 used for similar purposes ; whence it happens that the birds which have 

 short legs, as the swift, are most infested by insects. The expedients 

 resorted to by those birds which have short legs, — by the waders, in conse- 

 quence of the inflexible nature of their legs, — and by the goose tribe, from 

 the difficulty of scratching themselves, occasioned by the membrane which 

 extends between the toes, — are well deserving of attention, as illustrating the 

 ingenuity of animals, and the curious provisions made by Nature for their 

 cleanliness. " When birds," says Mr Ainsworth, " by accident or impri- 

 sonment, are deprived of the natural means of ridding themselves of vermin, 

 they often fall victims to these attacks. Walking one day along the shore 

 of Holy Island, off the coast of Northumberland, I disturbed an ash-coloured 

 sanderling ( Calidris Islandica, Step.) which flew heedlessly and as if injured. 

 On shooting the bird, I found that it was covered with vermin, more espe- 

 cially about the head ; so much so that the poor thing must have eventually 

 fallen a victim to their tormenting ravages. On farther examination, I found 

 that it had lost one of its legs, so that it was to its incapability to rid itself 

 of these insects that their extraordinary increase was to be attributed. 



" A circumstance of a somewhat similar kind also came under my notice, 

 connected with a swallow's nest. After the young birds had been hatched, 

 and had attained a certain size, a change was made in the arrangement of the 

 window, whereby the parents were frightened : from that time they continued 

 to feed their offspring, but never entered the nest ; and I soon observed 

 that the young ones were sick, and one by one they perished. I then took 

 the nest down, and found it crowded with acari, which were of a very great 



* Wilson's American Ornithology, v. 77, f Ibid. vi. 97. 



t Curtorius and several other genera have it. —Ed. 



