20 HA.BITS OF BIRDS. 



on a branch, in which case it has the peculiarity 

 of sitting lengthwise, and never, like other birds, 

 in a cross position. It would be interesting to learn 

 whether the Australian Podargus, which wants the 

 pectinated claw, perches in this singular manner. 



The following circumstance, which fell under our 

 observation, appears to show that swallows are not 

 provided with the means of freeing themselves from 

 parasite insects. On going to visit the ruins of 

 Brougham Castle, in Cumberland, we were struck 

 by the unusual tameness of a swallow (Hirundo rus- 

 tica, PLINY), which we found sitting on the parapet 

 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 ra- 

 pidity 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 we were inclined so to 

 interpret its pitiful looks. On taking hold of it, we 

 found the feathers swarming with an insect (Cr#- 

 terina hirundinis, OLFERS), somewhat larger in size 

 than the common house bug (Cimex lectularius) . 

 We 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 required our assistance *. 



The main instrument, however, by which birds 

 trim their feathers is the bill ; and if any fluid is used, 

 it must be produced from the salivaryt, and not from 

 the rump-glands. By attending minutely to the 

 operation, indeed, the tongue may be perceived to be 

 as actively employed as the other parts of the bill, 



* J. R. 



f Huber, De Lingua Pici viridis, and Architecture of Birds, 

 chap. xv. 



