8 HABITS OP BIRDS. 



not know ; but our ignorance of its real use fur- 

 nishes no support to the conjectural theory which 

 the preceding facts prove to be erroneous, no less 

 than some others connected with cleanliness which 

 we shall now mention. 



The Mohammedan Arabs of the desert, when they 

 cannot procure water to perform the stated ablutions 

 enjoined by the Koran, have recourse to dry sand, 

 with which they rub their bodies as a substitute* ; and 

 it is no doubt as a substitute for washing that some 

 birds, thence called pulverizers (Pulvinatores), are 

 fond of squatting in dust and hustling it into their 

 feathers. Caged larks may thus be seen rubbing 

 their breasts amongst the dry mould at the side of 

 their withered turf with the utmost eagerness. A hasty 

 observer might perhaps be led to conclude that this 

 was done with the design of looking for insects; but 

 the eye of the bird directed away from the spot and 

 expressive of inward pleasure, would show him that 

 such a conjecture could not be supported. A more 

 familiar instance of pulverizing may be observed in 

 the barn-door fowl, even the unfledged chickens of 

 which we have observed muddling in the dust by in- 

 stinct, it should seem, as they were too young to have 

 learned the practice from experience or by imitation. 

 Now, had the feathers of these pulverizers been pre- 

 viously smeared with any unctuous matter, such as 

 that in the rump-gland, the dust would have adhered, 

 and thus tended to soil rather than to cleanse them. 

 The design with which these birds hustle amongst 

 dust is supposed to be to suffocate or banish the bird- 

 lice (Nirmi), with which most birds are infested; on 

 the same principle as swine wallow in the mire, and as 

 the rhinoceros and elephant in Nubia roll themselves 

 in mud to defend themselves from the terrible breeze 



* Volney, Egypt and Syria, vol. ii. ' 



