68 The Natural History 



inclined to think it may conduce towards the explanation 

 of a difficulty that I have mentioned before, with respect 

 to the invariable early retreat of the hirundo cipus^ or 

 swift, so many weeks before its congeners ; and that not 

 only with us, but also in Andalusia, where they also begin 

 to retire about the beginning of August. 



The great large bat ^ (which by the by is at present 

 a nondescript in England, and what I have never been 

 able yet to procure) retires or migrates very early in the 

 summer : it also ranges very high for its food, feeding in 

 a different region of the air ; and that is the reason I 

 never could procure one. Now this is exactly the case 

 with the swifts ; for they take their food in a more exalted 

 region than the other species, and are very seldom seen 

 hawking for flies near the ground, or over the surface of 

 the water. From hence I would conclude that these 

 hirimdi)ics^ and the larger bats, are supported by some 

 sorts of high-flying gnats, scarabs, or phalcence^ that are 

 of short continuance ; and that the short stay of these 

 strangers is regulated by the defect of their food. 



By my journal it appears that curlews clamoured on to 

 October the thirty-first ; since which I have not seen or 

 heard any. Swallows were observed on to November the 

 third. 



LETTER XXVII 



TO THOMAS PENNANT, ESQUIRE 



Selborne, Feb. 22, 1770. 

 Dear Sir, 



Hedge-hogs abound in my gardens and fields. The 

 manner in which they eat their roots of the plantain in 

 my grass-walks is very curious : with their upper mandible, 

 which is much longer than their lower, they bore under 



^ The little bat appears almost every month in the year ; but I 

 have never seen the large ones till the end of April, nor after July. 

 They are most common in June, but never in any plenty : are a rare 

 species with us. 



