OF SELBORNE 79 



came to fix its winter station at such a distance from the 

 water. Was it determined in its choice of that place by 

 the mere accident of finding the potatoes which were 

 planted there ; or is it the constant practice of the aquatic- 

 rat to forsake the neighbourhood of the water in the 

 colder months ? 



Though I delight very little in analogous reasoning, 

 knowing how fallacious it is with respect to natural his- 

 tory ; yet, in the following instance, I cannot help being 

 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 apus, 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 

 hirundines, and the larger bats, are supported by some 

 sorts of high-flying gnats, scarabs, or phalxnse, 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 



* 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. 



