H4 NATURAL HISTORY OF SELBORNE 



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 history ; 

 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 opus, or swift, so 

 many weeks before it's 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 1 (which by the by is at present a 

 non-descript 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, m phalcena, that are of short continuance ; and that 

 the short stay of these strangers is regulated by the defect 

 of their food. 



[It is grievous to see from Dr. Solander's letter in the 

 Gent : Mag : dated from Rio de Janeiro with what insolence 

 the viceroy of Brazil treated those Gent: that have hazarded 

 their lives in pursuit of natural knowledge : & this is not 

 the worst of it : for when they arrive in the South Seas their 

 reception will be just the same from every Spanish Governor 

 from Chile to Mexico.] 



By my journal it appears that curlews 3 clamoured on 



1 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. [G. W.] This 

 forms the postscript to the original letter. [R. B. S.] 



3 See also Letters XXII and XXXVI (pp. 96 and 152). [R. B. S.] 



* The Stone-Curlew or Thick-Knee, (Edicnemus ctdicncmus. [R. B. S.] 



