62 THE NATURAL HISTORY 



up that matter, and had some fair specimens ; but, as they were 

 not well preserved, they are decayed already. You will, no doubt, 

 insert it in it's proper place in your next edition. Your additional 

 plates will much improve your work. 



De Bujfon, I know, has described the water shrew-mouse : but 

 still I am pleased to find you have discovered it in Lincolnshire, 

 for the reason I have given in the article on the white hare. 1 



As a neighbour was lately plowing in a dry chalky field, far 

 removed from any water, he turned out a water-rat, that was 

 curiously laid up in an hybernaculum artificially formed of grass 

 and leaves. At one end of the burrow lay above a gallon of 

 potatoes regularly stowed, on which it was to have supported 

 itself for the winter. But the difficulty with me is how this 

 amphibius mus came to fix it's winter station at such a distance 

 from the water. Was it determined in it's 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 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 men- 

 tioned 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 2 (which by the by is at present a non- 

 descript in England, and what I have never been able yet to pro- 

 cure) retires or migrates very early in the summer : it also ranges 

 very high for it's 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 



1 [Some years since I observed the water-shrew (Crossopus fodiens] in the stream 

 which passes in front of the Grange Farm in Selborne. It was hunting at the 

 bottom of the water among the aquatic plants for insects, and was so flattened that 

 the white of the belly was conspicuous as a narrow margin on each side of the black 

 back, forming a striking and pretty object. I found also in my garden a specimen, 

 recently killed, of the black-bellied variety, formerly known as Sorex remifer. It 

 was far from any water. Bell^\ 



2 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. 



