62 
NATURAL HISTORY OF SELBORNE 
for tlie quadrupeds of Britain are so few, that every new species is a 
great acquisition. 
The eagle-owl, could it be proved to belong to us, is so majestic a 
bird, that it would grace our fauna much. I never was informed before 
where wild-geese are known to breed. 
You admit, I find, that I have proved your fen salicaria to be the 
lesser reed-sparrow of Ray ; and I think you may be secure that I am 
right, for I took very particular pains to clear 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 its proper place in 
your next edition. Your additional plates will much improve your work. 
\ De Buffon, 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 of the white hare. 
As a neighbour was lately ploughing in a dry chalky field, far 
removed from any water, he turned out a water-rat, that was curiously 
lain 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 ainpldhms mus 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 1 
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 liirundo ajpus, 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 swtfts ; 
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 
liirundines and the larger bats are supported by some sorts of high- 
flying gnats, scarabs, or phaloencE, 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. 
* 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. 
t See also Letters XXII., XXXVL, and note. 
