26 
NATURAL HISTOEY OF SELBORNE. 
I mentioned to you in town. The person that brought me the last says 
they are plenty in harvest, at which time I will take care to get 
more ; and will endeavour to put the matter out of doubt, whether it 
be a nondescript species or not. 
I suspect much there may be two species of water-rats. Eay says, 
and Linnaeus after him, that the water-rat is web-footed behind, ^ow 
I have discovered a rat on the banks of our little stream that is 
not web-footed, and 
yet is an excellent 
swimmer and diver : 
it answers exactly to 
the mus amphibius 
of Linnaeus (see Syst. 
Nat.) which he says 
natat in fossis et 
urinatur." I should 
be glad to procure 
one " plantis palma- 
tis."^ Linnaeus seems 
to be in a puzzle about 
his mus amphibius, 
and to doubt whether 
it differs from his 
mus terrestris ; which 
if it be, as he allows, 
the " mus agi^estis cqpite grandi hrachyuros"'Y of Eay, is widely different 
from the water-rat, both in size, make, and manner of life. 
As to the falco, which I mentioned in town, I shall take the liberty 
to send it down to you into Wales ; presuming on your candour, that 
you will excuse me if it should appear as familiar to you as it is strange 
to me. Though mutilated qualem dices . . . antehac fuisse, tales cum 
sint reliquice ! " 
It haunted a marshy piece of ground in quest of wild-ducks and 
snipes ; but, when it was shot, had just knocked down a rook, which it 
was tearing in pieces. I cannot make it answer to any of our English 
clearer in tone than any of the other warblers, the nightingale excepted ; he is a 
delightful addition to our summer songsters. The black-cap has a very extensive 
geographical distribution, reaching northward to Norway and Lapland, and we 
have good authorities for its occurrence in Africa, Japan, Java, Madeira, and the 
Azores. Mr. Bennet has copied a note from Mr. Rennie's edition, in which the 
latter states : " Dr. Heineken informs us, that it (the black-cap) is stationary in 
Madeira, consequently Sir "W. Jardine is wrong in thinking our birds retire 
thither." We have no doubt whatever in Dr. Heineken being right, but it does 
not follow from that, that some do not migrate there also. The song-thrush 
generally is stationary in Great Britain, but hundreds migrate to and from every 
year, so do goldcrests, and many other species. *' Where it is probable they 
partly retire," are the words of the original note. 
* There is only one species of water-rat in Great Britain, Arvicola amphibius, , 
Desmarest. The feet are not webbed or palmated. The black coloured water- 
rat of the north is now considered as a variety only. 
t In the short-tailed field-mouse, or field-vole, Arvicola agrestis of Fleming and 
Ball. The Rev. Leonard Jenyns has given the distinctions of the British 
arvicolse in " Annals of Nati;ral History," vol. vii. 
WATER-RAT. 
