40 NATURAL HISTORY OF SELBORNE. 
whence it springs forth on its prey, catching a fly in the air, and 
hardly ever touching the ground, but returning still to the same 
stand for many times together. 
I perceive there are more than one species of the motaczlla 
trochilus. Mr. D2rham supposes, in “ Ray’s Philos. Letters,” that 
he has discovered three. In these there is again an instance of 
some very common birds that have as yet no English name. 
Mr. Stillingfleet makes a question whether the black-cap (sotacilla 
atricapilla) be a bird of passage or not: I think there is no doubt 
of it: for, in April, in the first fine weather, they come trooping, 
all at once, into these parts, but are never seen in the winter. 
They are delicate songsters.* 
Numbers of snipes breed every summer in some moory ground on 
the verge of this parish. It is very amusing to see the cock bird 
on wing at that time, and to hear his piping and humming 
notes. 
I have had no opportunity yet of procuring any of those mice 
which 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. Ray 
says, and Linnzus after him, that the water-rat is web-footed 
behind. Now 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 sus amphibius of Linnzeus (see 
Syst. Nat.) which he says “ zatat in fossis et urinatur.” I should 
be glad to procure one ‘‘Alantis falmatis.”+ Linnzeus seems to be 
in a puzzle about his sus amphibius,and to doubt whether it differs 
from his mus terrestris; which if it be, as he allows, the “‘ mus 
* The black-cap warbler, Sylvéa atvicafilla,Latham, is a rather late summer visitant, 
and his arrival is immediately betrayed either by his song, or by the few peculiar notes 
warbled as he flits from bush to bush. The voice is much clearer in tone than any of the 
other warblers, the nightingale excepted ; he is a delightful addition to our summer song- 
sters. 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 =lack-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 gold-crests, and many other 
species. ‘“‘ Where it is probable they partly retire,” are the words of the original note. 
_t There is only one species of water-rat in Great Britain, Avwicola amphibius, 
Desmarest. The feet are not webbed or palmated. ‘The black coloured water-rat of the 
north is now considered as a variety only. 
