'24 WATER-RATS. 



I perceive there are more than one species of the mctadlla 

 trochilus ; Mr Derham supposes, in Ray's Philosophical 

 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 

 (motacilla 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 in all at once into these parts, but are 

 never seen in the winter.f 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 Linnaeus 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 mus amphibius 

 of Linnaeus, (see Syst. Nat.) which, he says, " natat infossis et 

 urinatur" I should be glad to procure one " plantis palmatis" 

 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 agrestis capite grandi brachyuros" 

 of Ray, is widely different from the water-rat, both in size, 

 make, and manner of life. 



As to ihefalco, 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 reliquiae!" 



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 



* The three species are, the one mentioned in the text, the common 

 willow- wren, and the least willow-wren, or chiff-chaff. ED. 



f The black-cap is unquestionably migratory; it appears about the 

 middle of April and retires in September. ED. 



