OF SELBOBNE. 
69 
LETTER XIX. 
TO THOMAS PENNANT^ ESQUIRE. 
Selborne, Aug. 17, 1768. 
HAVE now, past dispute,, made out three 
distinct species of the willow wrens [Mota- 
cillce trochili) which constantly and inva- 
riably use distinct notes. ^ But at the same 
time, I am obliged to confess that I know 
nothing of your willow lark.'^ In my letter of April the 
18th, I had told you peremptorily that I knew your willow 
lark, but had not seen it then : but, when I came to procure 
it, it proved, in all respects, a very Motacilla trochilus; only 
that it is a size larger than the two other, and the yellow 
green of the whole upper part of the body is more vivid, 
and the belly of a clearer white. I have specimens of the 
three sorts now lying before me ; and can discern that there 
are throe gradations of sizes, and that the least has black 
legs, and the other two flesh-coloured ones The yellowest 
bird is considerably the largest, and has its quill feathers 
and secondary feathers tipped with white, which the others 
have not. This last haunts only the tops of trees in high 
beechen woods, and makes a sibilous grasshopper-like noise, 
now and then, at short intervals, shivering a little with its 
wings when it sings ; and is, I make no doubt now, the 
Begulus non cristatus of Ray ; which he says cantat voce 
striduld locustce.^' Yet this great ornithologist never sus- 
pected that there were three species. 
^ See antea, pp. 56, 57. 
2 Brit. Zool. edit. 1776, octavo, p. 381.— G. W. 
^ This is evidently the Wood wren. Ph. nbilatrix. — Ed. 
