NATURAL HISTORY OF SELBORNE. 57 
—— —_ <2 _ 
LBEERTER Lehx: 
TO THE SAME. 
SELBORNE, August 17t/, 1768. 
DEAR SIR,—I have now, past dispute, made out three distinct 
species of the willow-wrens (so¢acill@ trochili) which constantly 
and invariably 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 three 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 vegulus non cristatus of Ray, 
which he says, ‘‘ cantat voce stridulé locuste”’ Yet this great 
ornithologist never suspected that there were three species. 
* Brit. Zool.,” edit. 1776, 8vo, p. 381. 
