NATURAL HISTORY OF SELBORNE. 57 



LETTER XIX. 



TO THE SAME. 



SELBORNE, August ijt/'i, 1768. - 



DEAR SIR, I have now, past dispute, made out three distinct 

 species of the willow-wrens (inotacillce tro chili) 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 i8th, 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 ths tops of trees in high beechen 

 woods, and rna'tes 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 regulus non cristatus of Ray, 

 which he says, " cantat voce striduld locust <z" Yet this great 

 ornithologist never suspected that there were three species. 



* "Brit. Zool.," edit. 1776, 8vo, p. 381. 



