WATER-EFT WILLOW-LARK. 49 



this invaluable nostrum for his own emolument ; or, at least, 

 by some means of publication or other, have found a method 

 of making it public for the good of mankind ? In short, this 

 woman, as it appears to me, having set up for a cancer 

 doctress, finds it expedient to amuse the country with this 

 dark and mysterious relation. 



The water-eft has not, that I can discern, the least appear- 

 ance of any gills ; for want of which it is continually rising to 

 the surface of the water to take in fresh air. I opened a big- 

 bellied one, indeed, and found it full of spawn. Not that 

 this circumstance at all invalidates the assertion that they are 

 larva? ; for the larva of insects are full of eggs, which they 

 exclude the instant they enter their last state. The water-eft 

 is continually climbing over the brim of the vessel, within 

 which we keep it in water, and wandering away ; and people 

 every summer see numbers crawling out of the pools where 

 they are hatched, upon the dry banks. There are varieties of 

 them, differing in colour ; and some have fins up their tail and 

 back, and some have not. * 



LETTER XIX. 



TO THOMAS PENNAN 7 T, ESQ. 



SELBORNE, August 17, 1768. 



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

 distinct species of the willow-wrens, motacilla 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, 



* The eft is liable to a change in the size of its fins during the season 

 of love ; at which time the membranes of the tail and back increase con- 

 siderably. EB. 



f Brit. ZooL edit. 1776, octavo, p. 381. 

 P 



