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

 least appearance 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 larvse ; 

 for the larv^ of insects are full of eggs, which they 

 exclude the instant they enter their last state. The 

 water-eft is continually climbing over the brims of 

 the vessel within which we keep it in water, and 

 wandering away ; and people every summer see 

 numbers crawling out of the pools w^here they are 

 hatched, up the dry banks. There are varieties of 

 them, differing in colour ; and some have fins up 

 their tail and back, and some have not. 

 Selborne, 27, 1768. 



LETTER XIX. 

 To Tho:^ias Pennant, Esq. 



I HAVE now, past dispute, made out three dis- 

 tinct species of the willow-wrens {Motacillce trocliili) 

 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 



* Brit. Zool., edit. 1776, octavo, p. 381. 

 74 



