106 NATURAL HISTORY 



this neighbourhood about Michaelmas are 

 not English birds, but driven from the more 

 northern parts of Europe by the frosts, are 

 still more reasonable ; and it will be worth 

 your pains to endeavour to trace from 

 whence they come, and to inquire why 

 they make so very short a stay. 



In your account of your error with re- 

 gard to the two species of herons, you in- 

 cidentally gave me great entertainment in 

 your description of the heronry at Cressi^ 

 hall ; which is a curiosity I never could 

 manage to see. Forescore nests of such a 

 bird on one tree is a rarity which I would 

 ride half as many miles to have a sight of. 

 Pray be sure to tell me in your next whose 

 seat Cressi'hall is, and near what town it 

 lies.* I have often thought that those vast 

 extents of fens have never been sufficiently 

 explored. If half a dozen gentlemen, fur- 

 nished with a good strength of water-spa- 

 niels, were to beat them over for a week, 

 they would certainly find more species. 



There is no bird, I believe, whose man- 



* Cressi'hall is near Spalding, in Lincolnshire. 



