OF SELBORNE. 67 



LETTER XXIII. 



TO THE SAME. 



Selborne, February 28, 1769. 

 DEAR SIR, 



IT is not improbable that the Guernsey lizard and our green 

 lizards may be specifically the same ; all that I know is, that, 

 when some years ago many Guernsey lizards were turned 

 loose in Pembroke college garden, in the university of Ox- 

 ford, they lived a great while, and seemed to enjoy themselves 

 ' very well, but never bred. Whether this circumstance will 

 prove any thing either way I shall not pretend to say. 



I return you thanks for your account of Cressi-hall ; but 

 recollect, not without regret, that in June 1746 I was visiting 

 for a week together at Spalding, without ever being told that 

 such a curiosity was just at hand. Pray send me word in 

 your next what sort of tree it is that contains such a quantity 

 of herons' nests ; and whether the heronry consists of a whole 

 grove or wood, or only of a few trees. 



It gave me satisfaction to find that we accorded so well 

 about the caprimulgus: all I contended for was to prove that 

 it often chatters sitting as well as flying ; and therefore the 

 noise was voluntary, and from organic impulse, and not from 

 the resistance of the air against the hollow of its mouth and 

 throat. 



If ever I saw any thing like actual migration, it was last 

 Michaelmas-day. I was travelling, and out early in the 

 morning : at first there was a vast fog ; but, by the time 

 that I was got seven or eight miles from home towards the 

 coast, the sun broke out into a delicate warm day. We were 

 then on a large heath or common, and I could discern, as the 

 mist began to break away, great numbers of swallows (hirun- 

 dines rusticce) clustering on the stunted shrubs and bushes, as 

 if they had roosted there all night. As soon as the air became 



