OF SELBORNE 57 



LETTER XXIII 



TO THOMAS PENNANT, ESQUIRE 



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 a g niany Guernsey lizards were 

 turned loose in Pembroke college garden, in the university 

 of Oxford, 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 con- 

 sists 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 anything 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 dis- 

 cern, as the mist began to break away, great numbers of 

 swallows (hirundines rusticae] clustering on the stunted 

 shrubs and bushes, as if they had roosted there all night. 

 As soon as the air became clear and pleasant they all were 



