The Natural History of Selborm 97 



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 of wood, or only of a few trees. 



It gave me satisfaction to find we accorded so well about 

 the caprinntfgns; 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. 1 



If ever I saw anything like actual migration, it was last 

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

 ing ; 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 (hirundines rusticce} 

 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 on the wing at once ; and, by a placid 

 and easy flight, proceeded on southward towards the sea; 

 after this I did not see any more flocks, only now and then a 

 straggler. 



I cannot agree with those persons that assert that the 

 swallow kind disappear some and some, gradually, as they 

 come, for the bulk of them seem to withdraw at once ; only 

 some stragglers stay behind a long while, and do never, there 

 is the greatest reason to believe, leave this island. 2 Swallows 

 seem to lay themselves up, and to come forth in a warm day, 

 as bats do continually of a warm evening, after they have dis- 

 appeared for weeks. For a very respectable gentleman assured 

 me that, as he was walking with some friends under Merton 



1 The night-jar usually churrs when seated (lengthwise) on a bough ; the 

 trilled noise is undoubtedly voluntary, and is a love-call to its mate. ED. 

 2 No swallows winter in England, though a few stragglers may be seen 

 on warm days in late autumn or early spring. ED. 



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