NATURAL HISTORY OF SELBORNE. 175 



progressive succession. It does not appear that any wheat-ears 

 are taken to the westward of Houghton Bridge, which stands on 

 the river Arun. 



I did not fail to look particularly after my new migration of 

 ring-ousels; and to take notice whether they continued on the 

 downs to this season of the year ; as I had formerly remarked 

 them in the month of October all the way from Chichester to 

 Lewes wherever there were any shrubs and covert : but not one 

 bird of this sort came within my observation. I only saw a few 

 larks and whin-chats, some rooks, and several kites and buzzards. 



About Midsummer a flight of cross-bills comes to the pine- 

 groves about this house, but never makes any long stay. 



The old tortoise, that I have mentioned in a former letter, still 

 continues in this garden; and retired under ground about the 

 2oth November, and came out again for one day on the 3oth : it 

 lies now buried in a wet swampy border under a wall facing 

 to the south, and is enveloped at present in mud and mire ! 



Here is a large rookery round this house, the inhabitants of 

 which seem to get their livelihood very easily ; for they spend the 

 greatest part of the day on their nest-trees when the weather is 

 mild. These rooks retire every evening all the winter from this 

 rookery, where they only call by the way, as they are going to 

 roost in deep woods : at the dawn of day they always revisit their 

 nest-trees, and are preceded a few minutes by a flight of daws, 



that act, as it were, as their harbingers. 



I am, etc. 



LETTER XVIII. 



SELBORNE, Jan. 29*71, 1774. 



DEAR SIR, The house-swallow, or chimney-swallow, is un- 

 doubtedly the first comer of all the British hirundinesj and 

 appears in general on or about i3th April, as I have remarked 

 from many years' observation. Not but now and then a straggler 

 is seen much earlier; and, in particular, when I was a boy I 

 observed a swallow for a whole day together on a sunny warm 



