LETTER TO WILLIAM SWAINSON, ESQ. 511 



There is still another process by which an entrance is prepared for 

 birds in the boles of trees. Frequently a large branch fails without 

 any apparent cause, and it remains dead on the tree for many years. 

 At last down it comes, having given way close to the stem. On in- 

 spection, you will find that decay has entered deeply into the tree 

 itself, without any aid from rain-water. The surrounding live wood, 

 which kept swelling gradually while the dead branch remained on 

 the tree, now that the obstruction is removed, begins to advance over 

 the newly-exposed and distempered part. In the meantime, the birds 

 find no difficulty in excavating this part, and there forming a place 

 for incubation, or for a nocturnal residence. Mice and rats will also 

 find their way into these diseased parts of trees. I know of a crab- 

 tree in which a mouse lives. Its hole is about 5 feet from the 

 ground. 



I have written this paper first, to show the true habits of the tit- 

 mouse and the woodpecker, relative to their choice of a place for 

 their incubation ; and, secondly, to catch the eye of the proprietor 

 of the American Quarterly Review, who, I am informed, has thought 

 fit to heap anonymous abuse upon me with an unsparing hand. Let 

 this sage discern er of ornithological merit turn to pages 263-and 343 

 of the " Biography of Birds," and then blush for American ignorance. 



AN ORNITHOLOGICAL LETTER TO 

 WILLIAM SWAINSON, ESQ. F.R.S. 



SIR, I have a crow to pluck with you. As we are both bird-men, the 

 operation will cost us but little time and trouble. 



A recent letter from Philadelphia refers me to your " History and 

 Classification of Birds." " By the by," says the writer of the letter, 

 " this knight of the sublime theory of circles (alluding to you) speaks 

 rather disparagingly of the Yorkshire squire, whom he terms an 

 Amateur." 



