14-4- THE PASSENGER PIGEON. 



conception." I know that the force of a tornado 

 will break the trunk of a tree two feet in diameter, 

 because its force acts horizontally against the up- 

 right stem ; but how is it possible that a multitude 

 of pigeons, alighting upon a tree, could cause its 

 upright bole, two feet in diameter, to break off at 

 no great distance from the ground ? The branches 

 of the tree, which took their lead diagonally from 

 the bole, might possibly have given way under a 

 heavy pressure, because they were inclined more 

 or less from their perpendicular; but the upright 

 bole itself would stand uninjured, and defy for ever 

 any weight that could be brought to bear upon it 

 from above. 



I now leave the assemblage of wild beasts, the 

 solid masses of pigeons as large as hogsheads, and 

 the broken trunk of the tree two feet in diameter, to 

 the consideration of those British naturalists who 

 have volunteered to support a foreigner in his exer- 

 tions to teach Mr. Bull ornithology in the nineteenth 

 century. 



The passages upon which I have just commented 

 form part of " the facts" on which R. B., in the 

 Magazine of Natural History (vol. vi. p. 273.), 

 tells us that the value of Mr. Audubon's Biography 

 of Birds solely rests. No wonder that, ruit alto a 

 culmine. By the way, I observe, at the end of that 

 Biography, a most laudatory notice by Mr. Swain- 

 son. He tells us that Audubon contemplated Na- 

 ture as she really is, not as she is represented in 

 books : he sought her in her sanctuaries. Well, be 

 it so ; I do not dispute his word ; still I suspect, 



