144 THE PASSENGER PIGEON. 
immense beyond conception.” I know that the 
force of a tornado will break the trunk of a tree 
two feet in diameter, because its force acts horizon- 
tally against the upright stem; but how is it pos- , 
sible 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 exertions 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 Bio- 
graphy of Birds solely rests. - No wonder that, 
ruit alto a culmine. . By the way, I observe, at 
the end of that Biography, a most laudatery no- 
tice by Mr. Swainson. He tells us that Audubon 
contemplated Nature 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 
