Alfred Russel Wallace: Letters and Reminiscences, Vol. 2 by James Marchant
page 33 of 414 (07%)
page 33 of 414 (07%)
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of Argyll had given that special study to the flight of birds, and
deserved praise for having done so successfully, although he may not have quite solved the whole problem, or have stated quite accurately the comparative importance of the various causes that combine to effect flight. --Believe me yours very sincerely, ALFRED R. WALLACE. * * * * * HERBERT SPENCER TO A.R. WALLACE _57 Queen's Gardens, Bayswater, W. December 5, 1867._ My dear Mr. Wallace,--I did not answer your last letter, being busy in getting out my second edition of "First Principles." I was quite aware of the alleged additional cause of flight which you name, and do not doubt that it is an aid. But I regard it simply as an aid. If you will move an outstretched wing backwards and forwards with equal velocity, I think you will find that the difference of resistance is nothing like commensurate with the difference in size between the muscles that raise the wings and the muscles that depress them. It seems to me quite out of the question that the principles of flight are fundamentally different in a bat and a bird, which they must be if the Duke of Argyll's interpretation is correct. I write, however, not so much to reply to your argument as to correct a misapprehension which my |
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