The Complete Work of Charles Darwin Online

RECORD: Darwin, C. R. 1851.10. There is great difference in saying a Reptile cd turn into a Bird & saying they may have descended from common stock. CUL-DAR205.9.242. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)

REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 9.2021. RN1

NOTE: The brown crayon number '22' indicates that this document was filed by Darwin in his portfolio for the subject of Palaeontology: extinction.

Reproduced with permission of the Syndics of Cambridge University Library and William Huxley Darwin. The volume CUL-DAR205.9 contains notes on palaeontology and geology [regarding theory of evolution].

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[in margin:] 22

Oct /51/ There is great difference in saying a Reptile cd turn into a Bird & saying they may have descended from common stock. If we must take an existing form take Owen's Pouters! & convert them in either class - or the Ornithological although, these creatures have probably been specialised, for none of the higher animals seems to keep unchanged from the earliest times.

N.B. to show how imperfect Geolog Records - one look at Geolog. map of world & see small area of each formation, & then ask at each period

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separated by each formation - over whole ocean of that period, are we to suppose formations were formed & since removed. Surely more probable that formations formed only here & there, though of course over larger extents than now preserved.

Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)