RECORD: Darwin, C. R. n.d. By my theory animals with tibia & fibula separate. CUL-DAR205.5.43. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)
REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 1.2023. RN1
NOTE: See record in the Darwin Online manuscript catalogue, enter its Identifier here. Reproduced with permission of the Syndics of Cambridge University Library and William Huxley Darwin. The volume CUL-DAR205.5 contains notes on the principle of divergence, transitional organs and instincts.
The brown crayon number '11' indicates that this document was filed by Darwin in his portfolio for the subject of Divergence.
[43]
(11) 5
By my theory animals with tibia & fibula separate & with fibula quite anchylosed passed in old ages by insensible series (—& so with Birds & mammalia eyes) but Macrauchenia showing us the transition state is due not necessarily to it being one of the transition forms, but to its having inherited this one part of intermediate structure unaltered: so where we have an intermediate organ in an animal not exactly intermediate between the divisions having
[43v]
the two separate organs in question, we must consider such animal, as a descendant, which has chanced to preserve organ in an unaltered state — it is nothing to point how the animal has acquired this intermediate organ the fact shows possibility of gradation in such organ.—
Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)
File last updated 4 March, 2023