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(16

Ch. 5

necessarily the result of inheritance from a common progenitor similarly characterised. Such resemblances are more probably due to analogous variation – a subject elsewhere discussed by me * (9) – which follows from co-descended organic beings having a similar constitution & having been similarly acted on by the causes inducing variability. Analogous variations are, also, sometimes the result of reversion. With respect to the similar [word excised] – fore-arms in man & in certain monkeys, as this is common to almost all the anthro=

[121]

=pomorphous apes, it is probably due to direct inheritance; but not certainly so, as some very distinct American monkeys,  all things characterised. The same remark, is applicable to the tailess condition of man; for the tail is absent in all the anthropomorphs apes. Nevertheless this character cannot be attributed with certainty to inheritance from a tailless progenitor, as the tail,

[Descent, p. 194: "It must not be supposed that the resemblances between man and certain apes in the above and many other points—such as in having a naked forehead, long tresses on the head, &c.—are all necessarily the result of unbroken inheritance from a common progenitor thus characterised, or of subsequent reversion. Many of these resemblances are more probably due to analogous variation, which follows, as I have elsewhere attempted to shew,9 from co-descended organisms having a similar constitution and having been acted on by similar causes inducing variability. With respect to the similar direction of the hair on the forearms of man and certain monkeys, as this character is common to almost all the anthropomorphous apes, it may probably be attributed to inheritance; but not certainly so, as some very distinct American monkeys are thus characterised. The same remark is applicable to the tailless condition of man; for the tail is absent in all the anthropomorphous apes. Nevertheless this character cannot with certainty be attributed to inheritance, as the tail, though not absent, is rudimentary in several other Old World and in some New World species, and is quite absent in several species belonging to the allied group of Lemurs."]