152 The Descent of Man. Pah-i L 



early progenitors ; for it is impossible to study the figures given 

 by Escbricht of the arrangement of the hair on the human foetus 

 (this being the same as in the adult) and not agree with this 

 excellent observer that other and more complex causes have 

 intervened. The points of convergence seem to stand in some 

 relation to those points in the embryo which are last closed in 

 during development. There appears, also, to exist some relation 

 between the arrangement of the hair on the limbs, and the course 

 of the medullary arteries. 9 



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, or of subsequent reversion. Many of these resem- 

 blances are more probably due to analogous variation, which 

 follows, as I have elsewhere attempted to shew, 10 from co-descended 

 organisms baving a similar constitution, and having been acted on 

 by like causes inducing similar modifications. With respect to 

 the similar direction of the hair on the fore-arms of man and 

 certain monkeys, as this character is common to almost all the 

 anthropomorphous apes, it may probably be attributed to in- 

 heritance; but this is not certain, as some very distinct American 

 monkeys are thus characterised. 



Although, as we have now seen, man has no just right to form 

 a separate Order for his own reception, he may perhaps claim a 

 distinct Sub- order or Family. Prof. Huxley, in his last work, 11 

 divides the Primates into three Sub-orders: namelv, the An- 

 thropidse with man alone, the SimiadaB including monkeys of all 

 kinds, and the LemuridaB with the diversified genera of lemurs, 

 As far as differences in certain important points of structure are 

 concerned, man may no doubt rightly claim the rank of a Sub- 

 order ; and this rank is too low, if we look chiefly to his mental 

 faculties. Nevertheless, from a genealogical point of view it 

 appears that this rank is too high, and that man ought to form 

 merely a Family, or possibly even only a Sub-family. If we 

 imagine three lines of descent proceeding from a common stock, 

 it is quite conceivable that two of them might after the lapse of 



9 On the hair in Hylobates, see the Theory of Natural Selection,' 



'Nat. Hist, of Mammals,' by C. L. 1870, p. 344. 



Martin, 1841, p. 415. Also, Isid. 10 'Origin of Species,' 5th edit. 



Geonroy on the American monkeys 1869, p. 194. 'The Variation of 



and other kinds, ' Hist. Nat. Gen.' Animals and Plants under Domesti- 



vol. ii. 1859, }>. 216, 243. Esch- cation,' vol. ii. 1868, p. 348. 

 richt, ibid. s. 46, 55, 61. Owen, H ' An Introduction to the Classi- 



' Auat. of Vertebrates,' vol. iii. p. fication of Animals,' 1869, p. 99. 

 619. Wallace, ' Contributions to 



