14 The Descent of Man. Part 1 



of the panniculus ; they are also variable in development, or ai 

 least iu function. I have seen one man who could draw the 

 whole ear forwards ; other men can draw it upwards ; another 

 who could draw it backwards ;^ and from what one of these 

 persons told me, it is probable that most of us, by often touching 

 our ears, and thus directing our attention towards them, could 

 recover some power of movement by repeated trials. TLie power 

 of erecting and directing the shell of the ears to the various 

 points of the compass, is no doubt of the highest service to 

 many animals, as they thus perceive the direction of danger; 

 but I have never heard, on sufficient evidence, of a man who 

 possessed this power, the one which might be of use to him. 

 The whole external shell may be_cousidered a rudiment, together 

 with the various folds and prominences (helix and anti-helix, 

 tragus and anti-tragus, &c.) which in the lower animals 

 strengthen and support the ear when erect, without adding 

 much to its weight. Some authors, however, suppose that the 

 cartilage of the shell serves to transmit vibrations to the 

 acoustic nerve; but Mr. Toynbee,^" after collecting all the 

 known evidence on this head, concludes that the external shell 

 is of no distinct use. The ears of the chimpanzee and orang are 

 curiously like those of man, and the proper muscles are likewise 

 but very slightly developed."" I am also assured by the keepers in 

 the Zoological Gardens that these animals never move or erect 

 their ears ; so that they are in an equally rudimentary condition 

 with those of man, as far as function is concerned. Why these 

 animals, as well as the progenitors of man, should have lost the 

 power of erecting their ears, we cannot say. It may be, though 

 I am not satisfied with this view, that owing to their arboreal 

 habits and great strength they were but little exposed to danger, 

 and so during a lengthened period moved their ears but Httle, 

 and thus gradually lost the power of moving them. This 

 would be a parallel case with that of those large and heavy 

 birds, which, from inhabiting oceanic islands, have not been 

 exposed to the attacks of beasts of prey, and have consequently 

 lost the power of using their wings for flight. The inability to 

 move the ears in man and several apes is, however, partly com- 

 pensated by the freedom with which they can move the head in 



'' Canestrini quotes Hyrtl. (' An- lately been experimenting on the 



TiiJiric della Soc. dei Natu.-alisti,' function of the shell of the e:ir, 



Slortena, 1867, p. 97) to the same and has come to nearly the same 



eftect. conclusion as that given here. 



2- 'The Diseases f the Ear,' by "> Prof. A. Jhiculister, ' Ann^ils 



J. Toynbee, F.R.S., 1860, p. 12. and Mas:, of Nat. History,' vol. vii., 



A iHstiniruished physiologist, Prof. 1871. p. 342. 

 Prever, informs me that h( had 



