26 



Man alone exhibits in infancy and reproduces in later life the 

 ancestral hairy coat of the ear — a fact from which we may perhaps 

 infer that at one time his ears had sufficient lateral projection to 

 need other and more constant protection from the weather than 

 the hair of the scalp afforded. 



The shape of the head of our ancestor who had pointed ears 

 is not knowUj but it is highly improbable that his skull was of the 

 lofty, domed Caucasian type. If it were long and low, somewhat 

 after the style of the Eocene Adapis, the ears would be set much 

 higher in the head than ours, and would get no protection from 

 any hair growing upon the scalp. 



Several contributary pieces of evidence suggest that the 

 external ear is an organ diminished by disuse. Thus, it is no 

 longer functional ; it varies extremely and constantly in shape- 

 and size and in other particulars. It is by its position exposed 

 to sunburn, frost-bite, and injuries of all kinds, yet it is ill- 

 supplied with nerves of sensation and has a poor supply of blood. 

 Consequently it heals slowly when cut. One might compare our 

 external ear to an outpost once important, but now no longer 

 essential, from which the garrison is withdrawing. 



But evidences of degeneration are, for the purposes of this 

 enquiry, negative testimony ; let us seek for something positive as 

 a clue to ancestral shape and size. 



The most puzzling feature seems to be the abrupt counter- 

 march of the hairs upon the back of the helix. No anthropoid 

 or other quadrumanous animal, so far as my limited observations 

 extend, shows anything analogous. The arrangement is useless, 

 is not ornamental, but is so persistent that one is driven to 

 believe that its history, if decipherable, would throw light upon 

 the condition of the organ in past times. 



The theory which I propound upon this growth is sub- 

 mitted with extreme diffidence. 



This countermarch is in its incipience simply a divergence 

 or radiation of the lines of growth of the hair, such as is found 

 upon all funnel-shaped hairy ears where the diameter increases 

 outwards from a short tubular concha to a larger expansion. 

 This radiation is found among the hairs on the back of the human 

 ear, the growth starting spirally at the junction of the head and 

 concha, and diverging outwards, some to the one side of Darwin's 

 Point, some to the other. 



The divergence is easily explained, but the subsequent con- 

 vergence requires consideration. The convergence of the hairs, 

 as the curl in the helix is reached, suggests (as other phenomena 

 have already suggested) that this infolded rim is an atrophied 



