THE PAST EVOLUTION OF MAN 85 



Nevertheless, it is quite erroneous to suppose that 

 man has " lost his tail ": as erroneous as the explana- 

 tion — on Lamarckian principles — of this supposed 

 loss : that when man took to sitting his tail tended 

 to be rubbed away, and that this acquired character 

 was transmitted by heredity to his descendants. 



In point of fact, man still has a tail. In the 

 early stages of the development of the human 

 individual, this tail is actually visible and unmis- 

 takable—in accordance with the recapitulation 

 theory. At the (intra-uterine) age of four weeks, 

 the human tail is twice as long as the legs. But 

 even when we come to examine the adult we find 

 the imperfect skeleton of a tail — and more than the 

 skeleton. 



The human spinal column is terminated in the 

 adult by four degenerate and fused vertebras, the 

 single bone which, in the adult state, results from 

 their fusion being known as the coccyx. This 

 bone is curved, its front surface being concave 

 forwards, and thus it is both hidden and functionless 

 in man. Pain in this region is not infrequently 

 relieved by the surgeon, who excises the bone. 

 Only those individuals upon whom this operation 

 has been performed are properly to be called tail-less. 

 The rest of humanity can no more be denied 

 possession of a tail, because it is hidden and useless, 

 than the whale can be denied possession of hands 

 because they have ceased to indicate their existence 

 externally and are of no functional importance 

 to him. 



I have said that we possess more than the mere 

 skeleton of the tail. We also possess muscles 



