lOO EVOLUTION, GENETICS, AND EUGENICS 



theless, as some doubt attaches to this particular case, I do not press 

 it — and, indeed, only mention it at all in order that the doubt may be 

 expressed. 



Similarly, I will conclude by remarking that several other instances 

 of the survival of vestigial structures in man have been alleged, which 

 are of a still more doubtful character. Of such, for example, are the 

 supposed absence of the genial tubercle in the case of a very ancient 

 jaw-bone of man, and the disposition of valves in human veins. 

 From the former it was argued that the possessor of this very ancient 

 jaw-bone was probably speechless, inasmuch as the tubercle in existing 

 man gives attachment to muscles of the tongue. From the latter it 

 has been argued that all the valves in the veins of the human body 

 have reference, in their disposition, to the incidence of blood-pressure 

 when the attitude of the body is horizontal, or quadrupedal. Now, 

 the former case has already broken down, and I find that the latter 

 does not hold. But we can well afford to lose such doubtful and 

 spurious cases, in view of all the foregoing unquestionable and genuine 

 cases of vestigial structures which are to be met with even within the 

 limits of our own organization — and even when these limits are still 

 further Hmited by selecting only those instances which refer to the 

 very latest chapter of our long ancestral history. 



