EVIDENCES FROM MORPHOLOGY 163 
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 limited by selecting only those instances which refer to the 
very latest chapter of our long ancestral history. 
