The Descent of Man

of the Ichthyopterygia possess more than five
digits, and therefore, as I supposed, had retained
a primordial condition; but Prof.
Gegenbaur ('Jenaischen Zeitschrift,' B. v. Heft 3,
s. 341), disputes Owen's conclusion. On the
other hand, according to the opinion lately advanced
by Dr. Gunther, on the paddle of Ceratodus,
which is provided with articulated bony
rays on both sides of a central chain of bones,
there seems no great difficulty in admitting that
six or more digits on one side, or on both sides,
might reappear through reversion. I am informed
by Dr. Zouteveen that there is a case on
record of a man having twenty-four fingers and
twenty-four toes! I was chiefly led to the conclusion
that the presence of supernumerary
digits might be due to reversion from the fact
that such digits, not only are strongly inherited,
but, as I then believed, had the power of regrowth
after amputation, like the normal digits
of the lower vertebrata. But I have explained in
the second edition of my Variation under Do-