Char I. 
RUDIMENTS. 
29 
“ ‘ family vault.’ Again, M. Dupont found 30 per cent. 
“ of perforated bones in the caves of the Valley of the 
“ Lesse, belonging to the Reindeer period ; whilst M. 
“ Leguay, in a sort of dolmen at Argenteuil, observed 
“ twenty-five per cent, to be perforated ; and M. Pruner- 
“ Rey found twenty-six per cent, in the same condition 
iC in bones from Vaureal. Nor should it be left unno- 
“ ticed that M. Pruner-Rey states that this condition is 
• ‘ common in Guanche skeletons.” The fact that ancient 
races, in this and several other cases, more frequently 
present structures which resemble those of the lower 
animals than do the modern races, is interesting. One 
chief cause seems to be that ancient races stand some- 
what nearer than modern races in the long line of 
descent to their remote animal-like progenitors. 
The os coccyx in man, though functionless as a tail, 
plainly represents this part in other vertebrate animals. 
At an early embryonic period it is free, and, as we have 
seen, projects beyond the lower extremities. In certain 
rare and anomalous cases it has been known, according 
to Isidore Geoffroy St.-Hilaire and others, 39 to form a 
small external rudiment of a tail. The os coccyx is 
short, usually including only four vertebrae : and these 
are in a rudimental condition, for they consist, with the 
exception of the basal one, of the centrum alone. 40 They 
are furnished with some small muscles ; one of which, as 
I am informed by Prof. Turner, has been expressly 
described by Theile as a rudimentary repetition of the 
extensor of the tail, which is so largely developed in 
many mammals. 
The spinal cord in man extends only as far down- 
wards as the last dorsal or first lumbar vertebra ; but a 
39 Quatrefages Las lately collected the evidence on this subject. 
‘Revue des Cours Scientifiques/ 1867-1868, p. 625. 
40 Owen, ‘ On the Nature of Limbs/ 1849, p. 114. 
