ON THE VERTEBRATE SKELETON. 335 
proportions*and developes that process from its proximal end, the want of 
_ which in'man and most mammals deceived Vicq d’Azyr, as it has misled, 
more recently, M. Cruvelhier. The complex explanation of the serial homo- 
logies of the bones of the upper and lower extremities proposed by the last 
named pains-taking anthropotomist*, involves more unnatural transpositions 
and combinations of the parts than those of the D’Azyrian hypothesis, which 
its ingenious author could not but admit seemed paradoxical ; viz. that the 
anterior member of one side of the body repeated or corresponded with the 
posterior member of the opposite side. Cuvier, however, seems to sanction 
this idea by repeating the statement of Vicq d’Azyr, “C’est la droite d’une 
paire, qu'il faut comparer 4 la gauche de l'autret.” 
M. Flourens has exposed in detail the fallacies of this view in an excellent 
memoir in the ‘Annales des Sciences’ for 1838 (t. x. p. 35); in which he 
arrives at the same conclusions as Dr. Barclay, and from similar considera- 
tions from Comparative Anatomy, as to the serial homologies of the bones of 
the fore-arm and leg ; and he confirms those of the carpal and tarsal bones, 
which had been so truly and acutely discerned by Vicq d’Azyr. 
In mammalian quadrupeds generally the fore-limb takes the greater share 
in the support, the hind-limb in the propulsion of the body. The manus is 
accordingly-commonly shorter and broader than the pes ; this may be seen in 
the terminal segment of even the monodactyle hand and foot of the horse. 
Consequently the transverse direction prevails in the arrangement of the 
carpal bones and the longitudinal in that of the tarsal bones. 
The difference is least in the carpus and tarsus of the long and slender fore- 
and hind-hands of the quadrumana. If the carpus of the chimpanzee, for 
example, be compared with that of man, the first difference which presents 
itself is the comparatively small proportion of the scaphoid which articulates 
with the radius, as compared with that in man, in whom the distal articu- 
lation of the radius is equally divided between the scaphoides and lunare 
-which are on the same parallel transverse series. In the chimpanzee and 
orang, on the contrary, the scaphoid is elongated, and extends, almost as much 
from the os lunare as from the radius, along the radial side of the carpus, to 
reach the trapezium and trapezoides; it is, as it were, interposed between the 
lunare of the proximal row and the trapezium and trapezoid of the distal row 
of the carpal bones. The similarity of its connections, therefore, in the carpus 
with those of the scaphoid in the tarsus (fig. 25, se.){ is so close that the 
serial homology of the two bones is unmistakeable. The astragalus (2. a), 
then, in the foot, repeats the os lunare (/) in the hand, but usurps the whole 
of the articular surface of the tibia, and presents a larger proportional size, 
especially in man, whose erect position required such exaggerated develop- 
-ment of the astragalus, or homotype of the lunare. The prominent part of 
the calcaneum obviously repeats the prominent pisiforme (p), and the body 
of the calcaneum (cl) articulates with the fibula as the cuneiforme (cz) 
articulates with the ulna. The strain upon the homotype of the pisiforme to 
produce the required effect in raising the back-part of the foot with its super- 
incumbent weight upon the resisting ends of the toes, required its firm 
coalescence with the homotype of the cuneiforme ; in other words, the cunei- 
* “T/extrémité supérieure du tibia est représentée par la moitié supérieure du cubitus, 
et la moitié inférieure du tibia par la moitié inférieure du radius ; tandis que le péroné est 
représenté par la moitié supérieure du radius et par la moitié inférieure du cubitus.”—Anato- 
mie Descriptive, t. i. p. 315. 
+ Lecons d’Anat. Comp. t. i. 1836, p. 342. 
= The carpal and tarsal bones are indicated diagrammatically in fig. 25 ; their ossification 
has not commenced at the period of the embryonic skeleton there represented. 
