12S 



MORPHOLOGY OF THE EOXES OF THE LIMBS. 



to exist, interposed between the bones of the proximal and distal rows, and more 

 immediately between the scaphoid and lunar and the trapezium and trapezoid. 

 This bone is termed the os fcutrale, and several circumstances appear to indicate 

 that it most frequently corresponds to a part of one of the proximal bones. In 

 the carnivora and some other mammals, the scaphoid and lunar are tmited in 

 the adult into one bone, the scapho-lioia)-, and Flower has observed, that in the 

 young' dog there is frequently, but not invariably, a separate ossification in the 

 distal part of the scapho-lunar conresponding in position and relations with the 

 OS centrale of other animals (Flower, Journ. of Anat., vol. iv., 1870) ; and a similar 



Fi- 114. 



Pi..'. 115. 



Fig. 114. — Dorsal Surface of the Right CARPtrg op Man (Flower), i 



s, scaphoid ; I, lunar ; r, cuueiform ; jj, pisiform ; im, traiJezium ; td, traiJezoid ; 

 m, magnum ; u, unciform ; I — V, five metacarpals. 



Fig. 115. — Dorsal Surface op the Carpus op a Baboon (Flower). 



s, scaphoid ; I, lunar ; c, cuneiform ; p, pisiform ; tm, trapezium ; td, trapezoid ; 

 m, magnum ; v, unciform ; rs, radial sesamoid ; ce, os centrale ; I — V, five meta- 

 carpals. 



observation has been made in the carpus of the young lion by Wilder (187:^). 

 But in both of these animals in the adult this piece of bone has become com- 

 pletely ossified, so as to form one with the scapho-lunar. It seems probable that 

 in some animals a central bone may be derived from the separation of the 

 proximal part of the os magnum. 



The detennination of the homology of the navicular bone of the tarsus is not 

 yet fully made out, but it seems most probable that this ))one corresponds not to 

 any single or entire bone of the carpus, but rather to the <« centrale, together 

 with a detached portion of the scaphoid. 



In some animals there is a tenth separate bone of the carpus, which seems 

 most nearly to correspond to the tuberosity of the scaphoid : this constitutes the 

 typical i-(jd'ial8fsa mo id of Gegenbaiu', and the navicular bone of the tarsus may per- 

 haps coiTcspond to this along with the os centrale. It is interesting to remark that 

 this bone is sometimes found separate in the human hand. (See W. Grilber. 

 Struthers, Turner, and others, in Jom-n. of Anat.. and Mivart " On the Ap- 

 pendicular Skeleton of the Primates" in Philos. Trans. 1S()7.) 



The fl.v calfis is generally believed to correspond most nearly with the cuneiform 

 of the cai-pus, and by some it has been held to include the pisiform, — a view not 

 paiticipated in by Gegenbaui-. but of the truth of which any one will be 

 con\dnced by the inspection of the hand and foot of the bear. It is deserving of 

 remark that in the young of that animal, the much enlarged pisifonn possesses 

 an epiphj'sis of its own, exactly sunilar to the one known as existing on the 

 tuberosity of the calcaneum. — a fact observable also in other animals, and which 

 of itself refutes the view taken by some that the pisiform corresponds to the 

 epiphysis of the calcaneal tuberosity. (Allen Thomson.) 



The following tables present a sjTioptical view of the corresponding or homo- 

 logous bones or other parts in the thoracic and pelvic limbs. 



