80 



THE STRUCTURE OF MAN 



( = cuboid in the pes). The last-named bone (4 and 5, Fig. 57) 

 gives articulation to two metacarpals, viz. the 4th and 5th, and 

 its originally double nature is thus indicated. This is shown 

 (apart from comparison with the carpal skeleton of the lower 

 Vertebrata) by the occasional division of this bone into two, not 

 only in Man, but in the most varied Mammals (Marsupials, 

 Eodents, Cetacea). 



All who are in any degree acquainted with Comparative 

 Osteology, know what a great part is played by the os^centrale as 

 a component of the carpus and tarsus. To Gegenbaur belongs 

 the honour of having first recognised and appreciated this. 

 All investigations made after the year 1864 had to start from 



4+0 



FIG. 57. DIAGRAM OF THE HUMAN CARPUS. A, EMBRYO ; B, ADULT. 

 rd., radius ; ul., ulna ; u, ulnare (cuneiform) ; i, intermedium (lunar); r, radiale (scaphoid); 

 p, pisiforme ; 1, 2, 3, carpalia (trapezium, trapezoid, and magmim) ; 4 + 5 = united 

 4th and 5th carpalia (represented in the adult by a single bone, the uueiform) ; c, 

 centrale, which fuses later with the radiale (scaphoid) ; i to v, digits. 



the broad basis laid down in his extensive researches into the 

 limb-skeleton of representatives of the chief types of terrestrial 

 Vertebrata. In only one of these was Gegenbaur unable to reach 

 a perfectly satisfactory conclusion, and that was in Man himself. 

 It was reserved for Eosenberg, ten years later, to establish the 

 fact, that the centrale in an early stage of development (i.e. at the 

 beginning of the second month of intra-uterine life) is a distinct 

 carpal element. By this discovery the chain was completed, 

 Man forming the last link. 



Eosenberg's discoveries were soon confirmed and extended by 

 other anatomists, among whom may be mentioned Leboucq and 

 von Bardeleben. The former proved that the centrale did not 

 vanish, as Eosenberg believed, i.e. it was not resorbed, but incor- 

 porated into the radiale (scaphoid) in the second half of the third 



