'I III 



In the r,i/ tin iv an? iilno eight bones. Tho secoml, or pyramidalis, of the U|I]H i 



d> \. !o|n-d : it ixvupii > all tin' external IxinltT of tin- carpus, and articnl.iti-.- \N itli 

 tlit- ulna tin- tii>t l>oiie of the second row, and the tir.-t m< t ^carpal. Tho super* 

 IHIIK-, elongated, prismatic, and thickened ut its extremities, offer* in front two coal, 

 articular facets, one to convs|ond \vitli the ulna, tin- other to join tin- /<;//-n//i/W<///v 

 Tin- I "Hies c.f the inferior row decr< a-e in thickness from tho first to the fourth, and 

 -jtond: the first, to the first and second mctacarpals ; the second, t> the nn-tac- irp .1 

 i.f the third di</it; the third, to that of the fourth digit; the 

 Fig. ">;{. fourth, to the nictacarpul of tin- thumb. 



^ In the lh*\ there are only seven lmcs, as tho scaphoid 



and scmilunar IHHICH are united, but the general di.-]Ni.-ition 

 it) tho same an that in the < 'ni. 



Lastly, in the Ox and Slwep the carpus is oidy coin; 

 of six bones: four in the upper row, and only two in the 

 lower, where the os magnum and trajx-zoide.- areenn.-ol'dated. 

 The supercarpal bone has no groove for gliding, and the 

 pyramidalis articulates with the radius and cubitus. The 

 bones of the lower row only articulate with the principal 

 metacarpal bone. (Professor Gobaux, in 1865, exhibited 

 specimens which go to prove that of the two bones f the 

 lower row in the carpus of Ruminants, the internal really 

 represents two; so that these animuls actually have 

 carpal bones like the Horse.) 



2. Metacarpal bones. The number of metacarpal bones 

 varies much in the domesticated animals: 



In the Carnivora there are 5 



In the Pig there arc 4 



In Ruminants there are 2 



The five metacarpals of the Dog and Cat articulate with 

 each other, at their superior extremities, by lateral facets; 

 they offer, at their inferior extremity, a condyle prolonged 

 backwards by an articular surface resembling that of the 

 Horse. The middle two are always longer than the two 

 lateral. The smallest belongs to the fifth digit, or thumb, 

 and is terminated inferiority by a trochlea. 



The four metacarpals of the Pig articulate with each other, 

 as in the Carnivora. The second and third are larger than the 

 first and fourth. The fifth metacarpal is not developed. 



In Ruminants the metacarpal bones are two in number : 

 a principal, which itself results from the consolidation of the 

 second and third metacarpals, and another altogether rudi- 

 mentary. 



The principal metacarpnl is channeled on its anterior face, 

 and for its whole length, by a deep vascular fissure a trace 

 FORK-ARM AND FOOT OF o f the primitive separation of the bone in two pieces. This 

 THE DOG ; ANTERIOR fissure presents, inferiorly, the anterior orifice of a canal that 

 FACE - completely traverses the bone. The posterior face is :il-> 



1, First digit; 2, Second marked by a very slight longitudinal groove. Tho sujx-rior 

 digitj 3, Third digit; extremity exhibits, externally and posteriorly, a single diar- 

 throdial facet for the articulation of the rudimentary meta- 

 rarpal. The inferior extremity is divided by a deep notch 

 into two articular surfaces, which together resemble the single 



bones of the lower row surface in the Horse ; each corresponds to one of the digits ; 

 of carpal bonus; 10,11, the external is always smaller than the internal. In the 

 First and second bones foetus, the two long bones that form the great metacarpal 

 of the upper row; 12, are simply laid together, and their medullary canals are 

 Supercarpal bone ; 13, rated from each other by the double partition which results 

 Body of the ulna; 14, from this apposition ; after their coalescence, however, the par- 

 Ape of the olecranon ; titions are completely destroyed by resorption. and in a short 

 15, Beak of the olecra- time there is only a single medullary canal for the entire IM.IK . 

 non; 16, Body of the The rudimentary m< tacarpal is only a small osseous btylct, 

 radius. articulating, by a diarthrodial facet, behind and to the outsidfl 



of the superior extremity of the principal metacarpal ; it is 

 sometimes absent in the Sheep and Goat. 



4, '. mirth uigit ; 5, 

 Thumb; 6, 7, 8, 9, First 

 second, third, and fourth 



