158 



ANAT03IICAL TECHNOLOGY. 



TrQchitet 



Iroehln. 



EKtrem'tfas 

 proximalia. 



Crista, dakide 



The humerus of the cat presents a subcylindrical shaft — the 



diaphysis, and two enlarged and irregular ends— the Extremitates 



proximales and distales. 



Viewed from the ventral or dorsal aspect, the caudal and ce- 

 phalic outlines of the entire 

 bone are concave, the con- 

 cavity being both greater 

 and more regular on the cau- 

 dal side (on which the three 

 braces are placed). Seen, 

 however, from either the cau- 

 dal or cephalic side, as in 

 Fig. 68 and 70, the dorsal 

 and ventral outlines are 

 S-shaped. On the dorsal 

 side the sharper curvature 

 is near the distal end, while 

 the reverse is the case with 

 the ventral side. In other 

 words, tlie proximal extrem- 

 ity is more enlarged dorsad, 

 and the distal one v en- 

 trad. 



The cat's humerus does 

 not present the appearance 

 of having been tioisted which 

 characterizes that of man 

 and some other Mammals — 

 an appearance which is due, 

 at least in ])art, to the devel- 

 opment of ridges with inter- 

 vening furrows having a 



more or less distinctly spiral arrangement for the attachment or 



accommodation of muscles, vessels or nerves. 



§ 408. Description of Fig. 46. — This represents the ventral aspect of the right 

 humerus, that which is most commonly and fully examined and compared. The same aspect 

 of the left humerus is represented in Fig. 69, and the cephalic, caudal and dorsal aspects 

 in Fig. 68, 70 and 71 respectively. 



§ 409. Cannlis Biripitalis — The bicipital canal or groove (Fig. 30, 45, 46, 69, 70). — 

 This is a marked depression upon the ventro-caudal aspect of the proximal extremity. As 

 better shown in Fig. 45, it lies between the eminences called trochiter and trochin. In the 



epiZrochXean. 



€xtrein.Ltas 

 distaLis. 



'FciSa. ul-narts. 



J' 



CapitiLlu-nii 



Fig. 46.— TnE Ventral (Anterior) Aspect 

 OF AN Adult Right Humerus ; x 1. 



TracUi 



