140 



TEE BONES. 



is nearly obliterated ; that the trochanter has subsided nearly to a level with the articulat 

 head ; and that the trochlea is circumscribed by two equal-sized lips. 



The femur of the Camel more nearly resembles that of Man. It is long, slender, and curved 

 backwards. The body is prismatic in its middle portion, and the two br;)nches of the linea 

 aspera meet in the middle and diverge towards the ends. Tlie articular head is very much 

 separated from the trochanter major, which is below the level of the most prominent part of the 

 head. The internal condyle is smaller than the external, and the trochlea is narrow, while its 

 lips are equal. 



B. Pig. — In the femur of the Pig, there is also noticed a supra-condyloid fossa, but it is 

 wide and shallow ; the rugosities of the posterior face are replaced by some salient lines ; the 

 trochanter major is on a level with the head; the latter is supported by a somewhat constricted 

 neck, and is situated within, and in front of, the trochanter major. This latter disposition changes 



the direction of the great axis of the superior extremity, 

 which obliquely crosses tliat of the inferior extremity. 



C. Carnivora. — In the Dog and Cat, the femur is 

 long and curved like a bow. The rugged surfaces of the 

 posterior face are confounded, and furm two crests repre- 

 senting the linea aspera of the human femur. These 

 crests do not lie against eacli otiier in the middle portion 

 of the bone — they are merely parallel ; then they diverge 

 above and below, to terminate beneath the great and 

 small trochanters, and above the two condyles. The 

 trochanter major is not so high as the particular head. 

 Thft femur of Carnivora is also distinguished: 1. By 

 the complete absence of the third trochanter and the 

 supra-condyloid fossa — this last being replaced by a 

 small tubercle, which terminates below the external 

 branch of the linea aspera. 2. By the marked constriction 

 and length of the neck supporting the articular head. 

 3. By the depth of the digital fossa. 



In the Cat and Rabbit are found small bony nodules, 

 embedded like sesamoids in the substance of the lateral 

 ligaments of the femoro-tibial articulation. After mace- 

 ration, they often adhere to the condyles of the femur. 



D. Rodents. — The femur of the Rabbit reseinblea 

 that of the Dog. It is flat before and behind, and more 

 bent inwards at its upper end. The internal trochunter 

 appears as a crest, and not a tubercle ; and the sub- 

 trochanteric crest is very developed, and placed im- 

 mediately below the trochanter major. 



A. - B 



FEMTJR OF THE OAT AND RABBIT. 



I, Femur of the Rabbit. B, Femur 

 of the Cat. 1, Diaphysis ; 2, head ; 

 3, internal trochanter; 4, trochauter 

 major ; 5, subtrochanteric crest ; 

 6, trochlea; 7, internal condyle; 

 8, sesamoid imbedded in the internal 

 ligament of the femoro-tibial articu- 

 lation. 



Leg. 



This has for its base three bones : the tibia, 

 peroneus {gv fibula), and the rotula {or patdla). 



1. Tibia (Fig. 93). 



The tibia is a long prismatic bone, thicker at the superior than the opposite 

 extremity, and situated between the femur and the astragalus, in an oblique 

 direction downwards and backwards, constituting the principal portion of the 

 leg. It has a bodt/ or shaft, and ttvo extremitips. 



Bodf/.—Thk offers for study thref faces and thrpp borders. The faces are 

 wider above than below. The external is almost smooth, and is concave in its 

 superior part and convex below, where it deviates to become the anterior. The 

 internal, slightly convex on both sides, presents, superiorly, deep imprmts for the 

 attachment of the adductor muscles of the thigh and the semitendinosus. The 

 posterior, nearly plane, is divided into two triangular surfaces : one, superior 



