330 



PRINCIPLES OP IMPROVING DOMESTIC ANIMALS. 



tachment, and passing over it of tendons of muscles. 

 Jointed to tlie lower part of the femur is the tibia 

 or great bone of the leg, connected with which, by 

 ligamentous matter, is the small bone termed the fib- 

 ula. These two bones form properly the leg of the 

 horse; but they are, in popular language, termed the 

 thigh, although they correspond not with the bone 

 of the thigh in the human species, but with the leg. 



Next to these bones are those of the hock, which 

 correspond with the bones of the ankle or instep in 

 man; and on one of them the tibia works by means 

 of a hinge joint. They are six in number, and one 

 of them, corresponding with the great bone of the 

 heel in man, projects backwards and has powerful 

 muscles for extending the limb inserted into its ex- 

 tremity, so that it acts as a strong lever in aiding the 

 forward motion of the animal, and as in the fore ex- 

 tremities, we look to the size of the elbow as a point 

 to be regarded, so in the posterior limbs we look to 

 the size of the bone of the heel. 



The posterior extremities differ much from the an- 

 terior, not only in their superior strength, and in the 

 different lengths and directions of the parts, but also 

 in some degree, in their use. 



The femur, or thigh-bone, (3, 4,) is the largest of 

 the body, its vast inden- 

 tations and risings, al- 

 most peculiar to it, show 

 the great strength of the 

 muscles inserted into it. 

 It articulates with the 

 acetabulum, or hip joint, 

 by a strong head called 

 the whirl-bone. In this 

 situation it is held not on- 

 ly by a powerful capsular 

 ligament and still more 

 powerful muscles, but by 

 an admirable contrivance 

 resulting from a ligamen- 

 tous rope, which springs 

 immediately from the 



middle of its head, and is firmly fixed within the 

 socket of th3 joint. In its natural situation it is not 

 perpendicular as the human femur, but inclines to an 

 angle of about forty-five degrees. This bone pre- 

 sents large protuberances for the attachment of very 

 powerful muscles called trochanters. Throughout it 

 exhibits a mechanism uniting the combined qualities 

 of celerity and strength unknown to other animals. 

 The inferior end of this bone is received by its con- 

 dyles into depressions of the tibia, while the patella, or 



knee-pan, slides over the anterior portions of both 

 bones. The patella, (5), which is by farriers called the 

 stifle, is nearly angular, and serves for the insertioD 

 of some of the strongest muscles of the thigh, which 

 are then continued down to the leg. It thus appears 

 to act as a pulley. 



The tibia, or leg bone, (C, 6), is usually, in horse- 

 men's language, called the thigh. It is a bone form- 

 ed of a large epiphysis, with a small attached part 

 called the fibula, (7), a long body, and an irregular 

 inferior end, adapted to the peculiarities in shape of 

 the principle bones of the back with which it artic- 

 ulates. The obliquity in the situation of this bone 

 corresponds with that of the ftmur, being as oblique 

 backwards as the former is forwards. The length of 

 the tibia is a prominent character in all animals of 

 quick progression ; in this respect it corresponds with 

 the fore- arm, and the remarks made on that apply with 

 even more force, to this— that length is advantageous 

 to the celerity, but less so to the ease, of the motion. 



The fibula (7, 7,) forms a prominent instance, in 

 common with the splint bones, of what was remarked 

 in the outset of our osteological detail of the extrem- 

 ities — that many parts, whose uses were not apparent, 

 would be found to be organs of harmony, placed in 

 the body to prevent interruption to the completing 

 the general plan of animal organization. In this way 

 the fibula appears but a process springing from the 

 posterior part of the tibia, forming but the rudimente 

 of the human bone of that name. In the ox it is 

 wanting ; in the dog and cat, as requiring numerous 

 motions in their limbs, it is, on the contrary, perfect. 



The tarsus, or hock, of the horse (10, 10), is a strik- 

 ing instance of the perfect mechanism displayed in the 

 bony structure of this admired animal. It is formed 

 by an assemblage of six bones, and sometimes of 

 seven ; while in the ox, sheep, and deer, there are 

 seldom more than five. Between these bones there 

 is little motion, yet there is sufficient to give a spring 

 to the parts, and to preserve the joints from the effects 

 of shocks, &c. As the human anatomy is generally 

 received as the standard of comparison, we must, in 

 order to a proper consideration of the hock, consider 

 it as the instep and heel ; and all parts beyond it as 

 the foot The human tarsus, and that of some beasts, 

 as the monkey, and some varieties of the bear, makes 

 a right angle with the tibia in standing or walking ; 

 but, in the horse, the hock makes an open angle with 

 the tibia, and is far removed from the ground. In 

 him, and the greater number of quadrupeds, all the 

 bones, from the hock downwards, are much elongated^ 

 and form a part of Ike upright pillar of the limb. In 



