OF COL YM BUS TORQUATUS. 157 



at right angles from the inner aspect of the proximal extremity of the bone. The neck, 

 however, is so very short and thick, and projects so directly inwards, that the head appears 

 to be little more than a stout process of bone. It is, moreover, placed so low down on the 

 femur, that the great trochanter rises very considerably above its level. Its summit is as 

 usual occupied by a fossa for the insertion of the ligamentum teres. 



The trochanter extends upwards and outwards as a stout, somewhat pointed process, 

 and is so large as to seem to form the real " head " of the bone ; from the inner aspect 

 of it the real head appears as a short stout offset. The non-articular surfaces of the 

 trochanter are all roughened for the attachment of muscles. There is no trochanter 

 minor. 



The hip-joint is an exceedingly peculiar and interesting one, from the extent of the 

 trochanteric articulation. The smooth articulating surface of the globular head of the bone 

 is on the superior aspect continued uninterruptedly along the neck of the femur, to spread 

 out on the top of the trochanter into a large, smooth, plane facet, which occupies nearly all 

 the superior surface of that process. 



When the head of the bone is inserted into the circular ring which constitutes the 

 acetabulum, this articulating surface of the trochanter is applied closely to the smooth facet 

 which, as already described, lies above and a little behind the acetabulum, appearing like a 

 continuation from it, which in effect it really is. This abutment of the trochanter against 

 the ilium prevents the small head of the bone from sinking too deep into the cotyle, which 

 it would otherwise do from the very deficient character of this cavity ; and, moreover, 

 upon it seems to be borne the chief pressure of the weight of the body in some of its 

 attitudes. 



From this peculiar construction of the hip-joint, it results that a particular direction is 

 given to the position, and all movements of the femur, and that motion in some directions 

 must be exceedingly free, while in others it is greatly restricted, or wholly arrested. From 

 the direction in which the plane of the trochanteric facet is situated, it results that the most 

 natural and unconstrained position of the femur is outwards, forwards, and downwards, at 

 an angle of about 45° in each of these axes. This remarkable outward position, or great 

 amount of abduction, is necessary to enable the femur to clear the long ribs which project 

 outwards and backwards along its inner aspect, and also contributes its share towards the 

 wide separation of the feet. From this state of permanent abduction, any adduction, or any 

 further abduction, are equally impossible ; for the first would draw away the trochanter 

 directly from its articulation, the latter would pull the globular head directly out of the 

 cotyloid ring. Therefore, though muscles exist which arise from the horizontal ramus of 

 the pubes and are inserted into the femur at various points, and which are really the 

 analogues of our pectineus, adductors, etc., still, their line of traction, resulting from the 

 shape of the pelvis and position of the femur, is such that they pull it almost directly 

 backwards, having little if any adducting power. 



Antero-posteriorly, the normal position of the femur seems to be in a state of semi-flexion 

 forward at an angle of about 45°, Avith of course the divergence downwards and outwards 

 before mentioned. From this position the movements of flexion and extension are quite 

 free, the former particularly so. 



The element of rotation is a very prominent one in the motions of the hip-joint, affording, 

 as we shall presently see, the beginning of the very extensive power of rotation which the 

 whole limb enjoys. A special muscle, the obturator, inserted into the tip of the trochanter, 



