THE CHIMPANZEES AND ORANGS. 17 



lar ear- 



tlie insertion of the ligamentum teres is relatively larger and deeper. The articuls 

 tilage is co-extensive with the head at the upper half of the ball ; but it is defined by a 

 groove at the lower half from a rough non-articular tract, beyond which the neck begins : 

 the ridge defining the rough tract from the neck is most strongly marked below and behind, 

 where it forms a curve encroaching upon the head ; the non-articular tract of the head is 

 broader before than behind, and the head projects from or beyond the neck at this part. 

 The neck (fig. 6, c), having its least circumference near the head, expands quickly to join 

 the shaft, and much more so vertically than transversely ; so that it is subcompressed, 

 with the anterior and posterior surfaces rather oblique from above downward and back- 

 ward. The upper part of the neck is continued into the fore part of the great trochanter, 

 and forms the pretrochanterian protuberance there ; the lower part curves more rapidly 

 down to the shaft than in the Gorilla or Chimpanzee, the base of the neck being more 

 extensive, especially vertically, than where it expands to join the head. The trochanter 

 presents a rough convex subquadrate surface externally, is very thick and irregular with 

 protuberances and hollows anteriorly, thinner with an obtuse curved border behind, and 

 concave towards the head ; the upper part, terminating in the apex or upper and hinder 

 angle of the trochanter, is bent towards the head, but does not rise so high as that part : 

 on the concave side of the base of the trochanter is a large pit. On the outer convexitv 

 a rising, more or less marked, extends from the upper and hinder angle diagonally to the 

 lower and front angle ; to which rising or line the tendon of the meso-gluteus is attached. 

 On the smoother surface below the line a bursa is placed, over which the tendon of the 

 ecto-gluteus glides to its insertion. The posterior prominent border of the great tro- 

 chanter is continued, with a slight subsidence, to the small trochanter (e) ; which is 

 more prominent in proportion to its size than in the Gorilla or Chimpanzee, and 

 projects and is placed more inwards. A much lower ridge is continued from the upper 

 and fore part of the great trochanter obliquely downward and inward to opposite the 

 lower part of the base of the small trochanter, below which it passes in its way backward 

 to join the linea aspera. In its whole extent this ridge is called the 'spiral line,' and 

 to the upper half is sometimes applied the term 'anterior intertrochanteric line;' but 

 it does not join the small trochanter. Between this and the head is a nearly parallel 

 linear indication of the line of reflexion of the synovial bag : the capsular ligament is 

 attached to the anterior intertrochanteric line. 



The shaft, with a full oval transverse section at its upper fourth, gradually decreasing 

 in breadth, becomes more convex anteriorly in the transverse direction ; and the same 

 section, in the middle two-thirds of the shaft, presents a full pyriform shape, the linea 

 aspera forming the apex. 



A ridge (ecto-gluteal) beginning below the middle of the base of the great trochanter, 

 a rough tract from the small trochanter, and the ' linea spiralis ' converge as they descend 

 to form the ' linea aspera ' {g, g, fig. 6) : this is most prominent along the midde third of 

 the shaft, forming there a production of dense osseous matter, which must afford, like a 



VOL. V. — PART I. n 



