14 FISCHER ON THE PELVIS OF THE MAMMALIA. 



man the crest is 7" 6"' broad, the body only 2" 6'". The external surface is 

 broad in man, and marked with separated fluctuating lines ; in the quadru- 

 mana it is narrow, almost perpendicular, and deeply excavated, especially 

 forwards behind the anterior margin ; this happens especially in the simia 

 sajou and sylvanus. The internal surface is composed, in many quadrumana, of 

 three smaller ones first, an anterior ; second, a posterior and inferior ; and 

 third, a superior and posterior. The superior anterior surface is situated quite 

 anteriorly (this is the rudiment of the larger pelvis. Autenreith.) The poste- 

 rior and inferior surface looks more inwards, (and assists in forming a smaller 

 pelvis. Autenreith) The posterior and superior surface, rough and unequal, 

 forms the articular plane by which the os ilium is united to the os sacrum, and 

 embraces the superior, posterior, and broadest portion of the internal surface. 

 (In this surface is to be included that small portion which, at the back, overtops 

 the os sacrum. Autenreith,) In man, three margins are assigned to the os 

 ilium, an anterior, a superior, and an inferior posterior ; in the quadrumana also, 

 three are present, the anterior, the superior and posterior, which is indeed the 

 inferior margin in man, though being more parallel to the anterior, ought rather 

 to be called the posterior. The anterior margin is comparatively longer than in 

 man, and as long again as the superior. The superior margin, which is very 

 short, runs from the anterior to the posterior spine ; this spine touches, supe- 

 riorly, the os sacrum ; it is straighter in the simise, in some almost horizontal, 

 in others somewhat convex, as in the simia satyrus.* (In the cercopithecus, 

 the superior margin posteriorly is strongly curved downwards, anteriorly 

 making almost a straight line, and passing into the anterior margin of the os 

 ilium almost at a right angle ; as if with a knife you had divided the human 

 os ilium in the middle. Autenreith.) From the posterior spine there next 

 descends the posterior margin ; this is very long and composed of two equal 

 parts, the superior of which is perpendicular and joins the sacrum ; where 

 this articulation ceases the inferior portion of the posterior margin commences, 

 and is first curved anteriorly, then assumes a perpendicular direction as far as 

 the junction with the os ischium, and thus forms the incisura which in man is 

 called the superior ischiatic notch, without the aid of this bone. The varieties 

 in height, length, and breadth of the os ilium in different species of the quad- 

 rumana, may be seen in the annexed table of measurements. 



Section 8. 2. The os pubis does not differ so much in the simiae from the 

 same bone in man as the os ilium. It is also divided into a horizontal and a 

 descending branch. The horizontal branch, extending from the anterior part 

 of the acetabulum to the spinous tubercle of the symphysis pubis inclusive, 

 is in man longer than the descending branch ; in the quadrumana, however, it 

 is shorter, and on its external surface has no crest or fissure. The descending 

 branch commencing at the spinous tuberosity or tubercle, descends, and, with 

 its fellow forms the symphisis pubis, is in the quadrumana much longer ; the 

 symphisis pubis is increased, and at the same time the depth of the pelvis, for 

 the bones of the pubis are connected, not merely by the angles between the 

 descending and horizontal branches, but the descending branches themselves 

 are united throughout their whole length ; nevertheless this structure does not 

 prevail in all, for in the lemur tardigradus they meet only by the angles. By 

 this junction there arises in some that keel formed projection, which is clearly 

 * Camper 1. c., Tab. iii., Fig. 7. A.B.C.D. 



