12 PROFESSOR OWEN ON THE OSTEOLOGY OF 



niinent lateral ridges, bounding and deepening the groove for the flexor tendons : the 

 massive quadrate proportions of these bones are also very striking. The same characters 

 are shown, in a minor degree, by the second phalanges, with greater predominance of the 

 transverse over the antero-posterior diameter : the third phalanges are chiefly charac- 

 terized by their more slender tapering shaft, and their more tuberous and less flattened 

 terminations, than in Man. 



In the Gorilla the hand is an instrument for great power of grasp, and for sustaining 

 on the metacarpals of the fore fingers great weight : the length and strength of the 

 whole pectoral limb accord with these mechanical powers and requirements. In Man the 

 framework of the hand bespeaks an organ of varied and delicate prehension ; and the 

 form and proportions of the whole upper limb relate to the free motions and complex 

 functions of the instrument. 



The bones of the hand in the Chimpanzee agree in most particulars with those of 

 the Gorilla ; but they depart further from the Human type and approach nearer to that 

 of lower Quadrumana in the shorter thumb, and in the greater length, in proportion 

 to the breadth, of the whole hand. 



Bones of the Lower Limb. 



Os innominatum. — Plate VI. 



The ilium being the homotype or correlative of the scapula, the ischium of the 

 coracoid, and the pubis of the clavicle, I commence therewith the description and 

 comparison of the bones of the lower limb. In the upper limb the coracoid becomes 

 confluent with the scapula, the clavicle remaining free ; but in the lower limb the 

 ilium, ischium, and pubis coalesce with each other, forming that single composite bone 

 which in Anthropotomy is specified as the ' os innominatum.' 



The iliac portion of the bone shows in the Human species alone that degree of 

 expansion and forward inflexion of its upper and anterior border occasioning the 

 form that suggested the term ' pelvis ' or basin for the segment of the skeleton com- 

 posed of the ossa innominata and sacrum (PI. XII. fig. I). Every ape, until the Gorilla 

 became known to the anatomist, had presented an iliac bone, not only long and narrow, 

 but flat, or, if hollow, with the concavity directed backwards instead of forwards. Such 

 is the strictly quadrumanous condition of the bone in the common Chimpanzee (Tro- 

 glodytes niger, PI. VI. fig. 3), as well as in the Orang-utans and Gibbons. In the 

 Gorilla the iUac bone {ih. fig. 1, a, b, c d), besides showing a greater relative breadth 

 in proportion to its length than in the Chimpanzee, has the upper and outer border 

 a little bent forward (PI. XII. fig. 2), giving a moderate concavity or pelvic character 

 to that part of the skeleton ; it is, however, much inferior in degree to the Human 

 pelvis. 



The difference of size between the os innominatum of the Gorilla and that of Man 

 is enormous : this part of the great ape's frame would fit a human giant of ten feet in 

 height. But, besides size, there are well-marked differences in form and proportion. 



