OSTEOLOGY OF BIMANA. 579 



The arrangement of other muscles, in subordination to the 

 peculiar developement of this toe, makes it the chief fulcrum when 

 the weight of the body is raised by the power acting upon the 

 heel, the whole foot of Man exemplifying the lever of the second 

 kind. The strength and backward production of the heel-bone 

 relate to the augmentation of the power. The tarsal and meta- 

 tarsal bones are coadjusted so as to form arches both lengthwise 

 and across, and receive the superincumbent weight from the tibia 

 on the summit of a bony vault, which has the advantage of a cer- 

 tain elasticity combined with adequate strength. In proportion to 

 the trunk, the pelvic limbs, fig. 183, 65-68, are longer than in any 

 other animal; they even exceed those of the Kangaroo, fig. 211, 

 and are peculiar for the superior length of the femur, fig. 183, 65, 

 and for the capacity of this bone to be brought, when the leg is 

 extended, into the same line with the tibia, ib. 66. The inner 

 condyle of the femur is longer than the outer one, so that the shaft 

 inclines a little outward to its upper end, and joins a neck longer 

 than in other animals, and set on at a very open angle. The 

 weight of the body, received by the round heads of the thigh- 

 bones, is thus transferred to a broader base, and its support in the 

 upright posture facilitated. The pelvis is modified so as to receive 

 and sustain better the abdominal \dscera, and to give increased 

 attachment to the muscles, especially the ^ glutei,' which, com- 

 paratively small in other Mammals, are in Man vastly developed, 

 to balance the trunk upon the legs, and reciprocally to move these 

 upon the trunk. In comparison with that of the Apes the Hu- 

 man femur is distinguished by its greater length, both absolute 

 and relative to the trunk, by the more angular and less cylindrical 

 shape of the shaft ; by its forward bend, and the buttress-like deve- 

 lopement of the ' linea aspera ; ' by the greater proportional expanse 

 of the distal end, especially at and above the inner condyle, and 

 by the greater backward production of both condyles, especially of 

 the inner one. Only in the Chimpanzee and Gorilla is the ^ cer- 

 vix femoris ' relatively as long as in Man ; but it stands out at a 

 different angle, and the femora are parallel, fig. 340, 65, not con- 

 verging to the knee-joints, through the double obliquity of ^ neck ' 

 and * shaft ' which characterises the human femur, fig. 183, 65. The 

 great trochanter does not rise so high as the head of the bone in 

 Man : the small trochanter is more prominent and circumscribed. 

 The terminal expansion of the shaft is chiefly toward the inner or 

 tibial side. The major part of the rotular surface is on the outer 

 condyle. 



After the femur, the tibia, 66, is the longest bone of the skeleton 



P P 2 



