1 855.] A nthropoid Apes, and their relations to Man. 33 



with the apes. The great difference is the predominant develop- 

 ment of tlie permanent canine teeth, at least in the males of the 

 orangs and chimpanzees ; for this is a sexual distinction, tlie 

 canines in the females never presenting the same large proportion. 

 In man, the dental system, although the formula is the same as in 

 the apes, is peculiar for the equal length of the teeth, arranged in 

 an uninterrupted series, and shows no sexual distinctions. The 

 characteristics of man are exhibited in a still more important degree 

 in the parts of the skeleton. His whole framework proclaims 

 his destiny to carry himself erect ; the anterior extremities are 

 liberated from any service in the mere act of locomotion, and are 

 perfected to be the fitting instruments of the rational mind and 

 free will with which he is endowed. The speaker proceeded to 

 trace these modifications from the foundation upwards. 



With regard to the foot, it had been shown in a former discourse 

 *' On the Nature of Limbs," that in tracing the manifold and pro- 

 gressive changes of the feet in the mammalian series, in those forms 

 where it is normally composed of five digits, the middle is usually 

 the largest ; and this is the most constant one. The i^iodifications 

 in the hind foot, in reference to the number of digits, are, first, 

 the reduction and then the removal, of the innermost one ; then 

 the corresponding reduction and removal of the outer one ; next, 

 of the second and fourth digits, until it is reduced to the middle 

 digit, as in the horse. 



The innermost toe, the first to dwindle and disappear in the 

 brute series, is, in man, developed to a maximum of size, becoming 

 emphatically the " great toe," one of the most essential cha- 

 racteristics of the modifications of the human frame. It is 

 made the powerful fulcrum for that lever of the second kind, 

 which has its resistance in the tibio-astragalar joint, and the power 

 applied to the projecting heel-bone : the superincumbent weight 

 is carried further forwards upon the foot, by the more advanced 

 position of the astragalus, than in the ape tribe ; and the heel-bone 

 is much stronger, and projects more backwards. 



The arrangement of the powerfully-developed tarsal and meta- 

 tarsal bones is such as to form a bony arch, of which the two piers 

 rest upon the proximal joint of the great toe and the end of the 

 heel. Well -developed cuneiform bones combine with the cuboid 

 to form a second arch, transverse to the first. There are no such 

 modifications in the orangs, in which the arch, or rather the bend 

 of the long and narrow sole, extends to the extreme end of the long 

 and curved digits, indicating a capacity for grasping. Upon these 

 two arches the superincumbent weight of man is solidly and 

 sufficiently maintained, as upon a low dome, with this further 

 advantage, that the different joints, cartilages, coverings, and 

 synovial membranes, give a certain elasticity to the dome, so that 

 in leaping, running, or dropping from a height, the jar is diff'used 

 and broken before it can be transmitted to affect the enormous 



Vol. II. ^D 



