140 ERECT ATTITUDE PECULIAR TO MAN. 



great increase in length, so that it projects much more beyond 

 the forehead. The whole cast of the features is altered at the 

 same time ; so that it approaches more nearly to that of the 

 Baboons, and other inferior Quadrumana, than would be supposed 

 from observation of the young animal only. This increased pro- 

 jection of the muzzle is an evidence of want of perfect adaptation 

 to the erect posture ; whilst the absence of it in Man shows that 

 no other position is natural to him. Supposing that, with a head 

 formed as at present, he were to move on all-fours, so that his 

 face would be brought into the same plane with the ground, as 

 painful an effort would be required to examine with the eyes an 

 object placed in front of the body, as is now necessary to keep 

 the eyes fixed on the zenith ; the nose would be unable to per- 

 ceive any other odours than those which proceed from the earth, or 

 from the body itself, their aperture being directed backwards ; 

 and the mouth could not touch the ground to take up food (which 

 it must have done if the anterior limbs were used for support), 

 without bringing the forehead and chin also into contact with it. 

 131. The vertebral column in Man, though not absolutely 

 straight, has its curves so arranged, that, when the body is in an 

 erect posture, a vertical line from its summit would fall exactly 

 on the centre of its base. It increases considerably in size in the 

 lumbar region, so as to be altogether somewhat pyramidal in 

 form ; and it is set upon the sacrum by a very broad base. The 

 iliac bones are widely expanded, so that the whole pelvis is very 

 broad ; in this manner the hip-joints are thrown farther apart 

 from each other, so as to give a firmer basis of support. The 

 breadth of this is still further increased by the oblique position 

 of the neck of the thigh bone. The position of this bone, in 

 which its head is most secure in its deep socket, is when it is 

 supporting the body in a vertical position, that is, when it has 

 the same direction with the spinal column. In the Chimpanzee 

 and Orang, on the other hand, the most secure position is when 

 the spinal column is bent forwards at an angle upon it ; in several 

 other Mammals, as the Elephant, the spinal column forms a right 

 angle with the thigh bone ; and in many others, as the Horse, 

 Ox, &c., the angle is less than a right angle, the thigh-bone 



