49 DR DAVID HEPBURN ON 
wards as well as upwards, their venter slightly forwards as 
well as downwards, and their fore limbs may be considered 
as an upper pair and their hind limbs as a lower pair. When 
they do not walk on all-fours, they usually get their fore 
limbs clear of the ground by leaning upon a stick, ae, by 
artificially lengthening their fore limbs, or, by balancing 
themselves with outstretched arms, they may stagger along 
with an uncertain gait. 
The attitude of man is in marked contrast to that of the 
ape, for his vertebral column is carried vertically to the 
horizon ; his head is poised on the summit of his spine, his 
dorsum is directed backwards, his venter forwards, his lower 
or hind limbs are used for support and locomotion, and his 
upper or fore limbs principally for prehension. To quote 
the words of the late Professor Goodsir, “ Man alone walks 
erect.” It is to this erect attitude, so characteristic of man, 
that he owes much of his supremacy over the lower animals, 
for he thereby obtains a pair of limbs free to construct and 
handle weapons alike for purposes of offence and defence. 
If we now examine the modifications of man’s skeleton in 
view of his erect attitude, we shall find that his vertebral 
column presents a series of alternating curves impressed 
upon it by the great weight of the head. These curves are 
not found in the spine of any quadruped, and even the 
spinal column of the gorilla only shows a feeble approxima- 
tion to them, Another most important feature of the erect 
attitude is the condition of man’s hip-joint. In him alone 
can the lower limb be extended in a straight line with the 
back-bone, an arrangement which results from the configura- 
tion of the hip-joint, whereby, in the erect attitude, the 
weight of the trunk falls behind the hip-joints, which are 
provided with mechanical arrangements for maintaining the 
erect attitude independently of muscular effort. The atti- 
tude of such a bird as the Penguin must not be confounded 
with that of man, as an examination of the curves of its 
back-bone and the condition of the joints of its lower limb 
will readily show. 
The author then proceeded to point out that, whereas the 
young of most mammals are born provided with the attitude 
of their parents, this is not the case with man, who is not 
