754 KANSAS CITY REVIEW OF SCIENCE. 
man, in his upright position, they would be very valuable. "To their absence 
in man many a life has been and, will be sacrificed, to say nothing of the discom- 
fort and distress occasioned by the engorgement known as piles, which the pre- 
sence of valves in their veins would obviate." 
A noticeable departure from the rule obtaining in the vascular system of 
MammaHa also occurs to the exposed situation of the femoral artery in man. 
The arteries He deeper than the veins, or are otherwise protected, for the pur- 
pose — as a teleologist would say — of preventing serious loss of blood from super- 
ficial cuts. Translating this view into evolutionary language, it appears that 
only animals with deeply placed arteries can survive and transmit their structural 
peculiarities to their offspring. The ordinary abrasions to which all animals are 
exposed, not to mention their onslaughts upon each other, would quickly kill off 
species with superficially-placed arteries. But when man assumed the upright 
posture the femoral artery, which in the quadrupedal position is placed out of 
reach on the inner part of the thigh, became exposed. Were not this defect 
greatly compensated by man's ability to protect this part in ways not open to 
brutes, he, too, might have become extinct. As it is, this exposure of so large 
an artery is a fruitful cause of trouble and death. 
We may here mention some other disadvantages of the upright position 
which Dr. Clevenger has omitted. Foremost comes the liability to fall due to 
an erect posture supported upon two feet only. Four-footed animals in their 
natural haunts are little liable to fall; if one foot sHps, or fails to find hold, the 
other three are available. If a fall does occur on level ground there is very little 
danger to any mammal nearly approaching man in bulk and weight. Their vital 
parts, especially the heart and the head, are ordinarily so near the ground that 
to them the shock is comparatively slight. To human beings the effects of a fall 
on smooth, level ground are often serious, or even deadly. We need merely to 
call to mind the case of the illustrious physicist whom we have so recently and 
suddenly lost. 
The upright attitude involves a further source of danger. In few parts (if 
any) of the body is a blow more fatal than over what is popularly called the " pit 
of the ' stomach.' In the quadruped this part is little exposed either to acci- 
dental or intentional injuries. In man is quite open to both. A blow, a kick, 
a fall among stones, etc., may thus easily prove fatal. 
Another point is the exposure and prominence of the generative organs, 
which in most other animals are well protected. Leaving danger out of the 
question, it may be asked whether we have not here the origin of clothing ? 
The assumption of the upright posture may have made primitive man aware of 
his nakedness. 
Returning to the illustrations furnished by Dr. Clevenger we are reminded 
that another disadvantage which occurrs from the upright position of man is his 
greater liability to inguinal hernia. In quadrupeds the main weight of the 
abdominal viscera is supported by the ribs, and by strong pectoral and abdom- 
inal muscles. The weakest part of the latter group of muscles is in the region 
