es through life are due to
inevitable wear and tear, scarcity of food-fuel, of water, of rest, and
external accidents--injuries and infectious diseases. Still, it
occasionally happens that these little defects may furnish the point of
least resistance at which external stresses and strains will cause the
machine to break down. They are often the things which prevent us from
living and "going to pieces all at once, all at once and nothing fust,
just as bubbles do when they bust," like the immortal One-Hoss Shay. It
is just as well that they should, for, of all deaths to die, the
loneliest and the most to be dreaded is that by extreme old age.

These _vestigia_ or remnants--instances of apparently hidebound
conservatism on nature's part--are very much in the public eye at
present, partly on account of their novelty and of their exceptional and
extraordinary character. Easily first among these trouble-breeding
remnants is that famous, or rather notorious, scrap of intestine, the
_appendix vermiformis_, an obvious survival from that peaceful,
ancestral period when we were more largely herbivorous in our diet and
required a longer and more complicated food-tube, with larger side
pouches in the course of it, to dissolve and absorb our food. Its
present utility is just about that of a grain of sand in the eye. Yet,
considering that it is present in every human being born into the world,
the really astonishing thing is not the frequency with which it causes
trouble, but the surprisingly small amount of actual damage that arises
from it. Never yet in even the most appendicitis-ridden community has it
been found responsible for more than one half of one per cent of the
deaths.

Then there is that curious and by no means uncommon tendency for a loop
of the intestine to escape from the abdominal cavity, which we call
hernia. This is one of a fair-sized group of dangers clearly due to the
assumption of the erect position and our incomplete adjustment thereto.
In the quadrupedal position this necessary weak spot--a partial opening
through the abdominal wall--was developed in that region which was
highest from the point of view of gravity and least exposed to strain.
In the bipedal position it becomes lowest and most exposed; hence the
much greater frequency of hernia in the human species as compared with
any of the animals.

Another fragment, of the impertinence of whose presence many of us have
had painful proof, is the third or