point which has become a kind of settling
basin in the food-tube, its mouth gaping, as it were, to admit any
poisonous or irritating food, infectious materials, disease-germs, the
ordinary bacteria which swarm in the alimentary canal, or irritating
foreign bodies, like particles of dirt, sand, hairs, fragments of bone,
pins, etc., which may have been accidentally swallowed. Once these
irritating and infectious materials have entered it, spasm of its
muscular coat is promptly set up, their escape is blocked, and a violent
inflammation easily follows, which may end in rupture, perforation, or
gangrene.

Not only may any infection which is sweeping along the alimentary canal,
thrown off and resisted by the vigorous, full-sized, well-fed intestine,
find a point of lowered resistance and an easy victim for its attack in
the appendix, but there is now much evidence to indicate that the
ordinary bacteria which inhabit the alimentary canal, particularly that
first cousin of the typhoid bacillus, the colon bacillus, when once
trapped in this _cul-de-sac_, may quickly acquire dangerous powers and
set up an acute inflammation. It is not necessary to suppose that any
particular germ or infection causes appendicitis. Any one which passes
through, or attacks, the alimentary canal is quite capable of it, and
probably does cause its share of the attacks.

Numerous attempts have been made to show that appendicitis is
particularly likely to follow typhoid fever, rheumatism, influenza,
tonsilitis, and half a dozen other infectious or inflammatory processes.
But about all that has been demonstrated is that it may follow any of
them, though in none with sufficient frequency or constancy to enable it
to be regarded as one of the chief or even one of the important causes
of the disease.

One dread, however, we may relieve our anxious souls of, and that is the
famous grape-seed or cherry-stone terror. To use a Hibernianism, one of
our most positive conclusions in regard to the cause of appendicitis is
a negative one: that it is not chiefly, or indeed frequently, due to the
presence of foreign bodies. This was a most natural conclusion in the
early days of the disease, since, given a tiny blind pouch with a
constricted opening gaping upon the cavity of the food-canal, nothing
could be more natural than to suppose that small irritating food
remnants or foreign bodies, slipping into it and becoming lodged, would
block it and give rise to serio