130 HOUSEHOLD BACTERIOLOGY 
Now let us see how these germs are able to do such 
serious damage in the living body. This body is 
made up of a bony framework, around which various 
tissues and organs are securely and compactly grouped. 
Each one of these tissues and organs is composed of 
tiny structures called cells. The cells are little centers 
of energy stored up from the food we eat and the air 
we breathe—little laboratories in which chemical pro¬ 
cesses of the most subtle character are constantly go¬ 
ing on. And the life of the body is simply the sum 
of the more or less independent but co-ordinated lives 
of the cells which compose it, all acting in har¬ 
mony. * * * 
All these delicate and exquisitely adjusted elements 
of the body are able to adapt themselves to many 
vicissitudes without serious disturbance to that sensi¬ 
tive equilibrium which we name health. We may 
starve them, surfeit them, overwork them, and poison 
them in the most abandoned fashion. But they sway 
back to their respective tasks again when our abuse 
ceases. Unless we go too far; and then they may 
struggle on, but only in the halting, perverted way 
which we call disease. 
Now, what happens when into this happy family of 
cells, each nicely adjusted to the others, and all en¬ 
gaged in their various tasks, living bacteria enter, hav¬ 
ing escaped the outer safeguards ? 
But before we try to discover this, let us brush 
away a few cobwebs. 
