20 
HOUSEHOLD BACTERIOLOGY . 
Food of 
Bacteria 
&€ production 
of Bacteria 
gans like higher plants. They are simply transpar¬ 
ent bits of jelly-like protoplasm. 
Bacteria in general like the same kinds of food that 
man likes, although they do not require the variety 
in diet which to civilized man seems necessary. 
Some flourish best in 
meat juices, others in 
milk, some in starchy 
foods, others in su¬ 
gary solutions, while 
still others enjoy best 
Fi«k 11.. teiffgrcBt Forms of Bacilli. the fats. 
(a) Simple, detached forms. 
(b) Chains of united bacilli. They alsQ s p ow> p ke 
man, a surprising faculty of adaptation. If unable to 
get their favorite food, many will grow on whatever is 
at hand. Any organic substance which is not absolutely 
dry may becorpe food for some species of dust-plants. 
Dust-plants will not leave the moist surfaces upon 
which they fall, but where such surfaces become dry, 
then the plants are ready to be blown into the air by 
winds or carried along on anything which touches 
them. 
Ordinarily dust particles are probably never so dry 
that the bacteria or other micro-organisms clinging to 
them are killed. 
All bacteria reproduce by division of the parent 
into halves, which process is called fission. Fig. io. 
Sometimes these daughter cells remain attached even 
after they themselves have divided into two. A 
