MICROBES, OR BACTERIA. 125 
shell of Rhizopoda, protozoaria or microscopic animals 
which lived in incalculable numbers in the seas of the 
secondary period, and which still live at the bottom 
of oceans. Béchamp holds that the organic substance 
of these rhizopoda, or of the microbes which live in 
their midst, has retained its vitality in the mass of 
chalk, since a freshly cut piece, taken from the quarry 
with all possible precautions to exclude air-germs, is 
able to furnish microbes which multiply rapidly in 
a favourable medium, and produce various fermenta- 
tions. We have already seen that bacteria germs 
resist desiccation, heat, and all kinds of destructive 
influences, and remain for a long while, even for 
several years, in the condition of dormant spores; 
but the existence of spores of the same kind in chalk 
of the secondary period indicates a still more sur- 
prising vitality. It is not, however, inexplicable if 
we suppose that these microbes pass through 
successive periods of activity and repose, and if we 
compare these facts with those presented by the 
microbes of saltpetre, of mineral waters, and of the 
anaérobie microbes, which are able to live when 
deprived of the oxygen of the air. 
Béchamp was the first to observe the presence of 
granulations in coal, which appear under the micro- 
scope to be microbes. These microbes must be far 
more ancient than those of chalk, but they have lost 
all vitality ; it has been found impossible to develop 
them in infusions, and to obtain fermentations from 
