MICEOBES, OE BACTEEIA. 125 



stell 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. B^champ 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 precaution^ 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 Ave 

 compare these facts with those presented by the 

 microbes of saltpetre, of mineral waters, and of the 

 anaerobic microbes, which are able to live when 

 deprived of the oxygen of the air. 



Bdchamp 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 



