i6o 



The Theory of Atmospheric Germs. 



[April, 



called spore of Penicillium falling into watery fluid bursts 

 into a multitude of particles, each of which may be the 

 radicle of a living fungus ; the minute particles approximate 

 and unite in twos, forming a double cell ; moreover, they sub- 

 divide excessively rapidly, " so that the number produced 

 can scarcely be expressed " (see fig. 3). The minute particles 

 then unite in chains, constituting Leptothrix, which is not 

 a species but a form of vegetation common to many species. 

 In pure water development can go no farther, nor after a 

 few hours do the organisms continue to be formed ; for 

 further development the presence of a nitrogenous sub- 

 stance is necessary. The minute spherules (micrococci) 

 are the special ferments of putrefaction ; in the presence 

 of sugar the spherule enlarges and becomes a nucleated 

 cell (cryptococcus) identical with the yeast-cell (see fig. 4). 



Fig. 5. 



Fig. 





>© O Q 



deep*?® 



JQ)§ 

 (§3 © Q 0> e 



Cryptococcus in various grades of develop- 

 ment from Penicillium. (Hallier.) 



fP&K 



*8 a v-; ;. 80 d& "** °*° 



Milk ferment. 



A very similar change takes place in oil fermentation. 

 In milk the micrococcus elongates and forms parallelo- 

 pipeds or staff-like cells (see fig. 5) ; in acetic fermentation 

 the cells assume a lancet shape (see figs. 6 and 7). 

 These ferments increase by division, and are classed by 

 Hallier under the term arthrococcus. If we can accept 

 the teaching of the foregoing evidences, fermentation and 

 putrefaction are both due to the influence of a single agent 

 — vitalised matter — which is transported from place to 

 place by the air. We must believe that ordinary air con- 

 tains minute masses of living matter — call these particles 

 germs, germinal matter, protoplasm, bioplasm, or what we 

 will — that they are derived from the fructification of fungi 

 which can spring up wherever nitrogenous organic matter is 

 in contact with air ; that from such fructification it is not 

 the visible spores but minute fragments of these which are 

 the first causes of the subsequent decompositions ; that these 



