AND CONTENTS OF THE MOUTH. 179 



shall only remark that the pneumococci, or the exciters of salivary 

 septicaemia, being constantly found in the contents of the mouth, 

 are to be held, in our opinion, as one of the forms or phases of 

 the microphite or microphites of the mouth (zoogleic phases of 

 Billet). With regard to all the other bacteria we have just men- 

 tioned, it remains to be observed whether they are accidental — 

 i.e.^ proceeding from without— or normal, although modified in 

 their properties by variable conditions of pabulum or surroundings ; 

 and whether their numerous varieties are perhaps more apparent 

 than specific. 



As regards the experimental inoculations, we shall simply notice 

 the fact that they introduce, under the skin, in the cavity, or in the 

 circulation, all at once, myriads of bacteria. A single centigramme 

 of culture or of polluted material may contain, on an average, 

 twenty-five billions of bacteria, as we have elsewhere demon- 

 strated : and twenty-five milliards inoculated in a mouse are as 

 fifty or a hundred triUions (Italian measure) inoculated in a man. 

 Is it wonderful if local or general effects may be produced from 

 the sudden irruption of such a mass of parasitical germs, even 

 though in themselves innocuous ? Nevertheless, that is not the 

 real question; the real question is whether the different kinds of 

 bacteria (probably belonging to the same species) have the power 

 of attacking, spojitedLud on their own account, the human economy; 

 and whether, even penetrating it from their media, in an infinitesi- 

 mal number (as is the case in the ordinary infectious diseases), can 

 they develop in the human species the same effects following upon 

 the inoculation of their elements on the brutes? 



In other words, one is the receptivity through the natural pas- 

 sages and another through the continuous solutions ; one is the 

 slow, successive, and external action of a few germs, another that 

 of the sudden and internal mass of germs. Finally, one is the 

 receptivity of this or that animal species, and another that of the 

 human species. And all this is irrespective of the other more or 

 less questionable points, and especially of the query : If the mor- 

 bific action of the inoculations depends upon the bacteria, as 

 such, or upon the polluted matter in which they are suspended ; 

 or, it may be, upon their products of secretion and decomposi- 

 tion, as is at the present time generally argued. 



