254 OAT THE ORIGIN' 



and multiplying. The particles of this, making their 

 way through the vessels, and escaping, may live for a 

 considerable time, and having entered the blood of 

 another person, may excite in it changes which 

 accompanied their own development. 



Now, an organism which is about to be the subject 

 of an ordinary feverish attack, would probably, if 

 exposed to the influence of contagious disease germs, 

 become the seat of development of a specific and 

 perhaps fatal contagious fever. It is only reasonable 

 to infer that a state of things favourable to the rapid 

 growth and multiplication of disease germs, is not 

 very different from the conditions favourable to their 

 origin. 



It has been already shown that the living pus- 

 corpuscle and the living disease germ, like" every other 

 kind of living bioplasm, have been derived from pre- 

 existing living matter, and it would not be difficult to 

 suggest certain " laws " by which the retrograde evolu- 

 tion of the bioplasm might be said to be governed. 

 But of late so many " laws" have been made, that it is 

 not desirable to attempt to make any new ones. If, 

 at this present time, there is an intelligence sufficiently 

 perfected to reveal to us what kind of new disease 

 germs evolved under the then altered conditions of 

 society will afflict civilized man three centuries hence, 

 and what sort of new contagious diseases they will 

 necessarily excite, it is doubtful if, with the limited 

 powers of understanding with which most of us are 



