252 ON 7 "HE ORIGIN' 



It is not, I think, possible in the present state of 

 knowledge to reply definitely and conclusively to 

 many of these enquiries ; but it is well that they 

 should be made. And in considering the mode of 

 origin of contagious living matter, to which subject the 

 present section is devoted, it will be my duty to lay 

 before the reader, as simply as I can, the grounds 

 upon which are based the views I have been led to 

 adopt. 



The facts that the living matter of the blood of one 

 individual will live in the blood-vessels of the organism 

 of another ; that skin, periosteum, and other tissues 

 may be transplanted and grafted, prepare us for the 

 acceptance of the remarkable circumstance demon- 

 strated by experiment that living pus bioplasts which 

 have indeed been derived from normal bioplasm, may 

 traverse long distances, free and independent, and 

 then, gaining access to another organism, may live, 

 and grow, and multiply in it, and establish changes of 

 the same kind as those which were taking place at 

 the seat of its origin. 



Many of the lower and simpler forms of life, as is 

 well known, may continue to grow and multiply as 

 larval or imperfectly developed forms, and attain, 

 under altered conditions, a higher and altogether 

 different state of existence, during which the pro- 

 cess of multiplication in that way ceases. It is 

 possible that the exceedingly minute living particles 

 which constitute the " contagium " of contagious 



