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MY WORK AND BACTERIOLOGY |— 299 
ally found that microbes are extremely mutable, and 
that the barrier, formerly supposed by many to be 
impassable, between what are known as non-patho- 
genic and pathogenic organisms respectively, has 
been gradually broken down. The development of 
their science has been steadily giving rise to a great 
change of view in this respect, as it is now quite 
easy to show. But if the common ‘harmless organ- 
isms” referred to in the Saturday Revzew article, 
could in any way be gradually transformed so as to 
take on new properties identical with those possessed 
by the organisms associated with this or that con- 
tagious disease, a way would be found for the de 
novo origin of such diseases, though there would 
only be transformation of organisms, by whose aid, 
when thus modified, these same diseases might be 
spread indefinitely from person to person. 
That these are not my views only, but those of 
bacteriologists high in authority may be easily shown. 
It will be easy also to adduce instances in which such 
processes are believed to occur. 
Prof. Hueter said long ago, “Although it is 
impossible not to recognise the specific modes of 
activity of micro-organisms in the production of 
infective diseases, we need not on that account 
. deny that there is a certain unity in all these 
micro-organisms. I am of opinion that this unity 
is founded upon the processes of putrefaction, and 
that the specefic modes of activity must be regarded 
1 “Transactions of International Med. Congress,” 1881, vol. i. 
P- 329. 
