47 
1889-90.] Dr G. E. C. Wood on Enzyme Action. 
important a role to the toxines is indicated by the varying grades of 
virulence of the organism which at present may he said almost 
certainly to depend on the production of varying quantities of the 
poison, and by the fact that when a tolerance of the specific poison 
has been acquired either by a passing attack or by the previous intro- 
duction of the toxine, the disease germ loses its power of invading 
that animal. The microbe under such circumstances need not 
immediately perish, but may, and probably usually does, undergo a 
gradual process of attenuation from the increased reactive powers of 
the tissues, and then falls a victim to the “ phagocytes ” as does an 
ordinary saprophyte, or even a foreign body. This has been shown 
by Hueppe and myself* to be the case when animals have been 
rendered only partially immune to anthrax, the course of the disease 
is then much prolonged, and when death does occur the microbe is 
found to have become attenuated.! An Italian observer]: has 
rendered it probable that in a precisely similar way anthrax, when 
grown with another organism, whose products exerted no injurious 
action on it, undergoes a slow attenuation, an effect which we must 
ascribe apparently to the direct action of the one cell on the other. 
There is accordingly, as already asserted, no reason to assume that 
any other forces come into play in the destruction of disease germs 
in the animal body than those we see operating in our cultures. 
From a review of what has been said on the subject of enzymes, 
it is evident that very much less value attaches to the power of 
liquefying the gelatine, as indicating a fundamental distinction 
between two organisms, than that which is usually accorded to it. 
It is a property which is liable to great fluctuations in the degree of 
its development, each organism in this respect exhibiting specific 
idiosyncrasies ; and although the normal degree of development 
usually tends to return under cultivation, yet, as in the case of 
the anthrax vaccines, the lower grade may be retained with great 
* “Saprophytismus und Parasitismus,” Berliner Tdin. Woch., No. 13, 1889. 
t Since then, it has been shown by Woodhead and myself (Comptcs Rendus , 
Dec. 23, 1889) that, if the toxine is antagonised, the tissues are able to come 
into action, and we have either complete recovery, or the disease is mitigated 
or prolonged in its course ; the microbes on the death of the animal being then 
found to have undergone a process of attenuation by the action of the cells. 
X “ Sur la concurrence vitale des bacilles la fifevre Typhoide et du bacille 
Charbon,” Giorn. Internaz., ix., 1887. 
