78S 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
originated in tlie habit formed during the earlier struggle with the 
attenuated virus with which the animal had been previously inoculated. 
The behaviour of the leucocytes might be more readily explained by 
assuming that leucocytes had the property, analogous to that possessed 
by the zoosperms of the myxomycetes — namely, that of being attracted 
by certain bodies and repelled by others. MM. Massart and Bordet had 
proved that the products of the microbes exerted a very marked chemical 
action on the phagocytes. When a virus was introduced into the body, 
it proliferated, and secreted a substance which attracted the leucocytes ; 
the more active the virus, the more energetic were the poisons elaborated 
by it, and the cells which penetrated to the point of inoculation were 
paralysed in their action, and rendered incapable of taking up the 
microbes, which therefore proliferated without hindrance. Further, in 
certain diseases the virus produced a substance which was still more 
poisonous. In chicken cholera, for instance, the poison secreted by the 
microbes repelled the leucocytes from the point of inoculation ; it thus 
came about that phagocytes were never found in this particular affection. 
This, however, was not the case with animals which had been rendered 
immune either by inoculation of the attenuated virus, or by the injection 
of a suitable dose of bacterial products. If the animal were given a 
strong virus, phagocytes were attracted to the point of inoculation, and 
these possessed the power of taking up the microbes before they had 
time to elaborate effective doses of their toxic material. It was, there- 
fore, at the commencement of the disease that the critical struggle took 
place. If the leucocytes could not accomplish this at the beginning of 
the malady, their action at a later period would be useless, since the 
microbes would have produced enough poison to paralyse their activity. 
Every cause, therefore, that prevented the access of leucocytes to the 
point of inoculation facilitated infection. The theory of immunity pro- 
pounded by M. Metschnikoff did not exclude the possibility of there 
being other means of protecting the organism, but it simply proved that 
phagocytosis had a wider sphere of action, and was more efficacious, than 
any other means of protecting the organism. It seemed to explain all 
the facts, and was, moreover, eminently suggestive. It was in this way 
that the knowledge of microbic poisons and chemical inoculation had 
thrown light on what would otherwise have been obscure. Far from 
being shaken by the theories which were opposed to it, this theory of 
MetschnikofFs had gained by the opposition which it had met, and that 
was a guarantee of its soundness. 
Dr. Buchner, of Munich, criticized freely Metschnikoff’s views. The 
main objections he brought forward were as follows : — 
(1) Many observers failed to notice any destruction of bacilli by 
phagocytes, when naturally immune animals, such as white rats or 
pigeons, were inoculated with anthrax. 
(2) In diseases ending fatally, such as tuberculosis, mouse-septicaemia, 
&c., the micro-organisms were frequently found in the interior of 
phagocytes. 
(3) The experiments of Petruchky, Baumgarten, Pekelharing, and 
others seemed to show that the bacilli of anthrax perished in the living 
fluids of immune animals even when the bacilli were protected against 
the attacks of white corpuscles. 
