ZOOLOGY AND BOTANY, MICBOSCOPY, ETC. 
729 
organisms, but is also observable between different specimens of tbe 
same species but of unequal virulence. 
Bactericidal Power of the Body Juices.* — With regard to tbe ques- 
tion of immunity, Prof. J. Denys takes up a position between the strict 
phagocytists and the strict kumoralists ; for while he strongly upholds the 
bactericidal power of serum and of lymph, yet he admits that leucocytes 
are capable of destroying microbes. It is needless to remark that his 
position is not agreeable to the chiefs of the two opposing schools, and 
in a short memoir the author replies to Buchner and Metschnikoff. The 
humoralist is displeased with the author for asserting that dog’s serum 
has very little bactericidal action, but that the leucocytes have, and 
would explain the absence of this power by an alteration produced in 
the blood by filtration. But the author replies that the germicidal 
action reappears if leucocytes be restored, and that this action is pro- 
portional to the number present. Though the author accepts phago- 
cytosis, or rather makes use of the term, the phagocyte is not to him 
destructive in virtue of its military powers, but from its power of 
secreting a poison, leucocidine. j This phagocyte is therefore equivalent 
to a wandering gland. The objections of Metschnikoff, four in number, 
are then dealt with. The first of these is that the so-called bactericidal 
action is due to change of medium. The second is that it requires twice 
as much of the germicidal substance to kill the bacteria as to scotch 
them. Thirdly, though blood-serum is bactericidal towards the bacilli 
of anthrax, the spores are unaffected. The fourth and most telling 
objection is that there is no relation between the bactericidal power of 
the body-juices and immunity ; thus the serum of an animal which is, 
say, sensitive to a certain microbe, may be very bactericidal in vitro , 
while that of another which is unaffected by the microbe has no action 
whatever. The author finds that there is little ground for these objec- 
tions, that the first is explained away by, among other things, the fact 
that certain bacteria are killed off by fresh serum, while if this serum be 
heated to 60° they swarm. 
The replies to the second and third objections may be taken together, 
since they practically amount to the same thing. The author replies 
that spores are just as sensitive to the humours as the vegetating forms. 
To combat the last objection he cites the experiments of Leclef, 
who found that there is a strict parallelism between the pathogenic 
action of microbes and their resistance to humours. 
The author concludes by expressing the opinion that the last word 
on the bactericidal power of the juices has not yet been said, and that 
all that we can affirm at present is that the serum of certain animals, 
outside the body at least, contains a toxic substance which acts on 
microbes after the manner of an antiseptic, causing them to perish, 
though surrounded by everything necessary for their well-being. 
New Frog-spawn Fungus.f — Drs. A. Koch and H. Hosaeus describe 
a new organism which was obtained from a sugar factory. When in 
bulk the organism presented to the naked eye a brownish jelly-like mass, 
recalling the appearance of Leuconostoc mesenterioides. By squeezing a 
* La Cellule, x. (1894) pp. 463-72. f Cf. infra , p. 732. 
+ Centralbl. f. Bakteriol. u. Parasitenk., xvi. (1894) pp. 225-8 (1 fig.). 
