ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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blood-serum the growth is more rapid, but the colour of the colonies less 
white. Litmus milk turns red on the third day and coagulates. Milk is 
an excellent medium. Of eight cultures made from blood, two were 
negative; three gave pure cultures of the diplococcus; while the remain- 
ing three contained other cocci, notably a Staphylococcus , probably St. 
epidermidis albus. 
Non-Microbic Toxins.* — From an elaborate series of experiments 
made for the purpose of ascertaining the mechanism of immunity, M. A. 
Calmette and M. A. Delarde draw conclusions which may be summarised 
as follows : — The serum of animals naturally refractory to the toxins 
used (abrin and venin) rarely possesses antitoxic properties against these 
toxins. It may be remembered that the same phenomenon has been 
observed with regard to microbic toxins (tetanus). When the serum is 
antitoxic, as in the case of the hedgehog and mongoose, to serpent venom, 
the antitoxic power is but slightly marked, and bears no relation to the 
degree of immunity. Hence there is no correlation between the naturally 
refractory condition possessed by certain animals, and the antitoxic 
powers of their juices with regard to the toxins to which they are in- 
sensible. While warm-blooded refractory animals are able to form 
antitoxins under the influence of repeated injections of non-fatal doses of 
toxin, cold-blooded refractory animals are unable to do so. Cold- 
blooded refractory animals may acquire immunity to fatal doses of 
toxin without their serum becoming antitoxic. Antitoxic non-microbic 
serums may be practically employed for imparting passive immunity to 
man and animals against abrin and venin, and for the diagnosis of toxins 
in toxicological inquiries. The active substance of antitoxic serums is 
not altered by certain chemical reagents which destroy or profoundly 
alter the toxins ; when mixed in vitro with toxins the latter are unaf- 
fected. It seems to exist normally and abundantly in the protoplasm of 
leucocytes of vaccinated animals, whence it becomes diffused in the blood- 
serum and other organic fluids. It does not dialyse, and it has an 
energetic action on the leucocytes of fresh animals. Certain other 
substances devoid of specific action against toxins, such as meat-broth, 
normal serum, &c., appear to be able to impart preventive properties 
when injected into fresh animals. 
The authors further generalise their results and conclusions by 
pointing out that the antitoxic function is independent of immunity, as 
the latter may exist in the absence of the former, and that the two kinds 
of immunity, natural and acquired, are derived from a special property 
of the cells. The action of the toxins on the cells is compared to that 
of a magnet on a bar of soft iron. 
Ubiquity of the Typhoid Fever Bacillus.f — MM. P. Eemlinger and 
G. Schneider have made a series of observations which tend to show that 
the bacillus of typhoid fever has a universal distribution, that it exists 
in the soil, in water, and in the intestinal canal of persons unaffected 
with typhoid fever. Their remarks are preceded by an enumeration of 
the test characters of Eberth’s bacillus ; of these, eleven well-known 
and generally accepted criteria are merely mentioned, while two more 
are discussed at some length. These are the difficulty which the typhoid 
* Ann. Inst. Pasteur, x. (1896) pp. 675-707. f Op. cit., xi. (1897) pp. 55-66. 
