KLEIN AND PASTEUR. Bl 
on mice. Thus, mice inoculated with a given cultivation which 
had not formed spores remained perfectly well ; but if the same 
cultivation was allowed to grow to the surface of the gelatine, or 
broth, and there to form spores, inoculation with it after such 
spore formation killed the same mice with typical anthrax. ‘The 
presence of oxygen in sufficient quantities would, therefore, ap- 
parently enable the cultivation to maintain its full virulence against 
mice for an indefinite period. But, strange to say, the same culti- 
vation at any stage, whether spores were formed or not, produced 
typical anthrax in guinea-pigs and rabbits, and killed them within 
48 hours. Briefly, Klein’s conclusions are as follows :—Mice are 
insusceptible to the Bacillus anthracis, when cultivated artificially, 
after the cultivation has been kept for some time, provided no 
spores are formed; but such cultivation in minimal doses is fatal 
to guinea-pigs and rabbits. As regards the alleged cases of actual 
transformation of Bacillus anthracis into Bacillus subtilis, K\ein is 
disposed to think that sufficient care has not been taken to exclude 
germs of the latter, and that the alleged transformations have been 
simply cases of the survival of the fittest, the anthrax bacilli being 
all killed off by the abundant growth of the hay bacilli. 
The curious difference in the effects produced by the same 
virus upon different species of rodents, thus apparently demon- 
strated by Klein, cannot fail to give rise to much speculation and 
further inquiry. It shows that mice possess in this respect some 
peculiarity which is not possessed by guinea-pigs and rabbits, and 
it also indicates that artificially cultivated bacilli undergo some 
peculiar change as the period of incubation advances. With 
reference to the first of these conditions Klein points out that 
Algerian sheep are said to be altogether proof against anthrax, and 
therefore possess some peculiarity not found in French sheep. We 
may add that it seems to bear also upon the different degrees of 
resistance of various varieties of potatoes to the potato disease, 
and that it also calls to mind the mysterious peculiarity produced 
in man and animals by protective vaccination itself. For the rest, 
the apparent contradictions between the researches of Klein, 
Pasteur, and other micro-biologists are full of value. It is behind 
such anomalies that the truth lies, and it is from efforts to reconcile 
such anomalies that all great discoveries have been evolved. Those 
who have familiarised themselves with Pasteur’s work during the 
past twenty years will look forward with perfect confidence and 
great hope to his further statements of the subject.—JdZanchester 
Guardian. 
