THE BACTERIACEA. 187 
and death of these organisms, and their consequently diminished 
numbers ; but spore formation, when allowed to take place in those 
that were still living, gave fresh vigour to the culture. Dr. Klein’s 
experiments lead us to believe that spores are not formed in the 
blood-vessels of animals. 
With regard to the mutual convertibility of the hay bacillus and 
the anthrax bacillus, which Dr. Buchner considers to be morpho- 
logically identical, although chemically and functionally distinct, 
Dr. Klein states that they never become identical in any sense or 
during any cultivation ; and in this he is confirmed by Dr. Koch. 
Buchner cultivated the bacillus of anthrax, obtained from the 
spleen of a white mouse that had died of that disease, in a 0.5 per 
cent. solution of Liebig’s meat extract, with or without peptone or 
sugar, at a temperature of 35° to 37° cent. ; and he found that “the 
infectious activity of the fungus became the more diminished the 
more generations it had passed in the artificial cultivations.” This 
result was not, however, always attained. In one series of experi- 
ments, he found that the second cultivation was active, the third 
and fourth inactive, the fifth active, and that activity was still 
manifested even at the thirty-sixth cultivation. Dr. Klein con- 
siders that the variability of Buchner’s results is due to a variety of 
causes, the chief of which is the absence of spores from some cul- 
tivations and their presence in others. Dr. Koch explains these 
results by supposing that Buchner “ may have had, and probably 
did have, in some of his cultivations, the 2. anthracis originally 
sown, diluted or altogether suppressed by the growth of the non- 
pathogenic bacillus. He also maintains that when Buchner cul- 
tivated the hay bacillus in blood for many generations, and the 
animals died after inoculation with such blood, he did not produce 
the B. anthracis, but the bacillus of Koch’s “ malignant cedema.” 
It is to be hoped that future experiment may afford some 
explanation of the anomalous results of these researches of Pasteur 
and Klein, and that these observers may then be upon the track of 
the discovery of the true cause of the protective influence of 
vaccination, 
A more detailed account of Dr. Klein’s experiments will be 
found in an article written by him in the Quarterly Journal of 
Microscopical Science for last January, on “the relation of patho- 
genic to septic Bacteria, as illustrated by anthrax cultivations,” as 
well as in the Supplement to the Report of the Local Government 
Board for 1881-2. 
In view of the different opinions entertained by high authorities 
as to the significance of the presence of bacteria in fermentations, 
putrefactions, contagious diseases, and on the exposed surfaces of 
wounds, it would perhaps be premature to express any conviction 
as to the part which these organisms play in the various phenomena 
