610 
Proceedings of the Royal Society 
An analysis of this table shows that orange “ vaccine ” produces 
a local scab in a guinea pig, and that clear vaccine lymph pfoduces 
typical vaccination in monkeys. Vaccine cultivations and opaque 
variolous lymph produce an eruptive fever in calves, when inoculated. 
ISTo local result is produced. White variolous cultivation produces 
a mild variolous eruption in a monkey, which does not appear to 
be contagious to another monkey. No local result is produced at 
the points of inoculation. Protection is afforded from the poison of 
variola by previous variolation and vaccination with “vaccine” 
cultivations. White and yellow “ vaccine ” produce no local result 
in guinea pigs. They probably produce a mild constitutional 
result. The experiments appear to show that different vaccine 
materials possess different degrees of potency. 
Classification of Micro-organisms. 
In attempting to trace the life-history of the vaccine and 
variolous organisms from the preceding observations we are con- 
fronted by a preliminary difficulty. At present the fission-fungi 
are undergoing the most minute investigation, and the result has 
been attempts to improve upon the classifications of Cohn and 
Naegeli. Naegeli held that the bacteria were allied to yeasts, and 
should therefore be included in the class of fungi. The difficulty 
in accepting this view arose from the fact that fungi were supposed 
to be destitute of colouring matter. Owing to this, Cohn placed 
them among algse, but the tendency now is to amalgamate the 
colourless fungi (bacteria) and the colour-producing algse (bacteria) 
into one group, the thallophytes (Sachs). The latest classifications 
of Fliigge, 1883, and Zopf, 1885, appear to me to be unsatisfactory, 
and I prefer to follow the classification of Cohn into four tribes, 
including six genera. He believes that the form or shape charac- 
teristic of each tribe is adhered to throughout the life of the organism. 
Thus, a micrococcus cannot be transformed into a bacterium or 
bacillus, but retains its spherical shape. We have only to do at 
present with Cohn’s first group, the Sphserobacteria, comprising one 
genus, the micrococci. While, however, Cohn has settled the main 
lines upon wdiicb the classification of Schizomycetes should be 
based, he admits that his classification of the genera into species is 
defective. This is due to deficient knowledge of their physiological 
