1889-90.] Dr G. E. C. Wood on Enzyme Action. 43 
consisted of pure anthrax, and inoculation of mice indicated that 
their pathogenicity was unimpaired. It is but right to state here 
that Pasteur * has observed precisely similar phenomena in the 
case of certain moulds and mucors. These fungi, when grown with 
exclusion of the air, tend to produce, instead of the usual mycelium 
and ftyphce, cells much larger than normal and more globular in 
form, so much so that Pasteur would refer in part to this, the 
erroneous statements so many botanists have made concerning the 
transformation of these into yeast. The anaerobe cells of these 
fungi suggest by their appearance a tendency more or less pro- 
nounced to revert to the amoeboid state. Another appearance which 
may be noted in anthrax cultures grown anaerobiotically also indi- 
cates a change in the cell membrane. Under normal conditions this 
organism never forms on its cultivation fluids anything approaching 
to a surface membrane, at most only a narrow ring of growth 
appearing round the walls of the tube, which falls to the bottom as 
soon as it has attained any size; but when the air is excluded the 
superficial growth remains attached until almost the whole surface is 
covered. Now a surface membrane or zoogloea results, as does the 
matrix of cartilage, from the changes which the cell membranes un- 
dergo in swelling up and yet remaining in continuity, and a change 
in this respect is what we might expect when grown in this way> 
The vaccines under certain conditions exhibit an appearance, probably 
of a somewhat similar character, which points in the same direction. 
When virulent anthrax is grown aerobically in bouillon, the fluid 
remains clear and limpid, the growth collecting at the bottom as a 
whitish fluffy mass. The vaccines, if allowed to grow slowly, present 
a precisely similar appearance; but if placed at a higher temperature, 
where they grow more rapidly, the tubes of bouillon, especially in 
the case of the most attenuated, present a uniformly turbid aspect. 
The apparent change in the specific gravity of the organism, which 
permits it to remain in suspension in the fluid, is evidently to be 
ascribed to the condition of the membrane in the vaccine being still 
further accentuated by the rapid division of the cells at the higher 
temperature. The vaccines are described as morphologically indis- 
tinguishable from the virulent organism ; Gamaleia,f however, asserts, 
* Etudes sur la Mere, 1876. 
t Annales de VInstitut Pasteur, 1888. 
