FOOT-AND-MOUTH DISEASE. 
491 
similar to that presented by the streptococcus of foot-and-mouth 
disease, but with this difference, namely, that in gelatine tubes 
• the streptococcus of foot-and-mouth disease is a little faster in its 
growth, and its component granules are a little more distant. 
Nevertheless, I have tubes of both kinds of organisms in gelatine, 
and in agar-agar tubes, which cannot be, from their general appear¬ 
ance, easily distinguished. In faintly alkaline broth, or in broth 
and peptone, the micrococcus of the cow ulcers grows readily, and 
in the same manner as that of foot-and-mouth disease. But there 
is one test by which the two kinds of organisms can be very easi¬ 
ly distinguished : the streptococcus of foot-and-mouth disease, 
when grown in milk, does not affect the fluid character of the 
milk, whereas milk inoculated with the organism obtained from 
the cow ulcer, will, if kept for two days in the incubator at 35° 
C., have been turned completely solid. This difference is a very 
striking difference, and a few days growth in milk suffices for 
distinguishing without fail between the two. The microscopic 
examination of a culture in broth peptone, in gelatine, or in agar- 
agar mixture, shows that the growth consists of spherical micro¬ 
cocci, arranged as diplococci, and as shorter and longer, straight, 
wavy or curved chains—streptococcus—these latter sometimes of 
great length. 
As regards the shape of the micrococci, the mode of their divi¬ 
sion, the branchings of the chains, the presence here and there in 
the chain of a large element among the smaller ones, the organ¬ 
isms of the ulcers hardly differ from the description which I am 
preparing of the streptococcus of foot-and-mouth disease.”* It 
will be observed that the only point of real difference is the effect 
the growth of the streptococcus of the cow ulcer has upon milk, 
solidifying it, while the streptococcus of foot-and-mouth is asserted 
not to produce this effect. In connection with this point the fol¬ 
lowing may be quoted: “ But there is one point, in which, so far 
as I know, it (the milk) differs from all other milk, and that is in 
its coagulation on being boiled, or having its temperature only 
slightly raised by being mixed with hot gruel,” etc. i^Edin. 
i 
* Report on Milk Scarlatina to the Local Government Board, by Dr. E. Klein, 
London, England, 1886. 
