654 NOTES AND MEMORANDA, 
engaged in during the past year, and will give particulars 
as to the methods of investigation employed by them, which 
had not (we believe), previously to the meeting of the 
International Medical Congress, been given to the public. 
A remarkable negative result obtained by Dr. Koch, so 
far as his experiments with the new method of monosporous 
culture have yet extended, is, that there is no transition of 
forms amongst, at any rate, the pathogenous Bacteria—a 
Micrococcus produces Micrococci, and no other form; a 
Bacillus produces only Bacilli; a biscuit-shaped form (Bac- 
terlum proper) only biscuit-shaped forms; a Spirillum only 
Spirilla. Moreover, the facies of the discoidal or spherical 
mass formed by a growth, as seen with a low power excavat- 
ing its way in the gelatine is characteristic of species, so that 
a practised observer can, in some cases, recognise a particular 
Bacillus or Micrococcus by the naked-eye appearance of the 
growth alone, or, at any rate, without actually observing the 
individual units of the growth.—L. 
