NOTES ON MICRO-ORGANISMS. ty 
Before going into detail in connection with some of the 
members of this kingdom of the “infinitely little,” as it has been 
aptly termed, let us quote some every-day instances of effects 
produced by the development of Bacteria. We have the souring 
of milk, beer, and other liquids; the ripening of cheese, especially 
in the case of such powerfully flavoured varieties as Limburg, 
Roquefort, Camembert, etc.; the putrefactive decomposition of 
meat and fish, besides many other decompositions where a bad 
smell is a noticeable feature. Additional examples are furnished 
by ensilage and the German Sauer Kraut, which, by the way, show 
some sort of relationship to each other in their method of 
preparation. In all or any of the above-mentioned cases, Bacteria 
may be detected easily by the microscope. 
We will now endeavour to arrive at a general conception of the 
appearance and attributes of some commonly occurring Bacteria. 
In Plate I. we have the following varieties :— 
1. Spherical Bacterium ...... Micrococcus aurantiacus. 
mr ueetic Perment $1... 000:.. Bacterium aceti. 
3. Putrefactive Ferment ...... 5 termo. 
4. Lactic Ferment ............ Pe lactis. 
5. Hay Bacterium ............ Bacillus subtilis. 
6. Spiral ,, veseeeeeesee SPirillum volutans, 
We will briefly describe the properties of these organisms. 
I. Produces orange-coloured spots on white of egg, pieces of 
cooked vegetable, etc. The pigment produced is outside 
the organism. There are many other organisms of the 
same Class, producing different colours. Having seen this 
one myself, I select it as an example of spherical Bacteria. 
Il. The acetic acid or vinegar plant, used industrially for the 
production of vinegar. Much light has been thrown on 
the workings of this organism by Adrian Brown, in a very 
interesting paper to the Chemical Society. 
IIT. In the common accompaniment of putrefactive changes of 
all kinds, especially with decomposing animal matter. It 
is more often seen in an actively moving state than any 
other Bacterium. 
