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Agar-agar Slopes.
The growth is widespread and heaped up. The edges of the growth are smooth. The general appearance of the growth is smooth, shining, and hyaline. The condensation water is always cloudy with a considerable granular deposit.
Agar-agar Stabs.
The growth occurs throughout the whole extent of the line of inoculation, It is thread-like and granular. Its colour is whitish-grey. Considerable growth takes place on the surface of the columns of agar-agar. This ultimately reaches. the walls of the tube.
Peptone Bouillon.
In this medium the growth is frequently slow. The medium becomes diffusely cloudy.
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The extent of this cloudiness varies. It is accompanied by the formation of a considerable granular deposit, which on shaking the culture tube ises and breaks up and gives rise to a diffuse cloudiness. In the course of a few days the initial cloudi- ness more or less vanishes and the medium appears as a hazy fluid with an abundant deposit. Occasionally a delicate pellicle of growth forms on the surface of the broth. This membrane is so fine that the slightest handling of the culture tube tends to break it up-the fragments sinking as a deposit to the bottom of the tube,
Milk.
So far no strain has caused coagulation, even after several weeks. The reac tion of the medium is sligtly acid after the micro-organism has grown for so:ne time.
Potuto.
The growth on this form of medium is subject to considerable variation. Micro-organisms freely isolated from the living or dead animal grow very sparsely on this medium. In certain instances no growth at all is obtained. This seems to depend entirely upon the acid reaction of the medium-a circumstance which has always to be taken into consideration when dealing with such a variable form of nutrient medium as the potato. If the potato be not acid, a growth is always obtained. However this growth varies in its amount and appearance in different strains of the micro-organism tested.
In certain cases a typhoid like growth is obtained, delicate, moist, and in- visible. In other instances the growth is luxuriant, of a greyish-yellow or greyish- white colour. The colonies are flat or heaped up and present a shiny appearance. The medium in the neighbourhood of the growth is never pigmented.
Spore Formation.
There is no evidence of the formation of spores.
Resistance of the Micro-organism.
No experiments have been undertaken so far to determine the action of injurious agents upon the micro-organisms. It is proposed to undertake this in a later research.
Chemical Reactions. Pigmentation. Odour.
Pigment is formed under no condition. Cultures of the micro-organism have no characteristic odour.
H2S.
In albuminous and peptone medium this gas is constantly formed as shown by the reaction obtained with basic lead acetate.
Indol.
The formation of this body varies in amount. In certain cases it is accom- panied by a reduction of nitrates, so that the nitroso-indol reaction can be obtained, the formation of indol by this micro-organism depends as in other cases upon the particular form of peptone present in the nutrient medium.
Action on Carbo-hydrates.
No gas is produced in media containing the ordinary carbo-hydrates.
Phenol.
There is no production of phenol by the bacillus.
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