118 SPECIAL BACTERIOLOGY 



quarters to one hour. A series of cultures are now instituted in media 

 specially prepared for the growth of anaerobic organisms by the addition 

 of 1-5 to 2'0 per cent, of glucose. 



Kitt obtained pure cultures without using the heating process. 



The original material was reduced with sterile water, and the liquid 

 inoculated by means of stroke cultures on the surface of horse or sheep 

 serum media, and the cultures placed in an atmosphere deprived of its 

 oxygen by Buchner's method (see page 66). 



On Gelatine the colonies grow slowly, the central portion being of a 

 golden yellow colour, with numerous threads radiating from the centre. 



On Agar-Agar the colonies are very characteristic, the naked-eye 

 appearance being that of fine, fleecy clouds, which under the microscope 

 resemble a tangled mass of fine threads. The extraordinary fineness of 

 the latter enables the colonies to be distinguished from other anaerobic 

 organisms. 



In Gelatine Stab Cultures the growth has the appearance of a cloudy, 

 linear mass with outgrowths radiating into the gelatine from all sides ; 

 liquefaction follows slowly, with a coincident production of gas with an 

 unpleasant empyreumatic smell. 



In Agar Stab Cultures the growth has a very characteristic appearance, 

 resembling a fir-tree (see Photograph, Fig. 42). 



Bouillon is densely clouded. 



In Milk the bacilli grow without causing any changes. 



On Potatoes a moist invisible growth similar to that of the Bacillus 

 typhi abdominalis occurs. 



Pathogenesis. Mice inoculated with a minute portion of a pure 

 culture of the tetanus bacillus develop tetanic symptoms in twenty-four 

 hours, which end fatally in from two to three days. Rats, guinea-pigs, 

 and rabbits are similarly affected, but require larger doses than mice. A 

 fatal dose for a rabbit is 0*3 to 0*5 c.c. of a well-developed bouillon culture. 

 The period of incubation for rats and guinea-pigs is twenty-four to 

 thirty hours, and for rabbits two to three days. Pigeons are but slightly 

 if at all susceptible. 



The tetanic convulsions appear first in the neighbourhood of the 

 point of inoculation, finally becoming generalized. 



At the autopsy there is usually only a small hsemorrhagic spot at the 

 point of inoculation. No other changes are present, and the bacilli are 

 only found at the point of inoculation (see Photomicrograph, Fig. 44), 

 although, according to Schnitzler, they are sometimes found in the 

 lymph-glands in direct relation with the inoculated part. Buedinger 

 found that tetanus could be conveyed from an animal dead of it to a 

 healthy animal by transplanting from one to the other portions of the 

 lymph-glands associated with the seat of infection. 



Death results from the absorption of a soluble poison which has been 



