440 ^^ GTEBIOL OGY. 



duced by the bacteria in the culture from which they are 

 obtained and introduced with them into the tissues of 

 the animal at the time of the inoculation. In support 

 of the latter hypothesis : mice have been inoculated with 

 pure cultures of this organism; after one hour the point 

 at which the inoculation was made was excised and the 

 tissues cauterized with the hot iron; notwithstanding 

 the short time during which the organisms were in 

 contact with the tissues and the subsequent radical 

 treatment, the animals died after the usual interval 

 and with the regular symptoms of tetanus. 



The poison produced by the tetanus bacillus, and 

 to which the symptoms of the disease are due, has 

 been isolated and subjected to detailed study; some 

 of its peculiarities, as given by Kitasato, are as 

 follows '} 



" When cultures of this organism are robbed of their 

 bacteria by filtration through porcelain the filtrate con- 

 tains the soluble poison, and is capable, when injected 

 into animals, of causing tetanus. 



" Inoculations of other animals with bits of the 

 organs of the animal dead from the action of the teta- 

 nus poison produce no result; but similar inoculations 

 with the blood or with the serous exudate from the 

 pleural cavity always result in the appearance of teta- 

 nus. The poison is, therefore, largely present in the 

 circulating fluids. 



" The greatest amount of poison is produced by culti- 

 vation in fresh neutral bouillon of a very slightly alka- 

 line reaction. 



" The activity of the poison is destroyed by an ex- 



1 Zeitschr. fllr Hygiene, 1891, Bd. x. p. 267. 



