FLAGELLATED ORGANISMS IN THE BLOOD OF ANIMALS. 365 



sub-cutaneous tissue of the thigh of a healthy rat, free from 

 blood organisms, and which had been under observation for a 

 fortnight. 



The animal did not appear to be materially affected by 

 this procedure, and on February 12th it is recorded : The 

 rat continues to enjoy excellent health ; eats and drinks 

 freely. Not a trace of any organisms found in its blood, 

 although the flagellated organisms which had been introduced 

 into its tissues were found to be alive two days after the 

 operation in what remained of the mixture which had been 

 injected. 



It would thus appear that these organisms are at all events 

 not very readily transmissible by means of sub-cutaneous in- 

 jection from one rat to another. 



Nor have I succeeded in preserving them beyond two or 

 three days outside the body. Attempts have been made to 

 " cultivate " them in plain water, in sugar and water, glycerine 

 and water, and in salt and water, as, also, in the blood itself, 

 both with and without the aid of an incubator. But I could 

 not satisfy myself that they multiplied ; on the contrary, they 

 seemed to degenerate after removal from the animal hour by 

 hour. A weak solution of salt, as already observed, appeared 

 to be a more favorable medium for retaining their vitality than 



Fig. 3.— Flagellated organisms from the blood of a rat preserved in a 075 per 

 cent, solution of common salt. X 1000 diameters. 



any other which I have tried, and is a very convenient medium 

 for studying the various stages of the disintegrative process. 



