636 On Flagellated Organisms in the Blood of Animals. [part hi. 



It would thus appear that these organisms are at all events not very readily 

 transmissible by means of subcutaneous injection 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 

 favourable medium for retaining their vitality than any other which T have tried, and 

 is a very convenient medium for studying the various stages of the disintegrative 

 process. The different appearances which they presented as watched in such a solution 

 are sketched at Fig. 65 ; from which it will be observed that the organisms present a 

 striking resemblance to the more generally recognised forms of spermatozoa. On the 



\ 



Fig. 65. — Flagellated organisms from the blood of a rat preserved in a 0'75 per cent, 

 solution of common salt, x 1000 diameters. 



third day the specimens figured were no longer recognisable in the fluid in which they 

 were kept. 



Whilst watching these particular specimens I was further able to satisfy myself 

 that these, like the generality of flagellated organisms, moved with the lash in front — 

 that is to say, in the direction indicated by the arrow which is placed alongside of 

 the middle specimen in Fig. 66 on the opposite page. Since this period T have 

 frequently observed the same thing in other specimens, though it is scarcely possible 

 to be sure of the direction of the movement until after the parasite has become sluggish. 

 Moreover, they may also be observed to move with the thicker end forwards, but only 

 for short distances. 



As already remarked, when describing the specimens from the blood of the dog, 

 they seem to attach themselves to surrounding objects by means of some portion of 

 the thicker end. The specimen sketched in the left half of Fig. 66 was observed to 

 remain attached to a granular mass by the extreme point of its thicker end for a 

 considerable time, whilst the remainder of the parasite was seen to swing freely from 

 a to 6 and from a to c, the free end of the lash presenting a screw-like appearance. 

 Another specimen was watched for half an hour whilst it remained attached to a granular 



