PART III.] Flagellated Organisms in Blood of Healthy Rats. 



<^o5 



movements were so rapid, exact information as to their microscopical characters could 

 not be ascertained at the time- The slides were therefore placed under a bell-glass 

 until these should diminish. 



On the following morning the activity of the filaments was much less. Their 

 movements were more restricted and more undulatory in character, and the blood- 

 corpuscles, having become somewhat agglutinated, had apparently squeezed out the 

 organisms, so that the latter occupied the serum-areas of the preparations. After 

 watching their movements for some time under a Hartnack's No. 9 immersion objective, 

 it was observed that every now and then blood-corpuscles, some considerable distance 

 from any visible motile filament, would suddenly quiver. On carefully arranging the 

 light, it was eventually observed that this movement was due to the existence of a 

 very long and exceedingly fine flagellum, apparently a posterior flagellum, as the 

 organisms seemed generally to move with the thicker end forwards — the flagellum being 

 seen following it, and lashing the fluid during the moment it remained in focus. I have 



Fig. Tju .... X 700 diameters. 



Flagellated organisms in the blood of healthy rats. A few red blood-corpuscles and one white 



corpuscle are included in the figure. 



not been able to detect any flagellum at the opposite end. The greater number of the 

 figures reproduced in the woodcut (Fig. bb) represent these organisms as they are 

 observed a few hours after the blood has been obtained, when their movements are 

 not so rapid and the flagellum becomes recognisable. They may sometimes be kept 

 alive for two or three days, but generally the greater portion will have died within 

 twelve or twenty-four hours; and not only have died, but also disappeared from view. 

 When very carefully watched, the plasma constituting the thicker portion of their 

 substance may be seen suddenly to swell out at certain places— sometimes so as to 

 divide the " body " into two parts, as shown in the middle figure ; at other times two 

 or three such constrictions and dilatations may be detected, the dilatations being 

 possibly observable only on one side. At other times they assume an arrow-shaped 

 aspect, as shown in the lowest figure. Occasionally something like granularity may 

 be observed before their disappearance, but not a trace of them is left after their 

 disintegration: it seems as though they had been dissolved in the serum in which 

 they were found. 



