On the Organism found in the Tsetse Fly Disease. 281 



blood after death, the adult forms arranged in clumps. They appear, 

 upon watching them for a considerable time, to get tangled together 

 to form a large writhing mass ; then the movements become gradually 

 slower in the centre of the mass, and are only seen at the periphery. 

 At this stage, if the specimen be fixed, the mass appears to be made up 

 of a quantity of macro- and micro-nuclei, as the protoplasm does not 

 stain, except in the organisms at the periphery, i.e., those which have 

 arrived latest. Eventually these, too, become motionless, and the mass 

 becomes an indistinct collection of granular matter, which is not 

 infective, so that we look upon these tangles as a proof of death. 



Since these observations were made, there has been published an 

 important paper on the Eat Trypanosoma, by Lydia Eabinowitsch and 

 Walter Kempner in the ' Zeitschrif t f iir Hygiene,' vol. 30, Part 2. We 

 have been able to confirm many of the observations and statements as 

 to the morphology and reproduction of the Trypanosoma made by 

 these writers. But there is no mention made of the plasmodial stage, 

 or of any reproductive stage elsewhere than in the blood; and the 

 writers recognize only three methods of reproduction, namely, longi- 

 tudinal and transverse division, and division by segmentation. This 

 segmentation, they consider, arises from one organism, and they state 

 that it may divide up into as many as ten to sixteen elements. This 

 segmentation form would seem to correspond to our plasmodial stage, 

 but we have seen much larger masses than those mentioned above, and 

 they do not notice the enormous masses of plasmodia which infil- 

 trate the spleen in every direction, and which can be found also in 

 glands, and marrow. Moreover, their amoeboid stage (Kugelform) 

 would precede the segmentation form, and therefore the " Kugelform " 

 should be much larger than the ordinary adult form, but we have 

 observed that as a rule, our amoeboid forms are very much smaller 

 than the adult forms, some not being visible with any but the highest 

 magnifying powers ; so that we have been unable to accept this form of 

 division by segmentation, except in the form in which we have 

 described it above, i.e., our plasmodial stage. 



VOL. LXV. 



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