THE TRYPANOSOMA BRUOII. 459 



demonstrated iu the blood of spleeuless animals, also in 

 that of the more refractory animals, such as the rabbit 

 (as shown in figs. 9 and 10) and guinea-pig, when 

 repeated examination of the blood fails to reveal any of 

 the ordinary adult forms. They are also present in the 

 spleens of all the animals we have examined in greater 

 or less number. Another place where they are specially 

 found — and this is of importance from the clinical side — 

 is in the capillaries of the brain and medulla. Most of 

 our animals have died with symptoms referable to the 

 nervous system; either they become comatose and die in 

 a few hours, showing no symptoms till the coma appears, 

 or they have fits of an irregular character, or they become 

 paralysed in one or more limbs. Many of the cerebral 

 capillaries can in these cases be found to be quite plugged 

 up with these amoeboid forms, as is shown in figs. 40 

 and 41. The similarity of these appearances with those 

 of the cerebral capillaries in pernicious malaria is very 

 striking. In order to demonstrate these forms either in 

 the lung, brain, or elsewhere, films must be made from 

 the organs directly after death, and treated with the same 

 stains as described for blood. We have not found yet 

 any method of fixation of pieces of tissues fine enough 

 to demonstrate them in sections of these organs. 



These amoeboid forms can be seen in all stages of division, 

 and they appear to multiply much more rapidly than the 

 adult organism. Stages can also be seen intermediate 

 between these and the adult Trypanosoma. The method 

 of division corresponds closely with that of the adult 

 organism. First the micronucleus becomes rod-shaped, and 

 then divides; the macrouucleus enlarges at the same time 

 and divides a little after the micronucleus, and lastly, the 

 protoplasm divides. Many irregular forms are seen, espe- 

 cially in the bone marrow, resulting from the irregular division 

 of these amoeboid forms. 



Besides tliese there is another form, which we have, also 

 for convenience, called a " plasmodial " form. This is seen 



