460 J. R. BRADFORD AND H. G. PLIMMER. 



in figs. 37 — 39, It seems to consist of a protoplasmic mass, 

 containing a very lai-ge number of micro- and macronuclei 

 irregularly embedded in its substance ; in the central part 

 there are no divisions to be seen in the mass of protoplasm 

 surrounding the nuclei, but at the marginal parts amceboid 

 forms can be seen in process of detachment, such as is shown 

 in fig*. 37. These masses are best seen in the spleen of the 

 rat or mouse, but can also be observed in the blood of 

 animals from which the spleen has been removed. They can 

 be seen also in less quantity in the blood from the lungs of 

 most animals. In the bone marrow of spleenless animals 

 this form can also be demonstrated. At present, it does not 

 seem possible to say for certain whether this form is a true 

 "Plasmodium," i.e. a fusion of several elements, or whether 

 it is merely an aggregation of amoeboid forms. Our opinion 

 is in favour of the former view. This form is of the greatest 

 importance, as its presence not only causes the great enlarge- 

 ment of the spleen observed in certain animals, but is also a 

 means of very rapid multiplication of the organism. 



VI. The Disteibution of the Teypanosoma Brucii; its 

 Variatioiss in Different Animals, and their Resistance 



TO IT. 



The distribution of the Trypanosoma in the different 

 animals we have used varies considerably. In the rat and 

 mouse — animals that die in the shortest time— the organism is 

 found in the blood from forty-eight hours after inoculation, 

 and they go on steadily increasing till at the time of death, 

 usually from six to nine days, there may be as many as 

 3,750,000 per cub. mil. These are nearly all of the adult 

 form, and may be seen in all stages of longitudinal division, 

 and in conjugation. The spleen becomes, towards the end of 

 the disease, enormously enlarged, measuring about 5 to G cm. 

 by 1 to 2 cm., and it is found to contain an enormous quantity 

 of plasmodial material, as seen in fig. 38, some amoeboid forms 

 and a very few adult forms. The blood from the lungs con- 



