112 Messrs. Kanthack, Durham, and Blandford. 



The haematozoa are also found in the fluids of the serous cavities, at 

 any rate when they are present also in the blood. 



They have not been found in the intestinal contents, nor have they 

 been seen in the urine, except in one case in which haematuria and sub- 

 mucous petechiae of the bladder were present (rat). 



It is evident from these observations that, in order to investigate 

 the development of the hsematozoa in the rat, <fec., special attention 

 must be paid to the seat of inoculation and the nearest lymphatic 

 glands. 



Dead and non-motile forms may frequently be found in the circula- 

 tion and in the lymphatic glands, when the disease is advanced. These 

 are less defined and are ghost-like, being somewhat swollen in appear- 

 ance ; they are also generally in an extended condition. 



VII. Toxic Power of the Blood. 



The fact that animals may appear to be well for days while 

 haematozoa are abundant in their blood, suggests that the haematozoa 

 do not secrete much, if any, specific toxin, and indeed so far no direct 

 evidence has been obtained of a potent poison manufactured by the 

 haematozoa, either by secretion or by chemical changes induced in the 

 blood. 



Fresh serum after filtration through Berkefeld filters, and blood or 

 serum which had been kept for days in a sterile condition till the 

 haematozoa had died, have had no specific toxic effects, even when 

 large quantities have been injected into dogs, rats, or rabbits. Blood 

 in which the haematozoa have been killed by exposure to 50 C. has had 

 no more effect. The extracts of organs obtained from diseased animals 

 have also shown no poisonous properties. 



The whole available blood of highly diseased rabbits has been injected 

 immediately after removal into healthy rabbits, without producing 

 immediate symptoms of acute intoxication. 



The bile of diseased animals does not appear to be more toxic than 

 that of healthy animals. 



A cat, into the peritoneal cavity of which a collodiofl sac full of 

 fresh infected blood had been inserted, showed no signs of illness. It 

 was fully susceptible on subsequent inoculation. 



Dogs, when injected with large quantities of filtered serum from an 

 infected dog, showed no symptoms of a profound toxaemia. 



Our experiments do not point to the presence of any intense specific 

 toxin or poison in the blood, 



VIII. Immunisation and Cure. 



The endeavours to produce immunity, or to cure the disease after its 

 establishment, are shortly summed up as follows : 



