436 BLOOD DISEASES. 



large number of minute isolated granules of similar 

 appearance extend throughout the spleen substance. 

 This is probably broken-down blood pigment, and is 

 an invariable accompaniment of any disease in which 

 such extensive destruction of red blood-cells takes 

 place as in this. The amount of pigment varies with 

 the rapidity of destruction of blood-cells, and if very 

 great (which only occurs in very acute cases) it is 

 excreted by the kidney, giving rise to the appearance 

 of the urine which produces the striking symptom of 

 red water. In no instance have we observed such a 

 degree of blood change. In none of the cases has 

 there been even sufficient to cause the thickness of 

 bile which is one of the characteristic changes in the 

 severe forms of this disease. 

 (3) The kidneys showed extensive cloudy swelling in their 

 cells, their outlines being quite indistinct, while in a 

 case which had been ailing for weeks the cells 

 appeared quite normal. 

 ' (4) The other organs present, with the exception of 

 ansemia, no morbid pathological change. 



BIOLOGY OF THE OllGANISM. 



The organism appeared to be, as in Texas fever, either the 

 protozoon Pyosoma higcminum of Theobald Smith, or a form 

 closely allied to it. If any difference exists, it is chiefly in the 

 thickness of the flagella, which here appears to be greater. 

 Nearly all the stages of development, as described by American 

 authors, and figured in " The Johns Hopkins Hospital Eeports 

 for 1896," have been seen in my specimens. 



The American authors seem to be uncertain of the order of the 

 developmental stages, and I confess to be also somewhat uncertain 

 upon this point. Further observations of perfectly fresh blood 

 in the fields (a matter of great difficulty in a hot climate) may 

 lead to a correct conception of all the developmental changes. 



In my own specimens there appear to be at least nine stages 

 which show natural segmental changes, as seen in the photo- 

 micrographs. The illustrations Nos. 25, 25a, 25b, and 25o, show 

 what appears to be by far the most common form in the ox. 



