Development of Piroplasma Parvum in Various Organs of Cattle. 67 
seen in the blood at the commencement of an infection. They possess, in 
proportion to the whole parasite, a large nucleus, which contains a dis- 
tinctive Karyosome. In using Giemsa's stain one can see differences due 
to the staining in the plasma of the bodies belonging to the agamogonous 
stage as well as of the gamogonous one. There are dark blue forms along 
with light blue ones containing larger alveoli. It is possible that from the 
very start we have to deal with a sexual differentiation. The above 
nuclear phenomenon can easily be studied in preparations stained accord- 
ing to the dry and moist methods of Giemsa, as well as in those stained 
with hsemotoxylin. Microscopic examination of the various organs, par- 
ticularly of the spleen, does not always allow of definite conclusions. 
These organs represent a filter, which retains the broken-down parasites 
usually encountered in all protozoal diseases. When using the vital 
method I was never able to recognise the blue bodies, so that it is 
impossible for me to believe that these represent an assimulation product 
of the nuclei. The presence of Koch's bodies in the kidneys is of secon- 
dary importance. In East Coast Fever experimentally produced, either 
through the implantation of organs or in cases brought on by ticks, which 
finish rapidly with death, the formation of infarcts in the kidneys may not 
take place at all. My drawings of, and the communication referring to, 
Koch's granules, concern fresh material obtained with a syringe from the 
lymphatic glands and the spleen. In cases of East Coast Fever where 
fever is present without parasites being present in the blood, the diagnosis 
can be made by examining juice from the spleen and lymphatic glands. 
If in the juice obtained from the puncture of the lymphatic glands or the 
spleen are seen Koch's bodies containing only larger nuclei of a loose 
structure, and no forms of the second or gamogonous generation, it is 
possible that this latter does not take place at all, and no parasites are 
then found in the blood. Whether ticks which have been sucking the 
blood of such animals transmit the disease will be shown by later 
experiments. 
It remains to explain the fact that the blood of animals suffering from 
East Coast Fever injected into healthy animals does not produce the 
disease. It is possible that the blood contains forms which can only 
develop in the tick, and which, injected into the animal, die. In the 
transplantation of organs undertaken by Theiler and Meyer, Koch's 
granules are directly transmitted. These represent, under natural condi- 
tions, the stages which are formed only after the tick has transmitted the 
disease. The infection of the various glands in the body of an animal 
takes place through the blood current, and accordingly it becomes feasible 
to expect that the inoculation of blood also ought to produce the disease. 
A suitable occasion would probably arise when the plasma granules are 
found in the blood. Experiments to elucidate this will be carried out as 
