50 
Annals of the Transvaal Museum. 
Before discussing the question of Koch’s bodies, I wish to make some 
remarks on P. parvum. Last year Ollwig, at the Congress of Micro- 
biologists, in Berlin, stated that P. parvum and P. mutans were identical. 
My experiments leave no doubt that P. parvum and mutans are two 
different organisms, which view has been held for a number of years by 
different authors. Blood containing P. parvum in extraordinarily large 
numbers was injected subcutaneously and into the organs of various 
animals, and in no instance was an infection transmitted. On the 
contrary, it was an easy matter to transmit P. mutans to a healthy beast. 
An emulsion of 1 c.c. red corpuscles in 10 c.c. saline solution was 
sufficient to do so. As a further proof, it may be stated that Rhipicephalus 
appendiculatus in the Transvaal transmit P. mutans only in exceptional 
cases. 
P. parvum and P. mutans are, therefore, ivith regard to their 
pathogenic effect, two different parasites, which also show differences in 
their cycle of development. 
Together with the daily blood examinations, systematic punctures of 
glands and spleen were made. On comparing preparations from cattle 
suffering from East Coast fever with those infected with P. mutans , no 
doubts can be left about the cause of East Coast fever. Shortly before 
the parasites appear in the blood, one will notice segmenting forms of 
Koch’s bodies which throw off a great number of parasites. For this 
investigation the large shoulder glands are the most suitable. Neither an 
infection with P. bigeminum nor one with P. mutans , P. equi, or P. canis, 
shows similar evolution forms, whereby it is proved that Koch’s bodies 
represent a stage in the development of P. parvum, as already Koch 
himself had surmized. Accordingly, the view of Martin Mayer that the 
so-called Koch’s granules are not specific for East Coast fever falls to the 
ground. 
The blue bodies represent indeed a certain stage in the cycle of P. 
parvum which corresponds to the shizogony in the cycle of the malarial 
and: other parasites. 
These bodies (fig. 1-2 and fig. 5 c-d) appear both intracellularly and 
extracellularly, more particularly in the lymphocytes. Quite exceptionally 
polynuclear leucocytes are found to be infected. The development takes 
place more or less in the following manner. In the blue body (Agamont) 
a nucleus is first formed ; this grows and becomes richer in chromatin and 
plasma ; subsequently it divides successively into a great number of 
smaller nuclei similarly to what occurs in the cycle of haemoproteus which 
takes place in the organs of the pigeon and padda. The cells thus formed 
break up into as many sub-divisions as there are nuclei (fig. 4 -5a). One 
encounters and but rarely a second one to which I will refer hereafter. 
The explanation of this fact may be that this shizogonous stage, which I 
call, with Hartmann, agamogony, repeats itself. Accordingly again etes, 
resulting from the agamogonous stage, would grow into agamonts. I have, 
however, not been able to completely follow up the further development 
of these latter forms. 
The second mode of multiplication ends with the segmentation into a 
great number of small parasites undoubtedly resulting from the agamo- 
gonous multiplication (fig. 3-5). The young parasites enter into the red 
corpuscles and represent now the forms known as P. parvum. Thus we 
have in the organs, particularly in the lymphatic glands and the spleen, 
two different phases, which morphologically are not difficult to distinguish 
from each other, The nuclei of the one phase (agamogonous) when young, 
