244 
Annals of the Transvaal Museum. 
It must be stated that in the animal the disease commences with 
the appearance of these agamogonons forms. The temperature begins to 
rise, and reaches the maximum with the formation of the gamogonous 
forms ; the agamont which does not produce any more agametes divides 
into gamonts (figure 9 a) after its nuclei have eliminated the vegetative 
substance (figures 8a and 8c) by the formation of chromidia, and the process 
of reduction. 
These gamonts increase both in size and in numbers of nuclei, and 
finally divide up into gamotocytes which invade the red corpuscles, and 
now represent the parasite of East Coast fever known under the name of 
Theileria farm. 
The gamogonous forms are clearly distinguishable from the agamogon- 
ous form by their nuclei. The youngest gamonts (figures 96 and 10c and 6) 
measures about 0*8 micron, and possess a strongly refractile nucleus 
which takes the various stains intensively. In advanced stages (figures 
ll-13a and b) the nuclei possess distinct karyosomes, and occasionally in 
the youngest forms, along with the main nucleus, a second smaller nucleus 
is found, which may be compared with the blepharoplast of the flagellum, 
and which is of importance for the systematic position of our parasites. 
The multiplication of the nuclei in the gamonts takes place by a 
primitive mitosis in such a way that the karyosome splits the two fragments 
of the nucleus. Finally the gamont divides into gametocytes (figure 14 a 
and b) after leaving a residual body staining blue with giemsa. As already 
stated, the nuclei are characterized during life by strong refraction, and 
accordingly are easily distinguishable from the granules of the lympho- 
cytes, although contrary to what is seen in the agamogonous forms, their 
shape is more regular, being almost oval. 
Usually the intracellular gamonts supply a far greater number of 
gametocytes than those that are free. This is partly due to double infec- 
tions similar to what is found in intracellular agamogonous forms. The 
schizogony of the reduced agamonts within the lymphocytes (figure 86) 
and the further development of the young gamonts may take place at 
the same time, so that naturally there are a great number of gametocytes 
present. In many cases I could count 150-200 gametocytes, the products 
of the gamonts in one single lymphocyte. 
The evolution forms of Theileria farva of the gamogonous and agamo- 
gonous stages as described above have been known for some time under 
the name of Koch’s bodies or plasma bodies. They have been the subject 
of much discussion, especially after Martin Meyer believed he had found 
similar bodies in other diseases, including piroplasmosis. As I personally 
have seen preparations of Martin Meyer, and not having been able up to 
the present in a single case of piroplasmosis or other disease of a protozoan 
origin, to trace forms which could be mistaken for cycle forms, I must say 
that the so-called reaction products, as designated by Martin Meyer, have 
nothing to do with the so-called Koch’s bodies. 
I have been able to follow up the segmentation during life of the 
gamonts into- gametocytes, and to demonstrate these and other stages 
both in cattle and ticks in their natural state. With the large material 
