EEPOKT OF TRAVELLING PATHOLOGIST AND PKOTOZOOLOGIST 
161 
Experiments were conducted with numerous mosquitoes of the genera Mansonia, 
Tainiorhynchus, Culex, Myzomyia, Pyrctophonis in order to determine the intermediate host, 
hut with no result. Only those changes seen to take place in the fresh blood were again 
encountered in the stomachs of the mosquitoes. It is possible that the intermediate host is 
not a mosquito at all, hut that some other fly is responsible, as the Sergents and Aragao have 
demonstrated in the case of Ilamoproteus columbm. 
The infection varied very much in different guinea fowl. In old birds, as a rule, the 
infection was small, while young birds harboured the largest number of parasites. It is very 
probable that the young birds become infected soon after hatching, and that the infection 
gradually gets smaller with increase in age. In almost every bird prolonged search would 
reveal at least one or two parasites. In the majority of birds Haltcridium was present at 
the same time, and very commonly filaria embryos. In one, Proteosoma was found, while in 
two, trypanosomes occurred with the Leucocytozoon. It is interesting to note that, though 
practically all guinea fowl were infected with the Leucocytozoon, only two revealed this 
parasite and trypanosomes at the same time. The trypanosomes have been described 
at another part of this Eeport, but though superficially there is a certain resemblance 
between the trypanosomes and the spindle-bodies, this is only accidental, and the two 
parasites have nothing whatever in common. 
There have been two main views advanced as to the structure of the spindle-bodies. In 
one case the whole structure has been represented as a parasite which has engulfed a leucocyte, 
the nucleus of which is visible at the side of the parasite. This only applies to the older 
parasites. The younger forms are supposed to enter a leucocyte. This view was expounded 
by Schaudiun, and has been supported by Dutton, Todd and Tobey. The second view, and the 
one which is undoubtedly correct, is that the denser portion which surrounds the host-cell 
nucleus represents the whole of the parasite, while the drawn-out ends of the spindle-body 
represent the drawn-out ends of the host-cell. The parasite is like a IlaUeridium which lies 
around the host-cell nucleus. The second view is supported by Laveran, Berestneff, Sakharoff 
and others, and is the only one which can possibly explain the appearances. The first view 
seems to have been evolved by Schaudinn to fit in with his conception of the relationship 
between Leucocytozoon of the little owl and the trypanosome, in spite of the fact that 
nothing of a similar nature was known to occur with other blood parasites and the absence 
of evidence that trypanosomes would behave in the manner he described. 
In support of the second view many facts come to light from a study of the parasite of the 
guinea fowl. 
1. The character of the movements which have been described as taking place in the fresh 
blood. It is only the true parasite that moves. The host-cell may move, but this is purely 
passive motion. The escape of the gametocytes from the cell takes place in precisely the 
same way as the escape of the gametocytes of Halteridium. 
2. The occurrence of two parasites in one cell occurs commonly in the case of the guinea- 
fowl Leucocytozoon, as has been noted by other observers in the case of other Leucocytozoa. It 
might be suggested that a division had taken place in the endoplasmic portion, but such an 
explanation could not possibly hold in those cases w'here one cell contains both a male 
and female gametocyte. On Schaudinn’s hypothesis one would have to assume that two 
trypanosomes had engulfed one leucocyte between them, which is absurd. 
3. In one bird Proteosoma occurred together with the Leucocytozoon. Examination of 
films showed that in many cases the spindle-bodies were infected with the Proteosoma. It 
was only in the part of the cell beyond the Leucocytozooji that these parasites occurred. They 
were quite normal and developing in the same manner as the forms present in the red 
corpuscles at the same time. Plate XVI., tig. 7, shows such a double infection. In one 
No 
intermediate 
host found 
Intensity of 
infection 
Structure of 
the spindle- 
bodies 
Nature of the 
spindle-bodies 
L 
