occurring in the Red-faced African Mouse Bird, etc. 228 
I am informed that the bird was not noticeably infected with 
ectoparasites, and so no indication as to the transmission of the 
parasites is available from that source. 
Structure of the Parasite. 
A brief account of the morphology of the parasite may now be 
given. When a fresh preparation of a teased Miescher’s tube is 
examined the spores, sometimes known as Rainey’s corpuscles, 
appear as elongate, sickle-shaped bodies with a clear centre and a 
distinct refractivity. The general cytoplasm seems homogeneous, 
though a vacuole may be present. One end of the organism is 
more pointed than the other. The spores examined by me 
exhibited very little power of progression. 
Stained smears and sections show that the trophozoites present 
an elongate, tubular body with a definite envelope and a chambered 
or trabeculate structure. Various stages of the organism can be 
recognised. The large trophozcites contain numerous spores. 
Certain of them are solid owing to the spores practically fillimg their 
‘Interior, but the oldest and longest of them show a hollow centre, 
_as the spores there die and degenerate, leaving only the trabeculae. 
By the dehiscence of the tubes of the muscular system, invasion of 
the connective tissues is brought about. 
Large Miescher’s tubes are 2°5 mm. in length and have a 
breadth not exceeding 1 mm. They occur in the skeletal muscula- 
ture. The cardiac muscle contains much smaller tubes, possibly 
the result of the less size of the cardiac muscles invaded, as well 
as the possibility of younger trophozoites being present there. 
The Miescher’s tubes are easily seen in sections of infected tissue 
as they show great affinity for basic stains. Further details of the 
parasite as seen in sections will be given in a later publication. 
| The internal structure of the sickle-shaped spore, as seen in 
stained preparations, may be briefly outlined. Polymorphism 
occurs among the spores, at least two types being distinguishable : 
the one, narrow with more deeply staining contents, the other 
broader with paler contents. These spores are about 5 to 7m 
long, while their breadth varies from 1:5 w to 25. The dimor- 
phism may be due to growth and division. Occasionally “ giant ” 
Spores are seen. The nucleus is not central but is near the blunter 
end. The structure of the nucleus varies. Sometimes itis vesicular 
with a karyosome, which may be central or excentric. At other 
times the chromatin is evenly distributed in granules throughout 
the nucleus. The differences in arrangement of the chromatin 
are due to cyclical development. Near the more pointed end of 
the spore a polar vesicle is often seen, and sometimes the remains 
15—2 
