io6 THOMPSON YATES AND JOHNSTON LABORATORIES REPORT 
have preserved a considerable amount of their normal appearance, the connective tissue 
can be stained and the cross striation of the muscular fibres is very manifest, nor 
does it appear that the parasites themselves have been the seat of any pronounced 
artefaction. 
In Fig. 3 the spindle-shaped body is shown in transverse section, it is round 
or oval in outline, not encapsuled by a membrane, but the parasites lie in a mass of 
degenerated muscle substance, and the intermuscular connective tissue penetrates into 
and is then lost in the necrotic mass. In this section the parasites appear as round 
darkly staining bodies (section stained with haematoxylin) surrounded by a clear halo, 
and in other places empty capsules are visible. In P igs. 4 and 5, stained with methylene 
blue and eosine, the appearance of the parasitic bodies in Fig. 4 are seen to be for the 
most part grouped in columns parallel to the degenerated muscle fibres. They vary 
very greatlv in size, and in the bottom corner of the section there is a number of 
capsules in which the parasites have disappeared and the folded membranous sheaths 
are clearly visible. 
Structure of Parasite 
The parasite consists of a granular protoplasmic mass without visible differenti- 
ation of a nucleus. The protoplasm may be either finely or coarsely granular reticulated 
or vacuolated. Each protoplasmic mass is surrounded by a capsule. The thick- 
ness of the capsule is equal to about one-half that of the contained protoplasmic mass. 
It is limited by a definite membrane of double contour, whilst the portion intervening 
between the membrane and the protoplasmic mass appears to consist of a jelly-like 
material which assumes, under certain circumstances, a folded or spongy appearance, 
and often produces the appearance as if the central mass was suspended by a series of 
suspensory fibres. Occasionally a number of regularly arranged granules may be seen 
on the surface of the central protoplasmic masses, and from these fine filaments radiate 
out. In some instances we came across marked radiation as in the uppermost parasites 
in Fig. 8. In other instances, where the capsule was very large as in the lower fig. in 
Fig. 8, and from which the protoplasmic mass had apparently migrated, there can be 
seen marked evidence of radiating filaments which appear to extend from the periphery 
of the capsule to the innermost layer, which would be immediately in contact with the 
central protoplasmic mass ; at both points of attachment the ends of the threads appear 
thickened. The formation of these thread-like radiations appear to be most marked 
when the central protoplasmic masses have commenced to leave their capsules in the 
manner to be described. In the various stains which we used we found no specially 
selective stain for the central protoplasm. It stained readily with haematoxylin and 
with aniline dyes. The membraneous portion of the capsule stained sometimes best 
with methylene blue, but we did not obtain any specific reaction. The gelatinous 
intervening material did not stain. 
