174 BACTERIOLOGICAL DIAGNOSIS. 
show ameboid movements of greater or less rapidity. 
When the parasites are older they occupy a larger 
space in the corpuscles, and there are granules of dark 
pigment around their periphery. These granules are 
often the first indications of the presence of parasites in 
the examination of an unstained specimen. At a still 
later stage the granules will be found in the centre of 
the corpuscle (the haemoglobin of which is now almost 
entirely removed), and the parasite will show segmen- 
tation into a larger or smaller number of spores by lines 
which have a radial arrangement and give the whole 
Fic. 29.-—Malarial parasites in the blood. The dark area shows the 
parasite as it appears when stained with thionin. 
an appearance resembling that of a marguerite daisy. 
These are only found when a rigor is imminent. 
Crescents are found in the aestivo-autumnal form 
of malaria; they are crescentic bodies with rounded 
“horns,” and contain a ring of pigment granules in the 
centre. They cannot be mistaken for anything else, 
and if a single one is found it affords conclusive proof 
that the patient has been infected with malaria. 
Films for staining are made in the ways already 
described, and must be thin and perfect. They may be 
fixed by any of the methods we have recommended, the 
alcohol-ether and the alcohol-formalin methods being 
perhaps the best. They may be stained by Jenner’s 
