PROPHYLAXIS OF MALARIA. 
21 
After staining, the preparation is washed in running tap water until 
no more blue color comes from the film. The specimen is then al¬ 
lowed to dry, after which it is ready for examination. 
In specimens stained in this manner it should be remembered 
that, owing to the dissolving of the hemoglobin by the acid, the 
cytoplasm of the red blood corpuscles is not distinctly stained, the 
intracellular plasmodia appearing to be free in the plasma. The 
entire film is more or less pink in color, the plasmodia appearing 
as blue bodies containing more or less red chromatin against the 
pinkish background. The tertian and quartan plasmodia, if beyond 
the ring stage in growth, appear as irregular blue masses containing 
granules of red chromatin, while the ring forms appear as blue rings 
containing one or two red chromatin granules, or as minute, irregu¬ 
lar bodies, if viewed at an angle. The gametes are easily distin¬ 
guished, although the crescentic gamete of the estivo-autumnal plas¬ 
modia often appears distorted. Some experience is required to 
identify the plasmodia in these thick films, but a little practice will 
soon enable one to become expert in the use of this very valuable 
method of demonstrating the malaria plasmodia. 
THE MORPHOLOGY AND LIFE CYCLE OF THE MALARIA 
PLASMODIA. 
The malaria plasmodia were first described by Laver an 3 in 1880 
and are found in man upon and within the red blood corpuscles. In 
this situation they feed upon and destroy the corpuscles, producing 
thus the anaemia always present in every malarial infection, and 
by their sporulation the symptom complex which we know as the 
malarial paroxysm. Although the classification of these parasites 
has occupied the attention of zoologists for years, it can not be said 
that there is yet a complete agreement regarding the exact position 
of the species causing malaria in man. All are agreed that they 
belong to the Protozoa, and most authorities place them in the 
Sporozoa , and in the order Ilcemosporidia. At least three species are 
recognized by the vast majority of observers—i. e., Plasmodium 
vivax (the tertian parasite), Plasmodium malariae (the quartan 
parasite), and Plasmodium falciparum (the estivo-autumnal para¬ 
site). The latter species has been divided by many observers into 
two varieties, the tertian estivo-autumnal plasmodium and the quo¬ 
tidian estivo-autumnal plasmodium. The tertian species should 
be called Plasmodium falciparum , while 1 4 have proposed the name 
Plasmodium falciparum guotidianum for the parasite causing the 
quotidian type of estivo-autumnal malaria, believing it to be a 
subspecies of Plasmodium falciparum. 
