( 52 )
Prom the point of view of diagnosis by a microscopical examination the
following hints may be useful.
IE in a film we find a " crescent " ( Pl. "VII, 'Figs. 10 and 11), we know at
once that we are dealing with a case of malignant Tertian fever.
If, at different examinations of the same case, we find nothing but small
ring forms (Pl. VII, Fig. 8), no large forms being present, the case is also
probably one of malignant Tertian.
Small rings and crescents are
characteristic of malignant Tertian infections.
If we find a large irregularly shaped parasite in a corpuscle which is dis-
tinctly larger than the surrounding ones (Pl. VII, Figs. 1 and 2 ), we may be
sure that this is a simple Tertian parasite.
If we find regularly oval or rectangular parasites in corpuscles which are
practically unaltered in size and colour ( Pl. VII, Fig. 6 ), these are probably
Quartan parasites.
If in a film stained by Romanowsky's method we find red corpuscles swollen
and studded with red dots ( Plate VII, Fig. 2), we may be sure that the case is
. one of simple Tertian infection. This stippling of swollen cells does not occur
in Quartan or malignant Tertian infection.
The differences in the segmenting forms are well shown in Plate VII.*
Figure 7 is a pve-segmenting Quartan parasite. The different spores have
not quite separated from each other, but it is seen that they are eight in num-
ber and that they completely fill the corpuscle which, however, is practically
unaltered in shape and size.
Figure 3 is a segmenting benign Tertian parasite. The cell containing
the parasite is much swollen and decolourised.
Figure 4 is a completely segmented benign Tertian parasite which has escaped
from the red cell. About twenty-one spores can be counted and the round block
of black pigment is plainly seen.
Figure 9 is a segmenting malignant Tertian parasite. These are very
rarely seen in finger blood. It only occupies about one-half of the red
corpuscle which, if anything, is smaller than the surrounding ones.
In examining blood films, two other blood parasites which have no connec-
tion with malaria but which sometimes occur in man, should be looked for, as,
in the absence of malaria parasites, their presence may afford a clue as to the
nature of the case. These parasites are, "Filariæ" and " Trypanosomatta,"
and in order to give an idea of their appearance in blood films I have added
photographs of these important parasites ( Plate VIII, Figs. 5 and 6). As is
no doubt well known, the presence of filarial embryos in the blood is associated
with such diseases as elephantiasis, chyluria, lymph scrotum, etc., and the
presence of one species of trypanosome in animals is the cause of " Surra."
A species of trypanosome has lately been found in the blood of man in Africa,
though it has not yet been discovered in human blood in India.
Any student who desires to study practically the stages of the malaria
parasite in mosquitoes will find the methods for doing so described by the
present writer in the Scientific Memoirs of officers of the Medical and Sani-
tary Departments of the Government of India, new series No. 2. "Malaria
in India," which may be obtained from the Superintendent of Government
Printing, 8, Hastings Street, Calcutta, or from Messrs. Thacker, Spink & Co.,
Calcutta. ( Price Rs. 1-8.)
* The photographs have lost much of their distinctness in the process of repro-
duction.