Chapter I. 
THE MALARIA PLASMODIA. 
Methods of demonstrating the plasmodia. —The parasites causing 
the malarial fevers may be studied in either the living condition or 
in stained preparations of blood. For the military surgeon the 
examination of the fresh blood is of special value, for staining solu¬ 
tions will not always be at hand, and it is most unfortunate, from 
a military standpoint, that the study of the living plasmodia in 
fresh blood has been so entirely replaced by the use of stained prepa¬ 
rations. While, at permanent posts and base hospitals, where stain¬ 
ing solutions .can be prepared and used, the stained preparations of 
blood are to be preferred, every military surgeon should be familiar 
with the appearance of the plasmodia in fresh blood, for in the field 
the examination of unstained specimens will be found the most prac¬ 
ticable and rapid method of diagnosing malarial infections. Where 
stained preparations can be made, however, they possess the great 
advantage that the plasmodia are more easily seen and are less 
liable to be mistaken for other objects that may be present in the 
specimens examined. 
Apparatus. —The apparatus necessary in making a blood examina¬ 
tion for malaria is so very simple, occupies so little space, and is so 
easily transported, that there is no excuse for its absence even in 
military operations in the field. A good compound microscope pro¬ 
vided with a one-twelfth oil immersion lens, a bottle of immersion 
oil, microscopic slides and cover-glasses, two or three medicine drop¬ 
pers, a bottle of staining solution, and boiled or distilled water are 
all that is necessary to make the most exact examination of the blood 
for malaria. In operations in the field the bottles of staining solu¬ 
tion and distilled water could be omitted, the diagnosis of infection 
being made from the examination of fresh specimens of blood. The 
one-twelfth oil immersion lens is absolutely essential, for while the 
larger forms of the tertian and quartan plasmodia and the gametes , 
or crescents, of the aestivo-autumnal fevers may be seen with lower 
power lenses, the small, hyalin ring-forms can only be well seen 
when the one-twelfth lens is used. 
Preparation of living specimens. —The following procedure is rec¬ 
ommended if it is desired to procure fresh specimens of blood for 
examination for the plasmodia. The patient’s ear lobe or the tip of 
the finger is carefully cleaned with alcohol, dried thoroughly, a 
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