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The blood in malaria.—— As the malaria parasite is a blood parasite, we naturally expect that the primary effect of its presence will be exercised on, and manifested in, the blood; and as the parasite lives in and at the expense of the corpuscles, destroying a certain proportion of them—— in fact, all those attacked ——we look, in the first instance, for a corresponding diminution in the number of the corpuscles—— an oligocythaemia. Oligocythœmia.—— Accordingly, when in malarial disease we come to measure accurately the corpuscular richness of the blood, we do find a decided oligocythæmia. And not only this, but we find a degree of oligocythæmia greatly in excess of anything we might expect; or which can be accounted for by, or is in correspondence with, the proportion of corpuscles attacked and directly consumed by the parasite, judging by what we see in finger blood —— peripheral blood. If, for example, every hundredth corpuscle contains a parasite we might look for something like a quotidian, tertian, or quartan 1-per-cent. reduction in the total number of blood corpuscles; if every twentieth corpuscle contains a parasite—— a very high and unusual proportion—— we might look for a similarly-timed 5-per-cent. reduction.

Now, this is an amount of hæmolysis which should be easily compensated by the latent physiological hæmogenic margin, and which one would not expect to show as a definite anæmia, or would expect to show only after the recurring drain had been kept up for some considerable time. But what are the clinical facts? One or two paroxysms only, of some malarial fevers, may be immediately followed by an