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III] slight feeling of chilliness, the fever is said to remit to be a remittent. Sometimes there is no remission; such a fever is said to be continued. It occasionally happens that two distinct pyrexial attacks come off the same day; such a fever is said to be double. All sorts of blendings of malignant infections, benign tertians, and quartans occur; in such the infection is said to be a mixed infection.

Relation of the phenomena of the fever lit to the stages of the parasite.—— All the differences and peculiarities in the clinical phenomena of a malarial attack, complicated and hard to interpret in many cases though they be, are, it is believed, directly correlated to the phases of the intracorporeal life of the parasite; this organism is, in fact, the key to their interpretation. As already mentioned, as the time of rigor approaches, the pigment of the parasite, hitherto scattered throughout the substance of the little animal, becomes concentrated, and segmentation proceeds. Shortly before and during rigor, and as a direct cause of rigor, these segmented parasites are breaking up and, presumably, liberating their toxins. At the end of rigor, during the hot and during the sweating stages, the young parasites of the new generation the small intracorpuscular bodies and the leucocytes carrying the hæmozoin liberated at the breaking up of the segmented bodies—— are in evidence, and the toxins liberated, at the same time are being eliminated. During the interval the intracorpuscular parasites grow, become pigmented, and prepare for maturation. From the fact that parasites are present in the blood during apyrexia, and often in great abundance, it is evident that it is not the mere presence of the parasite in the blood corpuscle that causes the fever; most likely, as suggested, the pyrogenic agent is some toxin which is liberated and becomes free in the liquor sanguinis on the breaking up of the parasite. Consequently, we find that in remittent and continued types of malarial fevers segmenting parasites may be met with at all stages of the fever; and, conversely, that when parasites at all stages of development are