Page:Popular Science Monthly Volume 50.djvu/649

Rh pointed and transparent and have a pigment spot; also as spherical bodies, about the diameter of a red blood-corpuscle, showing active movements and containing in their interior numerous pigment granules. The movements of these bodies are due to the action of elongated filaments attached to their circumference—flagella. A third form in which these parasites present themselves in the blood is as motionless, spherical, or irregular-shaped bodies containing dark-red, rounded pigment grains. These bodies have no nucleus, and do not stain with carmine; they appear to be the ultimate stage of development of the above.

"The blood also contains free pigment granules, pigmented leucocytes, and vacuolated red corpuscles which contain pigment granules.

"These parasitic elements have only been found in the blood of persons sick with malarial fever, and they disappear when quinine is administered.

"They are of the same nature as the pigmented bodies which exist in great numbers in the vessels and organs of patients dead with pernicious fever, which have been described as melanotic leucocytes. Laveran, at the time his report was published, had found these bodies in one hundred and eighty out of one hundred and ninety-two persons examined in Algeria and in Tunis who were affected with various symptoms of malarial poisoning.

"The presence of the parasite described by Laveran in the blood of persons suffering from malarial diseases is confirmed by Richard, who has studied the subject at Philippeville, France, where malarial diseases abound. This author has invariably found the parasite of Laveran in the blood of malarial-fever patients, and has never seen it in the blood of persons suffering from other diseases. He finds that its special habitat in the blood is the red corpuscles, in which it develops and which it leaves when it has reached maturity. During the attack of fever many blood globules are seen which possess a small, perfectly round spot. Otherwise they preserve their normal appearance; they are simply, so to speak, stung (piqués). Beside these globules are others in which the evolution of the microbe is more advanced. The clear spot is larger and is surrounded by fine black granules. The surrounding hæmoglobin forms a ring which decreases as the parasite augments in volume. After a time only a narrow, colorless zone remains at the margin. This corresponds with the body No. 2 of Laveran, ‘having about the dimensions of a red corpuscle and inclosing an elegant collarette of black granules.’ This collarette is the microbe which has arrived at its perfect state, and which is provided with one or several slender prolongations, measuring twenty-five micromillimetres or more in