Page:Proceedings of the Royal Society of London Vol 69.djvu/516

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I have received from South Africa specimens of blood taken from cattle which contain a new species of Trypanosoma.

This new species can be at once distinguished from the Trypanosomas of Surra, Tse-tse Fly Disease, or Eat by its larger size, it being almost twice as large as any of the others. In general appearance it conforms closely to the others in possessing an oval protoplasmic body, a longi- tudinal fin-like membrane, and a single flagellum.

This new Trypanosoma was lately discovered by Dr. A. Theiler, who is in charge of the Bacteriological Laboratory of the Medical Officer of Health, Pretoria, Transvaal.

He states that at first he was under the impression that he had merely hit against the familiar Trypanosoma of tse-tse fly disease. He, however, was struck by its larger size, and tried a few inoculation experiments. He found that the new* Trypanosoma only infects cattle. Horses, dogs, goats, rabbits, and guinea-pigs are all immune, neither showing symptoms nor the presence of the parasites in the blood. With the same blood he infected two calves, which showed distinct febrile reaction, and at the same time the parasites appeared in the blood.

He found the parasite for the first time in the blood of a young ox Avhich had just recovered from an attack of rinderpest, and since then has successfully inoculated calves from two other cattle.

He describes the disease as an acute pernicious ansemia with grave blood changes, a general anaemia without deformation of the elements of the blood, or, lastly, only a slight fever, and that there exists a natural immunity in cattle against this Trypanosoma.

He is of opinion that this disease is the same as that attributed by Dr. Kolle who studied rinderpest in South Africa with Koch during the last outbreak to bovine malaria. Dr. Kolle overlooked the Trypanosoma, saw that the disease was infectious, and thought he observed endoglobular parasites and pigment in the red blood cor- puscles.

As this discovery seems to me to be an interesting one, and as Dr. Theiler deserves great credit for the observation, I would propose that this Trypanosoma be named after the discoverer Trypanosoma Theileri.