The first observation of a trypanosome is usually ascribed to Valentin (55), who in 1841 announced his discovery of certain amoeboid parasites in the blood of a trout.
The credit for first recognizing a trypanosome in human blood, and describing it as such, must undoubtedly be assigned to G.
A Trypanosome usually produces markedly harmful effects upon gaining an entry into animals which have never been, by their distribution, liable to its invasion previously.
Nevertheless, the fact, commented upon by several observers, that even here an infected fly is only infectious for a comparatively short period suggests that this species of fly, at any rate, is not the true alternate host in which the life-cycle of that particular Trypanosome is completed.
The main features of trypanosomosis, or illness caused by a Trypanosome, show a general agreement, whichever variety is considered; one symptom may be, of course, more marked than another in any particular case.
G, Hanna's Trypanosome from Indian pigeons.
A Trypanosome always possesses two distinct nuclear bodies, one the trophonucleus, regulating the trophic life of the cell, the other, the kinetonucleus, directing its locomotor activities.
In addition, a Trypanosome whose vertebrate host is yet unknown (T.
According to Schaudinn's account, he was dealing with two separate Trypanosome parasites of the Little Owl (Athene noctua), viz.
Rise to one of three types of Trypanosome individual: indifferent,, male or female.
The development of an indifferent ookinete into, an indifferent Trypanosome is shown in fig.
In short, it is quite possible Schaudinn did not sufficiently distinguish between the life-cycles of four distinct parasites of the Little Owl: a Trypanosome, a Spirochaete, a Halteridium and a Leucocytozoon; though, on the other hand, this is by no means proved.
Brumpt (5a), Leger (32, 33), Keysselitz (16), Prowazek (47), Minchin (41b) and others - has undoubtedly shown that much of Schaudinn's scheme of the life-history of a Trypanosome is well-founded.
- Development of an Ookinete (of Halteridium) into an indifferent Trypanosome (Trypanomorpha).
A very interesting modification of the life-cycle of a Trypanosome which must be mentioned has been made known by Minchin, in his account of T.
Certain individuals of a particular character form definite rounded cysts in the rectum of the fly; in this condition, the only sign of Trypanosome structure is afforded by the two nuclei, which remain separate.
This reveals a quite novel mode by which infection with a Trypanosome may be brought about; so far, however, T.
Lewisi (Kent), the well-known natural Trypanosome of rats (figs.
(As above mentioned, this form may not be a true Trypanosome.) Only one reptilian form is well known, T.
The larger nuclear body, which corresponds to the trophonucleus of a Trypanosome, is usually round or oval; the smaller one, representing a kinetonucleus, has the form either of a little rod or of a round grain, and is generally separate from the larger nucleus.
Nevertheless, the general appearance and structure of these motile forms so greatly resemble that of a Herpetomonad, or of the " pseudo-Herpetomonadine " forms of a Trypanosome which are obtained in cultures, that it cannot be doubted that the " Leishman-Donovan-Wright " bodies are closely connected with the Haemoflagellates.
Billet, " Culture d'un trypanosome de la grenouille chez une hirudinee," &c., C. r.
(1902), 1 34, p. 512; (21) idem, " Sur un trypanosome d'une chouette," C. r.
Mesnil, " Recherches morphologiques et experimentales sur le trypanosome des rats, Tr.
(1902), I, P. 475, figs.; (25) idem, Recherches morphologiques et experimentales sur le trypanosome du Nagana ou maladie de la mouche tse-tse," Ann.
(1903), 1 37, p. 957, figs,; (28) idem, " Sur la nature bacterienne du pretendu trypanosome des huitres, T.
Nepveu, " Sur un trypanosome dans le sang de l'homme," C. r.