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 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 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.
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.
According to Schaudinn's account, he was dealing with two separate Trypanosome parasites of the Little Owl (Athene noctua), viz.