228 THE HAEMOFLAGELLATES 



the other. Four days later the intestine contained numerous 

 Trypanosmes which could be readily distinguished as belonging to 

 one of Schaudinn's three types namely, indifferent, male, or female. 

 The male forms are very elongated and slender, provided with a 

 minute rostrum at the aflagellar end, and with a well -developed 

 flagellum at the opposite extremity, which renders them extremely 

 active ; they also creep or crawl with the rostrum in front. Their 

 cytoplasm is very clear and usually lacks granulations. Female 

 forms, on the contrary, are large and broad, with deeply staining, 

 usually granular cytoplasm ; the flagellum is only feebly developed 

 and the movement is sluggish. The indifferent individuals occupy 

 in most respects an intermediate position between the other two 

 types. A point of importance is that the kinetonucleus frequently 

 lies in about the middle of the body, and may be close to the 

 trophonucleus. There can be no doubt, it may be here remarked, 

 that these different sets of forms are of regular occurrence in, at 

 any rate, certain Trypanosomes. Since Schaudinn first described 

 them several observers have recognised them, in some instances in 

 the Vertebrate host, but always more sharply differentiated in the 

 Invertebrate. In general, the three types show the same charac- 

 teristics as noticed in the case of T. barlatulae. The indifferent 

 forms, Leger states, underwent active multiplication, by equal 

 fission ; those females which divided did so very unequally, by 

 a process somewhat like budding. The manner and form in which 

 the parasites passed back into the fish were not ascertained. 



'In his valuable contributions on the behaviour of Piscine 

 Trypanosomes in leeches, Brumpt (11) has noted developmental 

 phases of T. granulosum of the eel in Hemidepsis. Some hours 

 after arrival in the stomach of the leech, all the parasites become 

 pyriform, and by the position of the kinetonucleus close to the 

 trophonucleus recall Lager's Crithidia-typQ (see below). By active 

 multiplication, an enormous number of little forms are produced, 

 which by the end of forty-eight hours have nearly all passed into 

 the intestine. Here they rapidly become elongated, assuming a 

 Herpetomonad-form, which may be retained for several months. 

 Some, however, by the end of seventy-two hours, have given rise to 

 true Trypanosoma-forms, with typical undulating membrane, which 

 pass forwards towards the stomach, and may be found accumulated 

 in the foremost stomach-coeca and in the proboscis-sheath by the 

 fifth day. These are the forms which are inoculated into the eel, 

 becoming by simple elongation ordinary T. granulosum again. 



Miss Robertson has published (72) some interesting observations 

 on a Trypanosome met with in Pontobdella muricata, which she 

 regards as T. raiae. This view is rendered extremely probable from 

 the fact that Brumpt (10) has found that T. raiae does develop in 

 Pontobdella. According to both authors the earliest phases occurring 



