132 E. A. MINCHIN AND Ji. M. WOODCOCK. 



differs markedly from T, raiae, as will be seen from our 

 statements below. 



Owing to the scarcity of this parasite very few individuals 

 are present on our stained prepaj-ations. At the most two 

 occur on a film ; more usually only one has been found, and 

 on some smears there appear to be none. All the parasites seen 

 belong to one type and show no pronounced variation in size. 

 Individuals on "wet" smears are generally a trifle smaller 

 than those on " dry " ones ; we think the former are slightly 

 contracted. The average size of the trypanosorae, as seen on 

 Giemsa-stained smears, is 59 u in total length (i . e. inclusive 

 of the flagellnm) by 4"5/i in total width (inclusive of the mem- 

 brane). The free flagellum averages 8 /j in length. Fig. 29 

 shows a typical example of the parasite, with dimensions 

 almost as given. The longest parasite observed (fig. 81) has 

 a length of 62 ^ and a breadth of 4-7 /m. The length may be 

 really 2 or 3 /i longer, as the flagellum is very faintly stained, 

 and its free portion probably continues a little farther than 

 can be made out. On the other hand the parasite from 

 an iron-haematoxylin film drawn in fig. 51 has a total length 

 of only 54 /x and a width of only 4 n, inclusive of the mem- 

 brane; but here also the free part of the flagellum is so 

 faintly stained that we cannot be certain its entire length is 

 represented. 



All the trypanosomes on our slides belong to this long, 

 slender type. The flagellar extremity is narrow and finely 

 tapering (figs. 29—81), a feature which is more usual in these 

 parasites of marine fishes than in those of fresh-water ones. 

 The distance of the kinetonucleus from this end of the body is 

 generally about 6 /u, and may be as much as 7 /u. The free 

 part of the flagellum at the opposite end is comparatively 

 short, and varies from 6 to 10 /n. The trophonucleus is 

 generally in the flagellar half of the body (figs. 29-31), but 

 may be occasionally more centrally placed (fig. 30). The 

 undulating membrane is well developed. It appears under 

 two aspects. In the first, which we think represents the more 

 natural condition, it shows well-marked folds and pleats, of 



