N. H. SWELLBNGREBEL 
471 
the right-hand granule is still aflagellar. In this case the tilament 
uniting the basal granule to the blepharoplast is very distinct, it shows 
only the beginning of a longitudinal division, its fission follows that of 
the basal granule. This figure shows that the flagellum is divided 
before the blepharoplast. Fig. 2, a “ leptomonas,” shows the same as 
fig. 1, only here no connection is to be seen between basal granule and 
blepharoplast. Here the right-hand granule produces a flagellum which 
as yet is very short. It shows that there is no sharp differentiation 
between the flagellum and the basal granule, but that the latter is only 
the thickened basal part of the first. Fig. 3 is similar to fig. 2 only here 
the right-hand granule is more developed. Flagella in different stages of 
growth may be seen also in figs. 1 and 2 (Diagram VII). Fig. 4 shows 
how the undulating membrane is produced, the flagellum not piercing 
the blepharoplast, but pushing it forward, when growing out (fig. 4). 
Figs. 5—7 show the same phenomena in small trypanosomes, fig. 5 
shows the division of the basal granide, figs. 6 and 7 the growing out of 
the new flagellum. 
The thickened base of the flagellum (basal granule) is consequently 
the active part of this organellum; it divides and by growing out 
produces a new flagellum. The blepharoplast has nothing directly to 
do with it, except that the basal granule is united with the latter and 
so in a certain sense forms a part of it. The basal granule was never 
seen to be formed by the blepharoplast, nor did it produce the flagellum 
by a division (as is the case in T. noctuae). 
It seems that the basal granule, which is very distinct during the 
division of the flagellum, disappears after division is over. This 
seems to indicate that it is not an independent organellum as are the 
blepharoplast or the nucleus but only a part of the flagellum itself, 
endowed with a special function. 
(e) Different forms of the trypanosomes during the p)eriod of 
division. (Diagram XI.) During this period there is a marked poly¬ 
morphism among the full-grown cells, affecting the length and breadth, 
the undulating membrane, the free flagellum and the way in which the 
protoplasm is stained by Giemsa. 
Figs. 1 and 7 are two extreme types : tig. 1 short and broad, with a 
short free flagellum, the protoplasm staining dark blue; fig. 7 slender, 
spirochaetiform, with a long free flagellum and protoplasm staining 
violet. The first trypanosome is of the “ female ” type, the second of 
the “male” type. Between these two are all sorts of intermediate forms 
(figs. 2—G), so I do not think that in this case the dimorphism has 
