1 88 
Wager . — The Life-history and 
succeed, and swim rapidly away. The last two or three zoospores left in 
the sporangium sometimes find some difficulty in getting out, especially if 
the sporangium is a large one ; they swim about inside it, with apparently 
no sense of direction, for several minutes sometimes (Fig. si), but ultimately 
they find the opening and escape. In one case it took about five minutes 
for a sporangium with about 128 spores to empty itself, except for the three 
last spores, which were apparently unable to find their way out, and the 
last one of the three only succeeded in getting out at the end of 12-J minutes 
from the time the sporangium opened. In some cases the zoospores remain 
for a few seconds near the opening of the sporangium in a quiescent con- 
dition ; then with a slight jerking movement, as if to disentangle their cilia, 
they swim away. After moving about rapidly for about twenty minutes 
the spores come to rest for a few seconds now and then. They then begin 
to move about in a very jerky fashion, often resting for a few seconds. By 
7.10 p.m. only three could be observed in the neighbourhood of the empty 
sporangium : all the others had moved away completely from the field 
of view. At 7.15 I observed these three settle down, but they retained their 
cilia and remained in an intermittent quivering state for some time. At 
8.10 they had lost their cilia and were quite still and beginning to round 
themselves off into a spherical form (Fig. 49). 
The sporangia vary very considerably in size, and the variation in the 
number of zoospores produced is equally great. Nowakowski found in one 
case, in an asexual sporangium, that only two zoospores were formed, and 
I have constantly found sporangia in which from eight to sixteen zoospores 
only were formed. This variation in the number of zoospores appears to 
depend upon the amount of nutriment which can be stored up in the zygote, 
or upon the number of Euglenae attacked by a single individual. For, as 
I have constantly observed, the asexual sporangia are larger at the be- 
ginning, when the nutriment is more abundant, than at the end of an attack 
when the nutriment has been exhausted. The number of zoospores pro- 
duced in the asexual zoosporangia is as a rule much larger than those 
produced in the sexual zoosporangia. 
In stained specimens it is found that preparatory to germination the 
chromidial mass in the zygote loses to some extent its capacity for stains 
and is much less conspicuous (Fig. 74), allowing the two nuclei to come 
more clearly into view (Fig. 75). On germination, whatever is left of it 
passes with the two nuclei (Figs. 76-81) into the sporangium and there 
becomes disseminated throughout the cytoplasm. The two nuclei, which 
now stain more deeply but are still very small and quite unlike the primary 
nucleus of the asexual sporangium, come into close contact with one another 
(Figs. 79-81) and apparently fuse (Fig. 82). The exact process of fusion 
has not been observed, and it is quite impossible to say whether the 
chromosomes fuse together or become merely intermingled, to separate later 
