Laboulbenici chaetophora and L. Gyrinidarum . 343 
spore. The astral rays are observable up to this time, and in older stages 
lie much farther inward towards the nucleus and away from the limiting 
membrane than in the earlier stages, or for that matter in any other asci 
I have yet seen. They have been found here even more or less twisted 
about the attenuated neck of the nucleus (Fig. 64). These phenomena in 
themselves, even were lateral fusion of the longitudinal ribs of a globe 
physically possible, which is certainly not the case, are sufficient evidence 
that they do not fuse to form a protoplasmic membrane. The cavities in 
which the spores lie also appear to be lined by a protoplasmic membrane. 
The central body finally loosens its connexion at the older pole of the spore 
and takes up its position on the surface of the now spherical nucleus (Figs. 
65 and 69). 
The long axes of the spindles of the third mitosis lie in the long axis of 
the ascus, consequently the asters are directed towards the upper and lower 
ends of the ascus respectively. Since there is no relative change of position 
during spore-delimitation it is possible to state with almost absolute certainty 
that the lower daughter nucleus of each spindle functions as a spore-former. 
That they lie approximately side by side in two pairs is merely a natural 
consequence of the disposition of the four nuclei of the second generation 
(Figs. 57 and 63). The upper daughter nuclei, on the other hand, initiate no 
spores, and pass at once to the upper end of the ascus (Fig. 65), where they 
eventually disintegrate. 
Spores. 
From the first the spores lie with their long axes parallel to the long 
axis of the ascus. Almost spherical at the outset, they become broadly 
elliptical, then continuously more narrowly elliptical until their normal 
mature form is attained (Figs. 63-6). During the earlier stages of growth 
the nucleus remains at the upper or younger pole of the spore. At the same 
time chromatin is distinctly aggregated in proximity to the central body, 
simulating in a more or less striking manner the phenomenon of synapsis. 
Later the nucleus moves down well past the middle of the spore and there 
undergoes an ordinary homotypic mitosis, the chromosomes numbering four 
(Fig. 70). The spindle elongates somewhat and a thin septum is quickly 
formed between the daughter nuclei, dividing the spore into two cells. 
Whether or not a simple plate is formed progressively from the periphery 
of the spore inward I cannot say. Fibrils, possibly the spindle threads, 
may be seen passing from the nucleus to the young septum, and often 
a small plug lies at the centre of the plate, such as is represented in Fig. 67. 
Presumably there is a protoplasmic bridge, but only special refined methods 
would bring it out. The spore now completes its growth, and in addition 
to the ordinary wall, finally clothes itself with a gelatinous sheath which is 
A a 2 
