Davis . — Spore Formation in Derbesia. 9 
a funnel, and granules apparently pass outward to the plasma membrane. 
After the blepharoplast is formed the nucleus returns to the centre of the 
cell. This important work being accomplished, it is probable that the 
nucleus maintains connexions with the blepharoplast by very delicate 
protoplasmic strands, although such conditions would not be easily 
observed in Derbesia because of the numerous and crowded plastids. 
The characteristic clear areas at the tips of most zoospores of various 
algae indicate that these regions are occupied by protoplasm, which is 
kinoplasmic in character, and consequently likely to hold vital relations 
to the nucleus. It is clear that the blepharoplast of Derbesia is not a 
development from the plasma membrane, but from granules closely 
associated with protoplasm investing the nucleus. 
The Germination of the Zoospores. 
As has been stated, the zoospore comes to rest on the region of the 
protoplast within the circle of cilia, which spread out in a radiating 
arrangement over the surface to which the zoospore becomes attached 
(Fig. 2). The spore generally forms a small papilla at this region, which 
develops into a simple holdfast. The blepharoplast may be easily found 
during the earlier stages of germination. Fig. 28 (Plate II) shows the base 
of a germinating spore, the nucleus of which had not yet divided ; the 
blepharoplast appears in section, and it should be noted that the two 
rings are much more delicate than in the zoospore, although the magnifica- 
tion is twice as great. The nucleus or nuclei in the germinating spores 
come to lie near the periphery of the cell because of the development 
of a central vacuole which forces the protoplasm to take position just 
under the cell wall. Fig. 29 shows the base of an older sporeling which 
contained several nuclei ; the two rings of the blepharoplast are somewhat 
separated here. In both figures the blepharoplast is evidently pressed 
very close against the cell wall, which has been formed, and appears now 
to lie in the plasma membrane. The blepharoplast becomes fainter in 
older stages of germination, and can be found only with difficulty. It 
fades away, and probably at last entirely disappears. 
The mitoses in the germinating spore are difficult of study because 
the nuclei are so small. It is, however, very clear that the resting nucleus 
contains besides the nucleolus a chromatin network (Fig. 30) in place of 
the chromatin body, which is so characteristic of the nuclei that enter the 
sporangia (Figs. 6 and 7). This network, as has been shown, develops 
gradually in the nuclei accompanying the breaking up of the chromatin 
body into irregular cloudy masses. 
The chromatin network changes before mitosis into a spirem, upon 
which deeply-staining chromatin granules may be easily recognized. I 
