ALGOLOGICAL NOTES. 
91 
four, but are larger, and run up into an irregular and looser 
arrangement, the earliest stage of the formed spores, with a diam. 
of 10-13 /x (Fig. 13 b). Finally, scattered loosely in the hyaline 
tissue of the thallus, there are the spherical spores, up to 15 /a 
in diam., with a distinct cell-wall (Fig. 13c). 
A longitudinal section of the lamina shows its thickness to be 
25 /x near the base, and 30 /x at the uppermost part. At a short 
distance above the base the elongated green cells are arranged in 
pairs, end to end, in a direction perpendicular to the plane of the 
lamina. These divide, making a row of four (Fig. 14a), and are 
rather more developed than those of the surface view in Fig. 13a, 
and the thickness of the thallus is almost completely filled by them. 
No further division takes place, but they enlarge until they dis- 
place themselves and are irregularly scattered and mature 
(Fig. 145). 
The plants which produce the small bodies have a similar 
appearance to the sporiferous ones for some distance from the 
base of the lamina, excepting that the surface view shows a looser 
texture and a less regular arrangement in groups of four (Fig. 
11a), but this soon runs into the groupings of fours, the size 
being smaller (Fig. 116), and yet smaller (Fig. 11c), until the 
final division is reached, always in fours, and the breaking up is 
shown by the minute particles in the dissolving hyaline tissue 
(Fig. lie?). 
This examination of the surface, although sufficient to show 
that segmentation is repeated, would, however, fail to indicate the 
process in the interior of the thallus, which must be learnt by a 
comparison with a longitudinal section. The thickness of the 
lamina throughout is 30 fx. In the lowest region the cells are in 
pairs, about 5 fx thick, and 9 fx long, and there is a wide hyaline 
border formed by the sides of the lamina (Fig. 12a). A little 
higher the pair become two transverse rows of four each, these 
rounded cells having a diam. of 4 fx (Fig. 12 b). Enlarging and 
dividing again in three directions, so that each produces eight 
segments of 3 /x (Fig. 12c), the last stage is reached by a similar 
process repeated, and thus, finally, the thallus contains between its 
sides a row of sixteen corpuscles in eight pairs (Fig. 1 2d). 
These minute bodies have then a diam. of 1*5-2 /x, and only one- 
eighth or one-tenth that of the spores (Figs. 15, 16). They are 
almost uncoloured, and show only a slight granulation, with no 
trace of a cell-wall. On the other hand the contents of the spore 
are very dense, vividly green, with a slight projection or two, and 
are enclosed in a pretty thick wall. 
I think it must be concluded from the foregoing that we have 
in these minute bodies the male organs of Prasiola. Indeed, this 
was the suggestion of Dr. Bornet on an examination of specimens 
I sent him. In a sporiferous plant several pollinoids can be seen 
adhering to the surface, and I have observed some in a section. I 
