60 Verr BrecueR Wrrrrock. 
branched so as to look like claws or hands in two or more branches (pl. 5, figs. 4, 
5, 6,.7 h), with which they grasp smaller objects of an organic origin, especially 
particles of humus and such like things. Sometimes helicoids, ordinarily unbran- 
ched, are developed from cells that are not terminal; these helicoids can now 
have the same position as the normal (pl. 5, fig. 1 h) and now as the acces- 
sorial branches (pl. 5, fig. 3 h). — The spores are partly terminal and partly 
inclosed, and are found in the principal: filament as well as in branches of all 
degrees. The terminal spores are as a rule elongated and cask-shaped with a 
tapering and somewhat rounded top (pl. 2, fig. 13; pl. 4, figs. 13 and 16). As 
exceptions top spores are found, of a somewhat anomalous shape, such as pl. 
2, fig. 13 st and pl. 5, fig. 8 show. (As I have indicated in the paragraph 
treating the formation of spores, this anomalous top spore has without doubt been 
intended, from the beginning, for a helicoid). The inclosed spores can have two 
shapes. They are either swollen and cask-shaped (pl. 5, fig. 2 and pl. 2, fig. 13) 
or, though much more seldom, cylindrical (pl. 5, fig. 2 sc and pl. 2, fig. 13 sc). 
Connecting forms between both are rare. Inclosed spores of an irregular shape 
are found now and then. The anomalons shape most frequently has its cause in 
the circumstance, that the mother cell of the spore had begun, before the formation 
of the spore, to form a branch, but which was not completed; and from this cause 
the unfinished branchlet has come to belong to the spore, when it was afterwards 
formed, making something like a beak pointing upwards from the spore (pl. 2, 
fig. 14 sr, fig. 15 sv). A peculiarity in this species is, in specimens with no rhizoid 
or a rudimentary one, that the thallus is rather often ended downwards in a spore, 
which does then take the place of a rhizoid (pl. 2, fig. 13 syb; pl. 4, figs. 12 and 
14 sgb). The cause of this is, that the spore which has, by its germination, been 
the origin of the whole individual, has resumed its character of a spore when the 
germination was completed, by being filled from above with a protoplasm rich in 
chlorophyll, and by the formation of a new transversal cellwall above. (See more 
in extenso in the paragraph on the formation of spores.) ‘Twin spores are not rare 
in this species. Most frequently they occur in the top of short branches of the 1:st 
and 2:d (or 3:rd) degree, but now and then they are also found in the principal 
filament and in other places (pl. 2, figs. 14 and 15). The lower twin spore is gene- 
rally smaller, but sometimes it happens that they are of about equal size (pl. 2, 
fig. 14). In a couple of cases I have observed in this species triple spores 
(pl. 2, fig. 15 s!, s?, s3), formed in the manner indicated in the paragraph treating 
the formation of spores. Besides the spores formed in a normal manner (i. e. after 
a preceding passing upwards of the chlorophylliferous protoplasm, by bipartition), 
there occur in this species cells of the usual form, which contain, like the spores, 
an abundant quantity of chlorophyll (pl. 4, fig. 18 p). Probably they have the same 
purpose as the prolifie cells mentioned before in P. heewensis nob. q 
Rhizoid part of the thallus. In the germination of the spore a transversal_ 
wall, vertical against the longitudinal axis of the spore, is formed in its midst or 
in its lower part. The part situated below this oblique wall constitutes its rhizoid 
part. This part consists, as a rule, of one cell. Only in one case, the one represented 
pl. 4, fig. 18, I have found, in P. Cleveana nob., a rhizoid formed by more than 
one cell, As the figure here quoted shows, the rhizoid here consists of three cells, 
