14 Brannon . — The Structure and Development of 
Presently these small spherical bodies separate from their 
mother-cells and pass into the gelatinous layer which covers 
the patches of antheridia. 
These antherozoids are non-motile, consequently depending 
upon water-currents for distribution so as to come into contact 
with trichogynes. Repeated tests for their nuclei gave 
negative results, though the granular contents show deeply- 
stained fragmentary particles. 
Because the male plants are smaller and apparently much 
more rare than the female, and produce non-ciliated anthero- 
zoids, it is obvious that the male plants must generate an 
extraordinarily large number of them. This demand is 
abundantly supplied by the myriads of antherozoids developed 
in the apical manner described above. 
Development of the Cystocarp. 
The method of the development of the cystocarps, which 
are promiscuously distributed on either side of the female 
frond of Grinnellia , appears more difficult to harmonize with 
the theory of Schmitz than does the manner of formation of the 
frond and the antheridia. The study of the initial develop- 
ment of the cystocarp, however, not only shows that it 
conforms to his theory of the development of most of the 
Florideae, but further testifies that the whole tissue of this 
leaf-like Alga is developed by apical growth of ramifying 
threads. In the apical and marginal regions of partially 
mature female plants, and distributed promiscuously over the 
entire surface of young female fronds, are isolated individual 
cells assuming a triangular shape (Fig. io). They are 
directed apically outward and upward in such a manner 
that if a line were drawn through the long axis of any one of 
them to the median plane of the frond, an angle of 50° to 75 0 
with the midrib would be formed. These are centres of 
active growth, and develop groups of cells (Fig. 1 1 and Fig. 12) 
similar in appearance and outline to those at the apices of 
the growing plants. After twenty to thirty cells have been 
