Lewis. — The Life History of Griffithsia Bornetianct. 649 
Chromatophores apparently are absent from some lateral cells when 
first cut off ; nor have they been seen in the young procarps, in the hair- 
cells, in the stalk-cells of the tetrasporangia, or in the young tetrasporangia. 
While no leucoplasts have been demonstrated in these cells, it is possible 
that they are present. 
In dividing, the chromatophores simply pull apart. They first elongate 
and the pigment collects in each end ; then they assume approximately 
a dumb-bell shape ; and finally either separate completely, or more usually 
remain connected by a fine strand, as though the division were not quite 
complete (Fig. 33 ). 
Starch is normally present in the vegetative cells, as has been found 
to be true of Florideae generally by Biitschli (15), Bruns (14), Kolkwitz 
(50), and others. It occurs as very small granules in circular groups, or as 
larger granules lying in the cytoplasm between the chromatophores. Each 
starch grain is rounded or oval, usually with a dark centre ; no signs of 
lamination have been observed. Starch is especially abundant in sporelings, 
and in the cells of the attaching organ. 
Besides the starch grains, there are normally present in the cytoplasm 
rounded masses of various sizes of what seems to be proteid material. 
These spheres usually occur in small groups, each group being surrounded 
by a clear area. The groups seem to be specially abundant in the cells at 
the time of nuclear division, and often simulate nuclei (Fig. 9 ). Spheres of 
what seems to be the same material are usually present in the pads of 
protoplasm lying on the cross-walls, and small bits have been observed 
lying in the cytoplasmic strands connecting neighbouring cells (Fig. 6 ). 
Cell-division in Griffithsia is remarkable for the disparity in the size of 
the daughter-cells. It was first described by Wright (91), whose account 
was supplemented by the observations of Berthold (7). 
In the vegetative cell, division occurs ( 1 ) by the cutting off of daughter- 
cells from the terminal cell of the filament, ( 2 ) by the cutting off of small 
dome-shaped segments from the upper borders of cells below the apex. 
The first type of division simply increases the length of the filament, the 
second results in the formation of a new branch. 
There appear to be two methods of cell-division. The first occurs 
most commonly in the larger cells, and is always preceded by an accumu- 
lation of cytoplasm, nuclei, and to a less extent of chromatophores, which 
forms a dense, more or less homogeneous mass in the terminal portion of 
the apical cell (Fig. 34 ). A thin dome-shaped membrane is now laid down, 
with its convexity towards the apex, cutting a solid accumulation of 
protoplasm from the tip of the cell (Fig. 35 ). This membrane is formed 
simultaneously over its whole extent. There is no trace of cleavage in 
connexion with its formation, the protoplasm being in contact with it on 
each side. The nuclei appear to have nothing to do with its formation, 
