Lewis . — The Life History of Griffithsia Bornetiana. 651 
Wherever the second method of cell-division occurs, the partition 
is in one plane, never arched. In all the cases examined in which division 
occurred by the ingrowth of a cellulose ring, the partition cut into the 
central vacuole, so as to cut off a segment containing part of the vacuole of 
the mother-cell ; in the first method of division, however, the segment cut 
off is at first solid. The relation of the cleavage plane to the vacuole seems 
to determine the method of cell-division ; in the division of the vegetative 
cells, where the cleavage plane occurs so as to cut into the solid proto- 
plasmic accumulation in the apex of the cell, division takes place by the first 
method. Where the plane of division is sufficiently removed from the apex 
to allow the partition to cut into the central vacuole, division is by the 
second method. 
As mentioned above, the nuclei appear to take no part in cell-division. 
This seems to be the rule in coenocytic cells (Strasburger, 77 ), though 
Wille has noted an apparent exception in Acrosiphonia ( 89 ). 
The number of nuclei in the smaller daughter-cell just after its formation 
is various. The average number is between 12 and 20, but in some cases, 
and always following the second method of cell-division, the number is 
considerably greater. The cell next below the apex may show 30-350 
nuclei. 
Branched hairs are frequently borne on the upper borders of the 
younger cells. There are usually six or seven of these around each node on 
which they occur. 
Their mode of origin is very similar to that of the tetrasporic filaments 
to be described later. Small papillae arise nearly simultaneously around 
the upper border of a cell near the cross-partition, each papilla containing 
a single nucleus and dense, homogeneous cytoplasm. The papillae are cut 
off from the protoplast by an arched membrane, similar to that formed 
in the division of some of the vegetative cells. The nucleus now divides, 
and one of the daughter-nuclei wanders into a bud from the papilla, the bud, 
with its nucleus, now becoming cut off. A second, a third, and sometimes 
a fourth bud are formed and cut off like the first. Each of these daughter- 
cells behaves in the same way, cutting off three or more buds, and in this 
way a thrice compound hair is formed (Fig. 42). Each of the terminal cells 
divides into two. The basal cell of a hair becomes multinucleate, as do the 
cells of the first order of branching ; the cells of the second order of branch- 
ing remain uninucleate. The basal cell is connected with the cell on which 
it is borne by an intercellular connexion of the same type as that which 
occurs between neighbouring vegetative cells. 
After they are fully formed, the hairs elongate greatly and become 
hyaline. Each cell takes part in the elongation. A vacuole is formed 
in the cytoplasm which increases in size as the cells elongate. A very thin 
layer of cytoplasm lies between this vacuole and the cell-walls ; in the outer 
