1914] HUTCHINSON—MALE GAMETOPHYTE OF ABIES 153 
In the late telophase no well defined cell plate is formed, 
although thickenings of the fibers may occur (fig. 9). The central 
fibers of the spindle disappear, either ceasing to be differentiated 
by the stain, or, as is more probable, they move out and become 
peripheral (fig. 10). Gradually the spindle widens and moves 
away from the tube nucleus, thereby inclosing the generative cell 
in the form of a hollow globe (figs. 10 and 11). The fibers continue 
to move upward until they come in contact with the wall of the 
second prothallial cell (figs. r2 and 13). Meanwhile the cell mem- 
brane is formed in the position occupied by the peripheral fibers. 
When the wall is complete the fibers have disappeared. Although 
derived from the spindle, the cell wall does not originate from a 
cell plate, but from the fibers after they have surrounded the 
generative nucleus. Whether or not the fibers fuse laterally is 
difficult to determine; that they are very numerous and form a 
dense, almost continuous, envelope about the generative nucleus is 
shown in a polar view (fig. 14). The definite cell membrane which 
is formed is best shown in cross-section. Fig. 15 represents such a 
section of a cell at the stage shown in fig. 13. 
These peculiarities may perhaps be accounted for by the fact 
that the division is internal, and only one of the resulting nuclei 
is inclosed by a wall; hence this method of delimiting the cellular 
Protoplasm. One is reminded of the formation of the plasma 
membrane about the ascospore of Phyllactinia as described by 
ER, 
McMaster UNIVERSITY 
Toronto, CANapa 
