6 1 2 Wolfe. — Cytological Studies on Nemalion. 
demonstrated, although with several other Florideae entirely satisfactory 
tests were obtained with iodine. The inner surface of the chromatophore 
surrounding the vacuole presents a granular appearance (see Figs. 24 and 
25), but the nature of these granules was not further investigated. 
Assuming, then, that the views above expressed are correct, the 
chromatophore may be described as consisting of a hollow ellipsoid with 
vacuolar contents, the thick wall of which, granular on its inner surface, 
becomes gradually less dense in its peripheral region, whence numerous 
diverticula radiate to the cell-wall, within which they form a continuous, 
thin, clathrate membrane. 
Division of the Chromatophore . 
The accounts that have been given of this process in other plants 
suggest a considerable degree of variability in the process ; Davis, for 
example (’ 99 ), has figured a simple elongation and constriction as accom- 
panying the division of the single chromatophore in the spore-mother-cell 
of Anthoceros. Chmilowsky (’ 97 ), investigating the mode of multiplication 
in several green Algae, finds that contemporaneously with the division of 
that body the chromatophore splits from centre to circumference. 
The process in Nemalion is somewhat different, and recalls in appear- 
ance at least the method of cell-formation by gemmation so characteristic 
of this plant. In this connexion it should be noted that cell-formation 
precedes nuclear division by a considerable period. When the daughter- 
cell has very nearly reached its adult size, the thick wall of the central 
body of the chromatophore bulges out toward the young cell as if pushed 
from within (Figs. 26, 27, and 29). The bulge increases in size until the 
two together present the appearance of one elongated chromatophore 
(Fig. 30). Soon after this a slight constriction may be observed (Fig. 31), 
which rapidly increases until the two walls of the central body are in 
contact, when the two daughter chromatophores begin to separate from 
each other (Fig. 32). 
At about the time when this separation occurs, the cytoplasm loses 
its granular character, and becomes absolutely hyaline in the region that 
marks the position of the wall which is to divide the two cells (Figs. 32 
and 33). The appearances presented in these figures, and in Fig. 34, 
suggest that the cytoplasm in this region is transformed into the substance 
of the future wall. 
As can be seen from the figures, there is no exact correspondence in 
time between the events of nuclear and chromatophore divisions, although 
in general the nucleus divides contemporaneously with the chromatophore. 
The conditions seen in Fig. 28, which represents a terminal cell of a fila- 
ment of the young cystocarp, suggest that the process may be very 
