172 BOTANICAL GAZETTE [MARCH 
naria, stating that an initial cell divides longitudinally, thus forming 
two daughter elements which produce paraphyses. In demonstration of 
this two paraphyses are figured arising from the base of a many-celled 
structure. Miss Barton does not report the origin of the walls 
of the cryptostoma, but as the initial cell is believed to develop directly 
into paraphyses, we may assume that she believed the walls to arise 
from neighboring tissue in accordance with the views of the earlier 
writers. 
The development of the cryptostoma in Sargassum follows step by 
step the history of the conceptacle. The initial cell arises near the 
apical cell of a leaf or vegetative branch. Longitudinal and cross 
sections of this cell (figs. 12, 12a, m, b) show the same form and struc- 
ture as the longitudinal and cross sections of the initial cell of a 
conceptacle (jigs. 1, 1a, m, b). The activities of the two initials are 
also identical. The initial cell of the cryptostoma divides transversely, 
forming a two-celled structure (fig. 13) which is comparable in every 
way to the two-celled stage of the conceptacle (fig. 2), consisting as it 
does of a tongue cell and a larger lower cell. The lower cell divides 
longitudinally. A group of three cells then results (figs. 14, 15) which 
is entirely similar to the three-celled stage of a conceptacle (fig.3). 
The two lower cells of this three-celled stage then divide longitudi- 
nally in one or more planes, forming a structure which shows four 
or five cells in longitudinal section (figs. 6, 17). The center of this 
structure and of several which follow is occupied by the conspicuous 
tongue cell (figs. 16, 17, 18, 19). Thus by the continued longitudinal 
divisions of the products of the lower cell of the two-celled stage, the 
walls of the entire structure are gradually developed. Paraphyses 
begin to appear in the cryptostoma (jigs. 18, 20) as early as do the 
sexual organs in the conceptacle (fig. g). The activity of the wall 
cells in producing paraphyses, however, does not interfere with their 
functioning further in developing the cryptostoma (fig. 21). Enpider- 
mal cells at the mouth of the cryptostoma form here, as in the concep- 
tacle, a marginal ring one or two cells deep (compare figs. 8 and 19). 
The origin of the true walls of the structure, however, may be traced 
as in the conceptacle to the lower cell resulting from the transverse 
division of the initial. 
The behavior of the tongue cell in the cryptostoma is similar to 
