1896. ] The Development of Nemalion. 345 
form fascicles of branches by dichotomous division (fig. 
I, g). 
Thus tracing these different filaments to the tip, we find at 
the very last three main axial threads (fig. 11, 7, 2, 3) bearing 
lateral fascicles and ending in three distinct fascicles, 4, 5, 6, 
each bearing single arms, 7, 8, 9. like those formed lower 
down on the frond. These single arms, 7, 8, 9, by their in- 
ctease in length will extend upward beyond the divided arms 
or fascicles of branches, and by later division increase the 
length of the whole frond. 
Increase in diameter is produced by the pushing to the 
petiphery of direct or lateral branches of the axial filaments. 
These divide dichotomously to form new fascicles (fig. 11, 
4g, etc.). Very young tufts are thus found with fully fruited 
ones at the base of even the oldest fronds. Young undevel- 
oped trichophores are found in the next fascicle to one bear- 
ing ripe cystocarps. Agardh’s description of the mode of the 
development of the Nemalion frond is interesting, at this 
point, § 
Agardh states that the frond consists of three regions, ‘‘cen- 
tral, lateral and peripheral.” The peripheral branches grow 
'st, and send their branches inward, making the increase in 
diameter of the frond ‘‘like that of an endogenous tree from 
the outside to the inside.” ‘ 
definite resemblance between the structure of the tip of 
pe frond and the sporeling tip both in respect to the fascicu- 
Clearly seen. Both of these conditions have been already de- 
“ribed. The possibility of the development 
F l 
already been mentioned (fig. 14). The meeting of severa 
te "4 7 ite 
dean different strata of the frond seem to me to be peo i pig 
Wloped i Fitsts unless I am deceived, the peripheric strat Wt) 1 anches 
latter, at § : rected 
: : rst, by an ob ique course are hare urse. 
a then they take a dows wai direction, by 4 ep ee 
Pects, therefore, the growth of an endogenous ste 
