694 
Yendo.—The Development of 
in autumn or early in winter. If they germinate within a short time after 
liberation, the confervoid body observed must itself have passed through 
a resting stage of several weeks. Or, if the confervoid body had only just 
been formed as the result of germination, the spore must have had a certain 
period of rest. I am rather inclined to believe that the zoospores must pass 
through a resting period without germinating. The actual occurrence of this 
has been verified by Williams. 1 Okamura 2 reported on Undariapinnatifida 
that its spores germinated in July, as he observed at Omori, near Tokyo, 
shortly after the liberation of the zoospores. In Tokyo Bay, the young 
blades of that species are first seen late in autumn or early in winter. If so, 
the filamentous sporelings of Undaria must have spent a few months in 
developing into a minute frond. Drew’s recent observation that the game- 
tospores produce several sporophytes after a complicated process adds 
a new and quite different case to those already recorded. His view, how¬ 
ever, important as it is, requires further proof before universal acceptance. 
In the next stage, the apical cell of the confervoid body no longer 
divides in a transverse direction, but by a longitudinal septum through the 
middle point. The longitudinal division extends downwards, leaving a few 
basal cells in the initial state. The result is a linear-spathulate lamina 
constructed with two rows of cells in a single layer, with the monosiphonous 
stipe attached to the lower end. An exactly similar stage has been 
illustrated by Thuret 3 in Saccorhiza bulbosa. 
Another longitudinal division takes place in the cells of the lamina by 
two planes parallel to the first division-plane. The apical two cells, resulting 
from the primary division, do not divide in this case. As a consequence, 
each terminal cell is now seated upon the two newly formed cells. Thus 
the lamina becomes practically composed of four rows of cells disposed in 
a single layer. 
The second division above described begins its action in the cells next 
to the apical pair. The process goes on downwards, segment after segment, 
till it reaches the basal one upon the stipe. 
Successive divisions proceed, after the secondary division has been 
completed. They take place in two directions, the one parallel to the sagittal 
plane and the other passing through the middle of each segment, and 
perpendicular to the other. In any case, the two contiguous cells which are 
seated beneath the apical pair and embrace the axis of the lamina divide 
one step further than the rest. The lamina in these stages eventually 
becomes obovate in outline, the broadest part being at about the level of the 
two cells just mentioned. 
Figs. 1-5, PI. LIII, illustrate the various stages of development referred 
to above, all carefully drawn by the aid of Abbe’s reflecting camera. The 
1 Williams: 1 . c. 2 Okamura : Botanical Magazine, Tokyo, vol. xv, No. 163, 1900, p. 230. 
3 Thuret : 1 . c. 
