of the Genus Doassansia , Cornu. 5 
of the sorus at this stage shows the central portion to be filled 
with a mass of parenchymatous tissue, composed of rather 
large, thin-walled, polygonal cells, while the outside is covered 
by several compact layers of fine, almost unaltered hyphae. 
The large cells of the interior form the spores, and the process 
is accompanied by a gelatinization of the walls. The spores 
are nearly ripened before the cortical cells are indicated as 
such. The latter appear just under the now somewhat dimi- 
nished layer of hyphae, and seem to arise by the transforma- 
tion of an outer layer of cells in all respects similar to those 
from which the spores are formed. They gradually become 
elongated radially, lose their granular contents, and take on 
the brown colour of the wall characteristic of maturity. 
When the sorus is mature, the spores separate readily from 
one another and are ready to germinate. Many of them 
germinate while still in the leaf, especially if the leaf happens 
to be submerged. If the spores are freed from the sorus in 
a little water on a slide, and set aside in a moist chamber, the 
details of germination may easily be followed. This was the 
method employed in obtaining the account given below. The 
first germinations were obtained from the fresh material at 
Sharon Springs, N. Y. ; the later ones from dried material 
from the same place in the laboratory at Cambridge, Mass. 
The spores swell slightly on being placed in water, and the 
oil-globules become very conspicuous. In most cases there 
is only one (Figs. 1 and 2), but not infrequently there are three 
(Fig. 3) or four. After a few hours, the spore-coat bursts and 
a small germ-tube begins to protrude (Figs. 4 and 5). Usually 
the oil-globule or globules begin to approach the entrance to 
the tube at this time (Figs. 4 and 5). The germ-tube, or 
promycelial tube, elongates until it attains a length of 40 /x to 
50 j ix. The contents of the spore have gradually been with- 
drawn to fill the tube, and with them the oil-globules (Figs. 6 
to 9) ; the latter have split up into smaller and smaller globules 
until they are finally much reduced in size (Fig. 9). When the 
promycelial tube or promycelium has reached its full length, 
it begins to appear notched at the tip (Figs. 9 and 10). The 
