125 
In the present paper the author treats at considerable length 
the germination of the spore and the development of the prothal- 
lium and sexual organs, and gives a few very brief notes upon 
the embryo. 
The structure of the spores, and the first phases of germina- 
tion are treated very minutely, and are briefly as follows: The 
ripe spores are destitute of chlorophyll, of a yellow color, and 
possessing a membrane that shows a differentiation into three 
layers, perispore, epispore, and endospore, none of which are 
composed of unaltered cellulose. 
Shortly after sowing the spores chlorophyll is formed, and 
the spore membrane is ruptured, allowing the enlarging contents 
to protrude in the form of a papilla, which together with the rest 
of the spore contents, is now surrounded with a cellulose wall. 
The early stages of the prothallum do not differ in any marked 
degree from those of other Leptosporangiatz, resembling, per- 
haps the Osmundacee most nearly, especially in the not infre- 
quent formation of a cell- mass as the first stage of the prothallium. 
The prothallium usually grows for some time by a two-sided apical 
cell, which is later replaced by a row of equal marginal initials, as in 
otherferns. Sometimes, as in the Osmundaceze, a thickened midrib 
is formed very early, but usually the thickening is confined to the 
cushion back of the notch in front, as in the Polypodiacee. A 
tendency to form numerous lateral branches, capable of independ- 
ent growth, and a multiplication of the prothallia by this means, is 
shared with the Osmundacez. 
The development of the sexual organs, especially the archego- 
nium, is not treated with as much care as could be wished. The 
antheridia, in their development, are midway between the 
Osmundacez and Polypodiacee but one or two statements made | 
require confirmation. This is especially true of the statement 
that chlorophyll is found in the central cell of the young antheri- 
dium, as well as in the peripheral cells. This is certainly con- — 
trary to what obtains in all other investigated archegoniates, and 
as figure 58 of the memoir in which this is shown evidently 
represents a pathological case, as is evident from the collapsed 
condition of the central cell, the statement is probably incorrect. 
The account of the spermatozoids is also very confused, and the 
EN: 
