CHAP. III. 
MARSILEACEiE. 
263 
Their organs of reproduction are kidney-shaped two-valved 
cases, called tliecce^ sporocarpia^ conceptacles^ or capsules^ either 
1. filled with minute powder-like granules, which, in conse- 
quence of lateral compression, from being spherical, acquire 
the figure of irregular polygons; or 2. containing three or 
four roundish fleshy bodies, marked at the apex by a three- 
legged line, and each of which is at least fifty times larger than 
the granules contained in the first kind of theca; the latter 
are said by Brotero to burst with elasticity, an observation 
which requires verification. The first kind of theca is found 
in all species of Lycopodiaceae ; the second is only found in a 
a few. The contents of both are believed to be sporules ; but 
no satisfactory explanation has yet been offered of the cause of 
their difference in size, and probably also in structure. I would 
suggest that the powder-like grains are true sporules, and that 
the large ones are buds or viviparous organs, as has already 
been stated by Haller and Willdenow. A writer in the 
Transactions of the Linnean Society has figured and described 
the growth of the larger grains of Lycopodium denticulatum, 
and he considers that they exhibit the germination of a dico- 
tyledonous plant; but, independently of any mistrust which 
may attach to the account, it is obvious enough that his own 
drawings and description represent a mode of germination 
analogous, not to that of dicotyledons, but rather to that of 
monocotyledons, and also reducible to the laws which govern 
the incipient vegetation of a bud. 
The powder-like sporules are inflammable, and have been 
supposed by Haller, Linnaeus, and others, to be pollen, while 
the larger have been considered seeds ; and to a part of the 
surface of the theca the office of stigma has been attributed. 
The thecae themselves have been fancied to be male apparatus 
by Koelreuter and Gaertner. 
4. Marsileacece, 
This very curious little order consists of plants differing 
from each other so much, that, although consisting of only 
four genera, it is necessary to subdivide it into two distinct 
tribes. 
