430 TRANS. OF THE ACAD. OF SCIENCE. 
tal placente und one-celled capsule) or on a fold which 
extends to the centre and forms the dissepiments (central 
J. = (therefore poctuae distinguished by oneek 
— some extent also in J. Parryi, J. errs and J. 
a eus. The placente of J. Remerianus are ously 
developel into a spongy mass, which fills the shone part 
of the pe cavity. 
The c e opens almost always from top to the middle or 
to the base only in some of our species with subulate oo 
. scirpoides, J. nodosus) the separation of the valve 
mences in the middle, while at the top they remain aed 
for some time. 
Seeds.—The seeds, oe perfectly ripe, furnish some of 
the most ——— and constant characters, but they are so 
small and their markings so x soelinaae that only a strong glass, 
or, better, a microscope with a magnifying power - fitty or 
sixty diameters, will properly sip them. It may not be 
useless to caution botanists not to be deceived ts seeds 
loosely lying ea with the as as they very often 
will be found m 
he seeds pr san or (the elongated ones) more or 
less — with a lower end at the insertion of the funiculus 
and an upper one at the si ae both ends united by the 
raphe aoe often by a distinct fold of the testa. The setds 
are usually obovate or oblanceolate, thicker at the upper than 
at the lower end, mostly terete, or, in rare cases (J. trifidus), 
either abruptly or more gra — pointed, ae late or even 
fusiform (J. pallescens, nodosus, scirpoides). Very frequently 
the sg is slightly elongated email both ends of the body 
of the seed and forms a small, membranaceous appendage (//. 
Pande eon margin rene in such seeds the agundnel 
fold of the testa, mentioned above, also becomes more dis- 
tinct. In many, and apparently more in American and in 
alpine or arctic, species (J. Drummondii, Greenii, aman 
sis, etc.) these appendages become more conspic and 
extend beyond the seed itself as empty, dhvirolied. tala 
hs been called 
white, or, rarely, reddish sacs. Such seeds have 
scobiform ; their seed-coat is more Smad aahering ed some- 
can rea emoved. This or 
times (J. stygius 
of the testa is of great diagnostic value, but the absolute o 
proportionate length of the appendages is extremely enlahin; ; 
even in the same capsule I find the lower seeds with shorter 
tails than the upper ones, and in J. Canadensis we see forms 
