`~ 
IN FLOWERING PLANTS, 209 
When the seed is two-thirds developed, the cotyledons may 
be said to be perfected, they are thick-fleshy, with several vas- 
cular fascicles, and concave in the upper half, corresponding to 
the convexity of the sac of the quartine: the plumula is at this 
period considerably advanced, but occupies a comparatively 
small portion of the sac of the quartine. The exostome or 
micropyle is very distinct, still preserving its original situation 
with respect to the stigmatic canal. The apices of the co- 
tyledons are, as it were, constricted ;- this portion, as well as 
the corresponding portion of the integuments being distinctly 
sub-sphacelated. See pl. 56, D. 1. — 
The mature fruit is, as well as the immature ovule, almost 
entirely enclosed in the cavities of the torus, with which 
however, it is only united by its base. Towards its apex, and 
on the side it is marked with a callous spot, which is invaria- 
bly opposite to the side to which the exostome points. The 
teguments are cellular-spongy, the micropyle occupying its 
original situation, and perfectly distinct. Along the side with 
respect to the axis of the plant, and as usual, next the pla- 
centa, three vascular bundles, forming the raphe, run, which 
terminate in the chalaza: the tissue of which, as well as of 
the corresponding apices of the cotyledons, are, as I have said 
above, sub-sphacelated. 
Not much change has taken place in the cotyledons. The 
radicle is scarcely distinguishable. The plumule is immense : 
occupying the greater part of the cavity of the quartine, vitel- 
lus, or sac of the amnios. The cauliculus is very distinct, 
the leaflets of the plumule are unequal, that next the azis? 
being much the larger. The air cavities of the petiole of this 
are very distinct, as well as the septa: the communicating 
clefts of these, are, as I have shown in Eriocaulonee, visible. 
The vernation is involute. 
The sac of the amnios is excessively fine, and filled with a 
limpid gelatinous fluid. 
[Points to be determined,—site of darüpitule; and its corres- 
ponding air cavity in the parietes of the carpellum. Site of 
exostome, as to the axis ; ditto to the nucleus, visible in its ear- 
liest stage, and whether it is cellular or excavated prior to the 
appearance of the vitellus. 
e 2 x 
