CONTKTBUTIONS TO BOTANY. 
141 
essential difFercnce in the structure of the American and Asiatic 
species ; all that may be noticed is, that in the latter I have ob- 
served that the stamens are not introrse, as there seen, but that 
the anther-cells are imbedded laterally on each side of the fleshy 
filament, and that the three rows of stamens are fixed upon the 
outside of a very short gynophorus, in the summit of which the 
verticillated ovaries are partly sunk. Dr. Gray describes the 
external brittle tunic of the seed as loosely adhering to the 
“obscurely sculptured surface of the spongy membranaceous 
inner integument. Aceording to my observations on lUicium 
onisatum, the single seed, found in each of its follicles, is of an 
oval form, laterally much compressed, very hard and polished, 
and lies with its longest diameter horizontally and its transverse 
diameter vertically within the radiating pericarp, where it is 
attached to the axile placenta by its hilum, which there forms a 
large hollow cavity closed by a fungous substance : along its 
upper margin is a somewhat prominent ridge, which has been 
described as the raphe; but this is not correct, although the 
cord of the raphe exists below it, but in no way connected with 
it : this ridge is formed merely by the pressure of its growth 
against the corresponding sutural line of the pericarp. This 
outer shell of the seed is hard, crystalline, and somewhat brittle, 
consisting of a number of hexagonoid cylinders, which, under 
the microscope, appear formed of radiating spicula subsequently 
filled towards the external face with solid crustaccous matter; it 
is uniform in thickness and texture, except round the open 
mouth of its large basal aperture, which is closed by the fungous 
hilum; it is there somewhat thicker; it is lined throughout 
with a thin, pellicular, loosely adherent membrane with very 
distinct, large, oblong reticulations, and which is easily scraped 
off. Between this and the next coating is a layer of very elon- 
gated oil-cells or glands, in three or four adhering layers, which 
do not always run parallel with one another, but often cross, so 
as to form cancellated bands, thus producing the bullate and 
“ sculptured surface” mentioned by Dr. Gray : these oil-cells 
are coloured, translucent, with a minutely dotted surface ; and 
they dry into a brittle furfuraceous stratum, quite free from the 
surrounding integuments. The next tunic is very thick and 
fleshy, and may be detached in an entire state; it appears to be 
a continuation of the more solid or fungous hilar portion, near 
which it becomes gradually and considerably thickened : within 
the fleshy tissue of this integument is found the simple cord of 
the raphe, consisting of spiral and other vessels, which, origi- 
nating in the hilum, runs along the upper margin, and termi- 
nates near the other extremity in the chalazal disk. The nucleus, 
which completely fills this sac, is considerably smaller, of an 
