88 ‘MORPHOLOGY. 
tinguished as perisperm.! The seeds of the cardamom and 
of pepper represent simultaneously both forms of albumen, peri- 
sperm as well as endosperm. The chief contents of the 
albumen-cells belong nearly always to the class of protein 
substances, and are frequently developed, in part, in a crystal- 
loid form. With these is usually associated fat, and not rarely 
also amylum, sugar, and mucilage. This abundance of contents, 
which, moreover, are very commonly deposited in thick-walled 
cells, mostly imparts to the tissue of the albumen a firm, horn- 
like character. In the German usage of the word, there is 
accordingly sometimes understood (rather ambiguously) under 
the expression “‘albumen,” the entire tissue of the seed which 
contains the previously mentioned reserve substances, and some- 
times, in a chemical sense, that class of nutritive substances 
which are also termed protein bodies. 
The degree of development of the albumen is very variable. 
It is often much more extensive than the embryo, as in Semen 
Myristice (the nutmeg), Semen Oolchici, and in Nuzx vomica; 
in other cases, it appears only as an insignificant appendage, as 
in Semen Lini, or perhaps also disappears at a later period, so 
that it is no longer observable in the ripe seed. 
The embryo contains, in a more or less advanced state of 
development, the rudiments of the axis and leaf-organs, the 
former shortly attenuated in one direction as the radicle or cau- 
‘licle (this is always directed toward the micropyle), and in the 
opposite direction often bearing the rudiments of the stem and 
leaf structures, or plumula ;* the latter may very plainly be seen, 
for instance, in the almond, and also in Nuzx vomica. 
The leaf-organs, embryonal leaves, seed-lobes or cotyledons,°* 
usually form the preponderating portion of the embryo, and 
occur, especially in many dicotyledons, already developed in a 
delicate, distinctly leaf-like form, as in Vux vomica and Semen 
Ricini. In seeds destitute of albumen, e. g-, in the almond, 
bean, pea, and acorn, on the contrary, the cotyledons are of a 
* Hep around or about, and 6zépua seed. 
* Diminutive of pluma, feather. 
* KorvAy cavity, xorvAydwy cavity of a bone, pan. 
