128 THE AMERICAN WATER WEED. 
rather old—sometimes slightly yellow leaf by preference—torn 
from the stem and laid in a drop of water on a glass slip, and 
covered with a good sized cover glass, generally exhibits move- 
ments of the cell contents in a few minutes ; commenciig as a 
rule in the cells near the base and centre of the leaf. If kept 
wet and warm, the movement continues for many hours. 
In the axil of each leaf there are two tiny, flattened pear- 
shaped, exceedingly transparent glands (see figs. 2, ¢.; 3; 5, g:) 
Each gland consists of a double layer of thick-walled cells 
densely filled with granular protoplasm, and possessing large 
nuclei, but never any chlorophyll granules. The connection 
between the cells when mature is often very loose, especially 
between the two layers, which frequently separate from each 
other upon the rupture of the very delicate membrane which 
I have occasionally traced enveloping the whole gland. The 
whole gland in such a case becomes like a much flattened 
cup, around the mouth of which there collects a quantity of 
mucilaginous matter in which there may generally be seen em- 
bedded animal and plant remains. ach gland is in connection 
with certain special lines of vascular cells which traverse the 
tissue of the stem between the axial cylinder and the circumfer- 
ence. See fig. 5, g.7., where these vascular cells are shown in 
vertical section in connection with the section of the gland (g), 
in the axil of the leaf; and see also fig. 4, g.¢., in which 
horizontal section of the stem eight gland traces are shown. In 
fig. 2, which represents the growing apex of the stem, denuded 
of its older leaves, some of the glands may be seen in situ. 
They attain their full size long before the leaves have done 
growing, and become brown and very frequently disintegrated, 
whilst the leaves in whose axils they stand are still healthy and 
vigorous. 
Tf all the leaves are torn off a young growing piece of Ana- 
charis, the glands will in many cases be left on the stem, and may 
thence be readily detached for examination ; but if it is desired 
to see them on the base of a leaf, as in fig 3, it is better to scrape 
or shave the leaves off the stem with a sharp knife. 
Taking all the circumstances of position, structure, and re- 
lationship to the stem into consideration, I am disposed to 
attribute to these tiny glands the important function of absorb- 
ing nitrogenous matters; and to believe that they are in a 
measure analogous to the glands of Sundew—or more closely 
probably to the quadrified processes which line the bladders of 
Utricularia. Therefore, that they exercise a powerful influence 
over the life history of Anacharis, furnishing as they do to every 
node of the plant a set of organs equivalent in certain functions 
to roots. 
The flowers float upon the water and are very small, being 
only about { of an inch in diameter. They are greenish pink 
