intermingling and anastomosing of the currents described by
Mr. Varley.”
This membrane, which must be of exceeding tenuity, is,
hoAvever, in unhealthy states of the plant no doubt wanting.
In certain states of Chara, several large spherical masses
are noticed in the central fluid : these are supposed to consist
of portions of the innermost dense ch-cnlating fluid which
have become detached ; and it is by means of these tha t the
absence of the membrane can be demonstrated. The thick
circulating fluid does not seem to be visibly affected by
graA'ity, for it foUoAvs its usual course in whatever position
the cell may be placed : the spherical bodies, which are described
by both Mr. Varley and Mr. Slack, are, hoAA’eA^er,
sensibly aflected by gravity: if the cell be placed horizontally
and one of these bodies be in the superior current, it Avill descend,
slackening its speed as it enters the middle fluid, revolving
as it passes through it, and returning by the loAver currents
: then again, if the plant be reversed, the same globules
Avill again descend, and enter the former stream. The passage
of globules from current to current through the central fluid
proves that there is now no membrane surrounding it, and
also th a t the central fluid is lighter than the circulating.
Fig. 11. represents a cell containing several of these balls or
globules.
F o r the purpose of tracing and following the course of
these globules an apparatus, similar to Mr. Varley’s vial
rnicroscope, is necessary. Having now completed the consideration
of the circulation in the Characeoe, it remains
to treat of the reproduction of the o rd e r— a subject always
of the highest interest in productions belonging to the freshwater
division of the Algæ.
We will first describe the organs as they ohcur in Chara
vulgaris, and Avhich will serve as the type of the whole order.
The branches Avhich compose each whorl in Chara vulgaris
are usually nine in number, and consist of four or five cells,
the lower ones of which are surrounded by nine other smaller
cells, which pursue, like those covering the cells of the stems, a
spiral course. A t the junction of the major cells Avith each other,
and Avhich are surrounded by the nine smaller spiral cells, arise
or are placed the organs of reproduction: these are of tAvo kinds,
nucules and globules, Avhich have been denominated male and
female; the upper being regarded as the female and the lower
as the male apparatus. The female apparatus or nucule consists
of a seed-vessel, Avhich is composed of a membranous and
brittle envelope, around Avhich are Avrapped five spiral cells,
surmounted or crowned by five smaller cells. The cells, it is
remarkable, pass from right to left, th a t is, in a direction the
reverse of the cells on the stems and branches, and contrary
also to the course of the circulation. (See pi. l x i . fig. 4.) In all
these cells circulation is carried on. The brittle envelope referred
to may not be a real organized membrane. Fach seed-
vessel, according to the observations of Mr. Varley and others,
contains but a single nucleus or germ, Avhich has a proper
envelope: Avhen young, it is of a green colour, the tubes
being colourless: as it ripens it becomes darker, and then
begins to fade away, and ultimately separates and disappears.
The seed or nucleus is then ripe, and ready to separate, connected
only by the brittle envelope, which is entirely soluble
in acids. When this is removed the nucleus or kernel appears
with its dark and shining skin, “ Avhich is flexible and tough
enough to bear squeezing out of shape.” On the rupture of
this the contents issue forth, Avhich are compared to Avheat
flour by Mr. Varley. Such is a brief outline ofthe seed and
seed-vessels: the structure of the male blossom, if it may
be so termed, is more complicated. I t is spherical and
situated beneath the seed-vessel, surrounded by its four
sprouts or cells. (See pi. l x i . fig. 4.) Although these globules,
as well as the seed-vessel or nucleus, are placed at the juncture
of the principal cells Avith each other, they do not arise
directly from these, but rest on a number of smaller cells,
Avhich are there found, and which, as some of them present
phenomena, which are peculiar, and Avhich are accurately described
by Varley in vol. iv. part 1., it Avill be Avell to notice
before following up the anatomy of the globule. The cells
which present these peculiar phenomena are, first, tha t upon
which rests the stalk of the globule; secondly, that which supa
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