the largest forms of plant life.

The Macrocystis pyrifera, an Algae, is the largest of all known plants.
It is a sea weed that floats free and unattached in the ocean. Covers
the area of two square miles, and is 300 feet in depth (Reinsch). At the
same time its structure on examination shows it to belong to the same
class of plants as the minute palmellae which we have been studying.
Algae are found everywhere in streams, ditches, ponds, even the smallest
accumulations of water standing for any time in the open air, and
commonly on walls or the ground, in all permanently damp situations.
They are peculiarly interesting in regard to morphological conditions
alone, as their great variety of conditions of organization are all
variations, as it were, on the theme of the simple vegetable cell
produced by change of form, number, and arrangement.

The Algae comprehend a vast variety of plants, exhibiting a wonderful
multiplicity of forms, colors, sizes, and degrees of complexity of
structure, but algologists consider them to belong to three orders: 1.
Red spored Algae, called Rhodosporeae or florideae. 2. The dark or black
spored Algae, or Melanosporeae or Fucoideae. 3. The green spored Algae,
or Chlorosporeae or Confervoideae. The first two classes embrace the
sea-weeds. The third class, marine and aquatic plants, most of which
when viewed singly are microscopic. Of course some naturalists do not
agree to these views. It is with order three, Confervoideae, that we are
interested. These are plants growing in sea or fresh water, or on damp
surfaces, with a filamentous, or more rarely a leaf-like pulverulent
or gelatinous thallus; the last two forms essentially microscopic.
Consisting frequently of definitely arranged groups of distinct
cells, either of ordinary structure or with their membrane
silicified--Diatomaceae. We note three forms of fructification: 1.