Fig. 154.
Portion of chætophora
showing branching.
320. Position of œdogonium.—Œdogonium is one of the true thread-like algæ, green in color, and the threads are divided into distinct cells. It, along with many relatives, was once placed in the old genus conferva. These are all now placed in the group Confervoideæ, that is, the conferva-like algæ.
321. Relatives of œdogonium.—Many other genera are related to œdogonium. Some consist of simple threads, and others of branched threads. An example of the branched forms is found in chætophora, represented in figures [153], [154]. This plant grows in quiet pools or in slow-running water. It is attached to sticks, rocks, or to larger aquatic plants. Many threads spring from the same point of attachment and radiate in all directions. This, together with the branching of the threads, makes a small, compact, greenish, rounded mass, which is held firmly together by a gelatinous substance. The masses in this species are about the size of a small pea, or smaller. Growth takes place in chætophora at the ends of the threads and branches. That is, growth is apical. This, together with the branched threads and the tendency to form cell masses, is a great advance of the vegetative condition of the plant upon that which we find in the simple threads of œdogonium.
[CHAPTER XVII.]
COLEOCHÆTE.
322. Among the green algæ coleochæte is one of the most interesting. Several species are known in this country. One of these at least should be examined if it is possible to obtain it. It occurs in the water of fresh lakes and ponds, attached to aquatic plants.
Fig. 155.
Stem of aquatic plant
showing coleochæte,
natural size.
