Oscillatoria nigro-viridis.
Oscillatoria spiralis.
Calothrix semiplena.
in fleecy masses, or bearding with silky hairs the fronds of the sea-weeds themselves, we shall find abundant illustrations of such primitive types for our present purpose—that of slightly tracing some of the variations and adaptations of particular parts and organs by which Nature effects the beautification of the objects themselves. Nor as we regard these objects under the microscope—for it will require the high powers of that instrument to develop their minute structure—can we avoid being struck with the elegance of the twistings and contortions, the lacings and interlacings, of even the most simple threads, as they congregate and combine to form those dense masses, velvety tufts, or hazy films by which their myriads are made evident to the human eye. The development of certain cells into spores, and the wonderful generative processes by which the algæ are propagated, belong, however interesting, more to the domains of natural history than to our present inquiry. Suffice it to say that, by the impregnation of the endochrome of one cell by that of another, the spores—or seeds, as for expressiveness they may here be termed—are produced by the granulation of the mixed matter. Now, in the different aspects and conditions of these spore-cells arises that first divergence from the mere thread of beads by which Nature, while she retains the principle and object of the organ itself in its adaptation to special conditions, seems to vary in every possible manner and way, not only in form and sculpture, but often in colour, her most primitive organizations. Even the contraction of the endochrome itself, in the granulating process, by the production of intermittent vacant spaces, adds a pleasing variation to many of these moniliform filaments.
Sphærozyga Berkeleyana. Spermosira Harveyana.
