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Around this basin, inside elegant glass cases fastened with copper bands, there were classified and labeled the most valuable marine exhibits ever put before the eyes of a naturalist. My professorial glee may easily be imagined. The zoophyte branch offered some very unusual specimens from its two groups, the polyps and the echinoderms.
Professor Haeckel adduces the fossil Crossopodia and Phyllodocites as examples of the Annelidan forms, by the coalescence of which the Echinoderms may have been produced; but, even supposing the resemblance of these worms to detached starfish arms to be perfect, it is possible that they may be the extreme term, and not the commencement, of Echinoderm development.
There is no certainly known extinct order of Protozoa; there is but one among the Coelenterata that of the rugose corals; there is none among the Mollusca; there are three, the Cystidea, Blastoidea, and Edrioasterida, among the Echinoderms; and two, the Trilobita and Eurypterida, among the Crustacea; making altogether five for the great sub-kingdom of Annulosa.
There is, it is true, some exaggeration in the statement that its climate was equivalent to that of Central Europe. The palms which flourished in Central Europe did not reach Greenland, and there are differences in the northern Molluscs and Echinoderms which like the absence of corals above the north of England point to a diversity of temperature.
Agassiz had asked him for some help in his work upon echinoderms. 21 LOTHIAN ST., EDINBURGH, February 13, 1841.
Merely to point out the differences in the mode of development of animals is an interesting matter, and one could do worse things, but the philosophical naturalist cannot rest here. He also suggests that the development of the later larval forms of the Echinoderms is the same in kind.
Scarcely less difficult to understand is the process of the stomach-carrying-off mode of metamorphosis before spoken of as existing in the Echinoderms. Next, as to certain patent and notorious facts: On the hypothesis of pangenesis, no creature can develop an organ unless it possesses the component gemmules which serve for its formation.
Indeed in this respect the worms have been well compared to the relics which fill the shelves of one of our grandmother's china-closets. The four great branches are the echinoderms, mollusks, articulates, and vertebrates. The echinoderms, including starfishes, sea-urchins, and others straggled early from the great army.
At Claiborne, in Alabama, no less than 400 species of marine shells, with many echinoderms and teeth of fish, characterise one member of this system.
The Globigerinoe, Cyatholiths, Coccospheres, Discoliths in the one are absolutely identical with those in the other; there are identical, or closely analogous, species of Sponges, Echinoderms, and Brachiopods.
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