. Animal coloration; an account of the principal facts and theories relating to the colours and markings of animals. Color of animals. SKXVAL COLORATION. 255 species found off the coasts of Southern Australia, the males have three long horns projecting from the head ; if the males of this species were proved to tight for the possession of the females, there would lie a wonderful analogy in these horns to the antlers of deer. More striking still is the sexual dimorphism of the Echino- derms. This group includes the sea-urchins, sea-cucumbers, starfish, brittle-stars, and sea-lilies, which are c
. Animal coloration; an account of the principal facts and theories relating to the colours and markings of animals. Color of animals. SKXVAL COLORATION. 255 species found off the coasts of Southern Australia, the males have three long horns projecting from the head ; if the males of this species were proved to tight for the possession of the females, there would lie a wonderful analogy in these horns to the antlers of deer. More striking still is the sexual dimorphism of the Echino- derms. This group includes the sea-urchins, sea-cucumbers, starfish, brittle-stars, and sea-lilies, which are characterised by their radial symmetry, and by the presence of a calcareous skeleton, more or less perfect, beneath the true skin ; they are not active animals as a group, though the Conuitiilu can swim as well as crawl, and some of the starfish and brittle- stars can move about with a certain degree of rapidity ; many of them have eyes. Some of these echinoderms are among the most brilliantly coloured of marine invertebrates, but the colours can hardly have much significance, for the reasons stated in considering the fauna of the deep sea. Sexual differences have been discovered to exist in a good many species.* These differences may be seen extended to the colour of the sexes, for Oscar Schmidt in " Brehirfs Thierleben," p. 981, remarks that the males of Xt>'o»g>/lo- centrotux Ucid/ts (a common sea-urchin) are darker coloured, while the violet tint of the females tends more towards red. Prof. (1amerano,f while disinclined to admit any constant differences in colour, abundantly confirms Prof. Schmidt's description of other sexual differences in form and size. There can here be no question of preference in either sex, for the ova and sperm are, as in the case of worms, simply shed into the surrounding water. It should perhaps be re- marked that secondarv sexual characters, other than colour, t< j*—~™^™^^__ * Zool. Anzeiger., vol. iii., a paper by Prof.
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Keywords: ., bookauthorbeddardf, bookcentury1800, bookdecade1890, bookyear1892
