. Jelly-fish, star-fish and sea-urchins [microform] : being a research on primitive nervous systems. Nervous system; Jellyfishes; Starfishes; Sea urchins; Nerveux, Système; Méduses; Astérides; Echinides. RCHINS,. ctl spgmenta STAR-FISH AXD SEA-URCHINS. 319 spines, and pedicellari?e togetlier, so that they all approximate a point of irritation situated anywhere in that plexus ^ (2) of an internal i ^>j yous plexus which is everywhere in communication through the thickness of the shell with the external, and the functioii of which is that of bringing the feet, spines, and probably also the pe
. Jelly-fish, star-fish and sea-urchins [microform] : being a research on primitive nervous systems. Nervous system; Jellyfishes; Starfishes; Sea urchins; Nerveux, Système; Méduses; Astérides; Echinides. RCHINS,. ctl spgmenta STAR-FISH AXD SEA-URCHINS. 319 spines, and pedicellari?e togetlier, so that they all approximate a point of irritation situated anywhere in that plexus ^ (2) of an internal i ^>j yous plexus which is everywhere in communication through the thickness of the shell with the external, and the functioii of which is that of bringing the feet, spines, and probably also the pedicellarise into relation with the great co-ordinating nerve-centre situated round the mouth; (3) of central nervous matter which is mainly gathered round the mouth, and there presides exclusively over the co-ordinated action of the spines, and in large part also over the co-ordinated action of the feet, but which is further in part distributed along the courses of the main nerve-tiTuiks, and so secures co-ordination of feet even in separated segments of the animal. Special Senses. Before concluding, I must say a few words on the experiments whereby we sought to tost for the presence in Echinoderms of the special senses of sight and smell. We have found unequivocal evidence of the Star- fish (with the exception of the Brittle-stars) and the Echini manifesting a strong disposition to crawl towards, and remain in, the light. Thus, if a large tank be completely darkened, except at one end where a narrow slit of light is admitted, and if a number of Star-fish and Ecliini be scattered over the floor of the tank, in a few hours the whole number, with the exception of perhaps a few per \l. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Romanes, George John, 1848-1894. London : K. Paul, Trench
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Keywords: ., bookcentury1800, bookdeca, booksubjectnervoussystem, bookyear1895
