. 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. 02 JELLY-FISH, STAR-FISH, AND SEA-URCHlNS. m % I waves that course through the central zones, and this is not the case. Indeed, it is sui'prising how often the race is, as it were, neck and neck, thus showing that the relative conductivity of all the zones is precisely adjusted to their relative lengths; and forasmuch as in the unmutilated animal this adjustment must clearly serve the purpose
. 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. 02 JELLY-FISH, STAR-FISH, AND SEA-URCHlNS. m % I waves that course through the central zones, and this is not the case. Indeed, it is sui'prising how often the race is, as it were, neck and neck, thus showing that the relative conductivity of all the zones is precisely adjusted to their relative lengths; and forasmuch as in the unmutilated animal this adjustment must clearly serve the purpose of securing to the contraction-wave a passage of uniform rate over the whole radius of the umbrella, I doubt not that, if it were possible to perform the race-course section without interrupting any of the lines of conduction-tissue, neck and neck races would be of invariable occurrence. Interdigitating cuts, as might be expected, pro- long the time of contraction-waves in their passage through the tissue in which the cuts are interposed. For example, in a spu'al strip measuring twenty-six inches in length, the time required for the passage of a contraction-wave from one end to the other is represented by the line a h in the annexed woodcut. But after twenty interdigitating cuts had been interposed, ten on each side of the strip, the time increased to c d, the line e f Fig. 15. representing one second. And more severe forms of section are, of course, attended with a still more retarding influence. The effects of temperature on the rate of con- traction-waves aie very striking. For instance, in a rather narrow strip measuring twenty-eight inches i Ag and one and a half inches wide, the following variations in rate occurred :—. 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, 1848-189
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Keywords: ., bookcentury1800, bookdeca, booksubjectnervoussystem, bookyear1895
