Lectures on the comparative anatomy and physiology of the invertebrate animals : delivered at the Royal College of Surgeons . lined by vibratile cilia in Oceania **, which impress a vibratile move-ment upon the contents, like that which characterises the otoliticcorpuscles in the Mollusca. As the pigment-cell, when present, isdistinct from the cysticle it may do the ofiice of a light-appreciatingorgan, and tlie cysticle that of a simple organ of hearing. We maywith much reason regard as organs of touch the labial and marginaltentacles. The ciliograde Acaleph^e are beautifully represented in se
Lectures on the comparative anatomy and physiology of the invertebrate animals : delivered at the Royal College of Surgeons . lined by vibratile cilia in Oceania **, which impress a vibratile move-ment upon the contents, like that which characterises the otoliticcorpuscles in the Mollusca. As the pigment-cell, when present, isdistinct from the cysticle it may do the ofiice of a light-appreciatingorgan, and tlie cysticle that of a simple organ of hearing. We maywith much reason regard as organs of touch the labial and marginaltentacles. The ciliograde Acaleph^e are beautifully represented in seas thatwash our coasts by the little semi-transparent, delicately-tinted, sphe-roidal animals {Jig- 11.) called Beroe by Miiller, and now the typesof many genera, which have this in common, that their chief or-gans of motion consist of unusually large vibratile cilia, aggregatedin lamelliform groups (ib. c, c), Avhich seeming plates are arranged * CXLVn. p. 9. t CXLVI. p. 19G. pi. 1. fig. Ic, % CXLV. p. 416. § CXLVIL p. 8. 11 CXIV. pp. 64. 68. ^ XXIV. p. 6L ** Observed by Kolliker, quoted in CXLVIL p. 9. ACALEPHyE. 171. Cydippe. like the paddles of a propelling wheel, along eight equidistant convex bands, extending from nearone end or pole of the body-to near the other, like the me-ridians of an artificial organs by which the Beroecan attach itself to, or poiseits body on, a solid surface,are two very long tentacles,which are fringed on one sidewith cirri. These cirrated ten-tacles {d; d, Jig. 77.), whichcan be stretched out in somespecies to more than twenty times the length of the body, can beinstantaneously retracted into the two cavities or sheaths whichextend along each side of the slender intestine ; the marginal cirriin this act being as instantaneously coiled up in a series of closespirals, and the whole complex tentacles compacted within the limitsof a pins head. Like a planet round its sun, or, more exactly, like the comet withits magic tail, our little ani
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Keywords: ., bookauthorowenrichard18041892, bookcentury1800, bookdecade1850
