Lectures on the comparative anatomy and physiology of the invertebrate animals : delivered at the Royal College of Surgeons . on with the cavity of the body. Dr. Soulby, of Dover, informs methat he distinctly saw a stream of spermatozoa escaping, like smoke,from the terminal orifice of each tentaculum of a Halodactylus. Theanalogy of these cerearioids with the spermatozoa discovered byWagner in the tortuous generative tubes of the Actinia, indicatestheir real nature and importance in the generative economy of theBryozoa. Van Beneden has since communicated his discovery ofmale and female polype
Lectures on the comparative anatomy and physiology of the invertebrate animals : delivered at the Royal College of Surgeons . on with the cavity of the body. Dr. Soulby, of Dover, informs methat he distinctly saw a stream of spermatozoa escaping, like smoke,from the terminal orifice of each tentaculum of a Halodactylus. Theanalogy of these cerearioids with the spermatozoa discovered byWagner in the tortuous generative tubes of the Actinia, indicatestheir real nature and importance in the generative economy of theBryozoa. Van Beneden has since communicated his discovery ofmale and female polypes on the same polypary of the Alcyo7iella;the males are fewer than the females, and are recognizable bythe conspicuous spermatozoa, formed by a testis, which holds asimilar position in the male polype to that of the ovary in the female,viz. behind the To the same able observer w^e are indebted for illustrations of thedevelopment of the impregnated ova in another genus of Bryozoon,viz., Pedicellina. The ova are pyriforra, and are aggregated like * XXXV. pi. xxiii. fig. 5. t CXXXIV. p. 222. L 4 152 LECTURE grapes in clusters by tlie pellucid (chorionic ?) membrane in whichthey are enclosed {Ji(/. 73., 1.); tlie yolk is a germ-yolk, and has a;o vitelline membrane separated by a whitish fluid from thechorion. The fission of thegerm-cell is followed bytotal cleavage of the yolk, asin 2 ; it next subdivides intofour, as in 3; after which theformation of the germ-mass,4, proceeds rapidly. Its sur-face becomes smooth, largecilia are developed from oneend, which becomes markedoif by a constriction from theDevelopment of Pediceiiina. other, as at 5. The larva escapes from the chorion under the form 6, and swims freely ciliated margin expands, and renders that end of the larvafunnel-shaped. Tubercles bud forth from the funnel, and a pedicleis developed from the opposite end, as at 7 ; by this the larva attachesitself, and in the course of the subsequent metamor
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Keywords: ., bookauthorowenrichard18041892, bookcentury1800, bookdecade1850
