Elementary text-book of zoology (1884) Elementary text-book of zoology elementarytextbo0201clau Year: 1884 106 TUNICATA. parts are almost always reduced to a capsule enclosing a single egg and surrounded by blood. This capsule opens into the respiratory cavity on the right side, some distance from the nucleus, by a narrow stalk-like duct (tig. 567 b). After fertilization the stalk becomes A Sip El FIG. 5i37.—', Posterior end of Sctlpa democrat ica, seen from the ventral .side. Stp, Stolo prolifer; jV«, nucleus, h, Terminal portion of stolon=young chain, strongly magnified ; 0, mouth ; A, c
Elementary text-book of zoology (1884) Elementary text-book of zoology elementarytextbo0201clau Year: 1884 106 TUNICATA. parts are almost always reduced to a capsule enclosing a single egg and surrounded by blood. This capsule opens into the respiratory cavity on the right side, some distance from the nucleus, by a narrow stalk-like duct (tig. 567 b). After fertilization the stalk becomes A Sip El FIG. 5i37.—', Posterior end of Sctlpa democrat ica, seen from the ventral .side. Stp, Stolo prolifer; jV«, nucleus, h, Terminal portion of stolon=young chain, strongly magnified ; 0, mouth ; A, cloacal aperture ; jV, nervous centre (ganglion) ; If';/, ciliated pit; Tf7>, aroh of cilia ; End, endostyle ; Af, anus ; Br, gill; Nu-, nucleus; Of, ovary'; C, heart, e, Embryo of Kfil^ri ,], ,,,,11-,-ntlca (after C- Grobben). El, Elasoblast; PI, placenta ; Ph, pharyngeal cavity ; Kl, cloaoal cavity. shorter, so that the is in- creasing in size, ap- proaches closer and closer to the lining .of the respiratory cavity, and forms with its capsule a projecting cone in which, as in a brood pouch, the embryonic development takes place.* In the course of development a pla- centa is formed be- tween the • embryo * Besides E. Leuckart compare Kowalevski. ' Beitrag zur Entwiekelungs- geschichte der Tunioaten.' ' Entwickelungsgeschichte der Salpen.' Xm-Jir. run. (In- lidnii/l. GesclUrli. der WiwnxcJt., Nr.'li), Gottingen, 1868. W. Salensky, ' Ueber die embryonale Entwickelungsgeschichte der Salpen,' Zcitsclu'.fur'n-UK. Zonl., Tom 1876. W. Salensky, 'Ueber die Knospung tier Salpen/' Morpli. JnJirli., Tom. III., 1877.
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