The encyclopædia britannica; a dictionary of arts, sciences, literature and general information . 386 TUNICATA far back on the ventral surface, one on each side of themiddle line, and lead into short funnel-shaped tubes whichopen on the surface of the body behind the anus (fig. i8, al).These tubes correspond to the right and left atrial involutions. Fig. i8.—Semi-diagrammatic view of AppemUcularia from theright. at. br,brs, which, in an ordinary Ascidian, fuse to form the pcribranchialcavity. The heart, according to Lankester, is formed of twocells, which are placed at the opposite end
The encyclopædia britannica; a dictionary of arts, sciences, literature and general information . 386 TUNICATA far back on the ventral surface, one on each side of themiddle line, and lead into short funnel-shaped tubes whichopen on the surface of the body behind the anus (fig. i8, al).These tubes correspond to the right and left atrial involutions. Fig. i8.—Semi-diagrammatic view of AppemUcularia from theright. at. br,brs, which, in an ordinary Ascidian, fuse to form the pcribranchialcavity. The heart, according to Lankester, is formed of twocells, which are placed at the opposite ends and connected bydelicate contractile protoplasmic fibrils. The large ovary and testisare placed at the posterior end of the body. The remainder of thestructural deuils can be made out from figs. i8 and 19. Anus. ov, Ovary. One of the atrial apertures. PP. Peripharyngeal band. Tail. ng. Cerebral ganglion. Branchial aperture. «?. Caudal ganglion. Branchial sac. np Enlargement of ner\e cord Dorsal tubercle. in tail. Endost>le. so. Sense-organ (tactile) on Heart. lower Up. Intestine. Si, Ciliated aperture in Muscle band of tail. phar>nx. Ner\e cord m body. St, Stomach. Nerve cord in thetaU. leK, Testis. Oesophagus. tt. Urochord. Otocyst. Its cut end.
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectencyclo, bookyear1910
