The encyclopædia britannica; a dictionary of arts, sciences, literature and general information . Fig. 31.—Pyrosoma d^gans. I bands, and the endostyle are placed in the usual positi(each side of the anterior end of the branchial sac, cios TUNICATA 391 tions. Oneach side oi the anterior ena oi me orancniai sac, close to theperipharyngeal bands, is a mass of rounded gland cells which arethe source of the phosphorescence. The alimentary canal is placed. os in Various stages. br. Branchial apertures. /. Test. CSC, Young ascidiozooid of a future rp. Processes of test,colony produced by budding
The encyclopædia britannica; a dictionary of arts, sciences, literature and general information . Fig. 31.—Pyrosoma d^gans. I bands, and the endostyle are placed in the usual positi(each side of the anterior end of the branchial sac, cios TUNICATA 391 tions. Oneach side oi the anterior ena oi me orancniai sac, close to theperipharyngeal bands, is a mass of rounded gland cells which arethe source of the phosphorescence. The alimentary canal is placed. os in Various stages. br. Branchial apertures. /. Test. CSC, Young ascidiozooid of a future rp. Processes of test,colony produced by budding Branchial sacfrom cy, cyathozooid. ascidiozooid. posteriorly to the branchial sac, and the anus opens into a largeperibranchia! (or atrial) cavity, of which only the median posteriorpart is shown ) in fig. 33. The reproductive organs are developedin a diverticulum of the pcribranchial cavity, and consist of a lobedtestis and a single ovum at a time. The development takes placein a part of the peribranchial cavity (fig. 32, em). The segmentationn , ^ is meroblastic, and an elongated embryo is formed on Development ^j^^ surface of a mass of yolk. The embryo, after thes ms^ formation of an alimentary cavity, a tubular nervous_ s>stem, and
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectencyclo, bookyear1910
