. A manual of zoology. Zoology. Fig. 503.—.4, B, Salpa democraika with stolon, ventral and lateral views; C, Salpa mucronala, part of a young chain not yet separated, a, anus; c, tunic; d, digestive tract; e, atrial opening; en, endostyle;/, peripharyngeal groove; g, ganglion with horseshoe- shaped eye, and near it the tentacle and hypophysial groove; h, testis; i, mouth; k, gill; m, muscle hoops; st, stolo prolifer. nally of a cellulose tunic, lined internally with six or eight circular muscles, not always closed rings, like hoops. By their contraction the water is expelled through the poster
. A manual of zoology. Zoology. Fig. 503.—.4, B, Salpa democraika with stolon, ventral and lateral views; C, Salpa mucronala, part of a young chain not yet separated, a, anus; c, tunic; d, digestive tract; e, atrial opening; en, endostyle;/, peripharyngeal groove; g, ganglion with horseshoe- shaped eye, and near it the tentacle and hypophysial groove; h, testis; i, mouth; k, gill; m, muscle hoops; st, stolo prolifer. nally of a cellulose tunic, lined internally with six or eight circular muscles, not always closed rings, like hoops. By their contraction the water is expelled through the posterior or atrial end of the body, while on their relaxation fresh water enters the other or oral aperture. By the reaction the ani- mals swim through the water with the oral end for- ward. The cavity of the barrel corresponds to pharyn- geal and peribranchial chambers of the ascidian. In the Dolioliid;e the two chambers are separated by a partition perforated by gill slits (fig. 504); in Salpa the partition is reduced to a bar with transverse rows of cilia so that branchial and peribranchial chambers are not distinct; yet the endostyle and the peripharyngeal band are retained. The viscera lie in the muscular sac, where the bran- chial bar and the endostyle meet and are usually com- pacted into a mass, the 'nucleus' (intestine, liver, gon- ads, heart). The ganglion is distinct and lies dorsally opposite the endostyle, just in front of the branchial bar. Associated with it is a horseshoe-shaped eye. For a long time two kinds olSalpce have been known, one solitary, the other consisting of numerous individuals connected together like a chain or a rosette. Fig. 504.—Doliolum denliculalum. (For planation of letters see fig- 503-). Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Hertwig, Richard, 1850-1937; K
Size: 1281px × 1950px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectzoology, bookyear1912
