. A manual of zoology. Zoology. 44S CHORDATA (ha;. ,03, C). Al the l>c,i;inninL; of the last century the poet Chamisso discovered that the chain salps were produced bv tlie solitar\- indi\iduals, and that these in turn came from ilie chain , the hrst instance of allernation of generations. Tlie solitary salp is asexual; j,'onads are lacking, luit near the hinder end is a budding cone or slolo proliicr from which colonies of salps bud one after another. \\'hen the first is separated a second matures and a third begins. These colonial forms, the chain salps, are , aird each produc
. A manual of zoology. Zoology. 44S CHORDATA (ha;. ,03, C). Al the l>c,i;inninL; of the last century the poet Chamisso discovered that the chain salps were produced bv tlie solitar\- indi\iduals, and that these in turn came from ilie chain , the hrst instance of allernation of generations. Tlie solitary salp is asexual; j,'onads are lacking, luit near the hinder end is a budding cone or slolo proliicr from which colonies of salps bud one after another. \\'hen the first is separated a second matures and a third begins. These colonial forms, the chain salps, are , aird each produces a single egg from which a solitary indiyidual is formed. Since both the snlnary and the chain forms haye recei\'ed names, the species of 5d.'/>j* now ha\"C double names li!. Fig. 505.âSagittal section of CIosso- haldints wiiiutus ^diagram after ). c, proboscis cadoui; cc, colar CLtlom; co, collar; Ji, so-called heart; Ini, long muscles; »\ ?r, dorsal and ycntral ner\'e cords: e, cesophagus; p, prol)oscis; ;/c, so-callctl notochord; i^, gill slits; v', v-, dorsal and ventral blood-vessels; in, nioulh. ,c Salpa dcniocraliia-iiutiroiiula, ilcinocra/ica being the asexual, iinicroiiala the sex- ual, indi\idual, etc. From the true SdlpiC I'>o!ioluiir' is distinguished by the better de\elopc(.l gilis, the com]dete mitscular bands, and a more conipli- ;'' caied alternation of generations. Sub rn\xrM III. Exthropnevst.^ (,IIi;miciiordia) 'â ' The few marine forms here in- cluded are decidedly worm-like, and, like many worms, they luirrow in the mud. The body consists of three " ])artsâproboscis, collar, and trtnik (iig. 500). ddie proboscis, which sits in the collar like an acorn in its cup, whence Boliiiio;,;li'ssnf, contains a ,1' ca\"ity opening to the exterior by a dorsal pore, \\hile two similar ca\iiies in the collar open separately. These can be hllcd with water, and bv alter- , natcly enlarging and contracting these , parts the anitnal is a
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectzoology, bookyear1912
