464 



ZOOPHYTES. 



FIG. 223. 



not only affords an investment to the stem, but forms cups or 

 cells for the protection of the polypes, as well as capsules for 

 that of the reproductive bodies. In the Campanularidce, the 

 polype-cells are campanulate or bell-shaped, and are borne at the 

 extremities of ringed stalks (Fig. 223, c) ; in the Sertularidce, on 

 the other hand, the polype-cells lie along the stem and branches, 

 attached either to one side only, or to both sides (Fig. 224). In 

 both, the general structure of the individual polypes (Fig. 223, d) 



closely corresponds with 

 that of the Hydra; and 

 the mode in which they 

 obtain their food is essen- 

 tially the same. Of the 

 products of digestion, 

 however, a portion finds 

 its way down into the tu- 

 bular stem, for the nour- 

 ishment of the general 

 fabric; and very much the 

 same kind of circulatory 

 movement can be seen in 

 Campanularia, as in Tu- 

 bularia, the circulation be- 

 ing most vigorous in the 

 neighborhood of growing 

 parts. It is from the soft 

 flesh (/) contained in the 

 stem and branches, that 

 new polype-buds (b) are 

 evolved; these carry be- 

 fore them (so to speak) a 

 portion of the horny in- 

 tegument, which at first 

 completely invests the 

 bud ; but as the latter 

 acquires the organization 

 of a polype, the case thins 

 away at its most promi- 

 nent part and an opening 

 is formed, through which 



Campanularia gdatinosa:-^ upper part of the stem and ,1 vormO" nolvnP T>m 



branches, of the natural size; B, a small portion enlarged, tliy J ^ U1J & ! Jul jP e 



showing the structure of the animal; a, terminal branch trildeS itself. The OHgill 



bearing polypes; 6, polype bud partially developed; c, Q f fa e bodies Commonly 



horny cell, containing the expanded polype, a; e, ovarian , . 



capsule, containing medusiform gemmae in various stages DUG errOUCOUSly CleSlg- 



of development ;/, fleshy substance extending through the rioted i( OVarian Capsules" 



stem and branches, and connecting the different polype- / \ xi ] ,. "U 4. 



cells and ovarian capsules; g, annular constrictions at the \ e )l 1S CXaCtly S] 



base of the branches. their destination is very 



different. Within them 

 are evolved, by a budding process, the generative organs of the 



