HYDROZOA. 



37 



these elegant vases are formed the germs of their in- 

 numerable progeny, which, when mature, swim forth like 

 little bands of jelly (planulce} covered externally with 

 countless \ cilia, enabling them to roam at large in the sur- 

 jcniincfeg water, till they meet with a fit resting-place 

 whereon to settle down, and found another colony as 

 wonderful as that from which they sprung. 



Closely resembling the sea-wreaths so much so, indeed, 

 that they might be easily be mistaken the one for the 

 other are 



The Bell Corallines (Campanularia)* a specimen of which 

 is represented in the appended figure (Fig. 22). There 

 are, however, important dif- 

 ferences between the two fami- 

 lies, which it will be necessary 

 to explain. In the Sertularians, 

 as we pointed out, the Polype- 

 cells are sessile, closely sitting 

 on the stem. In the Campa- 

 nularians every Polype-cup is 

 raised on a small stalk or 

 pedicle, so as to resemble very 

 closely a little wine-glass, the 

 horny stem being ringed at in- 

 tervals, thus giving a certain 

 flexibility to all the branchlets. 

 The little vases, where the 

 young are formed, are always 

 found to sprout just from the 

 angle where the Polype-cells 

 join to the central stem, and 

 are much larger and of different 

 shape. The most important 

 difference, however, is, that in 

 this family the young, instead 

 of being ciliated germs (pla- 

 nulce), are active organisms, so unlike their parents, as to 

 be quite unrecognisable as belonging to the same stock ; 

 insomuch, indeed, that before describing them, it will be 

 necessary to make the student acquainted with another 

 series of beautiful creatures that await our notice. 



Acalephse.t The ocean in every climate swarms 



* Campanula, a little bell. f d/caA^rj, akalephe, a nettle. 



FlG. 22. FIGURE OF LAOMEDEA. 



