CNIDARIA 69 



correlated with the disappearance of the nutritive cells. Bj 

 means of it the posterior part of the larval body (Fig. 30 C, 

 po) is characterized as the fundament of the first polypite, 

 vrhereas the upper dorsal part is retained for a considerable 

 time as an embryonal remnant, which gradually diminishes 

 and is converted into the stem (like the yolk-mass of the 



Fig. 31. — Older larval stage of Eitiiidia aui-antiaca (after üktschnikoff, from 

 Balfour's Comparative Emhryology). so, somatocyst ; nc, second nectocalj x bud 

 hph, hydropliillium ; po, polypite ; t, tentacle. 



Ao-almidoe). At the same time the fundament of the necto- 

 calyx (Fig. 30 C, nc) has made considerable progress. The 

 hollow core of the bud is enveloped by a layer of entoderm 

 (hy), into which a part of the gastrovascular cavity is pro- 

 longed as the fundament of the vessels of the bell. Another 

 entodermal process (Fig. 30 C, so) becomes the so-called 

 somatocyst {Saftbehiilter). Between the entoderm and the 



