OBÖKUVATIOXS OX FUE«H-WATEU POLÏZOA. 



137 



Aftcrvvai'cls, what remains oî the granules in these eells is entirely 

 absorljed, and a linnen is formed inside the rod, converting it into a 

 tube, the rudiment of the funiculus. Thus, it will be noticed that 

 both the muscles and the funiculus are produced in sita from the 

 granular m;iss in the statoblast. 



When the devehjpment (jf the polypide is C(jmplete, two buds are 

 idreudy j)resent on the oral side of the cystid;d wall, one on each side 

 of the median plane. These buds are first seen in the stiige when the 

 intestine is still blind. The manner of their development will be 

 treated under the buddini;'. 



As noticed Ijefore, the granulnr cell mass compactly tills u|» the 

 entire body-cavity until after the formation of all the important organs 

 of the polypide. The cells then loosen themselves, as the conse- 

 quence of the decrease of granules, which are being constantly used up, 

 while the enhanced growth of the cystidal wall makes the body-cavity 

 more and more spacious. When the young pijlypide begins to 

 evaginate and expand their tentacular crown, naked conglomerates 

 of granules, each with a nucleus at the centre, are seen scattered in 

 the body- cavity. Mixed with these conglomerates, we see some <jthers 

 which have obtained a distinct wall, with the nucleus pressed against 

 it. In a somewhat later stage, the granules are no longer visible in 

 those cells with peripherally situated nuclei ; irjstead of them we see 

 a large vacuole in each cell, which has thus acquired the characters of 

 wdiat 1 have proposed to call blood-corpuscles. 



It is perhaps worth nijticing th-.it the developing polypide carries 

 the shell halves on the anal and the oral side of its body, presenting 

 an appearance comparable to the condition of shells in Brachiopods. 



