1 INTRODUCTION, 



whether a product of the endocyst or endosarc is still 

 undetermined. 



That the latter tissue is, to a large extent at least, 

 concerned in the production of the generative elements 

 can hardly he donhtedj and this fact is properly accounted 

 evidence of its non-nervous nature. 



According to Joliet the polypide is also produced by 

 gemmation from the endosarc, at least in many cases (he 

 is inclined to think, universally), and not from the endo- 

 cyst, as generally supposed. We must have a much wider 

 range of observation bearing on this point than we at 

 present possess before we can come to any general conclu- 

 sion about it. But in the case of Eucratea cheJata there 

 seems to be no doubt that the polypide originates from the 

 funiculus : we have the concurrent testimony of Joliet* and 

 Barroisf on this point. Further, in all the Cheilostomata 

 which he has studied, the former of these observers has 

 seen reason to believe that the bud is really formed on 

 some portion of the endosarc, and not on the endocyst. 

 In Hypophorella, Ehlers (allied to the Vesiculariidce) , it is 

 produced on the funiculus, in the centre of the cell, as 

 in Eucratea. In many cases it is developed at the very 

 base of the zooecium, immediately over the communication- 

 plate or septum and the orifices through which the connec- 

 tive threads pass, and therefore probably in connexion 

 with the endosarc. I have observed it in this position in 

 the young cell of Beania mirabiUs (Woodcut, fig. xx. bd) ; 

 and in this species Joliet has convinced himself that the 

 polypide is actually derived from the endosarcal cord. In 

 the rudimentary zooecium of Victorella (see page 560) the 



* Op. n'f. p. 50, pi. xiii. figs. 1, 2. 



\ ' Rovue Snientifiqiie' for Sept. 29, 1877. 



