12 BRITISH HYDROID ZOOPHYTES. 



Formation of Bud. It has already 

 been mentioned that each member of the 

 hydroid community is formed by what has 

 been described as an inflation of the body 

 wall, which consists only of an inner and an 

 outer layer of cells, and an intermediate 

 membrane. 



Hollow connection between parent 

 and bud. This statement implies that 

 there is a hollow connection between the 

 alimentary cavity of the parent and the new 

 bud, which allows the nutriment elaborated 

 by the parent to be conveyed to the young 

 bud for its nourishment. (Circulation of 

 nutriment.) This step is repeated with 

 every bud formed, so that it will be understood 

 that a regular circulation of nutriment 

 previously prepared in the stomach of each 

 polypite, can be continued throughout the 

 whole colony, and utilized by those members 

 requiring it. 



Circulation maintained by " Cilia." 



Each individual can either pass it at will into 

 the common channel, or can itself draw upon 

 it. The current of this material, passing up 



