THE CCELENTEEATES 



131 



Each of the little creatures has a tubular stalk which passes 

 through the hole at the base of the cup, and is continuous with a 

 tube of gelatinous material in the interior of the horny stem, and 

 thus each member of the colony is directly connected with all the 

 others, so that any nutrient matter collected and digested by one 

 member may be absorbed into the central tube for the nourishment 

 of the entire company of little socialists, the activity of the one 

 being thus made to compensate for the laziness or incompetency 

 of others. And this provision seems to be absolutely necessary for 



FIG. 81. THE HERRING-BONE POLYPE (Halecium halecinum) 



the well-being of the colony as a whole, for a close examination 

 will often show that a kind of division of labour has been established, 

 since it includes two or three distinct kinds of polypites, each adapted 

 for the performance of a certain function. Thus, in addition to the 

 feeding or nutritive members of the community, there are some 

 mouthless individuals whose sole function seems to be the produc- 

 tion of eggs for the propagation of the species, while others, also 

 mouthless, develop an enormous number of stinging cells, probably 

 for the protection of the whole community against its enemies, and 



