266 METAMORPHOSES OF MAN 



dilation, its office is to lie in wait for, seize and digest 

 everything in the shape of prey which comes within 

 reach of its arms. The nutritive juices thus prepared 

 flow through a system of canals to the main stem of 

 the polypidom, and then from it, to each of the indi- 

 viduals to which it gives attachment. The polyp to 

 which we have alluded is, then, solely employed in 

 nourishing the colony. 



Exactly the same thing occurs in the case of the 

 rose-tree. Most frequently the "bud becomes a branch 

 provided with leaves. The function of the latter is to 

 abstract from the atmosphere various gaseous fluids, 

 and especially carbonic acid ; to prepare from them a 

 liquid sap, which travels through the branches and 

 stem to the roots ; and to elaborate this compound, 

 and convert it into a nutritive juice, which, then 

 returning in the opposite direction, is employed in 

 nourishing the trunk itself and all its ramifications. 

 The leaves then are essentially the organs of absorp- 

 tion, exhalation, respiration, and elaboration, and the 

 branch to which they alone are attached has only a 

 function of nutrition to discharge. 



On the rose, therefore, as on the coryne, we find 

 certain individuals whose sole office is that of nourishing 

 the colony. 



At a given period the coryne gives rise to buds, 

 which at first are like the preceding ones, but which 

 eventually become polyps of a very different character. 

 These new beings have neither arms nor mouth, and 

 their digestive apparatus is quite rudimentary. To 

 compensate for these they are provided with organs 

 which, from the nature of their products, are judged 

 to be sexual. If these polyps were isolated, they would 



