i6 



SPONGES 



individual may acquire as the result of its particular mode of 

 growth, it remains to discuss the forms assumed as the result of 

 multiplication of individuals which remain united. Since the 



FIG. 22. 



Aphrocallistes Bocagei, Wright. (After Agassiz.) x if. 



sponge colony consists of an aggregation of sponge individuals, pro- 

 duced one from another by a process of budding, its form will 

 depend largely in the first instance on the type of sponge persons 



FIG. 23. 



Ventriculites, imagined reconstruction, r, root-like processes of attachment ; osc, osculum. 

 A piece of the margin is represented broken away to show the plications which form the in- 

 current and excurrent canals. 



of which it is composed. The other factors which influence the 

 form of the colony are, first, the way in which the individuals are 

 united together that is to say, the manner in which they are budded 



