EXAMPLE OF CONNECTION BETWEEN SUB-KINGDOMS. 63 



charge, a. Now there is a tribe, known under the name of 

 Bryozoa, which presents the same general plan of structure 



Fio. 24. PLUMATKM.A ; a, NATURAL StzK ; b, A GROUP ENLARGED ; c, ANAL OR;PICE. 



under a form so zoophytic, that it has until recently been un- 

 hesitatingly associated with the true Polypes (Fig. 24). The 

 most obvious features of resemblance shown by these animals to 

 Polypes, are the plant-like aspect of the composite structures 

 which they form, and the presence of arms or tentacles disposed 

 in a circular manner around the entrance to their digestive 

 cavity. But in the act of gemmation by which their composite 

 structures are formed, they are paralleled (as we have just seen) 

 by many Tunicata. Further, their tentacles are never used like 

 those of true Polypes, to grasp their food and thus to draw it 

 towards the mouth, but are clothed with the vibratile filaments 

 termed cilia (ANIM. PHYSIOL. 117), by whose action currents 

 are created in the surrounding water, which serve to convey the 

 nutritive particles into the digestive cavity. Now in this re- 



