336 HISTORY OF BRITISH ZOOPHYTES. 



The beaks are well placed for such a purpose, and their in- 

 cessant gaping and swinging must enable them readily to 

 detect the presence of trespassers. The avicularia, then, 

 must be regarded as part of the machinery of the axis, 

 charged with the special office of keeping the polypidom 

 free from extraneous matters. An analogous contrivance 

 occurs on others of the Bryozoa, consisting of large bristles 

 attached to the cells by a joint, upon which they move back- 

 ward and forward with considerable force. These clear 

 away obnoxious matter from the neighbourhood of the cell, 

 and keep the surface of the polypidom clean. I can con- 

 firm, from personal observation, the remarks which some 

 authors have made respecting the force with which the 

 movements of these hair-like appendages are executed/' 



How interesting and instructive are these observations ! 

 They show the kind care of the great Creator over the 

 minutest of His creatures. And will He not care for the 

 children of His own family for His ransomed ? Yea, 

 verily ; He who has sent His Son to save them, will give 

 His angels charge over them ; for it is written, " Are they 

 not all ministering spirits, sent forth to minister for them 

 who shall be heirs of salvation ?" 



