144 



THE HARMONIES OF NATUKE. 



activity even closing upon the beaks of their neighbours. No 

 one has yet divined the economy of these most singular organs, 

 but as several observers have noticed the seizure of small 

 roving animals by their pincer-like beaks, the conclusion is 

 pretty general that they are in some way connected with the 

 procuring of food. 



But it seems to have been forgotten, not only that the ' avi- 

 culariae ' have no power of passing the prey thus seized to the 



A Portion of a Cellularia magnified. B A bird's-head process, more highly magnified and seen in 

 the act of grasping another. 



mouth, but also that the mouth is situated at the bottom of a 

 funnel of ciliated tentacles, and is calculated to receive only 

 such minute prey as is drawn within the ciliary vortex. Thus 

 they cannot possibly serve as immediate or direct purveyors of 

 food ; but Mr. Grosse explains to us, in a very satisfactory manner, 

 how the seizure of a passing animal, and the holding of it in 

 their tenacious grasp until it dies, may be the means of attract- 

 ing the proper prey to the vicinity of the mouth. 



'The presence of decomposing animal substance in water,' 

 says this distinguished naturalist, f invariably attracts crowds of 

 infusory animalcules, which then breed with amazing rapidity 

 so as to form a cloud of living atoms around the decaying body, 

 quite visible in the aggregate to the unassisted eye ; and these 



