MANUAL OF NATUKAL HISTORY. 323 



reeedes more, perhaps, from the radiate type than 

 any of the others, the creatures comprising it hav- 

 ing long, flexible, worm-like bodies, but whose nerv- 

 ous system is composed of a collar surrounding the 

 gullet, from which filaments are distributed to 

 various parts of the body, and where the radiate 

 character is still preserved in the organs that sur- 

 round the mouth. 



Belonging to those organisms of a humbler type 

 of structure, but still created on the grand radiated 

 model, we observe the Polypifera, in which we find 

 the organs of the senses gradually disappearing, 

 and the individual becoming reduced to a mere 

 stomach, either fixed or endowed with locomotion, 

 and furnished with organs, by means of which it 

 procures itself food, for in these flower-like living 

 stomachs no digestive canal is appended, and there 

 is no distinct excretory orifice ; the growth, more- 

 over, is indefinite and plant-like, taking place by 

 gradual deposits on the outside, by means of a num- 

 ber of polyps, which we may compare to buds. In 

 the class of Parenchymatous-Parasites or Sterel- 

 mintha, we again observe a departure from the 

 typical form of this Sub-kingdom, in creatures of 

 low organization with a single oral aperture leading 

 to a simple stomachal cavity, and destined to sub- 

 sist on substances already elaborated by the animals 

 upon which they are parasitic. 



IV. — Sub-Kingdom — Radiate -Animals (Radiata.) 

 Nervous system without ganglia, composed of 



