MANUAL OF NATUKAL HISTORY. 323 



recedes 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 Polypi/era, 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 Stercl- 

 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 



