A FEW FACTS ABOUT ZOOLOGY. 



built on four plans, but that they grew by four methods of 

 development. 



Radiata. 



The radiate type of animal life is characterized by the idea 

 expressed in the word radiation. It will probably be best 

 understood by a description of a radiating animal. Fig. 1 



Fig. 1. 



is a picture of a sea-anemone. At B you will see a central 

 cavity; surrounding its circular opening will be seen tenta- 

 cles, or feelers, radiating from the center opening, or mouth. 

 A shows its upper surface; it is attached to the rocks by a 

 flat disk. These sea-anemones are much admired as animal 

 flowers ; they may be frequently seen in the rock-pools around 

 our shores; when in search of their prey they extend their 

 bright-colored tentacles, which 

 so much resemble flowers ; 

 when left by the tide they con- 

 tract into small, round, gela- 

 tinous masses. 



The ordinary jelly-fish, or 

 sea-nettle, is another specimen 

 of this somewhat spherical 

 style of animal architecture; 

 it is soft, gelatinous, and bell- 

 shaped, or saucer-shaped; they 

 float mouth downward in the sea; there are tubes radiat- 

 ing from the central cavity to the circumference, and 



Fig 



