CLASSIFICATION AND CREATION. 43 



the past, then it is well that all should share in 

 its teachings, and that it should not be kept, like 

 the learning of the Egyptians, for an exclusive 

 priesthood who may expound the oracle accord- 

 ing to their own theories, but should make a part 

 of all our intellectual culture and of our com- 

 mon educational systems. With this view, I will 

 endeavor to simplify as far as may be my illus- 

 trations of the different groups of the Animal 

 Kingdom, beginning with a more careful analysis 

 of those structural features on which classes are 

 founded. 



I have said that the Radiates are the lowest 

 type among animals, embodying, under an infinite 

 variety of forms, that plan in which all parts bear 

 definite relations to a vertical central axis. The 

 three classes of Radiates are distinguished from 

 each other by three distinct ways of executing 

 that plan. I dwell upon this point ; for we shall 

 never arrive at a clear understanding of the dif- 

 ferent significance and value of the various 

 divisions of the Animal Kingdom, till we appre- 

 ciate the distinction between the structural con- 

 ception and the material means by which it is 

 expressed. A comparison will, perhaps, better 

 explain my meaning. There are certain archi- 

 tectonic types, including edifices of different 

 materials, with an infinite variety of architec- 

 tural details and external ornaments ; but the 



