DISCOVERT OF THE PROGRAMME. iQl 



public. Their identity of fundamental plan impresses us 

 with awe and reverence, and breathes the thoughts of a 

 world-embracing scope of intelligence. The first converts 

 the animal creation into a vast menagerie for the curious 

 to wonder at ; the latter shows it to be a lesson of wisdom 

 traced by the finger of the Omniscient himself. 



Let us see what is the nature of this identity of plan 

 which runs through all existence and all time. It is a won- 

 derful fact in Nature. From the epoch of the St. John's 

 molluscs and the Potsdam trilobites, through all the dreary 

 ages of the earth's preparation for man, but four funda- 

 mental types of animal structure have ever existed. All 

 the varied forms of extinct monsters have been constructed 

 upon one or the other of these four fundamental plans. 

 Throughout the wide range of existing beings — inhabiting 

 the deep sea, populating the air, swarming over the land, 

 and the forest, and the jungle — countless equally in the 

 number of individuals and in the number of distinguishable 

 species — we discern but the same four foundation plans of 

 structure which we find exemplified in the creations of the 

 ancient world. As the seven fundamental intervals of the 

 gamut have in their endless combinations afforded us all 

 the varieties of melody that have ever greeted the ears of 

 the world, so these four fundamental plans of animalic 

 structure have furnished the endless variations and com- 

 binations which daily greet our senses with never-ceasing 

 novelty and delight. As Agassiz has aptly and beautifully 

 illustrated the idea, one of these fundamental plans is like 

 the fundamental harmony upon which an endless set of 

 variations may be played. Vary it to what extent you 

 will, the characteristics of the theme continually recur. 

 What are the zoological characters of these four funda- 

 mental forms may be learned from any elementary work on 

 the science. It is the magnificent generalization — for which 



