METHOD IN THE HISTORY OF LIFE. 319 



and showed in their structure a synthesis of features be- 

 longing to each of the four classes of vertebrates, 



The dawn of a new dominant idea in Nature is often 

 foreshadowed by penunibral types of an anticipatory char- 

 acter. The earliest representatives of a comprehensive 

 type were generally prophetic. Before reptiles were cre- 

 ated, hints of coming reptiles were dropped in the constitu- 

 tion of the fishes, as in the concavo-convex vertebrae of 

 the Ganoids. The winged bird was foreshadowed by the 

 flying and feathered reptiles ; and mammals were heralded 

 by the whale-like and paddle-bearing Ichthyosaurs. What 

 but prophetic types were all the first-formed creatures be- 

 longing to the four grand categories of structure, from 

 which have been developed the diversified beings of after 

 ages? All possibilities of vertebrate existence were folded 

 up in the constitution of the first fish which Omnipotence 

 called into being. In the organization of those primordial 

 Trilobites which figure in the vignette of animal history 

 were wrapped up in potentiality all the species which cre- 

 ative power has since evolved from the articulate type — 

 lobsters, barnacles, centipedes, spiders, butterflies, beetles. 

 These forms were all in full view of the Intelligence which 

 executed the plan that involved them, and which, in its 

 destined unfolding, must set them free upon the earth. 



Most impressive are the facts which show the ideas of 

 the far-off coming ages wandering in advance of their time 

 among the creations of an existing world, like streaks of 

 morning light which herald the approaching sun through 

 all the sky, while the world still sleeps under the reign of 

 darkness. It is as if the thoughts of the Creator were 

 busied with the plans of the distant future, while his hands 

 are occupied with the work of to-day. Thus were incor- 

 porated in the organisms of one age hints of the features 

 \viich were to blossom and unfold in the dominant ideas 



