WORLD-MAKING 



under embryonic forms, and at first in few and imperfect 

 species. Facts do not substantiate this. The first appearance 

 of leading types of life is rarely embryonic, or of the nature of 

 immature individuals. On the contrary, they often appear in 

 highly perfect and specialized forms, often, however, of compo- 

 site type and expressing characters afterwards so separated as 

 to belong to higher groups. The trilobites of the Cambrian are 

 some of them of few segments, and so far embryonic, but the 

 greater part are many-segmented and very complex. The 

 batrachians of the Carboniferous present many characters higher 

 than those of their modern successors and now appropriated 

 to the true reptiles. The reptiles of the Permian and Trias 

 usurped some of the prerogatives of the mammals. The ferns, 

 lycopods and equisetums of the Devonian and Carboniferous 

 were, in fructification, not inferior to their modern representa- 

 tives, and in the structure of their stems far superior. The 

 shell- bearing cephalopods of the Palaeozoic would seem to 

 have possessed structures now special to a higher group, that 

 of the cuttle-fishes. The bald and contemptuous negation of 

 these facts by Haeckel and other biologists does not tend to 

 give geologists much confidence in their dicta. 



Again, we are now prepared to say that the struggle for 

 existence, however plausible as a theory, when put before us in 

 connection with the productiveness of animals and the few 

 survivors of their multitudinous progeny, has not been the 

 determining cause of the introduction of new species. The 

 periods of rapid introduction of new forms of marine life were 

 not periods of struggle, but of expansion those periods in 

 which the submergence of continents afforded new and large 

 space for their extension and comfortable subsistence. In like 

 manner, it was continental emergence that afforded the oppor- 

 tunity for the introduction of land animals and plants. Fur- 

 ther, in connection with this, it is now an established conclusion 

 that the great aggressive faunas and floras of the continents 



