348 COSMIC PHILOSOPHY. [rr. 11. 



between vegetal and animal life. As we ascend the vegetal 

 scale, we find the ferns and lichens decidedly more hetero- 

 geneous than the alg?e ; and as we meet with endogens and 

 exogens, we find the increasing heterogeneity accompanied 

 by a definiteness and coherence of structure that is ever 

 more and more conspicuous. Going up the animal scale, we 

 find the annulosa, on the whole, much more heterogeneous, 

 definite, and coherent than the mollusca ; while the verte- 

 brata, on the whole, exhibit these characteristics more strik- 

 ingly than either of tire other sub-kingdoms. The relatively 

 homogeneous and unintegrated polyps are ranked below all 

 of these. Within each group the same principle of classifi- 

 cation is universally followed. Contrast the centipede, 

 whose multitudinous segments are almost literally copies of 

 each other, or the earth-worm, which may be severed in the 

 middle and yet live, with the highly differentiated and inte- 

 grated hive-bee, spider, or crab. Compare the definite and 

 symmetrical contour of the cuttlefish, which is the highest 

 of the mollusca, with the unshapely outline of the mollus- 

 coid ascidians. Or, to cite cases from the two extremes of 

 the animal scale, consider first the complicated mammal, 

 whose growth from the embryo we have lately contemplated ; 

 and then turn to the hydra, or freshwater polyp, which is a 

 mere bag of organized matter, digesting with its inner surface 

 and respiring with the outer, — yet so little specialized that, 

 if turned inside out, the digestive surface will begin to 

 respire, and the respirative surface to digest, as imperturb- 

 ably as if nothing had happened. In short, in a survey of 

 the whole organic world, progress from lower to higher forms 

 is a progress from forms which are less, to forms which are 

 more, differentiated and integrated. 



One further point must be noticed before we conclude this 

 preliminary sketch of the process of evolution. The illus- 

 trations above given refer almost exclusively to differentia- 

 tions and integrations of structure, or, in other words, to 



