436 THE EVOLUTION OF MAH. 



wonderful world of phenomena. But, if we recognize the 

 causal relation between the development of the germ and 

 that of the tribe, if we recognize the true causal connection 

 of Ontogeny and Phylogeny, which is expressed in that law, 

 then the wonderful phenomena of Ontogeny explain them- 

 selves most simply; then the facts of germ-development 

 appear but the necessary mechanical effects of the develop- 

 ment of the tribe, conditioned by the laws of Heredity and 

 Adaptation. The inter-operation of these laws among the 

 everywhere-active influences of the struggle for existence, 

 — or, as we may simply say with Darwin, Natural Selection, 

 — is amply sufficient to explain to us the entire process of 

 germ-history by the history of the tribe. Darwin's chief 

 merit lies in the fact, thait by the discovery of the inter- 

 action of the phenomena of Heredity and Adaptation, he 

 prepared the way for a correct, logical understanding of the 

 history of Evolution. 



Among the numerous and important evidences that we 

 have found for the truth of this view of our development 

 history, I will only call attention here once more to the 

 peculiarly valuable records of creation afforded by Dystele- 

 ology, or the doctrine of purposelessness, the science dealing 

 with rudimentary organs. It is impossible to emphasize 

 too often and too strongly the high morphological import- 

 ance of those remarkable parts of the body, which are, 

 physiologically, completely worthless and useless. In every 

 system of organs we find, in Man and in all higher Verte- 

 brates, some of these worthless primaeval heirlooms, which 

 have been inherited from our lower vertebrate ancestors. 

 Thus, first, we find on the outer surface of the body a scanty 

 rudimentary covering of hair, which is thicker only on the 



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