go Thomas Henry Huxley 



host of creatures great and small that dwell on the land 

 or dart through the air or people the waters, — that 

 all these had arisen by natural laws from a primitive 

 unformed material was known to the Greeks, was devel- 

 oped by the Romans, and even received the approval 

 of early Christian Fathers, who wrote long before the 

 idea had been invented that the naive legends of the 

 Old Testament were an authoritative and literal ac- 

 count of the origin of the world. After a long interval, 

 in which scientific thought was stifled by theological 

 dogmatism, the theory of evolution, particularly in its 

 application to animals, began to reappear, long before 

 Darwin published The Origin of Species. Buffon, the 

 great French naturalist, and Erasmus Darwin, the 

 grandfather of Charles, had expressed in the clearest 

 way the possibility that species had not been created 

 independently, but had arisen from other species. La- 

 marck had worked out a theory of descent in the fullest 

 detail, and regarded it as the foundatio" of the whole 

 science of biology. He taught that the beginning of 

 life consisted only of the simplest and lowest plants and 

 animals ; that the more complex animals and plants 

 arose from these, and that even man himself had come 

 from ape-like mammals. He held that the course of 

 development of the earth and of all the creatures upon 

 it was a slow and continuous change, uninterrupted by 

 violent revolutions. He summed up the causes of 

 organic evolution in the following propositions* : 



" I. Life tends by its inlierent forces to increase the volume 

 of eacii living body and of all its parts up to a limit determined 

 by its own needs. 



* See E. Clodd's Pioneers of Evolution, London, 1897, and 

 Osborn's From tlie Greeks to Darwin, New York, 1896. 



