18 EVOLUTION AND GENETICS 



always, how it occurs. The fact of its occurrence is accepted by 

 all schools of thought and the biologist can scarcely avoid the 

 conviction that there is still much to be explained on the basis of 

 known facts before recourse must be had to purely philosophical 



assumptions. • r, u • • 



That inherent curiosity which prompted man m the beginning 

 to investigate the conditions of life still persists, and with a vast 

 store of accurate knowledge, improved equipment and methods, 

 and probably a gradual increase in his own mental capacity, he 

 may one day solve the problem whose pursuit has already met with 

 such a gratifying degree of success. All of this work must deal with 

 processes, for with Darwin's contribution man became convinced 

 that the relationships which he had striven for centuries to explain 

 were the result of orderly natural development— of evolution. 



Summary. The history of biology shows that ideas of the 

 relationship and evolutionary development of organisms are by 

 no means of recent origin. The ancient Greeks foreshadowed 

 many of our modern discoveries and Lamarck, at the beginning 

 of the nineteenth century, formulated a valuable theory of evolu- 

 tion Between the time of Lamarck and Darwin, numerous con- 

 tributions appeared on the subject of evolution, but it remained for 

 Darwin to express the theory which gained a permanent place for 

 evolution in biological science. This he did in such a masterly way 

 that his eminence is well deserved. Even though his theories ol 

 evolutionary method are no longer regarded as an adequate expla- 

 nation of the way in which species are formed, they are still 

 accepted as an accurate explanation of natural processes which 

 play a part in evolution. Since Darwin's time a major tendency 

 has been the examination of natural phenomena by the exact 

 methods of observation and experiment. Theoretical contnbu- 

 tions have been made, but genetics and other branches of biology 

 have become the most important fields of progress m our knowl- 

 edge of evolution. The fact of evolution is now generally ad- 

 mitted but there is still much to be known of its processes. 



REFERENCES 



Packard, A. S., Lamarck, 1901. 



OsBORN, H. F., From the Greeks to Darwin, 1905. 



LocY, W. A., Biology and Its Makers, 1910. 



Lull, R. S., Organic Evolution, 1917. 



Newman, H. H., Readings in Evolution, Genetics and Eugenics, 1921. 



