Chap. 38 ORGANIC evolution — conservation 789 



Lamarck, but not as an evolution which he proposed for the first time and for 

 which he deserves great credit. He observed that the progress toward perfec- 

 tion in no wise followed a straight line, but was uneven and branched. He held 

 that the results of use or disuse of a structure, an arm or an eye, would be 

 inherited by the offspring and succeeding generations. This easy entrance of 

 recent change was emphasized and the theory became known as that of ac- 

 quired characters. By thousands of experiments and histories of succeeding 

 generations it has since been shown that acquired characters are not inherited, 

 at least in any such way as Lamarck maintained. The tails of horses may be 

 docked for generations but the tails of their descendants still grow long. La- 

 marck's theory fell into disrepute because of its mistaken explanation. Not- 

 withstanding this it drew attention to adaptation, exemplified by the honeybee 

 that fits the flower. Such adaptation was the same material to which Darwin 

 later applied natural selection. 



Franklin and Malthus 



Roughly within the span of Lamarck's lifetime, many another person was 

 thinking about the multiplicity of plants and animals and the great numbers 

 in human populations. There is room to mention only two of them, Franklin 

 and Malthus. In view of the great increase in the population of the American 

 Colonies, Benjamin Franklin (1706-1790) concluded (1751) that there is 

 no bound to the prolific nature of plants and animals except that which is 

 caused by crowding and competition for food. A similar principle was upheld 

 by Thomas Malthus in his Essay on Population (1798). Unless humanity re- 

 stricts its own rate of increase, war and hunger will do it. Malthus had been an 

 Anglican priest and when the essay was written he was teaching political 

 economy in Great Britain. He foresaw the disapproval that his book would 

 excite. But time never allowed him to know the constructive interest which it 

 was to kindle in the mind of Charles Darwin nor the important steppingstone 

 that it would be for the Theory of Natural Selection. 



Charles Darwin 



Charles Darwin (1809-1882) proposed the most adequate and influential 

 theory of organic evolution which has ever been stated. His materials were 

 plants and animals growing in their natural surroundings in various countries 

 and climates. His tools were keen observation and sound reasoning. His un- 

 limited use of these was his genius. 



Darwin's school education led him into changes in professional training, 

 and from his own testimony into a waste of time in taking courses, including 

 preparation for medicine. He was an independent observer and thinker in his 

 chosen field of natural history. It was through this that he became friends with 

 some of the great scholars of Cambridge University, especially Professor J. S. 



