EVOLUTION THE MASTER-KEY 



tailed expression to this theory. Undoubtedly he 

 exaggerated its importance, and it is significant 

 that the general doctrine of organic evolution did 

 not through it gain acceptance, but had to wait 

 fifty years until Darwin's assertion of another 

 factor came to its aid. At the present time, the 

 Lamarckian principle is in low repute, despite the 

 acceptance of it by Darwin and Spencer's long 

 championship of it. 



Nevertheless, it would be unwise to omit this 

 principle the inheritance of acquired characters 

 as a factor in organic evolution. It is assuredly 

 of more than historic interest. In his latest book, 

 the Wunderleben, Professor Haeckel declares his 

 continued adherence to a belief in what the school 

 of Weismann so strenuously deny; and Haeckel 's 

 discussion of the subject is heartily to be recom- 

 mended to the student, for, though the veteran 

 evolutionist of Jena is not above resort to inde- 

 cency in theological controversy, and is merely 

 ridiculous as a philosopher, he certainly disputes 

 with Weismann the honor of being the greatest 

 living biologist, and he has been fighting the battle 

 for organic evolution ever since 1866. 



Professor Haeckel adduces, in the book named, 

 an unquestionable instance of the transmission 

 of acquired characters. Every one knows that 

 when pathogenic or disease-producing bacteria are 

 passed through the body of a highly susceptible 

 animal, they become possessed of a much greater 

 degree of virulence than formerly. More accurate- 

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