EPOCHS IN BIOLOGICAL HISTORY 409 



LAMARCK (1744-1829) developed with great care the first 

 complete and logical theory of organic evolution and is the 

 one outstanding figure in biological uniformitarian thought 

 between Aristotle and Charles Darwin. "For nature," he 

 writes, "time is nothing. For all the evolution of the Earth 

 and of living beings, nature needs but three elements, space, 

 time, and matter." In regard to the factors of evolution, 



FIG. 211. Jean-Baptiste Lamarck. 



Lamarck put emphasis on the indirect action of the environ- 

 ment in the case .of animals, and the direct action in the 

 case of plants. The former are induced to react and so 

 adapt themselves, as it were; while the latter, without a 

 nervous system, are molded directly by their surroundings. 

 And, so Lamarck believed, such changes, somatic in origin 

 acquired characters are transmitted to the next generation 

 and bring about the evolution of organisms. 



