210 UNIVERSITY OF MISSOURI BULLETIN 



be doubted, however, that he anticipated many important ideas, 

 such as pangenesis, the struggle for existence, and both arti- 

 ficial and natural selection, but his most significant contribu- 

 tion was the view, destined later to assume great importance, 

 that the direct action of the environment produces structural 

 modifications in the organism which are transmitted by inher- 

 itance. 



Until near the close of the eighteenth century, England 

 had lagged far behind France and Germany in the progress 

 of evolutionary thought, and, with the exception of the com- 

 paratively crude writings of Lord Monboddo who, greatly 

 to the amusement and disgust of his contemporaries, main- 

 tained the kinship of man with the apes, practically no con- 

 tributions to the doctrine of descent were made in that coun- 

 try until the appearance in 1794 of the "Zoonomia" of Erasmus 

 Darwin, the grandfather of Charles Darwin, who expounded 

 both in prose and verse a doctrine of transformism and the 

 gradual and natural development of organisms from sponta- 

 neously generated primordial forms. The causes of evolu- 

 tional change he supposed to be due to the effect of the envi- 

 ronment in evoking functional reactions in the organism which 

 in turn produce heritable modifications. He also clearly rec- 

 ognized the significance of the phenomena of variation for the 

 transformation view and pointed out how species may arise 

 in nature in a way similar to the production of new breeds 

 of domesticated animals and plants by the selection of varia- 

 tions. The causes of the transmissible differences, however, 

 he supposed to be due to the efforts of animals to adjust 

 themselves to changed conditions of the environment, which 

 therefore acts only indirectly upon the organism. 



It is to the great French naturalist Lamarck, however, 

 that we owe the first definite and logically coherent system 

 of evolution which not only embraced the entire world of 

 organisms in its scope, but attempted to set forth definite and 

 specific factors to account for adaptations as well as the origin 



