SKETCH OF LAMARCK. iii 



tant than the similar efforts of all his contemporaries, even than the 

 similar work of Geoffroy Saint-Hilaire, and styles it "the greatest 

 production of the great literary epoch of the beginning of our centu- 

 ry." According to this naturalist's review of Lamarck's system, it 

 supposes that " all the forms of animals and plants which we distin- 

 guish as species have only a relatively temporary stability, and the 

 varieties are incipient species. Therefore the form-group or type of 

 the species is just as much an artificial product of our analyzing rea- 

 son as are the genus, order, class, and other categories of the system. 

 Changes in the conditions of life on one side, the use and non-use of 

 the organs on the other side, constantly exert a formative influence on 

 the organism ; through adaptation they bring about a gradual meta- 

 morphosis of forms, the principal features of which are transmitted 

 by inheritance from generation to generation. The whole system of 

 animals and plants is thus peculiarly their genealogical tree, and re- 

 veals to us the relations of their natural blood-kinship. The course 

 of development on the globe has therefore been continuous and un- 

 broken, like that of the earth itself. . . . Lamarck regarded life as 

 only a very complicated physical phenomenon ; for all the phenomena 

 of life depend on mechanical antecedents, which are themselves de- 

 pendent on the adaptedness of the organic matter. Even the phe- 

 nomena of the mental life are not different in this respect from the 

 others. For the conceptions and acts of the mind depend upon motor- 

 organs in the central nerve-system." He did not shrink from the solu- 

 tion of the difficult question of the origin of life on the globe, and 

 assumed " that the common primitive forms of all organisms were ab- 

 solutely simple beings which originated by spontaneous generation, 

 under the combined operation of different physical causes, out of the 

 inorganic matter in water." "Undoubtedly," adds Herr Haeckel, 

 " the greatest defect in Lamarck's work was the insufficient number 

 of observations and experiments which he adduced in proof of his 

 far-reaching theories." A great part of Darwin's immense success 

 was owing to the fact that he was backed by a host of clear and con- 

 vincing observations and experiments, while " poor Lamarck, trusting 

 too much to the logical acumen of the naturalist, in great part neg- 

 lected them." 



