114 'THE HISTORY OF CREATION. 



violent cataclysmic revolutions ; and in general the incon- 

 ceivableness of any miracle, of any supernatural interference, 

 in the natural course of the development of matter. 



The fact that Lamarck's wonderful intellectual feat met 

 with scarcely any recognition, arises partly from the im- 

 mense length of the gigantic stride with which he had 

 advanced beyond the next fifty years, partly from its 

 defective empirical foundation, and from the somewhat one- 

 sided character of some of his arguments. Lamarck quite 

 correctly recognizes Adaptation as the first mechanical 

 cause which effects the continual transformation of organic 

 forms, while he traces with equal justice the similarity 

 in form of difierent species, genera, families, etc., to their 

 blood-relationship, and thus explains it by Inheritance. 

 Adaptation, according to him, consists in this, that the per- 

 petual, slow change of the outer world causes a corre- 

 sponding change in the actions of organisms, and thereby 

 also causes a further change in their forms. He lays the 

 greatest stress upon the efiect of habit upon the use and 

 disuse of organs. This is certainly of great importance 

 in tlie transformation of organic forms, as we shall see 

 later. However, the way in which Lamarck wished to 

 explain exclusively, or at any rate mainly, the change of 

 forms, is after all in most cases not possible. He says, for 

 example, that the long neck of the girafie has arisen from its 

 constantly stretching out its neck at high trees, and from 

 the endeavour to pick the leaves off their branches ; as 

 giraffes generally inhabit dry districts, where only the 

 foliage of trees afford them nourishment, they were forced 

 to this action. In like manner the longr toncjues of wood- 

 peckers, humming-birds, and ant-eaters, are said by him to 



