5o6 STRUCTURE AND LIFE HISTORIES 



connection, but only a mental one; that is, they merely re- 

 flected the succession of ideas as they developed in the 

 mind of the Creator, but were not genetically related to 

 each other. ''We must . . . look to some cause outside 

 of Nature, corresponding in kind to the intelligence of 

 man, though so different in degree, for all the phenomena 

 connected with the existence of animals in their wild 

 state .... Breeds among animals are the work of man: 

 Species were created by God."^ 



But to state that species were created by God does not 

 satisfy the legitimate curiosity of the scientific man. 

 What he wishes to know is: By what method was creation 

 accomplished? God might have worked in various ways. 

 Now, the study of Nature has never revealed to us but one 

 method by which living things originate, and that is hy 

 descent from preexisting parents. Agassiz's hypothesis 

 contradicts this. All oaks now-a-days are derived by 

 descent from preexisting oaks, but the first oak, accord- 

 ing to the doctrine of special creation, was created by 

 supernatural means; it had no ancestors. The chief objec- 

 tion to the acceptance of this hypothesis is that the more 

 profoundly and accurately we study living things, the more 

 obvious it becomes that truth lies in another direction. 



2. Lamarck's Hypothesis. — The noted French naturaUst, 

 Lamarck, taught that all living things have been derived 

 from preexisting forms; that the effects of use and disuse 

 caused changes in bodily structure; that these changes 

 were inherited and accentuated from generation to genera- 

 tion; that, being of use, those individuals possessing the 

 changes in greatest perfection survived while others per- 



* Agassiz, L. "Methods of Study in Natural History," Boston, 1893, 

 pp. 146, 147. 



