BIOLOGY EEFOKMED. II 



logical development, or Phylogeny, dependent on the laws 

 of Inheritance and Adaptation. 



As I shall have, later, to explain this most interesting and 

 important coincidence more fully, I shall not dwell further 

 upon it here, and merely call attention to the fact that it 

 can only be explained and its causes understood by the 

 Theory of Descent, while without that theory it remains 

 completely incomprehensible and inexplicable. The Theory 

 of Descent in the same way shows us why individual animals 

 and plants must develop at all, and why they do not come 

 into life at once in a perfect and developed state. No super- 

 natural history of creation can in any way explain to us 

 the great mystery of organic development. To this most 

 weighty question, as well as to all other biological ques- 

 tions, the Theory of Descent gives us perfectly satisfactory 

 answers — and always answers which refer to purely me- 

 chanical causes, and point to purely physico-chemical forces 

 as the causes of phenomena which we were formerly accus- 

 tomed to ascribe to the direct action of supernatural, 

 creative forces. Hence, by our theory the mystic veil of 

 the miraculous and supernatural, which has hitherto been 

 allowed to hide the complicated phenomena of this branch 

 of natural knowledge, is removed. All the departments of 

 Botany and Zoology, and especially the most important por- 

 tion of the latter, Anthropology, become reasonable. The 

 dimming mirage of mythological fiction can no longer 

 exist in the clear sunlight of scientific knowledge. 



Of special interest among general biological phenomena 

 are those which are quite irreconcilable with the usual 

 supposition, that every organism is the product of a creative 

 power, acting for a definite object. Nothing in this respect 



