1 62 THE LIVING WORLD. 



It is also a fact of great interest that both of these 

 types of animals which acquired terrestrial habits, the 

 vertebrates and articulate types, have ended their 

 history with the development of mind. The devel- 

 opment of insects has ended in the production of the 

 complicated insects familiar to every one acquainted 

 with the habits of the bees and ants. The develop- 

 ment of the vertebrates produces the intelligence 

 which has reached its culmination in man. Both 

 types of terrestrial animals have developed the ner- 

 vous system, and in each type the mental nature is 

 the special character of the highest orders. It will 

 also be noticed that the development of instincts 

 among insects has been entirely independent of the 

 development of the intelligence of the vertebrates. 

 The two have not even progressed in parallel lines. 

 Each group has developed the functions of the ner- 

 vous system, but one has developed the reflex func- 

 tions to an extreme (instinct), and the other the 

 reasoning powers. The intelligence of the verte- 

 brates cannot then be regarded as a more highly 

 developed condition of the instincts of insects, 

 although both intelligence and instinct are func- 

 tions of the mental nature. That terrestrial life has 

 had the effect of stimulating both types of land 

 animals into the development of two distinct types 

 of mind, becomes therefore a matter of even greater 

 interest. 



The Modern Fauna an Impoverished One. 



Finally, we must notice that the present age is one 

 of short duration and comparatively impoverished 



