128 ANIMAL LIFE 



itself which is one of the most impressive facts of 

 natural history. 



The visible sign of this harmonic grace is the 

 nervous system. Placed as a mediator between the 

 conduct of an animal and the impulses that arise 

 within it or that fall upon it, the nervous system 

 determines that life and conduct shall not be a spas- 

 modic response to every call that circumstances make, 

 but that the general well-being of the race shall be 

 consulted, and that in each life-history traditional 

 answers shall be given at first, until education has 

 conferred the power of a strong individual line of 

 conduct. 



The nervous system co-ordinates the activities 

 of different parts of an individual being in order to 

 produce successful movement, good digestion, and 

 adequate breathing. It interprets as sensations the 

 stronger knocks that fall upon it from the outer world, 

 and to the tapping of light, sound, heat, odours, tastes, 

 and the like it answers by so many perceptions. It 

 responds to the calls that arise from within an animal, 

 and receives every moment of each day messages from 

 the organs that tell the condition of each one. If all 

 be well the messages are imperceptible to us ; if any 

 part be weak, its call upon the nervous system becomes 

 louder, and, if not silenced by adjustment of its need, 

 we ultimately become aware of that which the nervous 

 system has known all along, and we call it hunger, 

 pain, desire. 



Besides these faculties the nervous system is the 



