578 APPENDIX A. 



assimilates : neither is it in the oxidation alone ; for oxidation is 

 common to inorganic matter : but it is in the joint maintenance 

 of these the co-ordination of them. So long as the two go on 

 together, life continues : suspend either of them, and the result 

 is death. 



The attribute which thus distinguishes the lowest organic from 

 the highest inorganic bodies, similarly distinguishes the higher 

 organisms from the lower ones. It is in the greater complexity 

 of the co-ordination that is, in the greater number and variety 

 of the co-ordinated actions that every advance in the scale of 

 being essentially consists. And whether we regard the numerous 

 vital processes carried on in a creature of complex structure as so 

 many additional processes, or whether, more philosophically, we 

 regard them as subdivisions of the two fundamental ones oxida- 

 tion and accretion the co-ordination of them is still the life. 

 Thus turning to what is physiologically classified as the vegetative 

 system, we see that stomach, lungs, heart, liver, skin, and the 

 rest, must work in concert. If one of them does too much or too 

 little that is, if the co-ordination be imperfect the life is dis- 

 turbed ; and if one of them ceases to act that is, if the co-ordi- 

 nation be destroyed the life is destroyed. So likewise is it with 

 the aninibl system, which indirectly assists in co-ordinating the 

 actions of the viscera by supplying food and oxygen. Its com- 

 ponent parts, the limbs, senses, and instruments of attack or 

 defence must perform their several offices in proper sequence ; and 

 further, must conjointly minister to the periodic demands of the 

 viscera, that these may in turn supply blood. How completely 

 the several attributes of animal life come within the definition, we 

 shall best see on going through them seriatim. 



Thus Strength results from the co-ordination of actions ; for it 

 is produced by the simultaneous contraction of many muscles and 

 many fibres of each muscle ; and the strength is great in propor- 

 tion to the number of these acting together that is, in propor- 

 tion to the co-ordination. Swiftness also, depending partly on 

 strength, but requiring also the rapid alternation of movements, 

 equally comes under the expression ; seeing that, other things 

 equal, the more quickly sequent actions can be made to follow 

 each other, the more completely are they co-ordinated. So, too, 

 is it with Agility ; the power of a chamois to spring with safety 

 from crag to crag implies accurate co-ordination in the movements 

 of many different muscles, and a due subordination of them all to 

 the perceptions. The definition similarly includes Instinct, which 

 consists in the uniform succession of certain actions or series of 

 actions after certain sensations or groups of sensations ; and that 

 which surprises us in instinct is the accuracy with which these 

 compound actions respond to these compound sensations ; that is 



