CONSCIOUSNESS IN EVOLUTION. 397 



been applied. It differs from all the physical forces in this, that 

 while they are only exerted inversely as the square of the distance, 

 this one is in addition most excessive where pleasure has been ex- 

 perienced, and weakest where pain has left its deepest traces. In 

 other words, its movements express design, the essential condition 

 of which is consciousness. It is thus evident that it differs utterly 

 from all other forces, although a retrograde metamorphosis of mat- 

 ter is as necessary for its production as for that of any of the other 

 forces. Now, although the evidences that stimulated consciousness, 

 or if you choose, mind, can modify structure, are, as matter of 

 observation, not very satisfactory ; yet, since the essential pecul- 

 iarity of growth-force is its instant attendance on the needs of 

 consciousness, it is a permissible hypothesis that its activity is 

 immediately due to consciousness. This activity is located in 

 bioplasts which do not exhibit consciousness ; whether it co-exists 

 with consciousness in brain bioplasts is unknown. The successive 

 exhibitions of this force, from the lowest to the highest of living 

 beings, have ever been additions to the executive machinery of a 

 more and more specialized consciousness. Thus it is that its re- 

 sults in structure have ever become more and more complex, that 

 is, composed of an ever-increasing number of parts in some region 

 of the organism. Hence another point of distinction from other 

 forces exists, which has been pointed out in a previous paper. It 

 is quite evident that the higher forms of life are the result of con- 

 tinued superaddition of one result of growth-force on another, 

 some examples of subtraction or simplification of parts being gen- 

 erally accompanied by a great preponderance of additions. This 

 is evidence of the accumulation of the property of pi'oducing this 

 kind of force, since each successive addition imposes on the grow- 

 ing animals a great number of successive stages before the process 

 reaches its termination, maturity. This involves the belief that 

 the property of exhibiting frequent "repetitions" of growth-ac- 

 tivity exists in a higher degree in the reproductive bioplasm of the 

 more complex animal than in that of the lower ones. This is in 

 . accordance with the fact of the regular increase in relative com- 

 plexity and bulk of the nervous system, which accompanies com- 

 plexity of structure in other respects in tlie ascending scale of ani- 

 mals. Thus this force ditfers from all others, as remarked by Prof. 

 Ilartshorne, in that its expenditure ultimately increases the amount 

 of its production, because it constructs machinery which feeds its 

 especial organs more and more successfully. Althougli expended 



