12 ANTS AND SOME OTHER INSECTS. 



The so-called reflexes and their temporary, purposefully adap- 

 tive, but hereditarily stereotyped combinations, which respond 

 always more or less in the same manner to the same stimuli, con- 

 stitute the paradigm of automatic activities. These have the de- 

 ceptive appearance of a "machine" owing to the regularity of their 

 operations. But a machine which maintains, constructs, and re- 

 produces itself is not a machine. In order to build such a machine 

 we should have to possess the key of life, i. e., the understanding 

 of the supposed, but by no means demonstrated, mechanics of liv- 

 ing protoplasm. Everything points to the conclusion that the in- 

 stinctive automatisms have been gradually acquired and heredita- 

 rily fixed by natural selection and other factors of inheritance. But 

 there are also secondary automatisms or habits which arise through 

 the frequent repetition of plastic activities and are therefore espe- 

 cially characteristic of man's enormous brain-development. 



In all the psychic provinces of intellect, feeling, and will, 

 habits follow the constant law of perfection through repetition. 

 Through practice every repeated plastic brain-activity gradually 

 becomes automatic, becomes "second nature," i. e., similar to in- 

 stinct. Nevertheless instinct is not inherited habit, but phylogenet- 

 ically inherited intelligence which has gradually become adapted 

 and crystalised by natural selection or by some other means. 



Plastic activity manifests itself, in general, in the ability of the 

 nervous system to conform or adapt itself to new and unexpected 

 conditions and also through its faculty of bringing about internally 

 new combinations of neurocyme. Bethe calls this the power of 

 modification. But since, notwithstanding his pretended issue with 

 anthropomorphism, he himself continually proceeds in an anthro- 

 pomorphic spirit and demands human ratiocination of animals, if 

 they are to be credited with plasticity (power of modification), he 

 naturally overlooks the fact that the beginnings of plasticity are 

 primordial, that they are in fact already present in the Amoeba, 

 which adapts itself to its environment. Nor is this fact to be con- 

 jured out of the world by Loeb's word "tropisms." 



Automatic and plastic activities, whether simple or complex, 

 are merely relative antitheses. They grade over into each other, 



