152 THEORETICAL BIOLOGY 



are then more potent than all others. This happens at the 

 time when many animals put on their bridal apparel, and 

 the colours and patterns of their dress act on direction as 

 decisive indications. 



But there are many instances of reversal of the steering 

 gear, in which there is no proof that we are dealing with a 

 change of chemical tone. The best known example is that 

 of sleeping and waking. Bohn was able to show that in sea- 

 anemones the ebb and flow persisted as internal change of 

 tone after the animals had been transferred to the still waters 

 of the aquarium. The most remarkable example of one 

 single change of tone in the year is given by the palolo worm, 

 which, at the time of sexual maturity, and on one predictable 

 moonlight night, divides, and comes to the surface of the sea. 



Both the anatomical part of the directing apparatus 

 (which we usually call the reflex apparatus, and which by 

 analogy we understand as a mechanism) and the chemical- 

 tone apparatus (which from the mechanical point of view 

 we are only just beginning to understand) are the expression 

 of a machine-like framework. 



THE BIOLOGICAL POINT OF VIEW 



In contrast to physiology, biology considers the mani- 

 festations of the central nervous system, not as processes 

 going on inside of apparatus, but as processes within organs. 



Physiology concerns itself only with the machinery inside 

 the framework, which undoubtedly constitutes the great part 

 of the central nervous system. Biology also includes in its 

 consideration the protoplasm not entering into the frame- 

 work, which transforms apparatus into organs. Protoplasm 

 has the important task of continuously regulating the frame- 

 work of the central nervous system, and of making good such 

 injuries as arise. This super-mechanical activity raises the 



