CONSCIOUSNESS IN EVOLUTION. 395 



'o 



tions in knowledge of articles of food can only be accounted for 

 on the hypothesis of original, pleasurable or painful, conscious- 

 ness of the effects of external and internal contact with these sub- 

 stances, and retention of the impression in unconsciousness. The 

 impression reviving on the recurring of a similar contact, the sub- 

 stance is accepted or rejected as the former sensations were pleas- 

 urable or painful. And this is not incredible, if, as the researches 

 indicate, the structure of the protoplasm of these creatures is of 

 the same type as that of the bioplastic bodies of the gray tissue of 

 the brain. 



in accordance with this view, the automatic *^ involuntary " 

 movements of the heart, intestines, reproductive systems, etc., 

 were organized in successive states of consciousness, which con- 

 ferred rhythmic movements, whose results varied with the ma- 

 chinery already existing and the material at hand for use. It is 

 not inconceivable that circulation may have been established by 

 the suffering produced by an overloaded stomach demanding dis- 

 tribution of its contents. The structure of the Coelenterata offers 

 the structural conditions of such a process. A want of j^ropul- 

 sion in a stomach or body sack occupied with its own functions 

 would lead to a painful clogging of the flow of its products, and 

 the *' voluntary" contractility of the body or tube-wall being thus 

 stimulated, would at some point originate the pulsation necessary 

 to relieve the tension. Thus might have originated the " con- 

 tractile vesicle" of some protozoa, or contractile tube of some 

 higher animals ; its ultimate product being the mammalian heart. 

 So with reproduction. Perhaps an excess of assimilation in well- 

 fed individuals of the first animals led to the discovery that self- 

 division constituted a relief from the oppression of too great bulk. 

 With the increasing specialization of form, this process would be- 

 come necessarily localized in the body, and growth would repeat 

 such resulting structure in descent, as readily as any of tlie other 

 structural peculiarities. No function bears the mark of conscious 

 origin more than this one, as consciousness is still one of the con- 

 ditions of its performance. While less completely "voluntary" 

 than muscular action, it is more dependent on stimulus for its 

 initial movements, and does not in these display the unconscious 

 automatism characteristic of the muscular acts of many other 

 functions. 



Bearing in mind the property of protoplasm to organize ma- 

 chinery which shall work automatically in the absence of con- 



