64 ANDREWS. 



The constant correlation of the two sets of facts was 

 learned during careful study of contractile and transmissive 

 phenomena. 1 It is in place here to glance at extension of 

 physiological powers on the physical basis afforded by the 

 foam-structure arrangement of protoplasmic elements, and 

 peculiarly by an ectosarcal modification of this. 



The myriad potential and achieved differences of physiologi- 

 cal areas seem to be susceptible of at least partial analysis on 

 this basis. 



\^^\ In all areas whose office is direct displacement of the pro- 

 toplasm — that is, whose function may be termed muscular — an 

 increment of power, whether stable or unstable, seems to be 

 brought about on a physical basis of a given structure. That 

 is, more of the structure of Butschli or of the finer foam may be 

 involved, with the result at a given moment of a simple mathe- 

 matical increase of the energy, which may be represented by -j- 

 or X . It will be explained under Striation and Contractility 

 that the contraction may be complex, and the first contraction 

 on the structure of Butschli may be continued by succeeding 

 contraction based on the finer foam of the interalveolar material. 

 In such case, of course, the same conditions extend themselves 

 to the secondary contraction ; but it is without structural 

 reduction in the primary structure which may be coarser than 

 usual. 



\^y^ In all areas where the function is indirect displacement of 

 the protoplasm, — that is, in transmissive and sensory areas, — 

 I have found always so far a marked reduction of the foam 

 structure of the interalveolar substance, proved, it is thought, 

 by the optical evidences before advanced for such phenomena. 

 Somewhat more is to be said on this head in the section on 

 a new formula for the living substance, and much more in my 

 forthcoming work on transmissive areas. 



[68] The first sort of physiological extension may be termed 

 quantitative extejision ; the second, qualitative extension of 

 power.2 



Below and behind such grosser differences in the foam struc- 



1 See Striation and Contractility ; also New Formula. 



2 See also Selection of Environment. 



