THE LIVING SUBSTANCE. 



131 



shif tings of conditions as often occur inside and outside it, zvith 

 stick plastic unity of phenomena. It is this maivellons 7nainte- 

 nance of its sclfJiood which seems to 7ne more marvellous, more 

 worthy the powers of research workers, than any abnormal states 

 one can force upon the substance by virtue of its conditionings ; 

 — especially as amongst the latter we are unable to separate the 

 extrinsic from the intrinsic, — or to say which reaction is due to 

 these, wJiich to those. 



[124] Despotic as they seem from a familiar standpoint, the 

 external contact relations of organisms and species are not as 

 a rule the most important division of the sum total of such 

 influences which guide its destiny. They are the conditions 

 least under control, yet they are largely controlled by the 

 substance's use of that other set of environmental conditions 

 which it has gathered together for itself, and by which again 

 it moulds new reactions for its intercourse, as organism as 

 well as substance, with external environment. External en- 

 vironment represents rather opportunities for the organized 

 living substance. Internal environment represetits at a given 

 moment not only opportunities but intrinsic necessities for the 

 substance. That the substance may be, to an important and 

 often to a vital degree, influenced or even domineered over by 

 external environment is indubitable, but to say this is not to 

 say that the latter is its veritable control, or arbiter of its 

 fate. As matters now stand, external environment dominates 

 the living substance only in so far as it denies or inhibits it 

 from using, or perpetuating, its own peculiar and necessary 

 internal environment ; and the substance has devised many 

 ways of eluding and defying external conditions in this. 



Stimulus from external environment is transitory, while often 

 the substance reaction long outlives it, and that physical 

 organization on which such reaction was effected may outlive 

 both as it preceded both. In gross, the organized powers of 

 the substance as organism are seen to be used chiefly, if not 

 wholly, to obtain for the substance as such the material needed 

 to continue or to produce, physiological function and physio- 

 logical differentiation. And organization of this environment 

 is secured by contact extension, and by repetition of the same 



