356 



THE AMERICAN NATURALIST 



[Vol. LIII 



observed by him in these studies, among which the most 

 impressive was doubtless the making over of a softened 

 hemoglobin crystal by a process of "morphallaxis," i. e., 

 the readjustment of the matter already contained in the 

 fragment. There must thus be recognized in these non- 

 living masses of matter a tendency toward the attain- 

 ment of a specific form. And it seems plain that this 

 tendency may realize itself in more than one way. Yet 

 we should never, in this case, think of proposing any 

 hypothesis of "trial and error," nor speak of the choice 

 by the crystal of ' ' means " to an " end. ' ' 



Now^, I will hasten to express my own belief that the 

 phenomena in the two cases do not differ in any very 

 fundamental way. 1 am disposed to regard the regen- 

 eration of a crystal, the reconstruction of a mutilated 

 organism, and the solving of a problem by a mathemati- 

 cian as members of a single series of increasing com- 

 plexity. They have in common the reattainment of a 

 condition of equilibrium which has been overthrown. 

 The fact that the organism is possessed of life, or that 

 the mathematician has a conscious end in view do not 

 alter the situation. 



Such a ' ' regulative ' ' tendency in the inorganic world is 

 recognized by physical chemists as the "principle of 

 mobile equilibrium," or the "theorem of Le Chatelier." 

 As stated by Lew^is,^^*' this law asserts that "when a 

 factor determining the equilibrium of the system is 

 altered, the system tends to change in such a way as to 

 oppose and partially annul the alteration in the factor. 

 The same idea is conveyed by saying that every system 

 in equilibrium is conservative, or tends to remain un- 

 changed." Bancroft-"'' has given to this principle the 

 dignity of a "universal law," pointing out analogies in 

 the realms of biology, sociology and economics. More 

 recently, its importance in ecology has been urged by 

 Adams. ^^'^ 



23a ''A System of Physical Chemistrj-," Vol. II, 1916 pp 1-10-141 

 23b Science, Feb. 3, 1911. 



23cAMEaiCAN Naturalist, Oct.-Nov., 1918; Jan.-Feb., 1919. 



