Conceptions of Assimilation Reviewed 337 
properties, which electric energy, in certain respects 
related to it, does not possess. 
If, passing on now to assimilation, we examine the 
conceptions which the biologists have formed of it, we 
shall see that their opinions on that subject are quite re- 
markably concordant. 
Thus, for example, Lewes says: “The peculiarity 
of vital processes consists in this, that living matter under- 
goes molecular changes of composition and decomposition 
which are simultaneous, and by this simultaneity it 
preserves its integrity of structure.”?°4 
“Life,” remarks in his turn Oscar Hertwig, “mani- 
fests itself, expressed in the most general terms, in this 
that the cell, by virtue of its own organization and 
under the influences of the external world undergoes 
continual changes and develops forces whereby its organic 
substance, on the one hand continually destroyed with 
determined manifestations of energy on the other hand 
is regenerated.”—‘The life process depends then, on a 
continual destruction and reformation of organic sub- 
stance.” 255 
But the clearest and most suggestive of all is Claude 
Bernard in the following celebrated passage: 
“The characteristics of life considered in their essence 
and in their entirety can be classed in two groups.” 
“7, The phenomena of consumption, of vital de- 
struction, which correspond to the functional phenomena 
of the organism.” 
“2, Plastic phenomena or phenomena of vital crea- 
2547 ewes: The Physical Basis of Mind. P. 5. 
265Qscar Hertwig: Die Zelle und die Gewebe. Bad. I, P. 54, and 
Bd. II, P. 190—191. 
