Evolution. 45 



lution " of which Mr. Huxley makes this affirm- 

 ation, is something very different from the 

 indefinite nondescript which in popular writings 

 is often designated by the same term. Not 

 unfrequently " evolution " means simply pro- 

 gress or advancement. It is even used when 

 nothing more than growth is intended. It is 

 employed as if it were identical with " natural 

 selection," or " transmutation," or any other 

 mode of " development." But with Mr. Huxley, 

 evolution is something more than the emer- 

 gence of the chick from the egg, or the oak from 

 the acorn, or the frog from the tadpole. It is not 

 a mere increase of bulk, nor is it restricted to 

 any particular process, nor has it any special 

 aim. It is a change from simplicity to com- 

 plexity ; from incoherence and indefiniteness to 

 their opposites. 



Thus, for instance, the nebular hypothesis 

 supposes the evolution of the planetary bodies 

 from incoherent atoms, which come not merely 

 into mutual relation, but which also in that 

 process become grouped together in such a way 

 that the nascent mass becomes complex, con- 

 sists of parts. Again : the homogeneous proto- 

 plasm in which all organized beings commence, 

 shows, when under favourable conditions, first 

 the elements of tissues. These elements are 



