30 GERMINAL SELECTION. 



for the explanation of coadaptation, for the reason that 

 precisely similar coadaptive modifications occur in 

 purely passively functioning parts, in which, conse- 

 quently, modification by function is excluded. This 

 is the case with the skeletal parts of Articulata; e. g., 

 it is true of their articular surfaces with their complex 

 adaptations to the most varied forms of locomotion. In 

 all these cases the ready-made, hard, unalterable, chi- 

 tinous part is iirst set into activity; consequently its 

 adaptation to the function must have been previously 

 effected, independently of that function. These joints, 

 and divers other parts, accordingly, have been devel- 

 oped in the precisest manner for the function, and the 

 latter could have had no direct share in their forma- 

 tion. When we consider, now, that it is impossible 

 that every one of the numerous surfaces, ridges, fur- 

 rows, and comers found in a single such articulation, 

 let alone in all the articulations of the body, should 

 hold in its hands the power of life and death over in- 

 dividuals for untold successions of generations, the 

 fact is again unmistakably impressed upon our atten- 

 tion that the conception of the selective processes which 

 has hitherto obtained is insufficient, that the root of the 

 process in fact lies deeper, that it is to be found in 

 the place where jt is determined what variations ofjhe 

 parts of the organism shall appear — namely _ in /Ac 

 gmn. 



The phenomena observed in the stunting, or degen- 

 eration, of parts rendered useless, point to the same 

 conclusion. They show distinctly that ordinary selec- 

 tion which operates by the removal of entire persons, 

 personal selection, as I prefer to call it, cannot be the 

 only cause of degeneration; for in most cases of de- 

 generation it cannot be assumed that slight individual 



