GERMINAL SELECTION. 39 



and I enunciated precisely on this- account the princi- 

 ple of panmixia. Now, although this, as I still have 

 no reason for doubting, is a perfectly correct principle, 

 which really does have an essential and indispensable 

 share in the process of retrogression, still it is not 

 alone sufficient for a full explanation of the phe- 

 nomena. My opponents, in advancing this objection, 

 were right, to the extent indicated and as I expressly 

 acknowledge, although they were unable to substitute 

 anything positive in its stead or to render my explana- 

 tion complete. The very fact of the cessation of con- 

 trol over the organ is sufficient to explain its degenera- 

 tion, that is, its deterioration, the disharmony of its 

 ' parts, but not the fact which actually and always 

 occurs where an organ has become useless — viz., its 

 gradual and unceasing diminution continuing for 

 thousands and thousands of years culminating in its 

 final and absolute effacement. 



If, now, neither the selection of persons nor the ces- 

 sation of personal selection can explain this phenom- 

 enon, assuredly some other principle must be the effi- 

 cient cause here, and this cause I believe I have indi- 

 cated in an essay written at the close of last year and 

 only recently published.^ I call it germinal selection. 

 The principle in question reposes on the application, 

 made some fifteen years ago by Wilhelm Roux , of the 

 principle of selection to the parts of organisms — on the 

 struggle of the parts, as he called it. If such a strug- 

 gle obtains among organs, tissues, and cells, it must 

 also obtain between tl^e smallest and for us invisible 

 vital particles, not only between those of the body- 

 cells, strictly so called, but also between those of the 



J-Neue Gedanken sur Vererbungsfrage, Jena, 189s. 



