ORIGIN OF THE SPECIFIC TYPE 309 



organism : it exists at every period of its life, from the germ till 

 death, and what it brings about is quite as inevitable as what is 

 evoked through adaptation by means of personal selection. 



We can thus also understand that indifferent characters may 

 be contained not only in individual ids of the germ-plasm, but also 

 coincidentally in a great majority of them, as soon as we think of them 

 as dependent upon the characters estaljlished through personal selec- 

 tion, for these must be contained in a majority of the ids. 



But there is still another reason why indifferent characters should 

 become stable, and that is the effect of general variational influences 

 on all the individuals of a species, as, for instance, in many climatic 

 varieties, and probably also in many cultivated varieties. 



But even when we have fully recognized that, from the arcana of 

 the germ-plasm, new minimal variations are continually cropping up, 

 which are biologically indifferent, and nevertheless become variational 

 tendencies, and may increase even to the extent of causing visible 

 differences, and that therefore varieties of snails or of butterflies, or 

 of any animal or plant whatever, may originate through germinal 

 selection alone, it cannot for a moment be supposed that the transmu- 

 tation of species depends upon this process exclusively or even 

 preponderantly. This was Nageli's mistake, and that of his followers 

 as well, that he ascribed to his ' principle of perfecting ' the essential 

 role in directing the whole movement of evolution, while the general 

 structure of all species shows us that they are, so to speak, built up of 

 adaptations. But adaptations could not be— or could only be fortui- 

 tously and exceptionally — the direct result of an internal power of 

 development, since the very essence of adaptational changes is that they 

 are variations which bring the organism into harmony with the 

 conditions of its life. We are therefore forced either to underestimate 

 greatly the part played by adaptation in every organism — and that is 

 what Nageli did — or to leave the standpoint of natural science 

 altogether, and assume a transcendental force which varied and 

 adapted the species of organisms ^ja7'<^ i^assu with the changes in the 

 conditions of life during the geological evolution of our earth. This 

 would be a sort of j)re-established harmony, through which the two 

 clocks of evolution — that of the earth and that of organisms — kept 

 exact- time, although they had quite different and independent works ! 

 But that the determining significance of adaptations in organic 

 forms is underestimated even now is evidenced by the continually 

 repeated statement that species difier, not in their adaptive characters, 

 but in purely morphological characters, whereas it is obvious that 

 we are far from being able to estimate the functions of a part 



