is manifested by obscure sexual conditions, so in obscure sexual modifications specific distinctions arise.
That these "jumps" are considerable in comparison with the minute variations of "Natural Selection"—are in fact sensible steps, such as discriminate species from species.
That the latent tendency which exists to these sudden evolutions is determined to action by the stimulus of external conditions.
That "Natural Selection" rigorously destroys monstrosities, and abortive and feeble attempts at the performance of the evolutionary process.
That "Natural Selection" removes the antecedent species rapidly when the new one evolved is more in harmony with surrounding conditions.
That "Natural Selection" favours and develops useful variations, though it is impotent to originate them or to erect the physiological barrier which seems to exist between species.
By some such conception as this, the difficulties here enumerated, which beset the theory of "Natural Selection" pure and simple, are to be got over.
Thus, for example, the difficulties discussed in the first chapter—namely, those as to the origins and first beginnings of certain structures—are completely evaded.
Again, as to the independent origin of closely similar structures, such as the eyes of the Vertebrata and cuttle-fishes, the difficulty is removed if we may adopt the conception of an innate force similarly directed in each case, and assisted by favourable external conditions.
Specific stability, limitation to variability, and the facts of reversion, all harmonize with the view here put forward. The same may be said with regard to the significant facts of homology, and of organic symmetry; and our consideration of the hypothesis of Pangenesis in Chapter X., has seemed to result in a view as to innate powers which accords well with what is here advocated.