We find that on quite distinct and widely separated lines of Evolution, exactly similar organs have been developed. Bergson points out to us, in this connexion, the Pecten genus of molluscs, which have an eye identical in structure with that of the eye of vertebrates. [Footnote: The common edible scallop (Pecten maximus) has several eyes of brilliant blue and of very complex structure.] It is obvious, however, that the eye of this mollusc and the eye of the vertebrate must have developed quite independently, ages after each had been separated from the parent stock. Again, we find that in all organic evolution, infinite complexity of structure accompanies the utmost simplicity of function. The variation of an organ so highly complex as the eye must involve the simultaneous occurrence of an infinite number of variations all co-ordinated to the simple end of vision. Such facts as these are incapable of explanation by reference to any or all of the three theories of adaptation and variation mentioned. Indeed they seem capable of explanation only by reference to a single original impetus retaining its direction in courses far removed from the common origin. "That adaptation to environment is the necessary condition of Evolution we do not question for a moment. It is quite evident that a species would disappear, should it fail to bend to the conditions of existence which are imposed on it. But it is one thing to recognize that outer circumstances are forces Evolution must reckon with, another to claim that they are the directing causes of Evolution." [Footnote: Creative Evolution, p. 107 (Fr. p. 111).]