90 THE HISTORY OF CREATION. 
every organic form “as the inner original community” is 
the inner constructive force, which receives the original 
direction of form-production—that is, the tendency to give 
rise to a particular form—and is propagated by Inheritance. 
The “uninterruptedly progressive transformation,” on the 
other hand, which “springs from the necessary relations to 
the outer world,” acting as an external formative force, 
produces, by Adaptation to the surrounding conditions of | 
life, the “infinite variety of forms” (Gen. Morph. i. 154; 
i, 224). The internal formative tendency of Inheritance, 
which retains the unity of the original type, is called by 
Goethe in another passage the centripetal force of the organ- 
ism, or its tendency to specification ; in contrast with this he 
calls the external formative tendency of Adaptation, which 
produces the variety of organic forms, the centrifugal force 
of organisms, or their tendency to variation. The passage 
in which he clearly indicates the “ equilibrium” of these two 
extremely important organic formative tendencies, runs as 
follows: “The idea of metamorphosis resembles the vis 
centrifuga, and would lose itself in the infinite, if a counter- 
poise were not added to it: I mean the tendency to specifi- 
cation, the strong power to preserve what once has come 
into being, a vis centripeta, which in its deepest foundation 
cannot be affected by anything external.” 
Metamorphosis, according to Goethe, consists not merely, 
as the word is now generally understood, in the changes of 
form which the organic individual experiences during its 
individual development, but, in a wider sense, in the 
transformation of organic forms in general. His idea of 
metamorphosis is almost synonymous with the theory of 
development. This is clear, among other things, from the 
