Note 300 — Part III. ON THE FINAL CAUSES OF TRANSFORMATION. (continued 2)

“Über die Berechtigung,” &c., Leipzig, 1868. In this work will be found briefly laid down the theoretical conception of variability here propounded somewhat more broadly. [In the last edition of the “Origin of Species” Darwin states, with respect to the direct action of the conditions of life as producing variability, that in every case there are two factors, “the nature of the organism and the nature of the conditions.” 6th ed. p. 6. R.M.]