RETROSPECT 357 



powers of opposition of the thumb, rendering its 

 bearers fittest to survive, may have originated as 

 a happy accident. 



Environment as a transforming factor was ap- 

 parently observed late, for we have seen it first 

 develop in the writings of Bacon, de Maillet, 

 Buffon, Kant, Erasmus Darwin, Lamarck, Tre- 

 viranus, Geoffroy, St. Vincent, von Buch and 

 others. Variation is of seventeenth century ori- 

 gin, at least when considered partly as evidence 

 of, partly as a factor in. Evolution ; we have seen 

 it treated by Bacon, Leibnitz, Maupertuis, La- 

 marck and Geoffroy, terminating with its full 

 exposition in the first half of the century as a 

 link of Darwinism. 



It is impossible to condense into a few sen- 

 tences like the above all of the ancestral and suc- 

 cessive stages in the innumerable ideas which 

 clustered around the concept of Evolution. The 

 reader will be greatly aided by the Index, both 

 of pre-Darwinian authors and subjects, which 

 has been most carefully prepared. The Hst of 

 authors alone is as interesting as it is formida- 

 ble, including as it does the names of Abubacer, 

 ^schylus, Agassiz, Albertus INIagnus, Aldro- 

 vandi, Anaxagoras, Anaximander, Anaximenes, 

 Aristotle, Augustine, Avempace, Avicenna, the 

 two Bacons, Blumenbach, Bonnet, Bruno, Buf- 



