Note 46 — Chapter XXIII · DIRECT AND DEFINITE ACTION OF THE EXTERNAL CONDITIONS OF LIFE.
Reading edition
Professor Weismann comes to the same conclusion with respect to certain European butterflies in his valuable essay, ‘Ueber den Saison-Dimorphismus,’ 1875. I might also refer to the recent works of several other authors on the present subject; for instance to Kerner’s ‘Gute und schlechte Arten,’ 1866.