9/6. Id., 7th series, chapter 20. 9/7. Id., 2nd series, chapter 4. 9/8. At novitas mundi nec frigora dura ciebat, Nec nimios aestus. Lucretius, "De Natura rerum." 9/9. In this connection see the excellent introduction written by M. Edmond Perrier to serve as preface to the work of M. de Romanes: "l'Intelligence des animaux." 9/10. "Souvenirs entomologiques," 8th series, chapter 20. 9/11. To Henry Devillario, 30th March, 1883. 9/12. To Henry Devillario, 12th May, 1883. 9/13. To his brother, 1900. 9/14. Letters to his brother. "I am not sulking; far from it...I have no lack of ink and paper; I am too careful of them to lack them; but I do lack time...So you still think I am sulking because I do not reply! But imagine, my dear and petulant brother, that for several weeks I have been pursuing, with unequalled persistence, some abominable conic problems proposed at the fellowship examination, and once I have mounted my hobby-horse, good-bye to letters, good-bye to replies, goodbye to everything." (Carpentras, 27th November, 1848.) "You are right, seven times right to storm at me, to grumble at my silence, and I admit, in all contrition, that I am the worst correspondent you could find. To force myself to write a letter is to place myself on the rack, as well you know...But why do you get it into your head, why do you tell me, that I disdain you, that I forget you, that I ignore you, you, my best friend?...For my silence blame only the multiplicity of tasks, which often surpasses, not my courage, but my strength and my time." (Ajaccio, 1st June, 1851.) 9/15. "Souvenirs entomologiques," 10th series, chapter 8. 9/16. Id., 9th series, chapter 2. NOTES TO CHAPTER 10. 10/1. "Souvenirs entomologiques," 1st series, chapter 21. 10/2. Id., 9th series, chapter 2. 10/3. Id., 10th series, chapter 4. 10/4. Montaigne's Essays. 10/5. "Souvenirs entomologiques," 8th series, chapter 17. 10/6. "Les Ravageurs." 10/7. "Souvenirs entomologiques," 10th series, chapter 18, and "Merveilles de l'instinct: la Chenille du chou." 10/8. Id., 8th series, chapter 17. NOTES TO CHAPTER 11. 11/1. "Souvenirs entomologiques," 3rd series, chapter 8. 11/2. Id., 2nd series, chapter 14 et seq. 11/3. Id., 6th series, chapter 9. 11/4. Id., 5th series, chapter 19. 11/5. Tolstoy: "All that the human heart contains of evil should disappear at the contact of nature, that most immediate expression of the beautiful and the good." ("The Invaders.") 11/6. The "Livre d'histoires" and "Chimie agricole." 11/7. "Oubreto Provençalo. La Bise." 11/8. Id., "Le Semeur." 11/9. Id., "Le Crapaud." NOTES TO CHAPTER 12. 12/1. "Oubreto Provençalo. Le Maréchal." 12/2. "Oubreto Provençalo." 12/3. In this connection see the admirable passage in Sainte-Beuve's "Port- Royal," Book 2, chapter 14. 12/4. "Souvenirs entomologiques," 4th series, chapter 1. 12/5. Id., 1st series, chapter 17. 12/6. Id., 7th series, chapter 8. 12/7. Id., 7th series, chapter 10.