1893-1905. Private sorrows--Death of Pasteur--Ill-health --Senile atrophies--Premature death--Orthobiosis-- Syphilis (1905)--Acquisition of anthropoid apes (1903) 181 CHAPTER XXVIII Researches on the intestinal flora--Sour milk 196 CHAPTER XXIX 1908. The Nobel Prize--Journey to Sweden and Russia--A day with Léon Tolstoï 199 CHAPTER XXX Intestinal flora--Infantile cholera--Typhoid fever--Articles on popular Science 206 CHAPTER XXXI 1911. Expedition to the Kalmuk steppes to study tuberculosis --Plague 210 CHAPTER XXXII Further researches on the intestinal flora--_Forty Years' Search for a Rational Conception of Life_ 220 CHAPTER XXXIII Unpleasant incidents--The fabrication of lacto-bacilli--St. Léger-en-Yvelines--Return to Paris--First cardiac attack --Evolution of the death instinct--Notes on his symptoms 225 CHAPTER XXXIV 1914. Return to St. Léger-en-Yvelines--Norka--Studies on the death of the silk-worm moth--War declared--Mobilisation 237 CHAPTER XXXV 1915. Return to Paris--The deserted Institute--Memoir on the Founders of Modern Medicine--Metchnikoff's Jubilee--Last holidays at Norka 244 CHAPTER XXXVI 1916. Bronchial cold--Aggravated cardiac symptoms--Farewell to Sèvres--Return to the Institute--Protracted sufferings --Intellectual preoccupations--Observations on his own condition--The end--Cremation. 254 EPILOGUE 276 BIBLIOGRAPHICAL APPENDIX 285 INDEX 291 INTRODUCTION On a calm summer evening we were seated together on our terrace.