[165] See his Essays Upon Heredity and Other Biological Problems, vol. i, 1889, especially Chaps. I, “The Duration of Life,” and III, “Life and Death.”
[166] In his able and brilliant discussion on “The Biology of Death,” Scientific Monthly, March, 1921, p. 202.
[167] American Handbook of Physiology, 1897, p. 883.
[168] Mildly challenging Weismann’s non-inherited ability of acquired qualities is Irving Fisher’s “Impending Problems of Eugenics,” Sci. Mo., Sept., 1921.
[169] The Nature of Man, 1904, 309 pp. and The Prolongation of Life, 1907, 343 pp.
[170] See a valuable but unprinted thesis of W. T. Sanger, a pupil of mine, “The Study of Senescence,” Clark University, 1915.
[171] In her fascinating life of her husband, “Life of Elie Metchnikoff,” (1920) the widow of Metchnikoff describes him in his last days as anxious “that his end, which seemed premature at first sight, did not contradict his theories but had deep causes, such as heredity, and the belated introduction of a rational diet, which he began to follow only at fifty-three.” He was very anxious that his example of serenity in the face of death should be encouraging and comforting. He had no illusions and knew for a long time that he was living only from day to day. He speculated whether the end would come to-day or to-morrow and had several specific “death sensations,” pledging his wife to hold his hand when the end came. He was interested in the completion of her biography of him, begged for enough pantopon to bring an eternal sleep, directed his friend how to perform his autopsy and what to look for in the different organs, provided for his cremation and the final disposition of his ashes, etc. All was done as he wished, with no funeral and no speeches, flowers, or invocations, and his ashes now lie in an urn, as he directed, in the library of the Pasteur Institute.
[172] The Problem of Age, Growth, and Death; A study of Cytomorphosis, 1908, 280 pp.
[173] See his monumental textbook, A Laboratory Textbook of Embryology, 1903, 380 pp.
[174] Senescence and Rejuvenescence, 1915, 481 pp.