The hour of silence was over; the incineration accomplished. Of his body, little was left--a handful of ashes. They were enclosed within an urn and placed in the library of the Pasteur Institute. But his beautiful, ardent soul, his audacious and fertile ideas, all that rich inner life which had developed into a harmonious and puissant symphony, all _that_ cannot be dead, cannot disappear! The ideas, the influence we give to life must persist, must live; they are the sacred flame which we hand on to others and are eternal. EPILOGUE The life and work of Elie Metchnikoff are so intimately bound together that, in a biography, it is impossible to separate them. That is why the description of his work necessarily has been dispersed along the story of his life; but, just as, in order to judge of a work of art, one has to draw back and contemplate the whole, we must also, after following the evolution and successive stages of E. Metchnikoff's scientific works, take a full view of his work as a whole. He was a born biologist; everything connected with life interested him. In his childhood, he observed plants and animals. At the age of fifteen, he became acquainted with microscopic beings; they aroused in him such powerful interest towards the primitive forms of life that, from that moment, not only his future path was marked out for him but also his method of starting from the simple to elucidate the complex. He was imbued with Darwin's theory of evolution; having begun by the study of inferior animals, he began to look for their connections with other groups. He endeavoured to establish the continuity and the unity of phenomena in all living beings. According to his method of studying first what was simplest, he turned to embryology, for in the egg and the embryo it is possible to follow step by step the transformation of the simple to the complex and to see the origin and development of all the constituent parts of the organism. Moreover, the embryo is exempt from secondary complications, due to the multiple external conditions of post-embryonic life. Metchnikoff was able to establish, from embryological data, that the development of lower animals takes place according to the same plan and under the same laws as that of higher animals. In all of them, the segmentation of the egg is followed by the formation of embryonic layers, of which each gives birth to cells and to definite organs. Superior forms repeat, in their embryonic life, the evolution cycle of inferior forms.[37] [37] Thus the _parenchymella_, _phagocytella_, and _gastrula_ stages correspond in the embryo with the adult form of certain very primitive Metazoa and even to a colony of unicellular animals. This common plan in the embryology of all animals established their genealogical continuity and strengthened the Darwinian theory.