From the observations of the records we infer that Lamarck never had any long, lingering illness or suffered from overwork, though his life had little sunshine or playtime in it. He must have had a strong constitution, his only infirmity being the terrible one (especially to an observer of nature) of total blindness. Lamarck's greatest work in systematic zoölogy would never have been completed had it not been for the self-sacrificing spirit and devotion of his eldest daughter. A part of the sixth and the whole of the last volume of the _Animaux sans Vertèbres_ were presented to the Assembly of Professors September 10, 1822. This volume was dictated to and written out by one of his daughters, Mlle. Cornelie De Lamarck. On her the aged savant leaned during the last ten years of his life--those years of failing strength and of blindness finally becoming total. The frail woman accompanied him in his hours of exercise, and when he was confined to his house she never left him. It is stated by Cuvier, in his eulogy, that at her first walk out of doors after the end came she was nearly overcome by the fresh air, to which she had become so unaccustomed. She, indeed, practically sacrificed her life to her father. It is one of the rarest and most striking instances of filial devotion known in the annals of science or literature, and is a noticeable contrast to the daughters of the blind Milton, whose domestic life was rendered unhappy by their undutifulness, as they were impatient of the restraint and labors his blindness had imposed upon them. Besides this, the seventh volume is a voluminous scientific work, filled with very dry special details, making the labor of writing out from dictation, of corrections and preparation for the press, most wearisome and exhausting, to say nothing of the corrections of the proof-sheets, a task which probably fell to her--work enough to break down the health of a strong man. It was a natural and becoming thing for the Assembly of Professors of the Museum, in view of the "malheureuse position de la famille," to vote to give her employment in the botanical laboratory in arranging and pasting the dried plants, with a salary of 1,000 francs. Of the last illness of Lamarck, and the nature of the sickness to which he finally succumbed, there is no account. It is probable that, enfeebled by the weakness of extreme old age, he gradually sank away without suffering from any acute disease. The exact date of his death has been ascertained by Dr. Mondière,[45] with the aid of M. Saint-Joanny, archiviste du Dèpartment de la Seine, who made special search for the record. The "acte" states that December 28, 1829, Lamarck, then a widower, died in the Jardin du Roi, at the age of eighty-five years.