[9] The order of the paragraphs cited is slightly altered from that of the original. [10] By the courtesy of the Council of the Royal Society, I have been able to compare these annotations with certain manuscript letters of Nehemiah Grew's preserved in the Society's Library. This comparison confirms the view that the annotations are in Grew's own handwriting. [11] Manchet = a loaf of fine wheaten bread. (_An Etymological Dictionary of the English Language._ W. W. Skeat. New ed. 1910.) [12] Medullary rays. [13] Ernst H. F. Meyer, _Geschichte der Botanik_, vol. IV. p. 60, 1857. [14] M. Westermaier, "Zur Kenntniss der osmotischen Leistungen des lebenden Parenchym's." _Ber. d. deutsch. bot. Gesellsch._ Bd I. p. 371, 1883. [15] _The Anatomy of Vegetables Begun_, 1672. [16] Calyx. [Illustration: _Plate VIII_ STEPHEN HALES (1759)] STEPHEN HALES 1677-1761 BY FRANCIS DARWIN An error corrected--Hales' scientific contemporaries--Physiology or Physics--Hales the Founder of the experimental method in Physiology--His style--Cambridge days--Teddington--_Vegetable Staticks_--Experiments described--Transpiration--Root Pressure--Assimilation--Practical application to greenhouses--Distribution of growth first measured--Hales' other activities--Sachs' tribute. In attempting to give a picture of any man's life and work it is well to follow the rule of the _Dictionary of National Biography_, and begin with the dates of his birth and death. Stephen Hales was born in 1677 and died in 1761, having had experiences of the reigns of seven sovereigns. The authorities for the life of Hales are given in my article on him in the _Dictionary of National Biography_. Botanists in general probably take their knowledge of the main facts of his life from Sachs' _History of Botany_. It is therefore worth while to point out that both the original and the English translation (1890) contain the incorrect statement that Hales was educated at Christ's College, Cambridge, and that he held the living of Riddington, whereas he is one of the glories of Corpus, and was perpetual curate of Teddington. These inaccuracies however are trifles in relation to the great and striking merits of Sachs' _History_, a work which to my thinking exhibits the strength and brilliance of the author's mind as clearly as any of his more technical writings. Sachs was no niggling biographer, and his broad vigorous outlines must form the basis of what anyone, who follows him, has to say about the Botanists of a past day. To return to Hales' birth: it is of interest to note how he fits into the changing procession of lives, to see what great men overlap his youth, who were his contemporaries in his maturity, and who were appearing on the scientific stage as he was leaving it.