of growth. It found a new supporter in 1680 in the person of
Claude Perrault, who does not however appear[1] to have added
anything essentially new to Malpighi's conclusive arguments
for a returning sap. Nor did his opponent Magnol in his very
weak treatise published in 1709 succeed in saying anything
that will bear examination against the theory of circulation, which he too ascribed to Malpighi.
Among the phenomena of vegetation in woody plants, there is scarcely one so striking as the outflow of watery sap from wounded vines and from some tree-stems in the spring. This phenomenon, like the outflow of milky juice, gum, resin and the like, could not fail to be regarded with lively interest by those who occupied themselves with vegetable physiology in the 17th century. Even supposing the movements of water in the wood and of the milky and other juices in their passages not to be necessary accompaniments of the nutrition of plants, yet it was natural that the physiologists of the 17th century should see in them striking proofs of that movement of the sap which is connected with nutrition, and should therefore make them a subject of study. It might also seem to them that the problem in question was easy to solve, for it was not till long after that it came to be understood that these movements are in reality one of the most difficult questions of vegetable physiology. We discover the interest taken in these matters from a series of communications in the form of letters from Dr. Tonge, Francis Willoughby, and especially from Dr. Martin Lister, to be found in the Philosophical Transactions for 1670[2]. The phenomenon to which these men chiefly directed their attention was just the one best calculated to
- ↑ His views are known to me only from Magnol's paper in the 'Histoire de l'Academic Royale des Sciences,' 1709, and Sprengel's 'Geschichte der Botanik,' ii. 20. Perrault's treatise is according to Pritzel's ' Thesaurus ' of the date of 1680, but is published in the 'Œuvres divers de Perrault' of 1721.
- ↑ Especially in pages 1165, 1201, 2067, 2119.
