the case of linen, sponges, or powders. The Italian biologist Marcello Malpighi was the first person to describe and illustrate xylem vessels, which he did in his book Anatome plantarum ... (1675). Although Malpighi believed that xylem contained only air, the British physician and botanist Nehemiah Grew, who was Malpighi's contemporary, believed that sap ascended both through the bark and through the xylem. However, according to Grew, capillary action in the xylem would raise the sap by only a few inches; in order to raise the sap to the top of a tree, Grew proposed that the parenchymal cells become turgid and thereby not only squeeze the sap in the tracheids but force some sap from the parenchyma into the tracheids. In 1727, English clergyman and botanist Stephen Hales showed that transpiration by a plant's leaves causes water to move through its xylem. By 1891, the Polish-German botanist Eduard Strasburger had shown that the transport of water in plants did not require the xylem cells to be alive. See also Phloem Soil plant atmosphere continuum Stele Suction Tylosis Vascular bundle Vascular tissue Xylem sap Explanatory notes References Citations General references is the main source used for the paragraph on recent research. is the first published independent test showing the Scholander bomb actually does measure the tension in the xylem. is the second published independent test showing the Scholander bomb actually does measure the tension in the xylem. recent update of the classic book on xylem transport by the late Martin Zimmermann External links Plant anatomy Plant cells Plant physiology Tissues (biology)