Grew, Nehemiah

views updated May 21 2018

Grew, Nehemiah

(b. Mancetter, Warwickshire, England, 164; d. London [?], England, 25 March 1712)

plant morphology, plant anatomy.

Grew was the son of Obadiah Grew, a clergyman and schoolmaster, and Ellen Vicars. After early education at Coventry, he took his B.A. in 1661 at Cambridge, where he was a member of Pembroke Hall. Further study at Cambridge being impossible owing to his religious nonconformity, he qualified for the M. D. at the University of Leiden. Returning to England, Grew practiced first at Coventry and later in London. He relied almost entirely on medicine as a means of livelihood for the rest of his life. He first married Mary Huetson, who died in 1685, then Elizabeth Dodson, by whom he had at least one son and two daughters.

The Royal Society became the focal center of Grew’s activities, for in 1672 he was persuaded by some of the fellows, notably John Wilkins, the bishop of Chester, to move from Coventry to London to take up more seriously the study of plant anatomy, in which he had become interested. Fifty pounds were raised by subscription among the fellows to induce him to make this change. Through the Royal Society, Grew also came into contact with Robert Hooke, whose diverse activities included pioneering studies in the field of microscopy. The compound microscope was just coming into use. Hooke was instructed to make the Society’s microscope available to Grew. By 1677 both Hooke and Grew were secretaries of the Royal Society.

As a medical man Grew had been interested in the structure of animals before turning to plants. His philosophy and religious beliefs made him regard both plants and animals as “contrivances of the same Wisdom” and he therefore concluded that it would be just as rewarding to study the structure of plants as that of animals. Similar views had already been expressed by Francis Glisson, one of the founders of the Royal Society, in a published passage which Grew subsequently quoted in the preface to his first important book, The Anatomy of Vegetables Begun.

Grew was no narrow-minded specialist: besides plant anatomy he was interested in the occurence of crystalline materials in plant tissues. He also described and illustrated the intestines and related organs of many different kinds of animals. In 1672 he discussed the natrue of snow and noticed that it is composed of “icicles” of determined form. By 1675 he was interested in the taste of plants and attempted to classify them accordingly. In 1681 Grew’s Musaeum Regalis Societatis appeared, a thick volume which not only listed but described in detail, sometimes with illustrations, the objects in the Society’s museum at Gresham College. In 1701 Grew published his last great work, Cosmologia sacra. This religious and philosophical treatise reflects the beliefs in which he was brought up and which served as a background to his scientific work.

Grew’s chief claim to scientific distinction rests on his outstanding contribution to plant anatomy. The suggestion made by some botanists that Grew merely copied Marcello Malpighi’s results by referring to the manuscript of his Anatome plantarum between the time of its submission to the Royal Society for publication and its ultimate appearance cannot be taken seriously. A careful perusal of Thomas Birch’s History of the Royal Society, as well as the writings of Agnes Arber and W. Carruthers, shows that there are no grounds for the view that his results were secondhand. Indeed, Grew went to some trouble to demonstrate to fellows of the Royal Society instances in which Malpighi was in advance of him. For example, Malpighi was the first to demonstrate spiral thickenings in vessels. Malpighi and Grew appear, in fact, to have held each other in high scientific regard. Yet communication must have been impeded, for Malpighi could not read English and was less able than Grew to express himself correctly in Latin.

Grew communicated his ideas on plant anatomy to the Royal Society in a series of “discourse” which were so well received that he was asked to publish them in book form. Grew’s first three scientific books are much shorter than the fourth, which repeats and elaborates the contents of the first three. The publication of The Anatomy of Plants (1682) was therefore the highlight of Grew’s career as a plant anatomist. An examination of the text and the profuse illustrations in this great work reveals the tremendous advance in knowledge which it represents. Grew was so successful partly because he started with naked-eye observations and then passed on to higher magnifications. He next elucidated the structures of stems and roots by the combined use of transverse, radial, and tangential longitudinal sections—still the practice today—and also studied obliquely cut surfaces.

Grew’s primary aim was to discover the physiological functions of the various tissues. In this he was only partially successful, not surprisingly, for such mechanisms as the ascent of sap and the translocation of foodstuffs are still only partly understood. In Grew’s time much energy was dissipated in trying to establish physiological similarities between plants and animals. For example, attempts were made to discover a circulatory system in plants comparable with that in animals. On 23 June 1672 Grew was “desired” by the Royal Society “to discover whether, whilst plants are growing, there be a peristaltic motion in them.” On 7 May 1673 he pointed out to the Society that roots have the power to overcome the resistance of the soil as they grow downward as well as to absorb nourishment. This suggested to some of those present that the downward movement of the roots was sustained by muscular action. In such circumstances it is not surprising that Grew became involved in a controversy with Martin Lister which was mainly an argument about the flow of fluids in the plant body. Grew was more successful in recognizing structural differences in plants with different taxonomic affinities, and in so doing he foreshadowed the modern study of systematic anatomy.

Grew confirmed the existence of cells, already seen by Robert Hooke, but he had no idea that they contain the living substance, protoplasm. But Grew went further than Hooke, for he noted the vessels in wood, the fibers in bark, and the parenchyma of the pith and cortex. Indeed, he was responsible for introducing the term “parenchyma.” Grew found that the root consists of a skin, a “cortical body” commonly called the “barque,” and ’a “ligneous body” or vascular core. He found that the cortical body pierces the ligneous body by “inserted pieces,” which are evidently the structures now called medullary rays. In the ligneous body he described annual rings. He likened the vessels and fibers, together with the inserted pieces, to the warp and woof of a piece of cloth. He searched in vain to find valves in the vessels. The ascent of sap in the vessels was accounted for by capillarity, and he thought that the vessels were kept supplied with sap from neighboring parenchyma cells which served as cisterns. Grew believed that the sap rises through the wood only during the spring and that it moves through the bark at other times of the year. His concept of vessels was that their structure resembled a ribbon twisted spirally around an imaginary cylindrical object. He and many anatomists who followed him believed that the wood is in some way derived from the bark. Grew recognized the stomata as orifices or “passports” in the skin of leaves, but Malpighi seems to have understood their structure more completely.

Grew made important contributions to plant morphology as well as to anatomy. For example he studied flowers, fruits, and seeds, along with the vegetative organs. In the flower he termed the calyx the “emplacement,” me corolla the “foliature,” and the stamens and styles the “attire”. On pollination he observed that the pollen “falls down upon the seed case or womb and touches it with a prolific virtue or subtle and vivific effluvia.”

Unfortunately, Grew worked in circumstances that afforded no opportunity to teach students, and consequently, except for what he published, his knowledge died with him. Grew and Malpighi were more accurately informed about plant structure than their immediate successors, and it was not until the time of the German plant anatomist, Hugo von Mohl (1805-1872), that any really fundamental advances in the subject were made.


I. Original Works Grew’s scientific writings are The Anatomy of Vegetables Begun, With a General Account of Vegetation Founded Thereon (London, 1672); An idea of a Phytological History Propounded Together With a Continuation of the Anatomy of Vegetables, Particularly Prosecuted Upon Roots, and an Account of the vegetatian of Roots, Grounded Chiefly Thereupon, (London, 1673);The Comparative Anatomy of Trunks, Together With an Account of Their Vegetation Grounded Thereupon (London, 1675); and The Anatomy of Plants With an Idea of a Philosophical History of Plants and Several Other Lectures Read Before the Royal Society (London, (1682). He also wrote Musaeum Regalis Societatis or a Catalogue and Description of the Natural and Artificial Rarities Belonging to the Royal Society and Preserved at Gresham College. Whereunto is Subjoyned the Comparative Anatomy of Stomachs and Guts (London, 1681); and Cosmologia sacra or a Discourse of the Universe as It Is the Creature and Kingdom of God … (London, 1701).

The following are among the MSS concerning Grew’s activities to be found in the library of the Royal Society: “Letter Book, “V (1672), 443-446, and VI (1673). 321, dealing with the controversy with Martin Lister; and “Register Book,” III (4 Apr. 1672), dealing with the structure of snow; IV (25 Mar. 1675), the description and classification of tastes of plants: V (8 Feb, 1676), on animal anatomy, and (8 Mar.), on salts in plant tissues, There are others in both the Letter Book and the Register Book, but it is impossible to cite all of them here.

II. Secondary Literature. See Agnes Arber, “Tercentenary of Nehemiah Grew (164)-17(2): in Nature, 147 (1941), 630-632: The Relation of Nehemiah Grew and Marcello Malpighi in Chronica botanica, 6 (1941), 391-392; and “Nehemiah Grew and Marcello Malpighi,” in Proceedings of the Linnean Society of London (1941), 218-238; Thomas Birch, History of the Royal Society of London, 4 vols. (London, 1660-1687): W. Carruthers, “On the Life and Work of Nehemiah Grew,” in Journal of the Royal Microscopical Society, 129 (1902), 129-141; Robert Hooke, Micrographia or Some Physiological Descriptions of Minute Bodies made by Magnifying glasses with Observations and Inquiries Thereupon (London, 1665; facs. ed., New York, 1961); M. Malpighi, Anatome plantarum (London, 1675; 1679); C. R. Metcalfe. “A Vista in Plant Anatomy,” in W. B. Turrill, ed., Vistas in Botany (London, 1959), pp. 76-98; and Julius von Sachs, History of Botany (1530-1860), trans. by Henry E. F. Garnsey, rev. by Isaac Bayley Balfour (Oxford, 1906), p. 229–241

Charles R. Metcalfe