(b. Aberdeen, Scotland, 1 November 1819; d. London, England, 7 September 1859)
Apart from some important work on the process of vegetable fertilization, Henfrey made few original contributions to botany. He was more influential as an editor, translator, and author of textbooks and manuals. In these capacities he communicated to British naturalists the dramatic developments which were taking place during his lifetime in Continental, and especially German, botany. At a time when British botanists were preoccupied with collection and taxonomy, partly as a result of the influx of exotic new species from India and other British colonial possessions, Henfrey was conspicuous as an advocate of the emerging Continental emphasis on physiological anatomy and comparative morphology.
The son of English parents, Henfrey studied medicine and surgery at St. Bartholomew’s Hospital, London, where he was a favorite of Frederic Farre. In 1843, upon completing his clinical training, he was admitted to membership in the Royal College of Surgeons; but weak health dissuaded him from medical practice, and he thereafter devoted his life exclusively to botany. Elected a fellow of the Linnean Society in 1844, Henfrey was in 1847 appointed lecturer on botany at the medical school affiliated with St. George’s Hospital, London. In 1854, by which time he had been elected to fellowship of the Royal Society, Henfrey was chosen to succeed Edward Forbes in the chair of botany at King’s College, London, He held the chair until his death, having become in the meantime examiner in natural science to the Royal Military Academy and to the Royal Society of Arts. Henfrey’s wife, Elizabeth Anne, was the eldest daughter of Jabez Henfrey. Their son, Henry William Henfrey, was a prominent numismatist.
In reporting the developments in Continental botany, Henfrey often chose sides on the leading issues of the day. He aligned himself above all with those botanists who sought to overthrow Matthias Schleiden’s theories of cell development and vegetable fertilization. In his writings on cell development he accepted Hugo von Mohl’s conception that vegetative cell division normally takes place by the infolding of a distinct outer layer of protoplasm, the “primordial utricle,” whose role and very existence were hotly debated at the time. Like Mohl and many other botanists of the day, Henfrey effectively denied the nucleus a role in cell multiplication. On other general issues his thought often reflected that of the leading German botanists. He supported the efforts by Alexander Braun, Mohl... and others to replace Schleiden’s emphasis on the cell wall with an emphasis on the protoplasmic cell contents. Although sharing his contemporaries’ suspicion of Naturphilosophie, Henfrey did not embrace the mechanistic trend then emerging in German physiology. In The Vegetation of Europe, Its Conditions and Causes (1852), he joined Edward Forbes in advocating the hypothesis of special “centers of creation” for each plant species. He seemed never to doubt the doctrine of the immutability of species.
Henfrey joined the debate over vegetable fertilization at a time of great excitement about all aspects of plant reproduction. Wilhelm Hofmeister and others were developing the doctrine that sexuality extends throughout the vegetable kingdom and that the mode of reproduction is essentially the same in all plants. Henfrey confirmed in the case of ferns Hofmeister’s rule that the mode of embryo production in conifers is intermediate between those of phanerogams and cryptogams. Great interest had also been generated by the attempts of Giovanni Amici and Mohl to discredit Schleiden’s theory of fertilization in the flowering plants, and particularly his notion that the pollen grain was the ovule of the plant. Aligning himself quickly with Amici’s school of thought, Henfrey eventually focused on the question of when germinal vesicles first appear in the embryo sac. If it could be shown that germinal vesicles existed in the embryo sac before the pollen tube reached it, then Schleiden and the other “pollinists” might at last concede that the pollen tube was not ovular but merely a fertilizing organ which conveyed spermatozoa to preexistent germinal vesicles.
In 1856, in a paper on Santalum album, Henfrey showed that germinal vesicles do indeed exist in the embryo sac before the pollen tube reaches it, but in the form of naked protoplasmic units rather than ordinary cells. After the pollen tube reaches the embryo sac, a cellulose coat appears on that germinal body which is to give rise to the embryo. In confirmation of this point, Henfrey showed that the germinal vesicles in ferns also lack cellulose membranes until fertilized by contact with spermatozoa. He further suggested that much of the confusion over vegetable fertilization resulted from the circumstance that in their naked protoplasmic form, the germinal vesicles are readily destroyed or altered by external agents and endosmosis. In the same year Schleiden announced that he was abandoning his theory of fertilization; and although Henfrey’s work apparently had nothing to do with this change of mind, it did form part of the evidence used in confirmation and elaboration of Amici’s theory of fertilization.
I. Original Works. The Royal Society Catalogue of Scientific Papers, III, 275–276, lists 39 papers by Henfrey. These include a five-part report on the progress of physiological botany in Annals and Magazine of Natural History, 2nd ser., t 1848). 49–62, 124–132. 274–279. 436–443;4 (1849), 339 348. of the other papers, the most important are “On the Developement [sic] of Vegetable Cells,” ibid., 18 (1846). 364–368; “On the Reproduction of the Higher Cryptogamia and the Phanerogamia,” ibid., 2nd ser., 9 (1852), 441–461; “On thc Developement of Ferns From Their Spores” , in Transactions of the Tinnean Society of London, 21 (1855), 117–140; “On the Developement of the Embryo of Flowering Plants,” in Report of the British Association for the Advancement of Science. 26 (1856). Transactions of the Sections, 85–87; and “On the Developement of the Ovule of Sanialum album; With Some Remarks on the Phenomena of Impregnation in Plants Generally,” in Transactions of the Linnean Society of London, 22 (1856), 69–80. For citations of Henfrey’s works as editor, translator, and author of textbooks, see British Museum General Catalogue of Printed Books, CI, cols. 692 –694.
Of Henfrey’s several manuals and textbooks, two enjoyed considerable success. The Micrographic Dictionary, which lie wrote with J. W. Griffith, wein through four editions between 1855 and 1881. Between 1857 and 1884 his Elementary Course of Botany: Structural, Physiological and Systematic went through four editions and was for a time probably the leading British textbook on botany.
Besides a number of memoirs by Karl von Naegeli, Mohl, Hofmeister, and others, Henfrey translated J. F. Schouw’s Earth, Plants and Man (1847), Schleiden’s The Plant (1848), Mohl’s Principles of the Anatomy and Physiology of the Vegetable Cell (1852), Braun’s Reflections on the Phenomenon of Rejuvenescence (1853), and J. A. Stückhardt’s Chemical Field Lectures (1855). For brief periods he edited Botanical Gazette, Gardener’s Magazine of Botany, Annals and Magazine of Natural History, and Journal of the Photographic Society of Great Britain. With T. H. Huxley he edited and translated the natural history portion of Taylor’s Scientific Memoirs (1853).
II. Secondary Literature. Obituary notices are in Proceedings of the Royal Society, 10 (1860), xviii-xix; and Annals and Magazine of Natural History, 3rd ser., 4 (1859), 311–312. See also Dictionary of National Biography, IX, 409–410; and J. Reynolds Green, A History of Botany in the United Kingdom From the Earliest Times to the End of the Nineteenth Century (London, 1914), pp. 418–419.
Gerald L. Geison