As Sachs puts it:—"When Darwin's theory was given to the world eight years after Hofmeister's investigations, the relations of affinity between the great divisions of the vegetable kingdom were so well established and so patent that the theory of descent had only to accept what genetic morphology had actually brought to view."
Among Henfrey's original contributions other than those dealing with the burning questions already mentioned, was a series dealing with the Anatomy of Monocotyledons. This would appear to have led him on to study the Nymphaeaceae, and especially the anatomy of Victoria regia—a paper which may be compared perhaps with Prof. Gwynne-Vaughan's more recent study. Henfrey was quite alive to the monocotyledonous affinity, and the enlightened and, for that date, unconventional views to which he gave expression, drew an interesting notice by Hooker and Thomson in the first volume of their Indian Flora.
Another of his papers dealt rather fully with the development of the spores and elaters of Marchantia, where he filled in a considerable lacuna in the knowledge of that group. It is curious to find as late as 1855 so intelligent and well informed a botanist as Henfrey laying it down that the cells of Marchantia, in particular, and Liverworts in general, were destitute of nuclei. It is superfluous to say that this apprehension was quite baseless. Indeed, forty years later, the group of the Liverworts was deliberately chosen by Prof. J. B. Farmer, for the investigation of nuclear phenomena on account of the favourable conditions under which they could be studied!
Microtechnique at that time was of course a much simpler affair than it has since become. Contemporary papers as a rule say little about methods; however one of Henfrey's occasional notes in a magazine tells us that caustic potash, iodine, sulphuric, hydrochloric and acetic acids, together with ether were in common use. Schultze's reagent—chloride of zinc iodide—was invented in 1850, but does not appear to have been generally employed till many years later.
It would however be a serious error to underestimate the value of the earlier work in plant histology. The present writer once spent an interesting morning in Pfeffer's laboratory at Tübingen rummaging through hundreds of the great von Mohl's anatomical preparations. Among these were sections of palm endosperms in which the, at that time recently discovered, continuity of the protoplasm through the cell walls was plainly visible. The existence of these filaments had been detected by von Mohl some years before, but he had refrained from publishing his observations from over-cautiousness.
As a translator and editor Henfrey was responsible for the English edition of von Mohl's Principles of the Anatomy and Physiology of the Vegetable Cell, published in 1852, for two volumes of Reports on Botany in the Ray Society's publications, whilst he had a considerable share in Lankester's translation of Schleiden's famous Principles of Scientific Botany, 1847. In addition to these there were constant abstracts and critical reviews from his pen in the Annals and Magazine of Natural History—a journal of which he became botanical editor before the close of his life.
As a writer of text-books Henfrey was very prolific. First came his Outlines of Botany, 1847, followed by the Rudiments of Botany. Much more ambitious was his Elementary Course of Botany which became a standard text-book running through numerous editions after his death, under the editorship of the late Dr M. T. Masters. To these must be added, in conjunction with Griffith[106], the Micrographic Dictionary, a substantial volume dealing in innumerable special and general articles with the microscopic study of plants and animals. This work was no mere compilation, but embodied in its pages is a very large amount of independent observation. The illustrations covering nearly fifty plates were by Tuffen West, and reached a high degree of excellence. A well known botanist, a contributor to the present volume, has more than once assured me that it was to the Micrographic Dictionary that he owed his salvation!
Should anyone desire to get a vivid and accurate picture of the precise state of Botany in this country at the middle of the last century, he cannot do better than turn over the pages of The Botanical Gazette, a monthly journal of the progress of British botany, founded and conducted by Henfrey. It was about the size of our own New Phytologist, with which it had not a little in common. In one respect it differed; unlike the New Phytologist the Gazette was financially a failure and after carrying it on at his own expense for three years (1849-1851) Henfrey had to relinquish the undertaking.
A perusal of its contents clearly shows that its editor regarded his journal as one of the instruments of diffusing the New Botany. Having to rely largely for his subscribers upon the amateur collector he points out in the prefatory note that a feature will be made not only of home botany but also of contributions or abstracts from abroad dealing with floras which have much in common with our own. For the benefit of those whose collections had reached considerable dimensions, and for whom the lack of new plants might connote a waning stimulus, he held out the further inducement of papers on the general anatomy of familiar plants, of which an excellent example by Thilo Irmisch on the stolons of Epilobium was included in the first number.