# Makers of British botany/William Crawford Williamson 1816—1895

* Plate XX
* HENRY WITHAM OF LARTINGTON
WILLIAM CRAWFORD WILLIAMSON 1816—1895
By DUKINFIELD H. SCOTT
Early exponents of Fossil Botany—Witham of Lartington—Edward William Binney—William Crawford Williamson—early influences—first contribution to science—studies medicine—work on Foraminifera—appointed Professor at Manchester—successful popular lecturer—his influence in Natural History—investigation of the Carboniferous Flora—controversy with French palaeo-botanists—the magnitude of his output—defects in his work—later work at Kew—personal traits.
During the last forty years the study of fossil plants has come to be a specially vigorous and characteristic branch of British botany. The proper subject of my lecture is Williamson, the man to whom above all others the present strong position of the subject is due. But "there were brave men before Agamemnon," and there are two of the older masters, Witham and Binney, whom I cannot wholly pass over. I ought really to include others, and notably Sir Joseph Hooker, to whom we owe our first clear understanding of Stigmaria and of Lepidostrobus, but this course does not extend to those who, like Sir Joseph, are still living among us and still in active work.
I am indebted to Mr Philip Witham, a member of the family, for some information about Henry Witham, of Lartington, the first Englishman to investigate the internal structure of fossil plants.
Henry Witham was, by birth, not a Witham, but a Silvertop, having been the second son of John Silvertop of Minster Acres, ​Northumberland. As Henry Silvertop he came in for the Lartington property. He was born in 1779 and married Miss Eliza Witham, niece and co-heiress of William Witham of Cliffe, Yorkshire, when he took the name and arms of Witham.
The method of cutting thin sections of rocks and fossils had just been invented by Nicol, and this gave Witham the opportunity for his investigations. His papers are illustrated by the botanist McGillivray, to whom he may have owed some further assistance. Indeed he made little pretension to botanical knowledge, but the opinions which he expresses strike one as remarkably sensible, and he must have been a man of sound judgment, at least in scientific affairs.
Witham was the first investigator of that most famous of fossils, Lepidodendron Harcourtii; of the Craigleith tree (now Pitys Withami), of the Lennel Braes trees (Pitys antiqua and P. primaeva}, of the Wideopen tree (Pinites, now Cordaites Brandlingi) and of Anabathra pulcherrima. It is curious to notice that the Craigleith tree, a manifest Gymnosperm, was at first (1829) regarded even by the great Brongniart as a Monocotyledon, while others imagined it to be a Lycopod. Witham, however, soon set this right. He always speaks with great respect of Brongniart, then just becoming the recognised leader of fossil botany. The following passage from Witham's memoir on the vegetable fossils found at Lennel Braes, near Coldstream, is of interest.
"Now, according to that gentleman's [Brongniart's] opinion, out of six classes...only two existed at that period [Carboniferous], namely the Vascular Cryptogamic plants, comprehending the Filices, Equisetaceae and Lycopodeae, and the Monocotyledons, containing a small number of plants which appear to resemble the Palms and arborescent Liliaceae. The existence, therefore, of so extensive a deposit of Dicotyledonous plants, at this early period of the earth's vegetation, appears to demand the attention of the naturalist."
Brongniart's "Monocotyledons" were no doubt Cordaiteae. Witham, we see, set the great man right as regards the antiquity of Dicotyledons, in which, of course, Gymnosperms were then included.
​Witham's earlier papers were embodied in his book: The Internal Structure of Fossil Vegetables found in the Carboniferous and Oolitic deposits of Great Britain, described and illustrated, 1833. It is dedicated to William Hutton, author, with Lindley, of the Fossil Flora of Great Britain.
A passage from the dedication shows that Witham took his work seriously—"To lend my aid in bringing from their obscure repositories the ancient records of a former state of things, with the view of disclosing the early and mysterious operations of the Great Author of all created things, will ever be to me a source of unalloyed pleasure."
Witham thus fully realised the important significance of the work on which he was engaged. He must have been an interesting person of a somewhat complex character, and I wish we could know more about him. He died on Nov. 28th, 1844. Like all his family, he was a Roman Catholic.
Witham's localities on the Tweed remained practically unvisited until Mr Kidston re-explored them eight or nine years ago, with brilliant success—the results, however, are still unpublished.
Edward William Binney, the first investigator of the Lancashire coal-balls, was born at Morton in Nottinghamshire in 1812, and was thus only four years senior to Williamson. He settled in Manchester in 1836, and practised as a solicitor. He early showed scientific tastes; the Manchester Geological Society was started, chiefly by his influence, in October 1838. He was concerned in the discovery of the famous St Helen's trees, which first proved the connection between Sigillaria and Stigmaria. "Binney completed the proof that all coal-seams rest on old soils which are constituted entirely of vegetable matter; this was the seat-stone of a seam of coal" (Robert Hunt). He gave up the practice of Law, and, devoting himself to science, became a leading authority on northern geology, and rendered important aid to the Geological Survey by his ​long experience of the coal-fields of Lancashire and Cheshire. He assisted in the discovery of the Torbane Hill mineral or Boghead Cannel, a deposit once notorious as a subject of litigation, and more recently as a bone of scientific contention.
Binney died on December 19, 1881. Etheridge said of him: "He was a man of the highest honour and remarkably outspoken; his sturdiness and strength of character being rarely equalled." Binney was the discoverer of some now famous fossils, notably Dadoxylon (now Lyginodendrori) oldhamium, and Stauropteris oldhamia. His best known work is the monograph, Observations on the Structure of Fossil Plants, in four parts, published for the Palaeontographical Society, from 1868 to 1875. Thus his work on coal-plants overlapped that of Williamson.
The first part is on Calamites and Calamodendron—the names are used in the old sense, for Binney kept up Brongniart's distinction, though apparently not convinced of its validity. In this memoir he described the "cone of Calamodendron commune" now known as Calamostachys Binneyana.
Part II, on Lepidostrobus and some allied cones, is remarkable for the demonstration of heterospory in several species.
Part III, on Lepidodendron, deals partly with stems referred to L. Harcourtii, but now separated as L. fuliginosum. He also describes the structure of a Halonia and is led to the conclusion that it is the root of Lepidodendron. This view has not found favour, but our old ideas about Ulodendron and Halonia have been so upset of late, that everything seems possible!
Part IV is on Sigillaria and Stigmaria, the "Sigillaria" described being S. vascularis, since identified with Lepidodendron selaginoides , or L. vasculare, if we maintain Binney's specific name.
Binney was not a great theoriser. His object was rather to provide material for the botanists, he being essentially a geologist. This he did admirably, for his monograph is illustrated by magnificent drawings from the hand of Fitch, the famous botanical artist.
Binney stood more under the influence of Brongniart than did his successor Williamson.
* ↑ Since these words were spoken the veteran leader of English Botany has passed away. A notice of Sir Joseph's career will be found in this volume, and the present writer has given some account of his work on fossil plants in an Anniversary Address to the Linnean Society, May 24th, 1912.
* ↑ The portrait of Henry Witham is from the original picture in the possession of the Salvin family, at Croxdale; a photograph of the picture was kindly obtained for me by Mr Philip Witham.
* Plate XXI
* WILLIAM CRAWFORD WILLIAMSON (1876)
​I now go on to my principal subject. Williamson's father, John Williamson, originally a gardener, was well known for his researches on the Natural History of the Yorkshire coast, and was for 27 years curator of the Scarborough Museum. Previously to that, John Williamson kept a private museum of his own, and it was in the room next to this that William Crawford Williamson was born on November 24, 1816. John Williamson's cousin, William Bean, was also an active local naturalist, known especially for his work on the Yorkshire Fossil Flora; the genus Beania is named after him.
Our Williamson's mother, born Elizabeth Crawford, was the eldest of 13 children of a Scarborough jeweller and lapidary. Young Williamson used to spend much time in the Crawford's workshop, watching them cutting and working with the diamond—the agates from the gravels of the coast. "A youthful training," he says, "which became of the utmost value to me more than a third of a century later, when scientific research required me to devote much of my own time to similar work."
In 1826 the famous William Smith and his wife established themselves in the Williamson's house, and stayed there for two years. Williamson's early recollections of the "Father of English Geology" must have been inspiring. His father was also a friend and correspondent of Sir Roderick Murchison.
The appearance of Phillips' classic volume, Illustrations of the Geology of Yorkshire, in 1829, gave young Williamson his first introduction to true scientific work. His father at once set to work to name from this book the fossils he collected, and his son was called in to help. "My evenings throughout a long winter were devoted to the detested labour of naming these miserable stones." "Pursuing this uncongenial task gave me in my 13th year a thorough practical familiarity with the palaeontological treasures of Eastern Yorkshire. This early acquisition happily moulded the entire course of my future life."
Those were not the days of the half-educated. Young Williamson, in addition to his special scientific training, had the advantage of a classical education, at schools both in ​England and France. The French part of his education was not altogether a success, for most of the boys at the school were English.
Passing through London on his return he had breakfast with Sir Roderick Murchison, who took him to the Geological Society. This was in March 1832, when he was little more than 15. Certainly his entrance into the scientific world was made easy for him. Would it be made equally easy now for a boy in a similar position? In the same year, 1832, Williamson was articled to Mr Thomas Weddell, a medical practitioner at Scarborough. While with him, he continued to pursue Natural History as a recreation—bird-collecting for example, and also botany. He writes, "I was then forming a collection of the plants of Eastern Yorkshire, as well as trying to master the natural classification, which was already beginning to supplant the Linnean method, so long the one universally adopted."
A memoir on the rare birds of Yorkshire was communicated to the Zoological Society of London—an early work though not quite the earliest. While with Mr Weddell, Williamson contributed a number of descriptions and drawings of oolitic plants to Lindley and Hutton's Fossil Flora. He tells us how the drawings had to be made in the evenings on Mr Weddell's kitchen table. The plants he illustrated had for the most part been collected by his father and John Bean in a small estuarian deposit at Gristhorpe Bay. More than 30 species were thus recorded by him.
He also made diagrams to illustrate some lectures on Vegetable Physiology given by Mr Weddell at the Mechanics' Institution. It is rather surprising to find that such a course was given in a country town during the early 'thirties. Probably the learning displayed was not very deep, for Mrs Marcet's Conversations seem to have been the chief authority.
In 1834-36 Williamson published important papers, determining geological zones, from the Lias to the Cornbrash, by means of their fossils; subsequently he extended his zoning work up to the Oxford Clay.
The opening of the Gristhorpe tumulus in July 1834, when ​a skeleton, of the Bronze Age, was found in a coffin fashioned out of the trunk of an oak-tree, gave occasion to Williamson's one contribution to archaeology. His memoir was reprinted in the Literary Gazette for October 18, 1834 (still before he was 18). This was through Dr Buckland's influence; in a letter to Williamson he said, "I am happy to have been instrumental in bringing before the public a name to which I look forward as likely to figure in the annals of British Science." A second and third edition of this paper were called for.
In September 1835 Williamson was appointed curator of the Museum of the Manchester Natural History Society, and so began his long connection with the great northern town, lasting down to 1892. In those days the interest in the vigorous young science of geology was extraordinarily keen, and there was great activity, especially among the naturalists of the North, many of whom were working men. Williamson, about 1838, gave a course of lectures on geology at various northern towns, and thus raised funds for his removal to London, to continue his medical studies. It is interesting to find that Williamson, while at Manchester, helped to nurse John Dalton in his last illness.
While curator at Manchester, Williamson saw the rise of Binney as a geologist.
His remarks on the local study of botany at that time are interesting. "The botanical interests of the district were chiefly in the hands of the operative community. The hills between Lancashire and Yorkshire swarmed with botanical and floricultural societies, who met on Sundays, the only day when it was possible to do so." Some of these men must have had an excellent education, as shown by the good English they wrote, as for example Richard Buxton, a poor working man, author of a standard Botanical Guide. The society to which Buxton belonged had, in 1849, existed for nearly a century. It may be doubted whether an equal enthusiasm for science still prevails in that or in any part of England.
In September 1840 Williamson went to London to complete his medical training, and entered University College, making ​the acquaintance of Prof. Lindley, who had for so long known him only as a correspondent and collaborator.
Soon afterwards he was offered the post of naturalist to the Niger expedition, which he refused, and, as it turned out fortunately, for the journey proved disastrous. Stanger, of Stangeria fame, took his place.
In 1842, having then returned to Manchester and started in practice, Williamson made his first attempt at microscopic work, having become interested in the Foraminifera of the Chalk. He also began to examine Confervae, Diatoms and Desmids, finding perhaps, as others have done, that the Freshwater Algae give the best introduction to microscopic biology.
The work on Foraminifera became one of the most important in Williamson's career. In 1845 he wrote his valuable paper on microscopic organisms in the mud of the Levant. His work in this field culminated in his monograph of Foraminifera, issued by the Ray Society in 1857.
In 1851 Williamson was appointed Professor of Natural History, which included Zoology, Botany and Geology, at the new Owens College, Manchester. He tells us, "The botanical portion of my work was that for which I was least prepared"—"of the German language I was utterly ignorant." The almost insuperable difficulties of a triple Professorship were at first met by spreading the complete course over two years, a sensible plan which was rendered impracticable by the more rigid requirements of examinations. It was not, however, till 1872 that a division of the duties of the chair took place; Williamson was then relieved of the geological teaching by the appointment of Prof. Boyd Dawkins; in 1880 the zoology was taken over by the late Prof. Milnes Marshall, Williamson thus retaining the very subject, botany, with which he had originally been the least familiar.
In addition to his peculiarly arduous duties as Professor, Williamson was a great populariser of science. He was one of the first two members of the Owens' staff to start, in 1854, evening classes for working men. He gave numerous scientific lectures at the Royal Institution in London and elsewhere, his
* ↑ Reminiscences of a Yorkshire Naturalist, p. 6.
* ↑ Reminiscences, p. 12.
* ↑ Reminiscences, p. 33.
* ↑ Reminiscences, p. 78.
* ↑ Reminiscences, p. 136.
* Plate XXII
* Vascular system of stem of Lepidodendron selaginoides in transverse section
* Drawn by Williamson
​greatest work in this field being his lectures for the Gilchrist Trustees. He mentions that from 1874 to 1880 he delivered 158 of these lectures in 61 towns, and he continued this work with equal activity for another 10 years. He was a vigorous and effective lecturer, who always interested his audience; he illustrated his lectures by bold diagrams, drawn by his own hand. In order to form any idea of Williamson's many-sided activity it must be remembered that he was all the time engaged in active medical practice, both general and special, for he was well known as an aurist. Yet he always found time for fruitful original research, often of the most laborious character.
Prof. Judd says, in a letter written to me in February 1911:
"I have often been struck by the fact that Williamson, appointed to an impossible Professorship of Zoology, Botany and Geology, managed to initiate great movements in connection with each of these sciences.
"In Geology he was clearly the pioneer in the subdivision of formations into zones each characterised by an assemblage of fossils—Ammonites playing the most important part....But Williamson did another great service to Geology....Sorby visited Williamson at Manchester and learned the art of making sections which he applied with such success to the study of igneous and other rocks, becoming the 'Father of Micropetrography.'
"In Zoology, Williamson initiated the work done in the study of deep-sea deposits, by his remarkable memoir on the mud of the Levant, in 1845, when he was 29 years old. This led to his study of the Foraminifera (especially by the aid of thin sections) and to his monograph in the Ray Society on that group....
"Of his contributions to Botany through his sections of 'Coal balls' I need say nothing."
Prof. Judd makes no reference here to the papers which obtained for Williamson his F.R.S. in 1854. These embodied his researches on the development of bone and teeth, in which he demonstrated that the teeth are dermal appendages homologous with the scales of fishes. This important work dated back to 1842 and was inspired by his enthusiasm for the then novel cell-theory of Schleiden and Schwann.
​The interest aroused by this investigation is shown by the fact that the great German anatomist Kölliker travelled to Manchester, about the year 1851, to see Williamson's preparations.
As regards Williamson's work as a botanist, in which we are chiefly interested in this course, his best contribution to recent botany was no doubt his investigation of Volvox, published in 1851 and 1852, in which he traced the development of the young spheres and the mode of connection of their cells, anticipating the results of much later researches.
He was a great lover of living plants; his garden and greenhouses at Fallowfield, his Manchester home, were of remarkable interest, and he was a keen gardener. At the British Association Meeting of 1887 one of his guests said that "most of the distinguished botanists of Europe and America were in the garden, and not one but who had seen something growing he never saw before." Insectivorous plants and the rarer vascular cryptogams were specially well represented. It was from his private garden that his classes were supplied with specimens.
As we have seen, fossil plants engaged Williamson's attention in his earliest years, when as a mere boy he contributed to Lindley and Hutton's Fossil Flora.
His first important independent work in this field was his paper "On the Structure and Affinities of the Plants hitherto known as Sternbergiae" (1851), in which he proved, for the first time, that these curious fossils, resembling a rouleau of coins, were casts of the discoid pith of Dadoxylon, or, as we should now say, of Cordaiteae—the first step in the reconstruction of this early gymnospermous family. This investigation, to which he appears to have been led almost accidentally, through some good specimens coming into his hands, brought him back, as he says, to his old subject of fossil botany. It was long, however, before he got fairly started on his great course of investigations on Carboniferous plants.
In the meantime he had returned to the Yorkshire Oolitic plants and, about 1847, published a paper in the Proceedings of the Yorkshire Philosophical Society, "On the Scaly Vegetable Heads or collars from Runswick Bay, supposed to belong to the ​Zamia gigas." His full paper, in which he maintained the Cycadean affinities of the flower-like fossils, was written soon afterwards, but met with a series of misfortunes, and was not finally published till 1870, in the Transactions of the Linnean Society, before which body it had been read in 1868. Williamson was admittedly right in connecting the floral organs with the so-called Zamia foliage, and his interpretation of the complicated structure was as good as was possible in the then state of knowledge. The true nature of these fossils, now known by the name Williamsonia, given them by Mr Carruthers, could only be understood at a much later date in the light of [[[Author:Melchior Wieland|Dr Wieland]]'s famous researches on the American Bennettiteae, and has quite recently been made clear in a memoir by Prof. Nathorst. Perhaps, even now, some points remain doubtful.
Early in the fifties Williamson made some rough sections of a Calamite which came into his hands, and this was the beginning of his most characteristic line of work. A remarkable internal cast of a Calamite, figured by Lyell in his Manual of Geology in 1855, led to a correspondence with M. Grand'Eury, now so famous as the veteran French palaeobotanist. Williamson at that time had no intention of entering on the serious study of Carboniferous plants, for Binney was already in the field. Grand'Eury's letter, however, caused him to look up his old sections, which he found differed from the Calamitean stems figured by Binney. Matters for a time moved slowly, and Williamson's specimen was only described in 1868 in the Manchester Memoirs. This fossil, which he named Calamopitus, is now known as Arthrodendron, and is a distinct type of Calamarian stem, intermediate between the common Calamites or Arthropitys, and the more elaborate Calamodendron of the Upper Coal Measures.
Williamson was now fairly started on his Carboniferous work. His first memoir on the Organisation of the Fossil Plants of the Coal Measures was communicated to the Royal Society on November 11, 1870. It is amusing to find that the secretaries objected to the memoir being called Part I, since it bound the society to publish a Part II! Nineteen Parts were published, the last in 1893.
​The first memoir was on the Calamites, and controversy at once broke out. Williamson was from the first impressed by the manifest occurrence of exogenous, or, as we should now call it, secondary growth, both in the Calamites and the Lepidodendreae, groups which he was convinced were cryptogamic. The controversy with the great French school, headed by the illustrious Brongniart, is well known. As Williamson put it: "The fight was always the same; was Brongniart right or wrong when he uttered his dogma, that if the stem of a fossil plant contained a secondary growth of wood, the product of a cambium layer, it could not possibly belong to the cryptogamic division of the vegetable kingdom?"
In England, however, the dispute was on different lines. "In August of 1871," says Williamson, "the British Association met at Edinburgh. At that meeting I brought forward the subject of cambiums and secondary woods in Cryptogams, with the result that my views were rejected by every botanist in the room." There followed a controversy in the pages of Nature, which is of some interest, as showing the state of opinion in England at that time. Williamson tells us in his autobiography the principle by which he was guided in his work: "I determined not to look at the writings of any other observer until I had studied every specimen in my cabinet, and arrived at my own conclusions as to what they taught." In spite of this excellent rule it is probable that he was at first unconsciously influenced by the views of Brongniart, which may have led him to attach too much systematic importance to the occurrence of secondary growth. At any rate he proposed at the Edinburgh meeting "to separate the vascular Cryptogams into two groups, the one comprehending Equisetaceae, Lycopodiaceae and Isoetaceae, to be termed the Cryptogamiae Exogenae, linking the Cryptogams with the true exogens through the Cycads; the other called the Cryptogamiae Endogenae, to comprehend the Ferns, which will unite the Cryptogams with the Endogens through the Palmaceae."
It is curious to note in passing that his main divisions, so far as vascular Cryptogams are concerned, correspond to the
* ↑ Reminiscences, p. 190.
* ↑ Reminiscences, p. 203.
* ↑ Nature, Vol. IV., 1871, p. 357.
* Plate XXIII
* Root of Calamites (Astromyelon Williamsonis) in transverse section
* Drawn by Williamson
​Lycopsida and Pteropsida of Prof. Jeffrey, though the suggested relation to the higher plants would not be accepted by any modern botanist. In spite of Williamson's tactical error in weighting himself with a doubtful scheme of classification, and in spite also of a faulty terminology, it is easy to see now that he had the best of the controversy, for he knew the facts about the structure of the Carboniferous Cryptogams, which his opponents, at that time, did not. They stuck to generalities, and those who take the trouble to rake the ashes of this dead controversy will at least learn that dogmatism is not confined to theology!
An interesting point is that Williamson at that time spoke of Brongniart almost as an ally. The conviction that the old Lepidodendrons and Calamites were "exogenous" then seemed to him of greater importance even than his belief that they were Cryptogams. The English opposition, however, was never really formidable, and so a change of front became necessary, to meet the attacks of the powerful French school. Williamson was an energetic disputant; not content with his numerous English publications, he published, in 1882, an article in the Annales des Sciences Naturelles, entitled "Les Sigillaires et les Lepidodendrées." This was translated into French for him by his colleague Marcus Hartog, whose assistance he greatly valued. He describes this vigorous polemical treatise as "flung like a bombshell among my opponents."
In time they came over, one by one, to his views, and even the most redoubtable of the French champions Bernard, Renault, before the close of his life, had made very considerable concessions to Williamson's side of the question. There is no need to dwell on the controversy; every student now knows that the Club-mosses, the Horse-tails and the Sphenophylls of Palaeozoic times formed abundant secondary tissues homologous with those of a Gymnosperm or a Dicotyledon; the case of the Sphenophylls shows that the character was not limited to arborescent plants then any more than it is among Dicotyledons at the present day. At the same time, as Williamson maintained, these groups of plants were, broadly speaking, cryptogamic.
* Plate XXIV
* Cone of Calamostachys Binneyana; sporangia and sporangiophores
* Drawn by Williamson
​to Lepidodendron, besides other allied forms, and placed our knowledge of the comparative anatomy, once for all, on a broad and secure basis. His great monograph of Stigmaria, by some considered his best work, is still our chief authority for the subterranean organs.
In the Ferns he made important contributions to our knowledge of the group now familiar to botanists as the Primofilices of Arber. In particular his account of the plant now known as Ankyropteris corrugata is still among the best we possess of any member of the family.
In Pteridosperms, to use the modern name, Williamson may fairly be called the discoverer of the important family Lyginodendreae. He appreciated their intermediate position, speaking of them, in 1887, as "possibly the generalised ancestors of both Ferns and Cycads."
As regards both Pteridosperms and Gymnosperms proper, attention may be specially called to his work on isolated seeds, in which he was surpassed by Brongniart alone. This field of investigation, long neglected, has lately been revived with striking results.
I hope that all students of fossil botany will have at least turned over the pages and the plates of Williamson's works, for only by inspection of the original memoirs can any idea be gained of his vast services to our science.
His remarkable skill as a draughtsman (for all his memoirs are illustrated by his own hand) is not always done justice to in the published reproductions as the fine examples of his original drawings, so kindly lent for the lecture by Mrs Williamson, will show. At the time when Williamson's main work was in progress from 1870 to 1892 geologists were probably more appreciative of its value than botanists. Happily, in spite of occasional trouble with Referees, none of his work was lost, the Royal Society going steadily through with all the nineteen memoirs which were entrusted to them.
The one botanist, who, up to the year 1890, estimated Williamson's work at its full value was Count Solms-Laubach, ​who makes the honourable boast that he knew Williamson's collection as no one else did.
Williamson's writings are not easy reading, especially for the modern botanical student, for the terminology is often unfamiliar, and the arrangement of the matter unsystematic.
It would be out of place to enter on a criticism of details, but it is necessary to call attention to the one serious mistake which ran through much of Williamson's work, though at the last he to a great extent corrected it himself. He was always too ready to interpret specimens of the same fossil plant which differed in size and anatomical complexity, as developmental stages of one and the same organ. Such differences among fossils are more often due to the order of the branch on the plant, or to the level at which a section is cut. This error led to some mistaken, and indeed impossible views of the process of development. I mention this partly because I have noticed the same fundamental mistake in the work of much more modern writers. "We are none of us infallible—not even the youngest of us," and among the latest fossil-botany papers I have read, I have detected the very same confusion between differences of size and differences of age, which constitutes the most serious blemish in Williamson's writings.
As is well known, Williamson in his latest independent work corrected, as regards the Lepidodendrons, on the basis of a laborious re-investigation, the chief mistake he had made as to their process of growth; he thus displayed an openness of mind worthy of a great naturalist.
I first saw Williamson on February 16, 1883, when I attended his Friday evening lecture at the Royal Institution, "On some anomalous Oolitic and Palaeozoic Forms of Vegetation." I did not, however, make his acquaintance till six years later, when we met at the British Association Meeting at Newcastle-upon-Tyne, in 1889. This led to a visit to his house in company with Prof. Bower; it was on March 8, 1890, that ​I first had a sight of his collection. I find the entry in my diary: "Spent 7 hours over fossils, especially Lyginodendron and Lepidodendron, preparations magnificent." I at once became an ardent convert to the cult of fossil plants to which I had hitherto been indifferent, though I must in fairness admit that Count Solms-Laubach's Einleitung had done something to prepare the way. I well remember the state of enthusiasm in which I returned home from Manchester. A subsequent visit confirmed me in the faith, but it was some little time before I put my convictions into practice. In 1892 Williamson, then in his 76th year, resigned the Manchester Professorship and came to live near London. In the same year I migrated to Kew, and it was agreed that we should work in concert, an arrangement which received every encouragement from the then Director, Thiselton-Dyer. Williamson first came to the Jodrell Laboratory on Friday, December 2, 1892. Then, and on many later visits, he carried a satchel over his shoulder, crammed with the treasures of his collection. For some months he came pretty regularly once a week, afterwards less often. On these visits we discussed the work I had done on the sections during the interval, and sometimes our discussions were decidedly lively. In the end, however, we always managed to come to a satisfactory agreement. Our first joint paper (Catamites, Calamostachys and Sphenophyllum) was sent off to the Royal Society, rather more than a year from the start, on December 29, 1893.
During the early part of 1894 Williamson came occasionally to Kew, and our discussions were renewed, this time chiefly on Lyginodendron. Our second paper (Roots of Calamites) was despatched on October 30, 1894.
After a considerable interval Williamson again visited Kew, on December 12, 1894, when we started on his Lepidodendron sections, a subject on which we never published in conjunction. His last visit was on January 7, 1895. A few days later his health broke down, and though there were many fluctuations he was never able to come to the laboratory again. I saw him last, at his own house, on June 4th. On the 13th I read our joint paper on Lyginodendron and Heterangium at the Royal Society; on the 23rd he passed peacefully away.
​If Williamson could have lived it would, I think, have given him great pleasure to see the success, in his own country, of the work which he inaugurated and the progress of the subject to which he devoted the last 25 years of his life. I am happy to believe that he felt in the evening of his days, that the period of comparative neglect through which his work had passed, was at an end. For myself, I may say that my work, since I knew Williamson, owes its inspiration to him. But quite apart from our scientific relations it is a great privilege to have known him. Though his many-sided activity, as physician, professor, popular lecturer, geologist, zoologist, botanist and artist involved an amount of work which to us of a less strenuous generation is almost inconceivable, Williamson was as far as possible from being the mere student. His personality was intensely human. He was a man of most decided likes and dislikes; his conversation was often brilliant, and sometimes vigorous to an almost startling degree.
The grand old race of all-round naturalists found in Williamson its worthy culmination, and we can only regret that, from the nature of the case, he can have no equal successor.
* ↑ Three characteristic figures from these originals have been reproduced for this volume (Plates 22-24).
* ↑ Williamson, "On the light thrown upon the question of the Growth and Development of the Carboniferous Arborescent Lepidodendra by a study of the details of their Organisation." Mem. and Proc. Manchester Lit. and Phil. Soc., Ser. iv. Vol. ix. 1895.
* ↑ The portrait of Williamson is from a photograph kindly lent by Mrs Williamson, and taken, as she informs me, at Torquay in or about 1876, when he was about 60.