Case Studies

Beatrix Potter

Helen Beatrix Potter (1866-1943) is so well known for her children's books (with characters such as Peter Rabbit and Jemima Puddle-Duck) that the book cover shown here may come as a surprise. What has Beatrix Potter to do with champignons?

The fact is that for some years of her life Potter was a careful observer of fungi and lichens and that champignons book reproduces about 65 of her fungal paintings. However, not only did she produce several hundred paintings of mushrooms, boletes, jelly fungi and others - she also studied a number of these microscopically, drew what she saw under the microscope and her curiosity led her to experiment with spore germination. This mycological aspect of her life had been largely ignored for many years but has received more recognition in the past few decades. The wider reporting of her fungal and lichen work has led to some speculative or even incorrect claims. While it was foolish for her work to have been ignored in her lifetime, it is equally foolish now to make inflated claims of her achievements. What follows is a bare bones (very bare!) account of some of Potter's mycological work. For those wanting the details I strongly recommend the Noble's chapter and the biography by Lear given in the references at the end of this page. Much of the information on this web page comes from those two sources.

Beatrix Potter's first known fungal paintings date from 1887 and at least two paintings from this time still survive. Over the next few years she painted many more fungi but her serious study of fungi began in 1892 after her first fungal talk with the very knowledgeable and respected Scottish amateur naturalist Charles McIntosh (1839-1922). That meeting saw the start of a strong and mutually beneficial association and McIntosh could be summed up best as Potter's fungal mentor. He led her through the basics of fungal taxonomy, sent her interesting specimens and offered constructive advice about fungal illustration. For example in 1894 he wrote to her:

Since you have begun to study the physiology of the funguses you seem to see your drawings of them as defective in regard to the gills, but you can make them more perfect as botanical drawings by making separate sketches of sections showing the attachment of the gills, the stem, if it be hollow or otherwise, or any other details that would show the characteristics of the plant more distinctly.

Even today gill and stem characteristics can be helpful in identifying mushrooms and these are best shown by drawing a specimen that has been cut in half vertically. One of the technical books that Potter was to use was the Reverend John Stevenson's Hymenomycetes Britannici (British Fungi) which included a number of black-and-white drawings that showed both the overall form and cross sections of various fungi. Two of those drawings are shown below and you can see differences in stems as well as the ways in which the long gills meet the stems. Though simple, they are nevertheless examples of illustrations that are "more perfect as botanical drawings".

As well as continuing to produce paintings (with sectional views and depictions of different developmental stages) Potter became curious about spores, in particular spore germination. She was not the first to germinate spores and study the post-germination development. The great exponent of such studies was Heinrich Anton de Bary (1831-1888) who pioneered careful laboratory techniques for the study of fungal life cycles and who, through his publications and his students, had a major impact on experimental studies of fungi. De Bary worked with various micro-fungi, especially plant pathogens. Julius Oscar Brefeld (1839-1925), a one time assistant to de Bary and later a professor himself, greatly advanced the laboratory germination of single spores in sterile conditions. He recorded his findings about various micro and macro fungi in a multivolume work which was published from 1872 onward.

Potter experimented with various macrofungi and over time succeeded in germinating the spores of various species, independently of any of the continental European experimentalists. While undertaking this work she realized that she needed help of a different sort to that given by Charles McIntosh. She wanted to make contact with George Massee, the mycologist at the Royal Botanic Gardens at Kew, to see if he knew how fungi reproduced and if he had practical experience with germination. With the help of an introduction from her uncle Sir Henry Roscoe FRS, a chemist and vice-chancellor of the University of London, she succeeded in gaining access to Kew in 1896. Initially Massee was sceptical of her work but Potter soon realized that her work on spore germination was more advanced than anything Massee had done in that area. One thing Massee did, possibly in an attempt to fob her off, was recommend she read Brefeld's volumes. She admitted herself daunted but, being fluent in German, tackled the task. What she gleaned from questioning Massee and reading Brefeld convinced her that her work was worthwhile and her uncle urged her to write up her results in a paper for the Kew botanists. That she did. In her explanatory letter to William Thistleton-Dyer, director of the Kew gardens, Potter included the following statements:

I do not quite like to give the paper to Mr Massee because I am afraid I have rather contradicted him. Uncle Harry is satisfied with my way of working but we wish very much that someone would take it up at Kew to try it, if they do not believe my drawings. Mr Massee took objection to my slides, but the things exist, and will be all done by the Germans.

Not the most diplomatic wording - first there is criticism of Massee and at the end there is a hint that the far-sighted Germans will do the work if Kew doesn't. Sir Henry possibly had some say in the wording of this letter for he had studied in Germany under the famous chemist Bunsen and thought highly of German science. On her first attempt to deliver her paper, in early December 1896, Potter seemingly had a panic attack and fled, but returned after a few days and saw the Director and, though at other times tending to be shy, gave an energetic exposition of her views, Thistleton-Dyer was patronizing and Potter finished by telling him that "it would all be in the books in ten years". After leaving the director she went to the herbarium to see Massee and was astonished to find that "he had come round altogether and was prepared to believe my new thing". Potter came to like Massee and he did come to admit that her work was much better than he had originally thought.

When Beatrix next saw Uncle Henry he told her he had had a letter from Thistleton-Dyer, described it as "rude and stupid", but wouldn't let her read it. Sir Henry was annoyed and now planned to have her findings offered to the wider audience of the Linnean Society of London. Sir Henry, though not a botanist, had a scientifically trained mind and worked through Potter's arguments. Potter wrote in her private journal that her uncle was taking "a real interest in the business, and an immense amount of trouble in trying to understand the botanical part, and showing how to mend my Paper". Through Christmas and into the new year Potter worked at her microscope and re-wrote the paper to refine her argument. In a February 1897 letter to McIntosh Potter wrote that:

I have grown between 40 and 50 sorts of spore, but I think I shall send in only A. velutipes, which I have grown twice and Mr Massee has also grown according to my direction at Kew ... but unless I can get a good slide actually sprouting it seems useless to send it to the Linnaean

By "A. velutipes" Potter was referring to the fungus now known as Flammulina velutipes but which in Potter's time went by the name Agaricus velutipes.

The Linnean Society was a men-only affair and Potter could not present her paper in person and it was Massee who submitted it to the society. The business of the meeting of 1 April 1897 was the reading of the paper "On the Germination of the Spores of Agaricineae", the word Agaricineae being another term for mushrooms. It has been assumed that along with the paper Potter supplied one or more microscope slides showing germinating spores for, as she had commented to McIntosh, such slides were crucial evidence of her achievements. Papers read to the society were not automatically published. Many were withdrawn after such a presentation to allow the incorporation of feedback from society members at the presentation. The society's minutes record that a week later the paper was withdrawn and that concludes what is known of it. Nothing precise is known as to how it was received at the meeting and no copy of the paper has ever been found - not in the Linnean Society's archives, not at Kew nor in any holdings of Beatrix Potter papers. Nor has any abstract of the paper ever come to light so that no-one any longer knows just what her paper reported. Of course that hasn't stopped some people from making quite definite statements as to what was in the paper!

It is also unfortunate that her journal, which she had compiled (in code) for about 15 years, had finished without explanation on 31 January 1897, right at the height of the Kew-Linnean episode. It was in that journal that Potter had recorded, amongst other things, some of her mycological ideas and progress. The journal's last entry includes a comment about her fright at the prospect of going to see Harry Marshall Ward, Professor of Botany at Cambridge University and a mycologist who had done fundamental work on coffee disease in Ceylon. There is evidence that Potter did visit Cambridge in February 1897, but nothing is known of what happened.

There have been claims that this episode saw Potter give up fungal studies - either through despair or pique - and start writing children's stories. There is no argument that as an amateur and a woman she faced strong prejudices. However there are good reasons for thinking that she withdrew the paper because of a need to do more work on it - and she did continue her work, producing about 70 more microscope drawings over the next two years. In her last known letter to Charles McIntosh, in September 1897, Potter wrote of her continuing work on germination and mycelium growth. When, and why, she did finally stop her fungal work is not known. Incidentally, she had written her first Peter Rabbit story back in 1893 to cheer up the sick child of one of her childhood governesses.

Lichens

You may see it claimed that Beatrix Potter was the first to show that a lichen is an association between a fungus and an alga. That claim is wrong, though it is true that a lichen is either a fungus-algal or fungus-cyanobacterial association. Both algae and cyanobacteria (the latter sometimes still called blue-green algae) contain chlorophyll and so photosynthesize. In cases where a distinction between alga and cyanobacterium is irrelevant they are referred to generically as photobionts.

Lichens had been a puzzle. The photobiont cells had been observed in 1825 and were initially taken to be some form of propagating cells, and were termed gonidia. De Bary hinted at the truth in 1866 but it was Simon Schwendener (1829-1919) who first presented detailed evidence. Schwendener was born and educated in Switzerland, worked as a professorial assistant in Germany and in 1867 took up a professorship at the University of Basel in Switzerland. In September that year he gave a talk to Swiss natural historians in which he outlined his ideas about the fungus-photobiont association. Schwendener was one of the best microscopists of his time and by 1867 he had been studying lichens for a decade or so. A brief account of this talk appeared in 1867, another in 1868 and Schwendener published a detailed account in 1869. The last included three lithographic plates showing details of the microscopic structures and associations. Schwendener thought of the fungus as parasitic on the alga and wrote:

This master is a fungus, of the class Ascomycetes, a parasite, accustomed to live upon the work of others, its slaves are green Algae, which it has gathered around itself, at any rate, holds on to and forces into service. It invests them as a spider her prey, with a fine meshed web, which gradually is converted into an impregnable integument, but, whilst the spider sucks out her prey and throws it aside when dead, the Fungus stimulates the Algae, found in its net, to more lively activity, in fact, causes them to grow larger and causes thereby a luxuriant growth and the thrifty appearance of the whole colony.

The great majority of lichenologists of the day rejected Schwendener's ideas, at times quite vehemently. William Nylander, a leading lichen taxonomist referred to "Schwendener the fool" and, according to David Richardson's 1975 book The Vanishing Lichens, looked on any supporter of Schwendener as a personal enemy. However Schwendener's ideas were investigated further by other biologists. Amongst these was de Bary who accepted Schwendener's conclusions.

Schwendener had noted the importance of laboratory experiments to try to grow lichens. He observed that no-one had been able to grow lichens from either the gonidia alone or from the spores obtained from the asci. He suggested that success might follow if the spores from asci were allowed to germinate on algal colonies. Such experiments were done by a number of researchers over the following decades. At times the results were quite unsuccessful, at other times "pseudo-lichens" were produced but the 1870s and 1880s did see the publication of experiments, carried out in France and Germany, in which various lichens were successfully re-synthesized from their fungal and photobiont partners. However, none of this work was enough to make the leading lichen specialists accept the dual hypothesis for the rest of the century - and even into the next.

Schwendener had viewed the fungus as parasitic on the photobiont but others who accepted his ideas in general doubted the parasitic nature of the association. In a work about lichens published in 1877 the German botanist Albert Bernhard Frank (1839-1900) introduced the term symbiosis. Originally the term was used simply to mean "dissimilar organisms living together", with no implications as to the nature of the association. Later it gained the sense of "living together in a mutually beneficial association". Now it is again being used widely in its original sense, with the term mutualism used where there is some mutual benefit. Research in the last quarter of the 19th century showed symbiotic associations to be common in nature.

It is worthwhile to have this background, both to show what was happening and also to disprove the thought that Schwendener alone held to the idea of the dual nature of lichens.

With that background out of the way, back to Beatrix Potter. In her journal entry for 3 December 1896 she wrote "I found the idea of the lichens 27th." - but no further explanation as to how she found it. Certainly she did come across Schwendener's work at some stage. Perhaps she read his own words. In her journal entry for 30 December she wrote of visiting George Murray, Keeper of Botany at the British Museum:

I asked him about lichen books and drew out an exposition of his views on the Schwendener theory. I asked him whether the alga had spores too, or how it came to be always at hand. He said the algae grew by themselves but the fungus would not. I should have liked to have heard more but he fled, so did Miss Smith the Librarian.

Upon the subject of chlorophyll and symbiosis I am afraid I am unpleasant. I could hardly contain myself with amusement. I don't think anyone else is at it. He was so very high-handedly contemptuous of old-fashioned lichenologists.

She studied lichens under the microscope, drew their microscopic details and germinated the fungal spores of at least the lichen genus Cladonia. It appears that nobody else in the United Kingdom was doing the sort of advanced microscopic and experimental studies that were being done in continental Europe. Potter therefore had no-one whose expertise she could tap. Furthermore some of the British lichenologists were particularly vehement in their denial of the dual hypothesis, so much so that to some the word Schwendenerist was virtually a term of abuse. Being a woman amateur Potter had difficulties with access to specialist literature and given the prevalent anti-Schwendener attitudes it seems unlikely that she would have found any botanist to point her to research that supported Schwendener's ideas.

What if...

Beatrix Potter's biographer Linda Lear has written:

In most ways Beatrix Potter's foray into professional mycology was completely accidental ... It is hard to imagine that Beatrix would have gone so far into the study of mycology without his [McIntosh's] encouragement ... Without him she would have remained simply a painter of beautiful 'funguses'. It might well have ended there too if the experts at Kew had not been threatened by the questions of a bright amateur, and if her competitive and adversarial uncle, her other mentor, had not taken personal umbrage and thrust her into a world where no woman of her background and qualifications could possibly have been successful. Roscoe led Beatrix into the inner circles of the scientific establishment, where she acquitted herself well, but it was never a place she herself aspired to be. That she had the 'mind of a professional scientist and biologist', as one modern writer has claimed, may be overstating, but without question, Beatrix Potter was a brilliant amateur.

If Beatrix had a defined goal for her life by 1898 it was essentially what it had always been: to find something useful to do with her talents, and to gain a measure of economic and personal independence. She had explored scientific illustration and research and found that, however intriguing, it could not satisfy that end.

It is at times pointless to wonder "what if ...". However, on the basis of the above character assessment it follows logically that, had there been at least some gentle guidance from the professionals, Potter would most likely have continued with her mycological work. That's not to say that she would have become a full time mycologist, for she had shown curiosity in other areas of nature and clearly had an aptitude for achievements in quite disparate areas. For example, she later bred prize-winning sheep. However, she was capable of contributing more to mycology. That is shown by the fact that in both her letters and her artwork she accurately recorded several other fungal phenomena, without realizing what she'd seen. I will illustrate that statement with one example in some detail.

In one sheet of her artwork (reproduced in Noble's chapter as figure 125) she has shown the orange, disc-like fruiting bodies of the basidiomycete Aleurodiscus amorphus (then known by the name Corticium amorphum, though Potter has given no species names on this sheet). She has also drawn four spiny Aleurodiscus spores atop a basidium as well as several germinating Aleurodiscus spores. In addition, the sheet shows some germinating mould spores. Such contaminants are very hard to keep out unless the work is done under sterile conditions. Potter was quite aware of the threat of contaminating spores and took what steps she could to minimize that threat. Finally a few small globular spores are also shown, some with very short hyphal outgrowths. Those globular spores most likely belong to Tremella simplex, one of the jelly fungi and a common parasite of Aleurodiscus amorphus. It is interesting that in a letter to Charles McIntosh she had written that Corticium amorphum changed, initially looking like a small orange cup fungus but eventually becoming soft and gelatinous. What she had accurately described and illustrated, but not understood, was not a change in the one fungus, but a fungus that is initially parasite-free but which eventually is overgrown by a parasite. It is likely that, given time and a supportive environment she would have been capable of eventually realizing the connection between the two fungi - and then perhaps being spurred on to look for other examples of fungal-fungal parasitism.

References

Honegger, R. (2000). Simon Schwendener (1829-1919) and the Dual Hypothesis of Lichens. The Bryologist, 103, 307-313.

Jay, E; Noble, M & Hobbs, AS. (1992). A Victorian Naturalist: Beatrix Potter's Drawings from the Armitt Collection. F Warne & Co., London. [This book contains Mary Noble's long chapter, pages 55-135, about Beatrix Potter's mycological work. The chapter includes some of Potter's microscope drawings of lichen structure, asci, basidia and germinating spores.]

Lear, L. (2007). Beatrix Potter: a life in nature. St. Martin's Press, New York. [This is a detailed but highly readable biography of Potter, with her lichen and fungal work dealt with in chapters 4 (titled Experiments) and 5 (Discoveries).]

Noble, M. (1987). Beatrix Potter, Naturalist & Mycologist and Charles McIntosh, the "Perthshire Naturalist". Notes from the Royal Botanic Gardens Edinburgh, 44, 607-627. [This paper reproduces the known letters from Potter to McIntosh.]

Pitt, CC. (1919). A short history of lichenology. The Bryologist, 22, 77-85. [I have copied the English translation of Schwendener's master-slave comments from this paper.]

Potter, B. (1966). The Journal of Beatrix Potter, 1881-1897. (Transcribed from her coded writing by Leslie Linder). Frederick Warne, London.

Potter, B. (1996). Les Champignons. Bibliothèque de l'Image, Paris. [The cover, about 20 x 26 centimetres in size, shows the species Clitocybe infundibuliformis.]

Watling, R. (2000). Helen Beatrix Potter. The Linnean, 16(1), 24-31.