On the various contrivances by which British and foreign orchids are fertilised by insects, and on the good effects of intercrossing.

London: John Murray, 1862.

First edition of the first of Darwin’s works to publish extensive evidence supporting his theory of evolution through natural selection. In a letter to his publisher, John Murray, Darwin wrote: “I think this little volume will do good to the Origin, as it will show that I have worked hard at details, & it will, perhaps, serve [to] illustrate how natural History may be worked under the belief of the modification of Species” (24 September, 1861; Darwin Correspondence Project 3264). In Life and Letters (vol. III, p. 274), Asa Gray is quoted as saying: “if the Orchid-book (with a few trifling omissions) had appeared before the ‘Origin’ the author would have been canonized rather than anathematized by the natural theologians.” Darwin’s orchid book “was concerned with working out in detail the relationships between sexual structures of orchids and the insects which fertilise them, their evolution being attributed to natural selection. It is therefore the first of the volumes of supporting evidence. It was much praised by botanists, but sold only about 6000 copies before the turn of the century'” (Freeman, p. 112). “Darwin was adept at flanking movements in order to get around his critics. He would take seemingly intractable subjects like orchids flowers and make them test cases for 'natural selection.' Hence the book that appeared after the Origin was, to everyone’s surprise, The Various Contrivances by which British and Foreign Orchids are Fertilised by Insects (1862). He showed that the orchid’s beauty was not a piece of floral whimsy ‘designed’ by God to please humans but honed by selection to attract insect cross-pollinators. The petals guided the bees to the nectaries, and pollen sacs were deposited exactly where they could be removed by a stigma of another flower” (Brittanica). Darwin wrote of the book in his autobiography: “On May 15th, 1862, my little book on the Fertilisation of Orchids, which cost me ten months’ work, was published: most of the facts had been slowly accumulated during several previous years. During the summer of 1839, and, I believe, during the previous summer, I was led to attend to the cross-fertilisation of flowers by the aid of insects, from having come to the conclusion in my speculations on the origin of species, that crossing played an important part in keeping specific forms constant. I attended to the subject more or less during every subsequent summer; and my interest in it was greatly enhanced by having procured and read in November 1841, through the advice of Robert Brown, a copy of C. K. Sprengel's wonderful book, Das entdeckte Geheimnis der Natur. For some years before 1862 I had specially attended to the fertilisation of our British orchids; and it seemed to me the best plan to prepare as complete a treatise on this group of plants as well as I could, rather than to utilise the great mass of matter which I had slowly collected with respect to other plants.”

“Darwin emphasized the roles of inbreeding and outcrossing in formulating his theory of evolution and would later write an entire book on the subject – Effects of Cross and Self Fertilisation in the Vegetable Kingdom (1876). After all, variation is the raw material of evolution by natural selection, and even though Darwin was not familiar with Mendelian genetics, he and others, especially livestock breeders, knew that sexual reproduction among unrelated individuals had the potential to produce a higher level of variation than did inbred lines. But Darwin’s interest in the subject may have been more than academic. It has been argued that he had a personal interest in the subject of inbreeding, for the Darwin and Wedgwood families had intermarried for several generations. Of the 62 aunts, uncles, and cousins born in the four generations founded by Charles Darwin’s grandparents, Josiah and Sarah Wedgwood, 38 (61%) remained childless. Specifically, a total of 19 (73%) of the 26 children born from the first-cousin marriages in the ‘Darwood’ family did not reproduce. Perhaps some of these couples chose to remain childless. Others may have lost children due to lack of modern medical care (although the families were both wealthy and would have had access to the best physicians of the day). It is likely, however, that this high level of infertility (i.e., reduced ‘fitness’ in the sense of evolutionary theory) was due to genetic defects caused by inbreeding among the close relatives. Charles Darwin almost certainly recognized this fact. Even he married his first cousin, Emma Wedgwood, and several of their children died young (3 of 10) or suffered serious health problems. Only 3 of their 7 living children produced grandchildren for Charles and Emma. Could Darwin’s personal family life have influenced the development of his theory of evolution with its emphasis on fitness defined by reproductive potential and descent from parent to offspring? Some believe that this was precisely the case.

“Whatever the reason, Darwin went forth by publishing his orchid book to demonstrate that natural selection not only serves to explain animal evolution but plant evolution as well. One might assume that plants tend to self-pollinate (inbreed) more than do animals, because the former are stationary and their flowers generally hermaphroditic. If this were true, it would be a serious flaw in Darwin’s theory. Thus, he argued that outcrossing among plants must be more common than perceived, and he used as examples the complex behavior of orchid pollinators coupled with detailed descriptions of orchid floral structure to demonstrate that these, and most likely other plants as well, are perfectly adapted to avoid selfing. In fact, when you think about it, what better group of organisms to document this fact than orchids, which have hermaphroditic flowers in which male and female organs are intimately united into one. This is certainly an extreme case that would appear at first glance to promote selfing if ever there was one! This fact was not lost on Darwin, who stated in the book that ‘unless we bear in mind the good effects which have been proved to follow in most cases from cross-fertilisation, it is an astonishing fact that the flowers of Orchids should not have been regularly self-fertilised. It apparently demonstrates that there must be something injurious in this latter process, of which I have elsewhere given direct proof.’ He concluded the orchid book stating that ‘it is hardly an exaggeration to say that Nature tells us, in the most emphatic manner, that she abhors perpetual self-fertilisation.’

“While the advantage of outcrossing is a theme that runs through the entire orchid book, the fact that Darwin published it immediately after the Origin of Species leads us to believe that he had other motives as well. In his rush to publish the Origin as quickly as possible (as what he called an unfinished ‘abstract’), Darwin was unable to provide all of the supporting material that he felt bolstered his argument. Critics were quick to attack, and the orchid book served as a partial response … These detailed examples were provided not only for other naturalists but also for so-called natural theologians who were beginning to accept many of the facts presented by geologists, paleontologists, and biologists in terms of the origins and antiquity of life but still saw God as the force guiding all laws of nature. Just as people today continue to debate the driving force of evolution either by means of natural selection or the hand of a creator, so they did as well in the mid-19th century as the Origin became a bestseller. Throughout the book Darwin dismisses what today might be called intelligent design in orchid flowers and instead provides example after example of what he regularly called ‘perfect adaptation.’ For example, Darwin felt no need to invoke the hand of God in referring to the flowers of Spiranthes autumnalis as a ‘perfect adaptation by which the pollen of a younger flower is carried to the stigma of an older flower’ …

“Among the most celebrated of the detailed examples provided by Darwin in the orchid book is his hypothesis concerning the pollination of Angraecum sesquipedale. This orchid species endemic to Madagascar is often referred to as the ‘comet orchid’ because of its unusually long nectar spur (the specific epithet of the species, sesquipedale, translates to ‘a foot and a half’). Although the sphyngid moth pollinator of the comet orchid (Xanthopan morganii praedicta) would not be discovered until 1903, and in situ observations of visitation events would not be recorded on video until the early 21st century, Darwin’s hypothesis for explaining the co-evolution between the orchid and insect would prove to be a classic example of the predictive power of evolutionary biology. In his own words, Darwin explained that ‘We can thus understand how the astonishing length of the nectary had been acquired by successive modifications … As certain moths of Madagascar became larger through natural selection in relation to their general conditions of life [or their proboscis became elongated] … those individual plants of the Angraecum which had the longest nectaries (and the nectary varies much in length in some Orchids) … would be best fertilised. These plants yield the most seed, and the seedlings would generally inherit long nectaries; and so it would be in successive generations of the plant and the moth’ …

“The first edition treated 63 genera of orchids, and included 34 illustrations dispersed among 365 pages of text … For the most part, these were arranged according to the accepted classification system of the day as proposed by John Lindley (1827). Subfamilies were not considered, but Orchidaceae (excluding apostasioid orchids) were divided into tribes. Chapters 1 and 2 treat Ophreae, in particular the European terrestrial orchids such as Orchis and Ophrys, the bee orchids. A total of 73 pages were devoted to detailed observations and experimentation with the orchids with which Darwin would have been most familiar because they grew near his home in the English countryside. Among the genera considered are Orchis, Ophrys, Herminium, Peristylus, Gymnadenia, Platanthera, Habenaria, Disa, and Bonatea. Chapter 3 and 4 are short and consider tribes Arethuseae and Neottieae, respectively. Although Vanillais recognized today as only distantly related to these lower epidendroid groups, it was treated among the 12 pages of Chapter 3. Among the other genera discussed here are Cephalanthera, Sobralia, Pterostylis, Caladenia, and Pogonia. More recent systems of classification, especially those based on DNA evidence, have demonstrated that these orchids, which share plesiomorphic aspects of their floral morphology, actually belong to three different subfamilies. Likewise, many of the genera considered together in Lindley’s concept of tribe Neottieae and discussed by Darwin in Chapter 4 (Epipactis, Listera, Neottia, Epipogium, Goodyera, Spiranthes, Thelymitra) are now classified among different tribes of subfamilies Orchidoideae and Epidendroideae. Darwin devoted 34 pages to them.

“The subsequent chapters of the orchid book treated those orchids classified within Epidendroideae, the largest subfamily of Orchidaceae. Today we count nearly 20,000 different species in that group. However, in Darwin’s day less than 2000 orchid species were recognized in total. It is almost humorous to note that Lindley estimated that there might be as many of 6000 orchid species to be discovered eventually. It might not be surprising, therefore, to realize that Darwin only devoted 20 pages of text in Chapter 5 to tribes Malaxeae and Epidendreae. These are primarily tropical orchid tribes, and many of the most species-rich genera were still poorly collected, especially those from higher elevations of the Andes, New Guinea, and southeast Asia. Among the genera that were known to Darwin – primarily through relationships with horticulturists at Kew and from other glasshouse collections – were Malaxis, Bulbophyllum, Dendrobium, Cattleya, Laelia, Epidendrum, Pleurothallis, and Stelis. Darwin was intrigued by the odd flowers of Zootrophion atropurpureum ̧ which he knew and illustrated in Figure 20 as Masdevallia fenestrate …

“Following in sequence we reach Chapters 6 and 7, which are 74 pages in length and devoted to the plants Darwin said were ‘the most remarkable of all orchids.’ These are members of tribe Vandeae (as then understood), and particular emphasis was given to Catasetumand its fast-action mechanism of pollinarium ejection. This is not surprising because Darwin was obviously fascinated by plant movement. In 1875, he published Movement and Habits of Climbing Plants. That same year, his Insectivorous Plants considered the movement of sundews (Droseraspp.) and Venus’ flytrap (Dionaea muscipula Ellis). In 1880, he published The Power of Movement in Plants. Other orchids discussed in chapters 6 and 7 of the orchid book are Calanthe, Miltonia, Sarcanthus, Maxillaria, Angraecum, Coryanthes, Mormodes, and Cycnoches.

“Chapter 8 is devoted to the lady’s slipper orchids, with one genus (Cypripedium) at that time classified into tribe Cypripedieae. Among the 20 pages is also found a discussion concerning the homologies of orchid floral organs. This is a wonderful chapter in which Darwin demonstrated his skill as a keen observer and experimental biologist. For example, he described several attempts to introduce various insects to the flowers of Cypripedium calceolus in order to record their behavior, only to find that some ‘were either too large or too stupid, and did not crawl out properly.’ Originally he felt sure that lady’s slipper orchids were pollinated when ‘insects alighted on the labellum and inserted their proboscides through either of the orifices close to the anthers,’ but later realized that this made little sense given that ‘if an insect were to insert its proboscis, as I had supposed, from the outside through one of the orifices, … the stigma would be liable to be fertilized by the plant’s own pollen.’ This would be contrary to the argument made throughout the book in favor of mechanisms to ensure cross-fertilization, and so he was delighted to document that his experiments proved just the opposite — Cypripedium also manages to avoid self-pollination.

“An example of a hypothesis presented in the book that would eventually be proven incorrect, however, can be found in this chapter. Figure 36 in the book shows an artificial section through a monandrous orchid flower. At the time it was assumed that three anthers of an ancestral inner androecial whorl were modified to form the orchid clinandrium and apex of the column. One of the anthers from the outer whorl remained fertile, leaving two others ‘of the same whorl combined with the lower petal, forming the labellum.’ Today the structure and homologies of the orchid labellum are not viewed in this way. There is no evidence that sterile stamens or anthers are involved in its construction.

“Finally, in Chapter 9, titled ‘Gradation of Organs, etc. & Concluding Remarks’, Darwin provides a summary of the various examples he has presented throughout the book, and makes his final arguments. He states, ‘it may naturally be inquired, Why do the Orchideae exhibit so many perfect contrivances for their fertilization? From the observations of various botanists and my own, I am sure that many other plants offer analogous adaptation of high perfection; but it seems that they are really more numerous and perfect with the Orchideae than with most other plants.’ From that statement alone it is clear that Charles Darwin had a passion for orchids. One might even say that he contracted what today some would call orchid fever! During in his life he would write to colleagues such statements as ‘you cannot conceive how the orchids have delighted me’, ‘I am sillily and very idly interested in them’, ‘the orchids are more play than real work’, and ‘the orchids have been a splendid sport’. This highly respected and influential scientist, a man who was passionate about animal and plant biology and who would do so much to advance evolutionary theory, would state that ‘orchids have interested me more than almost anything in my life’” (Cameron).

Freeman 800; Norman 595. Cameron, ‘A look at the ‘Orchid Book’ in celebration of Charles Darwin’s 200th birthday,’ Lankesteriana 11 (2011), pp. 223-231.

8vo (197 x 122 mm), pp. vi, 365, [1, colophon], [32, publisher's advertisements dated December 1861], with 33 woodcuts in the text and one woodcut folding plate. Publisher’s original textured purple-brown pebbled cloth, embossed in blind on both boards, titled in gilt on spine, with a large gold-blocked orchid on front board, spine stamped and lettered in gilt, brown coated endpapers.

Item #5337

Price: $8,750.00

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