1The Essai sur l’Histoire Naturelle des Courges is the most detailed and complete literary document remaining that accompanies Duchesne’s drawings and describes his experiments with the gourds. Interestingly, without J. B. P. A. de M. de Lamarck’s request to Duchesne to contribute an article on the gourds to the famous Encyclopédie Méthodique, Botanique, of which Lamarck was editor, Duchesne may never have published a summary of his work with the gourds.

2“Of the three leaders of the botany of the Enlightenment, all three stimulated by the exuberant flight of Buffon’s scientific fancy, Adanson, Antoine-Laurent de Jussieu, and Lamarck, it was undoubtedly the third who made the deepest impression on biology in general” (Stafleu 1971). According to Stafleu (1971), Lamarck had, after military service, settled in Paris in 1768 to work as a bank employee. He also studied with Bernard de Jussieu, which eventually resulted in his three-volume flora of France, published in 1779, written in the vernacular in accordance with the Enlightenment ideals of wide diffusion of scientific knowledge. This led to his being appointed an adjunct member of the Academy of Sciences, through the influence of Buffon who then functioned as the intendant du Jardin du Roi (Comptroller of the Royal Garden).

3As Duchesne’s study with Bernard de Jussieu had led to the publication of his first book, Manuel de Botanique (Duchesne 1764), and as he began his study with gourds no later than in 1768, shortly before or at the same time that Lamarck began studying with Jussieu, it seems fair to speculate that Lamarck and Duchesne must have known each other personally. It also seems to have been unavoidable that Lamarck knew of Duchesne’s work with gourds and appreciated his analytical mind and power of observation; probably he was present at the meetings of the Academy of Sciences in 1779 at which Duchesne presented the results of his experimentation with gourds. Naturally, this would have led to Lamarck asking Duchesne to contribute an article on gourds to the Encyclopédie Méthodique, Botanique.

4In 1786, Duchesne prepared his contribution on gourds, however it was too long for inclusion in its entirety in the Encyclopédie. Lamarck edited the contribution, removing a number of paragraphs. As Lamarck’s view at that time was that species needed to be equally separated from one another, or at least differ from one another phenotypically to some minimal extent, and this degree of difference did not, in his opinion, occur between Duchesne’s Cucurbita moschata and C. polymorpha, he removed from the article Duchesne’s table of classification of the gourds that presented C. moschata as a species separate from C. polymorpha. Instead, Lamarck substituted a table with his own classification of the genus, which gave subspecific rank to both of these within one species, Cucurbita pepo. He did allow, though, the designation of Cucurbita maxima to remain.

5Charles Joseph Panckoucke, publisher of the Encyclopédie Méthodique, Botanique, and who published beginning in 1782 well over 100 volumes of encyclopedia series dealing with botany, agriculture, zoology, chemistry, anatomy, geography, social sciences, and others, was referred to by Stafleu (1971) as “The moving force behind this almost incredible outburst of synthetic scientific creativity” of the time. Apparently as a gesture of thanks, Panckoucke immediately composed the remainder of Duchesne’s contributed manuscript and the table presenting Duchesne’s classification of the genus Cucurbita, which had been left out of the Encyclopédie due to space considerations and Lamarck’s dispute of Duchesne’s classification. Using the same blocks of print he had just composed for the contributed article on gourds and together with the additional paragraphs and table, he printed the Essai immediately, as he needed to free up the type and equipment for composing additional articles of the Encyclopédie (Paris 2000b). An addition dated 18 August 1786 that appears at the end of the Essai indicates that it was printed either on that day or within several days immediately following. The massive, 400-page first part of the second volume of the Encyclopédie Méthodique, Botanique, within which Duchesne’s article on the gourds appeared, was issued on October 16, 1786 (Rickett & Stafleu 1961). Quite likely then, issue of the Essai preceded it, and therefore the Essai has priority for the naming of Cucurbita maxima by Duchesne (Paris 2000b).

6Later, Duchesne contributed an article on strawberries, Fragaria, to the Encyclopédie Méthodique, Botanique, at Lamarck’s behest (Duchesne 1788b). It was published in the 374-page second part of volume 2, which was issued on 14 April 1788 (Rickett & Stafleu 1961). As he did for the gourds, Panckoucke published a separate version for Duchesne, the Essai sur l’histoire naturelle des Fraisiers(Duchesne 1788a). However, in contrast to the situation with the gourds, the differences in the text between the two publications are very minor. And in contrast to the situation with the gourds, there is no indication in the Essai sur l’histoire naturelle des Fraisiers as to the date of its being printed. It does, though, have the same blocks of print as the encyclopedia article and therefore it is likely that it was collated, bound, and issued somewhat ahead of time (Stafleu 1964, Paris 2000b). The Essai, therefore, would have priority for any newly named species.

7As for Lamarck, he edited the first two volumes and part of the third of the Encyclopédie Méthodique, Botanique and was appointed in 1788 to the new position of keeper of the herbarium at the Jardin du Roi, an institution that had been formally established in 1597 but functional only since 1635. Then he became professor of zoology there during the revolution, when this institution was called the Jardin des Plantes and then was declared by the revolutionary convention in 1793 as the Muséum d’Histoire Naturelle. He by then had lost his interest in botany, turning to zoology. Sometime during the next seven years, the ideas held by Duchesne, Buffon, and cohorts seem to finally have had their effect as in 1800 Lamarck presented for the first time, in a zoology lecture at the Muséum d’Histoire Naturelle, his theory of biological transformation. Although the mechanism was wrong, this fundamentally new development in biological thought led toward the later theories of evolution. The following year, Lamarck coined the word “biology”, the study of living things (Stafleu 1971). Duchesne had conducted his experiments with plants he referred to as pépons (pepos) and yet the chapter in the Encyclopédie (Duchesne 1786c) and the Essai (Duchesne 1786b) itself refer to courges. Lamarck, as editor, must have been responsible for the designation courges, his intention being to cover the genus Cucurbita in the Linnean sense. Linné had presented five species of Cucurbita in his Species Plantarum (Linné 1753) and a sixth in his Mantissa Plantarum (Linné 1767). Therefore, the pepos (Linné’s C. pepo, C. verrucosa, C. melopepo, and C. ovifera) were to be discussed together with the bottle gourd (Linné’s C. lagenaria) and the watermelon (Linné’s C. citrullus). Duchesne (1786b, c) was obligated by his editor to use Linné’s demarcation of the genus even though he realized that the bottle gourd and watermelon were very distinct from the species of pepos.

8In keeping with the style of the other chapters in the Encyclopédie Méthodique, the chapter on courges (Duchesne 1786c) and therefore the Essai (Duchesne 1786b), too, were edited to open with an overview of the genus. The species of the genus were also considered in Linnean order. As Linné (1753) had listed the bottle gourd (his Cucurbita lagenaria) first, this is described first in the chapter and the Essai. This is followed by the pépons (pepos) and lastly by the watermelon (Linné’s C. citrullus, the last to be listed in Species Plantarum). At the end of the encyclopedia chapter (but not in the Essai) is a short description by Lamarck of the wax pumpkin or wax gourd, what he referred to as Cucurbita hispida, known today as Benincasa hispida (Thunb.) Cogn.

Gourd, Cucurbita; genus of monopetalous plants, of the Cucurbitaceae family, to which it has given its name; that has much in common with the cucumbers from which it is distinguished by seeds furnished with a distinct border; and that consists of vining herbaceous plants, supplied with tendrils, alternate leaves, axillary flowers, and fleshy, succulent fruits. Most of the plants of this genus are employed for nutrition and some other uses: it is among these that are found to be the most robust of their family and the largest fruits known. They are furthermore very interesting for the prodigious number of races and varieties that one can observe, and for the great differences that are encountered among any of them.

9In the “Preliminary Observations” of the Essai one cannot help but appreciate Duchesne’s painstaking observation of the plants. His observations and experiments with the gourds led him to repeat the same concepts that he had expressed from his observations and experiments on the strawberries 20 years earlier (Duchesne 1766). He recognized that the gourds were not native to France or anywhere in Europe but instead had originated in areas having a warmer climate. Distinguishing among species was difficult because each of them had been changed by people over time in such a manner that the variation within each of the species was similar. These changes had been passed on over time, from one generation to the next. Nonetheless, the species could best be distinguished on the basis of the characteristics of their permanent foliar trichomes (hairs), which are still recognized today as the best species indicator in the genus Cucurbita. Duchesne realized, by studying live plants instead of specimens in herbaria, that the conclusions he reached would be going against principles that were then established and recognized as authoritative. Although not specifically mentioned in the sentence, he seemed to have Linné foremost in mind as an establisher of principles. Linné and Duchesne corresponded with each other, and Linné did have a high estimation of Duchesne’s experiments on the taxonomy of strawberries, but nonetheless did not change his classification of Fragaria species accordingly (Lee 1964, Staudt 2003).

Preliminary Observations on the Gourds.
All of the species of gourds are regarded as annuals; they are in effect, since they produce flowers and fruits within a few months; but in warm climates of which they are native, they come to be persistent annuals; because the branches that trail on the ground root at a large proportion of their nodes, and new shoots are produced continually, often even after the complete maturity of the first fruits: this does not occur at all in the purely annual species.
In their living state, these plants of a soft, aqueous substance are false vines, which attach themselves to all objects that they encounter, clinging by their tendrils, but without surrounding them with their stems as these do not assume any spiral direction. The tendrils are borne next to the petioles; they are branching, and each branch elongates at first as a needle with very little curvature, contracts itself rather suddenly and winds itself as a spirallic twist or corkscrew, first to the right, afterwards to the left after eight or ten revolutions, afterwards quite often a second time to the right. The flowers are borne, in contrast, in the axils, and are most often solitary. All of the parts of the plant bear permanent hairs, except on the fruits where they fall when it begins to grow, and leaving the rind entirely smooth. The nature of these hairs forms important differences between the species; because the shape of the fruits, the cutting out of the leaves, the tendency of the branches to climb or to creep, is never constant. In effect, these plants submitted to domestication a very long time ago, are altered in such a manner that the species are quite ambiguous, and few genera in history are more confused in the books of botanists. Founded upon observation of living material, I dare to present them here in a new fashion, which will nevertheless be exact as well, though it seems to shock several recognized principles.

10Following this section of “Preliminary Observations”, Duchesne established his classification for the gourds. He referred to the bottle gourd, the pepo in the less strict sense, and the watermelon as trois espèces principales [three principal species]. At the time, the nomenclature of taxonomic ranking was still not entirely solidified. As Lee (1964) described, in his book on strawberries Duchesne explained that he preferred to use the term “race” or “race particulière” for what other botanists termed “species” and the term “species” for “genus”. In that work, Duchesne designated what are today termed species with Latin binomials, never with trinomials. His consistent and correct use of Latin binomials for species is also evident in his later publications. This means that, what Duchesne called “principal species” is what is referred to universally today as “genus”. Thus, he was indicating that the bottle gourd, the pepo in the less strict sense, and the watermelon should be regarded as separate genera, even though in the Table of Gourds he still retained the genus name Cucurbita for all three, in accordance with Linné. In effect, Duchesne had anticipated what occurred a half-century later, when the bottle gourd and the watermelon were removed from the genus Cucurbita and given separate generic names, Lagenaria by Seringe in 1825 and Citrullus by Schrader in 1836, respectively (Jeffrey 2001).

11Duchesne then divided the pepos, in the less strict sense, into what he called trois races principales [three principal races], what would universally be called today three species, on the basis of inability to cross and produce fertile offspring. He named these three species Cucurbita maxima, Cucurbita moschata, and Cucurbita polymorpha. Duchesne explained that the first of these was named to indicate the large size of its fruits. The second was named because of the perceived musky flavor of its fruit flesh. The third was appropriately named for its extreme polymorphy, but Linné had in effect already named this species Cucurbita pepo. The establishment of these three species is the foundation of understanding the taxonomy of the genus Cucurbita to the present.

12Duchesne then sub-divided his Cucurbita polymorpha, the pepo properly speaking, into cinq races secondaires [five secondary races], what might be referred to today as subspecies or cultivar-groups, and he noted that they can interbreed and form an infinite number of variants. These five, established by his painstaking comparisons of phenotype, are entirely consistent with evidence obtained using modern techniques of molecular genetics, and each can be placed within a particular modern infraspecific taxon, as explained later in the section on the genus Cucurbita.

13The last part of this section of the Essai is not included here, as it is the tabular presentation of Lamarck’s classification of the genus, the only one presented in the article in the Encyclopédie Méthodique, Botanique, edited by Lamarck.

I establish therefore the division of gourds into three principal species: namely, the Calabash, Cucurbita leucantha; the Pepo, Cucurbita pepo; the Watermelon, Cucurbita Anguria. But I further have to divide the species of the Pepo into three particular races, which are the Potiron, Cucurbita-Pepo maxima; the Melonée, Cucurbita-Pepo moschata; and the Pepo, properly speaking, Cucurbita-Pepo polymorpha. One can see that this last race is peculiarly variable, & that it presents five secondary races each of which is liable to produce variants without number.

Classification of the Gourds,
according to Mr. Duchesne
1. The CALABASH, Cucurbita leucantha.
a. The Cougourde.
b. The Gourde.
c. The Trompette.

The Pepos:
three principal races; namely,
2. The GREAT PUMPKIN, Cucurbita maxima.
a. The Yellow Great Pumpkin.
b. The Large Green Great Pumpkin.
c. The Small Green Great Pumpkin.
3. The MELON-LIKE PUMPKIN, Cucurbita moschata.
4. The PEPO, Cucurbita polymorpha.
a. The Orange Gourd & Other Round-fruited Gourds.
b. The Egg and Pear Gourds.
c. The Warted Gourds.
d. The Long-fruited Squash & the Pumpkins.
e. The Pattypans.
5. The WATERMELON, Cucurbita Anguria.