In February of 1845, while on a tour of Paris, Holland and Belgium, Joseph Hooker penned a friendly letter to Charles Darwin to share stories about the well-known European naturalists with whom he had conversed, and to update Darwin on the state of “the species question” in continental Europe. He related an anecdote shared with him by the French botanist Joseph Descaine about a strawberry plant reproducing with simple leaves (a variation on their usual ternate leaf-form); and wrote, reprovingly, “some make use of such exceptions to deny the existence of species at all, I have a tract on the subject for your perusal” (Letter). This “tract” refers to the French naturalist Frederic Gerard’s 1844 “De l’Espèce dans les Corps Organises”, originally published in the French Dictionnaire universel d’Histoire naturelle.

A contributor to Charles d’Orbigny’s Dictionnaire universel d’Histoire naturelle, Gerard wrote entries on topics such as biogeography, spontaneous generation, species, and genera. “De l’Espèce” (“Of Species”) expressly denounces those naturalists who, “affirm not only that the species [as a biological entity] is a reality, but that it is immutable and has existed for all of time.” Like Alexander Moritzi (1842), Gerard used the often arbitrary lines between described varieties, species, and genera to attack the notion that species are non-arbitrary natural biological units.  Darwin, who found Gerard’s writing more persuasive than did Hooker, took note and in his annotated copy of the pamphlet wrote “shows in great detail that vars. differ in same points as species” (Letter).  Just like Darwin, Gerard would conclude “I am therefore convinced, like Lamarck, Poiret, and Geoffroy, that varieties become species, and that this is how new species are formed…”.

The arguments for an evolutionary worldview in “De l’Espèce” draw on a broad spectrum of natural history knowledge from the early decades of the nineteenth century.  Gerard, like many other early evolutionists, noted the progressive nature of the fossil record. Gerard’s knowledge of horticulture led him to disavow the standard (and incorrect) view that interspecies hybrids were sterile and propose that interspecific hybridization could lead to the establishment of new species. Similar to Charles Naudin (1852), Gerard proposed that artificial selection by humans makes use of the very same tools of evolutionary change as found in a natural state. “[T]he modifiers put into action by man are none other than the natural agents, varying only in quantity and the duration.” Although coming precariously close (without realizing it) to a mechanism of natural selection, Gerard was fundamentally a Lamarckian at heart: modified environmental circumstances lead to evolutionary change.

Of particular interest is Gerard’s use of embryological information about organogenesis and how deviations in development might then result in biological (morphological) novelty and eventually lead to the creation of new species.  This may represent one of the first proposed mechanisms for descent with modification:  the heritable transmission of modifications of development.  In 1847, Gerard would be even more explicit about the role of development (which he referred to as epigenesis) and modification of organs (organogenesis) in both plants and animals as a method by which evolution could have occurred. “If, then, under our own eyes, in an environment whose changes are almost inapparent, it [an organism] may develop, occur, and atrophy organs, is this not all the secret of the creation of species, and, with the obvious changes in the surrounding environment, the cause of the modification of the types?” Here, Gerard foreshadows Haeckel’s evolutionary-developmental ideas.

Unlike Lamarck and many other early evolutionists, Gerard clearly saw the relationships of species as genealogical – a true tree of life:  “There is no longer, from this point of view, an ascending and continuous scale, without interruptions, without hiatus, but some parallel groups, other times without analogues and forming in a series of divergent branches, without anastomosis.”

Gerard brought a certain zeal to his attacks on creationists (referred to as “finalists”). Thus, his entry on species is not simply an argument for transmutation. It is a full-on attack on the flawed underpinnings of those who believed that species were eternal and unchanging.  His views clearly align with a materialist philosophy and this is apparent in his thesis that life (in the grand sense) is without purpose.  “Life is an immense arena, theater of permanent and necessary destruction, where all combinations hatch and die in turn: also, whatever the finalists say, it is a fact without purpose: it is simply a way of being elementary agents; and the role of each being is limited to the exercise of two functions, the only ones that constitute life: nutrition and generation.”

It is perhaps most surprising that the author of such forceful assertions of evolutionary views remains largely unknown today. The little known of his life (Bange and Bange, 1995) indicates that Gerard’s career was spent, not as a distinguished “man of science” in a museum or university, but as a translator in the Ministry of War for the French government. However he acquired his knowledge of natural history, he was an important editor of horticultural journals including Horticulteur universel, the Portefeuille des horticulteurs, and Moniteur de l’horticulture . He also authored the book Nouvelle flore usuelle et medicale, published in 1853. Befitting his regrettable anonymity in the annals of evolutionary thought, his name is lacking from his tombstone at Cimetiere Montparnassev.