The publication of The Origin of Species placed the study of Botanical Geography on an entirely new basis. It is only necessary to study the monumental Géographie Botanique raisonnée of Alphonse De Candolle, published four years earlier (1855), to realise how profound and far-reaching was the change. After a masterly and exhaustive discussion of all available data De Candolle in his final conclusions could only arrive at a deadlock. It is sufficient to quote a few sentences:—

“L'opinion de Lamarck est aujourd'hui abandonnée par tous les naturalistes qui ont étudié sagement les modifications possibles des êtres organisés….

“Et si l'on s'écarte des exagérations de Lamarck, si l'on suppose un premier type de chaque genre, de chaque famille tout au moins, on se trouve encore à l'égard de l'origine de ces types en présence de la grande question de la création.

“Le seul parti à prendre est done d'envisager les êtres organisés comme existant depuis certaines époques, avec leurs qualités particulières.”

Reviewing the position fourteen years afterwards, Benthain remarked:—“These views, generally received by the great majority of naturalists at the time De Candolle wrote, and still maintained by a few, must, if adhered to, check all further enquiry into any connection of facts Mrith causes,” and he added, “there is little doubt but that if De Candolle were to revise his work, he would follow the example of so many other eminent naturalists, and…insist that the present geographical distribution of plants was in most instances a derivative one, altered from a very different former distribution.”