ABSTRACT
The year 1859 saw a climax to the scientific publications of both Hewett Cottrell Watson and Charles Robert Darwin. In May, Watson published the fourth volume of Cybele Britannica, containing interpretations of phytogeographical data on individual species which he had published in the earlier volumes. In November Darwin published On the Origin of Species, culminating researches he had carried on since 1837. Darwin was so enthusiastic about Watson's findings that he was eager to read volume IV of Cybele Britannica. Watson realized that Darwin's expectations were too high, and gave his modest reply that he was only hewing stones for a later edifice. Having compiled a list of the European species in the Azores from several sources, Darwin sent a list of 77 non-domesticated species to Watson with a request for his estimate of how many of them might have drifted there on sea currents.
