The vegetation of the ocean thus offers the most remarkable example of _social plants_ of a single species. On the main land the Savannahs or grass plains of America, the heaths (_ericeta_), and the forests of Northern Europe and Asia, in which are associated coniferous trees, birches, and willows, produce a less striking uniformity than do these thalassophytes. Our heaths present in the north not only the predominating Calluna vulgaris, but also Erica tetralix, E. ciliaris, and E. cinerea; and in the south, Erica arborea, E. scoparia, and E. Mediterranea. The uniformity of the view presented by the Fucus natans is incomparably greater than that of any other assemblage of social plants. Oviedo calls the fucus banks “meadows,” _praderias de yerva_. If we consider that Pedro Velasco, a native of the Spanish harbour of Palos, by following the flight of certain birds from Fayal, discovered the Island of Flores as early as 1452, it seems almost impossible, considering the proximity of the great fucus bank of Corvo and Flores, that no part of these oceanic meadows should have been seen before the time of Columbus by Portuguese ships driven westward by storms. We learn, however, from the astonishment of the companions of the admiral, when they were continuously surrounded by sea-grass from the 16th of September to the 8th of October, 1492, that the magnitude of the phenomenon was at that period unknown to mariners. In the extracts from the ship’s journal given by Las Casas, Columbus certainly does not mention the apprehensions which the accumulation of sea-weed excited, or the grumbling of his companions. He merely speaks of the complaints and murmurs regarding the danger of the very weak but constant east winds. It was only his son, Fernando Colon, who in the history of his father’s life, endeavoured to give a somewhat dramatic delineation of the anxieties of the sailors.