34 INTRODUCTION 



prairie. Farther than the eye can reach is spread a yellowisn- 

 brown vegetation which covers the water as grass covers the 

 plain. Sometimes these weeds are so thick as to impede navi- 

 gation, and, seen from a little distance, seem substantial enough 

 to walk upon. At other times, according to seasons and condi- 

 tions of storm and wind, they are divided into strips or into 

 island-like masses, with spaces of clear water between. If the 

 sailor did not know the special conditions existing here he might 

 suppose he had come upon dangerous shallows; or were the 

 waters less turbulent he might dream that he was floating 

 among the water-weeds of an inland lake. 



This vast acreage of vegetation, as large as the continent of 

 Europe, lying southwest of the Azores and extending between 

 the Canary and the Cape Verde Islands, was first reported by 

 Columbus, and takes its name from the floating plant of which it 

 is composed, the Sargassum bacciferum, a species of the order 

 Fucacece, commonly known as gulfweed. Columbus's sailors took 

 fright at the marvelous appearance and wished to turn back, 

 thinking they had reached the end of the navigable ocean. They 

 thought, if land were beyond, it was guarded by shoals, and that 

 the weeds concealed dangerous rocks. Columbus threw out two 

 hundred fathoms of line, but did not reach bottom, and con- 

 tinued on his course for fifteen days before emerging into clear 

 water. From that day to this the Sargasso Sea has attracted the 

 attention of all navigators. It is especially interesting to scien- 

 tists. The physicist finds there the phenomenon of the ocean 

 currents holding in a vortex this immense mass of seaweed, the 

 zoologist finds a great pasture in whose protecting shelter are 

 living and breeding countless numbers of marine animals, and 

 the botanist is puzzled because the source of this species of plant 

 is clouded with doubt. 



According to one theory, the plants are dislodged by the tem- 

 pests from terrestrial beds and carried by the Gulf Stream into 

 the huge eddy ; but since there does not exist enough of the 

 attached plants of this species to supply the vast accumulation, 

 another and more generally accepted theory is that the gulfweed 

 lives also a pelagic life and adapts itself to the conditions of the 



