RIODEJANEIRO. 73 
iiig to the strength and direction of the prevaihng winds and 
currents ; but what may properly be called the Grass sea is 
comprehended between the 18th and 32d parallels of northern 
latitude, and between the 25th and 40th meridians of west- 
em longitude. The common opinion that the myriads of 
plants floating on this expanse are torn from tlie shores of the 
gulf of Mexico, and wafted by the stream wiiicli incessantly 
flows out of it to the northward, would seem to be one of 
those vulgar errors that has oJjtained general currency by 
gratuitous assent. If this species of Fucus be a native of the 
gulf, which I am not competent to decide, it would be found 
rather on the banks of Newfoundland and the coast of North 
America, towards which the stream flows, than on the sea of 
Sargasso^ a situation to whicli it covdd not have been brought 
either by wind or current. In fact, the plant has neither 
roots nor fibrils of any kind to indicate that it ever was at- 
tached to rocks or shores, but its central stem buried in the 
midst of its leafy branches makes it suflricientiy evident that 
it vegetates while floating on the surface of the fathomless 
deep. Some of the plants are many feet in diameter, others 
only a few inches ; all appear in a growing state ; the globose 
berries are in some plants green, in others red. If taken out 
of the water the plant becomes flaccid, and in the course ot 
twenty-four hours turns- brown or black. 
In returning home, the curious passenger cannot fail to 
derive great amusement in examining the bushes of fucus^ 
when crossing the sea of Sai^gasso. The naturalist in every plant 
will find a great variety of marine insects and worms, some 
naked, and others with testaceous covei'ings. A minute crab, 
