88 POPULAR GEOGRAPHY OP PLANTS. 



the open sea when most distant from land ; and lastly, that 

 it equally adapts itself to the calmest or most tempestuous 

 situations, to waters of uniform depths or those which rise 

 or sink with the tide, to dead water or to strong currents. 

 One thing alone it requires, and that is, a mean depth of 

 six or more fathoms ; for, like the Laminaria of our own 

 shores, it and others of the same tribe in the South invari- 

 ably form the outer belt of marine vegetation/' 



The first account of the gigantic dimensions of the Ma- 

 crocystis was given by Sir Joseph Banks ; on his authority, 

 and that of Solander, who called it Fucus giganteus, the 

 stems attain a length of a hundred and twenty feet. " That 

 these dimensions are considerably under the mark there is 

 little doubt, though the report that specimens have been 

 measured upwards of a thousand feet is perhaps as much of 

 an exaggeration." From the nature of the plant however, 

 and the manner of its growth, there are no impediments 

 to its almost indefinite elongation, ' f provided the water be 

 smooth and of sufficient extent." " Specimens measuring be- 

 tween one and two hundred feet are common ;" but as they 

 are always found broken off at the lower end, they afford 

 but little help in ascertaining to what length the plant is 

 naturally capable of extending itself. The longest speci- 



