276 NOSTOCHINE^E. 



analogous to what has been observed, though of course on a 

 scale much smaller in portions of freshwater, that the one 

 can scarcely be considered complete without a reference to the 

 other, and both are of the highest interest. In the " An- 

 nales des Sciences Naturelles," 3d Series, t. ii., there is an 

 able and elaborate memoir by Dr. Montagne, one of the first 

 Cryptogamic Botanists of Europe, " Sur la Phe*nomene de 

 la Coloration des Eaux de la Mer Rouge," which contains 

 a great number of references to works in which mention 

 has been made of the phenomenon of the colouration of the 

 sea. 



The sudden and periodical colouration of vast extents of 

 the sea, has been, to uninformed minds, in early times, a sub- 

 ject of superstition and dread, these appearances having been 

 regarded by the ignorant as Divine manifestations of anger 

 or impending calamity ; and that they should have been so 

 regarded in days in which natural science was all but un- 

 known, is scarcely surprising. The true explanation of the 

 cause of these sudden and remarkable appearances, while it 

 removes all feelings of superstition or dread, does not banish 

 those of amazement and admiration which indeed supplant 

 them. 



The following appropriate observations in the memoir of 

 Montagne, already referred to, occur : 



" The singular phenomenon of the colouration produced on 

 the surface of the Red Sea, a colouration in which we 

 have seen the waters themselves do not participate, has 

 been, each time that it occurs, a new subject of astonish- 

 ment for the people who have witnessed it. It cannot be 

 doubted, moreover, that the jugglers and charlatans, after 

 having probably calculated in advance its periodical return, 

 made use of it to govern the multitude by the menace 

 of an approaching calamity, of which they failed not to pre- 

 sent this sign as the undoubted precursor. It is also to a 

 cause, if not altogether similar, at least very analogous, that 

 is to be attributed, according to many naturalists, in the 

 number of whom figures M. Ehrenberg, those rivers, waters, 

 and lakes changed into blood in one of the plains of Egypt, 



