1C9 
OF THE SMALLER SPECIES OF ALGiE OR FLAGS. 
metamorphoses, or their capability of being perpetuated by seeds. It 
is a general law of nature that seeds will perpetuate a species but not 
a variety j and this is no doubt true, if rightly considered : and j et it 
may be urged, if this be so, how have the varieties, well known to 
gardeners and agriculturists, for many years been unceasingly carried 
on from generation to generation without change ? The long red, and 
round white radishes of the markets, for instance, have been known 
from time immemorial in the same state in which they now exist. 
The answer is this : a species will perpetuate itself from seed for ever 
under any circumstances, and left to the simple aid of nature; but 
accidental varieties cannot be so perpetuated; if suffered to become 
wild, they very soon revert to the form from which they originally 
sprung. It is necessary that they be cultivated with the utmost care ; 
that seed should be saved from those individuals only in which the 
marks of the variety are most distinctly conspicuous; and all plants 
that indicate any tendency to throw off their peculiar characteristics 
should be rejected. If this be carefully done, the existence of any 
variety of annual or perennial plant may undoubtedly be prolonged 
through many generations ; but in woody plants this scarcely happens, 
it being a rare occurrence to find any variety of tree or shrub producing 
its like when increased by seed .—Bindley s Introd. to Botany. 
Of the smaller Species of Alg/E or Flags. —The slimy matter 
often seen on rocks and stones, on hard gravel walks, and on damp w r alls 
and cellars, or on the glass of windows, garden pots, and so forth, and 
which is often so minute as to be lost to ordinary vision, consists of 
curious and most admirable vegetable structures. All the green pul¬ 
verulent coating, seen on old trees and palings, is also found, by micro¬ 
scopic observations, to be composed of an infinite number of small 
plants, of an exceedingly primitive formation. 
The slimy masses, known as Will-o’-the-Wisps, or Nostocs, are 
instances of other allied species, some of which are called by country 
people “ flowers of heaven ; ” a name which they deserve more than 
many that are often given to plants, if it be true, as the old herbalists 
declare, that “ infused in brandy, they cause a disgust to that liquor 
in those who drink of it:” for, as Johnstone adds, they 'would then 
become “ an excellent remedy for the yotatores summi 
Not one of the least curious of the lowly flags, is the “red snow,” 
which excited so much attention on Capt. Ross’s return from the North 
Pole, in 1819. This phenomenon seems in some cases to depend upon 
the sudden appearance of a very minute plant, which the microscope 
shows to consist of small cells, filled with a red fluid, and which is 
referred to a genus named, from its very simple structure, Froto-coccus = 
