
AQUATIC PLANTS OF FRESHWATER 

others, are generally to be had and may be planted with the lower ends 
embedded in the sand or pebbles or loosely floating on the surface of the 
water. They require a strong light and grow very rapidly. Goldfishes 
destroy them but with, Paradise fishes or for snail culture, they form hand- 
some aquatic gardens. 
A peculiar characteristic of the Bladderworts is that they are aquatic 
insectivorous plants. The bladders are provided with a valvelike trap on 
their lower sides and when filled with water also probably contain secre- 
tions which attract infusoria and small crustaceans, who upon entering are 
entrapped and absorbed by the plant. Of some species it is reported 
that they will capture the tiny fry of fishes, though in these latitudes there 
is no species with bladders sufficiently large to serve this purpose. 
HOTTONIA 
This pretty marsh herb is commonly known as Featherfoil, Water- 
feather, Water or Marsh-violet and Water-yarrow. Two species are 
native to North America. 
Hottonia inflata (Ell.) or Water-feather having an entirely submerged 
spongy close cluster of thick and soft stems with pinnate crowded leaves 
in verticils and clustered at the ends and joints of the stems. An interest- 
ing pond plant but does not usually survive in the aquarium. 
H. palustris (Ell.) the second species is more rarely met with, but in 
Europe is considerably cultivated as an aquarium plant. 
FRESHWATER ALG 
The Algz constitute one of the grand divisions of the Cryptogams 
or flowerless plants, embracing the sea weeds and lower water plants, 
the Fucas, Ulva and Conferve. The most of the Fuca and Ulva are 
marine forms; but in counterdistinction to Alge in general, the Conferve 
are an extensive section of the order of Alge, consisting of slender, often 
scum-like vegetation, the best known being the so-called ““Frog-spittle.”’ 
The simpler forms of Alge, the Nostocee, consist only of a cell wall con- 
taining a colored protoplasmic substance; but in the higher forms the cells 
are combined into a tissue, and the forms which they assume are more varied 
than in any other class of plants. Some appear as strings or linear masses, 
globules, laminz, etc. In others, the Fucacez, a distinct stem, branches, 
leaflike structures and rhizoids or rootlike structures are formed, but these 
have none of the characteristics of true plants and consist entirely of 
cellular tissue. . 
Each season of the year, every climate, every moist spot, has its species 
of Alge. Some may be found in healthy condition frozen into an icicle 
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