FRESH-WATER AQUARIUM. 
41 
and early in the morning, we shall find ourselves surrounded by 
acres of water-lilies, beneath which are the desired specimens. 
All along from this dam, towards Grafton, a chain of shallow 
ponds connected by rivers invites our attention, and the scenery 
alone would be a sufficient inducement to bring the naturalist to 
the spot. The three kinds of plants which are the best suited for 
the aquariam, of all our natives, are Ceraptopliyllum demersum; 
TJtricularia vulgaris , injlata , and minor ; Potamogeton natans , Clay- 
tonii , and others.* 
Besides these plants the floating Duckweed ( Lemna trisulca) is 
a very valuable addition to the collection. Water-lily plants are 
not only difficult to make grow, but their leaves are apt to be ill- 
proportioned to the size of the tank. In duckweed both of these 
troubles are done away with, for we have a plant which is easily 
grown, and one which gives to the aquarium the appearance of a 
miniature pond. It is found in brooks at the roadside and in 
shallow ponds ,especially in the autumn season. The Limnocharis 
Humboldtii , a lily sometimes grown in tanks in greenhouses, is 
also a good plant for the aquarium, where, if care be taken, it 
will blossom freely. There is a moss-like plant of bluish green 
color, found growing on stones in brooks, and under bridges in 
shacty places in the water. It is called Pontinalis antipyretica , 
and it is one of the few brook plants that will do well in the aqua¬ 
rium. The water buttercup, Ranunculus aquatilis , has only its 
* They are thus described by Dr. Gray. (Manual of Botany of the Northern States. 
By Asa Gray. 1867.) 
. li Ceratophyllum; Hornwort. Sterile flowers of 12-24 stamens with large sessile 
anthers. Fruit an achemium, beaked with the slender persistent style. Herbs grow¬ 
ing under water in ponds or slow flowing streams. The sessile leaves cut into thrice- 
forked thread-like rigid divisions (whence the name from /cepas, a horn, and 4>vK\ov, a 
leaf).” 
“ TJtricularia: Bladderwort. Lips of the 2-parted calyx entire or nearly so. Co. 
rolla personate, the palate on the lower lip projecting, often closing the throat. An¬ 
thers convergent, aquatic and immersed, with capillary dissected leaves bearing little 
bladders, which are filled with air and float the plant at the time of flowering; or 
rooting in the mud, sometimes with few or no leaves or bladders (name from Utriculus, 
a little bladder).” 
Potamogeton: Pond-weed. Flowers perfect. Sepals 4, rounded, valvate in the 
bud. Stamens 4 opposite the sepals; anthers nearly sessile, 2-celled. Ovaries 4 
(rarely only one), with an ascending campylotropous ovule. Stigma sessile, or on a 
short style. Fruit drupe-like when fresh, more or less compressed; endocarp (nutlet) 
crustaceous. Herbs of fresh or one in brackish ponds and streams, with jointed, 
mostly rooting stems, and 2-rauked leaves, which are usually alternate or imperfectly 
opposite. The submersed ones pellucid, the floating ones often dilated and of a firmer 
texture (an ancient name composed of 7rorapi6s, a river, and vetTwjj, a neighbor, from 
their place of growth).” 
