AQUARIUM 



AQUARIUM 



337 



287. Permanent aquarium made of 

 wood and glass. 



in a health}' condition for several months. Vallisneria 

 spiralis (eel-grass, tape-grass, wild celery) is a native 

 plant inhabiting streams and rivers, and often used in 

 the aquarium. Its long, narrow, strap-like blades or 

 leaves are more flexible than the sagittaria and the tips 

 float on the surface of the water. They are light green 

 in color and of softer texture. It is a difficult plant to 

 carry over winter, its natural propensity being to die 

 down in winter, just the season when it is wanted in 

 evidence in the aquarium. Ludvigia Mulerttii is one of 



the most conspicuous, 

 ornamental and useful 

 plants for the aqua- 

 rium and is always in 

 great demand. It is 

 much larger and a 

 stronger grower than 

 L. palustris of the 

 middle and northern 

 states. It is a native 

 of the southern states, 

 whence come our sup- 

 plies in winter in small 

 quantities and for high prices, the plants very un- 

 satisfactory at best. The difficulty is that plants, or 

 rather sprays, plucked from growing plants and shipped 

 North, receive a violent check in the change of temper- 

 ature and the closely confined condition of the packing- 

 case. The result often is that the plants or sprays lose 

 a great part of their foliage, and when afterward sub- 

 jected to cold running water are completely ruined. 

 The only safe way is to secure stock during the summer 

 or early fall, getting plants established in pots before 

 preparing the aquarium for winter. In this condition, 

 the plants will hold their own and winter over; but to 

 attempt to grow southern stock in winter in our north- 

 ern states is futile. There are a few other submerged 

 plants that might be used, but the above-mentioned 

 are the best and the best oxygenators for large or small 

 aquariums. Floating plants should be used sparingly 

 in the aquarium, an open, clean surface being most 

 desirable and even necessary for air. Moreover, the 

 majority of the floating plants are suitable only for sum- 

 mer culture. Another reason why surface or floating 

 plants do not succeed in a house 

 aquarium is that the water is 

 deficient of plant-food suitable for 

 such plants. Plants that die in an 

 aquarium would, if transferred to a 

 tur> containing a quantity of soil, 

 as well as water, make rapid and 

 healthy growth. Limnocharis Hum- 

 boldlii (water poppy) is a plant often 

 used in the aquarium. It is neces- 

 sary to plant this in the sand in 

 the same manner as other aquatic 

 plants, although the leaves are float- 

 ing, similar to the leaves of a pond- 

 lily. Eichhornia crassipes major 

 (water hyacinth) is a very desirable 

 plant for catching the fish spawn, 

 but under ordinary conditions lasts 

 but a few days in the aquarium. 

 Miniature plants of these are very 

 pretty, and fish are very fond of 

 nibbling at the roots to the detri- 

 ment of the plants. These, with 

 many other plants, are best adapted 

 for the summer aquaria where they 

 can enjoy the benefit of sunlight 

 and open air. 



Numerous free-floating plants are 

 adapted to the aquarium, but too 

 many must not be in evidence, or the 

 fish may become suffocated. The 

 azollas are very pretty, and the fish 



will occasionally eat the plants. The salvinia is another 

 small plant often seen in the aquarium, but under favor- 

 able conditions it grows very rapidly, and forms a com- 

 plete mat, which must be avoided. The European and 

 American frog's-bits (Limnobium Spongia, Hydrocharis 

 Marsus-ratue) are very attractive plants, their long, 

 silkj" roots reaching down in the water. 



In summer the plants and fish should be placed out- 

 of-doors in a fountain basin, pool, or a tub sunken in 

 the ground in a partially shaded place; and a fresh 

 aquarium should be stocked in the fall. 



Aquariums are rapidly increasing in popularity for 

 home use, and are of great service in nature-study. 

 A permanent aquarium need not be an expensive 

 affair. The rectangular ones are best if large fishes are 

 to be kept, but they are not essential. A simple home- 

 made aquarium of glass and wood (Fig. 287) is de- 

 scribed in Jackman's "Nature Study," as follows (the 

 dimensions being slightly altered): "Use an inch board 

 11 % inches wide and 12 inches long for the bottom, 

 and two boards of the same thickness and length, 10% 

 inches high, for the ends. Three-eighths of an inch 

 from the edge on either side, with a saw, make a groove 

 J^inch deep and wide enough to receive loosely double- 

 strength glass. Groove the end boards and fasten them 

 to the bottom with screws, so that the grooves will 

 exactly match. Partially fill the grooves with soft 

 putty, or, better, aquarium cement, and press into each 

 side a pane of glass. By making the bottom board \\]/% 

 inches long, an ordinary 10 x 12 window pane will be 

 the proper size. When the glass is pressed to the bottom 

 of the groove, draw the two ends in at the top until 

 the glass is held firmly and then fasten them in place 

 by narrow strips of wood, one on each side of the tank, 

 placed on top of the glass and screwed to the end pieces. 

 These strips also protect the hands from injury while 

 working with the specimens in the aquarium. Before 

 filling with water, the inner surface of the bottom and 

 ends should be well rubbed with oil or paraffin and the 

 grooves inside the glass well packed with putty." After 

 the box is made it would be well to let it stand in water 

 for a day or two. The wooden sides will swell and 

 tighten the joints, and leakage will be less probable. 



WILLIAM THICKER. 



288. Working drawings for making boi shown in Fig. 287. 



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