72 Aquatic Lite 
but for the effecting of a perfect balance 
of marine animals and plants it is still 
difficult to advanace any unfailing recipe. 
As with fresh-water forms, the animals 
depend largely upon the oxygen thrown 
me 8 6 OS 
6 a OS | as | 
QP moms bs mo ee 6 8 6 a ah a 1 Fs a a a as 9a a 9 
off by the plants, while the plants take up 
the carbonic acid gas exhaled by the ant- 
mals; and, as with fresh water, the 
iquaria whose capacities are measured 
vy the gallon are more satisfactory than 
those holding only quarts. There is small 
danger from an excess of plants, but too 
much animal life is certain to prove fatal. 
All-glass aquaria are the best for salt 
water, and are the only kind used at the 
New York Aquarium for small marine 
balanced aquaria. 
Le 
PS Os Oa 8 Os OR Sd a 6 Oa 6 Pt Ot 9 et OR En a 
A SELF-SUSTAINING SALT WATER AQUARIUM 
ot OS | ee et 
Marine collections of the “happy fam- 
ily” order are successfully maintained at 
the New York Aquarium in eight-gallon 
jars, with two kinds of plants, and as 
many as eleven forms of animal life. The 
plants are the red alga Soleria chordalis, 
sometimes attaching itself to rocks, and 
