THE MARINE AQUARIUM. 95 
reviving exhausted stock is wholly or partially to change 
the water; with marine stock, such a change is not 
easy, and the filter comes more legitimately into use. 
As already remarked, the necessity for aeration marks 
error in management, except when you have stock for 
which no proper receptacle is at hand, or any such 
special contingency. 
Decay of Plants.—The sea-weeds are apt to acquire a 
pale tint, which is the first evidence of decay. This 
generally happens with the first marine stock, when Ulva | 
and Enteromorpha are used to season artificial water. 
When the water gets ripe, the plants recover and make 
healthy growth, but if many white fronds appear, lift out 
the blocks on which the plants are fixed, trim away the 
decayed portions with a pair of scissors, and then scrub 
the stones with a small brush in a little waste sea-water, 
and replace them; they will soon recover. If red plants 
have been hurriedly introduced, and decay manifests 
itself, remove them at once, and waste no time in attempts 
at revival. Mr. Lloyd will supply a new stock for a 
trifle, and it is better to begin de novo than to attempt to 
cure the incurable. 
Death of Anemones.—If you observe any of the ane- 
mones to shrink up like button-covers, lift them out into 
a shallow vessel, and aerate them liberally. When small 
beads of gas appear upon them, you may rest assured 
that they have gone beyond the— 
‘¢ Bourne from whence no traveller returns ; ’’ 
for the first outward proof of death is the formation of 
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