THE MARINE AQUARIUM. OF 
CHAPTER VII. 
GENERAL MANAGEMENT. 
I sHALL in this Chapter only notice such particulars in 
the management of aquaria as belong especially to the 
marine department, since some of the directions given in 
the former division of the work apply to tanks of all 
kinds, and heed not be repeated. When preliminary 
difficulties have been surmounted, the matter of first im- 
portance is the selection of the stock, and its arrange- 
ment in accordance with just principles. 
Grouping.—In Chapters IV. and V. I have enumerated 
the kinds of animals and plants most suitable for aquaria, 
and must now caution the beginner against the injudicious 
grouping together of creatures of dissimilar habits. 
Anemones may, as a rule, be kept together. The several 
species agree well, and seldom or rarely injure each other ; 
but star-fishes and crabs are best kept in vessels apart 
from them. Star-fishes are very destructive, and readily 
absorb the bodies of mollusks out of their shells. If ex- 
ception is to be taken to any particular anemone, I think 
the grand plumosa must suffer by it; for this noble 
creature gives off a flocculent exudation, which seems 
injurious to other kinds. I have generally kept the 
plumose anemone in company with 4. mesembryan- 
themum, A. bellis, troglodytes, and others, without per- 
ceiving any bad result; but I have always been careful 
to remove the slimy exuvia daily, by means of the dipping 
tube. Respecting mollusks, and especially trochus and 
