
















266 THE MARINE AQUARIUM. 
And a scythe has been at work; none other than the 
tongue of the little shell-fish ; a description of its extraordi- 
nary mechanism (too long to quote here, but which is well — 
worth reading) may be found in Gosse’s Aquarium, p. 34. 
A prawn or two, and a few minute starfish, will make your 4 
aquarium complete ; though you may add to it endlessly, & _ 
one glance at the salt-water tanks of the Zodlogical i 
and the strange and beautiful forms which they contain, will A 
prove to you sufficiently. Le k 
You have two more enemies to guard against, dust and 
heat. If the surface of the water becomes clogged with dust, 
the communication between it and the life-giving oxygen of 
the air is cut off; and then your animals are liable to die, 
for the very same reason that fish die in a pond which is 
long frozen over, unless a hole be broken in the ice to admit 
the air. You must guard against this by occasional stirrug 
of the surface (it should be done once a day if possible), 
by keeping on a cover. A piece of muslin tied over ʻi 
but a better defence is a plate of glass, raised on wit sour 
half-inch above the edge, so as to admit the air. Jam 
next evil, which is heat. Against that you musts 
putting a curtain of muslin or oiled pape y 
and the sun, if it be very fierce, or simply (for simp 
pedients are best) by laying a handkerchief over it 
heat is past. But if you leave your vase in a suon with 
long enough to let the water get tepid, all 1s gen , 
your pets. Half an hour’s boiling may frustrate the 
weeks. And yet, on the other hand, light y ote 7 rtainly 
and you can hardly have too much. Some anım pe ; 
prefer shade, and hide in the darkest crannies; ‘ies 
them, if your aquarium is large enough, you™ e 
shade, by arranging the bits of stone into piles and 
But without light, your sea-weeds will neither 
keep the water sweet. With plenty of light you 
re 
is 
will < 
