MISSOURI BOTANICAL GARDEN BULLETIN 67 
is desirable for adding water, the small streams becoming 
well aérated. 
An evidence of sickness in fish is the dragging of the back 
fin which normally is carried upright. The movements also 
become sluggish and a tendency to hide in a dark corner is 
noticed. The body becomes thin, the fins split and are 
streeked with red, and the excrement shows a pale color. 
Sick fish should be removed quickly from the aquarium, 
and if the disease affecting it be contagious, the tank should 
be disinfected by adding three grains of potassium perman- 
ee to a gallon of water, having previously removed the 
h and the snails. 
The mineral constituents of the water are absorbed by the 
fish and plants to such an extent as to necessitate addition 
of these materials at intervals. A mixture of three parts of 
evaporated sea salt to one part of Epsom salts added at the 
rate of one teaspoonful to twenty gallons of water every two 
weeks will prove beneficial. Acid conditions resulting in 
the crumbling of the shells of snails may be eliminated by 
keeping a piece of plaster of Paris or gypsum in the aqua- 
rium. In dissolving, it neutralizes the acid, but as it only 
dissolves under acid conditions there is no danger of the 
water becoming too alkaline. 
In order to get rid of a good deal of decomposing matter 
in the aquarium, Japanese, African, and European red 
snails, as well as water mussels and weather-fish, are ex- 
tremely useful and should find place in every tank. The 
mussels are necessary for keeping down algal growth. 
Planting is done directly in sand which is spread to a 
thickness of one inch. Two inches of water is then added, 
the roots spread out, and another one-inch layer of sand and 
pebbles placed on top. The aquarium should be allowed 
to stand at least a day before the fish are added. 
A globe is one of the worst possible containers for fish. 
When filled the air surface is small in proportion to the wa- 
ter bulk; the convex surface of the globe acts as a lens, 
focusing light into the eyes of the fish; proper plant growth 
is difficult, and in addition overcrowding and overfeeding 
are apt to result. 
THE LINNEAN HOUSE 
The Linnean House, which was erected by Mr. Shaw in 
1882 to house the palm collection and part of the floral dis- 
lays and is the only greenhouse remaining of those built 
5 tay, has been radically remodelled and presents a novel 
