1900 SUPPLEMENT—RECENT INTRODUCTIONS, 
Aquatic Plants—continued. 
crippled the growth, or perhaps entirely destroyed other 
plants. In tanks, and also in ponds where there is but a 
slight current of water, various forms of confervoid alga— 
green, thread-like vegetation, members of a low order of 
the Vegetable Kingdom—will sometimes make their appear- 
ance, more especially during warm weather; these, upon 
rising to the surface of the water, should at once be 
removed, or they will soon form dense masses, detrimental 
to the growth of the other occupants. If the Water Lilies 
are well furnished with foliage, the alge would be less 
troublesome to deal with, and the introduction of a stock 
of fish would also prove very serviceable in keeping the 
same in check. 
For the removal of dead leaves, weeds, or any ac- 
eumulation of floating refuse, as well as to give the 
necessary attention to any plants requiring it in tanks 
See Atl 
Aquatic Plants—continued. 
visits, by destroying the buds and flowers of Water Lilies, 
but they may generally be captured without very much 
difficulty by means of tempting baits. Waterfowl might 
play bavoe with small plants if unguarded, but it is most 
desirable that these should be grown in reserved quarters 
until sufficiently strong to plant out. 
In selecting a site for an artificial piece of water it 
should be borne in mind that water naturally seeks its 
bed in low-lying ground; therefore, in the construction of 
a pond, it is very important that this particular should 
be observed wherever the conditions are favourable for 
doing so, or an unreal effect will otherwise be produced. 
The outline should be carefully considered, and circular 
or unnatural shapes should be avoided, as these would, 
to a cultivated taste, present a too artificial appearance. 
The sides should be represented by projections and 
Fic. 70. Hyprip WATER LILIES AT GUNNERSBURY HouSsE, ACTON. 
or small areas of water, a strong, light plank or ladder 
might be used of sufficient length to take a secure bearing 
at the ends; but in large ponds, where this is imprac- 
ticable, wading-boots have to be resorted to. 
Aquatics, more especially those with floating leaves, are 
fairly free from injurious attacks of insect pests, although 
sometimes they become affected with green and black Aphis. 
These can, however, generally be removed with the aid of 
a syringe or hose-spray; but the most effectual remedy is a 
natural one—a good heavy shower of rain, which also 
imparts to the plants an additional brightness. In some 
cases it may be desirable to use an insecticide, and should 
this be resorted to a solution of tobacco-juice will be found 
to answer the purpose effectually, without causing the 
least injury to the plants. Water-voles will sometimes 
become troublesome, if allowed to be undisturbed in their 
irrezular curves, avoiding the introduction of straight 
lines, which are invariably objectionable, and seldom occur 
in a natural formation. Artificial work, as far as possible, 
should be carefully concealed below the intended water- 
level line, or provision made for concealing it with 
vegetation when planting operations are in progress. If 
the soil is of a clayey nature and retentive of water where 
it is designed to form a pond, this work will be very 
much simplified; but should it be of a porous nature, 
then tempered clay will have to be introduced and puddling 
resorted to in ordor to prevent waste of water when the 
work is completed. When the soil has been excavated 
as deeply as may be desired—say to a minimum 
depth of abont 3ft. in the middle or deepest part, 
gradually diminishing to about 14ft. at the margin, 
the sides sloping outwardly—the surface of the 
