STOVE AND GREENHOUSE AQUATICS. 
195 
species, such as Nelumbium, are to be grown, 
a regular stove heat must be kept up during 
the growing season ; 75 or 80 degrees will then 
not be too much for most of these plants, but 
this heat is not requisite while they are rest- 
ing, any more than it would be with other 
stove plants. It is for this class of plants, 
too, that the warming of the Avater is particu- 
larly desirable. The ordinary greenhouse 
species require little artificial atmospheric 
heat, neither is it at all necessary that the 
water should be warmed for them. If, as 
most probably would be the case, a mixed 
general collection is to be grown, the extreme 
heat that would best suit the stove kinds, as 
well as the coolness proper for those of tem- 
perate climes, must alike give place to a 
mean temperature that will suffice to grow 
both to tolerable perfection ; when such a 
collection is to be cultivated, a temperature of 
70 degrees, as a maximum by natural or sun 
heat, and 60 degrees maximum by artificial 
or applied heat, will be enough; and this maybe 
allowed to fall several — six or eight — degrees 
at night. The water, in this case, may be 
warmed to about 60 degrees during the grow- 
ing period, and need not receive any artificial 
warming when the plants are at rest. 
In the sketch which is here given, provi- 
sion is made for accommodating a considerable 
number of the smaller growing species on 
the side benches. When, however, these are 
less cared for than the larger and more showy 
kinds, it would be more desirable to do away 
with the side benches, except, perhaps, at the 
ends of the house, and extend the tank in 
the centre, as far as practicable, on each side, 
the walk then passing close to the outside ; if 
this plan is followed, the upright glass of the 
sides should, for the sake of effect, extend 
down to the level of the path ; and this part 
of the house must also be a trifle more ele- 
vated in order to give head-room. If the 
side benches were done away, there would 
be abundant facility for growing any of the 
smaller kinds by suspending the pots in which 
their roots are planted, at a proper depth in 
the water, by means of metal hooks from 
the wall of the tank, so that there is no good 
reason why this arrangement should not, in 
all cases, be adopted, if preferred. The prin- 
cipal argument in favour of the side benches 
is this, that the water may be drained away, 
and the benches then used for other plants 
(not aquatics), for which the temperature of 
the house may happen to be suitable. 
The great point in growing aquatic plants 
successfully — at least the stove species, which 
are the most remarkable— is the maintaining 
of a proper and regular warmth in the water 
in which they are placed. They are often 
placed in tanks or cisterns, from which water 
is taken for the various purposes of watering 
plants (probably in other houses), syringing, 
sprinkling, &c, and when this is the case, 
and the deficiency so caused is made good by 
adding large quantities of cold water, the 
roots are subjected to continual chills ; and 
under these circumstances the plants never 
attain that perfection of which they are capa- 
ble ; many refuse even to grow so far as to 
produce flowers, but merely drag on a linger- 
ing puny existence. This, therefore, must 
be particularly avoided. A change of the 
body of water is indeed sometimes desirable, 
but this must be effected by supplying water 
less differing in temperature than ordinary 
cold water, from that which has been taken 
away ; this may be done by procuring it from 
a reserve cistern placed within the influence 
of the warmth from the heating apparatus. 
As water is the chief element supplied to 
these plants, it must be regarded as a matter 
of some importance from what source it is 
obtained. Rain water is best for all plants, 
aquatics included ; and when this is not to be 
had, pond or river water is next to be pre- 
ferred. Spring or well water is the very worst 
for horticultural purposes, unless previously 
to being used it is well aerated ; that is, ex- 
posed in shallow vessels to the sun and air. 
But though rain water is desirable, it must 
not run from the roof of the house into the 
tank where the plants are growing, as in 
some cases — though not always — this would 
be a worse evil than the one previously refer- 
red to, of filling up with cold water. The 
evil in this case would be principally felt in 
the early spring months, when the rain is 
often " cold," — sometimes mere melted snow 
— and the plants are making young growth. 
The plants should all be placed in pots, or 
pans, or tubs, for the convenience of removing 
them, and altering their arrangement and 
position with facility, and also for the purpose 
of facilitating their removal out of the water 
when in a dormant state. The floating species 
often increase very rapidly, and soon spread 
over a larger space than would be properly 
devoted to them individually; when this is the 
case, the plants must be kept within proper 
limits, by cutting away such parts as may have 
extended too far. In doing this it is necessary 
to observe that the extreme points of the shoots 
of many kinds are the most vigorous parts, 
and the root-stock the weakest; and when this 
is the case, too much of the extreme parts of 
the plant ought not to be cut away, but some 
parts thinned out, leaving the others at full 
length, or nearly so ; unless this is attended to, 
the strongest and best flowers, and the parts 
most likely to produce them, will be cut away, 
or perhaps the whole may be removed. So in 
the case of propasrating those which require 
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