378 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 
according to the time of year. During the winter months, when 
the days are short, about 60° should be maintained at night, and 
also on cold sunless days. Generally the temperature rises 
naturally a few degrees during the daytime through the influence 
of the sun or changes of the weather. Towards the spring 05° 
is necessary, with a rise of 5° to 10°. During the summer 
months a temperature between 70° and 80° should be maintained, 
together with a circulation of air from the roof of the house» 
In spring and autumn air should be admitted only on fine warm 
days. 
A thoroughly moist atmosphere is also necessary, the plants 
being very subject to thrip and red- spider ; consequently the 
house should be moistened several times a day. Syringe the 
plants once a day during the summer time, in the forenoon, with 
soft water if possible, and be particular to let the syringe play 
well from below, so that the foliage may be thoroughly wetted 
on both sides. Keep the walls clean by whitewashing them 
twice a year. 
During the winter-time syringing must be regulated according 
to the weather, and generally at this season of the year twice a 
week will be sufficient to keep the plants clean and the foliage 
in a healthy state. Green-fly will be found troublesome at times, 
but they can be easily kept under by dusting with tobacco-powder 
on the part affected, which is mostly the heart of the plants. If 
red-spider should appear, the plants must be washed at once with 
clean soft water. 
The varieties differ materially as regards their durability for 
decorative purposes, the coloured leaves of some being found to 
last far better than others, but this depends to a great extent on 
the mode of cultivation. If they are grown in a high tempera- 
ture and with a moist, close atmosphere, the foliage becomes 
tender, and coloured leaves so produced will never last long 
intact. Make it a rule, therefore, to grow the plants close to the 
glass and elevated on empty pots if the bed is at all low. Pay 
every attention to keep the soil in a re<)ular state of moisture ; 
do not let the roots suffer from dryness, and every day see that 
each plant is watered wh(!ii the soil is still moderately moist. 
Irregularity in treatment, such as dryness at one time, followed 
by excessive watering, combined with a damp atmosphere at 
aiiotlier, causes most of tlie roots to I'ot, the leaves become 
