Juty-Aucust, 1919.) THE ORCHID REVIEW rrr 
_plants may produce flowers of the best quality. Whenever possible, the 
ventilators should be freely used in the different houses, and the fresh air 
thus admitted will be greatly appreciated by the plants. This free 
ventilation, and the increased amount of sun heat, necessitates the use of a 
great amount of atmospheric moisture, making conditions under which all 
Orchidaceous plants thrive ; still, care must be taken that even this is not 
carried too far. During cool nights the plants should be allowed to get dry 
before nightfall. Plants grown under rational treatment as regards heat, 
light, and air, are better able to withstand any slight set backs they may 
meet with than those grown under hot, close, stuffy conditions. The health 
of the plants depends entirely upon the conditions provided for them, hence 
the necessity of careful observations of the outside conditions, especially 
_ when the changes are rapid. 
The ventilation of the different houses depends entirely upon the class of 
plants grown in them, and small houses will require more attention than 
larger ones, as in the former the temperatures rise and fall more quickly, and 
in all cases Orchids resent a dry and parched atmosphere as much as a wet 
and cold one, therefore the ventilators must not be thrown open in a 
haphazard way, but a continuous circulation of fresh air should be admitted 
at all times without causing draughts. The cultivator would shun draughts 
himself, and he should be careful that his plants are not exposed to them, 
as they suffer in the same way. Perfect development of growth is only 
possible under suitable conditions, hence the necessity of watchfulness. 
WATERING at this season needs careful attention, as the plants are im 
different conditions, some being in full growth and some only recently 
repotted, whilst others are well rooted and at rest. These different 
conditions must be carefully noted before applying water to the compost. 
Plants which are well rooted, and making rapid and vigorous growth, may 
receive liberal supplies, while those newly potted, and those which have 
not yet commenced to grow, must have it applied with care. In every case 
it isa wise precaution to see that the plant is dry before applying water 
to the compost. Orchids generally speaking make more roots in a 
moderately dry compost than in one continually saturated with moisture. 
PoTTinG.—Many persons will this season still suffer from the shortage of 
material and labour, though not to the same extent as formerly. Owing to 
this trouble, it will be advisable to hold over plants that are in a sweet and 
healthy compost, repotting those in which the rooting material is found to 
be sour and decomposed. No plant can make satisfactory root growth ae 
decomposed material, hence the necessity of repotting when the material 
becomes in that condition. A sweet, healthy compost is of the first 
importance, and the best is easily spoilt by the misuse of the water pot. An 
Opportunity will occur when repotting to re-stage the different varieties, 
