ORCHID CONFERENCE. 



433 



although good general plantsmen, profess to know little or nothing 

 about Orchids. Hence has arisen that off-hand assertion " all 

 Orchids are easy of cultivation." 



Another great requisite in the cultivation of epiphytic Orchids is a 

 full and free ventilation, not only during the day time, but also by 

 night, whenever it can be managed without creating a draught. With 

 Orchids in their natural conditions of growth, air is ever present in 

 quantity, for these plants not only grow on high rocks and branches 

 of trees, but in many instances on trees which are isolated and exposed 

 to a constant current of air. Vanda coerulea may be mentioned as an 

 example of the latter conditions. 



Therefore, under cultivation, these Orchids, whose natural position 

 is in the open, must have plenty of air; in fact, it is absolutely neces- 

 sary, for, if there be any shortage in the supply of this very important 

 element the plants cannot possibly acquire solidity in their various 

 parts, a condition so essential to healthy existence. Judicious use, 

 therefore, of the ventilators of the house is always important at all 

 seasons of the year. Growth made out of season is often attributable 

 to insufficient air on past occasions. 



To give an abundance of air when the sun shines, and to admit 

 it only by a chink on dull days and by night, are, to my mind, equally 

 absurd. This close-shutting system, especially at night with a view 

 to keeping up a desired temperature, produces on these Orchids an 

 amount of mischief difficult to calculate. I never could see the reason 

 why ventilation, if so beneficial during the day time, should not be 

 equally so during the night. Fresh air all night, with reasonable 

 temperature, must be more conducive to health and vigour than 

 anything approaching a stuffy atmosphere. This cooler and more airy 

 treatment at night is, I believe, more practised in present-day cultivation 

 than hitherto, but I am still of the opinion that it is not yet sufficiently 

 appreciated. Whenever the outside temperature is not below 40° F., 

 and the low level ventilators are left open at night, the fresh, moist 

 air is constantly streaming in, and not nearly the amount of damping 

 down is needed to keep the air soft and genial. • 



Eespecting the maintenance of suitable night and day temperatures, 

 there is little doubt that these, speaking generally, are often kept too 

 high. All Orchids require more or less heat, but many would be far 

 better under cooler atmospheric conditions than are at present allowed. 

 So sensitive are these plants to atmospheric influence that, no matter 

 how well they are treated in other ways, they cannot long continue in 

 a satisfactory condition unless a proper atmosphere is maintained 

 about them. Perhaps it would not be correct to say that " that which 

 is pleasant to the senses is right for these plants," but, at the same 

 time, one can usually tell, on entering a house, whether the air has 

 that soft, light and pleasant feeling so essential to their well-being. 



I never advise sticking close to a stated temperature, especially 

 when the outside climatic conditions are unfavourable, having always 

 found much better results accrue from working in accordance with 



VOL. XXXVIII. F p 



