64 AERIDES. 



climatic conditions are unsuitable for orchid life. On tlie map 

 illustrating the geographical distribution of Phaltenopsis we have also 

 inscribed the authenticated localities of the most important of the 

 cultivated Aerides, from which a better idea of the distribution of 

 the genus will be derived than can be conveyed by verbal description. 

 From an inspection of the map it will be seen that closely-allied 

 forms occur in localities remote from each other, a circumstance 

 that tends far to show that such forms are but geographical 

 deviations from a common type, and may in some measure account 

 for the diflficulty attending the botanical limitation of the species. 



CuJfura/ Nutc. — The Aerides should be cultivated in what is 

 usually called the " East Indian house," where they may be associated 

 with other orchids from the Indo-Malayan region. Although the mean 

 temperature of that region is one of the highest observed in the world, 

 it is found by experiment that most orchids brought thence to the 

 high latitude of Great Britain thrive better in the glass-houses of this 

 country in an average lower temperature than in a temperature raised 

 by artificial heat to nearly the same mean as that of their native 

 home. Thus, while the mean temperature for the whole year of parts 

 of India and Malaysia, in which Aerides abound, is as high as 27° C. 

 (80° F.), the temperature suited for them in the glass-houses of Great 

 Britain should not be higher than 21° — 24" C. (70° — 75° F.) from 

 March to October, the period during which the plants are in active 

 growth, raised by sun-heat on bright days 6° C. (10° F.) higher, and 

 reduced 3° C. (5° F.) by night, that is to say, to 18°— 21° C. 

 (G5° — 70° F.). In the winter months a night temperature of 15° 

 — 18° C. (60° — 65° F.), raised a little higher in the daytime is 

 sufficient. It is well known among cultivators that a high tempera- 

 ture maintained by fire-heat debilitates, while sun-heat strengthens the 

 plants, hence a light shading only is necessary during the middle of 

 the day in the summer months, while from October to March no 

 shading is required. The ventilation must be regulated according 

 to the season ; the rule is — admit as much fresh air into the 

 house as possible, and as often as it can be done without draughts 

 and too rapid a lowering of the temperature of the house. A high 

 degree of humidity must be maintained during the growing season by 

 damping down and by the direct application of water to the plants ; 

 in winter the watering must be restricted to just so much as is 

 sufficient to keep the sphagnum moist and to counteract the drying 

 effects of the hot-water pipes. Pots arc usually preferred, although teak 

 baskets are used by some cultivators, especially when it is desired to 

 grow the plants into large specimens ; in either case they should be 

 filled with clean, broken crocks to three-fourths of their depth, the 



