558 



THE GARDENER'S ASSISTANT. 



cultivated under the same conditions. They 

 come from the higher and cooler parts of the 

 countries they inhabit; the Mexican. Lselias (L. 

 anceps, &c.) from 6000 feet to 8500 feet 

 elevation, with an average mean temperature 

 of 50° to 70°; the Colombian Cattleyci Triance, 

 C. Mendelii, &c, from 2000 feet to 5000 feet 

 altitude, where they get full sun and a high 

 temperature by day, falling to about 50° at 

 night. This occurrence of a night temperature 

 much lower than that of the day is general, and 

 in the treatment of Orchids under cultivation 



it should also be followed. The altitude at 

 which a plant occurs in a wild state, especially 

 those which inhabit tropical regions, is im- 

 portant to the cultivator, a knowledge of it 

 often making all the difference between success 

 and failure. As a case in point may be men- 

 tioned the little scarlet-flow T ered Lcelia mono- 

 phylla, which, known only as a native of 

 Jamaica, was kept in a hothouse, where it 

 invariably failed; but on its being ascertained 

 that it was found wild only in the mountains 

 at an altitude of 5000 feet, where Filmy Ferns 



Fig. 682.— Intermediate Orchid House. 



were its companions, it was grown in a cool 

 house with success. 



The distribution of the large and variable 

 genus Dendrobium may be taken as another 

 example. It is found in most countries in 

 tropical Asia, including India, the Malay Archi- 

 pelago, the islands of the Western Pacific, and 

 also in Australia, a few also being natives of 

 Japan and New Zealand. The name Den- 

 drobium conveys nothing as to the cultural 

 requirements of the plants, but a knowledge of 

 the conditions and temperature under which each 

 species occurs affords a safe guide to its culti- 

 vation. By separating them into three or four 

 groups, according to the temperature and rest 

 they require, no difficulty is found in the culti- 

 vation of the majority of the species. 



Houses for Orchids. — Although it is not neces- 

 sary to build houses specially for Orchids, where 

 gardening under glass to any extent is carried 

 on, where it is intended to grow a large collection, 

 or a considerable quantity sufficient to fill one 

 or more houses, it is better to devote houses 



exclusively to them, either by converting already 

 existing structures or by building new ones. 

 If old, the house should be thoroughly cleaned, 

 and the arrangements for ventilation, staging, 

 and other details be in accordance with the 

 directions here given. 



Span -roofed houses facing east and west 

 have preference, as they allow of the greatest 

 amount of light reaching the plants; but if any 

 other aspect is more suitable or convenient, that 

 matter need not stand in the way. If it is 

 intended to build a house of one compartment, 

 it is better to arrange and heat it as an inter- 

 mediate house (fig. 682); but if the collection 

 to be grown is likely to be extensive and of a 

 general character, it will be better at once to 

 provide three houses or divisions, so that the 

 three temperatures necessary may be available. 

 For this purpose a span-roofed range, from 60 

 to 100 feet in length, with two glass partitions 

 dividing it into three compartments, will be 

 found to answer. The width may be from 10 

 to 1 8 feet, and the height to the top of the span 



