TREATMENT DUEING GEOWTH. 11 



moisture, but these should also have a considerable degree of 

 warmth during their growing season. 



Of late years we have had so many additions to what are 

 called Cool-house Orchids, that it is quite necessary there 

 should be added another house specially for their cultivation, 

 and which we may call the New Grenada and Peruvian house ; 

 this wiU accommodate a great number of plants from various 

 high mountain districts, which may be grown together under 

 the same treatment. I do not recommend ordinary greenhouses 

 for Orchids, for my belief is, that very few Orchid growers will 

 uphold that treatment long ; for although we are told by col- 

 lectors that many of the species of epiphytal Orchids are 

 found in localities where the temperature falls so low at 

 times that the plants are frequently covered with a white 

 frost, I do not think it expedient to subject them to such 

 cool treatment in this country. The house I recommend for 

 the Odontoglossutns and other genera and species that come 

 from similar regions, and, consequently, require the same 

 treatment, is precisely the same as the others, only it must be 

 kept at a lower temperature, say from 45° to 55° in winter, 

 and from 50° to 65° in summer. This house should be well 

 shaded from the sun, which will help to keep the heat down, 

 as too much heat is dangerous for the cool Orchids. No fire 

 heat will be required in summer except on cold or wet days 

 and nights, the object of then having recourse to artificial 

 heat, being to keep the house fi-om getting too damp, damp- 

 ness without warmth being very detrimental to plants of this 

 order. 



There are but few Orchids that will do without heat, except 

 those that come from North America and other cold climates, 

 and these are treated on in a chapter by themselves in another 

 part of this book. 



