SUBJECTS FOR HYBRIDISING 79 



on the seedling house, in addition to the lath roller blind, 

 running on supports carrying it well above the glass of the 

 roof, either a second lath roller blind running an inch or 

 so above the glass and beneath the upper one, or a per- 

 manent thin cotton shading, which may be tacked on in 

 spring and left until autumn ; or, preferably, so fitted that 

 it can be rolled up when it is not required. 



SELECTION OF SUBJECTS FOR HYBRIDISING 



The best varieties procurable should always be selected 

 for hybridising, it having been proved that crosses originally 

 made with indifferent varieties are much finer when raised 

 again from more carefully selected varieties. 



There seems to be no certain limit to the possibility of 

 crossing ; even the most dissimilar genera may be crossed 

 with some probability of getting a successful result. 



POTTING MATERIAL FOR HYBRID ORCHIDS 



From the time the little plants are well established in 

 single pots, the same potting material used for all of their 

 kind may be employed, the plants in the earlier stage having 

 the potting material in a finer condition than that provided 

 for the larger plants as they approach the flowering stage. 



As with other important operations, in Orchid potting 

 and in the material used the practice varies considerably, 

 even in the best collections, and this points to the fact that 

 if the accommodation is good, the houses properly heated, 

 and other details of culture carefully carried out, the exact 



