OECHID CONFEEENCE. 



437 



ference are due to Mr. Alexander for the very useful and interesting 

 paper which he has placed before us. 



Mr. J. Fraser said he was pleased to hear that Mr. Alexander 

 emphasized the importance of light and air to Orchids. Growing as 

 they do in more or less elevated positions on trees and other objects, 

 they were able to obtain a greater amount of light and air than they 

 could get, as a rule, in glass-houses in this country. It did not follow 

 that they were always exposed to intense sunshine, as that would vary 

 according to their elevation on trees, and whether they were fully 

 exposed or otherwise. Epiphytic Orchids were dependent on the 

 atmosphere for the carbon of their tissues, which they absorbed in 

 the form of carbon dioxide, present in small quantity in the air. They 

 depended also on the air for their nitrogen to some extent, for he 

 thought this might be absorbed by the roots when brought in contact 

 with them by moist air. This nitrogen was in the form of ammonia, 

 in exceedingly small quantity in the air. He had never heard of very 

 important results from the use of manures for Orchids. He also 

 stated that he once saw a fine batch of Phalaenopsis, with panicles 

 of flowers three feet long, and being in very small baskets the grower 

 put the latter into larger ones and packed them round with Sphagnum. 

 The plants never flowered again, but- gradually died. This he con- 

 sidered was due to the exclusion of a proper amount of air from the 

 roots. 



Mr. DE Barri Craw shay said it would be very interesting to know 

 when Mr. Alexander took charge of the splendid examples of Vanda 

 coerulea exhibited in the Hall downstairs. Most of those who 

 attempted to grow this plant had failed to do anything like Mr. 

 Alexander had done with it. Another point that struck him during 

 the reading of the paper was the remark that conditions were different 

 in almost every house in which Orchids were grown. He thought 

 this important point was not infrequently lost sight of by those who 

 sought explicit directions as to the times and frequency of watering, the 

 necessary temperatures, and so on. 



Mr. Alexander said the first plant came under his charge thirteen 

 years ago and was afterwards shown in the Hall downstairs, but 

 suffered subsequently from chill. Those now exhibited had come 

 under his care for the most part between five and ten years ago. 



Sir H. J. Veitch asked Mr. Alexander v/hat other Orchids he 

 grew with the Vanda coerulea, 



Mr. Alexander said that, speaking generally, the plants had a 

 house to themselves. 



Sir H. J. Veitch remarked that he thought that explained a good 

 deal in the success of their culture, as Mr. Thos. Lobb, the first plant 

 collector sent to the East by his firm, and certainly one of the most 

 successful that had ever left England, said he always found the best 

 plants of this Vanda growing on single trees in the open cultivated 

 fields, the plants there being very superior to any found growing in 

 plantations, thus showing that the more air and light they had the 



