18 



great abundance on the seashore on the north side of the island, 

 but collectors experience considerable difficulty in procuring the 

 plants, owing to the immense numbers of ants that these bulbs 

 always contain. I have no means of ascertaining at what period in 

 the life of this species the ants take possession. I do not think the 

 bulbs have any natural opening until they are mature or nearly so. 

 The ants are invariably found to accompany this plant, and a large 

 bulb on being split reveals a regularly constructed nest with galleries, 

 etc. Very many orchids are found to be infested with ants, but 

 usually it is only because an ant's nest is in close proximity to 

 the orchid. Several species of Oncidium, Coryanthes and Stan- 

 hopea, however, harbour ant colonies amongst their root masses. 

 Whether the ants in all these cases have anything to do with the 

 wellbeing of the plant other than indirectly protecting its roots has 

 not been recorded, but it is noteworthy that Diacrium bicornutum is 

 one of the most difficult of orchids to cultivate. It is, however, not 

 improbable that a uniformly high temperature, such as it enjoys at 

 sea level in Trinidad, combined with sea breezes, are indispensable 

 to success, let alone any physiological benefit the plant may acquire 

 from the presence of the ants. 



It has now been freely admitted that, speaking generally, all 

 those orchids that come from a very hot climate are difficult to grow 

 in this country. Doubtless it was with the early orchid growers that 

 the difficulty of orchid cultivation gained a reputation that has 

 taken a century or more of undoing. The reason was doubtless 

 this : that nearly all the original introductions of orchids were from 

 hot countries, quite a number coming from the West Indies. Such 

 were Epidendnim cochleatum, introduced in 1786, Neottia elata 

 and 2V. speciosa, introduced in 1 790, Epidendrumelongatum, introduced 

 in 1798, Vanilla planifolia, JVeottia picta, Epidendrum cuspidatum, 

 Ornithidium coccinewn, all introduced before 181 1. It is practically 

 impossible, in temperature alone, to give 7o-75°F. in this country, 

 such as these plants enjoy in their native habitat, in the w r inter when 

 our own temperature is anywhere between 20 and 40 F., and 

 occasionally lower still. 



Between the years 1820 and 1825 the importations of orchids for 

 commerce may be said to have begun in earnest, at least by this 

 country. The continental countries quickly followed, and to-day, 

 as everybody knows, a huge trade is done in imported orchids. 

 Many must have viewed with a certain feeling of sadness the regular sales 

 of such huge quantities of these interesting and beautiful plants from 

 their native countries. Fortunately, the supply seems to be equal to 

 the demand, and the reason is probably to be found in the prodigious 

 number of seeds a single seed-pod contains in the case of nearly all 

 orchids, though some genera produce more and others less ; and 

 it is fortunate that the orchids of commerce, such as Odontoglossum, 

 Oncidium, etc., produce the largest numbers of seeds. Darwin, in his 

 fascinating book, "The Fertilisation of Orchids" (p. 277), gives some 



