Sept.-Oct., 1920.| THE ORCHID REVIEW. 131 
(nom. vern. Laurel, avery useful timber, immune from the attacks of termites). 
Above that it favours Ulmus mexicana, and I was told by a peon that he , 
found a large plant on a “ Pizco,” Calyptranthes sp. 
Some of the Pleurothallidez, especially Lepanthes and many Masdev- 
allias, prefer somewhat sheltered situations to those fully exposed to rain 
and wind, and are found on the undersides of branches or in the folds of 
buttresses of trees where direct rain can rarely or never reach them. The 
latter genus, as a rule, grows in the lightest root-covering moss; the other 
may be buried in mosses or Hepatics half-way up its beautifully bracteate 
stem. Of this genus I made.an extensive collection, embracing some very 
attractive forms, and tried to bring them alive to Kew. Unfortunately our 
voyage was prolonged beyond reasonable expectation, and only the hardier 
or pseudobulbous genera survived the extreme conditions experienced. 
Among regretted losses was a strong little plant of Telipogon (Biolleyi ?), 
one of the gems of the upper middle zone. The whole centre of the large 
flower is an intense velvety maroon, bordered by palest green. These are 
difficult subjects to cultivate ; like Comparettias, they grow on slender and 
decaying twigs and refuse the enticements of pots or baskets. 
Coastal or lower zone Orchids are almost invariably inhabited by ant 
colonies, the Orchid providing by its matted roots an easy nest, and the 
ants by the simple fact of habitation furnish abundant nourishment. This 
is at least the case with the Pseudomyrmes, though some antsare, of course, 
destructiveto Orchids. Another group of ants (Camponotus 7), make use 
of Orchid roots to raise Coccid larve on, and then, of course, in due time 
the plant succumbs. Sometimesa very chain of symbotic association takes 
place. In the Turialba region, there is a tall-growing Epidendron (Barkeria 
sp. ?) whose roots invariably contain an immense ant’s nest, which has 
always in close vicinity a wasp’s nest, and that again a bird’s nest, some 
member of the Tyrannidz, usually Tyrannus melancholicus, T.satrapa, or 
occasionally Rhynchocyclus cineriventris. This, on the Atlantic side, is the 
parallel to the well-known case of the Bull’s-horn thorn Acacia, Pseud- 
‘omyrmi and the Tyrannus on the Pacific coast, where it is a much more . 
common object, and intrudes itself on every traveller. One soon learns not 
to brush against a “‘ Corinzuelo,” as the Acacia is termed. 
Coryanthes has not been recorded from Costa Rica before. Very 
fortunately one found in the Estrella Valley has travelled across success- 
fully, and is thriving well at Kew. It will probably prove to be a southern 
species; endemic forms are not likely to be found in either coastal zone. 
This is another great ant carrier, but I donot think it a necessary symbiosis 
as seems to be the case with Diacrium. 
Costa Rica will undoubtedly provide many dozen new species of Orchids, 
as more intensive exploration is undertaken, mostly, of course, small, mainly 
