PREFACE. 



have ])e('ii doriyocl are diil}' noted in their respective places. 

 The determiuatiou of tlie con-ect iiomenchiture of very many 

 species has necessitated constant reference to the oriL-iiial 

 ty])es preserved in the National Herbaria. To tlie heads of 

 these departments an especial acknowledgment is dne, a,nd we 

 tender our warmest thanks to Mr. W. T. Thisclton Dyer, 

 Dn-ector of the Royal Gardens at Kew, and to Mr. J. G. 

 Baker, the Keeper of the Herbarium, and his assistants ; also 

 to Mr. W. Garruthers, ()f the Natural History Museum, South 

 Kensington, and to his staff, for their unremitting kindness 

 and assistance in enabling us to inspect the herbarium 

 specimans under their charge, by which many perplexing 

 questions of nomenclature have been definitely settled. We 

 also gla.dly acknowledge our indebtedness to Dr. ^Maxwell T. 

 Masters for his article on the Teratology of Orchids and for 

 his assistance in the preparatory notes on the minute anatomy 

 of the leaves. And we must gratefully recognise the un- 

 remitting care which our assistant Mr. A. H. Kent has 

 bestowed on the preparation of this work. 



JAMES VEITGH & SONS 



Royal Exotic Nursery, Chelsea. 



