A GOOD many years ago Sir E. C. Buck, K.C.S.I., then Secretary 

 to the Government of India in the Department of Revenue and 

 Agriculture, requested me to prepare an account of the cotton plants 

 of the world with a view to assisting the Indian planters. I devoted 

 some time and attention to the subject, during a recess from India, 

 spent at Kew Gardens, and even had some of the illustrations 

 prepared which are now published. The pressure of official duties 

 that devolved upon me on my return to India retarded very greatly 

 the completion of my studies, and perhaps fortunately so, since I 

 was enabled to mature my conceptions of the species and varieties 

 of Gossypium and to verify and amplify my original notes. The 

 present publication thus incorporates the field studies of perhaps 

 twenty years, linked up with the results of a careful re-examination 

 of the collections preserved in some of the chief herbaria of the 

 world. 



I have to acknowledge a deep debt of gratitude to the former and 

 the present Director of the Boyal Gardens, Kew (Sir William 

 Thiselton-Dyer, K.C.M.G., and now Colonel D. Prain, C.I.E.), for 

 much personal kindness and valued encouragement. To the Keepers 

 of the Kew Gardens and the British Museum Herbaria (Mr. 

 William Botting Hemsley and Dr. Alfred Barton Eendle) I am 

 specially indebted for not only giving me every facility to examine 

 but (where I desired) permission to photograph the rich treasures 

 under their charge. To the Council of the Linnean Society of 

 London I have to record my acknowledgments for the ready permission 

 granted me to photograph the Linnean types, and to the Keeper of 

 the British Museum for the corresponding liberty to photograph the 

 types in the Sloane Herbarium and to reproduce Ehret's most inter- 

 esting and beautiful unpublished sketch of a cotton, which I give as 

 the frontispiece of this work. 



