Vi PREFACE. 



will not be thrown away upon me. It is almost impossible to 

 collect them unaided from the various Journals in which they 

 are published. 



I have given in the form of foot-notes, and also in some 

 instances, at the ends of the chapters, references to various works 

 relating to the subjects treated of. No attempt has, however, 

 been made to afford a complete bibliography; I have merely 

 noted down those works which I have happened to consult 

 myself, in the hopes that such references may be found of some 

 assistance. At the end of the book I have given a list of books 

 and papers published, relating to the " Challenger " Expedition. 

 This is no doubt far from perfect ; I have only made it as full 

 as my information allows. 



I should have wished to have been able to illustrate this 

 book more fully ; the reason I have not clone so is simply that 

 of expense. I have introduced amongst the figures, which are 

 otherwise new, about twelve which are printed from cliches, 

 and which may no doubt be familiar to some readers as occur- 

 ring in other works. I make no scruple to use them as illus- 

 trating the subject, and as being better than no figures at all 

 of the objects referred to. 



Since it was not considered expedient to attach a Botanist 

 to the " Challenger " Expedition, because the special work of 

 the ship lay in deep-sea exploration, I undertook the collection 

 of plants during the voyage. I received instructions at Kew 

 before starting. My best thanks are due to my friend Sir 

 Joseph Hooker for the constant encouragement in my work 

 which he conveyed to me by letter throughout the voyage, 

 and for the care and trouble bestowed on my collections. I 

 have to thank further my friend Prof. Oliver for the prompt- 

 ness with which he examined the collections and named them, 

 and made arrangements for the description and enumeration 

 by various authors of all the cryptogams as well as for kindly 



