PREFACE. 



of the liberated " spits." This process, carried on for 

 years, destroyed nearly all letters received before 1862. 

 After that elate he was persuaded to keep the more 

 interesting letters, and these are preserved in an ac- 

 cessible form. 



I have attempted to give, in Chapter III., some ac 

 count of his manner of working. During the last 

 eight years of his life I acted as his assistant, and thus 

 had an opportunity of knowing something of his hab- 

 its and methods. 



I have received much help from my friends in the 

 course of my work. To some I am indebted for rem- 

 iniscences of my father, to others for information, crit- 

 icisms, and advice. To all these kind coadjutors I 

 gladly acknowledge my indebtedness. The names of 

 some occur in connection with their contributions, but 

 I do not name those to whom I am indebted for criti- 

 cisms or corrections, because I should wish to bear 

 alone the load of my short-comings, rather than to let 

 any of it fall on those who have done their best to 

 lighten it. 



It will be seen how largely I am indebted to Sir 

 Joseph Hooker for the means of illustrating my 

 father's life. The readers of these pages will, I think, 

 be grateful to Sir Joseph for the care with which he 

 has preserved his valuable collection of letters, and 1 

 should wish to add my acknowledgment of the gen- 

 erosity with which he has placed it at my disposal, 

 and for the kindly encouragement given throughout 

 my work. 



To Mr. Huxley I owe a debt of thanks, not only 

 for much kind help, but for his willing compliance 

 with my request that he should contribute a chapter 

 on the reception of the * Origin of Species.' 



Finally, it is a pleasure to acknowledge the cour- 



