Cb. X.] 1843—1858. 183 



distinct ; but I have sometimes doubted of the wisdom of this, 

 and therefore I am glad to be backed by your opinion. I 

 must confess, however, I rather doubt the truth of the now 

 very prevaleut doctrino of all our domestic animals having 

 descended from several wild stocks ; though I do not doubt 

 that it is so in some caSes. I think there is rather better 

 evidence on the sterility of hybrid animals than you seem to 

 admit : and in regard to plants the collection of carefully 

 recorded facts by Kolreutor and Gaertner (and Herbert) is 

 enormous. I most entirely agree with you on the little effects 

 of "climatal conditions," which one sees referred to ad nauseam 

 in all books : I suppose some very little effect must be attri- 

 buted to such influences, but I fully believe that they are very 

 slight. It is really impossible to explain my views (in the 

 sompass of a letter), on the causes and means of variation in a 

 state of nature ; but I have slowly adopted a distinct and 

 tangible idea, — whether true or false others must judge ; for 

 the firmest conviction of the truth of a doctrine by its author, 

 seems, alas, not to bo the slightest guarantee of truth ! . . . 



In December 1857 he wrote to the same correspondent : — 



" You ask whether I shall discuss ' man.' I think I shall 

 avoid the whole subject, as so surrounded with prejudices; 

 though I fully admit that it is the highest and most interesting 

 problem for the naturalist. My work, on which I have now 

 been at work more or less for twenty years, will not fix or 

 settle anything ; but I hope it will aid by giving a large col- 

 lection of facts, with one definite end. I get on very slowly, 

 partly from ill-health, partly from being a very slow worker. 

 I have got about half written ; but I do not suppose I shall 

 publish under a couple of years. I have now been three whole 

 months on one chapter on Hybridism ! 



" I am astonished to see that you expect to remain out three 

 or four years more. What a wonderful deal you will have 

 seen, and what interesting areas — the grand Malay Archipelago 

 and the richest parts of South America ! I infinitely admire 

 and honour your zeal and courage in the good cause of Natural 

 Science ; and you have my very sincere and cordial good 

 wishes for success of all kinds, and may all your theories 

 succeed, except that on Oceanic Islands, on which subject I 

 will do battle to the death." 



And to Fox in February 1858 ;— 



" I am working very hard at my book, perhaps too hard. 

 It will be very big, and I am become most deeply interested 

 in the way facts fall into groups. I am like Croesus over- 

 whelmed with my riches in facts, and I mean to make my book 



