1 866.] PANGENESIS. 43 



There seems to have been a gradual amendment in his 

 health ; thus he wrote to Mr. Wallace (January 1866) : " My 

 health is so far improved that I am able to work one or two 

 hours a day." 



With respect to the 4th edition he wrote to Sir J. D. 

 Hooker : 



" The new edition of the ' Origin ' has caused me two 

 great vexations. I forgot Bates's paper on variation,* but I 

 remembered in time his mimetic work, and now, strange to 

 say, I find I have forgotten your Arctic paper ! I know how 

 it arose ; I indexed for my bigger work, and never expected 

 that a new edition of the ' Origin ' would be wanted. 



"I cannot say how all this has vexed me. Everything 

 which I have read during the last four years I find is quite 

 washy in my mind." As far as I know, Mr. Bates's paper 

 was not mentioned in the later editions of the ' Origin,' 

 for what reason I cannot say. 



In connection with his work on 'The Variation of 

 Animals and Plants,' I give here extracts from three letters 

 addressed to Mr. Huxley, which are of interest as giving 

 some idea of the development of the theory of ' Pangenesis,' 

 ultimately published in 1868 in the book in question :] 



C. Darwin to T. H, Huxley. 



Down, May 27, [1865 ?] 



... I write now to ask a favour of you, a very great favour 

 from one so hard worked as you are. It is to read thirty 

 pages of MS., excellently copied out, and give me, not length- 

 ened criticism, but your opinion whether I may venture to 

 publish it. You may keep the MS. for a month or two. 

 I would not ask this favour, but I really know no one else 

 whose judgment on the subject would be final with me. 



* This appears to refer to " Notes I Trans. Entomolog. Soc., vol. v. 

 on South American Butterflies," j (N.S.). 



