Alfred Russel Wallace 



as to Distribution of Land Mollusca' are at Vol. II., pp. 

 522-529. When you have read these passages and looked at 

 the general facts which lead to them, I shall be glad to hear 

 if you still differ from me. 



Though, of course, present results as to origin and 

 migrations of genera of mammals will have to be modified 

 owing to new discoveries, I cannot help thinking that 

 much will remain unaffected, because in all geographical 

 and geological discoveries the great outlines are soon 

 reached; the details alone remain to be modified. I also 

 think much of the geological evidence is now so accordant 

 with, and explanatory of, geographical distribution that it i. 

 is prima facie correct in outline. Nevertheless, such vast 

 masses of new facts will come out in the next few years 

 that I quite dread the labour of incorporating them in a 

 new edition. 



Now for a little personal matter. For two years I 

 have made up my mind to leave this place — mainly for two 

 reasons : drought and wind prevent the satisfactory growth 

 of all delicate plants; and I cannot stand being unable to 

 attend evening meetings and being obliged to refuse every 

 invitation in London. But I was obliged to stay till I 

 had got it into decent order to attract a customer. At 

 last it is so, and I am offering it for sale, and as soon 

 as it is disposed of I intend to try the neighbourhood of 

 Dorking, whence there are late trains from Cannon Street 

 and Charing Cross. 



I see your post-mark was Dorking, so I suppose you 

 have been staying there. Is it not a lovely country ? I 

 hope your health is improved, and when, quite at your 



^ Wallace points out that ** hardly a small Island on the globe but has some 

 land shell peculiar to it," and he goes so far as to say that probably air-breathing 

 moUusca have been chiefly distributed by air- or water-carriage, rather than 

 by voluntary dispersal on the land. See " More Letters/' ii. 14. 



288 



