i862.] MIMICRY. . .- 185 



a little more on the pairing of similar varieties ; a rather 

 more numerous body of facts seems here wanted. Then, 

 again, what a host of curious miscellaneous observations there 

 are — as on related sexual and individual variability : these 

 will some day, if I live, be a treasure to me. 



With respect to mimetic resemblance being so common 

 with insects, do you not think it may be connected with their 

 small size ; they cannot defend themselves ; they cannot es- 

 cape by flight, at least, from birds, therefore they escape by 

 trickery and deception .'' 



I have one serious criticism to make, and that is about 

 the title of the paper ; I cannot but think that you ought to 

 have called prominent attention in it to the mimetic resem- 

 blances. Your paper is too good to be largely appreciated 

 by the mob of naturalists without souls ; but, rely on it, that 

 it will have lasting value, and I cordially congratulate you on 

 your first great work. You will find, I should think, that 

 Wallace will fully appreciate it. How gets on your book ? 

 Keep your spirits up. A book is no light labour. I have 

 been better lately, and working hard, but my health is very 

 indifferent. How is your health ? Believe me, dear Bates, 



Yours very sincerely, 



C. Darwin. 



