644 TRAVEL IN EUROPE AND AMERICA. [1873, 



studied the svibject think that the increase of pop- 

 ulation in North America is not to go on at the rate 

 it has been going ; that the check is already apparent. 



A week or two ago appeared in the " Nation " an ar- 

 ticle (sent to you last week by post), in which I had 

 occasion to notice some other parts of your volume, 

 at considerable length. I have also been tempted to 

 give some account of your essay on Natural Selection 

 as applied to man ; but I find it would take me too 

 much out of my own line, and absorb time which I 

 cannot spare. Indeed, I have only looked over that 

 essay, and am not qualified to abstract, still less to 

 criticise it. The longest article of the volume, which 

 gives the title, I have not given as much attention to 

 as I ought, probably, or I should perhaps value it 

 more highly. But it seems to me that membership in 

 scientific academies — the three you take not ex- 

 cepted — is so largely affected by circumstance, irre- 

 spective of talent and of the value of work done, that 

 one cannot very confidently base general conclusions 

 upon the data. Yet I have no great confidence in my 

 opinion. Anyway, the article is full of interesting 

 matters. . . . 



What do you and Dr. Miiller say to Bornet's 

 memoir, on the nature of lichens? His exposition 

 is so clear that, if he is an honest and good investi- 

 gator, — as I cannot well doubt, — his conclusions 

 carry conviction. 



My sheet fills, and leaves now barely room for Mrs. 

 Gray's messages of kindest remembrances to yourself 

 and to Madame De CandoUe, in which I beg to join. 

 Long may you flourish, and much good work yet 

 do. For one thing, pray print the list of botanical 

 names ! Ever yours, A. Gkay. 



