i867— 1882] WALLACE'S HOOK 1 7 



you are right, I erred greatly in my Journal^ where I insisted Letter 392 

 on the former close connection between the two. 



P. 252 and elsewhere. — I agree thoroughly with the general 

 principle that a great area with many competing forms is 

 necessary for much and high development ; but do you not 

 extend this principle too far — I should say much too far, 

 considering how often several species of the same genus have 

 been developed on very small islands? 



P. 265.— You say that the Sittidae extend to Madagascar, 

 but there is no number in the tabular heading. [The number 

 (4) was erroneously omitted. — A. R. \V.] 



p. 359. — Rhinochetus is entered in the tabular heading 

 under No. 3 of the neotropical subregions. [An error: should 

 have been the Australian. — A. R. \\ '.] 



Reviewers think it necessary to find some fault ; and if I 

 were to review you, the sole point which I should blame is 

 your not giving very numerous references. These would 

 save whoever follows you great labour. Occasionally I 

 wished myself to know the authority for certain statements, 

 and whether you or somebody else had originated certain 

 subordinate views. Take the case of a man who had collected 

 largely on some island, for instance St. Helena, and who 

 wished to work out the geographical relations of his collec- 

 tions : he would, I think, feel very blank at not finding in 

 your work precise references to all that had been written on 

 St. Helena. I hope you will not think me a confoundedly 

 disagreeable fellow. 



1 may mention a capital essay which I received a feu- 

 months ago from Axel Blytt x on the distribution of the 

 plants of Scandinavia ; showing the high probability of 

 there having been secular periods alternately wet and dry. 

 and of the important part which they have played in dis- 

 tribution. 



I wrote to Forel, 2 who is always at work on ants, and told 

 him your views about the dispersal of the blind coleoptcra, 

 and asked him to observe. 



I spoke to Hooker about your book, and feel sure that he 

 would like nothing bitter than to consider the distribution of 



1 Axel Blytt, Essay on the Immigration of th N 

 Christiania, 1876. See Letter 387. 

 s See Letter 388. 

 VOL. II. 2 



