18671882] WALLACE'S BOOK 19 



where a varied fauna now exists, have been once more Letter 393 

 extensive e.g.. New Zealand, Madagascar : where there is 

 no such evidence (e.g., Galapagos), the fauna is very restricted. 

 Lastly, as to want of references : I confess the justice of 

 your criticism ; but I am dreadfully unsystematic. It is my 

 first large work involving much of the labour of others. I 

 began with the intention of writing a comparatively short 

 sketch, enlarged it, and added to it bit by bit ; remodelled 

 the tables, the headings, and almost everything else, more 

 than once, and got my materials in such confusion that it 

 is a wonder it has not turned out far more crooked and 

 confused than it is. I, no doubt, ought to have given 

 references ; but in many cases I found the information so 

 small and scattered, and so much had to be combined and 

 condensed from conflicting authorities, that I hardly knew 

 how to refer to them or where to leave off. Had I referred 

 to all authors consulted for every fact, I should have greatly 

 increased the bulk of the book, while a large portion of the 

 references would be valueless in a few years, owing to later 

 and better authorities. My experience of referring to re- 

 ferences has generally been most unsatisfactory. One finds, 

 nine times out of ten, the fact is stated, and nothing more ; 

 or a reference to some third work not at hand ! 



I wish I could get into the habit of giving chapter and 

 verse for every fact and extract ; but I am too lazy, and 

 generally in a hurry, having to consult books against time, 

 when in London for a day. 



However, I will try to do something to mend this matter, 

 should I have to prepare another edition. 



I return you Forel's letter. It does not advance the 

 question much ; neither do I think it likely that even 

 the complete observation he thinks necessary would be of 

 much use, because it may well be that the ova, or larvae, 

 or imagos of the beetles are not carried systematically by 

 the ants, but only occasionally, owing to some exceptional 

 circumstances. This might produce a great effect in distri- 

 bution, yet be so rare as never to come under observation. 



Several of your remarks in previous letters I shall 

 carefully consider. I know that, compared with the extent 

 of the subject, my book is in many parts crude and 

 ill-considered ; but I thought, and still think, it better to 



