318 EVOLUTION [Chat. IV 



Letter 233 and map, you will almost understand the book. The two old 

 parent connecting links just keep alive in two or three areas ; 

 then we have four widely extended species, their descendants ; 

 and from them little groups of newer descendants inhabiting 

 rather small areas. . . . 



Letter 234 To Camillc Dareste. 



Down, Nov. 20th, 1SC9. 

 Dear Sir, 



I am glad that you are a candidate for the Chair of 

 Physiology in Paris. As you are aware from my published 

 works, I have always considered your investigations on the 

 production of monstrosities as full of interest. No subject is 

 at the present time more important, as far as my judgment 

 goes, than the ascertaining by experiment how far structure 

 can be modified by the direct action of changed conditions ; 

 and you have thrown much light on this subject. 



I observe that several naturalists in various parts of 

 Europe have lately maintained that it is now of the highest 

 interest for science to endeavour to lessen, as far as possible, 

 our profound ignorance on the cause of each individual 

 variation ; and, as Is. Geoffroy St. Hilaire long ago remarked, 

 monstrosities cannot be separated by any distinct line from 

 slighter variations. 



With my best wishes for your success in obtaining the 

 Professorship, and with sincere respect. 



I have the honour to remain, dear sir, 



Yours faithfully, 



Charles Darwin. 



