,943—1882] SOCIAL PLANTS 425 



publicly on these heads, more especially in regard to a species Letter 325 

 remaining or ceasing to be social on the confines of its range. 



There is one other point on which I individually should 

 be extremely much obliged, if you could spare the time to 

 think a little bit and inform me : viz., whether there are any 

 cases of the same species being more variable in United 

 States than in other countries in which it is found, or in 

 different parts of the United States ? Wahlenberg says 

 generally that the same species in going south become more 

 variable than in extreme north. Even still more am I anxious 

 to know whether any of the genera, which have most of their 

 species horribly variable (as Rubus or Hieracium are) in 

 Europe, or other parts of the world, are less variable in the 

 United States ; or, the reverse case, whether you have any 

 odious genera with you which are less odious in other 

 countries? Any information on this head would be a real 

 kindness to me. 



I suppose your flora is too great ; but a simple list in close 

 columns in small type of all the species, genera, and families, 

 each consecutively numbered, has always struck me as most 

 useful ; and Hooker regrets that he did not give such list in 

 introduction to New Zealand and other Flora. I am sure I 

 have given you a larger dose of questions than you bargained 

 for, and I have kept my word and treated you just as I do 

 Hooker. Nevertheless, if anything occurs to me during the 

 next two months, I will write freely, believing that you will 

 forgive me and not think me very presumptuous. 



How well De Candolle shows the necessity of comparing 

 nearly equal areas for proportion of families ! 



I have re-read this letter, and it is really not worth 

 sending, except for my own sake. I see I forgot, in be- 

 ginning, to state that it appeared to me that the six heads 

 of your Essay included almost every point which could be 

 desired, and therefore that I had little to say. 



To }. D. Hooker. , ,, , 



■> Letter 326 



On July 5th, 1856, Darwin wrote to Sir J. D. Hooker: 



" I am going mad and am in despair over your confounded Antarctic 

 island flora. Will you read over the Tristan list, and see if my remarks 

 on it are at all accurate. I cannot make out why you consider the 

 vegetation so Fuegian." 



