424 CORRESPONDENCE. [1856, 



me, we will look after you like dutiful children, will 

 go with you to Niagara, or to Lake Superior, if you 

 will go so far, for there is nothing would give us so 

 much pleasure as a visit from you ; and if you would 

 bring Lady Hooker or Mrs. Evans, or both, with you, 

 it would be charming. The voyage is nothing to speak 

 of, traveling here is easy and rapid, although not so 

 very comfortable, as in England, and a good deal of 

 the country can be seen in a few weeks without much 

 fatigue. Pray do come, and exceedingly gratify, 

 Your affectionate and faithful A. GRAY. 



TO JAMES D. DANA. 



December 13, 1856. 



MY DEAR DANA, I duly received the sheets I 

 asked for. 



The right way to bring a series of pretty interest- 

 ing general questions towards settlement is perhaps in 

 hand (though I do not expect myself to bring any- 

 thing important to bear on it), viz., for a number of 

 totally independent naturalists, of widely different 

 pursuits and antecedents, to environ it on all sides, 

 work towards a common centre, but each to work 

 perfectly independently. Such men as Darwin, Dr. 

 Hooker, De Candolle, Agassiz, and myself, most of 

 them with no theory they are bound to support, 

 ought only to bring out some good results. And the 

 less each one is influenced by the other's mode of 

 viewing things the better. For my part, in respect 

 to the bearings of the distribution of plants, etc., I 

 am determined to know no theory, but to see what the 

 facts tend to show, when fairly treated. 



On the subject of species, their nature, distribu- 

 tion, what system in natural history is, etc., certain 



