M-r. 66.] TO A. DE CANDOLLE. 669 



plimentary to American ladies, and as you are such 

 an excellent judge, I must even give you the oppor- 

 tunity of extending your range of instances. 



But please do not give our young friends the op- 

 portunity of calling upon you, unless it quite suits 

 you. 



By the time this reaches you, Dr. -Hooker will be 

 on the way to us, we expect, and we are looking to 

 have a great run together over the Rocky Mountains, 

 and perhaps across the Continent. Wherever we may 

 be, you may believe me, 



Always yours cordially, ASA GRAY. 



TO A. DE CANDOLLE. 



CAMBRIDGE, June 4, 1877. 



MY DEAR DE CANDOLLE : . . . I meant to have a 

 good portion of my " Synoptical Flora of North Amer- 

 ica " to send you this summer ; but it will not be 

 quite ready at the time I expected, and I am now 

 likely not to have this summer for writing, but rather 

 for observation over a considerable range of country. 

 Dr. Hooker, it seems now almost certain, is coming 

 over in a month from now. Dr. Hayden has invited 

 him and me to join his expedition of exploration this 

 year, or rather to make a survey of much of his ground 

 in the Rocky Mountains ; and it is possible we may 

 even reach California. I am rather old for this work, 

 but judging from last year, I may well endure and 

 enjoy it. Would that you could join us ! 



We are in essential accord as to subgenus and its 

 nomenclature. Your letter to Cogniaux discusses and 

 decides as I had done for myself the questions 

 propounded. You will see I follow it out consistently 

 in my part of botany of California, while Watson was 



