Vi PREFACE. 



above named; especially, his First Zessons -in Botany, in which 

 the general principles of Botany and Vegetable Physiology are 

 fully explained. 



.1 acknowledge with gratitude the kindness of those friends, and 

 correspondents who have, in various ways, aided me in my labors. 



To the Rev. Moses A. Curtis, of North Carolina, to whom I 

 am pemiittcd to dedicate this volume, especial acknowledgments 

 are due, for valuable information derived from a long and instruc- 

 tive correspondence, for the generous contribution of new and rare 

 specimens, and for important assistance rendered me in every part 

 of ray work. 



To Professor Asa Gray, of HarvaVd University, I am under 

 peculiar obligations ; not only for the privilege of consulting his 

 valuable library, and his extensive herbarium, which contained 

 many plants previously unknown to me, but also for the benefit of 

 his advice in all mattei'S of doubt and difficulty, and for innumer- 

 able acts of kindness, bestowed in every way. 



To ]Mu. Daniel C. Eaton, of New Haven, who is making the 

 Ferns a subject of special study, I am greatly indebted for this 

 first and very careful elaboration of the Southern plants of that 

 interesting family. 



I embrace the opportunity to say to those who have aided me 

 hitherto, that, if they will continue to favor me with their discov- 

 eries, I indulge the hope of preparing a future edition of this work, 

 which shall be more worthy of their approbation. 



Al-ALACHKOLA, I'UJUIUA, Murcll 2G, ItJUO. 



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