XX INTRODUCTORY. 



unnecessary, but presumptuous, in view of the long labor they and Professor 

 Gray had bestowed upon the task. 



During the same interval, American botanists have received from the 

 pen of Professor Gray the first part of vol. 2, Synoptical Flora of North 

 America. It is not possible to overestimate the importance of this to the 

 science of our country. His work, when finished, must be forever the great 

 landmark in American Botany. 



Of hardly less importance, or labor, is Mr. "Watson's Bibliographical 

 Index to North American Botany, of which Part First, extending through 

 the Polypetalse, has been published during the year. The thorough man- 

 ner in which it has treated, and will continue to treat, the synonymy of the 

 subject, renders any extended citations out of place here. It is hoped that 

 the most important changes in nomenclature indicated in these works will 

 be found observed in this Report. 



Mr. H. W. Henshaw has aided at the Washington office in his careful 

 attention while this Report was passing through the several stages of proof. 



J. T. R. 



