PREFACE. 



In 1901 and 1902 Miss Janet Russell Perkins, Ph. D., under an 

 appointment as scientific aid in the United States Department of 

 Agriculture, was engaged at Berlin in a revision of the Leguminosae 

 of Porto Rico. The revision was based upon a study of collections 

 and literature, unaccompanied by field work in the island. It was 

 originally intended to publish the results of this work conjointly with 

 an account of the agricultural relations of the leguminous plants of 

 that island, but as it proved to be necessary to postpone the prepa- 

 ration of this latter paper for more detailed investigation Miss Per- 

 kins's paper is now presented separately for publication. 



This paper differs in several respects from the systematic treatment 

 of leguminous plants presented in other numbers of these Contribu- 

 tions, and such differences must be taken only as an expression of the 

 views of the author. 



Frederick V. Coville, 

 Curator of the United States National Herbarium. 



in 



