viii PREFACE TO PART IY. 



In the definition of the Hickories, represented in this part, we have 

 incorporated the important characters detailed by Prof. N. L. Britton 

 (Bulletin of the Torrey Botanical Club, XV, pp. 277-289), as based upon 

 a study of the staminate flowers, etc. 



Hoping our patrons who have been requested to wait so long for the 

 text will look leniently upon the irregular manner in which Part IV has 

 been issued, we bespeak for it the same kindly reception with which 

 they have received its predecessors, as the encouraging words of many 

 have assured us. 



LOWVILLE, 1ST. Y., Nov. 19, 1894. 



