24a 



UNITED STATES. 



In following with attention and assiduity, the varia- 

 tions experienced by certain species, until they ar- 

 rive at maturity, I have found in the young indivi- 

 duals, the stamp and type of their species. It is 

 thus that I became acquainted with the connexions 

 existing between them. To find out thQir a?ialogy I 

 availed myself of the means which nature herself 

 seems to have furnished me with : but on the one 

 hand, if an observer who follows the order of nature,, 

 succeeds by the analogy of the species, tocla&s them,, 

 on the other hand he will find himself embarrassed 

 when it is wished to determine each species, and ta 

 give to it proper and diiFerential characters. 



I have tried to dispose the different species of 

 American oaks in a natural series. To succeed, I 

 thought at first, that the parts of fructification would 

 furnish me with proper marks to establish this series^ 

 but none furnished the means, and I perceived very 

 trifling distinctions, such as the situation of female 

 flov/ers sometimes almost sessile, sometimes pedun- 

 culated; the size of the fruits, their different time of 

 maturity, kc. Neither has it been possible for me 

 to establish a sufficient distinction from the form of 

 the cup, I have then fixed my observations on the 

 leaves ; they have offered more striking distinctions,, 

 of which I made use to establish two divisionsin the 

 genus. The first includes the species v/ith mutlque 

 leaves, that is to say, deprived of setaceous points ; 1 

 have classed in the secoiidj thobC with leaves of Vvhich 

 the summits or the notches are terminated by a 

 bristle. . ^ 



The interval of time between the appearauc^ of 

 the flower, and in.a.turity of the fruit, is not alike in 



