IY. 



SPECIES AS TO VARIATION, GEOGRAPHICAL DISTRIBUTION, 



AND SUCCESSION. 

 (AMERICAN JOURNAL OF SCIENCE AND AETS, May, 1868.) 



fitsude BUT VEspece, a V Occasion cPune Revision de 

 la Famille des Cupuliferes,par M. ALPHONSE DE CAN- 

 DOLLE. This is the title of a paper by M. Alph. 

 De Candolle, growing out of his study of the oaks. It 

 was published in the November number of the B^b- 

 liotheque Universelle, and separately issued as a pam- 

 phlet. A less inspiring task could hardly be assigned 

 to a botanist than the systematic elaboration of the 

 genus Quercus and its allies. The vast materials as- 

 sembled under De Candolle's hands, while disheart- 

 ening for their bulk, offered small hope of novelty. 

 The subject was both extremely trite and extremely 

 difficult. Happily it occurred to De Candolle that an 

 interest might be imparted to an onerous undertaking, 

 and a work of necessity be turned to good account for 

 science, by studying the oaks in view of the question 

 of species. 



What this term species means, or should mean, in 

 natural history, what the limits of species, inter se or 

 chronologically, or in geographical distribution, their 

 modifications, actual or probable, their origin, and 



