SPECIES AS TO VARIATION, ETC. 181 



occasionally, or when observed over a wider area ; and 

 the practical question is forced upon the investigator, 

 "What here is probably fixed and specific, and what is 

 variant, pertaining to individual, variety, or race ? 



In the examination of these rich materials, certain 

 characters were found to vary upon the same branch, 

 or upon the same tree, sometimes according to age or 

 development, sometimes irrespective of such relations 

 or of any assignable reasons. Such characters, of 

 course, are not specific, although many of them are 

 such as would have been expected to be constant in 

 the same species, and are such as generally enter into 

 specific definitions. Yariations of this sort, De Can- 

 dolle, with his usual painstaking, classifies and tabu- 

 lates, and even expresses numerically their frequency 

 in certain species. The results are brought well to 

 view in a systematic enumeration : 



1. Of characters which frequently vary upon the 

 same branch : over a dozen such are mentioned. 



2. Of those which sometimes vary upon the same 

 branch : a smaller number of these are mentioned. 



3. Those so rare that they might be called mon- 

 strosities. 



Then he enumerates characters, ten in number, 

 which he has never found to vary on the same branch, 

 and which, therefore, may better claim to be employed 

 as specific. But, as among them he includes the dura- 

 tion of the leaves, the size of the cupule, and tEe form 

 and size of its scales, which are by no means quite uni- 

 form in different trees of the same species, even these 

 characters must be taken with allowance. In fact, hav- 

 ing first brought together, as groups of the lowest 



