42 riTTONIA. 



able witli age still seem to carry Avith tliem ;^ precepts wliich 

 both give support to, and are tliernselyes sustained by the 

 prevailing idea of the supremacy and finality of herbarium 

 determinations and decisions ; precepts which nevertheless 

 disi^lay in their construction quite as much of literary 

 ingenuity as of accord with well known facts. If the most 

 eminent botanists of the last two centuries have been some- 

 what equally divided in opinion as to whether Bergamot mint 

 and Peppermint — distinguishable from each other by odor 

 only — -are different species, or mere varieties of one, then it 

 must be confessed the question of tlie sufficiency of odor as 

 a distinguishing mark of species is still open to discussion, 

 and the time for receiving as axiomatic the Linna?an 

 aphorism is not yet come. Again, as regards flavor ; the 

 taste of Spearmint may or may not be quite the same to 

 every one ; yet it can hardly be that the flavors of Spearmint 

 and of Peppermint will by anyone be declared identical ; but 

 the perception of a difference is all we want. A definition 

 of either flavor would no doubt be impossible ; but no defini- 

 tion of either is necessary. The existence of a difference 

 is the essential fact.^ 



Organographical characteristics, especially of flower and 

 fruit, are fundamental— indeed, almost the only admitted 

 factors— in the general* classification of plants. Properties 

 are by common consent excluded from the regularly formu- 

 lated character, whether of an order or a genus ; but the 

 mention of them is usually made in a sort of note, or sepa- 

 rate paragraph at the end, as if they were of secondary im- 



^ Odor speciem Bunquam claredistmguit.— FniulamentaBolanica, No. 

 2G7. 



Sn^or pro ratione mauducantis siepe varii\l)ilis est, liiiic in differentia 

 excludatur.— Ibid. 268. 



2 It is even so in the case of morpbolo^^y, wliicli is definable. The 

 descriptive botanist calls one leaE-type or^irfe and another Untceolate. Tlio 

 terras are of couventional rather than absolnlely definitive force. But 

 they demonstrate a difference it may be between species ; and precisely 

 herein lies their essential visefuluess us terms. 



