90 III. INTRODUCED SPECIES. 



other such artificial situations, the more probable he 

 deems their nativity to be. No doubt there is good dis- 

 crimination in hitting u]3on this test, provided it be not 

 carried too far, but be kept strictly within the bounds 

 ■which the actual practices of botanical wi-iters may war- 

 rant. It may be said that such indications ought to be 

 good evidence ; and in some future age they may possibly 

 become so. But their present value, as tests of nativity, 

 will vary greatly with different Authors ; and they can 

 perhaps very rarely be relied upon with much confidence. 

 As a prevailing custom, Authors of Floras do not seem to 

 be very particular about stating all the situations in 

 which species occur ; rather indicating those in which 

 they have been observed most frequently or most conspi- 

 cuously ; and occasionally it is only the one situation 

 indicated on the label of a dried specimen. 



A notice of the kind of places or situations in which 

 species usually occur, was evidently deemed important to 

 geographical botany in the former volumes of the Cybele 

 Britannica. This is shown by the endeavour to form a 

 series of single terms for expressing those situations. 

 But their diversity in the case of many species, and the 

 consequent difficulty of comprehending all of them under 

 one or two of those terms, were alluded to in the para- 

 graph immediately following the series of terms proposed 

 (volume 1, page 66). In treating the individual species, 

 there was little endeavour to be exhaustive, by repeating 

 all the terms which might occasionally be applicable to a 

 plant. The object sought was rather that of indicating 

 the usual situations of the species ; the abbreviation 

 "&c." being sometimes added, in order to remind 

 readers that the term or terms applied were not to 

 be regarded as exhaustive. Now, it may be asked, if a 

 writer on geographical botany thus almost imavoidably 



