INTRODUCTORY ESSAY. 43 



do wed with great powers of migration, and that they have been 



aided in their dispersion primarily by those changes of climate, 

 land, and sea, which accompany, or are effected by what are 

 called geological changes, and secondarily by the elements and 

 the animal creation. Under these convictions, we feel it im- 



erounds 



mlk of forms 



with 



careful studv of the structural 



morphological characters of each. We shall, as a rule, banish 

 from our minds the idea that a species is probably new be- 

 cause hitherto unknown to ourselves or to the Flora of India ; 

 we shall, upon principle, keep two or more doubtful species 

 as one, carefully and prominently indicating their differences, 

 and, when expedient, ranking them as varieties ; in preference 

 to keeping doubtful species separate till they shall be proved 

 the same ; having ample proof that in so doing we shall avoid 

 the greater evil. We shall not think it desirable to adopt the 

 opinions of others in preference to our own* on points where 

 we have had the best materials to judge from. With regard 

 to nomenclature, we shall not alter names established 

 Linnaeus, and usuallv retained bv subsequent botanical au- 



names 



botany was systematized. W 



bility 



familiar names, though of doubtful 



do so. We 



namef of a plant, even when the genus requires 

 ercd. and shall alwavs srive ^reference to priority o 



> This may to some non-botanical readers sound dogmatical, if not prcsump 

 iub ; but the fact is, that a system is deeply rooted and widely spread, of keeping 

 known bad species in so-called deference to authorities ; in nine cases out o 

 . this is done to save the trouble of a re-examination, and in too many, simpl] 



to swell catalogues. The same authorities 

 unite what hair- splitters wish to k< p separate. 



are held 



Wit 



With 



regard to Willow- 



•T- 



