36 Elementary Species 



one character, often by slight differences in 

 nearly all their organs and qualities. Such 

 forms have come to be designated as " elemen- 

 tary species. " They are only varieties in a 

 broad and vague systematic significance of the 

 word, not in the sense accorded to this term in 

 horticultural usage, nor in a sharper and more 

 scientific conception. 



Genera and species are, at the present time, 

 for a large part artificial, or stated more cor- 

 rectly, conventional groups. Every systematist 

 is free to delimit them in a wider or in a nar- 

 rower sense, according to his judgment. The 

 greater authorities have as a rule preferred 

 larger genera, others of late have elevated in- 

 numerable subgenera to the rank of genera. 

 This would work no real harm, if unfortu- 

 nately, the names of the plants had not to be 

 changed each time, according to current ideas 

 concerning the genera. Quite the same incon- 

 stancy is observed with species. In the Hand- 

 book of the British Flora, Bentham and Hooker 

 describe the forms of brambles under 5 species, 

 while Babbington in his Manual of British 

 Botany makes 45 species out of the same ma- 

 terial. So also in other cases ; for instance, the 

 willows which have 13 species in one and 31 

 species in the other of these manuals, and the 

 hawkweeds for which the figures are 7 and 32 



