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 ea^ch time, according to current ideas 

 concerning genera. Quite the same inconstancy 

 is observed with species. In the Handbook 

 of the British Flora, Bentham and Hooker de- 

 scribe the forms of brambles under 5 species, 

 while Babington in his Manual of British 

 Botany makes 45 species out of the same mate- 

 rial. 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 



