*208 



PITTONIA. 



technical skill is needed to enable any one to distinrruish 



them. He 



^^ „ .^ ^..v^x, ^v^j.v.ou^j., ixvjvvcvcx iiiiitiifciiCj w au 



could not eyerywhere tell a Willow from a Poplar. But a 

 slight difference in the capsules, together with the more lax 

 sterile aments in Populus, is all which the great master can 

 discern as worth naming in the line of technical characters 

 by which to separate them. However, there seems little 

 practical need of even so much, if one appeal as he doee to 

 the "Propria Poimli facies qua differt a Scdicer 



It IS by an inexact and rather figurative use of terms that 

 men ascribe to Tournefort, or to any one who has yet appeared, 

 the credit of having discovered a scieniifc basis for the 

 genera of plants. If this author was in his day^and I douht 

 it not— the greatest of botanists who had up to that time 

 written a general treatise, it was because of the artist's eye 

 and the artist's delicate feeling by which he was enabled to 

 come at the truth respecting plant-relations where the "scien- 

 tific" test failed to give a satisfactory result. I take hk 

 generic characters, framed upon the basis of floral and carpo- 

 logical organography, to represent his sc/^nce of classifviug, 

 and the superadded notes upon the " propria facies " to rep- 

 resent the art, the genius of the great master ; and the latter 

 was worth more than the science. It was this to which final 

 appeal was always made, and made satisfactorily, where the 

 science had failed. Perhaps habit, general aspect, and sensible 

 qualities are m themselves real scientific factors in classifi- 

 cation ; but It is certain that they must forever elude our 

 attempts at verbal definition ; they are therefore practically 

 excluded from every method of systematizing which aims at 

 being purely scientific. Linnaeus, and after him two gener- 

 ations of his disciples, excluded these factors as seeming to 

 De elements of confusion and uncertainty, and admitted only 

 such genera as exhibited one or more technical characters, 

 liius did the natural genera of Tournefort give place in 

 11 erature to the empirical and often complex genera of 

 i^innfBus ; but, as already remarked, the consensus of botanists 



wifwV T -'^ '•'' ^'^'^^■°^°°y ^ith the Tournefortian rather than 

 with the Linniean conception of genera 



