40 rrrroxTA. 



as descriptive of some shade of color in the wood, bart, foli- 

 age or flower which is characteristic of the species- Even so 

 among the home-liest of weeds ; in Chenopodium for example^ 

 we have C. riibrum, so called because its fruit is red, and C. 

 allmm and viride, their herbage marked in nature, that of 

 the one by a light, of the other by a darker shade of green, 

 each fitly named in accordance with such difference of color. 

 To enumerate all the classical examples of the value of 

 color in the diagnosis of phanerogams, would be to write a 

 book- With the almost absolutely ordinal value of it in 

 the lower orders, from fSphagnaceiB and Musci down, all, even 



botany, must be acquainted ; and 

 yet we Lave botanists who will not listen to words in defense 

 of color as a distinguisliing feature among species of plants ; 

 men who still swear by the pleasing but rather vacuous 



ogamic 



aseolo 



AXALOGIES AND AFFINITIES. 



11. 



It is commonly asserted by medical botanists that the same 

 therapeutical qualities inhere, though often in very different 

 degrees, in all the species of a genus ; or even in all the 

 plants of an entire natural order. Systematic botanists in 

 general agree to this ; are apt to be well aware of it, altliough 

 such hind of fact is excluded from the formal diagnosis of the 

 genus or order as unimportant. In partial justification of this 

 exclusion it may be said that like principles, in so far as 

 medical activity is concerned, reside in plants of widely sepa- 

 rate natural alliances. But, while one may not well question 

 that the same active principles may reside in two genera of 

 plants not at all related, still, it may not safely be ignored 

 that the therapeutic effects may be induced by different active 



