BOTANICAL LITERATUBE. 203 



of two centuries since, and with M. Baillon of to-day, we 

 admit six or eight genera of these thistly herbs, or whether 

 with Cassini, S, F. Gray and their class of specialists we 

 allow thirty or forty, it remains true that our genns-making 

 is here almost entirely regulated by the value we place upon 

 the character of leaves or the simplest of all leaf-modifications, 

 the bracts of an involucre. Whether we speak of Carduns 

 or CnicuSj Centaurea or Cirsium, the foundations of the 

 "scientific botanist's" genus are the same wliich the ancient 

 fathers of botany are said to have built upon, and are at the 

 same time those which the intelligent farmer or woodsman and 

 even the untutored Indian generalize upon very successfully 

 to-day. Nor are the conclusions reached on either hand of a 

 nature to warrant any boasting on the part of the botanist's 

 technical knowledge over the plain ploAvman's common sense. 

 Either the Cardims or Centaurea of the former is— to take 

 an average of the varying opinions of professional botanists 

 a less definitely settled and not much less diversified genus 



than the Thistle of the latter. 



Thus much in illustration of certain crudities in method, 

 and diversities of result, incident alike to the earlier and to 

 the later attempts to classify plants. But cases of entire 

 though unconscious agreement between the unlearned and 

 the learned, as to the limits of a genus, are perhaps veiy 

 numerous. Let me assume that an intelligent farmer is 

 familiar with several sorts of field and pasture clover, and 

 also with two or three kinds of what are called sweet-clovers; 

 of the latter say a white-flowered and a yellow-flowerfd 

 species. If I speak to such a one of SweetXlover in general, 

 I recall to his mind a generic conception as perfect, though 

 not as extended, as I should awaken in the mind of the 

 director of a botanical garden by the mention oi Mehloius, 

 If to the former I should but name Clover, it would be all 

 the same as if I spoke to a botanist about Tn'folwm. The 

 'American farmer's Clover is as exnct a generic name with 

 him as the Trifoliim of those instructed in botany is to them^ 

 True it might be that if the rustic knew but a single kind of 



