174 OF THE FULCRA, ETC. 



are admirably characterized by the bristles of their 

 leaves, or of parts of their leaves, being hooked 

 backward or forward. We therefore accept the 

 272d maxim of Linna?us's Philosophia B'etanica 

 with that limitation which he himself has allowed in 

 his commentary upon it. " The Pubescence," says 

 he, {( is a ridiculous distinction, being for the most 

 part effaced by culture.'* After quoting examples, 

 he concludes : " We are therefore not to have re- 

 cour^e to the hairiness or spines of plants but in case 

 of absolute necessity." Such necessity every bota- 

 nist will allow r to have existed in the Menthcz and 

 in Myosotis scorpioides ; and though the degree of 

 pubescence varies from culture, and even its struc- 

 ture be changeable, as in Hedypnois hispida, Engl. 

 Bot. t. 554, and hirta, t. 555, its direction is I 

 believe as little liable to exception as any character 

 that vegetables present. 



