MAGNITUDE OF LEAVES. i^O 



surfaces, neither of which can be said to be superior. 

 The Blue flag, and other species of Iris furnish ex- 

 amples. 



Sempervireut leaves retain their verdure through 

 one or more winters, as in the Laurel, Pine, and other 

 evergreens, but in Northern countries, leaves are more 

 usually Deciduous, falling at the approach of winter. 



When the character of a leaf cannot be otherwise 

 precisely delineated, botanists qualify or combine the 

 terms which have been thus briefly defined. It is not 

 uncommon, for example, to find leaves which are in- 

 termediate between the ovate and the lanceolate forms, 

 and they are said to be ovate-lanceolate. Nor is it 

 unusual to find them with foot-stalks so very short, 

 that a student is unable to decide whether they are Ses- 

 sile or not ; but here the term sub-petiolate or sub-ses- 

 sile is used, and in this, as well as in all cases, the term 

 sw6, implies that the character in question is obscure 

 or not well defined. 



" By the judicious use of such means," says Dr, 

 Smith, " all necessary precision is attained. Perhaps 

 no mind, though ever so intent on the subject can re- 

 tain all the possible terms of description and their vari- 

 ous combinations, for ready use at any given moment. 



There are few natural objects, to which a variety of 

 terms are not equally applicable in description, so that 

 no two writers would exactly agree in their use. 

 Neither is Nature herself so constant as not perpetual- 

 ly to elude our most accurate research. Happy is that 

 naturalist, who can seize at a glance what is most char- 

 acteristic and permanent, and define all that is essential, 

 without trusting to fallacious though ever so specious 

 distinctions." 



13 



