198 



THE ALDER. 



PLAN OF LEAF. 



Their development is explained by the drawings. When fully 

 grown the leaves measure about three inches in length, and they 

 remain on the bough when autumn has robbed most other trees of 

 their foliage. In spring their colour is of the palest green ; but it 

 soon becomes dull and heavy in tone. The reflecting [iower of the 

 glaucous surface in a measure, however, compensates for this, while 

 the leaf is gummy enough to prove a death-trap for numerous small 

 insects. From an early stage the veins are clearly marked, and the 

 lateral ones are so stout and rigid as to cause the leaf-blade between 

 them to pucker. 



