92 



YOUNG AND OLD LEAVES. 



its becoming dried up. Then the sack opens, the 

 two scaly stipules fall apart, shrivel, and finally 



Fig. 18. VERNATION OF THE TULIP-TREE (Liriodendron Tulipifera). 

 (" Pflanzenleben.") 



fall off. There remain only two scars at the base 

 of the leaf-stalk to remind us that here in spring 

 were two stipules, which protected the tender young 

 leaves from too great evaporation of water. 



