16 THE LIFE OF THE PLANT 



of the scale (fig. 7) ; later still it appears like a small 

 bristle in the topmost hollow of the scale, and at last 

 disappears altogether (fig. 8). We are left with a thin 

 yellowish-green scale, reddish at the edge. Our leaf 



FIG. 6. 



has gone through its entire transformation before our 

 very eyes, so to speak. Its lamina has disappeared, 

 while its petiole has changed into an organ, similar in 

 origin and purpose to the scale studied in the bud of 

 the chestnut. The one as well as the other represent 

 a petiole, developed like a lamina. As the one protects 

 the young leaves of the bud, so the other protects the 



