28 
THE VEGETATIVE FUNCTIONS OF PLANTS 
FIG. 18. New Zealand raspberry (Rubus attstralis). The lower portion 
is the petiole; the blade is reduced to three spiny veins slightly expanded 
at the tip. 
FIG. 19. Homology of bud-scales in an ash (Fraxinus sp.). Series 
showing gradual transition from outer bud-scale (at left) to unexpanded 
foliage leaf (at right). The outer bud-scale is morphologically a leaf-base. 
