Fig. IS9 A, — The seasonal changes in a twig of elm. The uppermost picture 

 shows the condition of the buds early in April. The second picture shows the clus- 

 ters of flowers. The flowers of elm are monoclinous, but the pistil is not conspicu- 

 ous at the time the anthers are ripe; in the picture, the prominently exposed 

 stamens are quite evident. Pollination is by wind. The third picture shows 

 the condition of the green, winged fruit late in May. The young leaves have 

 not yet reached full size. In the fourth picture (September) the leaves are mature. 

 The last picture shows the twig late in October; note the condition of the 

 winter buds. — Redrawn from Bailey. 



(3S7) 



