^44 PLANT MORPHOLOGY 



side of the leaves (Fig. 119^). In these organs small cells, called sper- 

 matia (pycnospores), are formed by abstriction from the ends of slender 

 hyphae. The spermatia are exuded from the spermogonia in drops of a 

 sweet liquid. This attracts insects that aid in their dissemination. Soon 



Fig. 119. Pucciniagraminis. Stages on the barberry. ^, four basidiospores arising from 

 a basidium produced by a teliospore, X300; B, leaf of common barberry with groups of 

 aecia, natural size; C, enlarged view of group of aecia, X 10; D, longitudinal section of 

 aecium with numerous aeciospores arising in chains, X200; E, longitudinal section of 

 spermogonium producing numerous small spermatia, X200. {A, after Chamberlain.) 



after the appearance of the spermogonia, the mycelium on the barberry 

 produces larger, cup-like structures that appear in clusters on the lower 

 side of the leaves (Fig. 119S and C). These aecia, or cluster cups, con- 

 tain large numbers of aeciospores, which arise in chains from the bottom 



