260 



STRUCTURAL BOTANY 



pretty little yellow cups containing spores (Fig. 106, A). 

 This is the ^cidium form of the parasite, and, like the 

 p 



Fio. 106. Puccinia graminis. A, part of the lower surface of a 

 Barberry leaf ; on the swollen part (P) is a cluster ofjEcidium- 

 cups (a). Magnified about 10. B, vertical section of the 

 diseased part of the leaf ; e, e, epidermis ; p, palisade tissue ; 

 s, spongy tissue ; sp, sp, spermogonia of the parasite ; %, 

 2 , as, three stages in the development of the ^Jcidium-fmit ; 

 P, peridium ; h, hymenium. Magnified 40. 0, three chains 

 of secidiospores ; h, hymenial cells, i.e. intermediate cells. 

 Magnified about 200. (After Zopf and Kny.) 



