34-t 



UKEDINKAE. 



tlirougli the e})iderniis. The yellow uredospores are abjointed 

 singly from long sporophores ; they are unicellular and ovoid, with 

 a thin granular coat beset with germ-pores (Fig. 184). The uredo- 

 spores are easily conveyed to other grass-plants and germinate at 

 once, their germ-tubes entering by a stoma and developing into 

 a mycelium, which can produce a new crop of uredospores in a 



Fig. 18i.—Puccinia graminis. A, Portion of transvei-se section of leaf of Bcrberis 

 vulgaris, with a young aecidinm under the epidermis, v.. 



I. Section through an aecidium-bearing spot of a Barberry leaf. At x the 

 normal structure and thickness of the leaf is shown, the portion u to p is 

 abnormally thickened ; It to o, upper siirfaco of the leaf ; sp, pyenidia ; a, aecidia 



, sectiu 

 a peridinui (■\|»i-(-l in -u: 

 ^11. Matmv t^l. i, . 1 



in. TclcUlos'l..,,. . '.', ;,ll 



at its apex, the urcdcsjH 



(After l)e Bary, from Sach's Lehrbuxh.) 



-•idium marked p alone (without «) shows 



ly. 



. mg through the epidermis, e, from the 

 . t eleutospores. x 190. 

 s, ii,i\ The teleutospore has a germ-poro 

 ur gcnn-pores at their equator. x 390. 



few days. The uredospores are summer-spores, and spread the 

 fungus during the vegetative period of the host-plant ; they may, 

 however, hibernate. The teleutospores are more suited for 

 hibernation ; they are produced in autumn from dark brown 

 linear sori, distinguished from these of the uredospores by their 

 darker colour and greater length. The teleutospores are two-celled 

 and obovoid with smooth thick walls (Fig. 184); they arc, like 



