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TEXT-BOOK OF FUNGI 



reflexed, thus exposing the contained mass of spores. The 

 wall of the pseudoperidium is formed in the same fashion 

 as the chains of spores in its interior, only the cells are 

 sterile and empty. Aecidiospores have several germ-pores, 



FIG. 93. Puccinia pringsheimiana, a parasite on gooseberry leaves. 

 i, portion of a gooseberry leaf with three aecidia or 'cluster-cups' fully 

 expanded ; 2, section through an aecidium, showing at a the spores pro- 

 duced in chains, which soon break up and form an orange, powdery mass ; 

 b, the protective wall or peridium ; c, epidermal cells of the leaf; d, the 

 parenchymatous cells of the leaf containing chlorophyll : the mycelium 

 of the fungus is shown running between the cells of the leaf ; 3, portion of 

 leaf of a sedge bearing the sori or minute clusters of uredospores and 

 teleutospores ; 4, same as fig. 3, more enlarged ; 5, teleutospores ; 6, 

 uredospores. Fig. 3, nat. size ; remainder mag. 



or specialised portions of the epispore, through which the 

 germ-tubes protrude on germination. If a germinating 

 aecidiospore happens to be situated on the leaf or other 

 suitable portion of the proper host-plant, the germ-tubes 

 pass through the stomata into the living tissues below the 

 epidermis, where a mycelium is formed which in due course 



