98 British UredinecE and UstilaginecB. 



(Plate VI 1 1. Fig. 2). If the conidium germinate upon a 

 leaf, the germ-tube squeezes its point between the two 

 epidermal cells (Fig. 3), and soon produces in the leaf 

 a mycelium with haustoria. In from twelve to twenty 

 days after infection this mycelium produces the black 

 teleutospores, but not the conidia. 



The life-history of this species is peculiar : the teleuto- 

 spores germinating in autumn produce promycelial spores, 

 which, entering the young subterranean shoots of the host- 

 plant, develop a mycelium, which remains quiescent during 

 the winter, and in the spring produces, first the conidia on 

 the leaves, and afterwards teleutospores mostly in the stem. 



The entrance of the germ-tube in this species is (as 

 already stated above) between the epidermal cells. It 

 grows downwards in the partition wall, splitting it into 

 two laminae, and so makes its way through the epidermis. 



