134 



MORPHOLOG Y. 



295. Teleutcspores the last stage of the fungus in the season. The teleu- 

 tospores are developed late in the season, or late in the development of the 



host plant (in this case the 

 wheat is the host). They 

 then rest during the winter. 

 In the spring under favor- 

 able conditions each cell of 

 the teleutospore germi- 

 nates, producing a short 

 mycelium called a promy- 

 celium, as shown in figs. 

 161, 162. This promy- 

 celium is usually divided 

 into four cells. From each 

 cell 

 cess 



' ' sterigma. " Through this 

 the protoplasm moves and 

 forms a small gonidium on 



wheat rust. "(After Marshall- leaf through a sternal the end, sometimes called 



Ward - ) a sporidium. 



296. How the fungus gets from the wheat back to the barberry. If these 

 sporidia from the teleutospores are carried by the wind so that they lodge on 



a short, pointed pro- 

 is formed called a 



Fig. 159 



Germinating uredospore of 

 (After Marshall- 



Germ tube entering the 

 leaf through a stoma. 



. 101. Fig. 162. Fig. 163. 



Teleutospore germi- Promycelium of ger- Germinating sporidia entering leaf 

 nating, forming promy- minating teleutospore, of barberry by mycelium, 

 celium. forming sporidia. 



Figs. 161-163. Puccinia graminis (wheat rust). (After Marshall-Ward.) 



