FUNGI: WHEAT KUST, 



131 



ous spores, composed of two cells, and having thick, brownish 

 walls as shown in fig. 108. Usually there is a slender brownish 

 stalk on one end. These spores are called ieleutospores. They 

 are somewhat oblong or elliptical, a little constricted where the 

 septum separates the two cells, and the end cell varies from ovate 



Fig. 107. 

 Head of wheat showing black .rust spots 

 on the chaff and awns. 



Fig. 108. 

 Teleutospores of wheat rust, 

 Showing two cells and the pedicel. 



Fig. iog. 

 Uredospores of wheat rust, one 

 showing remnants of the pedicel. 



to rounded. The mycelium of the fungus courses between the 

 cells, just as is found in the case of the carnation rust, which 

 belongs to the same family (see Chapter XV). 



222. Uredospores of the red-rust form. — If we make a 

 similar preparation from the pustules of the red-rust form we 

 shall see that instead of two-celled spores they are one-celled. 



