FUNGI. 



249 



protruded. This third stage, or condition, is popularly 

 called " brand," and completes the cycle of this and 

 similar trimorphic uredines. 



The teleutospores are in most cases " resting 

 spores," that is to say, they do not germinate at once, 

 but undergo a period of rest, probably through the 

 winter months, germinating in spring, and then in- 

 fecting the seedling plants of its proper host, and thus 

 perpetuate the species. When the teleutospores ger- 

 minate a germ-tube is protruded through the germ- 

 pore, and, as this tube elongates, the contents of the 

 cell in germination pass into the germ-tube, and 

 retract to the upper or apical extremity, leaving the 

 lower portion empty. The free end of the germ-tube 

 is soon traversed by one, two, or three septa, com- 

 mencing from above downwards. Each cell now 

 formed by this septation 

 sends off a short pointed 

 branch, then the pointed 

 ends dilate and assume an 

 oval or kidney shape, into 

 which the contents of each 

 respective cell pass when 

 the swollen end becomes 

 constricted into a second- 

 ary spore, and falls off. 

 Thus two or three second- 

 ary spores, or promycelial 

 spores, as they are called, 

 are produced at the ex- 

 tremity of each germ-tube, from each cell of the 

 teleutospore (Fig. 50). When these promycelial spores 



Fig. 50. — Germinating teleutospore of 

 Piicciniu, 



