40 MICROSCOPIC FUXGI. 



on many plants of the pea and bean tribe. As it 

 may serve to illustrate some of tlie preceding, as 

 well as subsequent, remarks on development, an 

 abstract shall close this chapter. 



The spores of this species [Uromyces ajpioendl- 

 ' cidatus) are oboval cells, terminated by a rounded 

 point, provided with a deep brown, smooth, e]ji- 

 spoYBj or outer coating, and a distinct, but colour- 

 less endospore, or inner coating. These enclose a 

 granular matter, v/hich surrounds what has been 

 termed the nucleus, but which appears to be a 

 vacuole. At the top of the epispore is a pore 

 which is characteristic of the genus. The spores 

 are supported on a colourless, or slightly-tinted 

 pedicel of considerable length (plate VII. fig. 150). 

 By means of this pedicel, the spores are attached to 

 the fostering plant, on which they form pustules 

 or son of a blackish colour, and variable extent. 

 These spores are ripened towards the end of 

 summer or beginning of autumn. During winter 

 they remain in a state of repose, but in the follow- 

 ing spring the faculty of germination developes 

 itself. At this period, when moistened or placed 

 on a humid soil, they germinate at the end of a 

 few days. The spore then emits a curved and 

 obtuse tube, which soon ceasing to elongate itself, 

 gives origin to three or four sporidia, of a reniform 

 or kidney shape. WTien cultivated on moistened j 

 glass, these sporidia also emit a short, thin, 

 slender tube, which produce in turn secondary 



