88 MICROSCOPIC FUNGI. 



disease, to ascertain, if possible, tiie mode by wbicli 

 the minute spores of fungi inoculate growing 

 plants; and although at that time only a bare 

 suspicion of the nature of the bodies resulting from 

 the germination of " bunt " spores was enter- 

 tained, succeeding examinations in the same direc- 

 tion have brought to Hght extraordinary facts, and 

 manifested the progress of the successive develop- 

 ments of four generations. The spores of ^'^bunt^' are 

 larger than those of the different species of '^ smut," 

 and reticulated on the surface (plate Y. fig. 86). 

 When these are made to germinate a kind of stem 

 is protruded (fig. 87), upon which small clusters of 

 elongated thread-hke spores of the second gene- 

 ration, or sporidia, are produced (fig. 88). After 

 a time these spores conjugate, or become united 

 by short transverse processes in the same manner 

 as has been observed in some of the lower forms 

 of Algas (fig. 89). The conjugated spores in the 

 next stage germinate and produce a third kind of 

 fruit, different from either of the preceding, and 

 constituting a third generation (fig. 90). These 

 in turn germinate and produce a fourth order of 

 reproductive organs (fig. 91), so that in the process 

 of growth the " bunt '^ spores evidently pass 

 through four generations. Hence, as one result, 

 the number of germinating bodies is greatly in- 

 creased, as well as their power of inflicting injury 

 in a corresponding diminution in size. There are 

 still many points in the history of the growth and 



