Tcleiitospores. 



vera, poaruni). In either case the germinative process is 

 the same. This consists in the protrusion of a germ-tube 

 from the teleutospore through the germ-pore above men- 

 tioned, which tube is really an extension of the endospore 

 through the germ-pore. This tube consists of a hyaline, 

 homogeneous membrane, into which the protoplasm con- 

 tained within the spore passes. This tube (the promy- 

 celium) does not, like the germ-tubes of the uredospores 

 and aecidiospores, elongate indefinitely, but, after attaining 

 a certain length, ceases to grow onwards and terminates in 

 a blind, blunt extremity. Into the promycelial tube the 

 protoplasm passes from the spore, and accumulates towards 

 the peripheral extremity, so that the end nearest the spore 

 becomes empty. The distal end now exhibits one or more 

 septa, which are formed from above downwards. At the 

 same time, from each compartment thus divided off there 

 arises a single, short, pointed branch ; these at their points 

 dilate. The dilated end becomes the receptacle for the 

 protoplasm originally contained in each compartment, and 

 rapidly assumes an oval or subreniform outline (the pro- 

 mycelial spore), which in 'the course of a few hours becomes 

 abstricted and falls off (Plate IV. Figs. 2-10). The pro- 

 mycelial spores, when placed in water or upon any damp 

 surface, forthwith germinate (Plate III. Fig. 24). This 

 process consists in the outgrowth, from some point of their 

 surface, of a short but acutely pointed tube. Placed upon 

 the cuticle of a living leaf of the proper host-plant, this 

 germ-tube turns its point downwards, and, piercing the 

 epidermal cell-walls, enters the tissue of the leaf (Plate IV. 

 Fig. i). Having thus gained an entry into its host, the 

 protoplasm contained in the promycelial spore passes down- 

 wards into the germ- tube, leaving the spore empty. The 

 empty spore-cell falls off, and the minute opening through 

 which the germ-tube has entered the epidermal cell ceases 



