Germination of Tclcniospores of Ustilaoinccc 89 



secondary spores as effectually, as when two or three have 

 become connected, the only difference being that with 

 fused or conjugated spores larger germ-tubes and larger 

 secondary spores are produced. The secondary spores 

 (Plate VI. Figs. 9, 10) are at first cylindrical, but they soon 

 become reniform, and at length, by the attenuation of their 

 ends, more or less crescent-shaped. They may be pro- 

 duced from any part of the primary spores, even from the 

 connecting bridge, and at almost any distance ; very 

 seldom is more than one produced from each fused pair of 

 primary spores. Three or more primary spores have been 

 seen connected,* and double fusion between two has been 

 also observed.! Not only cio the primary produce second- 

 ar}' spores, but they may emit a pointed germ-tube, for 

 direct penetration of the host-plant. In like manner, 

 between the secondar}- spores all sorts of connections and 

 conjugations or fusions occur, with the same emptying of 

 the contents from one spore into the other (Figs. 11, 12). 

 The secondary spores are, however, essentially the spores 

 the germ-tubes of which enter the host-plant. 



In nahrlosung, according to Brefeld, the primary and 

 secondar)^ spores are larger, and are produced in greater 

 abundance. No conjugations or fusions occur, except 

 when it becomes exhausted. The primary spores, how- 

 ever, comport themselves ver)- differently in nahrlosung ; 

 they send out germ-tubes which are narrower than those 

 given off b}^ them in water. These tubes are unseptate, 

 but branch and inosculate with each other so as to form 

 a mycelium (Plate VI. Fig. 14), which, as it grows out 

 into the air, forms a white floccose mass. For five or 

 six days no secondary spores are found in well-nourished 

 mycelia, whereas spore-formation occurs soon in badl)' 

 nourished ones. The spores are produced only on those 



* Brefelcl, loc. at., t. xiii. '(\'g. 39. t Ibid., lig. 38. 



