Formation of Tclcutospores of UstilaginecE. 67 



crease in length and breadth, so that the pyriform swellings 

 become spheres, from 2 to }^\i across, attached to the hypha 

 by thin stems about \yi thick. These become differentiated ; 

 their contents vacuolated and oleaginous, and the con- 

 necting branches speedily wither (Plate VI. Figs. 5, 6). 

 The epispore subsequently darkens and becomes uneven, 

 while to many ripe spores the remains of the spore-forming 

 hyphce continue attached. 



In T. stncefonnis the process is very similar, but the 

 spore-forming hyphae are larger and more gelatinized, and 

 invest the spores to their maturity, after which they dis- 

 appear without leaving any trace. 



Doassansia* — The mycelial hyphae in the tissues of 

 the host-plant give off branches, which at certain points 

 become interlaced into tangled knots. From these knots 

 are formed the spores ; the central portions forming the 

 true spores, while the external develop into a 

 layer of oblong or wedge-shaped sterile cells, 

 which constitute an investing peridium. The 

 peridial cells are darker in colour than the 

 spores (Plate VIII. Fig. 4). 



Ejitylonia. — The spore-formation in Enty- 

 loma is very similar to that of Tilletia. De 

 Baryt investigated it in E. inicrosporiini and 

 calendulcB. The much-branched mycelium is 

 principally intracellular. At certain places 

 blister-like swellings appear along the spore- 

 forming hyphae, and also at their ends. The ^Jj- ''■^1%'. 

 contents of these swellings become differen- thr^teieutospores 



, . , , . , , within the spore- 



tiated mto spores, so that they are mtercalated forming hypha. 



(Dc Bary.) 



in the hyphae (Fig. 5). Often a series of 



spores, formed one behind the other, may be seen still con- 



* Cornu, Ann. dcs Science N^at., (f sen, Bot., tome xv. p. 280, et scq. 

 t De Bary, Bot. Zeitung {\%']\), pp. 81-93 ; pp. 97-108, t. ii. 



