324 



USTILAGINEAE. 



to be preceded by a considerable resting-period, during which 

 germination will not take place. 



D. Martianoffiana (Thiim.). In leaves of Potamogeton natans and P. 

 gramineas. 



D. occulta (Hoffm.). In fruits of species of Potamogeton. 



D. intermedia (Setch.). An American species found on leaves of 

 Sagittaria variabilis. 



D. comari (Berk.). In leaves of Comarum palustre in Britain. 



D. limosellae (Kunze.). In flowers of Limosella aquatica. 



D. hottoniae (Rostr.). In leaves of Mottonia palustris in Denmark. 



Thecaphora. 



Spores, large, spherical, and inseparably united into packets 

 of several spores. Germination results in the formation of a 



Fig. 177. — Theca;phora hyalina. Pluricellu- 

 lar spore, with two cells (spores) germinating. 

 (After Worontn.) 



Fig. 17S. — Sorosporium sajfiynariae (var. 

 Lycknidi£ dioicae.) Matui'e spore-mass, and 

 spores germinating. (After Woronin.) 



promycelium from the apex of which a single conidium is 

 produced. 



Thecaphora lathyri Kiihn. Spore-balls formed in the seeds 

 of Lathyrus pratensis, and escaping as a brown powder on 

 dehiscence of the pods. The spores germinate in water with 

 formation of a promycelium bearing a single apical conidium, 

 which produces a hypha, but never secondary conidia. In 

 nutritive solutions the spores produce a mycelium from which 

 conidia are continuously given off. 



Th. hyalina Fingerh. (Britain). This occurs in fruits of 

 species of Convolvulus. Woronin describes the spores as having 

 germ-pores through which a septate germ-tube is emitted ; the 

 individual cells of the germ-tubes develop into hyphae, without 

 formation of conidia. 



Th. affinis Schneid. In fruits of Astragaliis glycyphyllus (U.S. America). 

 Th. Trailii Cooke. In flowers of Carduus keterophyllus in Scotland. 



