32^ 



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. 

 grumineus. 



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



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

 Sagittai-ia varia h il is . 



D. comari (Berk.). In leaves of Gomaruni pcthistre in Britain. 



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



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



Thecaphora. 



Spores, large, spherical, and inseparably united into packets 

 of several spores. Germination results in the formation of a 



Fig. 117.— Thecapkoni hmilaa. Pluricellu- 

 lar spore, with two cells (spores) germinatlug. 

 (After Woronin.) 



'0 



Fig. its. — Sorosporium saponariae (var. 



Lychnidis dioicae.) Mature spore-mass, and 



germinating. (After Woronin.) 



promycelium from the apex of which a single conidium is 

 produced. 



Thecaphora lathyri Klihn. Spore-balls formed in the seeds 

 of Lathyrus ^9?'ai!e7ms, and escaping as a brown powder on 

 dehiscence of the pods. The spore^ 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 coiiidia. 



Th. affinis Sclmeid. In fruits of Astragalus glycyphyllus (U.S. America). 

 Th. Trailii Cooke. In flowers of Cardmis heterophylhis in Scotland. 



