SPHACELOTHECA. 



305 



period, and produce three-celled promycelia with elongated ovoid 

 conidia, which sprout indefinitely. In nutritive solutions two 

 or three promycelia may be produced. 



Schizonella.^ 



The spores are produced in series on the reproductive hyphae. 

 At first two-chambered by means of a cross-septum, they later 

 separate into two loosely-joined cells and form twin-spores ; each 

 half germinates like an Ustilago-STpoTe. 



Schizonella melanogramma (D. C.) (U.S. America). A 

 species found on leaves of various species of Gar ex. The spores, 

 when mature, escape by short fissures in 

 the upper epidermis of the host ; they 

 are black and coupled in pairs by a short 

 connection. They germinate in water 

 and produce a promycelium of three or 

 four cells from which conidia are given 

 off. In nutritive solution the promycelia 

 produce conidia, which fall off and sprout 

 yeast-like for a time. 



Tolyposporium. 



The sporogenous hyphae form tangled 

 masses, and produce their spores firmly 

 bound together in balls. The single 

 spores are large, somewhat angular or 

 spherical, and each germinates like a 

 spore of Ustilago. 



Tolyspormm junci (Schroet.) causes 

 the formation of gall-like outgrowths on 



the ovaries, flower-stalks, and haulms of Juncus bufonius and 

 J. capitatus. In these the spores are developed and escape as 

 spore-balls. The spores, after a prolonged rest, germinate in 

 water and produce four-celled promycelia, from which ovoid or 

 spindle-shaped conidia are given off. In nutritive solutions many 

 of the cells in each spore-ball germinate and produce promycelia, 

 at first four-celled, later further divided by new septa ; the 

 conidia sprout and grow on till they reach the air, where aerial 

 conidia are formed. 



^Sohroeter, Biologie d. Pfianzen, Bd. ii., 1877. 



u' 



Fig. 165. — Tolyposporium junci. 

 Spore-mass. One spore has 

 germinated and given off an 

 eighi>celled promycelium ; spori- 

 dia are being abjointed in wliorls. 

 (After Woronin.) 



