RUST FUNGI— UREDINEAE 



247 



species in which only teleutospores are known, and these do 

 not germinate for a long time after the foster -plant is dead ; 

 and the Lepto-pucciniae, in which also the species only possess 

 teleutospores, but the sori are compact, and germination takes 

 place at once and whilst the foster-plant is living. Of course, 

 outside of all these groups there still remain a rather large 

 number of species, of uncertain place, mostly with only the 

 teleutospores definitely known, but which it is suspected will 

 ultimately find a place in some of the foregoing groups, when 

 their life-history has been ascertained. Other Didymosporous 

 genera are Uropyxis, which seems to be hardly generically 

 distinct, in which the teleutospore is involved in a thick per- 

 manent hyaline integument ; and Diorchidium, which differs 

 chiefly from Puccinia in the septum being vertical. Gymno- 

 sporangium is most distinct in the teleutospores being agglut- 

 inated together in, generally, large tremelloid masses, the 

 teleutospores themselves being transversely uniseptate, or very 

 rarely biseptate, nearly hyaline, with long, sometimes very 

 long, pedicels. 



In Phragmosporae the teleutospores are three, or more, 

 septate,. in one direction. In most genera 

 they are destitute of a pseudoperidium, 

 whilst in Phragmidium 1 (Fig. 119) and 

 Xenodochus the uredospores are solitary. 

 The differences between these two genera 

 are slight: in the former the teleutospores 

 are cylindrical, the cells not readily break- 

 ing up into joints ; in the latter the cells 

 are more numerous and moniliform, soon 

 breaking up into the component cells. In 

 two genera the uredospores are catenulate, 

 of which Coleosporium is the most import- 

 ant; in this genus the uredospores are 

 associated in chains, and the teleutospores Pl °- H9-— Teleutospores 



. , , , m , °f Phragmidium. 



are three, or many, septate. The pro- 

 mycelium is continuous. In Ghrysomyxa the uredospores are as 

 in Coleosporium, the teleutospores are multiseptate, and simple or 



1 Hamaspora longissirna has been included under Phragmidium, but we doubt 

 if it should not be maintained as a distinct genus. 



