4 British Uredinee and Ustilaginee. 
CHAPTER. II. 
MYCELIUM OF THE UREDINEA’. 
THIS is, of course, common to all the different spore- 
forms, inasmuch as it is that part of the fungus which 
develops them. It consists of a number of hyaline tubes 
that extend themselves principally between the cells of 
the host-plant. In some instances these tubes send short 
branches into the cells (haustoria), but the haustoria are 
not so common nor so well developed as in some other 
parasitic fungi (Peronosporee, Ustilaginee). In the 
tropical genus Hemileia* the haustoria are unbranched, 
thin-stemmed vesicles, very like those of Cystopus. Bagn ist 
has figured the haustoria of Puccinia malvacearum, but his 
figure is of a doubtful character ; and Barclay} has depicted 
an arborescent haustorium on the mycelium of cidium 
urtice, var. himalayense. 
The mycelial tubes (Plate I. Figs. 1 and 2) consist of 
hyaline, membranous walls, containing usually a colourless 
watery fluid. They are rendered more distinct by the 
* Marshall Ward, ‘‘On Hemileia vastatrix,” Zinn. Soc. Four. Bot., vol. 
xix., and Quart. Four. Micr. Science, new series, vol. xxi. 
+ Bagnis, ‘‘ Obs. Vita et Morphol. Funghi Uredinei,” t. i. fig. 11. 
t Barclay, ‘‘ Scientific Memoirs by Medical Officers of the Indian Army” 
(1887), t. iv. fig. 4. 
