38 British Uvredinee and Ustilaginea. 
to form elevated ridges. As an accidental variety, one 
sometimes sees a few bicellular spores in the true Uro- 
myces spore-bed; this has been ob- 
served with Uromyces trifolit on Vicia 
sepium. 
The teleutospores of Puccinia are 
compound. They consist of two dis- 
tinct spores borne on one pedicel. The 
dilated upper extremity of the hypha, 
which is destined to become a Puccinia 
spore, soon assumes a fusiform shape, 
and is uniformly filled with granular 
protoplasm, while the lower part of the 
hypha contains only a hyaline or watery 
material (Plate ITI. Fig. 18). Soon a 
delicate transverse septum appears near 
Fig. 2.—Teleutospore the middle of the swollen part, dividing 
of Uromyces fabe germi- 
nating, showing the germ- it transversely into two nearly equal 
canal through which the 
promycelium ee compartments. The spore now becomes 
res fro abe a! invested by a stouter membrane (Fig. 
Mee Seer 19), which gradually increases in thick- 
ness so that the body now can be seen to consist of two 
distinct accumulations of protoplasm. As the thickening 
of the outer membrane goes on it becomes darker. This 
thickening is most marked at the apex of the upper com- 
partment. The granular protoplasm at first usually shows 
two or three vacuoles (Fig. 20), but these become reduced 
in number, so that in the mature spore only one is observ- 
able (Fig. 21). How this vacuole is. formed is not alto- 
gether clear, but it probably is produced by the protoplasm 
of each compartment accumulating more towards the walls 
of the cell than elsewhere. Each compartment, then, con- 
sists of a thick outer membrane, lined by a thin one (the 
endospore) which encloses the protoplasm and its vacuole. 
