STRUCTURE. 41 
whence they spring. In the best known species, Tilletia caries, 
they constitute the “bunt” of wheat. The peculiarities of 
germination will be alluded to hereafter. In Ustilago, the 
minute sooty spores are developed either on delicate threads 
or in compacted cells, arising first from a sort of semi-gelati- 
nous, grumous stroma. It is very difficult to detect any threads 
associated with the spores. The species attack the flowers and 
anthers of composite and polygonaceous plants, the leaves, 
culms, and germen of grasses, &c., and are popularly known as 
“smuts.” In Urocystis and Thecaphora, the spores are united 
together into sub-globose bodies, form- 
ing a «kind of compound spore. In 
some species of Urocystis, the union 
which subsists between them is com- 
paratively slight. In Thecaphora, on 
the contrary, the complex spore, or 
agglomeration of spores, is compact, Fi! 23.—Phecaphora hyalina. 
being at first apparently enclosed in a delicate cyst. In Zubur- 
cinia, the minute cells are compacted into a hollow sphere, 
having lacune communicating with the interior, and often exhi- 
biting the remains of a pedicel. 
ABcipiacet.—This group differs from the foregoing three 
groups prominently in the presence of a cellular peridium, which 
encloses the spores; hence some mycologists have not hesitated 
to propose their association with the 
Gasteromycetes, although every other 
feature in their structure seems to 
indicate a close affinity with the 
Ceomacei. The pretty cups in the 
genus dicidium are sometimes scat- 
tered and sometimes collected in clus- 
ters, either with spermogonia in the centre or on the opposite 
surface. The cups are usually white, composed of regularly 
arranged bordered cells at length bursting at the apex, with the 
margins turned back and split into radiating teeth. The spores 
are commonly of a bright orange or golden yellow, sometimes 
white or brownish, and are produced in chains, or moniliform 
Fic, 24.—cidium Berberidis, 
