398 FIRST FORMS OF VEGETATION. 
still more injurious fungus is developed called 
bunt (Z7lletia caries, 
Fig. 45). In this 
disease the seeds re- 
tain their original 
form and appearance; 
indeed, the bunted 
grain is plumper and 
of a brighter green 
than the rest, but the 
inside is completely 
converted into one 
mass of black dust 
of an exceedingly 
fetid odour, and 
greasy to the touch. 
Fic. 46.—Puccinira GRAMINIS. 
(a) Slightly magnified. (6) Sporidia, highly 
magnified. The surface of the 
spores is beautifully reticulated. When the wheat 
is thrashed, the infected grains, which retain their 
original shape to the last, are crushed, and the 
spores, being thus dispersed, adhere to the sound 
grains by means of the oily matter which they 
contain. Bunted wheat contains an acrid oil, 
putrid gluten, charcoal, phosphoric acid, phosphate 
of ammonia and magnesia, but no traces of starch, 
the essential ingredient in human food. When 
the black powder is accidentally mixed with the 
flour, it gives it an exceedingly disagreeable taste, 
