238 PHYLUM VII. CARPOMYCETEAE 
barley, bearing lines or spots of Red rust. First examine a 
few of the spores mounted in alcohol, with the subsequent 
addition of a little potassium hydrate. Then make very thin 
cross-sections through a rust spot, and mount as before, so as 
to see the parasitic filaments in the leaf, bearing the Red-rust 
spores upon little stalks. 
(d) In July, August, or September collect stems of wheat, 
oats, or barley bearing lines or spots of Black rust. Study the 
teliospores as above, and afterward make cross-sections also. 
(e) In early spring collect and examine the Black rust on 
wet stems of rotting straw. Look for germinating teliospores 
and sporids, which sometimes may be found. 
(f) Examine microscopically the gelatinous prolongations on 
“‘cedar-apples,” and observe the teliospores, which resemble 
those of Wheat rust. ‘‘Cedar-apples,” which are common in 
the spring on red-cedar twigs, are in reality species of rust of 
the genus Gymnosporangium. Their cluster cups occur on 
apple leaves. Uredospores are lacking. . 
(g) Collect smutted ears of Indian corn. Mount a little of 
the black internal mass in alcohol, followed by weak potassium 
hydrate.and observe the spores. 
(h) Make very thin slices of young fresh or preserved speci- 
mens and examine for parasitic and spore-bearing filaments. 
The outer tissues of the distorted kernels are generally best. 
(t) Make similar studies of the smuts of wheat, oats, or 
barley, which may be collected in June, or about the time of the 
“heading”’ of the grain. 
(7) Make hanging-drop cultures (in water) of the teliospores 
of Tilletia and Ustilago, and compare their germination. 
THe ImperRFecT FuNGI 
410. There are many fungi (about 16,000 species), in 
some respects resembling the Ascus Fungi (ASCOSPOREAB), 
of which we know only the conidial stages. They have 
been brought together temporarily in three orders under 
the general name of ‘‘ Imperfect Fungi.” 
411. The Spot Fungi (Order SPHAEROPSIDALES) are 
mostly parasitic on leaves and fruits of higher plants, 
