278 
PLANT STUDIES 
Here must probably be included the yeast-fungi (Fig. 
248), so commonly used to excite alcoholic fermentation. 
FIG. 247. The common edible morel (Morchella 
esculenta). The structure shown and used 
represents the ascocarp, the depressions of 
whose surface are lined with asci contain- 
ing ascospores. After GIBSON. 
FIG. 248. Yeast cells, repro- 
ducing by budding, and 
forming chains. LAND. 
The " yeast cells " seem to be conidia having a peculiar bud- 
ding method of multiplication, and the remarkable power 
of exciting alcoholic fermentation in sugary solutions. 
3. ^ECIDIOMYCETES (^Ecidium-Fungi) 
186. General characters. This is a large group of very 
destructive parasites known as " rusts " and " smuts." The 
rusts attack particularly the leaves of higher plants, pro- 
ducing rusty spots, the wheat rust probably .being the best 
known. The smuts especially attack the grasses, and are 
very injurious to cereals, producing in the heads of oats, 
barley, wheat, corn, etc., the disease called smut. 
