GARPOPHTTA. 179 



324. After fertilization other branches grow ujd around 

 the carpogone, and finally comple.tely enclose it, as in the 

 Mildews, described above (C, D, Fig. 101). In the mean 

 time from the cells of the enclosed carpogone branches 

 bud out, and finally produce many eight-spored sacs on 

 their extremities; after a time the sacs are dissolved, and 

 the spore-fruit, now of a sulphur-yellow color, contains a 

 multitude of loose spores. 



Practical Studies. — (a) Collect in the autumn a quantity of leaves of 

 the lilac which are covered with a whitish mould-like growth, the 

 Lilac-mildew (Microsphsera alni). Scrape off a bit of this Mildew 

 after moistening with a drop of alcohol ; _ mount carefully, adding a 

 little potassic hydrate. Look for conidia and suckers (haustoria). 

 Look also for spore-fruits, which appear like minute dark dots to the 

 naked eye. Carefully crush the spore fruits and observe the sacs 

 (4 to 7) with their contained spores (6). Notice the beautifully 

 branched tips of the appendages. 



(p) Collect and study the Mildews to be found on hops (Sphasrotheca 

 castagnei), on cherry- and apple-leaves (Podosphaera oxycanthse), on 

 hazel- and ironwood-leaves (Phyllactinia suiiulta), on willow-leaves 

 (Uncinula salicis), on leaves and fruit of grapes (U. necator), on wild 

 sunflowers, verbenas, etc. (Erysiphe cichoracearum), on peas, grass, 

 anemones, buttercups, etc, (E. communis). 



(c) Place a few slips of green twigs in an ordinary plant-press, 

 allowing them to remain until they become (1st) mouldy (conidial 

 state), and (3d) covered with minute yellow globular bodies (the 

 spore-fruits). These are known as the Herbarium-mould (Eurotium 

 herbariorum). Study as in case of the blights. 



Systematic Literature. — Ellis and Everhart, North American Pyre- 

 nomycetes, 1-56. Saccardo, Sylloge Fungorum, 1 : 1-87. 



325. The Truflles (Order 13. Tubeeoide^) are well 

 known from their large underground spore-fruits, which 

 are edible. Internally there are narrow tortuous channels 

 on whose walls sacs develop, each containing a number of 

 spores (Fig. 103). Little is known of their round of life, 

 and the sexual organs have not been discovered. 



326. The Blue Moulds (species of Penicillium) are mem- 



