CARPOASCI. 



121 



species of Mildew. A common means of prevention against their 

 attacks is to dust the diseased parts with sulphur. 



Sphccrotheca pannosa occurs on the leaves of Roses, and on the fruit of 

 Peaches and Apricots. S. castagnei on Humulus, Cucumis, etc. Erysiphe tuckeri 

 grows on the leaves and fruit of the Vine ; it spins its hyphae over the bunches 

 of grapes, curtails their growth, and causes them to burst, and to become de- 



FIG. 109. Eurotium glaucum : a portion of mycelium lying horizontally ; ft vertically- 

 placed conidiophore ; the mycelium gives rise to another branch near a ; the conidia are 

 abstricted from short flask-shaped cells ; b a ripe conidiutn; c, d germinating conidia; 



spirally-twisted hypha, commencement of an ascocarp ; / a stage later ; g still later, tlie 

 hypha at the base of the coil has given off branches which are applied to it; 7i, i sections of 

 young ascocarps. 



cayed and rotten (Grape-disease). The Fungus was first noticed in England 

 in 1845, and later was found in all countries whese grapes are grown. It is only 

 known in the conidial form (" Oidium tuckeri"). Many other species of Ery- 

 siphe are found on herbaceous plants. Microsphcera has appendages which are 

 repeatedly forked at their extremities. M. grossularice on Eibes grossularia. 



