296 



PART IV. CLASSIFICATION. 



ually assumes an olive-green colour as the conidiophores are developed ; 

 and finally bright yellow patches appear, indicating the formation of the 

 ascocarps. 



Specimens of Mildews can generally be obtained, in a wet summer, from 

 the leaves of the Rose or of the Hop. 



The ascocarp is a perithecium in the sub-order Hypocreacese, Sphseria- 

 cese, and Dothideacese (e.g. Claviceps, Cordyceps) : a stroma, which varies 

 much in form, is frequently present. 



FIG. 176. Eurolium repens. A A portion of the mycelium with a simple conidiophore 

 (c) bearing conidia; the conidia have already fallen off from the sterigmata (st) ; at, a 

 young ascogonium. B Ascos;onium (as) with a pollmodium(p). C Another, with hyphse 

 growing up round it. L> A cleistothecium seen on the exterior. E F Sections of unripe 

 cleistothecia ; 10 the investment; / ascogenous hyphffl arising from the ascogonium, 

 which subsequently bear the asci. 0? An ascus. H A ripe ascospore. (Magnified : after 

 Sachs.) 



Order III. Discomycetes : the ascoearp is an apothecium of various 

 form ; a stroma sometimes present; 



The order may be divided, according to the form of the apothecium, 

 into the two sub-orders Pezizaceae and Helvellacese. In the former the 

 apothecium is cup-shaped, the hymenium covering the concave surface 



