166 



BOTANY 



tilization of an ascogonium ; in Endomyces and the other genera, 

 the plants are entirely non-sexual. 



Order II. Protodiscineae 



The Protodiscinese comprise a small number of very simple 

 Ascomycetes, which are mostly parasites upon Flowering Plants. 



A ^^^ B 



FIG. 130. A, base of a Peach leaf distorted by Exoascus deformans. B, asci (X550). 



One of the most familiar is Exoascus deformans, which causes the distortions 

 of peach leaves known as "Curl" (Fig. 130). The mycelium of the Fungus 

 grows between the layers of the cuticle of the epidermal cells of the host, and is 

 composed of many short joints, all of which become ultimately transformed into 

 the asci which burst through the cuticle and form crowded patches covering the 

 leaf. This is thereby very much enlarged and crumpled, and often made bright 

 red in color. The masses of ripe asci form a delicate gray powdery film over 

 the affected parts. 



B 



Order III. Helvellineae 



In these Fungi the my- 

 celium is well developed, 

 and the asci are borne 

 upon large, characteristic 

 fruiting-bodies, upon parts 

 of which the closely set 

 asci form a continuous 

 layer (Hymenium) consist- 

 ing of the asci interspread 

 with sterile filaments, or 

 paraphyses. One of the 

 commonest forms belong- 

 ing to this order is the 

 Morel (Morchella), whose 

 spore-fruit consists of a stout stalk terminating in a conical cap 

 which is deeply honeycombed with broad pits lined with the 



FIG. 131. A, Helvella lacunosa. B, Morchella 

 cornea. (Natural size.) 



