ASCOMYCETES 



359 



According to Boudier (Bull. Soc. Bot. France, xxiii., 1876), Elapho- 

 myces is probably parasitic on roots ; but this is not certainly esta- 

 blished. 



In Onygena, which inhabits animal remains, the peridium is stalked, 

 and the ascospores (eight in each ascus) become free through the dis- 

 appearance of the ascus when ripe, and ultimately escape on the rupture 

 of the peridium. 



Origtx of the Sporocarp. 



The following types, selected by de Bary (' Comp. Morph.,' p. 197) 

 as illustrating the origin of the sporocarp of the Ascomycetes, show 

 an amount of variation in this process which, it may be anticipated, 

 will be extended with farther research into the subject, while certain 

 gaps between these types 



may be filled up. Taking d f 



the most simple instance of 

 the origin of such a sporo- 

 carp, that of Eremascus albus 

 Eid. described by Eidam, 

 the sexual act preceding the 

 formation of the sporocarp 

 IS manifestly the conjuga- 

 tion of two sexual elements 

 of identical structure. Two 

 cells of the septate mycele 

 send forth, close by the 

 septum which parts them. 

 each a short lateral tube, 



the two tubes being not only exactly alike but in close contact from the 

 outset. They continue to grow outward, winding round each other in 

 a spiral course, performing three or four revolutions apiece. At this 

 stage a septum grows across the base of each tube, and the apices con- 

 jugate. As a result of this act, a globular swelling arises at the apex, 

 the protoplasm of the tubes is withdrawn into it and enclosed by trans- 

 verse walls growing across the tops of the tubes. AVithin this body 

 (an ascus), which so strikingly resembles a simple zygosperm, there are 

 subsequently formed eight ascospores. [The carpogo7ie itself becomes an 

 ascus here.] 



The next type embraces such forms as the Erysiphe^e, Eurotium, 

 Penicillium, Sordaria, ]Melanospora from among cleistocarpous and 

 pyrenocarpous forms ; and Gymnoascus, Pyronema, Ascobolus from 

 gymnocarpous and discocarpous fungi, and the Collemacene (discocarpous) 



Fig. 302 



Ereuiasctis albus Eidam. Fertilisation and 

 formation of sporocarp. Stages in order of letters. In 

 y the ascospores are formed ( x 900). (After Eidam.) 



