144 



BASIDIOMYCETES. 



Sub-Class 2. Basidiomycetes. 



This sub-class embi'aces the most highly developed Fungi, with 

 large " fruit-bodies," which in ordinary language we shortly term 

 Funguses, Toadstools, or Mushrooms. 



They have no sporangia, but reproduce only by means of 

 basidiospores, conidia, chlamydospores and oidia. The chief 

 characteristic of this sub-class is the basidium (Fig. 145), i.e. the 

 conidiophore, which has a distinctive form, and bears a definite 

 number (generally 4) of characteristically shaped conidia (basidio- 

 spores, Fig. 145 c, c/, e). 



FIG. 145. Development of spores in Corticlum. 



The summit of each basidium is produced generally into four 

 conical points (sterigmata, Fig. 145 6), from each of which a 

 basidiospore is abstricted. The basidia may be classified into 

 three principal groups, each of which accompanies a distinctive 

 conidiophore: 1, the long, filamentous, transversely divided basidia, 

 with lateral sterigmata and spores, found in the Uredinacea3 (Figs. 

 146 D, 153), Auriculariacea? (Fig. 160 B}, and Pilacraceae ; 2, the 

 spherical, longitudinally divided basidia of the Trernellaceas (Figs. 

 160 cd; 161 iii. iv.) ; and 3, the ovoid, or cylindrical, undivided 

 basidia of the Autobasidiomycetes (Figs. 145, 163, etc.) ; the two 

 last have apical sterigmata and spores. 



The first two groups are the septate basidia (protobasidia), of the Protobasidio- 

 ini/cetes; while the unseptate basidia (autobasidia) of the Autobasidiomycetes 

 are the third group. On the formation of the basidiospores, the nucleus 



