DEVELOPMENT OF BASIDIOCARPS AMONG AGARICS 557 



eccentric stipes, those of Pleurotus being white-spored and those 

 of Claudopus pink-spored. Psalliota is purple-brown-spored and 

 has an annulus, and its gills are free from the stipe. Coprinus is 

 black-spored, and its gills deliquesce. 



Several developmental types exist among gill fungi. In Hygro- 

 phorus, Cantharellus, and Clitocybe the gills are gymnocarpous, 



Equal 



Unequal 



Flexuous 



Dichotomous 



Fig. 140. Diagrams of gill characters, as shown by the lower surface of the 



pileus. 



arising around the lower edge of a dome-shaped portion that is 

 to be the pileus. The lower margin of the pileus arches down- 

 ward toward the stipe primordium, and the hyphae from each 

 may intertwine beloM' the developing gills. In Armillaria, Co- 

 prinus, Lepiota, Lactarius, Alarasmius, Russula, and other genera 

 a schizogenously formed furrow encircles the stipe primordium, 

 marking the beginning of the differentiation of pileus and stipe. 

 This furrow arises endogenously, and hyphae from the ceiling 

 of the furrow grow downward to form the gills. The thin layer 

 of fundament tissue beneath the furrow and extending from the 



