192 



PENICILLIUM AND AGARICUS 



LESS. 



pestris) these lamellae are pink in young specimens, and 

 afterwards become dark brown. 



The mushroom is too tough to be readily teased out like 



FlG. ^i.Agaricus campestrts. 



A, Diagrammatic vertical section, showing the stalk (st) springing 

 from a mycelium (my], and expanding into the pileus (/), on the under 

 side of which are the radiating lamella? (/). 



B, transverse vertical section of a lamella, showing the hypha; (hy} 

 turning outwards to form the layer of club-shaped cells (a) from which 

 the sterigmata spring. 



C, one of the club-shaped cells (a), highly magnified, showing its two 

 sterigmata (^), each bearing a spore (sp). 



(B and C after Sachs.) 



the mycelium of Penicillium, and its structure is best in- 

 vestigated by cutting thin sections of various parts and 

 examining them under a high power. 



