192 



PENICILLIUM AND AGARICUS 



l.RSS. 



of the distance from the circumference of the pileiis to the 

 stalk. In the common edible mushroom {Agaricus catii- 

 pestris) these lamellae are pink in young specimens, and 

 afterwards become dark brown. 



^SR^'*/" 



Fig. 41. — J gar tens lampestris. 



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

 from a mycelium {my), and expanding into the pileiis {/), on the under 

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



B, transverse vertical section of a lamella, showing the hyphoe (ky) 

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

 the sterigmata spring. 



c, one of the club-shaped cells [a), highly magnified, showing its two 

 sterigmata {stg), each bearing a spore {sp). 

 (B and c after Sachs.) 



The mushroom is too tough to be readily teased out like 

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



