The Scottish Naturalist. 



65 



these latter cells gradually grow towards the exposed surface on 

 each side of the gill, b, b, they get considerably smaller in size, 



p 



Fig. I. — THE COMMON' MUSHROOM (aGARICUS CAMPESTRIS, L. 



Vertical transverse section through gill, showing '* trama," a, a, and the two liymeni 1 

 or spore-bearing surfaces c, b. X 250 diam. 



denser, and less and less transparent. The exposed surface of 

 the gill is the fruiting, spore-bearing, or hymenial surface, and 



