AGARICUS CAMPESTRIS 141 



borne on a stalk, or stipe. Is there a ring of tissue 

 (annulus) around the upper part of the stipe? 



(a) The pileus. Describe the shape, size, color, 

 and any characteristic markings on its upper 

 surface. Examine carefully and describe the 

 margin of the pileus. Are there any charac- 

 teristic elevations or depressions on the pileus? 

 If so, state how many and where they are. 

 Compare the color of the under surface in young 

 and old specimens. 



Describe the shape, arrangement, relative 

 number and color of the lamellae, or gills. 

 Are the margins (free edges) of the gills entire 

 or notched? Do they extend clear to the stipe? 

 Are they attached to the latter? Do they all 

 extend clear to the margin of the pileus? 

 Describe any variations in size. Count the 

 gills in a space of 10 mm., then calculate from 

 the circumference of the pileus the total number 

 of gills. 



(b) The stipe. Describe its shape, and color, and 

 any variations in color and diameter. Describe 

 its mode of attachment to the pileus. De- 

 scribe the method of attachment of the plant 

 to the substratum. Is there a mycelium or 

 other special means of fixation? If so, is it 

 continuous with the tissues of the stipe? 



(c) The annulus. If an annulus is present, de- 

 scribe its location on the stipe; its structure. 

 Compare its structure with that of the mem- 

 brane on the edge of the pileus. What is the 

 relation between the membrane and the annulus 

 in young specimens? When these structures 

 are united they form a veil. Is a veil present 



