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Type.-MUSHROOM. AGARICUS CAMPESTRIS. 



The common Mushroom consists of : — 



(1) The mycelium. 



(2) Th.e fructifications. 



(1) The Mycelium is composed of septated hyplise, 

 containing many small nuclei, and abundant 

 protoplasm. It vegetates on decaying animal 

 or vegetable matter. From the mycelium 

 spring a number of fructifications. 

 (2; Development of the Fructification. — This consists 

 at first of a solid, pear-shaped body composed 

 of young hyphse, all similar to one another. 

 At an early stage an annular air- cavity is left just 

 beneath the apex, the upper wall of which becomes 

 the under side of the inleu8^ and from this radial 

 hymenial lamell(B grow down, filling up the cavities. 



The tissue below the cavity elongates into a stalk, 

 while the hj^phse forming the margins of the pileus 

 constantly increase. 



The hyphse which lie beneath the air-cavity become 

 stretched and se^^arate from the stem from below 

 upwards and so form a membrane. This runs from 

 the upper part of the stalk to the margins of the 

 pileus, into which their hyphse are continued. As 



