350 LESSONS WITS PLANTS 



and fragile ones, but botanists make no distinction in the use of 

 the two terms. 



432c. The "spawn" or "brick" used by gardeners in mushroom- 

 growing is simply dried mycelium contained in a mass of more or 

 less decomposed vegetable matter, as manure. 



433. A plant of a common poisonous mushroom 

 is shown in Fig. 367. Here there is another 

 structure upon the bulb -like base, suggesting a leg 

 of a boot. This is called a volva. The annulus 

 is shown- just underneath the pUeus. 



433a. This volva, which is sometimes beneath the ground, af- 

 fords the best means of distinguishing the deadly amanita from 

 edible mushrooms. There are volvate mushrooms which are whole- 

 some, but one should never incur risk in eating them unless he is 

 perfectly certain as to the identification of the different kinds. In 

 fact, this caution may be applied to all wild mushrooms. Persons 

 who desire to be able to distinguish the edible mushrooms should 

 consult the writings of C. H. Peek, State Botanist of New York, 

 and those of Atkinson in bulletins of the Cornell University Experi- 

 ment Station ; also Gibson's "Our Edible Toadstools and Mush- 

 rooms," and Palmer's "Mushrooms of America, Edible and Poisonous." 

 Those who want to cultivate mushrooms should secure Falconer's 

 "Mushrooms: How to Grow Them." 



434. All the plants which we have thus far 

 studied have green leaves and twigs. They take 

 in crude food from the soil and also from the 

 air and work them over into complex organic 

 compounds. Usually, only those plants which have 

 green parts (that is, which contain chlorophyll) can 

 do this. The mushroom has no green parts. It, 

 therefore, generally absorbs food which already has 

 been elaborated or organized. That is, plants des- 



