144 THE VEGETABLE KINGDOM. 



peculiar to them, and in many cases exceedingly 

 destructive. The microscopic fungus Puccineagraminis, 

 is the parasite which fixes itself to corn and produces 

 the disease known as mildew, and the Uredo segetum 

 (another microscopic fungus) causes the " smut ; " the 

 " bunt " is caused by the Uredo foetida, and the " spur," 

 or " ergot," which attacks rye, is caused by the 

 Acinula clams. These fungi completely destroy the 

 grain of corn, in which they form, and propagate in 

 the most rapid manner; the ergot is moreover a 

 dangerous poison to those who eat the bread made of 

 rye infected by it. The Truffle (Tuber cibariuni) is a 

 kind of underground fungus, and is esteemed a dainty. 

 Mushrooms are also fungi, and several species are 

 sufficiently wholesome; these are the Field Mushroom 

 (Agaricus campestris) and the Fairy-ring Mushroom 

 {Agaricus pratensis) . 



4. LICHENES (Lichens), 



Are those dry scaly growths forming grey, green, or 

 yellow spots on the barks of trees and in various other 

 places, and they grow in a sort of leaf or 

 scale called a "thallus." They are used 

 as articles of food and as " dye-stuffs ; " 

 the Cetraria Icelandica is the " Iceland 

 Moss " used here for making a sort of 

 nutritious drink or jelly, the natives of 

 Iceland, however, use it as common 

 food ; the Cladonia rangifarina, or Rein- 

 deer Moss, is the chief food of that 

 useful creature which forms the whole 

 property of the Laplander ; and the Roccella tinctoria is the 

 substance from which the dye called " archil " is procured. 



5. FILICES (Ferns). 



The Ferns are a very numerous order of acrogenous 

 plants, growing in the temperate regions from a 

 rhizome or underground stalk (commonly called its 



