FUNGOID DISEASES OF PLANTS 129 



kind of growth which comes on a piece of Cheddar cheese 

 in the unlikely event, in these days, of its being left in 

 a damp cellar and forgotten. Here we shall see a sort 

 of blueish green fluff. Under a magnifying glass this flufE 

 will be seen to consist of extremely delicate filaments. 

 These are as much fungi as are the mushrooms and toad- 

 stools. In fact we will go the whole hog and give it its 

 proper name, Penicillium glaucum, but for the rest of 

 this chapter I shall fight shy of botanical names as niuch 

 as possible, as these are well calculated to break any 

 printer's fount of type, and are rather a clog to the general 

 reader. Some day let us hope that botanists will be 

 able to simplify their nomenclature, which varies too 

 with different authorities, but the secret is simple enough 

 as a rule once it is unlocked. 



The fungi in the foregoing table are divisible into five 

 sub-classes, viz. the Carpomycetes, or mushroom and puff- 

 ball fungi ; the Oomycetes, or parasitical disease fungi ; 

 the Zygomycetes, or mould and mildew fungi ; the Myxo- 

 mycetes or shme fungi ; and the Protomycetes or first 

 fungi, including yeast : the aflfix-mycetes, so common 

 in this order of plants, coming from the Greek word /tv/c?;?, 

 mukes, a mushroom. 



Fungi as a group are totally distinct from all other 

 plants, even the seaweeds and Hchens in their own order, 

 by reason of one vital property, which forms an absolute 

 fine of demarcation between them and the rest of the 

 vegetable kingdom, in that they contain no chlorophyll. 

 Chlorophyll is the green colouring matter which char- 

 acterizes all other plants. It may be disguised, as in 

 copper beech or red seaweed, but is there all the same. 

 This substance, which under the microscope usually 

 takes the form of a spiral ribbon within the plant cell, 

 performs the highly important function of extracting 

 sustenance from sunhght and air, and mineral substances 

 in the soil. Now the main difference between an animal 



■d a plant is that the former cannot live on minerals 



