SOME PLANT GROUNDLINGS. 95 



one indeed, and includes a vast number of species, 

 ranging from plants of very respectable size to those 

 of merely microscopic dimensions. The whole group 

 of those organisms, which cause the diseases of plants 

 known as smut, rust, mildew, blight, and the like, is 

 included under the name of " fungi ; " so that to the 

 gardener and the farmer, the study of these ground- 

 lings of the vegetable kingdom can be shown to be 

 fraught with very practical interest in view of the 

 cure, or, what is better still, the prevention of plant 

 ailments. 



To begin with, we may be clear about one point 

 regarding our mushrooms, toadstools, smuts, mildews, 

 and the like namely, that they are all of much 

 simpler structure than ordinary flowering plants. 

 Our buttercup or daisy is a complex being. It has 

 its parts specialised to form organs of distinct nature 

 such as root, stem, leaves, and flowers. Again, 

 when we take it to pieces under the microscope, we 

 see that its tissues or layers are made up of a whole 

 variety of different elements cells and fibres. 



Not so is it with our fungi. These, as a rule, 

 have no such development of parts into roots, leaves, 

 and the like, and all their tissues are built up of cells 

 only. No fibres exist in them. They are soft-bodied 

 plants, such as we know the mushroom to be. Yet 

 this is not all, as regards our fungi. Taking them 

 in their simplest phases, we find the essential part of 

 each fungus to exist as threadlike branching filaments, 

 which constitute the so-called mycelium. This is, in 

 truth, the fungus proper, and most of the duties of 

 life pertaining to nutrition, and so forth, are dis- 

 charged by these creeping threads. 



These latter, again, are white in colour. They 



