Groups into Which Plants Naturally Fall 451 



plant remains, thus turning them back into the general circula- 

 tion of nature and rendering a service to the remainder of living 

 things. This dependence upon other organisms for their food, 

 with the correlated absence of chlorophyll, is then 1 one great dis- 

 tinctive feature. 



The principal kinds of Fungi are these: Bacteria, commonly 

 called "germs," or "microbes," tiniest of living things, some of 

 them harmless, others useful, and others the causes of deadly 

 diseases; Yeasts, but the reader knows what they do; Molds, 

 which spring up on moist bread, preserved fruits, and other good 

 materials, spoiling them quickly for use; Mycorhiza, which form 

 caps of closely-felted threads over the ends of some roots, and aid 

 them to absorb materials from the soil; Water-molds, which form 

 the white haloes round dead insects or small fish in the water; 

 Blights and Mildews, showing as powdery or woolly white fuzzes 

 on grape leaves and others; Rots, which soften, discolor, and ruin 

 potatoes and other vegetables and fruits; Spots, which darken 

 round areas on various leaves; Smuts, which convert ears of 

 grain to an unctuous black powder; Rusts, the ragged red spots 

 which appear on the leaves of the wheat in over-wet seasons, and 

 on other grains also, to their infinite damage, but which are dear 

 to the botanical teacher because of their heterogeneously poly- 

 morphic ontogeny; Mushrooms, which are good to eat, and Toad- 

 stools, which are not; Puff-balls, whose names sufficiently describe 

 them; Black-knots, which form swellings on branches of Cherries, 

 with many destructive diseases of Chestnuts and other large 

 trees; Bracket-fungi, which appear on the outside of tree-trunks 

 as a kind of crude hemispherical bracket, unfortunately, however, 

 with the flattened side down; the Lichens, gray, crisp, brittle, and 

 crusted, living on rocks, fences and tree-trunks, and deriving their 

 food from certain kinds of small Algae which they hold enslaved 

 in their meshes; and a great many others not familiar to the 

 public but well known to botanical students. 



In shapes the Fungi are even more diversified than the Algae, 



