TO OTHER PLANTS H 



The various forms of saprophytic fungi grow on all sorts of dead 

 and decomposing matter ; the various forms of mould on bread, 

 on cheese, on chestnuts and on fruit are more or less familiar 

 objects to every one and yet few stop to think of them as genuine 

 plants, each with its peculiar mode of perpetuating its kind, each 

 with tastes and habits peculiar to itself, and each as distinct from 

 other forms of mould as pines and hemlocks are from oaks and 

 maples. More or less familiar also are the more conspicuous 

 forms popularly known as toad-stools or puff-balls, or forming in- 

 verted brackets on the stumps and half dead trunks of standing 

 trees. Less known are the myriad minute forms found on twigs 

 and branches and dead herbaceous stems and presenting as diverse 

 forms of structure as do the better known and more familiar flow- 

 ering plants. 



When we pass to the parasitic forms of fungi, we find scarcely any 

 limit to their habitat. From present indications it is probable that 

 nearly every species of the higher plants has growing upon it some 

 fungus species that has adopted it as a host and lives at its ex- 

 pense. Some of the higher plants have three or four parasites 

 preying upon them. The common spring anemone, for example, 

 besides fighting its way in the struggle for existence with other 

 plants of its own size and larger, supports a mildew, a cluster- 

 cup, a rust, a smut, and a Synchytrium as parasites, and we have 

 found three of these infesting the same leaf and the poor thing still 

 alive, if not flourishing ! 



Certain species of parasitic fungi exist under widely different 

 forms at different seasons, and frequently alternate from one host 

 plant to another a circumstance which adds greatly to the diffi- 

 culty of study and identification. Certain forms which were form- 

 erly recognized as distinct species, and even as members of dif- 

 ferent genera are now known to be simply the diverse stages of 

 the same parasite preying upon widely different hosts at different 

 seasons. 



Since we have spoken of the evident relation of fungi and algae 

 it is best to make a single reference here to the probable origin of 

 of the fungi. 



i . It is clear that the lower types of fungi known as algal-fungi 

 have been derived from their nearest allies among the green 

 plants. Some, doubtless, by continued living where there was 



