10 



on decayed wood and do not attack the living. They are saprophytes 

 and not parasites. This distinction should be kept in mind. 



The saprophytes are found on dead liuibs and trunks of the locust, 

 mountain maple, hickory, ironwood, ash, chestnut, basswood, elm, 

 walnut, oak, red maple, beech, willow, sassafras, golden rod, aster, 

 and many other plants. After a forest fire many forms of saprophytes 

 may be found on the dead limbs and trunks of various trees. 



What are fungi? They are plants produced by spores and in this 

 respect differ from seed-bearing plants. The ferns and the mosses 

 are also spore plants and are higher in the scale of plant life than 

 the fungi. The fungi include the moulds on bread, cheese, and pre- 

 served fruits; mildews, as the downy mildew causing the rot of the 

 Irish potato; rusts on wheat; black-knot on the plum and cherry; 

 mushrooms, edible and poisonous ; yeasts ; puff balls, etc. 



The total number of plants of all kinds known to science is about 

 two hundred thousand species. There are about fifty thousand 

 species of fungi, and of this number about fifteen thousand belong 

 to the sac-fungi (Ascomycetes). The sac-fungi are a very destructive 

 form- of fungus growth and produce a number of diseases on ac- 

 count of the fact that many of the species have the parasitic habit. 

 In this division of fungi, there are the leaf-curl of the peach; the 

 black-knot of the plum and cherry; many of the powdery mildews; 

 the large morels, prized for food ; the yeast plant, known to make.^s 

 of bread and beer; the green mould on cheese, as well as the deadly 

 chestnut blight. After the chestnut trees or sprouts have been killed 

 by the blight, numerous other fungi will attack the dead wood. These 

 mi:- 1" not be charged with the destruction of the tree or sapling. 

 These are the scavengers that come to feed upon the dead and are 

 known at. saprophytes. Between thirty and forty different species of 

 fungi are known to attack dead chestnut limbs, stumps, and logs. 



PROPAGATION OF THE CHESTNUT BLJGHT. 



The Diaporthe parasitica is propagated by at least two kinds of 

 microscopic spores. One kind of spore is developed in minute sacs. 

 Each sac conuiius eight spores and nature fills each tiny sac with the 

 eight S])ores as uniformily as one finds four legs on a dog and two ' 

 on a bird. These are sometimes called the winter spores. These 

 spore-sacs are developed in minute flasks resembling carafes or long 

 necked water bottles and are formed abundantly in the autumn. In 

 this way the fungus tides over the winter. Another kind of spore 

 more minute than the winter spore may be found in thread like masses 

 in early spring and during the summer. These are called summer 

 spores, or conidial spores. Conidial is derived from tlie Greek word 

 meaning dust. Sometimes the thread mass or spores is more than 

 half an inch in length. Such a thread will furnish millions of spores. 



