No. 33.] - 355 
We have thus seen that many fungi live upon dead plants, others 
take an active part in killing the plants in order to feed upon the 
dying tissues, while others live upon the outside or occupy the inside 
of the host without causing further harm than using part of the 
plant’s nourishment. Between these forms there are all gradations. 
A few words regarding the structure of fungi and their modes of 
reproduction may be prized by those unfamiliar with the subject. 
Fungi are plants of simple.organization, but yet of as great diversity 
of structure and habit asis found in the larger plants that fill up a 
landscape. They are often spoken of as one would speak of the 
cabbage family, for instance, but there is really no such close rela- 
tionship, they should rather be considered as varying from each 
other as much as do the various kinds of trees and herbs. 
The body of the fungus is composed of branching threads, except 
in bacteria, and a few other cases, where the threads, if they may be 
so called, are unbranched and extremely short. These threads taken 
together are known as mycelium. Sometimes the mycelium is com- 
pacted into a solid body of definite form, as in mushrooms, ergot, 
etc., but quite as often it remains as loose tangled threads. 
All fungi produce spores. These are minute bodies consisting 
essentially of a single cell, having some direct office in the reproduc- 
tion of the species. Sometimes the spores are compounded by several 
cells being united. ‘They may be globular or any other shape. They 
usually grow at last into another individual, that is, they are really 
seeds in function, except some of them which are only the male ele- 
ment in the sexual reproduction. Of this latter kind are the pollen 
.grains or pollen spores* of flowering plants, which are as truly 
spores as the spores of ferns, or of corn smut. There are many 
kinds of spores designated by names usually formed by putting a 
prefix before the word spore, for example pollenspore, ascospore, 
uredospore, etc. a 
Some fungi like some weeds are able to grow and fruit whenever 
cireumstanees are favorable, but the majority have their appointed 
seasonsasmuch astrees and herbs. Some produce but one kind of 
spores, as peach curl, while others have several kindsto meet the re- 
uirements of different seasons and conditions, as wheat rust. Some 
fungi complete their growth during warm weather, while some grow 
slowly all winter and have a fresh set of spores ready by spring, of 
which the black knot is an example. ; 
It we consider fungi in relation to the application of fun- 
gicides, they may be conveniently classed -as epiphytic, embrac- 
ing such as grow on the surface of plants, like the pea mildew, 
and endophytic, such as grow within the plant, like peach curl or 
oat smut. Many of the endophytic kinds send branches of the 
mycelium to the surface on which spores are borne, but the rest of 
* So called by De Bary, in Vergleichende Morphologie und Biologie der Pilze, 
1884, p. 140. 
