VOL. XXVIII.
INDIANAPOLIS, IND. MAY 6 1893.
NO. 18.
Written for the Indiana Farmer.
Molds.
BY OEO. W. MARTIN.
Believing tbat the subject of molds is
oftentimes a puzzling question to the practical farmers I have submitted this article
for the benefit of the agricultural class.
Molds are the representatives of the lower
forms of plant life. They belong to that
group of' plants known as _7tallopltytc_
(characterized by the absence of stems and
and leaves). The ThaXlophytes are divided
into Algae and Fungi. The one is always
known by the presence of chlorophyll
(green coloring matter) or various pigments, imparting a red, brown, yellow or
Fig. I.   This represents a mycelial "mass, showing
the manner of branching.    .
olive color to the organism, and is capable
of carrying on the process of assimilation.
They are neither parasitic (living on organized matter) nor saprophytic (living on
dead matter), but lead a purely independent life, devoting their whole life-work
to the manufacture of organic matter. The
other is known by the absence of culoro-
phyll and pigment colors, and thereby are
unable to do the work of assimilation, but
choosing the opposite, they lead dependent lives, subsisting on matter already
organized.   They therefore live the life of
Fig. 2. This diagram shows a surface mycelial
thread with upright hyphal branches each bearing
a conidium, the filament also showing root-like
structures which penetrate the substratum below.
either a parasite or saprophyte. The
former are producers of organized food,
while the latter are consumers. Hence, it
is this latter form of plant life, Fungi, on
which is based the subject of this paper.
There are several recognized classes of
fungus-growth, but the order of Mucorini
(common molds) will be taken as a type
to illustrate tho salient characters of
molds. Of this order mucor may be taken
as an example. This mold (a saprophyte)
is a very common one, found feeding on
various kinds of dead or decaying sub-
tances, such as bread, horse-dung, various
fruits, saccharine fluids, etc. It can always be recognized by the white, frosted
appearance it gives to substances when
first emerging upon their surfaces. To
the casual observer it is puzzling to know
the origin of such peculiar plant gr&wth.
The solution is this: The atmosphere is
thoroughly alive with spores (fungus-
germs) which, when they find the proper
host, thus furnishing them the proper
condition for growth and multiplication,
develop at once into long branching filaments (hyphae). One can obtain general
information on the whole group of molds
by taking a morsel of  bread moistened
Fig. 3.   This illustrates a conidium developing into a hyphal branch, wh'ch is th« miniature mycelium.
with water and placing under a tumbler
in a warm room for a day or so. The first
thing to appear on its surface is a film of
delicate, white, thread-like masses (mycelium). Presently the whole surface
growth changes from a white to black
color. This change of color indicates that
the plant has reached mature growth, and
this mature growth is shown by globular
bodies (conidia), terminating the upright
stalks (hyph.) rising from the filamentous
mass (mycelium) below. The conidium
which mounts the hyphal branch contains
an infinite number of spores which are
again taken up by the atmosphere and
sown broadcast.
When the spore first falls upon the bread
it develops at once into a filament (cylin-
Fig. 4. Showing amass of mycelial threads, with
conitlial chains surmounting the hyphal branches.
The conidia in this figure and in fig. 2, are produced by ordinary cell division.
drical tube); this filamentous growth both
in length and in sending down rootlike
structures into the substratum of the bread
resembles very much the growing vine of
the strawberry plant. But unlike the latter the whole mycelium consists of but one
cell, though infinitely branched; it is very
seldom that partitions are observed in any
of the filaments of the order mucorini.
In reference to the structure of the mycelial mass: The cell walls are thin and
colorless, however in the later stages of
growth they become black. Lining the
cell wall is a colorless layer of granular
protoplasm (semi-liquid) which seems to
be more abundant and condensed in the
growing ends of the mycelial mass—the
hyphcr; the central part of the much
branched cell is filled with a colorless cell-
sap.
To trace further the life history of this
saprophytic plant, mention should be
made of propagation—how it reproduces
itself. Two phases are represented, viz:
the asexual (without the sex act), and the
sexual. The former is effected in two ways,
(1) the hyphal branch standing on the mycelial thread may bear on its summit a
single conitlium or a chain of conidia; in
the latter case the topmost conidium is the
oldest of the chain, being cut off first; the
method employed by the hypha is that of
Fig. 5. A mycelial mass showing tlie a°erphase
by internal cell division, (a) Shows tlie early phase
of the sporangium, (b) the eater, and both contain
ing spores.Cach spore developing like ln fig. :*.
ordinary cell division—simply putting a
wall across or at right angles to the longer
axis of the filament, (2) or there may bo
found one large terminal cell—the sporangium on the summit of the hyphal
branch. This sporangium or mother cell
is formed by the dilatatim of the terminal
end of the hypha into a large spherical
body filled with condensed protoplasm.
This cell is separated from the hyphal
stalk by a cross wall, and presently
the protolasmic contents within the
sporangium, by internal cell division, are
broken up into an infinite number
of small cells (spores) having cell
walls of their own. As the spores
form a peculiar growth marks the terminal
end of the hypha, the cross wall separating
the two structures becomes convex on the
side of the mother cell, thus making the
upper end of the hypha club shaped.
The spores of the mother-cell are soon
set free by the absorption of the sporan-
Fig. 6.   Showing the conjugation of two hyphal
threads—the cells In actual contact—tlie terplutse.
gium wall. These spores are the same in
structuro and function as those liberated
from the conidia. The latter phase, the
sexual, which is a subsequent development
of tho asexual, is produced by the conjugation (a yoking together) of two specially
differentiated cells, whose contents become
fused and thus form a single cell (Zygospore.) The sex act may take place on the
surface or within the nutritive medium of
its host; at either place it consists in the
coming together of two hyphal branches.
As the ends of the branches approach each
other they become club-shaped. When
the ends come in contact both walls are
absorbed, the contents of both cells mingle
and become a single cell, a Zygospore, as
before named. At the same time the end
walls are absorbed, each hyphal branch
puts a cross wall back of its terminal protoplasmic mass, thus throwing the Zygospore between the two cross walls.
This Zygospore is the product of the sex
act, and for a time undergoes a resting
stage. While in this stage, it secretes a
thick wall around   itself   for protection.
<^^_SS
Fig. 7. Further development of iig. 6; a and b the
cells fused in one: c the result of the sex act—the
zygospore in a resting stage; thts cell produces a
mycelium—the same as in fi_. I.
Sooner or later this spore develops a mycelium, the same as before which in turn
produces again the asex and sex phases.
Such is the life-history of one of the common molds. In conclusion let me warn
the observer not to confound the molds
with mildews, for they are not the same.
Department Biology and Geology,
Indianapolis High School.
GOOD   VARIETIES OP   CORN   GROWN
BY INDIANA   FARMERS.
Their Record at Purdue University Experiment Station.
Editors Indiana Fabmeb:
It will be gratifying to the Indiana readers of the Farmer to learn that the varieties of corn which have been improved
by Hoosier farmers have made the best
average yields at the Indiana Agricultural
Experiment Station. The following table,
which is taken from bulletin No. 43 just
issued, shows the average yields of the
leading varieties produced by Indiana
growers as well as the time required by
each to mature:
No. Name No. years  No. days   Bushels
grown    to mature  per acre
1 Purdue Yellow.         S 112 68.73
2 White Prolific.         5 125 76.75
3 Yellow Nonesuch...        2 119 66.30
4 Boone Co. White        5 1.6 72.33
5 Riley's Favorite        5 123 69.91
6 -tfunn's Eary         2 HO 64.15
7 llartman's White...       3 117 65.68
8 Early Yellow        3 112 59 61
9 Fleming's Yellow...       3 113 69.51
10 Yellow speck'dd'nt       4              119 70.775
The bulletin above mentioned contains
a more complete record of the above
named and many other varieties of corn,
showing per cent of stalk and ear, shelled
corn, smut, etc. It also summarizes the results oi many other experiments with corn,
as well as with sugar beets.
The station bulletins are sent free to'all
applicants. Persons desiring the same
should address Prof. C. S. Plumb, director,
Lafayette, Ind. W. C. Latta, '
Purdue University. Agriculturist.