terior (the gleba), the remainder being sterile.
381. Many common puff-balls belong to the genus
Lycoperdon, the type of the family Ly coper daceae, of
which there are a good many species. The genus Cal-
vatia contains the Giant Puff-ball (C. maxima), whose
spore fruit is sometimes 30 centimeters or more in diam-
eter. Here it must be remembered that the proper plant
lives underground, obtaining its food from decaying vege-
table matter, while the great ball is a fruit containing
basidia and basidiospores.
382. The Bird-nest fungi (Order Nidulariales) are
so noticeable that they should be examined here. These
little fruits usually grow on twigs and sticks, and are
closed at first, and then open and cup shaped. They are
a centimeter or less in height and width, and when mature
contain several small brownish spore packets (the ''eggs''
of the little *' nests"). When young these *'eggs" are
small cavities lined with basidia and surrounded by a
dense layer of hyphae. When the tissues about them
deliquesce these spore-bearing cavities persist as hard
walled bodies.
\A
Fig. 109. — Development Fig. 110. — Development
of bird-nest fungi. of stinkhorn.
383. The Stink -horns (Order Phallales) live as sap-
rophytes, feeding upon decaying organic matter in the
ground, or less frequently as parasites in the roots of
various plants, eventually developing globose subterra-
nean fruits. These fruits produce their spores in a circu-
TOADSTOOLS 229
lar layer, and when mature become ruptured by the rapid
growth of their central tissues, resulting in the formation
of a stalk which carries up the slimy mass of spores to
some distance above the ground. The intolerable odor
of most of the species has earned for them their inelegant
but quite appropriate common name.
384. The Toadstools (Order Agaricales). The fruits
of these plants in some respects are the highest of the
Carpomj'ceteae. They are not only of considerable size
(ranging from 1 to 20 centimeters, or more, in height),
but their structural complexity is so much greater than
that of the other orders that they must be regarded as the
highest of the fungi. Like the Puff-balls, they produce
an abundance of vegetative filaments (mycelium) under-
ground or in the substance of decaying wood. These
filaments are loosely interwoven, becoming in some cases
densely felted into tough masses or compacted into root-
like forms. While mostly saprophytic some appear to be
parasitic, especially on the woody tissue of trees which are
rotted by them. Sooner or later these underground
filaments produce the spore fruits, which are mostly
umbrella-shaped, as in common Toadstools and Mush-
rooms, or of various more or less irregular shapes, as in
the Pore fungi, Coral fungi, etc.
385. The Mushrooms of the markets (Agaricus cam-
pcstris) so connnonly cultivated by gardeners, may illus-
trate the mode of development of the Toadstools (Family
Agaricaceac). The vegetative filaments compose the so-
called ''spawn" which grows through the decaying matter
from which it derives its nourishment. Upon this at
length little rounded masses of filaments arise, which be-
come larger and larger and are the young fruits. The
circular spore-bearing layer is first internal and su])ter-
ranean as in the Stink-horns, but it is brought above
230 PHYLU.M VII. CARPO^IYCETEAE
ground by tlie rapid growth of a central mass of stalk
tissue, and later by a rupture of tissues the hymenium be-
comes external.
386. At maturity the spore fruit of the Mushroom
consists of a short thick stalk, bearing an expanded um-
brella-shaped cap, beneath which
are many thin radiating plates, the
gills. Each gill is a mass of fila-
ments whose enlarged end-cells
(basidia) come to, and completely
Fig. 111. -Development of covcr, both of its surfaccs. The
mushroom. basidla produce spores in the usual
manner for plants of this class, that is, upon slender stalks.
387. In the Pore fungi (Polyporaceae) the basidia line
the sides of pores; in the Prickly Fungi (Hydnaceae) and
Coral fungi (Clavariaceae) they cover the surface of spines
and branches; while in the Leathery fungi (Thelephora-
ceae, Stereum, etc.) they form a smooth surface.
388. Nothing is yet known as to their sexual organs.
Several botanists have described such supposed organs
upon the vegetative filaments before the formation of the
spore fruit, but there are grave doubts as to the correct-
ness of the observations, and it is the general opinion that
these organs have become obsolete.
389. The vegetative filaments (mycelium) of some
species of this order (as Foines fovientariiis, etc.) often
form thick, tough, whitish masses of considerable extent
in trees and logs.
390. We know but little as to the germination of the
spores and the subsequent development of the vegetative
filaments.
391. Several families of more or less reduced basidium
fungi which probably have been derived from the fore-
going families, as the Ear Fungi (Auriculariales) , Jelly
i
LAHOUATORV STUDIES 2:U
Fungi (Tremellales) and the ytill more reduced Exoha-
sidiales are probably to be placed here.
Laboratory Studies, (a) Collect specimens of puff-balls in
various stages of growth. IMake very thin sections of the young
spore fruit, and look for the cavities lined with spore-bearing
cells (basidia).
(b) JMount in alcohol some of the dust which escapes from a
dry iniff-ball. Examine with a high power, and note the spores
and fragments of brokcn-up filaments.
(c) Dig up tiie earth under a cluster of young i)ufT-balls, and
observe the vegetative filaments. Examine some of these
filaments under the microscope.
(d) In the summer look for Earth Stars (Geaster) in which
the outer peridium is rolled back (open) when wet, and closed
when dry.
(e) Stalked Puff-balls (Tylostoma) may often he found witli
a stallv 3 to 10 or more centimeters long holding the spore
cavit}' aloft.
(/) Look for Bird-nest fungi in fruit on sticks and twigs on
damp ground. Note that when j^oung the fruits are closed
and solid, and that as they become older much of the internal
tissue deliquesces, leaving the little egg-like spore packets.
(g) Collect specimens of Stink-horns in various stages of
development and preserve in formalin. Make vertical sections
of the immature (globose) spore fruit and note the circular
spore layer. Study the basidia and basidiospores under a
high power.
(h) Collect a few toadstools in various stages of development,
securing at the same time some of the subterranean vegetative
filaments. Note the appearance of the young spore fruits,
and how they develop into the mature toadstool.
(0 Select a mature (but not old) spore fruit with dark-
colored spores, cut away the stem, and place the top (pileus)
on a sheet of white paper, with the gills down. In a few hours
many spores will be found to have dropi)ed from the gills uj)on
tlic paper; these are the so-called "spore-prints".
(j) Examine the minute structure of various parts of tiie
spore fruit and the vegetative fdaments, and ol)servo that tiiey
are composcnl of rows of cylindrical colorless oolis joiiunl end to
end.
232 PHYLU:M VII. CARPOMYCETEAE
(k) Make very thin cross-sections of several of the gills and
carefully mount in water or alcohol. Note the layer of spore-
bearing cells (hymenium), with basidiospores borne upon little
stalks.
(/) Examine the pores of fresh polypores in transection,
looking for the basidia and basidiospores in the pores.
(w) In like manner make transections of Prickly Fungi,
Coral Fungi, and Leathery Fungi, but in these look for basid-
iospores on the outer surface of the sections.
Class 16. TELIOSPOREAE. The Brand-Fungi
392. Here are collected a considerable number (4200
species) of extremely parasitic fungi, certainly related to
the fungi of the two preceding classes. On account of
their excessive parasitism they are structurally much re-
duced and degraded and this has served to hide their true
relationship.
393. The plant body consists of branching septate
filaments which run through the green tissues of higher
plants, eventually producing usually erumpent spore
clusters (sori), but no definite spore fruits (perithecia, or
apothecia). Conidia of one or two kinds are usually
present, and precede the formation of teliospores.
394. The Rusts (Order Uredinales) are minute,
parasitic, greatly degraded fungi
which grow in the tissues of higher
plants.
395. A common Wheat rust
{Puccinia graminis) may be taken
oraeciospores and pycnio- as au illustratiou of the ordcr. It
is common wherever wheat is
grown, and often greatly injures and sometimes entirely
destroys the crop. Its round of life shows four well-
marked stages, as follows: (I) In the spring clusters of
minute yellowish cups occur on the leaves of the
WHEAT RUST 233
BarbciT}'. These cups are at first internal rounded
bodies, in which spores (conidia) develop in chains,
at length bursting through the lower epidermis. The
spores quickly drop out and are carried away by the
winds. This stage is known as the cluster-cup stage,
and the spores as aecidiospores, or aeciospores.
396. Associated with this cluster-cup stage there are
usually flask-shaped structures known as spermogones or
pycnia, in which minute spores or spore-like bodies
(pycniospores) are produced. They resemble the struc-
tures which produce sperms in the Disk Lichens. If
they have a similar function in the rusts it has not yet
been demonstrated.
397. (II) The aeciospores falling upon a wheat plant
germinate there and penetrate its tissues, through the
stomata, sending haustoria into the cells. After a few
days, if the weather has been favorable, the parasite has
grown sufficiently to begin the formation of large red-
dish spores (uredospores, or urediniospores) just beneath
the epidermis, which is soon ruptured, exposing the
spores in reddish lines or spots upon the stems and leaf
sheaths. This is the Red-rust stage, so common before
wheat-harvest. These red spores fall easily, and quickly
germinate on wheat again, producing
more Red rust, and so rapidly increasing
the parasite.
398. (Ill) Somewhat later in the season
the parasitic filaments which have been
producing Red-rust spores begin to pro- fig. 113— uredo-
duce the dark-colored, thick-walled, l^nd'sporidsi""^"'^'
2-spored bodies characteristic of the
Black Rust. Each 2-spored body consists of a contin-
uous wall tightly enclosing the two spores, here called
*'teliospores." Being thick-walled, these spores endure
234 PHYLUM VII. CARPOMYCETEAE
the winter without injury, antl when spring comes (IV)
they germinate on the rotting straw forming a 4-celled
**promyceHum" and producing several (usually four)
minute spores, called sporids. This is the fourth and
last stage of the rust. Such sporids as fall upon
Barberry-leaves germinate, and enter directly through
the epidermis, giving rise to cluster cups again.
399. These stages (I, II, III) are so different in appear-
ance that for a long time they were regarded as distinct
plants, and received different names. Thus the first
stage was classified as a species of Aecidium, the second
as a species of Uredo, and the third as a Puccinia. We
still preserve these names by sometim.es calling the spores
of the first aecidiospores (or aeciospores) and of the second
uredospores (or urediniospores), while the third name is
retained as the scientific name of the genus.
400. For a long time many botanists did not believe
the statement that this Wheat rust lives for a part of its
life upon one host (barberry), and later upon another
(wheat), but now this fact (known as ''heteroecism") is
well established not only for Wheat rust, but also for
many other species.
401. The sporids cannot ordiiiarily produce rust
directly upon wheat, probably because of the toughness
of the epidermis; but it has been claimed (by Plowright)
that when sporids germinate upon very young leaves of
wheat-seedlings they penetrate the epidermis and then
soon give rise to a red-rust stage. In such cases the
cluster-cup stage is omitted. Possibly the rusts upon
the spring wheat, oats, and barley in the Mississippi
Valley and on the Great Plains where barberry is rare
are sometimes propagated in this way. It has been
shown also that on the Great Plains the red rust lives
through the winter on the little wheat plants, and that
SEXUALITY OF RUSTS 235
its spores blow to the north in the spring from field to
field, and back to the south in the autumn. Probably
this is the more common mode of propagation upon the
Plains. Recently it has been found also that teliosporcs
occur on and in wheat kernels, and it is thought that
young plants may be infected directly from these.
402. There are many kinds of rusts, distinguished
mainly by their teliospores, which are single (Uromyces
and Melampsora), in twos (Puccinia and Gymnospor-
angium), or several (Phragmidium). In many species
the round of life is similar to that in the Wheat rust
described above (heteroecious), the hosts, however, being
different, but in others there appears to be a constant
omission of certain stages. Moreover, in many species
all the stages develop upon the same host plant (autoe-
cious).
403. Cell fusions which are now regarded as having
a sexual significance, and whose ultimate result is the
production of teUospores, have been observed in the
mycelium of some of the rusts. The simple sexual or-
gans (usually end cells of adjacent filaments) coalesce into
binucleate cells, which develop short hyphae of cells also
binucleate. In some cases these produce directly one
or more teliospores; in others one or two additional spore
forms are intercalated as aeciospores and uredospores.
Thus we may have either aecia or uredinia or both form-
ing as the first result of the sexual act, but in any event
the ultimate result is the production of teliospores.
Accordingly these several spore forms are all primarily
binuclcated, but the two nuclei unite early in the young
teliospore, and therefore the promycelial cells and sporids
are uninucleate.
404. The Smuts (Order Ustilaginales). The i^lants
which compose this order are all parasites living in the
236 PHYLU:^! VII. CARPOMYCETEAE
tissues of Flowering Plants. Like the Rusts, they send
their parasitic threads through the tissues of their hosts,
and afterward produce spores in great abundance which
usually burst through the epidermis.
There is a still greater structural degra-
dation in the plants of the present order
than in the Rusts, probably due to their
excessive parasitism.
Fig. ii4.-TeUo- 405. The parasitic threads of the
spore and sponds. *^
Smuts are well defined, and consist of
thick-walled, cellular, branching filaments, which are
generally of very irregular shape. They grow in the
intercellular spaces and cell cavities of their hosts, and
some send out suckers {haustoria), which penetrate the
adjacent cells much as in the Mildews. The parasite
generally begins its growth when the host plant is
quite young (meristematic) and grows with it, spreading
into its branches as they form, until it reaches the place
of spore-formation. In perennial plants the parasite
may be perennial, reappearing year after year upon the
same stems, or upon the new stems grown from the same
roots; in annuals it must obtain a foot-hold in the young
plants as they grow in the spring.
406. The life history of the Smuts has been made out
for but few species. Three kinds of spores (conidia,
teliospores and sporids) have been observed in many
species, and their germination has been carefully studied,
but the sexual organs (if any exist) have not yet been
discovered.
407. The Smut of Indian corn (Ustilago maydis) is
very common in autumn. The parasitic filaments are
found in various parts of the host, and at last those which
reach the young kernels or other succulent parts become
semi-gelatinous and form spores internally. There is
SMUTS 237
much crowding and distortion of these soft-walled spore-
l)earing fihunents, but here and there this structure may
be made out. When the spores are ripe, the gelatinous
walls dissolve and, the watery portions evaporating,
leave a dust}' mass of black spores. The spores germinate
by sending out a short septate filament (promycelium)
upon which minute sporids are formed laterally, much
as in the Wheat rust. Like other smuts, that of Corn
is capable of growing as a saprophyte in the deca3'ing
vegetable matter of the soil, producing an abundance of
conidia. It has been found that when the sporids or the
conidia germinate upon the meristematic parts of the
growing plant or the projecting styles of the developing
ears the}^ penetrate the surface layers, and thus secure
admission to the tissues of their host.
408. Other Smuts, as Wheat smut or Black Blast
{Ustilago tritici) of wheat, Oat smut {U. avenae), Barley
smut ([/. hordei), etc., have a structure and mode of devel-
opment closely resembling the foregoing, but with most of
these the hosts can be infected only when very young, i.e.
during or shortly after germination, or through their
stigmas at the time of flowering.
409. The Bunt or Stinking smut of wheat {Tilletia
tritici and T. foelens) represent an allied family {Tille-
tiaceae) in which the sporids are formed in a whorl at the
end of the non-septate promycelium.
Laboratory Studies, (a) Collect specimens of cluster cups
(from barberry, l)uttercups, or cvenin
amine first under a low power without niakinfj; sections. Note
the cups filled with yellowish or orange conidia (aeciospores).
Note spermogones (minute dark spots) generally on the opposite
side of the leaf.
(6) Make very thin cross-sections through a mass of cups so
as to obtain vertical sections of the cups and the spermogones.
(r) In May, Juno or July collect leaves of wheat, oats, or
238 PHYLU.M VII. CARPOMYCETEAE
barley, bearing lines or spots of Red rust. First examine a
few of the spores mounted in alcohol, with the subsequent
addition of a little potassium hydrate. Then make very thin
cross-sections thi-ough a rust si)ot, and mount as before, so as
to see the parasitic filaments in the leaf, bearing the Red-rust
spores upon little stalks.
(d) In July, August, or September collect stems of wheat,
oats, or barley bearing lines or spots of Black rust. Study the
teliospores as above, and afterward make cross-sections also.
(e) In early spring collect and examine the Black rust on
wet stems of rotting straw. Look for germinating tehospores
and sporids, which sometimes may be found.
(/) Examine microscopically the gelatinous prolongations on
"cedar-apples," and observe the teliospores, which resemble
those of Wheat rust. *' Cedar-apples," which are common in
the spring on red-cedar twigs, are in reality species of rust of
the genus Gymnosporangium. Their cluster cups occur on
apple leaves. Uredospores are lacking.
(g) Collect smutted ears of Indian corn. Mount a little of
the black internal mass in alcohol, followed by weak potassium
hydrate and observe the spores.
(h) Make very thin slices of young fresh or preserved speci-
mens and examine for parasitic and spore-bearing filaments.
The outer tissues of the distorted kernels are generally best.
(i) Make similar studies of the smuts of wheat, oats, or
barley, which may be collected in June, or about the time of the
"heading" of the grain.
(j) Make hanging-drop cultures (in water) of the teliospores
of Tilletia and Ustilago, and compare their germination.
The Imperfect Fungi
410. There are many fungi (about 16,000 species), in
some respects resembling the Ascus Fungi (Ascosporeae),
of which we know only the conidial stages. They have
been brought together temporarily in three orders under
the general name of ''Imperfect F^ungi."
411. The Spot Fungi (Order Sphaeropsidales) are
mostly parasitic on leaves and fruits of higher plants,
IMPERFECT FUNGI 239
producing whitish or discolored spots, and eventually
developing small perithecia-like structures (pycnidia)
containing conidia. Species of Phyllosticta are common
on leaves of Virginia creeper, wild grape, cottonwood,
willow, pansy, peach, apple, wild cherry, elm, etc., while
species of Septoria are to be found on leaves of box-elder,
aster, thistle, evening primrose, wild lettuce, plum,
elder, etc.
412. The Black-dot Fungi (Order Melanconiales)
differ from the preceding mainly in the absence of a
distinct perithecium, the spores developing beneath the
epidermis of the host and ])ursting through so as to form
Fig. 115. — Septoria. Fig. 116. — Fig. 117. — Cercospora.
Gloeosporiuni.
small dark-colored or black dots (acervuli). Species of
Gloeosporium and Melanconium are common on leaves,
fruits, and twigs.
413. In the Molds (Order ]Moniliales) the conidia-
bearing threads emerge through the stomata of the host,
or grow out through the outer decaying tissues, forming
moldy patches or masses. Here are many common
parasites (e.g. species of Ramularia, Cercospora, Fusi-
cladium) and saprophytes (Monilia, Botrytis, etc.), some
of which are l)otli parasitic and saprophytic.
Laboratory Studies. Altliou«2;h the Imperfect Fungi are
quite too diliicuh lor the beginner to do much with, it is well
that he should become somewhat familiar with their general
appearance; accordingly a few studies are suggested.
240 PHYLU.M VII. CARPOMYCETEAE
(a) Look for Spot Fungi on the hosts mentioned above, and
especially for the minute black fruits in the spots, making
sections of the latter.
(b) Look for Black-dot Fungi on leaves, fruits and twigs of
many plants, especially for Colletotrichum on bean pods.
(c) Look for Molds on leaves, as well as on some dead
tissues.
414. Summary for the Higher Fungi. The theory
underlying the foregoing account of the Higher Fungi is
that these plants have been derived from the Red Algae
by modifications, mostly degradational, due to the change
from a holophytic to a hysterophytic habit, accompanied
by the equally significant change from aquatic to non-
aquatic life. It is here considered probable that the
earliest fungi were those known as 'lichens," which
became parasitic upon small algae. In them the dom-
inant modification was, of course, the disappearance of
chlorophyll, and the reduction of the plant body. In
the fruit resulting from the fertiUzation of the egg, the
homologues of the carpospores of the Red Algae divided
internally into spores, thus changing the carpospore
into the ascus, and resulting in the considerable multi-
plication of spores. Thus the asci and ascospores be-
came characteristic structures in the fruits of the fungi,
and gave name to the first class — Ascosporeae.
415. Later, in the subterranean fruits of the truffles
another modification took place whereby the spores
instead of remaining within the ascus, push out beyond
the ascus wall, so as to be more easily dispersed. In
this way the basidium with its basidiospores arose from
the ascus and its ascospores. These are thus to be re-
garded as homologous structures, in which the later-
formed basidia have superior means for dispersing their
spores.
416. In like manner in the Brand Fungi we find
PHYLOGENY OF FUNGI 241
teliospores instead of the homologous ascospores or
basidiospores, and in these plants the fruit body has
become so reduced as to be scarcely recognizable as such.
The excessive parasitism of these plants may account for
their physical degeneration. As to the origin of the
Brand Fungi it is probable that they came off from the
parasitic Ascosporeao rather early in the phyletic history,
and a possible relationship is here suggested with the
Exoascales, and the Phacidiales.
417. The Imperfect Fungi are thought to be mainly
Ascosporeae that may have lost their ascospores through
excessive degeneration. It is probable, however, that
many of them are the conidial stages of Ascosporeae and
Basidiosporeae whose relationship is not yet recognized.
In recent years many conidial forms hitherto placed here
have been found to belong to well known ascigerous
fungi.
LITERATURE OF CARPOMYCETEAE
F. E. Clements, The Genera of Fungi, Minneapolis, 1909.
P. A. Saccardo, Sylloge Fungorum, Vols. I to XXII, 1882-1913.
These are comiDrehensive works; the following include certain
portions of the Higher Fungi.
J. B. Ellis and B. M. Everhart, North American Pyrenomy-
cetes, Newfield, 1892.
Bruce Fixk, Lichens of Minnesota, Washington, 1910.
Albert Schneider, A Text-hook of Lichenulogy, Binghainton,