he Smuts of Austraiia.

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S00489871

THIS BOOK IS DUE ON THE DATE
INDICATED BELOW AND IS SUB-
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DESK.

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THE SMUTS OF AUSTRALIA

(USTILAGINEAE).

Frontispiece.

Florence. Ohio. Warden. Genoa.

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ZDdys affer Sowing.

8 Ddys af|-er Sowing.

9Dd.ys affer Sowirvg.

!0 Ddys aff'er Sowing.

RAPIDITY OF GERMINATION

OF

VARIOUS SEED WHEATS.

DEPARTMENT OF AliRICULTURE, VICTORIA.

THE SMUTS OF AUSTRALIA

THEIR STRUCTITRE, LIFE HISTORY,
TREATiAIENT. AND CLASSIFICATION.

Government Vegetable Pathuloijisf.

WITH WVl ILLUSTRATIONS.

^ ,mclbouvnr:

BY AUTHdUITV : .r. KKMP, <:<iVEKNMKNT rRI.NTKK,

V

niEFACE.

This volume on the Smuts follows on the same lines as that on the Rusts
of Australia, to which they are only second in importance from the amount
of loss caused by them, chiefly in the cereals and grasses. Like the rusts,
they are all parasitic, and have obtained the general name of Smuts from
the soot-like spores which are produced in such abundance, as well as from
the disagreeable odour which sometimes accompanies them.

From the plant pathologist's point of view, there is no question that these
two great divisions of parasitic fungi occupy the leading position on account
of the damage produced by them in cultivated crops. The diseases caused
by smuts are among the most destructive, since they often destroy the grain
itself which is the chief object of cultivation. From a utilitarian point of
view alone, they are worthy of the most exhaustive research, in order to
define them accurately so as ultimately to prevent their ruinous effects. The
smut fungi and smut diseases, together with their prevention, therefore
claimed next consideration to the Rusts.

It must be remembered that Australia is not as yet in the position of
• many of the countries of Europe and America, where the different divisions
of Botany have been investigated for a considerable period by a number
of trained workers. There, the systematic position of the principal groups
has been more or less fully wrought out, and starting from this vantage
ground, the investigator can devote his attention almost exclusively to a
consideration of the conditions and results of the vital activities of the
organisms he is dealing with. But in Australia the different groups of Funsi,
for instance, are as yet very imperfectly known, and we have still to classify
and accurately describe many of them.

Hence I consider the first duty of the investigator of these diverse organisms
in Australia is to fix their position in the general scheme of plant-life and then
to identify special structural features with particular physiological functions ;
in other words, to determine their life-histories as completelv as possible.
No doubt the knowledge thus acquired will be reflected in and possiblv
modify our classification ; still, to give definiteness to our researches, the
species investigated should be clearly defined.

The object of the present work, then, is to classify and descril)e all the
known species of Australian smuts, to supply photomicrograplis of their
spores and other important features so as to fix their identity, and to wive
an account of their life-history as far as present knowledge goes, in order that
a rational mode of treatment may be adopted for preventing their ravages
in our cultivated crops.

Besides, the photomicrograplis of the different species will alwavs mark
out their individuality, no matter what position may -be assigned to them
in any future scheme of classification. In a review of my previous work on
The Rusts of Australia, it was remarked that " There are far too many photo-
micrographs ; a few give verisimihtude to a paper and confirm the bona,

fides of the author, but good hand-drawings are always better for reference,
if they can be relied on." Notwithstanding this criticism, the present work
proceeds largely on the same lines, for the unquestioned fidelity to nature
which photomicrographs represent, far outweighs the seeming clearness
and explicitness of an ordinary drawing. It is really astonishing to find
how often scientific error is perpetuated, because it is based on drawings of
what the author imagined but did not really see.

I have to acknowledge the valuable aid given by my former Assistant,
Mr. G. H. Rotinson, and my present Assistant, Mr. C. C. Brittlebank, as the
various photomicrographs executed by them show strikingly the essential
features of the different species.

To all who have generously supplied specimens and copies of their papers
relating to the subject, I tender my sincere thanks. I am specially indebted
to Professor Ewart, Government Botanist, who allowed me free access to
the National Herbarium, and to the Director of the Royal Gardens, Kew,
who readily placed at my disposal such specimens as were available only
at that institution. My colleague, Mr. C. French, Government Entomologist,
and his Assistant, Mr. C. French, junior, have been indefatigable in securing
specimens, and noting the distribution of these harmful parasites.

It is hoped that the work may prove useful in the education of the farmer,
who is now becoming alive to the necessity of knowing the nature of the
pests which devastate his crops, for it is mainly by the knowledge of the habits
of the parasites which cause the disease that disease prevention can be
secured.

Not only to the man on the land does this work appeal, but now that
Agricultural High Schools and Colleges are established in most of the States
and a Chair of Agriculture has been founded in Sydney University, the
diseases of plants should become a recognised subject of study at all such
institutions. It is beginning to dawn on the minds of our legislators that the
importation of pests must be stopped, so that a Quarantine Act has been passed,
and it is only a step further to realize that the spread of disease within the
States must also be checked. All this legislation will demand increased
knowledge on the part of those who have to administer such Acts.

Attention is frequently called to the small average yield of wheat produced
by the Commonwealth — lOJ bushels to the acre — and how to raise it is
often discussed. While careful cultivation, suitable rotation, and judicious
manuring will all tend in that direction, it is hardly ever thought worthy
of mention that the ravages from various preventable diseases are responsible
for a considerable amount of the annual shortage.

With irrigation and intense culture, it is soon discovered that the sunshine
and the water, which promote the growth of our cultivated plants, favour
their parasites as well, and thus the study of Vegetable Pathology is becoming
more and more a matter of national importance, and must soon cease to be,
as it is at present, a neglected department of knowledge, if the industrious
settler is to reap the full reward of his labours.

Melbourne, April, 1910.

C 0 N T E N T S

I.— GENERAL C^HARACrEllS.

Chapteu.

I. Introduction

II. Vegetative Organs — Mycelium

III. Re])roductive Organs — Spores

IV. Spore-formation in Australian (:;enera
V. Germination of Spores

VI. Infection

VII. Smuts in their relation to Rusts . .

VIII. Parasitism and Immunity

IX. Relations between Host and Parasite in Smut Diseases

X. Indigenous and Introduced Species

II.^LIFE HISTORIES AND TREAT.MENT OF CEREAL SMUTS,

XI. Introductory

XII. Stinking Smut or Bunt in Wheat . .

XIII. Loose Smut of Wheat . .

XIV. Flag Smut of WHieat

XV. Loose Smut of Oats

XVI. Naked Smut of Barley . .

XVII. Covered Smut of Barley . .

XVIII. Head Smut of Maize and American Corn Smut

XIX. General Treatment for Smuts

PAGK
3
'J
II
1()

20
28
38
45
58
G3

07
70
8()
88
103
107
109
111
113

in.— LIFE HISTORIES OF \ARIOL'S (;RASS SMUTS.
XX. 1. Grain Smut of Sorglium

2. Brome Grass Smut

3. Kangaroo Grass Smuts

4. Wallaby Grass Smuts

IV.— FIELD EXPERIMENTS.

XXI. Field Experiments during Season 1909

V.-CLASSIFICATION AND TECHNICAL DESCRIPTIONS.
XXII. Classification
XXIII. Systematic Arrangement and Technical Descriptions^ —

Ustilago

]\Ielanopsichium

Cintractia

Sorosporium

Thecaphora

Tolyi)osporium

Tilfctia ' . .

Entyloma . .

Urocystis

Doassansia . .
Excluded Species
Explanation of Terms
Literature

Explanation of Plates
Host Index

Fungus Index witii Synonyms
General Index . .

121
123
125
126

139

140
ir.3
104
175
185
180
190
194
195
200
201
203
205
214
275
278
281

I.

GENERAL CllAKACTJ^KS.

185S.

InU fdiution.

CHAPTER I.

Introduction.

Every fanner is more or less familiar with tlie ordinary smuts, which are
so frequently seen in our cereal crops, either converting their ears into a sooty
mass, or indicating by their foetid odours, especially when crushed, the pre-
sence of a disagreeable and destructive parasite. But the}^ are by no means
confined to these hosts, for they are very common on grasses generally and
occur on a number of flowering plants. Only one smut has been found out-
side of this group, on the capsule of a Sphagnum, or peat-moss. It is in reality
onlv the spores which appear on the surface, as the body of the plant which
produces them is deeply seated in the tissues. The spores are formed in all
the different organs of the plant, generally where food material is most plen-
tiful, but usually are confined to one definite position, which is characteristic
for the species. The grains and seeds are favourite spots for the develop-
ment of the spores, since the supply of food is not only abundant and choice,
but they are also in such an exposed position that they are readily distributed.
They reach the healthy grain in various ways, and there is an evident advan-
tage in being carried and sown with the seed. One would hardly expect
to find smut spores produced at the collar of woody trees, but, according to
. Vuillemin ^ , this is the case with at least one species which produces woody
tumours on Eucalypts. The species which is known as Ustilago vriesiana
occurred in the Botanic Garden, Amsterdam, on various species of Eucalypts,
including E. globulus. E. amygdalina, E. rostrata, E. leucoxylon, and E. macror-
rhijncha and there is every probability that it exists in Australia, although
hitherto overlooked. It is the only Ustilagine known to produce a woody
tumour, and its spores, formed in cavities between the wood and the bark,
are described as violet-brown, oval, smooth, measuring 7-9 x 5-7 j-i. In one
of the smuts attacking maize the spores may be produced on the adventitious
roots above ground, stems, leaves, or inflorescence and the Flag Smut of wheat,
as the name indicates, is usually confined to the leaves. Even the anthers
of the flower may be invaded by a smut, as in the case of the Carnation and
other species of that family, where the spores of the smut replace the pollen
of the flower and are discharged just like the pollen.

The smut, as is the case with other parasites, may stimulate the part at-
tacked and cause an abnormal growth, so that the plant endeavours to meet
the extra demands made upon it by the fungus. The smut-boils of the Maize
are well-known examples, audit is interesting to note that they contain pro-
bably the same alkaloid as the Ergot, and the fluid extract is used in a similar
manner. Not only is there a smut used in medicine, but there is one used
for food, viz., Ustilago esculenta, P. Henn. Only the upper extremity of the
shoot of Zizania is smutted, and the swollen and deformed portion is eaten
in China as a vegetable.

Wherever the spores are produced they are in such countless numbers
that a supply for next season is usually assured, and if tlu> conditions are
favorable for their germination at the proper time, infection as a rule occurs,
and the smut is propagated.

The infection tube can only peuetrat(> the lio^t-plaut and hccomc para-
sitic at a spot where the tissue is young and tcndci'. This may he in the
young seedling, leaf, or stem, but it nui\- also occur in tlic llowering stage
when the young ovary is just forming.

u r ^talt Colltgf

4 lutrodnciion.

If we follow the spore of the Stinking Smut of wheat from the time it is
shed until it reaches a fresh plant next season, the way in which the disease
is carried from season to season will be evident. In a district where this smut
occurs, the sound grain may receive the spores by means of the wind or in the
threshing machine, and this seed with the adhering spores may be sown in
the same or in another district and thus introduce the disease. The grain
in due course germinates, and the self -same conditions which are favorable
to the germination of the wheat also suit the smut spores. They readily ger-
minate with moisture and produce secondary spores, or conidia, which in turn
put forth delicate threads, and these readily enter the young wheat seedling.
There they soon reach the growing point of the stem and continue to grow,
plant and parasite being supplied Avith food from the same source. Under
ordinarv conditions of growth the wheat-plant is able to provide sufficient
food material for both, and this goes on until the flower is formed and the
young ovary begins to develop. Then the plant ceases to manufacture fresh
material and transfers what has already been accumulated to the grain, for
the benefit of the young and growing embryo. Here the fungus luxuriates
in the rich supply of food and the filaments increase, multiply, and divide
into innumerable branches, from each of which spores are formed ; the wall
of the filaments becoming gelatinous. The wall soon deliquesces and is
absorbed by the growing spore, which soon assumes its firm black covering;
and what was at first intended as a store-house of nourishment for the embryo
has been converted into a charnel house, densely packed with the spores of
the overmastering fungus. These spores again reach the sound grain and
repeat the process in the succeeding crop. The principle on which the treat-
ment for the prevention of this smut is based, may be clearly seen from this
brief account, for if the spores on the grain are destroyed, or their germinating
power arrested, they will not be able to infect the young seedling and pro-
duce the disease.

The losses caused by this smut are enormous, and these are not only due
to the actual reduction in the yield of grain, but to the indirect loss brought
about by the sound grain having its commercial value lessened from the ad-
hering spores of smut, which are easily recognised by their objectionable smell.
It was estimated, from reliable data, that in one season this State suffered a loss
of £50,000, although in recent years the general treatment of the seed-wheat
has reduced considerably this preventable loss. Even the loss from Loose
Smut of wheat is considerable, although the farmer does not always allow
for it, and may even blame something else for the naked stalks throughout
his crop. In South Australia, it is considered that in some seasons more
damage is done to wheat by Flag Smut than even by the dreaded Rust, and
in certain districts of Victoria the yields are much reduced from that cause
alone.

In the countries of the Old World, the loss due to smut is regarded as only
surpassed by that caused by Rust, and in the United States, Swingle'^ has
calculated the yearly loss from Oat Smut to amount to £3,600,000, and for
the State of Ohio alone, Selby- has reckoned the Stinking Smut of wheat to
cause a loss of £50,000. For both these diseases a remedy has been provided,
and it Hes with farmers themselves to take advantage of it.

Historical. — While the mildew or rust of wheat is freely mentioned by
ancient w-riters, the smut of wheat is not specially noticed, and there is no
word to express it in the language of Greece or Italy. Pliny speaks of the
blasting of corn " which cometh of some distemper of the air," but this, in
all likelihood, refers to Rust, for he goes on to remark " this unhappy blast
falleth most often in places subject to mists and dews, such as hollow valleys
and low grounds." It does not necessarily follow, however, that it was not

Introduction. 5

known in ainicMit times, tor tho ])robabilities are that it was infludod under
the general term of mildew^ or blight. Thus, Bacon says, " Mildew falleth
upon corn and smutteth it," and even now. Rust and Smut are often con-
founded, the name of " Black Rust " having been applied to Flag Smut for a
number of years in South Australia.

In historical times, the nature and origin of smut were mucii discussed,
and the different views held by eminent writers brought it prominently into
notice. The Stinking Smut of wheat was evidently the lirst to attract atten-
tion, for TuU, writing in i7;);>, remarks that " Smuttiness is when the grains
of wheat, instead of flour, are full of a black stinking powder." Then, in 1755,
Tillet distinguished between la Carie the Stinking Smut, and la Charbon or
Loose Smut. The grains composing the smut were supposed to resemble the
spores of puff-balls, and being enclosed by the Avails of the ovary, Bjerkander'
classified this form as a Lycoperdon, in 1775. But this view was not generally
accepted, and Tessier, in 1783, while acknowledging the resemblance to Lijco-
perdon, considered it rather as a degeneration of the grain and not a, definite
and independent organism. He, along with others, had observed that the
powder was contagious, but did not know how that pow'der originated. In
seeking to account for it all sorts of wild notions were entertained. Some re-
garded the black particles as foreign bodies, others as infusoria, and still other.s
considered them as indications of an offended deity, for in an article on the
subject of smut, in the fifth volume published by the Bath Agricultural Societv,
in 1790, the following occurs : — " Premiums, offered for preventing evils which
originate from intemperate seasons and destroying blights, may excite inven-
tion, artifice, cunning, imposture, and deception, but can never extend the
boundary or expand the circle of human knowledge or human power. ■ He,
and He only, wdio can repel the malignant blasts of the East ; fraught with
myriads of consuming insects, which originate from what or where none but
Omniscience knows, and substitute the soft, healing, balmy zephyrs of the
West, can reward the labours of the industrious husbandman with plenty and
happin-.ess."

But the view of the smut as being due to degeneration of the plant itself
persisted for a long time, and was held by eminent scientists. Instead of re-
garding the smut powder as consisting of spores capable of reproducing the
fungus from wdiich they were derived, they were considered to be diseased out-
growths, morbid conditions, or eruptions of vegetable matter. As late as
18;3o, this was the view put forth by such a good observer as Unger. in his
work " Die exantheme der Pfianzen " and it was adopted by Schleideu even
in 1846. About a century ago, in 1807, Prevosti discovered the important
fact that the smut spores germinated in water, and consequently showed that
the smuts were of the nature of fungi. Unger, in referring to this, remarks
that, although fungus filaments were produced, there was no evidence to show
that they possessed the power of infectio)i. This evidence w^as only forth-
coming iu 1858, when Kuehn dii'cctly followed the penetration of the genn
threads in wheat.

With our present knowledge, it seems diilicult to conceive tliat even when
the snmts were acknowledged to be fungi, and that they produced spores, it
should titill be maintained that they were of tiie nature of diseased outgrowths
from the plant itself. The facts of their development were generally known ;
but that the spores were capable of infection had still to be experimentally
proved. Even such a distinguished physiologist as Meyen', in 18.37. did not
realize the importance of the spores in the production of the disease, although
he described their formation accurately as shown in the following passage : —
"I consider it to be an established fact, that the smut (Ustila(jo,L'u\k) is not a
contagious disease, but is inlierited, and arises from the stoppage of the saps

^

6 hitrodnciion.

produced by superabundant manure foreign to the nature of the pknt. At
one or at several places of the inner surface of the affected cells, small deposits
of mucus are formed from which filiform ramified bodies proceed, which are
colourless and almost transparent, but contain a quantity of small molecules
consisting of a somewhat more solid substance. These mucous filaments, in
the interior of the cells, soon present constrictions at various places, first
generally at the apices of the small lateral branches ; and these constricted
ends take an ellipsoidal and lastly, a spherical form, become of a yellow colom-,
and change into those minute brown vesicles of which the smut consists. The
destruction of the cellular walls by dissolution commences with the aggrega-
tion of these smut vesicles in the diseased cells, and then these vesicles are
found in great masses lying close together, filling entirely the diseased organ,
and frequently without leaving a trace of the original intervening cellular
wall.'" It is still deeply rooted in the minds of many farmers that the smut
spores are simply an exudation of the sap of the plant, blackened by exposure
to the air, or that the fungus, if fungus it be, has arisen spontaneously from
the soil in some mysterious fashion. It is only when the spores are seen to
germinate, and when the infected grain produces smutted plants, while those
produced alongside free from spores are perfectly healthy, that the fungus is
realized to be a parasite, the presence of which is necessary for the production
of the disease.

The next step in advance was by Tulasne\ in 1847, who investigated
methodically the germination of the spores in water, and proved that on ger-
mination they did not directly give rise to a mycelium, but to a short germinal
tube which produced minute reproductive bodies. He distinguished the
germinal tube as a promyceUum, and the reproductive bodies as sporidia,and
having a somewhat similar mode of germination to the teleutospores of the
rusts, he came to the conclusion that the rusts and the smuts were closely
allied. Next, Kuehn^, in 1858, carried out infection experiments with the
spores on various host-plants, and he found that the fully developed plants
were not capable of infection, but only when they were in the seedling stage.
The production of sporidia, as shown by Tulasne, and the mode of infection of
the host-plant as demonstrated by Kuehn, gave a simple explanation of the
development of the smut, and seemed to account completely for all the ob-
served phenomena. When one considers how intimately the smut fungus is
associated with its host, how it enters the young seedling and goes on growing
within the tissues of the apparently healthy plant, how it suddenly appears
in the ovary and replaces the floury contents of the grain with the black smutty
spores, it is not to be wondered at that it was regarded at one time as part
and parcel of the plant itself.

The mode in which the spores are formed next engaged attention, and
De Bary\, as early as 1853, extended our knowledge in this direction.
Fischer von Waldheim^ also carried on his investigations into the germination
of the spores and the mode of their formation. But it was only when Brefeld
began his masterly and epoch-making researches into the germination of the
spores of the various smut fungi in nutrient solutions that the subject was
dealt with in a thorough and complete manner."]. This was in 1883, when the
first part of Die Brandinlze was published, and there he showed that it is only
by rigorously following exact scientific methods that the boundaries of know-
ledge can be enlarged. He found that the germination of the spore in water
was often uncertain, slow, and in some cases, such as Maize Smut, it was diffi-
cult to secure it at all. He therefore hit upon the happy expedient of germina-
ting the spores in nutritive solutions, such as a watery extract of manure, or
of such vegetable substances as are contained in the soil. In the fluid extracts
of such materials, not only did the spores germinate as in water, but even

■Inlrihliii-flon. 7

spores wiiicli would not fiortniualc at all did so without (wccptioii. It was
further discovered that the genniuatiou went beyond that which occurred in
water and was not only more luxuriant, but that instead of stopping at that
stage, the secondary spores or conidia began to sprout on their own account.
These sprouting conidia as they are called by Brefeld, continued to multiply
indefinitely as long as the nutrient material lasted, and, becoming detachecl,
continued the process just like yeast-cells. Some of these sprouting conidia
had also the capacity of giving rise to aerial conidia, which, on account of
their minuteness, were scattered in immense numbers by the wind. The
final step was taken when infection was proved to t^ke place, not oidy in the
seedling, as in Stinking Smut of wdieat, but also n the }'oung and tender tissue
of developing maize plants as in the American Corn Smut, and in some cases,
in the flower itself. This floral infection was first practically demonstrated
and described in 1896, by Maddox.in the Tasmanian Agricultural Gazette, and
afterwards re-discovered, in 1905, by Brefeld.^ The probabilities are, that
some host-plants are capable of infection both through the young seedling
and the flower, but that has yet to be proved.

Hitherto, it was taken for granted that the parasitic fungi could only live
and grow upon the particular host-plants with which they were associated in
nature, and that it was only by confining observations and experiments to
the host-plants that the full course of their development could be traced.
f But Brefeld opened up a new field of inqub:y when he showed, in the most con-
vincing manner, that parasitic fungi can live outside of the host-plant, and
that in nutrient solutions they could grow as luxuriantly and sometimes even
. more so than they did on their natural hosts. While the smuts can maintain
themselves on the living plant, they are also capable of existing on dead
organic substances, and thus the line of demarcation between parasites and
saprophytes was shown to be less rigid than commonly supposed. In fact,
there are sources of infection quite outside the host-plant which have to be
taken into account when considering the propagation and prevention of
snmt.

Each successive step in advance has thrown fresh light upon what takes
place in nature, and the discovery of infection through the flower has explained
how it is that in Loose Smut of wheat, and Naked Smut of barley, disinfection
of the seed has not been successful in preventing the disease, and how the
smut may break out in places where it has never before been known, through
being carried in a dormant condition within the seed, even although that seed
had been carefully treated and there were no wild or cultivated grasses in the
neighbourhood from which it might have been derived.

Exflanation of Plates.

[To face PI :tf I. ]

MYCELIUM.

{a, b. after Plowright ; c, after Fischer von Waldheini.)

a. Ustilaj) nvswM .. Hypha from axis of inflorescence of Avena elatior ..

b. .. ,- • • Hypha gelatinized from same plant

c. Tilletia striaeformis . . Hypha from leaf with large vacuoles and showing

dou'ole contour in walls

xoOO

x500

x900

d. Ustilago olivacea

e. Ustilago zene

f. TJstilffjo violacea

g. Tilletia levis
h

I. Ustilnrjo violacea
m. ,. ,,

p. Usfiliigo iiia;jdis

q.

r. Ustilago scahiosa

SPORE FORMATION.

{d, after Brefeld*; e-k, after Fischer von Waldheim.)

Spore-bearing hypha, the swellings indicating the

formation of spores . . . . . . . . x 400

. . Gelatinized hypha showing the contents hreaking

up for spore formation . . . . . . x 900

Coalesced gelatinous hyphae in which spore formation

is taking place, and contour of spores distinctly

visible .. .. .. .. .'. x900

Spore-forming hypha with commencement of ])ranches

ending in spores . . . . . . . . x 900

Young spore still connected with hypha . . . . x 900

Young spores in various stages of development . . x 500
Separation of hypha into two branches with spore

at end of each of different degrees of ripeness . . x 500
. . Spore with shrivelled remains of spore-forming hypha x 500

SPORE GERMINATION.

{l-o, and r-s, after Harper; p, q, after Istvanffi.)

. . Germinating spore with nucleus . . . . x about 1500

. . Geriuinating spore after first nuclear division, one
nucleus remaining in spore, the other wandering
into germ-tube . . . . . . x about 1 500

Promycelium, with two daughter nuclei and a septum

between . . . . . . . . x about 1500

. . Conidium budding like yeast . . . . x about 1500

Germinating spore with single nucleus in promy-
celium . . . . . . . . . . X 950

Four-celled promycelium and conidia with a nucleus

in each . . . . . . . . . . x 950

. . Promycelium with four resting nuclei . . x about 1500

Four-celled promycelium and conidia with a nucleus
in each . . . . . . . . x about 1500

* The magnification of Brefekl's figures is generally too high, probably arii^ing from the mode of
reproducing them.

Plate 1.

G. II. KnlH„^,„|. I'hot.

MYCELIUM, SPORE FORMATION AND GERMINATION.

]'cgcfa//7'c (hi^aui. y

CHAPTER II.

Vegetative Organs — Mycelium.

Among parasitic fungi, such as the smuts, it is by means of the mycelium
that they obtain their nourishment from the plants on which they prey,
and it is therefore the vegetative part of the parasite. Hence, although
hidden in the interior of the tissues, it is the foundation of all the disease
and deformation which afterwards occur. It is not of itself an evident
cause of disease in the plant, for it is generally so intimately bound up
with the host-plant and grows so regularly with it, that there is usually
no external evidence of its presence. It is only when the spores are formed
that the fungus is revealed, and then what remains of it is often used up
in their production, so that there is no portion of the fungus which is more
easily overlooked or less seldom investigated than the mycelium. Commencing
in the young seedling, as it generally does, and growing steadily with it until
the seed again is formed, it can readily be understood that the fungus filaments
are difficult to detect among the tissues. They are most easily seen in the
vicinity of the spore-beds, but even in the early stages of their formation
they can be detected, as in the neighbourhood of the growing point uf cereal
seedli'igs.

The mycelium is composed of hyaline tubes, which are usually septate,
copiously branched and comparatively narrow, being only on an average
about 2-5 /( broad (Plate I., a, b). The walls of the hyphae are relatively
thick, and sometimes a decided double contour of the membrane is visible
(Plate I., c). When treated with iodine and sulphuric acid or chlor-zinc-
iodine there is no blue colouration produced, shomng that they are not
composed of cellulose. From the transparent nature of the walls and the
watery contents of the cells, often filled with vacuoles, it is necessary to use
reagents to make the mycelium stand out clearly from the surrounding tissue.
If the tissue of the host-plant containing mycelium is kept in a strong solution
of potash for 24 hours, the fungus filaments are rendered more distinct in
contrast with the clear and transparent tissue surrounding them. The
hyphae not only ramify between the cells of the host-plant, but may even
penetrate into them and form haustoria, which are seldom spherical, but
most frequently like a bunch of grapes. In the cereals, long unbranched
hyphse are mostly found in the internodes, Avhile in the nodes the}' are much
branched and convoluted.

Perennial Mycelium.

I}i the Rusts, the mycelium may cither confine itself to definite spots
and become localized, or it may permeate the entire plant, or at least large
portions of it. In the Smuts there is a similar arrangement. When the
young ovary is infected as in the Loose smut of wheat {Ustilago fritici), the
mycelium is restricted at first to that portion of the host-plant, but in most
cases the seedling is attacked, and then the mycelium perjneates the entire
plant. When the spores are being formed, it is most readily found in their
vicinity, but it originally existed throughout the plant, although the earlier
formed portions may have disappeared. The mycelium persists more
particularly in the nodes, where it remains dormant, but if the host-plaut
ir perennial and gives rise to fresh shoots next spring, it awakens into fresh
life, and enters the new growth, as in Ustilago perennans, Rostr.

lo Vegetative Organs.

I had a very good illustration of this in the case of a barley plant affected
with Naked smut {Ustilago nuda). It is commonly stated that the stubble
of wheat and barley will not sprout again, because the original forms are
annual ; but under our conditions with the ripening season in the summer,
and not in the autumn, they may be cut back while still somewhat green and
shoot again, and behave as if biennial. This occurred in a plot of Battledore
barley sown at Burnley on 2nd July. The ears in one plant were all smutted
with the Naked smut, and this smutted stool was cut close to the ground on
6th November, before it was dead ripe, in order to encourage a new growth.
The season was favorable and a second growth started, and by the 24th
December fresh ears were formed, which were also all smutted, as in the first
instance. In this case when the plant was cut down, the mycelium still
remained alive in the basal portion, particularly in the nodes, and when
fresh shoots were formed later on, the mycelium entered into them and
produced the disease. Sections of the lowest node revealed the presence
of fungus filaments, so that it was not by shoot infection, but from the
perennial mycelium that the fungus arose.

Not only may a cereal crop be cut once and shoot up again, but it may
even do so a second time. In Victoria this happened with a crop of oats.
The land was ploughed and sown in October, 1907, and about 10 acres were
sown with Algerian oats. The crop was cut in January, 1908, and yielded
about 25 cwt. to the acre. Then heavy rain set in and the crop was cut again
in April, yielding hay of splendid quality, and averaging 1 ton per acre.
The paddock was heavily stocked from April to October, when it was again
closed to stock, and the third cutting taken off in December, 1908. This
was the heaviest crop of all, and yielded about 30 cwt. per acre. The land
was open plain country, at an elevation of 3,500 feet above sea level. If
smut had been originally present in the crop it would probably have appeared
in each successive cutting.

Although the mycelium may thus permeate the entire plant, it is only
at certain definite spots where spore-formation occurs. In the case of
Tilletia tritici, however, Berkeley^ has recorded an instance w^here a streak
of the smut spores appeared on the outside of the stem, thus showing that,
while the normal appearance of the spores is in the grain, they may be
produced in the stem under rare conditions. I have also observed in Ustilago
tritici that, while the spores are usually produced in the spikelets, they may
occasionally occur in elongated streaks on the sheathing blade or shot blade
enveloping the ear in its earliest stages, as well as on the stem (Plate VI., c)

Localized Myceliu-ai.

It frequently happens that where the mycelium is confined, it gives
ri&e to swellings known as smut-balls or smut-galls, varying from the size
of a pin-head to that of a child's head. These swellings in the American
Corn smut, for instance, are not merely due to the multiplication of the
fungus filaments, but also to the luxuriant growth of the tissues of the host-
plant. The Gall smut of Barnyard grass may give rise to elongated swellings,
reaching a length of 9 cm. (Plate XXI.).

The mycelium is generally hidden in the tissues of the host-plant, but it
sometimes forms a fungus membrane on the outside. This only occurs,
however, in connexion with, and as a protective covering for. the spores
until they are ready for distribution.

Refrodncfivc Organs.

CHAPTER III.

Reproductive Organs — Spor us.

Just as ill the Rusts, the spores form the most prominent feature and play a
most important part in the determination of the species. Hence they have
received a hirge share of attention at the hands of investigators, and will
require to be carefully studied in their various bearings. There is a good
deal of confusion in the use of the term spore, since it may be applied in a
general way to all the reproductive bodies of these fungi, and in order to
fix definitely the exact position it occupies in the course of the life-history
a qualifying word is often prefixed to it. We refer to the spores which arise
in the form of a dark powder, and to which the familiar name of smut or
bunt is given.

Since the spore and its products are constantly being referred to, the
terms generally employed to designate them may be appropriately given
here, indicating at the same time those which will be commonly adopted
in describing the life-histories of the various species. As members of the
great group of Fungi, the smuts have necessarily much in common in their
vegetative and reproductive processes with the others, and there are conse-
quently general terms which are applicable to all, but, on the other hand,
there are special characters which distinguish them from the others, and to
express these distinctions special terms have been employed. The names
given will vary according to the different views held as to their relationships,
and they will presuppose affinities which may, or may not, be borne out by
facts. The following scheme shows at a glance the various names given to
the spore and its products by prominent investigators of this particular
group : —

General terms — Spore= ^ terminal Tube= Conidium=

Special terms — Promycelium (Tiilasne and Sporidium (De Bary)

Resting-spore (De Baiy) | De Bary) , Conidinm (Brefeld)

Olilamydospore (Brefeld) \ Hemibasidinni (Brefeld) Sporidiolum (Saccardo)

Teleutospore (Plowright) j ! Promycelial spore (Tulasne)

As regards the spore itself, De Bary calls it a resting-spore, because it
usually undergoes a period of rest before germination, and Brefeld speaks of
it as a chlamydospore, on account of its firm membrane, while Plowright
regards it as a teleutospore, being the supposed equivalent of that spore
in the Uredineae. Amid all this diversity of naming we will simply call it
a Spore, as it is the main reproductive body, and the other spore-like bodies
derived from it will receive special designations.

The spore on germination produces one or more germinal tubes of the
nature of a hypha. This hypha may either elongate, branch, and become
the foundation of the mycelium, or, as in the Rusts and Smuts, it may
be very limited in its growth, and give rise directly to other spore-like bodies
unlike the mother-spore, and then die off. On account of this special
feature of the product of germination in the Rusts, Tulasne called it a
Promycelium, because it represented a mycelium in a very abbreviated form,
and because a similar short and short-lived germinal tube was produced
in the Snmts, De Bary likewise gave it the name of promycelium. But
Brefeld introduced the term hemibasidium to indicate the relationship which
he considered to exist between the Ustilagineaj ai;d the Basidiomycetes.
The name of promyeeUum. however, is distinctive without involving any
particular view of relationship, and will be adopted here (Plate I.. Is).

12 Reproductive Organs.

The germinal 4:ube or promvceliuni (by a j^rocess of ab.striction) proceeds
directlv to the formation of reproductive bodies, which diSer in no essential
particular from the Conidia similarly produced in other groups, and Brefeld
has adopted that term. But De Bary uses the name sporidium as originally
proposed by Tulasne for the promycelial spore in the Rusts, and considering
that the term had already been used for the ascospore in the Ascomycetes,
and Saccardo had therefore altered it to sporidiola. it will avoid the unnecessary
multiplication of terms to retain the old name of Conidium (Plate I., q, s).

The typical description of the mode of germination will therefore be that
the spore produces its short germinal tube or promycelium, which in turn
gives rise to conidia. and there may be secondary and tertiary conidia
produced, or even those which sprout in a yeast-like manner, and are therefore
called sprouting conidia. Although I have adopted here, for the sake of
simplicitv, the term conidium for the product of the promycelium, it is not
to be regarded as necessarily different from the similar body produced in
the Rusts, for which the name of Sporidiolum was chosen.

Structure.

The spores are colourless at first, and gradually assume a brown or black
colour, which is confined to the outer thick membrane or exospore, while (he
inner or endospore is thin and remains colourless. The exospore is not only
coloured and thickened, but its surface may be either smooth or roughened
in various ways. It may develop spines, warts, or net-like markings, but
sometimes the markings are so minute as to be simply granular.

The spores are either free, as in Usfilago, or united into spore-masses, as in
Sorosporium. This formation of spore -clusters is brought about by the
sporogenous hyphfe becoming densely interwoven, and when the spores are
subsequently formed they grow together, and so remain united in heaps.
If they are not thus hrmly united, the spores may occur in clusters, and yet
be easily separated, so that they belong to the free-spored forms. The division
to which they belong can only be definitely settlecl by tracing their develop-
ment and mode of formation, unless when they are permanently and not merely
temporarily united. It can readily be understood that there is no great
morphological difierence between the forms Math free and with united spores,
and even in the germination of the individual spores there is considerable
resemblance. But the distinction is well marked where the spores of a cluster
have a special envelope consisting of sterile cells, as in Urocystis. These
outer sterile cells not only protect the fertile inner cells, but probably serve
as floats to carry them to a suitable place for germination. The protection
to the spores has reached its highest development in Doassansia, where the
clusters of spores are enclosed in a highly speciahzed peridium, consisting
of densely packed sterile cells, reminding one of the protective cells in the
Gasteromycetes. and there known as a peridium. The spores thus protected
are able to remain under water for a considerable time, and they may germinate
either under water or on damp earth by the germinal tube bursting through
the envelope.

Dispersion of Spores.

As in the great majority of fungi, the wind is the most important agent
in distributing the spores. When the smut is produced in the ear or
inflorescence, as it generally is in grasses, it is in a favorable position for the
wind to play upon it, and the gentle swaying to and fro of the plants will
help to shake out the spores even in a still atmosphere. The spores thus
distributed may fall upon the ground, or be carried to healthy grains where
they attach themselves to the surface, as any small particles of dust might

Kcproductivc Organs. 13

do, and in this wav may convoy the discv.se to groat distanci^.s troin its
original source. The conditions favorable for the geriniiiation of the grain
are those most suitable for the germination of the spore, and it is, generally
speaking, the best time for the infection of the young seedling as well.

In the case of Flag smut of rye or wheat, while a proportion of the spores
may be blown about by the wind, the greater number remain, attached to
the leaf, and when this withers up and falls away and becomes torn into
shreds, it not only forms a convenient means of dispersal, but pieserves the
spores in the soil until the next season, when they can infect the seedling
plant. The examination of commercial samples of wheaten cha:ff from
various parts of the State and the detection of spores of this smut in^ greater
or less quantity, show that this is a very efficient means of dispersion.

Thaxteri regards it as very probable that insects may serve to spread the
spores, as in some other fungi, for he notes that the smut of Onions {Urocystis
cepulae) appears to be attractive to the " flea beetles," which swarm over
the diseased seedlings, and apparently feed upon the spores, while they do
not seem to visit the healthy onion leaf.

Brefeld^ has observed that in some species the spores separate from one
another in water with a sort of jerk, as if some sort of intermediate substance
pressed them asunder, as in Cintractia spinificis, (Ludw.) McAlp. Probably
sweUing of the membrane, which occurs in spore-formation, also subse-
quently plays a part in spore distribution, but it may also be that the
mycelium left over after the formation of the spores retains the capacity for
swelling.

Spore Formation.

The spores are not formed from the ordinary mycelium, but at those spots
where the spores arise, the vegetative mycelium gives rise to special spore-
bearing iilaments. These filaments are produced directly as branches which
are quite distinct in their appearance and behaviour (Plate I., g-k).

In connexion with the various genera, it is not only necessary to determine
the nature of the spores, but also the mode of their formation, for it is only
by means of such characters that the genera can be properly distinguished.
Hence it follows that each genus will require to be dealt with separately,
but a general view of the process may here be given.

The spore-forming nlaments have their walls swollen in a gelatinous
manner, and contain a granular protoplasm in which a number of oleaginous
particles are often seen. This gelatinization of the walls of the filaments
is a fairlv constant character, but it does not occur in every species (Plate
I. e, f)/

The ordinary mycelium may change quite suddenly into the spore-
forming, as in Sorosporium saponariae, or it may be more gradual as in
TJstUago longissima, where the extremity of a filament may show the gradual
gelatinization and spore formation.

When a filament is preparing for the process of spore-formation, its walls
beconie distended, while its cavity is diminished. Then the whole enlarges
together with the lumen, and the protoplasmic contents are ready to be
transformed into spores (Plate I., d).

The spore is regarded by some authors as the result of a sexual process,
and it will be convenient to consider here the question of sexuality as
oc('urring in the Smuts. The evidence of sexuality is based upon the
behaviour of the nuclei, the presence of which is now firmly established in the
smuts, and not only so, but these nuclei are shown by Harper^ and others to
possess the same essential differentiations in structure that are met with
in the higher plants (Plate I., l-s).

14 Reproductive Organs.

Daiigeard^ found that the young cells of the mycehum or vegetative
cells contain two nuclei, although older cells may contain more than two.
Then when spores are about to be formed, this formation occurs in special
swollen cells, each of which contains two luiclei, as in the purely vegetative cells,
a fact also estabUshed by other observers. These nuclei afterwards fuse and
form a single nucleus, so that the mature spore is uni-nucleate. This fusion
of the nuclei is regarded as a sexual act, equivalent to the conjugation of
male and female pro -nuclei. The entire cell with its accumulated reserve
material constitutes an oospore, which increases in size and surrounds itself
with a thick membrane. Whether this is to be regarded as a sexual act or
not depends upon the view we take as to the essence of the process. If it
consists in the fusion of two nuclei, representing respectively the male and
the female element, derived from more or less speciaUzed cells and forming
the single nucleus of a new generation, then the above does not conform
to this view, where the blending nuclei are derived from different cells. The
fusion of nuclei in the individual spore may serve the same purpose as repro-
duction by giving it increased vigour, but it is only where a fertile cell is
stimulated to fiu'ther development by the entrance of a nucleus from without
that it is here regarded as true sexual reproduction. When the spore of
Ustilago, for instance, germinates in water, the single nucleus passes into the
germ-tube and divides, then a transverse septum is formed with a nucleus
in each division, or the nuclei may divide further and become four, before
the septa arise and form the typical four-celled promycelium. When the
conidia are formed, each contains normally a single nucleus, which is derived
from the division of the nucleus in the parent cell (Plate 1., q and s).

In Urocystis and Tilletia, where the conidia are formed at the apex of
the promycelium, the original nucleus becomes eight by successive bipartition,
which pass in order into the apical conidia.

There is another phase of so-called sexuaUty which has long been observed
in Tilletia and other genera, where the conidia unite in pairs. Two conidia
become connected by a tube like the transverse bar in a capital H, and
resemble very much the conjugating cells of Spirogyra, a fresh- water Alga.
Such fusions were naturally suggestive of a sexual union, and De Bary
maintained the view that they were analogous to a sexual process. In
support of this view he observed, first, the almost invariable occurrence of
pairing under the normal conditions of germination, as in water. Second,
the union occurred, in the great majority of cases, between two and only
two conidia. When an odd number of conidia were produced by the
promycelium, they still united in pairs, and the odd one did not fuse with any
of the others, although it would have been so easy and so natural to do so.
This would seem to show that a change had taken place in the fused pairs
which rendered a further imion difficult or impossible. This view of De Bary
was generally accepted as being the most probable explanation of the
phenomenon, that the conjugation of the conidia was a sexual union. But
Brefeld opposes this view, and considers the fusion a purely vegetative act,
as occurs in the coalescence of vegetable cells. He regards the essence of a
sexual union to He in the fact that the conjugating cells are incapable of
further growth by division, but become capable of further development
as a result of their union. Applying this test to the conidia, he finds that
they are individually capable of unHmited development when placed in
nutrient solutions before pairing can begin, and that fusion does not occur
under such conditions. He concludes that the fusions are purely vegetative,
perhaps resulting from a process of starvation, for so long as adequate
nourishment is supplied there is no appearance of conjugation.

Reproductive Organs. 15

Whatever view may be taken of the paiiiug of the couidia, whether of
sexual value or not, it is a very characteristic feature in certain genera, and
the nuclear phenomena underlying it ought to be taken into consideration.
Dangeard, in investigating the conidia of TiUetia, found nuclei in the fusion
tubes under such conditions that it suggested the view that they might serve
as a means of equalizing the distribution of the nuclei. It might happei\
that, in the formation of conidia, some might receive two nuclei and some
none at all, and the connecting tube would permit of the balance being
restored. It would be interesting to observe in this connexion if the unpaired
conidia always possessed a single nucleus only, for here we are merely dealing
with a possible supposition still awaiting facts to support it.

i6 Spore-forniation.

CHAPTER IV.

Spore-formation in Australian Genera.

The mode of formation of the spores is often characteristic of different
genera, and therefore it becomes necessary to see wherein the difference lies.
The much-branched spore-forming hyphaB generally become greatly swollen,
and their walls gelatinize. Then the spores arise within the old cells by the
formation of a new membrane, and it is in the details of this process that
variety occurs.

Ustilago.

The development of the spores has been closely followed by Fischer von
Waldheim.3 The fertile threads or spore-forming hyphfe become enlarged
and excessively branched, and are densely crowded together. Then the gela-
tinization of the walls begins, and this proceeds to such an extent that the
cavity is almost obliterated at first, only appearing as a narrow shining line
in the centre of the hyphse (Plate I., e). Next, a swelling of the surface of the
hyphee takes place at certain points, often close to one another, so that they
appear nodose, and the cavity at the same time is enlarged. The hyphae
continue to increase in size and consequently become intertwined and tangled
together, so that eventually they have actually coalesced. The irregularities
of the hyphfe become more marked, and it is evident that the spores are begin-
ning to be dehnitely formed as the swellings get more and more rounded. The
crowded spore-forming hyphse with their numerous branches, as they develop
the spores, ru}i together in a complex mass, so that their individuality is almost
entirely lost (Plate I., /). They appear as a gelatinous mass studded with
numerous shining points in the form of streaky or rounded bodies. The pro-
cess of spore-formation, or the commencement of the differentiation of the
protoplasmic contents to form a spore, is indicated by the entire mass of the
hyphse breaking up into distinct portions, which, however, retain their con-
nexion with one another until the spores are completely formed and they are
surrounded by a more or less dense gelatinous envelope. The spores become
more or less polygonal from mutual pressure, but ultimately separate from
each other and assume their typical spherical shape. The differentiated con-
tents increase in size and contain fat granules, and a distinct contour is per-
ceptible corresponding to the outer spore membrane. The outer edge of this
contour darkens, and even while still surrounded by a thin gelatinous envelope,
the irregularities of the epispore begin to appear. As the spores ripen the gela-
tinous membrane disappears and there is no trace of it at maturity, nor are
any remains of the mvcelial hyphae attached to them, although it is often seen
in Tilletia (Plate I., Z;).

Thus in Ustilago, the spore-forming hyphse with their numerous branches
are divided up by means of septa into short swollen cells, which become con-
verted into spores. These are produced in an irregular manner, so that the
entire mass of mvcelium is ultimately transformed into a dark-coloured mass
of spores (Plate I., d).

Melanopsichium.

In a cross-section of the rachis or axis of the inflorescence attacked by the
smut the plant tissue is seen to be excavated by the fungus, leaving a (^,entral
core more or less intact, and portions extending towards the epidermis. In these
cavities the sori are produced and the spores are first formed at the centre of
the sorus and graduallv extend outward all round, so that the younger and

Spore-for))jaiion. 17

immature spores are towards the circumference, while the older and fully-
formed are towards the centre. The sori generally surround the central core
of plant tissue as in Cintractia, but the mode of formation of the spores is
diiferent. The sori, to begin with, are probably distended cells, and several
of them run together so as to form a comparatively large cavity. In this war
swelling and distortion occurs, somewhat similar to that of the Club-root of
Cauliflower (Plate XXXIII.).

Cintractia.

A new genus was constituted by Cornu in 1883 on account of the develop-
ment of the spores in a regular manner, radiating from a central columella of
plant tissues and protected at first by a membrane composed of fungus cells.
It was named in honour of a French botanist called Cintract. This genus is
not universally adopted, as it is considered that the distinction between it
and Ustilaqo is not sufficiently marked to justify its being retained, but the
mode of development of the spores seems to be worthy of generic distinc-
tion. The mode of spore-formation has been described by Cornu l and Magnus^ .
The inner tissues of the host-plant form a central columella which is pene-
trated by the mycelium of the fungus, and this is aggregated into a compact,
continuous, gelatinous mass surrounding the axis. The entire outer surface
of this mass or stroma as it is called, may be fertile, producing spore-bearing
filaments, or there may be sterile rays projecting at frequent intervals be-
tween the spore-bearing filaments. The spores are developed in the hvphae as
minute colourless portions of protoplasm surrounded by a gelatinous enve-
lope. They are formed in succession, the oldest being always towards the
outside and the youngest nearest the centre.

As they approach maturity, the gelatinous envelope is gradually absorbed,
the gelatinous walls of the hyphae disappear, the outer coat of the spore
deepens in colour, and ultimately they are quite distinct.

In some cases the fertile layer or stroma is formed in the outer tissues of
the host as described by Magnus^ in C. krugiana, Magn. The mycelium grow-
ing luxuriantly in the parenchymatous and epidermal cells protrudes through
the outer wall of the latter and forms on the outside a dense mass of inter-
woven fungus filaments in the interior of which the spores are developed.

The mass of hyphae closely compacted and felted together on the outside
constitutes the envelope or membrane together with the spore-forming hypha?.
The matrix from which the spores are formed adjoins the tissues of the plant,
and the older ripe spores are on the outside, while the inner and vounger spores
are towards the base. This spore -formation occurs in a radial manner, and
each row is separated from its neighbour by the mass of hyphai between ,
which remains sterile. All the differentiated portions of the hyph;p of the
matrix do not grow to mature spores. A large number of them onlv form a
small cell cavity, and the gelatinous walls become swollen. The.}' appear later
to be absorbed, and probabh' supply material for the spores which grow
tx) nraturity.

The successive production of spores in spore-bearing filaments, arising from
a so-called stroma, radiating outwardly and firudy agglutinated at inaturity,
is characteristic of Cintractia, but the sterile rays are not always present.

SOROSPORIUM.

In this genus the spores are in clusters and not separate and distinct as in
Ustilago. Fischer von Waldheini'^ has investigated their formation in
*S'. saponariae. Rud., and it is as follows : — The extremely abundant mycelium
in the blossom and ovary rapidly changes into spore-forming hvpha\ from
4 to 7 /( in dianK^tcr. and like those of Ustilago are gelatinous and full of sliining

i8 Sforc-foniiai'ioii.

protoplasm. At the same time, the hypha? give rise at various points to in-
wardly curved branches, and several of these branched spore-forming hyphae
lay themselves together and twist themselves into a small ball, not unlike
what happens in the formation of a lichen-thallus. These convoluted and con-
torted hyphfe, being gelatinous, soon become so intertwined and entangled
that they lose their individuality, and on the exterior of this gelatinous ball
other hyphse are seen encircling it. These hyphae are also gelatinous and
soon become indistinct, although sometimes there are traces of a concentric
arrangement. Spore-formation is confined to the central gelatinous ball in
the middle of which it commences as circumscribed clear spots, which soon
assume a distinct outline, become brownish in colour, and are diSerentiated
into spore-like bodies varying in number from four to sixteen, or even more.
These bodies again subdivide, so that when the spores arrive at maturity
there are sixty to a hundred, or even more of them, in a spore ball. In the
young state these developing spores are polygonal from mutual pressure, and
they are to be found in spore-balls not more than 50 // in diameter. In the
subsequent development of the spores, the ball increases in size and the gela-
tinous zone swells also, but when the spores assume their characteristic deep
brown colour, this gelatinous zone begins to be absorbed, having been utilized
in the development of the spores. In spore-balls of 70 /< in diameter, the
gelatinous zone is only from 4 to 6 /i thick, and there is no trace of it in the
fully matured spore-balls, except occasionally as in &. solidum, where the rem-
nants were at hrst regarded as sterile cells like those in CJrocystis.

In a section of the affected portion of the host-plant concentric layers of
spore-balls to the number of six to eight occur, the peripheral layer being the
oldest, having been pushed outwards by the continued formation of the young
spore-balls in the centre.

Thecaphora and Tolyposporium.

The development of the spores has not been completely traced in these
genera. The spore-bearing hyphae are intertwined and interlaced into a
dense mass, and the early stages of the spore-balls are difficult to determine.

TiLLKTIA.

The formation of spores in this genus has been investigated by several, but
it is to Fischer von Waldheim that we owe the most complete account of the
process which is as follows : — When spores are about to be formed, the spore -
bearing hyphse give off pear-shaped buds in succession from their sides.
(Plate I., cj). These outgrowths increase in length, and at the same time the
swollen end of each increases in diameter and becomes rounded, so that it is
ultimately attached to the hyphse by a thin stalk (Plate I., h). The contents
derived from the hyphse are granular and vacuolated and particularly rich
in oil, and the membrane becomes somewhat gelatinized. Just before reaching
maturity the gelatinized membrane is absorbed and the young spore acquires
a double contour, the epispore gradually becoming darker and uneven
(Plate I., i, j). In some cases the gelatinous membrane of the hyphse invests
the spores up till the time of ripening, and then disappears without leaving any
trace. The stalks or connecting branches soon wither, and to many ripe spores
their remains continue attached (Plate I., k).

While in Ustilago the spore-bearing hyphse directly break up and form
the spores, in Tilletia the spores are formed singly at the ends of branches.

Entyloma.

De BaryS has investigated and described the development of the spores,
and it is found to be very similar to that of Tilletia. The fertile mycelium

Sforc-fonnation. 1 9

is much branched, and the spore-forming hyphic become swollen at certain
places along their length as well as at their ends. The contents of the cells
acquire the characters of spores, so that they are marked oi? or intercalated
between certain portions of the hyphtc. In Tilletia the spores are onlv
formed at the ends of the branches. In this intercalary formation a series
of spores may be seen arranged in regular succession with the intervening
remains of the hyphre. When mature, they do not break up into dusty
masses, but remain embedded in the tissues of the host-plant. Each matur(^
■spore possesses two coats, and the outer coat is sometimes gelatinous.

Urocystis.

The development of the spores has been studied principally by De Barv,
Woli?, and Winter. The spores are produced in compact clusters with a
special envelope of sterile cells, and the mode of formation of both these struc-
tures has been generally followed. The spore-forming hyphse branch at
their free ends, and the first beginning of a cluster is indicated by the branches
becoming swollen and curved, and winding themselves round each other
generally in a spiral manner, seas to form a glomerulus or ball.

Their walls become so gelatinized that they run into each other and blend
so that they are quite indistinguishable from one another. The spores are
formed entirely fro'n these gelatinized central balls and consist of a group of
cells firmly bound together. Each cluster of spores is surrounded at an early
stage by slender curved branches from the hyphte, and these outer branches
closely invest the spores and form the envelope. These investing hyphae, as
DeBaryhas shown, divide into short cells by means of transverse septa, and,
while most of them disappear as the spores ripen, a number varying with the
individual species persist and form the envelope of the mature cluster of spores.
The number of spores in a cluster vary and sometimes there is only one sur-
rounded by its sterile envelope.

DOASSANSIA.

Cornu, who founded the genus, Fisch, and Setchell have studied the de-
velopment of the spores. When a sorus is about to be formed, the hyph?e
give off numerous interlacing short branches which are soon formed into
tangled knots. It is from these knots that the spores are formed. The cells
of the hyphfe in the interior of the knots become swollen and form a mass of
large, thin-walled, polygonal cells, which become the spores, the process being
accompanied by a gelatinization of the walls. The external portion is at first
composed of compact layers of almost unaltered hyphte, but shortlv before
the ripening of the spores the "cortex" of sterile cells is indicated. These appear
just beneatli the reduced layer of investing hypha^ and arc probably formed
from a layer of cells similar to and adjoining those from which the spores are
formed. The sterile cells gradually become oblong or wedge-shaped, lose their
granular contents, and are filled with air. taking on the brown colour of the
wall characteristic of maturity.

Gcrmiiiaf'iou of Sforcs.

CHAPTER V.

Germination of Spores.

The spores may either germinate in water or in a solution to which;
nutritive material has been added. The germination of spores in nutrient
solutions has been studied in great detail by Brefeld, and has been shown
to differ somewhat from that obtained when only water is supplied. The
first to employ nutrient solutions in studying the germination of smut spores
seems to have been Hallier- in 1868, who used a variety of substances, such
as starch paste, white of egg, milk, a solution of sugar, &c. In every case
where germination has been carried out by myself it was first tried in water,
and then usuiilv in some definite nutritive medium for comparison.

The process of germination, wherever known, is given in connexion with
the various species, since it furnishes important systematic characters ;
but a general account is given here of the usual course of development.
When the spore begins to germinate under the influence of moisture, it puts
forth a longer or shorter germinal tube, known as a promycelium (Plate
I., m, n, 'p, r). Then small hyaline spore-like bodies are, as a rule, produced,
called promycelial spores or conidia (Plate I., q, s). In those cases
where infection of the flower takes place, as in Loose Smut of
Wheat, a much-branched mycelium is usually formed without any
conidia, and here we have an instance of the germinal tube developing
directly into a mycelium.

When conidia are formed, they may directly produce a germ-tube which
infects the proper host-plant and develops a mycelium, which again reproduces
the spores. Or they may bud even while still attached to the germinal
tube, and give rise to secondary or tertiary conidia, which may in turn
germinate and penetrate the tissues of the host-plant. It happens not
infrequently that the conidia unite in pairs, even in some cases before they
have become detached from the promycelium. A short transverse tube
connects adjacent pairs, and the protoplasm of the two is placed in direct
communication. This pairing is regarded by De Bary as a sexual act — a
process of conjugation ; but Brefeld considers it as analogous to the
blending which takes place between different branches of a mycelium.
However that may be, after this union has taken place, a slender germ-tube
is produced which receives all the protoplasm from the paired cells, and can
infect the proper host-plant where it develops a mycelium, which in turn
produces a crop of smut spores. This may happen either with solitary or
paired conidia. While the spore follows the general course of development
sketched above when germination takes place in water, it is somewhat
dift'erent when a nutrient solution is supplied. Hallier^ observed that in
rich nitrogenous substances, such as white of egg, the germinal tubes were
thick and distorted, but he also considered that they changed into various
moulds from his cultures not being pure. It was Brefeld, however, who was
the first to successfully apply nutrient solutions to the prolonged and pure
culture of smut spores. He mostly used a sterilized decoction of fresh
horsedung, and found that when such a solution is employed the germina-
tion is not only more rapid and much more luxuriant, but that it can be kept
up indefinitely as long as nutriment is supplied and the reproductive bodies •
themselves are sometimes different. He soon found that water alone was-

(icini'nmi'iO]i of Spores. 21

not the most suitable medium for obtaining the best results. In many cases
the couidia were formed, but they were often so passive that they did not germi-
nate, and without some additional means of quickening their germination and
development it was diflicult to account for the wide distribution of the snuits.
I have found a sterilized infusion of hay a good culture medium, and have also
used a variety of substances, such as malt extract, soil extract, somatose,
Cohn's modified solution, &c.

In onio cases it is v; ry difficult to get a spore to germinate even when the
various nutrient media are tried in addition to water. It may be that it is
not the proper season of the year, and some spores may require a rest before
starting germination. I may take Ustilago calandrinice, CHnt., as an illus-
tration of this class of spore. The spore i of the Tilletia type, with regular
reticulations of the epispore, and it was desirable to germinate it in order to
settle the genus. The only material in my possession at first was fully ten
years old, and it failed to germinate ; but that might be owing to its age.
Fortunately I came across fresh material in October, 1908, and it was also
supplied to me in November, as well as in January, 1009. The fresh spores
were placed in both tap and distilled water, as well as in a decoction of the
plant itself, also in ammonium nitrate, lactic acid, tannic acid, an infusion
of sugar-beet, sugar solution, and Cohn's modified solution. At the end of
six days only a very few germinated in distilled water and formed conidia, as
in Ustilago. But in the other solutions, although some of them were kept
till the fourteenth day, there were no signs of vitality.

In proper culture media the spore germinates as usual, and produces a
germinal tube, but instead of remaining short and forming conidia, it often
continues to develop and gives rise to sprouting conidia, which multiply by
budding after the manner of yeast. Or the germinal tube may grow
luxuriantly and produce a much-branched mycelium, from which in the
fluid itself or in the air conidia are formed. These conidia sprout at the end
again into one or several conidia. and we may distinguish them as water or
air conidia, according to the medium in which they are produced.

There is thus a great variety of reproductive bodies, although there is
only one kind of spore, and it is quite likely that the conidia, sprouting conidia,
and aerial conidia of the smuts are just as efficient means of distribution as the
different kinds of spores among the Eusts.

A w ord of caution is necessary, however, as to the interpretation of results
ol)tained from " pure cultures," as they do not necessarily represent Avhat
actually takes place under natural conditions. The researches of Klebs,'
Kaufmann,' and others have shown that the formation of reproductive
organs of a particular kind or their suppression is largely determined by food
and environment. Klebs was able to control at will the reproductive
processes in certain fungi, according to the composition and concentration
of the nutrient medium, as well as by the temperature, presence or absence
of light, &c. There is no reason to doubt that the same principle applies to
smuts, and that it will tend to explain the discrepancies in the results
obtained by different observers in the germination of the spores under
different conditions and in different media.

As has already been shown, the germination of the spore is uot always
easy of accomplishment, for we do not always know the precautions to be
taken. Some spores are capable of germination immediately after being
gathered, others require a period of rest. Some germinate in the water or

22 Gcrnii nation of Spores.

other liquid medium, others ou the surface of it, and still others require only
damp air, for if they come in contact with water they are abnormally
developed. The time required for germination is also very variable, as it
may occur within a few hours or take several days, as in the case of Tilletia
tritici. No doubt this is dependent on various factors, such as the age of
the spore and the conditions of the weather, which is most favorable when it
is warm, damp, and cloudy.

Duration of Germixating Power.

In quite a number of casei the spores are capable of germination as soon
as they are mature, and where cereal crops are concerned, this immediate
germination w ould evidently tend to the extinction of the fungus, since there
would be no suitable host-plant to infect at that season, and so the conidia
formed would probably perish. But it is now known that under such
circumstances special conidia are formed, which have the property of living
on dead or decaying vegetable matter, and thus tiding the fungus over the
period when living plants are not available. In the case of Loose Smut of
Oats, for instance, Brefeld brought about infection by means of the sprouting
conidia derived from the budding conidia grown in a nutritive solution.
In other cases the spores are only capable of germination after a period of
rest, and so are ready to infect the host-plant at the next period of vegetation.
This period of rest may extend over a number of years, if the conditions are
not favorable for germination. Thus the bunt spores have been known to
retain their vitality for eight years and a half when kept perfectly dry, and
the spores of Tolyposporium bursiim on kangaroo grass have germinated after
four years, the spores having been collected in November, 1902, and germinated
towards the end of 1906.

Types op Germination.

It was formerly taken for granted that .smut fungi could only live and
grow upon the host-plants with which they were found associated in nature,
and experiments and observations were accordingly confined to these hosts.
It was known that the spores could germinate in water just as they would
on the moist surface of the plant, but beyond that there was no independent
existence supposed to be possible. When it was discovered, how^ever, that
these smut spores could live and grow outside of the host-plant, then it was
realized that their developmental history could be followed apart from the
living organism. It is to Brefeld we owe this new point of view, which has
been so fruitful in results, and the use of artificial nutrient solutions, instead
of mere water, was the starting-point.

By studying the germination of spores in this way we have learned that
there are various types of germination, and concrete examples, occurring in
AustraUa, will be given of each type.

1. In Vstilago avence the germinating spore produces a germinal tube
bearing conidia, and these conidia multiply rapidly m the liquid by sprouting
in a yeast-Uke manner at both ends. (Fig. 1.)* Each of these daughter
conidia is capable either of repeating the sprouting in a nutritive solution or
of directly infecting the young seedling.

* Text figures are simply referred to as Figures, while tliose beloiuing to the Plates are always
preceded by the number of Plate.

(icrniuiatioii of Spores.

^3

a. h.

Pig. l.—Ustilago avence or Oat Smut.— a. Spore gerniiuating and giving
off conidia from germinal tube or promycelium x 450. b. Colony of sprouting
conidia, developed from one of the conidia in a x 350. (After Brefeld.)

2. In Ustilago hromivora the conidia produced by the germinal tube are
not sprouting conidia, but they form n-w germinal tubes or promycelia, which
in turn produce similar conidia. (Fig. 2.) As a rule the, promycelium is only
formed once direct from the spore, but here it is repeated, and is not confined
to the germinating spore.

Fig. 2. Ustilago hromivora or Brome Smut. — -A single spore producing a
two-celled promycelium, which forms conidia, and these conidia in turn again
develop a promycelium, and so on until quite a number is formed, as in Figure
X 400. (After Brefeld.)

3. In Ustilago olivacea the germinal tube is in abeyance, and conidia are
formed direct from the spore. These conidia multiply indefinitely in a
nutritive solution by sprouting in a yeast-like manner. (Fig. 3.)

^8 f.

)#=

Fig. 3. Ustilago olivacea or Carex Smut. — Spores producing conidia direct
without the intervention of a germinal tube x 400. (After Brefeld.)

34

Gcrminafion of Spores.

\. In Ustilago nuda the germinal tube does not produce conidia at all,
but grows out into a large and copiously branched sterile mycelium. (Fig 4.)

Fig. 4. Listilcu/o nuda or Naked Barley Smut. — Spore germinating and
producing a much-branched mycelium x 350. (After Brefeld.)

5. In Tilletia tritici the germinal tube produces a tuft of conidia at its
apex, and each of these conidia or the conidia united in pairs produce a single
secondary conidium capable of infecting the wheat plant. Or the conidia
may produce a large and richly-branched mycelium in the air, just like a
tuft of mould from which aerial conidia again arise, and this process is repeated
as long as the nutrient solution lasts. (Fig. 5.) The important fact is here
made evident that the smut fungi can reproduce themselves saprophytically,
and that these reproductive bodies are found to be capable of infecting the
proper host-plant and of producing the disease.

fHOnRTY LIBRARY

M. C. StaU College

Germination of Spores.

Fig. 5. Tilletia tritici or Bunt of 'v1/heat. — a. Genninating spores with
septate promyceliuni bearing elongated conidia at apex x 300. h. Apex
of promyceliura from which the six conidia fused in pairs have become detached

X 250. c. Conidia detached and fused in pairs, and some bearing sickle-
shaped conidia x 400. d. Mycelium like a tuft of mould produced from
conidium and bearing sickle-shaped conidia in all stages of development

X .350. (After Brefeld.)

Effect of Light and Darkness on Germination.

I tested the germination of some of the more rapidly germinating spores,
such as those of Ustilago readeri in light and in darkness. Spores were taken
from plants of Danthonia penicillata, collected on 6th December, 1908, and
placed on sUdes in ordinary tap water on 6th January, 1909. Some were
kept under a bell- jar exposed to the light and others in a seed germinator in
which the light was excluded, but the air admitted. Both were kept in the
same room, the only difference being the presence or absence of light. The
experiment was repeated several times and invariably liglit was proved to
favour germination.

In one experiment, the slides were examined after five hours, and while a
few of the spores exposed to the light had germinated, none had done so in
the dark. After twenty-four hours, they were again examined, and the great
majority of the spores had germinated in the light, while only a few had ger-
minated in the dark. In the light, promycelia wer<^ formed which sometimes

26 Germmafioii of Spores.

grew out into slender elongated filaments, but no conidia were formed. In the
dark a few of the promycelia produced on^- or two conidia. In another experi-
ment, there was no germination after two hours, but in four hours occasional
spores in the light had produced promycelia about twice or thrice as long as
the spore, while in the dark only a very few had germinated, and the pro-
mycelia were much shorter, only about the length of the spore. At the end
of twenty-four hours the slides Avere again examined. In the dark only a
comparatively few of the spores had germinated. The promycelia varied in
length from .30 to 52 ^(, either without septa or 1-3 septate, and bearing some-
times one or two lateral and a terminal conidium. Only in rare cases was a
conidium produced at the end of another while still attached. In the light
there was luxuriant germination, and the great proportioji of the spores had
germinated. The characteristic feature was that the promycelia grew out
into long, slender, often wavy filaments, which readily became detached,
reaching a length of 200 -.300//. Only rarely were conidia formed, and some-
times two promycelia proceeded from the same spore.

I have only tested the effect of light and darkness on the oi\e species of
spore, but Fischer von Waldheim^ also found that the germination of smut
spores was retarded by withholding the light — that light had a stimulating effect
o]i germination. In Ustilago carbo ( = Ustilago avence) it delayed the ger-
mination for several hours, and also caused the promycelium to be frequently
bent in a knee shape.

Effect of Exposure to Sunshixe on Germination.

It is a common belief among farmers that long exposure to the sun's rays
in summer kills the bunt spores, and they account for the general absence of
bunt in self-sown wheat by the spores on the exposed grain being destroyed
in this way. Laurent^ was induced to investigate the subject by observing
that in some districts a burning sun at the time of sowing the wheat diminished
the chances of infection. He took bunt spores and exposed them to the full
sunlight in a glass vessel, and at the same time he exposed other spores to the
same light passed through a layer of a solution of sulphate of cjuinine three
centimeters thick. The temperature of the surrounding air did not rise above
40° C. After eight hours it was found that the spores fully exposed to the
sunlight did not germinate at all, even in a nutrient solution of unfermented
beer, while the spores shaded entirely from the sun germinated freely. The
spores which were shaded from the chemical rays of the sun by the solution
of sulphate of quinine did not lose their germinating power, even after sixteen
hours of exposure to a very hot sun. so that it may be assumed that while
the exterior spores of a bunt-ball are killed under these conditions, the interior
spores are still capable of germination.

Farrer^ also carried out experiments to test the effect of dry heat on bunt
spores, and since it was believed that soaking the seed wheat in water for a
quarter of an hour at 57° C. had the effect of killing the spores, he tried this
heat in the dry state, as well as higher temperatures for the same time. The
result was that the higher the temperature the smaller was the proportion of
seeds which produced plants, and the greater the proportion of plants which
were bunty. At 54° C. of dry heat about 2 • 6 per cent, of the infected grains
lost their germinating power and 3 per cent, were bimty, while at 104° C.
three out of 136 seeds grew, but none formed ears. The direct heat of the sun
may have a different effect on spores than dry heat, yet Farrer^ says : — " My
experiment with dry bunt shows conclusively. I think, that it is not the heat
of the sun which kills the spores of bunt which are left on the ground: it is. I
think, moisture — the moisture from lains and dews, the moisture which comes

Gcrndnation of Spores. 27

from below to the surface of the soil, and possibly also the invisible hygro-
scopic moisture which the soil and vegetable matters absorb at night, especially
on nights when the fall of temperature is considerable — which causes the
great majority of the spores which are left m the ground to germinate. When
this happens, the absence of hosts (freshly germinated wheat-plants) to attach
themselves to and dry weather soon causes the young bunt-seedlings to
perish." It is probable that both methods occur in nature, and that while
the exposed spores are acted on by the sun's rays, those protected by the soil or
otherwise are induced to germinate by the moisture and perish in the absence
of a host -plant.

Effect of Temperature on Germination.

Eriksson found that the spores of some rusts germinated more freely after
being exposed to a temperature of 0° C, or even less, although an extremely
low temperature retarded germination. Schindler' experimented with
some smuts and found that with a dry heat the spores of Tilletia tritici could
stand 65° C. without losing their power of germination, but with a moist heat
of 45-50° C. they were rendered sterile. Cold, on the other hand, produced
but little effect, even after prolonged exposure to -20° C.

*******

In preparing slides of germinating spores for photographic purposes, the
water is first allowed to evaporate under cover, then absolute alcohol is added
as a fixing agent. This is gently moved to and fro for a few minutes, and after
drying, the stain is directly applied. The most generally useful stain is
Bismarck Brown, which gives a beautiful golden-brown tint to the promycelia
and conidia. Although it stains quickly the specimen may be left in it for
at least twenty minutes without injury. The excess of stain is next drained
off or washed off, and, if too deeply stained, it can be rendered lighter by the
application of dilute alcohol. The object is then mounted in glycerine and
water (half and half) in the usual way.

28 hijcci'ton.

CHAPTER VI .

Infection.

After the germiuatiou of the smut spores had been observed for a large
number of species, the mode of entrance into the host-pknt and the furtiier
development there until spores were again produced, was carefully studied
by a number of botanists. Among the most prominent investigators were
De Bary, Kuehn, Fischer von Waldheim, Wolf?, and Brefeld. They determined
the mode of infection in certain species, but a number still remain in which
the exact method of germination and infection has yet to be discovered.

It was generally found that infection occurred in the seedling stage of
the host-plant by means of the spores, which germinated and produced their
conidia. The young seedlings may be infected either by the smut-spores
attached to and so-rni with the seed, or they may be in the soil. While the
spores of some species of smuts remain in the soil in an inactive condition,
there are others, such as the flag smut, in which the infection is principally
from the soil. BrefekP showed in his experiments with loose smut of oats
that seed sown in an infected mixture of held soil and fresh horse-dung yielded
between 40-50 per cent, of smut ; but his''' recent similar experiments with
the loose smut of wheat and barley for three years in succession only yielded
negative results. The reason for these negative results lies in the fact that
infection does not occur in the seedling stage, but through the flower, as we
shall afterwards see. It is principally owing to the patient and long contiimed
investigations of Brefeld that our previous views regarding the modes of
infection have had to be considerably modified, and, in accordance with this,
the methods of treatment have been placed on a surer foundation.

Infection and Contagion.

When Meyen contended that the smut is not a contagious disease but is
inherited, he simply meant that it was not due to any external parasite,
but was inherent in the plant itself. Infection and contagion were in his
time regarded as synonymous, but now the latter term is generally applied
to those infectious diseases in which direct contact is necessary to produce
them. There is no necessity for the plants to be actually in contact in order
to contract the disease caused by the smut fungi, but the spores or germs are
conveyed to the plants, and so we speak of infection. Infection does not
consist in the mere penetration of the germ-tube of the spore or conidium
through the epidermis into the tissues of the host-plant, but the germ tube
must grow and develop at the expense of the living cells until it reaches the
apex of growth, and there become associated with the growth of the host,
so that finally fresh spores are formed. It is well known that the germ-
tube of the smut fungi may penetrate inside a plant, and there die oi? without
producing any injurious effect, and for convenience we might use the term
inoculation to signify merely that the spores or germs had been applied to
an otherwise healthy plant, while the normal infection would consist in the
entrance and growth of the germ-tube within the tissues of the plant and the
final production of spores. The period which elapses between the infection
and the production of spores through the multiplication of the fungus inside
the plant might also be called the " incubation period." Thus, in the case of
stinking smut, the incubation period extends from the infection of the
seedling to the production of spores in the ovary, and in the case of the
American corn smut, where infection is strictly confined to the young parts

Infection 29

♦of the plant directly attacked by the fungus, the period of iueubatioii is
within fourteen days. It has also to be noted that numerous infections nia v
occur in the same plant at the same time. Brefeld I'emoved the epidei'mis
from young seedlings that had been infected, and found it pierced by distinct
holes,' through which the germ-tubes had entered. In favorable preparations
he observed the surface riddled as if by drill holes and penneated by numerous
in-grown germ-tubes. This would explain such cases as I have met with
where ears from the same plant produced spores of both Tilletia intia and
T. levis, for if the grain was dusted with both kinds of spores they might both
infect the same plant. Even the case mentioned by Sorauer^. where both
species were found in the same ear, ould be explained in the same way. It
is not unusual to find cases with stinking smut and loose smut on diSerent
ears from the same wheat plant, but this is not difficult to account for. The
loose smut fungus was already in the grain of the wheat plant, since infection
takes place through the flower, and afterwards infection occurred in the seedling
stage by means of the spores of stinking smut.

Modes of Infection.

There are at least four typical modes of infection at present known, and t)y
giving a detailed account of each subsequently it will serve to show the nature
of the process and the means most likely to be successful in combating the
particular disease.

1. The most common mode is that the young seedlings are infected, the
resulting mycelium grows throughout the entire plant and the smut spore*
are produced usually in the flowers or inflorescence, as in oat smut ( Ust^lago
avenae). ■ *,' '0

2. A second tvpe is represented in the case where any young and growing
portion of the host-plant is capable of infection, and the mycelium is localized
where the infection occurs, as in the American corn smut not known in
AustraUa {Ustilago maydis).

.3. Infection may take place through the stigma of the flower, the spore
acting after the manner of a pollen-grain, or by piercing the young ovary wall,
the mj^celium developing in the ovary, lying dormant in the ripe grain and
growing throughout the entire plant next season, until it reaches the flowering
stage, when the smut spores are again formed, as in loose smut of wlieat
{Ustilago tritici) and naked smut of barley [Ustilago nuda).

While in the cereals it is generally considered that the wind is the agent
for carrying the spores to the stigma or ovary after fertilization has occurred,
it is highly probable that thrips are also concerned in it, for in our northern
areas particularly, these insects are in some seasons so common as to affect
the development of the ears of wheat. ■ '. * ; ;

4. Infection may take place as shown by Hecke,^ through the young
shoots which arise near the surface of the soil in tlie process known as
" tillering."

It is worthy of note that these different modes of infection are asso-
ciated with a different behaviour of the spores on gei'mination. In the
first and fourth type sprouting conidia are formed which are capable of
living saprophytically in the soil and infecting the plant from that source.
In the second aerial conidia are chiefly formed, and infection is mainly brought
about by the wind ; and in the third no conidia are formed at all. so that
the spores are carried to the stigma and germinate there after the manner of
pollen-grains, or they may fall u])on the surface of the very young ovary.

30 Infection.

1. Seedling Inb^ection.

This was at first considered to be the only mode of infection, as it was
tlie only one knowai, and even now it is recognised as by far the most common.
The spores are generally attached to and sown with the seed, and if both
germinate at the same time infection usually occurs. The spore on the moist
surface of the grain germinates and produces its germinal tube bearing
conidia. The conidium stimulated by the moisture puts forth a deUcate germ-
tube Avhich penetrates the young tissues of the seedling if it reaches i: at the
right time. The particular spot for infection is at the juiiction of the rootlet
just emerged wath the young shoot still wdthin the seed, and this is sufficiently
delicate to allow the germ-tube not only to reach the growdng point of the
primary shoot, but to branch out into any secondary shoots that may be
formed.

But the question has also been raised as to soil infection, wdiether the
spores in the soil and not on the seed wall infect the host-plant. As already
stated, Brefeld has shown that this may occur with loose smut of oats
{Ustilago avenae), and I have elsewhere proved by experiment that soil
infection occurs in flag smut of wdieat {Urocystis tritici). With regard to
stinking smut of w^heat, Bolley showed that when the spores winter in the
soil they do not infect the second crop, as they have already germinated by
that time. If smut-balls are in the soil, however, they may cause infection.
Seed was sown close to smut-balls in the ground, and it was found that when
the seed was untreated the spores of the smut-balls reached the seed, and
infected it, wdiile seed under similar conditions and treated with bluestone
Avas unaffected.

It would appear also that the greater the proportion of sjjores on the seed
s,wn the more severe the infection. Thus in inoculating the grain wdth bunt
spores, when one ball of smut was applied to a hundred w^heat grains, the
percentage of smutted plants in two cases was 56 and 58 respectively, while
when the spores were applied at the rate of one bunt ball to five grains, the
proportion was 79 and 81 per cent, respectively.

2. Local Infection.
This is seen to perfection in the American corn smut {Ustilago maydis)
where any young and growing portion of the host-plant is capable of infection
and the action of the fungus is strictly localized to these particular spots.
Brefeld^ carried out an extensive series of experiments in which he proved
that only those parts of the young plant become smutty which have been
directly infected, all the rest remaining perfectly normal, so that the action of
the germ is strictly localized. He began by inoculating young seedlings with
sprouting conidia produced upon a nutrient solution, and the few plants which
developed the smut swellings died completely. In those cases, however,
where the axis remained sound he expected to find smut developed in the ears
as in the case of grain smuts, but not a single plant v as smutty. This was
contrary to the idea then prevalent that infection could only take place
through the young seedling, and he came to the conclusion that the germ-
tube might penetrate into other parts which were in a young condition similar
to the teedling. Accordingly he infected the heart of the plant still growing,
and the result was that " the entire leaves were covered with a complete crust
of pustule, Avhich,in part, made them almost unrecognisable." He next in-
fected the fertile inflorescences in the bud condition, and none escaped.
Where the lower flower buds were infected, and not the upper, the latter always
remained sound, and even where the exposed ovaries at the tip received the
germs, they were swollen and smutted, while the ovaries lower down on
the same spike produced normal grains. The adventitious roots which

Iiiicction. 31

appear 011 tlie lower nodes of the axis were also infected as soon as tlieii' tips
were exposed, and tliey, too, soon showed swellings which developed into
smut pustules. Thus, wherever the tissues were young and tender, the ger-
minating conidia were able to penetrate and produce infection which, how-
ever, was strictly confined to the parts directly attacked.

■>. Flower Infection.

Infection throuj:;h the liower has only been recently experinientalh^ proved,
and on account of its practical importance, will recjuire to be fully considered.
For this mode of infection, those smuts are best adapted which have powdery
spores, and are, consequently, easily blown about by the wind. What are
known as Loose or Flying Smuts, fulfil these conditions perfectly, as the very
name indicates that they are readily scattered, and those of wheat and barley
are characteristic examples.

As far back as 189(5, Mr. Frank Maddox, then Agricultural Experimental-
ist to the Council of Agriculture of Tasmania, had practically demonstrated
infection by the flower, and his account of it in the Agricultural Gazette is well
worthy of being reproduced here. He writes : — " I will now give the conclusions
I have arrived at with smut (of wheat) from the results of my experiments.
I have never been able to cause infection and reproduce the disease with spores
on the grain or in the ground, which I can so easily do with bunt spores to
reproduce bunt. " The only way I have been able to infect grain and reproduce
smut (which seldom ever fails) is by putting the spores on the ovary of the
plant at flowering time, about the same time as the pollen-grains are being
shed. The grain will mat ; re without the slightest signs of being diseased. I
have hit the time so well now that I may say I never have a failure. I think
this accounts for when I did fail, viz., the ovary was not forward enough for
the spore to get its seed-bed, or possibly, sometimes the spores were not
matured enough. The comparison of bunt and smut spores finding their
seed-bed are the very opposite. It is really wonderful to me how the smut
spores do, as the ovary is well protected by the glumes or chaff, and there is
only a short period that infection seems to be able to take place. " There is
no doubt that here we have a practical demonstration of the fact that infec-
tion by the loose smut of wheat occurs during the flowering period, and that
this is the first record of it.

Next year, in 1897, Nakagawa' infected the flowers of wheat with the
matured spores of loose smut. The infected seeds were sown, and next year
the plants were found to be smutted. Soon afterw^ards, similar results in
flower infection with the spores of Ustilago tritici and U. nuda were obtained
by Hori', and he concluded " that the spores of those smuts which mature
at the flowering time of the host, and may be scattered easily by the wind,
will be retained in the inner side of the seed and give rise to the smut I'.isease
during the next flowering time of the host-plant."

In 1903, Brefeld" had also proved flower-infection in the wheat, and
Hecke^, in 1904, the same in th ? barley. In 1905, Brefeld published a series of
carefully conducted experiments. Spore material of the loose snuit of wheat
carefully selected and preserved through the winter, was dusted on to the
stigma of the wheat-flower, just as in the operation of crossing, and micro-
scopic examination showed that the spores germinated, and that the germ-tubes
passed down the style into the ovary, where a fine network of mycelial fila-
ments were formed. But the ])lants thus treated exhibited no signs of disease
and produced strong healthy grains in the ear. When the grains, however,
were sown next season, with all necessary precautions against outside infec-
tion, the resulting plants were so badly affected that the entire inflorescence
was destroyed. .\s the same result was always repeated the conclusion

3- Infection.

became irresistible, that tliis smut exclusively infects the flower, and that it is
not developed in the same year but remains latent in the mature grain. When
this grain is sown next season, the myceUum passes into the young plant and
then, on reaching the inflorescence, proceecb to the formation of smut spores.
It is very evident, therefore, that it was the mycelium in the seed which
caused the disease, for the grains were sterilized and disinfected before sow-
ing, so that every chance of infection from spores adhering to the grain was
excluded. Further, to protect them against contamination in the soil, the
grains were sown in germinating chambers on a layer of sterilized sand, and
when the developing grains had reached the immune stage, the plants were
carefully laid out and grown in the op3n.

The methods adopted by Brefeld in carrying out experiments to prove
that infection took place through the flower, are of sufficient interest to
justify mention of them, and they wera such as approached most nearly the
natural infection. The most favorable time was when the flowers were
most fully opened and the spores were powdery and easily scattered, condi-
tions met with in dry sunny weather. As the result of various preliminary
trials, Brefeld found that a hollow India-rubber ball was the best for apply-
ing the spores, an apparatus similar to that used for applying " Mortein,"
only the ball was larger. The smutted inflorescence was introduced into the
ball and a tube inserted in the opening, so that the smut spores could be
forcibly blown out in the form of a fine spra3^ The ears to be infected were
placed in a glass cylinder, closed below by cotton wool, and the spores were
blown in from above. After a short interval to allow the spores to settle,
the ears were removed from the cylinder and thus infection of the flowers
alone was made the subject of the experiment.

Of course only a limited number of flowers open at the same time to allow
access to the spores, for it is well-known that they do not op^sn all at once, but
generally those in the middle of the ear are most advanced, while those at the
top and bottom are later. Hence with only one infection a vertain proportion
are always missed, and there is no advantage in infecting the same ear at
different times, since the necessary handling hinders the normal development.
When infection tak.:!s place in the field, the chances are proportionately in-
creased, for the spores are being constantly scattered upon adjoining healthy
plants with the slightest breath of wind, and it is only interfered with by
rain or damp weather. Warm and dry weather is also unfavorable for the
germination of the spores, while it hastens the ripening of the grain.

A second and more delicate method consisted in the artificial infection of
each flower, just as in cross-fertilization, using a fine cameFs hair brush to
dust t e spores on the stigma of the flower.

This is more reliable than the " cylinder-infection," since all flowers not
infected may be removed, but it must not be assumed that each flower left
is actually infected, for all the flowers of an ear are not capable of infection at
the same time. By either of these methods, flower infection experiments
were carried out on wheat and barley, and while the grains produced seemed
Cjuite healthy and normal, yet on being sown the following year under strict
sterilization conditions, smutted ears appeared at harvest time in greater
or less proportion. Although Brefeld succeeded in inoculating the wheat-
flower, for instance, and observed a few days afterwards that the spores had
germinated in the stigmatic secretion and had sent hyphae through the stig-
matic tissues to the ovary, yet it must not be assumed that this is the only way
in which flower infection takes place in nature. It is well-known that the
flower of wheat is self-fertilized before opening, so that the smut spores will
in all probability, fall upon the young ovary wall when exposed and thereby
gain an entrance.

InfecUnn.

33

Hecke^, in 1905, also deinonstrated that the myceUum of the fungus was
in the embryo of the barley, even while still enclosed in the seed, after the
infection of the flower with the spores of naked smut. This anatomical proof
places the fact of flower-infection on a sound basis (Fig. 6). Flower-infection

experiments have also been carried out by the United States Department of
Agriculture, and in a communication, dated October, 1908, it is stated that
" During the last two years numerous inoculation experiments have been per-
formed with the loose smuts of wheat {Ustilago tritici) and loose smut of barley
{Ustilago nuda). In the case of both of these smuts infection takes plaee
only at the time of flowering of the host. The smut spores are easily carri'-d
by the wind, and as the wheat and barley glumes open for a &hort time during
the process of pollination, the spores readily gain entrance and infect the de-
veloping ovary. The smut-gerin then lives intraseminally until the grain
sprouts in the spring, after which it grows along with the host, and at Hower-
mg-time becomes evident as the well-known loose smut."

4. Shoot Infection.

The only method of infection recognised for a long time among the snmts

was that of the seedling being attacked by the germinating spore attached

to the seed, and this was known as Seedling infection. Next it was found

that in American corn smut young and growing ]iortioiis might be attacked,

is:,?. c

34 Infection.

and this was called Local infection. Then it was discovered that the young
ovary or other portions of the flower might be infected by the germ-tube of
the spore producing in some cases a mycelium inside the seed, so that when
the ripe seed was sown next season, the resulting plant was diseased. This
is known as Flower infection and occurs in Ustilago tritici and U. nuda.

Next Hecke-i discovered a fourth mode of infection, which he called Shoot
infection, and it was suggested by what occurred among the numerous Lychnis
plants which had been grown from seed obtained from the flowers that had
been infected. Such seed produced nothing but sound flowers in the summer,
but one plant formed a smutted flowering shoot in October (autumn). There
were, at least, two possible explanations of this. It might be accounted for
by flower infection, the summer flowering shoots escaping by their rapid
growth, while the fungus reached the growing point of the more slowly de-
veloping autumn flowering shoot, or there was the possibility that the plant
was originally sound and was subsequently infected by neighbouring diseased
plants grown in pots alongside. Such an infection could only be conceived to
take place by the mass of spores falling to the ground, germinating there, and
producing their conidia, which reached and infected the young shoots
arising at the collar or top of the root. In order to prove this possibility, he
experimented with perfectly sound two-year old plants of Lychnis alba. They
were grown from seed in pots and cut back in October as far as possible to the
collar or the portion level with the ground. Then the exposed collar was dusted
with spores of Ustilago violacea and covered with manure containing similar
spores. A few weeks afterwards the freshly formed shoots appeared at the
surface, and in May of the following year began to flower. The flowera pro-
duced were smutted and their diseased condition can only be referred to the
shoot infection which took place in October.

The Anther smut {Ustilago violacea (Pers.) Fckl.) is able to produce its
spores only in the anthers or male organs. This fungus infects the Campion
{Lychnis dioica) which has the sexes on separate individuals, and it not only
attacks the male plant where the anthers are normally developed but also
the female plant which normally never bears them. In the male plant it
produces its violet spores in the anthers naturally present, but in the female
plant it still produces its spores, although anthers are absent in the natural
conditio]!. It stimulates the female host in some way to the production of
stamens in which it may develop its spores, while the pistil normally
developed, is suppressed. The fungus is evidently able to induce the con-
ditions necessary to the formation of male organs, although elaborate experi-
ments by Strasburger failed to produce this effect in uninfected plants.
We must assume that both sexes exist, but the dominant one only becomes
visible while the other remains latent, and this dominance may be controlled
by an internal stimulus which may influence the particular kind of nutriment
available. Change of sex is here shown to be possible, but how it is brought
about cannot be definitely stated, further than that it is determined by
internal, not external factors, and since it is the young shoots which are
infected, the sex may be determined long before the appearance of the
flower.

A similar experiment was made with Urocystis occulta. The perennial
Secale montanum was employed as a host-plant, after it had been shown that
plants of this species, which were cultivated in gardens, became naturally
infected by Urocystis occulta produced upon the rye {Secale cereale). In this
experiment all shoots were likewise cut back to the collar and then infection
was made in the autumn with spores and manure containing spores. The
result was that in the spring of the following year, the shoots produced were
smutted.

Infection. 35

Dr. Hecke comes to the conclusion from these experiments '' that besides
the seecIHng and flower infection, there is still another kind of infection among
smuts, that is to say, shoot infection. It is probable that this kind of infection
occurs not only with Ustilago violacea and Urocystis occulta, but also with
other smuts as well. The smuts of perennial plants are especially considered
here, but it is possible that the same thing occurs in the case of infected shoots
of cereals. A series of experiments of this kind is being carried out with
different smuts, the results of which will be given later."

This will account for the infection of the shoots of cereals by Urocystis
occulta or flag smut, by these 5'oung and tender shoots coming into contact
with the diseased straw and other spore-bearing material in the soil, in the
process known as " tillering." When the primary or terminal bud has about
reached the surface of the ground, then lateral buds mav be formed in the
axils of the leaves about the same position. These lateral buds or " tillers "
as they are sometimes called, usually develop into branches, and these
branches may in turn produce other branches, so that from a single grain of
wheat a plant may be developed consisting of numerous stalks each bearing
an ear. Such an individual plant with numerous stems arising from a
common root is usually called a " stool " and the process by which the plant
thus adapts itself to its environment is known as " stooling " or " tillering."
This branching takes place at the joints or nodes near the surface of the
ground and as many as 125 stalks of Steinwedel wheat with 12.5 perfect ears,
with an average of fifty grains in each ear have been recorded and photographed
by Thompson' in New South Wales. It is evident that the smut fungus may
enter these numerous stalks, either by directly infecting the young seedling,
or by gaining an entrance through the young shoots, or, as in the case of plants
living more than one year, by a perennial mycelium..

The case already given of a smutted barley plant being cut back and the
fresh shoots being again infected by the mycelium persisting in the lower
nodes, shows that we have to distinguish between infection of the shoots from
without and from within.

Collection of Spore Material.

For successful infection it is necessary to have the material as fresh and as
well preserved as possible and taken direct from the fields where it is produced.
To preserve it in the best possible condition for the following spring requires
care and attention, for if special precautions are not taken, it may be injured
by moulds or by grubs so as to be quite useless. To guard against
such injurious influences, Brefeld adopted the following method of
collecting and preserving plenty of pure spore material as the result
of a lengthened experience. It should be gathered in sufficient ([uantity
soon after the exposure of the spores, before grubs or moulds can gain access
to it and preserved for about a week in a dry place. Then the spores are passed
through a fine sieve on to white paper and the residue is thrown away. The
result is that the spores which have passed through the sieve are in a powdery
and dry condition, and keep well until the next spring. The spores are next
placed in small tubes, only filling them to about a quarter of their capacity,
and the neck is securely closed with sterilized paper before laying them aside
in a cool dry place during the winter. A number of these tubes are filled, so
that if some should happen to deteriorate, the others mav be perfectly pure.

Just before using the spores in the spring for the infection of the young
seedlings, they were placed in pure water and thoroughly stirred up in the
centrifuge. This treatment of the spores and leaving thein to settle for one
day in the water, not only cleaned them thoroughly but rendered them most

36 Infection.

favorable for germiiiatiou, and when placed on the young seedling in dihite
nutritive solution, they germinated without loss of time and directly produced
infection.

In the case of stinking smut of wheat, there is no difficulty in securing
well preserved material. The unbroken smut-balls are filled with the un-
contaminated spores and require only to be crushed in order to dust the grain
to be infected.

The Influence of Temperature on Infection.

Brefeld* came to the conclusion, as the result of experiments with oat
smut, that a low temperature at the time of germination favours successful
infection, so that sowing in the spring, when a higher temperature than in
winter usually prevails, is less favorable to it. But Tubeuf- and others proved
quite the contrary, that a high temperature brought about a higher degree of
infection, and they recommend late autumn sowing as a means of reducing
the amount of smut.

On the other hand, it has been proved by carefully conducted experiments,
that in the case of stinking smut of wheat, sowing late in the autumn, when
the temperature is low, encouraged it, other things being equal. In all these
experiments, however, it must be borne in mind, that neither temperature
nor infection ought to be considered independently, but that there are modi-
fying factors which must be taken into account. Thus rapidity of germina-
tion and a quick growth, will counteract the effects of temperature, for if the
fungus cannot keep up with the rapidly elongating plant and reach the growing
point, the host-plant will remain sound, in spite of the temperature.

Hecke' has considered the influence of temperature in its threefold aspect
of — 1st. Effect upon the germination of the spores and the seed grain ; 2nd.
Upon the duration of the infective stage of the host-plant ; and 3rd. Upon
the possibility of the fungus reaching the growing point of the host-plant.

1. If the temperature of germination be compared for the fungus and
its host, it is found that in wheat the minimum is practically the same for
both. For the wheat it is 3-4.5° C, and for the spores of stinking smut, 5° C,
so that, usually, the wheat and the spores will germinate together. But in
the case of oats, there is a considerable difference. The minimum tempera-
ture for the germination of oats is 4-5° C, while the spores require 5-11° C,
hence the oat itself may germinate at a low temperature while the spores
remain stationary.

2. Cold and damp weather tend to retard growth, so that the infective
stage is prolonged, and at the same time, the tissues being soft and tender,
infection is rendered more certain.

In the stinking smut of wheat, the principal effect of a low temperature
consists in lengthening the period during which infection is possible, for the
spores and the wheat, germinating together, along with the retarded growth,
will insure the fungus filaments inside the plant reaching the growing point.

3. Since our Avheats are all sown in the autumn or early winter, there is
little rapid growth at first as a rule, so that the fungus has sufficient time to
reach the growing point and estabhsh itself in the host-plant. But it is in
the summer wheats that the influence of temperature is most marked in favour-
ing or hindering the fungus in reaching the growing point, and this may ac-
count for the great variety in susceptibility shown by such wheats towards
the stinking smut.

It will now be clearly understood why a low temperature at the time of
sowing, especially if the soil is damp, will be favorable to the infection of
wheat by stinking smut, while in the case of oat smut it will be rather the re-
verse, since it retards the germination of the spores.

Infection. 3-7

The clifl'ereut results obtained by Brefeld and Tubeuf in eoiiuexiou witli
'Oat smut may be explained from tiis fact that Brefeld used germinating conidia
mixed with earth 'in which oats were planted, while Tubeuf used conidia
Avhich had not germinated. In the one case the low temperature was applied
after the spores had germinated and it was assumed that in the slowly de-
veloping seedlings, owing to the cold, the fungus had penetrated to the grow-
ing point, and this produced a high percentage of smut. In the other, the
pots were placed in a low temperature during the germination of the spores,
with the result that the oats germinated, while there were very few spores to
infect them.

Whatever hinders the rapid development of the seedling and extends the
period of infection, will favour the access of the germ-tubes of the germinat-
ing conidia to the growing point.

Smuts in tJtcir Relation to Rusts.

CHAPTER YII.

Smuts in their Relation to Rusts.

It has always been more or less generally taken for granted that there is
some sort of relation between the rusts and the smuts, but the exact nature
of that relation has never been definitely settled. On a superficial view,
there are seen to be black masses of spores produced in both cases, often
bursting through the particular parts of the plant on which they occur, which
suggest some close connexion, and even the farmer has been misled by this
superficial resemblance, for he invariably calls flag smut of wheat {Urocystis
tritici) " Black rust."

On closer and deeper investigation, they are still found to have many
points of resemblance, so much so, that both were placed together by the older
writers under Fries' division of the Hypodermii. At the present time Brefeld'^
who has studied the smuts more thoroughly than any other living investigator,
regards them as the progenitors of the rusts, and this genetic connexion is
supposed to be proved by various structures which they possess in common.
There was one jarring note, however, introduced to disturb the harmonious
relations which were supposed to exist between the two, and that was by
De Bary, as early as 1853. He considered that the rusts were very closely
allied to the Ascomycetes, while the smuts were more nearly related to the
Phycomycetes, but in order to understand the points of difference, as well as
the points of resemblance, it will be necessary to make a general review of
the position.

There are three primary groups of fungi still generally recognised, which
are based upon purely morphological characters. The Phycomycetes or Alga-
like fungi are regarded as the primitive stock, and divergence has taken place
in two directions, the offshoots representing the other two main
divisions. The Ascomycetes are characterized by the ascus contain-
ing a definite number of spores, and the Basidiomycetes by basidia or large
terminal cells bearing naked spores at their free apex.

Brefeld*^ has pointed out that, in the Basidiomycetes there are two dif-
ferent forms of basidia. In the one case, the basidia are septate, and a spore
arises from each cell, while in the other, they are undivided and bear at the
apex a definite number of spores, usually four. The most primitive forms
of basidia are divided transversely, hence called Protobasidia, and the un-
divided basidia are known as Autobasidia. In the smuts, the promycelium
arising from the spore agrees with the divided basidium of the Proto-basidio-
mycetes, but there is nothing corresponding to the undivided basidium of
the Auto- basidiomycetes, when fully developed forms are taken into con-
sideration. There are still some who strain analogy so far as to make the
promycelium of the Tilletieae correspond with an undivided basidium, but
the septa or divisions are just as pronounced in their promyceha when mature,
as in any of the Ustilagineae. The promycelia of the smuts are, therefore,
regarded by Brefeld as primitive basidia, foreshadowing the special basidia
of the Basidiomycetes, and the only point of difference between the two con-
sists in the promycelia of the former bearing a variable number of conidia,
while the basidia of the latter bear a definite number. The smuts are there-
fore called by Brefeld Hemibasidii, forming a sort of half-way house to the
Basidiomycetes proper, and they show their primitive nature, like the rusts,
bv representing the type in which the basidia are still divided. The Tilletieae,

Smuts in their Relation to Rusts. 39

however, show a step in advance by the characteristic whorl of conidia at
the apex of the jointed promycelium.

According to this view, the smuts have given'_^rise to the Basidiomycetes
and form the connecting link with the Phycomycetes. But there are others,
such as MoellerandMassee, who assign a.different origin to the Basidiomycetes,
the latter regarding them as having originated independently from conidial
forms of the Ascomycetes.

Having shown that the smuts are, probably, most nearly allied to the
primary group of the Basidiomycetes, let us now see in what relation they
stand to the rusts. The smuts are all parasitic fungi, mostly occurring in the
tissues of the higher plants, more particularly in the Gramineae, which are
often seriously injured by them. The spores are produced, as a rule, in the
interior of special or sporogenous hyphae, the walls of which become gelatinous
and finally deliquesce, while the protoplasm in the interior, develops into the
spores. When the ripe spores are thus set free, they germinate under the
influence of moisture, after a longer or shorter period of rest, or immediately.
The outer coat of the spore bursts at a particular spot and a germinal tube is
protruded, which ultimately divides by means of transverse septa into two
or more cells. As in the case of the rusts, this germinal tube is called a pro-
mycelium, and it bears the spore-like bodies or sporidiola here called conidia.
De Bary regards this germinal tube as of the nature of a mycelium, while
Brefeld considers it a basidial structure, and if we accept this latter view, then
the smuts, as well as the rusts, are akin to the Basidiomycetes. The whole ques-
tion turns upon what is meant by a basidium. A basidium is generally con-
sidered to be a relatively large cell giving rise at its apex to a definite number
of naked spores, which are produced only once at fixed spots. It must be
granted at once that the germinal tube or promycelium in the smuts has not
the definite characters of a true basidium. It is divided into several cells,
conidia may be produced laterally as well as terminally, and when they fall
away, new ones may be produced. But it may well be regarded, in its most
primitive form, as a transition stage to the more definite characters met mth in
the rusts. In the rusts there is a definite promycelium, consisting of four
cells, and each cell bears a single conidium or promycelial spore, which is
only once produced, although Brefeld* has shown that the conidia in the
smuts may sprout and produce secondary and tertiary conidia in a nutritive
solution. It may be considered as the variable form from which the
definite rust form has arisen.

Not only was the product of the spore different from that of the rusts,
according to De Bary, but he pointed out that the snnits were essentially
different in the mode of formation of their spores. There, the contents of the
hyphae at certain definite spots are transformed into spores and the walls of
the sporogenoiis hyphae deliquesce and set them free, while in the rusts the
spores are pinched off from the ends of the hyphae. No doubt, this is a dis-
tinct difference, but when the sexuality of the rusts is considered and the
spores are seen to be the result of this, then a different mode of formation
was inevitable.

But porliaps the most important difference between the two, according
to De Bary^* is the conjugating cells. He writes :— " If, on the other hand,
we look for the points which are distinctly characteristic of the Ustilagineae,
the most prominent is that of the conjugating pairs of cells." He considers
the pairing of the promycelial spores or conidia as of the nature of a sexual
act, but it is not now regarded as such, according to the present state of ki^ow-
ledge. It is simply a means of mixing the protoplasm from two different
sources, through anastomosis, and occurs in germ-tubes and hvphae as well.
This brines us to the Question, however, of true sexualitv in both. I have

4° Smuts in their Relation to Exists.

akeady called attention in mv work on " The Rusts of Australia," to the dis-
coveries of Blackman and Christman, showing that there are true sexual cell
fusions in the aecidial stage of the rusts, and this has been extended to forms
possessing uredospores and teleutospores by Olive^ and others. Dangeard^
has also shown that when sexual reproduction, as he considers it, is about to
take place in the smuts, the cells concerned become swollen. Each single
swollen cell contains two nuclei, and the fusion of these two nuclei to form
one is regarded as an act of fertilization. But this is not the kind of fertiliza-
tion which occurs in the rusts investigated, and it will be necessary in order
to understand clearly the relation between the two. to give a brief life-history
of both.

In the rusts the condition in which two nuclei occur in a cell is shown to
arise in aecidia in the fusion cells or " basal cells," so called because they
subsequently give rise to the chains of a^cidiospores. The binucleate basal
cell is the result of the conjugation of two uninucleate cells, so that the contents
of two distinct cells enter into its composition. The nucleus, together with
the protoplasm of one cell passes into the other cell by means of a pore in the
wall separating the two cells, and the latter or receptive cell is thereby
fertilized. These sexual cell fusions may either represent true sexual
reproduction, in which the two uniting cells are clearly distinct like the
ovum and sperm, or the two uniting cells may show no appreciable differences.
The former, is called by Winkler,' Amphimixis and the latter Pseudomixis, so
that we have here an instance of Pseudomixis, for the two fusing cells, as
well as their nuclei, are approximately equal.

The myceUum which bears the uninucleate fusion cells has also single
nuclei, but the product of the fertilized cell is a growth with paired
nuclei. Hence all the constituent parts of the spore-bearing
generation or Sporophjte show in their cells the paired nuclei, including
the aecidiospore, the mycelium arising from them, the uredospores,
and teleutospores. When uredo- and teleutospores only occur, they originate
from similar fusion cells, and Olive has investigated a species possessing
only teleutospores, and found that the binucleate condition arises in the
basal cells, which give rise to teleutospores almost immediately.

The mycelium in the host-plant, bearing the sexual cells or gametes
which are all uninucleate, constitutes the Gametophyte. There are thus two
distinct stages of the rust starting in each case from a single cell. The
fertile cell is the starting point of the spore-bearing generation or Sporophyte.
and the spore is the beginning of the sexual generation or Gametophyte, and
there is a regular alternation of the sexual Gametophyte and the asexual
Sporophyte.

In the smuts, on the other hand, only the asexual generation is represented,
and the single spore corresponds generally to the teleutospore of the rusts.
The mycelium has two nuclei in each cell, at least when young. In certain
swollen cells the two nuclei already contained in the cell combine and fuse
to form one, and it is this nuclear fusion within the one cell which Dangeard
considers sexual reproduction. It may also be remarked that in the rusts the
two nuclei finally fuse in the teleutospore as it matures. But it is of the
essence of the sexual process that the nucleus passes from one cell, representing
the male, to the female receptive cell, and it is just here that the difference
lies between the origin of the spore in the rusts and the smuts. The binucleate
swollen cell wliich becomes the spore in the smuts is not connected in any
way with a sexual process, while the spore generation in the rusts is the result
of sexual cell fusion.

The smut spore otherwise, generally resembles the rust teleutospore in the
product of its germination. It produces a 3-4: celled filament bearing conidia.

Sniitts in their Relation to Rusts.

4t

but these coiiidia are not di'tiiiite in nuinber and may be produced more than
once from the same cell. This multiplication of the conidia seems a necessary
consequence from the fact that there is only one kind of spore. The conidia
may cither directly germinate and produce the sporophyte, or they may
multiply in a yeast-like fashion before doing so, according to the supply of
nutriment. The yeast-like budding of the conidia not only multiplies the
means of reproduction, but carries the fungus over the period when no host-
plants are available. The germination of the teleutospore in both rusts and
smuts does not always result in the production of a promycelium. In the
rusts every gradation may be observed from the ordinary germ-tube as in
aecidiospores and uredospores to the special conidia-bearing promycelium.
Its mode of germination evidently depends largely on surrounding conditions.
Fischer^ observed this in Gymnosporangium, where conidia were oiily formed
in air, while in water an elongated germ-tube Avas produced, and Magnus ^
has repeatedly observed that when the teleutospores of Puccinia graminis
were germinated in water, they produced a germ-tube just like that of a
uredospore. The teleutospore in the rusts has therefore departed from the
ordinary mode of germination of producing a germ-tube which directly
infects the host-plant, but multiplies itself by means of minute conidia suited
for aerial conditions, and giving rise in the host to a mycelium which bears
the sexual cells. The production of conidia, too, outside the host-plant
will also have an invigorating effect when they are nourished in a saprophytic
manner. Brefeld^ cultivated the conidia of rust fungi in a nutritive solution,
and found that they budded so as to form secondary and tertiary conidia,
and in smuts this mode of nutrition has produced the most luxuriant budding.
While in the smuts the spore produces generally a promycelium bearing
conidia, there is frequently only hyphae, and in infectioii through the flower
it is the rule for the spore to germinate direct and form a mycelium.

If we compare the life history of a smut with that of a rust there is seen
to be partial resemblance, with important differences such as the absence of a
sexual stage. There is sufficient resemblance, however, to indicate some
affinity, and the question is as to the nature of it.

As to the origin of the smuts, we can only arrive at a reasonable conclusion
by taking all the facts into consideration and comparing them with others,
seeking to find a place in the general scheme of life where they best fit in, and
associate them with those forms with Avhich they are most in agreement.

Brefeld regards them as having been derived from the Phycomycetes, and
as this group possess both sexual and asexual forms of reproduction, they
are supposed to have originated from the latter. He also lays a great deal
of stress on the fact that the spore on germination produces what he considers
a basidium, and since the rusts also give rise to a similar structure, more
definite and more nearly approaching the type, he regards the smuts as the
preeoursors or progenitors of the rusts, and through them of the whole group
of Basidiomycetes. But, as we have already seen, there is room for difference
of opinion as to the origin of the Basidiomycetes, and consecjuently of the
relation of the snmts to them.

My own idea is that the Ustilagineae may be simply regarded as forms
which have a distinct alternation of a saprophytic with a parasitic stage,
and with sexuality grafted on to this, they originated the TJredineae. It is
considered that the promycelium bearing conidia is a saprophyte, because it
generally grows freely in a nutritive solution

It is now generally accepted that all fungi were originally saprophytes,
living upon dead or decaying vegetable matter, and that some of them
gradually became accustomed to a parasitic habit. The division of fungi
into saprophytes and parasites is convenient, but not natural, for there are

42

Smuts in their Relation to Rusts.

saprophytes which are occasionally parasitic, and parasites which are
occasionally saprophytic. In the case of grey mould {Botnjtis) and blue
mould {PeniciUium) we see parasites in the making, as it were, for they are
able, under certain conditions, to enter the living plant and grow there as
ordinary parasites. It is not so well known, however, that there are also
true parasites, which spend a portion of their existence outside the host-
plant, and, not only so, but saprophytic and parasitic stages regularly alternate
in their hfe-histor3^

The smuts were originally entirely saprophytic, and this stage is still
represented of course in a much reduced form in the promycelium bearing
conidia. The promycelium is all that remains of what was once probably
a much more elaborate organism. Next, they became educated up to and
developed into the parasitic stage, and this gradually took the lead, until now
it is the most conspicuous form, and is represented by the internal mycelium
bearing spores. Only one kind of spore is produced, but by means of nuclear
fusion, which serves the purpose of a sexual act and foreshadows it, it is
invigorated and rejuvenesced. There is here an alternation of a saprophytic,
with a parasitic stage, and it may be represented graphically thus : —

Parasitic Sporophyte (Internal Mycelium).

Conidia or Sprouting Conidia. M 2J Spores,

Saprophytic Sporophyte (Promycelium).

The earliest alternation was that of nutrition, as represented by a
saprophytic and a parasitic mode of life, and this gradually developed into
an alternation of spore-forms, using the term spore in its widest sense. The
parasitic form ultimately developed into a sexual form, so that an alternation
of a sexual with a non-sexual generation arose.

With the development of sexuality a higher plane was reached, and greater
variety in the reproductive bodies secured, each specially adapted for
different conditions, and ultimately for different host-plants. This was the
starting point of the new group of rusts. It is interesting to note, in this
connexion, that Christman holds that the teleutospores are the primitive spores
of the rusts, and that the other kinds have been gradually intercalated in
their life-history. There is here, as in higher forms, a distinct alternation of
a sexual and asexual stage.

The sexual stage is represented by an internal mycelium bearing sexual
cells or gametes, the contents of which blend and produce the fertiUzed
cell.

The asexual stage is the product of the fertilized cell, and is represented
by the aecidisopores with their intercalary cells, and the mycelium produced
by them bearing uredospores and teleutospores. This is the parasitic form
of the sporophyte, which sometimes completes the cycle by the teleutospore
directly infecting the host-plant and producing a mycelium bearing the sexual
cells.

But, generally, the saprophytic form of the sporophyte asserts itself, by the
teleutospore producing a promycelium bearing conidia, and the conidia
infecting the host-plant.

Smuts ill their Relation to Rusts- 43

Th ' alternation of gonoiations in tlie Rusts may be thus graphically
represented : —

Conidi

Saprophytic Si)oro])liyte h ■^"*^ Gamctopliyte (.Myceliiun).

(Pro mycelium).

Ae:'idio-Ureclo- and \^5 ^J Gametes (Uninucleate).

Teleutosporeir
Parasitic 8i)oro])liyte. Vi 3/ Fertilized Cell (Biniuleate).

In both smuts and rusts there is a tendency to dispense with the sapro-
phytic stage, and become more perfect parasites, as, for instance, in the species
of smut infecting the host through the flower, and Puccinia (jraminis in
Australia dropping this stage altogether.

Alternation of Parasite and Saprophyte. — Only one kind of reproductive
body is formed inside the host-plant, and these smut spores are produced
by the j)arasitic form of the fungus. When these spores are set free and
scattered by the wind or other agency they may either immediately, or after
a period of rest, begin to germinate. This process of germination takes
place outside the host-plant, and gives rise to a promycelium which generally
produces conidia, either laterally and terminally, or only at the apex.
Germination readily occurs in a mitrient solution, and since the formation
of conidia has been carried on by this means from generation to generation
for more than a year, as in the oat smut, this must be regarded as the sapro-
phytic form of the fungus. In some instances, as in Tilletia, when food
material is abundant, the promycelium is not limited to a short germinal
tube, but grows into a large branched mycelium like a tuft of mould, which
bears conidia, differing slightly from those produced normally. While in
the rusts two different host-plants are often concerned, in the smuts there
is only one, but a saprophytic mode of life succeeds and alternates with the
parasitic mode of life. During the parasitic stage, there is a definite form
of spore produced which is capable of giving rise to conidia on a germinal
tube, and in the saprophytic stage the conidia formed are capable of sprouting
continuously, as long as the nutriment lasts, and then putting forth a germ-
tube which penetrates the living plant if it comes in contact with it at the
right stage. In the one case the living and the dead substratum exerts an
influence which results in the different reproductive bodies, in the other it is
the living substratum of different host-plants which produces the variety
of spore forms. The researches of Klebs^ already referred to, show that it
is just this exhaustion of food in the successive host-plants attacked which
brings about the different reproductive bodies.

The rusts have an advantage over the smuts in the variety of spores
produced, and their appearance at different seasons of the year. Not only
have they reached the highest degree of specialization in the selection of their
host-plants, often confining their attention to one particular species, but
they may select one plant for the production of spring spores and another
for summer and winter spores, so that their distribution is increased and
their adaptation to varying climatic conditions improved.

Aeci'lia-like Forms. — In the higher forms of smuts there is an approach
to the aecidia of the rusts, and the characters of Doassansia and Cintractia
are very suggestive in this connexion. In Doassansia the fertile spore-
clusters are enclosed in a peridium formed of closely packed sterile cells,
arranged in a single layer. In Cintractia the spores arc developed in rows,

44 Smuts in their Relation to Rusts.

the older and more mature being on the outside, and thev are often contained
in a special receptacle formed by several layers of sterile cells. So striking
is the resemblance that Brefeld asserts that if the characters of the two
genera were united in one form there would be almost complete agreement
with the aecidia of the rusts, and he considers it not improbable that such
forms may yet be discovered. In such a case the smuts might reasonably
be regarded as the progenitors of the rusts, the primary forms from which
they were derived.

If we sum up the principal resemblances and differences between the
smuts and the rusts, it is found that they agree in the following : —

1. They are all parasites.

2. They produce a promycelium bearing c0]iidia.

3. A peridium is sometimes present, and spores are produced in a

radiating manner resembling an aecidium.

And they differ : —

1. In the promyceKum producing a variable number of conidia.

2. In the promycehum of some species growing and branching in a

vegetative manner without the formation of conidia.

3. In the mode of production of spores, which are formed in the

interior of the hyphae and not pinched off at their apex.

4. In the production of one spore form, and not a variety.

5. In the absence of a true sexual process.

Parasitism and hnmnnitv. 45

CHAPTER VIII.

Pakasitism and Immunity.

In cGiinexiou witli tlio diseases of plants, where fungus parasites are con-
cerned, determined efforts have been made to study these parasites in such a
way that their Ufe-histories might be made out, and their mode of infecting
the host-plant and producing the disease thoroughly understood, the object
being, from the knowledge thus obtained, to prevent the parasite gaining an
entrance into the host. This has hitherto been usually accomplished, either
by destroying the spores of the fungus or preventing their germination, and
thus effectually preventing the appearance of the disease. By means of spray-
ing, for instance, at the proper time with suitable fungicides, a large number
of such diseases have been kept in check, and so successful had this method
proved that the hope was entertained by many that it only required a further
extension of our knowledge of plant parasites and their life histories, in order
to completely overcome their destructive effects. This was a great step in
advance, even although it involved unceasing warfare against the parasite,
and the Department of Agriculture of the United States of America led the
way in demonstrating the efficacy of the gospel of spraying.

But there were some serious diseases due to parasitic fungi which did not
•lend themselves to this mode of treatment, even although the history of the
parasite had been followed from spore to spore, and it became necessary to
devise other means for controlling the disease. Foremost among these was
the Rust in Cereals, to which, from the very nature of the mode of attack of
the parasite, and the manner of growth of the host-plants themselves,
it was found to be mechanically impossible to apply this method of
prevention.

It will be observed that in this method of grappling with disease, the host-
plant itself is left out of account, and attention is concentrated on the para-
site. But there is another possible way of preventing disease, and that is by
rendering the plant immune. Accordingly, attention was turned to the question
of immunity or resistance to disease, which has been for some time deepiy
studied and discussed in connexion with human diseases, and which has also
been observed in some species and varieties of cultivated plants, such as
wheats and other cereals. The definition of an immune plant as given by
Massee^ may be accepted. It signifies an individual of the same species as the
one on which a given species of fungus is parasitic, but which, owing to the
absence of the chemotactic substance in its tissues necessary to enable the
germ-tubes of the fungus to penetrate, remains unattacked. Only it is to be
understood that while the parasite may gain an entrance, it does not normally
develop in such an " immune " plant, and, consequently, cannot produce the
harmful disease or spread infection by means of its spores.

In dealing with the smuts \\dth which we are more immediately concerned,
there were various steeps for the seeds, or disinfectants, as they may be called,
such as sulphate of copper or bluestone, and formalin, which effectually pre-
vented the attacks of some of the more common smuts, but there were othei's,
su.ch as the destructive flag smut of wheat, which did not yield to such treat-
ment, and even here it is becoming apparent that immunity to the disease is to
be aimed at as a means of overcoming it. In short, at the presen' time, it is
felt that our present methods of fighting parasitic fungi is simply tinkering

46 Parasitism and Immiinitx.

with the disease, afiordiug only temporary relief, and that the only permanent
and natural means for overcoming them lie in following Nature's methods for
preventing extinction of the species, by rendering the plants themselves im-
mune, or at least, partially immune to such attacks. Before this goal is
reached, numerous researches in the laboratory and experiments in the field
will require to be carried out, but already there are sufficient instances
known to justify our hope and that of Rust in Wheat may be taken as an
example.

Rust Immunity.

There are, at least, three different kinds of rust which attack wheat, the
Black Rust (Pwcci/im gramims,'PeTS.), the Brown Rust (P. triticina, Eriks.),
and the Yellow Rust {P. cjlumarum,Yiv\ks. and Henn.). Only the two former
occur in Australia, and it is the so-called Black Rust which is so injurious in
certain seasons, while the Brown Rust is comparatively harmless. It appears
that in Britain and America the Yellow Rust does considerable damage, and
it is this one which has recently been made the subject of exact experiment.
Mr. Biffen, of the Agricultural Department of Cambridge University, found
in his plots a strain of wheat which was immune to this rust, for although under
observation for four seasons, and surrounded by varieties susceptible to the
disease, it remained free and showed no trace of infection. This Avheat
belonged to the sub-species, Triticum cofupactum, or Dwarf Wheat. On the other
hand, there was a type known as Michigan Bronze which was so liable that
not a single individual escaped, and comparatively few ripe grains were ob-
tained. On crossing these two types, the first generation consisted of plants
badly rusted without exception, even the awns and grains being affected, but
fortunately, a number of ripe grains were obtained for subsequent sowing.
Every available grain was sown to produce the second generation, in plots
alongside the parent varieties. The result was that while every individual of
the susceptible variety was infected and the immune variety escaped entirely,
the crosses were badly rusted, but certain individuals stood out perfectly
clean, not showing signs of disease, even on the withering basal leaves. The
second generation of the cross was thus composed of plants either badly rusted
or immune, and the exact numbers were 1,609 diseased and 523 immune, or
a ratio of o.07 to 1.

Biffen has found another wheat which possesses an even greater degree
of immunity to Yellow Rust than the American Club — the variety of
Triticum compactum already referred to. It is known as Einkorn, or
Triticum monococcmn, and is said to be exceptionally immune to the three
common rusts.

There is a principle here which is found to hold for diseases other than
rust, and it opens up great possibilities in the way of breeding plants immune
to disease. There are certain varieties of wheat, for instance, which are more
or less immune to rust, but lacking in those useful qualities which the farmer
desires, such as strength of straw, holding of grain, prolific yield, &c. But
when it is discovered that these unit characters, as they are called, go in pairs,
such as susceptibility and immunity to rust, and that they can be combined
with other characters which obey the same law, by crossing, then it is seen
to be possible in three generations to obtain a pure strain by crossing, com-
bining these desirable qualities with immunity to rust. If two fixed strains
are crossed, all the possible forms obtainable appear in the second generation
if a sufficient number of plants are grown, and a certain proportion of each of
these forms is already fixed. The third generation will show those individuals

Parasitism and ImmiDiit i

47

which are fixed, and breed true, and thus two generations are sufficient to pro-
duce and fix the new variety. There is also a definite proportion between the
fixed and unfixed sorts. In the particular instance given, where two con-
trasted characters are concerned, the susceptibility to rust is called the domi-
nant character, because it prevails over the other or recessive character in the
first generation, and this holds good irrespective of which plant was pollen-
bearing or seed-producing. In the second generation, the dominant " rusty "
plants and the recessive " immune " plants appear in the ratio of ."] to 1, as
nearly as possible.

Smut Immunity.

Although I am not at present (1909) in a position to give such defiiiite
results for smut as have just been given for rust, yet experiments are under
way to settle the point as regards Stinking Smut, or Bunt. The difficulty
here is to secure wheat-plants which are immune to this smut when
grown under conditions favorable to its development, such as the seed-
wheat being dusted with the spores, but this difficulty is being gradually
overcome.

There is a variety grown here, known as AUora Spring, which is most suscep-
tible to bunt, having yielded 95.5 per cent, of bunty plants when the seed
was coated with spores, while under the same conditions, Minnesota Blue Stem,
a strong flour variety, was the least susceptible of ten varieties tested,
only producing 12 per cent. But while a small proportion of rust is admissible
without seriously interfering with the yield or the quality of the grain, a very
small percentage of Stinking Smut is objectionable, and it is necessary, if treat-
ment of the seed is to be dispensed with, to have a variety or strain which is
absolutely free. Experiments in the direction of producing bunt-resisting
wheats have been hitherto mainly carried out by Farrer and Pye. The work
of Farrer is being continued by Sutton at the Cowra Experiment Farm.

Experiments of Farrer and Sutton in New South Wales.

When the grains of dift'erent varieties of wheat are thoroughly dusted with
bunt spores and sown at the same time alongside each other, it is found that
the percentage of bunty plants varies considerably according to the variety,
basing the calculation upon the number of plants which grew in each case and not
upon the number sown. Thus, in experiments carried out by Farrer^ with ten
different varieties, the percentage varied from 95.5 to 12, and the proportion
which remained clean might be owing to the fact that either the plants them-
selves, or the seeds from which they grew, possessed the property of resisting
infection. But there are various other causes which might produce this re-
sult, even on the assumption that the bunt spores germinated, such as germ-
tubes which penetrated the seedlings failing to reach the growing point, or the
growth being too rapid for the mycelium to keep up with it. So that the only
way to settle the point was to harvest the clean plants separately and sow the
seed after inoculation, in order to see whether any of them transmitted the
quality of bunt-resistance to their progeny. This was accordingly done with
different strains of AUora Spring, and the lowest percentage of bunty plants
was 87.1, and the highest 95.5. While carrying out these experiments,
Farrer hit upon the idea of selecting clean plants from the strains of his crosses
which showed the smallest percentage of bunt, in order to see if bunt-resis-
tance could be increased by a course of systematic selection. He observed
that the plants of the variable generation of a cross differed widely in their
liability to bunt, just as has been observed in the case of rust, and he came to
the conclusion that if the plants of this generation were ex]iosed to infection,

48 Piirasitism and hnnmmty.

by inoculating the seed from which they were grown, then a large proportion
of the plants which might otherwise have produced bunt-liable varieties would
be culled out, and a higher average of bunt-resistance would be secured in those
retained. And if the next generation was also similarly infected, further cull-
ing-out could be made and a still higher average of bunt-resistance secured in
the remaining plants.

In 1901. experiments were begun in inoculating with bunt the seed which
produces the variable generation of new crosses, and in reporting on these
Farrer? remarks : — " A large number of experiments were made in sowing
bunt-infected seed of unfixed and partially fixed crossbreds, with the object
of seeing into the possibility of making varieties which are valuable on account
of the resistance they offer to the infection of bunt. No good purpose would
be served by describing these experiments in detail. The results, however,
from sowing seeds produced by plants of the variable generation which were
free from bunt in 1901 are exceedingly encouraging, but it remains to be seen
Avhether and to what extent these good results are due to the exceptional
character of the season." And in his report for 1903^" he states : — "Whether
bunt-proof varieties will ever be secured is, of course, as yet uncertain ; but
I have on hand some neAver crossbreds which promise to yield varieties which
are better resisters of this parasite than are any of the first batch." And in
1905^^ he writes : — " The investigation, however, is very laborious and will
take a longer time than I am likely to live. That I am now in a position,
however, to select bunt-resisters as parents for crosses is in the direction of
helping matters on. Crosses for the special purpose of securing bunt-resis-
tance were made this last season (1904) for the first time."

The lamented death of Farrer, on ITth April, 1906, deprived us of the benefit
01 his scientific skill and ripe experience, but Sutton- has brought to fruition
the experiments which he initiated. The result is that he has succeeded in
producing varieties which apparently resist bunt, for he writes as follows in
the Agricultural Gazette of New South Wales for March, 1908 : — "Florence
and Genoa have, in our trial plots, shown themselves, under severe trial, to
be practically smut-proof, and in consequence, seed of them does not require
to be blue-stoned or treated with any other fungicide for the prevention of
smut." Florence and Genoa are the result of the same crosses, the parents
being White Naples, Improved Fife, Hornblende, and an Indian wheat. Al-
though only different strains of the same breed, they vary in the period of ripen-
ing, Florence being very early and Genoa about a fortnight later. Genoa also
stools much more freely than the other with us. The method followed was to
inoculate as thoroughly as possible the seed of each generation of the cross and
in tliis way to arrive at the most bunt-resistalit. " Florence and Genoa have
proved themselves to be over 99 per cent, smut-resistant, that is to say, that
out of 100 seeds thoroughly infected, ninety-nine plants have been found to
be entirely free from smut at harvest time." That is certainly a very good
record and justifies the hope that the treatment of the seed for the prevention
of smut may yet prove unnecessary; but in order to command full price, the
wheat must be, as near as possible, bunt-free. In order to get an idea of what
the trade required, I communicated with one of the largest dealers in wheat,
and received the following reply : — " When selling wheat, we do not allow any
percentage for smut. It entirely depends on the condition of the wheat ; if
the smut balls are not broken and the wheat not much contaminated, it will
probably be about Id. per bushel under prime wheat ; but if the balls are
broken and the Avheat badly smutted, the difference is often from 6d. to 9d.
per bushel." If the market rates are taken as a guide, there may be from
6d. to Is. deducted per bushel on account of smut. When good milling wheat

Parasitism and Imnmnity. 19

was selling at is. 5W. to 4s. 6d. per bushel, smutty was sold at 3s. 5d. to 3s. 9d.
for inferior, and 3s. lOd. to -is. for better samples. It is tbis necessit}' for
having wheat almost absolutely bunt-free that has hitherto deterred experi-
menters from even making the attempt.

Experiments with Florence and Genoa to test their Bunt-resistance

This question of immunity to smut is a very important one, and experi-
ments to test how far this immunity is hereditary or transmissible, and if it
is maintained under different conditions of soil and climate, heat and mois-
ture, were carefully planned. Mr Sutton willingly supplied seed- wheat of
Florence and Genoa for the purpose, and a sufficient quantity of grain was
mixed with bunt spores to allow of its being sowii in such distinct districts of
Victoria as Dookie Agricultural College, in the North, under the superintend-
dence of the principal, Mr. Pye : at Longerenong Agricultural College, in the
West, under the charge of Mr. Pridham ; and at Burnley Horticultural Gar-
dens, near Melbourne, in the South, under my own personal supervision.
The seed was all dusted ecjually with spores of Tilletia levis, derived from a
common source, and it is important to note that the experiments were all on
an equal footing as far as the amount and vitality of the bunt-spores are con-
cerned. A bulk sample of wheat was mixed with the spores as follows : —
Bunt-balls were taken direct from the wheat plant and then broken up by
rolling them in paper. The spores were next well dusted and rubbed over
the moistened grains, so that every grain looked as if it had been dressed with
soot. The grain Avas sent out immediately afterwards for sowing.

At Dookie, the sowing took place on 17th June, and the seed-bed was a
moist one. Superphosphate was applied at the rate of about 65 lbs. per acre.
The rainfall for April was .23 inches ; for May, 1.99 inches ; and for June,
4.36 inches. The bunted grain sown in a moist seed-bed was particularlv
liable to infection. The mean temperatures for May and June were 11 and
7° C. respectively.

At Longerenong, the seed was sown on 1st June, and the seed-bed was in
good condition and moist. The rainfall for April was .09 inches ; for May,
3.22 inches ; and for June, 2.55 inches. The mean temperatures for Mav and
June were 10 and 7° C. respectively.

At Burnley, the plots were sown on 16th June, the soil being a sandy loam,
and in a moist condition. The experimental ground was enclosed with bird-
proof netting so that the results were not interfered with in any way. As
this was the first season of the wheat experiments there, manure was sup-
plied at the rate of per acre, 1 cwt. superphosphate, J cwt. sulphate of am-
monia and I cwt. sulphate of potash. The rainfall for April was .33 inclies ;
fov May, .87 inches : and for June, 3.94 inches. The mean temperatures for
May and June were 11 and 8° C. respectively.

Since the weather conditions exercise an important influence on the ger-
mination of the spores, it may be noted generally for the first quarter of the
year 1908, that the rainfall was scarcely 50 per cent, of the average amount
and this was followed by one of the driest April months ever known. The
brealdng up of the drought occurred in May, and the rains in June were above
the average, so that altogether, the conditions were favorable for the germina-
tion of the spores and the seed-wheat at the same tune.

The results of the experiments have been carefully tabulated, and while
they show that Florence may have as much as 12 per cent, of Stinking Smut,
and Genoa, 22 per cent., yet on the whole, they are fairly resistant.

50

Parasitism and Immunity.

Table I. — Relative Susceptibility to Stinking Smut of Florence and

Genoa.

Variety.

3

Florence .

6

Genoa

8

Florence .

9

Genoa

12

Florence .

13

Genoa

14

Florence .

15

Genoa

16

Florence .

17

Genoa

Florence .

Genoa

Florence .

Genoa

Inoculation of Seed witli— ' Smutty.

Smutty.

7. — Burnley.

T. tritici
T. levis

T. tritici
T. levis

Florence . .
Genoa
Florence . .
Genoa
Florence . .
Genoa
Florence . .
Genoa
Florence . .
Genoa

Florence . ,
Genoa

Florence .
Genoa

Florence .
Genoa

Florence
Genoa
Florence
Genoa

j Florence
Genoa

General Average

T. levis — General Average

//. — Dookie.
T. levis ..

T. levis, re- smutted

T. levis . . "

T. levis, re- smutted

General xA.verage

T. levis — General Average

T. levis, re- smutted

III. — Longerenong.
T. levis ..

2

82

84

2.38

7

71

78

9.

10

69

79

12.65

5

78

83

6.02

7

79

86

8.14

0

75

75

5

79

84

5.95

17

58

75

22.66

41

818

859

4.77

41

774

815

5.03

65

1,127

1,192

5.45

1 70

1,056

1,126

6.21

1 58

966

1,024

5.66

! 46

927

I 973

4.72

1

84

85

1.17

1

74

75

1.3

8

85

93

8.6

5

76

81

6.17

3

77

80

3.75

2

72

74

2.70

3

83

86

3.48

5

73

78

6.41

4

79

83

4.82

14

72

86

16.28

19

408

427

4.45

27

367

394

6.85

4

161

165

2.42

3

146

149

2.

15

1 247

262

5.72

24

! 221

245

9.79

General Average

45

443

488

9.22

95

560

655

14.50

7

70

77

9.09

10

54

64

15.62

52

513

565

9.20

105

614

7 IS

14.60

I. Burnley. — There were seven plots of each variety sown, in two of them
the ordinary seed was used as a check, while in the others the seed was
thoroughly dusted with bunt-spores. Both T. tritici and T. levis were used
for infection, but no conclusions as to their relative virulence could be drawn
from the results of a single season's experiments. The general average for
the whole of the plots was over 5 per cent, for Florence, and over 6 per cent.
for Genoa. If the comparison is strictly confined to the plots in which T. levis

Parasifisin a>ul 1 ninuiuitx. 51

was used, as at Dookie and Longerenoiig, then Florence had .j.<J(J per cent,
and Genoa 4.72 psr cent, of Stinkhig Smut. In all cases the ordmary seed
was sown as a check and the plots were invariably free from bunt.

II. Bookia. — There were also five plots of each variety sown here to test
their s'.Hceptibility to bunt, and only T. levis was used. In order to make
the test as severe as possible, some of the grain already dusted with spores
was re-smutted in the following manner. One hundred smut-balls were
powdered and then made into a soft paste by the addition of water. One
hundred grains were placed in this paste, thus allowing one smut ball on an
average for each grain, mixed thoroughly and allowed to soak over-night.
By next morning the moisture had disappeared and the seed was sown the
same day. Infection in the re-smutted grains was the most virulent, for while
it yielded 5.72 and 9.7i) per cent, of bunt respectively in Florence and Genoa,
there w^ as only 2 . 42 and 2 per cent respectively w' ith the ordinary dusting of
the grain. The general average for Florence was 4 . 45 per cent, and for Genoa,
6 . 85 per cent. The higher average for Genoa was largely owing to one plot
in which the percentage was over 16, while in a plot alongside it was only a
little over 6. This difference was so striking, that these two adjoining plots
were again carefully examined with the same result. There was no evident
cause for the unequal infection.

III. Longerenong. — There were only two plots of each sown, a large and a
small one, together wnth the check plots, and the dusting of the seed w-as
entirely with the spores of T. levis. The general average w^as much higher
here than in the other two localities, being 9.20 per cent, for Florence, and
14.00 per cent, for Genoa. This may be due to the heavy rainfall in May.

It is clear, from the experiments, that Florence and Genoa no not possess
the hereditary quality of bunt-resistance, and Sutton evidently suspected this,
as he wrote to me as follows in May, 1908 : — " I have been referring to the
results of our trials wdtli these wheats while they w^ere being fixed, and I find
that in 1905, they were at Lambrigg fairly bunty, and this may indicate that
they are not constitutionally resistant to bunt, but that they escape bunt
through some peculiar characteristic of their growth immediately after ger-
mination." As elsewhere pointed out they are relatively rapid in their ger-
mination (see Frontispiece), and this may account for their escaping the bunt
to a large extent. But in order to secure complete immunity and the heredi-
tary quality of resistance, it will be necessary to breed from a variety which
has shown itself to be free when exposed to the most severe infection for a series
of seasons.

Experiments at Dookie Agricultural College.

Mr. Pye, principal of Dookie Agricultural College, had been working for
some years in conjunction with Mr. Farrer in endeavouring to produce bunt-
resisting wheats by selection after seed-infection. He is still continuing this
work and the most promising line lies in breeding from crosses of the Durum
variety, that resist the bunt. He found, for instance, that Medeah is not so
liable to bunt as many others, and he is using this variety as a parent. The
seed of the progeny is then dusted wdth bunt-spores and the seed from those
plants which escape infection is sown next season, and so on until a strain is
secured which will be bunt-resisting.

Not only have these experiments been carried on for a number of years,
but they are conducted on a most comprehensive scale, as during the past
season there were over 200 plots devoted to smuts alone. I have carefully
examined them and find that it is necessary to determine the bunted plants
when the growth is completed and all the ears are more or less mature. This

52

Parasitism and Iinmimii''

is owing to the fact that in many cases the secondary ears or later growths
may develop the disease, while the more advanced ears of the :-ame plants
are free.

To show the methods adopted by Mr. Pye, some of the more important
re.sults will be given here and they will indicate clearly how far he lias suc-
ceeded in producing a bunt-resisting wheat. Among the numerous varieties
grown, there Avere several which promised to be more or less bunt-resisting,
and these were used as parents for further crosses, but the only one found to
be absolutely free this season, after the most thorough infection of the seed,
was Medeah. Various selections and unfixed crosses are also being tested, and
naturally those containing Medeah blood receive special attention.

Out of numerous selections from various crosses, only two were found to
be clean after infection, apart from those containing Medeah. Ordinary seed
was invariably sown alongside infected seed, and only in two instances was
one plant found to be bunted.

In Table II. the number of selections from each cross is given with the
proportion of bunted plants, and towards the end, all those crosses are recorded
containing an admixture of Medeah blood.

Table II. — Selections from Crosses, with percentage of Bunt.

No. of
I Selections.

Queen's Jubilee
Stanley . .

College Purple Stravr
Langshan x Stanley

Langshan
Stanley . .

Burton . .
Stanley . .

Tripola . .
John Brown

Allorite . .
Semi-Durum

Langshan
White Fife

Blue Heron

Egyptian x Tardent's Blue

Tripola . .
Tardent's Blue

Tripola ..
Tardent's Blue

Tripola . .
Tardent's Blue

Tripola ..
Tardent's Blue

Missogen

Medeah x \Vhite Fife

Percentage of Bunty

Plants, varying '

from —

47 to 93

r 1

03 „ 75

50 „ S3

11 „ 57

28

Free

25 to 28

Free

6 „ 36

6 „ 29

16 „ 50

Parasitism and Imnutnity.

Table II. — Selections from Crosses, with percextage of Bunt-
coniinuad.

S2,

Cro<s.

Xo. of
Selectiouii.

2

Percentage of Bunty

Plants. varying

from —

Bobs X
Tripola

:Medeah . .

\
J

Free

Bolis X
Tripola

^Nledeali . .

I

.2

"

Bobs X
Tripola

-AEedeah . .

J

3

Bobs
xMedeah

1
1

3

OnewithOandtwo
selections free

Bobs
Medeah

1
J

5

8 to 16

Bobs
Medeah

1

1

6

Free

Bobs
Medeah

1

3

17 to 30

Several of the crosses turned out bunt-free, particularly those into which
Mecleah enters, and it only remains to be seen after further trial if this is a
hereditary quality. They will be tested in a similar fashion to Florence and
Genoa.

The difficulty and uncertainty here lies in making sure that the bunt-free
plants owe their resistance to constitutional characters, and not to the
accident of the spores failing to germinate or the mycelium of the fungus in-
side the plant being unable to reach the ovary. I have had numerous exam-
ples in different seasons of ears being only partially smutted and the reasonable
explanation is that from the nature of the season and the consequent growth,
the mycelium had not sufficient vigour, or was not sufficiently nourished in
the straAv to produce spore-formiiig hyphae in every grain. The clean grains
were taken from such partially-smutted ears and sown again after proper
inoculation, when it was found that they were liable to infection, thus proving
that there was nothing in the grain itself which caused it to escape. The ques-
tion as to the hereditary character of the bunt-resistance can only be definitely
settled by growing the seed from such bunt-resisting plants, for several sea-
sons in succession, after being thoroughly dusted with spores and proving
that immunity is or is not an inherent characteristic. Once an immune parent
is obtained, then the desirable qualities to be associated with this imnuinity
can be produced by further crossing. Attention has hitherto been so exclu-
sively devoted to providing remedies for smut, that the attempt to produce
smut-resisting plants is well wortlw of being persevered with, and the experi-
ments so far carried out are decidedly encouraging. There are thus, at least,
two methods of procedure in seeking to obtain a variety of wheat immune to
bunt, either to start from what is known as natural immunity, in which the
plant from its very constitution inherits a certain amount of resistance, as in
the case of Medeah, or by means of selection to arrive at a plant which has ac-
quired this character, as in the supposed case of Florence. It was the idea of
the late Mr. Farrerto inoculate the seed which produced the variable generation

54

Parasitism and lmmnnit\

of his new crosses with bunt spores, and then select bunt-free plants from
the new generation, hoping thereby to secure an immune strain, or one at least
less susceptible than the parents. But in either case, it has yet to be proved
that immunity is absolute and complete, and that rich feeding or starvation,
for instance, or the severity of the infection may not break down the power
of resistance. Insufficient food is said to increase the susceptibility to infec-
tion in the human subject, but this does not seem to hold good for plants.
Brooks^ in his infection experiments with Botrytis cinerea used lettuce plants.
as they are extremely susceptible to attack. He found that leaves just be-
ginning to turn yellow were readily infected w^hile normal green leaves were
immune. When grown under different conditions of mineral starvation,
they behaved similarly as regards infection to those grown under normal con-
ditions. Just as Ward^ found that, wath Puccinia dispersa, the starvation of
the host had no appreciable effect upon its abiUty or inability to cause infec-
tion, so here, the work on Botrytis confirms Ward's view that " Whatever
may be the causes at work in the living cell which confer immunity or predis-
position on the species of host-plant, or which confer virulence or impotence
on the spore, they lie deeper than nutrition."

Since Stinking Smut of wheat is so easily and certainly prevented by means
of pickling, there is not the same practical interest in producing a bunt-
resistant wheat, as in producing a rust-resisting wheat for instance. But it
must be remembered that there are other smuts, such as flag smut of wheat
and loose smut of wheat and barley, which are not so amenable to treatment,
and the methods by which a bunt-resisting wheat is obtained W'ill also be
applicable to the others.

Relative Virulence of Infection by Spores of T. levis and T. tritici,
It is well known in connexion with cereal rusts that a wheat may be
immune or comparatively immune to one species of rust, and susceptible to
another, so that it became necessary to determine if wheats reputed to be
immune to bunt were equally so to both species. In the case of Florence
and Genoa they were liable to infection by both T. levis and T. tritici, but in
varying degrees. Experiments were carried out specially with two other
wheats, viz.. Dexter and Federation, to see how far the two species of bunt
differed in their capacity for infecting them. Sound seed was sown in each
case along with the infected, and the sound seed invariably yielded healthy
plants. The results are given in the following Table and compared with
those obtained from Florence and Genoa collectively : —

Table III.

-Relative Amount of Infection by T. levis and T. tritici

RESPECTIVELY.

Dexter.

Federation.

Bunted.

„,„„„ ; Per cent,
t'ean. Bunted.

Bunted.

Clean.

Per cent.
Bunted.

T. levis
T. tritici

Mixed spores,bat mostly
T. levis ...

43
36

37
45

Florence.

53.75
44.44

55
43

547

21
45

365
Genoa.

72.36

48.86

59.97

T. levis
T. tritici

166 : 2,1.53
7 : 161

7.7l'
4.10

259 1 2,301 10.11
24 129 15.6

Parasitism and Immunity. 55

It will be seen from the above that T. levis is generally the most virulent ;
but iu the case of Genoa it was the reverse, T. tritici being considerably
more so.

It has been pointed out by Harwood^ that there is an evident difference
between the w^heat attacked by T. tritici and T. levis. With the former the
stalks are as tall as those with healthy grain, while with the latter they are
shorter, and this difference is so striking that in some parts of Michigan they
are spoken of respectively as " high " smut and " low " smut. This would
seem to indicate that the one smut interferes with the growth of the wheat
plant much more than the other, but in our plots there was no perceptible
difference between the two.

Kapidity of Germination and Smut Liability.

It is well known that wheats vary considerably in their susceptibiUty to-
wards stinking smut, and that while some varieties are very liable to it, such as
Allora Spring, others are very resistant, such as Minnesota Blue Stem and
Medeah. Dr. AppeP of Berlin observed that a square-head wheat originally
grown in Ohio was susceptible in a very slight degree, and that it germinated
so quickly that it very soon passed the stage when it was capable of infection
by the germinating spores of the smut. It is believed that this rapid germ-
ination is associated with a lessened liability to smut, as othei varieties with
similar properties germinated quickly, but we have yet to ascertain whether
this is a principle of general application as regards the wheats grow^n in
Australia. Kirchner^ has investigated a large number of spring and winter
varieties to see if any relation exists between their susceptibility to bunt
and their germinative energy. He did not find that a low germinative energy
was associated with susceptibility, nor that a high germinative energy was
an unfailing character for determining bunt resistance. But Hiltner\ who
found that rapid germination is characteristic of wheats that withstand the
smut, points out, with reference to Kirchner's results, that a good deal
depends on the mode in which the germination is conducted. The author,
with his specially constructed germinating apparatus, found that oats from
one district germinated 90 per cent, in five days, and from another district
in the same time 35 per cent. ; but when tested in the usual way, between
moist blotting paper, there was no distinction showai in the germinative
energy of the two.

Any tests made in connexion with the relative rapidity of germination are
worthy of being recorded, and the following refers to four varieties. I
received a sample of Ohio wheat and germinated it along with Florence and
Genoa, which are comparatively resistant to bunt, as well as Warden, which
has proved itself to be very susceptible. The seed was sown at an even
depth in shallow pans in a sandy loam, and well watered. As the weather
was very warm at the time, germination was rapid, and in four days two
seedlings of Ohio were above ground and one of Genoa. In six days the
totals were — Ohio 6, Genoa 4, Florence 16, Warden 14: ; and in eight days —
Ohio 20, Genoa 16, Florence 18, Warden 18. The photographs in the frontis-
piece show well the relative rapidity of germination and strength of the
seedlings of each variety, and it W\\\ be noted that the Ohio was much the
most vigorous, the Genoa and Florence being about equal, and the Warden
much slower and weaker. These differences in vigour tended to disappear
with age, till on the fifteenth day there was no perceptible difference between
the Ohio, Florence, and Genoa, though the Warden was scarcely so forward
(Frontispiece).

Escape of Injection hi/ individual Plants. — It is quite a common observation
that when the individual plants of a variety of wheat are all dusted equally

S6 Paras/tis/n and Inununitv.

\vith buut spores derived from a common source, in the same way at the same
time and sown on the same day in similar soil alongside each other, they are
not all equally infected. Even in the most favorable cases there are
generally a number which escape, and it requires to be explained how some
are smutty and others not. There are various reasons which may be assigned
and there are a number of conditions which must obtain at the same time
for successful infection. It need not be assumed that the failure is due to
the non-germination of some of the spores, for the germ-tube may penetrate
into the host-plant and yet not necessarily produce infection.

In the first place, the host-plant must be at the right stage of development
when the spore or conidiuni has put forth its germ-tube, and this period in
the young seedling does not last very long. Further, when the germ-tube
'has penetrated into the seedling, it must reach the growing point, otherwise
it would not continue to keep up with the growth of the host-plant and
finally produce smutty ears. Now, the slower this stage of growth is the
more likely it is that the germ-tube will reach its destination in time, whereas
the more rapid the growth the less likely it is to reach the growing point of
the young seedling before it begins to elongate. It is well known that
individual grains vary in the rapidity of their germination, and this might
be so hastened that the penetrated germ-tube would fail to reach the growing
point. This suggests another reason for some of the plants escaping
infection. Some varieties are very slightly susceptible to infection by bunt,
and only some of the plants would under these circumstances become smutty.
This applies particularly to Florence and Genoa, which are only slightly
susceptible, and in the case of Medeah it was the only one dusted with spores
which escaped infection entirely during 1908. In fact, the whole question
of Parasitism and Immunity or Susceptibility and Insusceptibility to disease,
seems to be bound up with the presence or absence of certain chemical substances
in the host-plant. Miyoshi^ of Japan, was the first to show that the germ-
tube of a fungus will only enter the tissue of a living plant and develop there
when the special substances which attract it are present. This sensitiveness
to certain chemical substances possessed by the fungi is known as Chemotaxis,
or Chemotropism, and the substance which exercises this attractive influence
is spoken of as a positively chemotactic substance. Miyoshi demonstrated
that the hyphfe of Penicillium glaucum for instance, pierced the epidermis
of living leaves when previously hypodermically injected with a chemotactic
substance such as sugar, and Massee^ proved that certain cucumber plants
were immune to a disease to which they were normally subject, owing to the
absence of the special substance which attracted the parasite. The quantity,
as well as the quality, of the dissolved substances and their unequal distribu-
tion influence the result ; and some substances are not only negatively
chemotactic, but they are positively injurious, and repel the entry of the
parasite into the tissues of the plant. It is easy to understand that in the
early stages of the seedling there will be a variety of substances dissolved in
the cells, and these may vary considerably in the neighbourhood of the
growing point. Sugar is the substance which is the great source of attraction
to the germ-tubes of fungi, and this will vary considerably in amount,
according to the nature of the growth, and may even be neutralized in its
action by the presence of other substances.

For individuals of the same variety we must assume a slightly hastened
or retarded development in the seedling stage, and a cjuicker or slower
growth afterwards, in order to account for the unequal infection ; but this
will necessarily be associated with a variation in the chemical composition
of the substances in solution in the plant.

Parasitism and Immunity. 57

This unequal infection is the crux of the whole position, and if we could
account for it satisfactorily it would help us to understand the conditions
under which infection occurs. At the present time the germ theory of
infectious disease in the human subject is on the eve of being considerably
modified, and this has a direct bearing on infection in plants. The sjnut
fungus produces its spores, and these, like the tubercle bacilli for instance,
give rise to certain symptoms in the host, which only occur in association
with this particular kind of organism. Further, the spores, like the patho-
genic or disease-jDroducing germs, have been isolated from the plant-bodv,
cultivated on artificial nutritive media, and then studied in the laboratory.
But it has been found that organisms which cannot be distinguished from
pathogenic germs exist in the tissues of persons who are apparently in perfect
health, and such persons have been designated as " disease -carriers."
Here is a case where the organism, supposed to be the definite causal agent,
is present without the symptoms, and the idea is gaining ground that the
so-called pathogenic germs are ordinarily harmless, but they require certain
conditions to develop their virulent properties. Just as the infection thread
from the germ of the smut can penetrate the plant but cannot produce
infection in the presence of substances known as chemotactic, so in the
human subject something is required to co-operate with or oppose the germs,
before they can be expected to show pathogenicity or the reverse. In the
plant, sugar is the great attraction for the parasite, and since sugar is usually
associated with ferments, it may be that in both plant and animal something
of the nature of a ferment must be present to excite the germs to activity,
and so the " Ferment " theory of infectious disease may yet explain why
under seemingly similar conditions the germ is pathogenic or disease-producing
i n the one case but not in the other.

58 Rdaiions heiivecn Host and Parasite.

CHAPTER IX.

Relations between Host and Parasite in Smut Diseases.

The smut fungi, which are dependent upon certain host-plants for their
existence, very frequently convert the seed into a black mass of spores, and
when this is done in a wholesale manner, the host-plant is unable to reproduce
itself. I had an instance of this in the case of Brome smut in the early part
of 1907, when a paddock sown with prairie grass {Bromus unioloides), in which
the seed supplied was smutted, showed not a single plant free from the disease.
The seed of the host-plant was entirely destroyed, and if this were to happen
over a large area, in the case of an annual such as wheat, the fungus itself
would run the risk of becoming extinct from the failure of its food supplies.
The law of self-preservation comes into play here, and the total extinction
of the host-plant may be guarded against by some of the grains becoming
more resistant to the entrance of the parasite on germination than others.
The less resistant would succumb, while the more resistant would survive,
and by a process of selection it might eventually come to pass that a race of
plants would be produced immune to the parasite. We have a parallel
case in the human race in connexion with pulmonary consumption.
As Sternberg 1 points out, there are certain races which may be specially
liable to infection by the tubercle bacillus, while there are others such as
Russian and Polish Jews, which enjoy comparative immunity, as shown
by vital statistics. But the same principle applies generally to infectious
diseases, and the above-mentioned author, in his recent work on " Infection
and Immunity," clearly expresses it as follows : — " In general, it may be
said that when an infectious disease is first introduced among primitive
races, who, by reason of their isolation, have been previously exempt from
it, it is apt to be exceptionally fatal. This is, no doubt, due to the fact that
there has been no opportunity for the operation of the laws of natural
selection, by survival of the fittest. But under the operation of these laws,
in process of time, a certain degree of race immunity is likely to be established."

In drawing analogies from human diseases it may not be out of place to
remark that the eminent surgeon, the late Sir James Paget, considered that
the study of plant diseases might be very helpful to human pathologists.
In an address on " Elemental Pcithologv " delivered before the British
Medical Association, at Cambridge, in 1880, he pointed out that many of
the morbid processes occurring in plants are quite comparable with those
occurring in animals, such as hypertrophy or excess of nutrition, atrophy or
defect of nutrition, repair of injuries and even inflammation in plants, which
has since been elaborated by Dr. Ransom in his work on " The Inflammation
idea in General Pathology." It is in the field of parasitism, however, that
the likeness is most striking, and which Paget considered the most Avorthy
of study, for he says : — " But of all morbid processes in plants, none, I think,
are so suggestive as are those produced by parasites, whether vegetable or
animal." I can foresee a great advantage in thus regarding plant diseases as
part of the general phenomena of disease, not merely as aids to human pathology,
Init in turning human pathology to account in the investigation of diseases of
plants. It has been too much the custom hitherto to consider plant pathology
as a thing apart, as dealing with a class of disease which had nothing in
common with the great discoveries in the domain of bacteriology, for instance,
From this point of view great possil^ilities are opened up, and investigations
are suggested which might otherwise be overlooked. The questions of

Relations betiueen Host and. Parasite. 59

immunity and parasitism when studied as they affect the pUint, with the
wider outlook derived from considering their hearing upon and connexion
with men and animals, are more Ukely to be fruitful in results and less liable
to be misunderstood. Bacteria, in their relation to plants, and plant
sanitation, are now receiving attention, and this is but the beginning of a
new era in the mode of regarding plants as affected by disease.

There is a sort of reciprocal action going on between host and parasite.
On the one hand, the more perfect the fungus becomes as a parasite, the
more deadly will be its effects on the host-plant, and, on the other hand,
the more resistant the host-plant becomes, the less chance will the parasite
have of surviving, unless it changes its host. But there is a common ground
of agreement in the fact that, while it is to the interest of the parasite that
the host should not become extinct, it is also naturally to the interest of the
host that it should survive, and the final result is that the general tendency
is in favour of the preservation of the host. The question is not so much
Which is to conquer in the struggle for existence ? but if one organism is
favoured at the expense of another, how is that other to maintain its ground
notwithstanding the struggle.

There are various ways in which this may be accomplished, and a few
may be recorded here.

1. The most permanent means would be the production or de-
velopment of immunity in the plant itself, so that, instead of being
predisposed to the disease, it would have hereditary tendeucies in an opposite
direction. This immunity may be more or less complete, and it is strongly
developed in the Durum varieties of wheat.

2. The germination of the seed may be so rapid that the young seedling
will outstrip the germinating spore of the parasite, and thus be too far
advanced for successful infection to take place. This property of rapid
germination is associated with various varieties of wheat, and it has been shown
experimentally that an Ohio variety of wheat, also Florence and Genoa,
which are highly bunt-resistant, are relatively rapid in their germination,
while a well known bunt-liable variety such as Warden is comparatively
slow.

3. There may be a form of symbiosis established between parasite and
host which will enable both to thrive in partnership. This is apparently the
case with the seed fungus of Lolium temulenticm or Darnel, which has been
investigated by Freeman, ', -, -^ and is now considered to be a smut.

In some of the smuts, such as the loose smut of oats, there is a profuse
development of spores, and consequently a relatively large destruction of
the host-plant. In loose smut of wheat, where infection takes place through
the flower, the parasite passes the first stage of its existence in the seed. If
the seed germinates and the conditions are favorable, there will be a production
of spores in the plant produced, but it is conceivable that spores may not be
formed, and then this would lead up to the case of the smut in Lolium. There
the mycelium of the fungus occurs in the seed, and a mutual understanding
is set up between the smut and its host-plant by the production of s})ores
being kept in abeyance. " The Lolium fungus symbiosis is therefore apparently
to be explained as a development from a smut parasitism of the loose smut
of wheat type, in which the spore formation is entirely lost or of very rare
occurrence, and in which a compensating mycelial infection of the host-plant
embryo has been substituted for it." In short the parasite here has to be
contented with a purely vegetative existence, and seems to exert a beneficial
influence on the host, for cultures showed that mycelium infected seeds
generally produced more vigorous plants and a greater number
of seeds than the uninfected. It is known that some Darnel seeds

1

6o Relations bet-a.'ccn Host and Parasite.

are free from the fungus, altliougli tliis is only discernible by the
mioroscope, and that they produce plants likewise free ; but the poisonous
property, due to the alkaloid Temulin, is only developed when the fungais is
present. This has been shown byHannig,^ and the production of this toxin
by the fungus may prevent its complete development just as the production of
alcohol will ultimately overpower the yeast. This raises the further cjuestion
whether immunity may not be due to the production of toxins and anti-
toxins by both the parasite and its host, Avhich neutralize the effects of the
parasite in the host or may actually destroy it.

The parasite as well as its host feeds and excretes, and the excreta are
probably toxic, so that when the nature of the toxins and anti-toxins in th-^
plant body is better understood and when they have been isolated and studied,
then some light will be thrown on the cause of immunity itself.

Potter^ has shown how parasitic diseases in plants may be checked by
taking advantage of this property of the waste products of metabolism, when
allowed to accumulate beyond a certain stage, checking the growth and
finally proving fatal to the parasite. He prepared a toxic solution in pm-e
cultures of the parasite which was not only fatal to it, but as might have been
expected, exercised also an injurious influence on the healthy cells of the host.
This influence, however, only extended to a limited area, and the wound soon
healed over. By this means he was able to arrest the decay caused by a
Bacterium and a Penicillium, so that the principle is probably applicable to
parasites in general.

4. This absence of spore formation in the seed may be due to hereditary
tendencies, as in the Lolium, or it may be brought about by external agencies
which affect the growth, and are intermittent in their character. Thus the
host-plant may not have every ear attacked, so that in the case of " tillering "
of wheat, some ears of the same individual plant may be completely free
from the parasite. Or only some of the grains in an ear of wheat may be
attacked, as happened particularly during season 1907, when there was only
a short growth of straw, but the weather at blooming time favoured the
production of large and vigorous ears.

If we take the concrete instance of bunt in wheat it will be seen how host-
plant and parasite get along together. As soon as the smut has infected
the seedling and the germinal hyph?e have reached the growing tissue, the
curious result is that they both grow together, and there is an inducement
for the host-plant to provide for both, as it is constantly, stimulated thereto
by the hyphfe growing between the cells. This concurrent gro^vth of host
and parasite goes along smoothly and without any external sign of disorder
until the grain begins to be formed. Then there is a struggle for existence
as to whether the host or the parasite is to be the winner in life's race, for
from the very nature of the case, unless the parasite produces its spores it is
likely to succumb, and, on the other hand, if the embryo is not formed, there
will be no future host-plant. It is a struggle in which it is apparently Avar to
the death, and the more successful the parasite is the more injurious it is to
the host. But what decides whether the host or parasite will win ? Well,
there may be a temporary truce when some ears, or it may be only some
grains in the ear, escape destruction by the parasite. But, in the long run,
among the combination of causes which favour the preservation of one or
other organism, it will be found that a compromise has been arrived at, and
the tendency to become immune is the important factor in enabling both
the smut and its victim to survive in the struggle. I have only noticed
the more evident factors in the struggle ; but it is really between
the tissues of the host-plant on the one hand and the germinal hyphae and
mycelium of the parasite on the other, and whatever external influences

Relations heiivccn Host ami Parasite. 6r

aft'ect the one or the other injuriously or favorabh" will have a beannt>' on the
result. Thus, if the autumn is wet when the seed is sown nearly all the seeds
with spores attached will become infected, because the tissues under such
conditions remain longer soft and succulent. There are also limitations imposed
upon the germination of the spores, for they are not always capable of putting
forth their germinal tube at any given time even when moisture is supplied.
It is a general characteristic of smut fungi that they confine themselves to
particular hosts. This denotes a high degree of specialization in thus exer-
cising a selective power for their food, for there are other parasites which are
omnivorous in their tastes and show little or no preference in their selection
of hosts.

Some of them such as the American corn smut utilize any young and
tender portion of the plant, be it leaf or stem or kernel of the cob, and when-
ever it is attacked do not at once proceed to use it up in its immature state.
The fungus stimulates the young and growing part to further growth, and
when it has multiplied excessively so as to form gall-like swellings, the food
stored up is rapidly appropriated and the spores are produced from a well
nourished and vigorously growing mycelium. Not only do they select a
host but in many cases they are only capable of infecting a particular stage
of that host, such as the seedling stage or the flowering stage. Wlien the
young seedling is infected, the parasite puts itself in touch with the growing
tissue and shares in all the growth and vigour of the plant until the criticaV
time arrives, when all the nutrient material prepared for the young embryo
is used up in the formation of smut spores.

But the perfection of specialization is reached in the Carnation Smut fungus,
where the anthers of the flower are alone chosen for the production of the
spores. The parasite enters the plant through the young shoots as shown
by Hecke, and reaches the flower just before it is completely formed. There
it confines itself to the young stamens, using the anthers for the production
of spores and leaving the rest of the flower quite normal. It is the doctrine of
substitution carried to its utmost limits, for not only have the spores replaced
the pollen-grains, but they are carried by the fertilizing insects to other
flowers, and thus their distribution is assured as they are likely to be deposited
on the fruit which is being formed. This is an instance where the fungus
has selected the most favorable spot for the production of spores, and timed
it so that they are carried to their destination as if they Avere the flower's
oAvn pollen. There are degrees of proficiency in the parasite, just as there
are powers of resistance in the host, and this is the highest attainable in the
mode of infecting the most suitable part at the most favorable time.

In considering the relations of the parasite to its host, we must take into
account all the phases of its life and distinguish between those which are
intimately bound up with the life of the individual plant and others which
ai'e passed outside of it. The mycelium of the fungus, for instance, ramifies
among the tissues and directly preys upon them, but there are portions of the
hyphfe detached at the surface for purposes of rapid propagation and known
as conidia, which are used to infect fresh plants. These conidia are known
to vary in their infective power, not only as we have seen, according to the
condition of the host, but dependent upon the nourishment they receive and
their age as well, or the generation to which they belong. If the mycehum
which produces them is well nourished, then as parts of the whole, they share
the increased vigour for a time, but with increasing age and the continued
absence of a host-plant tliey lose their capacity for infection. Biefeld^ has
shewn that these conidia can germinate in artificial nutritive solutions and
go on producing generation after generation of their kind. He cultivated one
form throuoh more than one hundred successive generations in the course of

62 Relations betit\een Host and Parasite.

a year, but towards the end their germinating power began to fail and at last
failed completely. " Smut germs which have lived too long and too exclusively
outside of the host-plant and multiplied in the form of yeast conidia lose
their infective power conjointly with the ability to throw out germ-tubes.'"

It has also to be noted that the climatic conditions which favour the para-
site are not always those which are most conducive to the well-being of the
host, especially when it is being attacked from the outside. The dull, damp,
cold weather which makes its tissues tender and renders its functions less
active are just those conditions which favour the entrance of the fungus, and
if the latter once reaches the growing-point, it is as certain to succeed as the
plant itself. Brefeld has shown this beautifully by demonstrating that if
the conidia are forced into the bud by means of a syringe, so that they can
germinate in contact with the young and growing cells, infection can always
be assured.

There is, generally speaking, a double set of factors involved in each case
of parasitism, the internal disposition or constitution of both host and para-
site and the external influences or environment affecting each. It is iu the
mutual play and interaction of these factors that all the varied and varying
effects are produced, and it can therefore be readily understood that no single
cause or set of factors will explain any case of parasitism, but that the life-
history of both host and parasite must be considered and all the agencies
which affect one or other favorably or unfavorably must be taken into ac-
count. The study of the parasitic diseases of plants, or the mutual relations
of host and parasite, thus becomes a very complicated problem, and the recog-
nition of the factors acting in concert or successively which bring about the
changes giving rise to disease, is the only way to arrive at its true nature.
While it is true that no single factor is entirely responsible for a disease, yet
it is customary to classify diseases according to their chief causes. John
Stuart Mill says that " in practice, that particular condition is usually styled
the cause, whose share in the matter is superficially the most conspicuous."
In this sense the weather might be said to be the " cause " of some parasitic
plant diseases, as they are conspicuously associated with particular weather
conditions. But among the various factors concerned, that one without
which none of the others would be effective in producing the particular symp-
toms, may be more truly termed the cause. Hence when the presence of a
fungus, such as the smut-fungus, is absolutely essential to the production of
a well-marked disease, it is the direct cause of it, even although such a co-
operative factor or contributing cause as the weather is necessary.

hidigciioiis and Introduced Species. 63

CHAPTEK X.

Indigenous and Introduced Species.

It is not always easy to determine what parasites are native and which
have been introduced, because although the introduced plant is liable to carry
with it the spores of some of the fungi which infest it in its native country on
the seed, or it may be only the hibernating mycelium inside the seed, yet
this is not invariably the case. While the potato has introduced into New
Zealand and Australia the well-known potato disease PhytophtJiora injestans,
the orange and the lemon in New South Wales are badly affected with a
disease caused by Phoma citricarpa, a fungus which is unknown elsewhere,
either in Italy or California, and wdiich has probably been derived from the
native Citrus trees. It will be safe, however, unless we have evidence to the
contrary, to regard as introduced those parasites which are found on intro-
duced plants.

The term alien is usually applied to those species wdiich, although now
growing spontaneously, have been introduced through human agency. Such
alien plants are, therefore, often called introduced plants, although we may
have no definite information as to how they were brought here. In the case
of cultivated plants, such as cereals and some grasses, there is historic evi-
dence as to their introduction, but beyond that there is very little certainty.
A species, therefore, which is found wild amid natural sm'roundings may be
regarded as indigenous, Avhile those found amid artificial surroundings or as
escapes from cultivation, may be considered introduced.

The introduced plants with smuts are confined almost exclusively to the
cereals, such as wheat and oats, barley and maize, and to a few grasses such
as rye-grass and Poa. From the principles laid down, the following may be
regarded as having been introduced : —

1. Ustilago avencs (Pers.) Jens., on Avena saliva, or Oats.

2. U. hordei (Pers.) Kell. and Sw., on Hordeum vulgare, or Barley.

3. U. nuda (Jens.) Kell. and Sw., on Hordeum vulgare.
•i. U. tritici (Pers.) Jens., on Triticum vulgare, or Wheat.

5. Cintractia sorghi-vulgaris (Tul.) Clint., on Andropogon sorghum..

6. Sorosporium reilianum (Kuehn) McAlp., on Zea Mays, or Maize.

7. Tilletia levis (Kuehn), on Triticum vulgare.

8. T. tritici (Bjerk.) Wint., on Triticum vulgare.

9. T. striaeformis (Westd.) Oud., on Lolium perenne, and Poa annua.

10. Urocystis tritici, Koern., on Triticum vulgare.

There is no difficulty in accounting for the introduction of the above smuts
as the spores would be associated with the seeds, or the hiliernating mycelium
would be inside the seed, as in the case of loose smut of wheat and barley,
and both spores and mycelium retain their vitality sufficiently long to allow
them to be transported long distances.

The only case calling for special remark is that of flag smut on wheat. It
is generally assumed to be the same species as that found on Rye in the Old
World, but since the spores from wheat will not infect rye, nor the spores from
rye infect wheat, it must be biologically distinct, and as a biological species
it may be called Urocystis tritici, Koern. The same form has also been found
on wheat in India and Japan, but how this biological species originated it is
impossible to say.

6^ Indigenous and Introduced Species.

The total number of species at present recorded for Australia is sixty-eight.
They are grouped under ten genera, and no new genera have been discovered
as in the case of Uromycladium among the rusts. There are two gall-form-
ing species, however, which are interesting, not merely from their producing
galls, but on account of their distribution. Melanofsichium Aiistro-Ameri-
canum occurring on species of Polygonum, was first recorded from South
America, then it was found in the United States, and now it has been met with
near Brisbane, in Queensland. The Queensland specimen was first deter-
mined by Mr. Broome as Ustilago emodensis Berk., but an examination of the
original type of this at Kew showed it to be quite distinct. Cintractia crus-
f/alli occurring on the common Barn-yard grass, is widely distributed in the
United States, but has only been found elsewhere near Sydney. A number
of afEected plants were observed by Mr. Hattrick growing in sandy soil, and
they attracted his attention by the large galls formed on the stems. Both
these gall-forming plants are adapted for moist situations.

Ustilago cynodontis may also be regarded as indigenous, since the host-plant
— Ci/nodon dactylon — is a native. It occurs in Europe, Northern Africa, and
India, to which Australia has now to be added.

The distribution of the species in the different States is very unequal. In
Victoria there are about double the number recorded for any other single
State, and this only shows how imperfectly known the smuts are. They do
not generally attract the notice of collectors, and in some cases they are in-
conspicuous and not easily recognised when the spores are enclosed in the
fruit. In West Australia only those species are known which attack culti-
vated crops, and those occurring on the native flora have yet to be discovered.

The following list shows the distribution of the species : — i ■ ., 45 r

Js"o. of
Species.

Victoria.

Xew Soutli
Wales.

Queens-
land.

South
Australia.

West
Australia.

Tasmania.

Ustilaso . .

18

12

„

S

10

9

ilelanopsichium .

1

1

Cintractia

11

7

1

4

•2

i

Sorosporium

13

fi

8

(i

1

2

Thecaphora

"2

1

1

Tolyposporium

7

4

2

•J

3

Tilletia . .

<)

0

0

•'

3

Entyloma

2

1

1

Urocvstis

7

7

1

1

1

Doassansia

1

1

Totals

G8

44

22

2-)

17

'

19

The smuts have not received the attention of collectors like the rusts, and
only nineteen new species have been added to the following genera : — Ustilago
(2), Cintractia (3), Sorosporium (6), Thecaphora (1), Tolyposporium (4), Til-
letia (1) and Urocystis (2).

II.

LIFE HISTORIES AND TREATMENT OF CEREAL

SMUTS.

Life Histories of Cereal Sniuts. 67

CHAPTER XI.

Life Histories of the Cereal Smuts. — Introductory.

Since the smuts are all parasitic in their nature and cause disease in quite
a number of our economic plants, investigations have been directed, not only
towards gaining a complete knowledge of their history, but also a practical
means of preventing their ravages. In order to control their course and
counteract their influence it is essential to have a knowledge of their life
history and mode of attack, how they gain a footing in the plant, how they
reach the stage when spores are produced, and how these spores behave until
the plant is again infected.

The hrst step in working out their life history was taken when Prevost\
at the beginning of the nineteenth century, established the fact that the spores
when placed in water germinated, and since then various investigators,
including Tulasne, Kuehn, De Bary, Fischer von Waldheim, and Brefeld,
have advanced our knowledge until at the present time Brefeld has followed
their history from spore to spore, and given us a complete account of some
of the more important smuts. Only the cereal smuts will be dealt with here,
on account of their economic importance, including those which occur in
wheat, oats, barley, and maize. In our wheat lields there are three which do
considerable damage, and require to be carefully attended to with the extension
of the wheat-growing area, viz., stinking smut or bunt {Tilletia tritici and
T. levis), loose smut {Ustilago tritici), and flag smut {Uroci/stis tritici). In
oats there is only the loose smut {Ustilago avenae), and in barley there are
the two species known respectively as naked and covered smut. In the one
case the smut is enclosed in a membrane which soon breaks, and the spores
are scattered as in loose smut {Ustilago nuda), while in the other the smut is
enclosed in the unbroken walls of the ovary, and generally remains solid
after maturity {Ustilago Tiordei). In maize there is only one smut Icnown
here, which is commonly called head smut, because it attacks the entire
head {Sorosporium reilianum), but this has so frequently been confounded
with the corn smut so common in America that an account of the latter is
also given. A great deal still remains to be done before anything like a
complete account can be given of the Ufe histories of the various Australian
smuts ; still a beginning has been made, and when the gaps are known it may
lead to their being filled up all the sooner.

In order to give a connected view of the cereal smuts and their different
peculiarities, I have arranged them in tabular form, and one of the most
striking features is that they naturally resolve themselves into two gi-oups,
according to their mode of infection — flower infection and seedling infection.
Among the flower infection forms there are only two, the loose smut of wheat
and the naked smut of barley. Both give rise directly to a mycelium on
germination without the formation of conidia, and the spores are scattered
naturally at the flowering season.

i> 2

68

Life Histories of Cereal S//n/ts.

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Life Histories of Cereal Smuts. 69

With the increase in our knowledge of the life histories of the cereal smuts,
it has been found necessary to split up some of the older collective species,
both on account of their morphological and physiological characters, into
several new species. Ustilago segetum (Bull.) Dittm. and U. carbo Tul. were
originally used to include several of the species occurring principally on wheat,
oats, and barley, and these names have now been discarded and replaced by
others.

At first the old species U. segetum was split up by Jensen', in 1888, into
the following four races : — U. segetum, var. tritici; U. segetum, var. avenue;
U. segetum, var. hordei, form fiuda ; U. segetum, var. hordei, form tecta.
And he showed, at the same time, that the smuts occurring on wheat, oats,
and barley were only able to infect the particular cereal on which they grew.
Then in the same year Brefeld found that the loose smut of wheat and
barley did not produce conidia on germination, and that their spores were
incapable of infecting oats. On these grounds he constituted a species
U. hordei, Bref., for the forms occurring on wheat and barley. In 1890,
Rostrup^ named the form tecto, determined by Jensen, U. jensenii, Rostr.,
because the spores produce a promycelium with conidia.

And, finally, in the same year Kellerman and Swingle^ raised Jensen's
two forms on barley to the dignity of species, and named them respectively
U. nuda (Jens.), Kell. and Sw., and U. hordei (Pers.), Kell. and Sw., so that
Brefeld's U. hordei was spUt up into the three species now retained — U. tritici,
U. nuda, and U. hordei.

The names that will be adopted in this work are the following : —

U. avenae (Pers.) Jens. (1889) — forming conidia on germination.

U. hordei (Pers.) Kell. and Sw. {18^0) = U. jensenii, Rostr. — forming
conidia on germination.

U. nuda{Jens.) Kell. and Sw. (1890) — forming no conidia on germination.

U. tritici (Pers.) Jens. (1890)= f/. hordei, Bref. (in part) — forming no
■ conidia on germination.

70 Stiiiknig S/nui or Baut in VC Jicat.

CHAPTER XII.
Stinking Smut or Bunt in Wheat.

{TUletia tritici (Bjerk.) Wint. ; T. levis, Kuehn.)

Perhaps there is no smut better known to the AustraUan farmer than
this one, since although it remains enclosed until harvested, it gives forth a
disagreeable odour like stinking fish, especially when crushed, and one cannot
fail to detect its presence. The spores do not escape as a powder, but are
enclosed in the ovaries and glumes, and although at first somewhat greasy,
they soon become dry and hard ; and the mass of spores in an ovary is known
as a bunt-ball, hence it is frequently spoken of as ball smut, and sometimes,
on account of its hardness, as stone smut. Since the spores do not burst
through, but are enveloped by the outer coats of the ovaries, it requires the
practised eye to detect the disease at first (Plate II.). The ears are rigid,
and of a somewhat darker green colour than the normal, the spikes are rather
smaller, and a little further apart, and stand out more from the axis of the
inflorescence, and the grains themselves in the early stages are of a deep
dark unhealthy green, and the upper straw is of a peculiar bluish-green
colour. The growth is arrested earher than in healthy plants, so that there
is premature ripening, and the leaves indicate the diseased condition by
their yellow colour. There is the disagreeable smell where the disease is
plentiful, which is due to trimethylamin, a decomposition product of the
nitrogenous constituents of the parasite.

There are two species of smuts responsible for this disease, the one with
smooth and the other with netted spores, but as both sometimes occur in
the same ear of wheat and generally agree in their life history, they will be
treated here as practically the same.

Germination.

This was one of the first species in which the germination of the spores of
smuts was observed. Prevost^ in 1807, germinated them in water, and figured
not only the promycelium, but also the primary and secondary conidia.
These observations were confirmed by a number of later observers, and
Tulasne\ in 1854, investigated the subject more fully. In 1858, Kuehn^
fully described the process, and then, in 1883, BrefekV added to our knowledge
by showing how the spores behaved in a nutritive solution.

The spore germinates in water or after being kept damp for two or tliree
days. The spores germinate freely under the following conditions : — Place
them on damp blotting paper on a plate under a bell jar, keeping them moist
for a few days, and the fine white mould which soon appears constitutes the
promycelia and the numerous sickle-shaped conidia of the germinating
spores. Or take a plate of plaster of Paris sprinkled with spores and place
it in water under a bell jar. In about three days there is a copious production
of conidia. The outer membrane of the spore splits, and a stout promycelium
of varying length is produced, which elongates at the apex. When this
reaches the air a tuft of thread-like branches is formed at the apex, and these
constitute the conidia. After all the protoplasm has passed into them from
the promycelium, they are cut off by a cross partition or septum, and if the
promycelium happens to be very long, then numerous septa are formed from,
below upwards. The length of the promycelium will vary according to th
distance to be traversed before it reaches the air, since conidia are only forme

Pr.ATK 11.

G. H. Robinson, Phot.

STINKING SMUT OF WHEAT

(Til/ctia Trifici and T. Levis.)

Sti)iking Smut or Bunt in Wheat. 71

in the air and not in fluid. If germination takes place in damp air then
the promyceUum is short, but if in a dense layer of water then it is long.
The contents of the spore pass into the tube, and then the contents of the tube
collect in the growing apex, and if this grows further the tube becomes divided
regularly by transverse septa. Lateral branches may also be formed which
grow in a similar fashion.

The mature conidia are filiform bodies arising from fine tubercles at the
apex of the promycelium, curved in various ways and varying in number
from four to twelve or more. They usually become united in pairs by the
outgrowth of a narrow tube passing from, the one and fusing with the other,
giving the appearance of the letter H. After this fusion germination occurs
by the production of a slender filament bearing a sickle-shaped secondary
conidium at its apex, into which the contents of the united spores have
migrated. According to Kuehn^ both the primary and secondary conidia
when placed in a damp atmosphere can give rise to a germ-tube which is
capable of infecting the wheat plant.

The primary conidia may become detached before germinating, and then
fusion between them is not so likely, but when it occurs the connecting
bridge is wider. Brefeld found that the conidia which did not fuse behaved
similarly to those which paired, only the resulting germ-tubes and conidia
were smaller and shorter. Three or more primary conidia have been
seen connected, and double fusion between two has occasionally been
observed.

Thus the normal mode of germination is for the spore to produce a stout
promycelium bearing a tuft of primary conidia at its apex, and each of these
conidia or the conidia miited Ln pairs to produce a single secondary conidium,
which puts forth a slender germ-tube to infect the wheat plant.

We must carefully distinguish, however, between w^hat takes place in
water or in moist air and in a nutrient solution. While the spores germinate
freely in water, they do not succeed in a nutrient solution, Brefeld there-
fore first germinated the spores in water up to the formation of primary and
secondary conidia, and then added a nutrient solution. Both primary and
secondary conidia produce germ-tubes which develop into a much-branched
mycelium, just like a tuft of mould, the hyphae of which are exceedingly fine.
On the aerial branches numerous short lateral shoots are formed which swell
up at their ends and become crescent-shaped conidia (Fig. M). These are
easily detached, and again give rise to a tufted mycelium capable of producing
further conidia in the manner already described, and this continues as long
as the culture is maintained in the nutrient solution. Xo conjugations or
fusions occur among these conidia. The branches of the mycelium which are
given off in the nutrient fluid do not produce conidia, but grow outwards
until they reach the air, when they produce terminal conidia or remain
sterile, in which case the liyphaj are septate and appear empty.

Adaptations to Unfavorable Conditions.

This account of germination would not be complete without referring to
the curious adaptations which Brefeld has observed to occur during germi-
nation, in order to provide against or to escape unfavorable conditions.

1. If the spores are submerged or the detached conidia fall into water,
they only produce a germ-tube which must either enter the wheat-plant or
die. The spores do not produce pi'imary conidia, nor the primary conidia
secondary conidia, because it would be a useless waste of energy, as they would
be sure to perish in the superabundant moisture.

72 Sfi///;/itg Smut or Bunt in Wheat.

2. But if the spore germinates in water and the promycelium at length
reaches the air, conidia are formed which become detached and are free to be
distributed by the wind.

3. If the detached and paired conidia happen to germinate in moist air,
they invariably produce secondary conidia, which are minute and easily de-
tached, and may readily be carried by the slightest breath of air to a distance.

4. If these secondary conidia reach a place sufficiently moist, they produce
a germ-tube for the infection of the wheat-plant, but if there is not sufficient
moisture, they give off another conidium at one side, and so on until even-
tually they may either produce a filament which will enter a wheat-plant or
die of exhaustion.

5. If nutriment is added to the water in the shape of organic matter, each
primary and secondary conidium is capable of producing filaments which
ultimately form a mass, like a tuft of mould, visible to the naked eye. The
aerial branches develop sickle-shaped conidia, which are easily detached and
readily distributed, and again give rise to a tufted mycelium bearing conidia,
and so on. This shows how the conidia may be preserved in an active con-
dition where organic matter is present. If there is sufficient moisture the
conidia will germinate, and instead of perishing, if there is no wheat-plant at
hand into which they may enter, they will absorb nourishment and grow
like a mould and produce secondary conidia, which may, in their turn, either
germinate or remain dormant according to the amount of moisture.

It is interesting to note that while Ustilago only produces spores in the
host-plant, Brefeld succeeded in producing spore-like bodies with Tilletia in
artificial cultures. Under these conditions the conidia give rise to hyphte,
which, after growth in length has ceased, begin to thicken in a moniliform
manner, and then transverse septa are formed which isolate the roimded cells.
After becoming free, they grow no more, but concentrate their contents
and thicken their membrane, gradually assuming a dark colour and net-like
markings on the walls. Although so far developed, they did not germinate
when placed in suitable solutions.

There are thus two stages in the life history of this smut to be clearly dis-
tinguished— the 'parasitic stage, starting from the period of infection up to
the time when spores are produced, together with conidia and secondary coni-
dia, and the sapropJiyfic stage, commencing with the germination of the coni-
dia in a nutrient solution and producing conidia in damp air which are capable
of infection.

Although the conidia arising from the promycelium and those produced
from the mould-like mycelium are distinct in their mode of origin and in their
shape, yet they have much in common. The former arise as a whorl at the
apex of the promycelium and are generally elongated and filiform, while the
latter are always formed singly from a hypha, and are shorter, thicker, and
sickle-shaped. But in a nutrient solution, Brefeld has shown that both coni-
dia form a mycelium, and when a number of cultures are made in water, those
produced by the hyphee assume all sorts of transition shapes, from the elon-
gated filiform to the typically sickle-shaped.

Duration op Germinating Power.

The spores produced in the ovary retain their power of germination for
two or three years at least, and Liebenberg^ states that he has germinated
them after eight-and-a-half years, of course after being kept under dry con-
ditions. Since these dry conditions do not exist under ordinary cultivation
for au entire season, it may safely be assumed that if a change of crop after

Stinking Snint or Bunt i>i W/ieai.

73

wheat is followed, the smut spores in the soil will have germinated and died,
and if two years are allowed to elapse before wheat is again sown the chances
are entirely against any smut spores having survived. Even the smut-balls
would be broken up by that time in the ordinary operations of working the soil,
or even by the slow movement of water in the soil. An experiment bearing
on this was carried out with unbroken smut-balls in the soil to see if the
spores were disturbed. Clean seed wheat was planted by hand in two rows
alongside each other, in one of which the seed was pickled with bluestone
and the other not, and unbroken smut-balls were planted close to the grains
in each row. The result was that the plants were all clean in the pickled
row, while in the unpickled several plants were bunted, thus showing that
the smut-balls in the soil, even when undisturbed by the plough, can infect
the seed wheat when not pickled.

Infection.

The mode of infection has been investigated, among others, by Kuehn^
who artificially infected the youngest seedling stage with the spores, and
afterwards traced the course of the germ-tubes by means of sections. He
found that both primary and secondary conidia were capable of infection,
and that the germ-tubes penetrate the epidermal cells directly through the
walls, always in the neighbourhood of the lowest node. Just as the young
seedling emerges from the grain, it is then in the most susceptible condition,
and it may be attacked at any point up to the first joint, which is sometimes
called the tillering point. The first joint is always beneath the surface of
the soil, when the grain is drilled or harrowed, and not lying on the surface
of the ground. Above that the plant cannot be infected, because the cuticle
is too tough to allow the penetration of the delicate germ-tube. Therefore,
unless the bunt spores were sown with the seed or existed in the soil, there
is no possibility of infection. Once the germ-tube has entered the young
seedling a mycelium is formed, which, if it reaches the growing point, keeps
pace with the lengthening plant, chiefly growing among the loose cells of
the pith, without interfering to any perceptible extent with the healthy
growth of the plant, and finally reaching the ovaries, where spores are formed.
It is thus seen how the parasite has conquered the host-plant in the long run,
for just at the critical time, when the wheat plant is about to store away in the
ovary for the benefit of the young embryo all the valuable materials accumu-
lated during the growing period, the fungus enters in and appropriates
them, rapidly growing at their expense, and forming a network of delicate
branching hyphcB, which give rise to the innumerable dark-coloured spores.

Since infection only occurs in the young seedling by means of spores
attached to the seed or by spores derived from smut-balls in the soil adjoining
the seed, and since these spores are known to be destroyed or their germination
prevented by bluestone solution, formalin, or hot water, the reason for
steeping the seed before sowing is evident, while at the same time it is not
seriously affected by the solution employed, particularly the two latter.

Artificial Infection of Seed.

Since a number of the plots were artificially infected, and as it is the usual
way of testing susceptibility to the disease, it seemed desirable to see if
dift'erent results were obtained, according as the spores were applied wet or
dry and in larger or smaller quantities to the seed. The Wallace variety
of wheat was chosen, and one plot was sown without infection as a check,
while another was infected and treated with bluestone for comparison!
When applied wet the spores wore made into a paste with water, and the

74

Stinking Smut or Bunt in Wheat.

grains rolled in this until they were quite black ; when applied dry the grains
were simply rolled in the dust from the crushed sniut-balls until they looked
as if coated with soot. The results are given in the following Table : —

Table IV.

-Infection with Spores applied Wet and Dry and in
Various Quantities.

As far as conclusions can be drawn from a single experiment, the wet
infection was a little more effective than the dry, and the increased quantity
to a given quantity of seed decidedly increased the chances of infection, as
might have been anticipated. Since this experiment was carried out I have
come across the record of a somewhat similar one made by Gleichen as far
back as 1781, and for the details of which I am indebted to a suggestive
Bulletin on the " Smut of Wheat and Oats," by Professor Arthur. Gleichen,
who seems to have been the first to test the method of infection experi-
mentally, soaked one lot of seed in water and then rolled it in smut spores
until completely coated, while another lot of seed was rolled in smut without
previous wetting. The results are given by him for clean and smutted heads,
and not for stools, but still they may be compared in a general way with
those already given.

1. Wheat sowed wet with Stinking Smut
2.

3. „ „ dry „

4. ,, ,, wet ,, ,,
5.

Good
Heads.

Smutted
Heads.

178

166

40

59

102

35

48

14

339

188

Per Cent.'of

Loss.

48.

59.5

25.5

22.6

35.6

In the four trials with wet seed there was a loss of 41 per cent., and in
the single trial with dry seed 25| per cent. ; so that the wet infection was
here also the most effective.

The Spores after Harvest.
This is usually spoken of as the wintering of the spores, but as in our
climate the wheat is reaped towards the end of spring and in early summer,
the term is inappropriate. The sowing takes place in the autumn months,
so that the spores pass the summer either on the grain or in the soil.

Sfiiikiiii! Smut or Bunt in Wheat.

75

It is generally recognised that the threshing machine has a deal to do
with the scattering of the spores and the dusting of the grain. When a
wheat stack infected with bunt is being threshed, the beaters of the drum
will break the bunt balls, and consequently the spores in countless millions
will be scattered by the wind, and the wheat coming down into the bags will
also be dusted with them. When the same threshing machine is used for
another stack, which maybe free from bunt, there are plenty of spores left
about the machine to infect a new lot of grain. The grain in the bags
will necessarily be stored in a dry place during the summer, and the spores
cannot germinate until moisture is supplied to them when they are sown in
the soil. It is well known that such seed dusted with spores and kept dry
during the summer will produce bunted wheat in the succeeding crop if not
treated, and even if the seed is kept dry for three years in a bag the spores
will germinate and cause the disease all the same. Clean seed may also be
contaminated by passing through a seed drill which has been used for bunted
wheat, and the sacks in which the seed is stored may also be a source of
infection. They should be disinfected by dipping in the solution used for
treating the seed wheat, say 1 lb. of bluestone dissolved in 5 gallons of water,
even although the wheat has been treated, for the seed may be reinfected
through dirty bags.

But if the spores were exposed to the vicissitudes of the weather, as in
the case of those falling upon stubble ground from the last year's crop, would
they live and infect the new crop ? BoUey'^ carried out experiments to
settle this point, and he found that when the seed was treated to prevent
any infection from that source, in no case were there any smutted heads.
He considered that the spores, having germinated, the conidia, even although
in the ground, Avere so minute that the probabilities were against their being
in the proper position to infect the young wheat plant at the proper time.
In every case where the seed was pickled there were no smutted heads, even
although the soil was smutted. The results of these experiments show that
spores falling to the ground lose their vitality the first season ; but it is
known that when bunt-balls remain unbroken in the ground and are broken
the second year the spores may infect the young wheat plant.

Re-inpection of the Seed after Treatment.

Reference has been made to the danger of re-infecting the treated seed
' J returning it to smut-infested bags, or sowing it by means of a seed drill
not properly cleaned. In the case of bluestone, a thin film of the solution
coats the grain, when it is properly soaked, and this is known to protect it
against infection from spores on the grain itself, and from bunt-balls iu the
soil. But what happens when the grain receives a fresh coating of spores
after treatment, either from broken bunt-balls or dirty bags, is a natural
question to ask. This has been investigated by the late Mr. Farrer, and our
own experiments are at present under way, the results of which will be
available later.

As early as 1899 Farrer- commenced experiments with various fungicides
for the treatment of stinking smut, and he found it necessary, at the same
time, to test the effect produced by bunt-balls left among the grain and soa\ti
with it. In treating the seed, if the bunt-balls are not removed in the process,
they are likely to be broken in the subsequent handling of the grain, and
possibly infect it afresh, even although all the loose spores on the seed may
have been destroyed.

The first experiments were designed to ascertain whether, and to what
extent, the bunt-balls when crushed and treated with fungicides were capable
of infection. The seed used was free from spores to begin with, and taken

76 Stinking Smut or Bunt in Wheat.

from a crop also bunt free. Only two experiments were made with formalin.
In the one the seed was infected from balls soaked for five minutes in a solution
of strength 1 in 109 of water, and in the other the strength was 1 in 207 of
water. In the first case the plants were all clean, and in the second 48.-3
per cent, were bunty. But since the strength of formalin required to destroy
the infective power of the crushed bunt-balls probably killed 73 per cent.
of the plants treated, as shown by another experiment, it was evident that
such a strong solution could never be used in practice. Several experiments
were made with bluestone solution of various strengths, and they all showed
a high proportion of bunty plants, ranging from 61 to 90 per cent., even
although the balls had sometimes been soaked as long as 45 minutes. To
take one experiment in Avhich the strength used and the time taken was
reasonable : The seed was infected from balls soaked for five minutes in a
solution of 1 lb. bluestone in 4 gallons of water. The result was that 77 per
cent, of the plants were bunty.

In the next series of experiments the treated and untreated bunt-balls
were placed in the soil at the time of seeding. Untreated bunt-balls w^ere
placed in the bottom of the drill, at 1 inch, | inch, and \ inch respectively
from each wheat seed, and on one side of it only. The result was that infection
occurred at the various distances, and the nearer the bunt-ball was to the
seed the greater the infection. This varied from 4 to 17 per cent., and in
one case there was no infection at all.

Bunt-balls treated with formalin, as in the previous experiments, dried
and placed in the bottom of the drill, \ inch from each seed and only on one
side of it, produced no infection. When bluestone, however, was used, the
bunt-balls being soaked in a solution of 1 lb. to 4 gallons of water for five
minutes, then dried and placed in the bottom of drill, it was found that when
placed 1 inch from each seed there was 1^ per cent, of bunty plants, and when
^ inch from each seed, a little over 6 per cent. These experiments show
that, if unbroken bunt-balls are contained in the seed after treatment, they
are liable to be broken subsequently and infect the grain, and even if unbroken
may infect adjacent untreated plants if sown with the grain.

In 1900'^ these experiments were continued, but only one is recorded
relating to infection after treatment ; and it is very suggestive as to the
protective effect of bluestone solution. Minnesota Blue Stem was the variety
chosen. The grain was soaked for five minutes in bluestone solution of a
strength of 1 lb. in 4 gallons of water, then dried, and afterwards infected.
The result was that 1^ per cent, of the plants were bunty, while grain of the
same variety taken from the same bulk, infected without any treatment,
yielded 12 per cent, of bunty plants. The coating of bluestone on the seed
evidently prevents the germ-tube of the fungus penetrating inside to any
great extent.

In 1901, further experiments were made, and Farrer^ records the results
of infections after treating different varieties of wheat with bluestone, and
then infecting the grains after drying. Purple Straw, Farmer's Friend, and
Allora Spring were tested, the grains of each being soaked for five minutes in
a 2 per cent, solution (1 in 50), then dried and infected. The percentage of
bunty plants varied for each variety. In Purple Straw there was no infection,
in Farmer's Friend nearly 2 per cent., and in Allora Spring nearly 9 per cent.
The date of planting for all of them was 10th July, and Allora Spring alone
was tried later, planting on 2nd August, and using a slightly stronger solution
of bluestone over .3 per cent. (1 in 30). Two different plots yielded as
nearly as possible the same percentage of bunted plants, viz., 19.74 and
19.77. The results here are rather discordant, and Farrer himself confesses

Stinking Smut or Bunt in Wheat.

77

that he cannot account foi" the inferior protection against infection Allora
Spring received when treated with a stronger sohition and planted later.

In 1902'*, the experiments were continued, but the drought which prevailed
and the excessive dryness of the seed bed at the time of planting were not
favorable for obtaining normal comparative results. Yandilla was the only
variety chosen, and the seed was soaked for 4 minutes in a 2| per cent,
solution of bluestone (1 in 40), then dried, and afterwards infected. A
second similar experiment was tried, the only difference being that the bluestone
was dissolved in water to which a little gelatine had been added to sec if a
thicker coating would be formed on the grain, and thus protect it all the better
against infection. The planting was done as late as 3rd September, and the
percentage of bunty plants was a little over 4 and 8 respectively. The addition
of gelatine did not add to the protective qualities of the bluestone solution.

It is evident from these experiments that grain may be re-infected after
treatment, and every precaution should be taken to prevent this re-infection.
The principal source of danger arises from smut-balls, which are liable to be
broken in the seed drill, but no sample of wheat containing smut-balls should
be used for seed purposes, and any stray ones should be skimmed off in the
process of pickling.

Proportion op Smutted and Sound Stalks in same Stool.
It is commonly stated that when a plant is infected with stinking smut
all the ears are generally affected, and that the cases are exceptional where
smutted and sound stalks occur in the same stool. But a lengthened exper-
ience in Australia has led me to the opposite conclusion, viz., that it is less
usual to find a stool in which all the ears are bunted, and it will be satisfactory
to give examples bearing out this contention. This occurred during the past
season at all the stations where bunt experiments were being conducted, but
actual figures will be given. At Burnley, Dexter wheat was infected with
bunt-spores — one plot with those of T. levis and another with those of T. tritici.
At the end of the season I selected ten stools with bunted ears at random from
each plot and counted the number of ears on each, separating them into
bunted and clean. The following table gives the result : —

Table V. — Bunted and Sound Ears in each Stool of Dexter Wheat.

stool

5.

stalks.

Clean.

Bunted.

stools

stalks.

Clean.

Bunted.

1

8

6

2

/ 1

20

14

6

2

16

13

3

'

2

8

3

5

•J

14

10

4

•■>

7

3

4

Infected

4

15

11

4

Infected

4

20

7

13

with

5

27

18

<)

with

5

9

6

3

T. levis

6

23

21

2

T. tritici \

(5

12

3

9

7

10

8

2

,

7

13

6

7

8

12

8

4

8

15

13

2

9

10

5

0

9

14

10

4

10

12

10

2

10

8

6

2

Totals

10

147

110

37

10

126

71

55

It is seen from the above Table that every stool was only partially bunted
whether the spores of T. levis or T. tritici were used, and that in both cases

78

St'uikiug Smut or Bunt in Wheat.

there was a greater proportion of clean than bunted. With T. levis, 75 per
cent, were clean, and with T. tritici, 56 per cent., so that the same plant, as a
rule, produces both sound and smutted heads.

I next examined a large number of bunted plants to try, if possible, to
find one in which all the ears were affected. Federation was the variety
chosen, because it is specially liable to bunt, as it was infected with T. levis,
and 72 per cent, were diseased. On examining 20 diseased stools at random,
as in the case of Dexter, the result was as follows : —

Table VI. ^Bunted and Sound Ears in each Stool of Federation Wheat.

stools.

stalks.

Clean.

Bunted.

1

14

1

13

2

16

1

15

3

9

3

6

4

11

2

9

5

20

0

20

f)

9

0

9

7

12

4

8

8

13

1

12

9

17

9

8

10

8

0

8

11

6

0

6

12

8

1

7

13

9

1

8

14

6

0

6

15

10

1

9

16

7

0

7

17

8

2

6

18

10

0

10

19

6

1

5

20

10

1

9

Total

209

28

181

Out of twenty plants, there were seven entirely bunted, and only 13 per
cent, of clean ears. When the variety is particularly susceptible, there may
be a considerable proportion entirely bunted, but under our conditions, a
mixture of smutted and sound ears in the same plant is the more common.

Grains of Wheat Partially Bunted.
The normal course of the stinking smut fungus is to produce its spores in
the ear, and in every ear of the stool attacked, as well as in every grain of the
ear, and the contents of each grain is converted into a foetid mass of spores.
But when a number of diseased specimens are examined, it is found that the
spores may occasionally occur on the stem, as well as in the ear, and that it
is not at all unusual in certain seasons for only some of the ears in a shoot to
be bunted, while a number of the grains in the affected ear may escape, and
even the grain itself may be only partially diseased. I have not, personally,
found bunt-spores elsewhere than in the ear, but Berkeley^ records an in-
stance of a streak of bunt appearing on the stem. The plant to which he
refers in the following sentence was grown from a grain infected with the spores
of bunt : — " In one of the bunted plants, not only the ear was diseased, but
there was a streak of bunt upon the stem, in which the foetid smell and

Stinking Smut ^or Bunt in Wheat.

79

peculiar structure were not to be mistaken, a circumstance whicli I have never
before observed, nor am I aware that the fact has been noticed by others."

The occurrence of bunted and clean ears in the same stool has already-
been fully referred to in Chapter VIII., and bunted and clean grains in the
same ear are illustrated in Plate II., B and C.

That the grain of wheat itself in a diseased ear should be only partially
bunted, is regarded by some as an impossibility, nevertheless, two examples
have been met with this season, confined to a single ear in each case, and one
of them is here photographically illustrated. This belonged to the variety
known as Cedar, grown at Dookie Agricultural College, and the one ear con-
tained all the gradations of sound, bunted, and partially bunted grains. The
three partially bunted grains were partly translucent and partly opaque and
dingy, indicating, apparently, the diseased and healthy portions. On making
transverse and longitudinal sections of the diseased grains, fungus filaments
and numerous spores were found interspersed between the outer skin and
aleuron layer on one side, while the other portion was of the normal character
and filled with starch granules. (Fig. 10.) In a longitudinal section, the
embryo was seen to be quite intact and partially surrounded by the numerous
spores, some of which were still in the early stage with fungus filaments at-
tached. The species belonged to Tillitia tritici, with the spores of which the
plants had been originally infected. The other specimen was found on Genoa,
grown at Burnley, and the ear contained sound and entirely bunted grains,
and only one partially bunted. This variety was infected with T. levis. so
that both species of smut produced partially bunted grains.

I have had a partially bunted grain photographed, both as it naturally
appeared, and in section, because Bolley-^ has stated very distinctly and em-
phatically, after making hundreds of sections of apparently sound grains,
that " In a crop of stinking smut, the grain product is made up of solid grains
and smut balls only. In other words, there are no grains which are partially
smut and partially flour." I grant that such an occurrence is exceedingly
rare, but it shows how diffcult it is to prove a negative.

Fig. 9. — Grain of wlioat partially buutoJ. Surface view

prain p;irtially

8o Stinking Smut or Bunt in Wheat.

Conditions favouring the Diseask.

There is no doubt that bunt is more prevalent in some years than in others.
In the season of 1898 it was so prevalent in Victoria that it was estimated to
have caused a loss on the year's crop of £50,000. In 1908, with a record har-
vest, there were certain districts, such as the Wimmera, where the value of
the crop was considerably reduced from this cause alone. Ten years ago, the
treatment of seed-wheat for smut was neither so general nor so well carried
out as it is now, although farmers asserted that every precaution had been
taken in the treatment, and even now there are some who neglect it altogether,
or do it in a slipshod manner.

Heat and moisture are the two controlling factors in its development,
especially the latter. It is generally considered that less moisture is required
to germinate the smut spores than the wheat, on account of their much smaller
size, hence it is a common practice in some districts to sow the seed unpickled
in a dry seed-bed, but to pickle it after rain. In the one case, the insufficient
moisture is likely to start the growth of the smut spores before the wheat,
and in the absence of a host-plant, the germ-tubes shrivel up and die, while
in the other, there is every probability of both germinating at the same time
and infection is sure to occur. A cold and wet period immediately after sow-
ing is more favorable to the growth of the bunt than of the wheat, and the
tissues of the young plant, being soft and tender, there is often a larger pro-
portion of bunt than usual. But in discussing the relations between the
nature of the season and the prevalence of bunt, there are no definite experi-
ments to guide us.

Effects upon the Crop.

When the smut appears in a crop, the farmer generally considers his loss
as being entirely due to the ears destroyed by the fungus and to the deprecia-
tion in price per bushel for the remaining sound wheat, but it has been shown
by Bolley3 particularly, that smutted ears are only an indication of more
widespread damage. Thus it was found that in stools with only one or a few
ears affected, the smut fungus was in all the straws, even when the heads
were sound. Further, in untreated wheat paddocks where only about one-
third or one-fourth of the crop had actually smutted heads, it was difficult to
find a stool or a straw free from the fungus, explaining why the crop was
materially reduced beyond the evident indications. Then the growth of the
straw may be seriously interfered with, as well as the formation of the heads,
for it has been observed that on stools bearing smutted ears there are often
several unheaded straws. Kuehn^ even found that, where smut infection
was very bad, youngr plants might die back completely. Where the straw
is completely formed, the heads may still be poor, for just at that period when
the grain is about to be formed, if the fungus is present, there is Hkely to be
a shortage of supplies. As we remarked in connexion with the rust-fungus,
" In the actively growin:T and feeding period of the plant's life, it is apparently
able to provide for the wants of the fungus as well as its own, and therefore
its vitality is not seriously alfected. But when the second period of forming
and ripening the seed arrives, when feeding is gradually ceasing, and the ac-
cumulated materials are being transferred to the seed, then the fungus draws
upon the plant's capital, crippling its energies, and checking the movement
of the food materials to the seed." If the fungus filaments are not sufficiently
robust to give rise to the spore-forming hyphae and invade the grain, they
are still capable of diverting food material from its natural destination — the
ear.

Siiiikiiig Snint or Ihiiit in Wheat. 8i

Diseases produced in Animals.

The disastrous effect upon the crop is not the only thing to be considered,
for the smut possesses poisonous properties which render the flour contami-
nated with it dangerous to human beings and the straw or chaff eaten by
cattle is also injurious. In seasons when this disease of wheat is prevalent,
owing to the seed-wheat not being treated properly, there is a good deal of the
chaff given to cattle and horses. Tubeuf^ referring to this particular smut,
remarks — " The symptoms in the few cases of disease observed do not agree
very closely. A paralyzing effect on the centres of deglutition and the spinal
cord seems to be regularly present. As a result, one generally finds a con-
tinuous chewing movement of the jaws, and a flow of saliva, also lameness,
staggering, and falling. Cattle, sheep, swine, and horses are all liable to
attack."

More recently, Giissow^ in the Journal of the Royal Agricultural Society
of England, has been writing in a similar strain. " The smut fungi {Ustila-
gineae) of our cereals and grasses, especially the fungus known as bunt {Tilletia
caries Tul.) have proved extremely dangerous to animals of the farm. After
feeding on hay which contains the spores of these fungi (often in enormous
masses so that they form clouds of black dust when the grain passes through
the machine), inflammation of the niucous membrane, laboured action of
chewing, flow of saliva, and occasional abortion have resulted."

Accordincr to Smithy fowls have been fed with bunted wheat without any
bad result, but that is not our experience here. At a poultry farm near Mel-
bourne, carrying 650 Leghorns, about the beginning of March, the egg yield
dropped in a few days from an average of 100 to 16, and that without any
apparent cause, the fowls being given the usual feed with a good supply of
meat. The wheat was examined and found to be smutty, and it M^as further
found that the egg yield began to drop from the time this particular line of
wheat was used. The use of the smutty wheat was at once stopped and now,
at the end of March, barley, with a fresh line of clean wheat, has been tried,
with the result that the egg yield has begun to improve and is steadily mount-
ing up. At the end of three weeks, after the use of smutty wheat had been
discontinued, the average yield of eggs had reached 80 per day. The smut in
the wheat w^as the only cause that could be assigned for the unprecedented
drop in the egg yield, as in every other respect the feeding was the same as
usual and the weather was good at the time. In some cases, fowls have
refused to eat badly smutted wheat, after being fed on it for several days,
preferring an empty crop. Other poultry-keepers have had similar
experiences of the injurious effects of feeding their birds on snuitty
wheat.

Experiments were also conducted with pigeons, to see the effect of feeding
with clean as compared with smutty wheat. They were kept under exactly
the same conditions for twenty-two weeks, the only difference being that the
one pair was regularly fed with clean wheat, while the other had a particu-
larly bad sample of smutty wheat. During that period seven eggs were laid
as the result of feeding with clean wheat, while the other, fed on smutty wheat,
only produced two eggs. Both pairs were in good plumage at the start, but
at the end one pair retained their lovely plumage, and were in good condition
and fat, while the other \)Vi\x were in poor condition, and the feathers all
standing up. The mouth inside was quite black froni the smutty wheat, and
there was a danger of disease being produced in time, such as cancer in the
throat. Experiments with a single pair of pigeons are too hmited in their
scope to aUow of final deductions being drawn. But it may be noted that
the pigeon fancier, from whom the birds were received and to whom they were

82 Stinking Smut or Bunt in W'licat.

returned, found that all his fifty pigeons were laying, with the exception of
the pair fed on smutty wheat, even although they were now being fed on
clean wheat.

Legislation Eelating to Plant Diseases.

A cargo of wheat was shipped to Victoria from Tasmania in which not only
every grain was densely coated with the spores of stinking smut, but the balls
containing millions of spores were freely scattered through it. Although
there was plenty of smutty wheat within our own borders, it was not deemed
advisable to admit it from a neighbouring State, so it was refused admission
under the Health Act as being unfit for use as human food in that condition.
But the importers, taking advantage of the absence of legislation on the
subject, labelled it as " Fowl's feed," and there was no law to prevent this.
Here was evidently a case where it was necessary to protect ourselves against
the introduction of grain which was proved to be injurious even to fowls, not
only as regards their general health, but seriously interfering with their
laying capacity. Accordingly a proclamation was issued under the authority
of the Governor in Council, whereby this particular disease was brought under
the Vegetation Diseases Act, and thus any further importations of that nature
were rigidly excluded.

This instance clearly shows the necessity for each State having the power
to protect itself, and prohibit the importation of diseased plants or parts of
plants, and not only so, but for the Commonwealth to have the power of
excluding any plants which might be the means of introducing disease into
Austraha. There are at present legal means in existence for accomphsh-
ing this end — the Vegetation Diseases Act in each State and the Quarantine
Act for the Commonwealth as a whole.

Summary — Answers to Questions.

This particular smut has been treated at some length, because it is the
form with which the farmer is most famihar, and it appeals to him as the type
of smuts in general. Therefore, it has been deemed advisable, by way of
summary, to conclude by clearly stating a number of questions which he
often, consciously or unconsciously, asks himself, and answering them as far
as observation and experiment will permit.

It is of fundamental importance for him to realize at the outset that the
smut plant is a fungus which develops from spores that are the equivalent of
seeds in other plants so far as the propagation of the species is concerned, and
that this plant grows as a parasite within the wheat plant until it reaches
the grain, and there produces its fruit or masses of spores (ball smut), similar
to those from which it started. In order to grow and develop properly, this
smut plant is dependent on surrounding conditions, just as much as the wheat
plant itself, and if we understood those conditions, it w^ould explain why the
spores sometimes germinate and sometimes do not, why the smut plant some-
times reaches maturity and forms its spores, and sometimes does not, just
as the seed-wheat may or may not germinate and the seeedhng may or may
not reach maturity.

It is also of prime importance to remember that the wheat is only infected
in the seedling stage, just as the young plant emerges from the seed beneath
the surface of the soil. Consequently, no infection can come through the
air, unless, indeed the grain germinates upon the surface of the ground, and
when it is properly planted, only the spores adhering to the seed or smut-
balls adjoining it can produce the disease. The farmer sometimes sees, or
fancies he sees, smut spores upon his fences, and when he has treated his wheat
after a fashion, and the smut still appears, he tells you that it was blown from

S////k///i^ SiiiNt or Ihtut in \\ heat. 83

the fences. But when the wheat plant is above ground, it is proof against
infection from bunt spores, so that there must be some other reason for the
failure of the treatment.

There are questions sometimes put by the farnier, however, which cannot
receive a definite answer, because his experience does not always take note of
the accompanying (;onditions, and because his love of paradox sometimes
overrides his experience. I am often asked by farmers, " Why is one part
of a paddock of wheat smutted and the other not, the seed in each case being
treated properh' and sown at the same time ? " It all depends here on what
is meant by proper treatment of the seed, as it is implied by the question that
the fault must be in the soil. But it is found by experiment that when the
seed is properly treated with bluestone solution and all the smut balls re-
moved, there is no smut in the crop, even although spores of the smut may be
in the soil from a previous crop or from self-sown wheat. Then the farmer
almost invariably upsets any answer you may give by adding that the next
season things were reversed, the clean part of the paddock being smutted and
the other not, even with the aforesaid proper treatment. Bearinor in mind
that there is no fungus disease known which can be more readily or more
absolutely prevented than this smut, we will now propound a few of the ques-
tions which arise in connexion with it.

1. Is the smut of loheat, oats, and barley the same ?

No, they are quite distinct, for the smut of wheat cannot infect oats or
barley, nor can the smut of oats or barley infect each other or the wheat.

2. Why does hunt sometimes appear in a paddock when the seed is supposed
■to he properly treated ?

This may be due to various causes, such as returning the treated grain
to bags which have not been disinfected and thus re-infecting the grain ; or
sowing the seed with a drill which has not been properly cleaned. It may
be, however, that the smut balls had not been skimmed off in the process of
pickling, and being crushed in the drill, the seed is infected.

3. Will the hunt spread from one paddock to another or from one plant to
■another, like the rust, ivhen the crop is groiving ?

Since infection occurs in the seedhng stage only, and the germ-tubes pene-
trate at the point where stooling occurs, and that is beneath the ground when
the grain is covered with earth, there is no possibility of the disease spread-
ing from one growing plant to another.

4. Should seed-wheat he used from a crop known to he hunted ?
Decidedly not, for there is a strong probability that the grain will not be

so plump as if perfectly healthy. A crop may have but comparatively few
actually smutted ears and yet give a much reduced yield and a poor quality
of wheat, because the smut was in the straw and affected the yield, although
it did not reach the ears before maturity of the grain.

5. Will spores lying on or in the ground from, last year's crop infect the next ?
This question of infection from the soil often crops up, but since it was

found by repeated experiments that properly treated grain, even although
grown on very smutty ground was free, it may be concluded that soil-infection
practically does not occur. I say practically, because there is a possibility
of stray infection taking place when there are numerous spores around the
germ end of the seed, where the young plant bursts through.

0. May hunt originate from self-sown ivheat ?

Self-sown wheat is rarely affected by bunt, still it may occur in some sea-
.sons. I have usually seen self-sown crops perfectly free, and have also found

84 St'nikiiig Smut or Bunt in Wheat.

a little, but not in sufficient quantity to injure the sale of the wheat. It is
generally stated that it is the heat of the sun in summer which kills the bunt
spores on self-sown wheat, but Farrer' showed that the rains and the dews
may also cause the spores to germinate, and having no germinating wheat
plants to penetrate, they soon perish. The heat of the sun and the dews at
night are likely to prevent the appearance of bunt in a self-sown crop, but if
the interval between the harvesting of the crop and the sowing of the next,
as well as between the ploughing of the land and the seeding is short, together
with cool and dry weather, there may be some danger of infection. In the
early days, many farmers used to expose on a cloth the wheat intended
for next year's seed. They found that the weather — dews, sunlight, and hot
dry winds — acting on the seed for a period of several weeks, killed the spores,
or rather, they discovered that it gave a comparatively clean crop, without
knowing the reason w^hy.

7. Why is there more hunt from the same seed in one paddoch than another ?
There may be various reasons for this. The land may be fallowed in the

one case and not in the other. It may also be more moist in one paddock
than another, and thus favour the germination of the spores at seeding time.
Actually wet soil would be inimical to germination. Whatever delays the
first growth of the wheat plant will be favorable to the increase of bunt.

8. Does the date of seeding influence the amount of bunt in the crop ?
Different conditions at seeding time are hkely to affect the result. Bolley^

carried out experiments to test this, sowing the same kind of seed on various
dates of April, May, and June. He found that the untreated seed yielded
the heaviest growth of smut in the earhest date, viz., April. " It was also
observed, in all tests, that the number of smutted heads stayed quite approxi-
mately in proportion to the total number of heads, the best crop of wheat pro-
ducing the best crop of smut.'' I carried out an experiment with flag smut
which shows that the date of sowing has a very decided influence. The seed
was purposely sown on 24th April and 16th July, or nearly three months be-
tween, on land that had borne a crop badly affected with flag smut the pre-
vious season. The first was sown when the ground was dry, but there seems
to have been no germination until the rain came, which germinated both the
seed and the smut, for there were up to 14 per cent, of diseased plants. The
later sown was about a month after the rain, and the ground was in excel-
lent order, but the spores had evidently germinated and perished in the in-
terval, for there was only about 1 per cent, of crop affected.

The weather and soil conditions enter so much into the result that a dry
or a moist seed bed at the time of sowing, or a spell of warmth, or of frost at
the time of germination, is bound to make a difference.

9. Why are some varieties more liable to hunt than others ?

As afterwards more fully discussed, this may be due to the fact that the
least liable variety germinates so rapidly that the smut plant is unable to
reach the growing point of the wheat, and so dies, or there may be some-
thing in the tissues of the variety unsuitable to the growth of the fungus, and
so the variety is said to have the hereditary or inherent quality of bunt re-
sistance.

10. When all the grains are equally inoculated ivith spores, tvhy are some
plants bunted and others not ?

It is quite a common occurrence for inoculated seed to be sown under
similar conditions, and yet a number of the plants escape infection. It is
not easy to answer the question, but a few considerations may help in this
direction. First of all, the young seedling must be at the right stage of

Stijikiiig Smut or Binii in }\']icat. 85

growth ill order that the germ-tube of the fungus may penetrate, and this
period is of very short duration. Next, the germ-tube must grow and reach
the growing point, or it would not be able to develop and produce the disease.
But a main reason for some plants being attacked and others not lies in the
fact that there are certain substances known as chemotactic substances in
the plant which favour the entrance of the germ-tube of the fungus and its
development inside. There are also substances which actually repel the
germ-tubes, and it is the presence or absence of these substances which deter-
mines whether an individual plant will be attacked or escape. The seed
from plants, however, which escaped infection in one season have been
sown the next and found to succumb.

11. Why are some iilants fartially hunted — only some of the ears being
affected and not all ?

It often happens that only the secondary or late ears are affected, the

others being clean, and this might arise from the fungus filaments at the

base of the plant only reaching the growing point of the slow and late

developing plants, while the others escaped. In other cases, where the
fully developed ears were bunted, the germ-tube had evidently reached the

growing point of the seedling, and the mycelium had kept pace with, the
growing plant.

12. Why are some ears only partially bunted ?

Under ordinary conditions the whole of the grains in an ear are affected,
but in certain seasons it is not unusual to find ears in which some of the
grains are bunted and others clean (Plate II., B). It may be that
one side of the ear has escaped, but usually the sound grains are interspersed
among the bunted. In one particular case the lower grains were all bunted,
then about the middle an occasional one was clean, and at the top both
smutted and sound occurred, the topmost grain, however, being diseased
(Plate II., C). The normal condition is that all the grains in an ear are
attacked, and when some escape it can only be owing to the spore-bearing
hyphae failinu; to reach these particular grains. It might be thought that
the grains -which escape the invasion of the fungu.s to form spores had some
resisting power, but when the clean grains in a partially bunted ear were
infected and sown they produced bunty plants, showing that there was
nothing in the grain itself to account for its escape.

13. Why are some grains of ivheat only partially bunted ?

This was a comparatively rare occurrence, only appearing in one ear
of the variety known as Cedar, grown at Dookie, and in one ear of Genoa,
grown at Burnley. In the latter ear there was only one grain partially
bunted, three entirely bunted, and all the rest free. In the partially bunted
grain the fungus had evidently exhausted itself in producing its spores only
on one side, and why the whole of the starch w^as not utiUzed, as is usually
the case, in the formation of spores, might be due to the slow growth of the
fungus, or its late entrance into the grain, as evidenced by the embryo having
had time to develop.

In fact, in all these cases, whether it is smutted and sound plants on the
same stool, or smutted and sound grains in the same ear, or even when the
grains are only partially smutted, the probable explanation is the same, that
by some accident of growth the fungus did not undergo its full development,
and was unable to reach all parts of the plant as usual.

86 Loose Smiif of Wheat.

CHAPTER XIII.

Loose Smut of Wheat.
{Ustilago tritici (Pers.) Jens.)

Of the three different species of smut known on the wheat plant in
Austraha this is one considered the least injurious, but it may be present to
a considerable extent and yet overlooked, because the stalks affected
are usually stunted. Like the oat smut it is produced in the ovaries, and
destroys the various parts of the flower, so much so that at harvest time
only the bare stalks of the ears remain after the spores have been blown
away. It is distinguished as loose smut from the powdery nature of the
spores, or flying smut, from the way in which it flies when blown, and the
ears are often spoken of as " snuffy ears" by the farmer (Plates III., VI.).
It differs from the much more common stinking smut or bunt in having no
objectionable odour, and the loose dusty mass of spores ripen and are blown
away while the wheat plant is in flower, instead of remaining and falling
what would otherwise be the grain with an evil-smelling compact mass of
spores, only broken up and scattered when being harvested or threshed.

When a stool is affected with loose smut, the stalks are generally of a
purplish tint, so that they can be readily picked out from among the general
crop. The same has been observed in the naked smut of barley, but it is not
particularly so in the case of loose smut of oats. This purpUsh colour is
natural to some wheats, such as Purple Straws, but it occurs in other varieties
as well when smutted. It is sometimes attributed to premature ripening,
the food materials in the straw not being completely converted into food for
the embryo. But I am incUned to think, as it occurs particularly in those
cases where flower infection takes place, that the young embryo is influenced
in some way by the fungus filaments present in the grain, and this is after-
wards shown in the peculiar colour of the straw.

Unlike the loose smut of oats, it is not uncommon to find stools with
both smutted and sound ears.

Germination.

Kellerman and Swingle"^ and Herzberg^ have described the germination
■of this species, and I have found it to germinate readily in water and in a
nutritive solution. After being kept for five months the spores germinated
at once. In water they germinated fairly well in 21 hours, and in three
days there were copious branchings. The main germ-tube was nearly always
slightly curved, although it might grow out quite straight. The numerous
branches might arise either beneath a septum or opposite to each other,
or sometimes a protuberance opposite to a septum grew out into two
branches alongside of each other, above and below the septum.

In a nutritive solution such as hay infusion, after eighteen hours a slender
germ-tube was formed, and it is generally characteristic of it that it curves
in a sickle-shaped fashion. After 24 hours branches are freely formed,
and the whole grows out into a much-branched mycelium without the
formation of any conidia. This pecuUar curvature of the branches is so
striking that when copious branching has taken place the whole resembles
a loosely wound coil of filaments.

Pl.ATK III.

G. H. Robinson, Phot.

LOOSE SMUT OF WHEAT

iUsti/cigo Trifici.)

Loose Smut of Wlicat. 87

Infection.

It has generally been taken for granted that the wheat snint, like the
oat smut, only infected the youn;^; seedling, and that the fully-developed
plant was immune. It was assumed that the spores fell to the ground,
retained their germinating power there, and that they caused infection the
next season in the young seedling. This view was rendered probable from
the fact that in some of the smuts, as will be shown in the case of flag smut,
the spores in the soil infected the young plant, so that treatment of the seed
did not prevent the appearance of the smut. Another view was that the
spores reached the flower and there remained on the seed which was formed
until the next sowing season, but, unfortunately for this view, the spores
only retain their germinating power for a few months. All these conflicting
views were finaUy disposed of when Brefeld and Hecke carried out their
conclusive experiments, and showed that infection took place through the
flower and not through the seedling. Previous to this, however, it had been
experimentally proved by Maddox, in Tasmania, that flower infectioai
occurs.

It is well known to every agriculturist that, when grain is dressed for
stinking smut or bunt, the dressings have no appreciable effect on loose
smut, and in my experiments with bluestone and formahn treatments I
have always found this to be the case. This fact can be easily explained
when it is remembered that the source of invasion is from within, and it is
not reached by the dressings usually employed. The mycelial filaments are
so intimately bound up with the living cells of the embryo that the destruction
of the one would involve the death of the other.

The only feasible measures for this disease at present seem to be to select
seed from crops free from the disease, and at a sufficient distance from any
diseased crop, so that air-borne spores could not be carried at least in any
great quantity. Also, as in the case of rust, to endeavour to breed a race
of wheat capable of resisting the disease. Quite recently the hot-water
treatment of the seed has been found effective, both in Loose smut of Wheat
and Naked smut of Barley.

88 Flag Smut of Wheat.

CHAPTER XIV.

Flag Smut of Wheat.
(Urocystis tritici. Koern.)

This smut, as the common name denotes, is most commonly found on the
leaf blades and leaf sheaths, but it may also occur on the stem and even on
the chaff ; but very rarely in the ovary, as it is seldom formed (Plates IV.,
VI.). Since it prevents the formation of the ear, this disease is very destruc-
tive in its effects, and in some seasons favorable to its development, such as
that of 1906, the harvest was considerably reduced by it in several districts
of Victoria. The serious nature of the disease and its widespread occurrence
demanded a thorough investigation, and, as far as time and opportunity
permitted, this has been done. Not only have Laboratory experiments been
conducted as to the germination of the spores and the mode of infection, but
field experiments are being carried out to determine how far special treat-
ment of the soil or a suitable rotation of crops can mitigate the disease, for
it has already been proved that the treatment of the seed so successful in the
case of stinking smut does not prevent the appearance of the disease. The
following account will give the present state of our knowledge with reference
to this disease and the measures that have been tried to keep it in check.

Although it has been known in Australia at least since 1868, it was only
in 1873 that Wolffs definitely determined the fungus causing it to be the
same as that on rye — Urocystis occulta — but as it is afterwards shown to be
biologically distinct from that spacies, the more striking differences between
the two may here be given.

Stem Smut of Rye and Flag Smut of Wheat Compared.

It is the characteristic of Urocystis on the wheat that it principally attacks
the leaf sheaths and the flag or blade, causing the latter to curl up and become
variously twisted and distorted, while the ear is very seldom formed (Plate
IV.). In the rye, on the other hand, the long grey streaks are formed on the
flag without causing much distortion, and even in observed cases, where the
whole plant was more or less affected, the lower and older leaves still retained
their normal shape, only splitting up towards their tips in lines parallel with
the streaks of the fungus and becoming frayed. But it is on the stems that
the streaks are principally noticeable, where they run together, more par-
ticularly at the base of the inflorescence, forming one dense mass of black
spores as the epidermis ruptures to expose them. Not only do the spores
escape on the outside of the stem, but the tissue is ruptured on the inside,
so that the cavity of the stem is more or less filled with the black spore-
powder. The ear is generally formed, but arrested in its development, only
becoming a sort of skeleton ear, and it usually droops, as the tissues of the
stem immediately beneath it are more or less destroyed by the fungus (Plates
V. and VI.). Hence the common names by which these diseases are generally
known — the flag smut of wheat, and the stem smut of rye.

Another feature of the flag smut of wheat is that all the stalks in a stool
are often affected, while in the rye, as far as my observation goes, this is
not the case. Thus, in one stool of rye there were eighteen healthy stalks
and five diseased, and the healthy ears all produced the normal grain. In
addition to these visible differences there are others which are microscopic,
and are duly noticed in the technical description of the fungus.

Plate I\'

FLAG SMUT OF WHEAT

(Urocysfis Tritici.)

Flag Smut of Wheat. 89

History.

The earliest record I can find of the prevalence of this disease in Australia
is contained in the Eeport of the South Australian Commission on Diseases
in Cereals in 18G8. There it is unfortunately referred to under the name of
" Black Kust," and even at that period it is spoken of as a disease with which
the farmers were familiar.

In New South Wales Dr. Cobb^ had referred to it in 1891 as behig a
serious plague, and remarked that " It is not rare for half the crop to be lost
through its ravages, and a loss of 10 per cent, is common." In 1892 I first
reported upon it at Kochester, in Victoria, where it had been prevalent for
some time, and had caused considerable loss.

On making mquiries as to its occurrence in Queensland, I am informed by
the Government Vegetable Pathologist there that only a single instance of it
had come under his notice in 1906 in a wheat crop grown in the heavy soil of
the Hodgson district. However, this does not imply that the disease was
confined to this one spot, for he significantly adds — " that it may have been
more prevalent than is indicated by this statement, since farmers are not in
the habit of calling attention to affections in their crops until these are
sufficiently pronounced to cause them some concern." In West Australia and
Tasmania there is no record of it so far.

This disease was at first only known on wheat in Australia, but now it
has been recorded on wheat in Japan in 1895 by Hori\ and on wheat in India
in 1906 by Sydow and Butler. ^

Origin.

Although this smut first appeared, as far as known, on wheat in Aus-
tralia, it does not necessarily follow that it originated here. It is always
difficult to trace the early beginnings of a particular disease, especially after
it has become rather widely distributed. It may have been introduced into
Australia through the medium of the seed or chaff of rye, and particularly
into South Australia where there are a number of German settlers. Mr.
Summers, of the Agricultural Department, Adelaide, has kindly made in-
quiries, and informs \wq that it has long been customary for settlers on the
hills to grow small plots of rye for early green feed. Once introduced, this
smut might adapt itself to the wheat plant, in the absence of its regular host-
plant — the rye — in sufficient abundance, and in such an extensive wheat-
growing country as South Australia its spread would be only a matter of
time. This, however, is only a surmise, as there is no record of smut on
the rye. It is hardly necessary to do more here than refer to the popular
notion that all smuts are practically the same, no matter on what plant they
occur, and that the flag smut of wheat may easily have Leen derived
Irom one of the others. It is quite possible that fag smut of
wheat may have been derived from rye smut, which also occurs,
although less frequently, on oats and barley, as it is closely allied
to it in structure and habit, but that is something very different from
saying that one smut may arise indiscriminately from another, even when
they are as distinct in their structure and life-history as stinking smut and
flag smut. There is another point worthy of consideration in regarding
this smut as having probably been derived from that of rye, and that is the
close affinity between the two host-plants. Eye is said to be more closely
related to wheat than any other cereal, although differing in several par-
ticulars, and the same rust has beeii found on it, viz., Puccinia gmminis,
Pers., which Eriksson found to produce aecidia on the Barberry, just as in
the case of wheat.

90

Flag Sinnt of Wlieat.
Symptoms and General Characters.

The first indications of the disease are seen on the leaves, where it forms
long grey streaks at first running parallel with the veins, and the black pow-
dery spores are set free by the rupture of the leaden-coloured epidermis.
The ruptured skin and long black streaks suggested a kind of rust to the farmer,
and so he called it " Black Rust." The ear is rarely formed, for what should

■^11

5]

1

1

Ij

.11

Fig. 11. Portion of Sheath
showing elongated black
imes caused by the fungus.

be the ear is generally only a twisted mass of diseased tissue as seen in
Plate IV. Occasionally the grain is formed, but it is extremely small and
shrivelled, and only in very exceptional oases have a few seemingly perfect
grains been found. On trying to germinate some of these they all died within
a few weeks.

The leaves generally become curled and twisted up, and the entire plant
often withers before it comes into ear. All the stalks in a stool may be af-
fected, which is usually the case, or only a portion of them. From the way
in which the affected plants die down in the midst of an otherwise perfectly
healthy crop the true cause of the shortage in the harvest is often not realized,
but the curled and twisted and streaky leaves of the earless plants are sure
evidence of this disease.

Effects.

In South Australia, where the disease has lon:^ been known in the wheat
crops, it is regarded as being in some seasons quite as injurious as the rust
itself. In Victoria as much as half the crop may be lost through it, and in
New South Wales Dr. Cobb has shoM^i it to be equally bad. It was observed
in Japan that all the wheat plants in an area of about one quarter of an acre
were entirely destroyed by it, but this was an exceptional case.

From the way in which some plants of a stool are affected — others not —
and from the fact that the disease generally prevents the formation of ears,
the farmer is often at a loss to know the true cause until his attention has
been specially called to it. He knows that his crop promised earlier in the

Pl.ATK \'

C. C. Brittlebank, Phot. ^ ^,„, ^,„^, , v^-^, ^^

A — STEM SMUT OF RYE. B GERMINATING SPORES OF UROCYSTI

OCCULTA. 0 GERMINATING SPORES OF UROCYSTIS TRITICI.

Flag Smut of Wl/cat.

91

year a much heavier yield, but the season is generally blamed for the shortage.
As will be shown afterwards, the twisted and curled leaves breaking up and
falling to the ground are the main sources of infection for next season, and
it can readily be understood that where wheat is grown year after year and no
nrecautions taken against this disease the effects are cumulative. This will
f^;CC0unt for the widespread and injurious effects of this disease in many
w^heat-growing districts.

Conditions favouring the Disease.

In the evidence given by farmers before the Commission on Cereal Diseases
in South Australia in 1868, various conditions and causes were assigned for
this disease. Early and self-sown crops were said to suffer most, and all
loose and richly-manured lands were supposed to be very liable. Ploughing-
in the straw was also said to encourage it, and early sowing, combined with a
spell of dry weather, was sure to bring the disease. Hence late sowing and
wet soil were recommended for its prevention, as it was generally understood
the later you sow the less likely you are to have it.

Among Victorian farmers it is also held that dry sowing is more subject
to the disease than wet, and one even went the length of saying that when
wheat was so^vn in very wet ground there was no flag smut. The lighter
ground is generally found to be the worst, and it is said that virgin ground,
in districts liable to this disease, generally bears two clean crops while the
third is attacked. This probably means that the disease has spread suffi-
ciently in the third crop to make it noticeable to the farmer as being in-
jurious.

The effect of early and late sowing, as well as of a dry and a comparatively
moist seed-bed on the appearance of flag smut, was put to the test in 1907.
Wheat was purposely sown on 24th April, when the ground was dry, on land
which had borne a crop of wheat badly flag-smutted the previous season.
There was practically no rain till June, when about an inch fell on the 20th.
This rain sr^ems to have germinated the seed-wheat and the fungus spores at
the same time, giving thereby a heavy proportion of diseased plants, up to
14 per cent. Alongside the early-sown plots a second sowing was made on
16th July, about a month after the rain. The ground at sowing time was in
excellent order, and it was a remarkable fact that at harvest the proportion
of diseased plants, taking all the late-sown together, averaged only 1 per
cent. The conclusion to be drawn from such a test is that early sowing in
a dry seed-bed following a dry summer is favorable to flag smut, since spores
and seed germinate together when the rain comes. On the other hand, if
the soil is moist and has been so for some weeks, most of the flag-smut spores
appear to have lost their effective power. These conclusions were supported
by results in the general crop on the farm, and these views so strongly confirm
those of the farmers that they practically amount to proof.

Conditions occurring in a 'particular Crop. — In the north and north-
eastern districts of Victoria the flag smut was very prevalent during 1906,
and was largely responsible, together with Take-all {Ophiobolus qraminis). for
the falling-off in the promised yield of many of the wheat crops. The con-
ditions under which it occurred were very closely followed, and the particulars
regardinjr it will be given for one district as a fair sample of the whole. In a
50-acre paddock near Wilby the Pur])le Straw Wheat was badly affected with
flag smut, so much so that what promised to be a 20 to 24-bushel crop only
turned out 8 bushels per acre. When inspected in the middle of November
the general impression was that of a fine crop, but for the numerous plants
scattered through it without ears, owing to flag smut. The conditions under
which the crop was grown and all the defects conducted with its cultivation

92

Flag Smut of Wheat.

were carefully recorded by tlie farmer, so that they are given here in con-
nexion with the appearance of the smut. The soil is a rich alluvial red loam,
with a sub-soil of clay at an average depth of 3 inches, and holding the
moisture well. On analysis it was found that lime was very deficient.

The land is level, low-lying, but not swampy by any means, and has
hitherto generally yielded splendid crops. The seed obtained from per-
fectly new land was carefully graded, dressed with bluestone at the rate of
4 lbs. to 50 gallons of water, and drilled in on 28th April. This was a very
dry month, only .25 inches of rain having fallen, although the preceding
month was very wet, having 5.55 inches. It was sown at the rate of 45 lbs.
per acre, and Florida superphosphate along with it at the rate of 75 lbs. per
acre. The Hag smut was first observed in this paddock in 1903, the year
after the dry season of 1902, and it was estimated that the loss due to it was
about 8 bushels per acre. The wheat was followed by Algerian oats in 1904,
with nitro-super. as manure. Then bare fallow during 1905, being ploughed
in August, disced in November, and scarified about the middle of April. The
ploughing was 3 to 4 inches deep. Up till about the beginning of October, 1906,
the crop looked perfectly healthy and fresh, and then signs of disease began
to appear. All through the crop the smutted plants were found generally
destitute of ears, alongside of strong vigorous plants just coming into ear.
To give an idea of the state of the crop, on 16th November a square yard of
the average crop was measured ofE and the wheat plants grown on it care-
fully pulled. There were 144 smutted straws producing no grain, and 62
clean straws with healthy ears, or 70 jier cent, affected with flag smut
(Plate VIZ.).

The average rainfall is about 18 inches, but this was much exceeded in
1906, and distributed as follows : —

January

February

March

April

May

June

Total

Inches.
.0
.16

5.55
.25

July

August

September . .
October

Inches.

.. 1.96

.. 2.28
.. 2.76
.. 1.87

2.74

November

.. 2.24

2.83

December

. . 25 . 27 inches.

.. 2.63

After the very definite results obtained from sowing on a dry and a wet seed-
bed, as regards the appearance of flag smut, it seemed rather contradictory
that the heavy rain preceding the sowing of the crop in 1906 should not have
tended to reduce the amount of smut rather than increase it. But, as the
farmer informed me that the cattle had the run of the whole paddock, both
before and after the heavy rain in March, it is evident how the paddock was
freshly infected with smut spores in the most suitable condition for germina-
tion. Laboratory experiments conducted in pots showed that with wheaten
hay affected with flag smut fed to horses, the resulting manure was capable
of infecting seed sown in the ground, and the farmer's cattle in this case were
fed on such diseased hay straw.

During 1908 the flag smut was not so bad in this particular locality. On
counting the smutted plants in a row 10 chains long it was found that there
were about two diseased straws to every square yard, and the yield was
13 bushels per acre. At Dookie and Longerenong there were evidences of it
being in the soil, but not widely distributed. At Dookie there were ten plots
of 1 acre each on which selected wheats were sown. The seed was treated
with bluestone, and the varieties were as follows : — Yandilla King, Marshall's
No. 3, Austrahan Talavera, College Purple Straw, Dart's Imperial, Jumbuck,

Plate VI.

■C. C. Brittlebank, Phot. Xat. Size.

A— FLAG SMUT. B,C— LOOSE SMUT OF WHEAT.

{Urocystis Tritici and Ustilago Tritici.)

Flag Siiinf of Wheat. 93

Jade, Comeback, Federation, and Bunyip. There was a little flag smut in
each plot, but it was confined to a few plants, and the yield in no case was
seriously affected.

At Longerenong there were also ten plots of selected wheats of 1 acre each.
The fla^ smut was not so much in evidence, but there was a little of it in the
four varieties — Australian Talavera, Dart's Imperial, Jade, and Federa-
tion.

Nature of Fungus causing Disease.

The flag smut of wheat belongs to the genus known as TJrocystis, because
the spores are provided with bladder-like appendages which in this case
completely envelop them, and thus act as a protective covering. The spores
are produced in long streaks on the flag, which soon curls up and withers, and
thus the smutted portions of the plant become mixed with the soil under
favorable conditions for the spores attacking the succeeding crop of w^heat.
As will be shown afterwards, they infect the plant at the seedling stage, or
when the young shoots are formed, and generally destroy the entire stool,
although sometimes a few ears may come to perfection beside those stalks
which have withered and died. The dissemination of the spores is well pro-
vided for in nature by mixing with the soil, and the withered shreds and patches
being blown about by the wind. Men and animals are also unconscious
agents, not only in transporting the smutted earth from one field to another,
but the agricultural implements may also carry it to otherwise clean fields.
It can also be readily distributed by means of chaff and horse or cattle drop-
pings. On examining 42 commercial samples of wheaten chaff from various
parts of the State, only one was found free from the spores of this smut, and
some of them were exceedingly bad with it. The disease was exceedingly bad
in two cases, very bad in seven, bad in ten, common in thirteen, slight in eight,
and very slight in one. Owing to the nature of the disease, the microscopical
examination of chaff samples furnishes a very accurate guide as to the pre-
sence or absence of the disease in any particular district.

Geographical Distribution.

Although an allied species of smut is well known on rye in both Europe
and America, the species on wheat is unknown there. It was first found in
Australia, and since then it has been met with in India and Japan, and that
is the extent of its distribution as known at present.

It is very widely distributed in South Australia, where wheat has
been so lon^ and so extensively grown, and in Victoria it is now
more or less prevalent in the northern areas. In New South Wales it is
probably more generally distributed than it is supposed to be, and in Queens-
land it has only been recently discovered.

Once this disease has gained a footing in a district there is every likelihood
of it spreading if not kept in check, for it can be carried about by the farm
implements and in the soil from diseased fields, and even in the manure from
horses and cattle fed on the diseased hay.

Germination.
The germination of this smut was specially studied, because the spores on
diseased straw in the soil, as well as those on the grain, were capable of in-
fecting the young seedling. It has been tested for a period extending over
three years, with spores of various ages, and at different seasons, in order to
determine the period of its greatest activity. The most luxuriant germination
was obtained about the beginning of April (autumn), and it is during the
autumn months that the wheat is generally sown. The. results of various
germination tests will now be given. Spores were taken from the wheat-plant

94 riag Sniut of Wheat.

immediately after maturity and placed directly in water on a slide,
but they did not germinate. With material, however, about a month old,
and kept seven days on soil, a small proportion of the spores germinated in
water after 24 hours. There was considerable variety, but it consisted gene-
rally of a promyceUum l-(3 celled, bearing at its apex 2-6 conidia. The pro-
mycelium reached a length of 66 /;< and a breadth of 3-5 \i. The conidia at
the apex were usually of unequal length, and they might either be unicellular
with protoplasmic contents throughout, or 2-3 celled and only partially filled
with dense protoplasm. At first they were close together, but gradually
diverged and stood out as finger-like processes. In some cases they grew out
into long slender filaments, reaching a length of 76 {.i.

Spores were finally taken from wheat of last season and floated on tap
water in a watch-glass in April. In about four days 40 per cent, had ger-
minated, showing various stages of development. The longer or shorter
promycelium was generally unicellular, but sometimes septate, and there
might be only one germinal tube from a cluster of spores or occasionally two,
and in one case each of the four spores in a ball germinated, producing conidia.
The conidia were generally 3-4, at first unicellular and cylindrical, but after-
wards becoming at least 1-2 septate. The earlier stages of germination show
the conidia close together and relatively short, then they diverge and grow
unequally. In some cases, one of the three or four may receive all the pro-
toplasm and grow out as an elongated slender curved filament, in others, all
the conidia may elongate and form variously curved and spreading filaments.
The behaviour of these conidia, even in water, indicates how their germ-tubes
may reach the host-plant, by growing stolon-like in the soil and penetrating
a suitable host, if they reach it at the proper stage (Plate V., C.)

The conidia are formed by the splitting up of the promycelium at the apex
into several branches, which are direct prolongations of it, like the fingers on
the palm of the hand, although not all in the same plane. The conidia do not
become detached, as a rule, although I have occasionally seen a few separate,
truncate at the base and producing a slender germ-tube at the apex.

The Flag smut of wheat is closely allied to the stem smut of rye, and the
germination of the latter is given here for comparison. Since Rye smut does
not occur in Australia, specimens were collected by P. Sydow in the neigh-
bourhood of Berlin on 21st July, 1907, and forwarded to me. The spores
were placed on a slide with tap water added on 13th September, or 54 days
after being gathered, and kept under a bell-jar. On the second day they
showed signs of germination, and on the third day they were germinating
freely and producing conidia at the apex of the germinal tube. The germinal
tube varied considerably in length, sometimes reaching 100 /< or more, and
at first was filled with protoplasmic contents. At the apex, a Avhorl of 2-6
cylindrical conidia were given off, generally 3-4. The germinal tube or pro-
mycelium is finally 4-5 septate and the contents in the lower portion of the
tube are transferred to the upper. The apical conidia are very variable in
size and shape. They are generally elongated, cylindrical, and either straight
or slightly curved. Sometimes they may become prolonged at the apex Avhile
still attached, into a tapering filament, reaching a length of 50 j.i or more.

The germination of stem smut of Rve has also been studied by Kuehn,
Wolff, and Brefeld.

According to Kuehn ^ the fertile spores readily germinate in water and
produce a longer or shorter unicellular germinal tube, which bears at its apex
a whorl, consisting of two to six cylindrical conidia. They sometimes unite
in pairs as in Tilletia, by means of a transverse bridge towards their upper
ends, and often germinate while still attached by putting forth a slender germ-
tube.

Plate VII.

G. H. Robinson, Pliot.

PRODUCE OF ONE SQUARE YARD
WITH FLAG SMUT.

Flai^ Sin lit of Wlicat. 95

Brefeld'' also germinated the spores iu water, and considers the whorl at
the apex of the promyceliiini as branches, since they never become detached.
In a nutritive sokition it was the same, only the whorl of branches grew out
and branched more freely. These cylindrical bodies at the apex of the pro-
mycelium behave Uke conidia, by putting forth a longer or shorter germ-tube,
and there is no evident reason why they should not be regarded as such.

The conidia are said to give off lateral germ-tubes, and Wolffs gives a
figure of one of the conidia producing a lateral germ-tube at its base. I have
examined thousands of germinating conidia, and while the germ-tubes grow-
ing out at the tip may curve laterally, or even backwards, none were produced
elsewhere than at the free end of the conidia.

Duration of Germinating Power.

These spores are well protected by their layer of sterile cells, and are well
adapted from their structure to retain their vitality for some time. How
long they retain their infective power, both in the soil and out of it, has not
yet been definitely settled. In considering measures for dealing with the
disease it is important to know how long this period lasts, for in a rotation of
crops which is the most likely means of coping with it, it is necessary to
know, if possible, how long the wheat crop has to be discontinued before it
will be safe to sow it again. Experiments are being conducted to settle this
point. A portion of a paddock, the soil of which is known to be badly infested
with the smut, has been fenced off, and wheat wall be continuously grown
in certain parts of it to see how long, under ordinary cultivation and conditions,
there is danger of infection, when every precaution is taken to prevent
re-infection. Already pot experiments have been carried out, in which it
was shown that seed dusted with spores from the crop immediately preceding
was infected, while seed dusted with spores from the crop previous to that
was not infected. But they are not sufficiently decisive and extensive
enough to allow definite conclusions to be drawn from them.

Mode of Infection.

Since the host-plant is generally destroyed by this smut before the
flowering stage is reached, infection through the flower is excluded, but
experiments were carried out to test if it occurred in the seedling stage or later
on. Seed wheat was obtained from a district in which this smut did not
occur, and planted in pots containing ordinary garden soil. There were
three pots — one used as a check in which the seed was uninfected, a second
in which the seed was dusted with plenty of spores, and a third in wliich
the spores were dusted over the plants when about 6 inches high.
The result was that the smut developed only where the seed was
dusted with spores, showing that it is probably the young seedling which
is attacked, and that there is no infection when the plant is above ground.
The experiment of dusting the seed with spores was re])eated with a similar
result, and when in another ex])eriment the young plants about 3 inches
high were also dusted with spores and kept moist by bein ;f covered with a
bell-jar, there was no infection. In another . experiment, affected straw
from the previous season's crop was added to the soil, and the clean grain
sown along with it. In about ten days after sowing the mycelium was
obtained in the young leaf, and in 40 days after sowing the first production
of new spores was observed. These conditions would be very similar to those
occurrhig in the field, only there the diseased straw would be more in patches
and not likely to be so generally distributed. In this experiment 18 plants
out of 35 were diseased, or a percentage of 51.

96

Flag Smut of W'Jieat.

The ordinary marketable chaff was also chosen, on which spores of the
smut had been found, and a small handful was added to the soil of a pot,
and the clean grain grown amongst it. Care was taken that there was no
grains among the chaif which might possibly be affected independently,
and in 40 days it was found that about 12 per cent, of the plants had become
infected.

Finally, manure was added to the soil from horses which had been fed
on diseased hay, and a small percentage of the plants was affected.

The following Table gives details of the experiments :—
Pot Experiments with Flag Smut, 1906-7.

Method of lulection.

No.
plants
germi-
nated.

No.
diseased

78

7

50

1

48

42

6

41

12

13.11.08

22.11.06

27.11.08
29.11.06

30.11.06
6.12.06

100

i Seed just germinated, then
I dusted with spores and

sown
50 Seed dusted, with spores

of 1908 crop

50

50

3.1.07 50

9.1.07 50

50

26.2.07 50

Seed dusted with spores
of 1905 crop

Chaff sample badly smut-
ted placed in soil and
grain sown

Smutted straw of 1908
crop put in pot,
22.11.08; grain sown,
30.11.03

Diseased hay fed to horse,
maniu-e put in pot and
grain sown

Diseassd straw of 1906
crop put in pot,
22.11.08 ; grain sown,
9.1.07

Diseased straw of 1906
crop kept in laboratory
till date of sowing and
then added to pot

Same as 5, manure in pot
since 6.12.06; sown,
9.1.07

Same as 5, but manure
left in box, only added
to pot when seed sown

Straw from 1906 crop kept
on soil till date of sow-
ing and then mixed with
soil in pot

35

19

18

Plants died very
rapidly, some pro-
bably diseased

All dead, 31.1.07 ;
probably more than
six diseased

All dead, 10.3.07

Plants began to die
rapidly about end
of March

All died very rapidly

Died very rapidly

1

Soon died ofi

Control plots in every case free from disease.

These experiments prove conclusively that not only does infection occur
in the seedling stage, or at least before the young plant has reached the
surface, and when the spores adhere to the grain, but also when the spores
are distributed through the soil on stubble or in the manure from horses fed
on diseased hay. The failure of the different treatments, such as formalin,
bluestone, and hot water, to prevent the occurrence of the smut, when the
seed thus disinfected was sown in the soil containing the spores, also proves

Flag Siiiiii of }Vhcat. 97

that infection may arise from the soil, as well as from spores sown with the
seed. By treating the seed dusted with spores with hot water, for instance,
the development of Fla^ smut has been prevented, and the artificially in-
fected grains p-oduced healthy plants, but then the seed was sown in soil free
from it. It was at first difficult to understand how the spores were able to
infect the young seedling when they were not in contact with the grain, or had
their germinating power destroyed by various re-agents. But, since the
spores are capable of germinating in the soil and producing their elongated
conidia, these conidia can in turn put forth a long tapering germ-tube, which
may eventually reach the young plantlet as it emerges from the seed, or the
young shoots formed beneath the surface.

Experiments in the infection of wheat with the spores of Urocystis tritici
have also been carried out by Hori^ in Japan. The spores were mixed with
the moistened grains before sowing, and as the result of two years' experi-
ments, while the uninfected seed produced clean plants, the infected seed pro-
duced both smutted and healthy plants in the ratio of 3 : 2. The conclusion
come to is as follows : — " These two years' experiments decidedly proved that
the smut is produced by the spores of Urocystis occulta \U . tritici] adhering to
the seed coat, whither they have been carried by careless thrashing. But it
may be possible, to some extent, that the matured spores, being easily scat-
tered by winds, could also reach the inner side of the flowers, and this may be
kept until thrashing time." The same investigator ^ also states that during
a period of five years he tried many experiments to test whether spores in the
soil iufsct the host. No details are given, only the general results. " After
thoroughly mixing the spores with the soil, seeds of the wheat were sown in
different intervals, partly on the same day, partly after five and ten days.
But the results were always negative, and no difference with the control plants
was noticed." In our experiments, as already shown, when diseased straw
was mixed with the soil in pots, there was invariably a crop of more or less
infected plants, while the control plants were clean. And not only so, but
in one case at least the infection was much more virulent from diseased straw
in the soil than from dusting the spores on the seed. It may be that suffi-
cient moisture is necessary to decompose the straw, or at least to scatter the
spor3s before they can produce their full effects, and in the pot experiments
the plants were always well and regularly watered.

The coiiclusions to be drawn from our experiments as regards infection
are — ■

1. Plants may be infected by coating the seed with spores.

2. Plants are liable to infection if seed is sown in soil containing

diseased straw of the previous crop.

3. Plants may become infected if sown on soil containing manure

from horses or cattle fed on diseased hay.

But a fresh light has been thrown on the infection of rye, and the same
probably applies to wheat. By the experiments of Hecke, already recorded
in Chapter VI., it was there shown that the spore has not only the one chance
of infecting the primary or terminal bud, but also the numerous chances of
infecting the lateral buds produced beneath the surface of the soil and growing
out into fresh stalks. There is not only seedling infection, but shoot in-
fection, and it is decidedly to the advantage of the parasite to multiply the
points of attack as much as possible. This will explain how in an infected
soil the seed may be quite free from spores and disinfected, while the young
shoots are infected by the spores already in the soil.

1858. E

98

Flag Smiit of VJhcat.

Infection and Treatment.

The mode of infection has to be understood before methods of treatment
can be inteUigently appHed, and this is particularly the case in dealing with
Flag smut, which may either arise from the soil or the seed. A series of
experiments were therefore carried out at Burnley Horticultural Gardens
this season (1909) in order to test the effects of various modes of infecting
the seed and of different kinds of treatment, both before and after infection.
There were ten small plots altogether, each sown with 25 grains of the
Federation variety of wheat, on 30th June, 1909, and three of these were used
as a check or control plants to compare with the others. Both spores and
diseased straw were used for purposes of infection. The wheat was
thoroughly damped and rolled in the spores, while the diseased straw was
chaffed up into small pieces and placed around the seed when planted. The
following table gives the relative results : —

Plot.

Grains

Grains

Mode of Infection and Treat nieiifc

•
Results.

sown.

germinated.

of Seed.

47

25

19

Clean

48

25

"

Dusted with spores

20 plants flag- smutted
= 83 per cent.

49

25

25

Dusted with spores and bhie-
stoned

Clean

50

25

18

Dusted with spores and diseased
straw added

15 plants flag-smutted
= 83 per cent.

51

25

21

Diseased straw only added

11 plants flag-smutted
= 52 per cent.

52

25

24

Bluestoned and diseased straw
added

7 plants flag-smutted
= 29 per cent.

53

25

25

Bhiestoned and spores added

Clean

54

25

25

.

Clean

55

25

24

.. ..

Clean

62

25

25 i

i
1

Treated with corrosive sublimate
and diseased straw added

1 1 plants flag-smutted
= 44 per cent.

Without laying too much stress on details, on account of the small size
of the plots, it is evident that infection may be produced either from spores
adhering to the seed or by means of diseased straw occurring in the soil where
the seed is sown. The addition of diseased straw to grain already dusted
with spores did not increase the virulence of infection.

Again, when the seed was infected with spores and afterwards treated
with bluestone, the germinating power of the spores was destroyed, as the
resulting plants were all clean, and when the grain was treated with bluestone
before the addition of the spores no infection occurred.

If, however, the grain was reated with bluestone and diseased straw
added, there was infection to the extent of 29 per cent. This could easily
be accounted for from the young shoots being attacked which had no pro-
tective coating of bluestone. Even when the grain was treated with
corrosive sublimate and diseased straw added there was . till a large
amount of infection.

Thus, the general results already obtained are corroborated, that if the
spores are only on the grain and no Flag smut in the soil, treatment with
bluestone is a preventive ; but if the diseased straw is already in the soil
from a previous crop, neither treatment of the seed with bluestone nor
corrosive sublimate is effective.

Flail Sniitt of Wheat. 99

nfectioii by diseased straw alone, as compared with spores on the (frain
was also tested in 1908. Two hundred grains of Federation were sown in four
divisions, the first having diseased straw added, and the other three had
the seed dusted with spores. The results were practically the same in each
case, as there were respectively 11, 13, 14, and 12 per cent, of Flag smut.

There is a discrepancy here Ix'tween the results obtained by experiments
in pots and in the field, lor in the pots the diseased straw produced much
more severe infection than the spores. This may be due to the fact that
the regular watering of the pots would have a tendency to remove the spores
adherent to the grain, while in the case of diseased straw it would tend to
be absorbed, and leave the spores undisturbed.

Infection of Wheat and Rye.

The Flag smut was first found on wheat in Australia and was determined
by Wolff in 187-3 as being the same as that so abundant on rye elsewhere, and
named Urocystis occulta. Then Koernicke in 1877 considered the form on
wheat to be a new species, basing his determmation on morphological charac-
ters alone, and named it Urocystis tritici. If the same species of smut occurred
on both plants, then they ought to be mutually infective, the spores from
rye infecting the wheat, and the spores from wheat infecting the rye, and
infection experiments alone could settle it.

The first experiment was carried out in pots containing ordinary garden
soil, and wheat and rye were cross-infected. There were six pots, and wheat
and rye were sown in them on 11th October, 1907. The ordinary seed of wheat
and rye was used as a check. Then seed wheat infected with the spores of
Flag smut from wheat collected on 28th September, and another lot with
those from rye collect3d on 21st July. Finally rye seed was infected with the
spores of Rye smut, and another portion with those from wheat.

The first outbreak was in the rye infected with Rye smut, -40 days after
sowing, and about a week afterwards the wheat infected with the Flag smut
of wheat showed the disease. The rye germinated about two days before the
wheat. Although several plants germinated, only one each of rye and wheat
showed distinct traces of the disease, and they were each infected with their
own particular smut. These pot experiments are very useful for giving in-
dications of what may happen in the field, and they often show what to avoid,
as well as what to follow, upon a large scale. Another experiment was planned,
conducted in my own garden, in which there were six plots, with 20 grains
each, but otherwise similar to the first ; the same smut of wheat and rye being
used for infection as before. They were sown on 23rd May, 11)08, and on the
28th October three wheat plants out of twenty were found badly infected
with Flag smut, the infection having been brought about bv the spores of
wheat Flag smut.

The plots were finally examined at the end of the year, but there was no
further development of disease. Although in these experiments there was
no disease in the rye, it was not owing to the spores being non-germinable,
for when placed on a slide in tap water and kept under a bell-jar thev ger-
minated freely in three days. On 12th August, 11)08, I duplicated the'plots,
in order to see what effect very late sowing might have upon the result. The
same smut of wheat and rye was used for infection. The late-sown rye grew
much bettor than the late-sown wheat, the latter in fact, turning out a com-
parative failure. In this experiment two plants of rye were found on (Hh
January, 1901). to be badly infected with their own smut, but none appeared
in the wheat plots, neither fr^m infection with Flag smut of wheat nor with
Ryfe smut.

K 2

Flao Smut of ]V//ca/.

A final experiment was undertaken at Burnley Horticultural Gardens, in
which 200 grains of Federation wheat were inoculated with the spores of Flag
smut derived from a crop of wheat grown in the north of Victoria the previous
season, and 200 grains of rye inoculated with the same smut. Clean seed of
both was sown alongside, the date being 28th June, 1908. The object of this
test was simply to see if wheat and rye could be infected by the same smut.
The results were taken on 29th December, and, while the wheat was diseased,
the rye was absolutely clean. There were 190 plants of wheat altogether,
21 of which were affected with Flag smut, and 169 clean, so that 11 per cent.
were diseased.

The diseased plants bore 85 ears, and on counting the ears of 21 healthy
plants of the same variety growing alongsida there w^ere 165, or nearly double
the number. The photograph of the two bundles of wheat, each representing
the produce of 21 plants, shows the difference in yield of the healthy and
diseased. A represents the growth of the healthy plants, and B of the
diseased, and the proportion of ears in A is nearly double that of B, indicating
that the number of ears on each plant affected with the Flag smut fungus
would be reduced, on an average, about one-half (Fig. 12.)

In Fig. 13 is shown the grain from the healthy and diseased plants, and the
yield from the former is fully three times that of the latter.

Fig. 12. — Clean and Flagsnuitted Wheat. Fig. 13. — Grain from healthy and diseased plants.

A. — 21 healthy plants ; B. — 21 diseased plants. A. — 21 healthy plants yielding about 8 oz. of

grain ; B. — 21 diseased plants yielding exactly

2i oz.

The main conclusion to be drawn from these experiments is, that the Flag
smut of wheat and rye are not mutually infective, and therefore the name
given to Flag smut of wheat by Koernicke in 1877, who received specimens
from R. Schomburgk in South Australia, should be retained, viz., Urocystis
tritici.

I'la^ Sii/n/ of W/icat. JOi

Prevkxtivio Measurf-is.

From the very nature of this disease it is difficult to cope with,
since it not only infects the young seedlin/ when the spores are attached
to the grain, but they may also be in the soil and carried by various
agencies from one paddock to another. Hence the soil would require to be
disinfected in order to render any treatment of the seed efficacious, and that
does not seem practicable at present. The effect of various manures has
been tried, including the application of ground quick-lime with the seed, and
two of lime to one of sulphur in combination, but the results were not promis-
ing. It is believed that a proper system of rotation will be one way of solving
the difficulty, and experiments are now being carried out in that direction.

There are, however, certain recommendations that may be made from our
present knowledge of the fungus, which will tend at least to reduce the ravages
of the disease —

1. Wheat after wheat should be avoided. — It is not only bad farming

practice to grow wheat after wheat, but it is a sure means of
perpetuating the fungus in the soil, since a fresh crop of the
fungus will be produced year after year if the conditions are
favorable. If we wish to starve out the fungus we must sow
some other crop on which it does not live, and it is well known
that oats are exempt from this particular smut.

2. Early fallow, with thorough ivorking.— The practice is now becoming

general of taking off only one wheat crop every three years.
The stubble is allowed to stand after harvest, and any grass
which springs up serves as pasture. Then, in the second
winter or spring after the wheat crop the land is fallowed, and
in the following autuinn the wheat is again sown. This is the
ordinary three years' rotation of grass, fallotv, and crop, and it
would be well occasionally to replace wheat with oats. The
thorough working of the land after rain through the spring and
summer is as important as the fallowing. By working the land
under these conditions air is admitted and moisture is conserved,
and this favours the germination of the spores, and, in the
absence of suitable plants to grow upon, they soon perish. On
the other hand, dry-worked land is specially favorable to the
disease, for this simply encourages the spread of the spores,
and preserves them in a dormant state, so that they are ready
to germinate along with the wheat plant.

3. Burning the sttibble. — This is not so commonly practised as it used

to be, since the value of the straw is now recognised. But
badly affected paddocks should be burnt off, in order to destroy
the spores of the fungus and check the spread of the disease,
and this must be done with reference to the object in view. If
the patches are too bare to burn where the Flag smut has been
then the harrows should be run over the stubble and the straw
will be drawn to such patclu^s and a profitable burn-off
rftVcted.

4. Selection, and breeding of resistant varieties. — Among the dif-

ferent varieties grown there may be some which more success-
fully resist the Flag smut than others when grown under
similar conditions, or there may be perfectly cliwn individual
plants among the diseased, and such might be selected for
further trial. Early varieties are said to be most susceptible.

I02 Flag^ Smut of Wheat.

and that is probably because they are more likely to be in-
fected by the spores at the proper time for germination. Late
wheats do not suit our conditions ; so that the selection should
be made from early maturing varieties.
Now that a certain measure o_' success has been gained in securing rust
and bunt-resisting wheats, similar methods may be adopted with regard to
Flag smut, and a smut-free late wheat, crossed with a susceptible early
variety, might lead to earUness combined with smut-resistance.

Summary.

Flag smut of wheat does not infect rye, and rye smut does not infect
wheat : so the form occurring on wheat is a distinct biological species, and is,
therefore, named Urocystis tritici, Koern.

Infection occurs in the seedling stage, also when the young shoots are
being formed, but not when the plant is above ground, and this infection may
arise either from spores adhering to the surface of the grain or from diseased
straw or fragments of flag in the soil. The spores may persist and retain
their vitality on wheaten chaff, and soil containing manure from horses and
cattle fed on diseased hay is capable of infecting the wheat plant.

The adherence of the smutted soil to the feet of men and animals may
cause it to be transported from one place to another, and agricultural imple-
ments also scatter and carry it.

Since this smut is only known to attack wheat, a change of crop will
evidently tend to starve it out ; but as it is not known how long the spores
retain their germinating power, the nature and extent of the rotation cannot
yet be -determined.

Loose Smut of UaU. 103

CHAPTER XV.

Loose Smut of Oats.
{Ustilaqo avenae (Pers.), Jens.)

This is a disease which is known wherever oats are cultivated, and caused
enormous losses before methods of prevention were discovered. The spores
are produced exclusively in the spikelets, and every part of the inflorescence
may be attacked, even the glumes and the awn (Plates VIII. and IX).
Th3 ovaries are filled with the spores, and the ovary wall remains as a delicate
wall around them. The diseased ears may be seen emerging from their en-
veloping leaf-sheaths, and when exposed the membrane is soon ruptured, and
the powdery spores are blown about by the wind, or washed away by the
rain, leaving only the bare axis of the inflorescence with the ragged remains
of the envelopes of the flowers. Generally, all the shoots of a plant and all
the grains of the ear are attacked, but in some cases the upper spikelets may
be free. In a partially-smutted ear, although the tip may be sound, the
base is always affected. In no case has the upper portion of the inflorescence
been found diseased, while the lower was sound, thus showing that infection
proceeds from below upwards, and that when the inflorescence began to
elougata, the smut had not reached the upp3rmost pohit of the panicle.

The spores are scattered before harvest- time, even before all the oat plants
have ceased flowering, and thus many of the smut spores are enclosed by the
scales, which gradually envelop the ripening grain, or they may fall on the
ground, where they will be ready to germinate under the same conditions
which favour the sprouting of the seed oats.

Germination.

This has been reported and illustrated in comparatively recent times
by Brefeld^ in 1883, by Kellerman and Swingle^ in 1890, and by Herz-
berg^ in 1895. Fresh material was gathered in November, 190(), and ger-
minated during the same month. When placed in water the spores begin to
germinate usually in six to eight hours, and it is more rapid in summer than
in winter, and with fresh spores rather than with those kept for several
months. A germinal tube or promycelium, occasionally two, is produced by
an out-growth of the endospore bursting through the exospore. and the
protoplasm contained in the spore passes into the tube. The rupture is
sometimes so pronounced that the projecting portions of the exospore are seen
along each side o' the base of the tube. Then it becomes divided by three to
four transverse partitions into equal compartments. From each of these com
par.ments, as a rule, little off-shoots or buds arise, generally near the septa,
and almost always one is produced at the apex. These buds constitute the
promycelial spores or conidia, and they become elongated and ovate, and
then fall away. The protoplasm in each segment is used up in the formation
of conidia, and if this is exhausted then no more are formed. But some-
times the protoplasm is not all used up, and the primary conidium, instead of
falling away, remains attached, and gives off at its free end a small bud.
which gradually becomes a secondary conidium, although it does not attain
the size of the parent.

The conidia »^hen detached undergo further changes in water. They may
either put forth a very narrow-pointed germ-tube, into which the proto-
plasmic contents pass, or two adjacent conidia may become connected by a
transverse branch, and tlie (■()nt;'nts pass from the one into the other. Then

104 Loose Smut of Oats.

the one with protoplasmic contents puts forth a germ-tube, or it may swell
out at the end and form another conidium. Thus fusion of the conidia
occurs where a number of them are aggregated together, and even more than
two may in this way be united.

This is the typical mode of development, the spore producin.g a germinal
tube or promycelium, from which conidia are budded off, but there ara various
departures from this. Under certain circumstances, according to Kuehn, the
promycelium may not develop conidia, but becomes an ordinary hypha and
penetrates the tissues of the host-plant by its pointed extremity. Again,
various fusions may take place by means of a tube from one segment to an-
other of the same promycelium, or the promycelia from different spores may
unite in a variety of ways by means of branches. Thus, the upper segment
may become connected with the lower segment of the same promycelium by
means of a curved tube, or two succeeding segments may become united by
w^hat Brefeld calls a buckle-joint or knee-joint. This is very common with
spores germinated in both water and nutritive solutions, and consists of the
unequal growth of one side of the promycelium at the level of a septum. As
this protuberance grows the promycelium itself becomes bent at an angle.

So far the behaviour of spores in water has been shown, but when placed
in a nutritive solution, such as hay infusion, there is a difference, as Brefeld
has pointed out. In the first place, they germinate cjuicker, as might be
anticipated, and the promycelia and conidia are larger. Then the various
fusions do not occur, but the most important difference is that the detached
conidia multiply themselves by budding after the manner of yeast and form
what are known as sprouting conidia. By keeping up a supply of the nutrient
fluid, Brefeld maintained this process of budding for more than a year, and,
■whenever this was exhausted, the budding ceased. The sprouting conidia
retain their vitality for about two months if kept moist, but when allowed to
dry there was no perraination after the sixth week. It becomes a question
of greal practical interest how long the various reproductive bodies retain their
germin ting power and under different conditions of moisture. While the
sprouting conidia only retained this power for about six weeks when kept
dry, Brefeld found that the spores germinated as freely at the end of two
years as when fresh. Another observer. Von Liebenberg^ germinated the
spores at the end of seven and a-half years, so that the time limit of germina-
tion may exceed that considerably.

Infection.

Infection by this smut has been specially studied by Brefeld,^ and a
description of it will give a clear idea as to how^ this happens in smuts of this
type. The spores are produced exclusively in the spikelets. It had already
been shown by Wolffs and Kuehn ^ that infection takes place only in the
seedlin ; stage, and Brefeld followed the mycelium in the growing plant until
it reached the ovary of the flower and formed its spores.

He brought about infection not directly with the spores, but with pure
cultures of the " yeast-spores," or sprouting conidia, derived from the budding
conidia grown in a nutritive solution. The young seedlings specially grown
were sprayed by means of an atomizer, with the " yeast-spores " mixed up in
water, and after a short time were planted out. Accordin ' to the stage of
growth at which the seedlings were infected, there was a definite percentage
affected with the disease. In the earliest stage of the seedling, while still in
the bud, 17 to 20 per cent, were diseased ; when about 1 cm. long, there were
7 to 10 per cent, diseased ; when 2 cm. long, and still enclosed in the sheathing
leaf, there were only 2 per cent, diseased ; while in older seedlings there was

PiATK VTir.

G. H. Robinson, I'hot.

LOOSE SMUT OF OAT

(Ustihiiio Avciuic.)

Loose Smut of Oats. 105

practicallv no infection — 0 to 1 per cent, diseased. These experiments con-
clusively prove that the younger the seedling the more susceptible it is to
infection.

The course of the infection was closely followed. The germ-tube pene-
trated the cuticle and grew obliquely through the cells. In the earliest stages
of the seedling the hyphae were numerous and distinct ; but as the tissues
lengthened and strengthened it was more difficult to trace the mycelium. In
the fully-formed plant the mycelium could only be detected in the tissue of
the nodes, in a more or less ruptured condition. The fungus is unable to
keep up with the rapid longitudinal growth of the plant, and its mycelium is
torn up into fragments, so that it becomes isolated and does not reach a
suitable spot for the production of spores. In the rapid elongation of the
internodes the oat therefore exercises a kind of check upon the parasite, but,
on the other hand, if the mycelium has once reached the growing point then
it is always present there, and finally produces its spores. It is evident,
therefore, that not every infection of the host-plant will necessarily attain to
the production of spores, but only in those cases where the fungus has been
able to reach the tissue of the growing point and continue to keep up with it
until the flowering stage. This supplies an explanation of the fact that in-
fection is much more successful in younger than in older seedlings, for in that
case the mycelium can much more easily reach the growing apex and remain
there than when the elongation of the internodes has taken place.

There are several conditions which render infection more or less certain,
and also affect its virulence. If the " yeast-conidia " used for spraying the
seedlings were cultivated in a solution obtained from fresh horse-dung, then
there might be as much as 46 per cent, of diseased plants, and if the spores
were cultivated for a number of generations the virulence decreased towards
the end. Spores that have wintered in the soil will, under suitable conditions,
germinate in the spring and form conidia : but whether these conidia will infect
young plants directly or sprout in a yeast-hke manner or die, will depend upon
the weather, particularly in regard to the heat and the moisture. Since our
sowing time is generally in the autumn and before the winter, the problem
we have to solve is what happens to the spores in the soil during the summer,
as, by the time winter is reached the spores have either germinated or have
missed infecting the seedling stage.

This smut produces its spores in the ovary of the flower ; then they are
dispersed by the wind or rain, and some of them fall on the soil or are carried
to healthy grain. Infection takes place when the seed begins to germinate,
and the young mycelium grows alon^ with the seedling, showing no external
signs of its presence until the flowers are produced, when it again forms its
spores in the ovary. Jensen^ proved that oat smut will not infect wheat or
barley, and that it is, therefore, biologically distinct from the smuts attacking
either of these cereals.

Between the loose smut of wheat and of oats there are marked differences
in the behaviour of the two. To begin with, the spores in the case of wheat
only retain their germinating power for a few months, while in oats thev have
been germinated at the end of seven years.

Then again, on germination the wheat loose smut only picduces a j^erm-
tube, which may be variously branched, while in oats not only are conidia
formed, but these in turn may give rise to sprouting, conidia.

These differences are correlated with the mode of infection. In wheat it
is flower infection, which must be done within a limited period, and after the
manner of a pollen-grain, and in oats it is seedling iiifection, which may be
prevented by treatment similar to that of stinking smut of wheat.

io6 Loose Stunt of Oats.

Treatment of Seed.

It is the seedling which is infected, and therefore the destruction of the
spores on the seed will prevent the disease • but from the nature of the smut
and the nature of the oat-grain itself, certain precautions must be taken in
the treatment of the seed. Unlike the stinking smut, the spores of the loose
smut are blown about by the wind before all the oat-plants have formed their
seed. The consequence is that spores find their way between the scales, v-hich
ultimately firmly clasp the seed, and any solutions which merely wr t the
outside will not reach these enclosed spores. Hence, any treatment to be
effectual must be sufficiently prolonged to allow the solution to reach the
spores beneath the hull of the oat. Treatment with hot water is, therefore,
very effective, and Close ^ has shown that sprinkling the seed with a 1 per cent,
solution of formalin entirely prevents the disease. The drawback to the use
of bluestone is that in order to reach the spores the seed must be dipped so
long as to injure it.

Platk IX.

C. C. Brittlebank, I'lu

LOOSE SMUT OF WILD OAT

iUsfilcioo Avciuic.)

A'akr/I Stniii of Barley. lO?

CHAPTEK XVI.

Naked Smut of Barley.
{Ustilago nuda (Jens.) Kell. and Sw.)
It was first pointed out by Jensen ^ that there are two distinct kinds of
smut on barley. The one completely destroys the ear, being at first enclosed
in a thin silvery-looking membrane, which soon breaks, and the povrdery
spores are scattered by the wind as soon as mature. This is known as the
Naked smut (Plate X.) in contradistinction to the other, which is called
Co/ered smut, because the compact mass of spores is enclosed in the unbroken
walls of the ovary, and remains intact for some time, even after harvest.
Jhe heads of barley with Naked smut resemble those of the wheat when
affected with loose smut, and this resemblance extends even to the mode of
infection, which in both cases occurs in the flowering stage.

Germination.

The germination of the spores of U. nuda and U. tritici is quite different
from that of U. avenae and U. hordei. In the two latter, as has been shown,
a promycelium is formed, giving rise to conidia, while in the two former a
typical mycelium arises. The spore on germination produces a separate
germinal tube, which continues to grow at the apex and forms lateral branches
which in turn branch again, and so a spreading mycelium is developed without
the formation of conidia. This important difference in the mode of germina-
tion led Herzberg^ to propose a new genus — Ustilagidium — for the reception
of these two species.

The germination of this species has been described by Kellerman and
Swingle,^ Brefeld,^ and Herzberg,^ among others. Spores obtained from
barley grown at Myrniong in 19()(i germinated freely in water and in a nutri-
tive solution in May, 1907. When grown in water a straight septate germ-
tube was first formed, the protoplasm of which was highly vacuolated, and
at first divided into four cells by transverse septa, then branches were spar-
ingly given off beneath the septa, sometimes at right angles, but generally at
an acute angle. The germ-tube sometimes became attenuated towards the
apex, and, although branches might be given off near the base, yet in no
instance was a spore met with producing two independent germinal tubes.

In a nutritive solution the branching was much more copious. Brefeld^
found that the filaments grew rapidly in various directions, and produced a
branching system like the mycelium of the higher fungi. The ends of the
filaments continued to grow in length, the contents passhig from behind
forward and formed very long tubes, which afterwards became septate.
Their branches were produced below the septa, and continued the process
until the central parts of the original mycelium were gradually drained of
their contents and carried to the circumference of the filaments.

The spores do not long retain their germinating power, as it was found not
to have lasted for a year, and this, along with the absence of conidia, would
seem to indicate that the spore must germinate as quickly and directly as
possible in order to penetrate the stigmas of the flowers that are in bloom.

Infection.
Brefeld' and Hecke^ have both recently shown that infection takes place
through the flower. It was found that when infection of seedlings was at-
tempted only negative results were obtained, and in every case sound healthy

jo8 Naked Sniiii of Barley.

plants were produced. But when floral infection was carried out the results
were the same as in the Loose smut of wheat, the mycelium remaining latent
in the seed and developing spores when the young ovaries of the host-plant
were formed.

From the nature of the flower of the barley and its being more firmly
enclosed in the glumes than is the case in wheat, it was not so easy to carry
out artificial infection and with the same certainty of results, but the experi-
ments showed that infection of the flower is the main, if not the only mode.
Hecke infected a number of the flowers of barley with smut spores when the
ovaries were still undeveloped, and the stigmas were quite fresh. Then, when
the fruit had normally ripened, and had been properly disinfected, it was
placed under sterile conditions in a germinating chamber, in order to examine
the embryo or young plant at different stages of development. If an
embryo is examined just beginning its development, even at this young stage
numerous hyphae are seen in a longitudinal section. In Fig. 6 a slightly
more advanced embryo is shown, and the mycelium is copiously developed
at the junction of the first leaf with the growing apex. {v). There can be no
doubt that this is the mycelium of the smut produced by flower infection,
since it is only found in infected seeds, and the subsequent infection of
the seed during germination is completely excluded by treatment with a
fungicide.

Pl.ATK X.

G. H. Robinson.

NAKED SMUT OF BARLEY

iUstildiio Niiiiii.)

Covered Smut of Barley. 109

CHAPTER XVII.

Covered Smut of Barley.

(Ustilaqo hordei (Pers.) Kell. and Sw.)

This smut is not so readily observed as the Naked smut, and therefore it
is sometimes said to be not so common, but as to relative prevalence it is
found to be the more common of the two. At Dookie, where a number of
varieties of barley are grown, it is much more general than the Naked smut,
and it is a very marked feature of the skinless barleys. This wider distri-
bution may ba due to the compactness of this smut, which gives it exactly
the same chance as Stinking smut of wheat, which is distributed in a whole-
sale manner in the form of smut-balls, and also to the fact that the floral
infection necessary in the Naked smut will be more uncertain (Plate XL).

The two species of smut found on cultivated barley {U. hordei and U.
nuda) have only comparatively recently been separated, and they were
formerly included under U. segetum. The differences between the two are
very marked, independent of what is indicated by the common name. In
the Naked smut the diseased ears are ultimately free from the leaf-sheath
and fully exposed, while in the Covered smut the ears are more or less en-
closed. The spores in the former are echinulate and powdery, and scattered
by the wind at the flowering period, while in the latter they are smooth,
slightly larger and compact in the mass, and remain intact till later harvest.
In the Naked smut the spores in the mass have a decided greenish tinge,
which is absent from the Covered smut. The germination, too, is very dis-
tinct. In the Naked smut only a germinal tube is formed, which elongates
and branches and becomes a regular septate mycelium, but in the Covered
smut conidia are produced. Lastly, the Naked smut has been proved to
infect the flower and not the seedling and the Covered smut infects the
seedling, as indicated by the certain treatment of the seed with bluestone
solution. The differences between the two may be briefly summarized : —

Covered Smut. Naked Smut.

Ears — More or less enclosed in leaf- Free from leaf-sheath.

sheath
Spores — Compact in mass, with Powdery, echinulate, and scattert(i

greenish tinge, smooth, and re- during flowering time.

maining intact till after harvest
Germination — Conidia produced . . No conidia.
Infection — Seedling . . . . Flower.

Germination,
The germination of the spores has been described by Kellerman and
Swingle,'^ Brefeld* and Herzberg. Affected barley was obtained from the
neighbourhood of Melbourne in November, 1906, and the spores germinated
freely in water in December. Also from Port Fairy in January, 11)07, and
when tested in June the spores readily germinated. The promycelium was
generally .'5-septate, only one being formed from each spore, according to
Herzberg, but I have found occasionally more than one. Promycelial spores
were produced both laterally and terminally, and were generally attached by a
slender sterigma. sometimes two being given off together, each with their
own sterigma. The promycelium was sometimes branched, the l)ranches
becoming septate and giving off conidia, and knee-joints were very common,

no Covered Sniint of Barley.

as in other species. Along with the single promycelium arising from the
spore, there might be given off at another part a large oval unicellular body
behaving like a conidium. The conidia which are elongated ellipsoid, readily
fall away when they multiply independently by budding.

In a hay infusion the promycelia branched copiously. Slender elongated
branches were given off, and sometimes on a level with the septum where a
knee-joint might have been, there were long jointed hyphae. Brefeld has
shown that the conidia multiply in a yeast-like manner and form sprouting
conidia, which continue to develop as long as nutritive material is supplied.

Infection.

This occurs, in all probability, in the seedling stage, as indicated by the
certain treatment of the seed and the formation of sprouting conidia in order
to tide the fungus over from one season to another. The spores are very
commonly found on samples of barley, so that they must reach the sound
grain during thrashing.

i

Pl\tk XI.

COVERED SMUT OF BARLEY

(Usfi/cigo Uordci.)

Head S?)!!it of Maize.

CHAPTER XVIII.

Head Smut of Maize.
{Sorosporium reilianum (Kuehn) McAlp.)

This is the only known smut of maize known at present in Australia, and
it is spreading in districts where maize is largely grown. It attacks the cobs
and tassels (Plates XII., XIII.), and is usually confined to them, but, in ex-
ceptional cases, a few patches of smut may appear on the upper leaves. The
smut is enclosed at first in a pinkish membrane, which soon ruptures in order
to allow the escape of the spores. It is distinguished from American Corn
smut [Ustilago zeae (Beckm.) Unger.) by not enlarging the ears and forming
large smut boils, by generally confining itself to the inflorescence and not
attacking the leaves and stems, and by the larger and more finely echinulat^
spores. It was probably introduced here from America, although not a
native of that country, for, as Clinton" says — " This is one of our most con-
spicuous but rather uncommon smuts. It has been introduced into this
country, probably from Europe." This species was first named from a speci-
men on Sorghum vulgare, Pers., sent by Dr. Reil from Egypt, and it was
afterwards found in Italy on the same host-plant. Its introduction into
America was probably by means of this host-plant, and then it spread to
maize, as it is found on both plants in the United States.

Germination.

The maize was taken from the field about the middle of March, just about
two months before maturity, and the smutted cobs were still contained within
their enveloping bracts. The smut spores were at once placed in tap water
on a microscopic slip and placed under a bell-jar, and in 17 hours several
had formed germinal tubes consisting of three to five cells, but usually four-
celled, although none had formed conidia. On germination there is an evident
rupture of the exospore, which is split into lobes where the germinal tube
protrudes. In 21 hours conidia were formed, both terminally and laterallv,
and the terminal conidia are the first to be formed. In one which was
specially observed the elongated terminal conidium was first formed, then one
laterally from the top of the second cell from the base, and a third just be-
ginning to be formed from the top of the basal cell on the opposite side. The
contents of the germinal tube are highly vacuolated when producing the
conidia, which are sometimes formed in pairs at the apex, and three lateral
conidia are sometimes produced together. Occasionally the germinal tube
may branch and the conidia may be borne direct or on elongated slender
sterigmata. The conidia bud in a yeast-like manner, and these sprouting
conidia again give rise to secondary conidia.

Brefeld^ germinated the spores in a nutritive solution after being kept
for about eight years, and the sprouting conidia retain their germinating
power for several months, if kept drv.

Infection.

The mode of infection has not been determined, hut, since according to
Freemai and Umberger,' the formalin and hot-water treatment of the seed
are ineffective, the probabilities are that it does not occur through the voung
seedling, as in the case of Bunt, but may ho in the grain itself. These authors
state that the only recoininiMulation that can he made at present is to ohtaiu

112 ' Head Simd of Maize.

seed from districts where it is not known to occur. It is interesting to note
that the " Milo " variety of Sorghum has not hitherto been attacked and
appears to be immune.

American Corn Smut.
[Ustilago zeae (Beckm.) Unger.)

This smut, which occurs on all parts of the maize plant, has not been
found in Australia, although there is another species met with which is con-
fined to the ear, but since this species represents one of the typical modes of
infection, it will be briefly discussed.

The spores have not been found to germinate in water, but very easily in
a nutritive solution or on manured soil, producing the fusiform conidia.
These do not directly infect the plant, but give rise to sprouting conidia, and
very often they also put forth fungus filaments which reach the surface of
the culture drop, and there develop quite a number of sprouting conidia in
the air, similar to those produced in the fluid. These air conidia are easily
scattered by the wind, and play an important part in spreading infection.

Since this smut occurs on all young and growing parts, most rarely on the
roots and most frequently on the stems, leaves, cobs, and tassels, it is evident
that we have not to do with a general infection of the plant, but
with a local infection, each smut-boil representing a single infec-
tion. Brefeld* carried out a systematic series of infection experiments,
infecting the various parts of the plant. He started with the young
seedling, as in the case of the oats, but produced only a few diseased spots,
and always in the neighbourhood of the collar or at the junction of root and
stem, while all the other parts of the plant were unaffected. Then, in other
parts he infected the leaves and the stem, the male and female flowers, and
even the young ovaries of individual flowers, always with the same result.
The infection was exclusively local, and it was only young and tender tissues
which the germinating tube could penetrate. When the fungus filaments
had reached maturity they broke up into spores in the usual way, with gela-
tinization of the membranes, and it was observed that from the period of
infection until the spores were produced and scattered was about three
weeks.

I' LAI I. \11.

G. H. Robinson, Phm. ^ Nat. Size.

MAIZE COB WITH HEAD SMUT

(Sorospoi-iiiiii Rciliciinim.^

I'l.MK Xlll.

MAIZE TASSEL WITH HEAD SMUT

{Sorosporiiim h'ciliiin iim.)

General Trcaimcnt for Smul',. T13

CHAPTER XIX.

General Treatment for Smuts.

It is only when the true nature and the life-history of the smuts are pro-
perly understood that intelligent measures can be devised for effectually
coping with them, and the treatment will depend on the individual history of
each particular species. But the general rule may be laid down that in every
case clean seed should be used for sowing, for, as Bessey^ emphatically points
out, " It has been demonstrated over and over again that perfectly clean
seed and clean ground will produce a clean crop. It is with smuts as with
weeds of all sorts, if we have seeds we shall have weeds growing up as a
result, but if we have no seeds there will be no weeds. So with smut. Clean
seed upon a clean field will result in a clean crop."

Since it has been clearly shown that the smuts are reproduced from spores,
it is evident that if the spores can be destroyed or their germination pre-
vented, the smut itself will not appear, and it is on this principle that the
direct treatment for smut is based. But this method is only practicable
when the spores are so located that they can be easily reached as in the seed
grain, and in other cases only indirect measures can be employed. In the buiit
or stinking smut of wheat for instance, where the spores adhere to the
grain and infection occurs in the young seedling, all that is necessary is to
treat the grain with some substance which, while harmle-ss to the grain, will
destroy or prevent the germination of the spores.

Quite a number of substances have been used for this purpos>, including
corrosive sublimate, and found more or less effectual, but there are only two
which are generally used by farmers in Australia on account of their ease of
application and comparative cheapness, and that is, first, a solution of sul-
phate of copper or bluestone, and, second, formalin. All methods of seed
treatment known depend for their success to a large extent on the precau-
tions taken to prevent re-infection after dipping. Careless farmers put the
l)ickled grain into smut-infested bags or omit to clean the drill. If the seed-
box contains bunt balls or spores of other siuuts the treated seed will be, in
part at least, affected.

1 adopt a very simple method in the treatment of the seed- wheat, the
solution being contained in a wooden cask. The mouth of the bag which
is immersed in the solution, and that is to contain the seed, is slightly folded
over the edge of the cask and fastened there with a bag ring or hoop. The
seed is then gently poured into the sack, so that all the unbroken smut-balls
as well as wild oats and light seeds float on the surface and may be skimmed
off. In the case of bluestone solution the time of immersion should never
exerted one minute, as every grain is sure to be thoroughly wetted in that
\\\w\ .V supply of the same strength of bluestone solution is kept ready.
in ()r(l(M' to replenish the solution in the cask used for pic^kling. as required.

Bl.UKsrONK TUKAI'MKNT.

This is the one most commonly used here, and consists in making a solution
at the rate of 1 11). of bluestone to 5 gallons of water, or a 2 per cent, solution.
The seed is then placed in sacks and immersed in this solution until every
individual grain is wetted, and that only takes about a minute, and should
not exceed it. The constant shaking and stirring while being immersed
sliould bring all bunt balls to the surface, and these should be skimmed off.
The bag is then allowed to drain, and when dry the seed is ready for sowing.

iJ-1 General Trcatmcitt for Smuti,.

It is to be noted that the solution of bluestone is always of the same
strength as when first prepared, no matter how much of it has been used up
in dipping or in coating the grain. It becomes, of course, reduced in quantity,
and if exposed to the hot sun for several days, it would become more concen-
trated, but under ordinary circumstances the standard solution remains
constant in its proportion of bluestone to water.

If more convenient the seed may be pickled on the barn floor by sprinkling
the solution over it and thoroughly turning over the seed until all the grains
are completely wetted.

The corrosive action of the bluestone on the grain is generally very in-
jurious, and this can be largely prevented by the use of lime. It may be
pointed out that the copper sulphate or bluestone is gradually decomposed
by the lime, and acting chemically upon the soil renders certain substances
available as plant food. The treated seed, while wet, may be sprinkled with
air-slaked lime, but this interferes with its ready passage through the seed drill.
As an alternative the treated seed may be transferred to lime-water. On?
pound of freshly-slaked lime in 8 gallons of water gives full strength after
standing one hour, and traces of alum or sulphate of magnesia increase the
solubility of the lime slightly. The grain is stirred in this solution for a few
minutes, then dried preparatory to sowing. An objection to the lime-water
treatment is that the film of bluestone coating the seed is removed, and the
grain is afterwards easily re-infected by stray spores or broken bunt-balls in
the drill, unless due precautions have been taken.

Formalin Treatment.*

Formalin is the trade name given to a solution in water of a colourless
pungent gas known as formaldehyde, and the solution ordinarily used con-
tains .36 to 4:0 per cent, of the gas. One pound of formalin (16 ozs. avoir-
dupois) of the above strength is added to 40 gallons of water, and the seed is
i;nmers:!d in this solution for five minutes, shaking and moving it about
sufficiently to insure the wetting of all the grains. The bunt-balls are also
skimmed off as before, or the seed may be pickled on the floor by sprinkling
the solution over it at the rate of about 1 gallon to each bushel of grain. It
is well turned over while being sprinkled so as to get thoroughly wet, and
after being in a pile for two hours, it is ready to be planted in the case of
wheat, but in the case of oats and barley the damp grain may be allowed
to remain over night, in order to allow the formalin to penetrate the husk.
Wheat treated with formalin should be sown within 24 hours of treatment
in a seed bed moist enough to insure germination in order to obtain the best
results.

In a farmers' Press Bulletin issued in 1*,K)4 by the North Dakota Agricul-
tural Experiment Station relating to " The effect of evaporation upon solu-
tions of formaldehyde " such questions are asked as — Must the solution
which is made up for treating seed grain all be used up the same day ? Will
it grow weaker from standing \ Must a new lot of solution be made up each
day % Does the standard formalin lose strength if left uncorked %

The results of special tests showed that solutions of formaldehyde grow
stronger by evaporation, the water being given off faster than the gas. A
solution, therefore, which has stood open for a number of days is fully as
strong as when first made. While this is so, and the water and methyl alcohol
or wood spirit of the solution evaporate first, leaving the formaldehyde, which

* By the new industry of wood distillation, Messrs. Cuming, Smith, and Co. are producing formalin at
Warbuiton, and can provide 1-lb. bottles of 40 per cent, strength (same as Schering's) at Is. 6d. |ier
lb., packages free.

General Treatment for Smuts. 115

is stronger, behind, yet this also eventually evaporates, especially in warm
places. It is therefora advisable to keep the solution corked, if only to keep
the strength even.

Whether bluestone or formalin be used, the treated seed should never be
put into old bags unless they have first been dipped in the pickle.

Another precaution to be taken is to skim of? any smut-balls as well as
imperfect seeds. Of course, the wheat used for seed should be free from
smut-balls, but farmers are not always as careful as they ought to be in the
selection of seed-wheat. It is well known that while sound grain sinks in
water the bunt-balls float. One hundred grains of each were taken of Federa-
tion wheat, and while the sound wheat weighed <)7| grains, the bunty wheat
was only 24^ grains, or a little more than one-third the weight. The bunt-
balls may at first be carried down with the sound grains and remain attached
by means of air bubbles, but by constant shaking and stirring they come to
the top. In practice it is found that all the bunt-balls do not rise to the sur-
face, but the probabilities are that these are cracked, and so their germinating
power will be destroyed by the solution.

Effect of Formalin and Bluestone on the Germination of
Seed Wheat.
While either of these substances has given satisfactory results in the treat-
ment of bunt or ball smut, as it is often called by farmers, there is considerable
difference of opinion as to their effects upon the grain, both as regards ger-
mination and the subsequent growth of the plant. Extensive experiments
were conducted to answer this question, extending over five successive
seasons, and in the last year, when 20 acres were treated, the seed was sown
with a drill, bluestone being used at the rate of 1 lb. to 5 gallons of water,
and formalin at a strength of 1 lb. in 40 gallons of water. The result of the
treatment was very conclusive, and was stated as follows : — " While the
untreated plot contained at least 50 per cent, of smut, careful search over the
treated plots failed to reveal a single smutty head. Thus both solutions were
equally successful in destroying the bunt, but it was noticeable that the plot
treated with formalin looked much better and w^as a little further advanced."

A special test was made with 1,000 grains each of the same variety
of wheat sown at the same time and under similar conditions, the formalin
and bluestone treatment being compared as before, with the following
results : —

Untreated . . . . . . . . 884 grains germinated

Formalin, 1 lb. hi 40 gallons of water . . 740 ,, ,,

Bluestone, 1 lb. in 5 gallons of water . . 606 ,, „

The bluestone treatment affected the germination much more injuriously
than the formalin, and the plants afterwards did not look so healthy.

In all these experiments, however, the grain was sown not more than a
day or two after treatment, but it sometimes happens in the ordinarv course
of farming that sowing is delayed after treatment owing to the state of the
weather, or grain is sown in some cases in anticipation of rain, which does
not come, and the question arises — how does the treated grain compare with
the untreated under such conditions, when germination does occur ?
Accordingly, tests were made with varying strengths of formalin and varying
periods of sowing after treatment. It may be noted here that formalin
exercises a hardening effect upon the grain, which soon becomes bone dry,
so that the young germ does not so readily force its way through the skin,
while in the case of bluestone there is a fine film of the substance left on the
seed after treatment, and this will likely have a preservative and protective
effect upon the grain.

i I 6 General Treat )}ieut for Simtts.

When seed was treated with varying strengths of formalin and sown after
24 hours, the results of germination were as follows : —

Untreated . . . . . . . . 84 per cent.

Formalin, 1 lb. in 40 gallons . . . . 77 ,,

2 lbs. in 40 gallons . . . . 62 ,,

3 lbs. in 40 gallons . . . . 41 ,,

The increased strength of formalin above the normal 1 in 40 decreases
the amount of germination in a progressive degree.

But when the treated seed was sown after being kept for varying periods
of time our experiments showed, on the whole, that wheat treated with 1 lb.
in 40 gallons of water loses its power of germination to some extent at least,
after being kept a few days ; that this effect is cumulative for a time at least,
but it gradually disappears again after, say, four or five weeks.

The late Mr. Farrer also arrived at practically the same conclusion from
his experiments in New South Wales, and he summed up as follows : —

" (1) Formalin does not exercise an injurious effect upon the vitality
of seed grain if it be treated just prior to planting, and the con-
ditions at planting time are favorable for its germination.
(2) It is undesirable (and previous experiments at Lambrigg prove
unnecessary) to treat seed-wheat with a stronger solution of
formalin than that made by mixing 1 lb. of formalin with 40 gal-
lons (400 lbs.) of water."

It was not considered necessary to carry out the same series of exhaustive
experiments with bluestone as with formalin, but grain treated at the rate of
1 lb. in 5 gallons of water actually germinated better, instead of deteriorating,
after being kept for nine and fifteen days respectively.

Formalin is a well-known antiseptic, disinfectant, and preservative, and
is extensively and most satisfactorily used for the treatment of Stinking smut
in both the United States and Canada. From its less corrosive action on
the seed and the higher percentage of germination which it yields it has
certain advantages over bluestone, and if the seed is sown within 24 hours
of treatment in a soil sufficiently moist to insure germination the freedom of
the resulting crop from bunt is assured.

Hot Water Treatment.

In addition to various chemical substances, heat has also been employed
for the destruction of the spores. At first a dry heat was used for the purpose,
but what we now know of the resistance of spores to such a heat makes the
success of such a method highly improbable. But the hot water treatment
of the seed introduced by Jensen in 1888 has proved highly successful. It
is a method, however, which is never likely to become popular with our
farmers, since without special conveniences it is rather troublesome, and as
the methods already given are simpler and equally effective they are
generally preferred. The process consists in immersing the seed in
hot water at a temperature ranging between 55° to 57° C. (132 to
135° F.), and then plunging it into cold water, and it is the regulation
of the temperature which makes the demands on the care and atten-
tion of the farmer. Where a steam jet is available it is easy to regulate
the temperature. I will just describe the method, as carried out by myself :
Three barrels were used — one with cold water, another with the water heated
to about 44° C. (111° F.), and a third in which the temperature was main-
tained at 55-57° C. The grain was placed in a wire mesh basket made for
the purpose, and then dipped into the barrel with water at a temperature of

Cici/crat Trcaiiiiciit I or Smuts. 117

about 44° C. in order to heat it ; then it was transferred to the higher tem-
perature, where it was plunged up and down and shaken from side to side for
five minutes, so as to bring every grain into contact with the hot water. Any
smut-balls floating on the surface were carefully skimmed off. As it is im-
portant to keep the water from falling below 55° C, since less heat would not
be so likely to prevent the germination of the smut spores, and from rising
above 57° C, since it might injure the grain, I attended to the time necessary
for dipping and the thermometer, while another kept continually agitating
the grain. At the end of five minutes it was immersed in cold water and
then spread out on a clean floor to dry. The grain thus treated germinated
well and came away quickly, as the heat and moisture combined seemed to
stimulate it.

******
It has already been pointed out that while these various methods of treat-
ment afford temporary relief, the only permanent means of overcoming the
disease is to secure by breeding or otherwise a race which will be " immune "
to the attacks of the parasite. In the case of those smuts which infect the
host-plant through the flower, this is seemingly the only means at present
known of meeting the difficulty.

III.

LTFE-HJSTORrES OF VARIOUS GRASS SjMUTS.

Explanation of Plates

PLATE XTV.

A. — Healthy and diseased plants (one-tenth natural size).
B. — Health}' Ear or Panicle (reduced 2| times).
C. — Smutted Ear (reduced 2^ times).
D. — Sound grains ( x 3).
E. — Smutted grains ( x 3).

Pr,ATK XIV.

C. C. Hrittlcbaiik. I'h. i. I'. I . x ;. \. i;. C. K. ,hi.-. ,

A -AMBER CANE, SOUND AND SMUTTED. B SOUND HEAD.

C — SMUTTED HEAD. D— SOUND GRAINS. E SMUTTED GRAINS.

Lije Histories of Various Grass Simits. 121

CHAPTER XX.

Life-Histories of various Grass Smuts.

Only a few of the smuts occurring on various grasses of economic im-
portance will be noticed here, in which the mode of germination of the spores
and infection are known, and a more or less detailed account given of their
life-history. There are still a number awaiting further investigation, and
among our native grasses practically nothing has been done in the way of
preventing the spread of the smuts attacking them, which are sometimes
very destructive.

1. Grain Smut of Sorghum.

(Cintracfia sorghi-vulgaris (Tul.) Clint.)

There are two kinds of smut which occur on sorghum, the Grain smut, so
called because it confines itself chiefly to the individual grains, and the Head
smut, because it converts the whole head, just as it emerges from the upper
leaf into one large smutty mass. The Head smut of maize has already been
described, and the same fungus which causes it is also found on sorghum, but
not hitherto in Australia. It is the Grain smut which has been found here
on broom corn, amber cane, and sugar sorghum, and wherever it occurred
was very destructive. The cultivated sorghums are placed under Andro-
pogon sorghum, Brot., by Hackel, of which there are a number of varieties,
such as broom corn, amber cane, and sugar sorghum, the latter variety being
usually called Sorghum saccharatum, Pers.

Effects and Losses.

The effects of this smut upon the host-plant is very noticeable in pre-
venting the formation of seed. The seed is replaced by an enlarged body of
a dirty white or brownish colour, splitting irregularly at the top and exposing
a mass of dark-brown spores. In a crop of sugar sorghum examined in
March there were about 14 per cent, of the plants affected (1 in every 7),
while amber cane grown in the same field was only slightly affected.

The smutted ears or panicles are readily recognised in the field, from the
grains being replaced by a horn-like projection of a dirty white or brownish
colour. The individual smut bodies are not only considerably elongated, but
usually somewhat stouter than the normal healthy grains (Plate XIV.). The
ear may be attacked by the smut even while still green, and a portion of it
only in flower. Occasionally there may be a few clean grains on an other-
wise smutty ear. In the case of broom corn the loss is not so serious as where
the sorghum is raised for seed. Nevertheless, the brush of an infected plant
is of an inferior grade, and almost worthless. In healthy broom corn the
rays are uniform in thickness and length, and all spring from nearly the same
point, but in infected plants the rays are of unequal length, and arise from
an elongated and thickened central axis. The number of large rays, too, are
always less, so that the commercial value of the brush is lessened. One
prominent grower stated that most of the heads that have smut on them are
of no account.

T22 Life Histories of Various Grass Smuts.

The monetary loss from this smut is considerable, since the crop is so
valuable. Amber cane, when it is grown for seed, may sometimes be worth
£25 to £30 per acre, so that the loss is serious enough to render preventive
treatment desirable.

Distribution.

It occurs in Southern Europe, Asia, Africa, and America, as well as in
Australia. It was brought to the United States through imported seed, and,
no doubt, it was also introduced here in the same way. I have examined
seed of amber cane and sugar sorghum obtained from the best seedsmen, and
in every instance the spores of the smut were present, even although it ap-
peared to be quite clean, as from the mode of hand-picking the seed and
winnowing, none of the smut bodies were found. Is there any wonder, then,
that the smut, from being a negligible quantity, should be gradually on the
increase, when the spores are regularly sown with the seed, without any
treatment ?

Germination.

The spores germinate readily in water. Fresh spores were taken in Feb-
ruary, and in twelve hours there was vigorous germination. They retain
their germinating power for a number of years, and De Bary states that
Liebenberg germinated them after being in the herbarium for six and a-half
years.

The germination has been described by Brefeld, Clinton, Norton, and
others. The spore puts forth a promycelium, which divides into three or
four cells by transverse septa. Quite a feature of the promycelium is the
formation of the so-called buckle or knee-joints. A short out-growth arises
at the end of one or more cells, and this bends over and unites with the ad-
joining end of the next cell. From these protuberances or from the end of
the promycelium slender filaments of varying length grow out, called by
Clinton infection threads, on account of their supposed function. Conidia
are generally produced either from the tip of the promycelium or at the apex
of the cells and readily fall away from their connexion.

In a nutrient solution the germination was more luxuriant and the for-
mation of conidia was increased.

Infection.

This takes place in the seedling stage, and may either occur by means of
infection threads from the promycelium itself or from conidia. These threads
must reach the growing tip of the plant in order to infect successfully, and
that is only possible when the cells are young and tender. Whenever the
young plant appears above ground it is then proof against infection.

Spore Formation.

A cross-section of a young infected ovary shows a central core of plant
tissue or columella, a firm outer wall, and the spores between. The outer
membrane is composed of a more or less distinct epidermis with a layer of
fungus cells beneath, which may attain a thickness of 40 //. The spores are
fully formed on the outside nearest the fungus layer and gradually become
immature towards the centre. If the spores are traced from the columella
they begin to be formed just outside the fibro- vascular bundles. The fungus
filaments seem to have gelatinized their walls, and the protoplasmic contents

Life FH'tforits of }'ar/<i//s Grass Smuts.

123

appear as colourless, aiuorphous bodies. These radiating strands become
more distinct towards the outside, and their cell-wall is firm and tinted. The
spores begin to take shape, and are at first colourless, but gradually assume
the olivaceous colour and the globose shape of the mature spores, which are
densely packed. In this way all the spores gradually become mature
and the diseased grains remain mostly unbroken unless knocked about in
harvesting.

The spores are thus seen to be formed, not simultaneously in the fertile
hyphae, but in a progressive mannu- towards the centre, and this mode of
formation of spores is characteristic of Cintractia.

Treatment.

Clinton^ found hot water treatment of the seed to be a preventive. Field
experiments also showed " that the amount of smut ordinarily occurring in
broom corn can be greatly increased by mixing a liberal supply of the smut
with the seed before planting, but was not increased by planting seed in land
that had smut in it or by placing smut on the plants after they appeared above
ground."

No matter whether ordinary or badly smutted seed was treated, the smut
was practically prevented. Freeman and Umberger^ have also proved by
experiment that formalin, hot water, or bluestone give satisfactory results.

-!. Brume Grass Smut.

{Ustilago bromivora (Tul.) F. v. W.)

Brome smut has been found here on soft brome [Bromus mollis, L.) and
prairie grass [Bromus unioloides, Humb.), both of which are imported, and
on sand brome {Bromus arenarius, LabilL), which is a native of Australia and
New Zealand. It is very general and widespread in its distribution. The

soft brome is sometimes
hundreds of acres. The

badly attacked that there is hardly a sound oar in
leep feeding in such paddocks are sometimes black

I.'ifc Histoties of 1 anoiis Grass Sinais.

over a large portion of their bodies from the spores, clouds of which rise in

the air as the flock Wd,lks through the grass, and yet, accordhig to Brefeld,

it is rarely found on this species in Europe.

It is also sometimes very bad on the prairi?

grass, not only destroying the grains but

even the base of the glumes (Plate XV.)-

In the early part of 1907 the attack was

particularly severe, and in some paddocks of

this grass every plant was infected.

In 1908 it became something of the nature
of an epidemic, and this splendid winter fodder
grass, the seed of which is now on sale in
Britain for this purpose, was very badly
affected in various districts of Victoria, where
it forms the principal pasturage. How it is
spread may be seen from the accompanying
figure, which shows a sample of seed brought
under my notice when the farmer found all
his crop smutted. On visiting this paddock
I found that not a single plant had escaped,
and recommended burning to destroy the
spores. But the farmer preferred to utilize it
as fodder, and so turned his cows into it, and
they also fed upon the cut hay without anv
seemingly injurious effects. Such diseased
plants have sometimes been reported to be
poisonous, but they were evidently not so in
this instance. This was in 1907; and last year
he informed me that any heads which sprung
from the self-sown grass were just as smutty
as before. It will be rather a difficult task to
get rid of it now, seeing that the spores retain
their vitality for years, but root and other
crops are being grown instead of grass. The
seed referred to was sold to the farmer by
leading seedsman, and such a case emphasizes
the necessity for some means of preventing
such seed being sold without inspection.

At first the glumes are leaden-coloured and
enclose the spores, but the glumes gradually
become disrupted and allow the spores to
escape. Occasionally in the prairie grass
several stalks are found springing from the
same root, of which one may be quite free from smut, while the others are
diseased.

Germination.

The spore germinates freely in water, and retains its germinating power
for some time. I gathered soft brome with this smut in November, 1904,
and in July, 190(5, it was still capable of germination. Then in May, 1907,
spores from the same plant germinated in water, so that they still retained
their germinating power for at least two and a-half years. The spores put
forth a small germ-tube or promycelium, and this bears at its apex a conidium,
which is soon detached. The conidia are colourless, elongated, cylindrical,
flat at attached end, rounded at free end, 13 - 17 x 3- 4 //.

nitidii of panicle
spikclets at base
V at top.

Platk x^■

G. H. Robinson

BROME GRASS SMUT ON PRAIRIE GRASS

{Ustilago Broniivora.)

/,//(■ //isiofii's of \ arid IIS CJrass Smuts. 125

In a iiutritve solution Brefeld found that the spore puts forth a germinal
tube, which is larger and more robust than that produced in water. It soon
divides into two cells, and this short promycelium produces couidia. These
conidia soon fall away, increase in size, and become uniseptate and behave
like the promycelium from which they sprung in producing secondary conidia,
hence Brefeld calls them bicellular sporophores. This formation of primary
promycelia from the spore and of secondary promycelia from the conidia
continues until the nutritive solution becomes exhausted. In more dilute
nutritive solutions the promycelium itself as well as the sporophores give off
mycelium-like tubes, and fuse in various ways.

U . hromivora is thus characterized by its conidia growing into bicellular
sporophores, which sprout directly into new conidia. True sprouting conidia
do not occur.

Infection.

When seed is sown with adherent spores infection readily occurs, and in
a favorable season the smutted seed produced plants in which not a single
one escaped the disease. In this instance the seed was not artificially in-
fected, but just as it was received from the seedsman (Fig. 14), and it shows
how efficient this mode of infection must be in this particular species of
smut.

Treatment.

When the seed is treated with bluestone or formalin, as in the case of bunt,
the spores are destroyed and no infection occurs.

3. Kangaroo Grass Smuts.

(a) Cintractia exserta, McAlp.;

{h) Sorosporium enter omor f hum, McAlp.;

(c) Tolyposporiwm hursum (Berk.) McAlp.

There are three smuts known on the Kangaroo grass in Australia belongmg
to the three genera of Cintractia, Sorosporium, and Tolyposporium respec-
tively. They are not as yet known to do much damage, except in certain
districts, but that may be simply owing to the fact that they have hitherto
escaped notice. They are all confined to the spikelets, distorting and de-
stroying them.

(a) The Cintractia smut is very characteristic, since it stands out from the
glumes as an elongated greyish membrane enveloping the spores and the long
rigid awn of the healthy plant has generally disappeared (Plate X\T., B. ('.).
Wlien a cross-section is made towards the base of a diseased spikelet the
formation of the spores is clearly seen. There is a central core of plant tissue,
and surrounding this is a colourless mass of fungus filaments, from which the
spore-forming hyphae proceed. As the spores are formed inside, from the
centre outwards, the walls of the hyphae deliquesce and become gelatinous,
and the final result is that a dense mass of spores is formed inside the envelop-
ing membrane. This membrane gradually decays and the mature spores are
exposed.

The germination of the spores has not been observed.

{h) The Sorosporium snmt has received its specific name from the ehmgated
and puckered membrane which encloses the spores, being often twisted uj)on
itself, and resembling the intestine (Plate XVI.. A.). The spore-balls arc
composed of spores which hang loosely together, and they ultimately escape
by the decay of the membrane.

Their germination is not known.

126 Life Histories of \'arious Grass Smuts.

(c) The Tolyposporium smut is readily recognised from the sac-like
yellowish membrane enveloping the spores (Plate XVIL). The spore-balls
are very black, and the spores are firmly and permanently united. They
germinate readily in water, even after being kept for four years, and produce
a promyceliura which bears lateral and terminal conidia. When the conidia
are detached they bud in a yeast-like manner.

4. Wallaby Grass Smuts.
{a) Black Smut (Ustilago readeri, Syd.)
(b) Bronze Smut {Ustilago comburens , Ludw.)

(rt) The black smut is fairly cc*mmon on various species of Danthonia or
Wallaby grass, and is found on the leaves as well as in the inflorescence. It
has been known for a considerable time, although only recently named by
Sydow, who recognised it as a new species. It had been previously named by
Cooke U. destruens, Schlecht.

It is a very conspicuous smut, as the entire inflorescence is invaded by it.
The glumes may remain, enclosing the blackened mass, but even they are some-
times partially or entirely destroyed (Plate XVIII. ). In its early stages the
diseased inflorescence is enveloped by the leaf -sheaths, but these soon fall
away and expose the black powdery mass of spores. On the leaves and sheaths
it also forms conspicuous lines, and altogether it is so destructive that the
grass is completely wiped out in patches.

Germination.

The spores germinate very readily in water, either immediately on ma-
turity or some time after. At the end of two years, however, only an
occasional spore is capable of germination. They produce an elongated
promycelium bearing lateral and terminal conidia, but their subsequent
history was not followed. No doubt, these conidia produce a delicate germ-
tube, which penetrates the young seedling and thus causes infection.

(b) The bronze smut is easily distinguished by its bronze-green colour, in
contrast to the other, which is black (Plate XIX.). It occurs in the upper
portion of the stem, as well as in the inflorescence, which it ultimately com-
pletely destroys. The spores are exceedingly numerous and very minute,
and, althou.h at first agglutinated together, they soon become powdery.

Germination.

This was not very successful. Fresh spores were placed in a Petri -dish
with water, and after nine days a few of them produced a one-septate pro-
mycelium, but there was no further development.

rr.ATK x^^^

G. H. Robinson, Phot. Xat. Size.

TWO KANGAROO GRASS SMUTS

(A — Sorosporiinii blntcroinorlilnim. B, C Ciiiti\ictia Kxscrta.)

Pl.ATF, X\II.

A KANGAROO GRASS SMUT

{Tolyposporimii Bursitin).

Pt.atf. XVTTT.

G. H. Robinson, p:

BLACK SMUT OF WALLABY GRASS

{U St 1 1 ago Reader i.)

Platk XTX.

G. H. Robinson. I'ii,i!.

BRONZE SMUT OF WALLABY GRASS

I UstiUigu Comhiirciis.)

FIELD EXPERIMENTS.

Field. Exfcrinicnts. 129

CHAPTER XXI.

Field Experiments during Season 1909.

The most appropriate place to give an account of the experiments just
completed for 1909, seemed to be at the close of a general study of the Smuts,
and before entering upon the consideration of their classification. There
were various questions of a practical nature which arose in connection with the
treatment and behaviour of the cereal smuts, and these required an answer,
even although that answer in many cases could only be fully and finally given
after further and continued experiment. A general idea of some of these may
be briefly given.

There were several preparations on the market for the treatment of smut
and other diseases, and it became necessary to test them in comparison with
such recognised substances as bluestone and formalin.

Then it was desirable to know how far the different species and sub-species
of Triticum were liable to bunt, so that in crossing there might be some guide
as to those which were most immune under our conditions.

Again, a number of the crosses made by Mr. Pye at Dookie Agricultural
College, with Medeah blood in them, seemed to resist the bunt there better
than many others, and various selections were chosen for trial to see how far
this resistance to bunt was a hereditary quality. Of course, these experi-
ments will require to be continued in order to settle the point satisfactorily.

There were also some doubts as to the relative virulence of the disease of
Flag Smut of wheat when the seed was sowai in clean ground with the spores
of the fungus upon it, and when clean seed was sown in ground containing the
diseased straw from a previous crop.

And finally, there were a number of previous experiments which required
to be repeated in order to see the effect on the result of different weather
conditions. From the exti-nt and variety of these experiments it was only
convenient to use small plots, and while the actual results obtained wnll re-
quire corroboration on a larger scale, still the relative results are of consider-
able value, as indicating at least in what direction the truth lies. The in-
formation obtained can generally be put in the form of Tables which will
show at a glance the essential points determined.

A Comparison op Various Fungicides for Bunt.
A sample of the powder known as " Fungusine " was supplied to us for
trial, and the chemist for Agriculture reported after analysis that the sub-
stance consisted principally of ordinary burnt lime, white arsenic, and crude
phenyl. This preparation was used, as well as phenol, and a comparison was
made between these two substances and bluestone and formalin respectively
as smut preventives. A variety of wheat from Tasmania was chosen for
treatment, naturally infected as it came from the machine, and it Avas cer-
tainly as smutty a sample as had ever come under my notice. The seed
wheat was all treated at the same time and sown on the same day (28th June)
in grountl which was as nearly as possible equal throughout. The formalin
and bluestone were used as already recommended, while the fungusine was
applied to the seed according to the instructions given, and the phenol was a
2 per cent, solution. 500 grains were sown in each plot, arranged in rows of
100 each, and the results were taken on 3()th December, when the wheat was
fully ripe.

1S5S. F

I30

Field Experiments.

Table VII. — Fungusine and Phenol compared with Bluestone and
Formalin as Fungicides.

Grains
Sown.

500
500
500
500
500

Grains
Germinated.

405
363
339
355

■128

Treatment.

Percentage

of
Germination.

Percentage of Bimt.

Fungusine . .

81

78 plants = 19.2

Bluestone . .

73

8 „ = 2.2

Formalin

68

28 „ = 8.2

Phenol

71

68 „ = 16.3

85

379 „ = 88

We are now in a position to compare the relative effects of fmigusine,
bluestone, formalin, and phenol, when used as a dressing for bunt-infected
seed, and it will be convenient for purposes of comparison to fix the numerical
relation between the effect of treatment with a particular substance and that of
untreated seed. Thus, in the case of fungusine, there was 88 per cent, of bunt
in tbe untreated plot, and 19.2 per cent, in the treated plot, so that if the
one is divided by tbe other it gives the numerical relation between the two
and fixes a standard of comparison -jl^^r = -4.5. This number represents the
factor or co-efficient of efficiency for fungusine.

If the other treatments are dealt with in the same way then the follow-
ing is the result : —

Co-efficients of Efficiency.
Bluestone . . . . . . . . 40

Formalin.. .. .. .. ..10.7

Phenol .. .. .. .. ..5.4

Fungusine . . . . . . . . 4.5

Thus, bluestone is nine times more effective than fungusine in the preven-
tion of bunt, and even phenol, when used alone, without the other ingredients
entering into the composition of fungusine, is slightly more efficacious. Apart
altogether from the relative efficiency of the various substances used, the fact
stands out prominently of the great saving effected in comparison with no
treatment at all, although, of course, no intelligent farmer would ever dream
of sowing such a smutty sample of seed.

The different Species and Sub-species of "Triticum" in relation to

Bunt.
In the quest for a smut-resistant wheat to be used as one of the parents
in crossing, the necessity for testing different kinds is evident. Accordingly,
I obtained from Germany samples of all the known cultivated species and
sub-species, which are classified by Hackel, as follows : —

' monococcum L., Einkorn or One-grained Wheat.
idieoccum Schrank, Emmer.
\speUa L., Spelt.
sativum Lam. ( Cvulgare VilL, Common Wheat

Triticum

. tenax

compactum Host, Club or Dwarf

Wheat.
turigdum L., Poulard or Rivet

Wheat.
durum Desf., Durum or Hard Wheat.

folonicum L., Polish Wheat.

Field Experiments.

131

The seed was of vaiyiiig ages, so that in some cases so few grains germinated
that the results were useless for comparison ; but my friend Professor Patrick
Wright, of the West of Scotland Agricultural College, has sent me fresh speci-
mens which will l)e caiefuUy tested in tlie forthcoming season.

Table \'111. — Relative .Susceptibility to Bunt of the Different
Species and Sub-species of Triticum.

Species or Sub-species.

•*-

1

1 i

A

Troatmrnt.

* t

.a a

s a

t'S.

0

oc

PMO

Percentage of Bunt.

25 ' 14

56

6 Triticum vulgare .

(Ordinary Wheat)

7 ..",... I 25 16 TiUrtlaJrvis'. 64 ' 11 plants = 68. 75

8 Triticum turgidum ^ 25 17 .. 68 ; —

9 .. .. I 25 U TiUctia Icvis . . —

10 Triticum spelta

11

12 Triticum polonicum
13

25 5 .. 20

11 : 4 Tilhtia lexis 36.3

20 7 .. 35

20 5 Tilletia Jeris 25

14 Triticum monococcum 18 14 .. 77.7

15 .. .. ' 18 8 Tilhiin Jeris 44.4

16 Triticum durum . .

17 .. .. ..

18 Triticum dicoccum
19

60 Triticun^ compactum

61 i

25 2 . . 8

25 1 TiUetia Jeris 4

25 9 .. 36

10 5 TiJJffia Jeris 50

25 24 .. 96 —

25 ; 25 TiJJitia Jeris WOO 24 plants = 96

3 plants

60

Note. — The seed of T. compactum was quite fresh, as it ws
Gardens the previous season.

grown at Burnley Horticultural

No definite conclusions can be drawn as to relative susceptibility, since
the proportion of plants which grcAV were sometimes so few as to constitute
a negligible quantity. In the case of T. eowpactum, there is no doubt of its
being very liable, and the solitary jilaut which escaped infection grew to a
height of 4 ft. 6 in., which was the average of the clean plot, while the general
average of the bunted plants was 3 ft. 6 in. The smut had evidently affected
the growth injuriously to tlie extent of 1 foot, and the seed from the one
plant which escaped infection will lie sown again.

Selections from Crosses tested for Susceptibility.

In the results of experiments at Dookie Agricultural College by Mr. Pye,
recorded at p. 52, it is shown that selections from his numerous crosses were,
in many cases, free from bunt after infection, especially those in which Medeah,
one of the Durums, was used as one of the parents. Mr. Pye kindly supplied
me with a number of the more promising selections for trial under the con-
ditions prevailing at Burnley Horticultural (hardens to test how far the smut-
resistance was hereditary and retained tliis quality under different conditions
of soil and climate, heat and moisture. The rainfall at the two Kxperiment
Stations throughout the year is given here for comparison.

13-

Ficld Experiments.

Rainfall at Dookie Agricultural College for 1908 axd 1909.
Points.

Year. Jan.

Feb. March.

April. ' May.

June.

July.

137
191

Aug. Sept.

169 260
363 183

Oct.

150

86

Nov.
75

Dec. 1 TotaL

i

1908 -li 54 ' 58

1909 4i 1 72 , 152

23 199
257 321

436
369

47 1,632
37 2.092

1

Rainfall at Burnley

Horticultural Gardens for
Points.

1909

AND

Average.

Year. Jan. Feb.

March.

April.

May. 1 Jnne.
1

July. Aug. J Sept.

Oct.

Nov.

Dec. ! Total.

1909 ' 324 1 147
Average 188 ^ 172

119
213

192
238

314 327
211 209

120 1 359 ! 185
185 1 180 ' 231

161
268

61
224

277 j 2.586
224 2,543

The sowing took place at Dookie in June, 1908, and at Burnlev in June,
1909. For tlie first four months, at Burnley, the rains Avere about the average
amount. The next four months — May to August — constituted a very wet
period, which culminated in the greatest general flood ever experienced in
Victoria. The abundant rains at the sowing season insured the germination
of the seed and the spores, and consequent infection by the fungus where the
seed was not treated.

Table IX. — Selections from Crosses tested for Susceptibility" to

Bunt.

Cross.

s

f

.§

Infection.

c -

51! =

B 3

Percentage of Bunt.

-e

1
1

.s

1

S a

.31

Tripola
Bobs X

Medeah

7

25

17

68

—

.32

7

25

16

TilJetia Ici-is

64

7

plants = 43.7

33

,,

8

25

17

68

—

U

„

8

25

17

TiUetia lei-i.s

68

13

plants = 76.4

3.5

„

9

25

23

92

—

36

,,

9

25

23

Tilletia If vis

92

21

plants = 91.3

37

Bobs X

Medeah

10

25

20

80

—

38

10

25

23

TiUetia Icvis

92

21

plants = 91.3

39

11

25

22

88

2

plants = 9

40

11

25

24

Tilletia levis

96

23

plants = 96

il

12

25

24

96

—

42

12

25

19

Tilletia levis

76

17

plants = 89.4

43

..

13

25

23

92

—

44

„

13

25

21

Tilletia levis

84

20

plants = 95.2

45

14

25

22

88

—

46

14

25

24

TiUetia levis

96

24

plants = 100

63

Medea h

••

25

15

TiUetia levis

60

7

plants = 46.6

Field Experiments.

133

The percentage of bunt varied from 43 to 100 where the seed was infected,
and only in one instance did the uninfected seed show any trace of the disease.
Medeah, which was bunt-proof at Dookie in 1908, turned out to be quite
susceptible witli us in 1909, having 4(3.6 per cent.

Results of Ixfectiox without Treatment.

It has already been shown in Table VII. that wheat may be naturally
infected with the spores of bunt so as to yield 88 per cent, of infected plants,
but when artificially infected it may even reach 100 per cent. This severe
infection is employed both in testing the capacity of different varieties for
withstanding the bunt as well as the effect of different kinds of treatment,
both before and after infection. In the following table it is shown that both
T. levis and T. tr itici msij Tpxoduce complete infection, and that when a smut-
ball is sown along with each uninfected grain there may be as much as 88 per
cent, of diseased plants produced : —

Table X. — Results op Infection without Treatment.

-g

Variety.

s
s

1

Infection.

i|

PercMitago

3f Bimt.

,

3

s

11

s

5

3

e^-^

22 Federation . .

25

23

92

2 plants

= 8.7

23

"

25

25

Smut-ball in con-
tact with each
grain

100

22

=. 88

30

25

20

TiUetia levis

80

19 ,.

= 95

58

25

20

80

—

72

25

25

100

2

= 8

74 :

25

14

Tillelia levis

56

14 '.]

= 100

70

25

25

„

100

25 „

= 100

71

25

20

TiUetia. tritiei

80

■20 „

= 100

56 Ohio

25

24

96

—

57 .,

25

23

TiUetia levis

92

1 plant

= 4.3

20 Genoa

25

24

96

—

21 „

25

22

TiUetia levis

88

1 plant

== 4.5

In two of the plots of Federation wheat, where the grain was sown with-
out artiHcial infection, there was 8 per cent, of infected plants, so that the
wheat to begin wdth was not perfectly clean.

Plots 70 and 71 were specially sown, and the grain infected witli T. levis
and T. tritiei respectively, in order to compare the resulting growth. It is
stated at p. 55 that Harwood found T. levis to have the effect of shortening
the straw and stunting the growth, while no such, effect was produced by T.
tritiei, but in this instance the very reverse was the case. The plants in-
fected with T. levis averaged 3 feet in height, but with T. tritiei they were
only 2J feet. No striking difference was generally noticeable, however, bet-
ween the infected and uninfected plots, as it is usually when the grain is
forming and not while the plant is growing tliat the effect of the parasite
begins to be outwardlv visible.

134 Field Experiments.

It will be observed that the Ohio and Genoa varieties were subjected to
the same severe trial as Federation, and that only a little over 4 per cent, of
the plants were affected in each case. It will be remembered that Ohio wheat
is one of those varieties which germinates rapidly, and is, therefore, supposed
to be less susceptible to bunt on that account, and the result of further ex-
periment bears this out. The strain of Genoa was chosen for further trial,
because it was absolutely free from Stinking Smut the previous season, and
the seed from clean plants of both Ohio and Genoa will be sown the coming
season. In both varieties only one plant was bunted and only a single ear in
each.

There are at least two methods for securing bunt-resisting plants, and both
lines of investigation are being followed. The one is to cross resistant with
non-resistant varieties, and thus secure in the hybrid the desired quality.
The other is to select the seed of resistant individuals for propagation, and
while the latter is the easier of the two, it is only likely to hold for the locality
in which the selection is made ; but in the other the quality, when secured, is
likely to be more permanent and independent of its immediate environment.

Entirely and Partially Bunted Plants.

As bearing on the amount of loss caused by this smut, it is interesting to
inquire whether the ears in affected plants are generally all destroyed or only
a portion of them. It has been already shown at p. 78, that smutty and sound
ears in the same plant is the general rule, and I had abundant opportunity of
verifying this fact during the past season. Taking a plot of Federation wheat
as an example, in which every plant grown was bunted, it was found that
when infected with Tilletia levis there were seventeen plants entirely and
eight only partially bunted, while with T. tritici there were fourteen plants
entirely and six partially bunted, or nearly one-third with the stool only
partially infected. In some cases therefore there may be even a greater
proportion of plants entirely bunted than only partially so.

Field experiments with Flag Smut {Urocijstis tritici) have already been
recorded at p. 98, showing the effects of seed treatment. It is not uncommon
to find with this smut that the entire stool has not produced a single ear, as
is only too evident to the farmer in his general crop, and the consequent dis-
appointing yield in a season when this disease is prevalent. Thus, in a plot of
Federation wheat, where infected grain was sown, nearly 17 per cent, of the
affected stools were without ears.

Relative Effects of Bluestone and Formalin on Germination,
Infection, and Yield.

As an object-lesson for farmers, five plots were sown under ordinary
farming conditions at Longerenong xlgricultural College with wheat of the
variety Jade, which had a little smut with smut-balls scattered through it.

Each plot was carefully laid out and measured, and contained .776 of
an acre.

The seed was sown at the rate of 50 lbs. per acre, and one lot was treated
with bluestone and formalin respectively on 12th March, 1909. Formalin
(40 per cent.) was used at the rate of 1 lb. avoirdupois to 40 gallons of water
or 1 in 400, and bluestone at the rate of 1 lb. to 5 gallons of water, or a 2 per
cent, solution. This was done to test the effect of treating the grain some
considerable time before sowing. Another lot was treated similarly on
17tli June, and the whole was sown on the 28th of the same month. The
earlier treated wheat was left in the bags side by side on the barn floor, with
a couple of sticks beneath to prevent their touching the brick floor, and
they were still moist at sowing time, but dried before being placed in the

Field Experiments.

135

seed-drill. Both bags were thus kept under exactly similai' conditions after
treatment, but the bluestone-troated seed was mouldy, iiiul a large proportion
of the grains soft and rotten, while that treated with formalin was a little
mouldy, but there were much fewer rotten grains than in the other.

The plots were critically examined on 9th December, and afterwards
stripped with the following result : —

Table XL — Treated and Untreated Bunty Wheat, compared as
TO Germination. Infection, and Yield.

Plot.

I'cd Treatment

Bluestone
Formalin

l^ntreated
Bluestone

Formalin

Bate of Treat 1

12th March. 1909

17th June, 1909

Gross
Yield.

Yield
per Aere.

bus. lbs.

Ims. lbs.

1 39

() 59

2 7
9 0

15 12
11 .55

19 35
15 21

12 47

1(5 28

Peri entat-'e of Bunt.

(1 plant af-
fected)
.85

(1 plant only
affected)

The experiments are at least suggestive, if not conclusive, and, as far as
th3y go, they are strictly comparative.

In Plot 1 the seed was so rotten that no one would think of sowing it but
for experimental purposes. The crop was very inferior, and the plants so
scattered that they were only stripped for comparison.

In Plots 4 and 5 the treated seed was kept for eleven days before sowing
on account of the weather, and the results of germination were relatively
similar to that already recorded on p. 115.

The treatment was practically effective in preventing the bunt, onlv one
diseased plant being found in the earlier formalin-treated and later bluestone-
treated plot respectively. In the untreated plot, the bunt was only .85 per
cent., the amount being calculated by counting the diseased plants in several
rows, then estimating the number of plants in a row, and this multiplied by
the total number of rows in the plot, gave the number of plants altogether,
and from the number of diseased plants in each row the percentage was
determined.

There is one outstanding fact in all the experiments for treating the
grain on a large scale — that the untreated gives a supei'icr yield to the
treated, the same amount of seed being used in eacli case. This shows the
necessity for so improving the treatment, that, wlirle destroying the spores
of the smut, it will not impair the vitality of the seed Experiinents by
Messrs. Sutton and Pridham' have shown tJie ameliorating eftoct of lime
after bluestone, but a fungicide which is fatal to the spore while >tiiuulating
to the seed is still a desideratum.

The loss caused by disease in crops must be very large in the aggregate,
and, as Mr. Pye' has remarked in his article on Diseases and Pests in Cereals
— " If statistics could be published of the financial loss to the State, due to
the ravages of fungoid and allied pests, the amount would be astounding."
It is practically impit>s!ble to oljtain exact data of the loss caused by diseases

136

Field Experiments.

of this nature, and estimates are only approximate, but, by giving the
estimates made by responsible authorities for bunt of wheat and smut of
oats alone, in certain countries, it may be brought home to the farmer what
a saving would be effected by simply treating his seed in the way experience
has proved to be efficacious.

Crop.

Disease.

state.

Period.

Estimated Loss.

Authority.

Wheat

Stinking smut
[Tilletia levis
and T. tritici)

Victoria . .

1898

£

50,000

McAlpine

,,

Ohio

Annual

52,083

Selby

Oats ..

Smut ( Ustilago

avence)

Kansas . .

1888

287,985

Kellerman
and
Swingle

" ' ■

" "

"

1889

177,199

Kellerman
and
Swingle

'•

1890

189,854

Kellerman
and
Swingle

Indiana . .

1889

166,151

Arthur

1890

126,115

Arthur

,>

Michigan

1891

166,666

Harwood

n

1892

208,333

Harwood

„

Wisconsin

1901-3

2,812,500

Moore

,,

United

1880-1890

33,845,210

Swingle

States

" ••

"

Annual

3,384,521

Swingle

V.

CLASSIFICATION A^D TECHNICAL
DESCRIPTIONS.

Classificatiuii. j^g

CHAPTER XXII.

Classification.

It is often hinted, or e\enly plainly stated, that the systematic classification
of Fungi is neither necessary nor useful where the object in view is to
investigate diseased conditions due to parasitic fungi. It is contended that
the physiology and not the morphology is the important thing, that if the
life-history is clearly traced and the abnormal conditions propeiiv studied,
nothing further is required for a correct diagnosis of the disease. This may
be true for isolated instances, but where the diseases of plants are compre-
hensively studied, and, particularly in a continent like Australia, where the
fungus-fiora is not as yet too well known, I consider it to be indispensable for
a proper appreciation of the nature and effects of the diseased conditions,
that the nature and affinities of the organisms causing them be definitely
known and defined if possible. As the President of the Field Naturalists'
Club of Victoria remarked in his annual address for 1907 — " In a new country,
until your objects have been collected in fairly large numbers, and dealt
with fiom a systematic point of view, it is difficult to see on what lines to
investigate the steps in their individual life-histories." In fact, until their
affinities are known, comparative study is impossible.

In the first place, if the parasite should happen to be a new one, it will
be a guide in our investigations to know how it is related to other forms, as
well as its modes of reproduction and so forth. In the next place, if it is
not a new one, its exact determination will enable us to learn what is known
about its habits and history, and possibly serve as a guide to some method of
treatment. In the third place, when it has been determined and catalogued,
it will enable the future investigator readily to know when he is dealing
with the same disease, and afford him valuable hints in tracing its course.
In the literature of Plant Pathology one often meets with more or less
elaborate descriptions of diseases, such as a Wheat disease, a Potato disease,
or a Lily disease, without a clue to the definite parasite, and in such diseases
there is often a doubt as to the distribution of the disease, and where the
symptoms vary somewhat there is difficulty in deciding as to its identity.
When the smut of maize was first discovered in Australia, it was naturally
concluded to be the corn smut common in America, and named accordingly,
but when its systematic position was settled it was found to be quite a different
smut, and while in some cases the determination of the fungus mav not help
us much in the way of treatment, in others, where its nature and mode of
attack are known, it may afford a clue of considerable value.

In short, there are at least four factors to be considered in the study of
any particular parasitic disease — (1) the organism which is parasitic upon the
plant, (2) the plant which is attacked, (3) the predisposing causes which have
favoured the entrance of the parasite into the plant, and (4) the mutual
reactions of plant and parasite.

The members of this group of parasitic fungi are, as a ruli'. easily
recognised by the production of soot-like masses of spores, and wliilr these
may be formed in any portion of the host-plant, the special parts in which
they occur are usually constant for each species, and this is frequently the
ovary which is thereby completely converted into a mass of spores. The
reason for the ovary ])eing so often chos;Mi foi' this purpose is ]ii()i)al>]y owing
to its being such a splendid situation for the dissemination of the spores.

14c Classification.

It may also be chosen because it is a perfect store-house of nourishment
provided bv the young embryo in a form easily assimilated, so that the
parasitic fungus steps in and utiUzes for its own reproduction what was
originally intended for the propagation of the species of the host-plant.

The most prominent feature of the smuts is their reproductive bodies
or spores, and they form the basis of our classification, taken in conjunction
with their mode of formation and germination. In fact, so important a
systematic character is the mode of germination of the spore that it
is used to divide the group into two main divisions, and in cases
where this has not been observed, there is often room for doubt as
to the exact position of the species. The spore, on germination,
puts forth a germinal tube, which may either divide transversely and
form lateral as well as terminal conidia, or it may remain at first
undivided and produce a crown of conidia at the apex. Too much
stress must not be laid on the midivided germinal tube, for it is the whorl of
conidia at the apex which is the distinctive feature. This is the basis of the
main division of the order into the two families of JJstilaginacece. and
Tilletiacece, and it shows how necessary it is for classificatory purposes to
determine the mode of germination of the spore. There is general unanimity
as to the division of the smuts into two families, but as to the limits of the
genera there is difference of opinion. The one touches the other at so many
points that there is always room for individual judgment in determining
whether a genus shall be circumscribed or made to include a number of
outlving forms, and what characters are to be regarded as essential.

Thus Cornu^ has separated out from the genus Ustilago those forms
which, instead of producing their spores more or less simultaneously, develop
them in succession in spore-bearing hyphae arising from a so-called fertile
stroma or persistent mycelium which surrounds a central columella, and
for such species he has constituted the genus Cintractia. Wherever this
feature is clearly shown of basipetal formation of the spores as in C. axicola,
there, as a matter of convenience, the genus is adopted, although some would
not consider it of sufficient importance to merit generic distinction.

Again, in addition to a central columella, there are some forms closely
allied to Ustilago which are provided with a definite fungus membrane
enclosing the spores, and which opens in various ways to allow them to
escape. On account of this pecuHarity, De Bary^ has placed them in the
genus Sphacelotheca, as illustrated in S. hydropiperis. But the fungus
membrane enveloping the spores shows every gradation from that of
Sorosporium reilianum, where it is partly composed of plant cells at the base
of the ovary and entirely fungus cells at the top, to that of Ustilago (Sphace-
lotheca) hydropiperis, where the false membrane forms a special receptacle,
splitting at the top to allow the escape of the spores. Besides, this membrane
enclosing the spore-layer also occurs in species of Cintractia (C crus-galU)
and Sorosporium {S. panici-miliacei) , so that the distinction is not suffi-
ciently definite, in my opinion, to justify the formation of a new genus.
Sometimes the plant tissues are hollowed out into cavities, and the simple
spores develop there, thus constituting the monotypic genus Melanopsichium.

In such a genus as Sorosporium, where the spore-balls readily separate
into their constituent spores, it is not always easy to separate it from
Ustilago, especially when the mode of germination is the same. In order to
be certain in some cases it is necessary to examine the spores in the early
stages of their formation.

In Thecaphora and Tolyposporium the spore-balls are rather permanent,
and it is mainly by the structure and germination of the spores that the
difference is determined.

Ustilagiiiacca. 141

Just as ill the family of the Tstilaginacete, the oeuus Ustilago is the
startino; point for a number of distinct genera, so in the family of the
TilletiacefB there are clustered around the genus Tilletia a number of distinct
types. AVhile the spores are simple in Tillelia, they may unite to form
permanent spore-balls as in Vrocystis, the spore-balls consisting of an
envelope of sterile cells surrounding one or several fertile spores. The spore
masses, instead of being powdery and erumpent, may be permanently
imbedded in the tissues. When the spores are simple and scattered through
the substance of the tissues, this constitutes the genus Entyloma, but in some
of the species the spores have a tendency to adhere irregularly in groups.
This leads up to the spores being in balls as in Doassansia, where the spore-
balls have a covering of sterile cells for the fertile spores.

The ten genera noted above are those which are definitely known to occur
in Australia, but it will give us a wider outlook if we glance at the principal
genera contained in the order as a whole. It is not so easy to settle what
genera should be included in such a survey. A number have to be excluded,
because they are now known to belong to other groups, and several have
been proposed which are hardly sufficiently distinct from existing genera.

There are altogether nineteen genera, which may be arranged according
to their outstanding features — whether the spores are single or in groups,
whether exposed or imbedded in the tissues, whether the spore-balls are
temporary or permanent, whether there are sterile cells at the centre or
circumference of the l)all, and finally the mode of formation of the spores and
their oermination.

USTILAGINACE/E Tul.
8ori usually forming exposed powdery or agglutinated masses. Germina-
tion by means of a septate promycelium producing lateral and terminal
conidia or sometimes by means of an elongated germinal tube without
conidia.

I. Spores, single —

A. Sori powdery at maturity.

1. Ustilago. — Oermination by 1-5 celh-d promyceliuin with lateral

and terminal conidia, or sometimes developing directly into
a mycelium.

B. Sori agglutinated at maturit}-.

a. Spores developed in a basipetal manner in liyphae

arising from a persistent my<olium surrounding a
central columella.

2. Cintractia. — Germination similar to that of Ustilago.

b. Spores formed in chambers inside the host-plant.

3. Mclanopsichiiin). — Germination as in rshlago.

1 Spores chiefly in pairs —

A. Sori powdery,

0. Sori usur.liy inside peduncles.

4. Mijkosi/rinx. — Germination not known.

B. Sori agglutinated.

a. Sori usually on leaves.

5. »Sc/»'sone//^/.— Germination as in Ustilaao.

142 ['sfilagiiiaccct — Tillctiacece.

III. Spores in balls —

A. Sori powdery.

a. Spore-balls rather temporary,

6. Sorosforium. — Germination by simple promyceliuni witliout

conidia or by septate promyceliuni with lateral and terminal
conidia.
h. Spore-balls permanent.

7. Thecaphora. — Germination by elongated septate promyceliuni

only producing a single terminal conidium.

8. Tohjposporium. — Germination by septate promyceliuni with

lateral and terminal conidia.

B. Sori agglutinated.

a. Spore-balls composed of spores with thick epispore.

9. Tolyposporella. — Germination by branched septate promycelium

producing single lateral conidia.
h. Spore-balls with peripheral spores and central sterile cells.

10. Testicularia. — Spore-layer surrounded by a membrane of

firmly united large round cells. Germination unknown.

TILLETIACEiE Tul.

Sori forming powdery erumpent spore masses or permanently imbedded
in the tissues.

Germination by means of a short promyceliuni, usually producing a
terminal cluster of elongated conidia, which, with or without fusing in pairs,
produce similar or dissimilar secondary conidia, or directly give rise to infection
threads.

I. Spores, single —

A. Sori powdery at maturity.

a. Spores without conspicuous hyaline appendage.

11. TUletia. — Germination by short promyceliuni with terminal

cluster of elongated conidia, which, with or without fusing
in pairs, produce a germ-tube.
h. Spores with elongated hyaline appendage.

12. Neovossia. — Germination as in Tilletia, and the conidia

produce a germ-tube without fusing.
B. Sori permanently imbedded in the tissues.

a. Spores scattered in patches through the tissues.

13. Entyloma. — Germination similar to Tilletia, and often in

addition tufts of conidia formed on protruding hyphae.

b. Spores in extended layers throughout the whole or portion

of the plant.

14. Melanotaenium. — Germination by short stout promyceliuni,

with terminal conidia not separating, but fusing in pairs.

II. Spores in balls —
A. Sori powdery.

a. Spore-balls with sterile peripheral cells.

15. C/roc^/s^w.— Germination as in Tilletia, or the terminal

cluster of conidia produce directly long infection threads.

Tillct/acece.

'43

B. Sori pci'niaiiciitlv itnhcdded in tissues.

a. Spoie-])alls with sterile i)eriphcral cells.

16. Doflssr/wsia.— Germination by a short proniyccliuni, with

terminal cluster of conidia, which often heai- secondary
and tertiary groups.
h. Spoie-balls without sterile peripheral cells.

«. Spore-balls with or without central sterile parenchy-
matous cells.

17. BuiriUia. — Germination as in Eutvloma.

p. Spore-balls with central network of filaments.

18. Tracija. — Germination as in Doassansia.

y. Spore-balls composed entirely of fertile spores which
are dark coloured.

19. Tuhurcinia.—GfQiLmiivAiioii by promycelium with terminal

conidia not separating, but fusing in pairs. Sometimes
surface conidia produced from hyphae, forming conspicuous
white growth.

144 Sy<^te.matic Arrangement.

CHAPTEE XXIII.

Systematic Arraxgemext and Technical Descriptions.

Considering the wide distribution of the smuts and the numerous host-
plants on which they grow, there is every reason to believe that there are
still a number to be discovered in Australia. Apart from those which attack
the cereals and which have consequently been brought prominently under
notice, they have not attracted much attention, and it is only at particular
seasons of the year that they are visible to the ordinary observer. Hence,
while the following descriptions include all those which are at present known
general conclusions cannot safely be drawn as to their distribution. Only
the eastern portion of the Continent has received the attention of collectors,
and the prevalence of smuts in the western portion is practically unknown.
Much closer observation and extensive search is required before anything
approaching a complete survey can be given, and if it be asked why then
attempt it at all, I would reply that a clear and definite account of the forms
already found will pave the way for further additions and discoveries. In
some cases, too, there are only solitary specimens available, and the procuring
of material at different stages and from various localities is desirable. The
ten Australian genera have already been shown in their relation to genera
in other parts of the world, and the 68 species have been described and
illustrated in such a way that their identity can always be traced. It will be
observed in the description of the species that I have used what is called
the anatomical method, that is to say, the deep-seated characters as well as
the more superficial ones, wherever possible.

Order — Ustilaginales.

Fungi parasitic in the tissues mainly of herbaceous flowering plants and
developing a mycelium, local or widely extended, consisting of delicate,
hyaline, septate, branching filaments, which often disappear partially or
entirely at maturity through gelatinization and deliquescence.

Fertile mycelium composed of compact masses giving rise to spores from
their internal contents, rarely forming conidia externally.

Sori evident, forming powdery or agglutinated masses of spores on definite
portions of the host, sometimes permanently imbedded in the tissues.

Spores generally dark coloured, single, in pairs, or in spore-balls, which
may be composed partly of sterile cells.

Grermination by a promycelium, usually producing lateral or terminal
conidia, which may either germinate in turn and directly penetrate the
host-plant or reproduce themselves by budding in a yeast-like manner, and
then germinating.

The Ustilaginales are typically parasitic fungi, which show the most
perfect adaptation to their host-plants, and produce their spores asexually
from single divisions or cells of the mycelium. But since parasites are
assumed to have been derived from saprophytes, they still retain the sapro-
phytic habit, and this is clearly seen, even in such pronounced parasites as
the smuts.

When the spores escape from the host-plant, they can germinate readily
in water, and produce a short germinal tube bearing single conidia, but in
nutritive solutions they go further than this, and continue to produce
reproductive bodies as "long as the nutriment lasts. The spore germinates

Systematic Arraiigojwiit. 145

outside the host-plant, and, as a rule, produces a germinal tube only once,
but the conidia formed multiply indefinitely by direct sprouting or budding.
This sprouting of the conidia in a yeast-like manner goes on until the nutri-
ment is exhausted, and then they develop slender filaments, which, if tliev
reach the host-plant at the proper stage, enter in and form the large septate
spore-producing mycelia.

We have here the formation of different reproductive bodies inside and
outside the host-plant. Inside a mycelium is produced, which finally gives rise
to spores, and outside, the conidia, formed from the germination of the spore,
sprout and multiply indefinitely. This continuous sprouting in a nutritive
solution is the counterpart of the mycelium-forming spores confined to the
host, and the germination of the conidia to form slender filaments in the
exhausted solution is the connecting bridge between the outside and inside
development. It may be represented graphically thus : —

'Sprouting Conidia

Outside Host-plant
(Saprophyte)

Inside Host-plant
(Parasite)

While this is the general course of development, there may be slight
deviations from it. In the American corn smut [Usiikup zeae) the
sprouting conidia may not only occur in the fluid, but in the air, as aerial
conidia. In Tilletia and other genera, not only is a whorl of conidia produced
at the apex of the germinal tube, but the conidia may form in the air a
mycelium like a tuft of mould, from which sickle-shaped aerial conidia again
arise, singly and irregularly (Fig. 5). In Entyloma there is the further
peculiarity that, in addition to the ordinary promycelial conidia, there are
tufts of conidia produced on hyphae projecting from the host-plant itself.

It may finally be noted that infection through the flower, which is the
only mode known in the loose smut of wheat and the naked smut of barlev,
is probably the most advanced form in which it occurs. The young ovary
is not only attacked in its earliest stages, but the embryo itself is permeated
by the fungus filaments, which are secure within the seed, and only await
the germination of the seed to develop within the host-plant and produce
its spores. The climax is reached in the Anther smut of the Carnation
family, where the uncertain and wasteful dispersion of the spores by the
wind is no longer relied on, but insects carry thein from flower to flower as
in the process of pollination.

The order may be grouped in two I'amilies. both of which are represented
in Australia, and are distinguished by the mode of germination of tlie spores
and the production of conidia.

FaM. 1. ITSTILAUIN-ACE^ Tul.

This family is characterized by the spores germinating by means of a
septate promycelium, which produces lateral and terminal conidia. The
genus Ustilago, from which the family is named, is the richest in Australian
species, and of the ten recognised genera, six of them have been found here,
viz. : — Ustilago, Melanopsichium, Cintractia, Sorosporium, Thccaphora, and
Tolyposporium.

146 l'stilc7go.

FaM. 2. TiLLETIACE.E Till.

This family is named from the genus Tilletia, which comes next to
Ustilago in the number of species. The spores produce on germination a
short promycelium, which usually bears at its apex a cluster of elongated
conidia. There are nine genera recognised, and only four are represented in
Australia, viz. : — Tilletia, Entyloma, Urocystis, and Doassansia. Entyloma
and Doassansia are d'stinguished by the spores being imbedded in the
tissues.

USTILAGO Pers.

Vegetative mycelium spreading in the tissues of the host and soon
disappearing.

Sori forming powdery, usually dark-coloured spore masses, on various
parts of the hosts.

Spores single, small, produced irregularly in the interior of clustered
terminal branches of fertile hyphae, which soon entirely disappear through
gelatinization.

Germination by a short septate promycelium, which produces conidia
both apically and laterally near the septa, or by a promycelium developing
directly into a mycelium.

Conidia germinating in water, usually producing slender infection threads,
but in nutritive solutions multiplying indefinitely after the manner of yeasts.

This genus contains the most species, and is the most important from an
economic point of view. It includes some of the most destructive parasites
of the cereals, and although it occurs on a great variety of hosts, the largest
number are found on the Graminese. The only other host-plants represented
here belong to the Cyperaceoe, Polygonace?e, and Portulacea?.

Brefeld divides this genus into three sub-genera or groups, according to
the mode of germination, viz. : — Pro-ustilago, Hemi-ustilago, and Eu-ustilago ;
but since the germination is not known in f|uite a number of Australian
species this classification cannot be followed.

Australian species, 18.

A vena, Arrhenafherum.
1. Ustilago avenae (Pers.) Jen;.

Jensen, Charb. Cereal, p. 4 (1889).
Brefeld, Unters. Gesammt., Mvk. V.. p. 54 (1883).
Brefeld, Unters. Gesammt. Mvk. XL, p. 23 (1895).
Sacc. Syll. IX., p. 283 (1891).^
Ustilago perennans Rostr.
Sori in spikelets, attacking all parts of the flower, even the glumes and
awns, usually completely destroying the ears and transforming
them into a dark-brown spore mass, which l:)ecomes powdery, and
is eventually dissipated.

Spores globose to subglobose, occasionally ellipsoid, pallid ta
olivaceous or olive brown, more lightly coloured on one side, finely
echinulate, 5|-6J /ii diam., or 7-8 x o-Q jf, occasionally reaching
an extreme length of 11 /' and a breadth of 7 /).
On Arena sativa L. — Oats.

Common — wherever Oats are grown.
On Avena fatua L. — Wild Oats.

Victoria — Dookie, Nov., 1908. Longerenong, Nov., 1908.
On Arrhenatheruni avenaceum Beaxiv.^ Avena elatior L.-— Oat ^rass.
Victoria ~ Longerenong, Nov., 1909 ^Gibson.)

I 'sfi/di'O.

147

This smut is vorv common ou cultivated oats, and occurs in all the States.
It is usually cautiued to the iutloresceiice, but Clinton^ records it as occurriiio;
ou the leaves iu rare cases, and Japp^ found it in the anthers. It has been
found on th? wild oat in California, and occasionally on the same host in
Victoria.*

Spore jormalion. — If cross-sections are made of an affected ovary in the
3^oung condition, the spores are seen forming around a central core of tissue,
the youngest and colourless spores being innermost. They are also formed
in isolated groups which may eventually run together. In these individual
groups there is a Cintractia-like formation of spores, the very minute colour-
less spores being towards the centre, and the dark-coloured mature spores
collected towards the circumference. The spores, however, are not agglu-
tinated together to form that cheese-like consistency which is characteristic
of Cintractia.

Germination. — Fi-esh material was taken from the field and the spores
germinated freely both in water and nutritive solution. Germination takes
place in a few hours, and a promycelium is produced, divided into segments
by three or four transverse septa. Each of the segments generally bears a
conidium, the top one producing it at the apex. The conidia may either
fall away or remain attached, and give rise at their free end to a secondary
conidium. The conidia when moist develop further, and may either directly
put forth a slender germ-tube or two o" them adjoining may become con-
nected, and the one reinforced by the protoplasm of the other gives rise to
a germ-tube. When spores are cultivated in a nutritive solution instead
of water, an important difference arises. The conidia are formed as before,
but they begin to sprout on their own account after the manner of yeast,
and form sprouting conidia. In liquid manure this process of sprouting can
go on indefinitely, and Brefeld maintained it over a year by keeping up the
food supply. It must be remembered that this result was obtained with
" pure cultures," but under natural conditions it is highly probable that the
process would be checked, if not entirely hindered, by the development of
other organisms. Spores have germinated after being kept for seven and
a half years, and thus, in the staying power of the spores and in the immense
numbers of sprouting conidia produced, this smut possesses unlimited powers
of spreading.

(Plates VIII., IX., XXVI.)

Ilordmm.
2. Ustilago hordei (Pers.) Kell. & Sw.

Kellerman and Swingle, Ann. Kep. Kans. Aur. Exp. Sta., p. 268

(1890).
Sacc. Syll. IX., p. 28:3 (1891).
Ustilago segetum (Bull.) Dittm.
U. jensenii Rostr.

Sori in spikelets, forming a black compact spore mass, enclosed in the
glumes and covered rathci' permanently bv the unbroken walls of
the ovary, hence called coxcrcd smut of barley. Spores remain
adherent, being bound toiicllici' bv ])atclies of tissue in interior of
spikelet.

* The wild oat can be infected witli smut from the tame oat, and the tame oat with smut from the
will oat, so that the same species occurs on both. The form on tlie oat grass resembles the tvpe in
stru-ture and germination, and the fact that the mycelium is perennial does not entitle it to sijeciflc
distinction. Cross infection with the oat will be tried during tlie coming season.

148 Ustilago.

Spores globose or subgiobose to elliijsoid, olive-brown to blackisli-
brown, often with a clear strip on one side indicating a thimier
portion of the wall, perfectly smootli, 6-9 /i( diam. or 8-11 x 5-8 /(.
On Hordeuni vulgare L. — Barley.

No doubt it occurs in all the States, although it has only been specially
noticed as under : —

Victoria— Port Fairy, Dec, 1903, and Jan., 1905. Mordialloc, Sep.,
1904. Camberwell, Nov., 1906. Toorak, Oct., 1907. Dookie.
Dec, 1907. Goulburn Weir, Feb., 1909 (Parris). Bacchus
Marsh, March, 1909.
Tasmania — Hobart, Dec, 1906 (Rodway).

South Australia — 1907. Found in shipments of barley to Victoria.
In a shipment of wheat from San Francisco, arriving here in March,
1903, there were heads of barley and detached portions mixed up with it
badly affected with this smut. Among the species of Ustilago on wheat,
oats, and barley, there is not sufficient distinction in the size of the spores to
discriminate between them, although the largest are found in U. hordei. It
has also to be noted that it is the only one with a smooth epispore. The two
species of smut found on cultivated barley — naked and covered smut —
have only recently been separated, and the}?^ were formerly included under
U. segetum. The hard and persistent mass of spores in the one case, however,
and the powdery mass dispersed when mature in the other, enable them to
be readily distinguished.

Spore formation. — A transverse section of the ovary shows the epidermis
still surrounding it, and the spores are in patches scattered throughout the
internal tissue. In each individual patch surrounded by plant tissue, when
the spores are not all fully mature, they are seen to be formed in the sporo-
genous hyphae in regular gradation from the minute colourless to the mature
coloured spore.

Germination. — Spores were germinated both in water and in hay infusion,
and they put forth a germinal tube which divided by transverse septa into
four cells, and canidii were produced laterally as well as at the apex. The
conidia multiplv in a yeast-like manner, and form sprouting conidia.

(Plates XL, XXVI., XXVII.)

Hordewn.
3. Ustilago nuda (Jens.) Kell. & Sw.

Kellerman & Swingle, Ann. Rep. Ivans. Agr. Exp. Sta., p. 277

(1890).
Sacc. Syll. IX., p. 283 (1891).

Ustilago segetum (Bull.) Dittm. *

Sori in spikelets, forming dense brownish-black masses, Avith a bronze-
green tinge, at first covered by the flowering glume, which is
converted entirely into a thin leaden-coloured membrane, or the
awn may remain green, then when free from the leaf -sheath becoming
naked, and the loosely adherent spores are scattered, leaving the
axis of inflorescence exposed.

Spores globose to subgiobose or ellipsoid, olive-brown, often with
clear strip on one side, distinctly but finely echinulate, 5-7 /< diam.,
or 6-7 X 4-5 /'.

Oil Ilordeum ruhjare L.— Barley.

Very probably known in all the States, although not specially recorded.
Victoria — Port Fairy, Nov., 1890 (Pearson). Caml)erwell, Nov.,
1900. Lindenow, Nov.. 190(3. Myrniong, Nov., 1900. and
May, 1907 (Brittlebank). Burnley, Nov. and Dec, 1908.

This is known as naked barley smut, in contrast to the covered barley
smut, under the life-history of which the chief differences have already been
pointed out. It also appears earlier than the covered smut, and evcrv ear is
generally smutted in an infected plant.

A cross-section of the affected ovary is difficult to get, because the entire
contents are ultimately replaced by spores, and even in the earlier stages only
small patches of plant tissue remain.

Germination. — The spores germinate freely, both in water and nutritive
solution. A septate germinal tube is produced which continues to grow
at the apex and forms lateral branches, which in turn branch again, and so a
spreading mycelium is developed without the formation of conidia. This
absence of conidia is associated with infection taking place in the flower and
not iji the seedling, as is usually the case.

Trentment. — I have just received a Bulletin through the courtesy of one
of the authors, E. M. Freeman, entitled The Loose Smuts of Wheat and Barley,
in which a method of successfully treating this disease is given. Hitherto
the only precaution known was to use healthy seed, since the mycelium of
the fungus was inside, and could not be reached by the ordinary " steeps "
used for other smut diseases. It has been found that Jensen's modified hot
water treatment prevents both the loose smuts of barley and wheat, and the
following method is recommended. " For barley, a soaking in cold water for
five hours, followed by a soaking in hot water for fifteen minutes at a
temperature of 52° C. ; for wheat, a soaking in cold water for five hours,
followed by a soaking in hot watej for ten min.utes at a temperature of 54° C.
These treatments, if carefully carried out, entirely prevent the smut, and pro-
duce only slight injury to the germination of the seed.

" Thorough drying of the seed after the application of Jensen's modified
hot water treatment is not injurious to the germination. When seed is
injured by the treatment, the germination improves after several weeks of
drying, and continues to improve for at least two months.

" The following method for farm practice is recommended : — Grow seed
in a small isolated seed plot, using clean heavy seed of the best cjualitv, and
of pure stock. Treat this seed carefully by Jensen's modified hot Avater
method as recommended, and sow the seed according to germination tests.
Plant the seed from the seed plot the following year for the general farm
crop. !M;untnn the seed plot every year."

(Plates X., XXVII.)

Triticum.
4. Ustilago tritici (Pers.) Jens.

Jensen, Ann. Rep. Kans. Aur. Exp. Sta. II., p. L'(ii' (1890).
Sacc. Syll IX., p. 283 (1891)

Ustilnc/o sejetam (Bull.) Dittm.
Ustilago hordei Bref. (in part).
Ustilago tritici f. folicola P. Henn.

150 U St Hugo.

Sori iu spikelets, attacking the glumes as well as the ovaries, forming
dusty dark olivaceous masses, entirely destroying the floral parts
as a rule, and leaving only the axis of inflorescence ; occasionally
on shot-blade forming elongated streaks, and also on rachis.

Spores pale olivaceous, more lightly coloured on one side,
globose, subgiobose, or shortly ellipsoid, minutely but distinctly
echinulate, 5-6 "5 j-i diam., or ()-8 x 4-5 '5 j-i.
On Triticum vulgare Vill. — Wheat.
Common in all the States.

This is usually called Loose or Flying smut, from the way in which the
spores are bloAvn about, or " Snuffy Ears," from the dark dusty powder in place
of the ear. The spores are blown about by the wind at flowering time, and by
harvest time only the bare stalks of the affected ears are left, with remnants
possibly of the chaffy scales.

It has been already noted that, while the spores are usually produced in
the spikelets, they are occasionally found on the sheathing blade or shot
blade, as well as on the stem (Plate Vic). This only occurred on one
variety. Red Egyptian, obtained from Vilmorin, of Paris, in 1908, and the
elongated streaks were very prominent on both surfaces of the leaf. It is
worthy of record in this connexion that Hennings^ also found it on the
leaves and leaf sheaths of a wheat obtained from Upper Egypt, and although
the spores Avere identical, he regarded it as a new form, and named it folicola.
It sometimes happens that the spores remain closely agglutinated
together, harden, and do not blow away, so that the axis of the inflorescence
is invested by the black remains of the affected ovaries. A cross-section of
such an ovary shows that the plant tissue has only been partially replaced by
spores, and that, while the immature and colourless spores adjoin the
vascular bundles, the dark dense mature masses are on the outside, the
development of the spores being from the inside outwards.

Germination. — Both in water and in a nutritive solution, the spore puts
forth a germinal tube which branches freely, and the tube with its branches
curve in a characteristic sickle-shaped manner. No conidia are formed, but
the whole grows into a much-branched mycelium. This species is adapted
for floral infection, hence the mode of germination of the spore.

(Plates III., YI., XXVIII.)

Bromus.
5. Ustilago bromivora (Tul.) F. v. W.

Fischer von Waldheim, Bull. Soc. Nat. Mosc. XL., p. 252 (1867).

Cooke, Handb. Austr. Fung., p. 325 (1892).

Brefeld, Unters. Gesammt. Myk. V., p. 123 (1883).

Sacc. Syll. VII., p. 461 (1888).

Cintraclia fatagonica, Cooke & Mass. Grev. XVIII., p. 34 (1889).

Sori in spikelets, usually confined within the glumes, but sometimes
attacking them at their base, at first bullate, then powdery, and the
black spore powder frequently dusted over the entire inflorescence.

Spores dark-brown to olivaceous, globose to ellipsoid or ovoid,
abundantly covered with minute tubercles, 7-10 /< diam., or "
9-11 X 7-9 p, occasionally 12 x 9 to 13 x 10 /'.
On Bromus mollis L.

Victoria — Common.

South Australia — Kangaroo Island, Jan., 1904 (Summers). Plains
of Adelaide, Dec, 1909 (Quinn).

I'sfihn'o.

()u

BroiHH.'^ (ire

iKiriiis Laliill.

Victoria—
1909.

-Murray Hiver (Xatit

)iial Hi-

■rharium) :

Se;

On

Bromus iinioloides H. B. & K. —

Prairie

grass.

Victoria — Toorak, Molbouriio,
Dec. 1906 (Ewart). Nar
cultural Gardens, Buriile\

Dec,

racaii, .
'. Oct.,

J9()(i. 1)

Jan. and ]

1907, to

oma
b^eb.
Oct.

Lake. March,

1, Melbourne,

1907. Horti-

1908, and to
Oct., 1909. Murchison, Oct., 1907 (Wallace). Dookie, Dec,
1907. Coode Island, Nov., 1908 (C. French, jun.). Melbourne,
Nov. and Dec, 1908 (C. French, jun.). Bairnsdale, Dec, 1908
(Smith). Burnley, Jan. to Mav, 1909. Mvrniong, Feb., 1909.
Treasurv Gardens, Melbourne, Feb., 1909. Balwyn, Nov., 1909
(C. French, jun.). Willsmere, Dec. 1909 (Searle). Burnlev,
Dec, 1909, and Feb.. 1910.

New South Wales— Singleton, Nov., 1903 (Cobb). Upper Hunter
(Turner).

The smut has been found on the Prairie Grass all the year round. Usually
all the spikelets of a panicle are infected, but I have found specimens in
which the lowest spikelet bore sound seeds, while all the others were affected.
In other cases the lower spikelets Avere affected and the upper clean (Fig. 15).

Spore formation. — A cross-section of the ovary shows dense dark-brown
firmly agglutinated masses of spores arranged around various vascular
bundles. The spores are seen radiating from these as a centre, at first
colourless, and minute, and gradually increasing in size until they becc me
mature and coloured.

The type of Cintrac'.ia pafar/onica on Bromus unioloides was examined by
Clinton, and found to be this species. He regards it as an unusually vigorous
form, because the basal parts of the outer glumes as Avell as the ovaries were
infected, but this was a very common occurrence in our specimens.

The Cintractia type is suggested from the way in which the spores radiate
from the various vascular bundles, but there is no central core of tissue from
which the mass of spores radiates.

Germination. — The spore germinates freely in water, and I found it to
retain its germinating power for at least two and a half years. It also ger-
minates in nutritive solution, when the germinal tube is larger and more
robust than in water. BrefekP- has shown that the conidia grow into
tiicellular sporophores, which sprout directly into new conidia.

(Plates XV., XXVin.)

(3. Ustilago bullata Bi

Agropyron.

Berkelev in V\. N. Zeal. 11.. p. 19(i (18.1.-)).

Cooke, Handb. Austr. Fung., p. 32(1 (18^»l').

Brefeld, Unters. Gesammt. Mvk. XII.. p. Ill (1S9.-)).

Sacc. Syll. VII., p. 468 (1888).
Sori produced in the inflorescence and destroying it, at first enclosed
in a greyish or leaden-coloured membraiie which is soon ruptured,
exposing the dark-brown to black compact mass of spores, .some-
times oidy attacking jxirtion of the s])ikelets.

152 Ustilago.

Spores globose to subglobose or ellipsoid, olive-brown, densely
waited, 8-11 /( diam., or 10-12 x 7-8 /<, occasionally reaching
a length of 14 /■.

On Agropijron scahnim Beauv.

Victoria — ^Burnley, near Melbourne. Ardmona, Oct., 189-5
(Robinson). ^ Mvrniong, 1900, Dec, 1901. Nov., 1904 and
1906, and Feb.,' 1909.' Mt. Blackwood, Jan., 1903. Elmore,
Apr., 1906. Rainbow and Lake Albacutva, Oct., 1908. Dookie,
Dec, 190.3 and 1907. Ardmona, Oct., 1909 (McLennan). Plenty
Ranges, Nov., 1909 (C. French, jun.). Angustown, Dec, 1909^

Tasmania— Hobart, Feb., 1907 (Rodway).
South Australia — According to Cooke.

The membrane enveloping the sori consists mainly of the epidermal
tissue of the plant.

I am indebted to the Director of the Royal Gardens, Kew, for specimens
of this species collected by Colenso in New Zealand in 1849.

In the Agricuhuml Gazette of New South Wales a new species was
described upon Agropyron scahrum as U. agropyri, but it was afterwards
discovered that the material contained a mixture of Danthonia and Agropyron,
and that it was really U. readeri Syd., which was there described as U.
agropyri McAlp.

Spore formation. — A section of the ovary shows a central core of vascular
tissue, sometimes very much reduced, with irregular outline and projecting
processes. From the margin of this tissue the spores are developed, at first
as minute colourless points, and gradually become coloured and mature.
They radiate from the centre tow^ards the circumference, where they form a
continuous mass of olive-brown spores surrounded by the membrane. The
membrane is ruptured, and the loose powdery spores escape.

Germination. — The spores germinate freely in water, and in about a
couple of hours there were indications of the germ-tube. Brefeld^ has
described the germination from a specimen on Agropyron orientale Roem.
and Schult. The spores germinated readily in water, but in a peculiar manner.
Several germ-tubes were apparently produced from the spore at the same
time, but all save one remained very short. This one elongated considerably
forming transverse septa behind as the contents moved towards the apex.
If the earliest stages of the germination are carefully observed, it will be seen
how this arises. The germ-tube is originally simple and unbranched, con-
sisting of three cells, of which only the lowest or rarely the two lowest grow
out directly into long filaments, without the formation of conidia. With
the outward growth of the lower cell the apex is turned to one side, so that
at an early stage it gives the impression of three germ-tubes originating at
the same time. If instead of water a nutritive solution is used, then it is
quite different. A normal promycelium is formed, producing conidia, of
which there was not even a trace in water. The single promycelium consisted
of three cells, but when several were produced from the same spore, each was
reduced to two cells. The elongated ellipsoid conidia sprouted even Avhile
still attached, but more luxuriantly when detached. The sprouting conidia
were very slow in their growth, and inclined to form filaments before the
nutritive solution was exhausted. In none of the cultures did fusions or
aerial conidia occur.

(Plate XXIX.)

Usiilago. 153

Culanlrinia.

7. Ustilago calandriniae Clint.

Clinton, X. Amer. Ustil. Proc. Bost. Soc, p. 378 (1904).
Sacc. Syll. XVIL, p. 472 (1905).
Sori in ovaries, at tirst of a deep dark-bluish tint, then purplish-black,
pulverulent, without perceptible smell.

Spores globose, brownish-purple, 15-10 ft diani. cpispore clear,
reticulated, with ridges about 1.5 /< high and polygonal meshes
about 2 /( diam.

On Calandrinia calyptrata Hook f.

Victoria— Minvip, Nov., 1897 and Oct., 1898 (Eckert). Rainbow,
Oct, 1908. Murtoa, Nov., 1908 (Eckert). Myrniong, Dec,
1908, and Jan., 1909 (Brittlebank).

The spores are at first colourless and may sometimes remain so even when
fully formed.

This smut does not prevent the host-plant reaching its full development,
only the seeds are destroyed by it, and it attacks the plants growing in the
same patch year after year.

This species was very abundan.t near Rainbow and wherever the plants
occurred in patches, some of them were sure to be affected with the smut.
It was only on close inspection that the smutted ovaries could be detected,
as the same plant might bear flowers and fruits and sm.utted heads. The
smutted ovaries were recognised by being more swollen than the healthy,
even before bursting to allow the spores to escape.

Germination was tried in water with fresh spores and spoi'es nine months
old, but at first without success.

Germination. — This spore, although quite fresh, was somewhat difficult to
germinate, and only after six days in distilled water. Only a few germinated
in that time but they showed distinctly the formation of conidia as in Usti-
lago. The specimen from which the spores were taken was collected on 2nd
January, and placed in germinating chamber on the 12th.

The spore may give rise to one (occasionally two) slender germ-tubes,
straight or slightly bent, and sometimes forking at the end, reaching a length
of 80-90 /( and up to 4-septate. The conidia are produced laterally and ter-
minally, and are colourless and fusiform. Sometimes a conidium germinates
while still attached, and produces a secondary conidium.

(Plates XXIX.. LIII.)

Danthonia.

8. Ustilago comburens Ludw .

Ludwig, Zeitschr. Pflanzonkr. III., p. 139 (1893).

8acc. Syll. XL, p. 231 (1895).

U. microspora Massee and Rodway, Kew Bull. p. 160 (190l).

U. exir/ua Sydow, Ann. Myc. I., p. 177 (1903).
Sori in upper portions of stem and in ovaries, ultimately destroying
entire inflorescence and exposed on the rachis, covering it with a
dense bronze-green powderv spore-mass, at first more or less com-
pact.

Spores globose or ellipsoid, olivaceous in mass, clear yellowish-
green individually, smooth, minute, 3-4 '5 /( diam. or 4-4 "5 x
2*5-3 /(, occasionallv reaching 5' 5 x 3' 5 /(.

154 Ustilago.

On Danthonia pilosa R. Br.

Victoria— Near Dimboola, Nov., 1892 (Reader). Kiewa, Nov., 1902
(Robinson). Kircheim, Oct., 1898 (Eckert). Lake Albacutya,
Mallee, Oct., 1900 (C. French, jmi.). Rainbow, Oct., 1908.
Mallee, Nov., 1903 (Williamson Wallace).
Tasmania — Risdon, near Hobart, May, 1899 (Rodway).
On Danthonia sp.

South Australia — Murray Bridge, Dec, 1892 (Tepper).
Dr. Ludwig has kindly sent me a portion of the original material which
is given as occurring on Stipa, but on comparing both the host and the fungus
with that found on Danthonia, it is seen to be the same, and that the host-
plant has been wrongly determined.

In Dr. Cooke's Australian Handbook this species on Danthonia is given
as U. segetmn Bull.

This species was first named by Dr. Ludwig in 1893 from specimens sent
by Mr. Tepper. Then Massee received a specimen from Rodway later and it
was named U .micros por a, but since the name was pre-occupied by Schroeter
and Henning in 1896, it was changed to U. exigua by Sydow. However,
the original name of Ludwig now stands.

Spore formation. — Cross sections of the stem show the various tissues of
the host-plant, and the fibro-vascular bundles are penetrated by the myce-
lium. On the outside of the outer ring of bundles a continuous stroma or
compact mass of filaments is formed, and the projecting hyphae develop spores
in succession. The inner are colourless, but towards the outside they become
olivaceous and are held together at first by the remnants of the stroma. All
the hyphae arising from the stroma seem to became spore-bearing, and de-
tached portions of the outer tissues occur among them.

CTermination of 1902 material was tried several times but did not succeed.
Spores collected in October 1908 were placed in a Petri-dish with water on
21st January, 1909. It was only after nine days that they began to germinate,
and produced occasionally a one-septate promycelium about 6 /j long.

(Plates XIX., XXXVII.)

Panicum.
9. Ustiiago confusa Mass.

Massee, Grev. XX., p. 65 (1892).
Cooke, Handb. Austr. Fung., p. 32-1 (1892).
Sacc. Syll. XL, p. 230 (1895).
Sori in ovaries, soon naked, pulverulent, violet-black.
Spores clear-brown, with a tinge of violet by transmitted light, sub-
globose or irregularly angular, epispore about 1 /' thick, perfectly
smooth, 11-12 /( diam.
On Panicum paradoxum R. Br. = Chamaeraphis paradoxa Poii'.

Victoria.
It was previously confounded with Ustilago destruens Schlecht, from
which it is distinct.

Specimen not seen, and informed that there is no material available at
the Royal Gardens, Kew. Whether this species agrees with others recorded
on species of Panicum can only be settled when the smut is again discovered
on this host-plant.

r St i I ago. 155

" I 1 Cynodon.

10. Ustilago cynodontis V. Hciin.

P. H.Miiiiims, Eiml. i^ot. -laliili. XI\'.. ]). :)«i9 (1S91).
Sacf. Syll. XIV., p. 41ii (1899).
Sori involviii»i' the young inflorescence and entirely destroyin<i- it while
still enclosed in its enveloping leaves, black in the mass and pow-
dery ; in some cases the digitate spikes have expanded before the
florets are destroyed : also in the axis of the inflorescence and
encircling it.
Spores olivaceous, subglobose. occasionally ellipsoifl. jilino-t smooth,
7-8 /( diam. or 9-10 x 5-7 //.
On Cynodon dactylon Pers. — Couch grass.

New South Wales — Svdnev Botanic Gardens, Jan. and Oct.. 19<)7

(Ch-el). Sydney," Feb.^, 1909 (Baker).

This species was first obtained from Abyssinia, then it was sent from

Simla in 1891 to Brefeld, who succeeded in germinating the spores. Magnus*

notes its distribution in Europe, Northern Africa, and India, and concludes

that the Ustilago on the same host-plant in America is quite distinct.

In Australia it has only hitherto been found in the Sydney Botanic Gardens
and on a lawn near Sydney. Although the host-plant is plentiful in Victoria,
no signs of smut have appeared on it.

Spore- formation. — Cross-sections of the stem and of the axis of the affected
inflorescence show the plant tissues in the centre surrounded by the vascular
bundles, and the hyphae are seen ramifying in the cells outside these bundles.
The mycelium bursts through the epidermis and forms a compact mass of
filaments from wdiich the spore-bearing hyphae are produced. The very
minute colourless spores are at the base, and they gradually increase in size
and assume a dark olivaceous tint towards the outside. Here and there are
slender strands of hyphae radiating towards the circumference and if the
spores were more firmly agglutinated together, the characters would be those
of a Cintractia.

Germination. — This occurred in water, and in a nutrient solution every
spore germinated. Spores were taken from a specimen collected in October,
1907, and in December, 1908, they germinated freely, thus showing that they
retain their germinating power for more than a year. The spore puts forth
a three-celled promycelium which produces elongated conidia laterally and
at the apex. In some cases tw^o promycelia are produced from one spore,
the spore itself being divided into two by a septum and each division giving
rise to a promycelium. The conidia multiply copiously by sprouting, and
these sprouting conidia, where they reach the surface of the fluid, become
aerial conidia.

(Plates XXII., XXXIV.. Llll.)

Triodia.

11. Ustilago hieronymi Scluoet.

Schroeter, Hedw. XXXV.. p. lM.3 (189(i).
Clinton. North Am. Ust., p. 3.'>8 (1904).
Sacc. Syll, XIV., p. 417 (1899).
Sori in the leaves and leaf-sheaths, usually forming elongated ])ustules
covered by the leaden-coloured cuticle which usually rujitures,
exposing the mass of powdery black spores.

Spores dark-brown, globose to ellipsoid, distinctly warted, 10-] 2 //
diam. or 10-13 x 7-10 /', occasionally reaching a length of l~) r-

156 Ustilago.

On Triodia mitchelli Beiitli.
Queensland — (Bailey).

Bailey kindly sent me a specimen from his Herbarium, and in an accom-
panying note remarked — " I obtained it many years ago and sent samples
to Berkeley and Broome, who at first named it Ustilago carbo TuL, after-
wards changing it to U. secjetum Berk.

In the original description of this species on Bouteloua ciUata Grisel. from
the Argentine, the spores are given as 11-15 x 8-13 i-i and said to be some-
what punctate. Clinton also records it on Triodia jmlcheUa H. B. and K.
from Arizona, and speaks of the spores as rather obscurely cchinulate, but
in the Queensland specimens they are prominently so.

This is a very variable species, and in the absence of sufficient material
on Triodia for fuller investigation, this particular smut will be retained here
for the present.

(Plate XXXI.)

Polygonum.

12. Ustilago hydropiperis var. columellifera Tul.

Berkeley. Journ. Linn. Soc. London XIII., p. 171 (1872).
Cooke, Handb. Austr. Fung. p. 327 (1892).
8ori produced in the ovaries, the solitary ovule of each being completely
transformed and replaced by the fungus ; the outer portion sharply
defined and compact ; composed of spore-like barren cells, forms
a distinct urn-shaped spore-receptacle, open at the top and with
reflected margin, the central por<-ion projects as a dark-j)urplish
body, the so-called columella, up to 4 mm. long, hollow in the centre,
composed of similar cells to that of the wall, and coated with a dense
mass of the violet-coloured spores.

Spores purplish, oblong to ovoid, but generally subspherical,
very finely echinulate, 10-13 n diam. or 11-12 x 8 / .
On Polygonum minus Huds.

Tasmania — Near Launceston, March, 1893 (Rodway).
On Polygonum sp.

Queensland — (Bailey).
In the transverse section of this fungus (PI. XXXII.) towards the base of
an affected ovary, the wall of the ovary is seen detached quite unaffected
by the fungus. Inside, the tissue of the ovule has been entirely replaced
by fungus cells, the centre being hollow. The inner colourless cells surround-
ing the cavity are similar to those on the outer side, and the dark-purple ring
between consists of the spores. The colourless cells readily separate from each
other and are subspherical, differing from the spores in having generally a
thicker wall, which is not echinulate. The spores gradually merge into them
on either side, and they are, in all probability, immature spores. When
fully developed, the outer wall splits at the top, forming an urn-shaped recep-
tacle, while the central portion elongates as the columella carrying some of
the spores with it.

The species of Avhich the above is considered a variety was made the type
of a new genus by I)e Bary, and named by him Sphacelotheca mainly on account
of the distinct spore-receptacle formed of fungus cells, but also because of
the central columella and the differentiation of the spore-layer into sterile

I'sfilago. 157

and fertile cells. The developiuent of this species, as described by l)e l^>arv,
will show so clearly the nature and origin of the different parts that it will
be given briefly before discussing the necessity for a new genus.

When the ovule is fully formed, the hyphae pass through the flower-stalk
into the ovary and reach the ovule through its funicle or stalk. There the
parasite penetrates the tissue to such an extent that the ovule is replaced
by a compact mass of densely interwoven hyphae with gelatinous walls.
The fungus is confined entirely to the ovule, and becomes differentiated into
a thick colourless outer wall, a central axile cylinder or columella, and be-
tween the two a dense mass of violet-coloured spores. The base of the ovule
remains undifferentiated, and there new hyphae are constantly being formed
which add to the height of the parts already formed and consequently give
them a cylindrical form.

The fully-formed wall consists of several layers of minute round cells,
similar in size to the spores and produced in the same way fi'om the hyjjliae
of the primary tissue, but with a colourless membrane. The columella has
generally the structure of the wall, and the spores are developed around the
columella in a dense ring about equidistaiit from the centre and circum-
ference. The wall of the ovary is not attacked by the fungus, and does not
follow the growth of the spore-receptacle so that it is soon ruptured. The
wall of the spore-receptacle itself is very fragile and readily bursts at the top
to allow the escape of the spores. The development and germination of the
spores are the same as in Ustilago, the compact mass of much-branched spore-
bearing filaments having gelatinous Avails as in that genus.

It will be seen from this description that the species differs considerably
from that of any other Ustilago, particularly in the distinct spore-receptacle
made up of fungus cells, but there are various gradations in the formation of
a fungus membrane enclosing the spores in different species, and the difficulty
is where to draw the line. The presence of a central columella is also not
uncommon, although it is often composed chiefly of the plant-tissues, and
the differentiation of similarly produced cells into colourless sterile cells, and
coloured fertile cells is foui\d in various other species of Ustilago, such as
U. cruenta, Cintractia as ('. leucoderma, and Sorosporium as S. panici-nnhacei,
so that the presence of a fungus membrane enclosing the spores cannot be
regarded as of generic value. While there is a general resemblance in this
variety to the type species which has already been recorded on Poh/c/oDum
minus in other parts of the world, yet there is sufficient distinction, perhaps,
to make it worthy of being classed as a variety. The cylindrical projecting
columella is very characteristic, and, on comparing the spores with those
from U. hi/dro pi peris in Rab. Fung. Eur. No. 2<)0l, they are slightly sniidler.

(Plate XXXII.)

( '(irc.r.
1:3. Ustilago olivacea (DC.) Tul.

Tulasne, Ann. Sci. Nat. Bot. III.. Vol. VIT.. p. 88 (1847).
Brefeld, Untcrs. Gesammt. Mvk. \'.. p. 1l'9 (1883).
Sacc. Syll. VII., p. iM (1888).

Ustilago catenata LudwiiX. Zeitschr. Pflanzenkr. III., j). 139
(1893).

8oi'i only j)roduced in some of the ovaries of the inflorescence, often
more or less concealed at first by the perigynium ; olive-brown
spore-masses, firmly agglutinated at first ; finalh' more or less
powdery and intermixed with conspicuous filaments.

158 I'sfilagfl.

Spores olive-brown, variable in size and shape, often arranged in
chain-like rows and accompanied by long hyaline filaments, sub-
spherical to ellipsoid or oblong to linear, densely warted, 6-7 /' diam.
when subspherical, and 7-13 x 4-(U /' when elongated.
In spikes of Carex fseudo-cyperus L.

Tasmania — Huon, Dec, 1894 (Kodway).
South Australia — Mount Lofty Eange, 1893 (Tepper).
A specimen was sent to Ludwig from South Australia hy Tepper on
a host-plant supposed to be Cyperus lucidus R. Br. He determined the smut
as a new species {U. catenata) but recognised it as being closely allied to U.
olivacea. Ludwig kindly forwarded me some of the original material, and it
was evidently the same as U. olivacea, but I presume Ludwig was mainly
influenced in making it a new species from being found apparently on a dif-
ferent genus of host-plant. On submitting the plant to L. Rodway, F.L.S.,
he determined it as unmistakably Carex pseudo-cijperus, so that I have made
Ludwig's species a synonym.

Spsgazzoni had already recorded it on this species from the Argentine
Republic, but Saccardo made it a variety — pseudocyperi — on account of the
spores being 6-12 x 6-10 //. We found no spores as broad as this, and have
retained the original species. This smut is confined to species of Carex and
chiefly those which grow under damp conditions. Only a few of the ovaries
of a spike are affected, but the rain readily spreads the spores over the parts
beneath. It is easily recognised, not only from the olivaceous tint over-
spreading the spike, but from the tufts of filaments which project from the
ovaries which are attacked, and it is this peculiarity chiefly Avhich has attracted
a considerable amount of attention to this species. Among the irregularly
twisted web of filaments there are two kinds to be distinguished — those
which produce the spores and those which remain barren. The spore-pro-
ducing filaments show the formation of spores at various stages. At first
the filaments exhibit swellings quite close to one another, like a string of
beads or a series of knots, then cross-partitions are formed separating each
swelling, the contents of which becomes a spore.

There are other filaments, however, which are sterile and do not form
spores, but are mixed up with the spores like the filaments composing the
capillitium in the Puff-balls. How these filaments originate and Avhat is their
function has not been explained, but probably they serve in some way to
scatter the spores over a wide area.

The characteristic elongated spores are usually found in chains from the
mode of their formation.

Germination. — ^This has l^een determined bv BrefekU both in water and
in a nutritive solution. The spores germinate readily in water after a few
hours, putting forth an exceedingly fine germinal tube, which elongates and
then becomes detached as a conidium. In the case of small spores this com-
pleted the germination, but with large spores a second conidium is formed.
The detached germinal tube gave rise to a secondary conidium and ended
there. In a nutrient solution the spore germinated as before, only giving
rise to a succession of conidia, each of which when detached produced a
secondary conidium, or several might remain attached to the spore and bud,
but large colonies were never formed. It will be seen from this description
that there is, strictly speaking, no germinal tube, it is unicellvdar and does not
differ from the conidium directly proceeding from it. Hence the only means
of multiplication is by sprouting conidia.

(Plate XXIX.)

Ustilago. 159

Sctaria.
14. Ustilago pertusa Tr. and Eaile.

Tracv and E-irle, Bull. Torr. Rot. ('lul). p. IT.-) (189.-)).
Saccl Syll. XIV., p. 415 (1899).
Sori ill ovaries, hird, compact, black, finally pulvinato.
Spores small, globose, brownish, epispore covered with piominciit
irregular spikes, very constant in size, 5-1) /' diam.
On Setaria macrostachya H. B. and K.

Queensland— 1890 (Bailey).
In the original description, the host is given as S. macrochaeta, but this is
evidently a misprint, as this grass does not occur in Australia.

In U. viridis Ell. and Ev. the spores are slightly smaller, and form a yel-
lowish-green coat on the outside of the seeds.

Ddiilhoiiia.
l.j. Ustilago reader! Sydow (in letter 1905).

Ustila/o a/wp>jn' McAlp. Agr. Gaz. New South Wales, p. 154

(189(5). ■

Sori in stems, leaves, and ovaries, black, pulverulent, usually destroying

entire inflorescence, at first enclosed by the leaf-sheaths Avhen in

ovaries, ultimately exposed and the spores dissipated, leaving the

rachis bare or with the glumes still attached.

Spores dark-brown, globose to ellipsoid, apparently smooth hut
delicately echinulate, 10-13 m diam. or 11-14 x 8-11 /'.
On Danthonia fznicillata F. v. M. — Wallaby grass.

Victoria— Burnley and Ardmona, Oct., 1892 (Robinson). Dim-
boola, Nov., 1892 (Reader). Myrniong, Dec, 1900 and 1908
(Brittlebank). Kergunvah and Killara, Nov., 1902 (Robinson).
Casterton, Dec, 1905" (Reader). Darebin Creek, Oct., 190(i
(C. French, jun.). Cheltenham, Oct., 1906 (Robinson). Emerald,
Nov., 1906 (McLennan). Camberwell, Dec, 1907, Oct. and
Nov., 1908 (C. French, jun.). Rainbow, Oct., 1908. Plenty
Ranges, Nov., 19 9 (C. French, jan.^ Angustown, Dec. 1909.
New South Wales— Penshurst, Nov., 1908 (Cheel).
South Australia— Port Elliot, Nov.. 19()I (Summers). Blumberg,

Nov., 1904 (Tepper).
Tasmania— Huon River, Jan., 1903 (Rodway). Ifoharf. -Ian.. !906
(Rodway). Devonport, Jan., 190') (Rol)inson).
On Danthonia sp.

Victoria— Carombv, Oct.. 1889 (Teppi-i). Wliittle.sea Ranges. Nov..
1898 (C. French, jun.)
U. danlhoniae Kalch. is (|uit(' distinct since the s])ores are given as 36 /(
diam.

I'his snpt is not at iiU uiicammon on DnMth.oiiia. attacking thi> leaves
and stems as well as the inflorescence, and it has, unfortunately, received a
variety of names. The earliest specimen, found in Victoria in 1889. was sent
through Tepper to Professor Saccardo-, who deterjnined it as Ustilnqo Icuco-
derma Berk. Berkeley's species was characterized liy being clothed exter-
nally with a white rugged crust, and was afterwards found to be a Cintractia
and named C. leucoderma (Berk.) P. Henn.'^ It has been found on Ri/ucho-
sfora aurea Vahl. in Viutoria, but it i- (jiiite distinct from the smut on Dan-
thonia.

i6o Usiilago.

Then in 1892 Massee determined a specimen sent from Victoria bv Reader
on Danfhonia penicillnM as TJstUaqo destruens Schieclit., and the same species
had been previously recorded on Danthonia by Coolie^. Finally, in 1896*, I
described what was really the present species under the name of U. agrofyri,
as there was a mixture of material of Agropyron and Danthonia which
was afterwards separated out.

It simply remains now to compare this species Avith that of TJ . destruens
Schlecht. = U. pamci-miliacei (Pers.) Wint. = Sprosporiiini 'panici-miliacei
(Pars.) Takahashi.

As Takahashi^ has clearly shown the species referred to by Massee is a
Sorosporium and not an Ustilago, the spore-balls being rather evanescent at
maturity. The smut pustules are covered by the epidermis of the host with
a layer of sterile hyphae in close contact and fibro -vascular bundles traverse
the pustule together with hyphal strands.

The external appearance as well as sections of U. readeri clearly show how
distinct this species is. On the stem it forms elongated bJister-like swellings,
and the leaden-coloured epidermis soon raptures to allow the escape of the
spores. It sometimes completely surrounds the stem which is longitudinally
furrowed as the swollen epidermis bursts and exposes the spores.

A cross-section of the stem shows the hollow cavity in the centre, and in
the plant tissue immediately beneath the epidermis scattered patches of
spores are developed. Sometimes these isolated patches blend here and there
and form a larger one, and finally the epidermis is elevated and ruptured to
allow of the escape of the spores.

A cross-section of the axis of inflorescence shows the central core of plant
tissue either solid or with a small cavity, and surrounding that the patches of
spores are developed, so numerous and so close together, that they ultimately
form a dense continuous mass, covered by the epidermis until it is ruptured.

A cross-section of the ovary shows the central vascular bundles comple-
tely surrounded by dense masses of spores. The spore-forming hyphae
have evidently penetrated the larger vessels as they are seen to be filled with
spores at different stages of development, and finally the entire tissue of the
ovary would be replaced by spores.

Germination. — The spores germinated readily in water and also very
luxuriantly in Cohn's modified solution. Fresh spores and spores one year
old readily germinate, but when the material is two years old only an occa-
sional spore germinates. It is one of the easiest sjDores to germinate, and if
not too old can always be relied upon to do so in a few hours. Spores taken
from Danthonia psniciUata F. v. M., collected in December, 1905, germinated
in July, 1906, and also in December of the same year. The germinating
spores figured (PL LIII., Figs. 203, 204, 205) are from Danthonia penicillata
collected in December, 1908, and they were germinated at once.

The spores when germinated in water put forth in a few hours
a straight promycelium which at first is non-septate (PL LIII., Fig. 203).
Then it elongates and becomes divided by several septa, when
it may either produce conidia (PL LIII., Fig. 204) or elongate further
(PL LIII., Fig. 205). The conidia are produced laterally and termin-
ally, only a few lateral and one apical. They are colourless, cylin-
drical, rounded at the ends, 6-9 /.t long, and may or may not be attached by
a short sterigma. Only occasionally one produces another by budding while
still attached. The promycelium, however, may and often does forego the
formation of conidia. It grows out at the apex of the septate portion or

Ustilago. i6i

laterally or even direct from the spore as a slender, elongated, more or less
wavy filament, which may reach a length of 200-300 p. At first it is non-
septate, but afterwards becomes septate and even branched. The spore
may give rise to two promycelia, one being usually shorter than the other.

Spores immersed in liquid do not germinate as readily as those floating
on the surface. Thus, after 18 hours on one occasion, the spores in the water
had failed to germinate, while by simply altering the focus and examining
the spores on the surface, they were all found, with very few exceptions,
to have germinated. This germination at the surface was in various stages.
Some had just put forth a short, slender, simple promycelium ; others had
produced an elongated, septate promycelium ; and still others had put forth
slender branches from the segments of the promycelium. In some cases the
septate promycelium tapered out into a long wavy filament, and when the
liquid began to dry up, these filaments became exceedingly long and exceed-
ingly wavy, and ultimately became detached.

(Plates XVIIL, XXXI., LIII.)

Stenotaphnim.

16. Ustilago stenotaphri McAlp.

McAlpine, Agr. Gaz., New South Wales, Vol. VI., p. 758 (1895).
Sacc. Syll. XIV., p. 415 (1899).
Sori on stem and leaves, giving them a blackened appearance as if charred,
compact, completely surrounding part attacked, which is usually the
younger growth.

Spores dark-brown, subglobose to ellipsoid or irregular, smooth,
16-17 X 10-13 p.
On Stenotaphrum glabrum Tr'in. (Buffalo grass) = S. americanum Schrank.

Victoria— Kew, June, 1890 (Ralph).
There is another smut affecting Buffalo-grass, but it occurs in the sjjike-
lets, and the spores are only 5-9 /< in length. This is U. affinis Ell. and Ev.,
but it was also named U. stenotaphri by P. Hennings (1898) and Massee
(1899) respectively. The host-plant is frequently regarded as an introduced
grass, but it is a true native of Australia, as well as of America.

(Plate XXXII.)

Amphipogon , Xeurachtie.
17. Ustilago tepperi Ludw.

Ludwig, Bot. Centr. 341 (1889).
Sori in stem and flowers, black, powdery, destroying the parts affected.
Spores globose or shortly ellipsoid, brown, papillate or rather
aculeate, 12-17 /.i diam.
On Amphipocjon strictus R. Br. and Neurachne ahpecuroides R. Br.

South Australia — Torrens Gorge and Highbury Scrub (Tepper).
I could not obtain a specimen of this smut, and have never met with a
smut of any kind on either of these hosts.

1 62 Ustilago.

Polygonum.
18. Ustilago utriculosa (Nees) Tul.

Tulasiie, Ann. Sci. Nat. Bot. III., p. 102 (1847).
Cooke, Hanclb. Austr. Fung., p. 326 (1892).
Brefeld, Unters. Gesammt. Mvk. XII., p. 139 (1895).
Sacc. Syll. VII., p. 476, (1888).

Sori inside floral envelopes, causing the blossoms to become swollen,
dark-violet to purplish, powdery.

Spores globose or subglobose, occasionally elHpsoid, transparent,
violet, reticulated with verv high ridges which form meshes 2-3 jx
wide, 10-13 /» diam. or 11-13 x 8-11 /..

On Polygonum minus Huds.

Victoria^ — Near Melbourne, June, 1884 (Reader). Tambo River,

Feb. (National Herbarium). Casterton, Dec, 1908 (Reader).
Queensland— (Bailey, No. 59).

On Polygonum frostratum., R. Br.

victoria— Dimboola, March, 1898 (Reader).

On Polygonum hydropiper L.

Victoria— Tinandra, May, 1909 (Whittekers).

The Queensland specimen was labelled Sphacelotheca hydropiperis. The
swelling of the ovaries and the dark purple spore-masses are very
characteristic.

Spore formation. — A cross-section of the ovary shows that the spores
originate from hyphae adjoining the vascular bundles, where they are seen
as minute colourless specks, gradually acquiring a round form and a netted
epispore, with the development of a violet colouration.

Germination. — This has been described and illustrated by Brefeld^.
The spores do not germinate, as a rule, in the autumn when they are formed,
but in the following summer, after lying on damp earth. In water they pro-
duce a triseptate promycelium, which soon gives rise to lateral and terminal
elliptical conidia. These become detached and again produce smaller conidia
without further development. In a nutritive solution, there is a more
luxuriant formation of conidia, with unlimited capacity for sprouting in a
yeast-like manner. Neither fusion of the conidia nor their germination
has been observed.

Spores from a specimen of Polygonum hydropiper L., obtained in May,
were placed in tap Avater towards the end of September. In two days they
germinated freely, and in three days the great majority had germinated. The
promycelium was generally three septate, 3-4 /t broad, and branches were
frequently produced beneath the septa, the terminal segment often giving
rise to a slender elongated filament. Conidia were produced both laterally
and terminally, but the formation of branches from the segments of the pro-
mycelium was more common. They generally arose from the basal and
terminal segments and reached a length of 60 f/, while the promycelium itself
was only 16 ^i on an average.

(Plate XXXII.

Mclaiiopsicliiui}).. 163

MELANOPSICHIUM Beck.

Mycelium intermixed with tlie diseased plant tissues, which arc hollowed
out into cavities, containing the spore-bearing gelatinous hyphae.

Sori on various parts of the host, forming compact, hard, conspicuous,
gall-like masses, black when cut across, and the galls consisting of a mixture
of plant tissue and hyphae.

Spores single, as inUstilago, and germination similar, developed in cavities
of various shapes and sizes, which are sometimes confluent.

There is only a single species of this genus known, which was formerly
placed under Ustilago. It was originally found in South America and now
in the United States and Australia. The development of the spores in cavities,
the walls of which consist of the plant tissues and the mycelium intermixed,
is the characteristic feature of the genus.

Australian species, 1.

'Pohjqonum.
19, Melanopsichium austro-americanum (Speg.) Beck.

Beck, Ann. K. K. Natur. Hofmus. Wien. p. 22 (1894).
Sacc. Syll. VII., p. 457 (1888).

Ustilaqo austro-americana Speg. Fung. Argent., pug. 4, No. 45
(1881)
Forming compact, hard, rough, lobed, oblong, ruddy-brown galls around

joints of stem, up to 1 cm. in size, black when cut across.
The gall consists of the various tissues of the stem — epidermis, cortex,
and fibro-vascular bundles — for the most part hollowed out into
cavities which are the sori.
Sori of various shapes and sizes, generally marked off by definite tissue,
round to oval or oblong, adjoining one another and sometimes con-
fluent ; ranging from 70 /i long w^hen young up to 500 /< or more
when mature.

Spores olivaceous, ellipsoid to ovate, prominently echinulate,
10-14 X 7-8 II.
On Polygonum sp.

Queensland — Near Brisbane, April, 1879 (Bancroft).
The spores are developed in gelatinous hyphae which deliquesce and set
free the spores in the cavity. As the sori are completely surrounded by the
outer tissues of the stem, the spores can only escape by the decay of the tissue,
or by the absorption of water and the oozing out of the ripe spores. Only
a single species of this genus has, so far, been known, and although in the
United States specimens the sori were chiefly in the inflorescence, and in
South America, where it was first found, chiefly on the leaves, yet the general
characters of this specimen agree so well with the type, that I have no hesita-
tion in referring it to the same species. A specimen examined from Clinton's
Ustilaginese C. 35, on Polygonum lapatJiifolium had the same characters.

This Queensland specimen was given by Cooke in his Handbook of
Australian Fungi as Ustilago emodensis Berk.

Berkeley founded this species on a single specimen from Tonglo, in the
Sikkim Himalaya, 10,000 feet high, and he described it as forming a lobed
tubercle ; spores ovate or elliptic, deep lilac, smooth, very minute, traversed

G 2

164 Mdanopsicliiitm — Cintraciia.

by radiating forking threads. Then Cooke supplemented this description
later by giving the size of the spores as 12-15 yi diam. and their surface is
described as delicately rugulose. There is no trace of lilac in the spores of
the Queensland specimen, which is, however, at least a quarter of a century
old, nor of the bifurcating filaments.

The original determination of this species as Ustilago emodensis Berk.
was made by Mr. Broome, as the following note from Mr. Bailey will show : —
" My only specimen of Ustilago emodensis was given to me by the late Dr.
Joseph Bancroft, who found it on Polygonum sp. at Kelvin Grove, Three-
mile Scrub near Brisbane, April, 1879. It was determined by the late Mr.
Broome."

Massee^ has made Ustilago treuhii Solms. a synonym of U. emodensis
Berk., but it has certainly no relation to the Queensland specimen. Dr.
Treub kindly sent me specimens from Java on Polygonum chinense, and they
show the clustered outgrowths, up to 1 inch long, forming a swollen head like
a Cantharellus. The swollen head splits across and allows the escape of the
violet-tinted spores, which are globose to ellipsoid, very delicately echinulate
and 7-8 /w diam. or 7-8 x 5-6 /l/. Dieted describes them as smooth and only
4 i-i diam. The arrangement of the spores and their size and colour are
altogether different to those of Melanopsichium.

On forwarding photographs of Melanopsichium austro-americanum and
Ustilago treuhii to the director of the Royal Gardens, Kew, he courteously
replied — "that an examination of the original specimen of Ustilago emodensis
Berk, had been made. The plant proves to be very different from Bailey's
Queensland plant, having spores irregularly globose, violet, thick-walled,
almost smooth, and measuring 5-7 ^1 diam. Ustilago treuhii Solms. (Exsicc.
No. 56) has also been examined and it is, as stated by Mr. Massee, practically
identical with Berkeley's species."

Germination. — This has been described and figured by Norton-. He says —
" It begins in water after a day or two and proceeds slowly. The promycelia
are small and slender, frequently branched, and irregular in shape. Conidia
few."

(Plate XXXIII.)

CINTRACIIA Cornu.

Mycelium usually persistent in the diseased parts, with a compact
gelatinous base from which spore-bearing filaments arise, in which the
spores are successively differentiated from the inside outwards.

Sori on various parts of the host, forming a compact usually firmly
agglutinated spore-mass, generally surrounding a central columella of plant
tissue.

Spores single, as in Ustilago, and germination the same, or only slightly
modified.

This genus was named by Cornu after a distinguished French botanist
called Cintract. It is not always recognised as distinct from Ustilago, but
the distinction lies in the spores remaining firmly agglutinated and compact
for a considerable time, while the spores themselves are developed successively
<rom a fertile stroma. Eventually they are generally freed by the absorp-
xion of water, as the host -plants usually occur in damp situations and the
moisture at the -same- time insures germination. The hyphae arising from

Cintractia. 165

the gelatinous base may be entirely spore-bearing, or there may be strands
of undifierentiated hyphae, between which the fertile hyphae produce masses
or pockets of spores.

The characteristic features of Cintractia are the central columella of
plant tissue, the development of spores from the inside outwards, and the
firmly agglutinated spores. As might be anticipated, there are some cases
where it is difficult to say whether the species should be regarded as an Usti-
lago or a Cintractia, as in Ustilago avenae, for instance, where there are only
the powdery spores to separate it from Cintractia, but if the three characters
given above are observed, then the genus will be a very convenient one.
Australian species 11.

Fimbristylis,
20. Cintractia axicola (Berk.) Cornu.

Cornu, Ann. Sci. Nat. Bot. p. 279 (1883).
Cooke, Handb. Austr. Fung., p. 324 (1892).
Sacc. Syll. VII., p. 480 (1888).

Ustilago axicola Berk., Ann. Nat. Hist., p. 200 (1852).
Ustilago fimbristi/Us Thuem., Bull. Torr. Bot. Club, VI., p. 95
(1875).
Sori usually at base of flower stalks, forming compact, black, roundish
swellings, at first covered with whitish false membrane, which soon
disappears, exposing the dark-coloured spore-masses.

Spores yellowish-brown, globose to subglobose when seen flat ;
compressed laterally, and appearing oblong when seen edgewise ;
smooth, average 13-14 /( diam. or 13-17 x 8-14 /(, intermixed
with hyaline, short, thread-like filaments derived from the stroma.

Sterile cells scattered among the spores, large, colourless, some-
times at least twice as large as the ordinary spores, and round^ or
irregular in shape, owing to undergoing gelatinization.
On Fimbristylis sp.

Queensland — Brisbane Kiver (Bailey).
Victoria (Mrs. Martin).
Fimbristylis is a small grass-like sedge, and when growing on wet un-
drained land, the smut is very abundant in some seasons. This was made
the type of a new genus founded by Cornu and differs from Ustilago in the
formation of a stroma or compact mass of filaments, from the outside of which
hyphae project, in which spores are successively developed.

Spore formation. — A section of the stalk shows the persistent mycelium
in the diseased portions composed of delicate colourless hyphae which become
aggregated into a dark-brown stroma around the medulla, and fibro-vas-
cular bundles.

Arising from the stroma and directed outwardly are dark-brown strands
of hyphae, slender and long-jointed, with the fertile hyphae between form-
ing pockets or compartments of spores which are at first young and pale and
gradually become dark antl mature. The outer spores are at first held
together by the remains of the strands from the stroma, but on maturing
gradually separate.

(Plate XXXVII.)

1 66 Cintractia.

Carex.
21. Cintractia caricis (Pers.) Magn.

Magnus, Abli. Bot. Ver. Prov. Brand., XXXVII., p. 78 (1896).
Ustilago caricis (Pers). Ung. Eiufl. Bodens, p. 211 (1836).
Anthracoidea caricis (Pers.) Bref. Unters. Gesammt. Myk. XII.,
p. 144 (1895).

Sori in ovaries, at first hidden by the perigynium, then exposed, pro-
tected at first by a white membrane composed of semi-gelatinized
cells, which soon disappear.

Spores firmly agglutinated, dark olivaceous, generally irregular,
polygonal, sometimes subspherical or ellipsoid, finely punctulate
16-23 X 9-15 i-i.
On Carex hreviculmis R. Br.

Victoria — Mount Blackwood, Jan., 1903 (Robinson).
Tasmania — Hobart, Dec, 1907 (Rodway).
The smutted ovary is hard and black on the outside as if the spores origi-
nated there, but the spore-forming layer arises exclusively in the epidermis,
the cells of which are ruptured by the expanding spores. They are at first
minute, colourless, and of an irregular shape, and punctulate all over, then
they become dark and opaque at the circumference, forming a dense mass of
agglutinated spores. The fungus winters in the rhizome, so that the mycelium
is perennial. Brefeld^ has made this the type of a new genus, Anthracoidea,
on account of the special mode of germination.

Germination. — The spores do not germinate at once but remain dormant
till the following spring. Then they germinate in water and push forth a
germ-tube into the air, which has not only a few septa, but is divided at the
apex, so that each of the two cells produces ellipsoid conidia. The upper-
most cell is elongated to form a sterigma — bearing conidia, which arise near
one another and form an irregular head, if not interfered with. The ripe
and fallen conidia do not sprout but only form simple germ-tubes, until
their contents are exhausted.

It is this division of the apex of the aerial promycelium into two cells,
each of which produces conidia, that Bref eld considered sufficiently distinct
to form a new genus, which he named Anthracoidea.

(Plate XXXIV.)

Andropogon.
22. Cintractia columellifera (Tul.) McAlp.

Ustilago carbo, var. columeUifem Tul., Ann. Sci. Nat. Bot. p. 81
(1847).
Sori in ovaries which are at first enclosed in the glumes. The walls of
the ovary are brown and firm, forming a continuous membrane,
but gradually decay in patches, exposing the dense agglutinated
mass of dark-brown spores with a central columella of plant tissue.
Spores pale-brownish to olive-brown, smooth, globose to sub-
globose, with finely granular vacuolated contents, very regular in
size, 7 fi diam., occasionally 8 jn.

Cintractia. 167

On Andropogon australis Spring.

Queensland — Kockhampton (National Herbarium).

This species is labelled Ustilago carho var. columeUifera, but the develop-
ment of the spores from the central columella outwards indicates that it
belongs to the genus Cintractia.

Spore formation. — A cross-section made just at the base of the ovary
where it joins the stalk shows a central core of plant tissue, consisting of
fib ro -vascular and parenchymatous tissue. Fungus filaments permeate it
towards the outside and appear as a layer from which the spores are pro-
duced. At the base the younger spores are seen which pass into the mature
form and constitute a dense dark agglutinated layer, the whole being at first
enclosed in the wall of the ovary.

I am indebted for the determination of this host-plant to Professor Ewart,
Government Botanist, but when distorted by the fungus, determination is
rendered difficult.

It differs from U. Ischaemi Fckl, found on the same genus, in which the
sori often involve the entire inflorescence, reaching a length of 10-30 mm.,
and provided with a fungus membrane which soon ruptures.

(Plate LIII.)

Panicum.
23. Cintractia crus-galli (Tr. and Earle) Magn.

Magnus, Ber. Deut. Bot. Ges. XIV., p. 392 (189G).

Sacc. Syll. XIV., p. 421 (1899).

Ustilago crus-galli Tracy and Earle, Bull. Torr. Bot. Club, XXII.,

p. 175 (1895).
Cintractia seyniouriana Magnus, Ber. Deut. Bot. Ges. XIV.,
p. 217 (1896).
Forming large irregular or elongated swellings which are thro\\-ii into
numerous brain-like folds, generally largest and most condensed
at the nodes and elongated or less swollen along the internodes,
up to 9 cm. long and 3 cm. at broadest part ; isolated minute pus-
tules also occur only 2 mm. long, involving the panicles, but very
rarely on leaves.
The sori are protected by a tough hispid membrane, which is derived
from the parent plant as it contains fibro-vascular bundles, and
this membraiie ultimately ruptures irregularly, disclosing the black
powdery spores.

Spores formed from a matrix or stroma and arranged in rows
with separating walls between of long-membered hyphae, globose
to ellipsoid, olive-brown, densely echinulate, 8-11 /i diam. or 8-10 x
<J'5-7 //, occasionally reaching a length of 11 '5 /'.
On Panicum crus-galli L. — BarnyarJ-grass.

New South Wales— Kooty Hill, March. lOOii and Marcli. 1907
(Hattrick).
The plants were found grownig m sandy soil and quite a number of them
■were affected. In some cases, a healthy inflorescence was produced from
a lower node, and a large gall formed around an upper node, while the in-
florescence proceeding from it would be destroyed by the smut. In other
oases, several larger or smaller galls would be formed at a lower node and

1 68 Cintractia.

the panicle proceeding from it would be affected by the smut, but from higher
nodes of the main stem a healthy panicle would be produced. Galls were
also formed on the stem independent of the nodes. The membrane consists
of epidermis slightly cuticularized with elongated hairs, large-celled cortical
parenchyma with starch granules and fibro-vascular bundles showing spiral
vessels.

This species is widely distributed in North America and in the numerous
American specimens examined by Magnus, the swellings or galls occurred
on the upper internodes of the stem, seldom on the long internodes beneath
the well-developed inflorescence, and very rarely on the leaves. The host-
plant is cosmopolitan and considered by the late Baron von Mueller
to be indigenous to Australia.

Spore formation. — In small and presumably young galls the individual
spores were seen at different stages of development, imbedded in a gelatinous
mass, due to deliquescence of the hyphae and small portions of the delicate
and distinct hyphae were still visible. Magnus ^ has clearly described and
illustrated the formation of the spores. Plate-like outgrowths from the axis
penetrate the pustule and branch in various directions (PI. XXXV., Fig. 79).
Among these cells as well as those of the axis itself, a mycelium grows and
spreads and forms a fungus layer both at the base of the pustule and on the
surface of the plate-like outgrowths. This constitutes the matrix or stroma
formed by the intercellular mycelial filaments interwoven with one another
into a felt-like mass. It is from this matrix the upright hyphae proceed, in
which the spores are formed (PI. XXXV., Fig. 80). The spores are first
formed at the base of the filaments and proceed outwardly in rows, while
separating them into compartments are strands of the elongated hyphae.
Not infrequently such a compartment may be further subdivided by the
development of a new strand of hyphae, showing that the matrix still retains
the power of forming either sterile or spore-forming hyphae.

It is worthy of notice that the formation of new spores at the base begins
with a characteristic twisting of the hyphae into a ball. As the hyphae unroll
and become upright, the spores begin to appear.

Germination has not been described.

(Plates XXI., XXXV.)

Rotthoellia.
24. Cintractia densa McAlp.

Sori produced in inflorescence, destroying the individual florets, and
arranged in compact dark-brown masses along the rachis, at first
covered with greyish membrane, but soon falling away and expos-
ing the spores.

Spores brownish, globose to subglobose or ellipsoid, with finely
granular contents, smooth, 6 "5-9 '5 /* diam. or 9-9*5 x 6 '5-8 /i/.
On Botiboellia com/pressa L.

Victoria — Biirnley, near Melbourne, Nov., 1892 (Eobinson).
Whittlesea Ranges, Nov., 1898 (C. French, jun.). Ivillara,
Oct., 1902, March, 1903, Oct., 1906, March, 1907 (Robinson).
Ararat, May, 190*4 (C. French, jun.). Killara, March, 1908.
River Flats, Shepparton, April, 1909. Near Melbourne, Dec,
1909 (C. French, jun.).
The spores form dense compact masses along the rachis which is some-
times 5J cm. long.

Cintractia. 169

&pore formation. — A cross-section of the racliis shows the plant tissue in
the centre and outside of the fibro -vascular bundles is the compact mass of
filaments from which the spore-bearing hyphae are produced. These pro-
jecting hyphae produce the minute colourless spores at once, which gradually
become brown and mature towards the outside. The young spores at first
are rather angular, but as they approach maturity they become ellipsoid.
Interspersed here and there among the fully formed spores are groups of cells
with colourless and gelatinized walls, identical with those of the outer mem-
brane.

Germination. — The smutted grass was very common at Killara in Oct.,
190G, and the spores germinated freely in water, both at that time and several
months later. The promycelium was four-celled, with a length of 3G /( antl
3 i-i broad, the protoplasm at first being highly vacuolated before the septa
were formed. Conidia are produced both laterally and terminally, and some-
times as many as three are formed at the apex in a tri-partite manner. They
are cylindrical to fusiform, 6-7 /j. long, and produce secondary conidia while
still attached. Spores were taken from specimens obtained in March, 1903,
and they also germinated freely, showing that they are able to retain their
germinating power for nearly five years.

Plates XXIII. , XXXVI. , LIII.)

Distichlis.
25. Cintractia distichlydis McAlp.

Sori surrounding internodes usually for their whole length, at first en-
veloped by the leaf-sheaths and also covered by the epidermis,
which gradually breaks away, exposing the dark-brown dense spore-
masses.

Spores bright olivaceous individually, globose to shortly ellip-
soid, smooth, minute, 5-6 n diam. or 6-7 x 4-5 "5 fi.
On Distichlis maritima Eafin.

Victoria — Oct., 1891 (National Herbarium — C. French, jun.).
Elsternwick, March, 1900 (C. French, jun.). Sandringham
Sept., 1905. Elsternwick, Feb., 1910 (Brittlebank).
This grass is sometimes much reduced in size owing to the fungus.
Spore formation. — Sections of the diseased stems show the tissues of the
plant in the centre and on the outside of the fibro-vascular bundles the spore-
forming hyphae arise. The hyphae with elongated joints soon begin to form
spores which are at first minute, rounded and colourless, but graduallv
towards the circumference they increase in size, assume an olivaceous tint
and become mature.

Ustilago hypodi/tes (Schl.) Fr., is given on this host in Arizona by Clinton*
and wliile there is a general resemblance, yet on comparing the spores of
C. distlchh/<lis with those of C. hi/pod>/tes the average size of the former is seen
to be decidedly larger than the latter.

Germination. — This takes place equally well in water or in a imtritive
solution such as somatose, in the course of 24 hours. The germ-tube is
elongated, 1-4 septate, with finely vacuolated contents at first, then graiudar,
30-54 ft long and 3 /.i broad. Conidia are produced both laterally and ter-
minally, generally on slender stalks. They are oval, hyaline, with finely
granular contents, 4-7 n long, and sometimes two may be produced at the
apex.

(Plates XXIV.. XXXVI.)

170 Cintraciia.

Anthistiria^
26. Cintractia exserta McAlp.

Sori ill spikelets, at first enveloped by a grayish membrane which gra-
dually decays, exposing the dark-brown to black mass of spores.
The elongated spore-mass, generally about | cm. long, consists of
several diseased and deformed spikelets blended together and a
central core of plant tissue running through.

Spores olivaceous, smooth, globose to subglobose, or shortly
elliptical, sometimes slightly angular, 6-8 ^t diam. or 6-8 x 6-6*5 fji.

On Anthistiria ciliata L. f. — Kangaroo grass.

Victoria — Kiewa Valley, Nov., 1902 (Eobinson). Plenty Kanges,.
Nov., 1909 (C. French, jun.).

In order to understand the appearance presented by this smut, it is ne-
cessary to know the structure of the normal inflorescence. The fertile spike-
lets bear a long, rigid, sinuous awn, over 6| cm. long, and this has generally
disappeared in diseased specimens so that they are readily recognised. The
ovaries are also shortly stalked, and since the development of the ovary is
prevented by the smut, it is the stalk which is distorted and destroyed by it.
Several undeveloped spikelets have become blended together, so that in longi-
tudinal section there are several such stalks seen.

Pi Sfore formation.— In a cross-section of a diseased spikelet the relation
of the various parts is clearly seen. There is an outer colourless layer of tissue,
representing the enveloping membrane and consisting of an epidermis of
flattened cells and fungus filaments beneath. There is also a central core
of plant tissue, consisting of parenchymatous cells studded with fibro-vas-
cular bundles, and the whole is surrounded by a ring of fibro-vascular bundles.
The parenchymatous tissue and a portion of each bundle are stained blue by
Schulze's solution, showing the presence of starch. Between the central
core and the outer membrane there is a dense mass of spores, the formation
of which is clearly seen. Surrounding the ring of fibro-vascular bundles
is the colourless stroma from which proceed the spore-bearing filaments. The
spores are seen at first as minute colourless points, soon assuming a round or
oval shape. They are at first embedded in the gelatinous mass formed by
the deliquesced walls of the spore-bearing hyphae. Gradually they become
more or less rounded in shape, acquire an olivaceous tint, and with a firm
wall they become the mature spores. They are closely aggregated together
towards the outside and the development is clearly from the centre out-
wards, all the hyphae being spore-forming.

Scattered among the spores here and there and sometimes forming chains
as in Plate XXXVIII., Fig. 100, there are colourless cells, generally resembling
those inside the epidermis forming the membrane, but they are as a rule
larger, thicker walled, and apparently undergoing rapid division. They
are stained yellow by Schulze's solution like the cells of the membrane. The
origin of these cells is apparent, and may be traced to the inner layer of the
membrane. The sterile fungus threads constituting the membrane tend to
break up towards the interior into their component cells or rows of cells.
The individual cells become globose or oblong with much-thickened walls,
which always remain hyaline, and these cells become detached and mixed up
with the spores.

(Plates XVI., XXXVIII.)

Ciutractia. 17 1

Dichehchne, Slifa.
27. Cintractia hypodytes (Schl.) Dietel.

Diotel, llemibasidii in Eno'I. and Prant. Naturl. Pflanzenf.,

p. 8 (1900).

Sori linear, at first covered by sheath, extending the entire length of the

upper intcrnodes and completely surrounding them with a firm

blackish coat of agglutinated spores, which ultimately become

powdery.

Spores in a dense layer, minute, dark olivaceous, globose or shortly
ellipsoid, with granular contents, smooth, held together by a gela-
tinous material, 4-5 /« diam. or 4-6 x .3-4 /<.
On Dichehchne crinita Hook f.

Victoria — Ardmona, 1895 (Robinson). Emerald, March, 1907
(McLennan). Dookie, Dec, 1907. Dookie, Nov., 1908 (Brit-
tlebank). Myrniong, Jan., 1910 (Brittlebank).
South Australia — Banks of Torrens River, Adelaide, Oct. (Tepper).
On Stifa flavescens Labill.

Victoria — Myrniong, Nov., 1904.
On Stipa setacea R. Br.

Victoria — Ardmona, Nov., 1898 and 1899 (Robinson) ; Mvrniong,
Dec, 1897 and 1902 (Brittlebank).

The upper internodes particularly are more or less completely surrounded
throughout their entire length and the pedicels of the spikelets are often
affected.

Generally the sheath encloses the diseased portion and there is little or
nothing to indicate a smut beyond the absence of an inflorescence.

Spore formation.— A cross-section of the stem shows the tissues of the
plant to be apparently unaltered, only the surface composed of the epidermis
is rather irregular in its outline. The mycelial hyphae ramify in the paren-
chymatous cells and reaching the surface form a compact gelatinous mass
of filaments. The outwardly directed spore-forming hyphae show the spores
in various stages of development, at first minute and colourless and radiating
in lines until they become fully mature and coloured. They form a continuous
dense layer on the outside, where they are held together by a gelatinous
material, but Avhen thoroughly mature they fall away readily from the dry
stems.

A specimen of Ustilago hypochjtes (Schl.) Fr. on Stipa spartea Trin., in
Clinton's Exsicc. Ustilag. C. 71, showed the same structure and in sections
where spore-formation was not too far advanced the spores were seen to be
formed from the inside outwards.

Germination. — A brief description has been given by Brefeld^ and an
illustration by Winter^. Brefeld says that the spores germinate readily in
water and in nutritive solutions they form mycelial hyphae, but in numerous
cultures long-continued he did not succeed in obtaining conidia. "Winter,
however, figures a spore germinating with one conidium. Plowright^ says —
" Although I have tried many times, I have never succeeded in getting the
spores of this species to germinate," and yet according to Berkeley-, the
smut may be prest^rved in a garden for years by simply introducing infested
plants.

(Plate XXXIV.)

172 Cintraciia.

Rynchospora.

28. Cintractia leucoderma (Berk) P. Henn.

P. Hennings, Hedw. XXXIV., p. 335 (1895).
Sacc. Syll. XIV., p. 420 (1899).

Ustilago leucoderma Berk. Ann. Mag. Nat. Hist., 2 Ser. IX.,

p. 200 (1852).
Cintractia hrugiana Magn. Engl. .lahrl). XVII., p. 490 (1893).

Sori surrounding flower stalks and stems, forming conspicuous elongated
bodies 3-30 mm. long, covered with a thick white crust of false
membrane, which gradually flakes away, leaving exposed the dense
black spore-mass.

Sterile pale coloured thin-walled cells, scattered among the spores,
with margin rather irregular, due to gelatinization.

Spores dark-brown, opaque, finely warted, globose to oblong
or angular, 13-16 }.i diam. occasionally 18 /t long.

On Rynchospora aurea Vahl.

Queensland — Bundaberg (Bailey).

Queensland— Gatton, Sept., 1898 (Shelton, per Bailey'').

The clear colourless spores produced inside gradually assume a smoky-
brown colour, then become darker towards the outside, and gradually fall
away as they mature. Although Berkeley describes the spore as smooth,
it is decidedly but finely warted.

The thick white crust constituting the false membrane is very con-
spicuous and may gradually become detached and fall away piecemeal from
the host-plant.

It is interesting to trace the history of this species from its earliest naming
by Berkeley, in 1852, until it was changed to Cintractia leucoderma by P.
Hennings in 1895. The original specimens were found on the sheaths of some
Sedge in the island of Saint Domingo, investing them with a white rugged
crust, and the spores were described by Berkeley as being perfectly smooth,
and 17 yn in diam. Next it was recorded on Cyperus rotundus L. (Nut-grass)
from Queensland by Dr. Cooke in 1892, and by F. M. Bailey in 1898. In 1893
Magnus determined a smut on Rynchospora gigantea Willd. as Cintractia
hrugiana, which P. Hennings showed in 1895 to be a synonym of this species
and therefore named it C. leucoderma.

Finally in 1890, Saccardo determined a smut on Danthonia from Vic-
toria as JJ . leucoderma Berk., but on receiving a specimen of the same material
from Professor Ludwig, I found it to be the common species on this genus
of grasses, viz., JJ. readeri Syd. A specimen from the National Herbarium
labelled Ustilago leucoderma on Cyperus ? was forwarded to Miss Annie
Lorrain Smith of the British Museum. She determined it as Cintractia
leucoderma and was able to settle the identity of the host-plant as Rynchospora
aurea Vahl. The National Herbarium specimen said to be on Cyperus is
probably the same as the specimen from Bailey in which case the only host
is Rynchospora.

Germination not described.

( Plate XXXVII.)

Ciniractia. 173

Androjwgon.

29, Cintractia sorghi-vulgaris (Tul.) Clint.

Clinton, liuU. 111. Agr. Exp. 8ta. No. 47 (1897).
Sacc. Syll. VII., p. 4.5G (1888).

Sponsorium sorghi Link (182.j).
Tilletia sorghi-vulgaris Tul. (1847).
Ustilago sorghi (Link) Pass. (1873).
Ustilago tulasnei Kuehn (1874).
Sphacelotheca sorghi (Link) Clint. (1902).

Sori generally in the ovaries, occasionally in the stamens, forming oval
to oblong or cylindrical projecting bodies up to 6 mm. in length,
at first protected by a fungus membrane which ultimately ruptures
at the top, allowing the escape of the dark -brown spore mass and
exposing the distinct columella composed of plant tissues.

The fungus membrane is composed of hyaline, subglobose to
oblong cells, on an average 9-13 f.t long.

Spores more or less agglutinated, globose to subglobose or occa-
sionally shortly elliptical, dark-brown in the mass but brownish-
olive individually, smooth, average 6 ft diam. and varying from
5"5 to 7 /<.

On Andropogon sorghum Brot. occurring on the varieties broom corn,
amber cane, and sugar sorghum.
Queensland — (Bailey) .

Victoria— Ardmona, 1895 (Robinson). Tatura, Feb., 1903 (Bald-
win). Tungamah, Feb., 1908 (Mallows) ; March, 1909. Lake
Rowan, March, 1909. Macorna, -Tune, 1909 (McDonald).

The grain is converted into an enlarged projecting body consisting of
the firm fungus membrane on the outside and the slender columella is often
seen remaining in the centre after the bulk of the spores have been scattered.

This smut has been placed under various genera, as seen from the
synonyms, but the mode of spore-formation shows that it belongs to Cin-
tractia. Ustilago cruenta Kuehn, is also found on Sorghum, but instead of
being confined to the flower it may occur on any part of the oanicle, and even
on the stem, while the spores are also larger on the average.

Germination. — The spores germinate readily in water within 24 hours,
forming a 3-4 celled promycelium. Conidia are produced terminally or
laterally, but not usually in great abundance. Buckle or knee joints are
commoiily formed by the promycelium, and from these, as well as from the
end of the promycelium, slender threads are produced, supposed to be in-
fection-threads. In a nutritive solution, germination is more luxuriant,
more conidia are formed, and either when connected or detached, they give
rise to secondary conidia by sprouting in a yeast-like manner. Finally,
when the nutrition becomes exhausted, these conidia throw out slender germ-
tubes.

(Plates XIV., XXXIX.)

174 C'lntractia.

Sjnnijex.
30. Cintractia spiniflcis (Ludw.) McAlp,

Luclwig, Zeitsclir. Pflanzenkr, III., p. 138 (1893).
Brefeld, Uuters. Gesammt. Myk. XII., p. 106 (1895).
Sacc. Syll. XL, p. 231 (1895).
Ustilago spiniflcis Ludw.

Sori in spikelets generally concealed by the glumes, destroying ovaries
and forming a dense tough brownish mass of spores.

Spores globose to shortly ellipsoid, pale olivaceous to brownish,
very minute, epispore finely punctulate, 3-4 /t diam. or 5 x 3 f/.

On Spinifex hirsutus Labill.

South Australia — Near Port Adelaide, Dec, 1892 (Tepper).

In the large dense globular head of this grass all the ovaries were des-
troyed and more or less completely replaced by a mass of spores which re-
main firmly united. This grass is often called the " Spiny Rolling Grass,"
since the flower heads of the female plant become detached on ripening and
are easily rolled about by the wind, at last sticking in the sand, and the in-
dividual spikelets separate. In this way the smut, hke the plant itself, is
widely distributed and probably occurs all round the Australian coast.

Brefeld' has specially examined this species and found that in water the
spores readily separate.

Spore formation. — A cross-section of the ovary shows the plant tissue
in the centre with the surrounding spores embedded in it. The plant tissue
consists of the large-celled parenchyma studded with fibro-vascular bundles,
in which numerous vessels are visible. Towards the outside there is a dense
layer of exceedingly fine fungus filaments felted together, yellowish in the
mass and forming a stroma from which numerous slender hyaline fungus
filaments project. In these the spores are developed, at first as minute colour-
less points, which gradually increase in size and assume a dark tint towards
the outside, until finally they form the dense firm brownish mass of mature
spores, arranged in rows and embedded in a gelatinous material. They burst
through and rupture the epidermis as they become mature, and the unbroken
epidermis may be seen alongside.

The s^pores are also formed in the interior, in cavities in the tissue. Sur-
rounding the cavity there is the dense yellowish stroma from which the
sporogenous hyphae project towards the centre and ultimately the cavity
is filled with a dense mass of spores which escape by disruption of the tissue.

Germination. — The spores germinated after being kept for about two
months, not in wafer in which they remained unchanged, but directly on
the addition of nutritive solution. The promycelium was typically four-
colled and relatively large in comparison with the spore, each individual cell
being about equal in length and thickness. Below each septum and at the
apex, elongated conidia are slowly formed which multiply by a process of
}'cast-like budding. Just before the solution is exhausted, the conidia may
p,row out into filaments, and if these reach the air they form aefrial conidia.
.So ,srcneral and so copious is this development in contrast to the rather sparing
multiplication within the solution, that the conidia form a fine film on the
surface like delicate down.

(Plato XXXII.)

Sorosporinin. 175

SOROSPORIUM Eud.

Sori in various parts of the host, forming dark-coloured dusty spore
masses. Spore-balls composed of numerous spores, often rather loosely
united and at maturity completely separating.

Spores usually of a deep-brown colour.

Germination similar to that of Ustilago.

The spore-balls are temporary, and when the spores entirely separate,
as they often do, at maturity, the genus cannot be distinguished from Usti-
lago. In such a case it is necessary to examine young stages and see the
young spore-balls. It is not surprising, therefore, that several Sorosporiums
have been described as Ustilagos. On the other hand, this genus is some-
times mistaken for Thecaphora and Tolyposporium, in which the spore-balls
are permanent. The sori are often provided with a false membrane, and the
order of development of the spore-balls is centrifugal, the youngest being
at the centre.

Australian species, 13.

Aristida.
31. Sorosporium consanguineum Ell. and Ev.

Ellis and Evcrhart, Journ. Mvc. III., p. 5G (1887).
Sacc. Syll. VII., p. 514 (1888).

Ustilago aristidae Peck, Bull. Torr. Bot. Club, XII., p. 35 (1885).

Sori in ovaries and entirely enclosed by glumes, but sometimes the
black mass shines through them.

Spore-balls irregular, subspherical to elongated oblong, up to
130 f-i in length, at first firm but afterwards readily separating and
in old specimens becoming completely broken up. Spores mostly
polygonal, also subgiobose to ovoid, smooth, or very finelv echin-
ulate, yellowish-brown, but dark-brown in the mass, 7-10 /ii long,
but may occasionally reach a length of 13 //.

On Aristida arenaria Gaud.

New South Wales — Namoi Kiver, 1887 (National Herbarium).
On Aristida hehriana F, v. M.

Victoria— Dookie, June, 1903 (Pye).

New South Wales — Narromine (Turner).
On Aristida lepfopoda, Bentli.

New South Wales — Liverpool Plains (Turner).
On Aristida raniosa R. Br.

New South Wales — Narromine (Turner).
On Aristida vagans Cav.

New South Wal-\s— Wingello, Man;li, 1900 (Maidtu).

Coolabah, Dec., 1908 (Maiden).
On Aristida sp,

Queensland — (Bailey).
In the specimens examined, every seed seemed to be affected. The spores
are generally smooth, but sometimes the epispore is finely echinulate.

1^6 Sorosporiimi.

Clinton lias examined the types of the species of Peck, and of Ellis and
Everliart, and found them to be the same ; hence, by the law of priority, the
smut ought to be called *S. aristidae. But the name of S. aristidae Neg. is
given by Saccardo in the Host Index of the Sylloge Fungorum, and as I can
find no description of it, one cannot be sure that this and Peck's species are
the same, so for the present the name had better be left unaltered.

The species on this host is entered as U. segetum in Cooke's Handbook-

Germination. — The specimen used was fully three years old, and the spores
germinated in water. In the course of five days the spores had freely ger-
minated, producing an elongated straight promycelium, often with vacuo-
lated protoplasm, generally 4-celled, and 30-40 /.i long, sometimes up to 50 /i.
Conidia were produced at the apex, and laterally, oval in shape and about
5 yit long.

Norton^, has also described the germination of this species. He found
that germination begins almost immediately in water, and that a promy-
celium of 30-40 /I long is produced. Then a conidiuni is formed at the apex,
three to four septa appear in the promycelium, and each cell produces a
lateral conidium at its upper end. The conidia soon fall away. In nutrient
solutions there is a similar but more vigorous germination.

(Plate XLI.)

Panicmn.
32. Sorosporium cryptum McAlp.

Ustilago crypta Mc Alpine, Proc. Linn. Soc, N.S.W., p. 42 (1897).
8acc. 8ylL XIV., p. 413 (1899).
Sori in spikelets, enveloped by the glumes, and ovaries converted into
a black spore mass, with a central core of plant tissue ; provided
with an outer membrane.

Spore-balls somewhat evanescent, variable in size and shape,
dark-brown when mature, oblong to oval or elongated ellipsoid,
80-150 f.i long. Spores olivaceous, globose to subglobose or ellip-
soid ; epispore firm, brown, very delicately echinulate, but in many
cases apparently smooth, 8-9 j-i diam. or 7-10 x 6-8 //.
On Panicum hicolor R. Br.

New South Wales— 1896 (Maiden). Braidwood District, Feb., 1909
(Eoor.iaan .
On Panimm effusum R. Br.

New South Wales— Glenariff. Darling River (Turner).
Queensland — (Bailey).
Spore formation. — The spore-balls originate from the central core of plant
tissue, from which strands of hyphal tissue proceed in a radiating manner,
and in the compartments between, the spore-balls are developed. At first
they are colourless and surrounded by an investment of gelatinous sterile
hyphae then they become pale olive, and finally dark-oUvaceous to brownish
at maturity. The spore-balls are arranged in concentric circles around the
central coi-e of plant tissue, the outermost being fully formed and mature.
Surrounding the outermost layer is a membrane consisting of epidermis and
cortex of the host, lined by a yellow layer of sterile hyphae, which ultimately
ruptures to allow the escape of the spore-balls.

Sorosporium.

177

The sterile hypliae are hyaline, closely septate, and the cells are either
cubical or rounded.

Germination. — Spores were taken from Panicum hicolor nine months after
being collected, and floated on water in a covered petri-dish exposed to the
sun. After 41 hours they were germinating luxuriantly. The spore puts
forth a promycelium which at first may be comparatively short and without
septa (13 ft long) and yet give rise to a terminal conidium nearly as Ion"- as
itself (10 ft). But generally the promycelia are septate, producing lat'eral
as well as terminal conidia. Occasionally two promycelia may be produced
from the same spore on opposite sides and branching may occur at the very
base of the promycelium. Buckle or knee-joints are also met with. The
conidia are elongated ellipsoid and vary in size. The apical conidium mav
elongate considerably, up to a length of 30 ft, becoming spindle-shaped and
tri-septate, and two may be produced one after the other.

The spore may also give rise to an elongated slender promycelium in which
the protoplasm collects at the end, and the terminal segment mav become
detached and produce slender filaments at either end. The promycelia may
thus either give rise to ordinary conidia or segments may be detached, and in
this way the smut is distributed.

Massee has determined a new species, Ustilago confusa on Panicum rxira-
doxum K. Br., from Victoria, in which the spores have a tinge of violet by
transmitted light, but there is not the slightest trace of it here, and since I
am informed that there is no available material at Kew, it cannot be decided
whether it is a Sorosporium or not.

There is a general resemblance to S. sijntherismae (Pk.) Farl., but I have
examined the specimen in Sydow's Ust. Exs. No. 41 on Panicum proliferum
Lam., from Ohio, and the spores are darker in colour and the echinulation is
much more pronounced.

(Plates XL., LVI.)

Antliisliria.
33. Sorosporium enteromorphum McAlp.

Ustilago entewmorpha McAlpine, Aor. Gaz.. N S W Xll
p. 154 (1896). "^ ' ■'

Sori in florets, enclosed in a somewhat intestine-shaped gray membrane,
at length brownish and decaying to allow the escape of the spores ;
spore-mass with membrane elongated and puckered, and sometimes
coiled upon itself, half-an-inch to fully an inch long.

Spore-balls irregular, oblong to sul)globose or elonoated, 20-10 11
diam. or 30-60 /< in length.

Spores globose to oval, olivaceous, loosely adherent, 5-8 // diam.
or 6-10 X 4-7 ft ; epispore thin, brown, very finely echinulate.
On Anthistiria ciliata L. f.— Kangaroo Grass.

Victoria— Near Melbourne, Dec, 1892 (Rol)ins()n). Dandenontr

Ranges, Jan., 1910 (C. French, jun.). '^

(Plates XVL, XL.)

1^8 Soros por'mm.

Eriachne^
34. Sorosporium eriachnes Tluiem.

Thuemen Symb. Myc. Austral. II., p. 4, No. 97 (1878).

Cooke, Haiidb. Austr. Fung., p. 328 (1892).

Sacc. Syll. VII., p. 514 (1888).

VstUaqo australis Cooke, Grev. VIII., p. 34 (1879).

Sori in ovaries filling the glumes witli a powdery mass of black spores^

Spore-balls small, irregular.

Spores very variable in shape, irregular, angular or quadrangular,
subglobose, or elliptic, smooth, opaque brown, 10-14 x 8-11 /<.

There are numerous large lemon-coloured smooth cells scattered
among the spore masses, globose to subglobose or ellipsoid, with
distinct thick walls 4-6 |u broad, 20-29 ^i diam. or 19-29 x 13-16 /<.

On Eriachne sp.

Queensland— (Mueller) ; Muckadilla, 1897 (Bailey*^).
New South Wales — (Mueller).

This genus of grasses is not represented in Victoria or Tasmania, although-
Cooke gives this smut as occurring in Victoria. A specimen labelled TJsti-
lago australis Cooke was kindly sent by the Director of the Royal Gardens,
Kew, and the spores were found in clusters although they readily fall away..
Mueller had evidently sent a specimen of this smut both to Thuemen and the
Kew Herbarium, and Cooke named it as above in his " Undescribed Fungi
in the Kew Herbarium," overlooking the fact that it had already been named
and described the previous year by Thuemen.

(Plate XLI.)

Eriochloa^
35. Sorosporium mixtum (Mass.) McAlp.

Tilletia mixta Massee, Kew Bull., p. 145 (1899).
Sorosporium eriochloae Griffiths, Bull. Torr. Bot. Club, XXXI.,
p. 84 (1904).
Sori in ovaries, oblong, about 2 mm. in length, enveloped by the glumes
and concealed by a conspicuous whitish membrane which ruptures
in lobes at the apex and exposes the black rather agglutinated spore
masses, with remains of the aborted pistil in the centre ; membrane
composed of closely compacted hyaline cells end to end, oblong to
cubical, with granular contents.

Spore-balls somewhat irregular, subglobose to oval or oblong,
readily separating into their component spores, 40-80 /< or more
in length.

Sorosporiid)!. 1)9

Spores dark-l)ro\vn, variable in shape and size, subglobose to
oval or oblong, sometimes polygonal from pressure, finely echinu-
late, 13-15 /< cliam. or 14-20 x 11-15 /(, average 16 /< long.
On Eriochloa punctata Ham.

New South Wales — Liverpool Plains. 1906 (Turner).
Eriochloa annulata Kunth.

New South Wales — Murrumbidgee, 1886 (Bennett).
This smut was originally found in Arizona on Eriochloa punctata. The
specimen collected by Bennett in 1886 was sent to Kew, and a portion of
the original material labelled TiUetia mixta was kindly supplied to me by the
director.

(Plate XLI.)

Chamaeraphis.
36. Sorosporium panici-miliacei (Pers.) Takahashi.

Takahashi, Tok. Bot. Mag. XVI., p. 247 (1902).
Ustilago panici-miliacei (Pers.) Wint. Die Pilze, p. 89 (1884).
Sori produced in the inflorescence, destroying the spikelets and causing
the ovary to swell, leaving the filiform spreading branches bearing
them curled up, occasionally only a portion of the inflorescence
attacked ; epidermis of the host envelops the sori, together with a
dense layer of sterlie hyphae.

Spore-balls irregular in shape and variable in size, round to
oval or oblong or polygonal, dark-brown, 50-100 /.i long.

Spores yellowish-brown, subglobose to angular or ellipsoid ;
epispore firm, very finely echinulate, 9-13 /« diam. or 9-14 x 8-11 i-i.
On Chamaeraphis spinescens Poir. z= Panicum spinescens R. Br.
Victoria— Murray Eiver, Jan., 1888 (Walter).
New South Wales — Near Corowa, Jan., 1906 (Pcscott).
This was determined by Cooke as U. cesatii Waldh., but the examination
of a portion of the original material from the National Herbarium showed it
to be a Sorosporium. This is the first record of the species for Australia, and
it thoroughly agrees Avith the characters given for it on Panicum miliaceum
by Takahashi^.

Spore formation. — The smut pustule is enveloped by the epidermis of the
host and a relatively thick layer of sterile hyphae in close contact with it.
It is also traversed longitudinally by the fibro-vascular bundles together
mth strands of sterile hyphae generally resembling those of the coating.

The spore-balls are formed in concentric rings around each fibro-vascular
bundle, the youngest being innermost and the outermost often blending
with those of adjoining bundles. The young balls have an investment of
sterile gelatinous hyphae, but at maturity this has disappeared, being used
up in the growth of the balls.

According to Trzhebinski^ the spores adhering to the seeds of this smut
are successfully destroyed by soaking the latter in a solution containing
• 5 per cent, of copper sulphate and • 25 per cent, of formalin.

(Plate XL.)

i8o Sorosporium.

Paspalum.

37. Sorosporium paspali McAlp.

Sori in inflorescence, usually destroying tlie whole, and leaving the
elongated remains of the inflorescence surrounded by a black mass
of spores.

Spore-balls dark-brown, globose to oblong or irregular, 30-40 //
in diam. or 30-50 fx long, at first firm, but afterwards readily sepa-
rating.

Spores brownish individually, oblong to polygonal or pear-shaped)
with thick epispore, smooth, variable in size, 12-18 x 9-14 ^,
average 13-16 x 10-13 fi.

On Paspalum scrobiculatum L.
Queensland — (Bailey) .

This specimen is given in Cooke's Handbook of Australian Fungi as Usti-
lago cesatii F. v. W., and as occurring in both Victoria and Queensland.
Portion of the original material forwarded to Cooke shows it to be a Soros-
porium, the spores being aggregated in balls and afterwards separating.
The individual spores are smooth and not echinulate, so that it is quite a
different smut.

(Plate XLIV.)

Scirpus, J uncus.

38. Sorosporium piluliformis (Berk.) McAlp.

Uredo piluliformis Berkeley, in Hook. Journ. Bot. II., p. 423
(1843).

Ustilago piluliformis (Berk.) Tulasne, Ann. Sci. Nat. p. 93 (1847)
Cooke, Handb. Austr. Fung., p. 325
(1892).

Ustilago marmorata Berkelev, Linn. Journ. XIII., p. 174 (1872).
Cooke, Handb. Austr. Fung., p. 325 (1892) _

Ustilago muelkriana Thuemen, Myc. Univ. No. 623 (1879).

Cooke, Handb. Austr. Fung., p. 324 (1892).
Sori in ovaries, compact, sometimes causing a marbling of the unbroken
epidermis which is ultimately ruptured and thrown off. Spore-
balls generally in clusters of five or six, subglobose to oblong, dark
olivaceous to dark-brown, readily breaking up after they are fully
formed, 49-120 /< long.

Spores very irregular in shape and size, thick-walled, tubercu-
late, subglobose to oblong or polygonal, 10-18 ^ long.

On Scirpus prolifer Eottb. = Isolepis prolifera E. Br.

South Australia— Mount Gambler, 1854 (Mueller, No. 94).

Sorosporium. i8i

On Juncus planifolius R. Br.

Victoria — Near River Loddon (Mueller). Killara, March, 1907.
Follett County, Dec, 1907 (Reader). Beech Forest, Dec, 1909.
(Brittlebank).

New South Wales— Centennial Park, Sydney, Sept., 1900 (Chcel).

Tasmania — Hobart, Dec, 1891 and Jan., 1906 (Rodway).

The type material of U. marmorata has been examined from the National
Herbarium. Berkeley in his original description, does not mention the
portion of the plant on which the smut was found. Cooke in his Australian
Handbook gives the leaves, while I have found it in the ovaries. I am in-
debted to the Director of the Royal Gardens, Kew, England, for a specimen
of U. muelleriana Thuem.

Sfore formation. — In a cross-section of the ovary the spore-balls are seen
to be developed from the inside outwards, and if the spores were not in balls
the species would be taken for a Cintractia. There is a central core of plant
tissue consisting of parenchymatous cells together with smaller thick-walled
cells. Surrounding this and radiating from it are very slender, delicate,
wavy septate hyphae which proceed in strands to the circumference, and
pockets are formed between the strands in which the spore-balls are formed.
The spore-balls are at first minute and colourless, but gradually increase
in size and become olivaceous until on arriving at maturity they are of a
ruddy-brown colour. Intermixed with the mature spore-balls and also in
the radiating hyphal strands, there are numerous coloiu'less simple spore-like
bodies which are ellipsoid, with coarsely granular contents, and generally
averaging 9-10 x 5-6 jk. These spore-like bodies may be seen forming in
chains in the hyphal filaments, and are probably abortive spores which have
never advanced sufficiently to become spore-balls. Berkeley figures these
abortive spores in his original article on Uredo piluUformis, and Tulasne in
describing this form as Ustilago piluliformis refers to the spores being in
clusters. This species is comparatively common on Juncus, but does not
appear so frequently on Scirpus.

(Plate XLII.)

Zca.

39. Sorosporium reilianum (Kuehn) McAlp.

Kuehn, Rab. Fung. Eur. No. 1998 (1875).

Brefeld, Unters. Gesammt. Myk. V.. p. 9i (1883).

Sacc. Syll. VII., p. 471 (1888).

Ustilago reiliana Kuehn.

Cintractia reiliana (Kuelm) Clint., Bull. 111. Asir. Exp. Sta.
No. 57, p. 346 (1900).

Sphacelotheca reiliana (Kuehn) Clint., Journ. Mvc. VIII., p. 141
(1902).

i82 Sorosporium.

Sori very prominent, blackish-brown, appearing in the tassels and ears
and forming compact masses, which may include the entire in-
florescence, at first enclosed in a pinkish to whitish membrane
which soon ruptures, and the spores are dispersed, leaving the ray-
like remains of the columella.

Membrane consisting of the outer tissues of the host-plant and
sterile cells derived from the fungus, which form several layers of
clear, more or less rounded cells, arranged in sub-spherical groups,
and which may also occur mixed up with the spores.

Spore-balls dark-brown, globose to oval or irregular, firm at first,
but afterwards readily separating, 80-112 yi in length.

Spores globose to subglobose, or sometimes slightly ellipsoid to
ovoid, somewhat opaque, minutely but densely verruculose,
10-13 /( diam.

On Zea Mays L.— Maize.

Victoria — Orbost, April., 1901 (Pescott) and April, 1906. Lindenow,

Feb.-May, 1908. Near Orbost, May, 1909.
New South Wales— Richmond, 1891. Singleton, May, 1899 (Wad-
dell).

This species was at first recorded as Ustilago niaydis Corda = U. zeae
(Beckm.) Ung. by Dr. Cobb in New South Wales, hut further investigation
soon showed that it was not the ordinary Maize Smut of America. It is
distinguished from that species by neither enlarging the ears nor forming
larg3 smut boils, by generally confining itself to the inflorescence and not
attacking the leaves, and by the larger and more minutely verruculose spores.
In addition, the spores are in balls at first and not solitary. It is fairly
common in some of the later crops in maize-growing districts. In a specimen
of U. zeae from Sydow's Ust. Exsicc. 157 on Maize from America, the spores
were coarsely echinulate and 8-11 /.i diam.

In the ovaries the membrane may envelop only spores mixed up with
clusters of the sterile cells, or in other parts of the plant there may be a
central core of plant tissues that have not been destroyed. The mycelium
enters the grain from the base and gradually replaces the tissue of the ovary.
At the base of the ovary you may still find some of the plant cells which have
not yet been completely disintegrated, and at the top the membrane may be
entirely composed of fungus cells. It is a case of gradual absorption of the
plant tissues by the fungus. The systematic position of this smut has re-
ceived considerable attention in America. Kuehn first named it U. rei-
liana in 1875, then Clinton called it Cintractia reiliana, and finally in 1902
SpTiacelotheca reiliana. Norton^ retained it as U. reiliana, although he observed
that "the spores are aggregated in masses, and this species seems much like
a Sorosporium, but until further studies of the development I have left it
here." In a very young smut cob the spores are seen to be in clusters as
shown in Plate XXX., so that its final resting-place is as a Sorosporium.
' I Germination. — This has already been described. The spore germinates
readily in water in 21 hours, and forms both lateral and terminal conidia.
In nutritive solutions there is a luxuriant development of conidia which
sprout in a yeast-like manner and form colonies.

(Plates XII., XIII., XXX.)

Soros pari uin. i8r

Setaria.
40. Sorosporium setariae Mc.Vlp.

Sori destroying tlie entire inflorescence and converting the ovaries into
a black powdery mass, or they may only affect one side of the in-
florescence and sometimes the base, while the upper part is sound.

Spore-balls dark-brown, variously shaped, globose to oval, oblong
to angular, consisting of numerous spores, varying in length from
60 to 160 //.

Spores brown to olivaceous, globose, ellipsoid to angular, smooth,
10-12 ^i diam. or 10-13 x 7-10 /..
On Setaria glauca Beauv.

Queensland — Near Cloncurry, May, 1909 (Eobinson).
This is the first Sorosporium found on this genus. A cross-section of
the ovary shows that the spore-balls are developed around the vascvdar
bundles, the youngest being nearest the bundle. Adjoining each bundle
may be seen the gelatinized hyphae concentrically arranged and enclosing
minute colourless points which afterwards become the spore-balls, and to-
wards the circumference are the dark-brown spore-masses fully mature.
There is also a central core of tissue around which the spore-balls are de-
veloped last of all, and the outer tissue of the ovary finally ruptures to allow
of the escape of the powdery spore-masses.

Germination. — The spores do not germinate readily. After floating on
water in a watch-glass for seven days, a few had put forth a colourless con-
tinuous germinal tube, usually without conidia, but, in some cases, with lateral
and terminal conidia. The conidia were minute, about 3 ^i long.

(Plate LIV.)

Schoenus.
41. Sorosporium solidum (Berk.) Mc Alp.

Ustikujo soUda Berk., Fl. Tasm. II., p. 270, (1860).
TJrocystis solida Fischer von Waldheim, Apercu syst. Ust,
p. 38 (1877).
Sori in ovaries, black, compact, globose, shot-like.

Spore-balls subglobose to oblong or irregular, composed of 30 or
more spores all similarly coloured when mature and somewhat
firmly united, 50-70 ^t long.

Spores dark-brown, smooth, with firm epispore, spherical to
sub-spherical, elliptical or polygonal, 20-24 /.■ long.
On Schoenus imherhis R. Br.

Victoria— Cheltenham (Mrs. Martin). Nov., 1906 (Robinson),
Tasmania — Penquite, Dec, 1845 (Gunn.)
On Schoenus apogon Roem. and Schult.

Victoria — Dimboola, Nov., 1892 (Reader).

Tasmania — Hobart, Nov., 1894 (Rodway).

F, von Waldheim, who recorded this as a Urocystis, speaks of the

glomerulcs of spores as having rarely three to four peripheral vesicles,

but the examination of a large number of spores failed to reveal any distinct

peripheral cells. But there are hyaline protuberances attached to the cells

184 Sorosporium.

wliicli, probably, gave rise to this view. They are probably the remains of
the enveloping hyphae, as they become detached and disappear on treat-
ment with caustic potash. (Plate XLIIL, Fig. 136).

Spore formation. — In a cross-section there is a central mass of parenchy-
matous plant cells, which are penetrated by colourless hyphae towards the
outside. These give rise to a dense mass of olivaceous hyphae surrounding
the central core of plant tissue, and one portion of the hyphae becomes spore-
forming while the other remains sterile. The sterile portion forms strands
of pale-coloured hyphae radiating towards the circumference, which are
slender, elongated, and regularly and closely septate. Between the strands
of sterile hyphae there are colourless hyphae, at first twisted into balls, and
gradually these become definite, colourless spore-balls. They increase in
size, the cell-wall becomes clearly defined, assumes a dark-brown colour, and
the whole forms a fairly solid mass at the outside. The spores may partially
separate from each other and are mixed up with shreds of the tissue of the
ovary, and the broken-up remnants of the sterile hyphae.

The structure is clearly seen in Plate XLIII., Figs. 132, 133, where from
the central core of plant tissue radiating strands of very fine septate fila-
ments proceed and form, as it were, so many compartments in which the rows
of spores are developed. The spores are seen in every stage of development,
from the minute colourless spore, then with transverse and radiating septa,
and finally as a dark-brown cluster of spores.

(Plates XXV., XLIII.)

Stipa.
42. Sorosporium tumefaciens McAlp.

Sori attacking and destroying entire inflorescence while still partially
enclosed in sheathing blade. The entire panicle becomes swollen,
dirty white to brownish, rupturing irregularly to allow the escape
of the powdery spore-balls, up to 5 cm. in length.

Spore-balls globose and ellipsoid, oblong or irregular, olivaceous
to dark-brown, 50-80 /^ long.

Spores olivaceous to brownish, somewhat firmly united together,
globose to ellipsoid or slightly irregular, smooth, often guttulate,
especially when germinating, 8^10 i-i diam. or 8-10 x 6.5 -7.5 ju.,
occasionally 11.5 /.i long.
On Stipa sp. and Stipa puhescens R. Br.

Queensland — Near Cloncurry, May, 1909 (Robinson).
Sorosporium granulosum Ell. and Tracy, has been found on Stipa in
America, but the spores are much larger, being 12-17 /j. in length. A cross-
section of an infected inflorescence, taken near its base, shows numerous
vascular bundles completely surrounded by spore-balls, the younger and
immature being towards the centre. The outer tissue is soon ruptured by
the swelling spore-masses, which escape as a black powder, while the vascular
bundles project in the form of numerous brown strands.

Germination. — This takes place readily in water, whether the spores are
placed on a slide or floating on water in a watch-glass. In twenty-four hours
numerous promycelia project from each spore-ball. They are hyaline,
elongated, slender, septate, and bearing conidia laterally as well as terminally.
The conidia are cylindrical, 6-10 j-i long.

(Plate LIV.)

Sorospflriiini — Thccafliora. 185

Eragroslis.
43. Sorosporium turner! McAlp.

Sori in ovaries, usually affecting each spikclet, ultimately exposed as
a dense black mass, with the remains of the pistil usually projecting
and a central columella of plant tissue.

Spore-balls irregular, subglobose to oblong, usually firmly united,
60-100 /I long.

Spores dark olive-brown, globose, with thin and smooth epispore,
10-11 ju diam.
On Eragrostis nigra Nees var. trachycarpa.

New South Wales — Near Armidale, New England (Turner).
The only two species of smut recorded on Eragrostis are Ustilago spev
mophora B. and C. in America and Sphacelotheca strangulans (Issat.) Clint-
in Russia. The spores are echinulate or aculeolate \\\ both.

(Plate XLIV.)

THECAPHORA Fingerhuth.

Sori in various parts of the host, but usually in the ovaries, forming a
dusty spore mass at maturity.

Spore-balls light-coloured, composed of few or many spores, firmly and
rather permanently united.

Spores smooth on contiguous sides but usually marked on free surface.
Germination by means of an elongated septate mycelium, and as far as known,
only producing a single conidium at the apex. This genus is distinguished
from Sorosporium by the firmly united spores, and their being marked on
the free surface but smooth on the united side,

Australian species, 2.

Lagcnophora.
44. Thecaphora lagenophorae McAlp.

Usiihiqo Itigenophorae McAlpine, Agr. Gaz. N.S.W., YL, p. 758,
(1895).

Sori in ovaries, forming brown powdery spore-masses.

Spore-balls cinnamon-brown, siib-globose to oblong, composed
of three to ten spores, firm.

Spores pale yellowish-brown, globose, sub-globose, or oval, waited
on outer surface, but smooth where united, 18-22 /« diam.
On Laqenophora emphysopus Hook. f.

Tasmania — Mount Dromedarv, at foot, Dec, 1894 (Rodway).
Sandford, Jan., 1908 (Rodway).
The entire flower-head is converted into a mass of spores by means of
this smut.

I did not succeed in getting the spores to germinate even when fresh, but
the light-coloured spore-balls and the spores being smooth on the united face
indicate this genus.

. (Plate XLV.)

[86 T/iccapJiora — Tolyposporium.

Leptocarpus.

45. Thecaphora leptocarpi Berk.

Berkeley, Linn. Journ. XIII. , p. 388 (1872).
Cooke, Handb. Austr. Fung., p. 328 (1892).
Sacc. Syll. VII., p. 510 (1888).

Sori in ovaries, black, at first compact.

Spore-balls forming indefinite masses, varying in number of spores,
but generally large.

Spores smootli, generally globose, sometimes shortly ellipsoid,
yellowish-brown to dark-brown, 9-11 ^t diam. or 9-12 x 7-8 /n
On Leptocarpus tenax R. Br.

Victoria— Wilson's Promontory, May, 1850 (National Herbarium).
Tasmania — Bellerive, near Hobart, May, 1889 (Rodway).
On Leptocarpus sp.

New South Wales — Upper Murray River, July, 1886 (National Her-
barium).
The spores cohere well, but in the process of mounting for the microscope
they break up into packets of various sizes.

(Plate LVI.)

TOLYPOSPORIUM Wor.

Sori in various parts of the host, but mostly in the ovaries, and forming
a granular spore mass at muturity.

Spore-balls dark-coloured, composed of numerous spores permanently
united.

Spores bound together by ridged folds or thickenings.

G-ermination similar to that of Ustilago.

The characteristics of this genus are the very firm spore-balls and the
union of the individual spores by ridged folds or thickenings of their outer coats.

It is distinguished from Thecaphora by the dark-coloured spore-balls
and the spores being inseparably united.

Australian species, 7.

Anthistiria.
46. Tolyposporium bursum (Berk.) McAlp.

Ustilago bursa Berkeley, Hook. Journ. p. 206 (1854).
Tolyposporium anthistiriae Cobb, Agr. Gaz. N. S. Wales, III.,

p. 1006 (1892).
Tolyposporium anthistiriae P. Henn. Hedw. XXXVII., p. 283
(1898).

Tolyposporium. 187

Sori ill spikes, and destroyiiio; them, cylindrical, 2-5 cm. long, at first
covered by the yellow epidermis, then ruptured.

Spore-balls very black, rounded, oblong or polyhedral, variable
in size, 40-150 /i diam.

Spores sub-globose or ellipsoid, cinnamon-brown, with thickish
(1 ^t) very finely punctulate epispore, 9-14 x 8-12 \i.

On Anthistiria ciliata L. f. — Kangaroo grass.
New South Wales— 1892 (Cobb).
Victoria — Kiewa Valley, Nov., 1902 (Robinson).
Queensland — Walsh River (Bailey)^.

Germination. — The spore germinates in water, giving rise to an elongated,
septate promycelium, which bears lateral and terminal fusiform conidia,
5-10 /-t long. The detached conidia bud in a yeast-like manner.

(Plate XVII., XLVI.)

Leersia.
47. Tolyposporium globuligerum (Berk, and Br.) Ricker.

Ricker, Journ. Myc. XI., p. 112 (1905).
Cooke, Handb. Austr. Fung. p. 328 (1892).
Sacc. Syll. VII., p. 509 (1888).

Thecaphom glohuligera Berk, and Br. Trans. Linn. Soc, 2nd
Ser., Vol. II., Pt. 1, p. 407 (1878)

Sori in ovaries, subglobose, 1-2 mm. diam., covered by yellowish-green
smooth membrane, which ruptures and exposes the black masses
of spores.

Spore-balls opaque, firm, composed ot numerous spores, 50-200 f.i
diam. or even more.

Spores olivaceous to brownish, subglobose to angular, rough,
and tubercular but not echinulate, generally polygonal, with obtuse
angles by which they are united to each other, average 9-11 //.

On Leersia hexandra Swartz — Rice grass.
Queensland — Brisbane River (Bailey).

This grass is common near water-courses and is often attacked by this
smut.

The swollen ovary retains its outer coat while the contents are completely
replaced by the spores.

The projecting processes of the spores and how they are united to each
oth°r is well shown in Plate XLV., and justifies the change in the genus
made by Ricker.

(Plate XLV.)

1 88 Tolyfosforium.

J uncus.
48. Tolyposporium juncophilum McAlp.

Sori in the stems, forming dense powdery masses of spores which burst
through and dust it over with a black powder.

Spore-balls opaque, composed of numerous, firmly united spores,
subglobose to oblong or irregular.

Spores olive-brown, subglobose to ellipsoid or polygonal, epi-
spore unequally thickened, smooth.
On Juncus pallidus R. Br.

Victoria— Cheltenham, Dec, 1909 (C. French, jun.).
New South Wales— Nov., 1901 (Helms).
Tasmania — -Hobart, Jan., 1906 (Rodway).
West Austraha— Mt. Barker, Oct., 1909"^ (Summers).
In T. junci (Schroet.) Woron. Schroeter says that the peripheral cells are
shortly echinulate on the outer surface, but in this species they are perfectly
smooth. In addition to this the spore-balls are generally more or less sub-
globose, while in T. junci they are elongated and contain fewer spores in
the ball.

(Plate XLVII.)

Lepidoholus.
49. Tolyposporium lepidoboli McAlp.

McAlpine, Proc. Linn. Soc. N.S.W., XXIX., p. 127 (1904).
Sacc. Syll. XVIL, p. 491 (1905).

Sori in ovaries, black, powdery, but completely enclosed in the small
fruits, surrounded by the enveloping bracts.

Spore-balls composed of numerous spores, firmly united into
irregular masses, subglobose to oblong, 80-120 i^i long.

Spores olivaceous in mass, globose to subglobose, ellipsoid or
polygonal, finely warted, 12-14 f.i diam. or 12-16 x 10-11 /*.
On Lepidoholus drapetocoleus F. v. M.

Victoria — Dimboola, Jan., 1903 (Reader).

(Plate XLVI.)

50. Tolyposporium lepidospermae McAlp.

Lepidosperma.

Sori enclosed in spikelets and not visible to naked eye, except from the
spore-balls, being scattered over the inflorescence, forming a black
granular mass.

Spore-balls black, opaque, variable in size and shape, spherical
to oblong, or irregular, 50-60 /< long, consisting of numerous spores
firmly agglutinated together.

Spores brown to chestnut-brown, subglobose to ellipsoid or poly-
gonal, strongly warted all over, variable in size, 15-17 n long.

Tolyposporiiiin 189

On Lepidosperma atVfustatuDi R. Br. = L. viscidum R. Br.
Victoria— Stawoll, Feb., 1904 (Reader).

On comparing this species with that of T. rodivayi occurring on the same
genus, it is found that the densely warted spores distinguish it at once. There
are also fewer spores in the ball, as may readily be seen on comparing Plate
XLVII., Figs. 154 and 155.

(Plate XLVII.)

Gahnia.
51. Tolyposporium muellerianum (Thuem.) McAlp.

Sorosporium muellerianum Thuemen, 8vmb. Myc. Austral. II.,
p. 5, No. 98 (1878).

Sori in spikelets, but scarcely visible to the naked eye.

Spore-balls black to dark-brown, sub-rotund to oblong or ir-
regular, consisting of numerous firmly united spores, 40-50 fj diam.,
or 50-70 i-i long, occasionally 80-90 /<.

Spores brown, pellucid, smooth, variable in shape, ellipsoid to
polygonal or pear-shaped, and then sometimes slightly prolonged
at the point.
On Gahnia radula Benth.

Tasmania — Hobart, Jan., 190G (Rodway).
On Gahnia trifida Labill. = Cladium filum R. Br. (in part).
Victoria— Nhill, Nov., 1898 (Reader).

(Plate XLVII.)

Lepidosperma.
52. Tolyposporium rodwayi McAlp.

Sori enclosed in spikelets, not visible to naked eye, and forming a black
granular spore-mass.

Spore-balls black, opaque, variable in size and shape, generally
spherical to oblong or elongated oblong, 30-60 /t diam. or 50-100 /(
long, consisting of numerous very firmly agglutinated spores.

Spores olivaceous to brown, smooth, ellipsoid to broadly oblong,
occasionally with beak-like projecting, blunt processes on inner side,
or wedge-shaped, and adhering together by dark folds of their
membrane, 15-21 x 9-12 /(.
On Lepidosperma laterale R. Br.

Tasmania — Longley, Dec, 1891 (Rodway).
It is only by strong meclianical pressure that the spores can be separated
and then only partially.

(Plate XLVII.)

ipo Tilletia.

TILLETIA Tul.

Sori in various parts of the host, usually in ovaries, generally pulveru-
lent, black or blackish-olive, often foetid, especially when moistened.

Spores single, free, usually produced singly in the ends of fertile swollen
hyphae, which generally disappear almost completely through gelatinization,
of relatively large size.

Germination by means of a short promycelium which bears a terminal
whorl of slender elongated conidia, and these often fuse in pairs, giving rise to
slender secondary conidia on germination.

This genus differs mainly from Ustilago in the mode of germination of
the spores, and where this is not known, species are placed here provisionally
on account of the relatively larger size of the spores as compared with those
of Ustilago.

Australian species, 6.

53. Tilletia fusca Ell. and Ev.

Ellis and Everhart, Journ. Myc. III., p. 55 (1887).
Sacc. Syll. YIL, p. 484 (1888).

Sori in ovaries of each spikelet, oblong, 3 mm. long, showing as dark
bodies while still enclosed by the glumes and afterwards rupturing
to allow the escape of the spores.

Spores reddish-brown to dark reddish-brown, globose to ovoid or
oblong, occasionally angular, with prominent regular reticulations ;
ridges showing at circumference as short blunt projections and en-
veloped bv a clear membrane probably gelatinous ; 23-25 /i diam.
or 23-26 x 18-20 ^/.

Sterile cells hyaline, relatively thin-walled, globose to oblong,
generally smaller than the spores, 16-23 /it long.

Occasionally small brown cells occur, smooth and only about
one-half the regular size, 10-13 fi.

Both the colourless and coloured cells with smooth walls appear
to be immature spores, in the one case from not having attained the
full size ; in the other from not having developed the colouring
matter.
On Festuca hromoides L. — Silver grass.

Victoria — Angustown, Dec, 1909, and March, 1910.
Although the Silver grass is widely distributed, I have not met with this
smut but in the one locality, where it is fairly common. The species only
occurs elsewhere in the United States of America, where it was first found on
Festuca.

Germination. — Spores were placed on a slide in water which had been boiled,
on 7th December, and it was only after 17 days, on 24th December, that ger-
mination occurred in a few. The promycelium was elongated, biseptate, with
the vacuolated protoplasm transferred to the last segment. There were
usually a crown of seven conidia at the apex, each elongated, slender, sUghtly
curved and tapering, 66-72 /u long, and one pair were observed with a
transverse bar uniting them near the apex.

(Plate LV.)

Tilletia. 191

Hordeum,

54. Tilletia hordei Koeni,

Kocrnicke Hcdw. XVI., p. 30 (1877).
Sacc. Syll. VII., p. 484 (1888).
Sori in ovaries, wliich are at first dark-green in colour, ultimately black,
concealed by the glumes, foetid, causing the spike to have a slight
club-head appearance.

Spores black in the mass, brownish individually, globose to sub-
globose, occasionally ellipsoid, 19-20 /it diam. or 19-22 x 17-19 n ;
epispore with raised ridges forming a network.
On Hordeum murinum L. — Barley grass.

South Australia — Orroroo District in the far north, Oct., 1909

(Summers).
New South Wales— Coolac near Gundagi, Nov., 1908 (Sullivan).
The odour is somewhat similar to that of Stinking Smut or Bunt of wheat,
but the spores are larger and more regular in shape. The wall of the ovary
still retains its texture and green colouring matter while enclosing the spores,
but blackens as the spores mature.

The smut-ball is shorter and stouter than the healthy seed.
This species has only hitherto been recorded from Persia.
Germination. — This was tried in a variety of ways with fresh spores and spores
a year old, but only in one instance did it occur with the fresh spores. Spores
were floated on water, immersed in water, placed in hanging drop, on plaster of
paris kept moist, and on damp blotting-paper. Nutritive solutions were also
tried, such as sugar, ammonium nitrate, and infusion of wheat. The spores
were carefully watched for about six weeks, but not the slightest attempt at
germination was observed. However, on the 43rd day, the fresh spores,
-dusted on a slide and placed over a jar of water, were found to be germinating
and producing the typical spores of Tilletia.

. (Plate LVI.)

Deyeuxia.
55. Tilletia inolens AlcAlp.

McAlpine, Agr. Gaz. N.S.W., VII., p. 154 (189G).
Massee, Bull. Kew, p. 152 (1899).

Sori produced in inflorescence and on upper leaves, black, pulveiuleiit.
without smell.

Hyphae septate, hyaline 4-5 /t broad.

Spores regularly globose, dark-brown, 30-39 /< diam., average
34 fj. ; epispore covered with very coarse warts which project like so
many lilunt teeth, and the whole is enveloped by a fine hyaline
membrane. The projecting teeth covered by the enveloping mem-
l)rane, give the appearance of a pale yellowish or yellowish-brown
border round the spore itself, 3-6 /.i broad. Between the warts
there are very minute projections on the epispore.
On Deijeuxia forsterl Kunth.

Victoria — Ardmona, Nov., 1894 (Robinson).

192 Tilletia.

The large coarse projections on the surface of the spore are very pro-
nounced, but the fine minute tubercles between are only to be seen by care-
ful focussing and fine illumination, or when a spore happens to be crushed
they may become plainly visible.

According to Massee this species appears to be closely allied to T. rau-
wenhoffii F. v. W.= T. hold (West.) Rostr.^ but an examination of the speci-
men in Sydow's Ustilagineen Exs. 372, shows the decided network of the
epispore, which is quite distinct from the warts of T. inolens.

Germination not known.

(Plate XLIX.)

I'riticum.

56. Tilletia levis Kuehn.

Kuehn, Hedw. XII., p. 152 (1873).
Massee, Bull. Kew., p. 144 (1899).
Sacc. Syll. VII., p. 485 (1888).

Ustilago foetens B. and C. in Grev. III., p. 59 (1874).
Tilletia foetens (B. and C.) Trelease, Parasitic Fungi of Wis-
consin, p. 35 (1884).

Sori in ovaries, concealed by the glumes, dark-brown to olivaceous,
foetid.

Spores black in the mass, pale brown to almost colourless in-
dividually, globose to elliptic, occasionally somewhat angular, very
variable in shape and size, 16-18 /n diam. or 19-25 x 16-17 ^ ;
epispore, smooth, 1^-2 /u thick.
On Triticum vulgare Vill. — -Wheat.

Probably in all the States of the CommonAvealth, like T. tritici. This
species generally resembles T. tritici, but the spore in addition to being smooth
is more irregular in shape and size. Both species may occur in the same ear,
but this is easily explained, as a number of spores may infest the one plant ;
and if the spores are mixed, then both forms might appear in the same ear.
This smooth-spored form is not a mere variation of the species with netted
epispore, for it has been used for infecting directly the different species and
varieties of wheat, and it remained true to its characteristics. Both species
were used for infecting wheat during the past season and invariably remained
distinct.

The smooth-spored form appears to be more common than the other, at
least in Victoria. This fungus was first named Ustilago foetens by Berkeley
and Curtis in Ravenel's Fungi Carol. Exsicc.X., No. 100, 1860, but no de-
scription was published and so the name cannot be accepted. Then Kuehn
in 1867 discovered the same form but only published his description in 1873,
when he named it as above.

I have already referred to the amount of loss caused by this smut, and
even in the present crop (October, 1909) the yield will be reduced by fully
5 bushels per acre in some parts of South Australia. It is also very notice-
able that in consecutive plots grown under exactly similar conditions some
varieties are much less susceptible than others. Thus Federation and Gluyas
were badly affected, while Carmichael's Eclipse showed hardly a sign of it.

Til hi la.

93

In some seasons, such as 1898, in wliicli the sinnnier is comparatively
rainless, the smut-balls are harder and firmer than usual, so much so, that
they give great trouble in the mill, since they do not break up as is usually
the case. It is generally considered that the seed-case was dried up and
had no opportunity of softening in the absence of rain. On examining sec-
tions of such hardened grains, it was found that the spores of the smut were
not fully matured and that many of them were colourless. This would account
foj- the spores forming a dense mass and sticking together, because it is only
when they are fully mature that they fall away like powder. The drying up
would also, of course, tend to make the entire grain firm and hard.

(Plates II., XLVIII.)

Loliiim, Poa.
57. Tilletia striaeformis (Westd.) Oud.

Oudemans, Bot. Zeit. XXXVI., p. 440 (1878).
Sacc. Syll. VII., p. 484 (1888).

Tilletia de Baryana Fischer von Waldheim, Bull. -Soc. Imp.

Nat. Moscow XL., p. 251 (1867).
Ustilago striaeformis (Westd.) Niessl, Hedw. XV., p. 1 (187G).
Ustilago 'poarum McAlp. Rov. Roc. Victoria, VII. (New Series),

p. 220 (1894).

Sori blackish to brownish-black, forming elongated streaks on the leaves,
leaf-sheaths and occasionally found in the ovaries, at first covered,
then free, becoming j)ulverulent.

Spores globose to ellipsoid or even somewhat angular, olive-ljrown
prominently echinulate 10-13 fx diam. or 13-1(5 x 8-10 /».
On Lolium perenne L. — Rye-grass.

Victoria — Creswick, Jan., 1892 (Robinson). Near Melbourne, Jan.,
1901. Pakenham, Dec, 1900 (Robinson). Port Fairy, March,
1899 and Aug., 1900.
On Poa annua L. — Annual Meadow-grass.

Victoria — Ardmona, Oct., 1893 (Robinson).
This species occurs on quite a number of grasses, but it has only hitherto
been found here on Rye-grass and Annual Meadow-grass. Every leaf of a
plant may be affected and growth is naturally prevented. It is only rarely
that in such diseased plants the ovaries are produced, and then they are com-
pletely destroyed by the smut.

This species was named T. de Bari/ana by Fischer von Waldheim 3, but he
afterwards found, on examining the herbarium of M. Westendorp that the
Uredo striaeformis of that author was the same species, and accordingly that
specific name has been adopted. Niessl, however, considered it to be an
Ustilago, and Clinton'* still places this species under that geiuis, seeing that
the germination of the spores has not been observed and that their general
aspect is that of Ustilago. But as F. von Waldheim- has shown, the spores
are formed at the end of spore-bearing filaments as in Tilletia, although the
spore is surrounded by a gelatinous envelope up to the time of ripening. In
the perfectly mature spore, however, there is no trace of it, and until its posi-
tion is definitely settled by the germination of thespore it will be retained here.

(Plate L.)
18.")S. II

194 TiUctia — Entyloma.

Triticum.
58. Tilletia tritici (Bjerk.) Wint.

Winter, Die Pilze, p. 110 (1884).
Brefeld, Uiiters. Gesammt. Myk. V., p. 14(3 (188.3).
Sacc. Syll. VII., p. 481 (1888).
' Lycoperdon tritici Bjerk. in Act. Suec, p. 326 (177-5).

Tilletia caries Tul. Mem. Ust., p. 113 (1847).
Sori in ovaries, blackish to olivaceous, more or less concealed by the
glumes and all or only portion of the ovaries of a spike infected,
foetid.

Spores spherical or sub-spherical generally, black in the mass,
brownish individually, 15-20 /i(, average 16 jtt diam., but some may
reach a length of 22 ^ ; epispore furnished with ridges 1-1 ■ 5 /x high
and forming a network with meshes variable in size and shape, but
generally 3-4 // wide.
On Triticum vnlgare Vill. — Wheat.

In all the States of the Commonwealth.
The spores are generally globose, but they are occasionally oblong to pear-
shaped, and then they may reach a length of 22 /(. They emit an ofiensive
odour something like stinking fish, and when the smut-balls are crushed or
moistened it is more pronounced.

The name of T. tritici, although later in point of time than T. caries, is
preferred, because, under the latter name, other species were included.
Germination. — This has already been fully described at p. 70.
(Plates II., XLVIII.)

ENTYLOMA De By.

Sori generally in the leaves and permanently imbedded in the tissues,
usually forming discoloured but otherwise slightly altered areas.

Spores single, scattered in patches through the tissue and produced
terminally or at intervals in the fertile hyphae, which do not disappear
entirely through the gelatinization.

Grermiuation similar to that of Tilletia and often in addition to the
promycelial conidia, tufts of conidia are formed on protruding hyphae, which
arise from the spore-bearing mycelium.

There is nothing characteristic about the spores to distinguish this genus,
only they are free in the tissues, which are usually pale-coloured, with
protruding conidial tufts.

Australian species, 2.

Eugenia.
59. Entyloma eugeniarum Cke. and Mass.

Cooke and Massee, Grev. XIX., p. 92 (1891).
Cooke, Handb. Austr. Fung., p. 327 (1892).
Sacc. Syll. XL, p. 233 (1895).
Sori in irregular dark-brown pustules, which are flattened, rounded, or
confluent, and then angular, up to ^ mm., collected in large
patches on unier surface of leaf.

Spores globose, oblong, or angular, with thick, smooth, pale-
brown epispore, 10-20 x 10-12 j^t, average 16 x 11 /.i.

Eiityloma — Urocystis. 195

On leaves of Eugenia.

Queensland — Harvey's Creek (Bailey^).
Sections of the affected leaves show that they are sometimes confluent,
and that they may extend almost from the bottom to the top of leaf.

(Plate L.)

Melilotus.
60. Entyloma meliloti McAlp.

Sori in leaves, forming on both surfaces minute, round, slightly raised
pustules, generally brown at margin, and pale or dark-coloured at
centre, often confluent and producing larger patches.

Spores colourless to honey-yellow, globose to ellipsoid or some-
times angular by pressure, smooth, 10-12 /< diam., or 11-13 x 9-9.5//.
On leaves of Melilotus indica All. = M. parviflora Des.

Victoria— Werribee, Oct., 1909 (C. French, jun.).
This is the first recorded species on Melilotus and even on a Leguminous
plant, for E. nectrioides]8])eg. is doubtfully referred to this family. In sections
of diseased portions of the leaf the spores are seen in great masses, and there
are numerous fungus filaments ramifying among them.

(Plate LVI.)

UROCYSTIS Kab.

Sori usually in leaves or stems, and forming dark-coloured dusty spore
masses.

Spore-balls permanent, with a special envelope of tinted sterile cells
enclosing one or several fertile cells.

Spores usually dark-coloured and variable in size.

Germination by means of a promycelium, either undivided or divided
into several cells, and bearing at its apex one or a whorl of elongated conidia,
which give rise to similar secondary conidia or to infection threads.

This genus is often rendered conspicuous by the distortion produced in
the affected parts. The cortex of sterile cells usually completely envelopes
the fertile cells, but it sometimes only forms a partial envelope.

Australian species, 7.

Agropijron.
01. Urocystis agropyri (Preuss) Schroet.

Schroeter, Abh. Schles., Ges., p. 7 (1870).
Sacc. Syll. VII., p. 516 (1888).
Sori forming long parallel black lines on leaves and stems, at first covered
by the leaden-coloured epidermis, then erumpent and pulverulent.

Spore-balls subglobose to oblong or ellipsoid, 20-30 // long, but
sometimes reaching a length of 42 /;<.

Spores deep reddish-brown, subglobose to oblong or angular,
1-3 not uncommon in a ball, sometimes 4 and 5, varving in
size, from 9-15 f.t in length ; sterile cells usually completely sur-
rounding fertile cells, yellowish and elongated.
On Agropijron scabrum Beauv.

Victoria— River flats near Shepparton, Oct., 1896 (Robinson).
Kergunvah Hills, Nov., 19o2 (Robinson).

196 Urocystis.

This species is closely allied to U. occulta, and by some has been considered-
identical, but no cross-infections on wheat or rye have been undertaken with
success. There is not usually the same rotundity about the spore as in
V. occulta, but it is more angular, while the cell walls are thicker and darker.

Germination not known.

(Plate LII.)

Banunculus.

62. Urocystis anemones (Pers.) Wint.

Winter, Die Pilze, p. 123 (1881).
Brefeld, Unters. Gesammt. Myk. XII., p. 176 (1895).
McAlpine, Art. Gaz., N.S.W., VII.. p. 155 (1896).
Sacc. Syll. VII., p. 518 (1888).

8ori on leaves, leaf-stalks, and stems, at first covered by the epidermis,
then splitting longitudinally and becoming powdery, black ; pro-
ducing large irregular, gouty swellings.

Spore-balls very variable in size and shape, 15-33 ^( long.
Spores 1-2 usually in a ball, occasionally 4-5, dark-broAvn, sub-
spherical, to polygonal, obscurely punctate, 12-15 j-i ; sterile cells
globose to somewhat oval, pale-brown or yellowish tinted, seldom
completely surrounding the spores, not numerous, sometimes
reduced to one or even wanting, 8-10 /< long.
On Banunculus sp.

Victoria — River flats near Shepparton, Nov., 1895 (Robinson).
On the stems and leaf-stalks particularly, the tissue is abnormally
thickened and broadened, giving rise to blister-like swellings.

This species is characterized by the small number of spores in a ball, and
the sterile cells being reduced in number.

Germination. — This has been recorded and illustrated by Fischer von
Waldheim^, Plowright^, andBrefeld^. Brefeld found that the spores did not
germinate immediately, but only after half-a-year's rest in damp earth.
When germinated in water they form a very short promycelium, and produce
a whorl of conidia at the end. Plowright succeeded in infecting the foliage
of Ranunculus with conidia, and remarks that — " This is one of the few
species in which mycelium is localized, and the infection of the host-plant
occurs at the same place at which the spores are subsequently formed."

(Plate LII.)

Wurmhea.

63. Urocystis destruens McAlp.

Sori in leaves, forming large swollen lines, at first covered by the greyish
or leaden-coloured epidermis, then rupturing and exposing the
black, pulverulent spore-masses.

Spore-balls generally globose or subglobose, 18-22 /ti diam., or
occasionally oblong, and reaching a length of 30 j-t.

Spores yellowish-bro^^^l to dark-brown, firm walled, smooth,
usually one, occasionally two, in ball, globose to subglobose or
oval, 10-14 p diam. ; sterile cells pale -yellowish, globose to ellipsoid,,
completely surrounding spore or spores, 6-8 ^i diam., or up to 15 }x
lone.

Vrocystis. 197

On \Yurmhea dioiai F. v. M.

Victoria — Near Melbourne, Sept., 1902.

This plant was in flower when this smut was obtained, and it afEected the
lower leaves badly, while the upper leaves merely showed indications of it.

There is generally only a solitary spore, and very occasionally two, but no
more were observed.

Although this species was first referred to U. colchici (Schl.) Rab. in Proc.
Linn. Soc. N.8.W., XXVIII., p. 102 (1903), yet on closer examination and
comparison it is found to differ sufficiently to constitute a new species.

The specimen of Uroci/stis colchici from Sydow's Ust. Exs. No. 246
shows that while the spore-ball may consist of a single spore, there are
frequently two and three or even four spores. The spores are of a sepia-
brown, subglobose to ovoid or irregular oblong, 12-15 /; diam., or varying
in length from 1()-21 /(. The spore-balls may occasionally reach a lenath
of 50 ^'.

(Plate LII.)

Hf/poxis.
!U. Urocystis hypoxydis Thaxt.

Thaxter, Ann. Rep. Conn. Agr. Exp. 8ta., p. 153 (1889).
Sacc. Syll. IX., p. 290 (1891).
Sori in the flowers, destroying and distorting them, also in the leaves,
especially in the basal portion, causing irregular swellings, at first
covered by the leaden-coloured epidermis, then rupturing to allow
the escape of the black dusty spore-masses.

Spore-balls spherical to ovoid or oblong, 25-5-t ^( long.
Spores ruddy-brown, spherical to oval or polygonal, smooth,
1-8 but mostly 3-5 in a ball, 9-1(5 /Lt, average 13 /t long ; sterile
cells yellowish to pale transparent brown, oval to ellipsoid, com-
pletely covering the spores, about same length as spores but not
so broad.

On flowers, leaves, and sheath of bulb of Hypoxis glabella R. Br.

Victoria — Ardmona, Oct., 1897 (Robinson). Warracknabeal, -Tulv,
1903, March, 1904 (Reader).
This species was found by Thaxter on Hypoxis erecfa L. in Connecticut, but
•only on the flowers, pedicels, and peduncles.
■n'[^Germination not known.

(Plate LII.)

Secale, Lolium, Poa.
65. Urocystis occulta (Wallr.) Rab.

Ra])enliorst in Herb. Viv. Myc. II., No. 393 (1856).
Brefeld, Unters. Gesammt. Myk. XII., p. 175 (1895).
Sacc. Syll. VII., p. 515 (1888).
Sori in leaves, leaf-sheaths, stems, and glumes, forming long streaks,
at first covered by the leaden-coloured epidermis, then erumpent,
exposing the powdery and l)lack spores.

Spore-balls globose, elliptical, or oblong, 20-3(5 x 14-32 //,
exceptionally 42 x 36 ;i.

Spores dark golden-brown, spherical to oblong, 1-3 or occasionally
4-5 in a ball, 12-18 ^t long ; sterile peripheral cells generally partially,
but sometimes completely, investing the spores, pale-yellowish, oval.
6-10 jii long.

198 Urocystis.

On Secale cereale L. — Eye.

Victoria — On plants infected with spores from Germany.
On Lolium perenne L. — Rye-grass.

Victoria— Myrniong, Nov., 1899 (Brittlebank).
On Poa caespitosa Forst. — Tussock-grass.

Victoria — Kergunyah, Nov., 1902 (Eobinson).

This is the well-known Rye smut, although it has not been met with natu-
rally on this host in Australia. Through the courtesy of P. Sydow, I received
fresh specimens from Germany. The spores are of a dark golden-brown
colour, and 1-3 in each spore-ball are fairly common, while 4-5 are rather
exceptional. The spores are either completely or often incompletely invested
by sterile cells, which are generally of a yellowish tint, oblong to oval, with
distended and regularly thickened walls.

Germination. — According to Brefeld^, the spores germinate readily in
water, giving rise to a longer or shorter germinal tube, and producing a
whorl of 4-6 conidia at the apex. The promycelium may become septate,
and the' conidia grow out into long branches, septate towards the basal end.

In a nutritive solution germination occurred in a similar fashion, only the
whorl of conidia grew more luxuriantly and became branched just like a
mycelium.

I also germinated the spores in tap water, and the promycelium was
invariably short, never longer than the conidia, and always unicellular. The
cylindrical conidia formed a whorl of 3-4 at the apex, close together at first
but gradually diverging. The average size was 12-15 x 3-4 yit, but sometimes
they reached a length of 24 /(. Germination occurred both on a microscopic
slide and floating on water in a watch-glass.

These spores were obtained from Rye plants grown in my garden, but in
a previous germination I used spores obtained from Berlin. They were
placed on a slide in tap-water, and they germinated freely the third day,
producing a whorl of 2-6 conidia at the apex of the promycelium, which
varied considerably in length, and was finally 4-5 septate.

(Plates v., LI.)

Stipa.
66. Urocystis stipae McAlp.

Sori in leaves, leaf-sheaths, and stems, forming elongated dark-coloured
streaks, at first covered by the epidermis, but ultimately becoming
free by the rupture or decay of the covering.

Spore-balls exceedingly variable in shape and size, globose, ellipti-
cal, oblong, or polygonal, light golden-brown, 22-32 ^ diam., or
28-40 X 20-32 /<. "

Spores round to oval smooth, 1-5 in a ball, average 3, 12-16 x
9-12 i-i ; sterile peripheral cells forming a single interrupted or com-
pletely investing layer, pale-yellowish, flattened oval, 8-12 /( long.

Ur OCX Wis. 199

On Sii'pa luehmanni Reader.

Victoria— Mallee, Oct., 1898 (C. French, jun.).

Tills species is distinct from U. occulta, as the spore-l)all.s are considerably
larger iu size, and the individual spores are smaller.

The grass is provisionally named, as Reader states that there is a certain
amount of hybridism taking place among the species of Stipa, and doubtless
new forms will be the result, so that it is just possible that this species —
S. luehmanni — may be reduced to a variety.

(Plate LI.)

Triticum.
67. Urocystis tritici Koeru.

Koernicke, Hedw. XVI., p. 33 (1877).

Urocystis occulta (Wallr.) Rab, in Sacc. Syll.f?VII., p. 515 (1888).

Sori in leaves, leaf-sheaths, stems, and occasionally on glumes, forming

elongated streaks running parallel to one another, at first covered

by the raised leaden-coloured epidermis, which gradually decays in

patches, allowing the escape of the black powdery spores.

.Spore-balls globose, ellipsoid, or oblong, bright golden-brown,
variable in size and shape, l()-40 /( diam., or 24-40 x 24-32 ^(>
average 32 x 24 /(.

Spores spherical or oval, 1-4 in ball, occasionally 5, 2-3 common,
9-12 ^t diam., or 12-lG /< long ; sterile peripheral cells generally
completely investing spores, or may be only partial, very pale-yellow,
ellipsoid to globose, and bulging, 9-12 /ii long.

On Wheat.

Victoria — Ballarat, Dookie, Longerenong, Netherby, Rochester,

Ruthergien, Tungamah, Yarrawonga, &c.
New South Wales — Common.
Queensland — Hodgson District, 190G (Tryon).
South Australia — Common.
This species is mainly separated from Urocystis occulta on account of the
spores from the one not infecting the other. The spores are commonly two
in a ball, although three and four are also met with, and the investing layer
of sterile cells is generally complete. The spore is delicately punctulate on
the surface, but this is more marked in Ur. occulta.

Koernicke- had determined the smut on wheat sent from South Australia
by Dr. R. Schomburgk iii 1877 as a new species, Urocystis tritici, and according
to him Ur. occulta is distinguished from Ur. tritici by the more distinctly
punctulate spores, which are not generally completely invested by the sterile
cells, and the sterile cells being more compressed and flattened.

Germination. — The spore germinates in water, sometimes in 24 hours, and
sometimes taking a fortnight, according to the age of the spore and the season
of the year. It produces a promycelium which may either be unicellular
or 2-3 celled. At the apex the conidia are formed, varying from 2-0. but
generally 3-4. They are at first upright and crowded together, but gradually
diverge so that they stand out as finger-like })rocesses. They are normally
cylindrical, rounded at the free end, and unicellular, but may develop one
or two septa. They vary in size, but are generally 12-15 m long, and 3 /( broad.

2od Urocystis — Doassamia.

Sooner or later the coiiidia, while still attached, begin to germinate at their
free end, by putting forth a slender germ-tube, only about half the breadth
of the conidium, and this grows ou^t to a varying length, according to the
supply of nutriment. It is filled with dense protoplasmic contents, more
particularly towards the tip. These slender delicate threads, when they
grow out to any considerable length, show an irregular curving, and represent
the infection-threads which penetrate the young seedling, if they reach it
at the proper stage of groAvth.

(Plates IV., v., VI., VII., LI.)

DOASSANSIA Cornu.

This genus stands higher than all the preceding in its morphological dif-
ferentiation. The Peridium formed by the sterile envelope of cells which
encloses the fertile spore-cluster is characteristic of the genus, and places it
at the top of all knoAvn Tilletiaceae. Since the hosts are either water or bog-
plants, the cortex of sterile parenchymatous cells filled with air, is evidently
a contrivance to enable the spores to float, or be surrounded by water until
they escape and germinate. As bearing out this idea, Brefeld-^ has observed
that the envelope is most strongly developed in those species on typical water-
plants, while it is less complete or only rudimentary on bog-plants. The
sppre-body can remain in water for a considerable time, and the spores ger-
minate at the surface or in moist air.

The spores on germination produce an undivided germ-tube, which
gives rise to a whorl of long spindle-shaped conidia. They directly produce
smaller secondary conidia in various branching chains, and in a nutritive
solution they form an unlimited number of aerial sprouting yeast-like conidia
in direct succession.

The conidia may also give rise to hyphae Avhich branch and again pro-
duce at various spots chains of conidia.

There is here again a clear distinction between the parasitic form pro-
ducing spores which give rise to germ-tubes, each with its apical whorl of
conidia, and a saprophytic form in which the conidia thus produced sprouted
directly in a yeast like manner.
Australian species, 1.

Lijtkrum.
68. Doassansia winteriana (Wint.) Magn.

Mao-nus, Berlin, Verh. Bot. Ver. XXXIL, p. 253 (1890).

Setchell, Exam. Doass. Ann. Bot. VI., p. 18 (1892).

Sacc. Syll. VII., p. 505 (1888).

Doassansia punctiformis Winter, Rev. Myc. VIII., p. 207 (1886).

Sori on both surfaces of leaf, globose, punctiform, very minute, scattered

or somewhat gregarious, brownish.
Spores numerous, collected into a ball, rounded to polygonal, isodiametric,
and 10-12 /lj diam. or a little elongated reaching 16 x 10*5 /t; epi-
spore thin, equal, smooth, sub-hyaline ; cortex composed of one
layer of polygonal cells, with thick, brownish, minutely granulated
walls.

Excluded Species. 201

On living leaves of Li/lJini»i, Iii/ssopifolia L.

Victoria — Near Mell)ourne, Oct., 1885 (Reader),
No specimen seen.

This species was named D. punctiformis by Winter in 188(5, but there
was a Protomyces punctiformis determined by Niessl in 1872, which was after-
wards reduced by Schroeter to D. punctiformis in 1887. Since Winter had
given his specific name previous to Schroeter, De Toni in 1888 considered
it necessary and convenient to change the name of D. punctiformis (Niessl)
Schroet. to D. niessUi, and allow Winter's specific name to remain.

However, Professor Magnus considers that the specific name must be
retained, independently of the genus in which the fungus is placed, ajid ac-
cordingly names Win.ter's species D. winteriana as above.

EXCLUDED SPECIES.

Some genera have been placed in this family whose affinities are doubt-
ful, such as C4rapliiola, and Cerebella, and as the balance of evidence is against
their inclusion, I have omitted them. Of course the species belonging to
these genera will also be excluded

The smuts on Polygonum are rather peculiar, and it is not to be wondered
at that they have sometimes been wrongly placed. The unique Ustilago
emodensis of Berkeley was supposed to be represented in Australia, but the
species mistaken for it is now shown to belong to the monotypic genus Melan-
opsichium.

The only other case worthy of special note is that of a supposed new
species of smut found by Berkeley on maize. He named ajid described it as
Tilletia epiphylla, although he observed its rust-like character, but a care-
ful examination of a portion of the original material shows that it is a well-
known rust.

It is rather interesting to observe that the first determination of this
species was the correct one, for Mr. Bailey, F.L.S., Colonial Botanist of
Queensland, wrote to me as follows, in 1893 : — " In the year 1878 the maize
about Brisbane was infested with a Uredo, which Messrs. Berkeley and
Broome determined to be Uredo maydis DC. After this, these two specialists
found thi'^ maize fungus to he a new Tilletia, and described it as Tilletia
epiphylla B. and Br"

1. Ustilago cesatii F. v. W. = U. rahenhorstiana Kuehn, the name given
by Cooke in his Handbook to the smut occurriiig on Paspalum scrohiculntum,
but on examining a portion of the original material forwarded to Coolce, it
is found to be a Sorosporium, and is now named S. paspnli.

2. Ustilago destruens Schlecht. is given by l)oth Cooke and Massee as
occurring on native species of Danthonia. but an examination of portions
of the original material shows that it is a dift'erent and, in fact, a new species,
Ustilar/o readeri Syd.

U. destruens Schlecht. is considered to be a synonym of U. panici-miliacei
(Pers.) Wint., and siuce this has been determined as a Sorosporium, the dis-
tinction from the one occui'i-ing on Danthonia is decided.

Sorosporium panici-miliacei (Pers.) Takash. has been found on species
of Panicum, so that it is only excluded here from l)eing wrongly determined
on Danthonia.

202 Excluded Species.

3. UstilagO emodensis Berk. — I have received some of the origmal ma-
terial from Queensland through the courtesy of Bailey, and find that the
spores are developed in cavities in the tissues of the stem, so that it belongs
to the genus Melanopsichium Berk.

4. UstilagO zeae (Beckm.) Unger=?7. maydis Corda. — The smut occur-
ring on Maize in Australia was naturally considered to be the common
American Corn Smut, and Dr. Cobb recorded it as such, but the examination
of a large number of specimens from different States showed it to be the
Head Smut. This smut generally confines itself to the inflorescence, hence
the name, and does not attack the leaves or stem, forming smut-balls, like
the other, It is quite a distinct genus, and the constant repetition of the
original error renders it necessary to emphasize the fact that the common
Corn Smut of America has not hitherto been found in Australia.

5. Tilletia epiphylla B. and Br. — I am indebted to Bailey for a portion
of the type specimen, and at first sight it certainly looks like a rust with its
gregarious minute pustules. On examining the spores this suspicion is
found to be correct, as they are provided with 2-3 equatorial germ-pores on
one face, as shown in the photograph. (Plate L., Fig. 183). From its size,
colour, and markings it evidently belongs to Puccinia maydis Bereng, The
original specimen was sent to Berkeley, who determined it as a new species
of Tilletia, giving the size of the spores as 36 i^i diam., but he evidently ob-
served its rust-like character for he remarks — " Uredo maydis DC, is a much
larger plant, with much smaller spores.

Then Massee^ in A Revision of the genus Tilletia gives the result of his
examination of the type specimen. He found the spore, instead of being
smooth "to be studded at regular intervals with very minute warts," and
concludes that — " the gregarious, small, linear pustules resemble a Puccinia
superficially." If he had only observed the germ-pores it would have shown
that there was more than a superficial resemblance.

6. Graphiola phoenicis (Moug.) Poit. — This genus, with its most commonly
occurring species found on palm leaves in Queensland, is now generally ex-
cluded from the Smuts, although its systematic position has not been de-
termined.

7. Cerebella Ces. — This genus, occurring in Queensland, with its two
species C. paspali Cooke and Mass. on Paspalmn scrohiculatum L., and
Anthistiria ciliata L. f. and C. andropogonis Ces. on Heteropogon contoHus
E. and S. — is now placed among the Hyphomycetes by Prof. Sa^cardo.

Explanation of Terms. 203

KXi*i.A.\.vri().\ OF ^ri':wMs.

Abstrktion. — The formation of a spore by pinching off the eml of a spore-forming hypha.
Aecidiosporc. — A spore formed in an aecidiuni, being produced in chains from the hymeniiun

lining tiie internal surface.
Aecidium. — The usually cup-shaped envelope witiiin which aecidiospores are jiroduceil.
Alien. — An introduced plant which has become naturalized.
Amphimixis. — The intermingling of the properties of the two sex-cells in the process of

fertilisation, when they are clearly distinct.
Anastomosis. — The union of hyphae by numerous cross-connexions, forming an irregular

network.
Anti-toxin. — A secretion wliicli neutralizes or counteracts the effects of a toxin or

poi.sonous secretion.
Ascomycetes. — 'A group of fungi in which tiie sijores are produced by free-cell fornu^tiou

in a mother cell or ascus.
Asciis. — The spore mother-cell, wliich is usually the swollen end of a hypha.
Autobasidium. — An undivided basidium, consisting of a single large cell.
Basidiomycetes. — A group of fungi producing spores on basidia.
Basidium. — A terminal tubular cell, bearing at its apex a definite number of spores or

conidia, usually four ; or divided transversely, and each cell giving rise to a

reproductive body.
i?f/.sipetaL— Applied to conidia or spores when the youngest of a chain are produced at

the base.
Bunt. — A common name applied to Stinking Smut of wheat.
Cereal. — Any of the grasses whose grains serve as food.
Chemotaxis or Chemotropism. — A form of sensitiveness which certain organisms possess

towards particular chemical substances.
Chlamydosporc. — -A thick-walled resting-spore.
CldorophyU, — The gi-een colouring matter of plants, which enaljles the chlorophjdl

grains to utilize inorganic food.
Conidium. — A reproductive cell asexually produced and arising by a process of budding.
Co)iju(/ation.— The fusion of sexual elements, the two uniting elements or gametes being

similar.
Contagion. — The transmission of disease by direct contact of the part afifected with the

Dominant. — Applied to such characters arising in the crossing of two individuals as prevail

and assert themselves over contrasted characters A\hich are kept in the back-
ground.
Echinulate. — Covered with short spines.
Endos pore. —The innermost coat of a spore.
Exospore. — The outer covering of a spore
Fertilisation. — The union of two ucnu-iclls derived from male and female organisms

respectively and becoming |ili\ ^inlogically one.
Fungi. — Plants destitute of chl<Mci|ili\ II. and without the systems of tissues characteristic

of higher plants, but may be unicellular or composed of more or less compacted

strands of cells or hyphae.
Fungicide. — Any substance which acts injvu'iously to fungi or destroys them completely.
Gall. — A monstrous growtli or morbid enlargement of the cells of a ])lant. due to

parasitic agency.
Gametes. — -CTcrra-cells derived from nuilc or female organisms, that from the male being

known as spermatozoon or sperm cell, and that from the female as ovum or egg-cell.
Gamefophyte. — The stage in the life-cycle of a plant which bears the sexual organs.
Germinal tube. — A tubidar process from a spore developing into a promyceliuni.
Germ-tube. — A tubular process from a spore or conidium developing into a Iiypha. and

ultimately into a mycelium.
Haustorium. — A short lateral brancli of a liypha. penetrating a cell of tlie liost-plant. and

acting as a sucker as well as an organ of attachment.
Hemibasidia. — A term applied by Brefeld to the promycelia of tli(> Suuits. as they siu)w

their primitive nature by being divideil and bearing a variable number of conidia.
Heredity. — ■" The genetic relation between successive generations," or " The transference

of similar ciiaracters from one generation of organisms to another, a process effected

by means of tiie germ-cells or gametes."
Host or Host-plant. — A plant whicii nourishes a parasite.
Hyaline. — Colourless or translucent.
Hymenium. — A spore-bearing layer of hyphae.
Hypha. — A tubular tlu'cad-like structure, collectively constituting the vegetative body

or mycelium of the fungus.

204 Explanation of Terms.

Immunity. — -The absence of susceptibility to an infectious disease, even although the

germ-tube of the parasitic fungus has entered the host-plant, without, however,

multiplying therein and producing disease.
Incicbation-period. — -The time which elapses between the introduction of the infective tube

and the production of the characteristic fungus.
Indigeyious. — Native to a country and not introduced, at least within the historic period.
Infection. — The introduction of a living micro-organism or the germ-tube of a parasitic

fungus into the host-plant, where it multiplies and produces disease.
In florescence. ^The arrangement of several flowers on a common axis, and in grasses the

axis or stalk is known as the Rachis.
Inoculation. — The entrance of the germ-tube of the parasitic organism into the host-
plant, irrespective of the causation of disease.
Intercellular. — Between the cells of the host-]ilant.
Intracellular. — -Within the cells of the h(ist-i)lant.

Lumen. — The cavity bounded by the walls of an organ, as the central cavity of a cell.
Jletabolism. — -The sum of the chemical changes in a living cell.
Micron or Micromillimctre. — -The standard unit for microscopical measurements equalling

1-lOOOth of a millimetre, or 1 -25000th of an inch, and indicated by the sign ^{.
Mycelium. — The vegetative portion of a fungus composed of hyphae.
Nucleus. — An organized prote'l constituent of the cell, playing an important part in its

nutritive and reproductive processes.
Oospore. — -The fertilised cvum or egg-cell.

Ooary. — ^That portion of the female organ of a flowering plant which contains the ovules.
Parasite. — An organism living on or in another living organism and at its expense.
Pathology. — The science of disease. Vegetable Pathology is that division of it which

treats of plant diseases.
Peridium. — The enveloping layer enclosing spores as -in the Puff-balls and the aecidium

of the Rusts.
Phycomycetes. — A group of fungi which are alga-like in their characters, with sexual and

asexual reproduction.
Predisposition. — The tendency to disease exhibited by an organism when the conditions

are favorable to the development of the parasite.
Promycdium.. — Applied to the germinal tube produced by the spore of the Rusts and Smuts.
Pronucleus. — The nucleus of a conjugating gamete which unites with another pronucleus

to form the germ-nucleus.
Protdbasidium. — -A basidium transversely divided and consisting of several cells.
Protoplasm. — -The living substance of which animals and plants are composed.
Pseudomixis.— The union of the sexual cells in the process of conjugation, when they are

approximately equal.
Pulverulent. — Powdery, applied to spores when they are dusty and not agglutinated

together.
Rachis. — -The axis or stalk in the inflorescence of grasses.
Recessive. — -Applied to such contrasted characters, arising in the crossing of two

individuals, as are kept in abeyance or apparently suppressed, at least, in the

first generation.
Saprophyte. — A fungus which preys upon dead organic matter only, in contrast to a

(Septofe.— Partitioned off into distinct divisions.

Septum. — A partition or cross- wall.

•Sorus. — A cluster of spores constituting a spore-bed.

Spore.— A detachable cell capable of reproducing the fungus.

Sporidium. — A spore abjointed from a promycelium, equivalent to a conidium.

Sporidiolum is the term proposed by Saccardo, since sporidium is already applied

to an ascospore.
Sporophyte. — The stage in the life-cycle of a plant which bears the spores.
Stigma. — The top of the pistil upon which the pollen is received.

Stroma.— Fundus body in the form of a cushion or expansion, bearing reproductive bodies.
Symbiosis. — -The living together of dissimilar organisms which mutually help and support

each other.
Teleutospore. — Generally regarded as the ultimate spore in the life-cycle of the Riists

which germinates and produces a promycelium. Sometimes also applied to the

spore of the Smuts.
Toxin.^A poisonous secretion of certain Fungi which kills the cells of the host-plant and

^prepares the way for the entrance of the parasite.
Unicellidar. — -Consisting of a single cell.
Uredospore. — A spore detached from the apex of a pedicel and producing a mycelium which

bears uredospores or teleutospores or both.
Vacuole. — A space in the protoplasm of cells which contains a watery fluid, the cell-sap.
Verrucose. — Warty, covered with small warts.

Literature. 205

\.YVVA\yVVV\V..

A.

1. Ahbot, r. — Smut in ^\■lleat. P. and Proc. Pvoy. Soc. Tasmania, p. it.3. 1880.

1. Appel, O. — Uer Steinhrand des Woizens und seine IJckiimpfiing. Westpreuss. Landw

Mitteil. IX., p. 234. 1904.
1. Appel, O., and CIassner. G. — Ucr Brand cks Hafcrs und seine Bekampfung. Flu"-

blatt. No. 38, Kais. biol. Anstalt f. Land und Forstw. 1906. "

2. Der derzeitige Stand unserer Kentnisse von den Flugbrandarten ties Getreides.

Alittsil. Kais. biol. Anstalt f. La .d— und Forstw., Ft. 3. lilOT.
3. Untersuehungen ueber den P;ind. inbesondere den Flvigbraiid desCietreides.

Ibid. Pt. 4., p. 9. 1907.
1. Arthur. J. C. — Smut of Wheat and Oats. ■Bull. Ind. Agr. Exj). Sta. No. 28. 1889.

2. Treatment of Smut in Wheat. Ibid. No. 32. 1890.

3. Loose Smut of Oats. Ibid. No. 35. 1891.

4. Grain Smut and the use of hot water to pi'event it. Agr. Sci., VI.. p. 393

1892.
5. Formalin and hot water as preventives of Loose Smut of Wheat. \nn.

Rep. Ind. Agr. Exp. Sta., XIIL, p. 17. 1901.
6. Rapid Method of removing Smut from Seed Oats. Bull. Punlue Asr. Exp.

Sta.. No. 103, p. 257. 1905.
1. and Stuart, W.— Corn Smut. Ann. Rep. Ind. Atrr. Exp. Sta.. XIL. p. 84.

1900.

1. Bailey. F. M. — Synopsis of the Queensland Flora, pp. 774-5. Brisbane. 1883.

2. ■ Ibid. Second Supplement, p. 127. Brisbane. 1888.

3. ■ — Ann. Rep. Dep. Agr. Queensland, p. 51. Brisbane. 1891-2.

4. Contributions to the Queensland Flora. Bot. Bull., No. 4, pp. 37, 38. Bris-
bane. 1891.
5. A Review of the Fungus Blights which liave been observed to injure living

vegetation in Queensland. Rep. Aust. Assoc. Adv. Sci. Hobart. I\'., pix 400-1

1892.
6. Contributions to the Queensland Flora. Bot. Bull., No. 10, p. 30. Brisbane

1895.
7. Queensland Blight Fmigi. Proc. Conf. Aust. Fruit-growers, New Zealand,

p. 208. Wellington. 1896.
8. -^ Contributions to the Flora of Queensland. Queensland Agr. Joiu-n., I., p 8''

1897.

9. Ibid. III., p. 205. 1898.

1. Barber, C. A. — Diseases of Andropogon sorghum in Madras Presidency. Bull. Dep.

Land Records and Agr., Madras, No. 49, p. 275. 1904.
1. BAR^^^CK, J. — Smut in Wheat. P. and Proc. Roy. Soc, Tasmania, pp. XV. and \XI

1889.
1. B.A.RY, A. de — Untersuehungen ueber die Brandpilze. Berlin. 1853.
2. Protomyces mkrosporus und seine Verwandten. Bot. Zeit. XXXII. p 81

1874.
3. Comparative Morphology and Biology of the Fungi, ]\Iycetozoa and Bacteria

English Edition. Oxford. 1887.
I. Berkeley, ^1. J. — ^Observations on the Propagation of Bunt (Urcdo caries DC.)

Journ. Hort. Soc, London, p. 107. 1847.

2. Introd. Crypt. Bot., p. 256. London. 1857.

3. Flora of Tasmania — Fungi. Hooker's Botany of tiic Antarctic Vovao-c

Vol. II., Pt. 3, p. 270. 1860. ^

4. Australian Fimgi. Journ. Linn. Soc., London, XIII.. ]). 174. 1872.

5. Fimgi in Handbook New Zealand Flora, p. 625. 1869.

1. Berkeley, M. J. and Broome, C. E. — List of Fungi from Brisbane, Queensland, with

descriptions of new species. Tr. Linn. Soc., London, 2nd Ser., Vol. II.. Pt. 1

p. 407. 1878: and Pt. 2, p. 67. 1882
1. Bessey, V. E.— The Wheat Smut. Bull. Iowa Agr. Coll., p. 118. 1884.
1. BiFFEX, R. H. — Jlendcl's Laws of Inheritance and Wheat Breeding. Journ. Agr.

Sci., Cambridge, j). 4. 1905.

2. Studies in the Inheritance of Disease Resistance. Ibid., p. 109. 1907.

1. Bjerk.\nder. C. — Anmiirkningar vid Kol-eller Sot-ax i Hvetet. Vetensk. Akad. Haudl.,

p. 317. 1775.

20t

Literature.

1. BOLLEY. H. L.— Grain Smuts. Bull. N. Dak. Agr. Exp. Sta., No. 1. 1891.

2. Treatment of Smut in Wheat. Ibid., No. 19. 1895.

3. New Studies upon the Smut of Wheat, Oats, and Barley, with resume of

Treatment and Experiments for the last three years. Ibid., No. 27. 1897.

4. ■ — The Prevention of the Smuts of Cereal Grains. Ibid., No. 37. 1899.

1. Brefeld, O.^Botanische Untersuchungen neber Hefenpilze. Die Brandpilze, I.,

Vol. V. 1883.
2. ■ Untersuchungen aus dem Gesammtgebiete der Mykologie. Basidiomycetes

III., Vol. VIIl., p. 224. 1889.
3. . Recent investigations of Smut Fungi and Smut Diseases. (Translation).

Journ. Myc, VI., pp. 1, 59, and 153. 1890 ; and Nachricht a, d. Club d. Land-

wirtlie zu Berlin, p. 1577. 1888.

4. — . — . — Untersuchungen aus dem Gesammtgebiete der Mykologie. Die Brandpilze, II.,

Vol. XI. 1895.

5. Ibid. Hemibasidii. Brandpilze III., Vol. XII. 1895.

6. — Neue Untersuchungen und Ergebnisse ueber die natiirliche Infektion und

Verbreitung der Brandkrankheiten des Getreides. Nachricht Club der Landwirte

zu Berlin, No. 460, p. 4224. 1903.

7. Mykologie — Hemibasidii. Brandpilze IV., Vol. XIII. 1905.

8. Ibid. Vol. XIV. 1908.

1. Brooks, F. T. — Observations on the Biology of Botrytis cincrea. Ann. Bot. XXII.,

p. 480. 1908.

C.

1. Clinton, G. P.— Broom-Corn Smut. Bull. 111. Agr. Exp. Sta., No. 47, p. 373. 1897

2. The Smuts of Illinois' Agricultural Plants. Ibid., No. 57, p. 289. 1900.

3. .^ — . North American Ustilagineae. Journ. Myc. VIII., p. 128. 1902.

4. . North American Ustilagineae. Proc. Boston Soc. Nat. Hist. XXXI., p. 329.

1904.
5. . — . The Ustilagineae or Smuts of Connecticut. State Geol. and Nat. Hist.

Survey, Bull. No. 5. 1905.

. — North American Flora — Ustilaginales. New York Botanical Garden. 1906.

1. Close, C. P.— Results with Oat Smut in 1897. Bull. N. Y. Agr. Exp. Sta. No. 131.

1897.
1 Cobb, N. A.— Diseased Maize Plants. Agr. Gaz. N.S.W., II., p. 285. 1891.

2. Smut. Ibid., p. 672. 1891.

3. Plant Diseases and how to prevent them. Ibid. III., p. 1006. 1892.

4. ._ The Hot-air treatment of Bunt or Stinking Smut. Ibid. VII., p. 82. 1896.

5. Effect of Engine-boiler Steam on the Vitality of Seeds and Spores. Ibid. XIV.,

p. 26. 1903.

6. Smut of the Prarie Grass. Ibid. XV., p. 14. 1904.

1. Cooke, M. C— Australian Fungi. Grevillea XI.. p. 99. 1883.

2. Australian Fungi. Ibid. XII., p. 20. 1883.

3. ___ Cintractia axicola Berk. Ibid. XIX., p. 53. 1890.
4. Australian Fungi. Ibid. XX., p. 65. 1892.

5. ___ Handbook of Australian Fungi., pp. 324-329. London. 1892.

1. CoRNt7, M. — Sur quelques Ustilaginees nouvelles ou peu connues. Ann. Sci. Nat.

Bot. W., 15, p. 269. 1883.
2. • Contributions a 1' Etude des Ustilaginees. Bull. Soc. Bot. Fr. XXX., p. 130.

1883.

1. Dangeard, p. a.— Recherches histologiques sur la Famille des Ustilaginees. Le

Botaniste III., p. 240. 1892.

2. ■ . — . La reproduction sexuelle des Ustilaginees. Compt. rend., CX^T^I., p. 496.

1893. T^

Recherches sur la reproduction sexuelle des Ustilaginees. Le Botaniste, p. 221.

1894.
1. Dietel, p. — -Hemibasidii (Ustilagineae and Tilletiineae) in Engler and Prantl's Bie

natiirlkhen Pflnnzenfamilkn. 1900.
1. DuGGAR, B. M. — Physiological Studies with reference to the Germination of certain

Fungous Spores. Bot. Gaz. XXXI., p. 38. 1901.

E.

1. Evans, J. B. Pole. — Smut in Wheat, Barley, and Oats, and how to prevent it.
Transvaal Agr. Journ. IV., p. 827. 1906.

Literature. 207

l'\

I. Fakkkr, W. — Note on Simit in Wlu'at and Diy Seasons. Agr. (Jaz., N.S. Wales X.,
p. 47!». 18!)!l.

2. Some Ex|)i'tiiiicn(s in dealini;- witli limit or tlie Stinking Smut of Wheat.

Ibid., XL, p. :{:}."). liiou.

3. — Results of tile l.aiiihriog Bunt Experiments of litOO. Il.i.l. XII., p. 41!J.

1!U)1.

4. — Experiments with V,\AiAs.-x\\%t {U rocystis occulta). Ibid. XII., ]>. iOliO. lUOl.

5. Note on Bunt in self-sown Wheat. Ibid. XII., p. 1182. 1901.

(3. Report of the Wheat Experimentalist. Ibid. XIII., p. 542. 1902.

7. The Effect on the Milling Quality and Nutritive Value of the resulting Crop

of Wheat when Bunt-infected seed is sown. Ibid. XIII., p. 1094. 1902.

8. Bunt Experiments of 1901. Ibid. XIV., p. 206. 1903.

9. — Report of the Wheat Experimentalist. Ibid. XIV., p. 855. 1903.

10. Report of the Wheat Experimentalist. Ibid. XV., p. 1050. 1904.

11. Some Notes for ^Vheat-growers — Treatment of Seed for Bunt. Ibid. X\T.,

p. 4(i8. 1905.

12. — The effect, in actual Farm-praitice, of treatment with Bluestone on the

germination of Wheat. Ibid. XVI., p. 1246. 1905.
1. Farrer, W., and Sutton, G. L. — The effects of some solutions of Formalin and Blue-
stone, which are in common use, on the germination of Wheat-seeds. Ibid. XVI.,
p. 1248. 1905.
1. FiNGERHUTH, C. A. — Mylvologisclie Beitrage. Linnaea X., p. 230. 1836.
1. Fischer, E. — Beitrag zur Kenntniss der Gattung Graphiola. Inaugural Dissertation.
Bot. Zeit. 1883.

2. Ueber Gymnosporangium sabinae (Dicks.) Wint. and G. con j mum Plow.

Zeitsclu-. f. Pflanzenk. I., p. 260. 1891.
1. Fischer von Waldheim, A. — Beitrage zur Kentniss der Ustilagineen. Bot. Zeit.
XXV., p. 393. 1867.

2. — Sur la structure des Spores des Ustilaginees. Bull. Soc. Nat. Mosc. XL.,

p. 242. 1867.

3. — Contribution to the Biology and History of the Development of the Ustila-

gineae. (Translation). Trans. N". York Agr. Soc. for 1870, p. 280. Albany. 1871
and Pringsh. Jahrb. Wiss. Bot. VII., p. 61. 1869.

4. Aper^u systematique des Ustilaginees. Paris. 1877.

5. Lss Ustilaginees et leurs plantes nourricieres. Ann. Sci. Nat. Bot. \J., 4,

p. 190. 1877.
1. Freeisian, E. M. — The seed-fungus of Lolium temulentum L. — the Darnel. Phil.
Tr. R. Soc, London. Ser. B., 196, p. 1. 1903.

2. Symbiosis in the Genus Lolium. Minnesota Bot. Studies, p. 329. 1904.

3. Affinities in the Fungus of Lolium temulentum. Ann. Myc. IV., p. 32. 1906.

1. — ■ ■ and Umberger, H. J. C. — The Smuts of Sorghum. U.S. Agr. Bur. Plant

Indus. Circ. 8. 1908.

1. ■ — and Johnson, E. C. — The Loose Smuts of Barley and Wheat. Bull. U.S.

Agr. Dep. No. 152. July. 1909.

1. C4ARMAN, H. — Hot water and bluestone solutions as remedies for Smut in Wheat.

Bull. Kentucky Agr. Exp. Sta. No. 69, p. 95. 1897.
1. GoFF, E. S. — The hot water treatment for the Prevention of Smut on Oats, Wheat, and

Barley. Bull. Wis. Agr. Exp. Sta. No. 50. 1896.
1. Grenfell, C. N. — Experiments with three kinds of Smuts. Agr. Gaz. N.S. Wales,

XI., p. 742. 1900.
2. Some experiments with Wheat, made at Blount Templeton. S.A. Ibid. XII.,

p. 1053. 1901.
1. Gussow, H. T.— Injurious Fodder and Poisonous Plants. Journ. Rov. Agr. Soc,

England, p. 32. 1907.
1. GuTTKNBERii, H. R. VON— Beitnigc zur physiologischen anatomic der Pilzgallen.

Leipzig. 1905.

H.

1. H.vllier, E. — Phytopathologie. Leipzig. 1868.

1. Hannig, E.— LVber pilrzfreies Lolium temulentum. Bot. Zeitg. LXV., p. 25. 1907.
1. H.A.RPER. R. A. — Nuclear phenomena in certain stages in the development of the Smuts.
!' Tr. Wis. Acad. XII., ]). 475. 1899.

2o8 Literature.

1. Harwood, p. M.— Smut in Oats and Wheat. Bull. Michigan Agr. Exp. Sta. No. 87.

1892.
1. HA\^LAND, E. — Report on four samples of Maize received from River Hastings.

Sydney. 1886.

1. Hecke, L. — Vorversuche zur Bekampfung des Brandes der Kolbenliirse. Zeitschi-.

Landw. Ver. Oesterr., p. 933. 1902.

2. ^— — Ein innerer Kranklieitskeim des Flugbrandes im Getreidekorn. Zeitschr.

Landwirt. Versucliswesen in Oesterreich, \T:I., p. 59. 1904.

3. ^ Zur Theorie der Bluteninfektion des Getreides durch Flugbrand. Ber. Deutsch.

Bot. Ges. XXIII., p. 248. 1905.

4. ^ . Die Triebinfeivtion bei Brandpilzen. Zeitschr. Landw. Ver. Oesterr., p. 572.

1907.

5. — . • Der Einfluss von Sorte und Temperatur auf den Steinbrandbefall.

Zeitschr. Landw. Ver. Oesterr., p. 49. 1909.

1. Henderson, L. F. — Smuts and Rusts of Grain in Idaho, and the most approved

methods of dealing with them. Bull. Idaho Agr. Exp. Sta. No. 11. 1898.

2. ■ Experiments with Wheat and Oats for Smut. Ibid. No. 53. 1906.

1. Hennings, p. — Ustilago tritici (Pers.) Jens, forma folicola P. Henn. Zeitschr. Pflan-

zenkr, IV., p. 139. 1894.

2. Fungi blumenavienses. Hedw. XXXIV.. p. 335. 1895.

3. Einige Beobachtungen ueber das Gesunden pilzkranker Pflanzen bei veran-

derten Kulturverhaltnissen. Zeitschr. Pflanzenkr. XIII., p. 41. 1903.
1. Herzberg, p. — Vergleichende Untersuchungen ueber landwirthschaftlich wichtige

Flugbrandarten. Zopf Beitr. Morph. Phys. Organ., V., p. 1. 1895.
1. Hickman, J. F.— Smut in Wheat. Bull. Ohio Agr. Exp. Sta. 2nd Ser. III., p. 205.

1890.
2. ■ — ■ Experiments in Wheat seeding and treatment of seed for Smut. Ibid. IV.

No. 4., p. 77. 1891.

3. . The Smut of Oats. Bull. Ohio Agr. Exp. Sta. No. 67, p. 2. 1896.

4. . — Experiments with Oats — Seeding on different soil to exterminate Smut. Ibid.

No. 101, p. 179. 1899.
1. HiLTNER, L. — Ueber die Abhangigkeit der Brandanfalligkeit des Getreides von dessen

Keimungsenergie und Entwickelungsgeschwindigkeit. Prakt. Blatt. Pflanzensch.

land Pflanzenbau VI., Pt. 6. 1908.
1. Hitchcock, A. S., and Carleton, M.A. — The effect of Fungicides upon the germination

of Corn. Bull. Ivans. Agr. Exp. Sta. No. 41. 1893.
1. Hitchcock, A. S., and Norton, J. B. S.— Corn Smut. Ibid., No. 62. 1896.

1. HoLLRUNG, M. — Die Verhiitung des Brandes inbesondere bei Gerste und Hafer durch

die Saatkornbeize. Landw. Jahrb. XXVL, p. 145. 1897.

2. — Handbuch der chemischen Mittel gegen Pflanzenkrankheiten. Berlin. 1898

1. HoBi, S. — ^Seed Infection bv Smut Fungi of Cereals . Bull. Imp. Cent. Aot. Exp. Sta.

L, No. 2., p. 163. 1907.

1. Istvanffi, G. von — -Ueber die Rolle der Zellkerne bei der Entwickelung der Pilze.
Ber. Deutsch. Bot. Ges. XIIL, p. 452. 1895.

1. Japp, 0. — -Beitrage zur Pilzflora der Schweiz. Ann. Jlyc. V.. p. 255. 1907.

1. Jensen, J. L. — The propagation and prevention of Smut in Oats and Barlev. Jom-n.

Roy. Agr. Soc, England XXIV., p. 4. 1888.

2. — -"Ls Charbon des Cereales. Copenhagen. 1889.

1. KAUF.M.A.NN, C. H. — A contribution to the Physiology of the Saprolegniaceae, with

special reference to the variations of the sexual organs. Ann. Bot. XXII., p. 361.

1908.
1. Kellerman. W. a. — Second Report on Fungicides for Stinkina; Smut of Wheat.

Bull. Kans. Agr. Exp. Sta. No. 21, p. 47. 1891.
2. — I. Smut of Oats in 1891. II. Tes-t of Fungicides to prevent Loose Smut of

Wheat. Ibid. No. 22, p. 73. 1891.
3. .— Experiments with Sorghum Smuts. Ibid. No. 23. 1891.

Literature.

209

1. Kellermax, AV. a. and S\vin(;le, W. T. — Proliminary Rc[)ort on Simit in Oats. Tl)i<|.

No. 8., p. <)1. 1S89.
2. ■ Preliminary E.Kporiments witii Fungicides for Stinkinir Smut of AVhcat. Ibid.

No. 12, p. 27. 1890.
3. Loose Smut of Cereals. Ann. Rep. Ivans. Agr. Exp. Sta. No. 2, j). 213.

1890.
4. Additional E\-])eriments and Observ^ations on Oat Smut. Ibi<l. No. l.">, i). 1)3.

1890.
1. KiRCHNER. O. — Investigations on the susceptibility of various varieties of Wheat

to Smut [Tilktiu tritici). Fiihling's Landw. Ztg. 57, No. 5, p. Kil. 1908.
1. Kirk, T. W.— Smut in Grain. Ann. Rep. N.Z. Dep. Agr., p. 298. 19o4.

2. — Smut of Wheat, Oats, and Barley. Ibid., pp. 341, 342. 190<i.

3. Smuts of Cereal Crops. Ibid., p. IGO. 1907.

1. Klebs. G. — Zur Phj-siologie der Fortpflanzung einiger Pilze. Allgemeine Betrach-

tungen. Pringsh. Jahi-b. XXXIV., p. 80. 1900.
1. Knowxes, E. L. — A Study of the abnormal strnctures induced by Ustihujo zeae iivujs.

Journ. Myc. V., p. 14. 1889.
1. Koernicke, F.— Mykologische Beitriige. Hedw. XVT., p. 33. 1877.
1. Ktjehn, J. — -Kranklieiten der Knllurucwiiclise. Berlin. 1858.
2. Die Anwendung des Kupl'iviti idles als Schutzmittel gegen den Steinbrand

des Weizens. Bot. Zeit. XX XT., p. .".(i2. 1873.
.3. • Ueber die Entwickelungsformcn des Getreidebranrles. Naturf. (Jes. Halle.

1874.

L.

1. Laurent, E. — Inlluence tie la lumicre sur les Spores du charbon des cereales. Bull.

Soc. Belg. XX\^IL, p. 162. 1889.
1. LiEBEXBERG. V. — Ueber die Dauer der Keimkraft der Sporen einiger Brantlpilze.

Oesterr. landw. Wochenblatt. 1879.
1. LoTSY, J. P.— Vortrage ueber Botanische Stammesgesehichte. Jena, 1907.
1. LuDWiG, F. — Contributions to the Fnngal Flora of Australia. Proc. Roy. Soc. S.

Australia XIII., p. 58. 1890.
2. ■ — Ueber einige Rost-und Brand-pilze Australiens. Zeitschr. Pflanzenkr. III.,

]). 137. 1893.

1. Maddox, F. — Notes and Results of Agricultural Experiments, p. 72. Tasmania

1897.
1. Magnus, P. — Ueber das Auftreten der Stylosporen bei den Uredineon. Ber. Deutscii.

Bot. Ges. IX., p. 85. 1891.

2. Ustilaginaccae. Eng. Jahrb. XM:I.. p. 490. 1893.

3. — Ueber die Ustilagineen-Gattung Setchellia Magn. Ibid., XIII., p. 408. 1895.

4. Eine nordamerikanische Ustilaginee auf Panicum cms galli. Ibid. XIV.,

p. 216. 1896.
5. Lss Ustilaginees du Cynodon dactylon L. et leur distribution seotrraphiijue.

Bull. Soc. Myc. France, XV., p. 265. 1899.
1. Maiden, J. H. — A Manual of the Grasses of New South Wales. Government Printer,

Sydney. 1898.
1. Massce. G. — -British Fungi — Phycomycetes and Ustilagineae. London. 1891.

2. A Revision of the Genus Tilletia. Kew Bull., p. 141. 1899.

3. To protect Cucumbers and Tomatoes from Fungus. Journ. Roy. Hort. Soc.

XXA^IL, p. 142. 1903.
4. ■ On the Origin of Parasitism in Fungi. Phil. Trans. Roy. Soc. Ser. B., Vol. 107.

p. 7. 1904.

5. A Text-book of Fungi. London. 1906.

6. A Text-book of Plant Diseases, 2nd Ed. London. 1907.

1. McAlpine, D. — Australian Fungi. Proc. Roy. Soc. Victoria, V., p. 22i). 1894.

2. Australian Fungi. Ibid., VI., p. 7.58.' 1895.

3. Sv.stematic Arrangement of Australian Fumxi. Dep. Agr., Victoria, pp.

184-187. 189.5.

4. Australian Fungi. Agr. Gaz. N. S. Wales, VII., p. 154. ISOfi.

5. New South Wales Fungi. Proc. Linn. Soc, N. S. Wales., p. 42. 1897.

1858. I

3 Literature.

McALPmE, D. — Bunt or Stinking Smut of Wheat and its Treatment. Guides to

Growers, No. 44. Dep. Agr., Victoria. 1899.
Stinking Smut Experiments in the Mallee and at Port Fairy, Leongatha, and

Longerenong Agricultural College. Ann. Rep. Dep. Agr., Victoria, p. 35. 1899.

■ • Flag Smut of Wheat. Ami. Rep. Dep. Agr., Victoria, p. 17. 1900

Experiments in the Prevention of Stinking Smut of Wheat — 1889-1900.

Ibid., p. 19. 1900.

10. Sulphate of Iron as a Preventive of Stinking Smut. Aor. Gaz.. N. S. Wales.,

XII.. p. 334. 1901.

11. • Experiments with Rust and Stinking Smut in Wheat dm-ing 1901. Aust,

Assoc. Adv. Sci., Hobart IX., p. 610. 1902.

Experiments in the Prevention of Stinking Smut or Bunt of Wheat. Journ.

Dep., Agr. Vic, I., p. 413. 1902.

13. Stinking Smut or Bunt. Ibid., p. 803. 1902.

14. Stinking Smut Experiments. Ibid., II., p. 165. 1903.

15. Treatment of Bunt of Wheat and Smut of Barley. Ibid., p. 355. • 1904.

16. Flag Smut of Wheat. Ibid.. III., p. 168. 1905. ^!viH,,

17. Germination Test of Seed-wheat treated with Formalin. Ibid., p. 266.' 1905.

18. Effect of Formalin and Bluestone on the Germination of Seed-wheat. Agr.

Gaz., N.S. Wales, XVII., p. 423. 1906.

19. Report of the Department of Agriculture for 1905-7, p. 30. Government

Printer, Melbourne. 1907.

20. Fungusine as a Smut Preventive. Journ. Dep. Agr., Vic, VI., p. 35. 1908.

21. The Stinking Smut of Wheat. Ibid., VII., p. 171. 1909.

22. — ■ — . — ■ Experiments relating to Rust and Smut Resistance. Ibid., VII., p. 255. 1909.

23. — The Treatment of Stinking Smut of Wheat — Experiments at Longerenong

Agricultural College. Ibid., VIIL, p. 53. 1910.

1. Me YEN, F. J. F. — A Report on the Progress of Vegetable Physiology during 1837.

(Translation). London. 1839.
1. MiYOSHi, M. — Ueber Chemotropismus der Pilze. Bot. Ztg. LII., p. 1. 1894.

1. Moore, R. A. — On the Prevention of Oat Smut and Potato Scab. Bull. Wis. Agr.

Exp. Sta. No. 98. 1903.

2. Oat Smiit and its Prevention. Ibid. No. HI. 1904.

1. MoTTAREALE, G. — L'UstUago reiliana fa. zeae e la Formazione dei Tumori staminali
nel Granone. Ann. R. Scuol. Sup. Agr., Portici, IV. 1902.

1. Mueller, F. von — Census of the Genera of plants hitherto known as indigenous to

AustraUa. Proc Roy. Soc. N. S. Wales., XV., p. 254. 1881,

2. Notes on Victorian Fungi. Vic. Nat. II., p. 80. 1885.

N.

1. Nakagawa, S. — Bull. Agr. Exp. Sta. Nishigahara, Japan., XII., No. 4. 1898.

1. Nelson, A.— The Grain Smuts and Potato Scab. Bull. Wyom. Agr. Exp. Sta. No. 21.

1895.
1. Norton, J. B. S.— Ustilago reiliana on Corn. Bot. Gaz. XX., p. 463. 1895.
2. A study of the Kansas Ustilagineae, especially with regard to then" germination.-

Tr. St. Louis Acad. N\\., p. 229. 1896.

3. Sex-determining Factors in Plants. Science, N. S., XXV., p. 139. 1907.

0.

1. Olive, E. W. — Sexual Cell Fusions and Vegetative Nuclear Divisions in the Rusts.
Aim. Bot., Oxford, p. 331. 1908.

1. Pammel, L. H. — The Grasses of Iowa [including the more common Smuts]. Bull.
Iowa Geol. Surv. No. 1., p. 217. 1901.

1. Peacock, R. W. — Bunt Experiment at Coolabah Farm. Agr. Gaz.. N. S. Wales, XIII.,

p. 1013. 1902.

2. Treatment of Seed- wheat— Formalin. Ibid., X^^:L, p. 911. 1906.

1. Plowright, C. B. — A Monograph of the British Uredineae and Ustilagineae. London.

1889.
1. Potter, M. C. — On a Method of Checking Parasitic Diseases in Plants. Journ. Agr.

Science, Cambridge III., p. 102. 1908.

Literature. 211

1. Prkvost, I. B. — MemoLre siir la cause immediate de la Carie ou Charbou des ble3.
Paris. 1807.

1. Prillieux, E. E. — Siir la Formation et la Germination des Spores des Urocystis. Bull.

See. Bot. France, XXVII., p. 204. 1880.

2. LeCharbondu Sorgho, Ustilagosorghi (Link) Pass. Ibid., XLII., p. 30. 1895.

1. Pye, H. — Diseases and Pests of Cereals. Journ. Dep. Agr., Victoria, VII., p. 308.

1909.

1 Reed, J.— Troatmcnl of Slinking Sinut in Wlical. IJull. Col. Agr. Exp. Sta. No. 79.

1903.
1. RoDWAY, L. — -Tasmanian Fungi. P. and Proc. Roy. Soc, Tasmania. ]>. 142. 1899.
1. RoSTRUP, F. G. E. — Ustilagineae Daniae. Copenhagen. 1890.

1. Saccardo, p. a.— Sylloge Fungorum. Vols. ^^I., IX.. XI.. XIV.. XVI.. X^'II.

1888-1905.

2. Fungi aliquot australiensis. Hedw., XXIX., p. 155. 1890.

1. Saunders, D. A. — Treatment of Smuts and Rusts. Bull. S. Dak. Agr. Exi). Sta.

No. 75. 1902.
1. ScHiNDLER. F. — Ueber den Einfluss verschiedener Temperaturen auf die Keimfahig-

keit der Steinbrandsporen. Forsch. Geb. Agr. physik.. III., p. 288. 1880.
1. ScHROETER, J. — Die Brand-und Rost-pilze Schlesiens. Abh. Schles. Ges. Abth. Nat.

Med., p. 1. 1869.
2. Bemerkungen und Beobachtungen ueber einige Ustilagincen. Cohn's Beitr.

Biol. Pflanz., II., p. 349. 1877.

1. Selby. a. D. — The Smut of Oats and its Prevention. Bull. Ohio Agr. Exp. Sta.

No. 64. 1895.

2. ■ Some Diseases of Wheat and Oats. Ibid. No. 97. 1898.

1. Setchell, W. a. — Preliminary Notes on the Species of Doassansia Cornu. Proc.

Am. Acad., XXVI., p. 13. 1891.

2. ■ An Examination of the Species of the Genus Doassansia Cornu. Ann. Bot.,

VI., p. 18. 1892.

1. Shelton. E. M.— The Cultivation of Wheat in Queensland— Smuts of Wheat. Bull.

Dep. Agr. Queensland. No. 22. p. 57. 1893.
1, Sjiith, W. G.— Diseases of Field and Garden Crops, p. 245. London. 1884.
1. SoRAUER, P.^Handbuch der Pflanzenkrankheiten, p. 328. Berlin. 1906.
1. Stephens, T. — Smut in Wheat. P. and Proc. Roy. Soc, Tasmania, p. 92. 1889.
1. Sternberg, G. M. — Infection and Immunity. London. 1905.
1. Stuart, W. — Formalin as a Preventive of Oat Smut. Bull. lud. Ao-r. Exp. Sta.

No. 87. 1901.

1. Sutton. G. L. — Wheat Smut and its Prevention. Agr. Gaz. N. S. Wales, XVII. n. 917.

1906.

2. Notes on some of the lesser known varieties of Wheats available for Farmers'

Experiments. Ibid., XIX., p. 339. 1908.

1. Sutton, G. L. and Pridham, J. T. — The Effects of some Fungicides recommended for
the Prevention of " Stinking Smut " (Bunt) on the Germination of Wheat Seeds.
Ibid., XVIII., p. 235. 1907.

1. Swingle, W. T.— Treatment of Smuts of Oats and \\'lieat. V. S. Dep. Agr. Farm,

Bull. No. 5. 1892.

2. The Grain Smuts. Ibid. No. 75. 1898.

1. Sydow. H. and P., and Butler, E. J. — Funiri Tndiae oricntalis. Vnn. ]\lvc. IV.,
p. 427. 1906.

1. Takahashi, Y.— On Ustilago panici-mUiacei (Pers.) Winter. Tok. Bot. Mag. XVI.,

p. 247. 1902.
1. Tate, R.— A list of the Charas, Mosses, Liverworts, Lichens. Fungi, and Algals of

Extra-tropical South Au.stralia. Proc. Roy. Soc, S. Au.stralia. IV.. p. 13. 1881,
1. Texis(.n-W<)..ds, J. E.,and B.vilev, F. M.— On' some of the Fungi of New South Wales

and Queensland. Proc. Linn. Soc. N. S. Wales.. V.. pp. 55, 83. 84. and 92. 1880.
1. Tepfek. .r. G. 0.— Notes on Australian Fungi. Proc. Rov. Soc. S. \u<tralia XII.

]). l.Vi. 1889. ■^ • '

212 Literature.

1. Tessier, H. a. — Traite des Maladies des Grains, p. 215. Paris. 1783.

1. Thaxter, R. — The " Smut " of Onions ( Vrocystis ctpulae. Frost) and Uroajstis hypoxidis

Thaxt. Ann. Rep. Conn. Agr. Exp. Sta., p. 129. 1889.
1. Thompson, J. L. — Tlie Tillering or Stooling Proclivities of Wheat. Agr. Gaz. N. S.

Wales, X., p. 1247. 1899.
1. Thuemen, F. von — Mycotheca universalis. Bayi-euth. 1879.
1. ToNi, J. B. de — Revision of the Genus Doassansia Cornu. Journ Myc. IV., p. 17,

1888.
1. Trelevse, W. — Preliminary List of the Parasitic Fungi of Wisconsin. Tr. Wis.

Acad.,\^.,p. 34. 1884.
1. The Genus Cintractia. Bull. Torr. Bot. Club, XII., p. 69. 1885.

1. Tryon, H.— Report on Insect and Fungus Pests, pp. 196, 198, 200. 1889.

2. — Ann. Rep. Dep. Agr., Queensland, p. 39. Brisbane. 1895-6.

1. Tkzhebinski, I. N. — Russ. Journ. Exp. Landw. 8. No. 1, p. 100. 1907.

1. Tubeuf, K. F. von — ^Diseases of Plants induced by Cryptogamic Parasites — Ustila-

gineae, p. 275. English Edition. London. 1897.

2. Arbeiten aus der biologischen Abteilung II., p. 328. 1902.

1. TuLASNE, L. R. and C. — Memoire sur les Ustilaginees comparees aux Uredinees. Ann.

Sci. Nat. Bot. Ser. III., Vol. VII., p. 12. 1847.

2. Second Memoire sur les Uredinees et les Ustilaginees. Ibid. Ser. IV., Vol. II.,

p. 157. 1854.

U.
1. Unger, F.— Die Exan theme der Pflanzen. Wien. 1833.

V.

1. Valdeb, G.— Preventives for Smut. Agr. Gaz. N. S. Wales, X., p. 197. 1900.
1. VxJiLLEMiN, P. — Sur les tumeurs ligneusss produites par une Ustilaginee chez les
Eucalyptus. Compt. rend, p. 933. 1894.

W.

1. Ward, H. M.— Smut Funoi. Gardener's Chronicle, V., p. 233. 1889.

2. E

xperiments on the Effect of Mineral Starvation on the Parasitism of Puccinia
dispersa on species of Bromus. Proc. Roy. Soc, LXXI., p. 138. 1902.

1. Wheeler, W. A. — Preliminary Experiments with Vapor Treatments for the Preven-
tion of the Stinking Smut of Wheat. Bull. S. Dak. Agr. Exp. Sta. No. 89. 1904.

1. WiNivLER, H. — Parthenogenesis und Apogamie im Pflanzenreiche. Jena. 1908.

1. Winter G. — Ustilagineas. Die Pilze., I., p. 79. 1884.

2. Fungi australiensis. Rev. Myc, VIII., p. 208. 1886.

1. Wolff, R. — Beitrag zur Kenntniss der Ustilagineen. Bot., Zeitung, XXXI., p. 057.

1873.

2. Der Brand des Getreides, p. 1. Halle. 1874.

1. WoBONiN, M. — Beitrag zur Kenntniss der Ustilagineen. Abh. Senck. Nat. Ges., XII.,
p. 559. 1882.

Z.

1. Zellner, J. — Chemie der hoheren Pilze, p. 90. Leipzig. 1907.

ri.ATK XX.

G. H. Robinson.

HEAD SMUT OF WHEAT GRASS

iUsfilago Bullatci.)

Pl.ATK XXI.

G. H. Robinson, riiot. Nat. Size.

GALL SMUT OF BARNYARD GRASS

iCintriictiii Cnis-Culli.)

Plate XXII.

G. H. Robinson, Phot.

SMUT OF COUCH GRASS

( Ustil(i}io Cyiiodoiitis.)

I'l.VTK Will.

G. H. Robinson,

SMUT OF MAT GRASS

(Ciiilrcictiii Dense!.}

Plate XXIV.

G. H. Robinson. Phot.

SMUT OF COAST GRASS

[Cintractia Disticlilydis.)

Plate XXV.

G. H. Kobinsoii

BALL SMUT OF WATER GRASS

[Sorospuriiiiii Solid inn.)

214 Explanation of Plates.

PLATE XXVI.

[All Figures x 500 unless othenvise stated.)

USTILAGO.

Fig.

1. Spores of U. a venae.

2. Spore-germination of U. avenue in water (after Brefeld) x 450. The upper row-

shows the formation of conidia. The lower row is an older stage, where the
formation of conidia has ceased, and the spore at the end sliows a " buckle
joint," i.e., one segment of the promyceliura becomes connected with another
by means of a curved tube.

3. Spore-germination of U. avenae in nutritive solution, showing the luxuriant formation

of conidia (after Brefeld) . . . . . . . . . . X 200

4. C4erminating spore of U. avenae forming a buckle joint.

5. Germinating spore of U. avenae emitting a long branched septate tube instead of the

ordinary promycelium.

6. Germinating conidium of U. avenae.

7. Spores of U. hordei.

8. 9. Germinating spores of U. hordei, with conidia.

10, 11. Spores of U. hordei germinating and forming branching septate elongated tubes.

Platk XXVI.

f^^

^o "- qje©

oo

o

^^ o

^. 1

%^%

® e &

^^ ^^f

•9'

5

Q-

i

i

o ^ o

o

o

.oo

^i

t

^

G. II. Robinsuii,

JOO, 4.iO. aii.i 500.

USTILAGO.

2i6 Explanation of Plates.

PLATE XXVII.

(All Figures x 500 unless otherwise stated.)

USTILAGO. .

Fig.

12. Strongly developed branched germinal tube from spore of U. hordei.

13. Spores of U. nuda.

14. 15. Germinating spores of U. nuda.

16. Stronglj' developed germinal tube from spore of U. nuda.

17. Germinating spores of XJ. nuda. showing different stages of development of the

germinal tube (after Brefeld) . . . . . . . . . . x 350

15. Spore germination of U. hordei in a nutritive solution (after Brefeld) . . x 350

Plate XXVII.

3 •

o ^

n'-

^V-<^ ii

v5>

G. 11. Robinson. IMiui

USTILAGO

2i8 Exflanation of Plates.

PLATE XXVIII.

(All Figures x 500 unless otherwise stated.)

USTILAGO.

Fig.

19. Spores of U. tritici.

20, 21. Germinating spores of U. tritici, showing typical curved germinal tubes.
22, 23. Strong growth from spores of U. tritici after being four days in water.

24. Spores of U. hromivora.

25. Germinating spores of U. hromivora after 48 hours in hay infusion. Promycelium

giving rise to conidia and one extremely long septate tube.

26. Two germinating spores of XJ. hromivorn, one with conidia forming.

27. Spore germination of U, hromivora in nutritive solution (after Brefeld) _ x 400

Plate XXVI i I.

'• 19

\

J

20

b

23

J

V

i>>

L

?

USTI LAGO

Explanation of Plates.

PLATE XXIX.

{All Figures x 500 unless otherwise stated.^

USTILAGO.

Fig.

28. Spores of U. hidlatu.

29. Germinating spores of U. hullata.

30. Germinating spores of U. hullata (after Brefeld) x 350. Tlie two spores producing

two and three germinal tubes respectively, but no conidia were germinated in
water. The others were germinated in nutritive solution, and show not only
the formation of conidia, but one conidium sproutin in a veast-like manner,,
and another producing a filament at both ends.

31. Spores of U. calandriniae.

32. Spores of U. olivacea from original material from Ludwig.

33. Spore-forming hyphae from same.

34. Spores of U. olivacea from Tasmanian material.

35. Spores of U. olivacea from Sydow's Ustilagineen, No. 357.

36. Spores and spore-bearing mycelium of U. olivacea from preceding.

PlatkXXIX

ig

C'

-,->,

28

O'

t

■73 W

o

0

G. H. Robinson, Phot.

USTILAGO.

Exflanation of Plates.

PLATE XXX.

[All Figures x 500 -unless otherwise stated.)

SOROSPORIUM REILIANUM.

Fig.

37. Spore-balls from a very young smutted cob of maize . . ... .-. x 250

38. Spores.

39. 40. Germinating spores, with formation of eonidia.

41. Spore germination in nutritive solution (after Brefeld) x 350. The successive

development of the germination shown, the eonidia finally becoming detached,
and sproi;ting in a yeast-like manner so as to form small colonies.

42. Germination of spores after three days in water (after Norton) „. .„ x 600

43. Spore germination in nutritive solution from another culture (after Brefeld) x 350

The spore on the right has produced three germinal tubes, bearing numerous
eonidia, some of which have formed germ-tubes while still attached.

Pi, All; XXX

G. H. Robinson, Fhoi.

X 250, 350, 500, and 600.

SOROSPORIUM REILIANUM.

524 Exflanation of Plates.

PLATE XXXI.

{All Figures x 500 unless otherwise stated.)

USTILAGO.
Fig.

44. Section through axis of inflorescence of Danthonia penicillata affected with

U. readeri .. .. .,. .. .. .. . . X 100

45. Spores of U. readeri on same, being part of specimen from Liulwig, labelled

U. leiicoderma Berk.

46. Spores of U. readeri from Danthonia semiannularis.

47. Spores of U. hieronymi from Triodia mitchelli.

Pl.ATF. XXXI,

G. H. Robins,.,,, I'hol.

X 100 ami 500.

USTILAGO.

1858.

226 Explanation of Plates.

PLATE XXXII.

{All Figures x 500 unless otherwise stated.)

USTILAGO AND CINTRACTIA.
Fig.

48. Spores of Cintractia spinificis from Spinifex hirsutus.

49. Spores of U. slenotaphri from Stenotaphrum americanum.

50. 51. Spores of U. utriculosa. Surface view showing the reticulated markings.

52. The same, sectional view.

53. Portion of inflorescence of Polygonum affected by U. hydropiperis var. columdlifera

Tul. Note the black columella projecting from each floret . . nat. size

54. Section towards base of columella of same. The dark crescent-shaped portion

represents the nearly-mature spores, the paler portions the immature spores in
process of formation . . . . . . . . . . . . X 20

55. Spores of same on Polygonum from Tasmania.

56. Spores of U. hydropiperis from Rabenhorst's Fungi Europaei, No. 2390.

Pi, All: XXX I I

9 *' ^ O ft"

••• /.;;»/. c°

''J y

• (

o % •

• €

<» •

• O

^^^^•0 /••<*<» S

c^

o 9

O

o

O

0 (^,

eg.

«br

OP sis G_

o^^

^^o

«

49

50

®

©

00

\3/

o© ©.£

o

\^

o

0

0

\.,:

G. H. Kobinsun. I'lu.K Nat. Si/l, aiul x JO aiul 500.

USTILAGO AND CINTRACTIA.

228 Explanation of Plates.

PLATE XXXIII.

{All Figures X 500 unless otherwise stated.)

MELANOPSICHIUM.
Fig.

57. Stem of Polygonum showing gall due to i¥.'a^(s^/•o-«men■ca?lMm .. .. nat. size

58. Section through gall, showing the distorted and enlarged cells containing spores x 20

59. Spores of above.

60. Galls of U. emodensis on Polygonum from Java . . . . . . nat. size

€1. Section of gall of U. emodensis . . . . . . . . . . x 100

(62. Spores of U. emodensis.

PlatkXXXUI.

G. H. Robinson, V

:0. 100, dn.i 500.

MELANOPSICHIUM

230 Explanation of Plates.

PLATE XXXIV.

{All Figures x 500 unless otherwise stated.)

USTILAGO AND CINTRACTIA.
Fig.

63. Section through axis of inflorescence of Stipa affected by G. hypodytes . . X 25

<34. Portion of a similar section . , . . . . . . . . x 150

(J5, Spores of same.

■06. Section through jjortion of axis of inflorescence of Cynodon dactylon affected by
Ustilago cynodontis .. . . . . . . ' . . . . x 100

<J7. Spores of U. cynodontis.

68. Section through ovary of Carex breviculmis affected by C. caricis . . X 150

69. Surface view of spores from above, showing markings.

70. Sectional view of spores.

71. Spores of C. caricis from Sydow's Ustilagineen, No. 360.

Pr.ATK XXXIV

USTILAGO AND CINTRACTIA.

!32 Exflanalion of Plates.

PLATE XXXV.

[All Figures x 500 unless otherwise stated.)

CINTRACTIA CRUS-GALLI.

Fig.

72. Spores from Panicuiii crus-galli.

73, 74. Spores and mycelium of the same.

75, 76, 77, 78. Germinating spores of the same.

79. Longitudinal section through two swellings caused by the smut on an internode of

the stem. The hairy epidermis is seen covering the smut, and plate-like
branching outgrowths pass from the stem into the pustule (after
Magnus) . . . . . . . . . . . . . . enlarged

80. Transverse section through the base of the pustule, showing the formation of spores.

The spores are in rows, the youngest towards the base, and hyphae with
elongated segments between the rows (after Magnus) «. .,. x 750

Pl.AlK XXXV

G. H. Robinson, I'lu.t. Knlarfjed. x 500 ami 750.

CINTRACTIA CRUS-GALLI.

234

Explanation of Plates.

PLATE XXXVI.

Fig.
81.

82.
83.
84,
87.

[All Figures x 500 unless otherwise staled.)
CINTRACTIA.
inflorescence of Distichlis maritima

affected
X

Section through axis of
C. disticfdydis

Portion of similar section enlarged . . . . . . . . x

Spores of same.

85, 86. Germinating spores of same.

Section through axis of inflorescence of Eotthodlia compressa affected
G. densa . . . . . . . . . . . . . . x

Portion of similar section enlarged . . . . . . . . x

Spores of same.

bv
25

150

150

Platk XXXVI.

G. II. Robinson,

CINTRACTIA.

50. 150. ami 500.

23^ Exflanation of Plates.

PLATE XXXVII.

LAll Figures x 500 unless otherwise stated.)

USTILAGO AND CINTRACTIA.
Fig.

90. Section through axis of inflorescence of Danthonia pilosa affected by

U. comhurens . , . . . . ... . . . . X 50

91. Similar section enlarged . . . . . . . . . . . . x 100

92. Spores of same.

93. Section through stroma of C. leucoderma on Bynchospora aurea. . . . x 60

94. Spores of same.

95. Section through stroma of C. axicola on Fimbristylis . . . . x 50

96. Spores of same.

Pl.ATK XXXVII.

G. H. Robinson. Phot. x 50, 100. ami 500.

USTILAGO AND CINTRACTIA.

2^8 Explouaiion of Plates.

PLATE XXXVIII.

(All Figures x 500 unless otherwise stated.)

CINTRACTIA EXSERTA.
Fig.

97. Portion of inflorescence of Anthistiria ciliata affected by C. exserta, showing the

distortion produced and the total absence of any vestige of the awn (compare
Fig. 101) .- .- .. .. .. .. .. X 2

98. Section through axis of inflorescence affected by C. exserta . . ., X 100

99. Spores of C. exserta.

100. Sterile fungus cells in chains, with walls thickened, and hyaline.

101. Portion of normal inflorescence of Anthistiria ciliata . , , . nat. size

Plate XXXVIII.

G. H. Robinson, I'liot, N.ii. Size, x _'. lUO, ami 5llO.

CINTRACTIA EXSERTA.

240 Exflanation of Plates.

PLATE XXXIX.

{AU Figures x 500 unless otherwise stated.)

CINTRACTIA SORGHI- VULGARIS.

Fig.

102. Diseased grains of Andropogon sorghum, showing distortion produced by C. sorghi-

vulgaris . . . . . . . . . . . . . . x 2

103. Spores from same.

104. Cross section through base of a rather young infected grain. Small portion of

columella is represented at the base, then immature spores passing gradually
into the mature, and at the top the false membrane composed of epidermal cells
and sterile fungus threads (after Clinton) . . . . . . x 250

105. Germination of spores in nutritive solution in different stages (after Bref eld) x 350

106. Germination of spores after 24 hours in water (after Norton).. .. X 600

Pr.A

XXXIX.

G. H. Robinson, Plic

X J. 250, 350, 500, ami (>C0.

CINTRACTIA SO R G H I V U LG A R I S.

1858.

242 Explanation of Plates.

PLATE XL.

[All Figures x 500 unless otherwise stated.)

SOROSPORIUM.

Fig.

107. Spore-ball of S. enteromorphum . . . . . . . . . , x 250

108. Spores of same.

109. Spore-balls of S. cryptum . . . . . . . . . . x 250

110. Spores of same, from Panicum bicolor, showing finely- warted surface,

111. Spores of same, sectional view.

112. Spores of same from Panicum effusum.

113. Spore-balls of 8. panici-miliacei from C'hamaeraphts spinescens ... x 200

114. Spores of same.

I'lATK XL.

^.

s

«

€

4

^ ^

o

'^

o

0

On

108

C^O-:

:^";^5-^4^'

.VJ^V-^

^?

GOo G

S O R O S P O R I U M .

244 Explanation of Plates.

PLATE XLI.

{All Figures x 500 unless otherwise stated.
SOROSPORIUM.

115. Spove-haWs oi S. consanguineum irom Aristidd hehriana .. .. x 250

UG. Spores of same.

117. Spore-balls of (S. erj«.c/»ies .. .. .. .. .. x 260

118. Spores of same, with one large lemon-coloured smooth cell.

119. Spore-balls of iS. mix-^Mwi from Eriochloa .. .. .. .. x 250

121). Spores of same, sectional view.

121. Spores of same, sm-face view showing warts.

122. Spore-balls of S. mixtum from Massee's type material of Tilletia mixta on

Eriochloa . . . . . . . . . . . . . . X 250

123. Spores of same, sectional view.

124. Spores of same, surface view showing warts.

Pl.VlK XLI.

G. H. kobiii^oii. 1':

SOROSPORI UM

246 Explanation of Plates.

PLATE XLII.

{^All Figures x 500 unless otlierwise stated.)

SOROSPORIUM PILULIFORMIS.
Fig.

125. Section through ovary of Juncus planifolius affected with S. piluliformi<! X 50

126. Isolated spores of S. piluUformis, labelled as U. marmorata in National Herbarium.

127. Spore-balls and isolated spores from Juncus planifolius.

128. Spore-balls of S. pilulijormis, labelled as U. rnarrnorata in National Herbarium.

129. Section through ovary of Juncus planifolius from Tasmania, affected v/ith S, piltUi-

formis, showing production of spore-balls . . . . , . x 150

130. Spore-balls of same.

Pl.ATK XLll.

G. H. Robinson, Phot. X 50. 150. ami 500.

SOROSPORIU M PILULIFORMIS.

248

Explanation of Plates.

PLATE XLIII.

{AU Figures x 500 unless otherwise stated.)

SOROSPORIUM SOLIDUM.

Fig.

131. Inflorescence of ScJioenus imberbis affected with S. solidum

132. Section through ovary affected with same

133. Portion of same enlarged

134. Young spore-balls of same treated with caustic potash

135. Mature spore-balls

136. Spore-balls partially broken up, showing the so-called, sterile cells.

X -25
X 100
X 2o0
X 250

I'l \TK XLiir.

G. H. Kolunsoii, Phui.

SOROSPORI U M SOLIDUM

250 Explanation of Plates.

PLATE XLIV.

{All Figure-s X 500 unless otherwise stated.)

SOROSPORIUM.

Fig.

137. Spore-balls of S. paspali . . . . . . . . . . x 250

138 Spores of same.

139. Spore-balls of same.

140. Spore-ball of S. turneri disintegrating.

141. Spore-balls of same .. .. .. .. .. .. x 250

142. Spores of same.

Pl.ATK XLIV.

SOROSPORIUM.

252 Explanation of Plates.

PLATE XLV.

{All Figures x 500 unless otherwise stated.)

TOLYPOSPORIUM AND THECAPHORA.

Fig.

143. Spore-balls of Tolyposporium globuligerum . . . . . . . . x 250

144, 145. Spores of same.

146. Spore-balls of Thecaphora lagenophorae.

147. Individual spores of same.

Note.- — Tolyposporium should be added to the title of the Plate.

Pr,ATK XLV.

1^ ^ V

o

oj

1^

r^

G. H. Robinson, Phot.

X J50 and 500.

THECAPHORA.

254 Explanation of Plata

PLATE XLVI.

{All Figures X 500 unless otherwise

TOLYPOSPORIUM.
Fig.

148. Spore-balls of T. hiirsum from Victoria „. „. „ .„ X 250

149. Spore balls of T. bursum on Anthistiria from Queensland. Type material of Ustilago

bursa Berk, in Bailey's Herbarium . . . . . . . . x 250

150. Spores of T. bursum from Victoria.

151. Spore-balls of T. kpidoboli . . . . . . ^ „ X 250

152. 153. Individual spores of T. lepidoboli.

Pi.AiK XTA'T.

G. H. Robinson, Phot.

TOLYPOSPORIUM,

256 Explaualioii oj Plates.

PLATE XLVII.

{All Figures x 500 unless otherwise stated.)

TOLYPOSPORIUM.

Fig.

154. Spore-balls of T. rodwayi . . . . . . , . . . x 250

155. Spore-balls of T. lepidospermae . . . . . . . . . . x 250

156. Individual spores of same, showing thick- warted ejjispore.

157. Spore-balls of T. muellerianuni .. .. .. .. .. x 250

158. Spores of same.

159. Spore-balls of T. junci from Sydow's Ustilagineen, No. 373 . . . . x 250

160. Spores of same.

161. Spore-balls of T. juncophiluin . . . . . . . . . . x 250

162. Spores of same.

Platk XLVIT.

:T-y C^

^.

G. II. Kohinson, Phot.

TOLYPOSPORI U M,

258 Explanation of Plates.

PLATE XLVIII.

[All Figures x 500 unless otherwise sta'ed.)

TILLETIA.
Fig.

163. Spores of T. Levis.

164, 165. Grerminating spores of same.

16(5. Conidia of same germinating and producing secondary sickle-shape conidia.

167. Coalesced conidia of same germinating and producing long threads.

168. Germinating spore of same with elongated septate promycelinm and abnormally

short conidia.

16!:). Spores of T. tritici, surface view . . . . . . . . . . x 250

170. Spores of same, sectional view . . . . . . . . . . x 250

I'l.ATK XL\in

oh

TILLETIA.

26o Explanation of Plates.

PLATE XLIX.

[All Figures x 500 unless otherwise stated.

TILLETIA INOLENS.

Fig.

171. Spores of T. moZews, sectional view .. .. .. .. X 250

172, 173. Spores of same, surface view . . . . . . . . X 250

174. Surface view of spore of same, showing bead-like markings on ridge.

175. View of same, median between surface and sectional.

176. Surface view of same.

177. Sectional view of same.

178. Surface view of spores of T. hold from Sydow's Ustilagineen, Ess. 372.

179. Sectional view of same.

Pl.ATK XLIX.

• •

•••

173 ^^

•

174

175

• ••••

Oo

0 #

G. H. Robinson, I'liot.

TILLETIA INOLENS.

i

262 Explanation of Plates.

PLATE L.

{All Figures x 500 unless othenoise slated.)

TILLETIA AND ENTYLOMA.

Fig.

180, 181. Spores of T. striaejormis from Rye grass.

182. Spores of same from Poa annua.

183. Spore of so-called T. epiphylla Berk, on Zea mays, from type material, showing

germ-pores, and proving it to be really a uredospore of Puccinia maydis.

184. Spores of Entyloma eugeniarum.

185. Section of leaf of Eugenia through sorus of same . . . . • . . x 100

Platk L.

(;. H. Robinson, Phot. x '"" ■'"''

TILLETIA AND ENTYLOMA.

264 Explmiaiion of Plates.

PLATE LI.

(All Figures x 500 unless otherwise stated.)

UROCYSTIS.

Fig.

186. Section of wheat, .stem affected by Urocystis tritici, showing the cavities partially

filled with spores . . . . . . . . . . . . X 20

187. Spore-balls of Urocystis occulta from Poa caespitosa.

188. Spore-balls of Urocystis tritici from wheat.

189. Spore-balls of Urocystis occulta from Rye grown in Germany.

190. Spore-balls of Urocystis stipae.

191. 192. Germinating spores of Urocystis tritici from wheat.

Pl.AlK LI.

<j. H, Robinson,

UROCYSTIS.

266 Explaiiaticii of Plates.

PLATE LII.

[All Figures x 500 unless otherwise stated.)

UROCYSTIS.

Fig.

193. Spore-balls of Uroci/stis agropyri.

194, 195. Spore-balls of Urocystis anemones.

196. Spore-balls of Urocystis hypoxidis .. . . .. . . x 250

197, 198. Spore-balls of same.

199. Spore-balls of Urocystis colchici from Sydow's Ustilagineen, Exs. •24(5.

200. Spore-balls of Urocystis destruens.

Pl.ATK T.I I,

# ti

<^<f

t

^

i

'^jP' ^"^V^

^

»

«

9

O

G. H. Robinson, Phot.

UROCYSTia.

268 Explanation of PLales.

PLATE LIII.

(.4^ Figures x 500 unless otherwise stated.)

USTILAGO AND CINTRACTIA.

Fig.

201. Sectioa tlu-ough axis of inllorescence of Andropogon australis affected by Cintractiu

columellifera . . . . . . . . . . . . x 100

202. Spores of same.

203. Spores of Ustilago readeri germinating in water, showing early stages of germination

with non-septate promycelium.

204. Germinating spores of same further advanced, showing septate promycelia and

formation of conidia.

205. Germinating spores of same after eighteen hours in water, showing elongated

promycelium septate towards the base, and protoplasm collected beyond septa.

206. Spore of Ustilago calandriniae germinating in water, showing two septate promycelia

from one spore and formation of conidia.

207. Spore of Cintractiu densa germinating in water, showing septate promycelia and

conidia.

208. Two spores of Ustilago cynodontis germinating in nutritive solution, with two septate

promycelia and lateral and terminal conidia (after Brefeld) . . X 350

209. Spore of Ustilago cynodontis germinating in water.

Pl,ATK LIII.

G. 11. Robinson, Pilot. x 100, 350, .md 500.

USTILAGO AND CINTRACTIA.

270 Explanation of Plates.

PLATE LIV.

{All Figures x 500 unless otherwise stated.)

SOROSPORIUM TUMEFACIENS.

Fig.

210. Smutted and sound heads of Stipa pubcscens R. Br. .:. „. nat. size

211. Cross-section of inilorescence showing vascular bundles surrounded by spore-

balls . . . . „ . . . ... X 4

212. Spore-balls .. . _ . . x 250

213. Spores.

214. Spore germinating in water, and showing septate branching promycelium bearing

lateral and terminal conidia.

SOROSPORIUM SETARIAE.

215. Smutted and partially smutted heads of Setarin glauca Beauv. .. nat. size

216. Cross-section of inflorescence, showing spore-balls around vascular bundles x 12

217. Spore-balls . - ■ . • x 250

218. Spores.

Platk LIV

C. Brittli-hanU. Fh

SOROSPORIUM.

272 Explanation cj Plates

PLATE LV.

{All Figures X 500 unless otherwise staled.)

TILLETIA FUSCA.

Fig.

219. Festuca bromoides with every spikelet smutted . . . . . . nat. size

220. Spores of the same in surface view, showing raised ridges and gelatinous envelope.

221. Spores in optical section.

222. Spore germinating after 17 days in water on a slide, witli elongated bi-septate pro-

mycelium bearing 7 conidia at its apex . . . . . . X 300

Plate LV.

C. C. Brittlebauk,

Nat. Size, x 300, 500.

TILLETIA FUSCA.

1858.

274

Exflanation of Plates.

PLATE LVI.

{A]\ Figures x 500 %inless otherwise stated.)

TILLETIA, EXTYLOMA, SOROSPORirM. AND THECAPHORA.

Fig.

223. Barley grass, with TiUetia hordei concealed by the glumes : glumes removed on

one side showing smut-balls . . . . . . . . . . nat. size

224. Spores in surface view, showing net-like markings and gelatinous envelope.

225. Spore germinating after 24 days in water, with one septate promycelium bearing

7 conidia at its apex . . . . . . . . . . x 300

226. Section through leaf of Melilotus indica, showing the spores of EntyJoma meliloti largely

replacing the ordinary tissues . . . . . . . . X 170

227. Spores of Sorosporium cryptum germinating after 41 hours floating on water. A —

Non-septate promyceUum only ; B — Elongated non-septate promycelium bear-
ing a single stout 2-septate conidium at apex ; C — Septate promycehum with
lateral and terminal conidia, the terminal conidium giving off at the side a slender
septate germ-tube.

228. Two spore-balls of Thecaphora leptocarpi . . . . .. . ■ X 250

PrAiF. LVI.

C. C. Hriltl.ib,mk,

Nat. Size, x 170. 300, 500.

TILLETIA, SOROSPORIUM. ENTYLOMA
AND THECAPHORA.

Host Index.

275

HOST INDEX.

Agropyron scabrum Beaux .

I'stilauo hullata (Herk.) McAl]).
l^rocystis a-Topyri (Preiiss) Scliroet.

Amphjpogon strictus R. V.v.

Ustilap;o tcpperi, Ludw.

Andropogon australis SpieiiK-

("intractia folunu'llifcra (Tul.) McAlp.

Andropogon sorghum Brot.

C'intraotia soighi-vulgaris (Till.) flint.

Anthistiria ciliata L. f.

Cintractia exscrta, McAlji.
iSorosporium enteromorplium, McAlp.
Tolyposporium bursiim (Berk.) McAlj).

Aristida arenaria (i and.

Sor(isi)()ri\nn cnnsanuuineuni, l']ll. and
Ev.

Aristida behriana F. v. M.

Soi()s]iorium cousancfuineum, EU. and
Ev.

Aristida leptopoda Beuth.

Sorosporium consanguineiini. Ell. and
Ev.

Aristida ramosa R- Bi.

Soros])orinin consanguineiini, Ell. and
Ex-.

Aristida vagans Car.

Sorosporium consanguineimi. Ell. and
Ev.

Arrhenatherum avenaceum Beam.

Ustilago avenac (IVrs.) Jens.

Avena fatua L.

I'stilago avenae (Pers. ) .Jens.

Avena sativa L.

I'stilago avenae (Pers.) Jens.

Bromus arenarius Lahill.

I'stilauo liroinivdra (Tul.) F. v. M.

Bromus mollis L.

Cstilauo l.ioniiv.ira (Tul.) F. v. .M.

Bromus unioloides H. H. and K.

rsfilaL'o l.ioinivoni (Tul.) E. v. .M.

Calandrlnia calyptraia Hunk. f.

rstiiao-,, calandriuiae, Ciinl,

Carex breviculmis \\. Hi.

Cinlnu-tia earici.s (Pers.) .Magii.

Carex pseudocyperus L.

I'stilaa,, ..livaeea (!).('.) Tul.

Chamaeraphis spinescens Poir.

Sorosporium iMiiici-miliacei (Pers.)

Cynodon dactylon Pers.

I'stilauo eynodontis, P. Henn.

Danthonia penicillata F. v. >i.

Ustilago readeri. Syd.

Danthonia pilosa R. Hi.

I'stilauo eoinl.unMis. i.ndw.

Deyeuxia forsteri Knnth.

Tilletia inolens. .McAlp.

Dichelachne crinita Hook. f.

Cintractia liypodytes (Schl.) Dietel.

Distichlis maritima.

Cintractia distichlydis, McAlp.

Eriachne sji.

Sorosporium criachncs. Thucm.

Eragrostis nigra Xees.. \ u. trachycarpa.

Soros))oriiim turneri. .Mc.Alp.

Eriochloa annulata Kunth.

Sorosporium niixtiim (Mass.) .McAlp.

Eriochloa punctata Ham.

Sorosi.orium mixtum. .Mc.Vlp.

Eugenia sp.

Entvl

iaruin, ( 'kc. and .Afass.

Festuca bromoides L.

Tilictia frsca. Ell. and E

Fimbristylis sp.

ixicola (Berk.) Cormi.

276

Host Index.

Gahnia radula Benth.

Tolyposporium muelleriamim (Tlinem.)
McAlp.
Gahnia trifida Labill.

Tolyposporium muellerianiun (Thuem.)
McAlp.

Hordeum murinum L.

Tilletia hordei, Koern.

Hordeum vulgare L.

Ustilago hordei (Pers.) Kell. and Sw.
Ustilago nuda (Jens.) Kell. and Sw.

Hypoxis glabella R. Br.

Urocystis hypoxidis, Thaxt.

Juncus pallidus R. Br.

Tolyposporium juncopliilum, McAlp.

Juncus planifolius R Br.

Sorosporium piluliformis (Berk.) McAlp-

Lagenophora emphysopus Hook. f.

Thecaphora lagenophorae, B. and Br.

Leersia hexandra Swartz.

Tolyposi)orium globuligerum (B. and
' Br. ) Ricker.'

Lepidobolus drapetocoleus F. v. M.

Tolyposporium lepidoboli, McAlp.

Lepidosperma angustatum R Br. = L.

vistidum R. Br.
Tolyposporium lei>idospermae, McAlp.

Lepidosperma laterale R. Br.

Tolyposporium rodwayi, :McAlp.

Leptocarpus tenax R. Br.

Thecaphora Icptocarpi, Berk.

Lolium perenne L.

Tilletia striaeformis (Westd.) Oud.
Urocystis occulta (Wallr.) Rab.

Lythrum hyssopifolia L.

Doassansia winteriana (Wint.) P. Magn_

Melilotus indica All.

Entyloma meliloti, Mc.\lp.

Neurachne alopecuroidas R. Br.

Ustilago tepi)eri, Ludw.

Panicum bicolor R Br.

Sorosporium cryptunij ]\IcAlp.

Panicum crus-galli L.

Cintractia crus-galli (Tr. and Earle)
Magn.

Panicum effusum R. Br.

Soi()s|n)rium cryjitum, McAlp.

Panicum paradoxum R. Br.

Tstilago confusa, Mass.
Paspalum scrobiculatum L.

Sorosporium paspali, McAlp.

Poa annua L.

Tilletia striaeformis (Westd.) Oud.

Poa caespitosa Forst.

Urocystis occulta (Wallr.) Rab.

Polygonum sp.

Melanopsichium austro-americanum
(Sj.eg.) Beck.

Polygonum hydropiper L.

Ustilago utriculosa (Nees) Tul.

Polygonum minus Huds.

Ustilago utriculosa (Nees) Tul.
Ustilago hydropiperis var. columellifera^
Tul.

Polygonum prostratum R. Br.

I'stilago utriculosa (Nees) Tul.

Ranunculus sp.

I'rocystis anemones (Pers.) Wint.

Rottboellia compressa L.

Cintiactia densa McAlp.

Rynchospora aurea Vahl.

Cintractia Icucoderma (Berk.) P. Henn.

Schoenus apogon Roem. and Schult.
Sorosporium solidum (Berk.) McAlp.

Schoenus imbsrbis R. Br.

Sorosporium solidum (Berk.) McAlp.

Scirpus prolifer Rottb. = Isolepis prolifer
R. Br.

Sorosporiuin piluliformis (Berk.) McAlp.

Secale cereale L.

I'rocystis occidta (Wallr.) Rab.

Setaria glauca Beauv.

Soros])orium sctariae ilcAlp.

Setaria macrostachya H. B. and K.

I'stilago pertusa, Tr. and Earle.

Spinifex hirsutus Labill.

Cintractia spinificis (Ludw.) McAlp.

Stenotaphrum glabrum Trin.
Lfstilago stenotaphri, McAlp.

Stipa flavescens Labill.

Cintractia hypodytes (Schl.) Dietel.

Host I tide X

277

Stipa luehmanni I'uail. 1.

Ticrystis stipac, :\IcAli..

Stipa pubescens R. Bi.

S()i-os|)()riuni tiimefaciciis. McAlp.

Stipa setacea i;. lii.

t'inlractia. Iiyp.Klytes (Sdil.) Dictcl.

Triodia mitchelli iiontli.

Ustilaud liieioiivnii, Scliroct.

Triticum vulgare \ ill.

Tillutia lev-is, Kik-1iii.
Tilletia tritici (Bjeik.J Win).
Urocystis tritici, Kocrii.

rstilauo tritici (IVrs.) .Jens.

Wurmbea dioica J', v. M.

I'nirystis destnifiis McAlp,

Zea Mays l^.

Sorosporium iciliaiuiin (Kiiclin) ^IcAIp.

278

Fungus Index.

FUNGUS INDEX.

Synonyms in italics ; * Excluded species.

Anthracoidea Bief.

CO) ids (Pers.) Bref. = Ustilago caricis (Pers.) Magn.

Cintractia Coinu.

axicola (Berk.) Cornii.

caricis (Pers.) Magn. . .

columellifera (TuL) McAlp.

crus-galli (Tr. and Earle) Magn.

densa, McAlp.

distichlydis, McAlp. . .

exserta, McAlp.

hypodytes (Sclil.) Dietel

krugiana Magn. = C. leucoderma (Berk.) P. Henn.

leucoderma (Berk.) P. Henn. ..

patagonica, Cooke and Mass. = Ustilago bromivora (Tul.) F. v. W

reiliana (Kuehn) Clint. = Sorosporium reilianum (Kuehn) McAlp.

seymouriana, Magn. = C. crus-galli (Tr. and Earle) Magn.

sorghi-vulgaris (Tul.) Clint.

spinificis (Ludw.) McAlp.

Doassansia Cornu.

wiiiteriana (Wint.) Magn.

punctiformis, Wint. = D. winteriana . .

Entyloma De By.

eugeniarum, Cooke and Mass. . .
meliloti, INIcAlp.

Melanopsichium Berk.

austro-americanum (Speg.) Berk.

Sorosporium Rud.

consanguineum, Ell. and Ev. . .

cryptum, McAlp.

enteromorphum, McAlp.

eriachnes, Thuem.

eriocMoae, Griff. = S. mixtum (Mass.) McAlp.

mixtum (Mass.) McAlp.

muellerianum, Thuem. = Tolyposporium muellerianum, Thuem.

panici-miUacei (Pers.) Takah. . .

paspali, McAlp.

piluUformis (Berk.) McAlp.

reihanum (Kuehn) McAlp.

setariae, McAlp.

solidum (Berk.) McAlji.

tumefaciens, McAlp. . .

turneri, McAlp.

Sphacelotheca De By.

reiliana (Kuehn) Clint. = Sorosporium reilianum (Kuehn) McAlp.
sorijJii (Link.) Chnt. = Cintractia sorghi-vulgaris (Tul.) Clint.

Thecaphora Fingerh.

globuligera, Berk, and Br. = Tolyposporium globuligerum (B. and
lagenophorae, McAlp. . .
leptocarpi, Berk.

fui/''//S hid ex.

279

PACK

Tilletia I HI. . . . . 190

r«/M.s Till. T. (ritifi (Bjeik.) Wiiit. .. .. .. .. .. ]<)4

Ih llid-nanii. K. V. W. = T. stiiaeforniis (We.std.) Oud. li).'}

rpiphi/ltd. lU'ik. and Br. = Pucc-iiiia maydis, Boreng. (L'icdo stage) .. 202

foeteiis (B. and ('.) Trcl. = T. lc\ is. Ruelui .. .. .. .. 1<)2

fusca. Ell. and Ev. .. .. .. l!)(»

hordei Kocrn . . . . . . . . . . . . 191

inolens, McAlp. . . . . 191

levis, Kiu'iui . . . . . . . . . . . . . . 192

w(>/f/, Mass. = Sorospoiiiiiii iiiixtuin (.Mass.) .Mi-Alj). .. .. .. 178

.sonjhi-vidgaris, Tul. = C'intiattia soiglii-vulgaris (Tul.) Clint. .. .. 1?:^

.striaeformi.s (Westd.) Oud. .. .. .. .. .. .. 193

tritiei (Bjeik.) Wint. .. .. .. .. .. ..194

Tolyposporium W oron. . . 18(>

(nillnsllriar. Cobb. ^ T. bur.sum (Beik.) McAlp. .. .. .. . . 18(>

antliisliriac, P. Henn. = T. bursuni (Berk.) Mc-Alp. .. .. .. 186

buisum (Berk.) McAlp. .. .. .. .. .. . . 18t>

-lobulisenim (Berk, and Br.) Kicker .. .. .. .. ..187

jiUKOi.'hiiuni. MeAl])... .. .. .. .. .. ..188

lepidoboli. McAlp. . . . . . . . . . . . . . . 188

lepid(is])erniae, McAlj). . . . . . . . . . . . . 18S

nmeJlcrianum (Thuem.) MeAlp. .. .. .. .. .. 189

rodwayi, McAIp. .. .. .. .. .. .. .. 189

Urocystis Rab. . . . . . . 195

agropyri (Preuss.) Sehroet. .. .. .. .. .. .. 195

anemones (Pers.) Wint. .. .. .. .. .. .. 1915

destruens, JIcAlp. .. .. .. .. .. .. .. 196

hypoxidis, Thaxt. . . . . . . . . . . . . . . 197

occulta (Wallr.) Rab. .. .. 197,199

Ao/((/«, F. V. W. = Sorosporium soliduni (Berk.) .McAlp. .. .. ..183

stipae, JMcAlp. . . . . . . . . . . . . . . 198

tritiei, Koern. . . . . . . . . . . . . . . 199

UstilagO Pers. . . . . . . 146

(K/miii/ri, McAlp. = U. readeri, Syd. . . . . . . . . . . 159

(iristiditc. Peck. = Sorosporium con.sanguineuni, Ell. and Ev. .. .. 175

(instrnlis, Cooke = Sorosporium eriachnes, Thueni. . . . . . . 17H

inislro-innericana, Speg. = Melanopsichium au.stro-aniericanuni (8peg.) Beck. 163

a venae (Pers.) Jens. . . . . . . . . . . . . . . 146

axicola. Berk. = Cintractia axieola (Berk.) Curnu. . . . . . . 165

bromivora (Tul.) F. v. W. . . . . . . . . . . . . 150

buUata, Berk. . . . . . . . . . . . . . . 151

6?trA'«, Berk. = Tolyposporium bursuni (Beik.) AIcAlp. .. .. .. 186

calandriniae, Clint. . . . . . . . . . . . . . . 153

carbo, Tul. = Various sjiecies . . . . . . . . . . . . 166

carbo var. columelUfera, Tul. = Cintractia columellifera (Tul.) ^IcAlp. . . 166

caricis (Pers.) l^ng. = Cintractia caricis (Pers.) ]\Iagn. . . . . .. 166

c(ile)ifita, Ludw. = U. olivacea (DC.) Tul. . . . . . . . . 157

*eesatii, F. v. W. (/See Sorosporium paspali, Mr.\lp.) .. .. .. 201

coniburens, Ludw. . . . . . . . . . . . . 153

cont'usa, Mass. . . . . . . . . . . . . 154

cru.i-r/alli, Tr. and Earle = Cintractia crus-oalli (Tr. and Karle) Magn. .. 167

cri/plfi. McAlp. = Sorosporium cryi)tum McAlji. . . . . . . . . 176

cvnodontis, P. Henn. .. .. .. .. .. .. 155

♦destruens, Schlecht. {See U. readeri Syd.) . . . . . . . . 201

*emodensi.s, Berk. ((See Melanopsichium austro-americanum (S])eg.) lieck.) .. 202

enteromorpha, McAlp. = Sorosporium enteromorpluun. .McMi). . . . . 177

exlt/iia, Syd. — Ustilago comburens Ludw. . . . . . . . . 153

^';/(/;;v'</////.v. Thuem. = Cintractia axicola (Berk.) Cornu. .. .. .. 165

fnrlciis. B. and C. = Tilletia levis, Kuehn . . . . . . . . 192

hieionvmi. Sehroet. . . . . . . . . . . . . . . 155

hordei" ( I'ers. ) Kell. and Sw. .. .. .. .. 147,149

hydropiperis var. columellifera. Tul. . . . . . . . . . . 156

jen-senii, Rostr. = U. hordei (I'crs. ) K.H. and Sw . .. .. .. 1-17

Iriqenopliofdc, McAlp. = Sorospoijuin laucnopiiorae. .Mc.Mp. . . . . 185

28o

Fmi^Ks Index.

UstilagO Ters— ro;(^'» uei.

leucoderma. Berk. = Cintractia leucoderma (Berk.) P. Hemi.
vuirmorata. Berk. = Sorosporium piluliformis (Berk.) iMcAl]).
*niaydis, Corda. (See Sorosporium reilianum (Kuehn) McAlp.)
uiirro-^jiord. Mass. and Rodw. = Ustilago comburens, Ludw.
iiiiK III ridiiii. Thuem. = Sorosporium jDiluKformis (Berk.) McAlp.
nuda (.lens.) Ivell. and Sw.
olivacea (DL'.) Tul.

panici-yniliacei (Pers.) Wint. = Sorosporium panici-miliacei (Pers.)
'perennans Rostr. = Ustilago avenae (Pers.) Jens,
jiertusa, Tracy and Earle

piluliformis (Berk.) Tul. = Sorosporium piluliformis (Berk.) McAlp.
poanim, McAlp. = Tilletia striaeformis (Westd.) Oud.
readeri, Syd.

reiliana, Kuehn = Sorosporium reilianum (Kuehn) McAlp.
segetiim (Bull.) Dittm. = Various species
' solida, Berk. = Soiosporium solidum (Berk.) McAlp.

sorgld (Link.) Pass. = Cintractia sorghi-vulgaris (Tul.) Clint.
spinificis. Ludw. = Cintractia spinificis (Ludw.) McAlp. . .
stenotaphri, McAlp. . .

striaeformis (Westd.) Niessl. = Tilletia striaeformis (Westd.) Oud,
tepperi. Ludw.
tritici (Pers.) Jens.

iritici f. folicola, P. Henn. = Ustilago tritici (Pers.) Jens.
tulasnei, Kuehn = Cintractia sorghi-vulgaris (Tul.) Clint.. .
utriculosa (Nees) Tul.
*zeae (Beckm.) Unger = L^. maydis, Corda

PAGE

172

180
12,202
153
180
148
157
179
146
159
180
193
159
181

148, 149
183
173
174
161
193
161
149
149
173
162

112, 202

General Index.

281

(JEXEEAl. IXDKX.

Arciilia-like Iniiiis ol' siliuls

Alien species . .

Alternation of sapro])hytii' and

parasitic stages . .
American corn smut (rstiltujd -.kk )

germinati 11 in nutritive solu-
tio7is . .

incubation period . .

infection, local

smut-balls or smut-galls
Ampiiiraixis . .

Anther smut (Vstiliigo riilaci'(i) 3,
Antitoxins
Ascomycetes . .
Asexual stage
Australian smuts, number

distribution
Autobasidia . .
Bacteria and toxic solutions
Barnyard grass, gall-.smut
Basidia

Basidiomycetes
Bismarck brown

Black rust (Urocy-stis In'tici) 3.
Bluestone and formalin 113. 11

effect on germination of wheat

Bluestone treatment of seed wheat

Brome grass smut (Ustilago hrG))ii-

vora) . . . . . .'2

germination

infection . .

treatment
Bunt resistance ami systematic

selection
Bunt spores, effect of dry heat . .
Carnation, anther smut {Ustilaijo
violacea) . . 3,

Cause of parasitic plant diseases
Cereal smuts, table of . .

not liable to attack othci'
cereals indiscriminately . .
( 'hangc of sex
Chcinotaxis or chemotropism —

)iarasitism due to positive and
negative
Chlamydospore
Cinlrdclia

s])ore formation

aecidia-like in loituatinn ot
spores . .
Cintractia erus-galli
Oinfracfin krugiann
Cintractia .ipi)ii/ici.'<
Classification . .
Classification of I'stilauinaccae . .

Tillctiaccac
Coeth.'icnl of cfhciencv

Pack

43

(i3

(.'ollcction of sp.i
Conidia, aerial
not formed

ire

ma

teria

41. 43

pairing

111'

secondary 0

r t

crti

ary

29. 3(»
10, til
40
34, 61
GO
38
42
fi4
(i4
38
(K)
10
38
38

■T-

38. 89

4, 130

115

113

13. 123
124
12.-)
12,-)

U. ()1
02

()8

11
lli4

43

t)4

17

13

139

141

142

130

sprout nig. .

water
Contagion and infection
Covered smut of barley [Untilago
horde i) —

differences from naked smut

germination

infection . .
Cross-breeding wheats for rust
resistance

smut-resistance
Cultures, pure
Cylinder infection
Cijnodon dadyloti. indigenous
Development of Fungi
Di.sease in crops, losses
Disjiersion of spores
Distiibutiou of Australian spcc-ies
IJoa.s.sansia ..

cortex of sterile cells

development of spores

spores enclosed in peridiuin. .

spore formation

spore structure
Dominant characters . .
Ory heat and spore germination
Duration of germinating power..
Klemental pathology .".
Kmbivd of liarlev. mvcclium in..
l-:nd.. spore
Kntircly and partially i)untctl

jilants . .
Kntijlotiia

spore formation
Krgot. alkaloid similai to that of

Maize snuit
Eucalyptus, smut on
Excluded speiies
Exospore

External influences or environ-
ment . .
Fallowing, effect on Hag smut . .
l-'erment theory of infectious

disease
Fertilisation . .
I''icld ex])eriments
Klae smut of wheat

coinpared witli stem smut of

Page
35
21, 24
24
14
20
7, 21
21
28

favouiin<j

tlispcision of spoK

109
109
110

4G
.-)3
21
32
t)4
38

135
12
(14

200
19
19
43
19
12
47
2<i
■'2
58
33
12

134

194

18

3

3

201

12

40
129

88

282

General Index.

Flag smut of wheat — continued.

duration of germinating power 95

eifects . . . . . . 90

geographical distribution . . 93

germination . . . . 93

history . . . . . . 89

in Houth Australia . . 4, 5

infection and treatment . . 99

mode of . . . . 95

of wheat and rye . . 99
nature of fungus causing

disease . . . . 93

of wheat and lye not mutu-
ally infective . . . . 100

origin . . . . . . 89

IDreventive measures . . 101

soil infection . . . . 30

symptoms and general charac-
ters .. .. .. 90

Florence and Genoa, experiments

to test bunt-iesistance . . 49
supposed bunt-resistant varie-
ties .. .. .. 48

relative susceptibility to bunt 50
relatively rapid in germina-
tion . . . . . . 51

Flower infection .. .. 31.

Formalin treatment of seed wheat 114
Formalin an I bluestone, effect on

germination of wheat 115, 134

Fungi, origin and development . . 38
Fungicides, comparison of various

for bunt . . . . 129

Fusion of nuclei . . . . 14, 40

Gall-forming species of smuts . . ()4
Gametes . . . . . . 40, 43

Gametophyte or sexual generation 40

Gasteromycetes . . . . 12

Gen3ra, Australian and number of

species . . . . <i4

General treatment for smuts . . 113
Germ theory of infectious disease 57
Germinal tube or promycelium .. 11
Germination, duration of germi-
nating power . . . . 22

effect of dry and moist heat. . 27

light and darkness . . 25

sunshine . . . . 26

temperature . . . . 27

of teleutospores of Puccinia

i/ifiininis .. .. 41

rapidity of and smut liability 55

types of . . . . . . 22

Germinating spores, methods of . . 21
staining for photographic pur-
poses .. .. .. 27

Grain smut of sorghum . . 121

distribution . . . . 122

effects and losses . . . . 121

germination . . . . 122

infection . . . . . . 122

spore-formation . . . . 122

treatment . . . . 123

Oymnosporangium . . . . 41

Haustoria . . . . . . 9

Page
Head smut of maize . . . . Ill

germination . . . . Ill

iiifection . . . . . . Ill

Hemibasidia . . . . . . 11, 38

Heredity . . . . . . 46

Host and parasite, relation . . 58

Host-plants, inijiorted and their

smuts . . . . . . 63

Hot water treatment . . . . 116

Hyphae . . . . . . 9

spore-forming or sporogenous Ki, 39

Immunity and parasitism

rust

natui-al . .
Immune plant, definition
Incubation period

stinking smut

American corn smut
Indigenous and introduced species
Infection and contagion

escape by individual plants . .

flower

influence of temperature

local

modes of

seedling . .

shoot

with and without treatment
Infectious disease, germ theory . .
Inoculation
Insects, distributing spores

eating spores
Internal disposition or constitution
Introduced species, list of
Kangaroo grass smuts . .

Cintractia smut

Sorosporium smut

Tolyposporium smut
Life histories of cereal smuts

American corn smut

covered smut of barley

flag smut of wheat

head smut of maize

loose smut of oats

loose smut of wheat

naked smut of barley . . '.

stinking smut of wheat
Life histories of grass smuts

brome-grass smut . .

kangaroo-grass smuts

sorghum grain smut

wallaby grass smuts
Light and darkness, effect on ger-
mination
Local infection
Localized mycelium
Lolium fungus symbiosis
Loose smut and stinking smut in

ears of same plant
Loose smut of oats

germination

infection . .

soil infection

treatment of seed

28

63

28

55

31, 34

36

30

29

30, 33

33, 34

133

57

28

13. 145

13

62

63

125

125

125

126

67

112

109

88

111

103

86

107

70

121

123

125

121

126

10
59

29
103
103

22, 28, 104
30
106

General I iidex.

283

Page

Loose smut of wheat . . . . 86

germination . . . . 8t)

infection of llower . . 20, 87

treatment of seed . . . . 14'J

Losses caused by —

oat smut . . ■ . 4, 18()

stinking smut . . . . 4, 130

Lycoperdon, supposed lescmhlance

of smut to . . . . .J

Maize, smut-boils . . . . 3

Alaize smut, difficult to germinate

spores in water . . . . 112

Manures and flag smut . . 101

Melanopsichium . . . . lt)3

spore formation . . . . 1<)

Melanopsichium austro-americauuin (i4
Minnesota blue stem, compara-
tively resistant to bunt . . 47
Modes of infection . . . . 29

Mycelium, as a protective covering

for spores . . . . 10

composed of hyaline tubes . . 9

localized . . . . . . 10

perennial . . . . 'J

Naked smut of barley [Ustiki'ju

nuda) . . . . . . 1(>7

germination . . . . 107

infection . . . . . . 10, 107

treatment of seed . . . . 149

Nuclei . . . . . . 13

fusion of . . . . . . 14, 40

in fusion tubes . . . . !•")

of mycelium . . . . 14

of spores . . . . 14

Nutrient solutions . . . . 20

Oat smut, losses caused by . . 4. 13<i

Oospore . . . . . . 14

Origin of parasites . . . . 41

Pairing of conidia . . . . 14

Parasites . . . . . . 41

Parasitism, factors involved . . 02

origin . . . . . . 41

specialisation . . . . 43, (il

Parasitism and immunity . . 45

Partially bunted ears . . . . 85

grains . . . . . . 85

plants . . . . . . 85

Pathology elemental . . . . 58

PeniciUiitin and toxic solutions . . 00

Perennial mycelium . . . . 9

Peridium . . . . . . 12, 209

Phycomycetes oi- alga-like fungi.. 38

Plants, entirely and partially bunted 1 34

Promycelial spores (see Conidia) 11
Promycelium .. .. ..II. 39

bearing conidia — a saprophyte 4 1

dis|)ensed with . . . . 23

Pronuclei, conjugation of male and

female . . . . . . 14

Protobasidia . . . . . . 38

Pseudomixis . . . . . . 4U

Puccinia (p-aminis. drop|)ing sa])ro-

])liytic stage . . . . 43

germination of teleutospores 41

Pure cultures . . . . . . 21

Rapidity of germination and smut

liability . . . . 55

Page

Recessive characters . . . . 47

Relations between host and para-
site . . . . . . 58

Reproductive organs, spores .. 11

Rotation of crops and flag smut 101

Rusts, accidial stage . . . . 40

differences from smuts . . 44

immunity . . . . 45

relation to smuts . . . . 38

resemblances to smuts . . 44

Saprophytes . . . . . . 41

Seedling infection . . . . 30, 33

Selection and cross-breeding wheat 48
Selections from crosses, for bunt-
resistance .. 48, 52, 131
percentage of bunt . .52, 132
Self-sown wheat and bunt . . 83
Septa . . . . . . 9

formation in jiromycelia 14, 38, 70

Sexuality in rusts . . . . 42

absent in smuts . . . . 13, 41

Shoot infection . . . . 33, 34

Smut-balls in soil, infection from 30

Smuts, differences from rust . . 44

gall-forming species . . 04

general treatment .. 113

highly specialised . . . . <U

immunity . . . . 47

indigenous and introduced . . 03

life-histories . . . . 07

relation to rusts . . . . 30

resemblances to rusts . . 44

Soil infection . . . . . . 83

Sorghum grain smut . . . . 121

distribution . . . . 122

effects and losses . . . . 121

germination . . . . 122

infection . . . . • • 122

spore-formation . . . . 122

treatment . . • • 123

Sorosporium . . . . • • 175

spore-formation . . • • 17

s|inrc masses . . . . I'i

Sord-^jKininn . iili rotnorphutii ■ ■ 125
S(>r(i--ji(,nNiii nilidiiiim. germina-
tion .. .." .. Ill

infection . . . . • . 11 1

Sorosporiion sapouariae ■■ 13. 17

Sonisporiiini solidiim . . • • 18

Specialisation of parasitism . . 01

Sphagiuim, smut on capsule . . 3

Spirogym, conjugating cells . . 14

Spores, collection for infection . . 35

develo])ment . . • • 10

dis]K-rsion .. 12. 13, 29

l)y insects .. ..13, 145

bv thrips . . . . 29

bV wind .. .. 12

formation .. .. 13. 10

gcitnination . . ..11. 20

factors influencing . . 21
living and growing outside of
lu)st-plant

Irui'tmv
itality . ,
linterinu.

14

12

.22. 72. 122. 12f>

74

;84

General htdex.

Sporogenous hyphae
Sporophyte or spore-bearing gene-
ration . .
Staining spores
Starvation of host and power of

infection
Sterigma
Stinking smut of wheat —

adaptation to unfavourable

conditions
answers to questions
artificial infection of seed . .
conditions favouring the

disease
diseases produced in animals
duration of germinating

power . .
effects upon the crop
germination
effect of temperature
grains of wheat partially

bunted
infection . .
legislation relating to plant

diseases
losses caused by . . . . 4

proportion of smutty and

sound stalks in same stool

Re-infection of seed after

treatment
spores after harvest
Stinking smut and Loose smut on

ears of same plant
Stroma

Stubble burning and flag smut . .
Sugar, influence on germ-tubes of

fungi . .
Sulphate of copper, in seed treat-
ment for smut . .
Sunshine, effect on germination . .
Surface markings of spores
Susceptibility of different varieties

of wheat
Symbiosis between parasite and
host
Lolium fungus
Systematic selection and bunt-
resistance
Teleutospore . . . . . . 1

germination in rusts and smuts
Temperature, effect on germina-
tion
influence on infection
Temulin, alkaloid only developed
when fungus is pressnt . .
Thecaphora

spore formation
Thrips, probably concerned in

flower infection . .
Tillering
Tilletia

spore formation
Tilleiiaceae . . . . 142

Page
39

54
109

Page

73

78
73

82
136

77

75
74

29

17

101

113
26
12

47

59
59

47
1, 43

36

60

185

18

29
35

190
18

146

Tilletia levis and T. iritici, on ears
of same j^lant
on same ear

relative effect on length of
straw . . . . . . 5

relative virulence of infection
Tilletia tritici. effect of diy and
moist heat
germination of spores
spores on stem
Tolyposporium

spore formation
TolyiMspotiiiin liuysuin, vitality of

Toxic solutions fatal to parasites

Toxins and anti-toxins

Triticum, species and sub-species

in relation to bunt
Types of germination . .
Uninucleate spores
I'nit characters
Urocystis

development of spores

special envelope of sterile cells
Urocystis cepulae

Urocystis occulta, shoot infection
Urocystis tritici, biologically dis-
tinct from U. occulta

soil infection
Ustilaginaceae
Ustilaginales . .
Ustilago

spore formation

spores free
Ustilago avenue, germination of
spore . .

effect of light and darkness on 26

infection of young seedUng. .29, 104

effect of low temperature on 36

soil infection . . . . 30

treatment of seed . .
Ustilago bromivora
Ustilago calandriniae, spore diffi-
cult to germinate
Ustilago cynodontis, indigenous . .
Ustilago esculenta, used for food . .
Ustilago longissima, spore forma-
tion
Ustilago maydis (= U. zeae), in-
fection

local
Ustilago nmla, conidia not formed

differences from covered smut

germination of spore

infection . . . . . ■'■

flower

inoculation experiments in
United States

mycelium in embryo of barley

second growth infected by
persistent mycelium
Ustilago olivacea, germination of
spore . .

promycelium dispensed with
Ustilago readeri, germinating

sjxtres in light and darkness

germination

29
29

133
54

27

. 24

10

186

18

22

60
60

130

14
46
195
19
12
13
34

. 63, 99

30

141, 145

144

146

16

12

.22, 103

106
123

21

64

3

13

29
30
24
109
24, 107
29, 107
31

33
33

10

25
126

General Index.

-^85

Uslildr/t) trilici, inivitii>]\ .. 2'.t

f lower . . . . . . :{ I

inoculation experiments in

United State.s . . . . :;;}

Ustilago viohicca, shoot inl'eetion. . .'U

Ustildijo iriesiana on Euealypts. . :{

Ustilmjn zeae = U. maydis " . . 112

Vegetative organs, mycelium . . <J

X'ariable gcneiation ot a cross
Vitality of spores . .22, 72

Wallaby grass smuts . .

Black smut, gernnnation
Bronze smut, germination
Wind distribution of spores
Wintering of spores
Zizania, smutted portion eaten

Page

47

, 12()

12(i

I2(i

12()

12

74

3

-PiiKC 155. Tlio discovery

tlic^ smut on Cynodon dtictyhin Pers. in Mctoria

fllp^fnli'""*'''' 1910.. lius rendered it necessary to add to tha locaXiii^^ iov'uluiZo^m^^^^
the tollowing :— \ ictona— OnKoadside near Melbourne, March, 1910 (Brittlcbauk)

•86

Issued by Department of Agriculture, Victoria.

T/te Smuts of Ansfralki : their Structure, Life History, Treatment, and Classificatinn.

288 pp. Cloth.

57 Plates, 312 Illustrations.

The Rusts of Australia : their Structure, Nature, and Classificatioii.

.350 pp. Cloth.

55 Plates (including 366 Figures).

Funrji'S Diseases of Stone-fruit Trees in Australia and their Treatment.
165 pp. Paper.
10 Coloured Plates and 327 Figures.

Fungus Diseases of Citrus Trees in Australia and their Treatment.
132 pp. Paper.
12 Coloured Plates and 186 Figures.

Systematic Arrangement of Australian Fungi, together with Host Index and List of Wor]

on the subject.

236 pp. Paper.

287

REVIEWS AND NOTICES

OF

The Rusts of Australia : their Structure, Nature, and Classification.

Bv 1). McALPlNE.

Professor .). ('. Artliiir, in Journal of Mycology. .Alaich, 1907.

Among the notable recent contribiilions to uretlinology, the voliune on The Rusts of
Australia: their structure. iKiliirc. (iiid classificatiov, by D. McAlpine, is worthy of special
attention.

Preceding the systematic part the first twenty chapters are devoted to a discussion
of the general subject of rusts in its various aspects, and from the most modern point of
view. It is by much the best account now available in the English language.

The thoroughness with which the author has accomplished his task, the culmination
•of many years of observation and study, has insured a valuable work of reference for
both local and other botanists. But even more than this, the broad spirit in which
the work has been conceived and the ability shown to discover and interpret the less
obvious morphological structures, give added value to the record of facts.

It is this clear insight, and the accuracy and fulness of details, that commend the w ork
to all students of the lusts in every })art of the world.

Professor C F,. Bessey in Science, January. 19U7.

Part I., consisting of 75 pages, is devoted to the general characters and mode of life
of the rusts. This portion would be a very helpful text-book for college students any-
where, since the matter is presented in a clear and comprehensive manner. Fifty-five
plates (eleven of them beautifully and accurately coloured) hel]) to render the descriptions
more easily understood. A glossary of technical terms, a bibliography, an aljjhabetical
host index, a fungus index (al])habetical l)y genera), and a general index, complete
this satisfactory volume. ^ji

Professor Dietel. author of f'.s///«7///(r/f' in EntrJer and Piantls Die Sutiirlichin Pflanzen-

fannlieiK

I am convinced tliat your beautiful work, hy its contents as well as l)y its excellent
ilhistralions, will meet with general recognition, and I trust that it may give a strong
impetus to the further investigation of the llora of your interesting country.

The letterpress of your book has given me much information, and it has l)een of great
interest to me to receive a com])lete account of the rust-tloia of Australia.

Professor Saccardo. author of Sylloge Funyoruiii. IS \'ols.

ining a monogra])h of the I'redines of .Australia. It
great care and exceedinirly well illustrated. 'J'he
s very clear and instructive.

Revues Geuerale des Sciences pures et appliquees, 'Mt\i Autrust. 11)07.

The retpiirements of agriculture, which constitutes one of the leading sources of
wealth for the Australian colonies, have necessitated, for a long time, the creation in
the States of De])artments of Agriculture, among which that of the State of Victoria
is distiniiuished by tiie indefatigable zeal which it displays in defence of the interests
with which it is charged.

The Department of Agriculture has obtained from one of the savants attached it — ■
Mr. McAli)ine — a study as eom])letc as possii)lc of the various rusts which occur in Aus-
tralia, 'i'he work, in which all these observations aie recorded antl illustrated with
numerous jjlates. some of which are beautifully coloured, reflects great credit on the author
and on the Department of Agricidture of \'ictoria.

This

magniticeni vi

>lunie

CI

out

\-eiy

important, ex

ccute

d

wit

limin

ary and genera

1 pan

t of

it

288

The Times, Weekly Edition Supplement, 24th May, 1907.

In its own particular sphere the book is highly instructive, and will be appreciated by
students of agricultural science and welcomed by suffering farmers as furnishing a solid
groundwork for the carrying out of experiments with preventive or remedial treatment.
The extent to which agricultural pursuits in Australia are hampered and injured by rust
is very great, and no more important work could be undertaken than that to which
Mr. McAlpine is devoting his attention.

The Journal of Botany, August, 1906.

He has earned the thanks of all plant-growers in Australia by this useful and interest-
ing account of rust-fungi. It remains with the grower himself to take advantage of the
knowledge offered, and to carry into practice the author's suggestions and recommenda-
tions.

The Victorian Xatiiralisf, August, 1906.

By patient work duiing a period of fifteen years, since the date of his first article on
the subject, Mr. McAlpine seems to have at last conc^uered many of the mysteries in the
growth and occurrence of these insidious pests, and has now arranged them in such a
way, and with such copious notes and references, that futuie workers have a good foun-
dation on which to base their observations.

The Age, Melbourne, 25th Jlay, 1906.

Altogether, the volume will be a welcome addition to the botanical literatui'e of Aus-
tralia, and should prove of immense assistance in future to those engaged in the pi-oblem
of the prevention or of the mitigation of disease.

jj c. State Colle««

By Authority : ]. Kemp, Government Printer, Melbourne.