UNIVERSITY OF B.C. LIBRARY

9424 00126 1376

f#€|f

»i

SIC RAGE ITEM
PiOCESSING-GNfc

Lpl-FISD
U.B.C. LIBRARY

■;:?-

^■tfr^^

.<•- 4»1-

«5W

V'

V."

' ^ ■■■■"■ " ^Z>'<.^'^t-

/^-c>

^1 '

SsJaviV;- ■Wji^-'i ->■'-*'> i\-' >■-■ ^ ' ' .: '■-' .•"••-•-■■»:. ."• "

•f.'^» "■'? T\ '"■ "^ i-'^ ■ ■ .' .

L'W-

■^^

■' 'Sf^;

.;^, ■ ^^,,

C -rV

■)i--v'.

i>[

-i;,^-

■■^v-

Digitized by the Internet Archive

in 2010 with funding from

University of British Columbia Library

http://www.archive.org/details/diseasesofplantOOtube

DISEASES OF PLANTS

Induced by Cryptogamic Parasites

Introduction to the Study of
Pathogenic Fungi, Slime- Fu7igi, Bacteria, cf Algae

BY

Dr. KARL FREIHERR von TUBEUF

PRU'ATDOZENT IN THE UNIVERSITY OF MUNICH

WILLIAM G. SMITH, B.Sc, Ph.D.

LECTURER ON PLANT I'HVSIOLOGY
UNIVERSITY OF EDINBURGH

THREE HUNDRED AND THIRTY ILLUSTRATIONS

LONGMANS, GREEN & CO.

LONDON, NEW YORK, AND BOMBAY
1897

Ail rights reserved

GLASGOW :

f rinttb at the anibnsitii X^rcss bg

ROBERT MACLEHOSE AND CO.

AUTHOR'S PREFACE.

In my research work, and in connection with my lectures at
the University and Technical School of Munich, I have for
some time felt convinced that there existed a very evident gap
in the literature relating to the diseases of plants. There was
need of a newer and more complete work on cryptogamic para-
sites and the diseases induced by them on higher plants, a work
furnished with many accurate illustrations, with a survey of
the newer literature, and with a general part wherein parasitism
and the relations between parasite and host are discussed from
a botanical standpoint. Therefore, I have undertaken to write
a book intended to supply in some degree this pressing w^ant.
Here the attempt has been made for the first time to review
in a general and comparative manner the biological, physiological,
and anatomical relationships accompanying the phenomena of
parasitism. Already De Bary has considered the varying degrees
of parasitism and the phenomena of symbiosis in his celebrated
Morphology and Biology of the Fungi ; while AYakker has laid
the foundations of our knowledge of the alterations in the
anatomy of plants diseased by the agency of fungi, more especially,
however, those alterations accompanying 'hypertrophy,' I venture
to continue this difficult and comprehensive chapter of plant
physiology, because for ten years I have devoted my time to
the study of plant pathology. The book may be all the more
acceptable since I have confirmed a large number of the
observations and added the results of my own investigations,
many of them now published for the first time.

The present time is favourable to my work. The great
Sylloge Fimgorum of Saccardo (with its appendices in Vols. ix.
and X.) has been recently completed ; the classic investigations

VI author's preface.

of Brefeld in the domain of mycology, and containing liis
classification of the fungi, are now well advanced ; the Krypto-
gamni-Flora of Kabenhorst is nearly completed ; and the newer
literature and observations are now periodically reviewed in the
Zcitschrift fur PflanzenTcrankheiten, and other magazines. The
recent publication of several investigations on the influence of
parasites on the anatomy of their host-plants greatly facilitated
the compilation of the general part of the work.

I have here attempted to summarize in a systematic manner
the preventive and combative agencies available against the
more important diseases of economic plants. In many cases
these are supported by facts given in the chapters on the
natural and artificial infection of host-plants, and their disposition
towards diseases produced by lower organisms.

As already indicated in the title-page, the book deals only
with those diseases of plants produced by the cryptogams and
other lower organisms of the vegetable kingdom. The large
number of jxirasites which attack such lower plants as algae
and lichens, although not altogether neglected, have as a rule
been omitted, otherwise the book could not have been brought
within the limits of a single volume. In the second or systematic
part of the book, the pathological phenomena are considered
along with the description of the organism producing them.
Where the diseases are of economic importance, measures for pre-
vention and extermination are also suggested. Notices of greater
length are given to such parasites and diseases as have formed
the subject of special investigations. We could only aim at a
complete list for Germany and the neighbouring countries, yet
we have included many species of interest occurring in other
parts of the world, notably in America.

Though it will be possible to identify most of the more
important parasites by the aid of this book, we do not intend
it to replace the systematic works ; we purpose rather to add
to the descriptions given in Eabenhorst, Saccardo, and similar
works. This book is intended above all to be, in the terms
of its title-page, " an Introduction " ; hence it seeks to orient
in a general way, to give a summary of our knowledge, and to
indicate the way to more detailed records. On this account
great care has been taken in the citation of home and foreign
literature, not only up to the time of finishing the manuscript

author's preface. vii

(Easter, 1894), but also during the time of proof-reading up
till the following Christmas.

Eeference to the book will be rendered easier by the numerous
illustrations, which are almost exclusively the work of the author,
and reproduced either from drawings or from photographs of the
living objects, in many cases taken in situ. I consider it more
essential to illustrate the habitus of pathological objects rather
than to give drawings of microscopic subjects ; those one may
find in other works. Some of the illustrations are copied from
the excellent plates of Tulasne, Woronin, De Bary, Klebs, Eeess,
Cohn, and Eobert Hartig ; while a number of woodcuts have
been borrowed from the well-known Lchrhuch cler Baumhrank-
Jieitcn of the last named author.

The grouping of the ' Fungi imperfecti,' wdiich have not yet
been worked up for the German flora, is based on Saccardo's
Si/Uofje ; hence the arrangement into Hyalosporae, etc., which
is intended for the benefit of those having access to Saccardo.
Particular attention has been paid in the two Indices to the
scientific names of both parasites and hosts, to popular names,
and to technical expressions.

In my labours I received great assistance from the following
sources : From the collection of pathological material begun by
Professor Eobert Hartig, and now carried on with my help in
the Botanical Institute of the Eoyal Bavarian School of Forestry
in Munich ; from the facilities for research and photography
afforded by the laboratories of the same institution ; from the
Eoyal Library of Munich, the Library of the L^niversity, and the
private pathological library of Professor Hartig.

Living material for investigation has been kindly sent to me
from many sources, particularly from the following gentlemen :
Herr Lehrer Schnabl of Munich, Geh. Oberregierungsrath Prof.
Kiihn of Halle, Hofgartner Kaiser of Munich, Prof. Dr. Fries
of Upsala, Forstrath von Plonnies and Oberforster Losch at
Amorbach. Preserved material came from Herr Hauptlehrer
Allescher of Munich, Director Dr. Goethe and Dr. Wortmann in
Geisenheim, Prof. Dr. Stahl of Jena, Prof. Dr. Magnus of Berlin,
Prof. Dr. Grasmann and Prof. Dr. Loew of Tokio. Dr. Bruns
of Erlangen kindly photographed some specimens in the botanical
museum there. Numerous botanists have greatly assisted me by
sending papers, especially Dr. Dietel of Leipzig ; I have also to

Vlll AUTHORS PREFACE.

thank him for valuable aid with the Uredineae. To Prof. Dr.
Soxhlet I am indebted for literature and the opportunity given
to establish a museum of pathological material in connection with
the agricultural division of the Munich Technical School. Dr.
Solla of Trieste, while working in our laboratory here, very
kindly translated the earlier fascicles of the ' Funghi parasitici '
of Briosi and Cavara as far as they were then published. Prof.
Dr. Wollny allowed me to carry out some researches on his
experimental fields. Very opportune were the investigations of
my pupils, Dr. Woernle and Dr. W. G. Smith, on the anatomical
changes in plants attacked by Gymnosporangeae and Exoasceae
respectively.

To all these gentlemen, and to many more who sent me
material, but whom it is impossible to name individually in
this place, I here express my warmest thanks.

The reproduction of my drawings and photographs has been
most carefully carried out by Herr 0. Consee of Munich. I am
also deeply indebted to the publisher, Herr Springer, for the
excellent manner in which he has done his work ; this will
no doubt be also appreciated by the reader.

v. TUBEUF.
Munich, December, 1894.

NOTE TO THE ENGLISH EDITION.

Since the publication of this work, I have received a large
contribution of original papers. Though there was no time to
embody all these in the English edition, yet many of them
have been used for its correction and amplification. Some were
of such a kind as to necessitate the re-writing of whole sections,
notably those on the genera Exoascus and Gymnosporangium.
The remainder will be thoroughly revised if a second German
edition be called for. I again take the opportunity of thanking
all those who have sent me literature, and I shall be grateful
if they will continue to do so in the future.

V. TUBEUF.
Munich, December, 1895.

PREFACE TO THE ENGLISH EDITION.

My justification for placing another translation in our libraries
is that no such book as this exists in the English language,
and that I could not, for some considerable time, see my way
to collect so many observations on the cryptogamic parasites of
higher plants, or to find so many suitable subjects for the
pictorial illustration of their habits and structure, as Dr. von
Tubeuf has given us. The work was undertaken all the more
willingly, because, while working under the guidance of the
author, I had seen the book take shape in his hands, and even
added some items to its pages.

The aims of the book are sufficiently set forth in the author's
preface, and in the preparation of an English edition these
have been kept in view. The first or general j)art and the
more important descriptions in the second part are practically
translations, but a certain amount of modification was found
necessary in adapting the work to the requirements of English
readers. With this object many additions were made both
by the author and myself. Those which I have inserted are
in most cases indicated by the use of (Edit.); this has, how-
ever, been entirely omitted in the group ' Fungi imperfecti,'
and nearly so in the Uredineae, on account of the number of
changes found necessary. I also thought it advisable to indicate
whether the different species of fungi had been recorded for
Britain and North America; this has been done generally by
the use of brackets, — (Britain and U.S. America.) The records
for Britain are taken from the works of Plowright, Massee, and
others ; those of three groups, — the Uredineae, Basidiomycetes,
and ' Fungi imperfecti ' were, however, revised by Professor J.
W. H. Trail of Aberdeen, a well-known authority. For America

X PREFACE TO THE ENGLISH EDITION.

the records of economic interest are selected chiefly from Farlow
and Seymour's Host- Index, which contains the complete list.

I here take the opportunity of expressing ray thanks to
Professor T. Bayley Balfour for valuable aid and advice; to
Professor J. W. H. Trail for kindly revising important parts of
the proofs; to my brother, liobert Smith, for assistance in proof-
reading, and to other friends who have aided me.

The difficulties of translation are well known ; in the present
case they have been increased by the technical nature of the
subject, and by the modification which the original has under-
gone. Faults there must be ; for those I ask the indulgence of
the reader.

W. G. SMITH.

Royal Botanic Garden,

Edinburgh, October, 1896.

BIBLIOGRAPHY.

The following are some of the more important general works and text
books. Books and papers on special subjects are given throughout the
text as foot-notes : —

General Works on Fungi.

TuLASNE. Selecta fungorum carpologia. 1861-1865.

De Bary. Comparative Morphology and Biology of the Fungi, Mycetozoa,

and Bacteria. English edition. 1887.
ZoPF. "DiePilze." Schenk's Handbuch der Botanik. 1890.
LuDwiG. Lehrbuch der niederer Kryptogamen. 1892.
Brefeld. Untersuchungen aus dem Gesammtgebiete der Mycologie.

1872-1891.
Tavel. Vergleichende Morphologic der Pilze. 1892.
Saccardo. Sylloge fungorum. 1882-1893.
Winter, Fischer, and Rehm. " Die Pilze." Eabenhorst's Kryptogamen-

flora.
Schroeter. " Die Pilze." Cohn's Kryptogamenflora von Schlesien. 1885-

1894. (Incomplete.)
Schroeter. " Die Schleimpilze und die Pilze." Engler-Prantl natiirlichen

Pflanzenfamilien. 1892-1894. (Not yet complete.)
Cooke. Handbook of British Fungi. 1871.
Plowright. British Ustilagineae and Uredineae. 1889.
Farlow and Seymour. Host-Index of the Fungi of the United States.

1888-1891.
Massee. British Fungus-Flora. 1892-1895.

Works ox Diseases of Plants.

Unger. Die Exanthema der Pflanzeu und einige mit diesen verwandte

Kraukheiten der Gewachse. 1833.
Wiegmann. Die Krankheiten und krankhaften Misbildungen der Gewachse.

1839.
Meyen. Pflanzeupathologie. 1841.

Xll BIBLIOGRAPHY.

De Bary. Untersuchuiigen Uber die Brandpilze und die durch sie verur-

sachten Kraiiklieiten der Pflanzen. 1853.
KtJHN. Die Kraiikheiten der Kulturgewiichse und ihre Verhiitung. 1858.
Hallier. Phytopathologie ; die Kraiikheiten der Kultnrgewachse. 1868.
Hartig, R. Wichtige Krankheiten der Waldbaunie. 1874.
Hartig, R. Die Zersetzungserscheinungen des Holzes. 1878.
Frank. Die Krankheiten der Pflanzen. I. Aufl. 1880, II. Aufl. 1894-1896.
Hartig, R. Lehrbuch der Baumkranklieiten. I. Aufl. 1882, II. Aufl. 1889.

(Editions in English, French, and Russian.)
Smith, Worth. G. Diseases of Field and Garden Crops. 1884.
Sorauer. Handbuch der Pflanzenkrankheiten. II. Aufl. 1886.
Wolf and Zopf. Krankheiten der landwirthschaftlichen Nutzpflanzen

durch Schmarotzerpflanzen. 1887.
Sorauer. Die Schaden der einheiraischen Kulturpflanzen durch thierische

und pflanzliche Schmarotzer. 1888.
Marshall Ward. Timber and some of its Diseases. 1889.
KiRCHNER. Die Krankheiten und Beschadigungen unserer landwirthschaft-
lichen Kulturpflanzen. 1890.
Frank and Sorauer. Pflanzeuschutz. 1892.
Prillieux. Maladies des plantes agricoles et des arbres fruitiers et forestiers

causees par des parasites vegetaux. 1895.
Zeitschrift fiir Pflanzenkrankheiten (since 1891).
The Publications of the Division of Vegetable Pathology of the Department

of Agriculture, U.S. America, issued from Washington.
The Bulletins of the Agricultural Experimental Stations, issued by many of

the States and Universities of the United States.
Exsiccata of Parasitic Fungi, by (a) Briosi and Cavara, (b) Eriksson.
" Economic Fungi " of U.S. America, by Seymour and Earle ; Exsiccata

begun 1890, (still being issued).

Etc., etc.

CONTENTS.

PART FIRST.

CHAPTER I.
THE PARASITIC FUNGI.

PAGE

§ 1. Definition of the Parasitism of Fungi, ... 2

§ 2. Classification of Parasites and Saprophytes, - - 3

§ 3. Mode of Life of the Parasitic Fungi, - - - 7

CHAPTER II.

REACTION OF HOST TO PARASITIC ATTACK.

§ 4. Effect of Parasitic Fungi on their Host, - - - 14

§ 5. Effect of Parasitic Fungi on the Form of the Host-Plant, 22

§ 6. Effect of Parasitic Fungi on Cell-Contents, - - 31

§ 7. Effect of Parasitic Fungi on the Cell-Wall, - - 36

§ 8. Effect of Parasitic Fungi on the Tissues of their Host, 40

CHAPTER III.

RELATION OF PARASITE TO SUBSTRATUM.

^ 9. Effect of the Substratum on the Development of the

Parasite, ------- 45

XIV CONTENTS.

CHAPTER IV.
§ 10. NATURAL AND ARTIFICIAL INFECTION, - - 50

I'AOE

CHAPTER V.
§ n. DISPOSITION OF PLANTS TO DISEASE, - - 58

CHAPTER VI.

§ 12. PREVENTIVE AND COMBATIVE MEASURES, - - 63

I. Extermination and Removal of the Parasitic

Fungi alone, - - - - - 65

II. Removal and Destruction of Diseased Plants, - 71

III. Avoidance or Removal of Conditions which Favour

Infection, ------ 75

IV. Selection of Hardy Varieties, - - - 81

CHAPTER VII.
§ 13. ECONOMIC IMPORTANCE OF DISEASES OF PLANTS, 83

CHAPTER VIII.
SYMBIOSIS: MUTUALISM, 86

CHAPTER IX.

SYMBIOSIS: NUTRICISM, 92

Ectotrophic Mycorhiza, ----- 93

Endotrophic Mycorhiza, - - - - - 97

Mycodomatia of the Alder, etc., - - - - 99

Mycodomatia of the Leguminosae, - - - . 101

CONTENTS.

PART SECOND.

SYSTEMATIC ARRANGEMENT OF THE CRYPTOGAMIC
PARASITES.

PAGE

I. THE PATHOGENIC FUNGI OF PLANTS, - - - 104

A. Lower Fungi (Phycomycetes), - . . . io6

(1) Chytridiaceae, ..... 106

(2) Zygomycetes, . . . . - - 114

(3) OoMYCETES : PEROyoSPOREAE, . - . .115

B. Higher Fungi (Mycomycetes), - . - .135

Ascomycetes, - . - - - - 136

A. Gymnoasci, ..... 137

The Parasitic Exoasceae, - . - 144

B. Carpoasci, - - . - - - 168

Perisporiaceae, .... 170

Pyrenomycetes, . . - - 183

Hysteriaceae, ..... 232

Discomycetes, - . . - . 240

Ustilagineae, ...... 275

Uredineae, . - . - . . . 328

Basidiomycetes, - . - . . .421

Fungi Imperfecti — I. Sphaeropsideae, . - . 463

II. Melanconieae, - - . 482

III. Hyphomycetes, . - - 496

II. THE PATHOGENIC SLIME-FUNGI, - - - 522

III. THE PATHOGENIC BACTERIA, - - . .53a

IV. THE PATHOGENIC ALGAE, - . . - 539

INDEX ,0F PARASITES, - - - - . - 556
GENERAL INDEX, 580

ERRATA.

Page 9, Fig. 1, for " Erysipheae " read " Erysiphe."

35, line 11 from foot, fur " tyrosin " read " tr3^psin."

181,
185,
195,
256,
305,
312,

337,
355,
403,
404,
420,

24, for " quercinium " read " quercinum."
6, for " Nectrina " read " Nectria,"

3, for " setuloso " read " setulosa."

6, for " Belionella " read " Beloniella,"
11 from foot, /c?" Tolysporium" read "Tolyposporium."
16, for " heloscladii " a7ul " Heloscladium " respectively,

read " helosciadii " ayid " Helosciadium."
10, for " Onybrychis " read " Onobrjchis."

25, for " Cichoria" read " Cichorium,"
9, for " Cypressus " read " Cupressus."
5, for " Escheveria " read " Echeveria."
3, for " Thecospora " read " Thecopsora."

PART FIRST.

CHAPTER I.

THE PARASITIC FUNGI.

The true Fungi, together with the Myxomycetes or Slime-fungi,
and the Schizomycetes or Bacteria, constitute a group of the
Cryptogams characterized by lack of chlorophyll. In consequence,
the members of the group are unable to utilize light as a source
of energy, and must obtain their food as organized material,
complex in comparison with the simple substances required by
green plants. These fungi, in short, are, in common with animals,
ultimately dependent for the greater portion of their support
on living or dead chlorophyllous plants. According as they
obtain nutriment from dead organic remains or from living
plants or animals, we distinguish them as Saprophytes and
Parasites respectively. The same mode of nutrition is found
in the case of most non-chlorophyllous Phanerogams, and also
in a few chlorophyllous plants, both Cryptogams and Phanero-
gams.

When parasitic Fungi, Bacteria, and other lower organisms
attack higher plants, they, as a rule, endeavour to penetrate the
living organs of their host. It is only when this penetration
has taken place to some extent, and the parasite has thereby
come into more or less close contact with the tissues of its host,
that conditions suitable to a parasitic mode of nutrition are
established.

To deal with the lower forms of vegetable parasites, with their
relations to their respective hosts, and with the structural altera-
tions which they bring into existence in the latter, is our object
in the present book.

A

2 THK PARASITIC FUNGI.

§ 1. DEFINITION OF THE PARASITISM OF FUNGI.

Parasitic Fungi are those whicli, stimulated by the cell-
contents of another living plant, penetrate wholly or partially
into its tissues, and draw their nutriment from that source.

Saprophytic Fungi are those which make no attempt to
penetrate the tissues of living plants, but derive their nutriment
from a dead substratum.

Intermediate between these two extremes come those fungi
which, in consequence of some stimulus, attempt to effect an
entrance into the tissues of living plants by the secretion of some
fluid or ferment, but only attain their object after first killing the
part they attack {e.g. Sderotinia sderotiorum). A special position
must also be ascribed to certain forms which inhabit the wood
of trees, but have not the power to penetrate through the outer
tissues ; they depend on first gaining entrance through wounds
into dead parts of the bark or wood, and, after living there for
a time as saprophytes, extend into the living elements and cause
their death.

Many parasites may be artificially cultivated so as to pass
some part of their life-history on dead pabulum, and even in
natural conditions many of them regularly live for a season in
a saprophytic manner. On this account it appears to me more
correct, in distinguishing between parasites and saprophytes, to
lay less weight on the adaptation to nutrition and more on their
response to the stimuli exerted by living plant-cells. The nature
of this stimulus which affects parasitic hyphae has not as yet
been investigated. It appears probable, however, especially from
the investigations of Pfeffer and Miyoshi,^ that the influence is
primarily a chemical one, and that the nutritive value of the
stimulating substance is not a measure of the ensuing effect.
Biisgen states that the formation of adhesive-discs by germinating
spores is induced by a stimulus due to contact, whereas the
production and penetration of the first haustorium is independent
of contact, and is probably due to some chemical stimulus (see
p. 9). Miyoshi's investigations have also proved that saprophytic
fungi are capable of penetrating into living plant-organs, even

^ Miyoshi. " Ueber Chemotropismus d. Pilze."' Botan. Zeitung, 1894; also " Die
Durchbohnmg von Membrauen durch Pilzfaden." Pringsheini's Jahrhuch, 1895

Pfeffer. " Uel)er Election organischer Nahrstoffe." PriiK/^liehn's Jahrhuch,
1895.

DEFINITION OF THE PARASITISM OF FUNGI. 3

of boring through cell-walls, if the part be impregnated with a
stimulating solution. They behave here completely as parasites.
For example, hyphae of Penicillium glaucum penetrate into living
cells of a leaf injected with a two per cent, solution of cane
sugar, while without previous injection of the leaf they have
never been observed to do so. Pcnicilliutn is also known, in
certain circumstances, to become parasitic.

Many species of fungi are capable of passing the whole or a
part of their life as parasites on living plants. Conspicuous in
this respect are the Uredineae and Ustilagineae, many Ascomy-
cetes, including all Exoasceae and Erysipheae ; and amongst the
lower fungi, most of the Chytridiaceae and all the Peronosporeae.
Nor does this exhaust the list, for amongst the remaining fungi
we may find isolated families, genera, and even species occurring
as parasites, while forms closely related to them are saprophytic.

To classify the parasites, saprophytes, and intermediate forms,
we shall adopt that arrangement proposed by Van Tieghem and
De Bary.

§ 2. CLASSIFICATION OF PARASITES AND SAPROPHYTES.

1. True saprophytes are such as regularly pass through their
whole life-history in a saprophytic manner. They may derive
their nourishment from different kinds of pabulum, or be limited
to some definite substratum. The true saprophytes do not come
within the scope of this book.^

2. Hemi-saprophytes (the 'facultative parasites' of De Bary)
are wont to pass through their whole development as saprophytes,
but on occasion are capable of existing wholly or partially as
parasites. Amongst them are included particularly such species
as may be designated " occasional parasites," which commonly
occur as saprophytes, and only under certain conditions become
parasitic.

3. True parasites (the 'obligate parasites' of De Bary). These
undergo no part of their development as saprophytes, but live in
every stage of existence as parasites.

4. Hemi-parasites (the 'facultative saprophytes' of De Bary)
are capable, if need be, of becoming saprophytes for a season

^Johow proposes the term Holo-saprophj'tes for those nonchlorophyllous
Phanerogams which live exclusively saprophytic on organic debris, in contrast
to those possessing chlorophyll, which he names Hemi-saprophytes.

4 THE PARASITIC FUNGI.

but as a rule they live througliout their whole development as
parasites.

Within each of these four divisions one may introduce a
number of subdivisions.

H emi-saprophytes.

The majority of saprophytes are never parasitic, yet there are
a number which become so occasionally. Thus some species of
Mucor and Pcnicillium can penetrate into thin-skinned fruits, and
this they do the more easily, the further the fruits are from the
condition of full vital energy, to use De Bary's expression.^
Related to these are other fungi which, although incapable of
effecting entrance into plants in active life, may yet do so as
the plant, though still living, begins to wither. In such cases
the parasitism is somewhat difficult to prove. In particular, the
so-called ' Fungi imperfecti ' contain forms of tliis kind.

Amongst the hemi-saprophytes we may include the species
of BotrytU, which are able to penetrate into unfolding parts of
plants, but not into the older parts. We may specially mention
Botrytis Douglasii as a form more generally known as a sapro-
phyte, but which becomes parasitic on immature organs, and
which penetrates young needles of various conifers to kill them,
whereas it is unable to attack older needles. In this case the
thickness of the membranes would seem to act as a protection,
just as the vital energy of the plant does in the preceding cases.
In Sclcrotinia sderotiorum, Scl. ciborioides, and Scl. Fuckeliana,
a saprophytic existence must, as in the example just mentioned,
precede the parasitic condition ; in fact De Bary holds that
these forms can only become parasites after their mycelium has
been saprophytically strengthened ; the parasitic condition is not
necessary to them, for they can go through their whole develop-
ment on a dead substratum. Pythium De Baryanum is also to
be regarded as a hemi-saprophyte which attacks and kills
seedlings of many plants as a parasite, but otherwise vegetates
on dead plant remains. Cladosporium herharum, one of the
commonest of saprophytes, behaves similarly, but it is of less
frequent occurrence than Pythium, and in fact its parasitism has
only been suspected quite recently.

^This has been confinned by Davaine (Compt. rend, lxiii., 1866, pp. 277 and
344) and Brefeld {Sitzun(jsher. d. naturforsch. Fr. zu Berlin, 1875).

CLASSIFICATION OF PARASITES AND SAPROPHYTES. 5

As further examples of fungi, capable, as parasites, of killing
living cells, but which pass through more or less of their life
as saprophytes, may be taken species whose mycelium inhabits
the wood of trees and shrubs. Amongst these are numerous
Polyporeac, which find admission only by wounds in the wood.
At first these destroy and derive nourishment from the substance
of dead parts of the wood, but later they begin to attack the
parenchyma of the living wood, and extending outwards kill,
as they go, cambium, bast, and rind, till they reach the exterior,
and there develop sporophores. As examples we may take
those species investigated by E. Hartig of Munich, e.g. Poly-
porus fomcntarius, P. igniarius, P. Hartigii, P. sulphurcus,
Stcrcum liirsutum, Tramctcs inni}

The heart-wood is a part of the tree generally avoided by
insects, which would in very short time destroy the sap-wood
with its rich starch-content, e.g. Annohiac in oak. Again, the
heart-wood resists the influence of certain saprophytic fungi
much longer than the sap-wood, hence it is preferred as the
timber used for railway sleepers. Although in these cases we
might describe the heart-wood as possessing antiseptic properties,
yet tliis would scarcely be accurate, since it is just this very
heart-wood which is always first attacked by the wound-parasites
of trees, and gives them a hold on the tree as parasites. See
also Chap. V.

Since these dangerous tree-fungi can live wholly as sapro-
phytes in the heart- w^ood, and in the sap-wood partly as such,
partly as parasites, they are also able to vegetate further, and
to reproduce themselves on felled stems, especially when the
necessary moisture is provided. Thus, for example, Agaricus
aclijjosus, a wound-parasite of the silver fir, produces its yellow
sporophores on felled stems and split wood during the whole
summer in moist parts of the forest, while in a cellar or other
moist chamber the development of sporophores may continue over
a year. In fact, I have found that a billet of beech-wood, after
being placed under a glass and allowed to lie completely dry,
on again being soaked from time to time, continued to produce
a crop of toadstools annually for five years.

Some wound-parasites occur occasionally as typical sapro-
phytes on dead wood. Thus Polyporus emnosus, perhaps better

^ R. Hartig, Zersetzungseischeiniuu/en des Holzes, 1878, and other works.

G THE PARASITIC FUNGI.

known as Traindt's radicipcrda, is an undoubted parasite of
pines, spruces, and other trees, yet on timber in mines ^ it
grows luxuriantly, and reproduces abundantly from sporophores,
which, however, ditl'er somewhat from the typical form. Again,
the rhizomorph-strands of Agaricus melleiis grow under dead
bark, in the earth, in mines, and in wooden water-pipes, while
other forms of its mycelium are completely parasitic ; thus
the apices of the rhizomorphs penetrate the bark of young
conifers, and, in the form of a mycelium, live parasitic on rind,
bast, and cambium.

Polyporus vaporarius, a true parasite on living Scots pine,
is also an enemy of timber in newly-built structures, or in
subterranean spaces and cellars, so long as it can obtain the
necessary moisture. Polyporus sulphureus produces sporophores
on the bark of living trees, as well as on the dead stools of
felled trees. Many other related forms would probably be able
to live on dead timber if they were not dependent on a certain
degree of moisture, and could submit to drying-up as easily as,
for example, Polyporus ahidinus, a true saprophyte, and one of
the most common enemies of old wooden bridges.

Fungi from other groups are also known to effect an entrance

into the wood of trees through wounds only, yet when once in,

they spread rapidly, and at length bring about the death of their

host. The spores of Cucnrhitaria lahurni were demonstrated

by me to germinate on the laburnum, on wounds produced

by hail and otherwise, and to send into the wood so exposed

a mycelium, which spread through the vessels and into the rind,

killing all the tissues on its way. Similarly Ncdria cinnabar ina,

after it has killed its host, lives thereon as a saprophyte, and

develops patches of conidia and perithecia on the dead bark.

Pcziza Willkominii, although really a strict parasite on the living

rind, yet continues to grow and to reproduce itself on the dead

branches.

Hemi-parasites.

If the examples already given, i.e. Mucor, Penicillium, Botrytis,
Pythium, are typical of hemi-saprophytes, then there may arise
a doubt whether the remainder, the wood-destroying Polyporeae,
Ncdria, Cucurhitaria, and Afjariciis mcUcus, should not be regarded

^ Harz, Botan. Centralblatt, 1888, Vol. xxxvi. ; Magnus, Botan. Verein d. Prov.
Brandenbnrii , 1888.

CLASSIFICATION OF PARASITES AND SAPROPHYTES. 7

as hemi-parasites. They must, however, be inchided amongst
the hemi-saprophytes, because doubtless they are capable of
going through their whole development as saprophytes. The
hemi-parasites include, amongst others, the XJstilagineae, all of
which live for a time as parasites, and cannot, even by artificial
cultivation, be made to complete their life-history as saprophytes.
While, however, many of the Ustilagineae are adapted to a com-
pletely parasitic life, others can, in the form of sprouting conidia,
live and multiply saprophytically. The conidia of Eo:ohasidimn
and Exoascus continue to bud off conidia for a considerable time
in nutritive solutions, yet in nature, the spores probably produce
infecting hyphae at once, and the fungus is but little suited to
sustain a saprophytic mode of life. Phytoijhtliora infcstans is
more easily reared as a saprophyte, and occurs in nature as such,
hence it approaches somewhat towards the hemi-saprophytes.

True Parasites.

The Uredineae may be taken as the most typical of the true
parasites ; they constantly pass through their whole life-history
on living plants, and cannot be cultivated on a dead substratum.
So also the Erysipheae, although frequently their spores only
reach maturity on a dead substratum, as do also those of
RhyfAsma and Polystigma. Ergot of grain and the Sderotinia
inhabiting berries, are also truly parasitic, even though their
apothecia or perithecia are produced from hibernating sclerotia,
and though their conidia can be saprophytically cultivated on
dead pabulum.

The Peronosporeae and Protomyces are also true parasites.
In many other forms the development of germ-tubes, or the
sprouting of conidia, may be obtained in artificial nutritive
solutions by exclusion of rival fungi and bacteria, yet it is
doubtful whether this takes place in nature.

§ 3. MODE OF LIFE OF THE PAEASITIC FUNGI.

The parasitic fungi may be divided according to the place of
their occurrence and their mode of attack on the host, into two
categories, which may be designated epiphytic and endophytic

8 THE PARASITIC FUNGI.

parasites. ^ The former have their vegetative mycelium spread
over the surface of the host-plant, the latter penetrate into the
plant and there develop their mycelium. I>otli receive nourish-
ment from the cells of the host-plants, generally by means of
special absorptive organs inserted into the cells of the host, the
so-called hansturia.

We may distinguish the following groups of parasites accord-
ing to the degree of their penetration into the organs of the
host-plant they attack :

1. Epiphytes: {a) with haustoria which only sink into the
outer membranes of the host ;

{h) with haustoria penetrating into the cavity of the host-
cells.

2. Endophytes : ('0 with a mycelium which grows in the
walls of the host-cell, and is generally nourished without the aid
of haustoria ;

{h) with a mycelium which grows in the intercellular spaces
only, and is nourished with or without haustoria ;

(c) with a mycelium which penetrates into the host-cells and
becomes an intracellular mycelium ;

(d) lower fungi which live completely in a host-cell.

1. Acquisition of nutriment by the epiphytic parasitic
fungi. The simplest mode of acquiring nutriment is found in
yeasts (Saccharomyces apiculatus, etc.) which frequent the outside
of living fruits, and live on the drops of sugary solution which
diffuse therefrom. -

^ Epiphytic parasites always produce their reproductive organs outside their
host-plant. In the case of endophytic parasites, the reproductive organs of
some are produced inside the host-tissue, e.(j. the zygospores and oospores of
Chytridiaceae and Peronosporeaf, the chlamydospores of the Ustilaffineae ; others
form their sporocarps wlioUy or partially embedded, the spores and conidia only
being discharged externally ; while a large number form sporocarps on the surface
after the epidermis lias been torn. Conidia are generally abjointed from the
free surface of the host-plant.

The terms epiphytic and endophytic parasites have been chosen with regard to
the development of the parasitic food-absorbing mycelium. Some authors regard
epiphytism somewhat differently, and include amongst endophytes those forms
which live on the surface of the host and peneti-ate only by haustoria. If this be
accepted, epiphytism is very exceptional amongst parasites of the higher plants.
Zopf (" Die Pilze") gives as examples of this condition only the following: the
Laboulbe7iiaceae inliabiting the chitinous skeleton of certain insects, and Jle/ano-
spora paralitica on filaments of species of Isaria ; these have no communication
between the mycelium and their host. Species of CAae/oc/of/mni parasitic on fungi
and absorbing the cell-wall of the host at the point of contact, could, strictly
speaking, no longer be classed as epiphytes.

-Biisgen. " Ueber einige Eigenschaften d. Keimlinge parasitischer Pilze."
Botan. Zeitung, 189.3.

MODE OF LIFE OF THE PARASITIC FUNGI. 9

I can however hardly regard as parasites, fungi like these
which live on an accidental outflow from plants or plant-cells,
even though they regularly frequent places where an outflow is
to be expected. They exert no influence on the host-plant,
and they are nourished by substances which can no longer be
regarded as belonging to the host. I would rather include
them amongst non-parasitic epiphytes which, without specially
adapting themselves, settle on any part of a living plant where
sugary solutions suitable for their nutriment may occur. One
might imagine however such epiphytes inducing a diffusion of
nutritive substance from the cells of the host-epidermis to the
closely adherent fungal hyphae ; then we should have the
simplest mode of parasitic acquisition of nutriment on the part
of epiphytes. They would take up food-material from the epi-
dermal cells in much the same manner as many intercellular
hyphae do from the adjoining walls of the host-cell.^

Epiphytic parasites frequenting the surface of plant-organs
generally endeavour to increase their supply of nutriment from
the host-cells by formation of haustoria, which pierce the cuticle
or the whole cell-wall. Blisgeu has shown experimentally
that the adhesive discs, often formed on the germination of a
spore, owe their origin to a contact-stimulus ; the formation and
direction of the infecting hyphae, on the other hand, though
depending on this, are much more determined by a stimulus
originating from the host-cell itself. In this we have a confirma-
tion of the accuracy of our definition of
parasite and saprophyte.

The appressoria, adhesion-organs or
adhesive discs just mentioned, are char-
acteristic of many parasites. They are
formed chiefly on epiphytic mycelia,
liut also accompany the earlier life of
other fungi. In the case of epiphytes,
pores are formed on definite places of ^ ^ , „ . .

^ Fig. 1. — gp, Spore of Erysipneae

such an adhesive-disc, and from these umhem/erarum germinating on the

epidermis of a host plant ; an ad-
haUStOria are developed, or a hypha is heslon-disc and haustonum have been
'^ ' *^ ^ formed. (After De Bary.)

given off and enters the host-plant to

form a mycelium. The appressoria of the Erysipheae are very

characteristic; in many they are broad lobed discs (Fig. 1); in

^ Compare those cases of parasites on insects and fungi already given, p. 8 (note).

10

THE PARASITIC FUNGI.

Others, like rodoq)ha('ra castcu/7ici, they take the form of broadened
closely-clinging hyphae with haustoria. Frank describes a swell-
ing of the germ-tube of Fusidadinm trcmulae just before the
infecting hypha pierces the cell- walls of its host. A similar
phenomenon can be observed in Poly stigma ruhrum, in Gnomonia
crythrostoma, and in the germinating aecidiospores of Mdampsora
Goejypcrtiana. Some other examples will l^e mentioned in our
next section.

Haustoria of the epiphytic Parasites.

The most inconspicuous haustoria are those of Herpotrichia
nigra and Trichosj)haeria varasitica, described by E. Hartig.^

Flo. 2. — Haustoria of Trichosphaeria }^arasilica. (Details on Fig. 88.)
(After R. Hartig.)

They are tiny hyphal processes resting on the host-epidermis,
and sunk into the outer walls of the epidermal cells, so as to
pierce the cuticle but not the whole wall (Fig. 2, d, e; also
Fig. 90). The Erysipheae are typical epiphytes, which weave
a mycelium over the surface of plants they attack ; the
mycelium retains its hold by adhesion-discs or appressoria, and
from certain parts of these a fine thread-like process is given
off, which, after piercing the epidermal wall of the host, swells
inside to a simple or branched sac, the haustorium. The

^ Lehrhurh d. Baiimhrankheiten, II. Aiifl. English translation by Professor
Somerville. Macmillan & Co., 1894.

MODE OF LIFE OF THE PARASITIC FUNGI. 11

haustoiia of Podosphaera castagnci (Fig. 71) are bladder-like,
those of Oidium Ttickeri are lobed.

The simplest formation of haustoria consists in an outgrowth
of the mycelium which depresses the cell-wall of the host
without piercing it (e.g. Pcronos2wra densa). In other cases the
cell-wall, at first only depressed, becomes ultimately broken
through.

Certain lower fungi live parasitic on other fungi and adhere
to their hyphae by means of well-developed adhesion-discs from
which haustorial structures are formed inside the hyphae of the
host. Thus Piptoayhalis frcscnia is parasitic on hyphae of some
species of Mucor, and produces from a swollen bulb-like appres-
sorium a tuft of very fine haustoria inside the il/^/(?o?'-hypha.
Synccphalis proceeds even further, for the haustorial process grows
and branches inside the host, becoming, in fact, an endophytic
mycelium. A further advance towards endophytic parasitism
is presented by the Chytridiaceae, low forms of fungi living
on alg-ae or fungi ; some send haustorial structures into their
host, others develop a mycelium whose attack however is
directed against only one host-cell. Fischer, in his " Phycomy-
cetes," thus describes the latter forms : " The vegetative body,
a resting swarmspore, consists of a spherical or ellipsoidal part
which becomes a sporangium, and of a filamentous vegetative
portion which spreads through the host-cell as a haustorium or
mycelium and dies away after the formation of the sporangium.
This primitive mycelium is unicellular, and may be unbranched
or very finely branched."

2. Acquisition of nutriment by the endophytic parasitic
fungi. The simplest case of the endophytic mode of life is
presented by those fungi which vegetate in the epidermal
membranes of their hosts, and derive their nutriment osraotically
through the inner cell-walls. They live covered by the cuticle,
which must have been penetrated by an infecting hypha at the
time of first attack. This mode of life is exhibited by many
fungi, particularly by the Exoasccac ; the mycelium of these
vegetates under the cuticle of the host plant, and ruptures it at
the time of ascus-formation. In spite of their limited distri-
bution the species of this group so influence the development
of their hosts as to induce pustule-like outgrowths, crumpliug
and distortion of leaves, and even "witches' brooms." In some

12 THE PARASITIC FUNGI.

of the E.coasccac the bases of the asci penetrate deeply between
the walls of the epidermal cells, so forming an intermediate
stage leading to other Uroasccac and endophytic fungi, with a
mycelium growing between, or in the cells of tissues which lie
deeper than the epidermis.

The mycelium of Cycloconium olcaginum grows in the epi-
dermal cell-membranes, branching dichotomously under the
cuticle and sending through it erect hyphal branches for pro-
duction of conidia.^ The germinating conidia of Sphaccloma
ampclinum are said by De Bary to penetrate the cuticle, and
to produce a mycelium which spreads thereunder and breaks
out just before formation of conidia. Mycoidca parasitica, an
alga, lives under the cuticle of leaves of Thea and Camellia.

We have next to consider fungi with a mycelium which
lives and multiplies in the intercellular spaces of living plants.
Like the Exoasccae just mentioned, they push their way between
neighbouring cells and spread through the already existing
intercellular spaces. Numerous Uredineae behave in this way,
and towards the period of reproduction the mycelium is capable
of increasing so much that the cells of the host-tissues become
isolated and even displaced. The various species of Hystcrium
have an intercellular mycelium, which kills those cells with
which it comes in contact. Certain forms, e.g. Caeoma pt'^'^Hor-
quum and Fcridermium piini (Fig. 247) possess a mycelium
which, while still intercellular, sends off here and there little
lateral branches into the host-cells. It is an easy step from
forms like these to forms whose mycelium is no longer strictly
intercellular, but derives nutriment by means of specialised
haustoria.

Haustoria of the endophytic Parasites.

A large number of endophytic parasites frequenting hosts which
do not immediately succumb to their attack, possess "haustoria"
or special organs for the ac(|uisition of nutriment from the
cells of the host. The haustoria are lateral outgrowths of the
mycelium with a limited period of growth and a more or less
constant form. They are more varied in form, but otherwise
quite comparable with haustoria of the epiphytes, especially
with those of the Erysipheae. One of the simplest forms of

^ Figures in Fumjhi Paro-sitti, Cavara and Briosi.

MODE OF LIFE OF THE PARASITIC FUNGI. 13

haustorium on an endophytic mycelium is that exhibited by
the parasite Cystoims ; the hyphae send off very fine filaments
which penetrate the walls of a host-cell and swell up to little
button-like sacs. Many Peronosporeae (P. i:)y(jraru:a, P. nivea,
P. viticola and Phytophthora omnivora) have haustoria of the
form just described, whereas others have them thread-like and
branched {P. calothcca of the w^oodruff), or crenately lobed {P.
"parasitica).

Amongst the species of Uredineae and Ustilagineae, haustoria
are not uncommon and present many varied forms. They are,
however, few in number, or confined to certain parts of the
mycelium, so that they may be easily overlooked.

Haustoria in the form of long sacs of various lengths are
produced by Mclamjjsora GoepjwrHana in the tissues of both
cowberry and fir-needle. Crymnosporangium in juniper has
occasionally very delicate button-like haustoria. Endophyllum
sempervivi in the house-leek has haustorial branches which,
according to Zopf, are coiled together and anastomose frequently
with each other. Tuhurcinia amongst the Ustilagineae possesses
short branched haustoria resembling one-sided clusters, and
Mclanotacnium endogenum has similar haustorial-tufts even more
branched.^ Urocystis pompliolygodcs in Hcpatica triloba has spirally
coiled haustorial hyphae, while Tilletia endopliylla, Sorosporiuni
sap)onariae,'^ and many species of Ustilago, have haustoria with
the form of knotted hyphae.

Amongst the Hymenomycetes, Exohasidium vaccinii forms
a mycelium which permeates the host-tissues with numerous
hyphae, but the only haustoria are hyphae which here and
there penetrate into a cell. No haustoria have as yet
been found amongst the Basidiomycetes,^ Pyrenomycetes, or
Discomycetes. The two groups last-mentioned have an inter-
cellular or intracellular mycelium, which as a rule quickly
kills all cells with which it comes in contact.

^ Senckenhtrgische nahirforsch. Ges. Ahhandl. 1880. Plates I. and IV.

^ Prinrjsheiin's Jahrhuch, 1869. Plates VII., VIII.

^Saraiiw has figured haustoria in mycorhiza of beech, without however
determining exactly whether they belonged to a Hymenomycete. Reess also
figures similar organs on mycorhiza produced bj' one of the Tuberaceae.

CHAPTER 11.
REACTION OF HOST TO PARASITIC ATTACK.

The reaction of the host to the attacks of parasitic fungi is
fairly constant for the same host and fungus. The various
fungi, however, exert on the same host-plant each an influence
of its own, while different host-plants behave very differently
under attacks of the same fungus.

§ 4. EFFECT OF PARASITIC FUNGI ON THEIR HOST.»

A. Killing of Host-Cells.^

1. Absorption of living cell-content by parasitic fungi.

The lower fungi give us examples of the simplest mode in
which fungus-parasites draw nutriment from their host-cells ;
particularly those forms parasitic on algae or other fungi.
The most primitive of all are numerous species which, applying
themselves to a host-cell, bore through its walls and enter
the cavity. There they derive nutriment at the cost of the
living cell-content, — the plasma, cell-sap, ehloroplasts, starch
grains, etc., — and finally kill the cell. The host-cell does
not survive the later development and reproduction of the
parasite. The effect of the fungus is however limited to the

^ Billroth ("uber die Einwirkungen lebender Pflanzen und Thierzellen aufeinan-
der, " Sammlunr/ Medic. Schriften. Wiener Hin. Wochenblatt, 1890), compares in a
masterly way the effects of micro-organisms and of injuries on animal and vege-
table tissues. He employs Virchow's terms " foi-mative stimulus " and "formative
irritability " ; the former to denote the capacity of micro-organisms in producing
outgrowths of definite form or the formation of new tissues ; the latter, the
capacity of the tissues to react to such stimuli, and to produce outgrowths,
etc. A comparison of the external phenomena of fungoid diseases in the case
of animals and plants recently formed the subject of a short paper by Lewin.

- Perniciasmus.

EFFECT OF PARASITIC FUNGI ON THEIR HOST. 15

cell attacked which is at once killed before it can enlarge or
otherwise react to the influence of the intruder. Good examples
of such parasites are presented by some of the Chytridiaceae
— the Archimycctes of Fischer — which, as a rule, inhabit only
isolated cells of their respective host-plants. This mode of
nutrition is equivalent to that of the Myxomycetes and Mycetozoa,
which absorb the cell-contents after completely enveloping the
living cell, or after slipping inside or sending a haustorial process
into it.

A second series of parasites consists of those which live
on the contents of the host-cell, and give it time to react to
the stimulus exerted by the intruder. The reaction generally
results in a cell-enlargement or fungus-gall, which in the simpler
cases includes one cell only. The gall harbours one or more
parasites, which gradually use up the cell-contents. As examples
we have Olindmm tumacfaciciis and 0. uredinis^ Pscudolpidium
saprolegniae, Olpidiopsis scq'trolegniae, Rhizoimjxa liypogaea} etc.
A specially striking case is that of Pleotrachcliis fulgcns, which
causes the rudiment of the sporangiophore of Piloholus Klcinii
to become hypertrophied and gall-like.^

We have as a third series those parasites which penetrate
into living cells and absorb their contents, at the same time
stimulating the host-cell to abnormal and increased growth, as
well as some surrounding cells not directly in contact with the
fungus. In this case the parasite exerts a far-reaching effect,
and produces a gall composed of more than one cell. Species of
Synchytrium are examples. The fungus itself penetrates into one
cell only, which enlarges ; but simultaneously the surrounding
cells grow and multiply to form a wall or rampart enclosing the
cell originally attacked. Other parasites do not absorb the
host-contents as a whole, but only withdraw osmotic substances
by means of delicate processes of the fungus-hyphae. These
haustoria penetrate the wall of the host-cell, but the fungal
protoplasm inside them remains separated from the host-proto-
plasm by a delicate membrane. In the case of the vine-mildew
and some other Erysipheae, the cells thus preyed on turn brown
and die. With other related forms {e.g. Sphacrothcca castagnci),

^ See Fischer's Phycomycetes.

- This causes a slight swelling of the root-hairs of various plants and absorbs
their content.

^Zopf, Beitrdge zur Physiol, u. Morphol. nied. Organismen, ii. 1892.

16 REACTION OF HOST TO PARASITIC ATTACK.

absorption by haustoria results in a deformation and distortion
of attacked organs, which embraces even cells far distant from
the point of attack, yet without death following directly to
any cell.

2. Absorption of cells or tissues by parasitic fungi. Tlie
total al).sorpti()u of colls or tissues by parasitic fungi constitutes
a special form of cell-destruction. Cases of this kind occur
particularly amongst the Ustilagineae. Thus Urocystis violae so
stimulates the cells of Viola that they divide and produce a
delicate tissue, rich in protoplasm ; this nutritive tissue is used
up when spores are formed, but without any great detriment to
the host-plant. At the time of spore-formation of other Ustila-
gineae a great destruction of the host-tissues may, however,
take place ; this is especially mai'ked in attacks of Ustilago
maydis, V. avcnac, Tillctia tritici, on the ovaries of their
respective hosts, as well as in other cases to be considered
later.

o. Killing of host-cells and tissues by fungi which excrete
ferments. The simplest case under this heading is presented
by species of Sdcrotinia studied l^y De Bary, e.g. Scl. sclerotiorum.
The mycelium of these, while still lying on the outer surface of
the host-plant, excretes a ferment which sinks through the mem-
branes into the cell-cavities, causing death to the protoplasm and
even destruction of whole tissues.

A similar process may be assumed in the case of numerous
fungi with a mycelium which grows only in the intercellular
spaces, yet causes immediate death to any cell it may touch.
This is the case with many leaf-spot diseases, like those due to
Cercos2)ora, Hystermm, etc. So also do the apices of rhizomorph-
strands kill portions of the bast of living Conifers with which
they may come in contact. The rapid death of tissue following
the attack of such deadly fungi as Phytophthora is probably
due not altogether to the deprivation of nutriment, but also to
the effects of a poisonous excretion. This, however, has not as
yet been satisfactorily ascertained.

B. Killing of Organs or Whole Plants.

A larsfe number of fungi have a mvcelium which never ex-
tends beyond a very short distance round the point of first
infection, and causes only local disease, frequently with no

EFFECT OF PARASITIC FUNGI ON THEIR HOST. 17

perceptible disturbing effect on the host. Such is the case
particularly with leaf-spot diseases ; the tissues of isolated spots
are killed and fall out, the leaf appearing as if perforated by
shot, but otherwise exhibiting no discoloration or other symptom
of disease. In contrast to these there are fungi which, directly
or indirectly, bring about death of their host or some part of it.

The simplest example of parasitic fungi killing their host
directly is presented by one-celled or few-celled plants, which
soon succumb to attack even on a single cell. Where, however,
the host is a highly organized plant, its organs will resist the
attack of the parasite for some time. Thus with Phytvphtliora
fagi, the mycelium spreads rapidly through the tissues of a
seedling, so that death ensues in a few days. Similarly species
of Peronospora rapidly kill leaves, branches, and fruits ; likewise
Clados23ormm , Sqotoria j^fc^'f^tsitica, and others.

Somewhat different in their action are those fungi which
kill some tender part of a plant directly, and thereby in-
directly further the death of other parts dependent thereon.
As examples, take Pestalozzia Hartigii (Fig. 301) and Phoma
ahietina (Fig. 293), which kill only some small portion of a
young plant or branch, but thereby cause drying-up of higher
or distal parts. GiUbcra vaccinii on stems of cowberry (Fig. 95)
is another example. Similarly cankers arising from Nectria
ditissima (Fig. 80), or Peziza Willhommii. Again, Agaricus
melleus and Tramctes radiciperda kill roots or lower portions of
the stem, and bring about the death of trees of all ages.

The case varies somewhat with certain wound-parasites like
Nectria cinncdjctrina and CucurMtaria lahurni. There the my-
celium extends so vigorously in the water-conducting organs,
as to kill them and fill up the vessels, causing thereby so
serious a disturbance in conduction, that branches or whole
plants wither away in summer. The wood-destroying Polyporcae
and Agaricini act similarly, although more slowly ; they attack
large branches and stems, destroying all parts of the wood,
duramen as well as sap-wood, and finally the bark.

There are also cases where organs of the attacked host
remain alive, but suffer on account of the hypertrophy of other
parts. In this way portions of a plant may be killed although
not directly the seat of the parasite. This is particularly the
case where hypertrophied organs undergo increased growth and

B

18 REACTION OF HOST TO PARASITIC ATTACK.

Utilize the water which would otherwise have ascended to
higher parts of the branch-system (Fig. 3). It must indeed
be assumed that the latter are preyed on by tlie hypertrophied
parts and give up plastic material, which they would otherwise
have utilized themselves or stored up as reserve material.
On branches attacked by mistletoe and other phanerogamous
parasities, it can easily be observed, particularly on broad-
leaved trees, that a supporting branch grows vigorously in the
parts under the influence of the root-system of the parasite,
whereas the distal parts of the same branch-system remain
stunted and finally die. The mistletoe-bush thus comes to form
the termination of the supporting branch. If, in consequence
of this, the branch ceases to produce the leaves necessary in
preparing food for it, then like every other leafless branch it
dies. Such branches carrying leaves of the mistletoe alone may
frequently be found on firs, pines, and broad-leaved trees ;
even whole tree-summits have been seen on the silver fir with
every branch terminated by a mistletoe-tuft, not unlike some
huge candelabrum.

In a similar manner a witches' broom, developed from a
lateral bud, exhibits throughout an increased growth, while the
branch supporting it remains thin and dies from the insertion
of the broom outwards. So also in attacks of Gymnosporangmm
on juniper it may be observed that the parts attacked have
their growth much accelerated and many of their dormant buds
developed, while the distal parts of the same branch die oE
In all such cases it is quite probable that, as the distal parts
die back, any food material which they may contain finds its
way into the hypertrophied region.

C Shortening of Life.

Many fungi inhabit a plant without disturbing the develop-
ment of any part or causing immediate death, yet with such
effect that the vegetative period of the organ in question
terminates earlier than normally.

A very striking example of this is presented by the needles
of silver fir on the witches' brooms caused by Aecidium
elatinuvi. The needles normally vegetate for several years,
but when infiuenced by this parasite they live only a single
season. So also needles of spruce attacked by Accidwm cor-

EFFECT OF PARASITIC FUx\GI ON THEIR HOST.

19

'^•^^*?icrfj?ix'

Fig. Z.—Exoascus cerasi. Witches' broom of cherry. The supporting branch is
dead from its apex backwards to the seat of aninfected lateral bud, which has
developed into a witches' broom. On the tree the supporting branch pointed
slightly more downwards than is shewn. J natural size. (v. Tubeuf phot.)

20 REACTION OF HOST TO PARASITIC ATTACK.

itscans, which may, in addition, bring ubont death of the whole
shoot. Needles of spruce beset by aecidia of Chrysomyxa
rhododcndri are cast after reproduction of the fungus in August
or September, while with Chry>iomyxa ahietis the needles of
Conifers fall in May. The latter examples differ somewhat
from the former in that the mycelium lives in the witches'
broom for years, and continues to send out new shoots with
deformed needles, whereas in the Chrysomyxa attack the my-
celium is confined to the needles and falls with them.

Examples from other groups of fungi are the witches' brooms
of Alnus incana caused by Exoascus einphyllus. The leaves of
these are fully developed though somewhat modified in form ;
their life-period is, however, shorter than that of normal leaves,
and they fall earlier. It may be observed here that this
phenomenon of- premature defoliation is one recorded as a
consequent of many parasites. The witches' broom twigs of
the alder grow and produce buds almost normally, yet the
whole broom-system dies in a few years, and long before the
normal life-period of the tree.

The war of extermination by mycelium against host-plant
may frequently last for a very long time. Hartig gives an
example of a larch which had carried on the combat with the
larch-canker (Peziza Willkommii) for over eighty years, because
during active vegetation of the host the parasite was unable to
make headway.

. D. Premature Development of Buds.

The unfolding of buds in spring in advance of those of
normal plants is also a feature of many diseased plants. This
is manifest in the earlier unfolding of buds on witches' brooms
of the silver fir and cherry. The alder witches' broom, already
referred to, is however exceptional, in that its buds open after
those of normal twigs.^

A premature flowering may also result, so that flower-buds
formed in summer unfold the same autumn instead of during the
following spring. Thus in a recent autumn a violet opened
in a plot in the garden of Professor Hartig in Munich. The
flower was found to be somewhat stunted, and its stalk beset

^ Smith, " Untersuchungen d. Anat. u. Morph. tier durch Exoasceen veru-
sachten deformationen." Inaug. Diss. Municli, 1894, p. 16.

EFFECT OF PARASITIC FUNGI ON THEIR HOST. 21

by pustules of Urocystis violae, the mycelium of which liad
perennated in the stem. Kerner in his " Pflanzen-leben " ^
mentions a similar case where flowers of Primula clmiana and
P. mijiima attacked by Uromyccs j^rimidae intcgrifoliac unfolded
prematurely in autumn.

E. Preservation of the Host-Plant and of Host-Tissues.
(Conservation.)

In contrast to those parasites which attack a plant, or parts of
it, and immediately kill it or otherwise exert a direct destructive
influence, we have these which live for a longer or shorter period
with their host without producing such an effect. Cohabitation
of this kind may last only for a short time and terminate with
the first reproductive period of the fungus, or it may last for
years as a perennating symbiosis, or as a perpetual one like that
of lichens.

This phenomenon is particularly conspicuous amongst the
Uredineae. These throughout their whole development adapt
themselves to an existence with living host-cells, so that the
latter die only after the reproduction of the fungus. Frequently
the mycelium lives in perennial organs for a length of time,
even for many years. The attacked parts are of course injured
to a certain extent, and hypertrophy of the most varied kind,
accompanied by characteristic phenomena, may take place, yet
this only towards the termination of the period of development.

The Ustilagineae are in a similar manner adapted to an exis-
tence in living organs, and there produce their spores. At the
time of spore-formation and liberation they are deadly enemies of
their host-tissues, yet previous to this they vegetate in the
living tissues with little or no apparent injurious effect. Some
like Ustilarjo pcrennans, even pass the winter in the living host-
tissue without killing it.

The individual species of the Hysteriaceae, Discomycetes,
Pyrenomycetes, Hymenomycetes, and lower fungi differ very
much in their action ; many of them inhabit living tissues for a
length of time without injurious effect, while not a few, like the
Exoasceae, even perennate from year to year. The galls pro-
duced as a result of Exobasidium do not die till the fungus has
reproduced itself. It is unnecessary at this place to give details

1 English Edition, Natural History of Plants (Oliver), n., p. 525.

22

REACTION OF HOST TO PARASITIC ATTACK.

of Other examples, since many of these will be referred to again
in other chapters, particularly when hypertrophy is under consi-
deration.

§ n. EFFECT OF PARASITIC FUNGI ON THE FORM OF
THE HOST-PLANT.

1. Arrest of growth, and Atrophy. While a large number
of fungi produce more or less extensive enlargement of parts
of their host, others cause arrest of organs, crippling, impoverished

nutrition, and even atrophy of
an extreme kind. Incompletely
developed organs of this kind
may originate even where the
fungus in possession produces
only local hypertrophy. In-
teresting examples are presented
by many species of Synchytrmm
{e.fj. S. tarao.ricum and S. cmi-
mones). The former is endo-
phytic in Taraoxicum, and exerts
a stimulus resulting in increased
growth, not limited to the
single cell attacked, but ex-
tending to neighbouring cells,
which, in consequence, multiply
and form a ring-like swelling
round it. The leaves as a
whole, however, are poorly developed, so that the lamina in
very extreme cases may be represented only by the midrib and
narrow margin (Fig. 4) ; while on leaves attacked on one side,
that side alone is stunted, the other is normal. Taraxacum
leaves badly attacked by Puccinia are not at all deformed,
whereas those of Anemone show striking arrest of growth (Fig.
190). Leaves of Cirsium attacked by P^iccinia snaveolens exhibit
an arrest of the same kind, remaining less divided and of
softer texture (Fig. 186).

Flowers affected by parasitic fungi present many striking
malformations. Magnus ^ describes such a case in Anemone

Fig. i. — Synchylriv.m taraxaci. Partial atroiihy
of laminae of Taraxacum officinale. About i
natural size. (v. Tubeiif phot.)

^ Magnus, " Einfluss v. Parasiten auf d. Ausbildung d. befalleneu PflAiizen-
theiles." Naturuiss. Bvndschau, 1891, No. 2o.

EFFECT OF PARASITIC FUNGI ON THE FORM OF HOST-PLANT. 23

ranuncidoides under the influence of Aicidiv.m imndaiiim. In
the simpler cases the floral leaves weie narrow, elongated, and
greenish, stamens were formed but not carpels ; in more pro-
nounced cases, the petals were only represented as small, simple,

Fig. 5. — Cherry tree in blossom, with three " witches' brooms " in foliage,
(v. Tubeuf phot.)

stalked, green leaves, the stamens were reduced in number and
there were no carpels. One case exhil)ited, in place of a flower,
only two leaflets terminating the flower-peduncle, one of them
palmately divided.

24

REACTION OF HOST TO PARASITKJ ATTACK.

True atrophy is best seen in those cases where flower-forma-
tion is suppressed. This effect of parasitic fungi on their host is
by no means uncommon, the fungus alone reproducing itself,
while the assimilating host-plant remains sterile. This atrophy
is found not only in annual plants, but also in those where the
symbiosis might be designated as perennial. The last-mentioned
case is exemplified in Accidium elatinum, the witches' broom of
which never bears flowers ; again, by witches' brooms of Exoascus

Fig. 6. — Euphorbia Ci/parissias. A healthy flowering normal plant compared
with the attenuated non-flowering form inhabited by Aecidiuni euphorbiae.
(V. Tubeuf phot.)

ccircsi (Fig. 5), which bears only leaves when the rest of the
tree is in blossom. Another perennial symbiosis behaving thus
is shown in Euphorbia Cyparissias attacked by Accidium
euphorbiae ; year after year the diseased shoots produce only
leaves, which assist in the reproduction of the fungus (Fig. 6).
Similarly with many other Uredineae.

Arrest of the seed occurs in ovaries of species of Primus under
the influence of Exoasci (Fig. 7). In flowers attacked by Ci/stopics

EFFECT OF PARASITIC FUNGI ON THE FORM OF HOST-PLANT. 25

the ovules become atropliied, whereas the rest of the flower
is hypertrophied. Similarly with
flowers of cowberry deformed by
Exohasidiv.m.

2. Hypertrophy. — Many para-
sitic fungi cause abnormal enlarge-
ment or other malformation of
plants which they attack. The
simplest case of hypertrophy is
seen in the enlargement of a uni-
cellular plant as a result of an
endophytic parasite, e.g. Filobolus
KIcinii with Plrotrachclus.

The same example is also the
simplest possible case of a gall
caused by a plant, and distin-
guished by the name of " fungus-
galls " or Mycocecidia, from Zooce-
cidia, the galls caused by animals.
Larger galls occur on leaves
attacked by Si/nchytrium, where
not only the single cell attacked

becomes enlarged, but also the surrounding cells ; these galls,
however, form but tiny points on diseased leaves. Similar
small and local enlargements of the leaf-cells, accompanied
frequently by cell multiplication, are caused by many other
fungi, e.g. species of Exoascus. More extensive malformation may
embrace some part or even the wdiole leaf, so that it is more
or less enlarged and beset with blister-like outgrowths, as with
other Exoasceae (see Figs. 62 and 64). Other gall-forms are
presented by Exohasidium on the alpine-rose (Fig. 259), where
the gall is always localized to a small area of the leaf, and
on the cowberry, where the gall may extend over whole leaves,
and even include the shoot (Fig. 256).

Hypertrophy of the whole shoot, resulting in elongation and
thickening of the twigs, is a phenomenon frec[uently met with
in the " witches' brooms," to be referred to later. And just
as entire branch-systems may become hypertrophied and elon-
gated, so may whole plants, if the mycelium, instead of remaining
localized, spreads throughout the plant. Examples of this will

Fig. 7. — Fruit of plum deformed by
Exoascus pruni ; the stone is shrivelled
and abortive, -i natural size. (v. Tubeuf
phot.)

26 REACTION OF HOST TO PARASITIC ATTACK.

be described when we consider Euphorbia with Accidium
etiphorbiac (Fig. 6), house-leek with EndoiyhyUum, anemone with
Aecidinm (Fig. 190), and cowberry witli Cab/ptosjiorn (Fig. 202).
Where plants, like the cowberry and anemone, live in com-
munities, then these elongated individuals rise above their
healthy neiglibours, and the fructifying fungus has a better
chance of having its spores distributed by wind. It must,
however, be observed that when hypertrophy of a whole shoot
or plant occurs, every part need not be enlarged to a propor-
tionate extent ; in fact some parts generally remain abnormally
small, r.(j. leaves in cases of rusts upon cowberry, fir, anemone,
and others. On the other hand, both shoots and leaves may
be abnormally enlarged, as in cases of alder with Exoascus
Tosquinctii or Ex. tpiphyllus}

Hypertrophy of the roots occurs on alder, where large tubers
are produced by Frankia (Fig. 21). On Leguminosae, tubercles
of various sizes are caused by Ehizohium (Fig. 22). Eoots
of Juncus develop thick-lobed outgrowths as a result of Schinzia
(Fig. 179). Eoots of turnip infested by Plasmodiopliora have
irregular swellings of all sizes (Fig. 315). Mycorhiza frequently
exhibit tubercles or balls formed by the massing together of
very short dichotomously branched rootlets into clumps (Fig. 18).
Cycad-roots, under the influence of Rhizobium and Nostoc, also
exhibit hypertrophy.-

We shall now proceed to consider hypertrophy of the repro-
ductive organs, and at the same time to notice some other
changes induced in the flower by parasitic fungi.

Influence of parasitic fungi on the development of reproductive organs

of host-plant.

Disease of the flower and fruit, when not caused by fungi
which kill the cell, generally causes striking floral malformation.
These we may group as follows :

1. Atrophy or total suppression of flowers.

2. Arrested development of flowers.

3. Development of rudimentary organs.

4. Abnormal formation of flowers.

5. Hypertrophy of parts.

6. Transformation into sclerotia.

^ See also § 7. -Schneider, Botanical Gazette, 1894, p. 25.

EFFECT OF PARASITIC FUNGI ON THE FORM OF HOST-PLANT. 27

The two first cases have already been considered. The arrest
of the flowers of anemone, as a result of Aecidium punctahim,
is a further example of Case 2, and at the same time exemplifies
Case 4, in that the floral leaves become crreen foliage leaves,
though of a very stunted kind. The petals of Cruciferae hyper-
trophied under the influence of Cysto2nifi candidvf; often become
green, and at the same time much altered in shape.

A particularly interesting case is presented by the develop-
ment of the stamens of the pistillate flowers of Lychnis dioica
infested by the mycelium of Usfilago violacca. These stamens
normally remain rudimentary, but in the diseased abnormal
flowers become fully developed like those of the staminate
flowers, except that the spores of the parasite replace the
pollen in the anthers. Giard ^ has designated this phenomenon
as " castration parasitaire," and he distinguishes three modifica-
tions amongst unisexual flowers.

{a) Stamens appear in pistillate flowers ("androgene castration
parasitaire "). This occurs, as already mentioned, in pistillate
flowers of Lychnis dioica frequented l)y UstUayo.

(b) Ovaries are developed in staminate flowers (" castration
thelygen "). Examples : Carcx praccox with Ustilago caricis,
Buchloe dactyloidcs with TUlctia liichlo'eana, and Androj^oyoti
provincialis with Ustilago andro^wgonis.

(c) In flowers of either sex the sexual organs of the other
appear in consequence of the influence of the parasite ("amphigene
castration parasitaire "). Giard compares these cases with that
of the development of the organs of the latent sex in animals,
e.g. of cock's feathers on an old hen, or growth of horns on
castrated or " gimmer " animals. In both cases the phenomenon
is due to the same cause; in the animals the organs of the
latent sex appear as the result of the normal organs becoming
functionless or being destroyed by castration ; in the plants
through stimulation of the latent rudiments by the fungus,
which does not, however, cause suppression of the organs
already present. In some respects the phenomenon is comparable
with what happens when the terminal shoot of a tree is lost
and some neighbouring lateral shoot turns vertically upward
to replace it.

The effect of fungi on the reproductive organs of plants

^ Mangin and Giard, Bulletin scient. de la France et de la Belgiqne, 1884.

28 REACTION OF HOST TO I'ARASITKJ ATTACK.

may also be seen amongst lower cryptogamic plants, two cases
of which may be mentioned here.^ Pleotrdchchts fulgens,
inhabiting the mycelium of Piloholus Klcinii, causes the
formation of galls and the suppression of sporangia, while at
the same time zygospores, normally rare, occur in large
numbers. Likewise a species of Syncrphalis parasitic in Pilohohis
vrystallinKs causes suppression of sporangia and stimulates
formation of zygospores.

The transformation of floral organs may resemble that observed
by De Bary, in which, as a result of attack of Peronospora
violacea on Knautia arvcnsis, the stamens appeared in the form
of violet petals. Doubling of flowers is also caused, as in
Saponaria officinalis, under the influence of Ustilacjo saponariae,
and Compositae with Peronospora radii.

The Ustilagineae, perhaps, cause the greatest amount of varia-
tion on the flower, because many of them produce their spores
in the floral organs of their host. Thus, in the anthers live
Ustilago violacea, holostei, scahiosae, intermedia, succisae, hetonicac,
major, scoi'zonerac, ca2Jensis, pinguicolae, VaUlantii, and Tiihurcinuc
jjrimulicola ; the last named also occurs in ovaries and stigma.
So also do many others inhabit the ovary or some other part.
Many, like Ustilago iiiaijdis, form spores throughout the plant
as well as in the flower, and bring about hypertrophy and
destruction of parts. Amongst these are Ustilago avenae,
perennans, hordci, nnda, tritici, pianici miliacci, reiliana, crucnta,
sorglii, Crameri, caricis, tragopogonis, Tillctia lacvis, etc.

Ogsto2)us (Fig. 35) causes very characteristic hypertrophy
of all parts of the flower, particularly an enormous outgrowth
of the ovaries and floral envelopes, whereas other parts are.
arrested in their growth. Wakker investigated a number of
Cruciferae with flowers deformed by this parasite, and found
variations in the form and anatomy of the deformations
produced on the different host-species.

PJ.cohasidium also causes w^ell-marked hypertrophy of flowers,
and even of the whole inflorescence of cowberry. Woronin ^
describes and figures such cases (Fig. 256). All parts of
the flower may be attacked and grow to a great size, becoming

^Zopf., Beitrage zur Physiol, und Alorph. niederer Orijanismen, 1892.
Zopf., "zur Kenntniss d. Infections-Krankheiten nied. Thiere u. Pflanzen."
yova Ada d. L Leop. -Carol. D. Akad. Hallt., 18S8, p. 356.
- Naturforsch. Gesellschaft Freiburg-i.-B., 1867.

EFFECT OF PARASITIC FUNGI ON THE FORM OF HOST-PLANT. 29

at the same time fleshy and of a bright rose-red colour ; the
ovules are sterile or abnormally formed. Wakker, however,
found no very marked change in the anatomical structure of
such flowers.

The species of the Exoasceae also produce striking hypertrophy
of flowers. Thus there are the sac-like outgrowths of the
catkin-scales or ovaries of poplar caused by Taphrina Johansonii
and T. rhizophora (Fig. 52), and the "pocket-plums" or "fools"
due to Exoascus loruni (Figs. 49 and 51). In these last-
mentioned cases, the outer layers of the ovary become thick and
fleshy, sometimes remaining green, while the stone and kernel
remain rudimentary. The alder, under the influence of Exoascus
alni incanac, has the catkin-scales much enlarged, deprived of
chlorophyll, and of a red colour (Fig. 53).

Mummification, or the transformation of the fruit into a fungal
resting-body or sclerotium, is not unfrequent. In some respects
this process resembles the change in ovaries brought about l)y
XJstilagineae. Here, however, we have to do neither with hyper-
trophy of the fruit, nor yet with its complete destruction. The
best-known sclerotium is that of Claviceps purpurea (Fig. 84).
It first fills up the base of the ovary, then kills it and grows
out as a large horn-like sclerotium. The sclerotium of the oak
{Sderotinia Batschiana) completely replaces the acorn, leaving
only the outer covering enclosing it. Likewise, in the mummified
berries of bilberry, cowberry, crowberry, cranberry, and others,
one finds the normal parts almost wholly replaced by the
resting-mycelium of some species of Sderotinia.

Formation of new Organs.

Although parasitic fungi commonly induce hypertrophy of
existent organs and development of normal latent structures,
they are seldom associated with formation of new organs. As
such, however, we must regard the formation of adventitious
buds on the fronds of Ptcris qv.adriaurita, Pietz, and Aspidium
aristatum, Sw., under the influence of Taphrina Laurenda,
and T. Cornu cervi, respectively.^ Buds or bulbils of this
kind occur normally on several species of ferns ; but in those
just mentioned they appear only as a result of the parasite, and
develop into structures reminding one of a witches' broom.

1 Giesenhawen, Flora, 1892.

30

REACTION OF HOST TO PARASITIC ATTA<JK.

Still more striking are certain structures resembling witches'
brooms, which are produced on Thujopsis dolahrata in Japan, under
the influence of the mycelium of Cdeoirui deformans (Fig. 8).
These consist of leafless non-chlorophyllous axes, dichotomously
branched, and with each branch ending in a disc. They arise
from shoots or leaves of the Thujopsis where structures of the
kind would never have arisen normally, and are wholly sub-
servient to the reproduction of the fungus, which forms its
sori under the epidermis of the terminal discs.

Fig. 8. Caeoma deformans. The nest-like structures are much-branched,
leafless shoots with each of their twigs ending in a caeoma-disc. (v. Tubeuf
phot.)

The galls produced by Ustilnr/o Trcuhii on Polyfjonum Saccha-
linensc are particularly interesting. Here, as a result of the
presence of the parasite, there are formed the so-called vegetative
canker-galls, and in addition, the fruit-galls, new organs derived
from lateral outgrowths of the host-plant, and of use only
in the spore-formation of the Ustilago; they contain a special
capillitium-like tissue, and serve exclusively for the shelter and
distribution of the fungus-spores.

EFFECT OF PARASITIC FUNGI ON THE FORM OF HOST-PLANT. 31

Somewhat doubtful cases are the outgrowths resembliiig aerial
roots which arise on Zaicrvs canariensis attacked by Ewhasidium
lauri. Geyler, their discoverer, regarded them as deformed stem-
shoots, but they resemble rather the galls of the alpine-rose.

§ 6. EFFECT OF PARASITIC FUNGI OX CELL-CONTENTS.

The most common and, at the same time, most apparent
effect of parasitic fungi in this direction, is the stimulation to
cell-division and cell-multiplication. This occurs chiefly in
young tissues, or in those still in process of growth, and gives
rise to numerous peculiar outgrowths and swellings, some of
which have already been referred to.

The parenchyma of mature tissues may also exhibit secondary
cell-division, when under the influence of a parasitic fungus.
This I found to be the case in leaf-
petioles of Umbellifera; attacked by
Protomyccs macrosporus (Fig. 9). The
epidermis and vascular bundles are never
disturbed, but the intervening tissues are
permeated by an intercellular mycelium,
which causes the cells to divide into a
large number of delicate-walled chambers,

° . . . Fig. 9. — Secondary cell-division

all containing nuclei smaller than those in parenchyma of petiole of ^er/o-

. - . . - , , podium as a result of Prototiiyces

of neighbouring undivided cells. The macrosporus. The nuclei of the

. new cells are much smaller than

same thing is observed in plants of those of the primary ceii. (Com-

jr- 1 } , ■ V. 1 -f 1 K rr ,■ P«r«Fi?-^'-) (V. Tubeuf del.)

ytola odorafa inhabited by urocijstis

violae ; the mature parenchymatous cells become divided up
by means of delicate walls running in various directions into
numerous chambers or secondary cells, which Wakker in
describing has named "nutritive tissue."^ This new tissue
remains permanently in attacks of Protomijces, but with Uro-
cystis it is almost completely used up during the formation
of spores. In some diseases caused by Exoasceae, a similar
secondary cell-division takes place ; for example, in the sub-
epidermal parenchyma of leaves of poplar with Taphrina
aurca (Fig. 63).

An interesting observation was made by Eosen - on the direct

^Wakker, " Untersuchungen. " Pringsheiyn's Jahrhurh, 1892.

2 Rosen, Beifrdge z. Kenntiiiss d. Pflanzenzelle. Habil.-Schrift, 1892.

32 REACTION OF HOST TO PARASITIC ATTACK.

effect of haustoria of Uredineae on the cell-nucleus. He describes
it thus : " The mycelium of Fucciriia asarina permeates between
the cells of the leaf-tissue of Asaruni, and sends into almost
every cell of the infected part, a short, sometimes branched,
hypha, which serves as a haustorium. This grows in almost
every case towards the nucleus of the host-cell, and becomes
firmly attached thereto, or completely encloses it. The nucleus,
in consequence, undergoes considerable deformation, sometimes
being tightly constricted by the haustorium, or the apex of
the hypha penetrates deep into the nucleus, pushing the nuclear
membrane before it."

Enlargement of the cell-nucleus occurs, according to Frank,
in the cells of the root-tubercles of Leguminosae caused by
bacteria; likewise in the cells of endotrophic mycorhiza of
orchids. Schlicht,^ in considering the endotrophic mycorhiza of
Paris quadrifolia, says, " One observes here, as in the mycorhiza
of the Orchideae, that the cell-nucleus, which is very large, can
exist in the cell beside the fungus-tissue. The hyphae, however,
frequently penetrate into the cell-nucleus, or surround it in
a close network." 2

The effect of parasitic fungi on the chlorophyll of tissues
attacked by them is very varied. We may distinguish three
cases, apart from those in which the parasite kills the host-cell
and its chlorophyll along with it. In the first, the green parts
of the plant attacked become bleached by the influence of the
parasite, and ultimately lose their green colour ; this we might
designate " mycetogenous chlorosis." Examples are the galls
of cowberry and species of rhododendron, the results of many
Uredineae, such as Chrysomyxa rhododciulri on spruce, Accidium
urticae on nettle, Gymnosporanrjium davariacformc on hawthorn,
and the leaf-galls due to Exoasceae.

In the second case, there is a preservation of the chlorophyll
in places infested by the fungus, in contrast to adjoining normal

iSchlieht. "Beitriigez. Kenntniss d. Verbreitung u. Bedeutung d. Mycorhizen."
Inaug. Diss. 1889, p. 14.

-Groom ("■ Thismia Aseroe and its Mycorhiza," Annals of Botany, June,
1895, p. 339) describes and figures a similar case. He says, "Tlie fungus
enters the cell as a single slender hypha, which at once grows directly towards
the nucleus of the host-cell." He also mentions an observation of Professor
Marshall Ward, "that in HemUeia of the coffee disease, the haustoria often apply
themselves to the nuclei of the host's cells." (Edit.).

EFFECT OF PARASITIC FUNGI ON CELL-CONTENTS. 33

parts, which become pale and die. This is exemplified in
Cronartium asdepiadeum on the leaves of ViTicetoxium, Gym-
nosporangivni davariacfonne on the quince, Uncinvla aceris on
the Xorway maple, Rhytisma fundatum on Acer spicatum.

Intermediate between these two extremes are cases where
the chlorophyll is retained, but in much reduced quantity. For
example, organs under the influence of Ejioascus alni incanac or
Aecidium elatinum, though still green, are pale in contrast to
those normally deep green; leaves attacked by Peronosporeae, e.g.
Corydalis or Anemone with Flamwpora pygmaea, and Anemone
with Aeeidium punctatum or Pvccinia fuscci: leaves of Cirsium
containing mycelium of Pnccinla siiaveolens ; leaves of alder
with U'oascus epiphyllvs, and many others. This paler coloura-
tion of diseased plants is frequently an easy means of recognizing
them amongst the healthy ones.

The third case is that of " mycetogenous chloranthy " or the
development of green colour in organs normally of some other
colour. Wakker has proved this in the petals and stamens of
Brassiea nigra and Sisymbrium pcinnonicum attacked l3y Cystojms
and Feronospora. Likewise Magnus showed its existence in
flowers of Anemone ranunculoides with Aecidium piunctcdum.

The cell-sap, in some cases of hypertrophy, assumes on the
sunny side a rose colour ; thus in galls caused by B-wbasidiuni
on alpine-rose and cowberry, pear-leaves with Foestelia cancdlata
and Polystigma rubnim, catkins of alder attacked by Exoascv.s,
and galls caused by Taphrina ccirnca on the sweet birch. The
epidermal galls, due to some species of Synchytrium {S. ruhro-
cinctum, S. anemones, etc.), exhibit an intense carmine coloui.
Yellow coloration occurs, according to Wakker, in nettle, buck-
thorn, and many plants when frequented by Uredineae. There
may also be a yellow colour due to the yellow oily contents
of the mycelium shining through the host-tissues, as in spruce-
needles with Chrysomyxa ahictis.

In considering the effect of parasitic fungi on the starch-
contents of the host-plant, two very distinct cases may be
observed. There may be, for a time, a greater accumulation
of starch in the attacked parts than in the normal, or the
parasite may dissolve any starch present and utilize it at once.

34

REACTION OF HOST TO PARASITIC ATTACK.

Acciiiaulation of starch is described by 11. Hartig ^ in spruce-
needles attacked by Laphodcrmium macrospornm. In the pre-
sence of the fungus-mycelium, an increased production and
storage of starch takes place at a time when it is being only
slowly formed in normal needles. If the needles become diseased
during May, a season when they are already full of starch,
this remains intact in the dead cells till October, when it begins
to be used up.

Wakker observed accumulation of starch in comfrey with
Aeculium aspcri/olii, in buckthorn with Accidium rhamni, in
hawthorn with Iloestelia lacerata, in Sisymhrium officiyiale and
other plants with Cystopus, in roots of Brassica inhabited by
Plasmodiophora hrassicae, and in hypertrophied scales of alder
catkins with Exoascus. Many other examples are given through-
out the literature of plant-pathology.

Particularly noteworthy is a case of starch preservation in
oak-wood destroyed by Polyporus dryadcus and P. igniarius
simultaneously."^ In the wood infested by
either of the fungi alone the starch is dis-
solved, but at the boundary where the two
meet it remains in the medullary rays ;
these, in consequence, appear snowy white,
and consist almost exclusively of unchanged
starch-grains, while the lignified cell-walls
have been converted into cellulose or com-
pletely absorbed (Fig. 10). Loew ^ remarks in
regard to this : " One must assume here a
variation in the kinds of diastase, and a
neutralizing effect of the one on the other,
in somewhat the same manner as pepsin acts
on tyrosin. One is also reminded of two
optical antipodes which easily unite into an
«f^oak-wo7dSroyed''by Optically ncutral body " {rjj. sugar isomers).
ftiirfuir''of'^™ The dissolution of starch by fungi has

(1"Tubeu7rho?r'"''"" been examined in detail by Hartig. The
wood-destroying fungi dissolve the reserve
starch-grains laid up in the wood-parenchyma in various ways.
Assuming the view of Naegeli, that starch-grains consist of a

1 Wkliti(/e Krankheiten d. Waldbdumen, 187-4.

-R. Hartig, Zersetziingserscheimimjen, 1878.

•■•Loew, O., Ein naturliches System d. Gift-Wirkungen. Munich, 189.3.

EFFECT OF PARASITIC FUNGI ON CELL-(;ONTENTS.

35

cellulose and a granulose part, Hartig describes the process thus
(Fig, 11). The mycelium of species like Polyijorits igniarius
gives oft' some ferment which dissolves the starch-grains, by cor-
roding them from the outside inwards, so as to form holes and
canals similar to those in
starch-grains in process of
dissolution in the cells of a
sprouting potato. In others,
c.ij. Thdqihora pcrdie, the
granulose is first dissolved
from without inwards, so that
finally only the starch-cellulose
remains, occupying a region ^^^ n.-staroh grains from the oak, m pro-

tnwavrla thi:^ nntor i-iQvt-o r>f cess of dissolution by ferments, o, of T/it/c/V.ora

tOWaraS Cnc outer parts Ol i,-;,,.ui.c ■ l,, oi Polr/porus sulplmreus ; c, of Poly-

thp (fVQin no n l-inrl <-.f ImoV j'orM i(/niarius. In a and b the iodine-reaction

Llie gldUl as a kina OI nUSK, Is shown by shading. (After R. Hartig.)

which is in time gradually

used up. In Polyporus sidphurcus the operation is reversed ;
the starch-cellulose appears to be dissolved out first, leaving
a residue of granulose. These observations were based on
the assumption that the starch-grain consisted of a granu-
lose portion wliich turned blue with iodine, and a starch-
cellulose portion which became yellow ; or again, on treating
the starch-grains with dilute acids the granulose was dissolved,
while the cellulose remained in the form of a skeleton.
Although more recent investigations have shown that the
cellulose-skeleton results from the action of the acids, and that
this view of the constitution of the starch- grain was not quite
correct, yet Hartig's observations prove that tlie various fungus-
ferments have each their own action on starch-grains ; his
results are also supported by other facts.

Other fungi besides Polyporeae utilize the starch of their
host-plants, thus Phytophtliora in leaves of the potato.

The formation of calcium oxalate is influenced by action of
parasites. From Wakker's synopsis of the phenomena of hyper-
trophy, we find that calcium oxalate normally present in crystal-
sacs in leaves and flowers of Rhamiius Frangida, is wanting in
parts deformed by Acculiivm rliamni ; crystal-sacs are less
abundant in diseased stems than in healthy ; the calcium oxalate
in galls of Erobasidium is not present in crystal-sacs, as in the
non-deformed organs, but as ill-defined solitary crystals of limited

36 REACTION OF HOST TO PARASITIC AITACK.

number ; on the other hand, crystal-sacs, normally absent, are,
under the influence of E.wascus alni incaimc, formed in hyper-
trophied catkin-scales of alder.

It may be here observed that calcium oxalate crystals are foinid in the
mycelium of many fungi. De Bary' found them very common, particularly
in the mycelium of species of Botn/tis, and he remarks thereon : " it ma}'
well be assumed that the oxalic acid is formed from the sugar inside tiie
living oxygen-absorbing fungus-cell, but is immediately ejected therefrom
by the carbon dioxide produced in respiration ; in other words, an oxida-
tion-fermentation takes place in the plasma of the mycelium. The oxalic
acid is probably separated in combination with potassium and converted
into calcium oxalate, when calcium is present in the pabulum of the
mvtelium.''

j; 7. EFFECT OF PARASITIC FUNGI OX THE CELL-WALT..

The effect of the mycelial hyphae of parasitic fungi on the
cell-wall may be either mechanical or chemical. The intra-
cellular hyphae of fungi and the apices of the haustoria of
intercellular fungi must penetrate through the cell-walls of their
host, either of the epidermis, or the membranes of other cells,
consisting of cellulose alone, or in some state of lignification.-

The membranes may be simply pricked, as Ijy a fine needle,
so that the opening, because of the elasticity of the cellulose,
closes up again after the perforating hypha has died. This
is the case with many Uredineae. In such cases the hypha is
constricted in passing through the cell-wall and swells out again
in the free cell-cavity. Frequently, as in the case of Prrono-
spora (lensa, the haustorium will only cause a depression in the
membrane of the cell without penetrating it.

In addition to purely mechanical perforation of the mem-
brane, the effect of the hyphae may also be a chemical one, so
that the wall is dissolved and the holes produced remain long
after the hyphae which made them have disappeared. This
solvent effect is probably always present in cases where per-
foration of lignified membranes takes place. It is a constant

1 De Bary. Botan. Zeitun;/, 18S6.

2 De Bary. Biology and Morphology of the Fungi. English Edition.
H. M. Ward. " On a lily-disease," Ann ah of Botany, 1888.

Miyoshi. " Die Durchbohrung v. Membranen durch Pilze." 'Pringsheim's
Jahrbuch, Vol. 28, 1895.

EFFECT OF PARASITIC FUNGI ON THE CELL-WALL. 37

accompaniment of the attacks of wood-destroying fungi on the
woody parts of trees and shrubs. Besides actual perforation
of the lignified membranes of their host, the hyphae of many
of the Polyporeae and Agaricini exert a solvent effect on the
walls, which extends over a considerable area, and is evidently
due to the excretion of some ferment. The dissolution of the
walls takes place, moreover, in a way sf) characteristic for each
species of fungus that they can be determined by it alone. From
this it must be deduced that each wood-destroying fungus
excretes a ferment peculiar to itself, which causes a character-
istic dissolution of the host. Our present sources of informa-
tion on these points are the very valuable investigations of
Professor Piobert Hartig of Munich. ^ Some of his results will
repay our careful consideration, but we must preface briefly
some facts regarding the process of lignification and the forma-
tion of heart-wood in our forest-trees.

The elements of the wood of dicotyledonous trees and woody
plants are derived from the cambium ; their walls consist at
first of pure cellulose, and when lignification takes place the
so-called incrusting substances are laid down in the thickened
cellulose wall, particularly coniferin, vanillin, wood-gum, tannin,
etc. ; or as they may be collectively called, lignin. The cellulose
membrane itself is coloured lilac with chlor-zinc-iodine ; when
lignified it no longer shows this reaction, but has others peculiar
to itself, the best known being red coloration on treatment
with phloroglucin and hydrochloric acid, or yellow coloration
with aniline sulphate ; chlor-zinc-iodine colours lignified tissues
brownish-yellow. Copper-ammonium-hydrate dissolves cellulose
but not wood.^ If the incrusting substances be removed from
the lignified membranes by treatment with Schulze's solution,
caustic soda, or other solvent, the cellulose remains and reacts
as such. In the process of conversion of alburnum into dura-

' The most important of these works are :

Die ZcrsktziuKjsi'rsche.hiunfitu d. Hohei d. Xadelhoher u. d. Eiche. With 21
coloured plates. Springer, Berlin, 1S7S.

Der echte Hausschicamm, Meridius lac/tryman-s, 1885.

Wichtir/e Kranl-heiten d. Waldhduma, 1874.

Lehrbnch d. Baumkrankheitm, I. and II. Edition, 1882 and 1889. English
translation of II. Edit, by Prof. W. Somerville.

Lehrhuch d. Anatomit u. Physiolotjie d. Pjianzen, 1891.
- For further reactions see :

Zimmermann. Die bofauische Microtechnik. 1892.

Strasburger. Das bofanische Praktikum, 1887. English Edition, 1889.

38

REACTION OK HOST TO I'AIIASITIC ATTACK.

men otlier substances make their appearance in the ligiiified
walls, chiefly tinctorial phlol)aphenes.

Tlie walls of the wood-elements are, however, not lignitied
to the same extent. The primary layer of the wall is, as a
rule, lignified most and contains but little cellulose. In con-
sequence, on treatment with lignin-solvents, it becomes first
dissolved while the secondary and tertiary membranes, although
their lignin is also partially dissolved out, remain behind as a
distinct framework of cellulose. AVith longer treatment destruc-
tion of the tissue proceeds till only the pure cellulose membi-anes
of the isolated cells remain. The ferments of many fungi act
in this way ; for example Tramctes 2nni, as shown in Fig. 1 2 ;
at a the wall is in its normal condition, showing a primary

Fio. 12. — Section of tracheides of pine-wood in process of dissolution by the
feiinent of Trnmeles innl. ^\^. (After R. Hartig.)

wall and two striated secondary membranes ; at h the fungus-
ferment has caused a splitting of the primary wall, which
formerly appeared as a single layer, and the elements are
separating from each other ; the " filling-material " of the inter-
cellular spaces (under c), and the ring of lime surrounding the
cavity of the pit d, remain for a longer time ; the right wall
of the cell h consists only of cellulose, (as indicated by the
striation being no longer shown, although still present) ; in
the cell <' the primary wall has disappeared, and the secondary
and tertiary membranes thin off towards / in which only
the ash constituents remain as fine granules, better seen in
Fig. 13.

In contrast to the lignin-dissolving fungi, there are those
which dissolve cellulose. When wood is treated with sulphuric

EFFECT OF PARASITIC FUNGI ON THE CELL-WALL.

39

acid the cellulose is dissolved out, and the primary wall remains
almost intact, while the secondary after swelling is converted
into sugar and gum. Certain fungi {e.g. Polyporvs vajwrcnHn.s,
P. Schv;cinitzii and P. svlphnmifi), act in the same manner,
first dissolving out and consuming the cellulose before attacking
the wood-gum. When wood is destroyed by fungi of this

Fig. 13.

Fig. 14.

Fio. 13. — Tracheid of Pinus si/lvestris destroyed by Trametes pint. The primary
cell-Wall is completely dissolved from below upwards to a, a ; 6, secondary and
tertiary layers of the walls consisting in the under portion of cellulose only, in
wliich granules of chalk are recoffnizable ; c, fungus-hyphae boring through the
walls, leaving holes d and c. (After R. Hartig.)

Fig. 14. — Tracheid of Pinus destroyed by Polyporui Schweiiiitzii. The cellulose
has been extracted, and the wall consists only of wood-gum. The fissures are a
result of drying-up, but they do not extend into the primary wall a, h. Crossing
of the fissures takes place at the bordered pits c, and at the bore-holes d and e ;
/, simple fissures. (After R. Hartig.)

kind, the primary wall, containing but little cellulo.se, is hardly
affected, and the secondary membranes shrink together, so that
numerous fissures are produced running in a spiral direction,
corresponding with that of the stratification (Figs. 13 and 14.)
The tertiary membrane varies in its nature ; it may consist of
pure cellulose or be more or less lignified, or even cuticularized.
In the wood-fibres of some plants {Cytisus, Hamulus,) this

40 REACTION OK HOST TO PARASITIC ATTACK.

layer becomes normally loosened from the other membranes, and
appears as a separate tube in the cavity of the fibre.

Variations of this kind in the structure of the wood must of
course influence the action of the attacking fungus. The decay
may be a local one, as with Tramek.s pini, T. radicvpcrda,
Thelcphora pcrdix, which cause destruction of isolated spots
only and produce holes here and there throughout the wood.
On the other hand, the wood may be uniformly converted into
H discoloured decayed mass. The walls may Ije simply pierced
by little holes corresponding to the perforating hypha, or large
portions of them may be more or less completely dissolved
away, and either the cellulose or lignin remain behind as a
skeleton. Hartig gives an interesting case which accompanies
dry-rot {Mcrulius lacrymmis): the mycelium adherent to the
cell-walls dissolves out the lime granules included in the mem-
branes by the excretion of some fluid containing carbonic (or
other weak) acid, in much the same way as roots corrode
limestone.

The dissolution of starch in wood has already been considered.

In conclusion should be mentioned Hartig's observation
that normal spruce wood, on treatment with ferric chloride,
the reagent for tarmin, gives no coloration, such as is given
by the same wood when destroyed by dry-rot.

§ 8. EFFECTS OF PARASITIC FUNGI ON THE ANATOMICAL
STRUCTURE OF THEIR HOSTS.

Effects of this kind can only be looked for where mor-
phological changes have resulted from the presence of parasitic
fungi, particularly in the case of hypertrophied organs. Wakker^
was the first to collect recorded evidence of anatomical changes
due to hypertrophy ; he added to these by his own investi-
gations, and classified the results. We shall therefore in this
division depend chiefly on his publications.

Enlargement of host-cells is one of the most frequent pheno-
mena accompanying attacks of parasitic fungi. It may take
place with both intracellular and extracellular parasites.

A single cell hypertrophied in this way is the simplest
possible form of a "fungus-gall" (see p. 25). Examples of

'Wakker, PriiKjsheim' s Jahrbiich, 1892.

EFFECTS OF PARASITIC FUNGI ON TISSUES OF HOST. 41

simple galls of this kind are cells of Filohulus Klcinii inhabited
by Pleotrachelus fulgens, cells of turnip infested by Plasmodio-
phora, or of dandelion with Sijnchjjtriurn.

Cell-enlargement resulting from the influence of extracellular
parasites is most distinctly seen in those algal cells, which
form lichens with the hyphae of certain fungi. Thus according
to Stahl, the algal cells of the lichen Endocarpon ^j^/.s?7/?(?7i
become enlarged six-fold.

Cell-enlargement accompanies all hypertrophy of plant organs,
whether the parasite lives purely intercellular, or has haustoria.
At the same time one generally finds a disappearance of the
intercellular spaces present in the normal tissues ; in some
special cases, however, these may become more numerous and
larger. Cell-enlargement, accompanied by disappearance of
normal intercellular spaces and chlorophyll, are shown by
Woronin's illustrations to be very marked in the galls on cow-
berry, due to Exobasidium vaccinii. Cell-enlargement is also
frequent in cases of hypertrophy due to Exoasceae ; thus in
Taphrina av.rea, although the mycelium is only subcuticular
or penetrates but slightly into the epidermal layer, yet the
cells are much enlarged and their walls are strikingly thickened
(Fig. 63). Smith ^ found that when leaves became thickened
in consequence of attacks of certain species of Taphrina, tlieir
cells became larger and rounder, so that the large intercellular
spaces of the spongy parenchyma disappeared and the char-
acteristic appearance of that tissue was lost.

The epidermis, as has already been indicated, is influenced
by fungi which live between the cuticle and cell-wall, as well
as by epiphytic fungi, whose haustoria penetrate it. The
epidermis is, however, more frequently destroyed by endophytes,
which rupture it in forming their reproductive organs. Some
of these produce their sporocarps inside the epidermal cells,
and, as they enlarge, cause detachment of the outer walls of
the cells from the remainder, to form for a time a covering
which is ultimately ruptured as the sporocarps attain maturity.
Where the fungi live under the cuticle (e.g. the Exoasceae),
this alone is ruptured when the asci are formed. The repro-

MVilliam G. Smith. " Untersuchung d. Morphologic u. Anatomie d. clurch
Exoasceen verursachten Deformationen." Inaiig. Dissertation, Munich, 1894;
also, For.stlich-iiaturwi.ss. Zeitschrift , 1894.

42 RKACTION OF HOST TO PARASITIC: ATTACK.

ductive inyceliuni of the following forms also grows only under
the cuticle : Rhytisma andromedac, the spermogonial mycelium
of Puccinia anemones, Fhragmidivm, and other Uredineae.

In many cases of hypertrophy the epidermal cells become
enlarged in a radial direction, and this, as in Taphrina aurea,
may be accompanied by considerable thickening of the walls.
In other cases, like that produced by Si/nrhi/fnuvi, the epidermal
cells may become gelatinous.

• The cork becomes abnormally increased in many examples of
hypertrophy. Thus in witches' broom of alder due to F.roasc/'s
qnphyUua a phelloderm is formed, while on normal twigs phellem
alone is produced. Cork is found in juniper needles with
(ri/mnosjjoraiu/iiim jvniperinum, though never in the normal needles.
On the other hand, cork-formation is suppressed in twigs of
hawthorn, deformed by Rocstelia lacrrata. The so-called "wound-
cork" is constantly associated with attacks of parasitic fungi ; it
separates diseased portions of rind and Imst from sound, forms
sheaths round bundles of sclerenchyma, and permeates the
medullary rays.

Collenchyma was found by Wakker to be absent in all cases
of hypertrophy of parts of plants where it is normally present ;
for example, in stems and petioles of cowberry attacked by
Exobasidium, stems of buckthorn with Aecidium rhamni, of
Crataegus with Rocstelia. lacerata, of nettle with Aecidium urticae,
and of Sawfuisorhia with Xenodochus carhonarius. On stalks of
Umbelliferae with pustules of Protomyces, I found, where the
collenchyma region was involved, that that tissue was not
developed (Fig. 46),

In all cases of hypertrophy, parenchyma plays an important
part. Most abnormal outgrowths result from multiplication and
enlargement of the cells of the parenchyma, the formation of
mechanical tissues being more or less suppressed. Thus the
gigantic examples of hypertrophy exhibited by turnips infested
by P]asmodiop)hora, consist almost exclusively of parenchyma.
Thickening of stems or branches is generally due to increase
of the rind-parenchyma, as in buckthorn under influence of
Aecidium rhamni, hawthorn with Gymnosporangium davariae-
formc, in most witches' brooms, and in many other cases. In

EFFECTS OF PARASITIC FUNGI ON TISSUES OF HOST. 43

the witches' brooms due to Accidium clatinum, the pith appears
enlarged as the result of increase of the medullary parenchyma.
In diseased leaves, i>alisade parenchyma can frec^uently no longer
be distinguished from spongy, and only irregular polygonal cells
are formed. As examples may be given needles of tir with
Accidium ahietinum, and leaves with galls due to Exoasceae.
Finally, there may be a marked increase of wood-pareijchyma,
both of medullary rays and the wood proper ; this is especially
well marked in Jvnipcrus communis affected by Chjmnos'porcmgiuvi
junipcrinum} where in consequence of an enormous increase of
the parenchyma of rind and medullary rays, the tracheidal
regions become separated by broad wedge-shaped rays, and at the
same time they are peripherally intersected by bands of paren-
chymatous tissue resulting from increased development of the
wood-parenchyma (Fig. 220, etc.).

The Sclerenchyma is generally suppressed where hypertrophy
occurs. Examples mentioned by Wakker are stems of cowberry
with Exohasidium, of hawthorn with (jrijmnosporangiutn, of
Sanguisorhia with Xenodockiis, and alder catkin-scales with
Exoascus. On the other hand, sclerenchyma is developed in
stems of Cirsium as a residt of Puccinia suaveolens, whereas
normally it is absent.

The secondary vessels of the wood frequently remain irregular,
and with imperfectly absorbed partition-walls. According to
Wakker, this is the case in Vaccinium with Exohamlivm,
Crataegus with Rocstclia, and Rhammi.s with Accidium.

Suppression of interfascicular cambium- was observed by
Wakker in buckthorn and nettle with their respective Aecidium
parasites. Prolonged activity of the same tissue he found in
Sisymhriam with Cystopus.

Arrest of lignification was found by Wakker in medullary rays
of Crataegus with Eoestclia, and in deformed scales of alder
catkins affected by Exoascus.

We have already considered increased growth in length and
thickness in connection with hypertrophy. It need only be
added that increased thickness of woody plants may be due to
increase of the rind, the bast, the pith, or medullary rays, and not

^ P. Wornle. " .Anatomische Untersuchung d. durcli Gymnosporangiuni-Arten
hervorgei'ufenen Missbildungen. " Inaixg. Diss., Miiiichen, 1894 ; also, ForstUch-
nafnnniss. Zeit-schrift, 1894.

44

REACTION OF HOST TO PARASITIC A'lTACK.

to increase in the actual wood elements. This is the case in
twigs of silver fir witches* brooms, in young swellings of juniper
attacked by fTi/mnoxporaiujiiini, and in the thickened twigs of
Alhizzia resulting from Uromyecs Tcp'pcrianiia (Fig. 181). There
may be, however, a distinctly increased growth of the wood.
Thus, with attacks of Gymno^'porangmm frequenting juniper,
especially G. mhinae, there is often a marked thickening of
branches due to increase in the xylem-elements. Again, one
finds cankers due to Aecidium elatinum, accompanied by stem-
swellings with a diameter twice or three times that of the
normal, and in which the bark and bast form but a thin layer
in proportion to the part made up by the wood. Exceptionally
striking are the gigantic woody knots formed on the Japanese

Pinus dcnsijiora, and P.
Thunbergii affected by Peri-
dcrmium gifjantcvtii (Fig.
15).

Wakker found that mu-
cilage canals of Rhamnua
Franyida affected by Aeci-
dium were not so well
developed as in normal
twigs.

IJesin-canals are often
irregularly formed and ab-

FK!. 13.—

at this

(V. Tnbeuf phot.)

13. — Wood-swelling on i'irtu^ (?c/isir?o/(t, attacked normally multiplied ill con-
place by Periderraium giganlev.m. J natural size. " *•

beuf phot.) sequence of parasites. The

(On Pmits r/iiuiterpustilllargerexaniples may occur.) ^ ^

resin-canals of the spruce
were found by Hartig to be so numerous in plants attacked by
Atjaricas melleus that an abnormal quantity of resin is produced
in the wood, and flows from the diseased roots ; hence has
arisen the name " resin-glut " or " resin-flux " by which the
disease has long been known. A particularly noticeable flux of
resin takes place from pine-bark in presence of Pcridcrmium
pini ; the mycelium grows in the medullary rays and resin-
canals, causing an excretion of resin from all living parenchyma
in the wood, so that both bast and wood become completely
impregnated with resin, and thin sections of wood transmit a
rose-coloured li^ht.

CHAPTER III.
KELATION OF PARASITE TO SUBSTRATUM.

§ 9. EFFECT OF THE SUBSTRATUM ON THE DEVELOPMENT
OF THE PARASITE.

A NUMBER of parasitic fungi live only on one species of
host. For example Sclcrotinia haccantm on Vaccinium Myrtillus,
Chrysomyxa ahietis on Picea excelsa, Triphragmmm ulmariae on
Sinraea ulmaria, Hysterium nervisequitmi on Abies pectinata,
Rhytisma androuudae on Andromeda yolifolia. De Bary^ proposed
for cases like this the term monoxeny, while to cases in which a
parasite frequents several different species of host he gave the
name polyxeny, or more particularly, dixeny, trixeny, etc. As
examples of polyxeny may be mentioned Rhytisma scdicinum
found on all species of willow, and Rhytisma aceriniim on the
genus Acer. Other parasites attack not only difierent species
of some genus, but also different genera ; thus, Pv.ccinia graminis
occurs on various cereals and grasses, Phytophthora omnivora
on many different plants, Phyllactinia suffulta on leaves of
Corylv.s, Fag us, and many other trees ; Clavice2)s 2^'^^''Wrea on a
large number of cereals and grasses, Cystoinis candidus on many
Cruciferae, and Ncctria cinnaharina on all kinds of broad-leaved
trees.

Monoxeny and polyxeny must be carefully distinguished from
the autoecism and heteroecism of the Uredineae. Many species
of this group go through their whole life-liistory, and produce
all their forms of spore on the same host, others, however, pro-
duce some forms of spore — spermatia and aecidiospores — on one
host, and the remainder — uredospores and teleutospores — on
1 Bofanische Zeitung, 1867, p. 264.

46 IIKLATION OF PARASITK TO SUBSTRATUM.

another host. Such heteroecious parasites may be, however, also
monoxeiious ; for example, Mclamjjsora Goeppertiana has its
teleutospore-form only on the cowberry, its aecidiuni-form
only on the silver fir. On the other hand, Chrysomyxa
rhododcndri frequents several species of Rhododendron, while
the aecidia occur only on Picca cccelsa ; Cronartiuni nsclcpiadeum
comes on both Gentiana and Cynanchum, the aecidial stage
only on Pinus sylvestris. With Gymnosporanyium clavariaeforrnc
this condition is reversed, the teleutospore-form occurs only on
Jimipcrus covwmniH, the aecidial on various species of Crataegits
and other genera.

The effect of various substrata on the development of any
fungus may l)e most conveniently investigated : {a) on facul-
tative parasites and saprophytes, (6) on polyxenous species of
fun<^i, (c) in cases where the fungus inhabits essentially different
organs or tissues of the same host.

The most obvious effect of the substratum is presented during
the germination of spores. The spores of most parasites ger-
minate in water. Those of certain smut-fungi, especially in
the fresli condition, will not germinate at all, or only to
a very limited extent in water, whereas they will do so
immediately and unanimously on being offered a nutritive
solution. Tilletia, a genus of Ustilagineae, behaves, however,
in quite the reverse way, it germinates only in water, and
refuses to do so in nutritive solutions. Hartig found that the
spores of dry-rot (Mcridius) would neither germinate in water
nor in the usual nutritive solutions, but that they did so at
once on adding alkalies to the water, such as those supplied
by addition of urine. Very characteristic is the behaviour
of these spores, which only germinate in contact with their
host-plants, like many Chytridieae ^ (Synchytrmm), as well as
Complctoria and Protomyccs? Others again send out germ-tubes
which remain small and soon die away if an immediate
opportunity of penetration into a host is not presented. De
Bary states this to be the case with swarm-spores of Cystopus,
Pcronospora nivca, Erysipheae, etc. Amongst the Uredineae, the
germ-tubes are short-lived ; they will penetrate into almost any

' De Bary, Morphology and Biology of the Fiiiuji, chap. vii.

"-' An exactly parallel case is presented by the seed of Orobaucheae, which
germinate only in contact with the roots of their host (Koch's "Orobanchen,"
Heidelberg, 1887).

EFFECT OF SUBSTRATUM ON DEVELOPMENT OF FARASTfE. 47

host, but soon die off, if it be not a suitable one. De Baiy
also observed a germ-tube of Peronospora pygmaea, which
frequents Anemone, making its way into Banimculus Ficaria,
but soon to die. Germinating spores of Cystcrpus canduhis will
enter the stomata on leaves of any of their host-plants, especially
Ccqosella, but will only develop further if they are successful
in penetrating into the cotyledons.

Variation in the substratum produces very great difference in
the formation of the reproductive organs. Thus many Ustila-
gineae produce conidia by continuous sprouting only when
cultivated in nutritive solutions, while their resting-spores are
developed only from a mycelium which inhabits the reproductive
organs of their host ; this is the case with Ustilayo caricis,
U. anthearum, and U. tritici. In others the spores are found in
all parts of the flower, and even in the inflorescence, as in
Ustilayo crucnta and U. trayopugonis, while in Ustilayo maydis
spores are also produced in leaves and stems.

The various parts of the same plant behave very differently in
this respect. The Ustilagineae just considered reproduce them-
selves only on certain organs of their host, although the
mycelium is also present in other organs. Other fungi behaving
similarly are Epiclilo'e typhina which produces its perithecia only
on the surface of the sheath of one of the leaves just below the
inflorescence ; Aecidium elatinum develops its aecidia only on
the needles of the witches' broom ; Aecidium euphorhiac has its
aecidia only on the leaves of its host ; JExoascus pruni has asci
only on the fruit ; Cedyptospora produces teleutospores in the
epidermal cells of the stem, never of the leaves ; and so on in
many other cases.

The formation of oogonia of Cydopua exhibits a striking vari-
ation according to the host-plant. Cystojnis candidus on Capsclla
produces conidia alone, never oogonia ; yet the latter are plenti-
fully developed in flowers of Brnssica, being confined, however, to
the flowers, while conidia are produced in all parts. Cysto2nis
hliti forms conidia only in the leaves, and oogonia only in the
stems of AmarantluLS hliturn}

The mycelium of many other fungi can only grow in certain
organs, while germ-tubes from the spores are only able to pene-
trate into certain parts of the host. Thus, Kronscus alni incanae
1 De Bary, Morphology and Biology of the Fungi, English Edition, p. 391.

48 RELATION OF PARASITE TO SUBSTRATUM.

has a mycelium only in catkin- scales ; E.i:oascus p7'nni, however,
hibernates in the twigs, and forms reproductive organs only in
the walls of the ovary ; Aeciclium struhilinum grows only on the
cone-scales of spruce; Claviceps frequents only the young ovaries
of cereals and grasses ; and so on, other fungi inhabit only leaf,
stem, root, or flower.

In this connection points of considerable interest are presented
b,y the behaviour of many Uredineae hitherto little investi-
gated. As was pointed out by De Bary, the germ-tubes
produced from both uredospores and aecidiospores (in Puccinia
dianthi those from sporidia also), penetrate into the stomal a
of any phanerogamous plant. If, however, that should not be
a host-plant of the fungus in question, then the germ-tubes
die away in the stomatal air-cavity. If the host suits the
fungus only in a limited degree, then no hypertrophy will
result, and the latter will attain only to the formation of spermo-
gonia. Let the host, however, be the one best suited to the
fungus, then hypertrophy will result and aecidia be developed.
Very conclusive evidence of this interesting condition has been
furnished by numerous experiments which I have carried out
with spores of Gymnosporanyium} If one infects Crata.rjjvH
Oxyacantlm with G. clavariaeforme, very marked stem- hypertrophy
results, even by the time the spermogonia have made their
appearance ; there is also consideraljle swelling of leaves and
slight enlargement of cotyledons, while aecidia are produced
in numbers everywhere. When the same fungus is used to
infect Pyrus Ancv/paria, no yellow spots or malformation
of any kind results, and spermogonia, hardly visible with a
lens, are formed only here and there. A similar infection on
Pyrus latifolia {P. Aria X tormincdis) results in a crop of
badly developed aecidia. If quince be infected, then without
any hypertrophy whatever, little red spots bearing numerous
spermogonia are formed on the leaves, but the development of
the fungus ceases there ; on the death of the quince leaves,
the chlorophyll is retained in the immediate neighbourhood of
the spermogonial spots, so that they remain for some time as
green islands on the yellow leaf. E. Hartig's infections with
Melampsora trcvndae also led to varied results ; on Pimis there
ensued a distinct disease of the cortex (Cacoma pinitorqinim)^
' V. Tubeuf, Centralblatt f. Bacteriologic u. Farasitenkunde, 1891.

EFFECT OF SUBSTRATUM ON DEVELOPMENT OF PARASITE, 49

while on Larb: only little cushions appeared on the needles
(Caeoma laricis).

These variations in the effect of the substratum on the
development and reproduction of the parasites assist us to
understand the well-known resistance of certain varieties and
species against epidemic diseases, which are sweeping off their
near allies. Thus, we know that some varieties of cereals suffer
from attacks of rust-fungi more than others grown under like
conditions. Similarly amongst the varieties of vine some are
known to be more sensitive to disease than others. These
points will be more fully discussed in a subsequent chapter.

CHAPTER IV.
NATURAL AND ARTIFICIAL INFECTION.

§ 10. Ill artificial infection we have a safe mode of distinguishing
whether a fungus is parasitic or not ; in other words, whether
it is capable of penetrating into the organs of living plants.
This method of investigation should always be resorted to in
determining the cause of disease, more especially if mycelium
or sporocarps of several fungi are present on the diseased
material simultaneously. For it not unfrequently happens that
the disease has made so much progress as to make it quite
impossible to determine whether or not any fungi present on
the dead remains are really the cause of disease. In many
cases where one finds a mycelium in living parts, it has
disappeared, and only sporocarps remain in portions already
killed.

Injuries due to insects frequently accompany fungi on a
diseased plant, so that it is extremely difficult to say which was
the primary cause of the damage, and artificial infection must
be resorted to. So also with injuries from some external source
like drought, heat, cold, moisture, and mechanical causes.
Fungi appear so soon after hurtful agents like these, that it
becomes doubtful whether they are the cause of the death of
the host, or the result of it.

Minute observations in situ of all the circumstances connected
with the attack, combined with examination of numerous speci-
mens and comparison with neighbouring plants, enable one,
after some experience, to say with a fair degree of certainty,
whether the disease in question is of fungoid origin or not.

NATURAL AND ARTIFICIAL INFECTION. 51

The exact proof, however, is best obtained by means of experi-
mental infection.

With many parasites the sporocarps are normally developed
saprophytically on a dead substratum, so that if parasitism
be suspected it can only be proved by infection. Thus the
perithecia of Nedria cinnabariiui develop only after the death
of the plant-organ, which the fungus attacked when alive. The
more complex reproductive organs of many fungi are developed
only on dead remains of the host, while on living or dying
parts one finds various forms of conidia of doubtful relation-
ship. In many cases it has been possible, by means of artificial
culture alone, or combined with artificial infection, to prove
various forms of reproductive organs to be stages in the life
of the same fungus.

When a group of fungi contains both saprophytes and parasites,
it is often necessary to determine whether some species is para-
sitic or purely saprophytic. This is particularly the case with the
groups of Pyrenomycetes, Discomycetes, Hymenomycetes, several
groups of the lower Fungi, the Bacteria, and Myxomycetes. It
is unnecessary, however, with the Uredineae, Ustilagineae, Per-
onosporeae, Exoasceae, and other groups known to contain
parasites exclusively.

But even in these last-mentioned groups experimental in-
fection is necessary for obtaining information on other points.
The reproductive organs of Uredineae cannot be reared in
artificial solutions, so that their cultivation must be carried out
on the living host-plant. In this way alone can we ascertain
the relationship of uredospores, teleutospores, and aecidial-forms,
where any doubt occurs as to their belonging to the same
species. Infection becomes particularly valuable when one has
to investigate heteroecious Uredineae, whose various forms of
reproductive organs inhabit several host-plants. Thus it was
by means of infection that De Bary discovered the connection of
Accidium herbcridis on the barberry, and Fuccinia graminis on
cereals ; likewise Hartig, the relationship of Mclampsora Gocp-
pertiamt on cowberry with Accidium coliimnarc on needles of
silver fir. There still remain many aecidia, teleutospores, and
uredospores, whose related forms have not yet been found.

Infections are also necessary to determine the species of a
fungus. It has been found, for example, that Gi/mnosporangium

52 NATURAL AND ARTIFICIAL INFECTION.

confusum and G. sabinnc may, in their aecidial stage, be dis-
tinguished as two species inhabiting distinct hosts — Crataerjiis and
P'i/riis respectively — whereas, in their teleutospore stage on juniper,
they scarcely vary. In infection we have an important aid in
determining the host-plants of the various forms of heteroecious
fungi, and in this way it has been found that the same fungus
behaves difierently according to the host-plant on which it
is present. Thus, in the genus Gy^nnosporangium, I have found
that a certain species had well-developed aecidia on one plant,
poorly developed ones on another, while on a third only si)ermo-
gonia appeared. Similarly, in that case already mentioned,
Hartig found the Mclam2)sora of the aspen to produce on the
pine a disease of the cortex, accompanied by marked deformation,
while on the larch the symptoms were mere inconspicuous aecidia
on the needles.

Amongst the Ustilagineae, experimental infection is necessary
to determine whether the natural infection of host-plants results
from germinating spores (chlamydospores), or from germinating
conidia (sporidia). Klihn was able by this means to demonstrate
exactly that the spores of Ustilagineae produced germ-tubes
capable of direct infection. Brefeld succeeded in observing the
penetration of germinating sporidia into a host-plant. In this
way he proved, amongst other facts, that maize may be attacked
by Ustilago maydis on any young part ; also, that the mycelium
remained local. Oats, on the other hand, could only be infected
by Ustilago avenae at the neck of the young seedling, and the
mycelium extended through the plant till it reached the inflor-
escence, where the spores are formed.

In the case of the Exoasceae, two points were cleared by the
aid of artificial infection — the penetration of spores into leaves of
host-plants, and the production of witches' brooms. Sadebeck,^
by means of infections of Exoascus epiphyllus on Alnus incana, has
produced witches' brooms artificially, thus proving that these
malformations really originated from the mycelium of Exvascus.

It is by infection-experiments that one determines into which
part of a host the germ-tubes penetrate, whether into leaf, flower,
fruit, stem, or root, and also whether it passes through the
epidermis, or between two adjacent epidermal cells, or through

^ Kritische. Unter.mchtinrjen iiber d. clwch Taphrina herioryehrachteji Baum-
kranl-heiten, 1890.

NATURAL AND ARTIFICIAL INFECTION. 53

the stomata. Also, whether the germ-tube formed from a
germinating spore penetrates direct, or if, as shown by De Bary
for Sderotinia, a mycelium vigorous enough to penetrate must
first be developed saprophytically.

In this connection De Bary ^ states that tlie germ-tubes from all aecidio-
spores and uredospores only penetrate by stomata, and thence extend through
the intercellular spaces. Entry through the stomata has also been observed
on the germ-tubes from sporidia of Leptopucdnia dianthi, and from spores of
Entyloma. On the other hand, germ-tubes from the spores of teleutospores,
from spores of Peronosporeae, Ustilagineae, Sderotinia, Polystigma, Pro-
tomyces, and Sijndiytrium effect an entrance through the outer cell-walls into
the epidermal cells or stomatal guard-cells. De Bary also describes the
peculiar behaviour of zoospores of Cystopus and Peronospora unihelliferarnm,
which, if they come to rest near a stoma, germinate, and the germ-tube
enters therein, whereas one developed in water soon dies. Certain fungi
penetrate sometimes through the membrane, sometimes by a stoma, e.g. —
Phytophthora infestans, Peronospora parasitica, Exobasidium vaccinii.

In the case of Phytophthora omnivora, Hartig found that the germ-tubes
from the zoospores crept along the surface of the leaf till they reached a
place where two epidermal cells adjoined ; there they entered, and only
rarely grow into the epidermal cells. The germ-tubes of Protomyces macro-
sporus and Tuburdnia trientalis enter their hosts in the .same wav.

From experiments, one is able to determine the conditions
favourable, or otherwise, to infection by parasitic fungi; to ascertain
the influence of temperature, air-moisture, water-content of the
host, hairiness of the leaves, and the effect of resin or other
excretions as protections to wounds. For example, it was in
this way that Hartig found Salix pulchra {pruinosn x daphnoides)
to be a hybrid which, on account of its hairy leaves, is more
resistant to Mclampsora than Salix pminosa.'^ Much investiga-
tion remains yet to be done in this direction to ascertain what
varieties or species of cultivated plants are likely to be least
liable to attack by epidemic diseases.^

The methods used in carrying out artificial infection are
based on the observation of cases of natural infection. Most
frequently infection is performed by means of spores, less often
with mycelium.

The spores of lower forms of fungi are generally distributed
by means of water, especially in dew or rain. Zoospores are

^ Morphology and Biolor/y of the Ftrngi, English Edition, pp. 361-362.
-Hartig, Diseases of Trees, English Edition, 1894, p. 171.
^See Chapter v. on "Disposition."

54 NATURAL AND ARTIFICIAL INFECTION.

completely adapted for distribution in water. Amongst the
higher fungi, spore-distribution almost always takes place by means
of wind. Insects as agents are rare, although one does occa-
sionally find special adaptations intended to secure their visits.
The spores of many fungi are forcibly ejected from the sporo-
carps, asci, or sporangia ; some of the many arrangements which
ensure this will be given in the special part of this book, others
will be found in the works of Zopf,^ and De Bary.^ Ludwig,
in his text-book,^ points out that the spores of many Ustila-
gineae frequenting entomophilous flowers, are provided with
ridges and spines, which are probably an adaptation to their
transportation by insects; smooth-coated spores are more common
on leaves, stems, and organs other than the flower, and are
evidently distributed l)y the agency of wind.

The mode of distribution and infection is quite apparent in
many fungi. Thus in the oat-smut (Ustilajo avenoe), the
diseased ears in a field rise above the sound, so that the light
dusty spores are shaken out in clouds by the slightest wind ;
they hibernate on the earth or on straw, and germinate in
spring to infect the oat-seedlings at the base of the stem.
Equally simple is the distribution of spores and conidia from
one plant to another by wind during summer. Good examples
of this mode are the conidia of the Erysipheae, and the
aecidiospores and uredospores of the Uredineae. Thus, the
yellow spores of C]irysomy.ra rlwdodcrulri, when the aecidia are
present in very large numbers on the needles of spruce,
may cause the phenomenon known as " sulphur-rain." It is
well known that this is generally due to the yellow pollen of
conifers caught and carried to the ground in showers of rain,
but E. Hartig describes a case observed by him near Achen-see
(Tyrol), where objects were covered by a yellow dust, consisting
exclusively of spores of Chrysomjpxi. Spores of this kind are
capable of transport to very great distances, so that heteroecious
species can still keep up their connection even though by no
means near each other.

Aecidiospores of all kinds are distributed more by wind than
by insects. In rare cases, however, the aecidia have a sweet floral

iZopf, Die Pilze, 1890, p. 349.

-De Bary, Morpholo</y and Bioloffij of the Fungi, English Edition, 1887.

^ Lehrhuch d. niederen Kryptogamen, e.g. p. .S70.

NATURAL AND ARTIFICIAL INFECTION. 65

odour, e.g. Aec. odoratum in America. The wind we must also
regard as the distributor of uredospores and of the sporidia of
germinating teleutospores. The Uredineae have typical spores
for distribution by wind with the exception of the so-called
spermogonia. These structures are produced by most Uredineae,
generally on the upper surface of the leaf and before the aecidia;
they are brightly coloured, and give out spermatia in a sticky
gelatinous slime, frequently with a distinct odour. Thus they
seem to be admirably adapted to transport by insects, and are
in fact visited by them. Their distribution, however, has little
importance, since they are, as far as known, incapable of
germination. They are regarded by many as degenerate forms,
either of male sexual organs, or of pycnidia. Some of the
spermatia have been made to germinate in artificial culture,
but of their incapacity to germinate in natural surroundings
there can be no doubt. I am not aware of any one who
has succeeded in bringing about infection with these spermatia,
but I have tried it often with no result.

It is much more difficult to ascertain how fungi, which
hibernate on the earth, find their way in spring to their
respective host-plants, in some cases even to the crown of very
large trees. Amongst such forms one frequently finds an
arrangement by which the spores are forcibly ejaculated. Thus
Rhytisma accrinvm, which reaches maturity only in spring after
hibernating on dead sycamore leaves, and Sckrotinia hctulac,
which does so on fallen fruits of birch, both have their spores
forcibly ejaculated and carried off by wind. Klebahn states
that the ejaculation takes place in dry weather, and that the
spores of Ehytisma are prevented from drying up by a gela-
tinous covering. In a similar manner the hibernating spores of
Erysipheae on fallen leaves must be carried up again by wind ;
so also those of Pohjstigma, which ripen on the ground and then
infect young leaves of plum and cherry trees.

Infection by means of the mycelium generally occurs where
the mycelium lives in the earth. Thus, the hyphae of Trametes
radiciperda grow rapidly from one root to another, causing a
centrifugal spreading of the fungus, so that forests attacked by
it have the trees killed off in patches. Mycelial infection is still
more effective in fungi like Agaricus mellcus which assume the
form of rhizomorphs. Infection by means of the mycelium may

56 NATURAL AND ARTIFICIAL INFECTION.

also occur amongst species of fungi living above ground. Thus
the mycelium of Botrijtix spreads from plant to plant, and on seed-
lings in hot-beds, may form felted masses. Similarly the myceUa
of Erysipheae, of Trichosphaeria, and of Herpotrichia make their
way from one part of a plant to a neighbouring part in contact.

Artificial infection may be carried out by means of spores
or by mycelium. In the case of swarm-spores, the operation
can only be conducted in a damp chamber and on well-
moistened leaves. Thus, young plants of beech must be well
sprayed, then infected with conidia of Fhytoplithora omnivora,
and placed under a bell-jar to prevent drying up. In this and
many other similar cases one finds that while the spores require
moisture to ensure germination, yet the germ-tubes easily leave
the water-drops and penetrate into the leaves ; in other words,
the living leaf exerts a greater influence on them than the water,
the chemotropic stimulus is stronger than the hydrotropic.

The spores of the lower fungi are best isolated by the aid
of a lens or microscope, then washed on to the place to be
infected. In the case of Ustilagineae and Uredineae the same
method is used, except that dry powdery forms of spore are
simply dusted on to the host-plant to be infected. When spores
of Ustilagineae are being used the addition of excrement of
some sort is frequently of advantage, since it promotes better
germination and the formation of conidia capable of infection
after it is exhausted. One must also pay attention to the fact
that some smut-spores can only infect the base of the stem or
parts in process of elongation, while others can only attack
parts of the flowers. The teleutospores of the Uredineae must
first be germinated in order to obtain the sporidia with which
infection is carried out ; this generally takes place in water.
Thus with species of Gymno^porangium it will be found best to
mix the whole gelatinous mass of teleutospores with a little
water in a shallow glass dish, and to ascertain, by microscopic
investigation after a few hours, whether any sporidia have been
produced. If this be the case, the gelatinous mass is thoroughly
broken up, more water added, and the yellowish water sprinkled
over the host-plant. Care must, however, be taken that the
larger portions of the teleutospore-mass are not left on the
leaves, otherwise death of the latter will occur at these places
without infection taking place. For a similar reason it is not

NATURAL AND ARTIFICIAL INFECTION. 57

advisable to lay portions of diseased leaves directly on healthy
ones, it is much better to place them near each other in a
moist chamber, hansinff the former over the latter.

When infection is carried on out-of-doors, it is best to obtain
a small plant which can be accommodated under a bell-jar. If
this be unattainable, it is often possible to bend one of the lower
branches down to the ground or other support, so that it can be
covered with a bell-jar. Again, a branch or portion of it may be
first sprinkled, then bound loosely up in a parchment-paper.
When carrying on infection it is of importance to avoid very
hot and dry or cold days ; moist, warm and cloudy days, or close
still nights, will be found best. In the case of diseases of the
rind, it is generally necessary to wound the periderm by a few
fine knife-cuts, then to place thereon a few drops of water with
infecting spores suspended in it.

Artificial infection by means of mycelium is generally
attained by placing a diseased portion containing living my-
celium in contact with the healthy, so that the mycelium can
grow from the one to the other. Thus, with bark-diseases, a
small portion of diseased rind is cut out and fitted into a
corresponding incision in the rind of the plant to be infected,
the oculation or graft being then protected against drying up by
gutta-percha, tree-wax, or parchment. The ingrafted portion
need not fit very accurately if well bound up, because the
mycelium will grow well in the moist chamber so formed. The
most vigorous mycelium is generally found on the boundary be-
tween healthy and diseased parts, so that portions from this
region should be selected for infection.

If the fungus under investigation frequents the wood, it is, as
a rule, a wound-parasite, so that for its infection the wood must
be laid bare, and a diseased portion applied to it. If a branch is
to be infected {e.g. with Nectria, or Cucurhitaria), then it should
be cut over a bud, the exposed end split, and a fine wedge of
diseased wood inserted, the whole being bound up. It is also
possible to graft a diseased branch on to a healthy. In the
case of stems, a portion of the healthy one should be removed, a
diseased piece inserted, and the wound closed over with grafting-
wax or clay. Pressler's growth-borer may in such cases be
used with good results to obtain a cylinder of diseased wood,
and to make a suitable receptacle for it in the sound plant.

CHAPTER V.
DISPOSITION OF PLANTS TO DISEASE.

§ 11. We must here distinguish between an internal or
inherent disposition dependent on the constitution of the living-
protoplasm of the host-cells, and an external or accidental dis-
position arising from anatomical peculiarities or from the con-
ditions of environment.

The condition of inherent disposition has as yet been little
investigated. In many cases it must be allowed that resting
cells are more disposed to disease than those in full activity
of life. Thus De Bary,^ basing his conclusions on the observations
of Davaine and P)refeld, points out that various species of Mvxor,
Pmicillium, and allied forms penetrate into ripe juicy fruits,
and remarks : " Observation of the fruits shows that the fungi
develop more easily, the nearer the vital powers of the plants
attacked are to their lower limit, and at this point the conditions
of saprophytic vegetation make their appearance." ^ Davaine
also found that the vegetative organs of several succulent plants
show the same phenomena as the fruits. As further examples
may be mentioned that fungi can frequently penetrate withering
plant-organs while they could not infect the fresh living tissue.
Hartig observed on Peziza Willkommii that the mycelium of this
bark-parasite advanced and killed the tissues only while the host-
cells were in a condition of vegetative rest, not during their
active period.

1 Morpholorjy and Biology of (he Fum/i, English Edition, p. 380.
-Wehmer (Beitrar/e z. Kennf. einheimi-'^cher Pilze, Jena, 1S95), has contributed
new facts to this subject, which are referred to later.

DISPOSITION OF PLANTS TO DISEASE. 59

Hartig ^ also found that Agaricvs mellevs, in penetrating into
stools of oak, only killed those cells which, as it were, rested,
whereas the cells of parts in communication with stool-shoots
are not attacked. Likewise, Schwarz states that the mycelium
of Cenangium ahietis only extends through pine-shoots at a time
when there is little vegetative activity.

Accidental disposition depends largely on the nature of the
epidermis enclosing plant-organs. The stems of many plants are
protected from intruding fungi from the time the epidermis is
replaced by a corky layer, still better after a bark is formed.
Hence young shoots are in a condition of greater disposition
than older ones. There are, however, various grades of dis-
position to be observed, even when a simple epidermis forms
the only covering, as is the case with most leaves, flowers, and
many fruits. The newly-formed epidermis is, as a rule, most
disposed while its walls are still delicate and uncuticularized,
hence many organs are exposed to attacks of fungi only in their
youngest condition. It is easy to infect and kill young leaves,
and shoots of conifers with Botrytis Dov.glasii, whereas older
needles will remain quite unharmed. Similarly with ChrysomyoM
rhododendri on spruce-needles, Calyptos'pora GoeiiiKrticma on
silver fir, and others. Flowers are also more easily infected
in the young stage, e.g. cones of spruce by Aecidhim strohilimim.

During early youth plants are insufficiently protected from
great cold and drought, and also from infection by parasitic
fungi. This may be because the young non-cuticularized walls
offer less resistance to the germ-tubes and haustoria, or because
they are more permeable to any ferment excreted by the fungus.
Organs developed late in the vegetative season resemble those
in the spring-condition in that they have not as yet matured,
and are but poorly protected against extremes of temperature,
or attacks of parasites.

The condition of disposition may be easily promoted for
purposes of artificial infection, by cultivating the host-plants in
a moist chamber, or under a bell-jar. The same condition
may easily arise in glass houses or hot-beds, hence one has, by
means of constant ventilation, to guard against it.

Many diseases of seedlings (e.g. Fhytojjhthora omnirora,
and Pythivm) are only to be feared so long as the stems of

^ Forstl.-vatnriciss. Zeitschrift, 1894.

60 DISPOSITION OF PLANTS TO DISEASE,

their hosts are unprotected by cork-forniation. Plant-organs
rich in water are in a condition which disposes them to attack,
much more than drier parts. The younger parts of any plant
are more disposed than older parts. Thus in a spruce-hedge
with young shoots appearing at different times, only those
shoots will be lia))le to attack, which are young at the time
of the scattering of the spores of Chrysomyxu abietis, or other
spruce-fungus. De Bary was of opinion that plants of Gapsella
were disposed to attacks of Cijstopus candklus, only as long as
they retained their cotyledons, because only those spores ger-
minating on the cotyledons form a mycelium which ultimately
finds its way through the plant, whereas plants which had
already lost their cotyledons at the time of infection were
in no danger. Many of the Ustilagineae attack cereals only
when these have just emerged from the soil, infecting the
young stems on the first slieath-leaf, whereas older and more
advanced individuals are exempt. While all plants with a
delicate epidermis or corky layer are liable to disease, yet some
are more so than others. This is exemplified by the different
powers of resistance to disease, or insect attacks exhibited by
nearly allied forms of our cultivated plants, e.g. vines ; a differ-
ence probably due to some variation in their outer membranes,
such as is further demonstrated by thick-skinned potatoes being
more resistant to disease than thin-skinned.

Disposition is often due to external circumstances. These,
however, act rather in presenting favourable opportunities for
infection by germinating spores, than by directly disposing the
plant to disease. Thus prolonged wetting of a leaf from rain
favours germination of spores, and at the same time by softening
the leaf, facilitates penetration of the germ-tubes. Stahl ^ has
pointed out that leaves on which water remains for any length
of time, present greater opportunity for growth of saprophytic
epiphytes or for infection by parasites, than leaves with a
smooth surface or of a shape which facilitates ready escape of
water from their surface. It is also well known that larches
in damp situations suffer more from Pcziza Willkommii than
those in drier places, the fungus-spores maturing and germinat-
ing only in moist air. Similarly, moist weather or damp

^ " Regenfall ii. Blattgestalt, " Ann. du Jardin hotan. de Buitenzorg, xi. , 1893,
p. 124.

DISPOSITION OF PLANTS TO DISEASE. 61

situations favour reproduction of mildew and other diseases ;
under such conditions a rapid increase of potato-disease during
July is easily observable and may be safely foretold.

The extension of Hciyotrichia is greatly facilitated by snow,
which weighs down young plants or branches of spruce and
pins them to the soil, where the fungus develops on its host
under the snow-covering. On this account elevated situations
and hole-planting render the spruce lialjle to disease.

Many plants which, as a rule, suffer from fungus-diseases
will be found to remain exempt in open or dry situations, or
during a dry period. The tops of trees are not attacked by
many fungi which frequent the lower parts of the crown. This
is particularly the case with epiphytic lichens and certain fungi^
which require a high degree of air-moisture. Tricho&phaerict
'parasitica, always very abundant in damp silver fir regenerations,
is almost absent from free-standing trees, or from the higher
parts of the crown in closed forest. It is, in fact, a parasite
well adapted for extension in the crowded masses natural to
the early growth of the fir, and the host is, during its youth,
disposed to disease from this particular parasite. A fungus on
the beech behaves similarly, occurring in Bavaria only in the
very damp parts of close high forest and in Alpine gorges. '
Other fungi have better means of protection against drought,
for example, Hysterium macrosporivin has its spores enclosed in
gelatinous envelopes and may be found on the highest point of
the spruce, although, on the whole, its distribution is most
favoured by moisture. Fungi which frequent algae, or are dis-
tributed by means of zoospores, depend absolutely on moisture ;
hence they frequent hosts growing on banks of streams, places
liable to flooding, or low-lying moist meadows, whereas the same
host-species remains completely exempt from their attacks in a
dry locality.

A plant may be said to be in a condition of abnormal
disposition to disease when deprived of its natural protection.
Thus wounds of any kind render a plant disposed to infection
from wound-parasites, which are unable to harm uninjured parts.
After severe hail-storms an outbreak of Nedria. ditissima is not
unfrequent amongst regenerated beech, or even in the canopy
of older forest. I have also observed an extensive outbreak of
Cucurhitaria labiirni on laburnum near Munich, obviously due

62 DISPOSITION OF PLANTS TO DISEASE.

to hail. Juicy fruits whose epidermis has become broken, soon
rot unless a protecting layer of wound-cork is rapidly formed.
Wounds in the wood present an entrance-gate to numerous
Polyporeae, otherwise unable to penetrate. In the case of
wounds to the wood of spruce or young branches of pine, a
protecting crust is frequently formed by the rapid excretion
of resin from the injured surface.^

The disposition of a host-plant depends then on some inherent
condition of the protoplasm or on some accidental circumstance.
The latter may be anatomical and due, for example, to thickness
or other property of the cuticle, or to a hair-covering ; it may
be morphological, from some defect, say on the part of the leaf
in not allowing easy escape of water. The disposition may be
periodic {e.g. in youth or at flowering), or it may be permanent.
It may be generic, or confined to some particular variety or
species, or it may be individual. It may be normal or abnormal.

The practical lesson of this chapter has been that we should
cultivate our plants so as to avoid the conditions which dis-
pose them to disease, and that we should rear and cultivate
these kinds least liable to injury from disease. The considera-
tion of these points forms the subject of our next chapter.

^ Resin is in itself not antiseptic, and in the fluid condition inside plants
affords no barrier to fungus-hyphae of Peridermium piiii and Nectria cucurbitiUa ;
the hardened crust on a wounded surface serves, however, to keep off spores
fi-oni the plant tissues, and prevents the penetration of germ-tubes.

CHAPTER VI.
PREVENTIVE AND COMBATIVE MEASURES.

§ 12. Measures are known for the prevention and cure of many
fungoid diseases of plants of agricultural, sylvicultural or horti-
cultural interest. These have been deduced from the biology of
the parasite and its relation to its host, and have been used
practically with more or less success. In a large number of
cases, however, little advice can be given, because as yet the
cause of many diseases is obscure, while for others suitable
reagents for cure have not been found. Many of the methods
known are impracticable from the cost entailed in carrying
them out. Others, directed against some widespread disease,
fail from lack of organized co-operation, the efforts of a few
individual cultivators here and there making but little headway
against the disease, so long as the patches of crop under treat-
ment are subject to fresh invasion from untreated places. It is
desirable on this account that the combating of diseases of our
cultivated plants should be conducted under some kind of state
supervision.

The first step towards combating the more destructive diseases
of plants is the spread of knowledge concerning them, and the
remedies available against them. In Bavaria and other German
states this is done for the diseases of sylvicultural importance by
regular courses of instruction in plant-pathology in the forestry
schools. In the same way it would also be advisable to give
similar instruction in agricultural schools, and also to make it a
subject for examination. Another important step consists in the
establishment of experimental stations where investigations in

64 PREVENTIVE AND COMBATIVE MEASURES.

plant-pathology may l>e carried out, while at the same time the
cultivator could have advice with regard to the nature of any
disease and its treatment. Another system for the supply of
information is to be found in collections of specimens of plant-
diseases arranged for easy reference in places accessible to the
public.

State supervision over crops under cultivation is also desirable
with a view to collect and distribute information concerning
prevalent crop-diseases. The same agency could also arrange
and, if need be, enforce a general and simultaneous treatment of
widespread epidemics, where proved methods were known and
advisable. Such regulations for supervising and combating a
plant-disease are already universally applied against the Phyl-
loxera. Similarly in Germany and other countries official
notice is annually given for extermination of mistletoe ( Visciim
album) on fruit-trees, and in Prussia the combating of Gnomonia
erythrostoma is carried out by order of the police authorities.
The tar-ringing of trees as a preventive against attacks of pine
moth {Gastrojyacha pint), is regularly enforced everywhere in
forest-countries, and with the best result. In a similar manner,
in most countries, this and other forest pests are supervised by
the penal code, and combated with success.

By arrangements of this kind it is possible to keep certain
diseases completely in check. Thus, as a result of regular in-
spection and the timely use of tar-rings, a dangerous outbreak of
pine moth is well-nigh impossible. Again, the universal steriliza-
tion of the seed-corn of cereals before sowing has done much to
exterminate smut-diseases. In the case of the Dodder-disease,
much can be done for its prevention by the careful purification
of clover seed.

We shall consider the methods for combating parasitic fungi
under the following heads :

I. Methods for extermination and removal of the parasitic
fungi alone.

(1) Killing of fungi attached to seed through sterilization by
means of hot water or copper steep-mixtures.

(2) Combating leaf-frequenting fungi by dusting or spraying
with mixtures containing sulphur or copper.

(3) Excision and extermination of the sporophores of Polyporeae
and- Agaricini on orchard or garden trees.

PREVENTIVE AND COMBATIVE MEASURES. 65

(4) Eemoval and destruction of dead parts of plants carrying
sporocarps or other hibernating stages of any fungus.

II. Methods for combating fungi by removal of diseased
plants or plant-organs.

(1) Eemoval of the parts of a host-plant harbouring fungi.

(2) Eemoval of the whole or part of a complementary host
of a heteroecious fungus, for the purpose of saving the other
host or hosts.

III. The avoidance or removal of conditions which favour
infection.

(1) Preventive measures against wound infection; antiseptic
and aseptic wovmd-treatment.

(2) Avoidance of localities favourable to disease.

(3) Avoidance of the massing together of plants of the same
species and like age ; rotation of crops on the same cultivated
area.

(4) Avoidance of neighbourhood of those plants which are
hosts of the same heteroecious fungus.

IV. Selection and cultivation of varieties and species of
cultivated plants least liable to the attacks of parasites.

I. Extermination and removal of the parasitic fungi alone.

(1) That the seed be clean and free from the spores of
parasitic fungi, is a most essential condition. The purity of
seed is investigated in seed-control stations,^ where special
attention is paid to purity of seeds {e.g. clover, from its
liability to contain seeds of the parasitic Dodder), and to their
freedom from spores of smut or other fungi.

As a preventive against smut, especially those forms due
to species of Ustilagineae, sterilization of the seed is adopted,^
This is chiefly carried out by the use of " steeps," which kill
the smut-spores adherent to the seed. The composition of the
steep-liquid, and the duration of immersion are the points to be
attended to, and for these various recipes are extant. Eecently

1 State-aided stations of this kind are fairly numerous in Germany, France,
and other continental countries, also in America. It is thus somewhat remark-
able that in Britain this important work receives no state recognition, but is
left in the hands of more or less experienced analysts, or others. (Edit.)

-Swingle, W. F. "Grain-smuts and theii- prevention." Yearbook of
U.S. Dept. of Ag7-iculture, 1894. A very useful summary. (Edit.)

E

66 PREVENTIVK AND COMBATIVE MEASURES.

it lias been pointed out that the different species of Ustilago
have different powers of resistance, and must be treated
accordingly. It has been found from experience that when
trustworthy and tested steeps are in general use in any neigh-
bourhood, the diseases of crops caused by Ustilagineae gradually
disappear. This is due to the fact that the smut-fungi frequent
principally the cultivated cereals, while they are comparatively
rare on the wild grasses from which, as in the case of " rusts,"
they might make their way to the cultivated forms.

Sterilization hy Copper Sulphate.

The " steep " which is in most general use is that first recom-
mended by Kiihn ^ in 1858. It consists of a i per cent
solution of copper sulphate prepared as follows : 1 lb. crushed
commercial sulphate of copper (blue vitriol or bluestone) is
dissolved in hot water and added to 22 gallons of water. The
seed is poured into the " steep " and allowed to stand covered
with the liquid for a night (twelve to sixteen hours). The
seed is then taken out and allowed to drip. An improvement
on this method consists in running off the copper sulphate
liquor and adding milk of lime (prepared by soaking 1 lb.
good lime in 4 gallons of water), after stirring for about five
minutes, again run off the liquor and allow the grain to drip.

If sown by hand the seed may be used in a few hours, if
by machine it must dry for twenty-four hours.

Sterilization hy Hot Water.

Jensen's method for treatment of seed-grain by hot water,
consists in placing the seed for a certain time in water at a
temperature which does not injure the grain, but is sufficient to
kill any adherent smut-spores. This takes place in five minutes
in water at 132° F. (55° C), but the germinating power of
the grain will not be injured though it remains a quarter of
an hour. The immersion is carried out by placing the seed in
a vessel easily permeable by water ; a bushel basket lined with
coarse canvas serves very well. A convenient quantity of seed

^Julius Kiihn, Die Krankheiten d. KnUnrgewdchse, 1858, p. S6. Numerous
articles on this subject have from time to time appeared in the agricultural
Journals and Bulletins.

PREVENTIVE AND COMBATIVE MEASURES. 67

to handle in such a basket would be a full half-bushel. The
hot water is best contained in two large boilers, the first at a
moderate temperature, serving to wet the grain somewhat and
to prevent cooling of the water of the second boiler, which
must be maintained between 130' F. to 134' F. A lower
temperature will not ensure death of all spores, a higher will
injure the grain. The grain is immersed a few minutes in the
first boiler, then placed in the second for fifteen minutes, being
meanwhile frequently shaken to ensure complete sterilization.
Next the basket and its contents are cooled in cold water and
the grain spread out to dry.^

The important point in the application of these methods is
their general and simultaneous use throughout a whole district.

For smut-diseases the removal of diseased plants is at the
same time a preventive and a combative measure. This is
not difficult where the plant is large or the disease conspicuous,
as with the maize-smut ; the diseased plants can then be re-
moved and burnt before the smut-spores are shed. If the smut
is not very prevalent it is possible to keep it in check by
removal of diseased specimens on such crops as maize, barley,
wheat, and oats. This treatment can also be applied to some
garden-smuts like that on violets.

Brefeld recommends as a preventive measure the avoidance
of the use of fresh farmyard manure. Smut-spores from in-
fected hay or straw, which finds its way to the manure heap,
germinate there and multiply yeast-like giving rise to conidia,
which, on exhaustion of nutrition, give rise to germ-tubes
capable of infecting seedling plants. The spores are capable of
germination even after being eaten with the fodder and passing
through the digestive canal of animals. In this connection
Professor Wollny carried out the following experiment at my
instigation : three fields situated at some distance from each
other were sown with maize, which I had mixed with living
spores of Ustilago maydis collected the previous autumn. One
field was left unmanured, the second received old farmyard
manure, the third fresh. All plants in the first plot grew up
healthy, two of the second were diseased, and eleven of the
third. The summer being a dry one the number of diseased

iln the literature issued from the United States Experimental Stations
other "steeps" are given, with results. (Edit.)

68 PREVENTIVE AND COMBATIVE MEASURES.

plants was smaller than usual. The immunity from smut with
old manure is probably explicable on the assumption that in
it the kind of nutriment suitable for the smut-conidia is ex-
hausted, so that any spores, which may sprout, die off.

It must, liowever, be here observed that the spores of some
species of smut-fungi {e.cj. TiUctia, the stinking brand of wheat)
do not germinate directly in manure, but do so in water easily.
The spores of most smuts are adapted to a long winter rest.

(2) Other diseases are fought and prevented from spreading
by the direct extermination of the fungus or its reproductive
organs while in full activity on the growing host-plant. For
this purpose Fungicides are used, either as powders or solutions
applied to diseased plants. These reagents are employed with
most success against epiphytic fungi, where the mycelium is
fully exposed on the surface of tlie host.

The Erysipheae are generally treated in this manner, especially
the powdery mildew of the vine {Oidium Tuckeri or Uncimda
sjnralis). This vine-parasite is combated by dusting from time
to time with dry powdered sulphur or flowers of sulphur. The
sulphur may be simply shaken from a tin with perforated lid,
or it may be blown on by a sprayer provided with a bellows,
or dusted on by a sulphur-brush, consisting of a hollow handle
filled with sulphur which distributes the powder through fine
perforations in its end to a tassel of fine bristles. In a similar
manner may be treated the powdery mildews of hop, rose,,
peach, apricot, apples, etc., caused hy Erysipheae.

Fungicides are also used against fungi with endophytic
mycelia. The Peronosporeae cause injury to quite a large
number of cultivated plants, and many methods of treatment
have been employed against them. The mycelium lives inside
the host-plant, especially in its leaves, and only the conidiophores
make their appearance externally. Dusting with sulphur or
spraying with preparations of copper has on this account little
effect on the mycelium, but will kill the conidiophores, while
any conidia or oospores, which may alight on the leaves, will
be prevented from germinating. The most general forms of
fungicides are various preparations of copper, of which the
following are some of the more important : ^

^ Considerable liberty has been taken here with the original. The author's
account has been extended with the assistance of the Jow'tial of Mycology and

PREVENTIVE AND COMBATIVE MEASURES. 69

Bordeaux Mixture or Bouillie-Bordelaise, a 2 to 4 per cent,
solution of copper sulphate and lime. It is prepared by dis-
solving 6 lbs. of copper sulphate in warm water, and placing
this mixture in a barrel capable of holding about -4-4 gallons ;
in another vessel slake 4 lbs. of fresh- burnt lime, and make it
up to a creamy whitewash with water ; strain the lime through
coarse canvas into the barrel of copper sulphate solution, fill
up with water, stir thoroughly, and the mixture is ready for
use. This mixture may be used either more concentrated, or
somewhat diluted.

Ammoniacal Solution of Copper Carbonate. This may be
prepared directly by dissolving 5 oz. of copper carbonate in
enough water to form a thick paste ; dissolve this paste in
three pints of strong aqua ammonia (or as much as may be
necessary to effect complete solution) then dilute to 45 gallons.
If copper carbonate cannot be obtained, make it by mixing (a)
3 lbs. of copper sulphate in 2 gallons of hot water, (b) oh lbs.
washing soda in 1 gallon hot water ; mix (a) and (b), add
water up to 10 gallons, stir up, and allow to settle; pour off
the clear liquid, fill up again with water and allow to settle ;
on again pouring off the clear water a greenish sediment of
copper carbonate remains. This dissolved in as much aqua
ammonia as necessary, may be kept till required when it is to
be diluted at the rate of 1 pint to 2 gallons of water.

Eau Celeste. Dissolve 2 lbs. of copper sulphate in about
8 gallons of water ; when completely dissolved add 3 pints of
strong aqua ammonia and dilute to 45 gallons. This may be
used in a modified form.

Fungicides like these are used chiefly against attacks of vine
mildew {Pcronospora viticola), potato disease {Phytophthora in-
festans) and Peronosporeae generally ; also for numerous other
leaf-diseases caused by various fungi. What the results of any
given experiment may be, is as yet difficult to say till more is
known of the effects of the reagents, the strength of the mix-
ture to be used, the kind of plant and its stage of development,
and other factors dependent on climate. The efficacy of a
fungicide lies less in its effects on the fungi actually present

other American literature, not the least important being " Bordeaux Mixture as
a Fungicide," by D. C. Fairchild ; U.S. Amer. Bulletin, No. 6, 1894. In this
connection reference may also be made to E. G. Lodemann's account of the
"Spraying of Plants" (Macmillan, 1S96). (Edit.)

70 I'HKVENTIVE AND COMBATIVE MEASURES.

and causing disease, than on its capacity to kill spores which
light on the leaf, or to jn-event their development to a dangerous
extent. On this account crops liable to attack should be dusted
or sprayed in early spring, and at intervals thereafter as long
as tliere is any risk of disease. Used in this way, fungicides
soon repay themselves in increased yield of healthy produce ;
on the one hand, they hinder the development of the fungus,
on the other hand, they act like antiseptic wound-treatment in
preventing infection. What part the copper compounds play
is as yet not completely established ; Itumm ^ considers that
they are not actually absorbed by the plant, but only give rise
to some electrical effect.

The advantage to be gained from the use of fungicides may
be greatly increased if all diseased plants or portions of them
be removed before the remedy is applied. Precautions nmst
also be taken against reappearance of the disease. In the case
of infected forcing boxes, frames, or glass-houses, disinfection
by some of the above fungicides is certainly advisable. Leaves
on other plant-remains containing resting-spores of the fungus
should be burnt, and soil containing diseased material should
be watered with a fungicidal solution which will kill the fungus
while it does no harm to the leaves or roots of plants. Finally
a rotation of crops of as long a duration as possible will do
much to keep epidemic fungoid diseases in check.

(3) Frequently the ravages of a parasite can be considerably
reduced, although not completely stopped, by destroying its
reproductive organs. Methods of this kind are particularly
useful in the case of the Polyporeae which inhabit the wood of
many fruit-trees. The excision of the sporophores must be
carried out once or twice a year, l)ecause the mycelium remains
alive inside the stems and continually gives off new sporophores
on the surface. The diseased tree lives on and produces fruit
for many years, maybe till the wood of its stem becomes so
much decayed that death ensues. Fungi of this family are
even more destructive on those trees which are cultivated not
for their fruit alone but also for timber, e.g. olive, sweet chest-
nut, and hazel.

(4) By the removal and destruction of dead plants or portions
of plants containing reproductive or hibernating organs of para-

^ C. Rumm, Berkhfe d. deut.'ich. hotan. Ges. 1S93.

PREVENTIVE AND COMBATIVE MEASURES. 71

sites, much may be done to shorten the existence of a disease,
and to prevent its reappearance in the following spring.

Fungi which reach maturity on fallen leaves are easily com-
bated in this way. Hartig gives a striking example of the
success of this measure. In the English Garden, a large park
in IMunich, the leaves are carefully removed at frequent intervals
as they fall, and utilized as stable-bedding ; here Rhytisma
acerinuvi, the black spot of the sycamore leaf, is hardly known,
whereas in the park at Nymphenburg, and in other places
round ]\Iunich, where the leaves are allowed to remain lying,
the leaf-spot is very common. Rhytisma salicinnm can be
treated in the same way in osier-nurseries. In plum orchards
Polystigma ruhrum may be held completely in check by removal
of fallen leaves. So also the numerous mildews (Erysipheae)
of our cultivated plants. Cherry leaves killed by G^nomonia
erythrostoma remain hanging on the trees, but the disease has
almost disappeared since the practice of removing and destroying
these was introduced in gardens, like those of the Altenland,
once completely devastated by this parasite.

The progress of the disease caused by Ncctria cinnabarina is
reduced if the branches which die during the summer be at
once removed and burnt before the red fructifying patches
appear. It would also be advisable to burn in the autumn
other dry brushwood, since it frequently contains Ncctria and
other wound-fungi, and if left over winter only serves as a
nursery and source of infection for all neighbouring trees. In
a similar way should be treated branches infected with sporo-
carps of Cucurhitaria lahurni and such-like fungi.

Immediate removal, burning, or burying of young trees
attacked by Phytophthora omnivora is of advantage in prevent-
ing the distribution of the fungus by conidia and swarm-spores
during summer, its hibernation in dead tissues, and its continued
distribution in the following spring. The hibernating oospores
of many other lower fungi may be similarly got rid of by
destruction of the plant-remains inhabited by them.

II. Removal and destruction of diseased plants or portions of these.

(1) The removal of symbiotic organs comes here particularly
into notice. Amongst these are the " witches' brooms " which

72 PREVENTIVE AND COMBATIVE MEASURES.

live for years on their host deriving nutriment from them ;
they also are detrimental to fruit trees because they bear
neither flower or fruit, and on some timber trees they so
deform the stems as to consideraljly reduce their value. The
witches' brooms of the cherry or the plum grow into large
infertile bushes of striking appearance, so that they may be
easily detected and removed in autumn or spring ; those on
hornbeam, birch, and alder are of less practical importance,
but should be cut off wherever accessible.

Great damage is caused by the witches' broom {Accidium
elatinum) of the silver fir in producing canker spots which
may in some cases attain gigantic dimensions and thereby
much reduce the value of the timber, or maybe render it quite
valueless. The cankered spots are, in addition, frequently attacked
by wound-parasites, whereby the stem is weakened and breaks
over at the canker, causing breaches in high forest, which can-
not be refilled. The witches' brooms should therefore, as far as
accessible, be cut off' while still young, and all cankered trees
should be removed at the first thinning.

The removal of twigs of plum bearing the so-called '"' pocket-
plums " or " fools " is also to be recommended, because the my-
celium of the fungi causing these hibernates in them. Eose-twigs
affected by rose-mildew {Sj^haerotheca pannosa) should also be cut
away as soon as possible, before many plants have fallen victims.
Portions thus removed are both worthless and dangerous, hence
should he destroyed. So also all trees rotted by fungi should
be removed from their healthy neighbours, and, if possible,
burnt or buried, or otherwise rendered harmless.

This forms a convenient place to consider generally the
wood-destroying wound-parasites of our timber-producing
plants.

The wood-destroying wound-parasites belong chiefly to the
families of the Polyporeae and Agaricini, and each possesses a
mode of life and method of destroying its host, so similar to
that of its relatives, that it is quite impossible to consider them
separately in a practical way. They are enemies of our fruit
orchards, our parks, and our forests, and the means to be em-
ployed against them varies in the hands of the fruit-grower, the
gardener, or the forester.

Every fruit-tree, whether grown in a garden, an orchard, or

PREVENTIVE AND COMBATIVE MEASURES. 73

on a roadside as in some countries, is an object of such value
that, if need be, costly methods can be employed on its behalf.
Its branches must be kept free of all intruders like the
mistletoe, witches' brooms, mosses and lichens, and above all,
from the sporophores which indicate the presence of a wood-
destroying fungus. This is all the more easy ]:)ecause the trees
are frequently closely examined for pruning, for crop, or for
insect attacks. The sporophores of fungi on stems and branches
should, as already indicated, be early and carefully cut out, the
wound scraped and tarred over.^ In this way the fungus will
be deprived of its sporophores and the safety of other trees
ensured, although it must be remembered that the mycelium
still continues to destroy the wood and probably to produce
new sporophores. If the sporophores appear on weak branches,
these would best be completely cut off and the cut end tarred
over. Trees although diseased and requiring annually to have
sporophores cut out should still be spared, as they often continue
to live and yield heavily for years. Amongst the sporophores
which appear frequently on fruit-trees are those of Polyporus
igniarius, P. fulvus, P. hisindus, P. sulphureus, P. squamosus,
P. spumcus, Hydmim Schicdcrmayri, and others to be more closely
considered in the special part of this work.

Particular attention of this kind is of course more difficult
for the park-gardener, because his trees are higher and stand
closer together. The trees are, however, of less value individually
than fruit-trees. It is advisable, as far as possible, to keep the
trees clean, to tar all wounds and to remove poorly developed
branches and stems.

To the forester in high forest all this is, however, a matter
of difficulty. The trees are high, the forest large, and the
individual trees of a value which does not allow of costly
labour being expended on them. Yet there is one forest
operation in which a plantation may at small cost be easily
cleared of diseased stems. This is the repeated process of
thinning, during which all diseased and backward trees should
be felled. In forests of high value with high-priced timber
and near towns or centres of industry, this cleaning out is, of
course, easy, but in remote forests with a small working staff,

^ The sporophores cannot be removed too young ; the wounds produced should
be treated with tar ; see Section iii., p. 77.

74 PREVENTIVK AND COMBATIVE MEASURES.

deficient modes of conveyance, and a small demand for the
thinned-out material, this may appear impracticable. I shall
give one example how the number of " fungus-sponges " (as
the sporophores are called) decrease with enclosure and intro-
duction of proper forest-management.^ Bischoffsreut is a forest
in Bavaria, near the Bohemian frontier, consisting of mixed
spruce and fir up to four hundred years, and beech up to
two hundred. Forty years ago the sporophores of Pohjporus
fomentarius, the tinder-fungus, were so numerous and large that
for their collection for manufacture of caps, gloves, tinder, etc.,
a sum of one hundred gulden (£8 10s. Od.) was paid annually
as rental. Ten years ago the same brought in a revenue of
twelve shillings ; to-day it is free. In course of time the
diseased stems have been gradually felled and less wood has
been allowed to remain lying in the forest to decay ; as a
result the wood-destroying fungi have now but little foothold.
A mixed damp virgin forest is especially favourable for the life
and distribution of fungi of this kind.^ All fallen wood remains
lying, while injuries from storm afford easy spots for infection.
In Bischoffsreut eighteen per cent, of the felled heavy wood
was at one time useless and rotten.

(2) It is often possible to avert diseases of valuable cultivated
plants caused by heteroecious fungi, by keeping the supplemen-
tary host at a distance, or, if the disease has already broken
out, to remove it altogether, with the view of keeping the
more useful host free from the dreaded disease.

The best example of this is presented by the heteroecious
rust-fungus Gymnosporangium sabinac. One host frequents
Ji/MijK'rus sabina (savin), the other damages pear-trees, causing,
in the case of a severe attack, considerable loss. It would thus
be easy to exterminate pear-rust by removing the not very
decorative savin-bush. Particularly in nurseries, it would be
well to avoid placing pear-trees near the savin, an arrangement
very suitable for cultivating the Gymnosjjorawjiv.m.

As another example we may take Mclam^jsora treimdae
frequenting the aspen, the supplementary host of (a) Cacoma
pinitorquum (the pine twister), and (h) Cacoma laricis (larch

1 V. Tubeuf, " Mittheiliing lib. eiiiige Feinde d. Waldes." AUeg. Forxt.-n.
Jarjdseitung, 1887.

-V. Tubeuf, " Vegetationsbilder, aus d. boehmischen Urwalde." Oefiferrcich,
Foritzeitiaiij, 1890, p. 108 ; with six figures.

PREVENTIVE AND COMBATIVE MEASURES. 75

needle-rust). The exclusion of the aspen from the neighbour-
hood of pine plantations is advisable as a means of limiting
the pine -disease, and is now being recommended in forestry.

Still another example is Puccinia graminis the rust of
wheat and its Accidivvi on the barberry. This is, in all
probability, able to reproduce itself by means of uredospores on
wild grasses, and to retain its position without the barberry, yet
the latter doubtless tends to distribute the disease, and its
removal minimises the risks of attack.

An investigation of the heteroecious rust-fungi will easily
furnish many examples of the same kind, and lead to the con-
clusion that Eupliorhia cyjyarissias, for example, should be
exterminated near fields of peas or other Leguminosae because
of Uroviyccs jnsi, and U. striatus.

III. Avoidance or removal of conditions which favour infection.

Various examples of this have already been given when
the conditions disposing plants to disease were under considera-
tion in our last chapter.

(1) The most important measures of this class are those
directed against infection through wounds. This may be
attained by avoiding any unnecessary wounding of woody plants,
and the immediate treatment of any wounds rendered necessary
in pruning or other operations.

When the stems of woody plants are injured, the first step
towards healing the wound proceeds from the tree itself.
Conifers containing resin have in it a very ready agent im-
mediately available ; the resin escapes from its ducts and soon
hardens into a crust on exposure to air. In the case of non-
resinous conifers and of broad-leaved trees, the first steps
towards healing are less obvious, but it has been found that a
healing tissue immediately begins to form on wounded surfaces.^
It consists of a parenchyma, the formation of which is induced
apparently by atmospheric air penetrating into the wood, and

^v. Tubeuf, " Ueber normale u. pathogene Kernbildung d. Holzpflanzeu
u. d. Behandlung v. Wunden derselben, Zeitschn/f f. Forst.-n. Jagd.-iresen, 1889.
Contains Bibliographj- of allied papers.

R. Hartig, IJist^asf" of Trees, English Edition, 1S94.

Gauneisdoifer, Si(ziuigd>er. d. k. Akad. d. Wisxen^ichaft , Vienna, 1881.

Boehm, " Ueber die Function d. veget. Gefasse," Botan. Zeitung, 1879.

76 PREVENTIVE AND COMBATIVE MEASURES.

its object probal)ly is to restore the same condition of gaseous
pressure inside the tree as existed previous to the injury. A
number of woody plants, for example, Robinia and Qucrcus,
which normally form tyloses in their heart-wood or sap-wood,
do the same on wounded surfaces, and thereby stop up all
the cut vessels.^

The formation of tyloses is due to sac-like ingrowths into the
vessels from adjoining parenchyma, and can only take place
where rapid growth of the closing membrane of pits or the thin
portions of the wall of annular or spiral vessels occurs. Tyloses-
formation takes place in normal heart-wood, and also in the
sap-wood of many kinds of trees, except in the very youngest
water-conducting year-rings. It also occurs in leaf-scars at the
the time of normal defoliation.^ Species of trees in which
tyloses are not normally produced in the heart-wood, but in
which the vessels of that region become filled with resinous
secretions, use these substances as healing agents in the case of
leaf-fall or wounds to the wood. For these reasons it is quite
correct to designate these preliminary steps towards w^ound-
closure as a pathogenic formation of duramen, and the tissue
derived from the process as wound-duramen. Similarly a corky
tissue — wound-cork — may be formed in consequence of wounds
to the bark or as an accompaniment of certain diseases. I
have repeatedly observed that the normal duramen is preyed on
for nutriment by many wound-parasites, and also that this
wound-duramen is not sufficient to keep out germinating spores
of the wound-parasites. It cannot therefore be designated a
protective wood, nor are the artificial methods of closing wounds
so superfluous as some would have us believe.^

Frank says : " The use of all such artificial means of healing wounds
is thus only necessary in serious cases, in which, in consequence of delay
in the healing-process, decay would be inevitable without some septate
agent. Smaller wounds, and particularly cut surfaces of twigs or thinner
branches, are, by the natural formation of protective wood accompanying
every wound of tlie wood, sufficiently protected for the few years the

1 Molisch, " Zur Kenntniss d. Thyllen," Akad. d. Wissenschaft, Vienna, 1888;
Wieler, Biolog. Centralblatt, 1893.

- Staby, " Ueber Verschluss d. Blattnarben nach Abfall d. Blatter," Flora,
1886.

^ Prael, Primisheim's Jahrhuch, 1888.
Temme, Landwirth>:chaftl. Jahrhuch, 1885.
Frank, Die Krankhtiten d. PJlanzen, 1894, p. 153.

PREVENTIVE AND COMBATIVE MEASURES. 77

wound must remain open till completion of occlusion." If we followed
this view, then numerous wounds would be left freely open as entrances.
for wound-parasites, and serious loss would result. It is just the numerous
smaller wounds {e.g. those produced by hail), which are the principal places
of infection for species of Nectria, Cucurhitaria, Hymenomycetes, etc., in
fact, they form very convenient places whence a tree may be easily infected
artificially.

The following points in regard to treatment of branches may
be conveniently summarized here. Trees in closed plantations
are naturally stripped of their branches by these dying in con-
sequence of deficient illumination ; they then break off, and
the short stumps are soon occluded or grown over. During
this process there is always a risk of infection by fungi, and
" snag-pruning " ^ is employed to shorten the period of occlusion
as much as possible. This at the same time prevents the in-
clusion of long branch-stumps in the timber, and reduces the
number of knots in sawn boards. Such dead snags or stumps
are deficient in nutritive materials and very dry, so that they
are less suited for the entrance of wound-fungi than wounds on
the living branch.

The usual process of forest-pruning is necessary to produce
clean boles, to increase the illumination for undergrowth, or
to utilize the branches so removed. In the operation, all
branches should be cut off close to the shaft, no snags should
be left, nor must injury be inflicted on neighbouring bark.
The operation is best carried out in autumn or winter when
the bark is most adherent to the wood, occlusion then begins
with the renewal of vegetative activity in spring and is well
advanced by the time the greatest dispersal of fungus-spores takes
place. Infection by fungi will, however, be rendered quite
impossible if wounds are immediately painted over with tar, or^
in the case of smaller wounds on garden stock, with tree-wax \
these reagents, if applied in winter, will easily penetrate into the
wood, and even replace the formation of protective wound-wood.
Hartig says on this subject : ^ " tarring produces satisfactory
results only when pruning has been done in late autumn or
in winter, because it is only then that the tar is absorbed by
the surface of the wound. It would appear that the absorption
of tar is due partly to the diminished amount of water in the

1 Trockenastung. - Hartig, Diseases of Trees. English Edit. p. 258-59.

78 IMIKVKNTIVE AND COMBATIVE MEASURES.

wood during autumn, and partly to the consequent negative
pressure of air in the tree. When pruning is undertaken in
spring or summer the tar altogether fails to enter the wood,
and the thin superficial layer does not prevent the cut surface
from drying later and forming fissures into which water and
fungi may enter." From what has been said it folio w.s that
dicotyledonous trees may be best pruned in the months of
October, November, and December — perhaps also in January
and February, — and that a good coat of coal-tar should be at
once applied to the wounds.

Conifers should also be pruned in autumn and winter, for
although the wounds resulting from removal of small branches
with no heart-wood are soon protected by an excretion of resin,
yet thicker branches with heart- wood, which secretes no resin,
must be tarred over. Similar precautions are advisable to
protect the stools of trees felled in order to produce coppice.

Wounds are produced on fruit-trees by removal of branches, by
pruning and grafting, and again during the fruit-harvest. Hail
and wind are frequent sources of wounding. Gnawing of the
bark by animals, such as mice and other rodents, may also occur.

Red deer, by peeling off the bark, are a source of great
damage in the forest. In this way spruce plantations may be
so peeled, and in consequence so subject to red-rot that they
have to be prematurely felled. The trees which suffer most
are those like spruce, silver fir, Weymouth pine, and Douglas
fir, which remain for a considerable time smooth-barked, whereas
species with a rough bark are comparatively safe ; the latter
can also cover up any wounded surface by means of an excretion
of resin. Conifers suffer most from peeling, but the broad-
leaved trees are not quite exempt. At certain seasons the deer
rub the fur off the young antlers or knock off the old ; for
this purpose they generally .choose younger plants, which, in
consequence of the injury, frequently dry up. Injury by deer
is more serious in summer than in winter, because with the
increased temperature and moisture the spores are able to
convey infection quickly and easily.

Injuries similar to peeling by deer are produced in gathering
resin, and in the process of " testing " the timber of conifers.
Both practices are, however, prohibited in well-managed forestry,
and occur only as misdemeanours. Resin-collecting of whatever

PREVENTIVE AND COMBATIVE MEASURES. 79

kind, whether from spruce, larch, pine or the silver fir, necessi-
tates removal of the bark, and probably cutting into the wood
itself. The exuded resin and naked wood dry up in course of
time and crack, thereby allowing the entrance of fungus-spores,
which germinate in the fissures of the wood and lead to its
destruction.

The forests of spruce and fir in Bavaria furnish valuable
wood suitable for the manufacture of violins and other musical
instruments. Till recently the practice was first to split a test-
piece from the standing tree to ascertain the cleavage of the
stem. If the test did not split true, the tree was left standing
and wounded ; such stems naturally were soon attacked by fungi
(Polyporeae and Agaricini) and succumbed to some storm.

The beech is frequently injured in a somewhat similar manner
by the woodmen, who hew out large pieces of the stem to obtain
material for wedges from the very tough occlusion-tissue which
is afterwards formed. Stems so damaged soon fall a prey to
Polyporus fomcntarius. Wounds to the wood are also frequently
produced during the felling of neighbouring trees, or as a result
of storms, or by the action of woodpeckers, ants, and other
enemies. In short, wounds are so common that the necessity
of practical remedial measures for closing them as entrances
for destructive parasites, must be at once evident.

(2) Localities should be avoided which are known to pre-
dispose certain plants to disease. Just as one avoids cultivating
tender plants in cold situations, or planting our less hardy
trees in places known to be liable to frost, so ought we to
avoid the cultivation of plants in localities which will render
them more than usually liable to infection by fungi. Thus the
formation of spruce-nurseries at considerable elevations has had
to be abandoned, because it was observed that they were there
liable to complete destruction by Hcrpotrichia nigra. For
similar reasons the hole-planting of spruce in elevated situations
must be avoided. In nj^oist localities nurseries of Douglas fir
and other trees are in danger of attack from Botrytis ; while
close glass-houses and hot-beds are breeding-places for many
parasites which would at once die away with good ventilation.

(3) The neighbourhood of plants which are supplemental
hosts of the same heteroecious fungus should also be avoided.
(See also p. 74.)

80 PREVENTIVE AND COMBATIVE MEASURES.

(4) The massing of numbers of the same species of plant
together is dangerous, because it presents a favourable oppor-
tunity for tlie rapid spread of epidemic diseases. On this
account the smaller fields of small holdings tend to prevent
any epidemic from assuming serious proportions. Still l:)etter
is a system where, as in Xorthern Italy, a few rows of vines
alternate with narrow strips of Indian corn with gourds or
melons on the ground below, and strips of grass or millet
intervene here and there.

Wherever similar plants must be cultivated in close neigh-
bourhood over extensive areas, as in vine cultivation, any
epidemic, which may obtain a hold, soon produces disastrous
effects. Our cultivated forest plants, when occupying extensive
areas, are particularly open to attacks of certain fungus-diseases.
Thus Pines from Hystcrium 2J'inastr{, Caeoma jnnitoi-qmim, and
Feridermium j^Jtm ; pole-forests of pure spruce from Hysteriurti
7nacrosporum, all plantations of conifers from Trametes radi-
ciperda and Agaricus mdleus, the latter especially if preceded
by beech forest, the stools and dead roots of which offer the
Agaricus an opportunity for easy and abundant development.

The prevention of many epidemic diseases is one of the
advantages claimed by Gayer ^ in favour of natural regeneration
and mixed plantations. On exposed areas the prevailing strong
winds facilitate distribution of many fungus-spores, while, at
the same time, they introduce the supplemental hosts of
of heteroecious fungi {e.g. aspen, ragwort, cowberry, etc.), which
would be excluded from a closed permanent mixed forest natur-
ally regenerated. Of course, we do not maintain that, under
these conditions, diseases are entirely absent, because it is just
on naturally-sown beech seedlings in closed forests that Phytoph-
thora finds a habitat. Similarly Trichosphacria on silver fir,
and other parasites, are in closed forest provided with that
degree of atmospheric moisture which favours them. In fact,
several parasitic fungi exhibit adaptations to such conditions.
Diseases, speaking broadly, are less dangerous in mixed forest ;
they never attain the same distribution, and they are more
easily restricted where trees of different dispositions are grown
together. Thus, the forests of Bavaria consist, in the lower
elevations, of mixed beech, silver fir, and spruce ; higher up
^ Gayer, De7- Waldbau.

PREVENTIVE AND COMBATIVE MEASURES. 81

the beech is omitted, and in the more elevated parts spruce
alone is planted. The fir alone is attacked by PJwma ahietina
Aecidium elatinum, Lophodcrmium nerviseqimiin, Tricliosphacria
jKirasitica ; the spruce, on the other hand, has to itself
Loj^hoderminm macrosporum, Chrysomyxa abietis, Hciyotricliia
nigra, while both are subject in youth to PcsUdozzia Harticjii,
and later to several wood-destroying fungi.

The storing together of crops like apples, potatoes, onions,
turnips, etc., should be carefully carried out. They should be
handled as little as possible, and decaying individuals should be
sought out, and destroyed when possible, to save the remainder.

IV. Selection of hardy varieties.

An important method for the protection of plants from disease,
both from the preventive and remedial side, consists in the
selection and cultivation of varieties and species of plants able
to resist the attacks of parasitic fungi.

It has already been mentioned that different varieties and
species show different powers of resistance against enemies. As
a further example, we have numerous American grape-vines
which are not attacked by downy mildew {Plasmo2)ara viticola),
that dangerous enemy of the European vine of cultivation
{VifAs vinifcra). Some American vines {r.(j. VitU riparia)
are proof against the phylloxera, the root-louse which attacks
the roots of European vines and devastates the vineyards of
the wine-producing countries ; while, on the other hand, other
American vines are no more resistant than the European. In
fact, it was the importation of those vines into Europe for
experimental cultivation which brought us both phylloxera and
the downy mildew. The cultivation of such disease-proof
species would ensure us immunity from the phylloxera, if it
were not that the wine from these vines has neither the quality
nor the flavour possessed by the European. On this account
the grafting of European vines on American stocks has been
introduced, whereby the roots remain unattacked by the
phylloxera, and the grapes are of tlie approved standard. Very
good results have also been obtained from experiments in
hybridization of American and European vines with the object
of obtaining roots from the American parent, and grapes from

F

82 PREVENTIVE AND COMBATIVE MEASURES.

the European. The long and patient experiments of Millardet ^
are the most conspicuous amongst many which, by means of
grafting and hybridization, have aimed at obtaining disease-proof
vines. Millardet, out of numerous hybrids raised by him, has
succeeded at last in obtaining vines with roots proof against
phylloxera, leaves resistant to attacks of downy mildew, and
grapes which impart the esteemed flavour to the various old
and well-known European wines. From these many ruined
vineyards of southern France have been already re-stocked, and
promise well.

The results obtained from Eriksson's investigations on cereal-
rusts ave also worthy of notice.'^ This investigator, after carrying
on cultivations for a number of years, has found that there are
varieties of wheat able to resist the more frequent forms of
rust, and in no way endangered by them. By a similar method
of investigation, varieties suitable for cultivation in the rust-
infested districts of Australia have also been obtained.

' Millardet, "Notes sur les vignes americaiues." 8er. in. Mem f/e /a -soc des
.sciences ck Bordeaux, 1891; Jonrn. d'a</ricidiiire praticjue, 1892; Compt. rend.,
1894; Zeitschrift f. Pflanzenkranklieiftn, 1894, p. 47, and 1895, p. 116.

Esser, " Die Bekiimpfung parasit. Pflanzenkrankheiten," Samml. wissennch.
Vortrd(/e; by Virchow u. Watteubach, 1892. With Bibliography.

-Eriksson. Zeitachrift f. Pflanzenkrankheiten, 1895, p. SO.

CHAPTER VII.
ECONOMIC IMPORTANCE OF DISEASES OF PLANTS.

.^13. The economic inipoitance of any plant-disease depends on
its distribution, its intensity, and the vahie of the plants attacked.
Of most consequence are those epidemic diseases of fungoid origin,
which cause rapid death of their host, and spread with great
rapidity over wide areas. Such, through repeated attacks,
may render the cultivation of certain plants impossible
in a locality. Almost equal damage may result from those
parasites, which, although they do not kill their host, yet
destroy or prevent the development of that part for which we
grow the plant. Amongst these are species which inhabit
Howers or fruits, the wood-destroying fungi of forest-trees,
and forms inimical to the foliage, roots, or tubers of plants
of economic value.

As examples of parasitic fungi which bring about rapid death
of their host, are the originators of many diseases of young
plants. Phijto'phtlwra omnivora may during a few days of damp
weather completely kill out not only healthy beds of seedling
beech or conifers in the nursery, but even the young plants
by which a forest is being naturally regenerated. Pestalozzia
Hartigii, a few years ago in the beech-forests in some districts
of Bavaria, exterminated three-fourths of the naturally-sown
plants from one to four years old. Herpotrichia nigra is
capable of completely destroying the young spruce plantations,
so important for the afforestration of bare slopes in mountainous
districts, and it may attack with such violence nurseries
established at great cost and labour that thev have to be

84 ECONOMIC IMPORTANCE OF DISEASES OF PLANTS.

iibaiiduiied. Whole ,<4iir(lL'ns of roses have been devastated hy
Ffruiiosjxirx sjxosa, and nurseries of conifers have been exter-
minated by Hyderivm ]nnasfri, or Ar/aricvs mellcvs.

Amonf2;st the fungi, which attack the organs of (jhler jilants
and cause serioiis hxsses to cultivators, are the following : the
well-known potato disease caused by PJiytoplUhora infcstanH;
the vine diseases arising from Uncinula S2nralis, Plasmopara
viticola, and Beinatoiiliora nccalrh:^ ; many diseases of conifei'S
and other trees. As destroyers of the fruit alone may be
mentioned the smut-fungi of the cereal crops.

Other cases of injurious diseases, of more or less practical
import, will be described in the special part of this book ; at
present we shall only select a few estimates of the loss result-
ing from them.

In the forest of Bischofl'sreut in Bavaria — a magnificent one,
containing spruce, fir, and beech — eighteen per cent, of the
felled timber consisted of wood rendered useless by decay ;
while fifty years ago the utilizing of the so-called fungus-sponges
of Polyporus fomentarius in the same forest for manufacturing
purposes and for tinder, was let for a small sum (see p. 74).

Higher figures are, however, reached when we calculate the
injuries on vines or cereal crops. Pierce,^ in 1892, furnished
estimates putting the loss resulting from the Anaheim vine-
disease in California at ten millon dollars. The area of infected
land was about 25,000 acres, in great part with an original
value of 300 to 500 dollars per acre, l)ut so depreciated in
the course of five years that it became worth not more than
75 to 200 dollars.

In the ZnUchrift filr PJianzenhranklwitcn 1893, the inter-
national phytopathological commission gave, from estimates
mates furnished by the Prussian statistics-bureau, a review of
the losses in Prussia from grain-rust. Amongst other esti-
mates we find that in 1891 the wheat harvest of Prussia
reached a total of 10,574,168 doppelcentner,- which at 22
marks per d.c. = £11,459,690 sterling. Of this 3,316,059 d.c. or
£3,593,758 was depreciated by rust. The rye harvest was
30,505,068 d.c. at 22 marks, of which 8,208,913 d.c.
or £8,896,364 was depreciated by rust. Oats reached

' The California Vint-.- Diseane. U.S. Dept. of Af/riculfure, Bull. 2,, 1892, p. l/i.
■-' Doppelcentner = 100 kilogramme.

ECONOMIC IMPORTANCE OF DISEASES OF PLANTS. 85

32,165,473 d.c. at IG marks, of which 10,325,124 d.c.
or £8,138,023 falls t(j be deducted on account of rust.
Thus on the crops wheat, rye, and oats, the loss reached the
sum of £20,628,147 sterling, or almost a third of the total
value of the crops. The year 1891 was a very unfavourable
one, but even taking the estimate at the half of tlie above
sum we have a yearly loss l)y rust amounting to £10,000,000
sterling.

In Australia the loss in the wheat harvest of 1890-91, on
account of rust, has been estimated at £2,500,000 sterling.

Consideration of the loss of sums of money like these, which
might be considerably reduced if energetic and universal measures
were employed against fungoid plant-diseases, will serve to em-
phasize the importance of remedial measures. It must also be
borne in mind that the use of diseased fodder,^ especially hay,
grass or grain, infested by rust or smut-fungi, is productive of
serious results to the various animals of the farm ; while the
use of meal or flour contaminated with smuts, stinking- smuts, or
ergot is dangerous for mankind.

' Frohuer, Lehrhur/i d. Toxikolonie f. Thkrdrzte, 1890.

CHAPTER VI 11.

SYMBIOSIS.

5^ 14. MUTUALISM.

Mutualism, or Symbiosis in the stricter sense/ has been
distinguished as a special case of parasitism. This condition
occurs when a parasite and its host mutually work for
the benefit of one another, each contril)uting to the other's
nourishment. The lichens furnish the most conspicuous example.
Here fungus-hyphae unite with algal cells, the algae furnishing
the fungi wdtli assimilated organic nutriment, the fungi pro-
viding water and dissolved salts for the algae.

While it is by no means uncommon to find two organisms
taking a mutual advantage of each other, yet mutualism in its
strictest sense is a rare phenomenon. For it generally happens,
and is indeed to be expected, that one or both .symbiotic
organisms modify in some degree their mode of life to suit the
altered conditions necessary for their mutual support. Thus
amongst the lichens, as a result of the union of fungus and
alga, a living organism originates, which in form, necessities,
and mode of life is quite nciv, and differs completely from
either of its components. In the lichen-community, the fungus
alone reproduces itself; yet the alga occurs as a free organism
in nature, while the fungus can only be reared in artificial
culture. This combination might perhaps be compared with
that of oxygen and hydrogen to form water, also to a certain
extent with the union of the sexual cells to produce a new

^ The term ISyml)iosis was applied by De Baiy, (who iutroduced it), bj' Frank
and others, to denote those cases wliere a cohabitation or partnership was
observed to take place between two different organisms. (Frank, Lehi-huch <L
Botanik; 1S92). " Mutualism" was first used l)y Van Beneden.

MUTUALISM. 87

individual. These, and other examples, will serve to illustrate
liow we have in the lichen an organism with peculiarities of
structure and of life, widely differing from those of either an
alga or a fungus. This unification of two living beings into an
individual whole, I have designated " Individuation.'" ^

In the case of the lichen-symbiosis, the chlorophyllous part
consists of minute algal cells, completely enclosed in a tissue
of fungus-hyphae, and the lichen lives as a perfectly isolated
and independent plant. The case is, however, different where
the fungus enters into parasitic relationship with the green
cells of a large plant. Union may then take place, so that the
fungus lives on, or inside its host, and removed from contact with
any other substratum. The fungus is, however, not in a position
to convey any nourishment to its host, and in fact is absolutely
dependent on it for the organic substance and water necessary
for growth. "Where, however, the relationship is such that the
parasitic fungus is still in contact with some other substratum,
then it may be assumed that, in spite of its parasitism, it
takes up nutriment from this source, and shares it with its
host. This, as has already been pointed out, is the state of
things in the lichens, where the fungus completely envelopes
the small isolated algae, and must, as a condition of the growth
of the lichen, remain in direct contact with the substratum ;
the fungus is believed to take from the substratum water and
inorganic food-material with which it supplies the algae, while
it receives in return plastic organic substance to be used in
its own growth. Of course cases do occur amongst the lichens,
where, in moist places, the alga is not dependent on the fungus,
or, on the other hand, where the fungus can itself take up
organic substance from its substratum.

Another example of the case is the union of fungi with
non-chlorophyllous plants which inhabit humus (e.g. Monoirojia).
Here the fungus takes up organic nourishment from the
sul)stratuui and supplies it to the higher plant, which, in
consequence of its lack of chlorophyll, is directly dependent on
the plastic organized substance from the soil, supplied through
the agency of the fungus. The latter, however, receives nothing
in return ; it requires nothing, since its substratum offers it
the most favourable conditions for nutrition. This form of

' Individualismi^s.

88 SYMBIOSIS.

symbiosis, in which the l"un<,'us becomes the nurse or feeder, I
distinguish as Nidricism. lietvveen the case just cited and
that in which the fungus is a pronounced root-parasite on
green plants, there exists every possible intermediate stage.

r)efore nutricism is considered in detail it vvoidd be well tf)
exemplify l)rietly from the ranks of plant-parasites, that piieno-
menon of individuation so sharply defined in the lichens.
A large uund)er of parasitic fungi cause local cell-enlargement and
cell-increase^ with the frequent result that an attacked plant-
organ becomes very much enlarged and its form much changed.
One speaks in such cases of hypertrophy and hypertrophied
organs. It is quite evident that in cases of hypertrophy the
attacked part must be better nourished, otherwise it could nevea-
sustain the great increase in number and size of its cells. The
hypertrophied organ is, in fact, indebted to the surrounding
healthy parts for its additional nourishment : in other words,
the place of demand drawls to itself the materials it requires.
This is all the more necessary when the region of increased
growth is deficient in, or altogether devoid of, chlorophyll, and
thus quite dependent on the assimilating green parts. . This
is frequently the case, as in the scales of alder catkins attacked
by E.mascm alni incanae, in the needles of silver fir deformed
by Aecidium elatinum, or in the yellow needles on spruce
resulting from Aecidium coruseans. So also must the woody
swellings of branches attacked by Aecidium clcdinum, Gymno-
sjjoranffium sahinae, and other fungi, be produced at the cost of
neighbouring parts of the host. The hypertrophied organs be-
have, in fact, like these plant-organs — flowers, roots, etc. —
which are normally deficient in chlorophyll, and to which
plastic material must be supplied.

In other cases the part of a plant attacked by fungi behaves
like a specialized organ, and, in combination with the fungus,
attains to a certain degree of independence. The so-called
"witches' brooms" furnish an interesting example. It is a well-
known fact that the direction of growth of the main axis of
plants is negatively geotropic, whereas that of the lateral branches
is only a modified form of this condition. If the terminal bud
of a tree (e.fj. a spruce or fir) Ije removed, then one or more
lateral branches, or even buds of those branches, will exhibit
an increased negative geotropism. This is very marked in

MUTUALISM.

89

the case of the so-called " storni-tirs " of the mountains, on
which are developed not a single apex, as in the normal lir,
but many, each of which grows up like a little independent
tree on the branches of the old stem. A similar result follows
where a portion of a lateral branch is planted as a " cutting,"
one bud grows directly upwards, the others form lateral branches.
The stimulating effect which the removal of the terminal shoot
produces on lateral branches is thus one wdiich extends to a
considerable distance. A stimulus of a somewhat similar nature
appears to be exerted on buds attacked by certain fungi, so

I-'lf;. 1,;. — Witches' Ijroom of Silver Fir, caused by Atcidiuiii datinam.
(V. Tubeuf phot.)

that the shoot produced from such a bud no longer retains its
normal direction of growth, but becomes negatively geotropic
like an independent plant. This marked negative geotropism
is characteristic of all witches' brooms (Fig. 16), and shows
clearly that they are no longer controlled by the same laws of
growth as the normal lateral branches. They have in addition
other peculiarities not exhibited by normal plants. Thus the
witches' broom of the silver fir caused by mycelium of
AecicUum datinum is not evergreen, but bears needles which
fall each autumn. Moreover, no witches' broom bears flowers
or fruit ; for example, that on the cherry (Fig. 5) produces
exclusively leaf-buds, which unfold simultaneously with the

90 SYMP.IOSIS.

opening of the Hower-ltuds of iinattiicked tvviys, tlie noniial
foliage coming later.

We have here an expression of llie existence of a closer
syniliiotic relationship between the fungus and its host-branch,
than between that host-branch and its main branch. It also
shows that the liost-branch is completely at the service of the
fungus, although the latter is dependent on the former for its
support. The host-branch is, at the same time, under the
necessity of conducting itself in the partnership in the way most
suitable to the development of the fungus.^ Thus the asci of
the Exoasceae are produced on the leaves of the witches' broom,
and ripen as the normal leaves unfold, so that the spores
are in a position suitable for successful infection of the young-
normal leaves.

From these facts it can be deduced, that parts of plants
attacked by fungi exhibit that kind of symljiosis with the fungus
which we call individuation, the joint community behaving
more or less as a parasite on the stem or branches of the host-
plant. This is clearly the case where the attacked parts exhibit
increased growth, and at the same time a diminished production
of chlorophyll resulting from degeneration of chloroplasts. Such
parts of plants are quite as individualized as the lichens, with the
single distinction that they remain in communication with the
parent plant and draw nourishment from it.

There are, however, other cases where the chloroplasts are
apparently increased, where at least they attain a lengthened
duration of life. This is evident in certain instances first
pointed out by Cornu, mentioned by De Bary, and on
which I have made extended observations. IMaples may
be found in autumn on whose discoloured, withered leaves
large green spots are still present. On Norway maple I have
observed these spots, very conspicuous on almost every leaf,
and especially on those of the lower crown. The green parts
were beset with the white epiphytic mycelium and perithecia
of Uncimda accris. Cornu describes similar appearances accom-
panying another Erydphe, certain Urediueae, and Cladosporiinn
dcndriticum. I have seen the same phenomenon regularly on
the mountain maple on leaves carrying black spots of lihi/tisma

1 Plant-galls caused l)y animals also exhibit adaptations serviceable only for
the gall-occupant.

MUTUALISM. 91

pundatiim (Fig. 129). As other examples may be mentioned
quince leaves, which I infected with Gynvnosjiorcmgivm dararwc-
forme, and leaves of Cynonchinn Vinctfo.vicwiii infested with
Cronartium asdcpiadeuin . In all these cases, nutritive sub-
stances seem to be still transmitted to attacked parts after
death of the rest of the leaf. The attacked spots show also
an independent behaviour in that they do not turn yellow
l)efore the fall of the leaf, l)ut continue to work at the
service of the parasite. One can even Ijelieve that these green
islands, so long as inorganic substance and water are supplied
to them, live with the fungus like lichens, especially those
lichens whose algae obtain water and inorganic material direct,
not through the fungal-hyphae.

CHAPTER IX.

SYMBIOSIS.
55 15. NUTRICISM.

FoH the greater number of the facts used in our (liscu.ssion
of this peculiar phenomenon, we are indebted to Frank, who
hiid the basis of our knowledge in regard to it. We have
chosen the expression Nutricism for reasons already stated
(§ 14), and would only add that its scope is variable in different
eases, and reaches its most comprehensive application in connec-
tion with Frank's views on the so-called mycorhiza. We shall
best explain the phenomenon by describing individual examples.

In a number of cases the symbiosis between fungi and higher
plants does not result in the fungus being supplied with organic
nutriment by its host, but rather that the fungus is in no way
indebted to the host-plant for nutriment, and may even, us in the
lichens, convey solutions of inorganic materials to it, thus assist-
ing in its nutrition. There are two cases distinguishable in this
connection. In the first, the fungus lives in humus and in
close external contact with the roots of its host, obtaining
food for itself, and at the same time supplying its host
with organic nutriment. In the other case, the fungus develops
in.side the root-cells of its host, and is probably nourished from
that source, till on dying it gives up certain albuminoid sub-
stances, which are absorbed and utilized by the host-plant. The
parts of the roots which shelter the fungi, Frank has named
" fungus-traps," the plants themselves being " fungus-digesting
plants."

The organs resulting from the symbiosis of root and fungus

NUTKICISM. 93

have been named niycorhiza ^ or fungus-roots. Where, however,
new structures (swelHngs, etc.) are produced on the roots, as a
result of symbiosis with fungi or bacteria, the name mycodomatia
or fungus-chambers has been apphed.

One division of mycorhiza consists of those which live in
humus, and act as intermediaries in supplying their hosts with
nutritive material. In this case the fungus covers the host-
root like an outer covering, forces itself between the cells of
the outer layers, and produces haustorial branches in the interior
of the host-cells. These Frank designates as ectotrophic
mycorhiza. The remaining mycorhiza do not form such an
external sheath, but live inside the fungus-traps, and produce
tangled coils of hyphae in the root-cells of the host. These
Frank distinguishes as endotrophic mycorhiza.

Ectotrophic Mycorhiza.

(1) On non-chlorophyllous plants living on humus.

Kauiinski - was the first to observe that Monotropa hypo^ntys, a
non-chlorophyllous plant living rooted in forest-mould, pos.sessed a
compact root system devoid of root-hairs, but covered with the
hyphae of a fungus. At the same time, he expressed the belief
that a symbiotic relationship existed between the fungus and
the roots of Monotropa, whereby the former supplied nutriment to
the latter. The fungus clothes the growing point, and extends
backwards to that part of the root which has ceased to elongate;
there the mycelium penetrates -^ inwards between the root-cells,
and remains intercellular. The mycorhiza of Monotnqxi thus
.showed complete agreement with those known earlier on the
roots of Cupuliferae,* and since proved by Frank to have a very
general distribution. Johow ■'' has pointed out that an external
mantle of fungi also exists round the root-apices of Hypointys
hypoi^haegea, a holosaprophytic plant devoid of chlorophyll.

^ Sarauw, Rodsymhiose o(j Mycotvhizer saer/if/ ho>< Slvrfraerne, 1893. With
BibliogiajDhy.

-Kaminski, Mem. de la soc. des sciences natur. de Ckerhow(/, T. 24, 1 882.

•^ Frank, Berichte d. deiitsch hotan. Ges., 1885.

••Muller, Studier over Skovjord som Bidrarj til SJcovdryhiimjens Theori, 1878.

•'' Johow, "Die chlorophyllfreien Hiimuspflanzen," Pringshei77i's Jahrhiicli, 1889.

94 SYMBIOSIS.

(2) On chlorophyllous plants.

Frank has extended Ivaminski's theory to include the
iiiycorhiza of trees and other green phints. This assumption
is founded on his observations of the common occurrence of
mycorhiza im the Cupuliferae, and many other plants. He says
that all trees are probably capable, under certain conditions,
of entering into symbiosis with mycorhiza-fungi, and that in
this way the tree is supplied not only with the necessary water
iuid mineral food-constituents from the soil, but also with organic
material derived directly from humus and decaying plant-remains.
The tree is thus enabled, through the mycorhiza, to directly utilize
organic vegetable remains. Frank supported this theory by
anatomical investigation of the mycorhiza of numerous plants
and later by physiological experiments. The latter consist in the
coniparative cultivation of seedling forest-trees in a sterilized
humus-soil, and also in a non-sterilized soil containing the
mycorhiza-fungi. These experiments showed, in the case of
beech, that those trees in sterilized soil with normal roots and
root-hairs without mycorhiza, were poorly developed, and died
after several years, while the others with mycorhiza grew
vigorously.

Frank also pointed out that mycorhiza are developed only
in soils containing humus, and in the humus layer. He
assumes that the fungus conveys to the tree-roots not only
carl^on compounds, but also, since the mycorhiza- cells contain
no nitric acid, niti'ogen in organic compounds.

The mycorhiza-caps suppress the formation of root-hairs, but
I have frecjuently seen hairs on neighbouring roots or on parts
of the same root behind the fungus-cap (Figs. 17 and 18). In
soil free from humus, root-hairs are always present and carry
on their work normally. Schlicht ^ found that pines growing
in poor sandy soil without humus had no mycorhiza, but only
normal root-hairs, lleess found that pines near Erlangen had
quite as many rootlets without mycorhiza as with. It would
thus appear that while every tree possesses a number of roots
with fungus on them, yet the complete transformation of the
whole root-system to mycorhiza is by no means so general as

^ Schlicht, Inaug. Dissertation, Berlin, 1889, p. 9.
Frank, B<'r. d. chutsch. botan. Ges., 1892, p. 588.
Reess, Ber. d. deutsch. botan. Ges., 1885, p. 295.

ECTOTROPHIC MYCORHIZA.

95

Fig. 17. — Spruce seedling in third year, grown in clay-loam. Typical coral-like
mycorhiza are absent. The strong root to the right shows, on its newer parts
and on all lateral roots, only root-hairs and no fungus. The remaining roots are
not modified in any way — some are covered with loose fungal caps, others
have both fungal caps and root-liairs, while otliers are quite free froin fungi.
<v. Tubeuf phot.)

96

SYMBIOSIS.

in Monotnqm. The root-system of a tree has not only to secure
nourishment, hut also the rigidity and stability of the tree.^
This latter can only be attained by a wide distribution of roots
in the firm subsoil free from humus, where normal roots with
root-hairs will be formed. The nursing function of the mycorhiza
seems thus to be less important than in the case of Monotnipa.

Fig. la.—Mijcorhiza of Pinv.s, Cemlrra. A, Typical mycorhiza. B, Root showing
c-histevs of niyporhiza as well as portions clad with fine root-hair.s. C, Rootlet
exhibiting button-like thickenings externally devoid of a fungoid mantle, but
internally completely destroyed by mycelium. D. Section through a thickened
branch of a mycorhiza-clu.ster : a, fungoid mantle ; '/, fungoid tissue between
the cells of the root, rendering them unrecognizable except by their large nuclei ;
tile inner parts contain no fungi, (v. Tubeuf del.)

My newest investigations on this subject ^ show that, amongst
the gymnospermous forest-trees, the Abietineae alone have roots
externally clothed with a fungus ; the remaining groups have
all endophytic mycorhiza. The Abietineae have frequently only
a fine mantle of fungus on their rootlets, and do not produce the
tufts of short, branched roots so characteristic of mycorhiza in
general. Frank does not seem to be altogether correct in his
view that the Abietineae are almost or quite incapable of multi-
plication by slips, because they would then require to exist for a
time without mycorhiza. Probably there is some other reason
for this, because the Salicaceae {cff. Poplars), which have typical
coral- branched mycorhiza, are almost exclusively multiplied by
slips.

iHoveler, ("iib. die Verwerthnng d. Humus liei d. Erniihrung d. cldorophyll-
fiihrenden Pflanzen." Inaug. Diss., Berlin, 1892), states that roots are a1)le to
utilize the soil-constituents without aid of fungi.

-Tubeuf, Fornl.-nafurii.-iss. Zeitwhriff, 1896.

ECTOTROPHIC MYCORHIZA. 97

After the mycorhiza have functioned as such for some time,
the fungoid sheath, as well as the hyphae contained in the
cortex of the root outside the endodermis, are thrown off by
internal cork-formation. This is, however, not always the case,
for the fungus may penetrate further and develop injurious para-
sitic characteristics; this is so with Polysaccum^ and JElaphomijeesr

Endotrophic Mycorhiza.

(1) On non-chlorophyllous plants living in humus.

Certain Orchideae — Neottia Nidus avis, Epipogon Gmelini,
Goodyera repcns, etc., as well as some Gentianeae,^ possess
roots developed as endotrophic mycorhiza. In Coralliorhiza the
fungus frequents the short coral-like rhizomes. The fungus in
these cases penetrates into the cells of the root-cortex, and
there forms a Ijall or coil of hyphae ; it neither covers the
roots externally nor inhabits the epidermal cells, so that the
production of root-hairs goes on quite normally. From the
circumstance that the hyphal coils become emptied and only
the remains of walls are left in tlie still living root-cells, Frank
concludes that the fungus after being nourished for a time by
the root-cells is ultimately deprived of its contents by them.
On this account he calls these roots " fungus-traps," and the
plants possessing them " fungus-digesting plants." It must be
remarkeil, however, that the fungus grows onwards from older
parts of the roots to younger, so that here, as in many other
cases, the contents of the hyphae may pass from the older into
the younger hyphae. Frank himself suggests* the possibility
that the roots take up nutriment without aid from the enclosed
fungus, and also that the latter receives its food parasitically
from the former. What ad\'antage the roots may receive from
reabsorption of food, which they have previously supplied to the
fungus, has not been closely investigated, nor has the question
whether the roots are in a position to nourish the plants equally
well without fungi.

The root-fungi of Orchideae have long been known, and Pfeffer^

'Brims, "Beiti\'ig z. Keiintniss d. Gattnng Polysaccum," Flora, 1S94.
- Reess, " Uutersiich. uber d. Hirschtrliffel, " Bihliog. Bottin. 1887.
-'• Priu'jsheinls Jahrhnch, xvi. and xx.

* Frank, Lehrbuch d. Botanik p. 267. ' Landicirth. Jahrhuch, 1877.

G

98

SYMBIOSIS.

su22ested that the reduced f'oMuatioii of hairs on their roots was

due to the funyus-hyphae Itehaviiig- physiologically as root-hairs.

Johow, in o])position to Frank, states tliat the non-chhno-

phyllous Wnllschlacfjclia, a relative of Neotiia, shows no trace of

Fio. 10. — Coral liorhiza wnata Br.
(v. Tiibeuf phot.)

Fig. 20.—Xtottic Nidus lu-is Rit'li.
(v. Tiibeuf i-hot.)

fungal hypliae about its roots, and yet derives nourishment direct
from humus. The same author found among roots of the Bui--
manniaccae, some free from fungi, and some with the rind, and
even the epidermis full of mycelium.

(2) On chlorophyllous plants living amongst humus.

According to the investigations of Frank, all our Ericaceae,
Epacrideae, and Empetraceae, living in the humus of moor, heath.

ENDOTKOPHIC MYCt)RHIZA. 99

or wood, possess endotrophic mycorhiza. These appear as fine,
elongated rootlets whose epidermal cells never develop as root-
hairs, hut become filled with coils of fungoid hyphae.

Schlicht mentions a large number of herbaceous plants out of
the most widely separated genera of Angiosperms, the finer roots
of which he found regularly developed as mycorhiza. These, how-
ever, possess in addition normal root-hairs, which without doubt
function as such. The endotrophic coils of fungi are situated in
the inner cells of the cortex surrounding the conductive tissues,
and Schlicht regards them as important in transmitting to the
conducting tissues substances taken up by the root-hairs. Since,
however, the fungus inhabits living cortical cells, it is quite
possible that these transmit the food-materials direct without
the aid of the fungus.

Schlicht found endotrophic mycorhiza on Leguminosae, while
Frank found them on the alder, l)oth being distinct from the
well-known tubercles of these plants.

Kiihn^ and GoebeP found endophytic root-fungi on Marat-
tiaceae, Ophioglosseae, and Lycopodivm ; Kilhn also found spores
which resembled those of Schinzia.

Endotrophic mycorhiza are also present in saprophytic green
orchids, as well as in hemi-saprophytic orchids without green
colour; and Meineke^ found hyphae passing through the little
cells of the endodermis of the aerial roots of orchids into the
mucilage-masses of the rind-i^arenchyma. Schimper found fungi
present on the adherent side of the roots of epiphytic orchids.

Mycodomatia of Myricaceae, Elaeagnaceae, and the

Alder.^

The above-mentioned plants possess a well-developed and
normal root-system, and also characteristic lateral outgrowths,

' Ktihii, " Untersnchmigen lib. d. Anat. d. Marattiaceen,'" Flora, 1889.
- Goebel, Botan. Zeltung, 1887.

^ Meineke, "Beitr. z. Anat. d. Luftwurzeln d. Orchideen," Flora, 1894.
^ Bibliography — Woronin, Mem. de I'acacl. des sci. de St. Petersburg, 1866.

Bruncliorst, Ber. d. deutsch. botan. Ges., 1885.

Brunchorst, Unters. awi d. botan. Inst. Tubingen, 1886.

MtiUer, Ber. d. deutsch. botan. Ges., 1885 and 1890.

Frank, Ber. d. dentsch. botan. Ges., 1887 and 18S9.

Atkinson, " The genus Frankia in U.S. America," Torrey
Club Bulletin, 1892, p. 171, with jjlate.

100

SYMBIOSIS.

which may increase to very large tubers, with surfaces resemb-
ling a bunch of grapes (Fig. 21). In the large cells of the
middle layers of the primary root-cortex of these growths,
coils of very fine fungus-threads are sheltered ; these extend
year after year into the younger parts of the enlarging tuber-
cles, and gradually disappear in the older parts. Wliat may
be the significance of these structures for plants possessing

Fig. -n.—Fiankia nlni Root-tubercles on the Alder, (v. Tiibeuf i)hot.)

chlorophyll and furnished with normal roots is as yet unknown,
riants which have grown well for years in water-cultures do not
show them. On account of the cork-covering with which these
tubercles are furnished, it would seem that they are not adapted
for taking nourishment out of the soil.

Woronin described them first on the alder, Warming on
P^laeagnaceae, while Moller proved their fungal origin.

The species of fungi which produce these tubercles have been

MYCODOMATIA OF THE ALDER, ETC.

101

provisionally distinguished as Frankia alni (Wor.) on alder, and
Frankia Brunchorstii (Mull.) on Myrica Gale.

Hiltner/ after a series of experiments, states that first-year
alders without tubercles do not thrive in soil free from nitrogen,
nor do they take up nitrogen from the atmosphere ; when,
however, provided with root-tubercles they assimilate nitrogen.
The tubercles also functionate in water, and soil rich in nitrogen
has the afiect of slightly increasing the assimilation of that
element. The tubercle-fungus is at first parasitic on the alder,
and is only of iise to the plant after the tubercles have fully
developed.

Mycodomatia of the Leguminosae.

All Leguminosae growing in their native soils exhibit the
so-called tul3ercles. These are accessory formations of the
primary root-rind and are furnished with
vascular bundles connected with the root-
bundles ; they consist of a cortex of normal
cells surrounding an inner large-celled
parenchyma with turbid cell-contents con-
sisting of numbers of bacteria, {Bacterium
radicola, Beyerink, or Rhizdbium leguminos-
arnm, Frank.) -

Frank describes minutely the formation
of these tubercles.^ The short rod-shaped
microlje forces its way into a root-hair
or epidermal cell, multiplies there, and is
conducted to the inner cortical cells by
plasma-threads continuous through the
oell-walls. A rapid division of the inner
cortical cells is set up, till a tubercle is
formed, which may still further increase
by continued cell-division from a meristem phot.)
at its apex. The bacteria multiply simul-
taneously, and are transferred into the new cells where a
great change comes over most of them ; they enlarge very

^ Hiltner, " Ueber d. Bedeutiing d. Wurzelknollchen v. Alnus glutinosa,'*
yohbe's Landi'-irtschaft . Versuchs-statio7ien, 1895.

-Woronin, 2Iem. de /'acad. des sci. de St. Petersburg, 1886.
^ Lehrhuch d. Botanik, p. 271.

Fig. 22.— Jihi:obcir„c Ufjam-
inosamm. Root-tubercles on
Genista tinctoria. (v. Tubeui

102

SYMBIOSIS.

much and become club-shaped or dichotomously branched
bodies without power of division, which may be designated
" bacteroids." ^ Brunchorst found the contents of the bacteroids

Fig. 23.—Jihi:ohlum kguminosarum. Root-twbercles on Kobinia Fseiulacacia
(V. Tubexif phot.)

to disappear at the time of the fruit-formation of the host-
plant. A small number of microbe-bodies still remain, according
to Frank's observations, capable of division, and these, after

' According to Moller, they undergo fatty degeneration.

MYCODOMATIA OF THE LEGUMINOSAE. 103

decay and break-up of the tubercles, reach the soil ready to
bring about new infections.

The great importance of the tubercles of Leguminosae is
that the plants bearing them are capaljle of taking up free
nitrogen from the atmosphere and utilizing it, while without
the tubercles they could not do so.^ If Leguminosae be grown
in soil rich in nitrogenous food-substances, the tubercles are
not so well developed.

According to Schneider,- the host-plant under the influence
of the Fihizobii'.ni i:>rod\\ces cellulose tubes, which become tilled
with the fungus. According to Beyerink,^ these tubes consist
of bacterial slime secreted by the Rhizohium. The epidermal
tissue of the tubercles consists of a loose layer of cork with
many intercellular spaces; this arrangement is stated by Frank*
to facilitate the usual transpiration.^

iHellriegel u. Wilfarth, Berichtt d. deuUch. hot an. Ges., 1889; also ZfAUchrift
f. d. BilbenzurJcer-Indwitrie, 1888.

- Ber. d. deutsch. hotan. Ges., 1894, p. 11.

■^Gentrcdbl. /. Bacterologie u. Parasitenkunde, 1894.

■* Ber. d. deutsch. hotan. Ges., 1892.

■"'Schneider (Bulletin of the Torrty Cluh, 1892), gives a slioi't account of
American Fhizohia, and refers to the chief works on this sul)ject. (Edit.)

PART SECOND.

SYSTEMATIC A1{EAXGE:\IENT OF THE CliYPTOGAMIC

PAEASITES.

I. THE PATHOGENIC FUNGI OF PLANTS.

The vegetative body of the Fungi is a thalloid structure
known as a mycelium, and composed of one or more liyphae.
The hyphae are cells included in a firm wall of fungus-cellulose
of varying composition ; they grow apically, and hence are
always filamentous in shape. In the simpler cases, the mycelium
is a non-septate tube unbranched or branched ; in the more
complex forms, it consists of a system of hyphae divided into
cells by cross-septa. By the union and anastomosing of numerous
hyphae, a tissue may be formed not unlike the parenchyma of
higher plants, hence receiving the name pseudo-parenchyma.
From this tissue may arise distinct structures of many kinds,
such as the sporophores of the Polyporeae, or strands of
tissue like the well-known rhizomorphs of Agaricus melleus,
or masses of resting-mycelium like the sclerotia of ChiviceiJs.
It is also not uncommon to find a differentiation in the structure
of the vegetative mycelium in the form of lateral outgrowths
of the hyphae, developed as organs for the collection of nutri-
ment— the haustoria, — or as organs of attachment — appressoria.
Reproduction may take place sexually by the union of two
cells or nuclei, the product of which is a spore or zygote capal^le
of germination ; or asexually by means of endogenous spores
or swarm-spores, or by the abjunction of conidia of different
kinds. Sexual reproduction is common amongst the lower
fungi, but in the higher forms, if existent at all, it is very

THE PATHOGENIC FUNGI OF PLANTS. 105

obscure and is replaced by numerous and complex modes of
asexual multiplication.

The lower forms of fungi, in the structure of the thallus, mode
of reproduction, and adaptation to an aquatic life, exhibit distinct
relationship with the Algae, particularly with the Siplioneac.

Since the fungi do not possess chlorophyll, their nutrition
is carried out by the absorption of organized material in a
saprophytic or parasitic manner. Parasitic fungi are the cause
of numerous and dangerous diseases of plants, whereas they
only rarely bring about a diseased condition of the animal body.
Bacteria on the other hand, which cause so many animal diseases,
seldom affect plants injuriously. While many parasites are
strictly limited to a parasitic mode of life, a large number
naturally spend a part of their lives as saprophytes, and others
may be made to do so artificially on nutritive substrata
under suitable conditions. The latter method forms in fact a
valuable aid for completing our imperfect knowledge of the
life-histories of parasitic forms. In addition to the well-marked
parasitic fungi, there are many saprophytic forms which become
parasitic for a relatively short time or under special conditions
of environment.

The Fungi are divisible into two large groups, the lower
fungi (Phycomycetes) and higher fungi (Mycomycetes).

The systems instituted by various investigators differ not
a little from each other. Three of the principal are :

De Bart. Zopf. Brefeld.

(1) Phycomycetes (1) Pliycomycetes (1) Phycomycetes

(2) Ustilagineae (2) Mycomycetes (2) Higlier Fungi

(3) Ascomycetes («) Basicliomycetes {a) Mesomycetes

(4) Ureclineae {h) TTredineae Heraiasci — Hemibasiilii

(5) Basidiomycetes (c) Ustilagineae {b) Mycomycetes

id) Ascomycetes Ascomycetes — Basidio-

mycetes

We shall in the present work consider the Puugi in the
following order :

Lower Fungi or Phycomycetes :

Chytridiaceae, Zygomycetes, Oomycetes.
Higher Fungi or Mycomycetes :

Ascomycetes.

Ustilagineae, Uredineae, Basidiomycetes.

1 06 PHYCOMY CETES.

A. LowKR Fungi (Phycomycetes).*-
The lower fnn,i,'i possess, at least in their earlier stages,
single-celled niyeelia, which may in the higher families become
branched. They reproduce sexually by oospores or zygospores,
asexually by conidia. The I'hycomycetes are divided into :
Chytridiacene, Zijijomijcdea, and Oom/jcdrs.

(1) CHYTRIDIACEAE.

The fungi of this family are chiefly parasites on aquatic
plants, or on land-plants inhabiting moist places. The my-
celium is one-celled, very rudimentary, or altogether absent.
Asexual reproduction takes place by the formation of zoo-
sporangia which usually produce uniciliate swarm-spores. Sexual
reproduction is rare, and is effected by fructification of one
cell by a fertilization-tube from another ; the resulting bodies
are zoosporangia which on germination set free swarm-spores.
Hibernation is effected by resting-spores produced from sporangia
in which the formation of swarm-spores is suppressed, and
which become clothed in a thick membrane. Some of the
species cause interesting deformations on the organs of plants.

The Chytridiaceae include the families of Ol])idiaccac, Synchy-
triaceac, Cladochytriaceae, Rhizidiaceac, Hyjjochytriaceac, and Oochy-
triaccae. Of these, only the first three contain species parasitic
on higher plants. They occur epidemic only in moist situations,
and rarely cause great damage to cultivated plants.

OLPIDIACEAE.

The whole vegetative body becomes a single zoosporangium
or a resting-spore. Sexual reproduction is very rare.

Olpidium.

The vegetative body consists of a naked mass of protoplasm,
the product of a single spore. This becomes later enveloped
in a thin wall of cellulose, and forms a zoosporangium with a
long neck through which the cell-contents are ejected as
uniciliate swarm-spores. The cellulose membrane may become
thicker and a resting-spore (sporangium) result, which in course
of time germinates and gives off swarm-spores.

^ Bibliography — A. Fischer in Rabeuhorst's Kryptogamen Flora, 1892.
Schroeter in Eiujhr-Prantl Pjlanzenfamilien, 1892.

OLPIDIUM.

107

Olpidium brassicae, (Wor.)^ { — Chytridium brassicac, Wor.)
Oabljage-seedliiigs die if this fungus finds its way into the tissue
at the neck of the root. The spherical sporangia are formed at
this place, and tlieir long necks project out of the cells enabling
the uniciliate swarm-spores to escape. Eesting-spores with a
warty thickened membrane occur in the cells of the epidermis.

Fig. 24. — Ch>jtHdiwn brassicae, Wor. Cell containing three sporangia, two of
which are discharging zoospores ; one sporangium is already empty. Resting-
spores inside the cells of a cabbage-plant. (After Woronin.)

The disease is favoured by moisture, and restricted by dry
surroundings. Ground subject to attack should be planted
with crops other than cabbage.

Olpidium trifolii, Schroet. { = Synchytrivrii trifolii, Pass.)
Produces deformation of the leaves and petioles of Trifolimn
repens. The fungus lives in the epidermal cells.

Olpidium lemnae, Fisch., in epidermal cells of Lcmna.

Olpidium simulans, De Bary and Wor., in Taraxacum
officinale.

A number of other species inhabit algae, spores, fungus-
mycelium, pollen -grains, and eggs of Rotatoria.

The genera Rcessia, Pscudolindium, Olpidiopsis, FIcotrachclus,
Ectrogclla, Pleolpidium are parasitic only on lower plants, especially
on algae.

SYNCHYTRIACEAE.

The whole mycelium divides up into a number of sporangia,
which remain together as a sorus. The winter resting-spores

1 Woronin, Pringsheini's Jahrhuchf. iciss. Botauil; 1878 (Fig. .31).

108 PHYCOMYCETKS.

originate from the whole niyceliuiu or parts thereof, and are
isolated or united into a sorus.

Synchytrium and Pycnochytrium.'

Here, as in Olpidium, the mycelial hyphae are wanting, and the
vegetative l)ody escapes from the spore as a naked mass of
plasma, which is later enclosed in a membrane. This vegetative
body may also develop into a sorus of thin-walled sporangia ;
these separate in water, and each ejects from a pore numerous
swarm-spores with a single long ciliuni. In the event of resting-
spores being formed, the membrane of the vegetative body
becomes thickened into a brown exospore. The resting-spores on
germination liberate their contents as a single mass, or as several
zoospores. In the former case the single mass divides at once
into zoospores, or into a sorus of sporangia, which ultimately
give off zoospores.

These fungi are found in the interior of cells, especially of
the epidermis. The one cell inhabited by the fungus grows
out as a simple papilla, or several neighbouring cells are also
modified, and grow out along with the original one to form a
gall-like swelling. The species of Sijnchytrium generally in-
habit the epidermal cells of land plants, yet disease caused
Ijy them is commoner in moist than in dry situations. They
cause so slight deformation and damage to cultivated plants that
they are of little practical importance.

The Pycnochytrium of De Bary is regarded b}' Fischer as a
sub-genus, by Schroeter as a genus.

Synchytrium.

The sori of zoosporangia are formed b}' direct division of
the mature sporophore, and are enclosed in the colourless
membrane of the mother-cell.

Synchytrium taraxaci, L)e Bary and Wor. (U. S. America).^
This produces, especially on Tarcoxicum, warty galls composed of
a diseased epidermal cell, enlarged and surrounded by a wall of

' Scluoeter : Cohn\ Beitriige z. Biol. d. Pflanzen I., 1875, and in Engler-Prantl
Pflanzenfamilien, 1892.

De Bary and Woronin, Bericht. d. natforsch. Gen. zu Freiburg, 1863.

- We propose to indicate in this way species recorded in Seymour and Farlou's
"Host-index" for North America; British species by (Britain). (Edit.)

SYNCHYTRIUM.

109

less swollen neighbouring epidermal cells. The sporangia contain
reddish-yellow drops of oil, so that the swellings appear yellow.
The organs attacked are much
distorted and more or less
stunted.

The same fungus occurs on
other Compositae, and is pro-
bably identical with S. san-
guineiun of Schroeter, which
produces dark red, crusty swell-
ings on Cirsium imlustre and
Cre'pis biennis.

Along with S. taraoxici one
often finds Olpidimn simulans.

S. fulgens, Schroeter (U. 8.
America), produces reddish-
yellow swellings on the leaves
of Oenothera biennis and 0.

, f . Fig. 2j. — Siiiichyti-lv.iit laiv.raci. Leaves of

innricata ; when reStmg-SpOreS Taraxacum qflcinaU so deformed by the fungus

. 1 « -I , that the laminae are all more or less undeveloped.

appear they form brown crusts, (v. lubeuf phot.)

The sori of zoosporangia are

detached from the liost-plant as single sporangia, which

become scattered over the leaves.

S. trifolii, Pass. ( = OJjridiuni trifolii, Schroeter), is as yet
little known.

Other American species are : —

S. papillatum, Farl., on Geranium.

S. decipiens, Farl., on Anqjliicarpaca.

S. vaccinii, Thomas,^, on Vaccinium, Gaidthcria, Kalmia,
Rhododendron, etc.

Pycnochytrium.

The sori of zoosporangia are not produced directly from the
mature sporophore, but the contents of the sporophore pass out
by a fine opening and form a thin-walled vesicle, the protoplasm
of which breaks up into sporangia.

Schroeter divides the genus into two sub-genera.

(A) Mcsochytrinm. The discharge of the original sporophore

1 Halsted, " Cranberry gall-fungus " ; N. Jersf^y Agric. Coll. Bullet. 64, Dec.
1889. With figures.

110

PHYCOMYCETES.

and the foriuation of zoosporaiigia take place in the cells of the
living host-plant. In addition, spores are formed which have
a resting period.

(B) Only one kind of spore is formed ; it has a resting period,
and only proceeds to produce sori of zoosporangia after decay
of the host-plant.

(a) Clmjsochytrium : protoplasm contains a yellow oil.

(b) Lcucochytrivm : protoplasm colourless.

Each of these divisions is sub-divided into forms with simple
vesicles, and those with compound.

Mesochjrtrium.

Synchytrium (Pycnochytrium) succisae, De Bary and ^^'or.^
This parasite forms warty swellings and yellow spots, generally

'r-\'

Fio. 2(3. — Si/nchytrium succisae. A, A mature sporocarp inside its host-cell.
B, In the upper part of the cell a sorus of swarm-sporangia after escaping from
its covering, which lies below it. C, Isolated swarm-sporangium. D, Swarm-
spores. (After Schroeter.)

on the radical leaves and base of stem of Scahiosa succisa.
Infection is lu'ought about in damp situations by means of
swarm-spores. These have a single cilium, and bore their way
into the host-cell. After entrance, they produce a plasma-mass,
which becomes enclosed in a delicate membrane. The cell so
formed sprouts at its uppermost pole, and gives rise to a new
spherical cell, into which the older discharges itself. In the
second cell numerous small sporangia are formed, so that it
represents a sporangial sorus ; beside it is always found the
empty membrane of the first cell. The sorus breaks up later
into single sporangia, which on opening, set free their contents

^Schroeter, " Pflanzenparasiten aiis d. Gattung Synchj'trium."' Cohn's Beit); z.
Biolog. d. Pflanzen, 1S75.

PYCXOCHYTRIL'M. 1 1 1

as zoospores swarming by means of a cilium. In addition,
resting-spores are developed singly or in groups.

The first effect on the host-cell of the entrance of a swarm-
spore is that it becomes distinctly larger. At the same time
neighbouring cells are so stimulated that they multiply and
form a prominent ring-shaped swelling. The sporangia discharge
their zoospores on the host-plant itself, and these pass into
other cells of the swelling ; here they form resting-spores and
the host-cells die. 8chroeter states that the resting-spores may
be found from August onwards.

S. stellariae, Fuck. On Stdlaria media and S. nemorum.
The reddish-yellow hemispherical swellings are produced on leaves,
stems, liower-stalks, and sepals, either isolated or as a crust.
The resting-spores generally form brown crusts. The host-leaves
may be somewhat crumpled, but beyond this undergo little de-
formation.^

Chrysochytrium.

(1) Forming simple vesicles:

Synchytrium myosotidis, Klihn (U. S. America). The epi-
dermal cells when attacked swell up to form club-shaped
processes, while the cells with no fungus remain unaltered.
The normal hairs of the host-plant are fewer on diseased than
on healthy parts. This parasite attacks Boragineae, e.g. Mijosotis
stricta, Litliospermvm arvense.

S. cupulatum, Thomas, produces red eruptions on PofentiUa
argeniia and Drijas octoiKtald. ; diseased cells of the host-plant
contain red sap.

S. punctum, Sorokin. On Plantei.go kmccoki.ta and P. media.

S. laetum, Schroet. On Gagca.

(2) Forming compound vesicles :

S. aureum, Schroet. Attacks many herbaceous plants as well
as leaves of many shrubs and trees. Frequent on Lysimaclna
Nmnmuhiriei, Fragevria, etc. The cells attacked are swollen and
enclosed in a patch of enlarged neighbouring cells.

S. pilificum, Thomas. On PotentUla Tormentillo. The
vesicles are hemispherical, and bear on their summits a tuft
of abnormally elongated hairs. Thomas ^ found this species

1 Clendenin (Botanical Gazette, 1894, p. 296) describes and figures a Synchytrimn
on Stellaria media in America (Edit.).

- Ber. d. dfvtsch. hotan. Ges., 1883, p. 496.

112

I'lIYCOMYCETKS.

on Stems, Hovver-stalks, radical and cauline leaves, and floral
envelopes.

Leucochytrium.

(1) Forniin;^ simple vesicles:

S. punctatum, Schroet. On Gayea pratcmis.

S. rubrocinctum, Magnus, forms little red eruptions on Scun-
frujja (jraiiuhitii, the cell-sap of the host-plant becoming red.

S. alpinum, Thomas. On Viula hiflora. .

S. anomalum, Schroet. (U. S. America). On Adoxa Moscha-
tcllviui, less common on Ranunculus Ficnria, Isojjyrum thalidroidcs
and Rumc^c Acetosa. The size and shape of the swellings, as well
as of the spores, are very variable.

(2) Forming compound vesicles :

S. anemones, De l>ary and Wor. (U. S. America). On
Anemone nemorosa, A. ranuncidoides and Thalidrum purpura-

FiG. ■27.—Syiicliytnw>i anemones. The sporocarps form black points on leaves,
petioles and perianth of the Anemone ; the lamintie are also stunted and distorted,
(v. Tubeuf del.)

sccns, attacking stems, leaves, or flowers, and forming eruptions
whose cells contain a red sap. In very bad cases, crumpling
and swelling of attacked organs occur.

pycnochytriu:m. 1 1 .^

S. globosum, Schroet. Where the attack is severe, this causes
pearly swellings or incrustations ; it frequents plants like Viola,
Galivm, Achillea, So'nrJws, My satis.

S. mercurialis, Fuck., is very common on Mercurialis perennis
though seldom injurious to it. One severe case is thus de-
scribed by Schroeter : " In spring the stem of the plant was
covered by a thick uneven glassy crust, which in course of time
became raised into wing-like processes running down the stem
and coated on both sides with white granules of the immature
parasite ; the leaves were completely rolled together, crumpled,
and covered with glistening prominences as with fine silver sand.
The plant in this condition developed poorly, scarcely flowered,
and soon died, so that by the end of Septeml)er few diseased
examples could be found."

CLADOCHYTRIACEAE.

The vegetative body is frequently a Ijranched mycelium. It
lives intercellular as a saprophyte, or intracellular as a parasite,
and forms intercalary or terminal swellings, in which zoospor-
angia or resting-spores are produced, then it disappears. Sexual
reproduction does not occur. The parasite lives in and forms
swellings on aquatic plants, or land plants in moist situations.
The genera Urophlyctis and Physoderma contain species parasitic
on higher plants ; together with the saprophytic Cladosporangivm,
these are regarded by Fischer as sub-genera of Cladocliytrivm,
and as such they are also here regarded.

Uroplilydis has both zoosporangia and resting-spores, Physo-
derma has only resting spores, Cladosjxiranyium only zoospor-
angia.

Urophlyctis.

The delicate mycelium is unbranched, or only slightly
branched, and lives endophytic, boring through the walls of
the host-plant. At the place where a hypha enters a host-
plant it forms a swelling or collecting cell (sammelzell), which
generally becomes differentiated into a larger cell rich in contents,
and an outer smaller one with few contents, but with fine
terminal bristles. From the collecting cells new hyphae
originate and produce other collecting cells in neighbouring
host-cells. The zoosporangia are situated outside the host-cells,

H

1 1 4 I'HYCO.MYCETES.

but send a hyphal process inside, whicli branches into a tuft
of rhizoids. Kestin^f-spores may be found, several in each cell.

Cladochytrium (Urophlyctis) pulposum, (Wallr.), causes on
leaves, stems, and Ihnvers of Chr/Kqjof/ium and Atriplcx glassy
swellings, in the undermost cells of which are situated the
zoosporangia. The resting- spores have brown shining walls and
lie inside the cells. The zoospores are uniciliate.

CI. (Ur.) butomi, Biisgen. On leaves of BidomuH umbellatus.
Black spores are produced containing resting-spores. The col-
lecting cells have tufts of hair.

Physoderma.

Zoosporangia are absent. Kesting-spores formed, several in
<?ach host-cell.

Cladochytrium (Phy.) menyanthis, De Bary (U. S. America).
On leaves and petioles of Mcayanthes trifoliata this forms
vesicles containing resting-spores. The collecting cells have
terminal hair-tufts. Diseased leaves are generally smaller than
healthy.

CI. (Phys.) flammulae, Biisgen, forms little swellings on
leaves of Ranunculus Fhimmula.

CI. (Phys.) Kriegerianum, Magnus, causes transparent swell-
ings on Car urn Carui.

CI. (Phys.) iridis, De Bary, on Iris pseudacorus.

Fischer mentions other species on Scirpiis,' Alisma, JRanunculiis,
Putentilla aiiserina, Silaus pratensis, Sium latifolium, Phalaris,
Cxlyccria, Symi^hytvm, Mentha., Rnmcr, AJlium, etc.

Prunet^ describes Cladochytrium viticolum as the cause
of the much-discussed Brunisure of vine ; also CI. mori as a
new disease of the mulberry.^

The same authority ^ designates as Pyroctonum sphaericum, a parasite on
wheat, which has become very abundant in Southern France.

(2) ZYGOMYCETES.

Unicellular fungi. Sexual reproduction does not take place by
the fertilization of an ovum in an oogonium by an antheridium,

iPrunet, Comj)t. rend., 1894. - Prunet, Compt. rend., cxx., 1895, p. 222.

■'Prunet, Compt. rend., 1894, ii., p. 108.

ZYGOMYCETES. 1 1 5

but by conjugation or union of two cells of the mycelium
separated off from the ends of two hyphae by transverse walls.
As a result of conjugation, a zygospore is produced, which is
a resting-spore and corresponds to the oospore of the Oomycetes.
The zygospore puts forth a germ-tube, which becomes a mycelium
bearing sporangia on sporangiophores. From each sporangium,
spores, never swarm-spores, are set free, germinate, and produce
a mycelium. Sporangia similar in form to the zygospores may
be asexually produced on the mycelium. The unicellular and
much-branched mycelium grows into its substratum, and is
nourished as a rule saprophytically. The Entomophtliorcac cause
important insect-diseases on Muscidae, Cabbage Butterflies, and
caterpillars of Trachea piniiJerda (the Pine Beauty).

Another common group of the Zygomycetes, the Mucorini,
penetrate into bruised places in living fruits, and produce decay
{see p. 180). Some other Zygomycetes are parasitic on fungi
(Conidiobolus), some on animals.

(3) OOMYCETES.

These fungi possess a one-celled and much-branched mycelium.
In their vegetative structure they most nearly resemble algae
like Vaucheria. Eeproduction is brought about, asexually by
means of swarm-spores formed in sporangia (conidia also occur) ;
sexually by oospores derived from oogonia and antheridia.

There are three families of Oomycetes : Saprolegniaccac, Mono-
hlcpharideae and Peronosporcae. Two of these groups contain
parasitic forms : Saprolegniaccac {e.g. Achyla prolifera, dangerous
to Fish and Crustaceans) ; and Peronosporcae.

PERONOSPOREAE.

The greater number of the Peronosporcae live as parasites in
the tissues of higher plants, and obtain nourishment generally by
means of haustoria. The mycelium, in earlier life at least, has no
dividing septa, and generally grows in the intercellular spaces of
the host-plant, and sends haustoria into the cells. Pteproduction
is effected asexually by formation of swarm-spores in sporangia,
and sexually by means of oospores. The latter are produced
from the fertilization of an ovum in an oogonium by an antheridium
whose contents pass through a fertilization-tube penetrating the

116 PHYCOM YCKTES.

oogonium wall.^ No formation of spermatozoids occurs, as is the
case in Vaucheria and otlier groups of algae showing close rela-
tionship to these fungi. In certain cases the formation of
swarm-spores in sporangia does not take place, but conidia
are produced, which germinate directly into a mycelium.

Preventive measures against the whole group consist in
destruction (by burying or burning) of diseased and dead parts of
host-plants which contain the hibernating oospores ; by change of
crop on infected fields ; and by treatment with copper reagents
(see Chap. VI.).

To the Peronosporeae belong the genera Fi/thimn, Fhi/toph-
thora, Cystopus, Basidi<yphora, Plasmopara, Scleros2)ora, Brcmia and
Peronos2)ora.

Pythium.

The mycelium possesses no haustoria, and grows both between
the host-cells and inside them. Cross-septa are not present at
first, but later these may be found at irregular intervals.
Pythium lives as a parasite in living plants, or as a saprophyte
on a dead substratum. The conidia are of various forms, and
either germinate directly into hyphal filaments, or discharge their
contents into a bladder where zoospores are developed and
liberated as free-swimming spores with two lateral cilia. The
oogonia contain only one ovum-cell, which is fertilized by means
of an antheridial tube applied to the oogonium. The thick-
walled oogonia on germination produce hyphae or discharge zoo-
spores.

Pythium de Baryanum, Hesse ^ (fJritain and U. S. America).
This parasite is injurious to the seedlings of various plants in
gardens and fields. Some of its commoner hosts are maize,
clover, mangel, millet, and many species of the Cruciferae ; it has
also been found on the prothalli of Eqnisdum and Lycojyodipm.^
It may also attack living or dead leaves and tubers of potato.

The sporangia have a lateral beak-like outgrowth, into which
the plasma passes and divides into biciliate zoospores. The

^In many species the fertilization-tube remains closed e.g. Plasmopara
viticola.

-Hesse, Pythium de Baryanum, Halle, 1874. Atkinson (Cornell Univ. Af/ric.
Expt. S/at., Bull. 94, 1895), describes and figures this and other fungi causing
" Damping-off." (Edit.)

•' Sadebeck, NaXurforsch. - Versammluiuj. , 1 876.

PYTHIUM. 1 1 7

sporangia, however, may first pass through a resting period.
Sexual reproduction consists in the impregnation of an egg-cell
by means of a fertilization-tube from an antheridium. The
oospores are formed singly in each oogonium, and are liberated
only after decay of the oogonium walls and the tissues of the
host-plant containing them. After a resting period they pro-
iluce a germ-tube, which penetrates into the host-plant and
becomes a delicate branched colourless intercellular mycelium.
Hibernation is accomplished both by these oospores and by resting-
oonidia, which remain amongst the decaying plant-debris on the
ground.

Humphrey has observed sickness and death of cucumljer
seedlings as a result of P}/. dc Baryanum. Wittmack found a
species {Py. Sadrhcckianum) very destructive on peas and lupines ^
in various localities ; it has been observed frequently since.

Py. gracile is parasitic oii algae.

Py. dictyospermum, Eac. occurs in Spirogyra.

Py. cystosiphon is found on species of Lemna.

Py. intermedium frequents prothalli of vascular cryptogam.s.

Phytophthora.

The mycelium is at first non-septate though much branched.
It grows both between and through the host-cells, and in some
species, {e.g. Ph. omnivora), has small haustoria.

The conidiophores branch and produce a large number of conidia
or sporangia in succession. The first conidia are terminal, but
are displaced towards one side and thrown off by further
growth of the conidiophore to produce other conidia.

The sporangia distribute their contents as swarming cells with
two lateral cilia ; the conidia produce a hypha directly. The
egg-cells are developed one in each oogonium, and are fertilized
by an antheridium. The spherical oospores germinate in spring
by means of a germ-tube.

Phytophthora omnivora, De Bary- (syn. Ph. farji, K. Hartig.)
This is a destructive enemy to the seedlings of conifers, and even
more deadly amongst naturally-sown beech-seedlings. Death of
the beech is preceded by brown-spotting of stems, cotyledons and

1 Vtrdn z. Bef. d. Moorkultur, 1891.

-R. Hartig, Ztitarhrift f. For>it u. Ja(jd-wesen ISlo; also, UntersurhinKjen aux
d. /orsthotan. Inst. Miinchens, ISSO.

118

I'HYCOMYCETES.

first leiiilets.
or swaniiiiiir

Til
cells

e (liseasc is spread during summer by conidia,
produced from sporangia. The passage through
winter is effected by means of
oospores, resulting from fertiliza-
tion of an ovum in the oogonium
Ijy a fertilization-tube from an
antheridium. The intercellular
mycelium is at first nonseptate,
later septate, and forms small
haustoria. Seedlings of other
plants, besides those already
mentioned, and also succulents
{e.g. Semjyervivum and Cactvs}
may be attacked and killed by
this same fungus.

This epidemic cannot well be
combated except by methods
applicable only in the nursery.
The most effective method is to
plant no young seedlings in
plots which have already been
diseased, but to reserve such
plots for older plants to which
the fungus is not dangerous. If
the disease be not very general,
attacked plants may be removed
singly and destroyed. Since
moist air is very favourable
to distribution of the disease,
all nettings or trellises should
be removed from seed-bed»
threatened by attack. In dry

Fig. 2S.—Pli!/toplit/ion: omnivora. Cotyledons airy loCaliticS there is IcSS-
ivnd primary leaves in earlv stage of attack ; ■, ,..

the disease forms brown spots where patches danger tO SeedlUlgS thail 111
of mycelium are developed. 4 natural size. -^i

(V. Tubeuf del.) " mOlSt.

The fungus often appears
in such force that seed-beds of beech or conifers are denuded
of every plant within a few days, and in the forest beech-
seedlings may, during damp weather, be completely exterminated
over great areas.

PHYTOPHTHORA.

119

Another parasite of conifer seedlings — Fasoma imrasiticum —
which somewhat resembles Phytophtlwra, is figured and described
amongst the " Fungi imperfecti."

Phytophthora infestans, De Bary.^ This parasite was first
observed in Europe in 1845, and has since then become

Fio. 29.

Fic. 30.

Fio. 29.— Celhilav tissue from diseased cotyledon of Beech. The starch-gi-ains
have been absorbed from the cellprotoplasm which has shrunk awaj* from the
cell-wall n ; b, b. Intercellular fungal hyphae with very tiny haustoria ; c, c,
fertilized oogonia, each containing a single oospore. (After R. Hartig.)

Fig. 30.— Phi/tophthora oinnivora on the epidermis of a Beech-cotyledon, c.
Outer wall of epidennal cell ; b, cuticle ; c, hyphae growing between cell-wall
and cuticle, causing the slight protuberance d ; e, spot whei'e a hypha has
emerged through the cuticle and developed as a sporangiophore/; after the first
sporangium has reached maturity a second begins to form, g and A, whereby the
first is displaced ; 1-, a stoma from which sporangiophores have developed.
(After R. Hartig.)

only too well known. It attacks leaves, shoots, and tubers
of potato and other Solanaceae, e.g. the tomato (S. Lycopcrsicum).
The potato leaves become discoloured, brown-spotted, and
crumpled, especially in damp weather. The sporangiophores
(gonidiophores of De Bary) issue from the stomata in

^ De Bary, Journal of Botany, 1876, and Journal of the. Royal Agric. Society,
1876.

120

I'HYCUMVCKTES.

tufts, and form a white border round the brown parts of
the leaf; they are monopodially branched and produce terminal
sporangia (gonidia), which are easily detached. The sporangia

on germination either pro-

duce a varying number of
zoospores, or germinate
directly like conidia to form
a mycelium capable of pro-
ducing new conidia. The
potato -disease is distin-
guished from Fhytoi^hthora
omnivora in the absence
of sexual reproduction by
oospores.' It is generally
assumed that the mycelium
hibernates in potato-tubers,
from which the fungus
recommences to spread in
spring. Boehm,^ however,
contests this, and holds the
hibernation of the fungus
to be quite unknown, and
that from the tubers of

Fig. 31.— Surface of a Beech-seedling with swarm- ;i disCaSCd plaut, either a
spores a, h ; the gerin-tubes from these penetrate '^

between adjacent epidermal cells ; c, sporangivmi with healtllY plant Or llOUC at
zoospores already germinating inside it, </, /'; c, a ^1

germ-tube which lias penetrated directly into an -^W reSUltS.
epidermal cell ; g, germ-tube which, after growing
^Aft^ *'?"L^"^*.'^^ '^ <=eU, has again made its way out. TllC PliytoplltJlOra potatO-

disease is quite distinct from
{a) the potato-blight or wet-rot which, according to Boehm, is the
result of closing up of the lenticels, with a consequent stoppage
of respiration ; (??) bacteriosis, which will be considered amongst
the bacterial diseases of plants.

Lagerheim^ has pointed out that Solanum muricatum
much cultivated in Ecuador on account of its edible fruit, has
been for many years subject to attack from Phytophthora
infcstans ; the fruits sicken and rot off before ripening. The

^ This is a well-known point of controversy, for an interesting discussion of
which we would refer to ''Diseases of crops," Worth. G. Smith, 1884. (Edit.)

2 Boehm, Sitztmysber. d. Zool.-hotan. Ges., Vienna, 1892.

■^ Riinsta Ecuatoriana, 1891.

PHYTOPHTHORA.

121

Fig. 3-l.—Phi/to/>hth.nra infeslaas. The Potato disease. A, Potato leaf with
brown spots and white patches of fungi on the lower iide. B, Groups of conidio-
j.hores emerging from a stoma close beside a hair of the potato leaf. C, Conidio-
I'hores and conidia, much enlarged. Z», Leaf of potato much shrivelled up and
brown, as in the later stages of the disease, fv. Tubeuf del.)

122 I'HYCOMYCETES.

same author also quotes the disease on Solannm caripense
at Quito, and on Petunia hyhrida at Upsala.

The potato disease is above all an associate of moist
weather. In such circumstances, the conidia are produced
very rapidly and the zoospores readily distribute themselves in
the moist soil. There is thus greater risk to the potato crops
on wet soils.

For wintering, potatoes as healthy as possible should be chosen.
This is particularly the case if the tubers are required as seed :
for the fungus-mycelium spreads from the tuber into the shoot.
Wliole tubers are less liable to infection than those cut or
broken. Some varieties {e.g. thick-skinned) are less easily
infected than others ; such should be selected and bred.

As a preventive measure the leaves may be sprayed witli
Bordeaux mixture, or with a copper carbonate mixture.^ J>y
these means conidia and zoospores which alight on the plants
are killed and their germination prevented. The leaves them-
selves remain uninjured if the copper compound bo used dilute
enough. These compounds may even be beneficial to the growth
of the host-plant, as was found by Eumm- for the vine, and
Frank and Kriiger^ for the potato.

Frank and Kriiger found on using a two per cent, copper
sulphate and lime mixture, in which the copper is known to be
the potent constituent, that the potato leaves were stronger, their
chlorophyll-contents greater, their power of assimilation and
transpiration was increased, the life of the leaf was lengthened,
and the yield and starch-contents of the tubers were increased.
They regard the effect of the copper on the leaf as the result of
a chemotaxic stimulus.

Jensen recommends disinfection of seed-potatoes by heating
at -40' C. for four hours.

Ph. phaseoli, Thaxter, lives in young bean-pods and causes
them to shrivel up. The fungus is as yet incompletely known,
having only been observed in America where Thaxter * reports
great destruction of Lima bean {Phascolus lunatus) near New
Haven.

' See also § \'l. Detailed expeiimeiits of this kind are frequently described
in the magazines relating to agriculture. (Edit.)
- Ber. d. deutach. botan. Ges., 1895, p. 189.
' Ber. d. dentKch. botan. Ges., 1894, p. 8.
'Thaxter, Botanical Gazette, 1889.

CYSTOPUS.

123

Cystopus (Albugo).

The mycelium is branched and grows between the cells of
living plants, obtaining its nourishment by means of haustoria.
The conidial cushions rupture the epidermis of the host. The
conidia or sporangia are smooth-coated, and are produced
acropetally in chains on short stalks from which they fall off
separately when ripe. The sporangia germinate and discharge

Fig. 33. — Costopi'.s candidus on plants of Capsella hario. pastorig. The fungus
has caused distortion and thickening ; the white porcellanous conidial cushions
shew up distinctly on the dark background, (v. Tubeuf phot.)

swarming spores with two unequal lateral cilia. The egg-cells,
produced singly in each oogonium, are fertilized by an antheridium.
The thick-walled oospores remain enclosed in the intercellular
spaces of the host-tissue, and on germinating in spring discharge
swarming spores.

Cystopus candidus (Pers.) Lev. White Paist. This fungus

124

PHYCOMYCETES.

is very frequent on wild and cultivated Cruciferae throughout
the whole world, and causes deformation of shoot, leaf, and flower.

Fio. 34. — Ci/Atopus canditli'n. B, Conidiophores isolated from the cushion ; the
conidia or spomiigia are united by intermediate cells. C, Sporangia breaking up
to form swarm-spores. D, Swarm-sporos escaping. E, Swarm-spores in motile
condition. F, Swarm-spores come to re.st and germinating. 0, Two germ-tubes
entering a stoma of Lcpidiuni scUivam ; the stoma is shown from the inside, so
that the spores from which the germ-tubes arise are on the outer surface and
unseen. (After De Bary.)

Fio. 35. — Flower of Radish (Raphanns sativus) hypartrophied by Ci/slojms
auididi'.s. The much-enlarged ovary stands out in the centre. The anthers are
leaf-like ; the petals are much enlarged and hang downwards ; the sepals are
somewhat enlarged. (Specimen from Botanical Museimi of Erlangen, and
photographed by Dr. Brims.)

The couidiai cushions form thick white stripes with a porcellaneous
appearance, by which they are easily distinguished from the
cushions of Feronospora parasitica often present on the same plant.

CYSTOPUS. 125

Besides conidia, spherical oospores may also be present ; these
are generally produced on the stems of the host-plant, but also
on Hower-stalks and ovary-walls.

The spherical conidia arise in simple chains on short coni-
diophores, and are loosely connected by tiny intermediate cells.
The conidial cushions rupture the epidermis and the ripe conidia
fall oft' to produce biciliate swarming cells (Fig. 34). These
give rise to oemi-tubes which enter the stomata of seedlings and

Fio. :i6. — Flower of Radish hypertrophied by Ct/stopi's cainiidv.s. The white
swollen conidial cushions occupy the enlarged petals, sepals and ovaries. (Dr.
Bruns' phot.)

develop to intercellular mycelia, fine short lateral twigs of
which pierce the wall of the host-cells and become little
spherical haustoria.

The oogonia arise as thick-walled spherical swellings on the
mycelium. The antheridium, after applying itself to the oogonium,
widens and projects a fine fertilization-tube through the wall to
the egg-cell. After fertilization is effected, the egg-cell is enclosed
in a firm uneven membrane, and hibernates inside the oogonium.
In spring the plasma of the oospore forms numerous biciliate

126

I'll V COM YCETES.

swarm-spores which escape from the enclosin;:^ coats and germinate

on seedling jdants.

De l>ary ' found germ-tubes of
Ci/n(opus entering all the stomata of
Lcpidiuiii sativinn and of Capsclla,
but they only developed further if
the part attacked were the cotyledons.

Magnus - observed an infection of
Haphanus Baphanistrum in which the
unopened buds were infected by swarm-
spores. Oogonia may be found in the
flowers of this same plant, whereas
conidia alone only are present in
OapscUa.

White rust is most commonly
observed on CapsrUit, causing slight
local swelling or marked hypertrophy.
It is also found to injure radish
{llaphanas sativus), horee radish
(Cochlcaria armor acia), cress (Lcjudium
sativum), species of cabbage and
turnip (Brassica Napus, B. nigra, B.
Bapa, B. olcracea), wall- flower (Cheir-
antJiKs Cheiri), water cress {Nasturtium
amphihium, etc.), caper-plant {Ca'pp)aris
s2nnosa), and other wild and culti-
vated plants belonging to, or closely
allied to the Cruciferae.

Wakker^ investigated the changes
brought about on a number of Cruci-
ferae by Cijstopus. Some plants showed
little or no deformation or anatomical
alteration, others showed much. While
the anatomical changes in the various
species examined agreed in general,
yet some showed a predominant or
exclusive formation of conidia, others of oospores. The changes

Fio. 37. — Cystojmi portulacae, D. C.
m, mycelium ; .;', basidia ; c, spores
with intermediate cells. (After
Tulasiie.)

' Morpholoijy and Biology of the Fungi. English fiditiou.
- Abhand. d. hofan. Verehis d. Prov. Brandenburg, xxxv.
.) Pringsheim's Jakrbuch, 1892.

CYSTOPUS. 127

observed on Crqisella may be summarized here : the fungus

attacks all parts above ground, and causes enlargement of

parenchymatous cells ; it forms only

conidia ; formation of chlorophyll is

increased ; the formation of interfasci-

cular cambium is diminished or altogether

suppressed ; the intrafascicular cambium

retains its activity longer ; accessory

vascular bundles make their appearance ; cX^v^^^i^^^^'^^^

no differentiation of tissue takes place

in the ovary wall, the secondary vessels remain incomplete,

and the embryo dries up.

C. portulacae, D. C. On Portulaca oleracea and P. sativa (U. S. America).

C. tragopogonis, Pers.^ (C. spimilos^is) (Britain and U. S. America). On
Compositae, e.g. Chamomilla., Achillea, Cirsium, Scorzonera, etc. The markings
on the spore-coat take the form of a double net- work.

C. convolvulacearum, Otth. (C ipomoeae-pandiu-anae, Farl.). On Con-
volvulaceae. (Halsted " gives this as one of the causes of rot in sweet potato
in America.)

C. bliti (Biv.-Bern.). On species of Amarantaceae (U. S. America).

C. lepigoni, de Bary. On Spergularia (Britain).

Basidiophora.

The non-septate mycelium inhabits intercellular spaces of
living plants, and is nourished by small haustoria. The conidio-
phores issue in tufts from the stomata, and have a characteristic
form ; they are unbranched with club-shaped ends, from which
arise several sterigma-like conidiophores with almost spherical
conidia. The conidia or sporangia are produced in large numbers,
and on germination discharge numerous zoospores with two
lateral cilia. The oospores are formed singly in the oogonia, and
appear as yellowish-brown bodies in the interior of the plant.

Basidiophora entospora, Roze and Cornu. On Erigeron ccma-
dcnsc, A.stcr, Solidago, etc. (Britain and U. S. America).

Plasmopara.

The mycelium is richly branched and grows intercellular,
nourished by little button-shaped haustoria. The conidiophores

^Magnus, Ber. d. deutsch. botan. Ges., 1893.

^ Zeitsrhrift f. PflanzenkranJchdten, 1895, j). 338.

128

PHYCOMYCETES.

arise in tufts from the stoinata ; they are branched in various
ways, and from each branchlet a single conidium is abjointed.
The contents of the conidia emerge as swarming cells with two
lateral cilia, or as vesicles which emit a germ-tube. The egg-cells
occur singly in each oogonium, and are fertilized by an antheridiun).
The oospores remain long enclosed in the thick-walled oogonium.

Fio. 39. — Planmopara viticola. Vine leaf with white spots on the under surface,
from which tufts of conidiophores emerge, (v. Tubeuf del.)

Plasmopara nivea (linger). (Britain and U. S. America).
Inflicts great injury on various wild and cultivated Umbelliferae,
e.g. carrot {Daucus Carota), parsley (Fetroselinum sativum), chervil
{Anthrucu>i Cerefoliuvi).

Plasmopara viticola, Berk.^ The Downy or False Mildew of

^Bibliography. De Bar}', Annal. d. sci. nat., 1863. Viala, Die Pilze d.
Wtiiistockts ; with good 1)ibliography. Prillieux, Annal. de. Vinstit. nat.
agronomigue, 1881. Cornu, Le Peronospora des Vignes, Paris, 1882. Sajo,

PLASMOPARA.

129

the Vine. This parasite was introduced into Europe from
America.^ It makes its appearance in early summer as white
patches on the under surfaces of leaves, sometimes also on stalks
and fruit. In the course of the summer the leaves show brown
spots and dry up.

The white patches consist of tufts of branched conidiophores,
from which ovoid conidia are abiointed. These on germina-

FiG. iO. —PlasmoiMi-a viticola. Conidiophores, much enlarged, (v. Tubeuf del.)

tion in rain-drops discharge six to eight swarming cells from
which germ-tubes grow into the epidermis of the host-plant ;
thus the disease spreads rapidly during moist weather and a

Peronospora viticola, 1890. Maguus, Wittviaclc's Gartenzeit, 1883. Scribuer,
Reijort of U.S. Dept. of ArjricuUure for 1886, pp. 96-105; this contains an
excellent account of this milde-n-. Articles on this subject dealing with remedial
measures are frequently published in the U.S. Amer. Department reports and
bulletins, in the bulletins from experimental stations, and in the horticultural
journals.

1 Seymour and Farlow give it as occuring on every American species of V\fis.

I

1 30 PHYCOMYCETES.

wet season is very favourable to it. The mycelium is uon-
septate and spreads through the intercellular spaces of the host,
nourished by button-like haustoria sunk into the host-cells.
The antheridium comes into contact with the oogonium by a
fertilization tube, which, however, remains closed. The oospores
hibernate in leaves and fruit.

Frcvcntion} Ammoniacal copper carbonate solution, eau
celeste, or Bordeaux mixture, prepared as described on p. 69,
may be used. The tirst-named solution seems least liable to
injure the foliage ; the others must, on this account, be used
with care. The first application is made about the time the

Fig. 41. — Plasmopara pycimaea on Anemone nemorosa. Conidiophores emerging
from a stoma. Intercellular mycelium with haustoria. (v. Tubeuf del.)

berries are well formed, and the sprayings are repeated every
twelve to fifteen days, or ofteuer if there are heavy rains, till the
grapes begin to colour. It must, however, be remembered that
sprayings of this kind do not reach the mycelium inside the leaf,
but only act superficially, killing any developing conidiophores
or conidia which may alight on the leaf. These fungicides are,
at the same time, remedies for powdery mildew (Uncinula).

" Sulphuring" as a remedy for this and the powdery mildew-
has been recommended hy continental writers.^ The burning
of all diseased vine-leaves is strongly recommended. Attention
also should be given to the cultivation of disease-proof varieties.^

PI. pygmaea (Unger). On Ranunculaceae (Britain and U.S. America).
PI. pusilla (De Bary). On Geraniums.

1 Galloway, "Fungous diseases of the grape and their treatment," U.S.
Dept. of Aijric, Farmera' Bulletin, No. 4, 1881.

-Oesterr. Weinbaukongress, 1891. Reported in Oe-it. landwirth. Wochenhlatl,
X., 1881.

^Millardet (see Chap, vi.)

PLASMOPARA.

131

PI. viburni, Peck. Oii Viburnum (U.S. America).
PI. densa (Eabh.). Oii Scropliularineae (Britain).
PI. ribicola (Schroet.). On Ribes rubrum (U.S. America).
PI. epilobii (Eabh.). On Epilobium pahistre, and E. parvifoliurii.
PI. obducens (Schroet.). On cotyledons of Impatiens (U.S. America).
PI. geranii (Peck.). On Geraniums in America.

PI. Halstedii, Berl. and de Toni. On Silphium, Rudheckia, Helianthus,
and many other American Compositae.

Sclerospora.

Mycelium intercellular in living plant-tissues, and deriving
nourishment by means of haustoria. The conidiophores are
thick, short, and divide at their apices into short broad branches,
from each of which a single conidium is abjointed. The conidia
in germinating discharge swarming cells. One oospore is formed
in each oogonium.

Sclerospora graminicola (Sacc.) lives in several species of
Setaria (U.S. America).

Bremia.

Mycelium intercellular in higher plants, and nourished by
little button-like haustoria. The conidiophores are branched,
and at their apical ends
become swollen in a char-
acteristic manner, so as to
resemble a hand held cup-
like with the fingers project-
ing separately upwards, like
the tentacles of Hydra. The jj^
conidia are aljjointed singly
from the tentacle-like pro-
cesses, and germinate, emit-
ting a germ-tube through a
definite thin spot in their
coat. Oospores originate
singly in oogonia.

Bremia lactucae, Eeg.
{Pcronospora gaiLgliun iformis
Berk.^) (Britain and U.S. America). The richly-branched conidio-
phores appear singly on attacked parts of plants. This fungus

' Cornu, Compt. rend., 1S78.

Fig. i2.— Bremia lo.ctucac. (v. Tubeuf del.)

132 PHYCOMYCETES.

may cause considerable damage to the lettuce {Ladvca saliva),
this being especially the case in France. The parasite is most
dangerous in forcing-houses during winter or early spring, and
spreads rapidly, favoured by the damp atmosphere. The young
diseased plants are stunted, and take on a pale colour, Karly
removal and destruction of diseased plants is to be recommended;
also abandonment for lettuce-cultivation of infected houses or
frames.

In addition to lettuce, this fungus attacks a number of
Compositae, cjj. Cineraria, Sonchiis, etc.

Peronospora.

The mycelium is intercellular in living plants. The haustoria
may be simple, button-shaped, or thread-like, or may branch
inside the host-cell. The long and much-branched conidiophores
produce conidia singly at the ends of their branches. The
conidia produce a germ-tube. The oospores are brown-coated
and are formed singly in the oogonia ; they germinate in spring.

Peronospora Schachtii, Fuck.^ is injurious to the inner
leaves of sugar beet and mangold {Beta vulgaris), while young
seedlings are killed by it. The mycelium hibernates in the
roots ; as yet oospores have not been found.

P. effusa (Grev.) This causes injury to spinach (Spinacia.)
oleracea) and other Chenopodiaceae (Britain and U.S. America).

P. Schleideni, Ung. Kills the leaves of cultivated and wild
species of onion {Allium) (Britain and U.S. America).

P. dipsaci, Tul. Injures stems and leaves of Dipsacus Sylvester
and D. FuUonum.

P knautiae, Fuck., of K7iautia and Scahiosa, is probably identi-
cal with last.

P. viciae (Berk.) (Britain and U.S. America). A dangerous
.species to many Papilionaceae (especially peas, beans, tares,
lentils, etc.), often causing great damage to field crops. In
recent years the new fodder-plant Lathy rus sylvestris has been
frequently attacked.^

P. trifoliorum, De Bary ^ (Britain and U.S. America). Dis-
tinguished from the preceding form by its irregularly marked

'Kiihn, Bofan. Zeitiuuj, 1873.

- Zeilschrift f. PJIaiizenkrankheifen, ii., p. 225 ami 28.3.

^ Smith, Disea^iC'i of Crops, Lontloii, 1SS4.

PERONOSPORA.

133

oospore-coat (oospores of P. viciae have a coat with a regular net-
work). It occurs on stems, leaves, and petioles of clovers, lucerne
and other Papilionaceae, often with disastrous effect.

P. sparsa, Berk. (Britain and U.S. America). This parasite
on the rose was first observed in England. It injures indoor
roses, causing a fall of the leaf, preceded by the appearance of
lilac-coloured spots which, on the underside of the leaf, are closely
beset with a white coating of conidiophores.^

Fig. 43. — Pu-onosporo. viciae. Conidiophores and conidia. (v. Tubeuf del.)

P. arborescens (Berk.). On leaves and shoots of wild and
cultivated poppies ; especially injurious to seedlings of garden
species.

P. parasitica (Pers.) (Britain and U.S. America). This pro-
duces greater or less deformation of attacked stems of many wild
and cultivated Cruciferae. Amongst cultivated plants the most
liable to injury are the varieties of turnips and cabbage, radish,
rape, cress, wallflower, also the mignonette. It is generally found
along with Cystopus candidus on shepherd's purse {CapscUa).

P. cytisi, Eostr.,^ attacks seedlings of laburnum in Denmark,
causing death in a few days. The leaves become brown spotted,

^ Zeitschrift f. P.-krank., ii., p. 386, (description of attack in Silesia.)
^ Rostrup, Zeitschrift f. Pflanzenkrankhdten, 1892.
Magnus, Hedicigia, 1892.

134

PHYCOMYCKTES.

and branched conidiophores with light-brown conidia arise from
their underside. Numerous oospores may be found in the leaves.
Kirchner ^ observed the disease on leaves of four-year-old plants,
yet without injurious effects.

The following are other British or American species:

Peronospora ficariae, Tiil. On Ranunculus, Myommis, etc.

P. corydalis, De By. On Corydalis and Dicentra.

P. violae, De By. On Viola tricolor.

P. arenariae var. niacrospora, Far!. On Silene.

P. alsinearum, Casp. On Cerastium.

P. claytoniae, Farl. On Claytonia.

P. lini, Scliroet. On Linum.

P. potentillae, De By. On Rosaceae e.g. O'eum, Fragaria, and I'otentilla,

P. Arthuri, Fail. On Oenothera.

b

Fio. 44. — Peronospora alsinearum. Sexual organs, c. Young condition ; b, for-
mation of ovum and fertilization-tube ; c, after fertilization, (periplasm some-
what contracted by preparation, and the fertilization-tube unusually thick) ;
n, anthcridium ; o, oogonium, x 350. (After I)c Bary.)

P. leptosperma, De By. On Conipositae e.g. Artemisia.

P. Candida, Fuck. On Androsace and other Primulaceae.

P. cynoglossi, Burrill. On Cynoglossv.m.

P. myosotidis, De By. On Myosotis and Echinospermum.

P. sordida. Berk. On Nicotiana and Scrophularia.

P. hyoscyami, D. By. On Tobacco in America and Australia (Gar<l.
Cliron. IX.).

P. linariae, Fckl. On Linaria.

P. grisea, Ung. On Veronica.

P. lophanti, Farl. On Lophanthus.

P. alta, Fckl. On Plantago.

P. (Plasmopara) cubensis is reported- as causing an extensive and
destructive disease of cucumbers (Cucumis and Cucurhita).

P. (Plasmopara) australis, Speg. On Ecldnocystis lohata and Sicyos
angulatus in America.

' Kirchner, ZeiUchrift f. PJlanzenkrankheiten, 1892.
-Humphrey, Beport of the. Mas%. Af/ric. Exper. Stat., 1890-92.
Masses, Gardener'.^ Chronicle, Vol. xvii., p. 656, 1895.

HIGHER FUNGI, 135

P. oxybaphi, Ell. and Kell. On various Nyctaginaceae.
P. polygoni, Thlim. On Polygonum.
P. euphorbiae, Fuck. On Euphorbia.
P. urticae (Lib.). On Urticaceae.
P. elliptica causes death of lilies.^

B. Higher Fungi (Mycomycetes).

The higher fungi are distinguished from the lower in possessing
a mycelium, which, from the first, is divided by means of cross-
septa. The mycelium of the lower fungi, though often much
branched, remains unicellular till cross-septa arise on formation of
reproductive organs or in the older stages of the fungus.^ In
higher fungi, septation begins with the first appearance of
mycelium and extends acropetally, growth in length proceeding
from the terminal cell. Sexual organs are without doubt present
in the lower fungi, but amongst the higher forms, Brefeld believes
that the sexual act no longer exists. On the other hand, certain
organs, found especially in the lichens, have been regarded as
sexual.

Dangeard regards the union of cell-nuclei as a sexual act,
and assumes its existence in the asci and basidia of higher
fungi. His more recent investigations on the nuclei of fungi,
combined with those of Pairault and Eaciborski, have laid the
way to a new systematic arrangement.^ Just as amongst the
lower fungi the cell produced by a sexual act contains a nucleus
derived from the fusion of two nuclei of distinct origin, so amongst
the higher fungi one also finds cell- nuclei derived from copulation.
The investigations of Dangeard, Eosen, Wager, Pairault, and
Eaciborski, lead to the conclusion that : * "a stage may be
found amongst higher, as well as lower fungi, in which two
cell-nuclei of one cell copulate. The cells known as oospores
of the Oomycetes, zygospores of the Archimycetes and Zygoviycetes,
chlamydospores of the TJstilagineac, and teleutospores of the

^ Smith, Disease of Lilies, 1888.

- Zopf. Die Pilze, 1890 ; and Bdtrdqe z. Physiol, u. morphol. niechrer Organismen,
Heft III., 1893.

^ Daugeard. " Recherches sur la reprod. sexuell d. champignons" Le
Botanisfe, 189.S. Pairault and Raciborski. "Sur les noyaux des Uredinees"
Jour, de Botanique, 1895.

■* Raciborski. Flora [ergdnziingsband), 1895, p. 439. Compare also: Stras-
burger. " Ueber periodischeReduktion d. Chromosomenzahl im Entwickelungsgang
d. Organismen," Biol. Ventralhlaft, 1894, p. 862. Wager. " Nuclear division in
the Hymenomycetes," Annals of Botany, 1893, f). 490.

13G ASCOMYCETES.

Uredincae, we designate amongst the Ascomycetes, as asci, and
amongst the Protomycctes and Basidiomycetes as basidia. This cell,
a homologiie of the primary embryo-cell of the Archcyoniatae
and Emhryunatac, indicates a turning-point in the development,
the beginning of a new generation. It either becomes a resting-
spore, as in Pliycomycctcs, Ustilayincae, Uredincae (exclusive of
Coleuspornim and Chrysomyxa), or divides at once to form free
endospores as in the Ascomycetes, and exospores in the Protomycetes
and Basidiomycetes. From these facts the distinction between
basidiospores and conidia, asci and sporangia, teleutospores and
chlamydospores, has been for the first time distinctly proved."

ASCOMYCETES.

The Ascomycetes show relationship to the higher fungi in the
possession of a septate mycelium. Their spores are produced in
cylindrical sacs called asci, whence the name Ascomycetes is
given to the group.

The primary nucleus of each ascus results from the copulation
of two nuclei of distinct origin and with no relationship to each
other. From the division of this nucleus and its daughter-
nuclei, there are produced a number of free endospores varying
according to the species. These may remain unicellular or, by
means of septa, become many-celled bodies from each of whose
individual cells germ-tubes may develop. It is advisable to give
the name spore to each cell-group which develops from one
nucleus.^

Ascospores are never zoospores, but are always quiescent and
possess a cell-membrane. They are generally forcibly expelled
from the asci. The asci originate either directly from the my-
celium, as in the Saccharomycetes and some Exoasceae,^ or a part
of the mycelium becomes differentiated into an ascogenous layer.
The ascogenous layer may include only a few cells, as in the
lower forms, or it may be a complex tissue. In the higher forms
the aggregations of asci are enclosed in coverings, but the asco-
genous layer takes no part in the formation of the enclosures
nor of the accessory organs known as paraphyses and periphyses.

■• De Bary held that each individual cell capable of germination is a spore, the
single multi-cellular spores he designated sporidesmia.

"Hansen, Centralhl. f. Bacteriolor/ie nnd Parasltenkiinde, 1S93.
Sadebeck, Die ixiranitischen Exoanceen, 1893.

ASCOMYCETES. 137

This ascogenous layer has been named the ascogonium, and it
was at one time generally believed that it arose from a female
cell, the homologue of the oospore of lower fungi ; a hypha
which applied itself to the ascogonium was regarded as a male
or antheridial organ, and called a pollinodium. In other cases,
a thread-like hypha, which proceeded from the ascogonium, was
called a trichogyne ; it was believed to be fertilized by means
of certain very small cells (spermatia) produced in special
structures, the spermogonia. These spermatia, though known
for a long time, have only recently been made to germinate, and
that only iil nutritive solutions. The significance of the pol-
linodium as a male organ is not necessarily wrong, though it
may be a functionless structure, such as we already know
antheridia of many of the Phycomycetes to be. So also we may
still consider the spermatia as sexual bodies, even though they
germinate like spores, for their never-failing production before
aecidia would seem to suggest some relationship. In the
following pages we will speak of these little spores, sometimes as
spermatia, sometimes as conidia.

Eeproduction of Ascomycetes may also take place by conidia
and chlamydospores, capable of germination to form mycelia.

Amongst the Ascomycetes one finds the higher stages of de-
velopment accompanied by an almost complete enclosure of the
aggregations of asci. The asci of the Saccharomycetes originate at
any spot whatever between the mycelial threads ; in GymnoasciLS
one finds a loose web of mycelium forming a covering to the asci ;
in higher forms an enclosure (sporocarp) of definite shape is
developed. On this account, the forms which do not produce
sporocarps are classed together as Gymnoasci, the sporocarpous
forms as Carpoasci. Amongst the latter, the sporocarp of the
higher forms possesses a definite opening from which the spores are
emitted after liberation from the asci ; certain lower forms (Peri-
sporiaceae) have indeed sporocarps, but these possess no opening,
and it is only after they have ruptured or decayed that the

spores are set free.

A . Gymnoasci.

{Ascomycetes loithout Sporocarps.)
The asci are produced over the whole mycelium, or from a
special ascogenous part of it, and are never enclosed in a sporo-
carp.

1 38 ASCORIYCETES.

The genera placed in the Gyninoasci are : Dipodascus, Ere-
mascus, Ascoidca, Protomyces, Taj)hrina, Exoascus, Magnusiclla^
Saccharomyces, Monospora, Endomyces, Fodocapsa, Ercmothecium,
Oleina, Bargcllinia, Ascodesmus, Gymnoascns, Ctenomyces.

Protomyces, Tcqjhrina, Exoasmis, Magnusidla, are true parasites
of higher plants: Endomyces, Ascoidca, and Saccharomyces occur in
the 11 ux diseases of trees ; the others are saprophytes, or
parasites on fungi (Podocajjsa).

Protomyces. 1

The genus Protomyces possesses a septate mycelium, and
in this shows relationship with the higher fungi. It is also
distinguished by the formation of sporangia (asci), which are
produced in an intercalary manner like the chlamydospores of
the Ustilagineae. Conidia are also developed, which sprout
yeast-like and conjugate like those of many Ustilagineae.
Thus Protomyces stands in one direction between the sporangi-
ferous lower fungi and the Ascomycetes, and in another between
the Ascomycetes and the non-sporangiferous Ustilagineae.
Brefeld allocates them with the Ascoidea and Theleboleae to
his intermediate group the Hemiasci. De Bary {Comparative
Morphology of the Fungi) agrees with Fiscli in placing them
between the Chytridiaceae and Ustilagineae, but in his "Beitrdgen"
considers them as the simplest forms of Ascomycetes.

In any case they do not show very close relationship with
any group.

Protomyces macrosporus, Ung. (Britain). This parasite lives
by means of an intercellular septate mycelium in leaves and stems
of Umbelliferae, especially Acgopodium Podagraria, Chaci'ophyUum
hirsutum, Heracleum Sphondylium, etc. It also causes injury to
cultivated carrots.

The disease shows itself externally as pustule-like swellings
on the organs attacked. These are caused, as shown in the
figures, by a mycelium which pierces the epidermis, and, after

^ De Bary, Untcrsuchungen ub. <1. Biandpike u. d. durch sie ventrsachten
Krankhcittn d. Pflanzen. Berlin, 185.3.

De Bary ii. Woronin, Btitriuie z. Morph. u. Phyxiol. d. Pilze, I. Btl., 1864.

Fisch, Beifrdrje z. Kenntniss d. Chytridiaceen, 1884, p. 41.

Brefeld, llefepilze, p. 176.

B. Meyer, " Untersuchuiigen nl). die Entwickelung einig. parasit. Pilze bei
saprophyt. Ernahrung." Inaugural Dissertation, 1888.

PROTOMYCES.

139

distributing itself through the intercellular spaces, stimulates the
parenchyma-cells of the host to growth and cell-division. The

Fig. 45. — Protomyces macrosporiis on leaf-stalk of AegopoO.ium Pod.agro.rio..
A, Mycelium and sporangium in- the tissue under the epidermis. B, Sporangia
in stages of development, (v. Tubeuf del.)

latter is a secondary process and consists (see Fig. 9) in the
formation of exceedingly delicate membranes inside the original

Fig. 46. — Protomyces viaci'Oiporus. Section of petiole of Aeyopodiv.rii with two
swellings containing spores. Secondary cell-walls have been formed, and a
coUenchyma region lies between the two swellings, (v. Tubeuf del.)

cells of the parenchyma, so that they become divided into
younger cells rich in protoplasm and each showing a distinct

140

ASCOMYCETES.

cell-nucleus. This tissue so formed may be compared to the
nutritive tissue formed secondarily from parenchyma as a result
of other fungoid diseases, e.g. in violas attacked by Urocystis
violae. If the formation of sporangia ensues in parts which
would normally become collenchyma, the tissues there remain
thin-walled.

The sporangia of rrotomyccs, according to De Bary,^ begin to
develop as soon as the young leaves and shoots of the host-
plants emerge above the ground in spring. The sporangia first

Fio. 47. — Protomyces -inacrosporui. Section through swollen leaf-stalk of Aego-
poiUuni. Towards the right end the cells are normal, elsewhere they are, under
the influence of the mycelium, much enlarged and sccoudarily divided ; two
roundish sporangia lie in this tissue, (v. Tubeuf del.)

appear as series of swellings on the hyphae and are easily
detected in deformed plants as large thick-walled bodies lying
in the intercellular spaces. They are liberated on decay of the
host-plant, and in spring the contents swell up so as to rupture
the thick outer wall, and the endosporium emerges as a vesicle
or sporangium into which the protoplasmic contents pass to
form numerous rod-shaped spores. The spores are ultimately
expelled with considerable force, and, after conjugating in couples,
they send forth a germ-tube which penetrates again into the
tissues of the host-plant.

' De Bary, Beilriuje z. Morph. u. Physiol, d. Pilze, also Botan. Zeltimg, 1874.

PROTOMYCES. 141

In nutritive solutions germination does not take place in this
way, but is replaced by a veasi-like sprouting of the sporangial
spores without disjunction of the sprout-cells.^

According to Meyer, these sprout-cells produce elongated
hypha-like cells with which, however, he did not succeed in
infecting a new host-plant. He also found that spore-conjuga-
tion takes place better in water than in nutritive solutions.

Pr. fuscus, Pk., occurs on Anemone in America.

Pr, pachydermus,Thum., occurs on Compositae esp. Taraxacum.

Pr. radicicolus, Zopf.- A form similar to P. macrosporus,
but furnished with coiled haustoria. It lives intercellular in roots
and kills the cells, without, however, causing external hypertrophy.
Zopf found it in roots of Stiftia Chrysantlw and Achillea
clypeolata in the botanic garden of Halle, but the plants were
not killed, because their roots were not all attacked.^

Endomyces.

The asci contain four spores which do not produce conidia.
The sterile hyphae give rise to chlamydospores and an oidial
form of spore.

Endomyces decijne^is lives as a parasite on sporophores of
Agaricus melleus.

According to Ludwig, species of Endomyces have much
to do with the slime-flux of trees, which contain in addi-
tion other forms of Gymnoasci, e.y. Saccharoviyccs Ziahcigii,
Ascoidccc ruhcscens, etc. We shall here devote some space to
the general consideration of the slime-flux of living stems.
This phenomenon remained uninvestigated until Ludwig took it
up and directed attention to it. He found several species of
considerable systematic interest, the pathological effects of which,
however, require further investigation.

^Brefeld, Srhimmelpihe, Heft ix., 1891.

-Zopf, Zur Kenntiiiss d. Infectionalranhh. nmlertr Thiere u. Pjlanzen, 1888,
" Saccardo, who ranks the Protomycetes along with the Chytridiaeeae, includes
a large number of species. Magnus places Protomyces (?) Jilicimis, Niessl. ( Vtr-
hand. des intemat. hotan. Kongreas in Genoa, 1892) in the neighbourhood of
the Phycomycetes ; it, however, possesses a septate mycelium and stylospores
Avhich are enclosed in a coat so that they recall spores of the Uredineae, hence
Magnus named it Urtdinopsis Jilicina on Phtgopteris vuJrjaris. This species
must not be confused with the species of Uredo occurring on Phegox>teris
Dryopleris, Cystopteris fragilis, and Scolopendrium officinale.

142 ASCOMYCETES.

The Slime- or Mucilage-flux of Trees.

This is a very common phenomenon in our avenues, parks,
and forests. It can be observed during the period of vegetation
on several species of trees, particularly on spots wounded Ijy
removal of branches, by frost rupture, or by some other cause.
The wound may, however, be so grown over or occluded tliat
at first sight the slime appears to flow from the uninjured
bark. These slime-fluxes are very common on dead branch-
snags and in places affected with sun-stroke or frost- wounds ;
while I have frequently found them on dead tree-stools
and on wooden water-pipes where the water trickled from
some fissure. It is thus probable that they are always
produced on the site of some wound, although Ludwig,
without giving any details, says that there may be no previous
injury. I have never observed any case where a tree with a
slime-outflow became sickly and died, and the cases of death
recorded by Ludwig are probably due to some other cause.
Ludwig, however, says decidedly that the white slime-flux on oak,
as well as the brown flux of apple, horse-chestnut, and
others, are really parasitic phenomena. I must say, however,
that I have carefully examined the occluding tissues on frost-
cracks showing slime-flux, and found them quite healthy.

The white slime-flux of the oak.'

According to Ludwig, the white slime-flux of the oak and
other species of trees takes place during moist weather, and
from June to September. It flows from branch-scars, former
frost-ruptures, and other wounded places ; also from apparently
uninjured bark. Ludwig believes that such wounds are infected
by the agency of insects, particularly hornets ; that the disease
spreads through the bark and breaks out in various places. On
such spots the edges of the wound are alternately occluded
and killed again, so that a flux-wound may come in course of
time to resemble a "canker-spot." Large areas of the bark die off,
and the death of the wood frequently follows.

1 Ludwig : (1) " Ueber Alkoholgiihrung u. Schleimfluss lebender Biuime u. deren
Urheber." Ber. d. dentsch hotan. Ges., 1886. (2) " Ueber profuse Guminose d.
Eichen u. waiter. Mitth. lib. Alkoholgahrung u. .Schleimfluss lebender Biiume."
Ceiitrhl. f. Bakt. u. Parasitenkunde, 1890. (3) Lehrbuch, 1892. (4) Forst.-natur-
wiss. Zeitschr., August, 1894.

ENDOMYCES. 143

The slinie-flux is the product of an alcoholic fermentation and
has at first a distinct odour of beer. The fermentation produces
a transparent foam in which are found Endomyces Magnusii
(Ludw.) and a jenst, Sacchaivmyces lAidwigii (Hansen); this latter,
Ludwig regards as a stage of the Endomyces. Later a gelatinous
slime is developed in the foam from the presence of Leuconostoc
Lagcrhcimii (Ludw.) Since this latter plant does not appear
in the early stages of the disease, it cannot be the cause, and
Ludwig says that the alcoholic fermentation due to the Endomyces
always appears first ; this conclusion requires confirmation.

The milky outflow of trees. ^

Towards the end of winter and in spring a white foamy slime
flows from freshly cut birches or hornbeams. According to
Ludwig, this is due to Endomyces vernalis (Ludw.)

Red slime-flux.^

Ludwig found on the cut twigs of hornbeam, a red fungus
which he called Rhodomyces dcndnyporthes. This may occur alone
or along with the white flux, which it colours red.

Brown slime-flux.^

This is found on apple-trees, elms, birch, horse-chestnut,
poplar, oak, etc., from spring till winter. The slime, Ludwig
says, is developed in the wood, and breaks through, causing
the bark to decay. The wood is destroyed and smells of butyric
acid. The slime contains micrococci {Micrococcus dendroporthes,
Ludw.) and a form of Torida {T. monilioides).

In Thuringia, many avenue- trees {e.g. chestnuts, apples, and
birch), are reported to have been killed from this cause. That
the disease was really the result of a Bacterium, and that death
was due to this slime-flux, has yet to be proved, as Ludwig
himself states.

Black slime-flux.

Ludwig considers briefly some forms he found in a black
slime-flux observed by him on beeches.

1 Ludwig, Lehrbuch der nied. Kryptogamen, 1S92.

- Ludwig, Centralhl. f. BakL u. Parasitenktcnde, 1888.

1 44 ASCOMYCETES.

Chocolate-brown slime-flux.'

A slime-flux of this colour appears on the stumps, of felled
beeches ; it contains numerous forms of Oidium, and later Ascobolus
Constantini (Roll) is developed in large quantity.^

THE PARASITIC EX0ASCEAE.3

In this family are included the genera Exoascus, Magnusiella,
and Tcqjhrina. The asci of most of the known species are
prochiced from a mycelium which lives under the cuticle of the
host-leaf, in a few {cjj. Magnusidla fiavci), the mycelial
hyphae are developed between the cells of the epidermis,
while in others {c.rj. M. iwtcntillac), the mycelium permeates
the whole leaf-tissue and the asci arise from hyphae situated
under the epidermis. T. Laurcncia and a few others have an
intracellular mycelium, and produce asci inside the epidermal
cells. A number of species are known to possess a perennating
mycelium, in the remainder the hyphae are wholly used up in
the formation of asci.

The ascospores produce conidia before leaving the asci, which
are therefore frequently found filled with minute conidia instead
of the usual ascosj)ores. In nutritive solutions the conidia sprout
yeast-like ; on a host-plant, they give rise to a hypha which
penetrates the cuticle.

' Ludwig, " Ein neuer Pilzfluss d. Waldbaume," Forst.-naturwiss. ZeitschHft ,
1893, and 1894.

-Kriiger lias found various micro-organisms, including a fungus {Prototheca)
and several algae, in the slime-flux of broad-leaved trees. (Zopf, Beitr. z.
Phjjiiol. 71. Morph. niecL Orfjanismen , 1894.)

■' Sadebeck : (1) Untersuch. iib. die Pilzgattung Esoascus, 1884. (2) Kritische
Untersuch. iib. die diirch Taphrina-Arten hervorgehrachten Bcmmkrankheiten,
1890. (3) Die parasitischen Exoasceen, 1893. (4) " Einige neue Beobachtungen u.
kritische Bemerkungen lib. die. Exoasceae," Ber. d. deutsch. botan. Ges., 1895.

Johanson : (1) Studier ofcer Svampslcujet Taphrina, 1887. (2) 0?m Svamp-
sU'igtei Taphrina orh dithoraude Svennka arter, 1885. i

Rostrup, Taj>hrinaceae Daniae, 1890.

De Bary, Beitriine z. Morph. ?<. Physiol, d. Pilze, 1864-1870.

Giesenhagen, " Die Entwickelungsreihen der parasitischen Exoasceen." Flora,
ErijunzniKjshcuid, 1895. With numerous figures from microscopic sections.

Atkinson, " Leaf-curl and plum-i)ockets." A contribution to the knowledge of
the prunicolous Exoasceae of the United States. Cornell Univ. A<jric. Exp.
Station, Bu'/etin 73, 1894. With numerous illustrations.

Patterson, "A study of N. America parasitic Exoasceae." Btdledn of the
Lab. iml . hist., (Jnir. of loica, 1895.

Smith, " Untersuch. der Morph. u. Anatomic der durch Exoasceen verui'sachten
Deformationen." Forst.-naturwiss. Zeitschrift, Munich, 1894; Italian, translation
by Berlese, Rirista di Patoloijia, 1895.

THE PARASITIC EXOASCEAE. 145

The presence of a perennatiug inyceliuiu is the cause of
many so-called " witches' brooms " on woody plants. In fact,
the majority of the structures known by that name are caused
by species of Rwascus, though these of barberry, silver fir,
acacia, and buckthorn, are due to Uredineae, and others are
ascribed to mites {Phi/to2>tus).

" Witches' Brooms " ( Hexenbesen) are bushy growths, which
remind one at first sight of stranger-plants growing, like
mistletoe, on the branches of other plants. They generally
originate from a bud which has been infected during the previous
summer, either directly or through its subtending leaf. This bud
produces a twig capable of abnormally increased growth, most of
its sleeping l)uds are developed into branches, and the whole
system shows marked negative geotropism. (See Fig. 3). The
spores of the fungus are produced on the leaves of the broom.
The characteristic features of a witches' broom are : that,
without regard to the direction of the liranch on which it is
borne, it is negatively geotropic in a marked degree, and
endeavours to develop like a terminal leader shoot ; that the
point of infection is distinctly conspicuous as the starting point
of the broom. Sadebeck regards any twig-hypertrophy as a
witches' broom, even that of Uxoascus Tosquinetii where there
is no basal swelling and the twigs exhibit only very slight
negative geotropism.

The forms of witches' brooms are very varied. Amongst
the best known are the hanging broom-like masses developed
from buds of the leader shoots {e.g. on cherry trees). As a
result of the rich growth of twigs and their premature death,
many of these brooms l^ecome tangled nest-like structures. The
twigs in some are much elongated, in others shortened, in
every case, however, they are abnormally numerous. As a rule
the original leader shoot, on which some lateral bud has developed
into a witches' broom, shrivels up and dies, its contents being,
as it were, absorbed by the hypertrophied branches. Other
general features have already been discussed in Part 1. of
this book.

Smith^ found that the form of the witches' broom is not
determined exclusively by the fungus. The perennating my-
celium indeed gives the first impetus towards its formation,

1 Smith, loc. cit.
K

146 ASCOMYCKTES.

but it is completed by the weight of the broom itself, the
excessive development of sleeping buds, and the premature
death of twigs. Smith also investigated the anatomical changes
occuring in witches' brooms due to Exoasceac. From his
resumii we select the following : " In a witches' broom the
increased thickness of the twigs and branches is due to a
proportionally greater increase in the bark than in the wood,
the hypoderm, especially, having its cells more numerous and
larger, while their normal arrangement in longitudinal rows
is lost. The cork-cells are enlarged and retain their plasma-
content longer. The phelloderm is Ijetter developed. In the
sclerenchyma-ring, the primary bundles of bast-fibres are smaller
and fuither apart from each other, or they may be quite
absent ; the bast-fibres are shorter and have thinner walls ;
sclerenchymatous cells are more numerous, larger, and have
thinner walls. The phloem is increased chiefly through enlarge-
ment and increase in number of its medullary rays; phloem
crystal-deposits tend to he multiplied. In the wood, the parts
most enlarged are the pith and medullary rays ; tracheae are
more numerous, but their component elements are shorter ; the
wood-fibres have thinner walls, wider lumina, and are often
cham])ered ; the normal course of the long elements is much
disturbed by the greatly enlarged medullary rays.

Sadeljeck has recently divided the parasitic Uxoasceac into
these genera : (a) Mafjnvddla, with asci isolated on the ends
of mycelial threads which lie between the epidermal cells ; in
the other genera the asci arise from a subcuticular hymenium ;
(&) Taphrina, without a perennating mycelium ; (c) E.roa>iCvs,
with a perennating mycelium ; {<!) Taphrinopsis may be taken
as another genus. Ascomyccs he does not reckon with tlie
Exoasceac.

Brefeld divide.s the family into Exoascus, with eight spores in the ascus,
and Taphrina, with four-spored asci. Sadebeck .shows, however, that
eight is the normal number of spores in all the species, and that variation
therefrom is frequent, four or more spores or numerous conidia being
formed.

Scliroeter separates the genus Magnusiella, as Sadebeck has done, then
divides the remainder into Exoascxis with eight-spored asci at time of
maturity, while those with mauy-spored asci are jilaced under Tavhria
(the older name given to Taphrina)

THE PARASITIC EXOASCEAE. 14T

According to Sadebeck, the Eroasceae may be divided as-
follows :

Exoascus.

The mycelium perennates in the tissues of twig or bud. The
subcuticular mycelium is developed from the perennating one, and
becomes completely divided up, without any differentiation, into
Hscogenous pieces. The species are all parasites and produce
hypertrophy of leaves, flowers, and shoots.

A. The mycelium perennates in the inner tissues of the
shoot. Thence, in the next vegetative period, it sends branches
into the leaves in process of development, at first into the
inner tissues, but later subcuticular for the formation of re-
productive parts of the fungus.

(1) Asci developed in the carpels, which in consequence
become hypertrophied ; asci with a stalk-cell : E. ^^nim
Fuck. E. Rostrv/pianus Sad. E. commvnis Sad. E,
Farlowii Sad. E. rhizijycs Atk. E. longipcs Atk. E.
confusus Atk. E. cecidomophihis Atk.

(2) Asci developed only in the foliage leaves.

(a) Asci with stalk-cell : E. insifAiiac Sad. E. cerasi
(Fuck.). E. nanus (Joh.). E. deformans (Berk.) E,
decipicns Atk. E. acerinus Eliass.

(b) Asci without stalk-cell : E. im.rpurascens (Ell. and

Ever.). E. aescidi (Ell. and Ever.).

(3) Asci developed on leaves and fruits.

{a) Asci with stalk-cell : E. mirahilis Atk.

B. The mycelium perennates in the buds of host-plants
and issues thence in the next vegetative period to develop in
young leaves, subcuticular only.

(1) Asci only on the foliage leaves.

(«) Asci with a stalk-cell : E. crataegi (Fuck.). E. minor
Sad. E. Tosquinetii (West.) E. epijdujllvs Sad. E.
turgidus Sad. E. hetidinus (Eostr.). E. alpinus (Joh.).

(6) Asci without a stalk-cell : E. caipini Eostr. E. baderi-
ospermus (Joh.). E. Kruchii Vuill.

(2) Asci on carpels ; without stalk-cell : E. alni incanae
Kiihn. E. Johansonii Sad. E. rhizophorus (Joh.).

(3) Mycelium grows intercellularly. E. cornu ccrvi Giesh.

1 48 ASCOMYCETES.

Taphrina.

The whole mycelium is subcuticular and differentiated into
one portion, which remains sterile, and into an ascogenous part.
Pereniiation of the mycelium does not occur. The species pro-
duce spots or hypertrophy on leaves or carpels.

A. The fertile hyphae are completely used up in the for-
mation of the asci.

(1) Asci with a stalk-cell : T. hullata (Berk, and Br.).

T. ostryae ]\Iass. T. Stu/rhrckii Joh. T. aurea
(Pers.) (may also occur without a stalk-cell).

(2) Asci without a stalk-cell : T. filicina Kostr. T.

polyspora (Sorok.). T. carnea Joh. T. coerulescens
(Mont, and Desm.). T. virginica Seym, and Sad.
T. cxtcnsa (Peck.).

B. The fertile hyphae are not completely used up ; asci with
a stalk-cell : T. hetnlae (Fuck.). T. ulmi (Fuck.). T. cdtis Sad.

Taphrinopsis.

Mycelium and hymenium developed only inside the epidermal
<^ells. T. Laurcncia Giesh.

Magnusiella.

The mycelium inhabits the inner tissues of living plants and
is always parasitic. Asci are formed at the extremities of
branches of the mycelium, either between the epidermal cells
or between cells of the inner tissues. The asci contain more
than four spores, which generally produce conidia inside the
ascus. The species generally cause leaf-spots, more rarely they
appear on stems.

(a) Asci without a stalk-cell : M. imtcntillae (Farl.). M. lut-
cscens (llostr.). 3f. flava (Farl.). M. githaginis (Kostr.). M.
umhelliferaruin (Rostr.).

(&) Asci with a stalk-cell : M. fasciculata Lag. et Sad.

Giesenhagen {loc. cit.) comes to the conclusion that the species
of the parasitic Exoasceae have developed from a common
ancestor simultaneously with the species of the higlier plants
inhabited by them, and that the development of host and parasite

THE PARASITIC EXOASCEAE. 149

lias progressed side by side. He shows that Exoasceae, living
on related hosts, agree so closely in their ascogenous forms,
that it is evident they are generically related species. On this
ground he sets up a genus containing many species, and names
it Taphrina. According to the host-plants, this genus is
divided into four stems, and from it twenty-five species are
separated off as tlie genus Magnv.sidla. Giesenhagen's systematic
division, gives a synopsis of the host-plants and their distri-
bution as follows :

I. Genus. Taphrina : asci club-shaped to cylindrical.

A. Filices-stera, on Ferns : asci slender, club-shaped; tapering to
both ends, rounded apex, greatest breadth in the upper quarter
of the ascus.

T. cornu cervi (Giesh.) on Aspidium. aristatum in East
Indies and Polynesia.

T. filiciiut (Eostr.) on Aspidium sjjinulosum in Scan-
dinavia and Balkan-peninsula.

T. Laurencia (Giesh.) on Ptcris quadricmrito in CeyLjn.

T. fasciculata (Lag. et Sad.) on Ncphrodinm in South
America.

T. lutcscens (Rostr.) on Asjndivm Thelypteris in Denmark.

B. Bctula-si&m on Juliflorac : asci plump, cylindrical, with
rounded apex or even a slight depression there.

(1) On Ulmaceae: T. ulmi (Johan.) on Uhmis montana and

[/. camjMstris in Central Europe and North America.
T. cdtis (Sad.) on Ccltis austmlis in North Italy and
Switzerland.

(2) On Bctnlaccae.
{a) On Bctv.la :

T. alpiiia (Johan.) on B. nana in Scandinavia.

T. nana (Johan.) on B. na.na in Scandinavia.

T. betukie (Johan.) on B. verrucosa, B. piu^'-'sccns, and B.

turlxestanica in Central Europe.
T. hetulina (Eostr.) on B. imlesccns, and B. odorata in

Germany, Denmark, and Scandinavia.
T. carnea (Johan.) on B. odorata, B. jjubescens, B. nana,

B. intermedia in Scandinavia, Tyrol, and Silesia.
T. haxteriospermum (Johan.) on B. nana in Scandinavia

and Greenland.

150 ASCOMYCETES,

T. flava (Farl.) on B. populifera and B. papyracea in

North America.
T. turgida (Sad.) on B. verrucosa in Germany and Tyrol.

(b) On Alnus:

T. epiphylla (Sad.) on A. incana in Europe.
T. Sadehcckii (Johan.) on A. f/hitinosa in Europe.
T. Rohinsoniana (Giesh.) on A. incana in U.S. America.
T. Tosquinetii (Magn.) on A. glntinosa in Europe.
T. ahii incanae (Magn.) on A. incana in Europe.
{T. alni glutinosae (Tubeuf) on A. glntinosa in Italy,
Sweden, and Denmark.)

(c) On CiLpulifcrae :

T. ostryae (Mass.) on Ostrija carpinifolia in Tyrol and

Italy.
T. v.irginica (Sey. et Sad.) on Ostrya virginica in Xorth

America.
T. carpini (Kostr.) on Carpinus Bctulus in Europe.
T. australis (Atk.) on Carpinus americcma in North

America.
T. Kruchii (Vuill.) on Qucrcus Ueo: in Italy and France.
T. cocrulescens (Tul.) on Quercus sessilijiora, Q. pcdun-

culata, Q. 'puhescens, Q. alba, etc., in Europe and

America.

(d) On Salicaceae:

T. aurea (Fries.) on Popidus nigra, P. p)yraniidcdis and

P. monilifera in Europe and North America.
T. Johansonii (Sad.) on Popidus trcrnnla, P. tremuloides,

and P. grandidentata in Europe and North America.
T. rhizopliora (Johan.) on Populus alba in Europe,
c. Prunus-^tem on Rosaceae : asci slender and club shaped.
(«) On Pomaceae :

T. cratacgi (Sad.) on Crataegus Oxycantha in Europe.
T. bullata (Tul.) on Pyrus commnnis and Cydonia japonica

in Europe.
(6) On Pruneae :

T. deformans (Tul.) on Pcrsica vulgaris and Amygdalus

communis in Europe and North America.
T. minor (Sad.) on Prunus Chanmcccrasus near Hamburg

and Munich.

THE PARASITIC EXOASCEAE. 151

T. insititiac (Johan.) on Prunus Tndtitia and P. domedica,

in Europe, and P. penmylvanica in Xorth America.
T. decipicns (Atk.) on Prunus americana in Xorth

America.
T. ccrasi (Sad.) on Prunus Ccrasus and P. Chamaecerasus,

in Europe, and P. avium in Xorth America
T. immi (Tul.) on Prunus domcstica and P. Pad us in

Europe and Xorth America.
T. mirahilis (Atk.) on Prunus angustifolia, P. hortulana

and P. americana in Xorth America.
T. Fadowii (Sad.) on Prunus serotina in Xorth America.
T. confusa (Atk.) on Prunus virginiana in Xorth

America.
T Rostrupiana (Sad.) on Prunus spinosa in Europe.
T. communis (Sad.) on Prunus maritima, P. pumila, P.

americana and P. nigra in Xorth America.
T. longipies (Atk.) on Prunus americana in Xorth America.
T. rhizipes (Atk.) on Prunus trifiora in Xorth America.

{c) On Poteniilleae :

T. jyotentillae (Johan.) on P. sylvestris, P. canadensis, and
P. geoidcs in Europe and Xorth America.

D. Acscul US-Stem, on Eucijclicar : asci phunp, cylindrical, with
Hat or rounded apex.

{a) On Sapindaceac :

T. aesculi (Ell. et Ever.) on Aesculus californica in
California.

(b) (Jn Anacardiaccae :

T. purpurascens (Robins.) on Rhus copallina in Xorth
America.

(c) On Aeerineae :

T. acericola (Mass.) on A. campestre and A. Pseudoplatanus

in Italy.
T. accrrim (Eliass.) on A. platanoides in Sweden.
T.polyspora (Johan.) on A. tartaricum in Europe.

II. Genus. Magnusiella : asci ovoid or spheroidal.

21. githaginis (Sad.) on Agrosfemma Githago in Denmark.

M. umbelliferarum (Sad.) on Heracleum Sjyhonchjlium,

Peucedanum palustre, and P. Oreoselinum in Europe.'

152 ASCOMYCKTKS.

T\m E.roaticcac may be grouped, according to the symptoms
of the disease produced, as follows ; for this purpose we shall
class all the species as one genus, ' E-roasci's ' (or Taiihrina) :

I. Species which cause deformation of the ovary or other part
of the fruit.

E. pruni (Fuck.) on PrinviiH domcstica, I'. Padns, 1\ vir-

f/miana.
E. Eostritpianvs (Sad.) on Pnmus spinosa.
E. communis (Sad.) on Frunus 2'>uiniUa, P. maritima, P,

nigra, P. americana.
E. Faiioivii (Sad.) {E. varius, Atk.) on Prunun scrotina,

causing also deformation of twigs.
E. lonr/ijn's (Atk.) on Prvni's americana.
E. confusi's (Atk.) on Prunus virginiana.
E. rhizipcs (Atk.) on Prunus triflora.
E. cecidomophilus (Atk.) on insect-galls on the fruits of

Priinvs virginiana.
E. mirahUis (Atk.) on Prunus angustifolia, P. liortv.Jana,

P. a.mcricana.
[Also species on Pruntis suhcordata, P. Clncasa, and ]\

pennsylvcmica.]
E. alni incanae (Ktihn) {E. amcntoruvi, Sad.) on Alnus

incana.
E. alni glutinosac (Tubeuf) on Alnus glutinosa.
E. Robinsonianus ((liesh.) on Alnus incana.
E. Johansonii (Sad.) on Populus trcinula, P. trcmuloides, P.

grandidentata.
E. rhizoj^horus (Johan.) on Po2)uh's alba.

II. Species which (1) produce witches' brooms, or (2) at least
cause deformation of shoots ; asci produced on the leaves.

(1) E. cjnpliylliis (Sad.) {E. ho/ralis, Johan.) on Alnus

incana (uniform grey coating of asci on both sides

of leaf.)
E. turgidus (Sad.) on Bctula verrucosa (coating of asci on

under surface accompanied by slight crumpling of

leaf).
E. hetulinus (Rostr.) on Betula ijuhescens and B. odorata

(coating of asci on under surface).

THE TARASITIC EXOASCEAE. 15^

E. alinnvs (Johan.) on Bdula nana (coating on under

surface).
B. carpini (Rostr.) on Carjmivs Betvlus (coating on under

side, and crumpling of leaf).
E. cerasi (Fuck.) on Frunus Cerasvs and P. avium (coating,

chiefly on under side, and crumpling of leaf).
E. insititiae (Sad.) on Frunus Lisititia, P. domestica, F,

2)cnnsylvanica, (F. spinosa?) ; (coating on under side,

and crumpling of leaf).
E. accrimis (Eliass.^) on Acer plafanoidcs ; (asci on Ijoth

surfaces).
E. aesculi (Ell. et Ever.) on Aescnhis californica; (coating on

both sides).
E. Kruchii (Vuill.) on Querci's Ilcr.
E. cornu cervi (Giesh.) on Asjndium aristaivm.
E. Laurencia (Giesh.) on Ftcris quadriaurita (with deforma-
tion of leaves).

(2) ^. nanus (Johan.) on Bdida nana (white coating on
upper side).

E. hacteriosiicrmus (Johan.) on BcMa nana (coating on both
sides).

E. decipieiis (Atk.) on Frunus americana (coating on both
sides).

E. jmrjmrasccns (Ell. et Ever.) on Bhus copallina (crum-
pling and red-colouration).

E. Tosquinetii (West.) on Alnus giutinosa and A. gluf.x
incana (large blisters and elongation of shoots).

E. pruni (Fuck.) on Frunus domestica (blistering and crum-
pling).

E. minor (Sad.) on Frumis Chamaccerasus.

E. deformans Berk, on Fersica vidgaris and Amygdalus
communis (blistering and crumpling).

E. crataegi (Fuck.) on Crataegus Oxyacantha (spots and
blisters on the leaves).

E. mirabilis (Atk.) on Frunus angustifolia, F. hortulana,
F. americana (on twigs, leaves, and fruits).

E. celtis (Sad.) on Celtis australis (brown spots).

E. githa,ginis (Eostr.) on Agrostemma Githago.

^Svenska J'et.-Akad. Handl. 20, 1895.

154 ASCOMYCETES.

III. Species whicli produce (1) pustule-like outgrowths, (2)
leaf-spot, or (3) smooth coatings of asci.

E. aureus (Pers.) on Populus nigra (incl. jnjramidalis)

and P. monilifera.
E. i)olys'porus (Sor.) on Acer tartaricum and A. Pseitdo-

■platanus.
E. hullatus (Berk, et Br.) on Pyrus commiunu and Cijdonia

japonica.
E. carneus (Johan.) on Betula nana, B. odorata, and B.

intermedia.
E. coerulescens (Desni. et Mont.) on Qucrcus j^uhescens, Q.

sessilijlora, Q. Cerris, Q. lanrifolia, Q. rubra, Q. tinxitoria,

Q. aquatica.
E. Sadchecldi (Johan.) on Alnus glvtinosa.
E. ulmi (Fuck.) on Ulmus camiMstris, U. moyitana, and U.

americana (spots and blisters).
E. virginicus (Sey. et Sad.) on Ostrya virginica.
E. australis (Atk.) on Car])inus americanus.
E. filicinus (Eostr.) on Aspidium spinulos^im.
E. potentillae (Farl.) on Potentilla geo'ides, P. canadensis, P.

sylvestris.
E. githaginis (Eostr.) on Agrostcmma GWiago.
E. lutescens (Eostr.) on Polystichum Thclypteris.
E. umhellife7^aruni (Eostr.) on Heracleum Sphondylium, Peu-

cedanum 'pnl^'stre and P. Orcoselinum.
E. ostryac (Mass.) on Ostrya carpinifolia (brown spots).
E. hctulae (Fuck.) on Betula verrucosa, B. pubescens, B.

turkestanica (whitish spots).
E. Jiavus (Farl.) on Betula populifolia, B. papyracea.
E. acericolus (Mass.) on Acer camjiestre and A. Pseudo-

platanus.
E. fasciculatus (Lag. et Sad.) on Nephrodium (whitish spots).

The following are some of the more important species of
Exoasceae :

Exoascus pruni Fuck. (Pocket-plums). This attacks the
ovaries of Prunus domcstica (plum), P. Padns (bird cherry), and
P. virginiana, causing the mesocarp to grow rapidly, whereby
the fruits increase in size and become much changed in form.

THE PARASITIC EXOASCEAE.

155

while the stone, including the embryo, remains stunted. (Fig.
49.) The "pocket-plums" (fools or bladder-plums) dry up, and
remain hanging on the tree till autumn. De Bary found on
the plum a withering of calyx and stamens resulting from the
development of the hymenium of this Exoascus ; on the bird
cherry, according to Magnus and Wakker, enlargement of the
stamens occurs. Sometimes a considerable thickening and
twisting of the young shoots takes place, and their leaves
curl up.

Fir 4^ — Eroascus pruni. Twig of Plum, with four deformed fruits ; one
iiuijiittl pluiii is partially hidden, the other is in the middle, i natural Mze.
(v. Tubeuf del.)

The mycelium hibernates in the soft bast of the twigs, and
proceeds thence in spring into young shoots and ovaries.
According to De Bary, the infected ovaries double their size
in two days, and are full grown in eight days. The asci form
a close layer under the cuticle of the ovary, and finally
rupture it.

15G

ASCOMYCKTES.

Exoascus Rostrupianus Sad. This fungus causes " pockets "
on rn/ni/,s spitiosa (sloe) similar to the preceding species.
According to Sadebeck, the asci in this case are more slender.

Pio. 49. — Exoascus 'prwui. Malformed
Plums — "pocket plums"; one which is
cut shows the rudimentary stone.

4 natural si/.e. (v.'Tubeuf phot.)

Fici. 50. — Exoascus prv.ni on twig of Prvnv.s
Padvs (at end of July). Four of the ovaries-
are m.alformed. (v. Tubeuf del.)

Flu. .01. — Exoascus prvni. Young twigs of Plum, showing effects of mycelium.
The shoots are swollen and distorted, one disea.sed leaf remains hypertrophled
and much crumpled; ou one spur a norm.al and a "pocket" plum are borne.
Specimens from the Museum at Geisenheim. J natural size. (v. Tubeuf phot.)

THE PARASITIC EXOASCEAE. 157

Exoascus communis Sad. This produces pocket-plums on
Primus amcricana, P. inLinila, and P. maritima in America,

Similar " pockets " also occur on Pricnus suhcordata, P. Chicasa,
and P. pciinsylvanica, in America, as a result of some Exoascus.

Exoascus Farlowii Sad. produces similar
deformation of carpels and floral envelopes on
Pruiius serotina in North America.

Exoascus Johansonii Sad. produces carpel-
enlargement on the female catkins of Populus
trcmula, P. trcmuloicles and P. grandidentaia ; the
contents of the asci are yellow. (Fig. 52.) The
anatomy of the deformed ovaries has just been
described by Sadebeck.^

Exoascus rhizophorus Johau. causes similar fio. -yi.-E.coascus

<> Ti J Johansonii Sad. on

enlargement or the lemale catkins oi Populus Popuiv.stremv.ia. (v.

^ ^ Tubeufdel.)

alba.

Exoascus alni-incanae Ktihn {Ex. amentoruvi Sad.) This
species is readily distinguished by the absence of a stalk-cell
on the ascus. It causes increased growth and enlargement
of the seed-scales of alder catkins, the fruit itself being seldom
attacked. The fleshy bladder-like outgrowths at first appear
as little red processes ; later, the asci are developed on the
outer surface as a whitish coating. On many of these red
processes may still be recognized the trifid apex of the normal
scale, (this is really formed from five smaller scales fused into
a single large one with a trifid apex). A number of these
red outgrowths are generally present on each infected catkin,
yet the alders continue to flower vigorously every year.

Wakker,^ in investigating the anatomy of the deformed scales,
found the following alterations : — ^the scales are increased to many
times their original size and contain two cavities; all parenchy-
matous cells become regular and iso-diametric ; lignification of
the elements of the wood is more or less interfered with, and
fewer wood-fibres are produced ; there is an accumulation of
transitory starch.

Exoascus alni-glutinosae Tubeuf. This is a new species
distinguished by v. Tubeuf in 1895. It occurs in the Sudetic
mountains, Italy, Denmark, and Sweden, on Alnus glutinosa.
Its habit is similar to that of Ex. alni-incanae, but the asci

1 Sadebeck (See Literature), 4. p. 144. - Printjsheim's Jahrhuch, 1892.

158

ASCOMYCETES.

contain only conidia, whereas those on Alnvs-incana are said
by Sadebeck to contain only ascospores, unless on very rare
occasions. In the lower and higher Alps, although both species
of alder are not infrequently found together, yet the Rvoascus
is found only on Alniis incana, and no species occurs on A.
glutinosa.

Fig. 53. — Exoascus abii-incanae in catkins of Alnus incana. Many of the scales
are developed as elongated red soft tongue-like structures, on which the asci arc
produced as a whitish coating, (v. Tubeuf phot.)

Exoascus epiphyllus Sad. (Ur. horealis Joh.^) The witches'-
broorn fungus of the white alder {Alnus incana.)

The author 2 was the first to describe and figure this form
of disease in 1884; and Sadebeck recently succeeded in pro-

^ K. Sven. Vet. Akad. 18S5 and 1887. Tubeuf, Botan. CentralU., 1890.
- Tubeuf, Beitrage z. KennUms d. Baun\h'anJcheiten, 1888.

THE PARASITIC EXOASCEAE.

159

ducing the brooms by artificial infection of alder. The disease
is common and epidemic, and a single tree may carry as many
as a hundred brooms.

The witches' brooms are
composed of many thickened
twigs, beset with an abnor-
mal number of lenticels,
and the point of infection
shows a distinct swelling,
from which the broom tends
to turn directly upwards.
The leaves are somewhat
modified, they are larger and
thicker than the normal,
they unfold later and wither
earlier, while their stipules
remain attached for some
time. The brooms of alder
only survive a few years,
and by their decay cause
the death of large branches,
and frequently of the whole
tree.

The asci, which are sunk
in a depression of their
stalk-cell, form a white
coating on both surfaces of
the leaves. The mycelium
hibernates in the buds.

Exoascus turgidus Sad.
causes the formation of
witches' brooms on Bet via
verrucosa. The leaves form-
ed on the brooms are some-
what crumpled, and the asci
are produced on their lower
surface.

Exoascus betulinus
Eostr. produces witches'
brooms on Betula puhescens and B. odorata.

Fig. 54. — Exoascus epiphyllus. Witches' broom
in first year, showing swelling at the point of infec-
tion. The leaves are already shed in autumn, while
the normal still remain 1 natural .size. After
V. Tubeuf.)

160

ASCOMYCETES.

* Witches' brooms on birch are very common in Scotland.
They appear as tangled masses of twigs, which at first sight
give the impression of some bird's nest. I have frequently
examined the leaves borne on these brooms, and have never
failed to find the asci of an Exoascus. Sadebeck gives in
his monograph the two above-named species as found on birches
bearing v.itches' brooms. Mites {cfj. PhyUyjitus) have also been
given as the cause of these malformations. On close examination
of brooms which undoubtedly bore Exoascus, I found that a
broom results from a prolific development of small twigs on
one or a few knotty swollen parts of a branch. Each central

Fig. (tb.^Witchf.s' Broom oftlic Hornbeaia. Exoascus carpini on Carpinv.s Belulus.
The bush measures about i metre across, and arises laterally from a branch, the
upper normal part of which has been removed, (v. Tubeuf phot.)

knot we may regard as the position of the Inid which was
first infected, and from which the broom system took its
origin. As one result of the attack of the fungus, the greater
number of the buds in the axils of the scales of the infected
bud have grown out as twigs, but not into well-developed
ones. In consequence, nearly every twig has been killed back
by the winter, but not completely, so that from each twig-
Ijase has sprung a new crop of stunted immature twigs like
the first, and equally liable to be killed in the following winter.
Thus has arisen that tangled mass of dead or sickly birch
twigs which we call a witches' broom. [Edit.]

THE PARASITIC! EXOASCEAE.

161

Exoascus alpinus Johan. and Ex. nanus Johaii. Both occur
on Bftuhi nana, and induce formation of hypertrophied twigs.

^'VK/. /

Fig. 56. — Witches' Broom of the Cherry. Exoascus cerasi on Prv.nus Cerasus. The
whole left side forms a large broom. A smaller example occupies the summit of
the crown, while another hangs downwards to the right. In winter condition.
(v. Tubeuf phot.)

The mycelium of Ux. nanus hibernates in twigs, and penetrates

L

162

ASCOMYCETES.

into the inner tissues of newly-formed twigs and leaves. The
mycelium of Ex. alpinus passes the winter in the buds, spreading
thence in spring into young twigs and leaves.

Fig. 57. — Exoascus cerasi on Prunus droius. Cherry-tree iii blossom, with the
exception of four witches' brooms. The tree is as yet leafless except the brooms,
which are in full foliage and show up dark. (v. Tubeuf phot.;

Exoascus carpini Eostr. is common on Carpinus Beiulus (horn-
beam) (Fig. 55). The brooms produced are bushy and densely
leafed ; the twigs are thickened and much branched ; the leaves

THE PARASITIC EXOASCEAE.

163

iire- somewhat curled up, and the asci appear on their lower
surface.!

Exoascus cerasi Fuck, occur.s very commonly on cherry
trees {Prunus Ccrasus and P. avium) both in Europe and America.^
It produces witches' brooms, which may be large, upwardly
directed, bush-like, and very conspicuous structures, with
numerous thickened and elongated twigs (Fig. 3); or they may
be small, hanging bunches of twigs with upturned free ends.
The leaves are somewhat wavy, slightly crumpled, and reddish ;
on their lower epidermis they bear asci, and fall otf prematurely.

Fig. i)S. — Normal twig of Cherry from a tree in blossom, as in Fig. 57.
(v. Tubeiif phot.)

The brooms are visible at a considerable distance in the winter
(Fig. 56), wiiile they are even more conspicuous during the
Howeriug season (Fig. 57). At the latter time, before the
leaf-buds open, the cherry trees are normally covered with
white blossom, while the brooms bear leaves only, and rarely
blossom. Hence they produce little or no fruit. Each tree

^ Wehmer (Bot. Zeituwj 1896) discusses the formation of these witches'
brooms. (Edit.)

- E. Rathay, " Uber die Hexenbesen d. Kirschbaumen." — Sitz%mgsher. d. K. K.
Akad. zu Wien, 1881.

164

AKCOJIYCKTKS.

may bear several brooms, and every tree in a fruit-gaiden
may be attacked, so that this disease has assumed consider-
able economic importance. As a preventive measure, the removal
of all brooms at the time of pruning the trees is strongly

recommended.

[According to Shirai {Tokio
hotanical magazine, 1895) witclies'
brooms are produced in Japan
on Prunus pseudo-cei'asv.s, by a
distinct species, Ex. j-iscufhi-
crrasiis.]

Exoascus minor Sad. This
species induces hypertrophy of
shoots of Prunus Cham.a(cera>>v.s
and P. Cerasi's, but cannot be
said to cause formation of
witches' brooms. The m^'celiuni
hibernates in the buds, and
spreads only underneath the
cuticle, while that of Kr. cerasi
lives in the tissue of the twigs
and leaves. It is characteristic
of this species that only leaves
here and there on a twig may

Fig. 5i».— Twig from witches' broom in bc attacked, whilc their ncigll-
foliage, as in Fig. 57. Photographed at same " . • i i i

time as Fig. .58 for compaiison. (v. Tubeuf l3ours remain quitc healthy ; both

flowers and fruit may also be
borne. Diseased leaves appear much crumpled, and Sadebeck
states they have an odour of cumarin ; they turn brown pre-
maturely and fall off.

Exoascus insititiae Sad. is found on Prunus domestica and
P. Lisititi.a in Europe, and P. pennsylvanica in Xorth America.
It causes formation of witches' brooms smaller than those on
the cherry tree, yet probably more common in the fruit garden.
They bear no fruit, and are a source of considerable loss.
The mycelium hibernates, like that of Ex. cerasi, in the bark of
twigs, and spreads in spring into the buds.

The leaves of the host bear asci on the lower epidermis ;
they are always more or less curled up, and fall off early.
To prune off" all brooms is the best preventive measure.

THE PARASITIC EXOASCEAE.

165

Exoascus deformans (Berk.) causes the " curl disease " of the
peacli {Frrsica vtilgaris), and may inflict ijreat injury. The

Fio. tiO. — E.'oaicas ininor. Curl disease of Cherry.

mycelium hibernates in bark, pith, and medullary rays of twigs,
50 that it reappears each year. An U'vasciis, wliich occurs

B

Fig. til. — £.i:oascus deformans. Comparison of uoriual seetion of leaf of Prv.nv.s
Persica with a hypertrophied one, B ; in the latter the mycelial hyphae have
been slightly shaded. The sections are from different parts of the same leaf, and
are drawn with the same magnification. (After W. G. Smith.)

on the almond {Aiiiyydalus communis), resembles Kr. deformans
so closely that they are now regarded as the same species.

1G6

ASCOMYCKTES.

This is supported l)y Smith's investigations, in which an an-
atomical comparison of diseased twigs of peach and ahiiond
showed no difference in the patliological effects.

Exoascus crataegi Fuck, occurs on Crataef/us Oxyacantha,
and causes red swellings on the leaves and flowers, accom-
panied by hypertrophy of shoots in which the mycelium
perennates.

Exoascus Tosquinetii (West.), The deformation caused by
this species is freijuent on the black alder {Ala us gliitinosa).
The thickened, elongated, wrinkled twigs render attacked parts
very conspicuous in contrast to the normally developed parts of

the tree. The leaves may l)e
wholly attacked and much
enlarged, or they may only
be hypertrophied at places so
as to form pustule-like swell-
ings. The epidermal and
mesophyll- cells of diseased
leaves become greatly en-
larged.

Exoascus aureus (Pers.).

The leaves of the lilack poplar

{Pdjni/us 'iiif/ra) attacked by

this parasite exhibit pustules

(Fig. 62). The asci are

formed as a golden coating

on the concave side of the

pustules, which is, in most

cases, the under side of the

leaf, rarely the upper. The

cells forming the pustules

have thicker walls and a

somewhat different shape from the normal epidermal cells, and

they are not unfrequently sub-divided by walls of secondary

origin (Fig. 63).

According to Smith, the cells of the palisade parenchyma have
also thickened walls, as well as being elongated and occasionally
chambered ; the cells of the spongy parenchyma are enlarged and
have thicker walls ; so also are the cells of the collenchyma of"
the leaf venation.

Fici. 0-. — Exoascus av.rtvs. Leaf of Popv.lv.s
nUjra, showing the p\istule-like swellings.
Tubeuf del.)

(V.

THE PARASITIC EXOASCKAE,

167

Exoascus coerulescens (Mont, et Desm.) produces similar
blisters on oak leaves.

Flu. 63. — Exoascus aureus. Leaf section from the margiu of a swelling, showing
normal and hypertrophied tissue. The cells of the swelling are abnormally
elongated with thickened walls, and some show secondary cell-division. The
bases of the asei are wedged in between the cells ; one ascus is shown with
conidia. (v. Tubeuf del.)

Exoascus cameus Johan. occurs on leaves of Brtv.la odorata,
B. nana, and B. intermedia. The pustular outgrowths rise above

Fici. G4 — Exoascvs cc

Tubeuf del.)

Fig. 6-5. — Section of nomial leaf of Betuta
odorata. (After W. G. Smith.)

Fig. 6G.- Section of leaf hypertrophied by
attack of Exoascus carntus; the asci of the
fungus coat the upper epidermis. Di-awn
with the same magnification as Fig. 65, for
comparison. (After W. G. Smith.)

168

ASCOMYCETES.

J\'v,

the upper surface of the leaf (Fig. 04), and the upper epidermis
alone bears the asci. In the pustules, the leaf may be two to
four times as thick as healthy parts. The greatly increased
thickness is due for the most part to enlargement of the cells
of the mesophyll, while at the same time their normal arrangement
is completely lost (Figs. 65, 66). The elements of the tibro-
vascular bundles are enlarged ; the cells of the upper epidermis
are more numerous, contain a reddish sap, and their walls are
thickened. All chlorophyll is destroyed in the pustules.

Ex. polysporus (Sor.) causes swollen
spots on leaN'cs of Acer tartaricum.

Ex. buUatus (Fuck.) causes similar
spots on leaves of pear {Pyrv.s
communis) and quince {Cydonia
japonicn).

Ex. Sadebeckii (Johan.) causes
simple spots on leaves of Alnus
(jlvMnom.

Many other species, named in our
list and in Sadebeck's papers, will be
found described in detail in one or
other of the papers already cited.

B. Carpoasci.

Fig. 67.— E.r.oascus /lolysporui on
Acer tartaricum from Sweden. Tho
:attacked leaf shows pale spots with
brown centres. The former result
from the Taphrina, and are covered
by a white coating of asci ; the brown
spots are produced V)y other fungi
which grow on the spots already
killed. * nat. size. (v. Tubeuf del.)

{Ascomycetes loith Sporocarps.)

The asci of the Carpoasci are not
formed directly on the mycelium, but
from a special part of it, which
becomes more or less enclosed in
another non-ascogenous portion. From
these two portions of the mycelium a sporocarp is formed, in
which we can distinguish three distinct constituents : («) the
envelope containing {h) the paraphyses and (c) the asci.
Amongst the Gymnoasci the envelope, if present, is never
more than a loose hyphal tissue, but in the Carpoasci both
paraphyses and envelope are present, the latter with char-
acteristics distinctive of each species. The sporocarps of the
lower Carpoasci are completely closed structures containing
only one or a few asci ; those of the higher forms, however.

CARPOASCI. 169

contain many asci, and the envelope is pierced by a definite
aperture.

Brefeld endeavours to explain the ascocarp of the Erysiplieae from the
sporangial structures of the Zygosporeae (Rhizopus and Mortierella) ; De
Barj^ and Zopf,^ on the other hand, see in it an oosporangium, like that
-of the Oosporeae. Under this latter view the envelope of the Carpoasci is
morphologically homologous to the antheridia of the Saprolegnieae and
Peronosporeae. In the latter group the antheridium generally takes the
form of an open fertilization-tube, in the Saprolegnieae it remains closed,
and is physiologically no longer an antheridium. Zopf found in one of
the Saprolegnieae {DictyucJttis carpophonis), an envelope resembling that
of the Erysipheae, and on this ground he, along with De Bary, links the
Erysipl'.eae to Oomycetes like Achyla through forms like Podosphaera.

The reproductive cells or ascospores result from direct nuclear
division inside the asci. They are generally simple and uni-
cellular, but it is not uncommon to find that, by the formation
of cross and longitudinal walls, each spore forms a cell aggre-
gation (sporidesm of De Bary), with each cell capable of
germination on its own account. The number of cells in each
aggregation, as well as the size and shape of each cell, are in
many cases constant, and form points for the determination of
species. Appendages to the spores are characteristic of many
species.

The Carpoasci possess, in addition to ascospores, other
means of reproduction. Thus, thick-walled chlamydospores occur
either in the mycelium as resting-spores (Hi/pomi/ces), or as
spores (oidia) resulting from a breaking-up of hyphae.
Many kinds of conidia may also be produced, some from the
germinating ascospores, some abjointed from a branch of the
mycelium or from some form of special conidiophore. These
latter may be produced isolated, or massed together in hollows
of the stroma, or in closed structures resembling ascocarps,
and called pycnidia. The various forms of reproductive organs
presented by each species will be more closely considered as
we proceed.

The Carpoasci are arranged, according to the structure of
the ascocarps, under the following divisions : — the Peris-
poriaceae, Pyrenomycetes, Hysteriaceae, Discomycetes, and Hel-

' De Bary. Beitrcige z. morph. u. Physiol, d. Pilze.

- Zopf. Beitrage z. Physiol n. morph. neider Organismen. Heft 3, 1893.

1 70 ASCOMYCETES.

vellaceae. All these groups include forms parasitic on plants,
except the last, which is saprophytic.

IriiinnoaxcuH and Ctcnomyccs are forms intermediate to the
(Jymnoasci and Carpoasci ; they have the asci enclosed in a
slimy envelope of mycelial tissue. We place them along with
the former group, although Brefeld puts them in the latter.

PERISPORIACEAE.

The Perisporiaceae are distinguished by having an ascocarp
or perithecium which never opens, so that the asci are only
exposed by decay of the envelope. It includes three families,
the Erysipheae, Perisporieae, and Tuberaceae.

ERYSIPHEAE.

The members of this family all live as parasites on the
outer surface of plant-organs, and have a much-ljranched,
white, septate mycelium, which derives nourishment from the
interior of the epidermal cells of the host by means of
haustoria of various forms.

The Erysipheae or Mildews appear as white spots and
coatings, on which the ascocarps or perithecia appear later as
black points. On microscopic examination, the perithecia
will be found to contain one or many asci, while externally
they are beset with thread-like appendages of a definite form
and definitely arranged, so that they are of great use in
determining the various species.

The fungus passes through the winter l)y means of the
ascospores. These do not ripen till spring, when, liberated by
decay of the ascocarp, they are carried to plants, where they
germinate, especially on the leaves, and form a mycelium. In
addition, the fungus is propagated throughout the summer by
means of conidia produced on special conidiophores in acropetal
series or chains, of which the distal terminal conidium (acrospore)
is the oldest and largest. The ripe conidia fall off and
produce a mycelium which is at once fixed in place by the
formation of haustoria.

Prevention. " Sulphuring " is the method chiefiy used for
combating mildew. This consists in dusting powdered sulphur
(flowers of sulphur) over the plant threatened with attack.

ERYSIPHEAE.

171

The operation is done by hand or by special implement. One
of the best known of these is the " Sulphur Puffl" This
consists of a brush with a hollow stem to contain flowers of
sulphur, the end of the stem being perforated to allow the
sulj)hur to escape on to the plant. Sulphuring must be
carried out during dry weather to prevent the pow^der being
washed away. It has also to be frequently repeated, so that
young growing shoots, flowers, fruits, leaves, and all parts
liable to attack, may be kept well dusted. Sulphur prevents
germination of conidia on the leaves ; it also kills the
mycelium, while the plant itself remains uninjured.

Besides sulphuring, various copper solutions give very good
results, while at the same time they act as a preventive
against the false mildews {Plasmopara, Fcronospora, etc.).

Sphaerotheca.

Perithecia spherical with thread-like appendages; they contain
one spherical ascus with eight colourless oval ascospores.

Fio. 08. — Kosc-milihu: Sjihaerollicca pentose. The fungus forms a white luealj-
coating on the leaf, especially on the lower side ; the leaves are also more or less
curled up. (v. Tubeuf phot.)

172

ASCOMYCETES.

Sphaerotheca pannosa Wallr. (Britain and U.S. America).
Tliti liose-niildevv. The mycelium forms a thin white coatiog on
the leaves, and is nourished by lobed haustoria inserted into
the epidermal cells. Young leaves or buds when attacked
become more or less deformed, their function is interfered with,
and death may result. In this way great damage is done in
rose-gardens. This parasite also attacks young leaves and fruits
of peach and apricot.

Vui. ijO.~ Hiihacrothcca pannosa on Peach. The mycelium aud conidiophoM
are shown on tlie epidermis of a leaf. (After Tulasne.)

Rose-mildew is propagated during summer by ovoid, uni-
cellular conidia abjointed in acropetal series from erect conidio-
phores. The perithecia have short simple appendages, and
contain elliptical spores.

The disease may be combated by " sulphuring "; according to
liitzeina-Bos, spraying with Bordeaux mi.xture has also shown
good results.

SPHAEROTHECA.

173

Sphaerotheca (Podosphaera) castagnei Lev. (Britain and

U.S. America). The Hop-mildew. The mycelium is found on
all parts of hop-plants, causing considerable damage, especially
when it attacks the young inflorescences. The perithecia have
recumbent, brown, simple appendages. This species appears
chiefly on various Compositae, Eosaceae (esp. Sjnraea Ulmaria),
Cucurbitaceae, Geraniaceae, etc. Sorauer reports it as very
injurious to apple-trees.

Fig. 70. — Sphaerotheca castariiiei on Spiraea Ulinaria. The white mycelial coating
covers every part of the inflorescences. Two specimens are much less deformed
than the others, (v. Tubeuf phot.)

Oidium farinosum Cooke. Attacks young leaves and calyx
of apple: it is easily distinguished from the oidium-condition of
the preceding species.^

Sph. mors-uvae B. et C. The Gooseberry-mildew. Is specially
injurious to Ilihcs Uva crispa and other species of Ribcs in
America. Spraying with a solution of potassium sulphide (i oz.
in 1 gallon water) at intervals of twenty days is recommended.-

^ Sorauer, Hedwirjia, 1889.

- Halsted (U.S. Department of Ar/riculture, Report for 1887) describes this
disease (Edit.).

174

ASCOMYiJETKS.

Sph. epilobii Lk. occurs on Epilohiiim (U.S. America).
Sph. Niesslii Tliiini. on Sorbus {Pyrns) Aria.
Sph. pruinosa ('. et Pk. on Ithun in America.

j2Q0QDo

Fio. 71.— Sphacrotheca castagnei. Epiphytic mj-celium on epidermis of S/ni-aea
Ubnaria. Three haustoria are embedded in epidermal cells. Two conidiophores
are shown, from one of which a conidium has become detached. A hair of
Si>iraea is sliowu at one side. (v. Tubeuf del.)

Podosphaera.

This genus is distinguished from Sphacrothcca by its upright
perithecial appendages, which branch dichotomously towards their
extremities.

Podosphaera oxyacanthae D. C. Apple powdery mildew,
also occurring on pear {Fijrus), hawthorn (Crataegus), mountain
ash {Pyrus Ancuparia), and medlar {Mcspilus). In America
this disease is very injurious to apple-cultivation.- It attacks
chietly young seedling plants, stunting their growth and causing
them to lose their leaves.

P. tridactyla Wallr. This causes injury to leaves of various
species of Primus (cherry, plum, and sloe)^ (Britain and U.S.
America).

-Accoimt by M. B. Waits {U.S. Department of Agriculture, Report for
1888) ; notes on treatment in Fairchilcl's experiments [Journal of Mycolorjy, vii.
p. 256), and elsewliere (Edit.).

3 Halsted Zeitschrift f. PJlanzenkrankheiten, 1895, p. 338) gives as additional
liosts; Apple, Crataegits Oxyacantha, Amelanchier canadensis and Spiraea (Edit.).

PODOSPHAERA.

175

P. myrtillina Schub. ou leaves of Vacdnium MyrfiUus (bil-
berry), V. aligiiiosum, and J^nipctrmn nigrum (crowberry), (U.S.
America).

Erysiphe.

The perithecia contain several asci, each with two to eight
oval hyaline spores. The appendages are like these of Sphae-
rotluca, simple and thread-like.

Erysiphe graminis D. C. Mould or mildew of grass and
wheat, (xrass and cereals, especially wheat, often suffer serious
damage from this parasite. The mycelium appears on the leaves
as white or brownish spots, generally on the upper surface.
Colourless conidia {Oidimii monilioides, Lk.) are produced acro-
petally in chains. The somewhat rare perithecia have brown
appendages, and contain eight to sixteen asci, with four to
eight spores each ; the spores mature in spring as the dead
leaves lie on the ground. This mildew^ has inHicted great
loss both in Europe and America. Dusting the threatened
crop with " flowers of sulphur " will
probably check the first stages of an
attack, but care in destroying infected
crops is by far the most effective
preventive.

Erysiphe martii Lev. This fre-
quents various Leguminosae (clover,
beans, vetches, peas, lupines, etc.),
Cruciferae, and other plants (Britain
and U.S. America).

Er. umbelliferarum De Bary.
Occurs on various Umbelliferae
(Britain).

Er. communis Wallr. on tobacco, also on various Eanun-
culaceae, Papilionaceae, etc. (Britain and U.S, America).

Er. tortilis Wallr. on Oorniis sangiiinea (Britain and U.S.
America).

Er. galeopsidis D. C. on Labiatae (Piritain and U.S.
America).

Er. cichoriacearum D. C. on Compositae, Boragineae, and
also causing considerable damage to cucumbers (Britain and
U.S. America).

Fig. 72. — £i-ysijihe v.mhelliterarum.
Germinatiou of a couidmni {sp) on
Aiithriscus syli'tstris. An attach-
ment-disc has been formed, and a
e;erm-tube has penetrated the epider-
mis to become the first haustorium.
(After De Bary.)

176 ASCOMYCKTKS.

Microsphaera.

The perithecia contain several asci with two to eight spores,
and the a})pendages have dichotoiuously branched ends like
those of Pi>(hifij)h(i(r(i.

Microsphaera astragali \). C. Occurs on Astrof/alus glyqi-
pln/Ilos and A. riryatns (Britain and U.S. America).

M. berberidis D. C. on Barberry (Britain).

M. lonicerae D. C on species of Lonicera.

M. grossulariae Walh\ on Gooseberry (Britain and U.S. America).

M. lycii Lasch. on Lycixim, and Desmodiinn (Britain and U^.S. America).

M. evonymi D. C. on Evonymus europaeiis (Britain).

M. alni D. C. on Almis ghitinosa, Betula verrucosa, and B. pubescens,.
Rhamnvs cathartica, Vihiirmim Opnlvs, and V. Lantana, etc. (Britain and U.S.
America).

M. densissima (Schwein.)'. This species forms orbicular patches on tlie
leaves of (^nereus tinctoria, etc., in North America.

M. Guarinonii Br. et Cav. on Cystisus Lalmrnum.

Also several other American species.

Uncinula.

The perithecia contain several asci with two to eight spores.
The appendages have involute ends, and are shnple or dicho-
tomously branched.

Uncinula spiralis B. and C- (U. S. America and Britain).
The Vine Mildew. This disease was first observed in England
in 1845, and since then has spread over the whole of Eur(j})e.
The conidial stage has caused widespread injury, but the perithecia
remained quite unknown till 1892, when they were ob.served on
vines in France by Couderc. and in 1893 in large numbers by
Yiala. In America, a similar disease is also well known ; its
perithecia have been long recognized and named Uncinv.lo
spiralis. The identity of the American and European mildew
was first suggested by A^iala in 1887, and may now be assumed.
The perithecia ^ when mature are brown, spherical, and beset with

1 Atkinson, Biilhtin of Torrey Botanical Club, Dec. 1894.

- In consetjueiice of recent investigations, this species has been trausfen-ed from
the genus Erysiphe, and revised with the author's consent. (Edit.).

Viala, Coinj)f. rend, cxix, 1S94, p. 411. Prillieux, Bu/l. de la Soc. niycol. de
France, 1893.

^B. T. Galloway {Botanical Gazette, 1895, p. 486), gives a recent account of
the development of this Uncinula. (Edit.).

UNCINULA.

177

appendages having hooked tips. Within the perithecia are
found the ovoid asci containing the spores ; there are from four
to ten asci in each perithecium, and four to eight spores in each
ascus.

The conidial stage was formerly known as Oidiam Tuclrri.
The conidia are abjointed as oval colourless bodies from simple
septate conidiophores, to the number of two or three in each chain.
They germinate at once, and as they are formed in large numbers,
especially in moist weather, the disease spreads rapidly. The
mycelium is non-septate, or almost so, and attaches itself to the
epidermal cells of vine-leaves and young grapes, by lobed attach-
ment-discs, from which simple sac-like haustoria make their way

Fig. 73. — Uncinulo, aceris. Perithecia. (After Tulasne.)

into the cells. The mycelium forms white spots, but after a
time causes the death of cells near it, so that brown withered
spots appear. The leaves generally wither, the grapes, however,
continue to grow at the places not attacked, till rupture of the
coat ensues, then they shrivel up or fall a prey to mould-fungi.
Sulphur is the preventive generally used (See p. 170).

Uncinula aceris D. C. (Britain). This appears as white spots
on the leaves of species of Acer, native and cultivated. When
attacked by this mildew, young unfolding leaves are stunted in
growth, while older leaves in autumn still retain their chloro-

M

178

ASCOMYCKTES.

phyll in diseased spots, so that when dead and yellow, they
ure still spotted with green. The conidia are oval, so also the
spores of whicli six to eight are found in each ascus.

U. Tulasnei Fuck, produces

a white coating over the whole
leaf-surface of Acer 2ilcUanoides.
The conidia are spherical.

U. circinata C. et Peck, is
found on species of Acer in
America.

U. salicis L). C. (Britain and
U.S. America). This species
occurs on leaves of the willow,
and produces white spots or
thick coatings on one or both
surfaces. It is also found on
leaves of poplar and birch.

U. prunastri D. C. on Prmius spinosa (Britain).

U. Bivonae Lev. on Ulmus montana (U.S. America).

Also other American species.

Fkj. 74. — Uiicinula salicis. Perithechim
(After Tulasne.)

Phyllactinia.

The spherical perithecia are flattened at the poles, and
enclose several asci containing two or three oval sulphur-yellow
spores. The appendages
are sharp-pointed hairs
with swollen bases.

Phyllactinia sufifulta
Kebent. {Fh. guttata
Wallr.) produces white
spots or coatings on the
leaves of many trees, e.;j.
beech, hornbeam, ash,
birch, hazel, oak, etc.
(Britain and U.S.
America).

PERISPORIEAE.

The Perisporieae include the following genera Thiclavia, Bime-
rosporium, Mafpiusia, Ccphalotheca, Zopfiella, Anixia, Eurotium,

75. — Fhi/llactinia siiff'idta on Fagus .'<>/lcalica. The
leaf is partially covered by a white mycelium, ou which
the perithecia apjiear as black points, (v. Tubeuf del.)

PERISPORIEAE.

179

Aspergillus, Pcnicilliuin, Zopfia, Fc/'isjjonurn, Lasiubotnjs, Apio-
sporiiitn, Capnodiuiii, AsUriiia, Microthyrium.

To this sub-division of the Perisporiaceae belong some com-
mon forms of mould-fungi which are generally only saprophytic,

Fig. 7i5.—Phyllacthiia suffulta from Beech. Perithecium, with characteristic
appendages. Contents of the perithecium : asci, spores, and chains of cells
resembling paraphyses. (v. Tubeuf del.)

but occasionally find their way into fruit with broken epidermis.
They are thus found carrying on secondary decay and rot, where
other diseases have begun the attack.

180

ASCOMYCKTES.

In this group are included certain species of fungi which are
able of themselves to induce rot in ripe fruit. Davaine ^ was
the first to direct attention to these, and recently they have been
made the subject of very searching investigations by Wehmer.-
According to this author, only a limited number of species of
fungi accompany this kind of rot and give rise to it primarily.
As a rule they effect an entrance by some wound, possibly also
through lenticels or other apertures. Some forms prefer certain
species of host-fruit, in some cases even certain varieties.

Wehmer gives the following synopsis :

Fruit.
Apple, ^
Peai',
Medlar, ;

Grape,
Plum,-

Cause of Ripe-kot.
[ Penicillmm glaucum.
\ Mucor piriformis.
\{Mucor stolonifer.)
f Pen icillium glaucum .
\^ Botrytis cinerea.
^ Mucor racemosus.
y Penicilliwn glaucum .

Fruit.
Orange,
Citron,
Mandarin
Cherry, -

Walnnt, -

C.VUSE OK KiPE KOT.

Penicillium italicmn,
Penicilliximolivaceum.

Pen icillium glaucum ,
(Botrytis cinerea.
y Penicillium glaucum .

He then arranges them according to their occurrence, beginning'
with the most frequent :

Penicillium glaucum Link. : on stone-fruits, pome-fruits, grapes,
walnuts, especially common on apples.

Penicillium italicum Wehiner : on southern fruits, c.f/. citron,
orange, mandarin,

Mucor piriformis Fisch. : on pome-fruits, particularly on pears.

Botrytis cinerea Pers. : on grapes and walnuts.

The following are less common species :

Penicillium olivaccum Wehmer : on southern fruits.

Mucor racemosus Fres. : on plums.

Mucor stolonifer Ehrenb. : on apples,

Eipe fruit should be so treated as to remove risk of infection as
much as possible. This is done by storing the fruits in airy, dry
places, and in loose contact with each other. A damp atmosphere
promotes infection and facilitates the progress of rot. All decaying
fruit should be separated at once, and valuable fruits are best
isolated by wrajDping singly in tissue paper before transportation.

'Davaine, " Recherches sur la pourriture des fruits et des vegetaux vivants,"'
Compt. rend., lxiii., 1866.
^Wehmer, Beitrage z. Kenntniss einheimischer Pilze, Jena (Fischer), 1895.

PERISrORIEAE. 181

Species of fuugi included in this group are the cause of
those black, sooty coatings found on leaves frequented by green
iiy {Aphis) and other leaf-insects. These are purely epiphytic
and saprophytic forms which derive nourishment from the
"honey-dew" excreted l)y the insects.-^ They multiply very
rapidly, and soon form dark coatings on the upper side of
leaves and twigs. Little damage need be feared, since the
leaves retain their green colour, and the coating is not enough
to stop access of light. Amongst them are species of Cap-
noclium, Meliola, and Apiosporium, as well as the conidial forms
Fmnago, Tonda, Antrnnaria.

Tlie modes of reproduction of these forms are exceedingly
varied. According to Zopf- they form: (1) ascocarps; (2) many-
celled large conidia ; (o) unicellular, very small conidia ; (4)
isolated and clustered conidiophores ; (5) gemmae; (6) buds in
a yeast-like manner ; while every fragment of a mycelium can
produce a new growth. Any of the species may frequent
many various plants, and can pass easily from one host to
another. Some of the better-known forms are :

Capnodium salicinum Mont. (Britain). This occurs on
species of willow, poplar, hop, and many other plants.

If it appears early and abundant on hop it may cause
considerable damage. {Fumcujo vafjans is a conidial form).

C. quercinium Pers. on oak. (U.S. America.)

C. taxi Sacc. et Eoum. on Taxus.

0. foedum Sacc. (spermogonium form = CJun'tophoma focda).
On the leaves of oleander. (U.S. America.)

The genus Apiosporium forms similar sooty coatings.

A. pinophilum Fuck. This covers with a black coating
whole twigs and leaves of silver fir ; the needles however retain
their green colour completely. {Antcnnaria and Tornla are
forms of this.)

A. rhododendri Fuck. ; A. ulmi Fuck. ; and other species.

The conidial form Pellicidaria wliicli produces grey coatings on the coifee-
plant is considered among the Hyphom3^cetes.

Species of Meliola also produce sooty coatings.

M. citri Sacc. and M. Penzigi Sacc, occur on Citrus in

' Biisgen, Der Honiijthau. Bio/oijische Studien an PJlanzeu. Jena (Fischer).
-Zopf, "Die Conidienfriichte v. Fumago. " yora nrta, Bd. 40. Also: Zopf,
Die Pilze; Tulasue, Select. Jung., iii.

182 ASCOMYCETES.

Southern Europe and America. Sooty mould of the orange is
also ascrilx'd to Capnodium ciiri Berk, et Uesm.^

M. camelliae Catt. on Camellia jajwnica. According!; to
Briosi and Cavara, this causes drying up of the leaves.

Stempliylium ericoctonum Br. et Baiy, the " sooty-dew " of indoor lieatlia
is considered amongst the Hyphoniycetes.

Lasiobotrys.

L. lonicerae Kunze.- The peritliecia form black masses on
green leaves of species of Loniceru. If these be removed the
epidermis remains uninjured, except for a slight cavity with a
lighter green colour than the neighl)0uring surface.

Thielavia.

Perithecia splierieal and without an aperture. The asci
contain eight brown unicellular spores. Paraphyses absent,
Conidia and ehlamydospores are formed.

Thielavia basicola Zopf.^ This is the only species of the
Perisporieae which causes a really serious plant-disease. It is
allied to the Erysipheae, and produces three kinds of repro-
ductive organs on the underground jDarts of plants of Lupine :
(1) Cylindrical, delicate, hyaline ehlamydospores, produced in
pistol-shaped branches of the mycelium. (2) Thick-walled,
brown-coated, resting conidia arranged several in a row, like
spores of a Phragrnidium. (3) Perithecia, or little, spherical,,
permanently closed, brown structures with ovoid asci containing
eight brownish lemon-shaped spores.

A white coating of the hyaline conidia is first formed, then
a brown coating of the dark conidia, and finally perithecia.
The mycelium bores through the cell-walls and fills first the
cells of the cortex, later those of the deeper parenchyma of the
host-root. The disease of the root soon causes a stunting of
the shoots and leaves, finally death of the plant. The roots
attacked are at first brown, then they rot and become detached.

iW. G. Farlow, Bvli. Biussey ImtUtite, i. 1876, p. 404; Swingle and Webl)er,.
"Diseases of citrous fruits," U.S. Dept. Ac/rk. Bxdl. 8. 1896.

- Jaczewski inchules Laniobotrys with the Cucnrhitariaceae.

•'Zopf, " Ueber die Wurzelhrilune d. Lupinen." Zeitsc/tri/t /. l\flanztril-ra))h'
liciten, I. p. 72.

THIELAVIA. 183

The fungus has been observed on Lupinus anovstifoliv.s, L. albus,
L. thermis, Trigonella cocrulea, OnobrycMs Crista gaUi, Pisi'm
sativum, Senecio elcgans, and Ci/clamcn}

Thielaviopsis ethaceticus Went.- has been given as the cause
of a sugar-cane disease in Java.

The Tuberaceae form a third sub-division of the Perisporiaceae.
The group includes the Tubereae and the Elaphomycetes. It
contains no forms injurious to plants.

In investigating ElaiJhomyces granulatus and E. raricgaivs,
Eeess^ found that it not only formed mycorhiza, but was also
parasitic on the roots of Plnvs and destroyed them.

PYKENOMYCETES.

The ascocarp or perithecium of the Pyrenomycetes is a closed
structure provided with an opening by which the ascospores
are discharged. The ascocarp of the Perisporiaceae, as has
already been pointed out, has no such opening. The inner wall
of the perithecium is clothed with («) the asci, {h) delicate fungal
filaments. Of the latter, those in the depth of the perithecium
are known as paraphyses, and among them the asci originate ;
others around the sides and opening of the perithecium are
the periphyses, which grow inwards so as to close both pore
and canal. Perithecia may occur isolated or massed together,
and are frecpiently sunk in a special cushion of fungoid tissue,
the stromata.

The Pyrenomycetes may also produce chlamydospores and
various forms of pycnoconidia and free conidia ; these also are
frequently developed on special stromata. According to Bref eld's
researches, the structures so well known as spermogonia with
their contained spermatia are only pycnidia containing conidia,
which have in many cases been artificially caused to germinate.

The Pyrenomycetes include a large number of forms par-
asitic on all parts of living plants, most of them are capable
of existing for some part of their lives as saprophytes, and as

^ This fungus is described as causing a root-rot of Viola odorata in U.S.
America [Connect. Agric. Exper. Stat. Report for 1891). (Edit.)

-Went, Archie/ voor de Java-Suiktrindustrie. 1893.

"Reessand Fisch., " Untersuch. iib. Bau u. Lebensgeschichte d. Hirschtriiffel."
Bibliotheca botan. Heft 7. 1887. With lUus.

184 ASCOMYCETKS.

a rule they reach maturity only on the dead remains of host
plants. Many of them are enemies of woody plants, and the
mycelium of some can live in the elements of the wood itself,
hence they constitute a dangerous group of wound parasites.
The Pyrenomycetes may be sub-divided thus :

1. The Hypocreaceae having soft coloured perithecia often
placed several tngeihcr (jn a stroma.

2. The Sphaeriaceae with firm dark-coloured perithecia
frequently embedded in a stroma.

o. The Dothideaceae with perithecia so embedded in a
.stroma that they have no distinct wall of their own.
All three divisions include forms parasitic on plants.

(1) HYPOCREACEAE.
The Hypocreaceae consists of a single family bearing the
same name. Of the seventeen genera contained therein only
.six contain plant parasites, viz. : — Gihhcrella, Calonectria, Ncdria
(including Nectriella), Polystigma, Ujnchloe, Claviceps. The re-
mainder are saprophytic only, and do not come within the
scope of the present work : they are — Melanospora, Selinia,
Ekviheromyccs, Hypomyces, Sphacrostilhe, Letendraea, Hypocrca,
Pleonectria. Barya, Oomyces, and Cordyceps.

Gibberella.

The perithecia have a transparent blue or violet colour, and
form tufts on the stromata. A stroma is not present in all
the species. The spores are light-coloured, and spindle-shaped
or oblong.

G. moricola Ces et de Xot. Passerini gives this as the cause
of a disease of young twigs of mulberry.

G. pulicaris (Fr.) is very frequently found on trees. (Britain).

Calonectria.

The perithecia are yellow or red, and occur isolated or several
together. The asci contain spores composed of three or more
cells, rarely of one cell.

C. pychroa Desm. causes death to young leaves of planes
(esp. P. occidciitalis) ; it also multiplies by means of conidia
{Fusarium platani).

NECTRIA,

185

Nectria.

Perithecia yellow or red iu colour, and generally produced
in close tufts on stromata of the same colour. The asci con-
tain eight bicellular spores and few or no paraphyses. Conidia
of various kinds and shapes are also produced.

Nectrina cinnabarina Fr.^ (Britain and U.S. America). The
Jbrighc-red, button-shaped conidial cushions of this fungus may

Fio. 77. — Nectria ciaiu'.bariiw., with peri-
tliucia on the dead bark of a still-living
stem of Elm. Infection has evidently
begun at the wound of a cut branch near
the middle, and extended outwards, (v.
Tubeuf phot.)

Fig. 78. — XectrUi ciivaalMnno.. Portion of
branch (magnified). Light-coloured cushions
of conidiophores with conidia are breaking out
towards the upper end, and colonies of hard
red perithecia towards the lower end. (After
Tulasne.)

he found almost at any time on the dead Ijranches of many
deciduous trees, e.g.,, Acsculus, Acer, Tilia, Morns, Ulmus, etc.;
also on Loniccra, Samhucus, Rohinia, and Pijrus, in America.^

^T\\\a.s,i\e, Select fiuifj., 1865.

- Behrens [Zeitsrh. f. P flanzenkrankheiten (1895) ascribes to NerAria the very
■common tuberous swellings on the twigs of Abies halsamea ; these, however,
may arise without the agency of the fungus.

186

ASCOMYCKTKS.

The dark-red masses of thick-coated, warty perithecia appear
in autumn and winter on the dead branches only ; the asci
contain eight biceUular hyaline spores which germinate
directly to form a mycelium. Infection of a new host-plant
is effected by the mycelium, which enters by open wounds into
living branches ; it is quite unable to penetrate the living
bark and is dependent on wounds. The mycelium spreads

rapidly through the tissues of
the host, especially through the
vessels of the wood ; the cam-
bium and rind are not attacked
directly, but are killed in conse-
quence of the destruction of the
wood.^ The regions attacked
in the wood appear as greenish
stripes, and withering of leaves,
followed by death of branch
after branch, results in conse-
quence of the growth of mycelium
in the water-conducting elements
of the wood.

For protection against this
and all other parasites, which
find entrance by wounds, it is recommended to prune or dress
trees only when necessary, and to paint all wounds with tar
or tree-wax. This Ncctria is one of the commonest parasites
of our parks and fruit gardens, hence all branches already
attacked should be removed and burned, likewise all blown
timber which might serve as a nursery for production of
spores or conidia.

Nectria ditissima Tul. (Britain and U.S. America). This
is a common parasite and a frequent cause of the canker of
beech, apple, and other trees.^ The mycelium lives chiefly
in the bark, causing it to die and form cracks. Under
ordinary conditions all cracks and fissures are occluded or

Fio. 79. — Nectria cinnahorinc. Enlarged
section of perithecial colony. Germinating
ascospores. (After Tulasne.)

' Mayr in Hartig's Unlersiichuwjeii a. d. forKt-hotan. Iiisttttit zu Mi'mchen, in.
Berlin, 1882. Brick, Arbeiten d. Iiofmi. Museums, Hamburg, 1892.

Wehmer {Zeiisch. f. Pflanzcnl-rankheiten, 1894 and 189.5), opposes Mayr's con-
clusions and holds that Nertria can penetrate intact, living bark.

-Goethe, " Ueber Krebs d. Apfelbiiume. " Rhtin. Blattf. Ohsf., Wein, u. O'ar-
tenbau, 1879. R. Hartig, Unttrs^ich. aus d. forst-hotmi. Listitut. zu Miinchen, i.

NECTRIA.

187

grown o^'er in course of time by the activity of neighbour-
ing living tissues, but the rapid development of the mycelium
of this Ncdria prevents any such healing, and brings about
death of more bark. As a result the so-called " cankers " are

Fig. 80. — Nectria ditissinia. Canker
on a stem of Beech, (v. Tubeuf
phot.)

Fig. 81. — Nectria ditissima. Canker on Huzel. The
l^lace of infection, a partially broken branch-fork.

produced. The mycelium at first gives off* tiny unicellular
conidia on the bark, then later white cushions bearing fine
conidiophores, from which are abjointed multicellular conidia,
shaped like a sickle. Infection is brought about by the
germination of spores or conidia on wounded parts of the

188 ASCOMYCETKS.

bark,^ and even on young unfolding leaves. The red lemon-
shaped perithecia break through the bark as compact patches.
They are distinguished from the perithecia of N. cinnaharina
by their smooth exterior and their smaller asci and asco-
spores.

Combative measures to be used are plentiful dressing of
wounded places with tar, and the burning of all infected
material.

Nectria cucurbitula Vx!^ (Britain and U.S. America). This
parasite on conifers generally, is particularly injurious to spruce
{Picca). It enters the host by wounds, such as those caused
by the caterpillars of the spruce moth {Graijholitha pactolana),
or by hail. The mycelium lives chiefly in the bark and bast ;
during the active growth of these tissues further extension of
the mycelium is almost completely hindered by the formation
of a secondary cork, but in the resting periods of these tissues
of the host, new hyphae are rapidly produced, lieproduction
is brought about by little unicellular, and larger multicellular
sickle-shaped conidia produced on conidiophores. The mycelium
frequently proceeds as soon as formed to give off the smaller
variety of conidia. The dark-red perithecia are produced later
on the same stromata as the conidia. The asci contain eight
bicellular spores ; the paraphyses are very delicate and slightly
branched.

The fungus sometimes occurs epidemic in spruce plantations,
and may be the cause of many deaths. According to ]\Iagnus,
the larch and cembran pine may also be attacked. As a pre-
ventive measure all dead parts should be cut out and burned.

Nectria Rousseliana Tul. lives in and kills leaves of the
box (B(Lvns).

Nectria pandani Tul.^ is said to be the cause of a disease
on FaiulanaSy also ascribed to Mclanconium pandani. The
Pandanus disease has been reported from the Botanic Gardens

' Young forests in districts subject to hailstorm, (e.ij. on the lower Alps
of Bavaria), may become completely infested with Xectria through hail-wounds.
( Edit. )

-R. Hartig, Unttrsuch. aui d. fors(-botan., Iti'ititut. i., 1888.

•'.Schroeter ("Ueber die Stammfaule d. Pandaneae," Cohii's Beitr. z. Biol. d.
Pllanzen. Bd. I., 1895) suggests that this Melanronium is a conidial form of
Nectria. During the investigation of a case of a Pandanii-i killed in the Palm
House at Edinburgh Botanic Garden, J. H. Burrage found both forms present
an I agreeing in order of development with .Schroeter's observations. (Edit.)

NECTRIA.

189

of Breslau, Berlin, Paris, Kew, Glasnevin (Dublin), and
Edinburgh.

Nectria ipomoeae Hals.^ Stem-rot of egg-plant and sweet
potato. In America this attacks young growing plants, and
causes stem-rot. The Fusarmm-sta,ge developes as a white
mouldy coating on the withered stem, and is followed later
by flesh-coloured clusters of perithecia.

V *■

Poly stigma.

On the leaves of species of Prunus, one finds bright-coloured
spots, these are the stromata of this family, and in them
are embedded pycnidia containing hook-
shaped conidia. Perithecia embedded
in a similar manner are developed
after the fall of the leaves, they contain
asci w'ith eight unicellular elliptical
spores, which are expelled on reaching
maturity in spring.

Poly stigma rubrum (Pers.) (Britain
and U.S. America). This appears as red
circular spots on the leaves of plum and
sloe. Micropycnidia are developed in
summer on the under-surface of the leaf
and give rise to curved conidia. The
perithecia begin their development in
summer, but only reach maturity in the
following spring, after the leaves have
fallen from the tree and lain on the

ground over winter. The asci are club- fig. &% - Pobjstig,u.. ruhrv,u
shaped, long-stalked, and contain eight proAcSred^SscoJtafn Sri-
spores, which are set free in succession "^^^^T^^ia^
from April to June. Germination ensues rfl£l'ieff!'7v.°?ubeufdd.7'''*
on young leaves, and in six weeks

pycnidia reappear. A variety, "Amygdali Desm.," is found on
the leaves of the almond {Amygdalus communis).

Frank and Fisch found in connection with P. rvhrum,
certain hyphae which they designate as trichogynes, while
they regard the small form of conidia as spermatia which

1 Description and illustrations in N. Jersey Agrk. Exper. Station Rejwrt , 1891.

190

ASCOMYUKTES.

fertilise the trichogyne and cause it to develo]) as an
ascogoniuni.

P. ochraceum (Wahlenb.) (P. fulvum 1). C.) causes yellowish-
red spots '111 leaves oi' Primus Paclm.

P. obscurum Juel. produces thickened leaf-spots on Astragalus
alpinus and A. oroboules ; on the under side these are whitish,
on the upper side they show the spermogonia as red points.

The damage caused by Polystifjma is easily kept in check
l)y burning infected leaves in autumn.

Epichloe.

The stromata form on the stems of grasses yellowish mould-
like coatings in which the flask-shaped perithecia are embedded.

Fig. 83. — Epichloe lyphina, forming numerous white cushions, which completely
encircle the grass-stems, (v. Tubeuf phot.)

The asci are cylindrical, and contain eight thread-like unicellular

EPICHLOE. 191

spores. The formation of perithecia is preceded on the same
stroma by that of conidia.^

Epichloe typhina Tul. ^Britain and U.S. America). This
may be found on many grasses as a mouldy coating which
surrounds the hauhns and causes withering of the parts above
it. The fungus not unfrequently attacks such fodder-grasses as
Dadylis, Poa, and Phleum 'pradensc, causing severe loss where these
crops are much grown. On the white stromata conidiophores are
produced, and from them small, ovate, unicellular conidia are
abjointed. These are followed later by perithecia embedded in
the same stromata. The asci, of a somewhat yellowish colour,
are long with button-shaped apices and contain eight thread-
like spores,

Ep. Warburgiana, Magii.- is an interesting species found on arrowroot
{Maranta) in tlie Philippines.

Claviceps.

The sclerotia are black horn-like bodies, and on them the
stromata are developed as stalked structures, with spherical
heads, in which the flask-shaped perithecia are embedded. The
asci contain eight thread-like spores.

Claviceps purpurea (Fries^) (Britain and U.S. America).
This fungus becomes most apparent, when in the stage of
the well-known "Ergot" grains, bluish-black curved sclerotial
bodies in which the mycelium perennates over winter. Ergot
is found in the ears of our cereals, especially in rye, also in
other cultivated and wild (Iramineae. The sclerotia fall into
the ground direct, or are sown out with the seed, and in
spring or early summer produce a large number of stromata,
each consisting of a violet stalklet carrying a reddish-yellow
head. The ovoid perithecia are completely buried in the head
of the stroma, and contain the asci, each with eight thread-like
ascospores. The spores, after ejaculation, germinate on flowers
of Gramineae, and the septate mycelium developes in the outer

^Atkinson, G. F. [Torrey Club Bulletin, 1894, p. 222), proposes a revision
of the species of Epichloe and other species of N. American graminocolous
Hypocreareae. (Edit.)

- Magmis, Internat. Bot. Coivjress, 1892.

•' Tulasne, Annal. d. sci. natur. 3 ser. xx. Kuhn, Mittheilunrjen d. land-
icirth. Imtitut. Halle, 1863.

192

ASCOMVC^KTKS.

coats of the ovary, till gradually l)Ut completely it fills up the
whole cavity. Outside the ovary the mycelium forms an

Fig. ii4.—C'lariceps iiurpurea. Ernot. Sclerotia or Ergot-graius in ears of Rye.
(v.'Tubeuf phot.)

irregular wrinkled white stroma or sphacelia, from the hollows
and folds of which little ovoid conidia are abjointed from short

CLAVICEPS.

193

conidiophores. A very sweet fluid, the so-called " houey-devv,"
is separated from the sphacelia ; this attracts insects, which
carry the conidia to other flowers. Since the conidia ai^e
capable of immediate germination, and give rise to a
mycelium which penetrates through the outer coat of the
ovary, the disease can be quickly disseminated during the
flowering season of the grasses. After the formation of conidia
has ceased, the sclerotia become firmer, with a dark wrinkled
cortical layer and an internal firm-walled pseudoparenchymatous

Fig. S5. —Claviceps purpurea. A, Sclei-otiuin with seven strotnata {ci). B,
median longitudinal section through the upper part of a stroma, the flask-shaped
perithecia {cp) are embedded in the head. C, Perithecium in longitudinal section
(highly magnified) — hy, hyphal tissue ; sh, cortical tissue of the stroma ; c/j, orifice
of the perithecium. " D, Isolated ascus ruptured, so that the thread-like asco-
spores (sp) have begun to escape. (After Tulasne, from Sach's Lehrlmch.)

hyphal tissue. In this condition they are introduced along with
grain into bread, which when eaten acts as a powerful poison,
producing very serious results (Ergotism). The sclerotia are
also used medicinally, and are collected for this purpose {Secede
cornutum).

Robert (Frbhner, Lehrbzich der Toxikologie fiir Thierartze, 1890) states
that Ergot contains three poisonous agents :

(1) Cornutin, an alkaloid which produces that particular effect of ergot
in causing contraction of the uterus.

(2) Sphacelic acid, a non-nitrogenous, resinous, non-cry stallizable sub-
stance, in.soluble in water and dilute acids, but soluble in alcohol, and

N

194

ASCOMYCETES.

forming, with alkalies, salts soluble in water. This is the real cause of
ergot poisoning and gives rise to gangrene. In large doses it produces
cramp similar to strychnine, and tetanus of the uterus.

(3) Ergotic acid, a nitrogenous, easily decomposed glycoside, which has
no effect on the uterus. It is more a narcotic which diminishes reflex
excitability and finally stops it.

Robert experimented chiefly with cattle and fowls. He found that an
acute course of the poisoning can be distinguished from a chronic ; also a
gangrenous ergotism from a spasmodic. The symptoms of the disease are :

(1) Gastro-enteric, an excessive salivation accompanied with rednes.s,
blistering, inflammation, wasting and gangrenization of the mouth-epithelium;
similar changes also occur on the epithelium of the gut, i)roducing vomiting,
colic, and diarrhoea.

(2) Gangrenization and mummifica-
tion of extremities, consisting of a
drying-up, a dying-off", and a detach-
ment of extremities, such as nails,
ears, tail, wings, claws, toes, and point
of tongue.

(3) Spasmodic contraction of the
uterus and consequent abortion.

(4) Nervous phenomena such as in-
sensibility, blindness, paralysis, etc.
The presence of ergot may be de-
tected both microscopically and spec-
troscopically.

The fungus may be combated
by careful separation and de-
struction of sclerotia, and by the
use of clean seed.^

Claviceps microcephala
( Wallr.) (Britain). This is found
on Fhragmifes, Molinia, Nardus,
etc. It has smaller sclerotia,
which, according to Hartwich,-

FlG 8(3.— Sclerotia of ttaiiceps ?m«-oc<;p^<nfc prmfoiii tbrpp finip<! q<« miipb
on Molinia coeridea. (v. Tubeuf phot.) COUtani lUree tUneS aS UlULZl

Ergotin as those of CI. inirpurca.

^ Smith {Diseases of field and garden crops. 1884. p. 233) describes and
figures Claviceps purpurea rar. Wilsoni on Glyceria flnitans near Aberdeen. It
is distinguished " in being whitish or j-ellowisli, instead of being pale piu'ple in
colour, and in the perithecia or coneeptacles being almost free on an elongated
club-like growth instead of being immersed in a globular head or stroma."

-Hartwich, "Sclerote du Molinia coerulea." Bidht. de la Soc. Mycoloy. de
France. 1895.

CLAVICEPS. 195

CI. nigricans (Tul.) on Heleocharis and Scirjms, with sclerotia
of a dark violet colour (Britain).

CI. setuloso (Quel.) on Poa. Stromata .straw-yellow in colour.
CI. pusilla Ces. on Andropogon Ischaeimim.

(2) SPHAEEIACEAE.

The group of the Sphaeriaceae includes eighteen families,
but only the following contain parasites of interest to us.

Families : Trichosphaerieae, Melanomeae, AmjjMsphaerieae,
Cucurhitarieae, Sp)1iacrelloidcae, Pleosporeae, Chiomonieae, Valseae,
Diatrypeac, and Mdanconideae.

TRICHOSPHAERIEAE

(including Coleroa and Herpotrichia).

Coleroa.

The perithecia have thin walls with radiating bri.stles, and
sit superficially on the substratum. The asci have thickened
apices, and contain eight two-celled, faintly coloured spores.

Coleroa chaetomium Kunze, occurs on living leaves of
Riihvs caesii's and IL Idacus. In addition to perithecia, it
forms conidia known as Exosporium rubi Xees.

C. alchemillae Grev. (Britain and U.S. America). On leaves
of Alclicmilla rvlfjaris.

C. andromedae Eehm. On lea\es of Andromeda polifolia.

C. potentillae Fries (Britain and U.S. America). Leaves of
PotcntiUa onscrina. It forms perithecia which are situated
on the leaf-ribs ; also conidia (Marsonia potentillae).

C. subtilis Fuck. On leaves of Potentilla cinerea.

C. circinans Fries. On leaves of Geranium rotundifolium and
G. tnolle.

C. petasitidis Fuck. On leaves of Pctasites officinalis.

Trichosphaeria.

Perithecia small, spherical or ovoid, and more or less hairy.
Paraphyses distinct. Spores with one, two, or four cells.

We give this genus a wider scope than Winter, and include species with
one, two, and four-celled spores of hyaline or light colour, and whose

196

ASCOMYCETES.

other characters cDincide ; this seems to be all the more justifiable since
one finds on the same species asci witli spores made up of one, two, or
four cells.

Trichosphaeria parasitica Hartig.^ (Britain and U.S.
America.) Everywhere in young naturally regenerated woods
of silver fir, especially in damp places or wdiere the plants
are crowded, one finds partially browned needles hanging
loosely from the twigs, held only l)y a fine white mycelium
(Fig. 87). In addition to this, one finds in spring young
twigs completely enveloped in mycelium, with all their

Fig. S7 .—Trichosphaeria parasitica on Silver Fir. The withered and dead
needles hang loosely downwards, attached to the twig only by a white mycelium.
(V. Tubeuf phot.)

needles killed, so that the twig itself soon dies. The white
mycelium grows especially on the under side of the shoot,
and on the lower epidermis of the horizontal needles. A
pseudoparenchyma, consisting of layers of mycelium, is there
laid down, the lowest layer of hyphae sending short cone-
shaped haustoria into the walls of the epidermal cells (Fig. 88).
Inside the needles, occupying the intercellular spaces, there
are numerous branches of septate hyphae, which kill the cells
of the leaf. The perithecia occur here and there on the
mycelial coating outside the leaf; they are spherical and
blackish, with radiating hairs. They contain paraphyses and

^ R. Hartig, " Ein neuer Parasit d. Weisstanne. " Alhg. For>ii,-u. Jayd-
Zeitung, Jan., 1884.

TRICHOSPHAERIA.

197

asci, the latter with eight four-celled light-grey spores, which
germinate directly and distribute the fungus over new host-
plants.

I found this same fungus on Tsuga canadensis ^ at Baden-
Baden, and on spruces in several parts of the Bavarian forests.^
It, however, rarely attacks spruces, although they often occur
in the same forest with firs. One of the cases of infection
referred to above was caused by the diseased branch of a fir
lying in contact with a twig of the spruce, so that the mycelium
grew from the one to the other ; the spruce needles were killed,
and woven on to the twig by hyphae.

Fig. 88. — Trichosphaerio. 'parasitica. Mycelial cushion on lower side of Fir
needle, a. Filamentous mycelium, which, at h, sends downwards numerous
bi'anches to produce a cvishion of parallel hyphae, c. Where the mycelium rests
on the epidermis, rod-like haustoria are sunk into the outer wall of the epidermal
cells, e e; d shows the mycelial cushion slightly detached from the epidermis, so
that the haustoria have been withdrawn. / /, Epidermal cells filled with brown
contents. ;j g, Chlorophyllous mesophyll, which becomes brown after the
mycelium has penetrated to it. i. Outer court of a stoma filled by a mycelium
with no haiistoria, but adhering to the waxy granules of the stomatal aperture.
(After R. Hartig.)

In woods of young silver fir naturally regenerated, this fungus
causes great damage by killing numerous twigs. It occurs every-
where in young fir forests, e.g. the Alps, Bavarian forests, the
Black Forest, etc. On dry airy situations, on free-standing
trees, and on the highest branches of a tree, it is rarely present.

1 V. Tubeuf, Beitrarje z. Kenntn. d. Baumtrankheiten, Berlin (Springer), 1888.
-V. Tubeuf, " Trichosphaeria parasitica der Fichte." Botan. Centralblatt,
XLi., 1890.

198

ASCOMYCETES.

Its injurious effects can be minimized by removal of attacked
branches.

Trichosphaeria sacchari Massee, is regarded as a dangerous woinid
parasite of cane-sugar in the Antilles ; it seems to obtain entrance chiefly
by the canals left by a ciiterijillar.'

Herpotrichia.

The smooth dark perithecia bear long brown hairs, wliicli
do not stand erect and stiff, but are more or less prostrate.

Fig. 89. — Herpotrichia nigra on a branch of Pinus raontana. The ends of the
twigs, with most of the younger needles, are still green ; the others are dead and
felted together by hyphae into a black mass. (v. Tubeuf phot.)

The asci contain eight spores, at first generally two-celled, later
becoming four-celled.

^Massee G. , Annalii of Botany, 1893, p. 515.
Barber, " Experimental Cultivation in St. Kitto," Leeward Islands Gazette,
1894.

HERPOTRICHIA.

199

Herpotrichia nigra Hartig.^ This parasite is distinguished
by its grey inyceliuui, which covers and completely envelops
twigs and young plants. On the dwarf mountain pine it is
not uncommon to find branches bearing patches of blackened
needles closely bound together by gossamer threads, the other
parts remaining still green and forming a background against
which the blackened masses show up prominently (Fig. 89).
Young spruce plants under a metre in height and the lower
branches of taller trees are frequently completely enveloped in
mycelium, and, where they have been pressed down to the
ground by weiglit of snow, the twigs may be woven round
and fastened to the earth by a felt of mycelium.

Fig. 90. — HerpotricMo. nigra, a, hyphae weav-
ing a granular mycelium on the surface of the
needle and forming tuber-like bodies over the
stomata ; rod-like haustoria are sunk into the
outer walls of the epidermal cells. (After R.
Hartig).

Fio. 91. — Herpotrichia nif/ra. Ascus with
germinating spores, (v. Tubeuf del.)

I have frequently observed the fungus on Junijjerus com-
munis, especially in Bavarian forest-land, and on Jiiniperus
nana in the Alps. Professor Peter found it on the latter
host in Sweden.

The spherical dark-coloured perithecia are covered with
prostrate hairs, and contain asci with eight four-celled spores.
The spores germinate directly to hyphae. The mycelium closely

^ R. Hartig, "Herpotrichia nigra." A/le//. ForsL-u. Jafjd-Zeitung, 188S.
V. Tubeuf, " Mittheilung lib. einige Feinde d. Waldes." A/lPf/. Forst.-u.
Jagd-Zeitung, 1887.

200 ASCOMYCKTES.

envelops the needles and sends out haustoria similar to
Triclio.sjjhaeria 2^<^'''<^sitica (Fig. 90).

Herpotrickiu is, in high-lying situations, a very dangerous
enemy of young spruces, and nurseries in such places have
frequently to be abandoned owing to the death of all the
plants. Serious damage also frequently results in young planta-
tions where snow lies long and keeps the young trees pressed
down towards the earth. Then the fungus, even under the
snow-covering, weaves round and fixes the shoots so firmly
together, that only the healthy ones are able to free themselves
again and to resume their growth in spring.

As preventive measures, nurseries should not be established
in high situations, nor in valleys where there is a large snow-
fall ; while in localities liable to attack, the planting of young
trees in basins or cups (hole-planting) should be avoided. The
loss from crushing-down l^y snow may be lessened by laying
trunks and branches of felled trees amongst the young plants,
and by going over them in spring, raising up all prostrated
plants.

MELANOMEAE.

Rosellinia.

The perithecia generally occur in numbers together ; they
are black, and smooth or studded with bristles. The asci
contain eight oval, spindle-shaped, dark-coloured, one-celled
spores. Filamentous paraphyses are always present.

Rosellinia quercina Hartig.^ The oak-root fungus. This
fungus lives in the roots of oak seedlings one to three years
old, and causes the leaves and shoots to become pale and to
dry up. It spreads only during damp weather, especially
in June, July, and August. In wet years it may cause very
serious damage, especially in seed-beds. The mycelium pene-
trates into the living cells of the root-cortex, extending even
to the pith. At first the mycelium is hyaline, but later it
darkens, and the hyphae become twisted together into spun
thread-like strands — the rhizoctonia. These structures apply
themselves to roots of neighbouring plants, and soon enclose
them in a weft of hyphae ; by this means the disease is

1 R. Hartig, Untersuch. ati-t d. forsthotan. Instihit zu Miinchen, Berlin, 1888.

ROSELLINIA. 201

propagated through the soil from plant to plant. There is a
resting-stage in the form of chambered sclerotia, black tuber-
like bodies which have their origin in the cortical parenchyma
of the roots and break out through the cortex. Eeproduction
is effected throughout the summer by means of conidia, pro-
duced from a mycelium which vegetates on the surface of the
soil ; this mycelium bears conidiophores with whorled branches,
from which the conidia are abjointed.

The perithecia are spherical structures composed of hyphae
with walls which swell up in a gelatinous manner. At first
the inside of the perithecium is a gelatinous mass containing
the paraphyses and the rudiment of the ascogonium. As the
asci are developed, they push their way into the gelatinous
mass amongst the paraphyses. Each ascus is a long club-
shaped tube, the apex of which is thickened and stains blue
with iodine, showing at the same time a canal piercing it.
The ascospores are canoe-shaped with sharp ends, and when
mature have a dark brown colour. The spores germinate in
spring ; in w^ater-cultures germ-tubes are emitted twenty-four
hours after sowing. The spores open by a longitudinal slit, and
a germ-tvibe emerging from each end branches into a mycelium
which soon takes on the form of a rhizoctonia-strand. Infection
takes place through the tender non-cuticularized apices of roots.

The fungus may be combated if diseased portions of seed-
beds are isolated by means of trenches dug round them. If
boards soaked in carbolic acid or coal-tar are placed upright
in the trenches, greater certainty will be secured that the
disease does not spread.

Several species of Rhizodonia, probably related to the above,
may now be briefly considered.

Rhizoctonia violacea Tul.^ (U.S. America). Eoot-fungus of
lucerne and clover. The presence of this disease is shown in
summer by the plants withering, and finally dying. The mycelium
lives inside the roots, and covers them externally with violet
coatings on which the sclerotia appear as black tubers.

On plants with sclerotia, Fuckel found pycnidia and perithecia of
Leptosphaeria {Trematosphaeria or Byssotkecium) cirnnans ; whether the
various forms were related could not, however, be determined.

^ Eostrup, Undersoefjelser angaaende Svampedatqten Ehhoctonia, 1886.
Tulasne, t'umji h^por/aei, PI. IX. and XX., 1851.

202 ASCOMYCKTES.

The disease spreads through tields in a centrifugal direction
from a starting-point. Besides the above plants, it is also
said by Kiilni to attack carrots, sugar-beet and mangolds,
fennel and p(;tatoes ; and Tulasne gives asparagus and red
clover as hosts. Prunet ^ believes that the fungus remains
three years in the soil, and recommends that diseased fields
should not be cropped with lucerne or clover for several years.
He also advises the isolation of infected land by surrounding
it with a deep trench in which sulphur is strewn, then covered
over with soil. The enclosed plot should next be deeply
trenched between June and August, and all plant-remains
removed and burnt.

Rh. crocorum D. C.^ The Saffron destroyer. This parasite
attacks and kills corms of the saffron {Crocm sativum). The
mycelium finds entrance by the stomata of healthy corms,
and covers them externally with a web of violet- coloured
mycelium.

Rh. solani Kuhn. occurs as black sclerotia on the skin of
potato-tubers.

Rh. batatas Fr. occurs in America on sweet potato.

Rh. allii Clrev. occurs on tubers of shalot (Allium ascalonicum)
and onion {A. sativum).

Rh. betae Klihn is said to attack beet-root in America.^

We may also consider at this place :

Dematophora necatrix Hartig.* The vine-root fungus.
This parasite causes a very destructive disease of the vine,
and is often confused with attacks of the Phylloxera-insect.
It occurs in the United States, and is common throughout
France, Switzerland, Italy, and South-west Germany, being
known under a variety of names.^ Occasionally it has been
known to attack the roots of fruit trees and other plants
cultivated in vineyards.

' Prunet, " Sur le Rhizoctone de la Luzerne." Compt. rend., Paris, 1893.
Fr. Wagner, " Das Vorkommen des Wurzeltiiters d. Luzerne." Zeitsch. d.
Landwirth. Vtrdn in Baytrn, 1894.

-Prillieux, "Sur la nialadie des Safrans." Compt. rend., xciv. and xcv.
Tulasne, Fungi hypogaei, PL VIII., 1851.

■^ loica Agric. Exper. Station, BuUetin 15, 1891 ; with illustrations.

■* R. Hartig, Untersuchungbn aim d. forMhotan. Inntitid zu Miinchen, iii., 1883.

5 Wurzelpilz, Weinstockfaule, Pourridie de la Vigne, Pourriture, Blanc des
Racines, Blanquet, Champignon blanc, Aubernage, Mai nero, Morbe bianco, etc.
(Hartig's Lehrburh).

DEMATOPHORA.

203

Fifi. 93. — Vine-root with rows of black
sclerotia exposed, and bearing bristle-like
conidiophores here and there. (After R.
Hartig.)

Fig. 92.— Vine-stock with Dematophora necatrix
(after a prolonged stay in a moist chamber), a. Fila-
mentous myeelium passing over into rhizoctonia-
.strands (6), which anastomose at c c. d and i,
Rhizomorphs growing outwards from the interior.'
(After R. Hartig.)

Fig. 94.— Portion of Fig. 93 after for-
mation of conidiophores. x f . (After
R. Hartig.)

204 ASCOMYCETES.

Dcmatophora forms fine rhizoctonia-strandH which grow
througli the soil from root to root. The mycelium kills the
fibrous rootlets, and spreads from these into older roots to
form rhizomorph-strands, which, however, have a structure
quite distinct from those of Agaricus mellcus. The rhizomorph-
strands may pass out of the root into the soil, there to form
a filamentous mycelium, or, remaining in the root-cortex, may
produce rows of black tuberous sclerotia which on maturity
break out to the exterior. On the sclerotia, or other parts
of the mycelium, bristle-like conidiophores may be developed
as branched panicles from which ovoid colourless conidia are
abjointed.

This enemy of the vine is rapidly assuming great import-
ance. Thus, for instance, in Baden,^ there is no Phylloxera,
but whole tracts of vine land are infested with Bematophora.

According to Viala," De^natophora forms perithecia, which,
however, only develop after artificial culture for several years
on decayed plants. If this be so, the fungus should be classi-
fied between the Tuberaceae and the Elaphomycetes. Berlese,^
however, contests this view, and regards it as nearly related
to Rosellinia.

Hartig * suggests impregnation of the vine poles with creosote
as a means of combating this disease.

Strickeria.

Strickeria Kochii Korb. develops its perithecia on the cortex of living
Rohiaia I'seadacacia ; its parasitism is however not yet fully established.

CUCURBITARIEAE.

Gibbera.

The black perithecia, beset with stiff bristles, are developed
in large groups on a dark pseudoparenchymatous stroma.

Gibbera vaccinii Sow. (Britain). In damp situations amongst
moist patches of Hypnum and other mosses, one often finds
the cowberry {Vaccinium Vitis-Idaea) with its leaves and

1 Beinling, Das Au/treten v. Rebenkrankheilen in Baden, 1891.

2 Viala, Jfonoijraphie du PoiirridU d. Vifjnes, 1891.
^ Berlese, liirisfa di patoloi/ia veyetale, i.

*R. Hartig, Lehrhuch d. Baumkrankheiten, English edition, 1894, p. 87.

GIBBERA.

205

twigs brown and dead (Fig. 95). If more closely examined,
the twigs will be found to bear patches of coal-black,

Fig. 96. — Gibbera vaccinii. Isolated asctis
with eight spores ; isolated hair from the
outside of a perithecium. (v. Tubeuf del.)

Fig. 95. — Gibbera vaccinii on
Cowberry. The perithecia form
black patches on the living leafy
branch, as well as the dead Jarown
one. (v. Tubeuf del.)

Fig. 97. — Gibbera vaccinii. Cross-section of Cowberry showing
a patch of perithecia in section ; the hairy perithecia contain
paraphyses and asci with spores ; a mycelium permeates the
cortical tissue of the host. Short hooked hairs cover the
epidermis of the stem. (v. Tubeuf del.)

spherical perithecia, which are coated by short, acute, unicellular,
black hairs (Fig. 97). The perithecia contain paraphyses and

206 ASCOMYCETEH.

asci, the latter with eight or fewer bicelhilar dark-coloured
spores. The niyceliuin is dark-coloured, very vigorous, and
furnished with many lateral bladder-like outgrowths ; it permeates
the whole cortical tissue as far in as the wood, and under the
epidermis forms a brown pseudoparenchymatous stroma, which
extends over the cortex, and gives rise to numerous perithecia.
The living cells of the cortex turn brown in presence of the
fungus-mycelium, and collapse, causing the whole shoot above
the place of attack to wither and die.

Cucurbitaria.

The dark perithecia and pycnidia break through the epidermis
in large numbers. The asci contain six to eight In'own spores,
divided by cross-septa.

Cucurbitaria laburni Pers.^ (Britain). The spores of this
fungus germinate on wounded parts of laburnum (Cytisus
Lahurnum), and, as the branches of attacked plants soon die
off, considerable damage to nursery stock may result. The
mycelium spreads through the wood, particularly the vessels,
in spite of the early stoppage of these by a yellow wood-gum.
Diseased parts of the wood of living branches appear as dark
strips ; reproductive organs are produced in the bark, and
there the plant attempts to isolate the diseased parts by con-
tinued cork formation.

If diseased, but still living spots on stems be examined,
they will be found to include many yellow and l)lack pustule-
like swellings, some buried in the bark under a periderm eight
to ten cells in thickness, others in process of breaking through
or altogether exposed. Many of the pustules will attract
attention from the presence of red, twisted, elongated tendrils
on them. On the lower parts of dead branches the same
appearances will be found, but, in addition, the periderm will
generally be ruptured, and the openings so produced filled with
spherical dark grey or black fructifications. These are variable
in form, and amongst them can be distinguished some which
are very large, round, smooth-coated, and light-coloured, with
a round pore ; others, which appear more warty, and have a
depressed opening ; while still others, generally smaller, have

1 V. Tubeuf, ^'■Cucurbitaria laburni." Botan. Centralblatt, xxvi., 1886.

CUCURBITARIA.

207

an acute beaked pore. Where the bark has been lost, a
good lens may distinguish the spherical or ovoid dark-coloured
perithecia. On the finer twigs the whole
bark is often perforated by numerous tiny
pycnidia, hardly distinguishable with the
naked eye.

If these various forms of fructification be
submitted to microscopic examination, sections
through the yellow pustule^ will show them
to have that colour, because the transparent
periderm has become loosened from the rest
of the bark ; underneath the corky layers
will be found a red stroma of pseudo-
parenchymatous hyphal tissue. This stroma
by its growth causes a gradual rupture and
loosening of the corky and other layers of the
periderm ; wherever this takes place, conidio-
phores are developed, and give off numbers of
tiny, hyaline, ovoid or cylindrical conidia.
The stroma itself is somewhat spongy, and
encloses numerous cavities which also become
lined with conidiophores. At a later period
the tissue enclosing these cavities may become
dark coloured, so that structures similar to
pycnidia are formed. In such cavities the
red colour disappears, and the hyphae, coni-
diophores, and conidia appear transparent.
The real pycnidia appear later, and consist of
a peridium of coarse pseudoparenchyma con-
taining conidia similar to those just described
(Fig. 99, a). From the openings of these
pycnidia the conidia emerge as red tendrils,
rising as much as one centimetre above the
pore. Adjoining these forms of sporo'phore
just described will be found others : unde-
veloped perithecia with young asci ; dark-
brown pycnidia with brownish-grey, multi-
septate, compound conidia ; or similar pycnidia
with unicellular spherical, brownish -grey conidia.

Where the disease has made further j)rogress, the pustules

Fig.

hljirnii.

fiS. — Cacurbitaria
Plant of La-
burnum (diagrammatic);
tlie branches 1, 2, 4 are
still living, and were in
full foliage during the
preceding summer ; a, h,
c, d, e, places where the
rind is dead and the
cork -layer ruptured ; at
a and b the perithecia
are already developed,
and the mycelium has
extended into the wood.
(After V. Tubeuf.)

208

ASCOMYCETES.

will be fuuiul chaiijj;ui<^- from yellow to black on account of
the peritlerni and dead stroma becoming darker. On dead
branches the large cushions of fructifications will be found to
include : (a) perithecia with a warty exterior and pores set
in a depression; (b) large pycnidia, standing out from the
cushions, with brown smooth coats, and full of compound
multiseptate conidia (Fig. 99, b; see below No. 3, a); (c)
other smaller pycnidia containing the same conidia, but whose
pore is situated on a sharp prominence (No. 3, h). All or any
of the three forms may be present.

Fig. 99. — Cucurbitaria laburni. A, Stroma with pycnidia containing minute
unicellular conidia. B, One of the large smooth pycnidia. (After v. Tubeuf.)

The mature perithecia have a peridiuin consisting of a loose
pseudopareiichyma with a rough warty exterior and a pore set
in a distinct depression (Fig. 100.) The paraphyses are long,
strong threads, often branched, and between them arise the
long cylindrical asci with rounded ends. The normal number
of ascospores is eight in each ascus, but fewer is no exception.

In addition to the forms already described, pycnidia of still
another sort occur (No. 1, c). They are spherical, with a
dark-coloured coarse peridium, and are smaller than the stroma-
pycnidia. These pycnidia contain no conidiophores, but give off

CUCURBITARIA.

•209

unicellular couidia, at first white, later grey. It is these pycnidia
which cause the fine perforations of the periderm of twigs.

Yet another form of pycnidia, previously known as Biplodia
cytisi (Awd.), (No. 4). This, like the last, breaks through the
corky layers of the bark. It has a peridivmi composed of loose
pseudoparenchyma and, without the intervention of conidio-
phores, produces two- celled conidia of a dark greyish-brown

Fig. lOa.—Cucv.rUtaria loMv.rni. Perithecium isolated. A, Ejaculating ascus
■with the inner membrane as yet unruiitured, but emerging beyond the outer
ruptured coat. (After v. Tubeuf.)

colour. This form, however, I failed to find in the course of
my investigation, although I looked through much material.
Tabulatinfj these various forms of fructification we have :

A. Pycnidia.

1. White transparent, small, unicellular conidia on long conidiophores :
(a) Free on the stroma.

(6) Enclosed in cavities in the stroma :

(a) In cavities as yet not resembling pycnidia.

{(3) In cavities with firm dark-coloured periphery,
(c) Enclosed in dark-coloured free pycnidia, with a peridiuui of coarse
pseudoparenchjina.

2. Brown, unicellular, round conidia, in little brown pycnidia (Fig. 99, a).

O

210 ASCOMYCETES.

3. Brown, inulti.septate coiiiilia :

(m) In lnowii, very large, sniootli-coated pycnidia (Fig. 99, b).
(b) III darker and smaller jncniilia with pointed ajiertnre.

4. Brown, bicellular conidia, in little daik pycnidia (iJiphdia a/tisi).

B. rERITHKClA.

5. Brown, multiseptate a.scos])ores, in perithecia generally of flark colour,
and with dej)res.seil jjore (Fig. 100).

Oucurbitaria sorbi Karsten. This fungus appears to pro-
duce disease in a manner similar to C. laburni. It was described
by me in 1886 ^ from specimens collected in the Bavarian
forest-land from young PijruH Aiicnparia. They were easily
distinguished in August by their withered twigs, both bark and
wood being killed in tracts by the mycelium. In another
locality I found well-developed perithecia, also on P. Aw-wparia.

Oucurbitaria pityophila Fries, occurs on the living branches
of various conifers, e.g. Pinus Ccmbra.

SPHAERELLOIDEAE.

Stigmatea.

The naked perithecia are superficially seated on the sub-
stratum. The ascospores, eight in each ascus, are clear and two-
celled. The species are parasites.

Stigmatea robertiani Fr. (Britain and U.S. America), Occurs
on living leaves of Geranium Pohcrtianum.

St. ranunculi Fries. On living leaves of Ranunculus rep)cns
(Britain and U.S. America).

St. mespili Sor. (U.S. America). This species appears in
spring as reddish-brown spots on the leaves of wild pear-trees.
At these places the epidermis becomes ruptured, and cushions
are formed from which brown, conidia are given off from short
conidiophores. This stage was formerly known as Mortliiera
mespili. The conidia are at first obovoid, l)ut later seem to
consist of four separate cells arranged in a cross, and each
furnished with a transparent bristle. Each conidium produces
a germ-tube which penetrates the epidermis, and in a month

' 1 have since found from Saccardo that tliis fungus was descrihed hy Karsten
{Mijcol. Fenn., ir. '^ ad nxmos dejectos Sorhl a iirii/xtricu: in Fennia merid. et media");
it was, however, unknown for Germany to that author. (Auth.)

STIGMATEA. 211

new conidial cushions may appear. The mycelium itself is
brown. From winter to sprinsj, brown perithecia containing
eight-spored asci may be found on the same leaves formerly
occupied by the conidia. The colourless spores consist of two
unequal cells ; they germinate in May, before or after ejaculation
from the asci, and bring about new infections.

St. polygonorum Fr. occurs on leaves of Folygonura. (Britain and U.S.
America).

St. andromedae Rehm. On living leaves of Andromeda polifolia.

St. alni Fuck. On living leaves of Alnus glutinosa.

St. juniperi Desm. On living needles of Juniperus communis.

Ascospora.

The mycelium forms brown crusts under the host-epidermis,
and there the perithecia develop. The asci are small and
contain unicellular hyaline spores. The perithecia contain no
paraphyses.

Ascospora Beyerinckii Yuill.^ The conidial form of this
fungus {Curz/iiei'vi BinjcrincJcii) produces a form of the " gum-
flux " of cherry ti'ees. The mycelium lives in leaves of cherry,
peach, plum, apricot, almond, which in consequence become
spotted, and die off along with the young fruit. Mature
perithecia may be found in spring. The fungus lives to a
certain extent as a saprophyte.

Sphaerella.

The delicate perithecia are emljedded in the tissues of the
host-plant ; they contain asci with two-celled colourless spores,
but no paraphyses are present.

Sphaerella laricina Hartig."- The needle-cast fungus of
Larch. This fungus is the cause of a dangerous larch-disease
found everywhere, except in mountainous localities over 1200
metres. The symptoms of disease consist in the needles becoming
brown-spotted and falling prematurely in summer. Cushions of
conidia are formed in June on the brown spots ; these enlarge,
and from their surface rod-.shaped, four-celled conidia are

^ Vuillemin, Tifres ei travaux scientifiqnes, 189U.

- R. Hartig, Forstlirfi-nattirn-isi. Zeifxchrift, 1S95, p. 445.
Through the kindness of Prof. Hartig we have been enabled to add an
account of this important new disease, with the accompanying tigures. (Auth.
and Edit.)

212

ASCOMYC'ETES.

abjoiiited (Fig. lOo); iu the iuterior of the spots are produced
tiny conidia (Lcjjtostroma laricinum), incapable of germination.

Fio. 101. — Tuft of larch needles, the greater number of which are more or less
attacked by Sphaerella laricina. (After R. Hartig.)

The rod-shaped conidia infect particularly the lower needles of
the crown, and three weeks thereafter new conidial cushions

Fig. 102.— Sphaerella laricina. Section through a diseased spot on a hirch
needle. The interior of the leaf is permeated with the intercellular mycelium.
Two conidial cu.shions are shown ; from these numerous long rod-shaped conidia
are given off externally (those of the upper cushion have nearly all been carried
off by rain), while cavities inside the cushions are filled with micro-conidia.
X ^K (After R. Hartig.)

appear. Their distribution and germination are facilitated by
wet weather. The perithecia (Fig. 104) are matured towards

SPHAERELLA.

213

spring in the fallen needles, which lie on the ground over

winter. The ascospores are mature and capable of infection

at the beginning of June. In forests of

pure larch, or in mixture with spruce, the

ascospores are easily distributed by wind.

In larch, underplanted with beech, the spores

are kept down towards the ground by the

canopy of beech foliage, so that, during the

summer, they cannot be carried up to the

larch crown.

Hartig gives the following interesting facts

on its distribution.

,, , , , 111 • 1 • 1 Fig. 103.— «, Rod-shaped

As already remarked, the perithecia de- comdia before and after

, . . ,1 n 1^ ^ ^ -l^ detachment from the

velop in spring on the lallen larch needles, basidia. b, Micro-conidia

-, . , , . IT,- ,1 ^ from the interior of the

and in low-lying localities the spores reach cushions, x ^i". (After
maturity at the beginning of June. Xew ^' ^^^^^^-^
conidial cushions are not found on the larch in our neighbourhood
before July. The parasite has thus four months at its disposal

Fig. 104. —Sphaerella laricina. Section through a diseased larch needle in June
after it has Iain on the ground from the previous year. The mycelium is thick,
thick-walled, and of a light-brown colour. The perithecia contain asci and asco-
spores. To the extreme right is a pycuidium containing little oblong conidia,
alongside a perithecium. x ly^. (After R. Hartig.)

for distribution by means of conidia. As, however, we ascend
into the mountains, the snow lies longer, so that the perithecia
cannot begin to form so early, the ascospores are correspondingly
late in reaching maturity, and the season during which the
parasite may spread is still further shortened by the earlier
commencement of winter. At an elevation of 1500 metres,

214

ASCOMYCETES.

active vegetation begins about two and a half months hiter than
in the plains, i.e. at the beginning of June. The season of
mature spores of Sphaerella is thus delayed till about the
middle of August. On 2Gth September I found at this elevation
only a few spots on the larch needles, and
on these hardly any conidial cushions. By
28th September this larch plantation was
already under snow."

" It will thus be seen, that while at a
high elevation the larch can flourish witli
a vegetative period extending only to three
and a quarter or four months, the Si^hacrcUa
has not the time necessary for its develop-
ment, so that the larch, though much
handicapped, remains healthy. Similarly
with the larch in Siberia, it grows there,
as in the mountains, very slowly, yet this
parasite can no longer reach it."

Sphaerella fragariae Tul. Strawberry
leaf - blight.^ In summer free conidia
{Ramularia Ttdasnei Sacc.) and pycnidia
are produced, while the perithecia ripen in spring.

[This destructive disease of the strawberry has been recorded
from all parts of the United States. It first appears on the
upper surface as small reddish spots, which rapidly enlarge,
the centres withering and browning. The growth of the plants
and the crop-yield is seriously impaired.] (Edit.)

Sph. gossypina Atks.^ [Cotton leaf-blight is a disease on
leaves of the cotton plant caused by the 6'«'co.5por« -stage of this
fungus. Small reddish spots appear on the leaf, enlarge, and
become dry whitish spots with a red margin. The conidia
are elongated and produced in long chains. The asci contain
eight elliptical spores, which are slightly constricted at the
septum when mature, one cell being usually somewhat smaller
than the other. This disease frequently accompanies that one
known as " yellow leaf-blight," or mosaic disease.] (Edit.)

Flo. 105.— Enlarged asci.

a, Immature asci without
paraphyses, as on April 30.

b, Mature asci, from one of
which tlie spores are escap-
ing, as on June 1. x i|".
(After R. Hartig.)

^Trelease, Wincoiisin Exptr. Station, 1885.
Scribner, F. L., Report U.S. Dept. of A(/ricuftitre, 1887.
papers by Arthur, Dudley, and Garman.

2 Atkinson, Bulletin Torrey Bolan. Club, Vol. xviii., 1891.

Plate. Other

SPHAERELLA

215

Sph. mori Fuck, causes a similar disease on leaves of mulberry (U.S.
America).

Sph. taxi Cke. On the yew.^

Sph. longissima Fuck. On living leaves of Bromus asper.

Sph. depazeaeformis (Auersw). On living leaves of Oralis acetosella and
Ox. corniculata.

Sph. brassicicola (Duby.). On withering leaves of Brassicae. (Britain
and U.S. America.

Sph. laureolae (Desm.). On living leaves of Daphne laureola.

Fig. IQ&.^SfihaereUa fragarme on leaf of Strawberry. The section through a
spot shows formation of conidia. (v. Tvibeuf del.)

Sph. hedericola (Desm.). On living leaves of ivy. (Britain).

AUescher- describes other fungi on ivy.

Sph. Gibelliana (Pass.). On living leaves of Citrus limonum and C.
medica.

Sph. polypodii (Eabli.). On living fronds of Poli/podiuin vidgare, Aspidium
Filix-mas, Asplenium TrichomaneSy Pteris aquilina.

Sph. vitis Fuck. On withering vine-leaves.

^ Worth. (4. Smith, Gardejier'>i Chronicle, xxi., 1884.

2 AUescher, " Blattfleckenkrankheit d. Ephues," Zeitsch.f. Pfl.-krankheiten, 1895.

216 ASCOMYCETES.

Sph. sentina (Fr.) (U.S. America). In spring of 1891 this caused at
Geisenheini ' a severe spot-disease on the leaves of certain varieties of pear.

Other related species occur on pear.

There are numerous other sj)ecies of Sphaerella. Saccardo gives 279
species, many of which are probably more or less prejudicial to jjlant** in
orchard or gai'den. None, however, are recorded as very injurious.

Lae stadia. -

This genus is similar to SphaercUa, but has one-celled
conidia ; it is distinguished from Physalospora by the absence
of paraphyses.

L. maculiformis (Bon.) on living leaves of various trees.

L. (Physalospora) Bidwellii (Ellis) ^ (Britain and U.S.
America). The Black-rot of the Vine. This parasite attacks
all young organs and shoots of the vine. On the leaves the
symptoms are spots with dark sharply-defined margins, on which
the pycnidia appear later as minute black pustules. The leaves
die, but do not fall off, as with Sj^haccloma amjjclinvm. The
berries show disease when only the size of peas, and finally fall
off singly or in clusters. The grapes are not dusty with a
mealy powder, nor do they burst as in attacks of Oidivm
Tuckcri. Two kinds of pycnidia occur: one sometimes described
as spermogonia, has very small rod-like conidia, borne on thread-
like conidiophores ; these conidia have not as yet been seen to
germinate. The other pycnidial form {Plioma uvicola of Berk,
and Curt.) contains forked filamentous conidiophores, from
which one-celled ovoid conidia (stylospores) are produced and
soon germinate by emission of a septate hypha. The latter
form of conidia is produced after the spermogonia, and may be

* Geisenheim Jahrbuch, 1892.

-According to the laws of priority this genus must, as shown bj' Magnus
{Oesterrekh. hotan. Zeit., 1894, p. 201), be called Carlia. Bon.

" Bibliography : Cavara, Intorno al disi^ecamento dei yrappoli della vile, 1888.

Thiimeu, "Die Black-rot Krankheit d. Weintrauben." Alleg. Wdnzeitunrf,
Vienna, 1891. ,

Galloway and Scribner, Reports for 1888-89, U.S. Dept. of Agriculture.

Viala and Ravaz, Le-^i Progrts ar/ric. et vitirole. Montpelier, 1888-89.

Rathay (1), Dtr Blark-rot, 1891. With 19 figures (2). Berkht iih. eine nach
Frankreirh z. Erforschuiii/ d. Black-rot Krankheit Beise, 1891. With 7 figures (3).
Der White-rot in die Wcinlaube, 1892.

Viala. Die Krankheiten d. Weiiistockex.

Linhart u. Mezey, Die Krankheiten d. Wein.sforke'i, 1895 (Hungarian).

Lr..S. Dept. of Agriculture. Numerous references in reports and bulletins,
where details of treatment experiments will be found.

LAESTADIA. 217

found right on into autumn, even throughout the winter.
Hibernating sclerotia are also produced, the cells of which grow
out directly into septate conidiophores with oval conidia.
Perithecia, externally resembling pycnidia, are formed in May
and June on the fallen berries of the preceding year. The
asci have gelatinous walls, which swell and burst so as to
ejaculate their spores. Viala and Eavaz successfully infected
living grapes by means of the larger conidia, and also by
the germinating ascospores.

The disease is one of the most dreaded in America. It has
been found also in Europe, having been observed in France
since 1885, though not as yet in Germany, Switzerland, Italy,
or Spain. Moist situations are favouraljle to it. As with
other diseases of the vine, the various varieties have different
powers of resistance, and a judicious selection of varieties may
prove a good preventive measure. According to Yiala, the
black-rot is found in the United States on both wild and
cultivated vines, but never on the fruit of Vitis rivpestris, V.
Berlancieri, V. cincrca, V. Linsccomii, V. Ilonticola, and V.
candicans, and very rarely on their leaves. The "vine-stocks"
themselves suffer little or nothing from the disease. Eathay
says that Vitis rlparia, V. rupestris, and V. SoJonis, so im-
portant as grafting-stocks, are seldom affected ; the green
shoots of other species, however, may be attacked and the
disease be transmitted through the graft-slip.

For combating the disease, Galloway, Prillieux, and I'Ecluse
recommend Bordeaux mixture.^

Laestadia buxi (Desm.). The perithecia of this species are
found as tiny points on yellow spots on the lower surface of
green leaves of box. This fungus, regarded by Desmazieres as
saprophytic, is said by Briosi and Cavara to be parasitic.

PLEOSPOREAE.

Physalospora.

The perithecia are formed under the epidermis, but are
otherwise devoid of covering ; they contain asci and paraphyses ;
the spores are one-celled, and ovoid or elliptical.

1 For details see Eathay [loc. cit. ), the American bulletins, etc.

218 ASCOMYCETES.

Physalospora laburni (Boiiord.) nccui's on living twig.s of C'litima Lahxrnv.m.
Ph. fallaciosa Sacc. On withering leaves of Aletris and J/usa in Berlin
Botanic Garden.

Didymosphaeria.
Perithecia similar to Fhi/salospom, Ijiit with two-celled spores.

Didymosphaeria genistae Fuck, occurs on Genista pilosa.

D. epidermidis (Fries). On living branches of Berheris, Samhucus, Sah'x,
and E>'ca///pt)(><. (Britain and U.S. America).

D. albescens Niessl. On living branches of Lonicera XylosUum and
Myricaria germanica.

D. dryadis (Spe^azz.). On living leaves of Dryas octopetula. (U.S.
America).

D. populina Yuill. Prillieux and Vuillemin^ regai'd this as a parasite,
and the cause of a peculiar dying-off of Populus pyramidalis throughout
Germany ; Rostrup, on the other hand, ascribes this to Dotldora sphacriodes
Fr. Prillieux legards Xapidadmm trenudae as a conidial form of Didymo-
sphaeria ; Vuillemin, however, believes it to be saprophytic.

Venturia.

The perithecia are embedded in the stroma, and have stift"
bristles round the pore ; they contain both paraphyses and
eight-spored asci. The spores are two-celled, with or without
colour.

Venturia geranii Fr. occurs on the living leaves of Geranium pjusillum,
G. molle, etc.

V. rumicis (Desm.). On withering leaves of Rcme.i: (Britain).

V. maculaeformis (Desm.). On living leaves of Epilohinm.

V. vermiculariaeformis Fuck. On withered leaves of Euonymus europaeus
and Lonicera Xylosteum.

V. Straussii Sacc. et Roum. This I have found as a parasite on Erica
carnea in Tyrol. It is also .said to cause a disease on Ericaceae in France.

The various conidial forms at present placed amongst the
"Fungi imperfecti " as Fusidadiuin are probably related to
Vcnfvriri.

Fusicladium dendriticum AVallr. on apple, and F. pirinum
Lib. on pear, are at present the subject of an investigation at
the hands of Aderhold,- who has, on account of their perithecia,

^ Bidlet. de la see myrol. de France, 1892; Compf. rend, 1889; Eerw myroL,
1892.

2 Aderhold, "Die Perithecienform v. F^l■s. dendriticum'' Vorlaufig Mittheilung,
Ber. d. deutsch. botan. Ges., 1894, p. 338.

VENTURIA.

219

placed them in the genus Vcnturia. His investigations are,
however, not quite complete.

The scab or black spot of apple and pear is a very familiar
disease in America and elsewhere. It attacks leaves, young
shoots, and fruits. Dirty greenish spots appear first, then enlarg-
ing, they run together, and darken in colour till almost black. If
the attack occur on young foliage, it may be dwarfed and killed ;
the newly-formed fruit will in such cases be attacked, shrivel
up, and fall. If the attack be deferred till the foliage and fruit
are well advanced, then spotting results and the fruit remains
hard, perhaps cracks. The conidia are oval, unicellular, and
yellowish-brown ; they are produced from short conidiophores

Fig. 10". — Venturia {Fusicladium) dendritic am forming brown spots on an
apple ; those still in the earlier stages have a radiate margin and bear conidia.
The enlarged section shows two rows of large-celled parenchyma of the apple,
covered by a stroma of pseudopai-enchyma bearing conidiophores and conidia.
(v. Tubeuf del.)

with warty prominences which grow on spots of leaf or fruit
(Fig. 107). The perithecia (as yet described) are distinguished
by black bristles surrounding the pore, and occur on fallen
leaves. The asci contain eight greenish ovoid spores with two
or three cells.

In addition to the injury to leaves and destruction of young
fruit, the disfiguration of the apples is a cause of considerable
monetary loss. Dilute Bordeaux or copper sulphate mixture
applied before the opening of buds, and once or twice after

220 ASCOMYCETES.

" setting " of the fruit, is recommended. No fungicide should,
however, be applied towards tlie ripening season.^

Gibellina.

The spherical perithecia are embedded in the stroma, their
necks projecting. The asci contain eight brownish spores,
oblong or spindle-shaped, and bicellular.

Gibellina cerealis Pass. This parasite of wheat has hitherto
been fairly common in Italy ; recently it has appeared with
disastrous effect in Hungary. According to Cavara, it produces
on the under part of the stems, grey plate-like coatings w^ith a
brown margin ; these may remain as spots, or enlarge till they
form a ring round the stem. The perithecia are little black
points arranged in rows, and embedded under the epidermis,
except the black projecting necks. The asci have thin walls and
break up inside the perithecia ; they contain eight spores arranged
in two rows. The spores are spindle-shaped and bicellular, but
their germination has not as yet been observed. The mycelium
is found in all the host-tissues, besides forming a stroma-like
sheath round the stem. The plants attacked l^ecome brown and
limp in early summer, and no fruit is produced.-

Cavara recommends early removal and burning of affected
stems, and the cultivation of crops other than cereals on the
infected ground.

Leptosphaeria.

Perithecia black, rarely with bristles ; at first they are em-
bedded in the host, without a stroma. The spores occur four to
eight in each ascus ; they are spindle-shaped and generally
multicellular by means of cross- walls only. Thread-like para-
physes are always present.

Leptosphaeria herpotrichoides de Not. This species, gene-
rally regarded as a saprophyte, was found by Frank ^ as a
parasite on rye. The stalks attacked break over at a node or

' Further details of treatment-experiments are given in Gall and Scribner's
" Report on Experiments for 1889," U.S. Amer. Depf. of Afjriat/fnre BuUetin ii. ;
also in the Bulletins of various Experimental Stations. Tlie above account has
been considerably extended by aid from the American literature. (Edit.)

-Cavara (ZeiUchrift f. Pflanzenkranl-htiten, in., 1893, p. 16) gives a detailed
account of this fungus with illustrations.

■'Frank, Zeitschrift f. Pflanzenkrankheiten, 1895.

LEPTOSPHAERIA. 221

just over the root, thus resembliug the symptoms accompanying
an attack of Hessian Fly.

L. tritici Pass, is said by Frank t<:> be destructive to wheat in Germanv.
(See also Cladospomi.m).

L. subtecta Wint.^ In Tyrol the perithecia of this sjjecies accompany
disease of the leaves of Erica carnea. Simultaneously Hypodenna ericae
Tub. and Sphaeria ericina Tub. were found, the former appearing to cause
the disease (see jj. 234).

L. anceps Sacc. On living branches of Riles nigrum.

L. vitigena (Schulzer). On living tendrils of the vine.

L. circinans Sacc. (see Rhizoctonia p. 201).

L stictoides Sacc. on Liriodendron tulipifera is an American species.

Pleospora.

The black perithecia are not developed on a stroma, and
are at first concealed in the host-tissues only. They contain
paraphyses and eight-spored asci. The spores are multiseptate,
and generally coloured.

Pleospora hyacinthi Sor.- produces black coatings on the
bulb-scales of hyacinth. The mycelium inside the tissues is
colourless, but outside is dark red, and its presence causes disease
of healthy parts. Certain perithecia which appear on the bulb-
scales in autumn may perhaps belong to this fungus.

P. tropaeoli Hals, is given as a disease of Tropaeolum in U.S.
America.'^

P. hesperidearum Catt. The conidial form {Sporidesmium
hesp.) appears as a black coating on the orange.

P. ulmi Fr. {var. minor) Allescher, causes a leaf-.spot on young
elm-seedlings, and the leaves drop off prematurely.

P. napi Fuck, is the cause of rape-smut. Leaf-spots carrying
conidial cushions {Sporidesmium cxitiosum Kilhn) appear on the
rape and other allied root-crops.

Other " black smut-diseases " have been ascril )ed to Polydesmus (Spori-
desmium) exitiosum {var Dauei) on carrot ; Helminthosporium gramineum
Eabh. causing withering of rye and barley leaves ; and Sporidesmium
putrefaciens Fuck, which attacks and kills the youni:' lieart-leaves of beet-
root.

'v. Tubeuf, Botan. Centralblatt, xxi., 1885.

-Sorauer, Handhiich d. Pflanzenh-ankhtittn, ii. Aufl., p. 340; and Unfersuch.
i'lb. die EimjeUcranhheit u. d. Russthait d. Hyacinthen. Leipzig, 187S.
^N. Jersey Agric. Exper. Stat. Report, 13, 1892.

2.-rj. ASCOMYCETES,

Dilophia.

The genus is parasitic and causes swellings. The perithecia
remain permanently embedded in tlie tissues of the host-plant.
The asci contain eiglit transparent, thread-like, finely-pointed,
multicellular spores.

Dilophia graminis Sacc. (Britain). This causes deformity of
the leaves and intlorescences of wild grasses ; also of rye in
France, and wheat in England and Switzerland. Fuckel assumes
a relationship between this species and Dilopliospora graminis
Desm., but this we regard as doubtful.

Ophiobolus.

Perithecia scattered and almost spherical ; they contain para-
physes and eight-spored asci. The spores are hyaline or
yellowish, thread-like, and unicellular or septate. The fungus
is minute and inhaltits stems and haulms.

Ophiobolus graminis Sacc. was indicated by Prillieux,
Delacroix, and Schriliaux as the cause of a cereal disease in
France. The cereals attacked broke over very easily near the
ground ; they continued to develop, but produced ears of a poor
quality, and often quite withered. The disease was designated
" maladie du pied des cereales," and described in Jour. (VAgric.
practique, 1892; also under the name "la maladie du pied du
ble " in Travcmx du labor, de pailiol. vegdtale inst. agronom.,
1890. The perithecia have a curved lateral beak; the asci
contain eight long, spindle-shaped, multiseptate spores.

Frank also records this disease as injurious to wheat in
Germany in 1894.

GNOMONIEAE.

Gnomonia.

Perithecia without a stroma, and generally remaining
embedded in the host-tis.su es, with only a beaked opening pro-
jecting ; they contain no paraphyses. The asci have a thickened
apex with a fine central poie. Tlie hyaline spores consist of
from one tu four cells.

Gnomonia erythrostoma Auersw.^ This is the cause of an

1 Frank, Ber. d. dm/sch. holan. Ges., 1S86 and 1887; also Zeitschrift f.
Pjianzenkrankheiten, 1891.

GNOMOXIA. 223

epidemic disease of the cherry (Prunus avium and P. Cerasvs),
observed for several years past in Xorth Germany and else-
where. The fungus attacks the leaves, and there the mycelium
grows. The leaves wither prematurely, but remain all winter
hanging from the tree by a reddish-brown mycelium. Pycnidia
and perithecia are produced in the leaves, the latter reaching
maturity in spring, when the two-celled ascospores are ejaculated.
The pycnidia contain short conidiophores bearing hook-shaped
conidia. The fruit is also attacked, and ripens unequally, so
that the cherries are distorted : then they crack and rot.

Frank has succeeded in carrying out artificial infection. This
takes place in June, and immediately on germination the gerni-
hypha produces an attachment-disc on the host-epidermis, whence
a hyphal tilament penetrates the epidermal wall, grows through
the cell, and reaches an intercellular space. A thick septate
mycelium is formed and spreads, especially amongst the spongy
parenchyma. There is no stroma, and the perithecia hibernate
on dry leaves.

Frank recommends the plucking and burning of dead leaves
hanging on the trees. This must of course be done throughout
the whole district attacked. In one part of Prussia (Altenlande)
this precaution was taken twice each winter for two years,
with the result that the disease, which had long completely
ruined the cherry crop, disappeared, and the harvest increased
to its former amount.

Gnomonia quercus-ilicis Berl.^ causes brown spots on leaves
of Qhc/'cus Ilex.

VALSEAE.

Mamiania.

Perithecia produced in a black stroma, from which their long
necks project. The asci have a thickened apex, and contain
eight oval hyaline spores with one or two cells.

Mamiania (Gnomoniella) fimbriata Pers. (Britain and U.S.
America). The stromata of this appear in summer as little
black cushions on the leaves of the hornbeam {Carjnnus). The
perithecia are developed in these spots, and tlieir long black
beaks projecting distinctly above the surface of the leaf cause

^ Berlese, BivUta di Pato/ogia vegefale, i.

224

ASCOMYCETES.

rupture of the epidermis. Numerous leaves may be diseased
and each carry many cushions, yet Vuillemin, who described
the disease,^ does not believe the host-plant is affected to any
serious degree.

M. (Gnom.) coryli IJatsch. (Britain and U.S. America). The
black sLiumata are found in withered spots on the leaves of
hazel {Coryhis) ; as a rule, each stroma carries only one peri-
thecium witli a long beak similar to that of M. Jimbriata.

Fig. lOS. — Mo.miana fihibviala on Carpinua Betx'.lvs. Leaf of Hornbeam seen
on lower surface. Stroma (enlarged), with the long black necks of the perithecia
projecting from the ruptured leaf-epidermis, (v. Tubeuf del.)

Valsa.

A stroma is generally present, but is of very variable appear-
ance ; embedded in it are the perithecia, with only their beak-
like mouths projecting. The spores are hyaline or light-brown,
unicellular, and generally bent. Xo paraphyses are present.

Valsa oxy stoma Eehm.- This causes disease and death of
branches of Aim's viridis in the Alps. The symptoms are
withering and drying up of single branches on an otherwise
green bush. This disease causes severe loss in the Tvrol,

1 Titres et travaux scientijiques, 1890.

^v. Tubeuf. " Zwei Feinde d. A\]yGner\e,'' ForstUch-natw-H-i'iS. Zeitschrijt, 1892.

VALSA.

225

where leaves of the alder are dried in summer for use as
winter-fodder for goats.

In the branches attacked, a mycelium is developed in the
vessels of the wood, whereby the supply of water is stopped
and the bark dries up. Black lens-shaped stromata arise
under the epidermis of the twig and rupture it. The perithecia
are produced under the stromata in the bark, and communicate

oo

OG

K-

Fig. 109.— Fa/«a oxystoma on Alnus viridls. A, Portion of branch with stroma
of Vaha breaking through the periderm at four places. B, Enlarged section
through a stroma from A. C, Asci and ascospores, isolated from a perithecium.
D, Portion of younger branch with periderm ruptured by stromata, in which,
however, the perithecia are not yet developed. E, Enlarged section through a
stroma of D. (After v. Tubeuf.)

with the exterior by means of long projecting necks. The
asci contain eight unicellular spores of a slightly bent, rod-
like shape. Maturity is reached on the dry dead twigs.
Externally this disease is identical in appearance with one
I ascertained to be due to a beetle {Cryptorliynchus lapaflii),

226 ASCOMYCETES.

the larva of which bores canals in the wood of alders, birches,
and willows, causing them to die.

Most of the other species of Valsa cause only leaf-spot, or
occur on dead leaves,

Anthostoma.

The perithecia are embedded in the substratum or stroma,
and have generally long necks. The asci contain eight brown
or black, oval, unicellular spores. Paraphyses are always absent.

Anthostoma xylostei (Pers.) occurs on living and dead
branches of Lonicrra Xylodeuvi. (Britain).

Anthostomella pisana Pass, lives on leaves of Chamerops humilis and
kills them.

DIATRYPEAE.

Calosphaeria.

Xo stroma is formed, the perithecia arising singly or in
groups in the bark under the periderm ; th ey have often long
beaks. The asci are club-shaped, and frequently long-stalked ;
they contain eight or more spores, which are little, unicellular,
and somewhat curved.

Calosphaeria princeps Tul. occurs on living branches of
cherry and plum. (Britain and U.S. America).

Quaternaria Personii Till, has black perithecia and, according to Will-
komm, causes death of twigs of beech. (Britain and America).

MELANCONIDEAE.

Aglaospora.

The perithecia are beaked and embedded in the stroma. The
spores are furnished with appendages.

Aglaospora taleola Tul.^ {Diaporthc takola Fries, and pro-
bably nearly related to those Melanconi with appendages on
their spores, e.g. Mel. thelebola, previously known as Aglaospora
thel. Tul.). (Britain and U.S. America). This fungus causes
a disease of twigs and young stems of oak which have not

^ R. Hartig, " Eine krebsartige Rindenkrankheit d. Eiche," Forstlich-naturwiss
Zeitsclirift, 1893.

AGLAOSPORA.

227

Fig. 110. — Examples of Oak-stem attacked by Aglo.oipora taleola. 1, Portion
diseased for two years ; a, the portion still healthy ( x \). 2, Portion diseased
for four years ( x -5). 3, Section with spots diseased for four, seven, and ten
years respectively ( x y). (After R. Hartig.)

228

ASCOMYGETES.

as yet formed a bark. Portions of the rind become brown,
dry up, and peel off; this on stronger twigs may be followed
by a more or less complete occlusion of the wounded part.
The browning also extends into the underlying wood. The
mycelium is found both in rind and wood, where it probably
obtains entrance through small wounds in the bark. In the
second year after infection, a circular stroma is formed in
the bark under the periderm. Sickle-shaped conidia are

Fig. 111. — Acilaospora ialeola. Portion of cortex with embedded stromata.
«, Corky layer; h, after removal of corky layer; c, section of stroma. ( x f.)
(After Hartig.)

ff;tst)5-*«*»*»« (k.-'''-^*

Fio. 112.— Section of stroma of ^e'?nos7?om. a, Boundary
of stroma formed of dark brown fungu.s- mycelium ;
h, sclerenchyma-strand of the cortex ; c, conidial cushion ;
rf, union of necks of two perithecia. (After Hartig.)

Fig. 113. — n, Conidia; 6, asco-
spore of Agki.ospora toJ.eola
( X ^^). (After Hartig.)

superficially abjointed from the stromata; while embedded
in it are groups of perithecia with necks which join together
into one or a few common channels opening externally. The
asci contain eight spores, which are two-celled and bear five
thread-like appendages, one on each end, and three round the
median septum (Fig. 113).

AGLAOSPORA. 229

Ag". profusa Fr. (Britain and U.S. America). This occurs
along with, and probably is some form of DothiorcUa rohiniae.
Prillieux and Delacroix ^ blame it for killing young twigs of
Rohinia pseudacacia in France.

Fenestella.

The stroma is similar to Eu- Valsa, and contains several
long-necked perithecia. The spores, eight in each ascus, are
coloured and multiseptate, as in Cucurbit aria.

Fenestella platani Tav., to this is probably related Gloeo-
sporium nerviseqimim (Fuck.), the cause of a disease on the
leaves of Platanus, and described under Gloeosporium.

(3) DOTHIDEACEAE.

Phyllachora.

The perithecia are small and produced in a black stroma
buried in the tissue. The asci contain eight hyaline, oval,
and unicellular spores.

Phyllachora graminis (Pers.). (U.S. America). This species
causes elongated black swellings on grasses and sedges (Luzula
and Carcx). The black perithecia occur massed together, and
embedded in the leaves. The asci contain eight hyaline uni-
cellular spores.

Ph. trifolii (Pers.), with conidial form known as Polythrincium
trifolii Kunz. (Britain and U.S. America). The mycelium
causes the formation of roundish dark spots on the green
leaves of clover frequented by it, and death ultimately follows.
On the spots, especially those on the lower epidermis of the
leaf, the conidiophores make their appearance as brown septate
structures, constricted at intervals so as to become rosary-like ;
they bear terminal, brown, two-celled conidia, the upper cell
of which is somewhat spherical, and larger than the lower.

Ph. cynodontis (Sacc). On living leaves of Cynodon Dactylon.
Ph. podagrariae (Rotli.). On living leaves of Aegopodium Podagraria
(Britain).

Some other species are found on withering leaves.

^Bulletin nor. myrol. de France, 1890.

230 ASCOMYCETES.

Diachora onobrychidis (D. C.).^ This fungus is common
on sainfoin (Ouabft/chis mtiva) and Lathyrus tuhcrosus, causing
black spots on both surfaces of the leaf. During summer
pycnidia arise on the spots, and from them are produced spindle-
shaped conidia (spermatia) with tail-like appendages. Later
there arise spherical perithecia containing usci arranged in tufts
on the walls. The asci contain eight oval, hyaline, unicellular
spores.

Dothidella.

The perithecia are black and embedded in the stroma,
similarly to Plii/UacJiora. The pale-coloured spores are, how-
ever, two-celled.

Dothidella betulina (Fries.). (Britain and U.S. America.)
The black stromata form spots on the upper surface of
birch leaves. In these the perithecia arise, and reach maturity
in spring. The asci contain eight elliptical greenish spores,
consisting of two unequal cells with rounded-oft' ends.

D. ulmi (Duv.). (Britain and U.S. America.) A species
similar to the preceding, and causing round blistered spots
of a grey colour on the upper surface of elm leaves. Pycnidia
{Piggotia astroidea) are formed in summer, perithecia in the
following spring.

Dothidea.

The stromata have the form of black projecting cushions,
in which numerous perithecia are embedded. The asci contain
eight greyish or brown spores, consisting of two cells with a
constriction between them.

Dothidea virgultorum (Fries.) attacks living branches and
stems of birch, and develops further on the dead parts. The
stromata originate in the wood, then breaking through the
bark, make their appearance externally as large black cushions.
Whole stems may be covered by these cushions.

D. sphaeroidea (Cke.) occurs on living needles of juniper.

Plowrightia.
The stromata are black, and run together in masses. The
asci are eight-spored ; the ascospores ovoid or oblong, hyaline
or light yellow, and two-celled.

'J. Mtiller, Pringsheim's Jahrhuch, 1S9.3.

PLOWRIGHTIA.

231

Plowrightia morbosa (Sch.) (Britain and U.S. America).
Black-knot of the plum tree.^ In America this is a very

Fig. Wb. — PloKfirjhtia mor-
Ijosa. Ascus, with eight
spores. Spores in germina-
tion. Filamentous para-
physes. (Cop. from Farlow.)

Fig. 114. — PloKcightia morbosa. (v. Tubeuf phot.)

injurious and widely distributed disease of various species of
Prunus, especially plum and cherry. The living branches and
twigs become coated with a crust of warty excrescences, and
at the same time are more or less thickened and deformed.
A mycelium permeates the tissues of those swollen twigs, and
forms black crusty stromata in which the perithecia are
embedded. The perithecia contain simple paraphyses and eight-
spored asci. The spores consist of a larger and a much smaller
cell. (Pycno-conidia are produced frequently in artificial culture,

1 Farlow, Bulletin Bussey Institution, Part v., 1876.
Humphrey, Anmial Report of Mass. Exper. Station, 1890.
Lodeman (Cornell Univ. Exper. Station, Bulletin No. 81, 1894) gives
general account of Black-knot and a Bibliography.

232 ASCOMYCETES.

but are rarely found in natural conditions ; as yet infection
with these lias had no result.)

[Remedial treatment must be promptly applied. Trees liable
to attack should be frequently examined, so that any young
knots may be early removed. If the disease is of long standing,
the only remedy left is to remove all knotted branches and
burn them immediately.] (Edit.)

HYSTEKIACEAE.

The ascocarps of the Hysteriaceae, like those of the Discomy-
cetes, are known as apothecia. They are distinguished from
those of the Pyrenomycetes and Perisporiaceae in that
the ascocarp, although formed in or under the epidermis of
attacked plant-organs, is not a closed structure or flask opening
by a pore only ; it is, indeed, at first completely closed, but
later it, as well as the epidermis covering it, splits open and
freely exposes the whole hymenium. So long as the apothecium
is closed, it is filled with paraphyses, between which the
developing asci gradually wedge themselves. The spores
are generally thread-like, with a gelatinous membrane. The
mycelium lives intercellular, and is often parasitic in living
plants. The apothecia, however, only reach maturity on parts
which have been killed. In addition to apothecia, little pycnidia
(spermogonia) are formed, containing small unicellular conidia.
The Hysteriaceae include the Hystcrincae, Hypodcrmuac, Dicliac-
naceac, and Acrosj^ermaceae.

HYSTERINEAE.

Hysterographium.

Apothecia black, highly vaulted, and dehiscing by a linear
fissure. The asci are club-shaped and thick-walled ; they con-
tain eight multicellular spores, which are at first transparent,
but later dark-coloured. The branched paraphyses of the
upper part form a coloured epithecium.^

Hysterographium fraxini (Pers.) (Britain). This occurs on
various Oleaceae and some other species of woody plants.

^ The excipulum of De Bary.

HYSTEROGRAPHIUM.

233

Eostriip ^ regards it as a parasite on Fraxinus. Twigs of the
ash attacked show flat collapsed plates of bark, on which are
developed pycnidia containing one-celled conidia, and, later,
the apothecia. On young twigs the diseased part often extends
round the whole circumference, and causes the death of the
upper living part. As yet I have only found this fungus as
a saprophyte.

HYPODERMIEAE.

Hypoderma.

The apothecia are oblong, and at first closed by a thin black
cover, which opens by a long fissure. The asci are sessile in

Fig. 116. — Hypoderma strobicola on Pinus
Strobiis. Ascus containing eight ascospores
■with gelatinous coats ; paraphyses with
clavate ends. (After v. Tubeuf.)

Fig. \\~ .—Hypoderma strobicola. Isolated
ascospores : with and wlthovit a gelatinous
coat, and one- or two-celled. (After v.
Tubeuf.)

some species, but have a delicate stalk in others. The spores,
eight in each ascus, are never long and thread-like, but always
much shorter than the asci, and two-celled when mature. The
paraphyses have button-shaped or hooked ends.

Hypoderma strobicola- (Rostr.). Needle-blight of the Wey-

1 Rostrup, Fortsattt Undersoegdstr ov. Siiyllesvampes Angreb pact Skov-
traeerne, 1883.

-Rostriip, Fortsatte Under-ioegel^er, 1883.
V. Tubeuf, Beit. z. Kenntniss d. Baumkrankheiten, 1888 ; also Botan.
Centralhlatt, XLi,, 1890.

Note : When I decided to place Lophodermium hrachysporum under the
genus Hypoderma, there already existed a Hypoderma brachy-tportwi Speg.
(1887). For the future I shall therefore call Loph. hrachysponon Rostr. as
Hypoderma strobicola.

234

ASCOMYCETES.

mouth pine. Accordinif to the observations of Kostrup in

Denmark, and myself in various localities of Germany, this
is a dangerous parasite on Pinus Strobus.
It kills the needles and young shoots,
and may devastate whole tracts of forest.
The diseased needles become brown in
summer, and fall ofi" during next winter.
On them are produced apothecia containing
club-shaped asci and paraphyses with button-
shaped ends. The eight spores of each ascus
are at first unicellular, later apparently bi-
cellular, and enclosed in a very mucilaginous
coat. The asci have an average length of
120 fJL, the spores 20 jul, and when swollen
28 to 30 m.

H. pinicola Brunch.^ forms linear apothecia
on needles of Pinus sylvcstris.
H. ericae Tubeuf.- In Tyrol and Northern Italy, this fungus

causes a disease on Erica carnca. It is common and epidemic,

causing death of the leaves.

Fig. I18.--Leaf of ^cica
carnea with apothecia of
Hjipoderma ericae on the
lower surface. 1, An
entire and a dehiscing
ascus ; a two-celled aseo-
spore. (v. Tubeiif del.)

Hypodermella.

Similar to Hypoderma, except that the spores are pear-shaped
and unicellular ; they occur four in each ascus, and are shorter
than it.

Hypodermella sulcigena (Link)" has four long, club-shaped,
unicellular spores. Eostrup regards it as parasitic on Pinus
montana and P. sylrcstvis, its mycelium being found in living
green needles, and causing their death.

' Hyp. laricis Tubeuf.- This is a new fungus of the larch-
needle I'ouiid by Tubeuf on the Sonnenwendstein (Bavaria) in
September, 1894. It was present in large quantity on larches
on the upper part of the mountain, and was in every way so
decidedly parasitic in character, that there is little doubt as to
its being an epidemic disease. The full-grown needles on many
of the foliar spurs had died off and turned brown. The

^ Brunchorst, Xo(/fe norskc skorsytfdomnie in Bergom Mu>i., 1892.
-v. Tubeuf, Botan. Centralblatt, xxi., 1885, and LXI., 1895.
^Rostrup, Fortmtte Undtrsoeridser, 1883.

HYPODERMELLA.

235

apothecia were present on the upper surface of the needles as
isolated black spots or united into lines ; they dehisce by an
elongated fissure. The asci are cylindrical with rounded apices,
and measure about llO/w in length; they are almost sessile.
Each contained four hyaline, unicellular, club-shaped spores

Fio. 119. — Hiipodermella sulcigena. The
apothecia form black lines on the needles.
Ascus containing four spores (enlarged).
Single spore with a gelatinous covering
(still further enlarged). (Cop. from
Rostrup.)

Fir,. 120. — Hypodenndla lands. Larch-
needle with apothecia on the under side.
A, Paraph yse, and an ascus containing
four spores. B, Isolated (enlarged) asco-
spore in its gelatinous coat. (v. Tubeuf
del.)

(66/u X 16yw) with a gelatinous membrane. The paraphyses
are simple hyaline filaments, shorter than the asci.

Lophodermium.

The oblong apothecia are embedded in the host-tissues under
a thin black cover, which breaks by a long fissure. The club-
shaped asci contain thread-like unicellular spores, with a
mucilaginous membrane. The paraphyses are sometimes septate
and furnished with hooked or button-shaped ends. The spores
reach maturity on killed portions of plants, and are forcibly
ejaculated. The formation of pycnidia (spermogonia) precedes
that of apothecia. Many members of this genus are destructive
enemies of plants.

Lophodermium pinastri (Schrad.).^ Pine-blight or needle-
cast. (Britain and U.S. America.) This disease of the Scots pine
{Pimts sylvestris) is very injurious to young plants, especially
those in nurseries.

^Hartig, Diseases of Trees, Eng. edit., 1894.
Prantl, Flora, 1877 ; also, ForsUciss. Ctnlralhlatt, 1880.

236 ASCOMYCETES.

" Casting " or premature withering and tall of needles is not
uncommon in nurseries of pine. Amongst some of the causes
which lead to tliis are:^ frost, drought in winter on frozen
ground free from snow, drought in summer on dry soil, over-
crowding of plants in the nursery, and, finally, a " casting " due
to fungi.

The symptoms in the case of the present fungus are spotting
and withering of the needles, due to the presence of a mycelium
inside them. In early autumn, or later if the weather be dry,
the pycnidia (spermogonia) make their appearance as little black
prominences containing tiny unicellular conidia. The tiat black
apothecia are developed later, on first-year seedlings during
the first autumn, or on older plants during the second autumn,
but generally they do not appear till the third year ; they
reach maturity on needles still attached, more frequently, how-
ever, on fallen ones. Dehiscence consists in the rupture of
their delicate black covering, through pressure of the swelling
asci and spores in damp weather. The asci are club-shaped
and contain eight thread-like one-celled spores, more or less
twisted round one another. The septate paraphyses have a
slightly bent point.

Diseased seedlings die olf, generally without loss of their
leaves. Two-year-old and older plants are always weakened by
the loss of needles, and in severe cases are killed. On such,
the " casting " or sudden fall of all infected spurs and needles
takes place in spring. The mycelium often makes its way
from the needles into the tissues of the shoot, and then death
of the whole plant soon follows. Disease of the needles of
old trees may also occur without inflicting much damage on
the trees themselves ; they will, however, act as centres for
infection of younger plants, particularly those in seed-beds
and nurseries in the vicinity.

Confirmatory experiments on infection of pines by this
Lopliodcnninm were first carried out by Prantl, later by Tursky
and Hartig.

The disease appears with such virulence and frequency, that
the whole of the young pine-growth of a locality may be
destroyed. It is thus a most dangerous disease, and at the
same time one difficult to combat. Districts which have

' Holzner gives a summary of numerous theories on leaf-cast, (Freising, 1877).

LOPHODERMIUM.

'237

suffered by it should, where other soil conditions permit, be

planted with Weymouth pine {Pinvs Strohus) and the Douglas

fir {Pmudotmga Douglasii), which are, as yet, exempt from

attacks of this parasite. Infection would seem to be brought

about chiefly by westerly winds (in Germany), which carry

diseased leaves or fungus-spores from infected

places. Large areas run greater risks than

small patches or young trees naturally sown

out. Seed-beds of Scots fir should not be

placed under the drip of older trees of the

same kind, particularly if this fungus is

known to exist there. Shelter- belts of other

trees often afford much protection from this

disease.^

Lophodermium macrosporum Hartig ^
{Hysteriurii). (U.S. America). Scab or rust
of the spruce. This disease exhibits itself
in various ways. Frequently the needles of the preceding
year turn brown in spring, and perithecia are produced in

Fig. 121.— 1, Lophoder-
'iidv.rii macrogporuni on
Spruce, (v. Tubeuf del.)

2, Lophodemiiiim ahi-
etis on Spruce. (After
Rostrup.)

Fig. 122. — Lophoderniium macrogporum. Section through a mature dehiscing
apothecium. (After R. Hartig.)

summer, reaching maturity on two-year-old needles. Again, the
needles of the two-year-old shoots become brown in autumn,
and perithecia appear on them in the following summer,

^ Preventive measures are discussed in greater detail in Prof. Somerville's
translation of Hartig's Diseases of Trees, p. 115.
^ R. Hartig, Wichtifje Krankheiten d. Waldbdume, 1874.

238

ASCOMYCKTES.

ripening in the spring of the fourth year. Or, again, a
"casting" of brown one-year-old needles may take place in
autumn.

The disease is found everywhere, but in some parts {e.g. in
the forests of Saxony ^), it is exceedingly common and very
dangerous. The apothecia ai'e developed as long, shining, black
swellings on the two under surfaces of the quadrangular needles
(Fig. 121). The club-shaped asci emit
thread-like spores with gelatinous coats.
The ascospores produce a strong germ-tube,
which grows inside the needles to an
intercellular mycelium without haustoria.
Browning and shrinkage of the cells of
attacked needles soon follow. The myce-
lium also penetrates into the cells of the
epidermis, and develops there a coil of
hyphae, which, under a black membranous
cover, forms an apothecium containing
paraphyses and club-shaped asci (Fig.
122). When ripe, the apothecia rupture
the overlying epidermis. Little black
pycnidia (spermogonia) may also occur on
diseased needles.^ On needles which have
been prematurely cast, only little spherical
apothecial knobs will be found.

According to Hartitf, the effects of this
fungus on the cells of attacked needles is
very interesting. If the disease of the
needles appears in autumn, the cells, which
at this time are void of starch, become
brown and die. If the disease attacks in May, when the
needles are rich in starch, their death ensues soon, but the
starch only disappears gradually from October onwards, as it
is used up l^y the fungus-hyphae. If the disease appears in
spring, when starch-storage is just beginning, the cells already
attacked become quite full of starch, whereas the other cells of
the same needle remain empty.

' Nobbe, Ber. cl. sdchsisches Forstvereins Versa7nmlung zu Scha7idau, 1891.

-Another ascomycetous fnngus — Naevia piiiiperda Rehm — occurs alone or
together with this species ; Rehm regards it as parasitic (Hedicigia,1892, p. 302).

Fig. 123. — Lophodermium
macrosporum on Spruce.
■Germinated ascospores ;

some have germinated
inside the ascus. (After
R. Hartig.)

LOPHODERMIUM.

239

Lophodermium nervisequium (D. C.)^ (U.S. America). This
very common fungus attacks both old and young silver firs.
The needles die after becoming brown, and remain for a long

1/

1

Fig. 124. — Lophoderhiium nervisequhun
■on Abits pectiiiata (Silver Fir). 1, Under
surface of needle with apothecia. 2,
Upper surface with pycnidia.

Fig. 125. — Lophodermium nerciseqv.ium. Section
of a needle of Silver Fir. h, Pycnidium on
upper surface shedding conidia. o, Apothe-
cium on the lower surface. (After R. Hartig.)

Fig. ]2i3. — Lophodermium nervisequium on Silver Fir. Portion of a ripe apothe-
cium. a a, Filamentous paraphyses ; rod-like cells (conidia?), k, ahjointed from
the apex of the paraphyses ; the asci contain eight spores about half as long as
the ascus itself, four occupying the upper half, four the lower ; c, a rudimentary
ascns ; some mature spores possess a gelatinous coat, others do not ; sfiores
escape by an apical opening, e, or by rupture of the ascus./; two gei-minating
spores are also shown, one with a gelatinous coat, the other without. (After
R. Hartig.)

time hanging on the twigs. The disease varies in its develop-
ment on the mountains and lowlands, according to climatic
■conditions.

^ R. Hartig, Wichtige Krankheiteii, 1874.

240 ASCOMYCETES.

The mycelium lives intercellular, and produces the same
effects on the cells of the fir-needles as those of Loj^h. macro-
sporum on the spruce. The mycelial hyphae penetrate into the
epidermal cells and form a cushion, which bursts the epidermis
and gives rise to numerous straight conidiophores, with very
small, oval, unicellular conidia. The apothecia are developed
while the needles are on the tree or after they have fallen ;
they form shining black stripes on the middle nerve of the
lower surface of the needle (Fig. 124). The thread-like spores
have a mucilaginous coat, and are ejaculated from clvib-shaped
asci (Fig. 126). Pycnidia (spermogonia) are often produced
before the apothecia as long wavy bands on the middle nerve
of the upper surface of the needle (Fig. 125).

L. juniperinum (Fries.) (Britain and U.S. America). A
common species on dead needles of J^tniper communis, also on
needles on the branch ; I have, however, never seen it in such
mass as to believe it to be a dangerous parasite.

L. gilvum Rostrup ^ attacks and kills living needles of the
Austrian Ijlack pine.

L. laricinum Duby. The pycnidia and apothecia of this
fungus are common on dead needles of larch, but parasitism has
not been proved.

L. abietis Eostr. A species found by Eostrup on needles of
spruce, causing yellow spots and then large black points (Fig.
121, 2).

DISCOMYCETES.

The Discomyeetes have an apothecium of varying shape, but
always more saucer-like than spherical. The ascocarp, at first
a closed structure, opens sooner or later and exposes the
hymenium. The apothecium is composed of two distinct portions
of mycelium. The essential part, often called the hymenial
layer, consists of hyphae which give rise to the asci. The
remaining portion of the ascocarp forms a support or envelope
for the hymenium; it consists of a pseudoparenchyma, and may
be differentiated into a sub-hymenial layer or hypothecium with
its hyphae interwoven with those of the hymenium, and a
lateral portion or excipulum usually more or less cup-shaped.

^ Rostrup, Fort sat te Under soegtlser, 1883.

DISCOMYCETES. 241

The paraphyses are developed from the mycelium of the
envelope and occupy the interior of the ascocarp, while the
asci arise later from the ascogenous hyphae and force their way
in. The formation of asci and paraphyses may go on for a
long time. Periphyses are not produced.

The Discomycetes include five divisions, the Phacidiaceae,
Stictidrac^ Tryhlidieac, Dermateaceae, and Pczizeac. Many of
the species included in these are parasitic on cryptogamic
plants to form lichens, the majority are saprophytes, and only
a few isolated groups are true parasites on higher plants. The
latter belong to the Phacidiaceae, Dermateaceae, and Pczizeac.

(1) PHACIDIACEAE

The apothecia are black and thick-walled, at tirst embedded
in their substratum, but later breaking through it. The asco-
genous layer is spread out on a delicate flat hypothecium.
The black apothecia of the species of Phacidium are frequent
on leaves and needles. Eehm divides the group into two
families : the Puphacidieae and the Pseudophacidieae.

EUPHACIDIEAE.

The apothecia are embedded in the tissues of the host ; the
superincumbent layers of the substratum forming over them a
blackish membranous plate, which is ruptured into lobes and
exposes the black apothecial disc.

Phacidium.

The apothecia are fused with the superincumbent layers of
the host-plant, and the black cover so formed is split into
several lobes. The club-shaped asci contain eight colourless,
unicellular, ovoid or spindle-shaped spores. The paraphyses
are filamentous. The pore of the ascus is coloured blue by
iodine.

Phacidium repandum Fr. (Britain). Occurs on living leaves
and stems of AspcralcL odorata, Galium mollugo, and other
Eubiaceae. The pycnidial form is probably Phyllachora
jpunctiformis Fr.

Q

242 ASCOMYCETES.

Schizothyrium.

The roundish or oblong iipothecia (It'liisce by lobes. The club-
siiaped asci contain oblong', hyaline, two-celled spores.

Sch. ptarmicae Desni. (Britain). This occurs as a parasite
on living green leaves and stems of Achillea Ptarmica. The
apothecia form little black points, which on rupturing break

Flo. 12". — Sc)dzolhyriuin ptannicae on Achillea Ptarmica. (v. Tubeuf del.)

up the epidermis into lobes. The thick asci contain two to
four large two-celled spores. Paraphyses are present. A pycnidial
form is known as Leptothyrium i^tarmica^ (Sacc).

Rhytisma.

The fungi of this genus live in the tissues of living plants and
form sclerotial cushions as isolated black spots. In these places
the pycnidia are developed, and are followed by apothecia after
the death of the leaves. The apothecia open by a fissure, and
contain thread-like paraphyses and club-shaped asci with eight
needle-shaped spores, which are septate when mature.

Rhytisma acerinum (Pers.) (Britain and U.kS. America).
Towards the close of summer, the large black spots caused
by this fungus on leaves of various species of Acer (sycamore
and maple) are by no means uncommon. Pycnidia (Melasmia
accrimim L^v.), containing little unicellular conidia, are first
produced under the cuticle, while the epidermis and under-
lying cells become filled with mycelium till a black sclerotium

KHYTISMA.

243

is completed. In the following spring, the sclerotium-spots
on the fallen leaves have become thicker and superficially
wrinkled. At this stage the apothecia are produced, and
dehisce by fine elongated fissures ; they contain club-shaped
asci and thread-like paraphyses with hooked ends. The thread-
like ascospores are ejaculated with considerable force, and reach

Fig. 128. — Rhytisma oxerinv.m. Two apotheclal cushions on leaf of Acer
campestre in iirst summer. A, Leaf-apex of Acer platcmoides witli the mature
apothecial cushions as seen in the second summer, with their characteristic
wavy marking, (v. Tubeuf del.)

maturity in May or June. According to Klebahn,^ the spores
have a mucilaginous membrane, but this does not throw much
light on the problem of how they reach the leaves of trees ;
wind, however, would seem to be the agent for distribution. In
three weeks after infection, leaves show yellow spots ; in eight
weeks the pycnidia appear.

^Botan. CentraMatt, lvhi., 1894, p. 321.

244

ASCOMYCETKS.

The disease is best combated by prompt removal of fallen
leaves in autumn; where this rule is followed Rhytisma is seldom
found (see p. 71).

Rh3rtisma punctatum (Pers.) (Britain and U.S. America).
Whereas the spots of the Rhytisma just considered are large,
those of this species seldom exceed a few millimetres. They are

Fio. 129 — Rhytisma punctatum. Leaf of Acer Pseudoplatami.s with apothecia ;
the leaf is yellow, but the spots enclosing the apothecia are still green,
(v. Tubeuf del.)

black in colour, angular, and scattered over the whole leaf-
surface. After the leaf has turned yellow, portions of it sur-
rounding spots of this Rhytisma retain their green colour, so
that we have black spots on green islands in the yellow leaf.
The sclerotia dehisce by valves. The apothecia contain thread-
like paraphyses and asci. The asci are club-shaped and contain

RHYTISMA.

245

eight needle-shaped unicellular spores ; pycnidia (spermogonia)
with little unicellular conidia are also formed.

The fungus attacks leaves of sycamore {Acer Fseudoplatanus),
the black spots making their appearance in September. The
apothecia ripen on the ground during the following summer.^

Fig. 130. — Sections of Maple leaves
showing the upper epidermis ruptured
by 1, Rhytisma acerinum ; 2, Rhytisnia
puncto.ti'.m.

Fig. 131. — Rhytisma symmetricuni Mull. Two
leaves of Sa.lix purpurea with stromata. A, The
upper side. B, The lower side. C, Longitudinal
section through the same leaf, showing numerous
apothecia on the upper side, fewer on the lower ;
the shaded middle part represents leaf-tissue,
the remainder is the light fungal stroma in
which the darker apothecia are embedded,
(v. Tubeuf del.)

Rh. salicinum Pers. (Britain and U.S. America). Thickened
black wrinkled spots appear frequently on living leaves of various
species of willow, e.g. Salix Caprea, S. cinerea, etc., also on some
alpine willows, e.g. S. reticulata. These contain apothecia of this
fungus, which reach their full maturity during the second
summer.

^ Dyscomycopsis rhytismoides Abtill. Black spots similar to those of Rhytisma
appear on the leaves of sycamore. The black crusts are here only subcuticular
and enclose a transparent tissue from which large spherical spores are produced.
The systematic position of this fungus is unknown.

246 ASCOMYCETES.

Rh. symmetricum J. Mliller {Rh. autumnalc Schroeter)^ is a
form oceuniny; ou Salix intrpurca and recently separated as a
distinct species. Tliis willow, one of the best for cultivation,
may often be seen with its leaves covered with black spots,
and the disease may spread over every tree in a nursery.

The apothecia are found on the upper surface of the leaf,
on ])lack, shining, and much wrinkled cushions. In addition,
black apothecial cushions are developed on the under surface
of the leaf, which is not the case with any other species of
Rhytisma. According to Schroeter, the spores ripen in autumn
on still living leaves.

(This species may be synonymous with Rh. australe Dur. et Mont, on
Salix purpurea in Algeria.)

A species which causes little thick cushions on Salix Caprea has been
called Rhytisma ^imhonatum Hoppe.

Rh. andromedae Pers. occurs ou leaves of Andromeda polifoUa. (Britain
and U.S. America).

Rh. empetri Fries, on leaves of Empetrum nigrum. (Britain).

Rh. juncicolum Rehm on Juncus Hostii.

Rh. urticae Fr. on stems of Urtica dioica. (Britain and U.S. America).

Rh. bistortae D. C. on Polygonum viviparum in France, Greenland, and
America.

PSEUDOPHACIDIEAE.

The apothecia are at first embedded in their substratum,
under the superincumbent layers of the host-tissue, and form
blistered patches ; on rupture, this cover forms a rim round
the apothecial cushion; the excipula of the apothecia themselves
are membranous, generally black, and dehisce by lobes or
fissures on the apex.

Cryptomyces.

The apothecia break out from the substratum as black crusts.
The asci contain eight oval, unicellular, colourless spores. The
paraphyses are thread-like and septate.

Cryptomyces maximus Fries.^ (Britain and United States).
This fungus lives parasitic on twigs of various species of willow.

'J. Mliller, "Zixr Kenntniss d. Runzelschorfs," Prinysheim's Jahrhuch, 189.3.
Schroeter, Flora v. Srh/esien, 1894.

Both appear to be identical with Rh. amphigenum Wallr. (Flor. Crypt, ii. 412).
■^ Tulasne, Select, fuwjoriim Carpologia, in.

CRYPTOMYCES.

247

especially Salix incana, but also on S. purpurea. When the
black apothecial cushions break out through the bark, the twigs
of the host-plant are frequently still green and leaf-clad.

The apothecia originate in the lower bark and so loosen
the epidermal layers as to cause the appearance of yellow spots.
Black centres appear in the spots, due to the formation of a

a

Fig. 132. — Cryptomyces laaximun. 1, Cross-sectiou of a twig of Salix incana,
with stroma a b ; the mycelium occupies the rind and bast into the cambium, so
that a wood-ring for the current year has been only partially developed ; the
shaded part between a and h is an aerating tissue, formed of loose hyphae, which,
with a, forms the stroma proper ; h, the ascogenous layer. (Lens-magnification.)
2, Asci, showing a dry ascus ; one to which water has been added, so that it is
elongating ; one ruptured and ejaculating spores. 3, Young stromata in spring,
still covered by the epidermis of the Saliy. 4, Willow twig after det.achment of
the patches of Cryptomyces in autumn, (v. Tubeuf del.)

black apothecial cover underneath the epidermis. On rupture
of the epidermis, black apothecial cushions emerge and cover
large areas of the living twigs. Rain causes the apothecia
to become gelatinous, and to swell considerably ; on drying
the cushions roll up and fall off, leaving scars in the bark
(Figs. 132,4).

248 ASCOMYCETES.

A lonffitudinal section through a cushion exliibits a thick
hypothecium, consisting of a close pseudoparenchynia of hyaline
fungal cells, which permeate every tissue of the bark and cause
death of the cambium ; above this comes a looser layer with
many air-spaces, and over this the layer from which the asci
and paraphyses arise.

The asci contain eight oval unicellular spores with distinct
cell-nuclei. When a section is placed in water, a very
evident swelling takes place, and the asci elongate to twice
tlieir original length. I have not observed ejaculation of
spores, but rupture of the asci occurs in water-preparations
and the spores are set free in large numbers. The spores
probably germinate and infect young shoots, the mycelium
hibernating there.

The effects of this fungus are death of diseased twigs of
willow above the spot where a sporogenous cushion is
formed.

Tliis species is also said to frequent Cornvs in America.

Cryptomyces pteridis (Eebent.) occurs on fronds of FteriH
aquiiina, but whether a parasite or not is as yet uninvestigated.
The asci ripen after the fronds have passed through the winter.
To this belongs the conidial form Fusidium pteridis Eabh.

Clithris.

The apothecia, at first spherical, become oblong, and break
through the superincumbent layers by a lobed fissure. The
apothecial disc is oblong and flat. The club-shaped asci contain
eight hyaline spindle-shaped or thread-like spores, with one or
more cells. The paraphyses are thread-like. The majority of
this group are saprophytes.

Clithris (Colpoma) quercina (Pers.) (Britain). According to
Schroeter,^ this causes disease and death of living branches of
oak. The oblong apothecial discs are greyish-white, and covered
at first by a brownish-grey wall which, later, becomes ruptured.
The ascospores are simple. Cylindrical pycnidia, with somewhat
bent conidia, are also produced.

CI. juniperi (Karst.) occurs on living twigs of junii^er. Nothing is
known of its parasitism.

1 Schroeter, Pike Schksiens, 189.3.

DOTHIORA. 249

Dothiora.

The spherical apothecia are embedded in the substratum, which
they rupture into lobes, while they themselves dehisce by
irregular fissures. The club-shaped asci contain eight colourless
or yellow, club-shaped or spindle-shaped, multicellular spores.
Paraphyses are never present.

Dothiora sphaeroides (Pers.) is regarded by Postrup as the
cause of a disease of the Lombardy poplar {Fopulus pyramidalis),
in which the branches, particularly those of the upper part
of the tree, die one after another till all are gone. The spores
are club-shaped and constricted at the middle ; each half is
divided by four or five cross-septa, and each cell so formed
is again subdivided by a longitudinal septum.

Vuillemin ascribes the same disease to Didyinosphaeria
pojndina Yuill. (see p. 218).

According to Pehm, Bo. spliaeroidcs also occurs on Fopulus
tremula, and is distinguishable from Bo. mutila (Fr.) on both
Fopulus italica and F. trcmida.

Heterosphaeria.

The spherical apothecia are at first embedded, but later emerge
through the covering layers and dehisce, their apices breaking
up into teeth-like lobes : they are dark-brown or black in colour.
The asci are club-shaped and contain eight spores, which are
colourless, oblong or club-shaped, and consist of one, tw^o, or
four cells. Iodine colours the pores of the asci blue. The
paraphyses are colourless and thread-like.

Heterosphaeria Patella (Tode). (Britain and U.S. America.)
The asci contain eight bicellular spores. The paraphyses are
thread-like and septate, some being forked or branched ; they
bear scalpel-shaped conidia.

The mature apothecia are found chiefly on the stems of
various UmhcUiferae, e.g. Bcmcus Carota, Anetlmin graveolens,
Fetroselinvni sativum, Fastinaca, etc. A variety cdj^testris occurs
amongst the mountains on Heraclev.m Spliond^ylium, also on
Gentiana hdm, Vcratrum viride, etc. Pehm and others believe
that the fungus attacks living green parts of plants, and reaches
maturity in the following year on the killed organs.

250

ASCOMYCETES.

Scleroderris.

A black stroma is formed in the bark of twigs attacked
by this fungus, and thence the apothecia break out in great
numbers, at first as closed spheres, later as stalked open
cups with finely lobed rims. The asci are cylindrical or club-

FlG. 134. — i-clerndcrris fidiginosa on living twig of Salic alba.
J, Three apothecia, two in section, the third seen from above,
showing the cross-like fissure. B, .Sections of diseased branches,
whose growth has been arrested in the shaded parts ; on the
dead bark apothecia are present. C, Asci, spores and paraphyses.
(v. Tvibeiif del.)

Fig. Vi3.- -ScleroiUrris full-
ainosa on living twig of
Salix Caprea. (v. Tubeuf
del.)

shaped, and contain eight colourless spores which are club-
shaped, needle-shaped, or thread-like, and divided by septa into
four to eight cells. The pores of the asci are coloured blue
by iodine. The paraphyses are thread-like.

SCLERODERRIS. 251

Scleroderris fuliginosa (Fries). (Britain and U.S. America.)
This was considered to be a saprophyte till my attention was
directed to its injurious nature. It occurs on living branches
of Salix Caprea, S. trinndra, S. alha, etc., and brings about
their death. The black crusts, on which the apothecia develop,
appear both on weakly twigs and strong branches. The my-
celium makes its way through the tissues to the cambium, which
it kills, causing this and neighbouring parts to become brown.
Adjacent parts, as yet unattacked, continue at first to grow in
thickness, but they too are gradually killed. As a result, the
twigs attacked grow irregularly according to the extent and
number of diseased places (Fig. 134); and when all or most
of the lower tissues of a twig are killed, the higher parts
die off with their leaves. Wherever the fungus appears, many
trees are generally attacked.

Sc. aggregata (Lasch.) develops on the living steins of Rhinantliaceae
and )natui-es on thfe dead.

Sc. ribesia (Pevs.) is a common species on twigs of red and black currant,
but whether parasitic or not is unknown.

(2) DERMATEACEAE.

The apothecia are developed at first either under the sub-
stratum or altogether superficially. The ascogenous layer
extends over a thick hypothecium.

The Dermateaceae contain the Cenangicac, Dcrmateac, Patcl-
larmceae, and Bidgariaccae.

CENANGIEAE.

Apothecia at first embedded, then exposed. They are sessile,
clavate or cone-shaped, and broaden out to discs on opening.

Cenangium.

Apothecia globose ; on dehiscence at first cup-shaped, but
afterwards flatter and more saucer-shaped, with entire margins ;
they may occur singly or massed together. The club-shaped
asci contain eight colourless, oblong, unicellular spores, and
filamentous paraphyses with tliickened apices.

Cenangium abietis (Pers.). (Britain and U.S. America.) This
fungus is usually a saprophyte, but Thlimen suggests it as an

iio'J ASCOMYCETES.

occasional parasite. Schwarz^ has recently described it as
attacking pines, weakened by an impoverished water supply to
the twigs and by other unfavourable conditions. It appeared
for a time as an epidemic in the pine forests of Germany, Vjut
very soon disappeared again.

The symptoms of disease were, withering of twigs in .spring
from the apex downwards into tlie region several years old.
The epidemic had been previously noticed in the spring of
1892, and was described by Hartig, who, along with Kienitz,
regarded it as a result of the long dry preceding winter. The
disease has never been observed on pines under five years old,
and serious injury only results when the fungus is accompanied
by damage done by insects. The apothecia containing the asci
are generally produced only on dead twigs and needles.

Schwarz regards as a conidial form of this species, Brun-
cliorstia dcstnccns Erikss., which will be described in greater
detail amongst the " Fungi imperfecti." In addition to Brun-
chorstia, other pycnidia with unicellular conidia occur.

DERMATEAE.

The apothecia, at first spherical and embedded in their host,
break out in clumps; they are generally short and thick-stalked,
and open to form a roundish saucer-shaped disc with an un-
broken rim. The hypothecium is thick and often coloured.

Dermatella.

A stroma is developed under the bark of the attacked parts
of the host, and in it originate dark brown apothecia with
short thick stalks. The bark is ruptured and the apothecia
emerge as flat, expanded, .saucer-shaped discs with a complete
rim. The asci are club-shaped and thick-walled. The spores,
at first unicellular, later multicellular, are large and colourless
or brownish. The paraphy.ses are septate and generally forked ;
they often form a coloured epithecium.

Dermatella prunastri (Pers.) (Britain and U.S. America).
According to Ludwig, this lives as a parasite on the living
bark of plums, apricot, sloe, and other species of Prinms.

^Schwarz, Die Erhrankunij d. Kiefern durch Cenangium abieti^, Jena, 1S95.

DERMATELLA. 253

Apothecia and pycnidia {Sphacroncma spurium Fr.) are both
developed. The ascospores are one-celled and hyaline.

[Wagner^ adds the following species found bv him in Saxony as more
or less marked parasites : (Edit.)

Dermatea (Pezicula) cinnamomea (Pers.) on Querciis. It attacks the
lind in places injured by deer, and causes injury to the trees.

D. (Pez.) carpinea (Pers.) kills many young hornbeams ; it probably
obtains entrance through wounds.

D. (Pez.) acerina Karst. is a doubtful parasite on Acer Fseudoplatanus.']

BULGARIACEAE.

Bulgaria polymorpha Wett. (B. inquinans Fr.) (Britain and U.S.
America). A dangerous enemy of the oak,- causing death. Researches
into its parasitism are still wanting. The sporocarps develop on dead
bark, especially of beech.

(3) PEZIZEAE.

The apothecia are never embedded, but appear as saucer- or
cup-like structures on the substratum ; they are fleshy or waxy,
and often of bright colour. The hypothecium is very strongly
developed.

The families included in this group are : Mollisieae, Helotieae,
Eupezizeac, and Ascoboleac. Of these, all except the last con-
tain parasitic forms. The Mollisieae and Helotieae contain also
a number of lichen-fungi not con.sidered of sufficient practical
value to be included here. The Ascoholcae live as saprophytes on
animal droppings.

MOLLISIEAE.

The apothecia generally sit free throughout their whole
existence on a close, firm substratum of hyphal tissue, or they
may be sunk in the host and break out later ; they are at
first closed and spherical (rarely tapering downwards), but after-
wards open and expose a cup-like, saucer-shaped, or flat disc of
asci. The disc is waxy and soft ; externally it is brownish
and generally smooth ; exceptionally it may be downy or beset
with short hairs or bristles. The sporocarps are brown and com-

^ Zeitsch. f. PJlaiizenkrankheiten, 1896, p. 76.

^ Ludwig, Oentrcdblatt f. Bactcriologie u. Parasitenkimde ; also, Lehrbuch d,
niederer Kryptogamen.

254 AHCOMYCETES.

posed of pseiidopareiichyiua, which, towards the luargiiis, becomes
more elongated and prosenchymatous. Hypotliecium generally
poorly developed.

Mollisia.

The sessile brownish apothecia on opening generally exhil)it a
flat, saucer-shaped, transparent stratum of asci. The spores are
unicellular, hyaline, and spindle-shaped or club-like. The
paraphyses are hyaline or coloured, sometimes forked.

Mollisia Morthieri (Sacc). The apothecia are developed on
yellow spots of the lower epidermis of living leaves of Ruhns
Schleicheri and B. fruticosus. The young apothecia are reddish-
brown and spherical ; when open they form yellowish-brown
discs with very delicate margins. The asci contain eight
spores, arranged in two rows. The spores are unicellular, club-
shaped, and colourless. The paraphyses are colourless or
brownish, with slightly bent points.

Niptera.

Apothecia as in Mollisia. The spores, however, on com-
pleting their development are two-celled.

Niptera hypogaea (Bres.).^ Found by Bresadola in Southern
Tyrol, underground on the roots of Adenostyles albifrons. The
apothecia are massed togetlier on brown hyphae in blackened
parts of the host-roots. The ascogenous disc is greyish-brown
or whitish, with fine fibrous margins. The asci are spindle-
shaped, and contain eight spindle-shaped colourless spores,
which are at first one-celled, later two-celled. The septate
colourless paraphyses are forked.

Pseudopeziza.

The members of this genus live as parasites in the leaf-
tissue of higher plants and produce dead brown spots, in which
the ascocarps are afterwards developed. The apothecia have
delicate walls, and, after rupturing the epidermis, emerge
as delicately-coloured saucer-like hymenial discs. The club-
shaped asci contain eight spores, arranged in two rows. The

^Bresadola, Fiuuji trident, A. Lxxv. , Fig. 1.

PSEUDOPEZIZA. 255

spores are ovoid or elliptical, colourless, and unicellular. The
colourless paraphvses have thickened apices, rarely forked.

Pseudopeziza (Phacidium) trifolii (Bernh.). Leaf-spot
disease of the clover. This disease appears on the leaves of
various species of clover in Europe and America ; its attacks
may attain considerable severity, and inflict great injury to
crops. The leaves become spotted, and finally die off. The
apothecia occupy brownish-yellow discs on the surface of the
leaf, and hence are not unlike pustules of a Puccinia. The asci
are club-shaped, and contain eight ovoid, unicellular, colourless
spores. The paraphyses have broadened apices, rarely forked.
A coniclial form (Sj^haeivnema ijhacidioides Desm.) is generally
allocated to this species.

Ps. trifolii {var. medicaginis) (Lib.) is found on species of Medicago
(Britain and U.S. America).

Ps. bistortae (Lib.). This occurs on the lower epidermis of living leaves
of Polygonum Bistorta, and P. viviparum, causing dark-brown swollen
spots where the apothecia are developed. Juel ^ has transferred this species
to the Phacidiaceae, and named it Pseudorhytisma bistortae (D. C).

Ps. alismatis (Phill. et Trail) causes spots on leaves of Alisma Plantago
(Britain).

Fabraea.

This genus is distinguished from PseudoiKziza by the spores,
which, though at first unicellular, become two or four-celled.
The species are parasitic in the leaf-tissue of higher plants.

Fabraea astrantiae (Ces.). The mycelium lives in the leaf-
parenchyma of Astrantia major and A. carniolica, causing dead
spots. A form occurs on Sanicula europaea.

F. ranunculi (Fries.) (Britain). The apothecia of this are
very common on brown spots on tbe leaves of various species
of Ramtnculus.

F. cerastiorum (Wallr.) frequents leaves of Cerastiv.m (Britain).
F. Rousseauana (Sacc. et Bomm.) occurs on leaves of Caltha palnstris.
(A British species if synonymous with Pseudopeziza calthae Mass.).

Beloniella.

The gregarious apothecia are at first embedded, but break
out later. Externally the apothecial discs are rough, dark brown,

^Mykol. Beitr. Vetemk.-Akad., 1894.

256 ASCOMYCETES.

and striped, the margin being tibrous. The asci contain four
to eight spores. The spores are generally ovoid or spindle-
shaped, at first unicellular, but divided later into two to four
cells by means of cross walls. The colourless paraphyses
have thickened club-like apices.

Belionella Dehnii (Rabh.).^ This parasite covers stems
and leaves of Fut> iitilla norvegica, and is distinguished by its
sharp, spindle-shaped, bicellular spores.

HELOTIEAE.
The apothecia are generally (|uite superficial ; less commonly
they are at first embedded, and emerge later ; or they may
develop from a sclerotium. In form they are spherical, cup-
shaped, or top-shaped, and a stalk of some kind is generally
present. On opening, they form a cup or flat plate, on which
the hymenium lies exposed ; the cup is soft or waxy, and
enclosed in a delicate wall, which is externally either smooth
or hairy. The sporocarps consist of a pseudoprosenchyma
(after Rehm).

Sclerotinia.

The sclerotia "^ give rise to smooth-stalked ascocarps with the
form of beakers, funnels, or saucers. The stalks often produce
rhizoids. The asci contain eight unicellular hyaline spores,
elliptical or spindle-shaped, and of equal or unequal sizes.
The paraphyses are thread-like. In several families conidia are
formed before the sclerotia. Some forms are heteroecious. Most
of the species are parasitic on plants.

The Sclerotium diseases of the Vaccinieae.^
These are a well-known group of sclerotium diseases, and

amongst them the following have been named as species.
Sclerotinia vaccinii Wor. {Scl. Urnula Weinm.). The

sclerotium disease of the cowberry. The young shoots and

1 Figures in Hedivigia, 1881,

-Literature: Ue Bary, " Uebereiuige Sclerotien u. Sclerotienkrankheiten,"
Botan. ZtUiuui, 1886; aXso Morphology and Biology of the Fungi, English edition.

Brefeld, Schimmelpilze, Heft. iv. u. x., and Botan. Zeilung, 1876.

Saccardo, Sylloge, Vol. viii.

^Woronin,3/e'/n. deVacadem. imp4r. d. sci. d. St. Petersburg, vii. Ser., t. 36, 1888
f with ten plates) ; also Berichte d. deutsch. botan. Ges., 1894.

SCLEROTINIA.

257

leaves of Vaccinium Vitis-Idaca exhibit in spring a mould-
like coating, consisting of chains of lemon-shaped conidia.

Woronin thus describes it : " In the outer layers of the cortex,
amongst the dying elements, a pseudoparenchymatous cushion is
formed, from which simple or dichotomously branched hyphae
grow out through the overlying cuticle. The individual members
of the chains of conidia are separated from one another by a
spindle-shaped piece of cellulose — ' the disjunctor.' "

The disjunctor spoken of here is a spindle-shaped cellulose
body found between the single conidia ; it easily breaks across
and so facilitates the breaking up of the chains of conidia

Fig. 135. — Sderotinia vaccinii on Vo.ccinium Vitis-Idaea. Mummified Cowberries
in fresh condition and in the following May, after development of Pezizo.-cwps.
A, Chain of conidia united by disjunctors. B, Germinating conidium after treat-
ment with iodine ; the plasma has shrunk, but remains connected with the
sporidia in process of abjunction. (After Woronin.)

(Fig. 135). It has its origin as follows: The conidia at first lie
closely end to end, enclosed in a delicate primary membrane ;
the partition-membranes split into two lamellae, each of which
takes part in the formation of a cellulose body which gradually
becomes spindle-shaped. In the course of its growth this cellulose
body — the disjunctor — ruptures the primary enclosing membrane,
and, being released, becomes more elongated, so that the conidia
are pushed away from each other and fall apart.

The conidia have a strong characteristic odour of almonds,
attractive to insects, which carry off the conidia and dust them on
the stigmata of other Vaccinium flowers. Wind is also, in all
probability, an agent in the distribution of the conidia. The

258

ASCOMYCETES.

coiiidia germinate and give off long septate hyphae which, follow-
ing the course of the pollen-tube, reach the ovary, and soon
fill all four loculi with a white mycelium. The growth of this
mycelium proceeds from the central axis towards the walls, and
forms a hollow sphere open above and below. The diseased
berries cannot be distinguished till ripe ; then, whereas the
normal are red, the diseased are yellowish-brown to chestnut-
coloured, and soon shrink up, leaving only the outline of the
sclerotium.

The dead or mummified berries fall prematurely, and lie over
winter on the earth. In April or IVIay, the sclerotia give rise

Fifi. l^G.— Sclerotinia oxycocci on Faccinivm Oxycoccvs. Young shoot of Cran-
berry with mature conidial cushion and diseased upper leaves. A, Pfsira-cup
developed from a sclerotial fruit ; numerous rhizoids proceed from the base of the
stalk. B. Ascospores in stages of germination. C, Conidia in germination, with
remains of disjunctors still attached. (After Woronin.)

to several primordia or horn-like stalks, on the extremity of
which an apothecium is afterwards formed. Ehizoids are pro-
duced at the base of the stalk and attaching themselves to the
ground act as supports and organs of nutrition. The apothecia
contain both asci and paraphyses ; the latter are septate, dichoto-
mously branched filaments, with club-shaped ends, and coated
with a brown resinous substance. The asci have a canal at
one end through which are ejaculated eight spores of almost
equal size. These produce sporidia in water ; in nutritive
solutions, however, they form a septate mycelium with conidia.
The ascospores bring about infection by means of one or two
germ-tubes which penetrate the outer membranes of young

SCLEROTINIA.

259

cowberry shoots, the stomata being always avoided. In less
than three weeks conidia are produced.

The mode in which the germ-tubes attack the host-plant is
very remarkable. Woronin says : " The germ-tubes developed
from the ascospores grow inwards tow^ards the vascular bundles
of the host-plant and enter them ; then they continue to
develop, but now in the opposite direction from the interior of
the plant towards the periphery. Here a peculiar phenomenon is
exhibited, the fungus exerts its injurious effects on the surrounding
tissues of the host-plant, then, having killed these, it utilizes

Fig. 137. — Sclerotinia baecarum on Vo.cciniuin Mi/rtillus. Young shoot of Bilberry
with deformed branch bearing white conidial patches on its lower side ; also a
withered leaf. A, Conidial chains, and a portion enlarged. B, Shoot with an
iipper healthy ripe berry and a lower mummified one. C, Peziza-c\ip develoi^ed
from a sclerotium. D, Ascosijores ; the smaller incajjable of germination, another
germinating and giving off sporidia. (After Woronin.)

them as food-material." " Finally, the germ-tubes penetrate
between the elements of the outer rind already killed, and there
develop to a stroma-like mishion of large-celled pseudo-
parenchyma from which the chains of conidia emerge through
the ruptured cuticle."

(Saccardo also mentions Scl. oreophtla Sacc. on leaves of Vaccinuim
Vitis-Idaea. )

Sclerotinia oxycocci Wor, The sclerotium disease of the
true cranberry ( Vaccinium Oxycoccus). The spores of this species
are smaller than those of the preceding; each ascus contains four

260

ASCOMYCETES.

larger and four smaller spores, the latter appearing to he rudi-
mentary and incapable of germination.

Scl. baccarum Schroet.' (Britain).' The sclerotium disease of
the bilberry ( Vacc. Myrtillus). This varies from the other species
in having round conidia incapable of germinating in water, in
having more robust apothecial beakers, and in lacking rhizoids.
The spores are similar in numlter and arrangement to the
preceding species.

Scl. megalospora ^^'or. The sclerotium disease of the crow-
berry {Empetrum nigrum). This species is distinguished by the

Fio. 138. — ScUrotinia megalospora on Vaccinium uliginosum. Partially withered
leaf with a white conidial cushion on the mid rib. A, Conidial chains produced
on a mycelium, resulting from an artificial culture of ascospores in plum-solution.
B, Isokited conidium with remains of disjunctors still attached. (', Twig with
upper mummified berry. E, Ascospores ; one in its gelatinous envelope, the other
giving off a germ-tube and sporidia. (After Woronin.)

form of its conidia, and the manner of their germination ; in the
form of the sclerotium, and the absence of primordia ; in the
absence of rhizoids ; and, particularly, in having large ascospores
almost similar to each other.

The " white berries " of the Vacciniaceae are distinct from the
mummified berries caused by Sdcrotinia.^

Scl. aucupariae Ludw. The mummified fruits of Pyriis
Aucuparia, resulting from this fungus, were first observed by

^Schroeter, Hedicii/ia, 1879 ; Woronin (loc. cit.).

- Sclerotia of this species have been found in Scotland by Professor TrailL
^Magnus and Ascherson, Bei'ichte d. deutsck. hotan. Ges., 1889; also ZooL-
botan. Ges., Vienna, 1891.

SCLEROTINIA. 261

Woronin ^ in Finland, and later by Ludwig in the Erz mountains.
The ascocarp developed from the sclerotia has no rhizoids. The
ascospores infect leaves, and there the conidia are produced.

Scl. padi Wor. Causes mummification of the fruits of
Prunus Pacliis. Woronin regards Monilia Linhartiana Sacc. as
belonging to this Sclerotinia.

Woronin also considers the conidial form Monilia cinerea
as related to the mummified fruits of cherry.

Oimlaria nelans on Mespilus is probably also a form of some Sclerotinia.

A Sclerotinia occurring on Cotoneaster nigra produces mummification of
the fruit, and forms conidia on the surface.

Monilia fructigena of the apple, pear, quince, plum, peach, etc., is in
all likelihood a form of some Sclerotinia, although the ascus-form is still
unknown (see also " Fungi imperfecti ").

Scl. betulae Wor. (U.S. America). This sclerotium of the
birch-fruit was discovered by and briefly described by Woronin
in 1888. Nawaschin - has recently re-investigated it, and
named it the " birch-catkin disease." It is found on the green
catkins in June. The fruits containing sclerotia are obcordate
in shape, instead of the normal elliptical form with both ends
acute ; the wings are similar to those of healthy seeds. The
sclerotium is composed of a very hard white pseudoparenchyma,
which passes in the form of a horse-shoe round one side of the
apex of the fruit (Fig. 139). The outer layer is black and very
firm. Sclerotia placed on moist sand produced ascocarps at the
beginning of May. Development in the open also takes place
about this time. In the birch forests near St. Petersburg this
disease is common, and birch-catkins containing sclerotia may
be found abundantly amongst fallen leaves about the month of
May. From each sclerotium there are produced one or two
ascocarps, with rhizoids and stalks of a length varying with
the depth of dead leaves on the ground. The apothecia
are at first funnel-shaped, but later became saucer-shaped
and l-4mm, broad, with a golden or fleshy colour. The asci
contain eight spores which are forcibly ejaculated, and if a
handful of damp birch leaf-mould is thrown up into the air

iWorouin, Berichte d. deutsch. hotan. Ges., 1891; also Man. de Vacad. imp.
d. sci. de St. Petersburg, 1S95. With five plates.

^Nawaschin, Sclerotinia betulae, Wor. Russian brochure with four coloured
plates, 189.3.

262

ASCOMYCETES.

a cloud of spores so ejected may easily be seen. Infection
takes place on the birch flowers. It is possible to promote
germination in water and on moistened leaves, but the germ-
tubes soon die.

This disease, on account of the small size of the birch fruit
and the tiny sclerotia, remained for a long time quite un-
observed, yet it seems to be common everywhere ; in Russia it
has been found frequently, also in Germany, North America,
and Japan. It possesses considerable economic importance,
since diseased seeds are no longer capable of germination.

Fio. 159.— Sclcrotinia betulae. a, Birch fruits with sclerotia, which have
germinated and formed cup-like apothecial discs ; rhjzoids have developed on
the stalks, b, Birch fruit, somewhat enlarged, with semilunar sclerotia. (After
Nawaschin.)

Hormomyia hctulac Wtz. often occurs along with the above.
It causes the production of thick spherical fruits with little or
no wing. Sderotinia adusta Karst. has also been found on
birch leaves in Finland.

Scl. aini ISTaw. Vforonin found this lirst on catkins of
Alnus inrann. Xawaschiii has more recently investigated it.^

Scl. rhododendri Fischer.'- This was first discovered by
Fischer in 1891 in fruits of the Alpine-rose {Rhododendron
ferrugincum and B. hirsutvAii) in Switzerland. It has since
been observed in various parts of Switzerland and the Tyrol.

^Nawaschin, Berirhte d. deiit-tch. liotan. Ges., 1894; Maul, Hedivigia, 1894,
p. 213. With two plates.

-E. Fischer, Naturforsrh. Ges. Bern, 1891 ; also Berirhte d. schiveiz. hotan. Ges.,
1894. With figures.

SCLEROTINIA. 263

Fischer succeeded in obtaining stalked ascocarps from sclerotia
of one and two years old. They resembled most closely those
of Scl. vaccina, their stalk being provided with numerous rhiz-
oids. The asci contain eight similar spores which germinate
directly on ejaculation. They develop a mycelium and, later,
chains of chlamydospores which separate by means of disjunctors.
The little conidia found by Woronin on Vacciiiium are never
produced. The paraphyses are generally unbranched and corre-
spond in length to the asci.

The mummified fruits are easiest found after the healthy
capsules have dehisced, then the diseased ones remain closed.
In winter the healthy capsules remain attached to the plant,
the diseased fall off. Seeds of diseased capsules are completely
overgrown by hyphae.

Wahrlich ^ found sclerotia in capsules of PJwd. daJiuricum.
from Siberia. They gave off a sclerotial ascocarp with a stalk
devoid of rhizoids. The mummified fruits resemble closely those
of Scl. rhocloclcnclri.

Scl. heteroica Wor. et Xaw. = Scl. ledi Naw.' occurs on
Leclum ivduMrc in liussia and Finland, It is very similar to
Scl. rhododcndri, but is distinguished by the paraphyses being
swollen and frequently forked at the end. In nutritive gelatine
a copious mycelium is developed, and produces chains of ripe
conidia with tiny disjunctors. Woronin found that these conidia
are produced only on Vaccinium uliginosam, never on Ledum ;
but the conidia so formed can successfully infect the ovary of
Ledum. We have here the first known case of heteroecism
outside the Uredineae.

Scl. sclerotiorum Lib.^ (Britain and U.S. America). The
sclerotia of this fungus are found in many various plants.
They fall to the ground with the dead plants, hibernate under
snow, and on the arrival of warmer weather in spring give
rise to several stalked apothecia. The ascospores are ejaculated
from the asci, germinate, and produce a parasitic mycelium,
described thus by De Bary : " The ripe spores of Pcziza
sclerotiorum produce germ-tubes on any moist substratum.

^ Berichte d. deutsrh. hotan. G'e.s., 1892.

-Nawaschin, Berichte d. deutsch. hotan. Ges., 1894, p. 117.

^Brefeld, Srhimmelpihe, iv. and x. ; De Bary, Morphology and Biology of the
Fungi ; and Botan. Ztitung, 1886.

264 ASCOMYCETES.

These develop to strong mycelial threads if they reach any
source of nutriment, such as disorganized bodies and particularly
dead plants. On any other substratum the germ-tubes never
pass beyond a rudimentary stage. The gerra-tuljes developed
in water cannot make their way into living plants. If, however,
grown in suitable nutriment, the mycelial threads are smaller
and capable of penetrating as parasites into suitable hosts. This
they are able to do because they give off a fluid which enters
into and kills living plants. The dead parts of the plants
serve as nutriment to the fungus, which makes its way into
the tissues and causes death of cells in direct contact or im-
mediate neighbourhood. The deadly tiuid separated by the
fungus contains, as an essential constituent, an enzyme soluble
in acid solutions and capable of dissolving the cell-walls ; also
a number of imperfectly known organic and inorganic acids
and salts, amongst which oxalates can certainly be proved.
The mycelium generally penetrates parts covered only by cuticle
or a thin periderm. It does so by hyphal branches which grow
into the air till they reach some suitable host ; then, stimulated
by the pressure, they give off characteristic organs of attachment,
which secrete a cell-killing fluid and cause disorganization of
the place attacked ; they derive nourishment from the products,
and give off branches which penetrate into the plant."

Conidia capable of germination are never produced, though
rarely tiny spermatia or conidia incapable of germination are
abjointed from the mycelium.

A Botri/tis-stage is certainly never present in the life of
this species.

Scl. sclerotiorum is one of the worst enemies of cultivated plants.
De Bary observed total or partial death resulting from it to
the following plants : Fhascolus vulgaris, Petunia nyctcujinijlora
and P. violaceae, Solamim fuhe7vsum, Zinnia elcgans, Helianthus
tuberosus, and Daucus Carota. It has also been found on species
of Brassica, Beta, Cichorium, Dahlia, Tojnnambur, etc., and on
seedlings of numerous other dicotyledons. It is thus evident
that many and varied plants, belonging to widely removed
families, may serve as hosts ; on the other hand the fungus
avoids certain plants, and is known to injure species in one
locality, which it avoids in another.

De Bary regards a destructive canker on hemp in Paissia

SCLEROTINIA. 265

(Peziza Kauffmaniana Tichom.)^ as related to, or identical with
Scl. sclerotiorum. Behrens, ho^vever, is inclined to ascribe it
to Scl. Fuckeliana, which has occasionally a Botrytis-st^ge. This
hemp disease has also been found in Alsace.-

Humphrey ^ regards this species as the cause of a disease
of indoor cucumbers ; he ascribes a Botrytis-stage to it.

Scl. sclerotiorum is Ijest known by the conical funnel-shaped
depression in the hymenial disc, not present in other species.

Sclerotinia trifoliorum Eriks * (U.S. America).^ Clover
is not attacked by the Sclerotinia last considered, but falls an
easy prey to this species, which again derives but scanty nourish-
ment from such food as fresh carrots. Scl. trifoliorum is
observed wild only on species of clover, and is there fairly
common ; many other plants, however, have been artificially
infected by it. Host-plants are attacked through their green
foliage, wdiich very soon becomes brown and shrivels up. If
the atmosphere be sufficiently moist, the mycelium emerges
on the exterior and spreads to neighbouring organs or plants.
Sclerotia are not often formed superficially as with Scl.
sclerotiorum, because the mycelium lives principally inside
the plant tissues. This mycelium resembles that of Scl.
sclerotiorum in its peculiar property, that successful infection
only follows if the fungus has lived for a time saprophytically ;
on this account direct infection by spores is harmless. In the
secretion of an enzyme and of oxalic acid, and in the manner
in which it destroys the tissues of its host-plant, this species
behaves like Scl. sclerotioruTn just described. It is distinguished
by its larger ascospores, and the absence of a central funnel-
shaped depression in the hymenium. Spores germinated in water
produce numerous bodies (so-called spermatia) which distinguish
the species from Scl. Fuclceliaiia where this does not take place.

Eostrup '' found in Denmark that Meclicago hqmlinct suffered

^Tichomiroff, BuU. soc, nat. de Mosrou, 1868.

"Behrens, " Ueljer das Auftreten d. Hanfkrebses im Elsass. '" Zeitschrift f.
Pflanzenlcranhheiten, 1891, p. 208 ; " Trockene u. iiasse Faule d. Tabaks," idtm,
1893, p. 82.

•^ Humphrey, Af/ric. exper. station Mass., 1892, pp. 212-224.

* Ktihn, " Die Sklerotieiikrankheiten d. Klees." Hedivir/ia, 1870.
Rehni., Entirirkdunysgesch. ehies d. Kleezerst6rendenPil~.es.

^ Massee (British Fungus-flora, iv. , 1895). "There is no evidence of this species
having occurred in Britain."

^Rostrup, Tidssh-ift for Landohonomie, 1890.

266 ASCOMYCETES.

most from this l'uiigu.s ; red clover was less affected, though
the disease often had its origin in that species ; while white
clover was least often' attacked. He recommends keeping out
Mcdicago from clover mixtures, and the addition of a large
proportion of grass-seeds. Fields badly affected should be
kept out of clover-cultivation for several years. English and
French white clovers he found to be very sensitive, but distri-
bution of the fungus did not take place by means of seed.

Scl. tuberosa (Hedw.) (Britain and U.S. America). This
on the rhizomes of Anrmone ucmorosa causes formation of
sclerotia larger than filbert-nuts. The ascospores on germination
produce groups of flask-shaped processes from which are given
off chains of spherical conidia incapable of germination. Certain
pycnidia which appear on the anemone-plants or on the sclerotia
l)eloiig to a parasite (Pt/cnis sclerotivora Brefeld).

Scl. bulborum Wakk.^ (Britain). Wakker observed this form
on hyacinth, onion, etc. It is very similar to Scl. trifoliorum,
but the hyacinth-fungus will not infect clover, and vice versa.
The leaves attacked become rotten and the plants die.^

Eriksson describes, from Wermland (Sweden), a destructive appearance of
biilij-i'ot (hie to sclerotia, which he attributed to ScL FuckeJiana De Bary.

Scl. candoUeana Lev. on oak-leaves.

Appendix.

Sclerotia of Unknown Affinity.

Scl. oryzae Catt. Eice plants {Or//z(i safiva) are often
attacked by this Sclcrotium, and a disease called " Brusone "
produced. The sclerotia are found during June in the sheaths
and stems. The symptoms are blackening at the base of plants
and withering of upper parts.

Scl. rhizoides Auersw. occurs on living plants of Phcdaris
arundinacea, and Calamagrostis ; also on dead leaves of Dcictylis
glomerata.

Scl. rhinanthi Magn.^ forms sclerotia on the roots and root-

^VVakker, Atlijem. Vereeiwj. voor BloemhoUencultur, 1883-84; also Botan.
Centralblatt, xxix., 1887.

^G. Massee (hardener's Chronicle, Vol. xvi., 1894) gives description and
figures.

3 Verhand. d. botan. Ver. d. Pror. Brandenbimj, xxxv. 1894.

SCLEROTIA OF UNKNOWN AFFINITY. 267

neck of living Bltinanthus minor: these bodies begin their
development in the cambium and bark, which they kill ; after-
wards the wood itself may be attacked.

Sclerotinia with Botrytis-conidia.^

Scl. Fuckeliana De Bary. This Sdcrotmia is distinguished
from all preceding ones by its passing through a Botrijtis-
conidia stage {Botrytis cinerca). If conidia are sown out on
plum-juice gelatine, there appear within fourteen to twenty- one
days round groups of sclerotia, which soon
give rise to conidia. From such artificially-
reared sclerotia I have never succeeded in
getting the Bcziza-{xu\t, so easily cultivated
from sclerotia gathered in the open-air {e.g.
from vine leaves).^ Thus the actual proof
that Scl. Fucheliana and Botrytis cinerca are FiixMkma.' m^lmt^oi
stages in the life of the same fungus is not scTerotfa^^' (v.'^^Tubeuf
reached by this experiment.^ The two forms ^^^'^
are, however, very frequently met together.

The sclerotia of Scl. Fuckeliana are produced in the mesophyll
of the leaves, also in the parenchyma and epidermis of the
host-plants, but never in the wood. Fcziza-ixwit^ with flat
apothecia are produced from them. Sclerotia are found in vine
leaves and over-ripe grapes (Fig. 140), especially of the Riesling,
Orleans, and Sylvaner varieties."^ Other plants and fruits may
also be attacked. Diseased parts become brown from the
effects of the parasitic mycelium, and die off. The mycelium
can only live parasitic after it has been strengthened by a pre-
vious saprophytic existence. Ascospores are thus unable to
effect direct infection. The Botrytis-aouidm seem, however,
capable of directly infecting a host-plant, at least I have always
succeeded in infecting Conifers successfully with the conidial
form Botrytis Douglasii.

^See also Botrytis amongst the "Fungi imperfecti."

^Brefeld, Heft iv., p. 129, and x. , p. 315; Tubeuf, Beitrdge z. Kenntniss d.
Baumkrankheiten, 1888.

^Zopf. {Die Pilze, p. 742) states that Feziza-ivnits may be reared from these
sclerotia after they have rested a year.

■* Muller-Thnrgau, "Die Edelfaule d. Trauben." Landwirth. Jahrhiich, 1888
(Ref. in Botan. Gentralhlatt, xxxv., 1888, p. 94).

268

ASCOMYCETES.

Epidemics of j,aeat magnitude have been ascribed to attacks
by the Botrytis-forms of this Sclerotinia. Thus on lilies in
England,^ on yellow gentian,- on male flowers of Conifers, and
on the twigs of Conifers and other plants. This is especially
the case in houses under glass, where the fungus, favoured by
the moist atmosphere, lives as a saprophyte on dead plant-remains,
and multiplies till it becomes strong enough to act as a
parasite. It is, however, quite possible that conidial forms of
other sclerotia {e.g. Scl. sderotiorum) may be confounded witli
this species.

Fig. lil. ~}1'iI,-'ii:.s cuurra (■•Scl. Fucl-diana). Branch of Prv.nus triloba with two
disuased shoots, withered and dead. (v. Tubeuf phot.)

The presence of Botrytis and allied forms on the vine is the
cause of a disease of great economic importance, because severe
loss may be incurred through rotting of the grapes and the
injurious after-effects on the "most."

A decay of the potato-plant is said to be caused by sclerotia
formed inside the stems, and also l^y a Botrytu? Smith'* has
figured similar sclerotia, which he ascribes to Peziza postuma
Berk, and Wil.

iH. M. Ward, Annals of Botany, 1888.
^ Kissling, Hediviijia, 1889.

^ Fdtzema-Jios., Zeitsrh. f. Pflanzenkranhheiltn, 1894; 0. Kiichner, Wurtemhurg.
Wochenhlatt f. Landwirth., 1893.
■• Woithington G. Smith, Diseases of Field and Garden Crops. London, 1884.

SCLEROTINIA WITH BOTRYTIS-CONIDIA.

269

Sclerotia, along with Botri/tis-comdia, have been found fre-
quently on diseased geraniums.

During the summer of 1894 a withering of twigs of Prunus
triloba occurred in several gardens at Munich (Fig. 141). A
mycelium was found in the bark, leaf-petioles, and young
ovaries, while Botrytis-coni(\.i?i were
developed on the dead parts.
With these I successfully infected
young needles and twigs of spruce.
Sclerotia were also formed on plum-
gelatine in fourteen days. The
parasite in this case had killed old
twigs of Prunus, and also infected
twigs of Conifers.

Botrytis Douglasii is a parasite
which I studied some time ago on
account of its presence along with
a disease on the Douglas fir (Pscii-
dotsuga Douglasii)} I have since
had reason to believe that it is
allied to some form of sclerotium
like that just considered, and my
view is supported by Behrens."
The disease as seen in various
parts of Germany is characterized
by withering, curling-up, and death
of young shoots towards the sum-
mits of young seedlings, and on the
lower twigs of older trees up to
about five feet above the ground.
In autumn, black sclerotia about
the size of pin heads, break through
the epidermis under the old bud-
scales, at the base of dead shoots,

and on the needles. In addition to these, smaller masses of
tangled hyphae are also formed. When sclerotia are placed
in a moist chamber, tufts of erect conidiophores arise, and
branch, forming numerous whorls of conidiophores, from which

1 V. Tubeuf, Beitrclge z. Kenntniss d. BaumkranMieiten, Berlin, 1888.
-Behreiis, Zeitsch. f. Pflanzenkrankheiten, 1895.

Fig. 142. — Botrytis Douglasii on the
Douglas Fir. The young shoots and
apex of last year's shoot are dead.
(After Tubeuf.)

270 ASCOMYCETES.

oval liyaline conidia are abjointed. These germinate at
once in water, and infect young developing shoots or needles
of Douglas fir, silver tir, spruce, and larch. Death of these
ensues in a few days, and finally tlie whole plant is killed.
On the dead needles a copious development of Botrytis takes
place, and the conidia being easily detached, spread the
disease in damp localities. The mycelium and conidiophores
are very sensitive to drought. The .sclerotia serve to carry
the fungus over winter, and may be found in autumn and
winter.

I have found JvMvperis communis with its young shoots dead,
and sclerotia similar to the above on the needles.

Whetlier Sclerotinia Kerneri Wettst. found on needles of Abies pectinata
is paiasitic or not, I do not know.

Scl. galanthi Ludw.^ Ludwig observed this disease on
snowdrops. In place of the flower a shapeless mass was pro-
duced, completely covered with conidiophores of Botrytis. The
sclerotia develop inside the tuber.

Scl. pseudotuberosa (liehm). {Sd. Batschiana Zopf or Ciboria
2}scndotnb€rosa Uehm) (Britain). The cotyledons of acorns are
sometimes found replaced by a firm sclerotium, from which a
peziza-fruit (Ciboria) is produced. Nothing is known in regard
to mode of infection or the parasitism of this species.

EU-PEZIZEAE.
The apothecia, at first closed, open out to form saucer-
shaped or cup-like discs, with a margin. The discs have
usually a thick hypothecium ; they are fleshy or waxy in
texture, and are often brightly coloured.

Dasyscypha.

The waxy or membranous ascocarps are sessile or shortly
stalked, and beset on the outer surface and margin with hairs
of various colours. The asci dehisce by a round apical opening.
The spores are ellipsoidal or spindle-shaped, unicellular, and
hyaline. The paraphyses are thread-like. Most of the forms
are saprophytic on dead plants ; the following species alone
is known to be parasitic.

^ Liidwig, Lehrbuch d. niedtren Kryptogamen.

DASYSCYPHA.

271

Dasyscypha (Peziza) Willkommii, Hartig.^ The Larch Canker
(Britain and U.S. America). Everywhere in the mountains, the
home of the larch, one finds, on young branches and old stems,
depressed canker-spots, on which the sporocarps of Dasyscypha
Willkommii are developed. Young twigs, when attacked, are
already conspicuous in July and August by their pale and
withered needles, and on them small
canker-spots will be found ; these rapidly
enlarge so that on older stems they may
reach very great dimensions. Hartig easily
succeeded in producing canker-spots on
healthy trees by artificial infection.

If canker-spots are examined soon after
the death of the bark, the stromata will
be found as yellowish- white pustules.
Conidia are produced either on the free
surface or in the internal cavities of a
stroma ; they are tiny unicellular hyaline
bodies, produced from little conidiophores.
Hartig never succeeded in getting these
spores to germinate. If the atmosphere
be moist enough the apothecia make their
appearance later on the same places ; they
are externally yellow, and internally orange-
coloured. The apothecial disc carries long
thread-like paraphyses and cylindrical asci
with rounded apices (Fig. 143). The asco-

spores are oval, unicellular, and hyaline. They germinate and
give off one or two germ- tubes which are unable to penetrate
the periderm of a host-plant, and only find entrance through
wounded places. Wounds are very common on larch as the
result of hail, or injury to twigs by snow or ice, or destruction of
needles by insects. For example, the Larch-moth {Cokopliora
laricella) is well known to cause less damage on the mountains
than in the lower regions, and in the same degree Dasyscypha is
least injurious to mountain forests.

The mycelium is septate and much branched ; it spreads
chiefly through the soft bast, especially in the sieve-tubes and

Fig. 143. — Dasyscypha
Wiltk-ommii. Three asci and
two paraphyses isolated
from an apothecium. (After
R. Hartig.)

^ R. Hartig, Untersuch. mts d. forsthotan. InMitut Miinchen, i., ISSO. M. Will-
komm, Mikros. Feinde des Waldes, ii., 1868.

272 ASCOxMYCETES.

intercellular spaces, but it may also penetrate the wood as far
as the pith. The fungus only spreads during autumn and
winter, never during summer, the vegetative period of the
larch. The attacked tissues of the bark turn brown and shrivel
up, causing the depressed canker-spots. Healthy parts continue
their growth normally, and are frequently cut otf from diseased
areas by formation of layers of secondary cork ; this isolation
is, however, rarely effective, since fresh invasions of mycelium
from the wood into the bast take place annually, and thereby
the canker-spots keep enlarging for an indefinite time.

The fungus develops reproductive organs only in damp marshy
situations. On this account spore- formation is less frequent on
mountainous slopes than in moist valleys and ravines. The
larch, on its first introduction into the low- lying parts of Germany,
Denmark, and England, was much cultivated as a pure forest in
close damp localities, and with great success ; but now this parasite
has followed its host from the mountains and causes ever
increasing damage.

As preventive measures may be recommended : larches in
low-lying districts should be grown in open, airy situations, and
never massed together nor placed in the neighbourhood of diseased
larches.

Lachnella.

The reproductive organs are similar to Dasyscypha, but the
apothecia are firmer and generally have no stalk ; the spores as
a rule become two-celled at maturity.

Lachnella pini Brunch.^ occurs in Norway on twigs of Pinus
sylvestris, as a parasite which quickly kills young plants and twigs.
It is rare on old plants. The apothecia resemble those of D.
Willkommii, but are larger, externally brown, and covered with
brown hairs and scales. The disc is reddish-yellow with a whitish
margin. The asci measure about 100/x by 9ya, and contain
colourless unicellular spores about 20yu long.

Rhizina.-

This genus contains the single species Rhizina undulata

^ Bfunchorst, Xoc/le norske skovsygdomme, Bergens Mus., 1892.

- Rhhina has a position somewhere between the Pezizeae and the Helvelleae.
Saccardo places the genus under Pezizeae, while Schroeter makes for it the
special group of Rhizinacei, included under his Helvellinei.

RHIZINA.

273

Fr. {Eh. infiata, Schaeff.). Eoot fungus, or Eing-disease.^ This
fungus is found as a saprophyte on the earth, especially where
forest fires have occurred ; also as a parasite on indigenous and
exotic conifers. As such it has been observed in nurseries in
various parts of Germany, and in woods of Pinus Pinaster in
France. The fungus itself is known in Britain, though not as
a parasite.

Fig. 144. — Sporophores of Rhizina undulata.
<i., Upper surface ; 6, lower surface ; c, small
sporophores. (After Hartig.)

Fig. 145.— Section of hymenium. a, Para-
physes; 6, secreting- tubes ; c, asci, each with
eight spores. (After Hartig.)

The disease extends from a centre and attacks one plant
after another, causing them to lose their needles and die.
The sporophores are large (f to 2 inches), chestnut-brown,
flattened or undulating structures, which sit directly on the
mycelium, without a stalk. On the upper surface is the
ascogenous layer which, when moist, is peculiarly sticky and

iR. Hartig, Forstl-)iaturwissen. Zeitschrift., 1892, p. 591; Prillieux, Compt.
rend, de la Soc. des Agric, 1880.

S

274

ASCOMYCETKS.

glutinous ; it consists of small eight-spored asci over which
project septate paraphyses, and also non-septate paraphyse-like
structures which discharge a brown secretion. The ascospores are
unicellular, hyaline, and canoe-shaped : on germination they give
ofl' a germ-tube which immediately develops into a septate
mycelium. The mycelium is found in the intercellular spaces
of the rind-parenchyma, but in the bast it grows both inside the
cells and between them, so that the sieve-tubes are often completely

Fig. U6.— Ront-system of a Silver Fir
overgrown and killed by the mycelium of
Rhizina ■undvlvla. (After Hartig.) dZ^;

Fio. 147. — Ascospores of Rhizina. a, As
taken from the ascus ; h, 24 hours after
sowing ; c, 48 hours after sowing ; d, the
spore of c enlarged. (After Hartig.)

filled up. Masses of fungoid pseudoparenchyma are frequently
formed between the dead and diseased tissues. Strands of the
nature of Bhisoctonia emerge from the diseased roots, many
of them carrying thread-like processes, at the extremity of
which an oil-drop is secreted and escapes on rupture of the apex.

According to Hartig, very tiny conidia are abjointed from
the mycelium.

De la Boulage^ and Prillieux have both come to the conclusion
that " la maladie du rond " of Finns syh-esfris and P. moritima
is the same disease as the " ring-disease " caused bv Bhizinn.

^ BhU. de In soc. des Agric. de France, 1880.

THE HELVELLACEAE. 275

Appendix.

The Helvellaceae.

This family is well known, some as poisonous, others as
edible fungi (morel, etc.), and a few are suspected of being para-
sites. The ascogenous la^'er occupies the upper surface of the
sporophores, which grow on the earth and assume many various
forms. As a rule they are erect and fleshy, and more or less
lobed, wrinkled, or folded.

USTILAGINEAE.

The Ustilagineae or Smut-fungi are distinguished by their
dark-coloured or black chlamydospores, which, on germination,
produce some form of promycelium capable of giving rise to
an indefinite number of conidia or sporidia.^ The chlamydospores
themselves are produced in large numbers from a mycelium,
and serve as resting-spores to carry the fungus through the
winter, being often, in fact, the only part which persists. An
endogenous formation of spores in sporangia as in the lower
fungi, or in asci as in the Ascomycetes, does not occur in
the Ustilagineae, Uredineae, or Basidiomycetes.

The resting-spores of the Ustilagineae contain only one
nucleus, the result of copulation of two nuclei ; their formation
thus marks the end of one generation, and their germination
the beginning of a new. In the case of the Uredineae, Basidio-
mycetes, and Ascomycetes, the beginning of the new generation
is indicated by the germination of the teleutospore, the formation
of basidiospores on the basidium, and the germination of the
ascospore respectively.

All the Ustilagineae are j^^^i'^sitic on higher plants, the
mycelium growing intercellularly and nourished by means of
haustoria sunk into the host-cells. The mycelium itself causes
neither disease nor deformation of plants, and it is only when

1 Brefekl regards the promycelium of the Ustilagineae not, like De Barv, as
a mycelial structure, but as a conidiophore or basidial structure. In accordance
Mdth this view he has founded his intermediate group, the Hemibasidii corre-
sponding to the Ustilagineae. Brefeld then subdivides this group into («) Ustila-
gineae (Usti/ago, Sphace/othf.ca, Scliizoiif-lla, Tolyposporium), which as a rule
have a septate promycelium ; and {/>) Tilletieae ( TUIetia, Entyloma, Melanotaenium,
Schroeteria, Thecaphora, Sorosporhun), with non-septate proniycelia. (Schimmtl-
■pilze, Heft v., 1883, and Heft xi., 1895.)

276 USTILAGINEAE.

the resting-spores are developed that deformation occurs. These
spores arise by intercalary growth in the mycelium, which is
generally completely used up in their formation ; they are
produced in large numbers, and scattered after decay of the
tissues enclosing them.

As a result of the germination of the resting-spores, there
is produced either a mycelium capable of immediate infection,
or a promycelium from which conidia ^ are abjointed. In the
latter case, conidia are generally formed in succession, and
continue to be given off from the promycelium for a considerable
time. They either give out a germ-tube capable of infecting a
new host, or give rise to further conidia. The latter process
is most frequently observed in artificial nutritive solutions,
where the conidia continue to sprout in a yeast-like manner
till nourishment is exhausted, when they germinate and form
niycelial filaments. In the host-plant, chlamydospores alone
are developed, conidia exceptionally (Tuburcima and Ent//-
loma).

The Ustilagineae are very dangerous and injurious enemies
of cultivated plants, especially to the various cereal crops. The
species are fairly easy to identify, because each is, as a rule,
confined to one or a few species of host. The smut-fungi are
best combated by sterilizing the seed of suspected cereals in
a copper sulphate solution or in hot water shortly before
sowing out ; (see General Part, chap, vi.) In this way any
adherent smut-spores are killed, and where this preventive
measure is regularly carried out, disease is less common and
its effects considerably minimized.

The Ustilagineae include the following genera : Ustilago,
S2:)]iacclothcca., Schizondla, Tolyposporiiwi, Tilldia, Entyloma,
Melanotacnium , JJrocystis, Tuhurcinia, Daossansia, Schmcteria,
Thecaphora, Sorosporium, Graphiola, Schinzia, Tuhercularia.

Ustilago.

The vegetative mycelium makes its way through the tissues
of the host-plant without causing any deformation. The spores
are developed in certain parts of the host, and form a much-
branched, compact, sporogenous mycelium, with membranes

' ' Conidia ' = the sporitlia of De Bary.

USTILAGO.

277

which at first swell up in a gelatinous manner. Spores are
formed inside the ultimate ramifications of the mycelium, and
as they reach maturity, the membrane loses its gelatinous
character, the cells break up, and the spores are set free ; they
are dispersed as a dry dusty powder after rupture of the tissues

Fio. 148. — Ustilarjo maydU. The head has been exposed to view by dissectino
away the enclosing leaves ; it is beset towards the apex by smut-boils.
(V. Tubevif phot.)

of the host enclosing them. The spores germinate, giving rise
to a promycelium (basidium), which becomes divided up by
means of cross-septa into several cells, from each of which
conidia are laterally abjointed. These conidia sprout yeast-
like, and give off new conidia, or they produce a mycelium ;

•278

USTILAlilNEAE.

the former is the case when nutrition is abundant, as when
under artificial cultivation, the latter under less favourable
nutrition ; in ver_^ unsuitable conditions, the constituent cells

Fig. 149. — Ustilago maydii. Diseased Maize-heads after removal of enclosing
leaves. The heads are beset with smut-boils of all sizes, some iniptiired, others
still unbroken, (v. Tubeuf phot.)

of the promycelium may each develop directly into hyphae
capable of infecting a new host.

USTILAGO.

279

Ustilago maydis (D.C.)^ (Britain and U.S. America).'^ This
smut of Zi:o. Ma'ix. produces large and conspicuous deformations
on leaves, leaf-sheaths, stems, roots, and all parts of the male and
female flowers. These are whitish,
gall-like swellings and blisters,
containing a mass of gelatinous
mycelium, from which spores are
produced. The swellings may
attain to the size of a fist, or
even larger. The spores appear
at first as dark olive-green
masses seen through the lighter-
green outer tissues of the host-
plant. When mature the spore
masses cause rupture of the
enclosing host-tissues, and escape
as a dusty powder. The spores
are dark-brown in colour, irregu-
larly spherical in shape, covered
with delicate spines, and measure
9-12,u in diameter. They re-
main capable of germination for
many years.

On being sown from the host-
plant directly into water, very
few spores germinate at once,
yet if sown in the following
spring they readily do so. In a
nutritive solution (^f.g. plum-juice
gelatine) an abundant germina-
tion may be obtained at any
time. A delicate hyaline hypha
is given out first, and after be-
coming divided up by several cross-septa, it proceeds to abjoint
conidia from various places. The conidia sprout in the gelatine

Fig.
Maize.

150. — Uitilago 'inaijdis
(v. Tubeuf phot.)

head of

1 American Literature: U.S. Dept. of Aijrindture Report, 18S9, p. 380, with
description and recommendations as to treatment. Also Ohio Agric. Exper. Stat.
Bulletin, Vol. in., p. 271, 1S90.

-The principal authorities for the occurrence of the Ustilagineae in Britain
and the United States are Plowright {British Ustilar/ineae, 1889), and Farlow
and Seymour (Host-index of Fungi of U.S. America, 1891). (Edit.)

280

USTILAGINEAK.

ill a yeast-like iiianner, hut on exhaustion of the nutritive
materials, the i)riniary conidia, and even the constituent cells
of the proiiiyceliuni, i^ive off jferni-tubes. Conidia are never
found on the maize-plant itself, but iJrefeld's investigations
have demonstrated their production on dung-cultures, so that
conidia may possibly be produced on manure-heaps or manured
soil, and young plants be infected by them. Brefeld has,
by means of germinating conidia, successfully infected maize-

FiG. 151. — UstilaijO maydis. Maize-hciid
completely malformed into smut-boils, which
have not yet riipt\n-ed. (v. Tubeuf phot.)

Fio. ir)2.—Ustilago maydis. Smut-boils on
stem and leaf of a Maize-plant, (v. Tubeuf
phot.)

seedlings as well as growing points and otlier young parts of
older plants.

Infection may take place on any immature part of the
host. The mycelium does not grow through the whole plant,
but only inhabits a part in the vicinity of the place infected.
The heads are most frequently attacked, with the result that
the grain fails to reach maturity, or is destroyed during the
formation of fungus-spores.

Owing to the danger of infection, grain mixed with smut-
spores should never be used for sowing ; nor can such be
safely used for feeding cattle on account of its injurious effects
on them.

USTILAGO. 281

Knowles,^ Cuoini,'^ and Wakker^ have investigated the
anatomical changes produced 1)t this fungus. The latter
investigator found that the xvlem -elements with unlignified
walls remain incompletely developed, and have a peculiarly
twisted course ; that normal sieve-tubes are absent ; that the
cells of parenchyma undergo secondary division, and give rise
to a new tissue provided with little fibrovascular bundles, and
rich in starch-contents, in other words, a nutritive tissue to be
used up in the spore-formation of the smut.

The disease may be found wherever maize is cultivated,
and often causes a very serious diminution in the harvest.
It may be combated by early removal and destruction of the
smut-galls. As a preventive measure, the treatment of seed-corn
with copper sulphate solution* is recommended. The avoidance
of fresh manure is also advisable, since conidia capable of germi-
nation may be lodged in it.

The following are the results of an experiment carried out
at my instigation by Professor Wollny in his experimental
plots at Munich. Three plots were selected distant from each
other about 70 metres. On 2nd May, 1893, these were marked
out in rows 40 centimetres apart, in which maize was sown at
intervals of 50 cm. The grain was previously mixed with
smut-spores obtained from the Tyrol in autumn, 1892. Plot
No. 1 was left without manure, Xo. 2 was treated with old,
No. 3 with fresh cow-manure. Maize had never been grown
in the vicinity, so that no infection could result from external
sources. The results were :

Number of Plants.
Plot No. 1, luimaiiured, - - 148

„ 2, old cow-manure, - - 124
„ 3, new cow-manure,- - 132

Ustilago Schweinitzii Tul. from Carolina U.S.A. is probably identical
with Cst. maijdis.

Ust. Fischeri Pass.'' This smut, observed in upper Italy,

^ Knowles, E. J., Atntr. Joiirncd of Mycology, Vol. i\., 1SS9.
^ Ciigiiii, " II carbone del grano turco," Boll. dell. stat. Ayrar. di Modtna, 1891.
3Wakker, Priwjshtwvs Jahrhuch, Bd. 24, 1892.

^See "General Part," chap, vi., and also " Vergleicheude Untersucliungen
lib. Flugbrandarten." P. Herzberg in Zopf's Beitragen, 189o.
^Passerini, Jiist's botan. Jahrhiich, 1889, p. 123.

bsol,

Smutted.

Per cent.

0

0

2

1-6

11

7-6

282 USTILACIIXEAE.

attacks the axis of the maize-heads. Its spores are spherical
with slightly granular coats, and measure only 4-6^ in diameter.
It causes damage through shrivelling up of the grain.

Ust. Reiliana Kiihn. This smut frequents Sorf/Imm ha/rpi n.sr
and >S'. ruhjarr (Durra or Indian millet); also maize in various
parts of Europe and America/ as well as in Egypt and India.
It is called " Haniari " in the xVrabic lanijjuafje.

Klihn ^ thus describes it : " This species causes the ears of
Durra to become large smut-galls of roundish or ovoid shape,
with a height of 60-95 m.m. and a diameter of 40-60 m.m.
At first the smut is enclosed in a whitisli skin, which is ruptured
into shreds to allow the escape of the black spore-powder.
After the smut-spores are shed, there remains a stiff skeleton
consisting of the fibrovascular bundles of the aborted ear."

The spores are distinguished from those of Ust. Tnaydis by
their greater size (9-1 o/x), and their almost smooth membrane
with very small spines. According to Brefeld, the spores are
capable of germination in nutritive solutions after eight years.
In the fresh condition they germinate in water to a limited
extent, producing multicellular promycelia which give off conidia.
In nutritive solutions they germinate and produce thick promy-
celia with three or four cells, from which multitudes of conidia
(o-12y(x long and 3-5/x broad) are abjointed. The conidia
fall off and sprout till the nutritive substratum is exhausted,
when they give rise to thread-like conidia which do not coalesce.
If kept dry the conidia easily retain their vitality for months.

Kiihn distinguishes further Sorosporium Ehrenbergii Kuhn on Sorghum
cernuum.

Ust. cruenta Kiihn.^ Another parasite on the ears of
Sorghum. It is described by Klihn as follows : " (3n the
spikelets little reddish-brown protuberances of roundish or
oblong shape are formed and enclose moderately-sized masses
of dark-red smut-powder. If the pustules are very numerous
they coalesce with each other, and the branches of the ear
become more or less shortened, thickened, and twisted. Where

1 Norton, " Ustilago Reiliana," Botanical Gazette, 1895, p. 462.
- Kiihn, " Die Brandfonnen der Sorghum-arten," Mittheil d. Ver. f. Enlhunrh
zu Halle, 1877.

•'Kiihn [loc. rit.) and Hamhurqer Garten- Zeitiuuj, Bd. 28.
Brefeld, Heft v., p. 91.

USTILAGO.

283

the pustules are fewer in number the parts of the ear retain
their normal position, but all the floral organs contained in
the glumes are wholly or partially converted into irregular
greyish smut- masses. Isolated pustules may occur under the
inflorescence, on the next internode of the haulm."

Fir;. 153. — VstilAiiju craenta. Smut of Durra or Sorghum. The head has been
divided up and the isolated branches photographed. The ovaries are transformed
to long crooked sacs, and pustule-like outgrowths are also present on stalklets and
stalks, (v. Tubeuf phot, from material supplied by Prof. Dr. Jul. Kiihn.)

The spores are yellow to brown in colour, smooth-walled,
and of very variable shape, 5-1 2/x long and o-9/u. broad. As
a rule, germination in water results in the formation of a germ-
tube composed of four or five cells, which elongate to long
mycelial threads or, exceptionally, produce a single conidium.
As a result of germination in nutritive solutions, a lively

284

USTILAGINEAE.

formation of conidia ensues ; the conidia multiply in a yeast-
like manner, and only grow out as hyphae on exhaustion of
nutritive material. Infection takes place on seedling-plants.

Kiihn oiltivated this species on Sorgimm saccharatum and S. vulgare,
and suggests that a common disease of Durra in South Africa may be
caused by this parasite.

Ust. sorghi (Link.) {UsI. Tulasnei Kiihn) (U.S. America).
This is another widely distributed parasite of Sorghum vulgare
and S. mccharatiim. Its external appearance is described by
Kiihn somewhat as follows : " Diseased plants attain to almost
their normal size, and the flower-head is developed as far as
the glumes. The ovary, however, is completely metamorphosed
into a sac filled with spores, its outer wall forming a delicate

Fig. 154 — UstHayo cruenta. Spikelet
enlarged from a head of Sorghum. The
ovaries are transfomied into long flask-
shaped sacs, from slits of which the
spores are emergring as a black jMwder.
4 natural size. (v. Tnbeuf del.)

Fig. 165. — Ustilago cri'.enia. Germin-
ating and sprouting conidia from a
cultivation in plum-gelatine, (v. Tubeuf
del.)

whitish coat, which is easily torn, and, when the spores have
escaped, a columella will be found to occupy the centre of the
smut-mass. The stamens may also become filled with spores,
and be externally more or less irrecognizable. As a rule, all the
flowers of a head are smutty; if any escape, they remain more
or less rudimentary."

The spores, according to Brefeld, germinate onlg in nutritive
solutions. They produce a four-celled promycelium, on which
few conidia are formed.

Ust. sacchari Eabh. Dust-brand of cane sugar. This fungus
injures the stems and heads of Saccharum officinale, S. cylindricum,
and S. Eriantki in Italy, Africa, and Java.

Ust. sacchari-ciliaris Bref occurs on Saccharum ciliare near
Calcutta.

Ust. avenae (Pers.). The smut or brand of the oat occurs

USTILAGO.

285

very frequently on Avena sativa, also on Avena orientalis,
A. fatua, and A. strigosa in Europe and North America. So
common is it that one seldom sees a field of oats free from the
black smutted ears (Fig. 156).

All parts of the flower are attacked, the ovary, stamens,
glumes, and even the awns. The grains become filled with
the black spore-powder, which shows through the transparent

Fig. 15(3. — Ustilago avenae. The Oat-smut ou Avena sativa. (v. Tubeuf phot.)

membrane of the ovary wall. The diseased ears emerge from
their enclosing leaf-sheaths, and become exposed to wind and
rain, under the effects of which the delicate membrane soon
becomes ruptured and the spores are blown or washed away,
till only the axes of the spikelet are left with a few ragged
remains of the flower. As a rule every shoot of a plant and
all the grains of an ear are attacked ; if single grains do escape,
they remain poorly developed.

The spores (5-8;a) have a smooth or slightly granular coat, and

286 USTILAGINEAE.

retain tlieir capacity fur gerniinatiou for years. In water they
germinate immediately, and produce a single (rarely two) proniy-
celium consisting of four or five cells, from the ends or partition-
walls of which oblong conidia continue to be abjointed for about
two days. The cells of promycelia may become connected with
one another by lateral branchlets. Delicate germ-tubes are
given off by the promycelial cells, by the conidia, or by secondary
conidia. In nutritive solutions, on the other hand, the spores
germinate much more vigorously, the promycelium is stronger,
the conidia are continuously abjointed from little sterigmata,
and go on sprouting in a yeast-like manner till, on exhaustion of
the nutriment, they germinate to form vigorous mycelial filaments.
The fusion of the cells of promycelia never takes place in nutritive
solutions.

The infection of oat-plants takes place on the soil by means of
the germ-tubes produced from the conidia, promycelia, or spores.^
These infect the first leaf-sheath — that one which on germination
emerges from the ruptured seed-coats as a whitish or yellowish-
green shining shoot, and continues to grow as a sharp-pointed
cylinder till, pierced by the first green leaf, it dries up. In
36 to 48 hours after infection, mycelial threads were found
to have pierced the epidermal walls, and to have branched freely
in the tissues. The mycelium grows from the leaf- sheath into
the first green leaf, passes straight through it into the second,
and so on till it reaches the haulm or stem." The young
mycelium grows steadily onwards, and the plasma of older
hyphae passes over into it. In this way the fungus keeps
pace with the host-plant, exhibiting externally no symptom
of its presence till the flowers are reached, where the chlamydo-
spores are formed.

Sterilization of seed-corn by Jensen's hot-water method is
strongly recommended.^ In America, steeps containing potassium
sulphide, copper sulphate, or lime are also used. As preventive
against infection, late sowing is advisable. This is founded on
Brefeld's investigations, in which he found that oat-smut germin-

1 Wolf , Der Brand den Ge.treides, 1874.

2 According to Kiihii, and in Brefeld's infections (Heft xi., 1895), the majority
of the germinating conidia are said to penetrate into the young shoot-axis.

*" Treatment of Smuts of Oats and Wheat," U.S. Department of Agriadtitre,
Farmers' Bulletin Ko. 5, 1892; "Grain-smuts and tlieir prevention," Yearbook
of U.S. Dept. of Arirknlture, 1894.

USTILAGO.

287

ated best at 10" C, and not so well above 15" C. This
conclusion is supported by experiments of Kellermann and
Swindle. Neither these investigators nor Jensen, however, aqree

Fig. 157. — Ustilago perennans on Arrhenatherum elatius (Oat grass). The grains
are transformed into black smut-masses ; the appearance of the infected spikelets
is qviite distinct from that of the healthy one to the right, (v. Tiibeuf phot.)

with Brefeld's view, that the fungus is introduced into fields
with fresh farmyard manure.

Kellermann and Swingle have found a smut on oat.s in America wliicli
they distinguish as Ust. avenae var. levis.

Ust. Kolleri Wiile. This is another species of oat-smut recently dis-
tinguished ; it has smooth spores, and is said to cause even greater damage
than Ust. avenae.

288 USTILAGINKAE.

Ust. perennans lujstr.' This Hiuut or dust-brand occurs
frequently in the Howers of Arrhenathervmi elatius (Fig. 157).
The mycelium perennates in the rhi/ome.

An Udihujo nearly allied
to the preceding one occurs
also on Feduca ^j/"«<t'/(.sis-,
Loliicm ijereniie, and other
grasses.

The Smut of Barley.
There are really two species
of Ustilago found on barley,

in plum-gelatine, (v. Tubeuf del ) ^^'^- "u/ail dUO (JbC. uauu.

Ust. hordei (Pers.) {Ust.
Jenscni Kostr.) (Britain and U.S. America). This has black
spherical spores (6*5 to 7"5;U in diameter), which germinate
and give otf conidia from a promycelium. The spikelets gene-
rally remain enclosed in their coverings. Treatment of seed-
corn with a half per cent, copper steep is a certain remedy.

Ust. nuda (Jens.) (U.S. America). In ears diseased by this
smut the epidermis of the glumes is early lost, so that the
spore-powder lies freely exposed when the ears emerge from
the leaf-sheath. The spores on germination give off a four-
celled promycelium, which however produces no conidia, but
develops directly to a septate mycelium. The spores are
smooth-coated and oval (5-7m long and 5-6-5ya broad); they
are matured and set free at the flowering season of the barley,
and probably infect seedlings in spring. The spores of this
smut are very resistant against treatment with copper steeps,
and it is recommended to soften the barley for several hours
in cold water before applying Jenson's method.

Ust. tritici (Pers.) (Britain and U.S. America), Wheat-brand.
The spores are developed in the ovary of the wheat, and are
black with a tinge of olive-green. On germination they im-
mediately form a non-septate mycelium (Fig. 160).

Hemiing- has described spore-cushions on the leaves and leaf-sheaths of
Triticum mdgare in Upper Egypt,

Ust. bullata Berk, on Triticum orientale in Turkestan.

^Rostrup, Ustilagineae Daniae, 1890.
-Heuning, Zeitsclirift f. Pflanzenkrankheiten, 1894.

USTILAGO.

289

Ust. secalis Eabenh. liye-brand. This occurs but rarely,
and (k'Strciys only the grain.

Ust. panici-miliacei (Pers.) {Ust. destruens Duby). Smut
of Millet. This smut occurs on the flowers of Panicvm milin-

FiG. 159.— Ustilago honlei. Barley-smut on Bon/eum distichum. (v. Tubeuf phot.)

cewn, P. chcirtaginicnse and P. Crvs-cjaUi in Italy, France,
Germany, and North America. Sometimes it is very abundant
and causes great damage. The mycelium makes its way into
young plants and grows upwards with them, penetrating every

T

290

USTILAGINKAE.

shoot. Spores are developetl only in the inflorescence, which
in consequence fails to reach its full development as a panicle,
and remains more or less spike-like and enclosed in a leaf-
slieath. Tlie parts of tlie inflorescence Ijecome completely fllled

Fl(!. 160. — Uslilago tritici. Wheat-smut. The central ear is normal and
healthy, the others are smutted and most of the spores are already shed,
(v. Tubeuf phot.)

with a sporogenous mycelium from which arise the spore-masses ;
these are at first enclosed in whitish coverings consistincr of
tissues of the host-plant, but when mature they escape as a black
dust or powder.

U8TILAG0. 291

The spores are smooth-coated and spherical or elliptical, 9-12 ju
long, aud 8-1 0/x broad. According to Brefeld, they germinate
in two or three days in water, and produce proraycelia with four
or five cells ; the cells may either bud out directly and become
hyphae, or do so after previous fusion.

Spores placed in nutritive solutions germinate in about three
days, and produce several strong septate promycelia with spindle-
shaped couidia. The conidia as a rule germinate directly into
branching hyphae ; fusion of conidia is not known, and secondary
conidia are only rarely formed. The hyphae become septate
in their older parts, and produce conidia in two ways, firstly,
from hyphae in the solution itself; secondly, from aerial hyphal
branches which rise out of the solution and give off conidia
in a manner similar to mould-fungi.

Brefeld states that infection takes place by means of the
germinating conidia. Only resting-spores are produced on the
plant itself, and these retain their capacity for germination
for years.

Ust. Rabenhorstiana Kiihn^ (U.S. America). This is found
on Pdiiica'iii mil lace luii, P. fjlabrum, P. lineare, and P. saiiguinale.
It destroys flowers, ears, and upper part of haulms. The spores
are brown and spiny ; they germinate, but do not produce
conidia.

Ust. sphaerogena Burrill. An American species causing
distortion of the spikelets of Panicum Crm-galli. The malforma-
tions resemble those produced on the same host by Tohjposporium
hullcdum, but differ in having a rough surface with short rigid
hairs. The spores are free and germinate easily in water,
producing promycelia which give off conidia. The conidia
frequently sprout for a time in a yeast-like manner.

The following are American species :
Ust. diplospora £11 et Ev. On Panicum sanguinale.
Ust. trichophora Lk. On Panicum colinum.

Ust. setariae Rabh. On Panicum sanguinale ; jjrobably identical with
Ust. Rohenhorstiana.

Ust. panici-leucophaei Bref. On Panicum leucophaeurn in Eio de Janeiro.

Ust. digitariae Kze occurs on the flowers of Panicum
{Dirjltariii) sa/iiji'i/iale, P. glabnim, and P. repcns. The spores
are smooth-walled.

^Klthn, Hedia'tjia, 1876.

292 rsTILAdlNEAE.

Ust. panici-frumentacei V>Y^^{'^ is found on Panicum frumen-
tacrum, 11 cultivated Himalayan millet. Only isolated grains
in an ear are attacked, becoming enlarged to twice their
normal size. (Termination of spores takes place sparingly in
water, but abundantly in nutritive solutions. Two-celled promy-
celia are produced bearing numerous sprouting conidia. On
exhaustion of nutrition, the conidia give oft' one or two filaments
on the surface of the liquid, and from these other sprouting
conidia arise.

Ust. Crameri Korn. completely destroys the ovaries of Setaria
italica, S. ri/'idis, and S. amhirjua, leaving only the outer wall
as an enclosure for the spore-powder. The spores are brown,
smooth-walled, and 6-9 yw broad, 10-12ya long. The promycelia
consist of four or five cells, which, in water as well as nutritive
solutions grow out into long threads without producing conidia.

Ust. neglecta Xiessl fills with its black spore-powder the
ovaries of Setaria glauca, S. verticillata, and >S'. viridis. The
cells of the j^romycelium develop into a mycelium without pro-
duction of conidia.

Ust. Kolaczekii Kiiln:. Un Setaria genicvJata in Berlin Botanic Garden.

Ust. bromivora Fisch, (Britain and U.S. America). This
appears in flowers of species of Bromits, so that the ovaries
become filled with a dark-brown or black spore-powder, l)ut
the glumes or heads undergo no deformation. The spores are
smooth, and on germination in water produce only a spindle-
shaped one-celled (rarely two-celled) promycelium ; in nutritive
solutions, Brefeld found they generally produced two-celled
promycelia, bearing conidia fi'om which are produced further
promycelia with conidia : yeast-like colonies are never formed.

Ust. ischaemi Fuck, attacks Andro'jpofjon Ischaenium. The
inflorescences remain almost completely enclosed in the upper-
most leaf-sheath, and are destroyed except their axes. The
spores are brown and smooth-walled. Brefeld states that in
nutritive solutions they produce conidia which remain adherent
to the promycelium and grow out into long hyphae without
coalescing.

Ust. andropogonis-tuberculati Bref. on Andropogon tuberculatum from
Simla.

Ust. andropogonis-annulati Bref. on Andropogon annvlatvm from C'ulentta.

' Brefeld, Scliinimelpihr', Heft xii., 181I.3.

USTILAGO. 293

Ust. grandis Fries. lieed-smut. (Britain.) Thi.s frequents the
haulms ot Pliragniites covimunis (also Typlia latifolia and T.
minor) ; the internodes of the host in consequence swell out
and appear as if the stem carried one or more bulrush-heads.
The mycelium permeates the whole host-tissue and produces
spores, which escape as a black dust on rupture of the epidermis.
According to Kiihn, the spores are capable of immediate ger-
mination and retain their vitality for a whole year. A
four-celled promycelium is produced and becomes detached from
the spore ; then follows an al;)j unction of oblong conidia from
the septa of the promycelium. In nutritive solutions, Brefeld
found that germination took place in the same way, but more
rapidly and vigorously. Xumerous conidia are produced, but
these only rarely give off secondary conidia, and then only a
single one ; more commonly they produce promycelia, as the
spores did, and conidia again arise from these ; yeast-like
sprouting does not occur. The resting-spores may continue
to give off promycelia in succession for some time. (In ex-
haustion of nutrition the cells of the promycelium, as well
as the conidia, develop into mycelial threads, to which alone
Brefeld ascribes the capacity for infection.

Ust. longissima (Sow.) (Britain and U.S. America). This
forms elongated brown spore-patches on the leaves of various
species of Glycerin. Brefeld states that the smooth spherical
spores germinate in water, and give off a short unicellular
promycelium which undergoes no further development. In
nutritive solutions the spores germinate in like manner, but
the promycelium becomes thread-like and septate, and gives
off conidia laterally ; new promycelia continue to be given
off from a cell which remains behind inside the spore, and the
conidia ultimately develop into hyphae.

Ust. hypodytes (Schlecht). This species forms dark smutty
coatings on haulms and leaf-sheaths of Glyccria jiuitans, Dip-
lachnis fusca, Agropyrum repens, Calamagrostis epigm, Psamma
arenaria, Stipa pcnnata and S. ccqnllaris, Broimis erect us, Triticinn
repens and T. vulgare, Elymus arcnarius, Panicum repens, Plirag-
mites communis, Aruiulinaria, etc. The spores are brown,
smooth- walled, and irregularly spherical or quadrangular ; they
germinate in water or nutritive solutions, producing mycelia
direct, without previous formation of conidia.

294 USTILAGINEAE.

Ust. grammica I?, et P>. is reitoitcd on liaulins nf Aira and 0'h/r/>r>ii
in Knj,'lanil.

Ust. echinata Sihioet. inoduccs snmt-sti ijis on leaves of Phahirix
(irnndiivdi'ii. (I'.S. Amer.)

Ust. cynodontis Mcnn. On Cijnodon Dactylon from Sinda.

Ust. arundinellae r>rcf. On Aritndinella near Calcutta.

Ust. aristidae-cyanthae l>itf. On Aristida cyanlha from Himalaya.

Ust. coicis JJii'f. On Coix l<u-Tym<i from Sinda.

Ust. esculenta Hcnn.' causes deformation of plants of Zizania latifoliu
in Toufjuin and Japan. The deformed parts are eaten, while the spores
are u.sed for dying of liair and eye-brows, as well as in the manufacture
of a varnish.

Ust. paspalus-dilatati Henn. On Paspalus dilataUis.

Ust. olivacea D. C. frequents species of Carex. The olive-
brown spore- masses hang loose and Heecy from the destroyed
ovary. The spores, according to Ikefeld, are produced from
long hyphae which become thickened at intervals and broken
up l)y cross-septa into portions corresponding to the future
spores. The hyphae, however, are not completely given up to
spore-formation, but parts remain and form fine filaments which
give the fleecy appearance to the ruptured ovaries. Germina-
tion in water results in the formation of a single conidium, a
second being rarely formed. In nutritive solutions similar
conidia are produced one after another successively, and sprout
off conidia in a yeast-like manner without the formation of pro-
mycelia. On failure of nutriment, hyphae are finally produced.

Ust. Vuijkii Oudem. et Beyerk. The ovaries of Luzula
camjicsfris become filled with spores, some colourless, some
light-brown. The spores germinate in water, giving four-celled
promycelia with ovoid conidia, which do not, however, coalesce
or develop further, even in nutritive solutions.

Ust. capensis Rees. In fruit of Juncus.
Ust. luzulae Saw. In fruit of LxLzxda.

Ust. scabiosae (Sow.)- {Ust. Jlosculornm Tub). (Britain.) The
anthers of Kiiaufia and Scahiusa attacked by this fungus become
filled with a fiesh-coloured to violet spore-powder, and swell
to little sacs. The flowers otherwise are but little altered.
Brefeld found tliat spores from KnaiUic artensis germinate
easily and abundantly in water, and produce promycelia con-

ip. Hennings, Jledwiiila, 189"); Miyal)e, Tokio Botanical Magazine, 1895.
^Fischer v. Waldheini, Bat. Zei/nng, 1867.

USTILAGO.

295

sistincf of three or four cells with conidia, and sometimes
secondary conidia. Coalescence of conidia may take place, and
thereafter production of little mycelial threads. In nutritive
solutions everything proceeds more luxuriantly, and conidia are
produced in large numbers ; they are easily detached and sprout

Fig. 181.— Ustilarjo tragopogonis. Plants of Tragopogon in flower and fruit—
1, normal fruit ; 2 and 3, normal flowers ; 4, two normal flower-buds. The
remaining specimens are attacked by the fungus, and, in consequence, remain
in the bud cundition, and filled with black spores which escape by the opening of
the involucre, (v. Tubeuf phot.)

yeast-like, till, on deficiency of nutrition, fusion and subsequent
germination takes place.

Ust. intermedia Schroet. {Ust. Jlosculorum D. C.) (Britain).
The anthers of Scabiosa Cohnnharia become filled with the dark
violet spores of this smut. The spores germinate in water,
and, according to Brefeld, produce three-celled promycelia with
few conidia ; some of these, as well as the cells of the promy-

296

U.STILAGINEAE,

celia, may develop to myceliu; cuale.sceiice of eonidia i« uukiiuwn.
In nutritive solutious eonidia are formed in large numbers, and
multiply ycast-liki' till nutriment fails.

Ust. succisae Magn.^ frequents the anthers of Scabiosc Suaisa,
and forms pure white spores, easily distinguished from those
of the two preceding species. The anthers appear to Ije thickly
covered with glassy granules. The spores produce four-celled
promycelia from which eonidia are formed. (Britain.)

Ust. tragopogonis (Pers.) (Britain).
Tliis fungus forms its .spores in tiowers
of species of Trarjopogoyi, and in many
localities has a wide distribution.
The development of the flower is
retarded, so that it retains externally
the appearance of a flower-bud en-
closed in its bracts (Fig. 161). The
dark- brown or violet spores escape
through intervals between the bracts ;
they are 13-17/>i long, 1 0-1 5/u liroad,
with reticulate markings on their
coats. They easily produce in water
four or five- celled promycelia from
which eonidia are given otf, often
followed by coalescence. In nutritive
solutions development is much more
vigorous, secondary eonidia may be
produced, and coalescence always takes place.

Ust. scorzonerae (Alb. et Schwein.) is at first sight very
similar to Ust. fragopogonis. Its spores are found in fiowers
of Scorzoncra humilis, Sc. purpurea, and cultivated species, e.g.
Sc. hispanica ; while its mycelium hibernates in the perennial
root-stocks of these. The spores are produced rapidly and
in large numbers ; they germinate easily in water, forming a
four-celled promycelium, and thereafter eonidia which do not
pair.

Ust. cardui Fisch. v. Waldh. (Britain). This is the cause
of a stunting of the flower-heads of Cardmcs aeanthoidcs, C.
nutans, and Silyhum Marianum, while at the same time they
become filled with a brownish-violet spore-powder. The spores

^ Magnus, Htdwiijia, 1875.

Fig. 162. — Ustilago tragopogonis.
Development of spores: successive
stages of development, in order of
the letters, a, Sporo8:enou8 branch,
just appearing on the surface of
young corolla of Tragopotjon pro-
tensis, and beginning to form a tuft
of branchlets. b and c, Formation of
.spores from the mycelium. </, Spore-
clump with several ripe spores, the
episporium of which is coloured
dark-violet and thickened in a
reticulate manner, (x 300). (After
De Bary.)

USTILAGO. 297

are about 20// in diameter, aud form in water promycelia with
conidia. In nutritive solutions Brefeld found conidia produced
in large numbers, and multiplying by yeast-budding. The
promycelial cells grow out as septate branched twigs, from
which conidia are abjointed, and after coalescing in pairs, produce
germ-tubes.

Ust. violacea (Pers.).^ Carnation-smut (Britain and U.S.
America). In Silene, Viscaria, Saponaria, Dianthus, StcUaria,
Malachium, Cerastium, and Lychnis, the pollen sacs of other-
wise well-developed flowers become filled with dark-violet
spores, which escape and discolour the other floral parts.
Pistillate flowers of Lychnis attacked by this fungus develop
stamens containing the smut-spores (p. 27). On germination
in water, promycelia of three or four cells are formed, and
become detached from the spores. Primary and even secondary
conidia are produced, while coalescence of promycelial cells and
conidia is common ; but only a few of them produce germ-
tubes. In nutritive solution, according to Brefeld, evervthing
proceeds much more vigorously; from tiny conidiophores on the
promycelia numerous conidia are produced in succession, and
from these other conidia are budded off like yeast-cells till
nutriment fails, when they grow out to form hyphae. The
conidia are longer than those formed in the water-cultures,
and coalesce in pairs to give rise to longer and stronger
germ-tubes.

Ust. holostei De Bary on Holosteimi umbellatum. The host-ovaries
become tilled with spores which germinate to four-celled promycelia from
which pairing;' spoi-idia are formed.

Ust. Duriaeana Tul. In the ovary of Cerastium.

Ust. major Schroet. On Silene Otites. The spores germinate only in
nutritive solutions. (Britain.)

Ust. seminum Juel. In the ovules of Arabis petraea in Scandinavia.
The spores on germination produce simple hyphae.

Ust. entorrhiza Schroet. In root-cells of Pisura sativum.

Ust. pinguicolae Kostr. (3n Finguicula vulgaris in Denmark.
According to Brefeld, the spores germinate equally in water or
nutritive solutions, forming three-celled promycelia, which separate
from the spore and bud off conidia from each cell.

1 Tulasne, ^4)/?j. d. sciences natur., .Ser. iii., Vol. vii. , 1847.
Atkinson {Amei-ican Carnation Society, 1S9.3), describes this and other smuts
frecjuenting American Carnations. (Edit.)

298 USTILAGINEAE.

Ust. betonicae Beck.^ occurs in the anthers of Betonica
Alo/ircnrus. Its spores are larger than those of Ust. violoxm,
and have larger-meshed reticulations on the spore-coat. The
spores germinate in water, and as a rule produce a three-celled
promycelium from wliich conidia are abjointed. These at once,
or after production of conidia, coalesce in pairs and give off germ-
tubes. In nutritive solutions germination takes place much
more vigorously, numerous conidia are formed and continue to
bud off new conidia till the nutriment is exhausted, when
coalescence of conidia and development of hyphae takes place.

Ust. bistortarum I). C. frequents leaves of Polygunum and
Bunic.':. (Britain and U.S. America.) Brefeld states that the
spores are dark-red and germinate to four-celled promycelia,
from which conidia are produced and readily coalesce, especially
in presence of abundant nutriment.

Ust. marginalis (Lk.) on Polygomim- Bistorta. The spore-masses
are dark-violet, and occur chietly on the margins of the leaves.
The spores germinate in water and produce a four-celled promy-
celium with oval conidia, which do not .sprout, but either pair
or grow out as hyphae.

Ust. anomala Kunze. On leaves and in ovaries of Polygonum (U.S. America;.

Ust. utriculosa (Nees). In ovaries and anthers of Polygonum. The
greyisli-violet spores, Brefeld says, germinate during the following summer,
and give otf four-celled jii-omycelia with conidia which do not coalesce in
pairs. IJritain and U.S. America.)

Ust. Parlatorei Fisch. On twigs and leaves of Rumex maritimns and R.
obUisifolius.

Ust. Kuhneana Wolf. Inhalnts all parts of Rumex Acetosa and R. Aceto-
sella (Britain).

Ust. Goeppertiana Schroet. On Rumex Acetosa, especially in leaves and
leaf-petioles. The sjiores germinate in water or nutritive solution. The
promycelium is unicellular and remains inside the spore, giving off a single
conidium, which for a time buds off other conidia {Ust. olivacea alone behaves
in this same way).

Ust. Molleri Bref. On Polygomim hispidum.

Ust. Koordersiana Bref. On Polygonum harhntiim in Java.

Ust. domestica Bref. On Rumex domesticus in Norway.

Ust. vinosa (Berk.). On fruits of Oxyria (Britain and U.S. America). The
spores germinate in water or nutritive solutions, and produce a four-celled
promycelium from which conidia are given off, especially in nutritive
solutions ; the conidia ultimately produce germ-tubes.

^ Zoolo(j.-hotan. Gt-^ell., Vienna, 1880.

USTILAGO. 299

Ust. Vaillantii Tul.^ appears in the anthers and ovaries of
Giujea, Scilla, Muscari, etc. The perianth of diseased flowers
remains, but is somewhat enlarged. The ovaries and anthers
become filled with spores ; the latter organs are, however, fully
developed and may even contain pollen-grains mixed with spores.
According to Brefeld, the spores germinate easily in water and in
nutritive solution. A promycelium is formed which, after detach-
ment from the spore, becomes three-celled and develojjs conidia.
These sprout for some time, then produce three-celled promycelia.

Ust. ornithogali (St-lim. et Kze) fomis leaf-swellings on Ornithogalum and
Gagea.

Ust. tulipae (Heufl.) produces swellings on the leaves of the tulip.
Ust. plumbea Rostr. occurs on leaves of Aruvi maculatum in Denmark.
Ust. ficuum Reich. In the fruits of Ficus Carica in Asia Minor.
Ust. Trabutiana Sace. In berries of Dracaena Draco in Algeria.

Ust. Vrieseana Yuill.- In the Botanic Garden at Amster-
dam, the roots of several species of Eucalyptus exhibited woody
tumours from which proceeded outgrowths resembling " witches'
brooms." These contained the mycelium of an Ustilago which
produced spores in the cortical tissues.

Ust (?) adoxae Bref. On Adoxa raoschutellina in cells of the subterranean
stem. The spores produced only simple filaments without conidia.
Ust. Lagerheimii Bref. On Rumea from Quito.
Ust. Schweinfurthiana Thum. On Imperata cylindrica from Cairo.
Ust. boutelouae-humilis Bref. On Doutelona humilis from Quito.
Ust. Ulei Henn. On Chloris.
Ust. spinificis Ludw. On Spinifex hirsuta from Adelaide, Australia.

Ust. Treubii Solms.^ This Javanese fungus and the galls
produced by it deserve a somewhat lengthened notice on account
of their general biological interest. It causes a hypertrophy on
Polygonum chinensc in Java, which further exemplifies the
phenomena already noticed in connection with Caeoma deformans
on Thujopsis (p. 30).

The stems at attacked places show strong hypertrophy and
great change in their anatomical structure. Solms designates
the thickenings, in conmion with those caused by Caeoma.

^Tulasne, Ann. d. science natur., Ser. in., Vol. vii. , 1847, with plates of Musrnri.
Worth G. Smith (Gardeners Chrouiile, xv., IS94, p. 463), give.s a figure
and note on occurrence of this smut in Britain. (Edit.)

^Vuillemin, Compt. rend., 1894.

^ Solms, Annul, du jardin boian. de Btiitenzorej, Vol. vi. , 1886-87, 13. 79.

300 USTIL.UilNEAE.

(Icformans and Fcrvlermium dnHiiMii, as " vegetative canker-
galls." On those places are crowded iieshy brittle outgrowths,
consisting of an irregular bent club-like stalk, longitudinally-
furrowed, and expanded at its upper extremity into a broadened
head containing the Ustilcujo spores. Solms calls these out-
growths " fruiting galls," ' and he describes them as follows :
" if one of these protuberances be divided, the spore deposit will
be found as a flattened violet layer, extending to the margins
of the head and roofed in by a slight plate of tissue. This
last becomes ruptured, shrivelled, and brown. The violet
spores are thus set free, along with a loose woolly capillitium-
tissue, which apparently facilitates distribution of the spores
by rendering them difficult to moisten, a contingency very
likely to happen in the heavy tropical rains of Java, and with
the result that germination would occur before the spores had
time to be transported to a new host. After shedding of the
spores, the succulent stalk remains. The fruit-galls consist of
a hypertrophied tissue developed from the cambium; they first
emerge as roundish naked protuberances, covered externally by
a smooth epidermis, and containing a meristem from which
fibrovascular bundles are developed. The galls are composed
of a homogenous parenchyma of large thiu-walled cells, elongated
in the direction of the long axis of the galls, and containing
large cell-nuclei. The epidermis consists of little, polygonal,
nucleated cells, and is pierced by a few stomata. The galls
are internally permeated by a number of irregularly arranged
fibrovascular bundles which show a slightly developed wood
and bast region. As the anterior end of the fruit-gall elongates,
the bundles keep pace by repeated forkings, and form a
system of branches diverging at very acute angles and ter-
minating a short distance from the surface of the gall. The
violet-brown sporogenous layer is situated just at the termination
of the bundles, and is covered by a slight layer of parenchyma
under the epidermis. The sporogenous layer appears as if
composed of columns arranged beside one another in a palisade
manner, and connected above and below with the enclosing
tissues. At the margins of a section the columns easily separate,
and will be seen to consist of a central strand of elongated
cylindrical cells filled with a reddish gum-like mass. The cells

^ Frnchtgallen.

USTILAGO. 301

belong to the tissue of the Polygonum and may form simple
filaments, or several such filaments may become bound together
by lateral connections. Each strand becomes surrounded by
spores of the Ustilago which are set free on rupture of the
fruit-gall, while the cell-strands laterally bound to each other
are loosened from the surrounding tissue as the capillitium.

" The spores germinate in water, producing short unicellular
promycelia and fairly large conidia, which coalesce before they
germinate. The mycelium is confined to a small part of the
stem, twigs, or inflorescences of the host-plant. The hyper-
trophied parts of the stem contain abnormal spongy wood,
which easily decomposes and brings about the death of the
galls, along with parts of the stem situated beyond them, or
even the whole plant. The normal production of cambium is
completely destroyed in the galls. The pith and primary rind,
however, remain uninfluenced. The cambium produces, both
outwards and inwards, such a mass of thin-walled parenchyma
that the normal bast is forced a.sunder and disarranged. In
this way ^rupture of the sclerenchyma-layer ensues, whereby the
primary rind is destroyed, and the abnormal tissue formed by
the cambium emerges to view. It is from such places that
the excrescences described have their origin."

It will be seen we have here the partners of a symbiosis
becoming so adapted to each other that the host-plant produces
a special tissue for the distribution of the spores. This case
goes further than most of those already mentioned in § 5;
but the bushes produced by Ca.coma deformans for the formation
of its spores are again a distinct advance on the " fruit-galls "
of this UstUago.

Cintractia.

Spore-masses developed inside a stroma and passing outwards
so that the mature black spores lie freely exposed.

Magnus 1 has recently separated Ustilago caricis Pers. and U. submdusa
Koni., and placed them under this genus, because their spores are developed
only in the ejjidernial cells of the host-ovary.

Cintractia caricis (Pers.)^ (Britain and U.S. America). The

iCornu. Annal. d. sciences natiir., Ser. vi., Vol. xv., 1883. Plate XV.
Magnus, Botan. Vtrein d. Prov. Braiidenhurq, xxxvii. Brefeld, Schimmelpilz,
Heft XII., 1895.

302

USTILAOINEAE.

mycelium tonus a stroma on the ovary-wall ; there the
spores originate and pass out to the periphery as they attain

maturity. The spores adhere in hlack
^ masses, and germinate in water in the

following spring. A promycelium is pro-
duced, and on emerging into the air
becomes divided by means of a cross-
septum towards its apex ; from both
cells so formed conidia are developed
and grow out into germ-tubes without
previous sprouting. This species occurs
on many species of Carex, and the
mycelium perennates in the rhizomes.
The spores vary somewhat on the
different hosts.

C. subinclusa (Korn.) (U.S. America).
The spores form coal-black masses in the
ovaries of many species of Carex. They
develop on a stroma from within out-
wards, and are more easily detached than
those of C. caricis ; their coat-markings
also take the form of thicker and shorter
processes. On germination in water
after a resting period, the spores produce
two-celled promycelia, from the apical
cell of which an ovoid conidium is
abjointed, while from the lower cell a lateral conidiophcre is
produced. Xumerous conidia are given off from both cells, and
grow out without previous sprouting.

C. (?) sorghi {Endothlaspis sorghi) Sor. The uiycelium envelopes the grain of
Sorghum cernuum, and fills it with black spore-masses. It has only been
observed in Asia..

Other species of Cintractia occur outside of Europe, but are of no
practical importance.

Fk:. 163. — Cintractia co.rlcis.
Two ovaries have been replaced
by black spherical fungus-fruits ;
an isolated normal triangular
ovary is shown in longitudinal
and cross section, (v. Tubeuf
del.)

Sphacelotheca.

The sporocarp is sharply defined, and consists of a columella
round which the loose mass of spores is disposed, the whole being
enclosed in a covering formed by non-sporogenous hyphae.

Sphacelotheca hydropiperis (Schum.). De Bary describes

SPHACELOTHECA.

303

this fungus as follows : ^ " Sphacelothcca forms its compound
sporophore in the ovule of its host. When the ovule is normally
and fully developed in the young flower, the parasite, which
always grows through the flower-stalk into the place of insertion
of the ovary, sends its hyphae from the funiculus into the ovule,
where they rise higher and higher and surround and penetrate
its tissue to such an extent as
almost entirely supplant it, and
thus an ovoid fungus-body of
densely interwoven hyphae takes
the place of the ovule. The
micropylar end of the integu-
ments alone escapes the change,
and remains as a conical tip
(Fig. 164 C) on the apex of the
fungus-body and gradually turns
brown and dries up. The fungus-
body is at first colourless and
uniformly composed of much-
branched hyphae, which are
woven together into a compact
mass and have the gelatinous
walls of the simple sporophore of
JJstilago to be described below.
If it has retained its ovoid
form as it steadily increased
in volume, differentiation begins
first in the apical region into a
comparatively thick outer wall
which is closed all round, an
axile columnar cylindrical or
club-shaped Ijody, the columella,
both parts remaining colourless, and a dense spore-mass which
fills the space between the two and becomes of a dark violet
colour (Fig. 164 C, I)). The lower part which corresponds to
the funiculus and chalaza of the ovule remains undifferentiated,
and an abundant formation of new hyphae is constantly taking
place in it. This new formation is so added from below to
the differentiated portion, that the latter constantly increases

^ De Bary, Morphology and Biology of the Fungi, English Edition, p. 173.

Fig. 104. — Sphoxelotheca hydropiperis in the
flower of Polygonv.hi Hydropiper. A, Ripe
compound sporophore of the fungus project-
ing from the perianth of the Polygonum.
B, The same, with the mass of spores emerg-
ing from the sporophore. C, Median longi-
tudinal section through a young fructifica-
tion and its environment. D, Longitudinal
section through an older sporophore. c, The
columella, p, The perianth. /, The wall of
the ovarj'. o, The integument (micropyle) of
the ovule, g, The style. In C and D the
sterile or young tissue of the fungus is
shaded by longitudinal lines, the mass of
ripening spores is darker. Further explana-
tion in the text. (Slightly magnified.)
(After De Bary.)

304 USTILAGINEAE.

in height wiUiuut becoiain^i;- niiitciially broader, and maintains
therefore the form of a cylinder pointed at the upper end.
Where the parts below approach the wall, columella, and spore-
mass, they assume their structure and colour. In other words,
each of the three portions grows from its base by addition of
new tissue-elements, which are constantly being produced and
pushed onwards from a basal formative tissue, and are difif'eren-
tiated and assume their ultimate form in the order in which
they are produced (Fig. 164, C and D). The development
and mature structure of the spore-mass are the same as those
of Ustilago, which will be described presently. The wall in
its fully developed state is a thick coat formed of many irregular
layers of small round cells not very firmly united together.
These cells are formed in the same way as the spores from
the hyphae of the primary tissue, and are of about the same
size as the spores with a delicate colourless membrane, and
for the most part with watery hyaline contents. The columella
has the structure of the wall, but it usually incloses in its tissues
evident brownish fragments of the tissue of the ovule, and
consists at its uppermost extremity of much larger, firmer
hyaline cells, the origin of which I am unable to explain. I
may also observe that the upper extremity in young specimens
always ends blindly in the spore-mass {C), but in some older
ones reaches to the apical portion of the wall and passes into
it {D)\ it is still uncertain whether tliis is a difference in the
individual plants or a difference of age.

" The spore-receptacle which has now^ been described is formed
only from the ovule. The perianth and stamens of the flower
continue in their normal state. The wall of the ovary and the
style are also not attacked by the fungus ; they do not follow the
growth of the spore-receptacle, and as this advances the lateral
wall is distended and at length bursts transversely : the style
with the upper portion of the wall dries up into a small point
at the apex of the receptacle, which is borne by the latter as
it grows out of the perianth {A). The wall of the spore-
receptacle, especially where it is covered above Ijy the withered
remains of the wall of the ovary, is very fragile, and tears
asunder at the slightest touch to discharge the spores (B)."

The dark- violet spores have a finely- warted exospore.
According to Brefeld, they germinate in water after a resting

SPHACELOTHECA.

805

period, and produce three-celled promycelia with elongated ovoid
conidia, which sprout indefinitely. In nutritive solutions two
or three promycelia may be produced.

Schizonella.^

The spores are produced in series on the reproductive hyphae.
At first two-chambered by means of a cross-septum, they later
separate into two loosely-joined cells and form twin-spores ; each
half germinates like an Ustilago-spove.

Schizonella melanogramma (D. C.) (U.S. America). A
species found on leaves of various species of Carex. The spores,
when mature, escape by short fissures in
the upper epidermis of the host ; they
are black and coupled in pairs by a short
connection. They germinate in water
and produce a promycelium of three or
four cells from which conidia are given
off. In nutritive solution the promycelia
produce conidia, which fall off' and sprout
yeast-like for a time.

Tolyposporium.

The sporogenous hyphae form tangled
masses, and produce their spores firmly
bound together in balls. The single
spores are large, somewhat angular or
spherical, and each germinates like a
spore of Ustilago.

Tolysporium junci (Schroet.) causes
the formation of gall-like outgrowths on

the ovaries, fiower-stalks, and haulms of Juncus hufonius and
J. capitatus. In these the spores are developed and escape as
spore-balls. The spores, after a prolonged rest, germinate in
water and produce four-celled promycelia, from which ovoid or
spindle-shaped conidia are given off. In nutritive solutions many
of the cells in each spore-ball germinate and produce promycelia,
at first four-celled, later further divided by new septa ; the
conidia sprout and grow on till they reach the air, where aerial
•conidia are formed.

Fig. 165. — Tolyposporium junci.
Spore-mass. One spore has
germinated and given off an
eight-celled promycelium ; spori-
dia are being abjointed in whorls.
(After Woronin.)

^Schroeter, Biolorjie, d. Pflanzen, Bd. ii. , 1877.
U

306 USTILAGINEAE.

T. buUatum Seliroet. (U.S. America). The ovaries of Pamcum
Crii.s-f)(dli are tianstbrmed by this fungus into spherical tumour-
like bodies, which project from the otherwise unchanged flower
and enclose the black spore-masses. . The spore-balls consist of
hundreds of spores which, Brefeld says, germinate in water in
the following year. Each produces one, two, or three two-
celled promycelia, which give off terminal spindle-shaped conidia;
these sprout in nutritive solutions and ultimately form aerial
conidia.

T. Cocconii Mor. In leaves of Carex recurva in Nortli Italy.
T. penicillariae Bref. On Penicillaria spicata from Simla.
T. cenchri Bref. On Cenchrus echinatus.

Tilletia.

Spores formed from hyphae, which swell up in a gelatinous
manner. Conidia spindle-shaped or filamentous, and produced
in whorls from the extremity of a non-septate promycelium ;
they are developed only in air and generally fuse in pairs
before being detached from the promycelium.

Tilletia tritici (Byerk.) {T, caries Tul.) (Britain and U.S.
America). Smut, stink-brand or stinking-smut of wheat.

This constitutes one of the most destructive smuts of wheat-
grain, not only destroying the grains actually attacked, but the
black spores cause such damage to the remainder, when threshed
or ground, that it is useless for bread-making. The presence
of this fungus is most obnoxious from its strong odour of herring-
brine or trimethylamin, hence the name stinking-smut or stink-
brand. The smut also possesses poisonous properties which make
flour contaminated with it dangerous to human beings, and the
straw or chaff injurious to cattle.

Certain diseases are jjrodiiced in animals by the consumption of smnt-
fungi with food. The effects of each species of smut have not as yet been
closely investigated, but Tilletia tritici seems to be one of the chief causes
of trouble. The following are also suspicious : Ustilago maydis and the
various species of Ustilago which attack oats, barley, wheat, and grasses.
The symptoms in the few cases of disease obsei-ved 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
continuous 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.

TILLETIA.

30/

The black spore-powder is developed as an evil-smelling mass
in the ovaries of the host, which are completely destroyed except
the onter coats. As a rule every grain in an ear is attacked.
The smut is at first oily or greasy, but gradually dries up to
form a hard stony mass enclosed in the fruit-glumes and

Fig. 167. — Titletia tritici. A, Two spores germinated in
moist air ; a short promycelium is developed, and bears a
crowu of conidia (sporidia), several of which have fused in
pairs. Fushion of conidin, germination, and development of
a secondary conidium, C, are also shown. B, Two spores
germinated in water with promycelia which elongate till the
water surface is reached, where they form sporidia ; the
. . promycelia are septate and the plasma passes over into the
Fio. Ib6. — TiUetia triUci. younger cells, (v. Tubeuf del.)
Stinking-smut of Whecit. Ear of
wheat with smut-grains indi-
cated black. The isolated spike-
let contains two smut-grains,
which, as well as the isolated
examples, show fissures in the
original ovary wall. One smut-
grain in section shows the in-
terior filled with black spores,
but the ovary wall still intact.
(v. Tubeuf del.)

pales. The spores, therefore, do not escape as dust on the
field, but remain in the heads and are garnered with the crop.
Smutty ears are easily distinguished on the field by their
stiff erect position towards harvest-time, as compared with the
more or less nodding healthy ears ; their florets also lie more
away from the axis of the ear, the chaff-glumes are more spread

308 USTILACINKAE.

out, and the grains are somewhat compressed. In earlier
stages of development the diseased ears are less easily dis-
tinguished, Vjut they grow more rapidly than the normal, their
ovaries are earlier formed, and have a dark greenish-brown
colour. According to Kiihn,^ the ears in their earlier stages,
as they emerge from the leaf-sheath, possess abnormally thickened
seed-coats, especially towards the apex, while in section they show
a dark-green colour. He also found the grains to be replaced by
a white and easily detachable mass of fine mycelium. Spores
are formed as swellings on the ends of the sporogenous hypliae,
and into these the plasma-contents of the hyphae pass over. The
mature spores are dark-grey and spherical, with netted markings
on the episporium. They germinate in water, and produce a
promycelium of varying length. The conidia arise as a whorl
of thread-like branches on the end of the promycelium, and into
them all the protoplasm passes over, while the promycelium,
after being cut off by a cross septum, disappears, leaving the
conidia as isolated bodies (Fig. 167). The conidia become united
in pairs, frequently before isolation. After fusion comes germina-
tion, and the emission of a filament from the end of which
sickle-shaped conidia are abjointed. Klihn states that these
conidia, as well as the whorled primary conidia, if placed in a
damp atmosphere, can give rise to a hypha capable of infection.
In water, however, the hyphae continue to grow longer, the
plasma from the older parts passing over to the younger, and
no conidia are formed (Fig. 167).

The conidia which remain unpaired were found by Brefeld to
behave similarly to those which pair, except that the resulting
germ-tubes and conidia remained smaller. Spores refuse to
germinate in nutritive solutions. Conidia grown in water
cultures and placed afterwards in nutritive solutions, give off
a fine mycelium, from which short, lateral, aerial branches
become cut off by septa, and devote their contents to the pro-
duction of a few sickle-shaped conidia ; these are easily detached,
and produce a mycelium capable of giving off further conidia
in a manner similar to that just described.

The investigations of Brefeld have also given the interesting
result that hyphae which produce conidia may also give rise
to spore-like bodies. The hyphae, after growth in length has
' Kiihn, Die Krankheiten d. Kxdturgewdchse, 1858.

TILLETIA. 309

ceased, begin to thicken, at first equally, then more at some
places than others, so that they become nodose or rosary-like,
with swellings at irregular intervals. The spores originate in
the swellings, and between them are formed cross-septa which
split and bring about isolation of the spores.

Klihn's experiments on infection are of considerable interest.
He investigated the germination of this and other smut-fungi,
cultivating many of them in his garden at Halle, and published
his results as early as 1858.^ In his artificial infections he
dusted seedlings with spores of Tilldia, and investigated the
different parts of them microscopically. Sections showed him
that the germ-tubes penetrate direct through the walls into
the epidermal cells, and always in the neighbourhood of the
lowest nodes. Thence the mycelium grows upwards with the
lengthening plant, especially through the pith, and the plasma
of the older mycelium passes onwards into younger parts. In
this way the hyphae, without greatly disturbing the growth of
the wheat-seedlings, reach the ovaries, and with the formation
of spores begin the work of destruction.

Kiihn was also able to demonstrate that both germinating
sporidia and conidia are capable of infection, and that, where
many had infected the same plant, so much mycelium could be
produced that death of the host ensued. According to the
same authority, the fungus attacks spring wheat more than
winter wheat, and the common forms {Triticum sativum and
T. turgiclura) with nearly allied varieties, more than " spelt "
{Triticum spelta).

As a preventive measure against Tilletia, the experiments of
Kellermann, Swingle, Kirchner, and others, lead them to recom-
mend Jensen's method of placing the seed in hot water immedi-
ately before sowing. (See Chap. YI.)

Tilletia laevis Kiihn. (U.S. America.) This is another stink-
ing smut of wheat similar to T. tritici, except that its spores
have perfectly smooth coats.

T. controversa Kllhn. Found in grains of Triticum repens
(couch-grass) as well as Tr. vulgare and Tr. glaucum. The
spores are distinguished from those of T. tritici by the higher
ridges and wider meshes on the episporium. The mycelium

1 Previous to Ktihn, Pi-evost and Tulasiie hail in 1853 carried out experiments ;
also Gleiclien in 1781.

310 USTILAGINEAE.

perennates in the rhizomes. The spores, according to Brefeld,
germinate in water after a resting period of two years ; in
two years more they lose their capacity for germination.

T. secalis (Cord.) ^ is epidemic and destructive in ovaries of
■ Sccale cnralr.

T. decipiens Pers. (Britain). In fruits of Agrostis vulgaris
and A. stolonifera. Schroeter says the plants remain stunted.
Brefeld states tliat spores germinate in water after a resting-
period of three years, and lose their capacity for germination
ill the following year.

T. lolii Auersw. frequents the ovaries of cultivated Lolium
perenne, and of X. temulentum (darnel-grass).

T. hordei Korn. occurs in grain of Hordeuiix frarjile and H. mvrinv.rii in
Persia.

T. separata (Kunze). In grain of Apera Spica-venti.

T. calospora Pass. In grain of Andropogon agrestis in Italy.

T. Rauwenhoffii Fisch. In grain of Holcus lanatus in Belgium.

T. olida (Piess.) forms stripes on the leaves of Brachypodium si/lvaticum
and B. pinnatum.

T. sesleriae .Tuel forms similar stripes on leaves of Sesleria coeridea.

T. striiformis (Westend.) occurs on leaves, leaf-sheaths, and stalks of
Alopecurus, Anthoxanthum, Milium, Holcus, Arrhenathentm, Briza, Poa,
Dactylis, Festv.ea, Bromus, Agrostis, Lolimn, etc. (Britain and U.S. America).

T. calamagrostidis Fuck. On leaves of Calamagi-ostis epigaea, C. //alleriaaa
and Tritirum repens.

T. epiphylla Berk, et Br. Stink-brand of Australian maize.

T. Fischeri Karst. In fruits of Carex canescens in Finland.

T. arctica Rostr. On leaves and stalks of Carex /estiva in Finniark.

T. thlaspeos Beck. In fruit of Thlaspi alpestre.

T. zonata Bref. On Sporoboliis ligularis from Quito.

T. (?) glomerulata Cocc. et Mor. occurs in Italy on leaves of Cynodon
Dactylon, Plantago laweolata, and Medicago.

T. sphagni Nawaschin - was once regarded as a second form of spore of
Sphagnvm.

T. oryzae Pat. The fungus to which this name was given forms
sclerotia in the grain of Oryza sativa (Rice) in Japan.

Brefeld^ found that dark spores are given off from the surface of the
sclerotia. These spores, on germination in nutritive solution, produced a
septate mycelium which, in dilute solutions, gave off pear-shajjed colour-

^ Kiihn, Botan. Zeituntj, 1876, p. 470. Cohn, Jahrburh d. Schles. Ges. f.
vaterland. Kidtur, 1876. Niessl, Iledivujia, 1876.

- Nawaschin, Uiiher die Brandkrankheit d. Torfmoo^e, 1893 ; and Milamjes
biologiques, t. xiii., liv. 3, 1893.

•^ Botan. Centralblatt, lxv., 1896, p. 97.

TILLETIA. 311

less conidia incapable of germination. When the nutritive solution was
frequently renewed, the mycelium grew vigorously and formed a sclerotium-
like body, from which the dai'k spores were laterally abjointed and set
free. On this account Brefeld founded a group with the generic name of
Ustilaginoidea ; it includes this species as Ustilaginoidea oryzae and an-
other similar one on Setaria Crus-Ardeae he calls Ust. setariae. The group
has affinities with the Ustilagineae and Ascomycetes like Claviceps, and
Brefeld sees in it a connecting link between the two families.
Several other American species of Tilletia have been recorded.

Neovossia.

Characters similar to Tilletia, except that the conidia produced
on germination of the spores do not coalesce. Conidia sown
in nutritive solutions produce a mycelium with two kinds of
secondary conidia.

N. moliniae Kornike. The black spore-powder is developed
in enlarged ovaries of Molinia cocrulea. The smooth ovoid
spores are enclosed in a transparent mantle, and have a hyaline
tail-like appendage. Each spore is produced at the end of a
hyphal filament, which remains attached after the spore-mass is
freed and forms the appendage. The spores germinate in water
at once, and send up a simple aerial promycelium, on the apex
of which a crown of many needle-like conidia are produced.
Septation of the promycelia may take place if they become very
long, the protoplasm passing into the apical segments and leaving
the basal empty, as in Tilletia. Branching of the promycelia
may also occur. The conidia (ju being shed give off sickle-
shaped secondary conidia. In nutritive solutions, however, the
conidia produce a mycelium from which either sickle-shaped or
needle-shaped conidia may be given off, the latter however never
as a crown or circlet.

N. Barclayana Bref. In the fruits of Pennisetum triflorum in Simla.
(This is not synonymous with Ustilago 'penniseti Rabh.).

N. (?) bambusae Bref. In fruits of bamboo from Brazil.

Entyloma.

Mycelium intercellular and never gelatinous. The spores
are of intercalary origin, and arise here and there on any part
of the mycelium. The spore-clusters appe'ar externally as
spots, and the spores never leave the host. The spores on

312

USTILAGINEAE.

germination produce a thread-like promycelium bearing apical
conidia, which conjugate in ])n'n-H before emerging from the
host-tissues.

The following species form conidia on the host-plant :

Entyloma serotinum Sohroet. occurs on leaves of Symphytum hiherosum,
S. ojici/tafis, and Borago officinalis.

E. canescens Schroet. On Myoaotis (Britain).
E. fuscum Schroet. On Papaver Rhoeas and /'. Argemone.
E. bicolor Zojif. On Papaver Rhoeas and P. duhium (Britain).
E. ranunculi (Bon.) fdrnis; white spots on species of Ranunculus. Tufts

of hyphae emerge from the stomata and
form conidia, which on germination again
give oif conidia.^ (Britain.)

E. corydalis De Bary on Con/dalis
cava and ('. solida.

E. heloscladii Magn. on Helosdadium
nodifloi'um.

These do not produce conidia on
the host-plant :

E. thalictri Schroet. on Thalictrum
minus (U.S. America).

E. verruculosum Pass, on Rununcxdus
lanuginosvs.

E. Fischeri Thiim. on Stenactis bellidi-
^ora.

E. chrysosplenii (Berk, et Br.) on
C'hri/sospleniam alternifolium (Bi'itain).

E. linariae Schroet. on Linaria vulgaris
(U.S. America).

E. picridis Eostr. on Picris hieracoides.

E. eryngii (C'orda) on Eryngium planvm
and E. campestre.

Calendula, Hieraci^im, Arnoseris, Arnica,
168).
and Dactylis in Italy.

The following produce gall-like swellings :

E. microsporum (Ung.) {E. Ungerianum De Bary) (Britain and
U.S. America). On Ranunculus repens, R. bulbosus, and R. Ficaria
(Fig. 168).

E. Aschersonii (Ule) on roots of Helichrysum arenarium (Fig. 169).

E. Magnusii (Ule) on roots of Gnaphalium uliginosum and G. luteo-alhnm
(Fig. 170).

Fio. l(iS. — Entylonta calendulae. a, My-
celial filament, with two young resting-
spores. h, Resting-.spore germinating ;
the anterior pair of primarj- conidia
shows conjugation or fusion at the base.

Eiiti/lonia viifrosporum. c, Germinat-
ing restiug-spore ; four primary conidia
fusing in pairs at their apices. <?, The
same specimen seven hours later; com-
mencement of abjunction of a secondary
sporidium on each pair. (After De
Bary.)

E. calendulae (Ondem.) on

Bellidiastrum, etc. (Britain) (Fig.

E. crastophilum Sacc. on Poa

^ H. M. Ward, Philosoph. transactions of Royal Sac. London, Vol. 178, 1SS9.

ENTYLOMA.

313

Still to mention are :

E. EUissi Halst., known as "white smut."^ It inhabits spinach
{Spinacia oleracea), discolouring the leaves.

E. ossifragi Eostr. on Narthecium osdfragum in Denmark.
E. catenulatum Eostr. on Aira caespitosa in Denmark.

Fig. 169. — Entyloma Aschersonii. Germin-
ated spore with septate promycelium ; one
promyoellal branch remains rudimentary,
the other (to left) has produced two bi^anches,
one of which has elongated and bears a coni-
dium. (After Woronin.)

Fig. 170. — Entytoiua Magnusii. Germin-
ated spores ; the promycelium of one shows
a whorl of three branches with apices
elongating to fonn germ-tubes ; the other
shows two, out of three, germ-tubes giving
off branched sporidia (conidia). (After
Woronin.)

E. leproidum Trab.'- \Oedomyces leproides (Sacc.)]. Diseased beet-root
exhibits irregular outgrowths, which enclose spaces filled with the brown
spore-powder of this fungus.

E. nympheae (Cunningham) Setch.^ on various species of Nymphea in
America, Africa, and Europe.

Melanotaenium/

Spores unicellular in patches on an intercellular mycelium
lying deep in the host-plant ; they have a thick dark brown

^ Halsted, Xew Jersey Af/rlc. Exper. Station Bulletin, No. 70, 1890.
^Trabut, " Sur una Ustilaginee parasite de la Betterave." Compt. rend.
ex VIII., 1894.

^Setchell, Botaniccd Gazette, 189-i, p. 188 (with illustrations).

•*Schroeter, Kryptogam. Flora v. Schlesien. Woronin, Senckenberg Oesell, 1880.

314

USTILAGINEAE.

epispore, and the clusters appear l)lack or leaden-grey. Ger-
mination as in EiituhniHi.

Melanotaenium endogenum (Unger) (Britain). This is
found on Galuon Moll u go and G. verum. The mycelium
permeates the whole intercellular system of the host, and is

nourished by large tufted haustoria.
The host-plants remain small, with
shortened internodes, shrunk leaves,
and undeveloped flowers. The
spores occur in patches in de-
formed flowers, and on leaves and
internodes. They ai^e formed in
summer, and by autumn are capable
of germination in water ; Woronin
could not keep them alive over
winter. On germination a bifur-
cate promycelium is produced, one
branch of which remains rudimen-
tary, while the other grows on,
and, if long, becomes divided by
cross-septa. At its apex, a number
of conidia arise, and, after many of them have fused in pairs,
they germinate directly to a septate filament into which the
plasma passes over (Fig. 171).

Mel. caulium (Schneider) causes the stem of Linaria v^dgaris to swell
lip like a quill.

Mel. cingens (Beck.) on Linaria yenistifolia. According to Brefeld,
this species only germinates after resting for four years, whereas Juel
easily caused Mel. caulium to do so after a short rest.

Fig. 171. — Mtladotoxniv i,i endor/enum.
Germinating spores. Cue has already
produced a promycelium with a whorl of
five branches, of which two have fused.
(After Woronin.)

Urocystis.

Spores massed into balls, consisting of several spores sur-
rounded by smaller companion-cells incapable of germination.
The central spores are clearly distinguished from the others
by their larger size, darker colour, and thicker coat. The balls
of spores are developed inside coils of hyphae, which become
entwined together and swell up in a gelatinous manner. The
central spores on germination give rise to a promycelium, with
terminal conidia which do not as a rule fuse in pairs, but grow
out directly into mycelia.

UROCYSTIS.

315

Urocystis occulta (Wallr.). (Britain and U.S. America.) This
species is common on the hauhns, leaves, leaf-sheaths, and less
commonly on floral parts of Secede ccreedc (rye). It causes the

Fig. 172. — Urocyslis occulta on Rj-e. The ears are stunted, and the spore-
powder emerges from longitudinal fissures in the upper part of the stems,
(v. Tubeuf phot.)

formation of grey stripes, from which a black spore-powder
escapes. The haulms become diseased and smutty, thereby
preventing development of the ear, which remains stunted and

316 USTILAGINEAE.

empty (Fig. 172). Spore-formation causes the parenchyma of
the stem to be destroyed in strips, along which rupture takes
place, and the haulm, losing its rigidity, falls over. The balls
of spores consist of one or two smooth spores enclosed by
companion -cells. Germination takes place easily in water, and
a circle of cylindrical conidia are produced from the end of
each promycelium. The conidia, without becoming detached,
give off a lateral germ-tube. The mycelium does not hibernate.

While this smut does not occur on cereals so commonly as
species of Ustilago and Tilletia, still it may sometimes cause
severe loss. Treatment of seed by Jensen's hot- water method,
or by a copper sulphate steep, may be resorted to, but the
results have not as yet been always successful.

The only other smut of rye is Ustilagu secalis in the grain,
and it is only rarely found. "Winter, however, considers rye
amongst the host-plants of Urocystis agnrpyri.

Urocystis agropyri (Preuss.) (Britain ami U.S. America). Leaves and
haulms of Triticimi repens, Arrhenatherum elatizcs, Festuca rubra, and
Brotmis inermis are the habitat of this species.

U. festucae. Another species distinguished by Ule on Festuca.

U. Ulei iNIagn. In leaves, more rarelv in inflorescences, of Poa pratensis.

U. luzulae Schroet. On leaves of Luzula pilosa.

U. colchici (Schlecht.). On leaves of ColcMcum cmtunmale,
Muscari comosum, M. raccmosum, Paris quadrifolia, and Scilla
hifolia. (Britain and U.S. America.)

U. cepulae Frost.^ (U.S. America). Onion-smut. This
frequents the green leaves and subterranean scales, producing
pustules, which break when mature and allow the black spore-
powder to escape.

U. ornithogali Korn. frequents leaves of Oniithogalum umhellatum.

U. gladioli (Req.) is found in tubers and stems of Gladiolus (Britain).

U. anemones (Pers.). (Britain and U.S. America.) Anemone-
smut. This may be found in leaves or stems of many
Eanunculaceae: Anemone Hepatica, A. nemorosa, A. ranunculoides,
Pulsatilla alpina, P. vernalis, P. Pennsylvanica, P. acuiiloba, P.
haldensis, etc. ; also on Atragene alpina, Aconitum Leucoctonum,
Actaea spicata, Helleboriis viridis, H. niger, Ranunculus Ficaria,
R. hulbosus, R. repens, R. sardous, Eranthis hiemalis. Brefeld
says the spores germinate in water, after resting for half-a-year.

^ R. Thaxter. Report of Connecticut Ayrk. Exper. Station for 1889.

UROCYSTIS.

317

U. Leimbachii (Oertel.) causes globular swellings of the
stem-base of Adonis aestivalis at Jena (Fig. 173). Patouillard
regards this species as a form of U. anemones, differing somewhat
on account of its underground habitat.

U. sorosporioides Korn. (Britain). On Pulsatilkt alpina, Thalic-
trum minus, and T. foetidum, forming pustules and swellings.

Fig. 173. — A, Urocyitu anemones on Hellebore. Spore-patches on stalk and
mid-rib. (v. Tubeuf del. ; specimen from Herr Schnabl of Munich.)

B, Urocystis Leimbachii (U. anemones), causing swelling at base of stem of Adonis
oAStivo.lis. (v. Tubeuf del.; specimen from Prof. Stahl of Jena.)

U. violae (Sow.). (Britain and U.S. America.) The deforma-
tions induced by this brand are not uncommon on Viola
odorata in gardens, also on V. tricolor, V. ladcnsis, and V.
hirta. Its presence is shown externally by the marked thick-
ening and malformation of leaf-petioles, runners, leaves, and
fruit-stalks (Fig. 174). The swellings extend round the whole
stem, and form pustular outgrowths on the leaves ; the black
spore-masses appear after rupture of the epidermis. The
flower may develop normally although other organs are diseased.
In a case from the garden of Prof. Hartig, a flower-bud
unfolded prematurely in the autumn, its stalk was very
much deformed, the flower itself was somewhat stunted, yet

318

USTILAOINEAK.

the plant as a whole did not seem to be niiicli affected. On
the other hand, a case was observed near Munich where a
large plot of violets was completely killed out in a few years
by this fungus.

The anatomical changes induced on Viola odorata were
investigated by Wakker^ with the following results : a swelling
of the stems, leaves, and flower-stalks occurred, often accom-
panied by considerable twisting and rupture of the epidermis ;
these changes were not caused by any enlargement of cells, but

Fig. 174. — Urocystis violae on Viola. Smut-pustules are present on leaf-stalks
and fruit-stalks, accompanied by malformation, (v. Tubeuf jjhot.)

the cambium remained longer active in the stem, and a secondary
division of rind-parenchyma or mesophyll could be observed,
along with a disappearance of intercellular spaces ; accessory
vascular bundles were formed, but the secondary vessels remained
incompletely developed. In short, new growth occurred, not
in the earlier stages of the host's life, but in the adult.
Especially noteworthy is the formation of a small-celled tissue
resulting from cell-division in the rind-parenchyma and the
mesophyll ; this serves as a nutritive tissue for the fungus,

^ Wfikker, Pringsheim's Jahrhuch, 1892.

UROCYSTIS. 319

and is destroyed during spore-formation, so that the balls of
spores are found in large cavities in the host-tissue.

In the spore-masses the enveloping companion-cells are more
transparent than the spores proper. The latter germinate^ easily
in water, and produce promycelia which grow towards the air.
On the extremities of these several conidia arise, and, without
becoming detached, proceed at once to give off short conidio-
phores with terminal conidia. As this process is repeated
indefinitely, chains of conidia are formed. Fusion of conidia
never occurs.

U. Kmetiana Magn. Magnus- describes this as destroying
and filling with black spore-powder the ovaries of Viola tricolor
(var. ar vends).

U. filipendula Fuck, occurs particularly on petioles and leaf-ribs of
Spiraea Filipendula. Brefeld found the spores germinating after a year.

U. (?) italica (Sacc. et Speg.). In seed of Castanea vesea.

U. purpurea Hazsl. Ovaries of Dianthus deltoides and D. prolifera in
Hungary.

U. (?) coralloides Eostr. In roots of Turritis glabra in Denmark.

U. orobanches (Fr.). In roots of Orohanche.

U. (?) monotropae (Fr.) In roots and stems of Monotropa in Belgium.

U. Johansonii {U. Junci. Lag.). In leaves of Juncus filiformis in
Switzerland.

Tuburcinia.

Spores forming balls as in Urocystis, but all are equally
capable of germination. The spore-aggregations form large or
small, slightly thickened spots and crusts, which do not cause
very marked deformation of the host. Germination results, as
in Tilletia, in the formation of a promycelium bearing a tuft
of conidia at one end. White conidia are also produced from
the mycelium on the host-plant.

Tuburcinia trientalis (Berk, et Br.)^ (Britain and U.S.
America). Plants of Trientalis eurcypaea attacked by this fungus
are conspicuous in early summer by their swollen dark-coloured
stems and their smaller lighter leaves, which fall prematurely.
The conidia appear as a white mould-like coating on the lower

^Prillieux, Bullet, de la Soc. hotan. de France, 1880; and Bi'efeld (loc. cit.).
Heft XII.

- Magnus, Naturforsch. Fr. d. Prov. Brandenburg, xxxi.

^Woronin, Senckenherg. naturforsch. GeselL, 1881. Plates I., II., III.

320 USTILAGINEAE.

side of the leaf. The black spore-masses are formed in the
rind-parenchyma, and sometimes in the pith ; they are set free
by rupture of the epidermis.

In autunm the symptoms are different. The plants appear
normally developed, and have no coatinj,' of conidia ; dark
swollen spots, however, appear on the leaves and leaf-petioles,
in consequence of the massing of black spore-balls in the par-
enchyma under the epidermis.

The summer mycelium consists of colourless irregularly
branched and slightly septate hyphae occupying the intercellular

Fi(i. 17 :j.—Tuburcinia trientalU. Spore- Fig. 176.— Apex of an isolated promy-

mass germinating ; several promycelia have celium from Fig. 175 ; it carries a whorl of

been produced and are proceeding to form branches, some of which have fused in pairs ;

whorls of branches. (Aiter Woronin.) aU are developing conidia. (After Woronin.)

spaces of the pith and rind-parenchyma, also the vessels. The
hyphae apply themselves closely to the cell-walls, and certain
short branched hyphae actually penetrate into the cells. The
spore-masses are developed from delicate branched multiseptate
filaments of the vegetative mycelium. They begin as two or
three little cells round which a coil of hyphae is formed ; the
central cells, increasing in number and size, become a ball of
dark smooth-coated spores, while the enveloping coil of hyphae
disappears.

The spores germinate during the same autumn, frequently
in the position of their formation. A. promycelium is first
formed, and on its extremity a circlet of conidia arises ; there-

TUBURCINIA. 321

after the promycelium becomes divided by cross-septa in its
upper part, and the conidia too are frequently divided by one
or two septa. The two j)romycelial cells become detached,
while the conidia begin to fuse together by means of out-
growths near their base ; thereafter each conidium gives
out a secondary conidium, into which the plasma-contents
pass over. A similar formation of secondary conidia may take
place without previous fusion of the primary conidia. The
conidia fall apart, and they, as well as the upper promycelial
cells thereby left isolated, grow out as hyphae. It must be
these hyphae which infect the rudimentary shoots of Trientalis
when they are already partially formed for next year. The
resulting mycelium permeates the shoots in the following spring,
and branches of it emerge through the stomata, or pass between
the epidermal cells and break the cuticle, to grow up either at
once as conidiophores, or to form on the surface of the leaf a
web from which conidiophores arise. The pear-shaped conidia
are attached by their broader side, and easily fall off, leaving
the conidiophores free to produce new conidia. The conidia
are capable of immediate germination, and may produce a
lateral germ-tube, which grows directly upwards, and gives oft'
secondary conidia ; or the conidia themselves grow out into
hyphae, capable, as Woronin proved experimentally, of carrying
out infection. Such hyphae penetrate between the walls of
adjacent epidermal cells, and give rise to a mycelium which
spreads in a centrifugal direction and forms the spore-
masses.

This same fungus has also been found on Euphrasia lutea
and Paris quadrifolia. On Eicj)hrasia, according to Winter,
it causes formation of large swellings, accompanied by consider-
able deformation of leaf and stem.

T. primulicola (Magn.) Klihn.^ (Britain). This smut attacks
flowers of Primula acaulis, P. officinalis, P. clatior, P. farinosa.
In cases described in Germany, the blooms were generally
attacked in the filaments or connective of the stamens, but also
in the anthers, the ovaries, pistil, stigma, and sometimes in the
calyx-tube ; while the whole flower-head was more or less
discoloured by the black spore-dust. The mycelium permeates

1 Magnus, Botan. Vereiii Brandenburg, 1878. Kiilin, "die Eutwickeliings-
gesch. d. Primelbraudes," Naturforsch. GeselL zu Halle, 1892.

X

322 USTII.A(;iNKAK.

the whole host and hibernates in the root-stock. The spores
are developed from the ends of hypliae in the host-tissue, and
are either isolated or joined into packets. They germinate
easily in water, and produce either a fine germ-tube, or a
thick promycelium with four ol)long conidia on its apex. The
conidia are easily detached, and either develop to fine hyphae,
or give off secondary conidia. Germination on the whole is
similar to that of T. trientalis. Conidia may be also produced
directly on the host-plant ; these were first described by Klihn,
who named them Faipalo2ms Irmischiae ; later, however, he
succeeded in infecting plants of Primula with the conidia, and
in proving their relationship to this Tahurcinia.
T. Cesatii Sorok. occurs on geraniums in Russia.

Here, according to Setcliell, the following American genera should be
placed :

Burillia : B. pustulata on Sagittaria.
Cornuella : C. lemnae on Lemna folyrhiza.

Doassansia.

Spore-masses consisting of numerous spores capable of ger-
mination, enclosed in a layer of sterile cells. The latter are
most conspicuous in the species frequenting aquatic plants, and
are filled with air, — Brefeld regards them as swimming-organs.
The spore-masses lie in groups embedded in the host-plant.
The species inhabit plants with an aquatic or moist habitat,
and produce on them leaf-spots with black pustules.

Fisch ^ investigated the life-history of Doassansia sagittariae.
He found an intercellular mycelium which, inside the stomata,
formed sporocarps, consisting of sclerotium-like coils of hyphae
enclosing several cells which form spores. The spores on germina-
tion give rise to promycelia, which produce sporidia in a manner
similar to Entyloma. The sporidia easily germinate in water,
and can immediately infect young leaves. The germ-tubes
creep on the surface of leaves, and attaching themselves by
an adhesion-disc over the wall between two adjacent epidermal
cells, they penetrate this wall. The hypha, while passing

^ C. Fisch., Ber. d. (hAitach. bo/an. OeselL, 1884, p. 40.5. Cornu, Annal. d. sci.
natur. xv. , 1883. Setchell (Botanical Gazette, 1894) records the American
species and comments on tliem.

DOASSANSIA. 323

through the wall, remains thin, but on emerging into an inter-
cellular space it soon thickens and branches into a mycelium.
Infection results in the appearance of yellow spots, due to
rapid destruction of the chlorophyll and death of cell-contents.
Experiments in germination have been carried out by Setchell
and Brefeld.^

Doassansia sagittariae (West.) (Britain and U.S. America).
In leaves of Saijitta/ria. The spores, according to Brefeld,
germinate in water, after hibernation. They produce unicellular
promycelia with a terminal tuft of more or less spindle-shaped
conidia, which at once begin to sprout and fall off. On the
surface of a nutritive solution they continue to sprout yeast-
like, and form close mouldy coatings. {Doassansia is the only
genus of the Tilletiae in which Brefeld found yeast-like sprout-
ing of conidia.)

D. alismatis (Xees) (Britain and U.S. America). This
inhabits leaves of Alisma Plantago and A. natans, producing
knotty swellings. The spores are enclosed in a layer of com-
panion-cells containing air, whereby the masses swim on water.
On the promycelium the conidia arise from tufts of conidio-
pliores ; they fuse in pairs, and secondary conidia are developed
from each pair or even from single conidia.

D. Niesslii (de Toni) forms small spots on leaves of Buto-
mus umbellatus. The spores are surrounded by companion-cells
containing air. They germinate before leaving the spore-patch,
and produce conidia, even secondary conidia, before rupture of
the host-epidermis takes place. Brefeld describes the spores
as germinating in water to form a very short promycelium
with short thick conidia which fuse in pairs and give off larger
secondary conidia from their apices. In nutritive solution
conidia are developed, which give off septate filaments whence
further conidia arise. Aerial conidia are ultimately developed.

Magnus found that the spores of D. alismatis, D. Niesslii,
and other species germinated at once on reaching maturity.
Brefeld, however, found that this took place only after they
had lain over winter. It may be that here, as with some
higher plants {e.g. Finns Ccmhra), there is an immediate
capability of germination, but also a deferred, the latter requiring

1 Setchell, Annals of Botany, vi., 1892. Brefeld, Schimmelplhe, Heft xii.,
1895.

324

USTILAGINEAE.

to be preceded by a considerable resting-period, during which
germination will not take place.

D. Martianoffiana (Tliiim.). In leaves of Potamogeton natans and P.
gramineus.

D. occulta (Ilottin.). In fruits of species of Poiamogeton.

D. intermedia (Setch.). An American species found on leaves of
Sagittaria vai'ia/n/is.

D. comari (Berk.). In leaves of Comarum pahistre in Britain.

D. limosellae (Kunze.). In flowers of Limosella aquatica.

D. hottoniae (Rostr.). In leaves of Hottonia palvMris in Demnark.

Thecaphora.

Spores, large, spherical, and inseparably united into packets
of several spores. Germination results in the formation of a

Fio. 177. — Thecaphora li/mliiia. Pluricellu-
lar spore, with two cells (spores) germinatiug.
(After WoroniD.)

Fici. 178. — Sorosporiuni saponario.e (var.
Li/chnidis diolcae.) Matui'e spore-mass, and
spores germinating. (After Woronin.)

promycelium from the apex of which a single conidium is
produced.

Thecaphora lathyri Klihn. Spore-balls formed in the seeds
of Lathyrus jJ7Y^i!c7/.s/.s, and escaping as a brown powder on
dehiscence of the pods. The spores germinate in water with
formation of a promycelium bearing a single apical conidium,
which produces a hypha, but never secondary conidia. In
nutritive solutions the spores produce a mycelium from which
conidia are continuously given off.

Th. hyalina Fingerh. (Britain). This occurs in fruits of
species of Convolvulus. Woronin describes the spores as having
germ-pores through which a septate germ-tube is emitted ; the
individual cells of the germ-tubes develop into hyphae, without
formation of conidia.

Th. affinis Sclmeid. In fruits of Astragalus gl^cyphi/Uus (U.S. America).
Th. Trailii Cooke. In flowers of Carduus heterophyllus in Scotland.

THECAPHORA. 325

Th. Westendorpii Fiscli. In Lolium perenne in Belgium.

Th. pimpinellae Juel. In fruits of Pimpinella Saxifraga in Sweden.

Th. aurantiaca Fingli. In leaves of Urtica dioica.

Th. pallescens Fingh. In leaves of Fragaria collina.

Sorosporium.

Spore-formation takes place in a mass of twisted gelatinous
hyphae. Spores at first embedded in a gelatinous investment
and united into packets, but later becoming separate. Promy-
celium filiform and septate.

Sorosporium saponariae Ptud. This causes deformation of
llowers of Diantltus dcltoides, Scqjonaria officinalis, Silene injlata,
and S. vclutina, Stcllaria Holostcu^n, Cerastium arvense, Lychnis
dioica, and Dianthus prolifer.

S. dianthi Eabh, on Dianthvs pii'olifer, is probably identical with the
preceding species.

We append here as doubtful Ustilagineae, the genera Graphiola
Schinzia {Entorrhiza), TvJjerculina, and Schrocteria.

Graphiola.

The sporocarps of this genus are formed on the surface of
plant-organs containing mycelium ; they are little spherical
structures enclosed in a peridium, and contain filamentous
septate hyphae. The hyphae may be sterile or fertile ; the
spores are produced on lateral cells of the fertile hyphae.
From the germinating spores, either a thread-like mycelium or
spindle-shaped conidia arise.

Graphiola phoenicis Pait,^ (Britain.) This fungus is a
parasite on leaves of palms (e.g. Phoenix dactylifera and
Chamcrops humilis) in the open in Italy and other Mediter-
ranean countries, in hot-houses elsewhere. The sporocarps make
their appearance as little black protuberances on both sides of
the leaf. The mycelium forms a close hyphal tissue, which
encloses and kills parenchymatous cells, displaces the bundles
of sclerenchyma, and ruptures epidermis and hypoderm. De-
formation is, however, localized to these spots.

^ Efl. Fischer, " Beitrag z. Kenntniss d. Gattung GVap/tio/a," Botan. Zeitung,
1883.

326 USTILAfUNEAE.

The sporocarps consist of a two-layered peridiuin, u sporogenoiis
layer, and tufts of sterile hyphae. The outer layer of the
peridium forms the outer layer of tlie black protuberances on
the leaves ; the inner layer is delicate. The sporogenous hyphae
originate from the centre of the underlying hyphal tissue, and
form a palisade-like layer in the bottom of the sporocarp cavity,
the remaining space being filled with spores and tufts of barren
hyphae. These latter hyphae rise amongst the sporogenous
ones, and project as a fine brush-like tuft out of the ruptured
peridium. The sporogenous hyphae grow vertically upwards,
and become septate, forming chains of loosely united, roundish,
hyaline cells or joints. The terminal joints give off several
spherical cells laterally, and die away, leaving the cells loose
in the sporocarp cavity. From division of the spherical cells
yellow spores result, and, on rupture of the peridium, are
carried out on the tufts of sterile hyphae to be scattered by
wind. The spores germinate in water, and produce either a
promycelium or conidia.

Gr. congesta Berk, et Eav. occurs on leaves of Chamcrops
Palmctta.

Schinzia (Entorrhiza).^

Spores produced on the ends of lateral branches of a mycelium
in the cortical cells of the root of the host-plant. Germina-
tion results in production of a simple or branched sporophore
(promycelium), from which kidney-shaped conidia (sporidia) are
produced.

Schinzia cypericola Magn. This causes deformation of the
roots of CjiiM'vns favcsccyis (Fig. 170).

Sch. Aschersoniana Magn. causes swellings on the roots of Juncus
hufoniu.'< [J hi tain].

Sch. Casparyana Magn. In roots of Juncus Tenageia.

Sch. digitata Lagerh. In roots of Juncus articulatus.

Sch. (Naegelia) cellulicola Naeg. In roots of Iris in Switzerland.

Sch. (Entorrhiza) solani Faut.-' [This is given as the cause of a disease
on potato. The plants droop and ultimately rot at the neck, the leaves
become yellow, and neither flowers nor tubers are produced.] (Edit.)

^ P. Magnus, at Botan. Vereiu il. Prov. Brandenburg, 1878; " Ueber einige
Arten d. Gattung Schinzia," Bar. d. de-nt-sch. hot an. Ge.s., 1888, p. 100; C. Weber,
Botan. Zeituwj, 1884.

■^ Fautrey, Revue viycoh;/., 1S96, p. 11.

TUBERCULINA.

327

Tuberculina.

Mycelium parasitic on hyphae and spore-patches of JJredineae,
Short rod-like hyphae spring from the spore-patches, and give
off' from their apices, globose conidia, which on germination
produce branched promycelia bearing sickle-shaped conidia.

Fig. 179. — Scydmia cypericola on Cyperus jlavescens. Several roots show palmately-
divided swellings. Isolated sjjore. (After Magnus.)

Tuberculina persicina Ditm. The lilac-coloured spores are
found on aecidia of Peridcrmium ^j^mw and other aecidial forms,
also on some species of Caeoma.} (Britain and U.S. America.)

1 Plowright {British Ustikiffineae) gives al.so Aec. asperifolii, Aec. tussilaginisy
and Roestelia lacerata as hosts.

528 USTILAGINEAE.

T. maxima Rostr. Occurs on rust-patches on "Weymouth
pine. It has larger spores than the preceding species.

Schroeteria.'

Spores joined in pairs, rarely in threes, with their broad
faces together. They are developed from single joints of a
septate non-gelatinous mycelium, particularly from short curled
lateral hyphae. Spherical conidia are produced, like those of
Penicillium, by intercalary growth in chains from the end of a
conidiophore which is generally unbranched.

Schroeteria Delastrina (Tul.) occurs in seeds of Veronica
ari-ensis, V. hcdcrifolia, V. triphyUa, and V. praccox. The spores
terminate in water, and produce conidia incapable of further de-
velopment, even when transferred to a nutritive solution. In such,
however, spore-germination is more vigorous, and an abundant
mycelium results, but it seems to be unable to produce conidia.

Sch. Decaisneana (Bond.). In seeds of Veronica hederifolia at Paris.

UREDINEAE.

The Uredineae or Eust-fnngi possess several forms of spores,
one of which, the teleutospore, is rarely, if ever, absent from
the life-cycle of any species. The teleutospores consist of one,
two, or more cells enclosed in a thick coat of dark colour, and
thereby well adapted to carry the fungus over winter. When
germination occurs, each cell of a teleutospore gives off a germ-
tube through a pore or thinner place in its wall, and from
this a promycelium- is formed, consisting as a rule of four
cells. Each teleutospore originates from a sporophore of its
own, and in the course of development two nuclei, originally
present in each cell of the young teleutospore, fuse together.
When germination takes place, and the promycelium is formed,
the single cell-nucleus, derived as above, divides into two, then
into four, so that a nucleus is produced for each of the cells
of the promycelium. From the promycelium four sterigmata
are given off, and each produces a single sporidium.- These

^Brefeld regards the species as forms of higher fungi, not as Ustilagineae (Heft
XII., p. 204).

^Brefeld considers that the promycelium and sporidium are respectively a
basidium and a basidiospore.

UREDINEAE. 329

sporidia on germination give infecting mycelial hyphae. In
the case of Colcosjjorium, the promycelium is formed inside the
teleutospore in a manner similar to the Protobasidiomycetes.

Besides teleutospores, there occur uredospores. These are
given off from patches or sori throughout the summer till
autumn, when they are followed by teleutospores on the same
sori. The uredospores somewhat resemble the teleutospores,
but generally consist of one cell only with a thinner coat of
lighter colour ; they either germinate at once without a resting
period, and give rise to a germ-tube capable of direct infection
of new hosts ; or less frequently they are resting-spores for
a time.

A third foVm of spore occurring in the life-history of the
Uredineae is the aecidiospore, produced in a special structure,
the aecidium. The aecidium is developed inside the leaves or
other organs of the host-plant, and when mature ruptures the
overlying epidermis ; it has as a basis a firm hyphal tissue,
the upper surface of which becomes a disc of short erect sporo-
phores. From each sporophore there is formed by intercalary
growth a chain of cells consisting alternately of spores and
smaller intermediate cells, which do not become spores. The
youngest cells in an aecidium are those next the sporophore-
disc, and they are forced outwards by intercalation of younger
cells between them and the disc. The cells so produced
become alternately intermediate cells and spores ; the former
increase for a time, then decrease and disappear, the spores
however continue to increase in size as the chain grows forward
and to take on the characters of the mature aecidiospore till
they are finally shed from the aecidium. The production and
distribution of aecidiospores may thus go on continuously for
a considerable time. The sporophores at the periphery of the
disc do not however produce spores ; chains of cells are also
produced from them by intercalary growth, but the cells are of
equal size, and remain closely connected with their neighbours,
so as to form a membranous covering over the spore-sorus,
this is the so-called peridium, on rupture of which the aecidio-
spores escape. In many Uredineae the peridium is suppressed
(Caeoma) ; in others {Phragmidium) it is replaced by other
structures, the paraphyses. The spores of the genus End(yphyllu7n
are produced in series in aecidia enclosed by a peridium, but in

330 UREDINEAE.

germination tliey behave more like typical teleutospores than
aecidiospores.

Before the relationship of these various forms of spores was
known, Aecidium and Cacoma were regarded as independent
groups, and named as such ; even yet many isolated forms of
uredospores, teleutospores, and aecidiospores are known, the
relationships of which are quite obscure.

The aecidia are always preceded or accompanied by a further
form of spore produced in a special structure of its own. These
spores have hitherto been called spermatia, and their sporocarps
spermogonia, on the assumption that they were male organs.
Now, however, many of them are known to be capable of
germination in artificial nutritive solutions, hence they are more
probably a form of asexual bud, and better named conidia,
their sporocarps pycnidia. The pycnidia are flask-shaped
structures sunk in the tissue of the host, with a pore or
mouth emerging through the host-epidermis ; they generally
occur in leaves, and occupy the upper epidermis, the aecidia
occurring on the lower. From the mouth of the pycnidium
there frequently emerges a tuft of fine filaments, outgrowths
from the inner wall of the flask. The pycnidia possess a lively
colour and flowery odour, hence it has been suggested that
the conidia may be distributed by insects; but they do not
appear to be able to germinate in the open, and infection-
experiments with them have never as yet succeeded. On this
account they are regarded as degenerate structures.^

The various forms of spores are also distinguishable by the
manner in which they bring about infection. Teleutospores on
germination produce sporidia, which pierce the membranes of the
prospective host at a spot where two adjoining cells are in
contact, and thus make their way into the intercellular spaces.
Uredospores and aecidiospores, however, first seek a stoma and
enter the intercellular spaces of the host through it.

The following different forms of Uredineae exist : (1) Those
which possess teleutospores alone, e.g. Chrysomyxa dbietis ; (2)
those with teleutospores and uredospores, e.g. Puccinia pruni
sjmiosae ; (3) those with all the forms of spores, e.g. Puccinia
graminis ; (4) those without uredospores, e.g. Gymnosporangium.

^ Rathay, " Untersuchungen iiber die Spermogonien d. Rostpilze," Denlschrift
d. Wiener Akad. d. Wisseiisch., 1883.

UREDINEAE. 331

The different forms of spore may be found on one and the same
host-plant (autoecious Uredineae), or the aecidiospores and
pycnidial eonidia may frequent a different host from the uredo
and teleutospore-forms (heteroecious Uredineae).^

A mycelium may be produced from the germinating aecidio-
spores, uredospores, or sporidia. It spreads throughout the
intercellular spaces of attacked organs and causes thickening,
distortion of the tissues of its host, or the formation of " witches'
brooms." Xutriment is frequently obtained by means of cone-
shaped or button-like haustoria in the interior of host-cells.

Hibernation of rust-fungus is most commonly attained through
the teleutospores, the thick coats of which make them peculiarly
suited to pass through a lengthened resting-period. Some forms,
however, hibernate by uredospores, by aecidiospores, or by the
mycelium remaining on or in living perennating stems, twigs, or
underground rootstocks of their host.

Aecidiospores on germination produce, as a rule, a mycelium
which gives rise to uredo- or teleutospores, rarely to aecidiospores
{e.g. Puccinia senccionis and Uromyccs crvi)} Uredospores on
germination, produce a mycelium from which uredospores are
first given off, then teleutospores. The sporidia of teleutospores
give rise to a mycelium which frequently produces pycnidia
and aecidia. In rare cases, the sporidia of species, which normally
form aecidia, are said to develop a uredo-mycelium {e.g. Puce,
graminis according to Plowright).

The Uredineae are for the most part strict parasites, and
exhibit marked adaptation to their respective host-plants. Several
of the polyxenous members frequenting several species of host-
plant have been found to vary according to their habitat, so that
one and the same species assumes a slightly different form on each

^ The phenomenon of heteroecism was till quite recently known only amongst
the Uredineae. Woronin and Nawaschin have, however, recently pointed out that
it exists in Schrotinia ledi, one of tiie Ascoinycetes (p. "277). The eonidia of
this species are produced only on Vaccinimn uli(jvio»nin, the apothecia only on
Ledum, and alternate with each other, so that the Ledum can be infected only
by germinating eonidia, the Vaccinimn by germinating ascospores.

-Dietel (Naturforsch. Verein in Vienna, 1S94) pointed out further cases of
this kind, in which aecidia were produced the summer through, and no
uredospores, while in autumn teleutospores were formed. He has more recently
stated the general conclusion (Flora, 1895, p. 394) ; that with these species of
Uromyce>i and Puccinia, which produce aecidia and teleutospores, but no uredo-
spores, the aecidiospores are capable of reproducing aecidia when no perennating
mycelium is present. Similarly with those few species which produce a very
small number of uredospores.

332 UREDINEAE.

host-Species. I liave previously showii,^ with regard to the
mistletoe (Viscum album), that the different forms on Finns,
Abies, and various broad-leaved trees, which some authors regard
as distinct species, might equally well be regarded as forms of
one species differing slightly on account of their different
substrata. Magnus - designates as " habitat-races " these forms
of heteroecious Uredineae whose aecidial generation has become
adapted in some varying degree to each of their respective
species of host-plant. Thus the various forms of Accidium
convallariae, on its different host-plants, he regards as forms of one
and the same fungus, the Puccinia of which occurs on Phalarvi
arundinaccn.

The manner in which such adaptations originate is indicated
by my experiments with Gi/mnosporanyium. Thus G. davariae-
forine can infect leaves of Crataegus and produce aecidia
without failure ; whereas the same infection carried out on
Sorbus and Cydonia results in incomplete development of aecidia
(see Table, p. 385). In this way there might easily be pro-
duced one form which infected Crataegus, and another confined
to Cydonia. The same thing occurs with the various Pcridcrmia
of pine-needles ; these, according to the investigations of
Klebahn, are caused by one or other species of Coleosporinm
from very different species of host-plant.^

The best examples of all, however, are presented by the

cereal-rusts, as demonstrated bv Eriksson. This investigator

.* . " . . . .

believes that the forms distinguished by him as " specialized

forms " (by Eostrup as " biological species or varieties ") are

of common origin. In course of time these have taken on

different biological characteristics in adapting themselves to

the varied nature of their substrata, their various host-plants,

so that in many cases they can no longer suit themselves

to the host-plant of the original parental form. In fact, species

were found with aecidia of similar shape when occurring on

the same host-plant, yet completely specialized from the aecidia

on another host. They thus present a stage intermediate to

that of the " habitat-races " just mentioned.

^ V. Tubeuf, Botcm. Centralhlatt, XL., 1889, p. 312.

- Hedivigia, 1894, p. 77, and 1895.

•'Klebahn's views on this subject, along with further investigations on other
fungi, will be found in Zeitschrift f. Pflanzcnhcinkhf^ittn, 189o, p. 153.

UREDINEAE. 333

The eiiropeau Urediueae comprise the following families and
genera : Puccinieae ( Uromyccs and Puccinia) ; Phragmidieae
{Triphra/pnium and Phragmidium) ; Melampsoreae {Melampsora,
Melam2JSorella, Cahjptospora, Coleosporium, Chrysomyxa, and Cron-
artium) ; Gymnosporangieae {Gymnosfporangium) ; Endophylleae
(UndophyUiim) ; also the genus Uredinopsis on Ferns.

Uromyces.

Teleutospores unicellular and produced in flattened sori.
Only one teleutospore is abjointed from each sporophore.
Teleutospores with a single germ-pore. Uredospores, aecidia,
and pycnidia are not present in every species.

(1) All forms of spore presc at on the same host-plant:

Uromyces ervi (AVallr.) (Britain).^ Vetch-rust. The aecidia
are produced on Vicia hirsuta in May and throughout the
summer. Scattered amongst the aecidia are the sori from
which uredospores are sparingly given off in early summer ;
the teleutospores are given off abundantly from the same
sori from July onwards. The aecidiospores germinate on the
vetch plants, and produce therein a mycelium from which the
aecidia and teleutospores arise. Infection by means of sporidia,
derived from the teleutospores, results in the production of a
mycelium which bears aecidia only. Pycnidia (spermogonia)
are absent in this species and also in U. fahac.

U. fabae (Pers.), [U. orohi (Pers.)] (Britain and U.S. America).
This occurs on species of Vicia and Lathyrus. Sori are formed
abundantly and give off both uredospores and teleutospores — ■
the latter being smooth-coated. Xo pycnidia have as yet been
observed.

U. trifolii (Hedw.). Clover-rust. Parasitic on various species
of clover. Uredo- and teleutospores are generally produced ;
aecidia have been found only on Trifoliiim repens (Germany and
Britain), T. incarnatum (Italy), T. pratense (Denmark, Britain,
and America). On Trifolium rep)cns both teleutospore and
aecidium generations cause swelling and distortion of leaf-ribs
and petioles, the deformation being most marked where the
mycelium has hibernated and produced teleutospores in spring.

1 The chief authorities used for the occurrence of the Uredineae in Britain
and North America are Plowright {British Ure.dineae, 1889), and Farlow and
Seymour [Hod-Index for U.S. America, 1891). (Edit.)

334 UREDINEAE.

U. appendiculatus (I'ers.), [U. pluiseoli (Pers.)]. On species
of Phascolus. (IJritiiiu and U.S. America.)^

U. primulae Lev. On Primula hirsutn.

U. limonii (D. C). On Armerut and Statice. (Britain and
U.S. America.)

U. polygoni (Pers.). On PolygoniLrn and Pi.umcx. (Britain
and U.S. America.)

U. acetosae Schroet. On Rumex.

U. silenes (Sclilecht.). On Silene and Dianthus.

U. euphorbiae (Schwein.). On UnpJiorhia Prcslii in Italy,
and some other species in America.'^

U. geranii (I). C). On Geraniums. (Britain and U.S. America.)

U. betae (Pers.). On Mangel Wurzel and Beta. (Britain
and U.S. America.)

U. parnassiae (D. C). (Britain.)

U. salicorniae (I). C). (Britain.)

U. Valerianae (Schum.). On Valeriana dioica (Britain).

(2) Pijcnidia {sperinogonia) and aecidia produced on one host; the
related urcdo- and tcleutospores on another host :

Uromyces pisi (Pers.) (Britain) Pea-rust. The uredospores
and teleutospores are developed in various species of Pisum,
Lathyrus, and Vicia. The teleutospores are finely punctured.
The aecidia appear on the under surface of the leaf of Euphorhia
Gyparissias, and are preceded by pycnidia.

Attacked plants of Euphorhia become completely changed in
their appearance. The stems are much elongated, and as a
rule remain unbranched. Flowers are seldom or never produced ;
if so, they are permeated by mycelium and deformed. The
leaves are short, thick, and rounded-off; they have a pale-green
colour, and are distant from each other on the shoot. Their
internal structure is also considerably modified. Wakker states
that the cells of the mesophyll become enlarged, while no
collenchyma is developed in the ribs. Fentzling^ gives the
following changes : the epidermal cells become broader ; stomata
are more numerous on the upper surface of the leaf, and fewer
on the lower ; the laticiferous tubes below the upper leaf-

1 Description, illustration, and treatment in N. York Agric. Exper. Station.
Bull., 48, 1892.

2 Magnus, Berichte d. deutsch. botan. Ges., 1893.

3 " Untersuchung d. Veranderungen welche durch Rostpilze hervorgerufeu
werden." Inaugural Dissertation. Freiburg, 1892.

UROMYCES.

335

epidermis are reduced in number ; intercellular spaces are formed
in the normally compact palisade parenchyma, and its cells
become shorter and broader, while those of the spongy paren-
chyma are increased both in size and number ; the fibro-vascular
bundles remain unchanged, although the cells surrounding them
may be more or less abnormal. Where thickening of the stem
takes place, it is chiefly due to multiplication of the cells of

Fig. 180. — Uromycei pisi. Comparison of liealthy flowei-ing plant of Euphorbia
Ci/parissias, with a much-elongated, non-flowering plant bearing aecidia of Pea-
rust, (v. Tubeuf phot.)

corte.K and pith, while at the same time those of the cortical
parenchyma become somewhat enlarged and altered in shape ;
the woody portion is less developed than normally ; and
laticiferous tubes are neither so large nor so conspicuous as
usual.

The aecidia of this species are found only on the lower
surface of the leaf; they are saucer-shaped, and have a broad
lobed white margin.

336 UREDINEAK.

As a preventive measure, it would l)e advisable to keep
down spurge-plants near fields or gardens where peas are likely
to he attacked.

U. striatus Schroet. (U. S. America). Uredo- and teleutospores
on species of LotiiJi, Mrdicago, Trifolium, and sometimes Vicia.
Pycnidia and aecidia are produced on Evphorhia Cy2xirissias ;
the mycelium induces- changes in the tissues similar to the
preceding species, but the Eiqjhorhia remains stunted instead
of elongating as in attacks of U. ^;m.

U. dactylidis Otth. Uredo- and teleutospores on species of
Foa, Dactylis, Arena, and Brachy2:)odium. Aecidia on several
species of Ranunculus (not on R. Ficaria). (Britain and U.S.
America.)

U. poae Rabli. Uredo- and teleutospores on Foa ; Aecidia
on RaninicuhiH Firaria, R. bulbosus, and R. repcns. (Britain).

U. lineolatus Desm. (U. maritimus Plowr.).^ Uredo- and
teleutospores on Scirpus maritimus. Aecidial iorxas = Aecidium
six latifolii on Slum and Aec. hipptiridis on Hippuris, also a
form on Glaux maritima in Britain.

U. junci Desm. Uredo- and teleutospores on species of Juncus.
Aecidia on Fulicaria. (Britain and U.S. America.)

(.■-5) Only urcdosjjores und teleutospores known ; they frequent
the same host.

Uromyces caryophyllinus (Schrank.)^ Carnation Piust. [This
attacks carnations at all stages of growth. The mycelium extends
inside the plant and forms spore patches which rupture the
epidermis. Uredospores are produced first, then the teleuto-
spores ; the former germinate at once, the latter only after a
resting-period. The use of sprays of potassium sulphide or
copper sulphate, and the cultivation of hardy varieties have been
recommended.] (Edit.)

Uromyces scutellatus (Schrank.). On species of Euphorbia.
The mycelium is perennial in the root-stock and permeates the
whole plant. Teleutospores developed in dark-brown spots on
the under surface of leaves. Diseased stems are generally un-
branched, and carry only small leaves and no flowers.

1 Plowright, Gardener's Chronicle, 1890.

-Halsted, N. .Jtrsey Agric. Coll. Exper. Station Report, 1891. Atkinson,
"Carnation Diseases," American Carnation Sac; with Illustrations. X. York
Aijric. Exper. Station Bulletin, 1896.

UROMYCES. 337

U. tuberculatus Fuck. On Euphorbia exigua.

U. prbeminens Duby. On species of Euphorbia.

U. sparsus (Kuiize et Schni.). On Spergularia, and Stellaria (Britain).

U. Schroeteri De Toni. On Lychnis and Silene.

U. cristatus Schroet. et Niessl. On Viscaria and Bianthus.

U. ficariae (Schuni.). On Rammcuhis Ficaria (Britain and U.S.
America).

U. astragali (Opiz). On Astragalus (U.S. America).

U. genistas (Pers). On Genista, Cytisus, Colutea, Galega, Garagana,
Onybi -y cli is, etc.

U. anthyllidis ((Irev.). On Anthyllis and Lupinus (Britain).

U. lupini Sacc. (Jn Lupinus (U.S. America).

U. trigonellae Pat. On leaves of Trigonella Eoenum-graeciim in France.

U. glycyrrhizae Rabh. On Glycyrrhiza.

U. cacaliae (D. C). On Adenostyles and Cacalia.

U. rumicis (Schum.). On Rumex (Britain).

U. alpinus (Schroet.). On Rumex alpinus. Magnus^ has recently sep-
arated this as tlie single species of a new genus Schroeteriaster, allied to
Uromyces and Puccinia. The uredospores arise from patches of sterigmata
without peridia or paraphyses ; they are unicellular and have lateral
germ-pores. The teleutospores are also unicellular, and form lentil-shaped
patches composed of five or more layers of spores ; the spores have a
somewhat thickened apex, but no distinct germ-pore.

U. chenopodii (Dul)y). On Chenopodium and Schoberia.

U. terebinthi (D. C). On Fistacia and Rhus (U.S. America).

U. brevipes (B. et R.). On Rhus Toxicodendron in America.

U. ambiguus (D. t'.). On Allium Scorodoprasum.

U. acutatus (Fuck.). On Allizcm.

U. veratri. (D. C). On Veratrum.

U. alchemillae (Pers.) (Britain). This is a species which
in habit resembles a Phragmidium, and is sometimes regarded
as a representative of a separate genus — Trachyspora (Fuck.).
It forms patches of reddish-yellow uredospores or brown teleuto-
spores on the lower surface of leaves of Alchemilla vulgaris.
Aecidia are unknown.

(4) Pycnidia, aecidia, and, teleiUospo7'cs on the same host-plant ;
uredospores unhnovm.

Uromyces excavatus (D. C.) Magn. On Pujjhorbia Ger-
ai^diana, E. verrucosa, etc.

U. Behenis (D. C). On Mene. (Britain.)

U. lapponicus Lagerh. On Astragalus in Norway and the Alps ; aecidia
only in the latter locality.

^ Berichte d. deutsch. hotan. Ges., 1896, p. 1.30,
Y

.338 UREDINEAE.

U. minor Scliroet. On Trifolium montanum (U.S. America).
U. hedysari-obscuri (D. C). On Hedysarum in Europe and America.
U. scrophulariae (I). V.). On Scroplndaria and Verhascum (Britain).
U. erythronii (1). ('.). On LiUum, Muscari, Scilla, Allium, Fritillaria.
(U.S. America).

(5) TeleutosjJOi'es alone known; after death of tlie hod they
undergo a resting-period, then germinate :

U. solidaginis (Somm.). On Solidago virgaurea.

U. ph3rteumatum (D. C). (Jn Phyteuma, accompanied by elongation of
the leaf-stalk.

U. scillarum ((4rev.). On Scilla and Muscari. (Britain.)

U. ornithogali Lev. On Ornitliogalum and (Jagea. (Brit<ain.)

U. colchici Massee. On Colchicum spectabilis at Kew.^

(6) Tclevtospores alone known; germinating at once on the
living host :

U. pallidas Niessl. On Cytisiis.

(7) Only teleutospores and pycnidia known; present on the same
host :

Uromyces Tepperianus Sacc.^ Tliis causes on twigs and
branches of Acacia a deformation consisting in an all-round
swelling followed by rupture of the periderm and the develop-
ment of brown teleutospore patches on the exposed wood. Tepper
found in South Australia shrubs of Acacia scdicinia and A.
tnyrtifolia attacked and killed : the former, near Adelaide, being
almost exterminated. He also found it prevalent on Acacia-
spinescens, A. hakioidcs, and A. myrfi/olia in another part of
Australia (Murray Bridge).

The same fungus was found by Warburg on Alhizzia montana
in Java, likewise by Solms-Laubach and Stahl (Fig. 181).

Magnus ^ found that Warburg's specimens showed the rupture
of the rind only on one side, those of Stahl, however, agreed
with the Australian specimens. 0\\ investigation of the galls,
Magnus found a multiseptate and intercellular mycelium with
numerous and somewhat branched haustoria. The formation

^Grevillea xxi., 1892, p. 6.

^Ludwig, " Eine neue Rostkrankheit australischer Akazien," Centralblntt f.
Bakte.r ?(. Parasilcnkundt, 1890, p. 83 ; further : Htibvuiia, 1889, and Forst-
lich-naturwiss. Zeit!<rhrift, 1894.

•'Magnus, Ber. d. dentsrh. hotan. GeselL, 1892, p. 195; Hennings, Fungi
Warburgiani, Hedicigia, 1893.

UROMYCES.

339

of pycnidia precedes that of teleutospores. The latter have
a flattened concave base and rounded apex ; their episporium
is marked with delicate ribs running from apex to base.

Fig. ISl.—Uromucts Teppirianas on twigs of AlbUzia moiUana brought by
Prof. Stahl from Java. (v. Tubeuf phot.)

Puccinia.

Teleutospores two-celled, and each abjointed from its own
sporophore from large distinct sori. Each cell has as a rule
only one germ-pore. Uredospores, teleutospores, and pycnidia
(spermogonia) are not known in all the species.

(1) Pycnidia, aecidia, uredospores, and teleutospores develop on the

340 UREDINEAE.

hviiitj host. The latter, Jwivcvcr, (jcrininatc only u/l death of the
host aiul after a resting-period (Eu-puccinia, Schroeter).

(«) Autcitpuccinia : rdl forma of sjjore are pirscnt on the same
host-pl(nit.

Puccinia helianthi. Scliwein. Suntiower-rust. This (langer-
ous enemy of Heliaidhus was first observed in South Carolina
and Pennsylvania, U.S. America. In Europe it appeared first
to a serious extent in Kussia, where the sunflower is cultivated
on a large scale ; now it has a very general distribution. In
America it attacks both sunflower {H. annims) and Jerusalem
artichoke {H. tiiberosus), Ijut its presence on the latter is as
yet doubtful in Europe. The mycelium appears first in the
lower parts of the plant and thence extends upwards ; its
presence is indicated by large brown leaf-spots, on which the
uredo-patches arise about the end of June. The teleutospores
make their appearance in autumn ; the aecidia and pycnidia in
spring (Aec. helianthi Wor.). Combative measures consist in
burning, or otherwise destroying, all sunflower debris in autunni.

P. cirsii Schroet. On Cardiius lanccolata. (Britain.)

P. prenanthis (Pers.). On Prenanthes, Lactuca, and Midge-
divrii. (Pritain and U.S. America.)

P. lampsanae (Schultz). On Lampmna. (Britain.)

P. montana Fuck. On Centaur eu.

P. violae (Sclium.). (Britain and U.S. America.) The Yiolet-
rust. This parasite appears on both wild and cultivated species
of Viola, and frequently causes much damage. Malformation
and stunting of the host may accompany the formation of
aecidia. Fentzling investigated the swollen outgrowths produced
on the lower surface of the violet leaves, and found an increase
in all forms of the leaf-parenchyma ; the spongy parenchyma
included more cells, while both spongy and palisade parenchyma
consisted of rounder cells more closely packed together than in
the normal.

P. aegra drove. On Viola cornida, etc., and somewhat
different from the last species. (Britain.)

P. mirabilissima Peck. On Berheris repens in America.

P. silenes Schroet. On Silene and Lychnis. (Britain.)

P. pimpinellae (Strauss). On Pimpinella, Ghaerophyllum,
Anthriscus, Myrrhis, Athamantha, Ostericum, Angelica, Hereicleum,
Eryngium, etc. (Britain and U.S. America.)

PUCCINIA. 341

P. saniculae Grev. On Sanicula europaea. (Britain and
V.S. America.)

P. soldanellae (D.C.). (Britain.) On various species of
Soldanella. This disease is often very common in the mountains,
and is conspicuous because it attacks only leaves here and there
on a plant. The leaves are yellowLsh with petioles distinctly
elongated ; their laminae, which bear aecidia on the lower side,
are smaller and somewhat cup-shajDed. Diseased plants do not
seem to bloom.

P. menthae (Pers.). (Britain and U.S. America.) This is
a most destructive rust to all kinds of cultivated mint. It
attacks species of many genera of Labiatae.

P. calthae Link and P. Zopfii Wint. On CaWia palustris
in Europe and Xorth America.

P. epilobii-tetragoni (D.C.) (P. pidvcrulenta Grev.). On
Upilohium. (Britain and U.S. America.)

P. Peckiana Howe [P. intrrstitialis (Schlecht.)]. This species
occurs on several species of Ruhus in America, and causes con-
siderable damage in blackberry culture.^

P. gentianae (Strauss). On Gentian. (Britain and U.S. America.)

P. galii (Pers.). On (jalium and Asperula (Woodruff). The teleutospores
hibernate on the dead stems. (Britain and U.S. Ameiica.)

P. convolvuli (Pers.). On Convolvulus. (Britain and U.S. America.)

P. primulae (D. ( '.). On .species of Primula. (Britain.)

P. obtusa Schroet. On Salvia verticillata.

P. thesii (Desv.). On The-mim. (Britain and U.S. America.)

P. albescens (Orev.). On Adoxa MoschateUina. (Britain.)

P. aristolochiae (D. (_'.). On Aristolochia.

P. asparagi (D. C). (Britain and U.S. Amei'ica.) Asparagus-rust. The
teleutospores hibernate in dry remains of the plants, which should therefore
be burnt in autumn.

P. porri (Sow.) Onion-rust. On both wild and cultivated Allium.
Sometimes very destructive to chives {A. scJioenoprasitm). (Britain.)

(h) Hcicrcupurcinia. Uredospores and teleutospores developed
on (I host othrr fluni tliat of the pyenidia and aceidia.

Puccinia graminis Pers. (Britain and U.S. America). Black-
rust or summer-rust." Uredospores and teleutospores occur on
various species of Gramineae, the pyenidia and aecidia on
species of Berheris or 3fahoma.

^ Clinton in Beporf of Arjricult ural Station of University of IlUnoi-^, 1893.
-A valuable monograph on the rusts of cereals has been pulilished by
Eriksson and Henning (Die Getreideroste, Stockholm, 1896).

342

UREDINKAE.

The two-celled Leleiitospcjres arise from cushions or sori
wiiich form black lines on the haulms and leaves of grasses ;
they hibernate on the decayed remains and germinate in spring.
Each cell of a germinating teleutospore
gives off a four-celled basidium (promy-
celium), with four short sterigmata from
each of which a basidiospore (sporidiura)
is abjointed (Fig. 182). The sporidia are
carried off the grass-host and germinate at
once if they alight on leaves or flowers of
Berberis or Mahonia (Fig. 183). Germ-
tubes are formed which penetrate the outer
walls of the host into the epidermal cells.
The mycelium which results is a branched
septate one, and spreads through the inter-
cellular spaces of the leaf. About eight
days after infection, little yellow spots make
their appearance on the upper surface of
the leaf. Embedded in the spots will be
found the pycnidia (spermogonia), spherical
flask-shaped enclosures developed on a web
of hyphae, and with their inner walls clad
with short rod-shaped conidiophores (sterig-
mata), each of which gives off a tiny coni-
dium (spermatium) (Fig. 184). A tuft of
periphyses arising from the upper part of
the pycnidium wall carries the conidia out
of the pycnidia in drops of a honey-like
fluid emitting a characteristic odour. In
regard to the function of these conidia
nothing definite is known.

The next stage begins with the appear-
ance of yellow spots on the lower epidermis
of leaves. These indicate the presence of
a mycelium from which the aecidia take
their origin. The aecidia are at first en-
closed in a one-layered peridium under
the leaf-epidermis, till by their increasing size they rupture both
coverings, and project above the surface as cups containing
spores (Fig. 184). The aecidiospores originate in a layer of

Fia. 182. — Puccinia firam-
inis. Gerrninatiiig teleuto-
spore. The promycelium
has formed three sterigmata,
from the ends of which
sporidia are in process of
abjunction. (After Tulasne.)

PUCCINIA.

343

hyphae forming the bottom of the aecidium-cup. These hyphae
■give rise to numerous short sporophores, from each of which
a single long chain of spores is abjointed in basipetal succession,
the spores being at first separated by temporary intermediate
cells. The sporophores round the margin of each aecidium do
not, however, give off spores ; they also produce chains of
cells basipetally, but these grow larger and, without the inter-
vention of intermediate cells, remain sterile and become joined

Fig. 183. — Puccinia (/raminis {Aecidium herheridis) on Berberis convmunis. The
lowest leaf and two others are seen on the upper surface, and show red spots with
light margins, in which the pycnidia are embedded. The other leaves show the
under surface with patches of aecidia. (v. Tubeuf del.)

to their neighbours to form the peridium. Diseased portions
of leaves become considerably thickened. The cells of the
single layer of palisade parenchyma are abnormally elongated,
and the intercellular spaces of the spongy parenchyma, instead
of being large, are small and filled with mycelium. The aecidio-
spores escape in July to germinate on Gramineae. The germ-
tube enters the host by the stomata only, and develops into
an intercellular mycelium ; this in about eight days produces
uredospores from cushions or sori which form lines, and break

344

UREDINKAE.

through tlie epidermis. The yellow uredospores are ahjoiuted
singly from long sporophores ; they are unicellular and ovoid, with
a thin granular coat beset with germ-pores (Fig. 184). The uredo-
spores are easily conveyed to other grass-plants and germinate at
once, their germ-tubes entering by a stoma and developing into
a mycelium, which can produce a new crop of uredospores in a

Fig. 184. — Puecinia gramiiils. A, Portion of transverse section of leaf of Berherii
vulgaris, with a young aecidium under the epidermis, v..

I. Section through an aecidium-bearing spot of a Barberry leaf. At x the
normal structure a:id thickness of the leaf is sliown, the portion u to .v is
abnormally thickened ; h to o, upper surface of the leaf ; »p, pycnidia ; a, aecidia
in section ; />, their peridium. The aecidium marked p alone (without a) shows
a peridium exposed in suiface-view only.

II. Mature teleutospore-jjatch breaking through the epidermis, e, from the
tissue, It. of a leaf of Triticum repens; I, teleutospores. x 190.

III. Teleutospores, t, and uredospores, kc. The teleutospore has a germ-pore
at its apex, the uredr^spores have four germ-pores at their equator. x 390.
(After I)e Bary, from Sachs Uhrbuch.)

few days. The uredospores are summer-spores, and spread the
fungus during the vegetative period of the host-plant ; they may,
however, hibernate. The teleutospores are more suited for
hibernation ; they are produced in autumn from dark brown
linear sori, distinguished from these of the uredospores by their
darker colour and greater length. The teleutospores are two-celled
and obovoid with smooth thick walls (Fig. 184); they are, like

rucciNiA. 345

the uredospores, developed from long sporophores, and are in
this way distinguished from those of Puce. ruhi{jo-vcra, which
are very short. The teleutospores germinate in spring after
hibernation, each cell giving off a single germ-tube.

Both uredospores and teleutospores are injurious to our
cereals, — wheat, oats, and rye. They may also be found on
the following species of grasses : Anthoxanthum, Alopeeurus
Phleum, Agrostis, Arm, Avena, Briza, Arrhcnnthcru-m, Poa,
Dactylis, Festnca, Bromus, Triticum, Secale, Elymv.s, Hordeum,
Lolium, Agropyrum, Andropogon, Bryzopgrum, etc.

The disease may ruin a whole harvest of grain, and render
the straw disagreeable, if not dangerous, for stable use (see
also p. 84). Removal of barberry bushes is said to reduce the
rust, although many believe that the barberry is not necessary
for the existence of the fungus.^ Plowright, for example, found
that sporidia from teleutospores infected wheat-seedlings directly,
without intervention of the aecidiospore stage. It is also possible
that the mycelium hibernates like that of Puce, i'uhigo-vera, in
some wild grass, to grow again and produce uredospores in spring.

No very effective measures against this fungus are known.
Early sowing has been suggested; and certain varieties of grain,
known to be less liable to attack than others, might be used.

Eriksson and Henning,^ from the results of their infection-
experiments, have provisionally distinguished the following
varieties of P. graminis :

A. Definite — (a) distinct varieties :

1. Var. sccalis on Secede cerecde, Hordeum vulgeire, Triticum

repens, and Elynius ctrenarius.

2. Var. avcnae on Avena sedicei. Milium effvsvm, Aloptecurus

prcdensis, JDacfylis glomercdei (and Arena clcdior).

3. Var. aiirie on Aira cacspitoscL

(j8) somewhat uncertain varieties :

4. \q.\\ agrostis on Agrostis canina, and A. stolonifera.
o. Var. poeix on Poa comprcssa (and P. p)r(densis).

B. Xot sharply defined :

6. Var. tritici on Triticum vulgare.

^ An interesting discussion of this subject is given by Wor. G. Smith {Diseases
of Crops, Chap. xxv.). (Edit.)

-Eriksson and Henning, " Untersuchungen lib. cl. Getreiileroste,"' Zeitsrh.
f. Pflair.enkrankhfittit, 1894.

346 UREDINEAE.

Puccinia coronata (•oidu. (JJiitain and I'.S. America.)
Eriksson, from his own experiments and those of Klebahn,
distinguishes the following specialized varieties :

►Ser. I. Aecidia on lihamnus cathartica, Rli. elaeoides, llli.
grandifolia, Rh. alnifolia {Puccinia coronifcra Kleb,).

1. Var. avi'nar on Avcna sativa.

2. Var. alopcciiri on Aliypccurns pratenais.

3. Var. fediicac on Feshica clatior (and F. ruhra).

4. Var. lulii on Lolium percnnc.

In addition to these, Klebahn found a form on Avena elatior, and one
on Uolcus lanahis, in regard to whose specialization nothing is known.

Ser. II. Aecidia on Rliamnus Frangula {Puccinia coronata I.,
Kleb.).

5. A^ar. calamagrosHs on Calamagrostis arundinacea (and

C. lanccolata).
In addition : forms on Dactylis glomerata, Festuca sylvatica (? Puce.
gibberosa Lagerh.), Agrostis vulgaris, Holcus lanatus {1 H. mollis), and
Phalaris arundinacea.

Ser. III. Aecidia on Rhcnnnvs dahnrica {Puce, coronata var.
himcdcnsis, Barcl.).

Indian forms on Brachgjyodium sylvaticum, {Piptatherum holciforme, and
Festuca gigantea,) of which nothing more is known.

Ser. IV. Aecidia unknown, probably do not exist.

6. Var. mclicae on Melica nutans.

Amongst our cereal crops the oat alone is attacked by this
species, and much damage may result.

The uredo-patches have no paraphyses like the preceding
species, and they form reddish-yellow spots and stripes ; the
teleutospore-patches are black. The upper cell of the teleuto-
spores is surrounded by a crown of six or seven blunt teeth.

The presence of aecidia on Rhamnus is accompanied by
thickening and twisting of young shoots, and blister-like de-
formation of leaves, calyces, and ovaries. Wakker^ thus
summarizes his investigations on the anatomical changes induced
by the fungus on Rhamnus Frangula : " It causes the cells
of every part to become abnormally enlarged, at the same time
giving rise to an orange coloration of the cell -sap and an
accumulation of starch ; there is no longer any formation of
interfascicular cambium, and there is a partial or complete

1 Wakker, Prinyshehn's Jahrlnirh, 1S92.

PUCCINIA. 347

suppression of secondary vasa, mucilage canals, and calcium
oxalate."

The deformation induced by P. coronata on Ithamnvs cathartica
was investigated by Fentzling.^ The changes were relatively
slight : the parenchymatous cells of the rind were enlarged
and separated by large intercellular spaces ; so also the paren-
chyma of the bast ; vessels were more numerous in the wood
affected ; the epidermal cells in some parts of the leaf were
broadened and those of the mesophyll enlarged, abnormally
shaped, and with large intercellular spaces ; in diseased leaf-
stalks the epidermal cells are thinner-walled and broader, while
all parenchymatous cells become enlarged, thinner-walled, and
with many intercellular spaces ; the fibro-vascular bundles are
enlarged, chiefly from an increase of the wood-parenchyma ; this
tissue, in normal petioles, occurs as single rows of cells running
radially between the vessels, whereas, in diseased places, three
parallel layers of cells may separate neighbouring vessels.

P. dispersa Eriks. et Henn. Brown-rust. (Britain.) The follow-
ing specialized varieties of this species have been distinguished :

Ser. I. Aecidium on A7ichusa arvensis and A. officinalis (Aec.
anchusar).

1. Var. scccdis on Secale cerealc^

Ser. II. Aecidium unknown. (Whether distinct varieties,
somewhat uncertain.)

2. Yar. fritici on Triticum vulgare.

3. A^ar. hromi on Bromus arvensis (and Br. hrizacformis).

4. Yar. acirofyri on Triticum repens.

P. rubigo-vera (D.C.) (P. straminis Fuck., P. striaeformis West.).
(Britain and U.S. America.) This, in its uredo- and teleuto-
spore stages, frequents various grasses, while the aecidia occur on
Boragineae. A variety on species of Horcleum has been designated
P. simplex. The teleutospore-patches are enveloped in numerous
brown paraphyses ; the teleutospores have very short stalks.

The anatomical changes produced in leaves beset with aecidia
have been stated by Wakker as follows : The swelling of the
leaf-petioles is due to enlargement of their cells ; the large
intercellular spaces of the spongy parenchyma are no longer

1 Fentzling, Inawjural Difsertatlon. Freiburg, 1892.

^ Found along witli the Aecidium at Montrose (Scotland) by Prof. J. W. H.
Trail. (Edit.)

348 UREDINKAK.

present; the palisade layer is doubled, and rupture of the
epidermis takes plaee ; cldorophyll-fonnatiou is suppressed, the
cell-sap becomes yellow, and starch tends to accumulate.

P. dispersa may cause serious damage to wheat and rye ; F.
rvMgo-vcra, also on barley and oats. The spore-patches are
found on stalks and leaf-sheaths more than on the lamina. The
mycelium may hibernate in grasses, so that the fungus is not
dependent on the aecidial stage ; for this reason the disease is
not easily combated.

P. glumarum Eriks. et Henn. Golden-rust. This species,
hitherto generally included under P. ruhif/o-vera (D. C.) has been
separated by Eriksson and Henning.^ Experimental infection
on Boragineae gave negative results.

Eriksson distinguishes the following specialized varieties of
this species :

A. Definite (and undoubtedly distinct).
1. Var. fritici on Triticum vulgare.

'1. Var. hordci on Hordeiim vulgare (somewhat uncertain),
o. Var. dymi on Elymns arenarius.

4. Var. agrupyri on Triticum repcns.

B. Not sharply defined :

5. Var. Hccalis on Sexale ccrecde.

The uredospore-sori are lemon-yellow in colour, and form
lines on the leaf-blade wliich may run together and reach a
length of 10 mm. The teleutospore-sori form long, tine, brown
or black lines: the sori are divided into numerous chambers,
each enclosed in a circle of curved brown paraphyses. The
spores germinate in the autumn of tlie same year. The pro-
mycelium is yellow till the spores^ are abjointed : in this way
it is distinguished from P. dispersa.

P. poarum Xiels. (Britain). Uredo- and teleutospores on
Poa. According to Nielson, the aecidia occur on Tussilago,
Pctasites, and Adcnostylcs. Fentzling (Joe. cit.) has described
certain anatomical changes wliich accompany deformations due
to the aecidia.

P. phlei-pratensis Eriks. et Henn. This lias a hibernating mycelium
wliich produces uredospores continuously on Phleum and probably also
on Festuca. Aecidia have not as yet been observed.

'Eriksson and Heiiniiig (/oc. cit.).

pucciNiA. 349

P. agrostidis Plowr.' Teleutospores on Agrostis vulgaris; aecicliiim =
Aec. aquilegiae Pers. (Britain and U.S. America).

P. festucae Plowr.' Uredo- and teleutospores on Festuca ovina and F.
duriuscula ; aecidiiun = Jec. pericbjmeni Schum. (Britain).

P. phragmitis (Schiini.). Uredo- and teleutospores on Phragmites.
Aecidium = Jet-, ruhellum on Rumej crispus and other spec-ie.s of Rume.i\
also on Rheum. (Britain and U.S. America.)

P. Trailii Plowr. Uredo- and teleuto.spores on Phragmites communis.
Aecidium on Rvme.r Acetosa. (Britain.)

P. Magnusiana Korn. Uredo- and teleutospores on Phragmites communis.
Aecidium on Ranunculus repens. (Britain.)-

P. moliniae Tid. Uredo- ami teleutospores on Molinia coerulea. Aecidium
(according to Eostrup's out-of-door experiments), on Orchis repens, 0. mascula ;
probably also on other Orchideae. (Britain.)

P. nemoralis Juel. Uredo- and teleutospores on Molinia coerulea ;
aecidium {Aec. melampj/ri Kze. et Schm.) on Melampi/rum pratense.

P. australis Koi'n. Uredo- and teleutospores on Molinia in Tyrol ;
aecidium {Aec. erectum, according to Pazschke) on Sedmn rejle.ve, S. acre, etc.

P. perplexans Plowr. Uredo- and teleutospores on Alopecurus pratensis ;
aecidium on Ranunculus arris. (Britain.)

P. persistens Plowr. On Triticum repens. Aecidium = J t'r. thalictri
(Britain).

P. sesleriae Reich. On Sesleria coerulea. Aecidium on Rhamnus
saxatilis.

P. Winteriana Magn.^ {P. sessilis, Schn.). Uredo- and teleutospores on
Phalaris arundinacea. Aecidium on Allium ursinum {Aec. cdliatum Rbh.).

P. sessilis Schn. (including P. digraphidis Soppitt and P. paridis Plowr.)
(Britain.) Uredo- and teleutospores on Phalaris arundinacea. Aecidium,
according to Soppitt,* on Convallaria majalis, also on Majanthemum, Paris,
Polygonatum, Lilium canadense and IStreptopus Smilacina. Klebahn's experi-
ments confirm the relationship of the aecidium on Majanthenium, Convallaria,
Polygonatum, and Paris.

P. phalaridis Plowr. On Phalaris arundinacea. Aecidium {Aec. ari) on
Aruni italicum and ^1. maculatum. (Britain.)

P. agropyri Ell. et. Ev. On Agropyrum. Aecidium = . 4 ec. clematidis
D. C. on Clematis Vitalba and C. recta, etc., in Europe and America.

P. caricis (Schum.) (Britain and U.S. America). Uredospores
and teleutospores on species of Carex. Aecidia, according to
Magnus, on Urtica (Fig. 185). The same author also believes
that the uredo-stage can hibernate.

iPlowright, Grevillea, xxi., 1893, p. 109.

- Klebahu (.^ej^sc/t. /. Pflanzenkrankheiten, 1892) confirms Plowright's observa-
tions on this.

^Magnus, Hedwigia, 1894.

* Soppitt, Journal of Botany, 1890.

350

UREDINEAE.

Stems, leaf-stalks, and leaf-nervature often undergo one-sided
thickening and curvature as a result of formation of aecidia.
Wakker thus summarizes lii.s observations on the anatomical
changes in these malformed parts of Urtlca : there is an en-
largement of cells and an increase in the number of large inter-
cellular spaces ; no formation of collencln-ma, interfascicular
cambium, and chlorophyll ; a diminished formation of calcium
oxalate ; an orange coloration of the cell-sap ; and a distension
or rupture of the epidermis.

Fig. 1S5. — Paccinia co.ricis on Stingiiuj JS'cttU. The aecidial cushions have caused
swelling and distortion of stems and leaf-stalks, also swollen outgrowths on the
leaves, (v. Tubeuf phot.)

Klebahn and Magnus believe that there is a Fuccinia on
Carex acuta and C. Goodenoughii related to an Accidium on
Hibcs Grossularia, H. ruhrum, and B. aurcnm ; also a Fuccinia
on Carer, riparia with an Accidium on Rdjcs nigrum. On this
account Klebahn ^ distinguishes Fucc. caricis i., ii., and in.,
agreeing respectively with F. Fringsheimiana Kleb., F. caricis
(Schum.), and F. Magnusii Kleb.

P. Schoeleriana Plowr. et Magn.^ (Britain). Uredo- and
teleutospores on Carex arenaria ; aecidia on Scnrcio Jacohaea.

^Klebahn, Zeilschrift f. Pflanzenkrankhtitcn, 1892, 1894, and 1895.
- Hedwigia, 1886.

PUCCINIA. 351

p. sylvatica Schroet. (Britain). Uredo- and teleutospores on
Carcx ; aecidia on some Compositae. Schroeter ^ regards an
Aecidium on Taraxacum officinale and Seriecio nemorensis as
related to the teleutospores on Carcx hrizoidcs and C. 'praccox.
Klebahn - reared aecidia on Taraxacum after infection with
teleutospores from Carex arenaria ; E. Fischer obtained aecidia
only on Taraxacu'm officinale. Dietel ^ regards Aecidium
Bardanae on Arctium Lappa as related to this species.

Attacked leaves of Tarcuxicum are frequently much deformed,
stunted, and twisted. Those of T. officincde have orange-red
warts on the lower surface, and there Fentzling {loc. cif.) found
both spongy and palisade parenchyma increased and more or
less deformed, the cells being elongated and enclosed in
hyphae.

P. leucanthemi Pass. According to E. Fischer, the uredo- and teleuto-
spores are found on Carex montana; the aecidia {Aec. leucanthemi) on
Vhrysanthemum, Leueanthemum.

P. tenuistipes Eostr. Uredo- and teleutospores on Carex muricata ;
aecidia on Centaurea.

P. arenariicola Plowr. et Magn. On Carex arenaria ; aecidia = Jec. cent-
aureae on C. nigra. (Britain.)

Ed. Fischer found that the species of Puecinia on Carex montana (one
with its aecidia on Centaurea Scabiosa, the other on Centaurea montana),
were specifically different.

P. limosae Magn. Uredo- and teleutospores on Carex limosa ; aecidia
on Lfislmachia tliyrsifolia and L. imlgaris.^

P. extensicola Plow. (Britain.) Uredo- and teleutospores on Carex
extensa ; aecidia on Aster Tripolium.

P. dioicae Magn. (Britain and U.S. America). Uredo- and teleutospores
on Carex dioixa and C. Davalliana ; aecidia on ('/;■.?»<//« (according to Kostru]>
and Schroeter).

P. firma Dietel. Teleutospores on Care.v Jirma ; aecidia on Bellidiastrum.

P. vulpinae Schroet. Uredo- and teleutospores on Carex mdpina ;
aecidia on Chrysanthemum Tanacetum.^

P. paludosa Plowr. (Britain). Uredo- and teleutospores on Carex vulgaris,
etc. Plo Wright gives Aecidium pedicularis as the aecidial form. The
attacked plants of Pedicularis are often considerably deformed.

P.- uliginosa Juel.** Uredo- and teleutospores on Carex vulgaris ;

' PUze Schlesiens.

-Klebahn, Zeitschri/f f. PJlanzenkranl'heiten, ii., 1892.

■* Dietel, Oesferreich. botan. Zeitung, 1889.

^ Magnus, Taghl. d. Naturforsch. Vereins in Miinchen, 1877.

•''Schroeter, P'dze Schlesiens.

^Juel, Mycoloij. Beit. Vetenscaps-Ahid. FiJrhandl, 1894.

352

UREDINEAE.

aecicUa {Aei: parnassiae Schleclit.) on I'arnassia jxiluatru. .Spermogoiiial
pyciiidia are unknown.

P. scirpi D. C. (Britain). Uredo- and telentospores on Sdrpus; aecidia,
according to Chodat, = Aec. nymphaeoides on Nymphaea, Nvpltur, and Lim-
nanthemum nymph rtonirfcK.

Fio. 186. — Puccinia suavcolens on Cirsium arvense. The plants are abnormally
elongated ; the leaves have remained smaller and simpler, and are thickly beset
on the lower side with patches of chocolate-brown uredospores. (v. Tubeuf phot.)

P. eriophori Thiim. Uredo- and teleutospores on Eriophorum latifolium
in Siberia and Denmark ; Rostrup gives as the aeeidial form Aec. ciuerariae
Rostr.

P. obscura Schroet. Uredo- and teleuto.spores on Luzula; aecidia on
Dellis perennis (Plowriglit). (Britain and U.S. America.)

P. septentrionalis Juel. Uredo- and teleuto.spores on Polygonum vivi-
parum; aecidia, {Aec. .Sommerfeltii) on Thalictrum alpinum in Scandinavia,

PUCCINI A. 353

Iceland, Greenland, and Switzerland. Juel states that this is the only
heteroecious Puccinia whose uredo- and teleutospores inhabit a dicotyle-
donous plant.

{2) Accidia are absent ; jjycnidia, v.rcdospores, and teleutospo7'es
dndoped on the same %)lctnt. {Brachypuccinia, Schroet.) :

Puccinia suaveolens (Pers.) (Britain and U.S. America).
One form on Oirsium arvense, and a second on Centaurca Cyanus.
Pycnidia and uredospores appear first, then teleutospores develop
amongst the later-formed uredospores.

The shoots and leaves of attacked plants are permeated with
m}xelium and rendered conspicuous by their elongated shape,
lighter colour, and smaller, less lobed, softer leaves (Fig. 186).
Diseased plants bear no flowers. AVakker on investigating the
diseased stems found : non-development of those sclerenchyma-
sheaths of the primary tissues situated towards the interior of
the stem, whereas those towards the outer side show secondary
thickening ; irregularities occur in the interfascicular cambium,
so that the phloem becomes abnormally developed and propor-
tionately more extensive than the wood, it may also be divided
by a band of sclerenchyma.

P. hieracii (Schum.) (Britain and U.S. America). On numerous Com-
positae, e.g. Carlina, Cirsium, Carduus, Centaurea, Leontodon, Scorzonera,
Ci'epis, Hieracium, Cichormm, etc.

Plowright distinguishes two allied species on Compositae, viz. P.
centaure<ie, Mart, on Centanrea nigra, and P. taraxaci Plowr.

P. bullata (Pers.) (Britain and U.S. America). On Urabelliferae, e.g.
Aphim, Petroselinum, u^thusa, Selinum, Conutm, Anethum, etc. On culti-
vated species {e.g. Parsley, Dill, Celery, etc.) it may prove troublesome.^

P. oreoselini (Strauss). On Peucedamim and Seseli. (U.S. America.)

P. helvetica Schroet. On Aspenda taurina.

(3) Uredospores and teleutospores alone known. The related
'pycnidia and aecidict have either not as yet been traced, or do
not exist. {Hemipuccinia, Schroet.) :

Puccinia sorghi Schwein. {Puce, rnaydis Ber.). This rust of
Sorghum and Zca Mais occurs in America, Italy, Germany, etc.
The leaves become more or less beset with little pustules, in
which the sori of uredospores or teleutospores are contained
(Fig. 187-189).

P. purpurea Cke. On Sorg/mm vulgare in India, and Zea in Africa.

^Descriptiou and figures in X. J. Agric. Exper. Station Report, 1891.

Z

354

UREDINKAE.

P. elymi West. {Rostrnput ehfmi Lagerh.). On Ehjmus urenarius and
E. mollis.

P. Baryi (lierk. et Br.). On Brachypodium in Euroi»e and Britain,
Bambvsa Thouarsii in India, Andropogon, etc., in America.

P. longissima Schroet. On Koeleria cristata in Germany ; A'. Bei-ythrifi
in Ey_v|)t.

Fig. 18". — Puccinia sorghi
(Puce, maydtg). Portion of
Maize-leaf showing spore-
patches, (v. Tubeuf. del.)

Fio. lSi». — Puccinia iorghi. Three teleutospores and two
uredospores. One of the latter exhibits the tiny point -like
projections of the membrane, (v. Tubeuf del.)

Fig. ISS.— Puccinia sorphi. Section of leaf of Zea Mois filled with mycelium.
The epidermis is ruptured by a spore-sorus. At one end there are still the remains
of a uredospore-sorus and a few uredospores. (v. Tubeuf. del.)

P. paliformis Fuck. On Koeleria cristata. (Britain.)

P. anthoxanthi Fuck. On Anthoxanthum odoratum. (Britain.)

P. gibberosa Lageih. On Festuca syhatica.

P. angustata Peck. On Scirpus and Eriophorum. (U.S. America.)

P. junci (Strauss). On Juncus. (U.S. America.)

P. oblongata (Lk.). On Lv.zula. (Britain.)

puccixiA. 355

P microsora Korn. On Carex vesicaria.

P. caricicola Fuck. On Carex supina.

P. allii (D. C;.). Onion-rust. (U.S. America.)

P. iridis (I). C). On Iris. (Britain.)

P. veratri Niessl. On Veratrtun album and T'. viride. (U.S. America.)

Puccinia pruni I*ers. Plum or Prune Piust. [This is a
common species in both Europe and the United States ; it
attacks ahiiost every kind of cultivated drupaceous fruit, includ-
ing prune, plum, peach, nectarine, apricot, cherry, and almond.
The uredospores are brown, the teleutospores darker, and both
are as a rule found only on the under surface of the leaf
(Fig. 82). The leaves first show yellowish or reddish spots
which rapidly enlarge and darken in colour till rupture of the
epidermis takes place, and they rapidly dry up. The fruit is
thus altogether lost or much injured, while ripening of the wood
is more or less interfered with.

The remedies suggested are : sprayings with modified eau
celeste, or ammoniacal copper carbonate (see p. 69)].^ (Edit.)

P. cerasi (Bereng.) Chei-rv-rust on Prunus Cerasus, P. AmygdaluSy
and P. Persica.

P. oenotherae Vize. On American species of- Oenothera.

P. giliae. Haik. On Phlox and Qilia. (U.S. America.)

P. tanaceti D. C On Tanacettim vulgare. (Bi'itain and U.S. America.)

P. sonchi Rob. et Desm. On Sonchus. (Britain.)

P. endiviae Pass. On Cichoria Endivia in Italy.

P. carthami Corda. On Carthamus tinctoria.

P. balsamitae (Strauss). On Tanacetum Balsamita.

P. picridis Haszl. On Picris in Hungary.

P. bistortae (Strauss) (Britain and U.S. America). On Polygonum
Bistorta and P. viviparum. The teleutospores have no papilla on their
germ-pores. Soppitt {Grevillea, 1894) claims relationship between this
species and an Aecidium on Conopodiian denudatum (^Aec. bunii {])).

P. mammillata Schroet. (U.S. America). On Polygonum Bistorta. The
upper cell of the teleutospore has an apical thickening.

P acetosae (Schum.). On Rumex Acetosa, R. arifolia, and R. Acetosella.
Ludwig says it liibernates in the uredo-form.

P. polygoni Pers. (Britain and U.S. America). On Polygoneae.

P. rumicis-scutati (D. C). On Polygoneae.

P. oxyriae Fuck. (Britain and U.S. America). On Oxyria.

P. castagnei Thlim. On Apmm graveolens in France.

P. cicutae Lasch. On Cicuta virosa.

1 Pierce (Journal of Mycology, vii. , p. 354) gives an account of this disease as
found in California, and describes application and results of various remedies.

356 UREDINEAE.

P. stachydis I). ('. On Stucliyn recta.

P. argentata (Sohultz). On Impatiens. (BriUiin and U.S. America.)

P. Berkeley! I'ass. On Vinrn. (Plowriglit rlistinf^uishes also P. rincae.)
(Britain.)

(4) Uredospores absent or only rudimentary. The other spore-
forms — pycnidia, aeeidia, and teleutosporrs — derehqj on the snmr

hosf-ph/nf. (Pveciniopsis, Schroei.) :

Puccinia tragopogonis (Pers.) (Britain). On Trayopogon,
Scorzimcrii, Fodusjicrin/'m, and Galasia. The leaves of diseased
plants are conspicuous in spring from their slenderness and
pale colour.

P. senecionis Lib.^ (P)ritain). The mycelium inhabits species
of Srncrin ; it probably arises from aecidiospores, and produces
both aeeidia and teleutospores.

P. ipomeae Cooke. On Ipomea in U.S. America and S. Africa.

P. bunii (D. C). On Carum Didhocastanum and Pimpinella Soj-ifraga
(Britain).

P. smyrnii Biv. On Smyrnum Olusatrum. (Britain.)

P. trollii Karst. On Aconitum Lycoctonum and Trollius europaeus.

P. Valerianae Carest. On Valeriana officinalis and Centranthus
Calcitrapa.

P. liliacearum Duby. On Ornithogalum, Scilla, and Gagea. (Britain.)

(5) Teleutosjjores cdone p>^^oeluced ; they hibernate in dead host-
remains {Mieropv.ccinia, Scliroet.) :

Puccinia fusca (Ptelhan.). (Britain and U.S. America.)
Anemoue-rust. The brown spore-patches of this fungus occur on
various species of Anemone, Thcdictrum, and Pulsatilla. Attacked
plants of Anemone nemorosa (Fig, 190, 6 and 7) have their leaves
much altered, the petioles being abnormally long and the laminae
much thickened, with narrowed segments, and conspicuously pale-
green. The teleutospore-patches form chocolate-brown spots on
the lower surface of the leaf, and stripes on the leaf-margins.
Flowers are rarely developed on diseased plants: Fentzling,-
however, found flowering plants with aeeidia on the leaves ;
three of the perianth-parts being stunted. The same investi-
gator found a few anatomical changes in deformed plants ; in
petioles the middle one of the three vascular bundles normally
present was larger than those on each side of it ; in the dis-
eased lamina the parenchyma-cells were enlarged, while inter-

^Dietel, Hedwigia, 1891, p. 291; also Zeltichrirt f. Pjlanzenkrankhdten, 1893,
p. 258.

PUCCINIA.

357

cellular spaces were more numerous and also larger. Other
minor differences are also £;iven, but there seems to have been

Fig. 190.— Anemov.e-Rv.sl. 2 and 3, Normal pUmts of Anemone ranv.ncv.loid.es.
4, A'cidiuiii punctatuiii on Anemone ranuncuioides ; aecidia on the lower surface
of the leaf; the plants are abnormally elongated, and the leaf -segments are
smaller. 6 and 7, Pv.ccinia j'usca on Anemone nemorosa ; the plants rem lin small,
6 is completely deformed, 7 partially. 1 and 5, Aecidium lev.cosiwmum on
An-mune nemorosa; the plants are abnormally elongated and the leaf -segments
smaller, (v. Tubeuf del.)

358

UKEDINKAE.

some confusion between plants infested with this Faccinia and
those with species of Acculium. The changes induced on
anemone by either Aecidium Icucosjjermwm D.C. or Ace. j)unctatu7n
Pers. are quite distinct (Fig. 190).

Fig. 191. — Paccinia ribis on Red Currant (/ii(/i.s rubruin). Teleutospore-patches
on leaves and fruit, (v. Tubeuf phot.)

P. singularis Magn. On Anemone ranunculoides in Austria and
south-east of Europe. The teleutospore germ-pore is situated at the centre
of the lateral wall of the lower cell, thereby distinguished from that of
P. fusca.

P. atragenis Ilaussnj. On Atragene alpina.

P. thalictri Chev. On species of Thalictrum. (Britain and U.S.
America.)

PUCCiNiA. 359

P. Fergussonii Berk, et Br. On Viola pahcstris, etc. (Britain and U.S.
America).

P. alpina Fuck. On Viola hiflora.

P. geranii-sylvatici Karst. On Geranium sylvaticum?- (U.S. America.)

P. Morthieri Korn. On Geranium.

P. Holboelli (Horn.). On Arahis Holboelli and Erysimum narcissifolium
in Denmark and U.S. America.

P. drabae Eud. On Draba aizoides. (U.S. America.)

P. dentariae (Alb. et. Schwein.). On Dentaria hulbifera and D.
enneaphylla, causing pustule-like outgrowths on the leaves.

P. ribis (D. C.) Currant-rust. On Ribes rubnim, R. nigrum, R. alpinum,
R. Grossularia, and R. petraeu7n (Britain and U.S. America). (Fig. 191.)

P. saxifragae Schlecht. On Saxifraga. (Britain and U.S. America.)

(P. Pazschkei Dietel. On Saxifraga elatior and S. Aizoon.)

P. rhodiolae B. et Bi-. On Sedum rhodiola. (Britain.)

P. sedi Korn. On Sedum elegans.

P. aegopodii (Schum.). On Umbelliferae, e.g. Aegopodium, Astrantia,
and Peucedanam. (Britain.)

P. enormis Fuck. On Cliaerophyllum aureum.

P. asarina Knze et Schm. On Asarum. (Britain.)

P. rubefaciens Joh. On Galium boreale in Scandinavia and U.S. America.

P. campanulae Carmich. On Campamda and Jasioae. (Britain and
U.S. America.)

P. conglomerata (Str.). On Homogyne alpina.

P. expansa Link. On Adenostyles and Senecio.

P. virgaureae (D. C). On Solidago. (Britain and U.S. America.)

P. cardui Plowr. On Carduus lanceolatus., and C. crispus. (Britain.)

P. Andersoni. B. et Br. On Carduus heterophyllus. (Britain.)

P. bellidiastri (Ung.). On Bellidiastrum. (The aecidium on the same
host belongs to Piicc. firma Diet.)

P. adoxae D. C. On Adoxa. moschatellina. (Britain and U.S. America.)

P. betonicae (Alb. et Schwein.). On Betonica officinalis and Stachys
recta. (Britain.)

P. Schneideri Schroet. On Thymus Serpyllum. (Britain.)

P. scillae Lk. Ou Scilla bifolia in Hungary.

P. tulipae Schroet. On Tulipa Gesneriana.

P. Prosti Moug. On Tulipa sylvestris and T. Celsiana in Italy and
France.

P. Schroederi Pass. On Narcissus poeticus.

(6) The teleutospores germinate on the living i)lants, and again
produce teleidosjyorcs. All other forms of spore arc absent. {Lepto-
puccinia, Schroet.) :

Puccinia malvacearum Mont, occurs on various Malvaceae.

'Barclay (Annals of Botany, v., p. 27) describes and figures a rar. himalensis
on Geranium nrpalense.

360

UREDINEAE.

This rust is indigenous to Chili, and was introduced into France
about 1868, whence it rapidly extended throughout the whole
of Europe, and during the last ten years has made its appear-
ance in the United States. In many places it has completely
exterminated both wild and cultivated mallows, and rendered
the cultivation of garden hollyhocks impossible. It ap])ears in

Fig. 102.— Pvccinia inalvoxearum. Malluw lc:vf, with teleutosijore-sori. Three
teleutospores, one germinating, (v. Tubeuf del.)

May or June on the leaves, stems, and petioles of the host ;
all are more or less deformed, and the leaves may in severe
cases wither up long before the flowers appear. Sponging
with a solution of permanganate of potash (two tablespoonfuls
in one quart of water), has been found an effective remedy.

P. Sherardiana Korn. On mallow in America.

P. heterogenea Lager. On hollyhock in South America.

P. anemones-virginianae Schwein. On Anemone. (U.S. America.)

PUCCINIA. 361

p. thlaspeos Schub. On Thlaspi cdpestre and Arahis hirsuta

P. spergulae D. C On Spergula. (U.S. America.)

P. arenariae (Schuni.). On Alsineae and Sileneae, e.g. cultivated Diantlnis

bia-hatus. (Britain and U.S. America.)

P. chryosplenii Grev. On Chrysosplenium. (Britain.)

P. circaeae Pers. On Circaea. (Britain and U.S. America.)

P. buxi D. C On Buxus sempervirens. (Britain.)

P. umbilici Guep. On Umbilicus. (Britain.)

P. valantiae Pers. On Galium. (Britain and U.S. America.)

P. asteris Duby. (Britain and U.S. America.) On Aster, Artemisiay

Achillea, Cirsium, Scabiosa, Doronimm. Plowriglit regards P. millefolii

Fckl. on Achillea as a distinct species.

P. veronicae (Schroet.) (Britain). 1

P. veronicarum D. C. (Britain and U.S. America). !-0n Veronica.^

P. albulensis Magn. J

P. glechomatis D. C. On Glechoma {Nepeta). (Britain and U.S. America.)

P. annularis (Strauss). On Teiha-ium. (Britain.)

Hemileia.

Hemileia vastatrix, Berk, et Br. This occurs on the leaves of the coffee
plant in Ceylon, Java, and Sumatra. It causes a very destructive disease.
Sadebeck recommends as remedies : (1) Removal of infected leaves and
their steiilization by dilute acids or Bordeaux mixture. (2) Spraying
the beds with Bordeaux mixture, so as to kill the spores which have
fallen there.

Several genera which do not occur in Europe may be mentioned here,
viz. : Uropyxis, Diorchidium, Chrysospora, and Sphaerophragmium ; also
Masseella, Phakospora, aud Schizospora.-^ They contain but few species,
and none of practical importance.

Triphragmium.^

Teleutospores three-celled ; one cell is attached to the sporo-
phore, and carries the other two ; each cell has one or more
germ -pores.

Triphragmium ulmariae (Schum.). (Britain.) Uredospores
and teleutospores produced on the same plant, Spiraea Ulmaria.
The teleutospore-patches are dark-brown, the uredo-sori reddish -
yellow, while the pycnidia (so-called spermogonia) are yellowish

1 Distinction, see Magmis, Ber. d. deutsch. hotan. Ges., 1890, p. 167.
^Sadebeck, Forsd-naturwiss. Zcitschri/t, 1895. M. Ward, Sessional Paqjers"^
XVII., Colombo, 188 1.

=^Dietel, Bcrichte d. deutsch. botaii. Ges., 1895, p. 3;^2.

■* Bibliography and Revision, by G. Massee, Grevillea, xxi., 189'S, p. 111.,

362

UREDINKAE.

points. The so-called aecidia are really a form of uredo-sori ;
tliey occur as thick cushions and cause thickening or twisting
of the leaves and petioles.

T. filipendulae (Lasch.) (Britain). On Spiraea Filipendula.
T. echinatum Lev. occurs on Meum ; tele utospo res alone are known
(U.S. America).

T. clavellosutn Berk. On leaves of Aralia in the United States.

Phragmidium.

Teleutospores multicellular, the individual cells forming a
single series ; they show a variable number of germ-pores. The

Fig. 194. — Phrut/midium subcorticium
on a Rose leaf. The black spots are
teleutospore- patches on the uuder-
sm-face of the leaf. (v. Tubeuf del.)

Fig. 103. — Triphragnuv.m v.lmarine on
S/>iiv«rt Ulmaria. Germinating teleuto-
spore, with promycelia and sporidia.
(After Tulasne.)

teleutospores are produced in loose patches. The aecidial patches
have no covering, but are surrounded by club-shaped paraphyses.

The genus frequents only Eosaceae.

On species of Rosa : ^

Phragmidium subcorticium (Schrank.). Teleutospores, uredospores, and
aecidia mi leaves of wild and cultivated roses. (Bi'itaiu and U.S.
America.)

Phr. tuberculatum J. Miill. All the forms of spore occur on Rosa
canina.

Phr. fusiforme Schrot. \PJu: rosae-alpinae (D.C.)]. On Rosa alpina
(Britain).

Phr. speciosum (Fr.). On North American roses.

Phr. devastatrix Sor. On roses in Asia.

' J. Milller, " Die Rostpilze d. Rosa. u. Rubus-arten," Ber. d. deiUsch.
botan. Ges., 1885.

PHRAGMIDIUM.

363

On species of Potent ilia :

Phr. fragariastri (D. C.) (Britain and U.S. America).

Phr. potentillae (Pers.) (U.S. America).

Phr. tormentillae Fuck. (Britain.)

Phr. papillatum Dietel, from Siberia.

Phr. nepalense Barcl. and Phr. laceianum Barcl. in Ind

On species of Iluhus :

Phr. rubi (Pers.) {I'lir. hidhosum
Schlecht.) (Britain).

Phr. rubi-idaei (Pers.). On leaves
of raspberry. (Britain and TT.S.
America.)

Phr. violaceutn (Schultz) (Britain).

Phr. rubi-miniatum J. Miill.

Phr. albidum (Kiihn).

Phr. quinqueloculare Barcl.

Phr. octoloculare Barcl.

Phr. Barclayi Dietel, from Hima-
laya.

Phr. gracile Farl., America.

And other species.

On Sanguisorha :
Phr. sanguisorbae (D. (.'.). On
Sanguisorha minor. (Britain.)

Phr. carbonarium (Schlecht.)
(Jjiitain). This species has also
been placed in a separate genus
Xenodochus. It occurs on San-
guisorha. Uredospores are want-
ing ; the teleutospores form firm
black crusts ; the aecidiospores
form chains ; and the paraphyses

are club-shaped. Diseased leaves and petioles are thickened and
bent. Wakker's investigation .showed : a slight enlargement of
parenchymatous cells and rupture of epidermis on spore-formation ;
a diminution in the intercellular spaces and in formation of
collenchyma and sclerenchyma ; a suppression of all production
of chlorophyll and calcium oxalate.

Fig. 195.— Phragmidium rvhi from Rubm
rrutirogui. One spherical immature te-
leutospore, and two well-developed and
germinating ones. (After Tulasne.)

Melampsora.

Teleutospores dark and unicellular, in some cases multi-
cellular by formation of new walls, generally in a vertical

364 UUEDINEAK.

direction ; tlieir sori form dark spots whieli break out from
beneath the epidermis. The yellow uredospores have a coat
beset with fine spines, and are given off from sori which may
or may not be enclosed in a peridium. The sori of the
aecidium-stage have no peridium, and are known under the
generic name of Cdcoma ; they fre([uently occur on other hosts
than those of the teleutospores. Pycnidia are produced in little
yellow patches.

Melampsora tremulae Tul. (Britain). The sori of uredo-
spores appear as little yellow protuberances on leaves or young
shoots of Popidus tremula. The dark -brown patches of teleuto-
spores appear later on the under epidermis, and where they

Fie. 196. — Caeoma piniiorquum. Section showing four pycnidia, from one
of which (.tp) numerr)us conidia are being disch;irged. Cfnom/i-TpMches are
developing beneath tlic cortical layer, as yet unbroken. (After R. Hartig.)

occur in large numbers, an early fall of the leaf may result.
The teleutospores hibernate in dead leaves on the ground. In
spring the sporidia germinate and infect young shoots of Pinus
sylvcstris, producing the disease known as Caeoma j^initcn'quvm}
This disease attacks pine-seedlings, appearing generally on
the needles. It is most frequent in plantations from one to
ten years old, rarer in those of ten to thirty years, and not
as yet observed in older. Finals sylvcstris is most commonly
attacked, but it has also been observed on Pimis montana in
Jutland. After formation of the C«fowff-patches, the young
thin shoots generally die off, but thicker ones become twisted
at the place attacked, whence the name " pine-twister " commonly
given to this disease. If the leading shoot be attacked, the
seedlings may succumb altogether. The disease develops rapidly,

^ R. Hartig, Wichtuje Krankhdtcn d. W'aldhiinine, 1874.

mela:\ipsora.

365

particularly in a damp and cold spring, and may prove very
destructive if it appears for several years in succession. The
mycelium evidently perennates in pine-shoots, and prodnces
new Cacoma--p(itches year after year till death of the host results.
It grows intercellularly especially in the rind parenchyma, but
also in the medullary rays of wood and bast ; the contents
of the host-cells are absorbed by means of short lateral haustoria.

Fig. 107. — Caeoma piiiitnrqiurii. Portion of C'/(0?)i'( -patch (enlarged). /, Cortical
cells partially absorbed or nnich compressed ; !/, basidia from whicli spores (c) are
abjointed in succession : the younger with delicate walls and separated by
membranous lamellae, which disappear on formation of the spore-coats (d).
(After R. Hartig.)

The pycnidia are produced at end of May or beginning of
June, between the epidermal cell-wall and the cuticle of green
twigs ; before breaking out they may be observed externally
as light patches on the shoot. The Ca^oma-patches develop
later in the second or third layer of the rind-parenchyma
(Fig. 196). In each patch the spores are produced serially from
.short stalks to the number of twenty or thereabout, and ultimately
escape about June, when the cells of the parenchyma and
epidermis are ruptured. At first the spores are connected
together by intermediate cells which are afterwards absorbed
(Fig. 197). The mature spores are globose, oval, or polygonal

366

UREDINEAK,

in shape, yellow in colour, aiul their outer coat is beset with
spiny projections. The stalk-cells grow out into elongated tubes,
after completion of spore-formation. In the vicinity of the
scar of a C«com«- patch, the twig turns brown and its tissues
become permeated with resin, while the tissues underlying the
patch die even into the pith.

Hartig's ^ investigations show that this same Melampsora causes
Gaeoma laricis on the needles of the larch. Plowright - also
produced a similar Cacoma-ioxm from Melampsora betulina, and

Fio. 108. — MiUdiipxorn betulhin. Teleutospore-sorus, with many of the spores
producing promj-celia and sporidia (x). i\ Mycelium ; p, parenchyma ; c, portion
of ruptured epidermis. (After Tulasne.)

succeeded in re-infecting Betula alba from Caeoina laricis.
Eostrup obtained Cacoma mcrcuria.lis by infecting Mercurialis
with Mel. trcmulae ; yet this may have happened because two
different species of Mdamiisora occurred on the aspen leaves.
Klebahn ^ was successful in infesting Populus tremula with
Gaeoma laricis but did not succeed W'ith the birch.

^R. Hartig, Allef/em. Fo7:sL %i. Jar/d-zeiiung, 1885.

-Plowright, " Impfversuche in. Rostpilzen, " Zeitarhri/t f. Pjlanztnkrankheiten,
1891.

•'Klebahn, Zeitschrift f. Pflanzenh-ankhtiten , 1894.

MELAMPSORA. 367

The patches of Cacoma laricis Hartig,^ appear as golden-yellow
cushions on the underside of the needles, The sporophores from
which the aecidiospores are abjointed, form the centre of the patch,
the periphery being occupied by numerous sterile threads, which
grow out as long paraphyses ; it may so happen that the whole
cushion consists only of these last. The formation of Caeoma-
patches is preceded by that of little pycnidia (spermogonia),
which break out from under the cuticle. The mycelium lives
intercellularly, and dies after the shedding of the Caeoma-
spores.

Melampsora betulina (Pers.) (Britain and U.S. America).
Uredo- and teleutospores occur on the leaves of the birch
{Bctula alba). Plowright^ found from arti-
ficial infection that this species produced
Caeoma lai^icis on the needles of Larix
curopea. A second form of Cacoma laricis
was obtained by Hartig, both from infec-
tion by Mel. tremulae Tul. from the aspen,
and by 3Icl. 2J02yulina Jacq. from the black

poplar. Fig. 199. — Mebimpsont

M. populina (Jacq.)'^ (Britain and U.S. uredospore-LTus?'' (After
America). Uredo- and teleutospores found ^uiasne.)
on Pojjulus nigra and P. halsamifcra.

M. po2mliiia and M. tremulae are probably identical, for Hartig
has found the same Melampsora on black and balsam poplars
as on aspen, and in each case he produced Caeoma laricis by
means of the uredospores. Schroeter states that the Melampsora
of Populns nigra produces Cacoma allii of Allium.

M. aecidioides D. C. (Britain). Uredo- and teleutospores on
leaves of silver poplar {P. alba and P. canescens). Plow-
right connects with it a caeo7na-iorm on Mercurialis {Caeoma
mercurialis). Schroeter states that the Melampsora of Populus
tremula produces Caeoma mercurialis.

The Mclampsorae of Willows were until recently grouped
under a collective name, M. salicina ; several species are now
recognized, others require verification.

1 R. Hartig, Wiclitige Krankheiten d. Waldhaumen, PL V.

^Plowright {Joe. cit.).

^'R. Hartig, Botan. Centralhlatt, XLVi., 1891; " The leaf-rust of cottonwoods,"
U.S. Dept. of Agricidhire Report, 1888, p. 390.

368

UREDINEAE.

M. salicis-capreae (Pers.) (liritaiii and U.S. America).
Uredo- and teleutospores on leaves of Salix Gafrca and several
other species. According to Rostrup, Caeoiiui cuonymi (Gmel.)
is a staije of this.^

M. Hartigii Thiini.- {M. epitca Thlini.) (Britain and U.S.
America). Uredo- and teleutospores on leaves of Scdw: |jr<<.mo.sa.
S. daphnoidcs, S. viminalis, etc. Eostrup regards C. ribesii Lk.
of Bibes as a caeoma-form.

Fig. 200. — Mi lampsoni salifix-caprfaf. Section through leaf of SaUx Caprea,
with a uredospore-sorus on the lower epidermis ; on the upper side a teleutospore-
sorus is in process of development, but is as yet completely closed over. (After
Tulasne.)

M. repentis Plowr.^ Uredo- and teleutospores on Salix repens. Caeoma
on Orchis maculata. ' (The Caeoma orchidis of other orchids is probably
identical with this one.)

M. arctica Eostr. on S(di.i- lierhacea^ S. c/lauca, and .S'. groenlandica in
Oreenland.

M. mixta (Schlecht). (Britain). The related Caeoma is unknown.

Thiimen also gives M. Castagnei Thlim. on S. amygdalina.

M. vitellinae D. C. on Salix frag His is said by Schroeter to have its
Caeoma on Galanthus nivalis (Britain).

The rusts of cultivated willows are very detrimental to them

^ M. salicis-capreae {M . caprearimi D.C. ) is cUvidecl by some autliorities into
M.farinosa (Pers.) and M. epitea (Kze. et Schni.).

-See Thiimen, "Mel. salicina," Mittheilungen aus d. forstlich. Versuchswesen.
Oesterreich, 1879.

^Plowright (loc. cit.).

MELAMPSORA.

369

and cause great damage. The yellow
sori appear in large numbers on the
lower surface of the leaves, w^hich
wither prematurely, especially towards
the ends of shoots (Fig. 201). The
teleutospores hibernate on fallen leaves,
hence such should be raked together
and burnt. Saliv pruinosa is found
to be much more sensitive to attack
than *S'. pruinosa X daphnoides, whose
leaves are more hairy, a property
which seems to protect them from
spores.

The following species have only
uredospores and teleutospores, related
Caeoma-iorms being unknown :

M. lini (Pers.) (Britain and U.S.
America). Flax-rust. The uredo- and
teleutospores occur together on Li num.
This may inflict serious damage in
fields of cultivated flax.

M. sorbi (Oudem.). On leaves of
Pyrus Aucuparia and P. torminalis.
Dietel ^ has recently placed this as
the single species of a new genus
Oclirospora. The light-yellow spores
are at first one-celled, but before
the death of the host-leaves they
divide into four (rarely three) cells,
each of which gives off a sterigma
with a single sporidium. In these
points the spores follow the develop-
ment of Cohosporium ; the sporidia,
however, are quite different, they are
spindle-shaped, '21-2hix long and Syu
l)road.

1

.^1

'?^

,X

Fig. 201. — Mdcmpsora Hnrtigii ou Salic pruinosa. The upper leaves
have ab-eady vrithered atid curled up, the lower, though as yet un-
changed, are beset with the point-like sori. (v. Tubeuf deL)

1 Berichte d. deutsch. hotan. Ges., 1895, p. 401.
2a

370 UREDINEAE.

M. ariae (Schleicli.). On h-avi-s of I'yrvs aria.

M. padi (Kunze et Sdium.). On leaves of Prunm Padus. (Britain.)

M. hypericorum (D.C!.). On Jlypericnm. (Britain.)

M. pustiilata (Pers.). On Epilohium. (Britain and U.S. America.)

M. circaeae (Schuni.). On Circaea. (Britain.)

M. vaccinii (Alb. vt Sclini.). On leaves of Vncdnmm. (Britain and U.S.
Anioiica.)

M. pirolae (Gniel.). On Pyrola. (Britain and U.S. America.)

M. sparsa Wint. (U.S. America). On Aretostaphylos alpina (also A.
offii'liKih'a ace. to Rostrnp).

M. carpini (Nees.). On leaves of hornbeam.

M. galii (Lk.). On (iaVnini.

M. (Thecopsora) agrimoniae (D.C.) On Agrimonia.

M. vemalis Niessl. Teleutospores only on Sa.rifraga gramdata.

M. helioscopiae (Pers.). On Euphorbia. (Britain.)

M. euphorbiae-dulcis Ottli.

Melampsorella.

The unicellular teleutospores are developed in the cells of
the epidermis and t'orui reddish patches. The patches of
uredospores are enclosed in a peridiiim.

Melampsorella cerastii (Pers.). Uredo- and teleutospores on species of
Stellaria and Cerastimn. (Britain and U.S. America.)

Calyptospora.

The teleutospores are developed inside the epidermal cells,
and are divided into four cells by vertical septa. The aecidia
have large peridia. The pycnidia are small and precede the
aecidia.

Calyptospora Goeppertiana Kiihn.i (U.S. America). The
common disease of cowberry {Vaccinium Vitis-Idaca) caused by
this parasite is shown externally by a very marked swelling
and elongation of the shoots (Fig. 202). Diseased plants
elongate conspicuously above their neighbours, and in this way
distribution of their spores by wind is facilitated. The mycelium
hibernates in the cortical tissues, and maintains itself for years.
It grows intercellularly, sending haustoria into the cortical cells.
As a result of its presence, cell-growth is much accelerated,
and a marked thickening of attacked twigs frequently occurs :

iR. Hartig, Lehrhvrh cf. Baumlranl^Jieiten, i. Aiifl. p. 56 and PI. II. (The
2nd edition and the English translation are somewhat abridged.)

CALYPTOSPORA.

371

intercellular spaces become enlarged, and the contents of all
cortical cells, except those of the epidermis, takes on a red
colour, whereby the young shoots have at first a delicate rose-
red colour, though they afterwards turn brown. The lower
leaves have a similar red colour, but shrivel and fall off early,
while the upper ones develop normally and remain attached.

Fig. 202. — Cali/ptospora Goeppertiana. Normal and malformed shoots of
Vo.ccinivm Vitis-Idaea. (v. Tubeuf phot.)

Shoots infected one summer show the symptoms in the
following year. The swelling is confined to the basal part of
a year's growth, and the apices of shoots remain normal to all
external appearance, although permeated with mycelium. Hartig
has explained this by assuming that the fungus-mycelium only

372

UREDINEAK.

influences yoiuif; cells attacked by it duiin<,' their period of
growth, whereas cells already in the adult condition remain
unaffected.

Inside the diseased shoots a well-developed mycelium will
be found between the epidermal cells, and nourished by haustoria.

Fig. •20i.—Calypto.*pora Gorpptrtiana. Section through epidermis and cortical
parenchyma of a diseased shoot of Vo.ccinium. The mycelium is intercellular, but
swoUen branches penetrate the cell-walls and become sac-like haustoria. The
iiyphae under the epidermis become considerably swollen, and give off into the
cells either haustoria {fi) or the sac-like processes (c, c), which become the mother-
cells of the teleutospores. x 420. (After R. Hartig.)

The spores originate from processes of the mycelial hyphae,
which bore their way into the epidermal cells, and swell up
inside to form spherical sacs. The cells thus entered turn
brown, and are filled up by four to eight cells produced from
the sac-like processes of the mycelium (Fig. 203). From each
cell of this kind a four-celled teleutospore is formed and hiber-
nates in sihc. In spring the teleutospores emit a process through
the outer wall of the epidermal cell, and this, after division
by cross-septa into four cells, becomes a promycelium with short
sterigmata, from each of which a single sporidium is abjointed
(Fio-. 204). The sporidia germinate, as Hartig proved, about the
middle of May, on young needles of silver fir (Abies iicctinata).
By the middle of June the mycelium is distributed through
the intercellular spaces, and forms aecidia with long white sac-
like peridia on the under surface of the leaf (Figs. 205, 206)
The aecidiospores escape on rupture of the peridium and the

CALYPTOSPORA.

373

host-epidermis, to germinate on the epidermis of another cowberry-
shoot. The germ-tube either enters by a stoma, or forms an
adhesion-disc and sends out a process from this through the
epidermis.

Fig. 204. — Dise.ised stem of Vnccintura in a
later stage than Fig. 203. In each epidenual
cell (n, (0 six mothei'-cells have been formed,
each subdivided into four teleutospores.
Proniycelia (6) have developed from many of
the latter, and are in process of abjointing
off the sporidia from lateral sterigmata.
X 420. (After R. Hartig.)

Fig. 205. — Co.b/ptospora Goeppertiana.
Aecidia on the under surface of needles
of Silver Fir. (v. Tubeuf del.)

Fig. 206. — Aecidium in a needle of
Silver Fir (much enlarged), b, Series
of aecidiospores and intermediate cells.
'•, Germinating aecidiospores. (After
R. Hartig.)

This aecidium is also fouud on Abies cephalonica in Upper
Bavaria.

Barclayella deformans Diet.^ This has been found in the Himalaya
region on needles and young twigs of Picea Morinda (Smithiana). Teleuto-
spore-sori are developed, accompanied by distortion of the host. Aecidia
and uredospores are unknown.

^Barclay, "Oil a Uredo of the Himalaya Spritce-Jir."
Hedwigia, 1891.

Calcutta, 1886; and

374

UREDINEAK.

Coleosporium,

The teleutospores form a soft, reddish, waxy cushion, and
germinate in situ producing four-celled proraycelia; in these
respects they exhibit great resemblance to Auricularia. Uredo-
spores are developed in chains. The aecidia, as yet known,
have a distinct peridiuni.

Many species infect the needles of pine trees and produce
aecidia known by the generic name Peridermium ; other species
also known as Peridermium and living on bark are really
species of Cronartium. The species here mentioned with their
Peridermium-i'orm on pine-needles, so much resemble one an-
other as to be almost indistinguishable, and
the question arises whether they are really
species, or only varieties due to difference
of substratum — habitat-races.

Coleosporium senecionis (Pers.). (Britain.)
The sori are produced on leaves and stems of
various species of Senecio (without doubt on
>S'. vulgaris, S. sj/lvaticus, S. viscosus). The
uredospores are slied in June from yellow
spots. The teleutospores follow later on
dark-red patches, there they hibernate and
in spring produce a four-celled promycelium,
each cell of which gives off a sterigma with
one sporidium. The latter germinate on
needles of Pinus sylvestris. A mycelium is
formed in the intercellular spaces of the
needles, and, nourished by means of haustoria sunk into the
host-cell, perennates and produces crop after crop of aecidiospores.
Hyphae are produced in such numbers that the cells of the
needle-parenchyma are tightly pressed together, and those
adjacent to pycnidia and aecidia turn brown, secrete resin, and
die. The needles tliemselves, although filled with mycelium,
remain on the tree till the time of their normal fall.

Pycnidia are developed by April or May under the cells of
the epidermis. They are little obtuse cone-shaped enclosures
appearing as brownish-yellow spots scattered over the inner
faces of the needles. On attaining maturity they rupture the
host-epidermis and give out their conidia.

Fig. 207. — ColeoKporiuvi
xnucioiii'i on a bifoliar
spur of Fiiixis Ki/lveiitfis.
Peridia and scars of the
pycnidia are shown, (v.
Tiibevif del.)

COLEOSPORIUM.

375

The aecidia are produced amongst the pycnidia on needles
two or three years old ; they have long white peridia and
are known as Peridermium ohlongisporium Fuck. The aecidio-
spores are yellow when mature, and originate in chains, which
in the earlier stages of development consist of intermediate
cells and spores, but the former gradually disappear (Fig 208).
The spores have an average length of 30'5/x and breadtli of

Fig. 208. — PerUb rmiv.ni jiin'i (Coko-yioridm .■<• nirionix). Portion of an aecidium
with basidia (b) giving off spores and intermediate cells (d) ; outside the
peridiuni (p) other basidia (■ ) with club-shaped ends force up the epidermis ;
II, the thick mycelium in the leaf-iiarenchyma. (After R. Hartig.)

20/tA; in form they are generally longish-oval, few being round;
the spore-coat is moderately thick. Aecidiospores are capable
of immediate germination, and produce ZJ/vrZo-patches on Scnecio
by June.

The uredospores have an average length of 28"0/u, and
breadth 15"5ja; they are generally oblong, with a moderately
thick coat beset with spiny warts.

37S UREDINEAE.

Klebahn and Fischer^ assert that several other species of
Colcosporium produce their aecidium-stage on Finns sylvestris.

C. euphrasiae (Scluun.) (Britain). Uredospores produced from
reddish-yellow, teleutospores from orange-red patches during
July and August on various Rhinanthideae (Bhinctnthus major,
II. minor, Bartsia Odontites, and Eiqihrasia officinalis). The
spores from Bhinanthns germinate on needles of Finns sylvestris
and produce an aecidium called Fcridermium Siahlii Kleb.
The aecidiospores of F. Stahlii average 26/x in length, 19'5/a
in breadth, and are round or shortly oval, with a coat and
markings finer than those of F. ohlongisporium. The uredo-
spores average 22/x x 15-5/>c; they are irregular and somewhat
angular, with a thin finely marked coat.

C. melampyri (Eeb.) (liritain). Uredospores on Ifclant-
2)yrum (certainly on M. jyrafensc). The aecidia — Fcridermium
Soraueri Kleb. — follow after a year on needles of Finns sylvestris.
The spermogonial pycnidia alone are developed in the summer
of infection.

0. tussilaginis (Pers.) (Britain). Tliis ColcosjJorinm is found
all summer on the underside of leaves of Tnssilago farfara,
the uredospores forming yellow patclies, the teleutospores darker-
coloured ones. Aecidia are produced on needles of Finns
sylvestris, and are known as Fcridermium Flowrightii. Pycnidia
and aecidia are formed in the summer following infection.
The aecidiospores average 25"5^t x 19ya and are shortly oval
or round, with coats and markings more delicate than those
of F. Stahlii. The uredospores average 26 fx x 19/x and are
roundish oval with somewhat firmer and thicker coats than
those of C. euphrasiae.

Klebahn's infections of Fctasitcs with aecidiospores from Finns
gave no result.

C. inulae Kunz. Spores of this obtained by Fischer- from
Imda Vaillantii and /. Helrnium produced Fcridermium Klehahni
Fiscli. on needles of Finns sylccstris.

C. sonchi (Pers.) (Britain and U.S. America). Klebahn
considers this as a provisional species including a number of
imperfectly investigated forms whose uredo- and teleutospores

^Berichted. deutsch. hotan. Ges., 1S94; Znt-schrift f. Pflanzenkrankheiten, 1894,
and 1895, p. 73.

"Botan. Cenfralblatf, lix., 1894, p. 1.

COLEOSPORIUM. 377

occur on various species of Sonchus (without doubt on S.
arvcnsis). Aecidia are unknown. He relates it to Pcridcrmhim
Fisclieri Kleb. on needles of Finns sylvestris.

C. synantherearum Fr, A provisional collective name for
aecidia on Adcnostylcs, Pdasites, Gaccdia, Senecio, etc., the life
history of which is as yet unknown.

C. campanulae (Pers.) (Britain). Uredo- and teleutospores
on Campanulaceae {Camjjcmida and Phytnnna). The aecidial
form is Feridermimn Rostriqni on pine-needles.

C. pulsatillae (Str.). Uredo- and teleutospores on Anemone
Ftdsatilla and A. pratcnsis. Aecidia unknown.

C. ipomoeae (Schwein). Uredo- and teleutospores on species
of cultivated Ij)oinoca. in United States. Aecidia unknown.

Fischer ^ obtained pycnidia on needles of pine by infection
with a Coleos.'poriuni from Campemula Trachelium.

Chrysomyxa.

The teleutospores are formed closely together in yellow sori ;
each spore consists of an acropetal series of cells, the distal
one of which, without leaving the sorus, germinates to produce
a promycelium of several cells. Uredospores are not always
present. The aecidia have well-developed peridia.

Chrysomyxa rhododendri (D. C.).^ This is a common rust
on the Alps where the Alpine-rose {Rhvdodeiulron ferrugineum and
R. Mrsvtnm) occurs. Immediately after the break-up of the
winter little dark-red cushions of this rust appear on the under-
side of the leaves. These contain the sori of teleutospores
already partially developed during the previous autumn, and
now, after hibernation, ready to increase in size and to rupture
the host-epidermis (Fig. 211). The teleutospores so exposed
germinate without leaving the sorus, and produce four-celled
promycelia, with sterigmata, from each of which a single
sporidium is abjointed. The sporidia make their escape in
June, and alighting on the unfolding needles of the spruce
{Picca cxcelsei), they germinate at once and produce Aecidium
ahictinum, the blister-rust of the spruce (Fig. 212).

An intercellular mycelium is developed in the spruce-needles,

^ Botan. Centralhlalt, Lix., 189-4.
^De Bary, Botan. Zeitung, 1879.

378 UREDINEAE.

and small yellow pycnidia are produced during July (jr
August. The aecidia follow from August till September,
occupying yellow zones on the otherwise green needles ; their
white peridia project as much as 2 mm. above the surface of
the needle, and dehisce by rupture of the apex. The aecidiospores
are formed in large numljers and, carried l)y wind, reach leaves
and shoots of alpine-rose where they immediately germinate.
The resulting mycelium produces in September yellow clusters
of uredospores on brownish spots on the lower epidermis of
the leaves, and on the bark of last year's shoots (Fig. 210).

Fig. •209.-^Chi-y«omyxa rhododendri. Twig

of Rhododendron hh-xutinn with sori of uredo- Flo. 210.— CJi ryxomym rhododendr! on KUo-

spores ou the lower epidermis, causing dis- doth ndron u i-i-iKj'ni'vm. Uredospore-.sori in

coloured spots on the upper, (v. Tubeuf September as elongated white stripes on the

del.) stem below the leaves, (v. Tubeuf del.)

The uredospores are yellow and ovoid, with granular protuber-
ances on their coats ; they are developed in series from the sori.^
The disease may be further propagated during the same year
by the uredospores. In districts where spruce does not occur,
it is probable that these spores hibernate, and in the following
spring produce germ-tubes which infect other alpine-rose leaves.
It frequently happens that whole forests of spruce are so attacked
by this fungus that many of the trees retain only a few
healthy needles. Diseased needles die and fall in the summer
of attack, so that the trees may l)e almost wholly stripped,
and thereby suffer considerable damage.

Chr. ledi (Alb. et Schwein.)^ (U.S. America). This fungus

1 Raciborski regards the Uredo as a Caeoma-iorm.
-De Baiy, Botan. Zeitnnrj, 1879.

CHRYSOMYXA.

379

occurs on Ledum palustre. It is difficult to distinguish from
the preceding species, and causes the formation of similar aecidia
on spruces in Northern Germany and other parts where Rhodo-
dendron is not indigenous. Its uredospores are also capable
of hibernating and of propagating the fungus where spruce is
absent.

Ohr. himalayensis Barcl. occurs on leaves of Rhododendron
arhorrvm in the Himalaya.

Fii;. 211. — C'h ri/somyxa rhododfndi't. Teleuto-
spore-sorus which has ruptured the lower epi-
dermis of a leaf of Rhododendron hirsutuin. The
teleutospores are jjluricellular, and one of them
has germinated, giving a promycelium with
sterigniata, from which little sporidia are being
abjointed. (After De Bary.)

Fig. 212. — Ckri/somi/xa rhododtndH
on Spruce. The needles are beset
with aecidia ; discoloured parts of
them are shown black, the normally
green being left white, (v. Tubeuf
del.)

Chr. abietis (Wallr.).i Xeedle-rust of spruce. Tliis is parasitic
on the spruce {Pieca exceha), and is found on the Alps up to
an elevation of over 1700 metres. About the beginning of
May the hibernating teleutospores produce promycelia and
sporidia. The latter germinate at once, and the germ-tubes
make their way through the epidermis into young unfolding
needles. The mycelium is well-developed and lives inter-
cellularly, sending haustoria into the host-cells ; it contains
yellow oil-drops, so that by the end of June needles contain-
ing it exhibit yellow-coloured stripes. For the remainder of
the year reddish-yellow elongated teleutospore-cushions are

' Reess, Botan. Zeitiuif/, 1865 ; Die Bostpilzformen d. deut$rhe)i Coniferen, 1S69.
Willkomm, Die mikrosropisrheii Feinde dfs Wahles, 1868.

380

UREDINEAK.

formed, and in this condition the fungus hibernates, to develop
furtlier in the following spring. It is only in very dry cold
winters that the needles dry up and fall off; as a rule they
remain on the trees. About the l)eginning of May the spore-
cushions break through the epidermis and give oft" multicellular
teleutospores, which are as a rule branched.
Thence arise the four-celled promycelia, with
sterigmata, from which a single sporidium is
abjointed.

Diseased needles remain green except in
areas inhabited by mycelium ; yet needle-cast
soon follows liberation of the fungus-spores.
Starch is laid up in large quantity in diseased
needles during the first summer, but is com-
pletely used up again by the mycelium for the
formation of the teleutospore-patches. Spruces
may suffer considerably from loss of foliage
induced by this fungus, yet the risks are by
no means so great as in the case of Chryso-
oiiyxa rlwdodendri where the whole existence of the plant is
endangered.

Uredospores are unknown for this species and an Aecidmm
stage has not as yet been discovered. lieess has shown experi-
mentally that the teleutospores germinate directly on spruce
without intervention of an aecidial stage.

Chr. piceae Bare. On needles of Picea morinda in India.

Chr. empetri (Pers.) (Britain and U.S. America). Uredospores on
Empetnim //I'r/rum. Caeoma empetri (Pers.) is the aecidial form.

Chr. pirolae (D. C) (Britain and U.S. America). Uredo- and teleuto-
spores on Pi/rola. Aecidia unknown.

Chr. albida Kiihn. On Ruhus fruticosus in Germany and U.S. America.

Fig. 'ilZ.—Chriisomyxa
ahiclis on PiciKi cxcdsa.
The sori occupy the
middle portion of each
needle, which is in con-
sequence yellow, while
the apex and base arc
still green, (v. Tubeuf
del.)

Cronartium.

Teleutospores unicellular and remaining attached together
in tlie form of a long coiled process; they germinate in
situ and give off sporidia. The masses of teleutospores arise
on the place formerly occupied by a uredospore-sorus. The
ovoid uredospores are abjointed from short stalklets enclosed
in sori with a short peridium. Aecidia are developed on other

CRONARTIUM,

381

host-j^lants, and several species produce blister-rust on the bark
of species of pine.

Cronartium asclepiadeum (Willd) (U.S. America). Uredo-
and teleutospores occur on Cynanchum Vincetoxicum (perhaps

Fig. 214. — Cronartium agcUpiadmoii on Cynanchum Vincetoxicum. The uredo-
sori show as spots, the teleutospore-sori as processes on the leaves, (v. Tubeuf
del.)

also on Gcntiana asdepiadca). The aecidial stage, known as
Peridcrmium Cornui Eostr. et Kleb. produces a blister-rust on
the bark of Finns sylvestris.

Fig. 215. — Cronartium asclepiadnnn. Section of a
Cynanchum leaf. The leaf -parenchyma is permeated with
mycelium, and sori are formed on the lower epidermis.
A, uredo-sorus ; B, televitospore-sorus, many spores of
which have germinated and given off promycelia with
sporidia. (v. Tubeuf del.)

Brown spots may be found on the leaves of the Cynanchinn'^
during July, August, and September (Fig. 214). On examina-
tion of the spots with a lens, the leaf-epidermis will be found

^A very common plant in Europe though not indigenous to Britain. (Edit.)

382 URKDINKAK.

pierced by a circular opening under which lies the yellow
uredospore-patch of the Gronartium enclosed in its peridimn.
The ovoid yellow uredospores have a coat beset with short
spines and are abjointed singly from short cylindrical sporo-
phores (Fig. 215). From the uredo-sorus there next arises a
protuberance which lengthens till it forms an elongated slightly
curved brown cone or column consisting of cylindrical teleuto-
spores firmly built together (Fig. 215). The teleutospores
germinate without becoming detached from the mass, and
produce a four-celled promycelium with small sterigmata from
which globular sporidia are abjointed. The sporidia on reach-
ing the branches of Scots pine produce in its bark at first
pycnidia, later aecidia. The pycnidia (spermogonia) give off
yellow drops of liquid with a characteristic odour. The
aecidia are yellow thick-walled sacs ; their spores are set free
in spring and infect young plants of Cynanchum.

Since the sporidia of the Cro?iarh'wm -stage are shed by
September, the fungus would seem to hibernate only in the
form of mycelium in the branches of pine.

The effects of this fungus on the pine will be considered
along with those of Feridermium pini, another blister-rust
of pine closely resembling this species (p. 411).

Cr. ribicolum Dietr. Uredo- and teleutospores are developed
towards the end of summer on leaves of various species of
Ribes (e.g. Ribcs nigrum, ruhrum, aureum, alpinum, sanguineum,
americanum, rotundifolium, setosuvi, and Grossularia). The
aecidium-stage {Peridcrmiuvi sirohi Kleb.) forms the blister-rust
of the bark of Weymouth pine (Pinus Strohus). Pycnidia
appear in the summer of infection ; the aecidia a year
later. Externally this bark-rust resembles that of Ferulermium
Corn III and P. pini on the Scots pine. It may cause con-
siderable damage to Weymouth pine lioth in nursery and
plantation.^

It is probable that other two forms of Aeciclimn are identical
with this, viz., that on Pinus Lambcrtiania in America, and
P. Cemhra especially in Russia.

Cr. flaccidum (Alb. et Schwein.) (Britain and U.S. America).
Uredo- and teleutospores on Paeonia, causing the leaves to dry

1 Magnus [Gartenflora, 1891) has pointed out that both the Gronartium and
the Periderminm are unknown in America, the home of the Weymouth pine.

CROXARTIUM.

383

and curl up. In some districts very common. Aecidial stage
unknown.

Gymnosporangium. ^

Teleutospores bicellular and furnished with .stalks which have
gelatinous walls, so that the spores come to form part of a
gelatinous mass.- The first-formed teleutospores are thick-

o

1 \^ ^ ^ '^

'i^ ''^o o

^'■"vf A 0=.s>.'^<i;;^

^

Fig. 21G. — Gyriinoiporangium, clavariafforrm. 1, 2, 3, Stages in development of
the spore-cushions. U, 5, 6, Isolated spores (enlarged); -5 is thin-coated, the
others are thick-coated. 7, Germinating spore with promycelium abjointing
sjxiridia ('>). 9, A germinating sporidiiim. (After Tubeuf.)

walled, the succeeding ones are thin-walled. Uredospores do
not occur. The aecidia have a thick peridium. The teleuto-

^v. Tubeiif : (1) Centralhlatt f. Bakter. v.. Parasite Jihmde, 1891; with a review
of the current Literature. (2) "Infectionen mit Gymnosporangium." ForstUch-
natunciss. Zeitsrhrift, 1893, p. 75. Woemle, "Anatomische Untersuchungen d.
durch Gymnosporangium-Arten hervorgerufenen !Missbildungen," idem., 1894.
American Literature, see p. 40L

- The gelatinous substance is obviously well-adapted to absorb rain-water
and so facilitate germination of the teleutospores in situ ; the sporidia pro-
duced are then carried off by rain or liberated after the cushions dry again.

384

UREDINKAK.

spores grow on needles and twigs of Coniferae, the aecidia on
the leaves of various Eosaceae (Pomaceae). Five species occur
in (rerniany, but there are many in America.

Gymnosporangium clavariaefonne Jacquin. (Britain and
U.S. Anu'rica.) The mycelium of this species perennates in
twigs of Junijyeriis communis. Infection is brought about by
aecidiospores. In the following year a swelling of attacked
places is evident, and this increases till death of the host
ensues. In spring, about the beginning of April, little light-
yellow cone-like structures break out on the swollen places,

Fio. 21".— Section through a swelling on a sixteen-year twig
of Juniper attacked by Gvmnosporancfium iu its eighth year;
three conical spore-cushions are indicated, also a cushion-scar
with the scar-tissue. (After Woerale.)

Fig. 21 S.— Longitudinal
section of a spore-cushion
of Gymnosporonniinn cUi-
viirinrfornu. Somewhat
diagrammatic. (After

Woernle.)

and during rain swell up into long club-.shaped sporophores,
containing long-stalked, spindle-shaped teleutospores, some thick-
coated, some thin. The sporophores swell and ultimately form
a common mass in which the teleutospores germinate. The
spores have four germ-pores, each capable of giving off a
promycelium with pointed sterigmata producing sporidia, which
are cast loose and distributed by wind.

Germination of sporidia takes place on leaves, cotyledons,
petioles, and shoots of various Pomaceae, where they may
induce swellings or curvature, often to a considerable extent.

GYMNOSPORANGIUM.

385

Experimental infection with teleutospores of Gymnospor-
angium davariarforme from Jumpcrus communis gave the fol-
lowiiig results :

On Host-plant.

Spore-form.

Authority.

Crataegus Oxyacantha,
Pyrus communis,

: :} (0 . .

- Plowriglit.

Crataegus tomentosa,

- R. lacerata, -

- Thaxter.

Crataegus Oxyacantha,

„ monogyna,
Pyrtis communis,

yR. lacerata, -
- Roestelia (?), -

- Eiitliay.

Pyrus torminaUs,

- pycnidia,

)>

Pyrus Mains, -
Amelanchier, -

- R. lacerata x.

- Oersted.

- Thaxter.

Crataegus Oxyacantha,

Crataegus grandiflorus,
„ sanguinea,

„ nigra,

Cydonia mdgaris,
Pyrus AuGuparia,

Pyrus la ti folia,
Cydonia vulgaris,

Crataegus nigra,

Crataegus Douglasii,
Pyrus Aria,
Pyrus Aucuparia,

Pyrus communis.

fR. lacerata aud aecidia "i
J with long tube-shaped hTu
[ peridia,

beuf.

-1

i-R. lacerata.

little )

- only pycnidia,

- only pycnidia,
C pycnidia and
[ aecidia, - - - (
[pycnidia and aecidia ^

- - with long tube-shaped ^Peyritsch.

[ peridia, - - - I

(pycnidia and little ]

\ aecidia, - - - (

)) ?) )' »

- only leaf-spots, - - „

- no result, . . - ,,
( pycnidia and aecidia with ~)

( a long peridiuni, J

Note. — Before the relationship of the teleutospore-forms was known, the
aecidia were designated respectively : Roestelia lacerata on Graiaerjus, R. comuta
on Pyrus Aucujiaria, and R. pencillata on Apple.

The most abundant germination of sporidia takes place on
species of Crataegus, and pycnidia (spermogonia) may make
their appearance within fourteen days after infection on little
yellowish sticky spots on leaves and shoots. By the time conidia
(spermatia) have made their appearance, deformation may be
far advanced. I did not succeed either in procuring germination
of the conidia, or infection by means of them.

2b

386

UREDINEAE.

The aecidia are developed about the beginning of June, and
on Crataegus their peridia in dehiscing split up into very
narrow lobes so as to form a bristly tuft over the mouth of

.2 *

5 5«

tr O

<^2

~ c 2
a I. e

I « ?5

each aecidium. Ou cultivating infected plants of Crataegus
indoors, I found the peridia to develop quite abnormally ; they

GYMNOSPORANGIUM. 387

may be as long as 10 m.m. and are bent like a horn (Fig. 219).
A similar case is described by Barclay^ in which the peridia
of aecidia on Rhammis dahnrica were very long if produced
in dry weather, but short if in moist weather. ^

The aecidiospores are shed during the early part of June,
and germinate at once on the bark of young juniper-twigs ;
the mycelium growing thence into the spurs or branches to
spread and hibernate. Teleutospores wdiich germinate on
Pomaceae other than species of Crataegus have apparently a
normal mycelium, but produce pycnidia only, or aecidia with

Fig. 220.— Cross-section through a swelling caused by Gymnosporo/iunv.m on
Juniper-stem ; parenchyma ^^^th large cells and thin walls is jjresent in abnormal
quantity. (After Woernle.)

peridia differing from those on Crataegus. My own experiments
on the quince and mountain ash regularly produce pycnidia only.
Wakker^ summarizes the anatomical changes induced in
deformed shoots of hawthorn as follows : cork, collenchyma,
sclerenchyma, and chlorophyll are not formed, lignification of
the cells of medullary rays no longer takes place, and there
are few intercellular spaces. Interfascicular cambium is not
formed, while activity of the intrafascicular cambium is suspended
at an early period, so that the vessels remain incompletely
developed. The epidermis is irregularly formed and liable to
rupture. All parenchymatous cells undergo enlargement in a
radial direction. Starch is stored up in large quantity, and
the formation of calcium oxalate is diminished.

1 " On the life-history of Puccinia coronata var. liimalensis,''^ Tran>i. Liiinean
Soc, London, 1891.

- This probably is the explanation of the long peridia obtained by Peyritsch
and described by Magnus (fiericACe d. naturwiss. medic. Verein, Innsbruck, 1892-93).

'^ Prmgsheim's Jahrbuch, 1892.

388

UKEDINEAE.

The anatomical chanf^es induced in diseased plants of Jnaipcni^
communis by G. rlavariaffonne were investigated ijy Woeinle
under my direction. His results were these: in vigorous branches,
increased growtli took place in the wood, bast, and rind ; in
weakly and poorly-grown branches, the wood increased less in
proportion to the bast and rind. The most marked increase
took place in the bast, and to an almost equal extent all
round the branches. This abnormal growth absorbs so much

-^^-y/i'

■M i!

kQ#(g

Q

mm

m

m

Fk;. 221. — Cross-section of a tmct of
parenchyma in a malformed .limiper-
twig. (After Woernle.)

ill PA- "

Fig. 222. — Radial longitudinal section
through a zone of parenchyma similar to
Fig. 221. (After Woernle.)

water and plastic material that higher parts of the branch
gradually die off, and dormant buds break out on the swelling.
Increased growth results in increase in the number of medullary
rays, while in the tangential section their height is increased
from 2-10 cells to 10-20 and more; the wood parenchyma is
also more abundant, and together with the rays frequently forms
large masses of parenchyma in the wood (Figs. 220-223). The
tracheae no longer follow a straight course, and numerous
intercellular spaces appear between them ; the tracheal walls
frequently become thickened and have an increased number of

GYMNOSPORANGIUM.

389

fissure-like pores in place of bordered pits. The wood-eleraents
iu cross-section are no longer round but polygonal ; the bast
becomes very irregular, parenchyma grows rapidly, bast fibres
remain thin-walled and have no longer a straight course. The
mycelium fills the bast and rind, forming masses in the inter-
cellular spaces ; it is easiest found in the tangential section.
()n the fall of the club-shaped sporophores, a scar is left and
under it will be found a layer
of cork many cells thick ; when
new sporophores are formed iu
later years, they seldom break
through the cork layer, Ijut
emerge through some new por-
tion of the bark.

Gymnosporangium tremel-
loides Hartig ^ on Junipcrus com-
munis. The sporocarps of this
species occur on the branches
and needles; its aecidia — Roe-
stelia penicillata — on leaves of
apple {Pyrus Mains), Pyrus Aria
and P. Chamaemespilus. This
Roestelia is externally very like
that of G. davariacformc on
Crataegus. The markings. on the

cells of the peridium consist of somewhat wavy lines, not of
short rod-like markings as in R. corniita; and the cells of the
peridium are joined by a characteristic hinge-joint (Fig. 224,
19 and 20).

The mycelium perennates iu the rind of Junipcrus communis
and ./. liana, causing thickening of the twigs and a premature
death of the distal portion above the swellings. The chocolate-
brown velvety spore-cushions break out between the bark-scales
on the swollen places, about the middle of April (Fig. 225, i).
The teleutospores are two-celled, the earlier formed ones being
short, ovoid, and slightly pointed at each end, while the
later ones are thinner- walled and often more elongated
(Fig. 225, 6-10).

^ Hartig, Disease.-i of Trees, English edition, 1894. Dietel, For-itlkh-natur-
u-iss. Zeitschrift, 1895, p. .348. E. Fischer, Hedivigia, 1895, p. 1.

Fig. 223. — Tangential longitudinal sec-
tion thi'ough the parenchyma-zone of
Fig. 220. (After Woernle.)

390

UREDINEAE.

In May or June the cushions swell up and become large
brownish-yellow gelatinous clumps, dotted over with dark points,
the teleutospores. Proniycelia arise from one or more germ-
pores in each spore, and give off basidia with sporidia (basidio-

Fio. 224. — Aecidia and Pycnidia of various species of Gt/mnoxporangium :

G. tremelloides — 1 and 3, aecidia on leaf of Pyrun Aria ; 0 and fi, aecidia on leaf
of Pyrv.s Mains ; 10 and 20, portions of the peridium of an aecidium from Ci,
showing the peculiar articulation of the colls.

G. junlpitinuui — 3 and U, aecidia on Pyrun Aucuparia; 7 and S- aecidia on
Amelancfiier vulgaris.

G. clavariafforme — 9 and 10, aecidia on Pyius latifoUa; 11, 1'2, and IG, aecidia
on Crataegus Oxyacantha, grown out-of-doors; lU, the same aecidia, enlarged;
ti, I'j, and 17, aecidia on Crataegus Oxyacantha, indoor culture ; 18, deformed
twig of Crataegus bearing pycnidia. (After Tubeuf.)

spores) capable of immediate germination. The gelatinous mass
dries up from time to time, leaving a bright yellow scar on
the swollen part of the host-branch. The sporidia germinate
most easily on species of Surhus (Fi/rns). Infections with

GYMNOSPORANGIUM.

391

Gymnosporangivin juniperimim

L. and G. trcmcUoides

Hart, from

twigs and needles of Juniperus communis produced :

Ou Host-plant.

Spore-form.

Authority.

Pyriis (Sorbics) Aucvparia,

Rostelia cormita, -

Tubeuf.

Aronia rohuidifolia,

short aecidia,

Eathay.

Pyrus Mains, -----
Pynis {Sorhus) Aria,

Ipycuidia,

)>

Cydonia vulgaris, . . - -

Roestelia ((), -

)j

Pyrus (Sorbus) Aucuparia,

(?) - - -

Plowright.

Pyrus Malus, -----

pycnidia,

Thaxter.

Amelanchier canadensis, -

Rostelia cormita, -

))

Pyrus {Sorhus) Aria,

R. penicillata, - .

Hartig.

Pyrus Malus, - - - - -

R. penicillata,

Nawaschin.

Pyrus (Sorbus) Chamaemespilus,

R. penicillata,

Mespilus macrocarpa,

spots, - - - -

Peyritsch.

Pyrus communis, - - - .

thick spots, -

It

Pyrus (Sorbus) Aria,

pycnidia and aecidia,

))

Pyrus (Sorbus) Aria x Chamaemesp.,

thick spots, -

??

Pyrus Malus, - - - - -

pycnidia and aecidia.

11

Pynis (Sorhus) Chamaemespilus,

pycnidia only,

11

Pyrus (Sorhus) Aucuparia,

pycnidia and aecidia.

11

Aronia rotundifolia.

)) )»

11

Pyrus (Sorbus) torrninalis.

pycnidia and spots only,

))

Crataegus Pyracantha,

)> »)

11

Cydonia vidgaris, - - - -

)) )>

11

Pyrus Malus, -----

Rostelia penicillata.

Eostrup.

Formation of pycnidial spermogonia always precedes that
of aecidia.

This fungus is of practical import on account of its occurrence
on leaves of apple-trees. Its attacks may be very virulent
and widely distributed. Eriksson mentions that near Stockholm
it is common on apples, and so virulent that many trees have
every leaf studded with Roestelia. (American apple-trees suffer
from Roestelia pirata, the aecidia of Ggmnosjjorajigium macropus
and other species. See p. 402.)

Gymnosporang-mm juniperinum (L.) {G. conicum Hedw.)
(Britain and U.S. America). This species, also frequenting
Juniperus communis, is distinguished by its shorter spores,
which, as Dietel pointed out,^ have a colourless papilla over
each germ-pore. The teleutospores are found on both twigs
and needles, on the former, however, they are much smaller

"^ Forstiich-naiuriciss. Zeitiichrift, 1895, p. 378.

392

UREDIXEAE.

than those of G. frcmcUoidca. The aecidiospores — lioestdia
cormita — occur on species of Pyrus {Sorhus); they are much
smaller than those of Rocstelia pr/?-ict7/a<a. The Rocstdia
themselves are long, curved, and horn-like, while the walls of
the peridial cells are beset with short processes (Fig. 224).
Where Pyrus Aucuparia occurs mixed with Pyrua Malvs,
it has been observed that Roestclia cornuta is confined to the
former species exclusively. The Rocstdia is the cause of a

Fio. 2'2o. — GyiiinoHpoi-aagiv.iti juniperiniim and G. tremclloides. 1, Young spore-
cushions breaking through the bark ; ~', the same in swollen condition ; 3, gela-
tinous cushion arranged to show its lower surface ; i, Juniper-needle with three
spore-cushions ; 5, young Juniper plant bearing cvishions on its needles ; 6 to 10,
spores of various kinds, to show the variation in size, shape, and thickness of
wall ; 11, cell of a promyceliuni with a sporidium attached ; ii', germinating
sporidium. (After Tubeuf.)

marked deformation of leaves, petioles, and even (though rarer)
fruits of Pyrus Aumrparia and Aronia rotundifolia, both in
the lowlands and mountains.

I have produced Roestclia cornuta on Pyrus Aucuparia by
artificial infection with portions of spore-cushions from twigs
of juniper, and have observ^ed a mountain ash in closed forest,
with abundant Roestclia, directly beneath an overhanging juniper
with diseased needles.

GYMNOSPORANGIUM. 393

Woernle investigated the anatomical changes induced by the
various Gi/mnosjjorangia frequenting the twigs and needles of
Juniper us communis. In the needles tiie mycelium lives inter-
cellularly, at first outside tlie endodermis, but later also penetrating
within this. The sporogenous cushions originate on the upper
surface of the leaf to right and left of the middle nerve,
where the stomata occur and hypoderm is absent. At these
places a cushion or stroma of pseudoparenchyma is produced
and ruptures the epidermis (Fig. 226). This however is at
once healed over by a cork -formation round the margin of the
cushion, again to be ruptured as the latter increases in size,
once more to be healed by cork-formation, and so on. In

Fig. 226. — Comparison of (k) uoi-rual Juuiper -needle with oue (h) bearing teleuto-
spores of Gymnosporangium. In a the double outline indicates the hypoderm;
the central vascular bundle and an underlying resin-canal are shown. (After
Woerule.)

this way a corky layer is formed under the sporogenous cushion
and gradually displaces it. If in a following year the cushion
be again formed, the scar is ruptured and heals as before.
Xeedles frequently remain in position for two, three, or four
years, but most of them fall off in the first autumn. Under
the sporogenous cushion the cells of the mesophyll increase
l)oth in number and size.

In considering the twig-deformations, Woernle distinguishes
the form assumed by the Crym^iosporangium on the needles, as
just described, from a form which inhabits the thicker twigs.
Both cause deformation of twigs, but their effects differ as follows :
" The needle-inhabiting form can only cause a slight swelling
extending almost regularly round the whole twig; the twig-
inhabiting form, on the other hand, always gives rise to a very

394

UREDINEAE.

marked swelling on one side only (Fig. 227). In the needle-
form tlie swelling results from increased growth of the rind,
with a siniultiineous decrease of growth of the wood ; in the
twig-form the growtli of both wood and rind is much increased.
With the twig-inhabiting form the medullary rays and wood-
parenchyma increase, and at the same time become filled with
mycelium (Fig. 228); whereas with the other form the medullary
rays are at most only somewhat broader, and no mycelium can
be found in tlie wood. The greatly swollen rind in the case

Fig. 227. — Section of ii nine-year twig
of Juniper attacked hy Gymnosporanyimn.
The rind under the spore-cushion is
much thickened ; the wood towards the
same side is much broken up by tracts
of parenchyma. (After Wocriile.)

Fio. 22S. — Tangential section through diseased
wood beneath a spore-cushion. The wood-
elements are much displaced by abnormal tracts
of parenchyma. (Only one of the latter has been
filled in, the others left blank.) (After Woernle.)

of the twig-inhabiting form is due more to increased growth
of the cortical cells than to increase of bast-parenchyma; in
the needle- form, however, the swelling is the result of increase
of the bast, especially of the bast-parenchyma. In twigs
infected by the needle-form, the mycelium may be found all
round, but it has difficulty in making its way radially to the
cambium; in the twig-form the mycelium, as early as the
spring following infection, will be found to be in close contact
with the cambium on the infected side, although it requires
several years to pass round to the cambium on the opposite
side of the twig. The mycelium and spores of the two forms
differ little from each other." '

GYMNOSPORANGIUM.

395

The strikingly characteristic cleavage of the wood by the
overgrown elements of the medullary rays and the wood-
parenchyma, in the case of the twig-inhabiting form, will be
seen from the figures (Fig. 229). As already noticed, the
sporogenous cushions are generally formed on one side. After

Fig. 229. — Two sections from a swelling on a .Juniper-branch, ti. From the
middle of the swelling ; the rind under tlie spore-cushion is much thickened, and
the wood is much broken up by tracts of parenchyma. 6, Section from 2 cm.
under a ; abnormal development of parenchyma in the wood has begun in the
outer year-rings. (After Woernle.)

the shedding of the cushion, a corky layer arises in the paren-
chyma underneath it, and so a bark-scale is produced.

Gymnosporangium sabinae (Dicks.). (Britain.) The mycel-
ium hibernates chiefly in Juniperus Sabina (Savin), and induces
swellings on the twigs. It also occurs on Jan. Oxyccdrus,^

1 1 found this host-species near Fiunie.

39G

UREDINEAK

Jun. virgiiiiana, and Jim. pkocnicea. (A reported oecurrence ou
Finns halqjcnsis is probably an error.)

The sporogenoiis cushions are little dark-lnown protuberances
which l)i-(3ak forth in spring from swellings, or on green

Fig. 230. — Gymnos/toronfjium snhirKie on twigs of Junipirun SdOimi, at the time
of lilionition of spores, (v. Tubeuf jihot.)

twigs and scale- leaves. These bodies absorb water, swell, and
run together, forming transparent gelatinous masses (Figs. 230
and 231). The teleutospores resemble those of G. juniperinu7n,
but have only four germ-pores ; they germinate on the
gelatinous masses, and produce promycelia and sporidia. The
latter germinate at once, chiefly on leaves of Pyrus com-
munis. The pycnidia are produced on the upper epidermis
as sticky yellow spots bearing darker dot-like pycnidia. The
aecidia (Boestelia canceUata) are found in September on the
under-surface of the leaves of pear, also on leaf-petioles, young
shoots, and even on the fruits. The peridia differ from both

GYMNOSPORANGIUM.

397

the species already described in remaining closed at the apex,
the spores escaping through trellis-like slits on the lateral walls
of the peridia (Fig. 234).

This fungus will not germinate on apple-trees, but on pears
every leaf may be thickly covered with aecidia and pycnidia,
and considerable damage to the crop thereby ensue (Fig. 233).

Fig. 231. — Longitudinal section tbrougU
a conical teleutospore-sorus of Gymno-
sporanrjium Sahinae. (After Woernle.)

Fig. 232. — Teleutospores of G. sabinac.
The elongated thin-walled ones are
lighter in colour than the thick -walled.
(After Woernle.)

Infections on various hosts with Gymiiosjjorangium sahinae
from Juni2Jcrus Salnna gave :

Spore-form.

:l
■ J

- Rostelia cancellata,

:\

On Host-j)lant.
Pyrus communis,
Crataegus Oxyacantha,
Mespilus germanica, -
Pyrus communis,
Pyrus communis,

„ 3Iichau.vii,

„ tomentosa,
Pyrus communis,
Pyrus communis,
Crataegus Oxyacantha,

(?)

Authoi'itv.

Plowright.
Oersted and De Baiy.
Eathay, Tubeuf, etc.

Eeess.

E. Fischer.
Klebahn.

,, (uncertain).

398

UREDINEAE.

The anatomical changes exhibited in diseased parts of pear-
leaves have been briefly described by Feutzling.^ He found a
radial elongation of the cells of the spongy parenchyma and an
accompanying accumulation of starch. Wakker, about the same
time, obtained similar results in the case of Crataegus Oxijacantha
deformed by G. clavariaeforme (see p. 387). Wakker observed
a diminished formation of calcium oxalate ; Fentzling, however,
found increased deposit of the same salt, not only in the form of

Fig. m.—Gymnosporangiuni mbinae in the form of Roeslelin cancellata on
leaves of Pear. A few twigs showing the abundance of aecidia over the whole
tree. (v. Tubeuf phot.)

isolated crystals but as masses. Cork-formation was suspended
in Wakker's case, while in Fentzling's a partial formation of
cork was distinguishable beneath the epidermis. The increased
thickness of diseased leaves is due principally to multiplication
of the spongy parenchyma, the upper layers of which frequently
become more or less palisade-like. When pycnidia (spermogonia)
are formed on the upper leaf-surface, the palisade parenchyma

^ Fentzling (loc. cit.) and Peglion [Rivista di Patologia Vegetale, ii.), also describe
these alterations.

GYMNOSPORANGIUM.

399

of the spot in question is either completely destroyed or trans-
formed into irregular cells, separated by intercellular spaces.

The anatomical changes in swellings (Fig. 235) induced by
G. sabinae on' Junipenis Sdbina were investigated by Woernle
with the following results. Wood, bast, and rind are increased
round the whole circumference of the stem. Along with
the broadening of the year-rings, however, there occurs a
change in the structure of the diseased wood. The same

Fig. 234. — A few leaves enlarged from Fig. 233. The leaf to left hand bears
pycnidia on red spots on the upper surface of the leaf ; the remaining leaves bear
aecidia on raised portions of their surface. Several aecidia still further enlarged
show the peridia dehiscing by longitudinal slits, (v. Tubeuf del.)

tissues occur in the year-rings as already described for G.
davariaeforme, viz. thickened twisted tracheids, loosely connected
together and with fissure-like pits ; medullary rays more
numerous and broader ; the limits of the year-ring difficult to
distinguish ; and a yellow pigment deposited in the walls of
all the elements. A tissue of this nature may be found round
the whole circumference of a twig even in the first year after
infection, and regularly each succeeding year. Woernle only
rarely found zones of irregular cell-formation like those

400

UREDINEAE.

characteristic of U. clavariaefnrme. Xo mycelium occurred in
the wood. A comparison of normal bast witli that of infected
twigs revealed changes similar to those already described for
G. davariaeformc. In addition, it is to be noted that the
thickened bast-fibres no longer occurred in closed masses, but
were often completely absent in the first year after infection,
while in all diseased twigs every intermediate stage exists
between thin-walled bast-elements and thick-walled bast-fibres,
such as never occur in the normal twigs ; in fact, many twigs
had thin-walled elements only.

Fio. 23.1. — Swelling from
a branch of Juniperux
Sfiljino. attacked by Gymno-
xporinigiviii sahiiuu. Dia-
meter at thinnest part 1"T
centimetre, at the thickest
(5 cm. (v. Tubeuf phot.)

Fig. 236. —Sections of a twig of Savin attacked by G. xnhinai .
ti, At thickest part of the swelling ; 'j, 3 cm. under a and normal.
In n is shown one of the hollow teleutospore-cnshions ; five
cushion-scars ; in the second-year ring are two shaded zones
of wood, chiefly composed of i)arenchyma. ( x 25.) (After
■Woei-nle.)

The sporogenous cushions of G. sahinae are formed in quite
a different manner from those of G. davariaeformc. Beneath
each cushion the bast increases very rapidly and forms an out-
growth, which is still further enlarged by the addition to its
apex of six or seven rows of radially arranged cells, rounder
and smaller than the bast-cells of the cushion. The mycelium
penetrates between these outer cells, and forms over the whole
cellular outgrowth a pseudoparenchyma from which the sporo-
senous tissue arises.

GYMXOSPORANGirM. 401

A sharply defined roundish scar of a light-yellow colour
remains after the spores are cast. This is composed of a
superficial layer of coloured pseudoparenchyma, wit]i an under-
lying scar-tissue of characteristic constitution. The latter con-
sists of several layers of cork-cells extending from one edge of
the scar to the other, separating the cushion from the twig-
tissues. This scar-tissue is not broken through next year, but
the new sporogenous cushions break out through other parts
of the bark (Fig. 236).

G. confusum Plowright.^ (Britain.) This is found on
Janipcrv.H Sahina along with G. salnnac, from which it is
difficult to distinguish. Pycnidia and aecidia are produced
generally on Crataegus Ox'yacantha and Cydonia vulgaris, rarely
on Pyriis communis. The aecidia on Crataegus resemble those
of G. clavariaeformc on the same host, and dehisce by the
ruptured apex of the peridium. Those produced on FyrvjS
commvnis are distinguished - from aecidia of G. sabinac on
the same host by dehiscing through the open apex of the
peridium.

Infections of Gym. confusum from Juniper us communis gave
the following results :

On Host-plant. Authority.

Ci/doitKi rulqaris, - - -^ *^^ i i -j- ll,. lischer.

"^ ^ ( tubular pendia, - - j

Crataegv.s O.cyacanthci, - „ „ „ „

Pyrus communis, - - „ „ „ „

Crataegus O.ryacantha, - „ „ „ Plowriolit.

The following American species of Gymnosponriigivm have
been described:-'

On Arborvitae or white cedar :

G. biseptatum Ellis. On twigs and needles of Chamaccyparis
thyoicles and Lihoccdrus clccurrcns. The aecidia on Crataegus
tomentosa and Amelanchier canadensis.

^ Plowright, Lhmean Soc. Journal {Botany), 18S7. E. Fischer, Zeitschrift f.
Pflanzenkrankheiten, i., 1891 ; with suinnmry of literature. Klebahn, ForsfL-
naturwiss. Zeitschrift, ii., 189.S.

2 E. Fischer (lor. cit.).

^Farlow, The Development of the Gymnosporanuia of the United Stales, 1886,
and other papers. Thaxter in various papers on Gymnosporangia, 1886 to
1891. Halsted (Report on Vegetable Pathology for 1888, U.S. Dept. of Agri-
culture) gives a resume, with description and figures of G. macropus and
treatment for orchard-rust. Fischer, Zeitschrift f. PJkmzenkrankheiten, i., 1891.

2C

402

UREDINEAE.

G. Ellisii l>erk. (Jii Cluiiiuuxjjpark tJujui(l<:n. The aecidial
stage on Pifrvs Mains and P. arhutifolia.

On red cedar (Junijjnws virr/ininna) :

G. macropus Lk. The aecidia and pycnidia occur on Pyrus
Malm, P. coronaria, P. arhiti/olia, Crataegus tumeniosa, C.
Douglasii, and Amelanchier canadensis ; they are known as

Fig. 237.— Spores of
Gym. hiscptatuiii. (After
Woernle.)

Fig. 238.— Spores of
Gyin. Ellisii. (After
Woernle.)

Fig. 239.— Spores of
Gym. macropu*. (After
Woernle.)

Rocstelia pirata. This is one of the commonest causes of
apple-rust and of the deformation known as " cedar apples " (Fig.
240), The anatomy of the latter structures has been described
by Sanford.'^

G. clavipes Cooke et Peck, occurs on Junipcriis communis.
Its aecidia and pycnidia are found on Pyrus Mains, P. arhuti-
folia, and Amelanchier canadensis.

' Sanford, Annaln of Botany, i., 1887.

GYMNOSPORANGIUM.

403

G. globosum Farl. Aecidia on Pz/rus Mains, P. communis,
i'ljihyaia cuhjaris, Sorhus americana, and species of Crataegus.

G. nidus -avis Thaxt. Aecidia and pycnidia on Pyrus Mains,
Amclanchier canadensis, and Cydouia vulgaris. On the red cedar
it causes the " bird's nest " deformation of the branch-system.

G, speciosum Peck. On Junipenis
■oecidcntalis.

G. Cunninghamianum ]jarcl. On
Cyprcssus turulusa in the Himalaya.
Aecidia on Pyrus Pashia.

The following genera do not occur
in Europe. Colcopuccinia, Bavenclia,
AJcrolar ia , Ti ■ h-h ospo ) 'a .

Ravenelia alone amongst these
■contains parasitic species of import-
ance. They all occur on Leguminosae
and Euphorbiaceae in the warmer parts
of India, Africa, and America.^

Ravenelia Volkensii Henn. has teleutospore-sori which appear
on " witches' broom " deformations of the twigs of an Acacia in
Usambara.

Rav. pymaea Lager, et Diet, produces its teleutospores on
malformed branches of Phyllanthus in»'Ecuador.

Certain forms of Aecidinm which cause deformation of species
of Acacia should probably be included in this genus (see p. 410).

Fig. 240. — Cedar Appks caused
liy GJ/iiinoyiorangii'.m maci-opus.
(v. Tubeuf del.)

Endophyllum.

Teleutospores originate serially on cushions which are enclosed
in a peridium similar to aecidia ; on germination, a four-celled
promycelium is produced.- Leaves of Euphorlia, Scdum, or
Scmpcrvivuni inhabited by mycelium develop abnormally.

Endophyllum euphorbiae-silvaticae (D. C.) (Britain). Accord-
ing to Winter, the peridia are regularly distributed over the
underside of the leaf of Eupliorliia amygdcdoidcs ; they have
white fissured margins either erect or somewhat turned liack.

^Dietel, "The Geuiis Ravenelia," Hedwvjia, 1894.

- The teleutospores of this genus might be described as aecidiospores which
produce promycelia.

404 UREDINEAE.

Spores yellow and polygonal. Leaves when attacked remain
broad, short, and pale coloured.

E. sempervivi (Alb. et Schw.)^ (Ihitain). 'J'he aecidium-like
patches of teleutospores occur on wild and cultivated species of
Srdvvi and Eschcrcria. The spores produce promycelia from
which arise sporidia which germinate on the same host-plant.
True aecidia are unknown, but orange-red pycnidia (spernio-
gonia) may occur. Leaves of attacked plants are pale and
abnormally lengthened.-

E. sedi (I). C). Teleutospores occur on species of Scdvm.

The genus Pncciniosiro. found in Ecuador contains few species,
and none of them important parasites.

Aecidium-Forms

The relationships of I'-Jiich arc uncertain.

Aecidium elatinum Alb. et Sehw. (Britain and U.S. America).
The witches' broom of the silver fir.^ This Aecidium is widely
distributed in forest's containing silver fir {Abies pectinata),
and produces canker of the stem frecjuently accompanied by
that deformation of the l)ranch system known as a witches'
broom.

In Germany it has also been observed on Abies Nordvianniana,
A. ccphcdoniea, A. Pinsapo ; in North- America on A. balsa.mea.-y
and in Siberia on A. Pichta.

As a result of the presence of this fungus, globose or barrel-
shaped swellings make their appearance on stems and branches
of all ages and on all parts of the trees. A single stem may
carry one or many of these, and they continue to increase with
its growth. If, as is frequently the case, the bark covering
the swelling becomes ruptured and partially detached, then
the wood left uncovered becomes a wound, and falls an easy

'Leveille, Bnlhi. Science. I\\itnr., xvi., 1825.

-Illustrated iii Kerner's Xatural Bistory of PlanL^, English Edition (Fig. 358).

^De Baiy, Botan. Zeitunn, 1867. Weise, " Zur Kenntniss d. Weisstannen-
krebses," Mi'mdener Forsftiche Hefte, 1891. Heck., " Dtr Wei<^stanvenkreh^."
Springer, Berlin, 1894 ; with Illustrations and Bibliography.

The canker is common throughout Britain, but witches' brooms have not
been often lecorded. (Edit.)

AECIDIUM-FOKMS.

40r)

prey to wood-destroyiug fungi. ^ The presence of such rotting
spots renders the tree liable to break over in their neighbour-
hood, while they, as well as the swellings on the trunks, cause
a considerable depreciation in the value of the timber.

The malformations of the branch-system known as witches'
brooms are frequently induced by this fungus. They occur as
a rule on the horizontal branches and form a richly branched
busli easily distinguished, even at a distance, by a marked

Fig. 241.— witches' B.oom oj Silvo- Fir (winter conditicm). The needles, with
spores of Accidiurii ilatinum, have fallen off, but the normal foliage remains,
(v. Tubeiif phot.)

negative geotropy of its twigs. Tlie brooms not uufrequently
start from a marked basal swelling. They may be found of all
sizes, on young as well as old trees, on any part of the branch-
system, and in all localities where the fir occurs (Figs. 241
and 242).

The aecidia of Accidiiim datinum are developed only on the
deformed needles of the witches' brooms. These needles are
produced anew each spring, live only one season and are cast

^ Polyporus Harthjii and Agariciui adiposus in particular accompany this
canker and bring about decay of the wood.

406

TKEDINEAE.

the same autuiuii; they are small, oiie-poiiited, and pale from
an almost complete lack of chlorophyll. In these respects they
are quite distinct from the larger double-pointed normal needles
with their dark-green colour and a period of growth extending
over several years. All the needles on a broom are as a
rule stunted in the manner described, yet single branches
may be found with needles quite normal ; such contain no
mycelium, or, if so, it has found its way in too late to have
any effect on their growth.

Fio. -112.- Witche.^' Bi'iOia or .'illvey J-'lr (summer condition). The nuu-kcdly
negative geotropic broom has its origin in a distinct basal swelling, (v. Tubeuf
phot.)

The various tissues of the witches' brooms also undergo
considerable modification as compared with normal twigs. A
thicker and softer bark is present, due to the parenchymatous
cells of both outer rind and bast having enlarged in size and
increased in number ; the cork layers are also abnormally in-
creased. The same changes may be observed in the rind of the
swellings, and to this their increased size must be chiefly ascribed.
The wood l)Oth in twigs and swellings is much increased;
the year-rings however are very variable, sometimes they are
broader than the normal, again they may be diminished or
even altogether wanting; where however the wood decreases,
there the bast increases in proportion. This lack of uniformity

AECIDIUM-FORMS.

407

in the growth of the wood disturbs the elements, so that
they are irregularly developed and more or less twisted.^

A mycelium inhabits the tissues of abnormal twigs and
cankered swellings. It grows in the intercellular spaces of
the rind, between the bast cells and outer parts of the wood,
and derives nutriment by means of haustoria : these either bore
through the cell-walls, or only press closely against them so
as to cause depressions.

Spore-formation takes place on the needles of the witches'
brooms. The pycnidia (spermogonia) are produced on the
upper side beneath the cuticle
and emerge through it as little
yellow points. The conidia (sper-
matia) are tiny globose colourless
bodies. The aecidia come later
during June and July in irregular
rows on the under side of the
leaf. Their peridia break out as
low dome-like structures, the
apices of which rupture irregu-
larly to allow escape of aecidio-
spores. In spite of numerous
infections, De Bary was unable
to observe the penetration of a
germ-tube into needles or twigs
of silver fir. Weise believes that
infection of the fir takes place
on twigs which have just emerged
from the bud.

As a preventive measure, all
witches' l)rooms should be cut off
before spore-formation begms, and

stemswith canker-wounds should be removed during forest-thinning,
For further details the monograph of Heck may be consulted. .Sj

Aecidium strobilinum (Alb. et Schw.)- (Britain). Spruce-

Fig. 2i3. — A(cidiv.rii slyohilinv.m on n Spmce-
cmic. (v. Tubeuf phot.)

^Note. — Further details of the anatomical changes induced in the tissues of
these witches' brooms may be obtained in the German edition of this work
(pp. 420-421), or in the original thesis by Hartmann, (Anatom. Vcnjleirhung d.
Hezenhesen der WeAsatanne. Inaugural Dissertation, 1S92. ) (Edit.)

-Reess, RostpU'.formen d. Coniferen., 1869. Oerstedt, Xaturh. for VidensJc.
Medd., 1863, i.

408

UREDINEAE.

cono ru.st. This disease is I'ouud. on Llie cones oi' spruce.
The aecidia are brown somewhat flattened spheres, and appear
in lari^c ininibers on cones distinguished by their scales standing
stiMly o})en even in damp weather (Fig. 243). The germ-
tubes of the fungus find entrance in spring into the flowers
or young spruce-cones, and the mycelium lives ]»arasitic in
the green scales without causing any marked change in
their growth, although the ovules are more or less injured.
No mycelium has ever l)een found in tlie lower cone-axis, nor
in the shoots, so that the disease must be the result of in-
fection by spores only.

j^a/"

3

Fio. 244. — Aie'alimii strobiliiiuia. 1, Cone-scalu of Spruce wiUi aecidia, those to
left dehiscing their yellow spores, those to right still closed, (v. Tubevif del.)
2, Section through an immature aecidium. 3, Part of 2 enlarged — pi r, peridium ;
sji, spores; ;?o, intermediate cells; uptr, sporophores ; m, mycelium; jurr, the
scale-parenchyma. (After Reess.)

The aecidia break out on the inner (rarely the outer) side
of the bases of the cone-scales ; each is enclosed in a firm
brown lignified peridium, which ruptures by a cross-fissure
and becomes an open disc. The young spores are joined by
small intermediate cells, which are gradually absorbed to
form a layer of gelatinous lamellae on the spore-coats
(Fig. 244).

Teleutospores of this Aecidium are unknown.

AECIDIUM-FORMS. i09

Aecidium pseudocolumnare Kiihn/ Occurs on needles of
Ahics 2Kdinata in (.iermany ; in Britain, however, on this and
several other species of Ahics. It is distinguished by its large
white spores from the Arc. columnarc of Ccdyptospora (p. 372).

Aec. Magelhaenicum Berk. This species occurs on various
.species of barberry. The mycelium hibernates in the shoot-
buds and causes them to develop as witches' brooms, Ijearing
on the lower surface of their leaves aecidia with long, white,
sac-like peridia. The allied teleutospore-form is as yet unknown.

Aec. clematidis D. (_'. (Britain and U.S. America). On Clematis Vltalha,
C rectu, and otlier s})eeies. It is related to Puccinia agropijri Ell. et Ev.-

Aec. Englerianum Henn. et Lind.^ produces a peculiar antler-like
branching of the twigs and leaves of a Clematis at Eriti'ea (Lytri) in the
Grecian Archipelago.

Aec. punctatum Pers. {Aec. (juadrijidum D.C) (Britain and U.S. America).
This is a common species on Anemone (Fig. 190) and Eranthis. The
aecidia have white peridia, wliich on dehiscence break into four lobes.

Aec. leucospermum D. C. (Britain and U.S. America). On Anemone
nemorosa (Fig. 190).

Aec. hepaticae Beck. On Anemone Hepatica.

Aec. ranunculacearum D. C. (Britain and U.S. Ameiica). On species
of Ranuncuhis. A collective name for aecidia of several species of Uromyces
(p. 836), and Puccinia (p. 349).

Aec. aquilegiae Pers. (Britain and U.S. America). On Aquilegia
vulgaris and other .species. (See Puccinia agrostidis, p. 349.) •

Aec. actaeae (Opiz.). On leaves of Actaea spicata in Europe and America.

Aec. barbareae D. C. On species of Barbarea (Britain). (See Puce.
featiwae, ]>. 349.)

Aec. circaeae Ces. On species of Circaea.

Aec. grossulariae Schum. (Britain and U.S. America). On liibes Gi'ossu-
laria and R. ruhrum. Klebahn believes it is related to a Puccinia on Carex.

Aec. bunii D. C. On Conopodium denudatum in Britain. (See Puce.
histortae, p. 355.)

Aec. periclymeni Schum. On species of Lonicera. (Britain.) (See Puce,
festucae, p. 349.)

Aec. compositarum. A provisional species-name for a large number of
aecidia frequenting Compositae, and by no means resembling each other.

Aec. leucanthemi D. C. A European species with its Pnccinia-form on
Carex montana.

Aec. cyani D. C. On Centaurea Cyanus.

Aec. ligustri Strauss. On Privet.

^ JIedw{<jia, 1884.

^Dietel, Oesterreirh botan. Zeitung, 1892.

•'Engler's Botan. Jahrburh, 1893.

410 URKDINEAK.

Aec. phillyreae D. (.'. On species of I'liiUyrea (Britaiii '().

Aec. fraxini Scliweiii. Tliis causes serious damage in America to the
foliage of Fra.rinvs riridix auil Fr. (imcncana} It has also appeared in
Europe on the latter species introduced from America.

Aec. nymphaeoidis D. ( '. On leaves of Liinnanthemum, Nuphar, and
Nymph<ir,i. (IJiitain.)

Aec. pedicularis Tiili. On VcdicuUtri)^. (Britain.) (See /'"«•. pahidosd,
p. 3.-il.)

Aec. prunellae Wint. On I'rmuMa vidfiaris. (Britain.)

Aec. euphorbiae Gmel. is found on many species of Eupliorhia. It is
prolial)ly the .li'vvV///'//;-forin of Uromyces pini. (Britain and U.S.America.)

Aec. convallariae Sclium. (Britain and U.S. America). Probably a
provisional species-name for aecidial forms found on Vomxdlaria, Polygon-
atum, Paris, Lilium, etc. (See under Puccinia.)

Aec. ari Desm. {Aec. dracontii Schwein.) is found on species of Arum.
(Britain and U.S. America.) (See Puce p/i(d(ri-idi.<<, p. 349.)

The following species are found on Acacia and seem to have
strong aftinity witli the genus Ravenalia :

Aec. esculentum Barcl. produces deformation of twigs of Acacia ehuraea
in India. Twigs of this kind, likewise shoots deformed by Aec. urticae var.
liimalayense Barcl., and ])ine-shoots deformed by certain species of Perider-
mium, are eaten in various [)arts of the world.

Aec. acaciae (Henn.) on Acacia ethaica in Ab^'ssinia. This is said by
Magnus to cause witches' broom deformation.

Aec. Schweinfurthii Henn. causes malformation of fruits of Acacia
Fixtida in A'frica.

Aec. ornamentale Kalch. causes curvature of shoots of Acacia horrida
at the Cape.

The following are some of the more important species
recorded for North America only :

Aecidium dicentrae Trel. Leaves of Dicentra and Corydcdif.

Aec. monoicum Peck. Leaves of Arahis.

Aec. drabae Tr. et Gall.

Aec. lepidii Tr. et Gall.

Aec. proserpinacae B. et ('.

Aec. Mariae-Wilsoni Peck. I., ■ c i-- 7

-On species of I tola.

Aec. Petersii B. et ( '. )

Aec. cerastii Wint.

Aec. pteleae B. et C. On leaves of Pleha trifoliata.
Aec. xanthoxyli Peck.

Aec. splendens Wint. In the cotyledons of Croton moiianthogyim.^.
Aec. aesculi Ell. et Kell.

Aec. psoraleae Peck, and Aec. onobrychidis Burr. On species of Psorafea.
^ Pound, American Xaturalist, 1S8S. ''

AECIDIUM-FORMS. 411

Aec. Peckii De Toni and Aec. oenotherae Mont. On leaves of species
of Oenothora.

Aec. sambuci Schwein. On leaves and stems of Samhueus.

Aec. ceanothi Ell. et Kell.

Aec. abundans Peck. On species of Symplioncarpus.

Aec. cephalanthi Seym. On Cephalantlms occidentctle.

Aec. erigeronatum Schwein. On many species of Erigeron.

Aec. asterum Schwein. On species of Aster and SoUdago.

Aec. polemonii Peck. On Poleinonium and Phlox.

Aec. apocyni Schwein. On leaves of Apocipium.

Aec. Jamesianum Peck, and Aec. Brandegei Peck. On leaves of species
of Asdepias.

Aec. myosotidis Burr. On leaves of Mi/osotis verna, etc.

Aec. plantaginis C'es. On leaves of species of Plantago in Europe and
America.

Aec. pentastemonis Schwein. On species of Pentstejuon.

Aec. giliae Peck.

Aec. lycopi Gerard. On leaves antl stems of Lycopms europaevs.

Aec. iridis Gerard.

Aec. macrosporum Peck, and Aec. smilacis Schwein. On species of
Smila.'-.

Peridermium.

Peridermium pini (Willd.)^ is found on pine-trees in Europe,
Britain, and United States. A teleutospore-stage of this has not
as yet been identified, although a very similar species {Peri-
dermium Cornui Eostr. et Kleb.), also occurring on the bark of
pines, has been proved to have as its teleutospore-fonn Cronartium
asdepiadcumr

The mycelium of Peridermiuni pini lives intercellularly in
the rind, bast, and wood of Finns sylvestris, P. Laricio, P.
hcdcpensis, P. maritima, and P. montana. It lives and extends
through the stem for years, attacking the living cells and
absorbing nutriment from them by little haustoria. The cells
of parenchymatous tissues are those most generally attacked,
and the mycelium has been found to penetrate along tlie
medullary rays to a depth of 10 cm. into the wood-mass.
The cells of attacked parts lose their normal content including
starch, and secrete crude turpentine in such quantity as to
completely permeate their walls, and even to form drops. In
this way portions of the wood become completely saturated

^ R. Hartig, Wichticje Krankheiten d. Waldhdumem.
^Klebahn, Berichte d. deutsch. hoton. Geselhchaff, 1890.

412

LKKDINEAE.

with resin, and as the same process goes on in bast and rind,
the tiui)entine overflows from fissures or wounds in the bark.
Daring the summer the mycelium grows amongst the dividing
cambium-cells and kills them. WhfMv this occurs the year-

FlG. l'46. — Pd-khnaiuiii piiii (corOcola).
Young twig be.iring numerous aecidia.
(v. Tnbeuf phot.)

Fig. •lib.—Pirido-rahi.rii jtidi (rorlicola).
Branch :ind lateral twigs distinctly
swollen where attacked. Tliey also bear
aecidia. (v. Tubeuf phot.)

ring ceases to thicken, but as the mycelium seldom succeeds
during the first year in killing the cambium all round a

PERIDERMIUM.

413

branch, the living jDortions of the ring grow on with increased
vigour, and even attempt to close over the injured portion.
This irregular growth, continued in many cases for years, pro-
duces abnormal cross-sections (Fig. 248). The mycelium
grows out centrifugally from diseased spots, so that the wounds
continue to enlarge, and the disease becomes easily noticeable
on account of the deep channels and distorted swellings on
the pine branches and stems. As the disease spreads inwards
into the stems, the conduction of water is interfered with and
the branches above such wounds dry up and die oft'. AVhereas

Fig. -247.— Pt, -id', -mlum p!ni (coiticolo). o, c. Mycelial stroma developed in the
rind ; the host-cell.s have become isolated from each other and contain
haustoria, h, of the fungus. /-, Basidia composed of much smaller cells than in
the needle-inhabiting aecidia. ;<, The peridium. (After R. Hartig.)

young plants soon succumb to attack, the struggle with old
trees may go on for years. Fresh infection of older stems
occurs generally in the higher parts of the tree, where the
bark is still thin.

Pycnidia (spermogonia) are developed between the rind-
parenchyma (periderm) and cork, generally towards the margin
of diseased spots. The conidia emerge from the ruptured
cork-layers of the bark as a honey-sweet liquid. H. Mayr
states that this liquid is given off in such quantity from
species of Pcridermium in Japan, that it is collected and
eaten bv the natives.

414

UREDINEAE.

Tlie aecidia appear in .lane as wrinkled yellow sacs
emerging from the bark of swellings. They continue to develop
in succession for years on the living parts of attacked
branches, but according to Hartig they cease to make their
appearance on old stems, even when a mycelium is present.
This disease is the cause of great damage to pines, especially
where planted as pure forest. One case is recorded ^ of a
forest near Kohlfurt where 90 per cent, of the trees in an
old plantation were " stag-headed " on account of a deficient

J^

v-- ^ _ Jf- -■

^

%

f'

^^-

^'

Fio. 24S. — Pi'ridermium pin.!. Section through a diseiised stem uf Pine showing the
gradual killing of the cambium by the fungus, (v. Tubeuf phot.)

supply of water in the crown accompanying attacks of this
fungus. Until more is known of its life-history, preventive
measures cannot be well extended beyond cutting down
infected trees.

The following species of Peridenniuin have been observed
on species of Pinus:

A. On the needles:

Peridermium oblongisporium Fiick. (now Coleosporium senecionis) on
Pinus s//!ve.s(ris ;uk1 P. (ni^tnaca (p. 374).

P. Klebahni, P. Soraueri, P. Stahlii, P. Plowrightii, and P. Fischeri.
On Piaus sylvestris ; related to various species of Coleosporiuni.

P. piriforme Peck. On Pinus speciosa in U.S. America.

P. cerebrum Peck. On Pimis rigida in North America.

^ Marker at Schlesien. Forstverein, 189-3.

PERIDERMIUM.

415

P. filamentosum Peck. On Piiius ponderosa, also in America.
P. Harknessii Moore. On Pinus ponderosa, P. itisignis, P. Sabineana,
and /*. nontorta in California.

Fl(i. "249. — Pii-kkrmium gigantcum on P'uiux Thunhc-gd from Japan, (v. Tubeuf
phot.— the specimen presented by Prof. Grasmann of Tokio.)

P. brevius Barcl. On Pinus exeelsa in India.

P. complanatum Barcl. On Pinus longifolia in India: on rind as well
as needles.

B. On the rind or bark :

Peridermium Cornui Rostr.
et Kiel), (now Vronartium
asclepiadeum, p. 381). On
Pinus si/lvestris.

P. strobi Kleb. (now Cro-
nartiam ribicola, j). 382). On
Pinus St rob us, P. La mberiia na,
(and P. Cembra).

P. pini(\Yind.). On Pinus
sylvestris. (Britain and U.S.
America.)

P. orientale Cooke. On
Pinus rigida and P. virgini-
ana in America ; also P.
longifolia in India.

%;^

.^^^

Fig. '250. — Pi i-kUrraiv.ra ghianttuui on Piav.s ilcnsifiora
from Japan, (v. Tubeuf phot.)

416

UREDINKAK.

P. Ravenelii 'I'liiiiii. On I'inns (insd'afis in Noitli America (probably
a variety nf /'. (ihlungis^porlitin).

P. deformans Mayr. On I'iiiun mid's in Aur'I ita.

P. giganteum (Mayr). On /'iuuK deuaijiom and /'. Tltuuherfil! in Japan.
'Iliis causes very con.spicuous deformation of its host (Kiys. 24!) and 2r)()).

P. complanatum Bard. On Pinns longifoli<i in India.

The following species frequent other hosts :
Peridermium conorum Thiini.^ This aecidiuni first found l»y
Dc 15;UT in Thiiriui;ia, has recently been reported in Denmark,

Itussia, and America ; also in
Upper Bavaria by v. Tubeuf
in September, 1895. It takes
the form of two large aecidia,
which make their appearance
on the outer or inner side of
the cone-scales of spruce. The
white peridia break through
the epidermal tissues which
then remain as a brownish
sheath around each ruptured
peridium (Fig. 251). The
spores are separated by inter-
mediate cells, and their outer
coats are studded with poly-
gonal warts. The cone-scales
bearing aecidia contain a very
large quantity of starch. Tel-
eutospores of the species are
unknown.

Peridermium coruscans
Fries.- The mycelium of this
fungus seems to perennate in
twigs and buds of spruce. Twigs unfold from the bud as
deformed, shortened, cone-like shoots bearing very short broad
needles of a pale colour. The aecidia are produced on the
deformed needles as broad lineal cushions with white peridia.
They originate under the epidermis which they rupture, and
break out on one side of the needle.

^Reess, Ro>itpihformen, 1869.

-Rostrup, Videusl: Geld: Forhamll., 1SS4.

/pir—

j^er

FlCi. 251. — Aecalium conorum-picmc. pf,; Peri-
dium ; xj), spore ; ,:»!■, intermediate cells ; xptr,
.sporophore ; m, iiiycelinni ; pros, in-osenchyma.
(After Reess.)

PERIDERMIUM.

4ir

The soft hypertrophied shoots are eaten. They occur chiefly
in Scandinavia, but recently were observed by Gobi and Tranzschel
in the neio-hbourhood of St. Petersburo.^

Fig. 252. — Accidiuiii coruscans on malformed shoots of Spruce. The compact
abnormal shoots thickly covered with white aecidia contrast strongly with the
normal portions, (v. Tubeitf phot, from material presented by Prof. Fries,
Upsala.)

P. Engelmanni Thiim. On cones of Picea Smithiana. (U. S.
America.)

P. piceae Barcl. On needles of Picea Smithiana.

P. Peckii Thiim. On needles of Tsuga canadensis (U.S. America).

P. balsameum Peck. On needles of Abies halsamea (U.S. America).

P. ephedrae Cooke. On Ephedra in U.S. America.

P. cedri Barcl. On needles of Cedrus Deodara in India.

P. Balansae Corn. On leaves of Dammara ovata in New Caledonia.

^Also reported at Haslemere (Britain), Grevillea, xix., 1890.

2d

418

UREDINEAE.

Caeoma.
Caeoma abietis-pectinatae Keess.^ The aecidiospores may
be found on the lower surface of young
needles of silver fir ; the aecidia are yellow
elongated cushions situated on either side
of the needle mid-rib, and are without
peridia. Pycnidia (spermogonia) are pro-
duced before the aecidia. The mycelium is
septate and intercellular with few haustoria.
I have found the fungus fairly abundant
on the Alps and in the Danube valley near
Passau. Teleutospores are unknown.

Caeoma deformans (Berk, et Br.) Tubeuf
{Uromyces deformans Berk, et Br.- or Caeoma Asanuro Shirai).^
This induces the formation of " witches' brooms " or of antler-like

Fig. 253.— Cii'oma nl/atlx
pnctinalat. Needle of Silver
Fir showing Caco/Ha-patches
on the lower surface, (v.
Tubeuf del.)

Fig. 254. — Cafoma dijonnang on Thxiiopxis dolabrata. (v. Tubeuf phot, from dried
material presented by Prof. Grasmanu of Tokio.)

1 Reess, Rostpihformen, 1 869.

^Berkeley, "The fungi collected during the expedition of H.M.S.
lenger.'" Jour, of Linnean Soc, xvi., 1876.
•' Shirai, Botanical Magardne, Tokio, 1889.

'Glial-

CAEOMA. 419

leafless shoots on Tlm.jopsis dolabrata in Japan, whence they were
sent to me (Figs. 254 and 255). One example (not figured) was
as large as a young child's head.

The shoots of the witches' brooms are furnished with vascular
bundles and possess a parenchyma rich in starch-content.
Each branch of the deformed shoot termi-
nates in a hemispherical saucer-shaped
/.Y<fo?««-cushion, at first covered over by
the epidermis, but with no peridium. The
caeowia-discs are at first brown, but after
the epidermis bursts and rolls back, the
yellow dusty spores appear. The spores Fif- rob.—co.eoma defor-

^ ^ . mans. Portion of the pre-

arise serially from very short basidia ; they ceding figure enlarged to

■^ "^ . ./ show the Caeoi/io-discsonthe

are vellow and have striped membranes. ends of twigs, (v. Tubeuf

mi • del.)

The witches' brooms also exhibit marked
hypertrophy (Fig. 254). In the supporting branch both wood
and bark are considerably increased. Large meiUillaryrays occur
in the wood, and nests of thin-walled parenchyma are interpolated
between the regular tracts of tracheae, so that the general
arrangement resembles that shown in juniper by Wornle's
researches on Gijmnoqjorangium. The parenchymatous groups
of cells in the wood appear to the naked eye as brown spots.
They are permeated by a vigorous intercellular mycelium, which
sends off' large haustoria into tlie adjacent cells.

Caeoma laricis (Westeiid).^ On needles of Larix. (Britain.)

C. orchidis A. et S. On orchids. (Britain.)

C. chelidonii Magn. On Ckelidonium majus (U.S. America).

C. fumariae Lk. On Corydalis.

C. euonymi (Gmel.). On Euonymus eiiropaeus (Britain).

C. confluens (Pers.). On Rihes alpiimm, R. ruhntm, etc.

C. nitens (C. himinatum) is the well-known Blackbei'ry-rust so common
in the United States. It is probably a form of Puccinia Peckiana.'-

C. aegopodii (Eebent.). On Aegopodium Podagraria and Cliaerophyllum
aromatic/' III.

C. ligustri (Rabh.). On Ligustrum vidgare.

C. ari-italici (Duby). On Arum maculatum.

C. alliorum Link. On Allium ursiman, A. oleraceum, etc.^

C. saxifrag-ae Strauss. On Saxifraga granvlata?

C. mercurialis (Mart). On Mercwrialis perennis.^

^ This aud most of the other species are only stages of some Melampsora.

-Clinton, Botanical Gazette, 1895, p. 116.

^ These three species are given as British in Plowright's ' Uredineae.' (Edit.)

420 UREDINEAE.

Uredo-Forms of uncertain relationship.

Uredo agrimoniae (J). ( '.). On spciies of AyriiiKinin (liiitain and U.S.
America). Dietel regards it as related to Melampsora (Thecospora) agri-
moni<(e.

U. Muelleri Schroet. On Jinbns friiticosus (Britain).

U. symphyti D. C On Symphytuin officiiiole (Britain).

U. phillyreae Cooke. On Pliillyrea media (Britain).

U. macrosora De Toni. On Epllohin.m tetragonum. (U.S. America).

U. vitis Thiini. This species first attracted notice as a disea.se-
])roducing fungus in Jamaica in 1879, but it had been found previously
in the United States. It causes spots on the upper surface of leaves.'

U. fici Cact. On Ficiis Carica in Italy and U.S. America.

U. quercus (Brond.). On species of Quercus (Britain and U.S. America).

U. iridis. On many species of Iris (Britain).

U. glumarum Rob. On Zea Mais in Belgium and England.

U. sorghi Fuck. On Sorghum halepense in Greece ; (compare with
Uromyces and Puccinia on the same host.)

U. gossypii Lager.-' This has been observed in South America causing
a rust on cdtton-jjlants and injuring the yield, of cotton. It appears as
small purple-brown spots ; the spores are oval and yellow.

Uredinopsis.^

[This is a new genus found by Magnus to contain several
Uredineae parasitic on Ferns.* The aecidial stage is unknown.
The uredospores are abjointed singly from the ends of sporo-
genous hyphae ; they are unicellular and without germ-pores.
The uredospore-sori are enclosed in a pseudoperidium of elon-
gated tubular cells. Unicellular teleutospores (?) are given
off from sori similarly to the uredospores. Pluricellular teleuto-
spores are developed from the mycelium in the intercellular spaces
of the host-plant, never from crust-like sori. On germination
four-celled promycelia with spherical sporidia are produced.

Uredinopsis filicina (Niessl.) Magn. On lower surface of fronds of
Phegnpteris {Polypodium) vulgaris, causing death.

Ur. struthiopteridis Stoermer. On sterile fronds of StnUhiopteris
germdiiicn.

Ur. pteridis Diet, et Holw. On Pteris aquilinaJ] (Edit.)

^ Massee (GrtviU.ea xxi., p. 119) states this species to he identical with U.
Vialat of Lagerheiin (Revue gen. de Botanique, 1890).

- Lagerheim, Journal of Mycology, vii. p. 48.

■'Dietel, '' Uredo pal i/podii (Pers. )" Oeslerreich. hotan. ZeitHchrift, 1894; also
" Der Gattung (Jrediuopsis," Ber. d. deutsch. botan. Ges., 1895, p. 326.

"• These host-plants do not come strictly within the scope of this work, but
a short note on the genus is necessary. (Edit.)

BASIDIOMYCETES. 421

BASIDIOMYCETES.

The sporophores, known as Ijasidia, are structures with a
definite shape, and with lateral branches, the sterigmata, from
which a definite number of exospores — basidiospores-^are ab-
I'ointed, the basidia then becoming functionless. Basidia and
basidiospores are characteristic of all Basidionwcetes, conidia
and chlamydospores being produced only exceptionally.

The basidia generally arise from an extended layer — the
hymenium — which in the higher genera forms part of a con-
spicuous complex sporophore. The basidia do not therefore
originate from the germination of a spore, as do the promycelia
of the Uredineae and Ustilagineae, but from special sporophores
(rarely from the mycelium itself), whose surface they occupy,
or in which they are enclosed.

In the course of development, two nuclei have been found
to copulate in the basidial cells. Thereafter they divide and
produce four (rarely two) new nuclei (Autobasidiomycetes), or
after the division of nuclei, cross-septa are formed, thus making
the basidia pluricellular (Protobasidiomycetes). In both cases
the nucleus passes through the sterigmata into the developing
basidiospores, and on the germination of these spores, it divides
into two nuclei, the starting points for further nuclear division.

As just indicated two divisions of the group may be dis-
tinguished: (1) Protobasidiomycetes, (2) Autobasidiomycetes.

Protobasidiomycetes.
Under this class are included the Auricular ieac, Pilacrcac, and
Tremellinae, the first two possessing basidia divided, as a rule,
by cross-septa into four cells, the last with basidia also divided
into four cells, which are formed, however, by two longitudinal
walls set at right angles to each other. A sterigma grows out
from each cell and produces a single spore, after which the
basidium dies away. The basidia of the Pilacrcac are produced
inside closed sporocarps (angiocarpous), those of the other two
groups are exposed (gymuocarpous). Parasites are unknown
amongst the Protobasidiomycetes.

Autobasidiomycetes.
Basidia unicellular (autobasidia), the sterigmata formed on
the apex of the basidium, and each giving off a single basidio-

422 BASIDIOMYCKTES.

Spore. The Ijasidia originate Iroin b.isidial layers <»r from coniplex
hymeuia, produced either inside some special structure, or on
the surface of special sporophores, or on some definite ])art
of these.

The group may I)e sub-divided into the Da.crymnycdes, Hymeno-
viycefcs, and Gasteromycetes (including Phalloideae). Of these only
the Hynu'7iomycetcs contain species parasitic on plants, the others
include harmless saprophytes, which live in the soil, some of
them, however, taking part in the formation of mycorhiza.

THE HYMENOMYCETES.

Tile unicellular basidia give oft' from their apices four (any
numl)er from 2 to 6 may occur) sterigmata, from each of
which a single basidiospore is abjointed. The basidia arise
from free exposed liymenia, which generally occupy the whole
or part of large compound sporophores. The greatest develop-
ment of the sporophore is attained in the umbrellas of the
Ayaricincae, and the large discs of the Polyporcac. It is only
amongst the lowest genera, like Exobasidwm, that the basidial
layers are produced directly on the organs of the host, and the
basidia arise directly from the hyphae.

Reproductive cells, other than basidiospores, are rare. In a
few cases amongst the Pulyporrar, lirefeld and others have
observed conidia and chlamydospores (Oidia, etc.) ; while some
few Agaricineae have the latter form of spore, but never conidia.

The mycelium is of a very varied nature. It frequently
inhabits wood, and in many different ways brings about
destruction of lignitied tissues. Other modifications are seen
in the forms of mycelium known as rhizomorphs, rhizoctonia,
mycorhiza, and other closely felted masses of various shapes,
which will be considered in detail as occasion requires. The
formation of clamp-connections is also a special feature of the
mycelium of the Hymenomycetes. In many cases the mycelium
retains its vitality and perennates for several years.

The genus Mcohasidium consists of parasites which produce
malformation of their host ; many of the Polyporcac and
Agaricineae are deadly enemies of forest and fruit-garden,
while as wound-parasites many of them are specially dangerous.
The oeneral means of combating them consist in cutting out

HYMENOMYCETES. 423

any sporophores and applying tar to the wound, while diseased
stems in the forest should be felled. Immediate artificial
closure of wounds in the wood is a very effective preventive
measure.^

The Hymenomycetes are divided into Tomentelkac, Exobasi-
diacear, Hypochnaccae (included by Brefeld in the Tomentelleae),
Thdejyhorcac, Clavaricac, Hydncac, Polyporeae, and Agaricineac.
All contain parasitic species.

EXOBASIDIACEAE.

Exobasidium.

The basidia are formed on the extremities of branches of
the mycelium, which break out through the cuticle of attacked
organs. Tlie mycelium lives inside the host-plant, and induces
considerable malformation. The basidia emerge on the surface
of the host (similarly to the asci of the E-coasci), and from
each of the four sterigmata a single spore is given off.

Exobasidium vaccinii Wor.- (Britain and U.S. America).
This is the cause of a very common and conspicuous deformation
which affects the leaves, flowers, and shoots of Varcinivm Vitis-
Idaea (Fig. 256). Leaves, where affected, become thickened
and form irregular blisters vaulted towards the lower surface
of the leaf, so that the lower epidermis covers the convex
side and the upper epidermis lines the concavity. Chlorophyll
is absent in the swollen tissues, but where blisters are exposed
to direct light a bright red cell-sap is developed. Parts of
the leaf adjoining diseased spots may remain normal and
green. Flowers or their parts undergo similar malformation ;
twigs become more or less thickened and twisted, their chloro-
phyll disappears, and a reddish cell-sap is produced. On such
diseased places spores are produced during the summer, after
which the poorly developed tissues dry up and wither.

AVlien this fungus is present in the young tissues of its
hosts, it exerts a very marked influence on their development.
The palisade cells of the leaf become enlarged, while their
chlorophyll almost wholly disappears, and is replaced by a red

^Further details on this point have already been given, General part, p. 7"2.
^Woronin, Verhand. d. natvrfor. Ges., Freiburg, 1867 ; with 3 plates,
Brefeld, Schimmelpihe, viii., 1889. Wakker, Prinrjsheim's Jahrbuch, 1892.

424

r.ASIDIOMYCETES.

cell-sap. Colls of the parencliyina in llower and stum eiilarii^e to a
still greater degree. Intercellular spaces are as a rule obliterated,
l)ut when present are filled witli a fine mycelium. Wakker gives
us further results of the fungoid attack ; crystal-glands, normally
numerous, are no longer formed, but are replaced to some extent
by indistinctly defined crystals of calcium oxalate. Transitory
starch is stored u]) in large quantity. Tlie fibro-vascular Inindles

Fig. 256. — Ecobasidiiim vaccinii inducing outgrowths on leaves of Vaccinium
Vitis-Idaca. (v. Tubeuf phot.)

present a striking modification, the primary xylem alone is
normal, the vessels of the secondary wood remaining rudimentary;
other parts are not lignified, and the phloem is only indistinctly
laid down.

A mycelium is present in all deformed parts, but absent in
normal green tissue. It becomes massed to form a hymenial
layer beneath the epidermal cells or between their outer walls and
the cuticle. The sterigmata do not exceed four in number, and

EXOBASIDIUM.

425

from each a spindle-shaped spore is abjointed (Fig. 257). The
liasidiospores divide in water by formation of cross-septa, and
a germ-tube arises from each terminal cell. On a young leaf
of Vaccinium the germ-tube
penetrates and gives rise to
a mycelium (Fig. 258) ; on
other substrata the germ-tube
sprouts into several very fine
sterigmata, from the extremi-
ties of which a series of conidia
are abjointed ; the conidia
may give off secondary coni-
dia, perhaps also tertiary. In
nutritive solution, Brefeld ob-
tained an increased number of
germ-tubes and a continuous
production of conidia ; in air,
conidia were produced on conidia, but inside the solution the
conidia gave off hyphae from which new conidia arose.

Fig. 2o7 .— Exohasidivm vaccinii. The basidial
layer is shown developing from the intercellular
mycelium of the shoots. (After Woronin.)

Fig. 258. — E.rohasidiv.m vaccinii. Germinating basidiospores. The septate spores
have given off germ-tubes which penetrate into the cowberry leaves, either by
stomata or through the epidermis. The lowest spore is forming conidia. (After
Woronin.)

This Exohasidmm is very common on the cowberry ( Vaccinium
Vitis-Iclaea)} It occurs less frequently on the bilberry {Vac-

^ Several American Ericaceae are given as host-plants in the "Host-Index.''^

426

I'.ASIDIOMVCKTES.

cinium Myrtillus) ' causing a premature fall of the leaf and
suppression of the flower. The external symptoms of the disease
differ somewhat from those on cowberry. Diseased leaves are
much larger than the normal, hut are neither thickened nor
blistered ; on the under side they have a whitish or reddish
coating, and fall off easily. I have never observed the disease
on the stems of bilberry. In spite of these external differences,
it is believed that the host-plants are in both cases attacked by
the same species of Exobaddium, but I do not know of any
observations on the reciprocal infection of the two hosts.

Fig. 2o9.—Ej:oUi.skliu.,i> rhododendri on Rhododendron ferruginevm. (v. Tiibeuf phot.)

A disease due to an Exohaddium is by no means uncommon
on Vacdnium idiginomm (bog whortleberry ).2 Shoots of diseased
plants are deformed, while their leaves become more or less
thickened and assume a beautiful rosy colour.

On Vacnnivvi Oxycoccos (true cranberry) the shoots and
leaflets also become thickened and rose-coloured. Rostrup dis-
tinguishes this as a separate species {Exobasidmm oxycocd).

Ex. andromedae Peck, produces on Andromeda j^oHfolia
symptoms .similar to those just described for the preceding
species. (Britain and U.S. America.)

' Saclebeck (Bo/an. Ctntralblatt, 1886) records it in large quantity near Harburg.
This is the host-species given by Massee (British Fiunjui-F/ont, 1892).
- Tubeuf . " Mittheilungen." Zeitsch. f. Pflanzenkrankheitfti, 1893.

EXOBASIDIUM. 427

Ex, rhododendri Cram. (Ih-itain and U.S. America). This
causes gall-like outgrowths on the leaves of the Alpine- rose
{Iihododendron fcrrugincvm and Eh. liirsutvm). The swellings
may be small and fairly hard, or, attaining the size of cherries
or plums, they may be soft and spongy so that they shrivel
up soon after the twig is cut; in colour they are yellowish-
white, but on the side exposed to sunlight become rose-red :
the Uxobasidium-galh may even be formed on the small rolled-
up leaves caused by attacks of mites.

Ex. Peckii Hals.^ [This species occurs in tlie flowers of
Andromeda Mariana in the United States. It is confined
almost entirely to the intlorescences, and causes considerable
distortion. The l)ell-shaped corollas are replaced liy ones quite
polypetalous, and the ovary becomes raised above the re-
ceptacle.] (p]dit.)

The following five species have been recorded on Ericaceae
in America :

Ex. azaleae Peck. On Rhododendron nudiflorum.

Ex. discoideum Ellis. On Rhododendron viscosum.

Ex. decolorans Hark. On Rhododendron viscosum and R. occidentale.

Ex. arctostaphyli Hark. On Arctustaphylos pungcns.

Ex. cassandrae Peck. On Cassandra calycv.lata.

Otlier species to be mentioned are :

Exobasidium ledi Karst. On Ledum jxdustre.

Ex. Warmingii Eustr. (U.S. Amei'ica). This occurs on Saxifraya Aizoon,
S. hryoides, S. aspera, etc. ; it causes marked hypertrophy of the leaves, and in
tliis way. as well as by its many smaller spores, is distinguished from :

Ex. Schinzianum Magn. On the leaves of Saxifraga rotundifolia, causing
whitish spots which soon become brown and die.

Ex. symploci Ellis. On Symplocus tinrtoria in North America.

Ex. graminicolum Bres. On leaves of various grasses, e.g. Brornvs.,
Arrhenatherum, etc.

Ex. lauri Geyl.^ is said to produce Ijranched outgrowths of over three
feet in lencrth on Laurus nohilis and L. canariensis in the Canarv Islands.

Urohasidiam rostruturn Ghgn. occurs on the "witches' broom," out-
growths caused by Taphrina cornu-cerri Ghgn. on Aspidium aristatum
in India.

^Halsted, Bulletin of the Torrey Club, xx., 1S93, p. 4.37.
^Geyler, Bolun. ZeitniKj, 1874, p. 322, PI. Yll.

428 BASIDIOMYCETES.

HYPNOCHACEAE.

Hypnochus.

The mycelium forms a cobweb-like covering on living or dead
parts of plants. The sporopliores take the form of superticial
coatings composed of club-shaped basidia developed on a felted
hymenial layer of fungal tissue. Each basidium gives off two
to six colourless smooth-coated spores from fine sterigmata.
Some species are parasitic, and cause disease.

Hypnochus cucumeris Frk.^ In 1882 Frank found at Berlin,
on the surface of withering and dying cucumber-plants, greyish
coatings of the hymenial layers of tliis fungus. They occurred
principally near the base of the stem, and caused its partial
destruction. The symptoms consisted in leaves becoming rapidly
yellow from tip to base, and dying off the plant, the lower
first. Only cucumbers were attacked, and no further stages
could be observed on the Ivilled plants.

Hyp. solani Prill, et Del.- Fine grey crusts, consisting of
the hymenial layers of this fungus, were found by these investi-
gators on potato-plants ; there was, however, no injurious effect
on the crop-yield.

Aureobasidium.

Aureobasidium vitis Viala et Boyer.^ The cause of a vine
disease which has done considerable damage in southern France
on several occasions since 1882. The grapes when attacked show
spots, then shrivel up, their interior becoming completely per-
meated by a colourless septate and branched mycelium. On
rupture of the epidermis, a firm yellow tissue emerges, and
thereon a hymenial layer is developed. The basidia are thick
and club-shaped, with a varying number of short sterigmata ;
these give of!" cylindrical unicellular light-yellow spores slightly
curved in shape and with rounded ends. Leaves are also attacked,
and fall off after gradually assuming a deep red colour. If
this occurs in April, or early in May, the fruit never attains
any size.

'Frank, HeAivirjia, 1883; and Berichte d. denfsrh. botan. Ges., 1883.
-Prillieux and Delacroix, Bulletin de la Soc. myrol. de France, 1891.
3 Viala and Boyer, Compt. rend. 1891, p. 1148, and xix., 1894, p. 248; Annal.
de VEcole nat. d'agric. de MontpeUier, vi., 1891.

THELEPHORA. 429

THELEPHOREAE.

Thelephora.

The sporophores of this genus assume very varied forms, from
simple incrustations to mushroom-like structures. They consist
of two layers only, the middle one being absent. The basidia
are club-shaped and produce four roundish or oval, hyaline or
light-coloured spores.

Thelephora laciniata I'ers. is not a true parasite, yet it is a
dangerous enough enemy to trees. In damp situations, it is
common and thrives, growing over young trees and so enveloping
them with its sporophores that suffocation ensues. (Britain and
U.S. America.)

Th. pedicellata Schw. has been reported from America ^ as a dantferous
parasite on apple, Qverctis coccinea, and a palm.

Th. perdix Hartig, a parasite on oak-wood. (See Stereum frvMulosum.)
HeHcobasidium Mompa. Ichik.^ This is injurious to the mulberry tree
near Tokyo, Japan. It first attacks the roots, and in consequence the
growth of shoots is arrested, the young leaves die ofi", and gradually death
of the tree follows. The mycelium permeates the tissues of the host, and
forms an external velvety coating of basidia.

Stereum.

Sporophores generally differentiated into three layers, and
forming leatliery or woody encrustations, or flattened hemi-
spherical structures attached by one edge only.

Stereum hirsutum (W.) Fr. White-piped or yellow-piped oak.
(Britain and U.S. America.) A very common fungus, occurring as
a saprophyte on dead branches, on boards, and posts of various
kinds of timber, as well as parasitic on living wood, particularly
on oak.

The sporophores first appear as crusts, later they become
cup-shaped ; externally they are brown and roughly hairy with
acute yellowish margins. The smooth hymenial layer is orange-
red and marked by zones. Between the sterile leathery sporo-
phore and the hymenial layer there lies a firm white
intermediate tissue.

^Galloway, Journal of Mijcologn, vi., y>- H^.

-Nobujiro Ichikawa, "A new hymenomycetous fungus," Jour, of College of
Science. Imperial University, Japan, 1890.

430

BASIDIOMYCETKS.

It. Hai'tig ^ has investigated in detail tlie phentnnena accom-
panying the wood-destruction in tlie oak. This begins in the
branches and extends in white or yellow concentric zones
throughout the stem, so producing that appearance which has
given rise to the name " fly-wood." Portions of the wood appear
only white-striped, other parts have a more regular yellowish-
white colour. In the white strips the wood has been transformed
into cellulose and the middle lamellae of the walls dissolved out ;
that of the yellow parts has not undergone this transformation
into cellulose, bub the destruction has begun from the cell-cavity.

WM^:

Iff •111 I

Fig. 2(50. — Slereum Jrustulosum. Destruction of Oak-wood. Lougitudin.il
section showing the brown wood with isolated hollow spots containing white
mycelium, (v. Tubeuf phot.)

Stereum frustulosum Fries. (Thelephora perdix Hartig).^
(Britain and U.S. America.) The sporophores form greyish-
brown plate-like crusts with concentric markings ; they are small,
never exceeding the size of a finger-nail, but generally occur
in numbers together. The hymenial layer is composed of club-
shaped basidia beset with hair-like outgrowths ; some of the
basidia produce four spores, others are sterile and grow on to
form the hymenial layer for the following year.

1 R. Hartig, Zevfietzunr/ser-fchemnnfjcn d. Ilolzes, 1878, Plate XV-^III.
- R. Hartig, Zersetzunfjsersckeinu7i(/e)i, Plate XIII.

STEREUM.

431

^It^-JJ

The very characteristic destruction of oak-wood caused by
this fungus was investigated by Ii. Hartig. The diseased wood
has a uniform dark-brown colour, broken at intervals by white
rounded spots or hollow cavities ;
hence it receives the name of
" partridge-wood." In the white spots
the wood has by the action of the
mycelium become transformed into
cellulose, the middle lamellae and
starch-grains being dissolved out. In
the neighbourhood of old eaten-out
cavities the process of decomposition
is slightly changed, so that the cell-
walls disappear without previous trans-
formation into cellulose.

CLAVARIEAE.

Typhula.

Sporophores iilanientous, and, as
a rule, developed from sclerotia.
Basidia, with four colourless smooth-
coated spores.

Typhula graminum Karst.^ This
appeared on wheat plants in Sweden,
killing them and forming yellow
sclerotia {Sclerotium fulvum Fr.).

Fio. ■2in. — SU

fnigtulosum.

Later stages of Oak-wood destnic-
tioii. Loneritudinal section sliowing
holes in the timber, (v. Tubeiif
phot.)

HYDNEAE.

Hydnum.

Sporophores very variable in form and structure. The
hymenial layers are spread over teeth-like projections. The
basidia bear four white spores.

Hydnum diversidens Fr.- (Britain). The sporophores form
yellowish-white crusts or brackets, with spiny outgrowths on
the lower side. The hymenial layer consists at first of basidia
only, later, however, hyphae grow up through it and build

' Eriksson, Landtbr. Akad. Hand. v. Tidskr., 1879.
- R. Hartig, Zersetzungserschehiwir/en.

432

I5ASIDI0MYCETES.

ovor it ii new hyuicniuiu ; tliis is continued for some time so
that the sporopliore consists of successive layers, and the spiny
outgrowths hecome much thickened. Infection, as was experi-
mentally shown by Hartig, takes place on wounds.

The wood-destruction, consisting of a white-rot, was studied
by Hartig, chiefly on the oak and beech. It begins by the

Fig. 262. — Poli/porus igniarius. Causiug death of a White Aider plantation at
Petneu, Stanzer Thai, Tyrol. The stems bear sporophores, and die from above
downwards, (v. Tubeuf phot.)

appearance of yellowish longitudinal bands (not white as with
Sterenm hirsv.fum), and extends gradually till the wood becomes
uniformly yellow. The mycelium causes the inner layers of
the cell-walls to swell gelatinously without previous transfor-
mation into cellulose, and finally to dissolve out leaving the
middle lamellae longest intact.

HYDNUM.

433

iliuj^^m

■I

I '' f ♦

Hydnum Schiedermayeri Henfl. (U.S. America). Sporo-
phores fleshy, with a sulphur-yellow colour both outside and
inside, and with a smell of anise. They occur on living-
apple-trees, less frequently on other species of Pyrns. Accord-
ing to Schroeter, Thlimen, and
Ludwig, the mycelium spreads
through the stems and kills
the trees.

Thlimen ^ thus describes the
diseased wood of the apple: "It
has a greenish-yellow colour,
which passes over gradually
to the normal colour of the
wood : it becomes soft and
friable, smelling, like the
sporophore, faintly of anise."

Sistotrema fusco-violaceum

Schrad. (Britain.) This acconlin^
to Skiljakow- is parasitic on liviiii^
pines, entering by wounds, and
carrying destruction throughout
the wood.

POLYPOREAE.

Polyporus.

Sporophores large and
usually shaped more or less
like a hoof or small bracket.
The sporogenous layer is com-
posed of cylindrical tubes,
which generally occupy the
lower surface of the sporophore.

The substance between the tubes is different from that of the
rest of the sporophore.

Polyporus (Fomes) igniarius (L.).-^ (Britain and U.S. America).
Sporophores on living stems of oak, alder, apple, willow, and other

Fli;. 263. — Polyporus i(jnio.rius on Oak. At
tlie upper end a wood-pecker's nest-hole. (v.
Tubeuf phot.)

^Thumen, " Ein Apfelbaum-Schadling." Zeitsch. f. Pflanzknkrankhdten, 1891.
-Skiljakow, Scripta botan. horti univei'sitatis PttropoUtanae, 1890.
^R. Hartig, Zersetzungserscheinungen, PI. XV. and XVI.

2e

434

decidi

BASIDIOMYCETES.

uous trees. Tliey are brown or grey in colour, tul.er-like or
hoof-shaped, and continue to grow for several years ; the upper

o s > 3 las- V.~o9~"^ ■
9. u ■' o-^ -a-rsc'-^i.

^ "."Sll^ i s "•Si-? .

3 1 1 T3 P S I 0 S -^ = ^ S

ca common Bntisli species. (Erlit, \ " iungub ^rig. _o_j. it is

species. (Edit.)

POLYPORUS. 435

side is concentrically marked, and has a stone-hard coating which
is generally more or less cracked ; several zones and layers of
tubes will be found when the sporophore is cut in section.

This fungus produces a white-rot in the wood, and is one of the
most common and dangerous of wound-parasites. The wood
attacked by the mycelium is at first dark in colour, then
yellowish-white and soft. According to Hartig, a delicate
mycelium fills up the elements and eats away the inner layers
of the walls ; then the middle lamellae are transformed into
cellulose and absorbed by it (Fig. 264).

Polyporus fomentarius (L.) (Fomcs fommtarius (L.) Fr.) ^
(Britain and U.S. America). " Tinder-fungus." Sporophores
broad and shaped like reversed brackets or hoofs. Their upper
side, at first brownish and velvety, becomes afterwards smooth,
grey, and marked with broad concentric zones. The margin
is rounded and uniformly grey. The pore-layer is smooth and
greyish-brown. A longitudinal section shows a homogenous
tinder-like mass, covered on its lower surface by layers or
zones of pores.

The tinder-fungus is parasitic on beech, elm, and mountain
maple. It is particularly common in beech-forests, and was
even more so at one time when the infected trees were allowed
to remain standing. The sporophores may be found on living
stems, on remnants of trees broken by wind, and on felled
trees. For some distance above and below the seat of the
sporophore runs a furrow on the stem, marking a tract where
the mycelium has penetrated to the cambium and killed it, so
that growth in thickness ceases (Fig. 266, a).

The mycelium causes in the wood a white-rot of a light
yellow colour. ^^Qiere the wood is still firm, though diseased,
it will be found to be divided into cubical portions by white
tracts of mycelium which run both radially and vertically. A
very characteristic feature of the destruction consists of broad
white leathery bands of mycelium, formed in a radial direction
through the wood ; these are best seen on stems shattered by
storm, or on wrought timber.-

iRostriip, Tidsskrift pa Skovhurg, 1883. Tiibeuf, " Mittheikmgen," AUeg.
Forst-. u. Jagd-Zdiuiuj, 1887. A commou British species. (Edit.)

- Kriill (ScA^e.t. Ge.s. f. vaterland. Kidt., 1893) distinguishes a gelatinous mycelium
and a cushion-mycelium.

436

BASIDIOMYCETES.

Tinder, prepared from the soft central part of the thick
sporophores, was at one time used, with the help of steel and
Hint, for procuring Hame. It is very effective in stopping

Fio. 265.— Scene in the Bavarian forest near Bischoffsreut. In the foreground, a living
Beech with seven sporophores of Polyporus j'omentarius. (v. Tubeuf phot.)

haemorrhage from cut blood-vessels, and is still used in surgery.
The larger pieces can be manufactured into caps, gloves, vests,

POLYPORUS.

437

and hose. The privilege of collecting the tinder-fungi was
rented out and regarded as a source of forest-revenue, while the
tinder-industry was formerly an important one in many districts,
where sporophores were more frequent and larger than now.

Measures against this fungus have already been considered
in our General Part (§ 12).

Fig. 2li<j. — Pohiporux fomentarivs on living Beech, f, A fiuTow extending
above and belov? the insertion of the .sporophore. h, An injury iirodvioed by
tearing of the wood in felling, (v. Tubeuf phot.)

Polyporus sulphureus (Bull.) ^ (Britain and U.S. America).
The .sporophores are flat and soft, the upper side being bright
orange-red and the lower sulphur-yellow. They last only for
one year, hence are small ; they frequently occur in masses,
one above another in tiers. After death they lose colour,
become brittle, and are easily detached. According to De

^R. Hartig, Zer.setzum/ser.scheinwigen. A veiy common species in Britain.
(Edit.)

438

BASIDIOMYCETES.

Fig. ■lij~. — l'uL,ij„j,'o..< 6i4//Jiit,ti!,< on a Willow {Sallx alOo.) at llirscliaii. jiua
Munich, (v. Tubeuf phot.)

POLYPORUS.

439

^^ ST

Seynes/ three other kinds of spores are produced in addition
to Ijiisidiospores.

Willow, poplar, oak, sweet chest-
nut, alder, ash, hazel, pear, cherry,
robinia, larch, silver fir, etc., are
common hosts of this parasite.

Wood infested by the mycelium
darkens in colour, exhibitinL^ a red-
rot. Vessels and all clefts or spaces
become filled with white felted
masses of mycelium. The wood, in
course of destruction, becomes richer
in carbo-hydrates, and the walls of
the wood-fibres shrink so that fis-
sures with an upward right to left
direction are formed, but do not reach
the middle lamellae. Finally the
wood becomes dry, brittle, and powdery.

Polyporus borealis (Wahlenb.) Fr. '^ (Britain and U.S.
America). Sporophores annual, white, and fleshy ; the upper

Fig. 208. — Polyporus »ulphn.reus.
Hymeuial layer, with basidia and
spores. (After R. Hartig.)

/

^--

Fio. 2ii!'. — Poh/porus xulphureus. The white mycelium forms concentric zones
and radial lines on the cross-section of Oak. (After R. Hartig.)

surface is shaggy when fresh, and no internal zones are exhibited.
The shape is somewhat cushion or bracket-like, but very variable ;

1 De Seynes, Annul, dc Sci. nat., Sur. V., Vol. i., 1S64.
-R. Hartig, Zersetziuu/serscheinuugeit, PI. X.

440

BASIDIOMYGETES.

many generally grow near eacli other. The pores have a torn
margin and cystids are frequent between tlic hasidia.

The sporopliores are common in spruce plantations, and are
accompanied l)y a very characteristic wood-destruction. The
wood, in the earlier stages, becomes brownish-yellow and inter-
sected by radial and vertical canals filled with a white mycelium
(Fig. 270). (Iradually, however, it breaks up into small cube-

Fii:. ■i'il- I'o/i//)onis honalis. Ue.structioii of
Spruco-Wddd. The white nij-eelium is present,
dividing the decayed wood into cubical pieces.
(V. Tubeuf phot.)

1

1

A

'Ji

iiii*--''

Fiii. 271. — Pol)>/>oru.'< Ijoreo.lis. Later stage
of destruction. The Spruce-wood is broken
up into cubical pieces, and the mycelium has
disappeared, (v. Tubeuf phot.)

like pieces, particularly evident when the wood is broken (Fig.
271). The cell-walls are dissolved from the cell-cavity out-
wards, the lignified wall being first converted into cellulose and
disappearing, finally the middle lamella.

Polyporus dryadeus Fr.^ (P. j^-^ciidoif/niarius Bull.) (Hritain
and U.S. America). Sporophores, annual, large, shaped like
tubers or hoofs, and generally situated towards the base of the

^R, Hartig, ZtrsetzuiKjxfrsrheinnngen, PI. XVII. A coiiiinon British .species.

POLYPORUS.

441

steins of oak-trees. At first they are soft, later hard and brown
with grooves on the upper side. The dark heart-wood of the
oak exhibits white or yellowish longitudinal stripes of rotten
wood converted into cellulose (Fig. 272). In the white portions

Fig. 272. — Polyporv.s dryai-lfvs. Tlie m>celiuiu forias longitudinal stripes
in the Oak-wood. (v. Tubeuf phot.)

the destruction is more complete than in the yellow, where dis-
solution of the lamellae has not as yet taken place (Fig. 273).

A simultaneous destruction of the wood by P. dryadcus and
P. iyniarius may occur (Fig. 274); in this case, the medullary

442 BASIDIOMYCETES.

rays appear snowy white at the place where the two forms
of rot meet ; this is due to an acciiniuhition of starch left
after the cell-walls have; hcen almost completely dissolved.

Polyporus (Poria) vaporarius (Pers.)^ (liritain and U.S.
America). The sporophores are white, and have a pungent
odour; they form crusts (never 1)racl<ets) closely adherent to
dead substrata, especially to l)eams and other timber in buildings,

mm

mi

\

-ttfii^/Lit-i" Fi<!. 274. — Poli/povus dryade\i.>< and Pol/i-
porus iflniarms. Destruction of Oak-

FiG. i'S.—Pohjporus dryadeus. Later wood under the combined agency of

stage of decay of Oak-wood. The darker both fungi. The wood i.s yellowish and

places still consist of firm brown wood ; perforated ; the medullary rays are

the white, however, are soft cellulose. snowy-white, from the accumulation of

(v. Tubeuf phot.) unchanged starch, (v. Tubeuf phot.)

where this fungus does great harm. They are also found, how- ,
ever, on bark of living stems of spruce and fir. The destruction
takes the form of a red-rot, the wood attacked becoming red-
brown, cracked, and soft. The mycelium is found in stems and
roots of trees ; in cracks in the wood and below the bark, and
on the surface of timber in buildings, it forms fan-shaped strands
of a permanent white colour. The mycelial strands of the
" dry-rot fungus " {Mcrulius /acrpudus) differ from it in being

' Very common in Biitain on dead wood, less so on living trees. (Edit.)

rOLYPOKUS.

443

at first white but becoming grey, and in exhibiting an internal
differentiation which those of P. vaporarius do not.^

The hyphae in the course of their growth do not seek out
the pits, but grow straight through the walls and bring about
dissolution of the middle lamella for some distance around. At
the same time numerous short oblique fissures in the walls are
produced vertically one over the other, especially in the elements

vSr^Tsvr

Fig. 275. — Polyporus sqiiamosus on Acer Negundo. The three upper sporophores
are borne on a separate piece of wood, from which a fourth has been cut off.
(v. Tiibenf phot.)

of the thick-walled autumn wood. (Compare with P. sistotre-
moidcs, Fig. 280). The phenomena accompanying destruction of
wood by this fungus are so characteristic that Conwentz"' could
distinguish it quite clearly in tree-remains enclosed in amber.

Brefeld succeeded by artificial culture of the spores, in raising
a mycelium on which basidia were formed, at first directly,
afterwards from large sporophores.

Polyporus squamosus (Huds.). (Britain and U.S. America.)

^ R. Haitig, De}' echte Hausschicamm, Berlin (Springer), lS8o.
■^Conwentz, Monographie d. baltischen Bernsteinhdume, 1890.

444

BASIDIOMYCETES.

Sporophores annual. occiuTin;.( from spring to autumn ; at first
tender and fleshy, later leathery or almost woody. In form
they are short-stalked, flat, semi-circular or kidney-shaped, and
attached by one edge ; they may also be stalked and circular
or cup-shaped. Their upper surface is yellowish, with flat brown
scales arranged in concentric lines. The hymenial layer is
continued well on to the thick fleshy stalk of the sporophore;
it is yellow in colour, and consists of short angular pores.

--n »f ~-

: .' :" /

Fig. '270. — Polyporv.H hispidus on pieces of living Ash. (v. Tubeuf ishot.)

The spores are spindle-shaped and colourless. The fungus is
especially common on living hazel, ash, species of maple, beech,
mountain ash, horse-chesnut, elm, oak, willow, pear, lime, etc.

The wood of the specimen in Fig. 275 exhibited extensive
white-rot, the inner parts being completely converted into a
soft white spongy mass of mycelium.

Polyporus hispidus (Bull.).^ (Britain and U.S. America.)
Sporophores annual, soft and spongy, with a rough brown upper

^A very common form on ash trees in Britain. (Edit.)

POLYPORUS.

445

surface, and a smooth yellowish hymenial surface. They are
large and flat, the thickest part being at their insertion
(Fig. 277). Several frequently occur on the same stem, especially
if wounds or frost injuries are present. The spores are brown
and roundish. Conidia are said, by Schroeter, to be formed on
the upper surface of the sporophores.

This species is a deadly enemy of fruit-trees, especially
apple. In the vicinity of Munich the sporophores are common
on ash. Schroeter gives elm and plane as hosts, and Prillieux

_{:S-«=^.j3=

— » m '" — ^'^'Yi^'i W

■'rtt',-

— ""'•Mu^Bw,,

Fig. 277. — Polyporv.s hl-j^ . L i.jitudiijal acction through a living stem of
Ash, and a sporophore of P. hifjjcdux. The stem shows symptoms of wood-
destruction, in that it becomes brown and has short white longitudinal and
radial stripes, (v. Tubeuf phot.)

and Delacroix state the fungus to be very dangerous to the
mulberry in France.

It causes^ brown discoloration of the wood accompanied by
characteristic short white lines in both radial and vertical
directions, so that the wood becomes marked out in squares.

Polyporus (Poria) laevigatus Fr.- Sporophores dark-brown

1 Prillieux (Bullet, de la Soc. mycolog. de France, ix. , 1893), gives details of
the destruction of the wood.

-Mayr, Botan. Centralblatt , xix., 1884.

446

BASIDIOMYCETES.

and forming crusts on the bark of birch. Spathulate cysti(Ua
occur between the basidia. Spores colourless, and acutely ovate
in shape.

This is parasitic on birch. The mycelium kills and permeates
the wood-parenchyma which forms the greater mass of the
later-formed parts of each year-ring, with the result that the
various year-rings of the wood separate from each other as
concentric hollow cylinders. The mycelium varies according as
its pabulum consists of cells just killed, or of wood, or of
elements in the last stages of decomposition ; in this latter case
it suffers from want of food. In woody elements in contact

with air, or those destroyed
by Polyporvs hctulinvs, the
mycelium is brown and
forms vesicular tyloses
similar to Afiaricvji mrllcns.
Polyporus betulinus Yi:
(Britain and U.S. America).
The sporophores are annual,
and emerge as spherical
structures from the unin-
jured bark, or from bore-
holes of Beetles, or other
wounds. When mature
they are hoof-like or semi-
circular and short-stalked ;
when dead they become
soft and break off. The upper side is light-brown in colour, the
pore-layer is white. A section through the sporophore shows it
to be white and homogeneous without zones. Lanceolate cystidia
occur between the basidia. The spores are rod-like. The pore-
layer and the upper brown layer are easily detached, and strips of
the remaining tissue are sometimes iitilized as razor-strops.

This parasite frequents living birches, ultimately causing death.
It is known to occur on both Bdula verrucosa and B. puhcsccns
in Britain, America, and Europe. Its parasitism and injurious
results were first demonstrated by Kostrup.^ ]\Iayr- investigated

^Rostrup, •' Snyltesvamper Aiigreb paa .Skovtraeerne," Tidssh'i/t pa Skov-
huru, 1883.

-Mayi-, Botan. Centralblatt, xix., 1SS4.

Fig. 2"S. — Polyporus betulinus on Betula verrv.cosa.
The sporophore was developed horizontally on a
fallen stem ; it is here, however, set up vertically
and photographed from the lower side. (v. Tubeuf
phot.)

POLYPORUS. 447

in greater detail the destruction brought about by its mycelium.
He found that it penetrates lignified cell-walls, entering the living
elements and causing their death; it spreads most rapidly in the
vertical direction through wood, bast, and rind, growing through
parenchyma and sieve-tubes, and even boring its way into the
sclerenchymatous stone-cells; it absorbs the secondary tliickening
by dissolving out first the ligneous incrustation, next the cellulose,
while the middle primary lamella remains behind untouched.

Polyporus (Fomes) fulvus (Scop.) (Britain). vSporophores
woody and very hard, at first hairy but later smooth, dark,
and cracked ; in form they are tuberous or triangular. In-
ternally they show no stratification. The fungus is very common
on living plum where it causes undoubted injury : it also occurs
on hornbean and aspen.

Polyporus fulvus var. Oleae Scop. In northern Italy
may be frequently observed a peculiar splitting of the stems
of olive trees into two or more portions ; the fissures occur
generally on the lower parts of the tree, and may extend so
deeply that the stem appears to stand on stilts or props.
Hartig ^ ascribes this phenomenon to the presence in the olive
stems of the mycelium of Folyporus fulvus causing rotten places
which are cut out by the Italian cultivators ; the disease, how-
ever, continuing to make progress, it may be necessary in course
of time to cut so deeply into the stem, that tracts extending
right through may be removed ; this takes place all the more
rapidly if several diseased spots are being simultaneously
operated on. The destruction of the olive-wood by this parasite
is similar to that produced by P. igniarins on oak and other
trees. The sporophores appear on rotten spots, but are gener-
ally quickly removed by the cultivator. Infection takes place on
wounds, hence it is advisaljle at once to apply tar after cutting
out any decayed wood, and also to paint pruuing-cuts or other
exposed surfaces with tar. Xeighbouring fruit-trees, liable to
suffer from this same fungus, should be similarly treated, both
for their own safety and that of the olive trees.

Polyporus (Fomes) Hartigii AUescher- (P. igniarins var.

iR. Hartig, "Die Spaltimg der Oelbilume." Forstlkh-naturn-iss. Zeitschrift ,
1893.

2R. Hartig, Zersetziuir/sei-scheinunrien, PI. VII. Forst/ich-nafuririss. Zeit-
schrift, 1893, p. 61.

448

BASIDIOMYCETKS.

pinuiim Bresadulii or P. fulvus Scop, of II. Haitig). Sporopliores
on silver fir, less commonly on spruce. Their form varies much,
according as they occur on a branch (n- on the stem. In the
former case, the sporophore forms a swelling below and on each
side of the more or less horizontal branch. On the stem they
are more or less bracket-like. The sporopliores are reddish

brown with a smooth upper surface on
which zones are only faintly indicated
or altogether absent. Internally they
are of a biownish or tawny colour, and
exhibit concentric strata, which do not
extend into the pore-layer; they are thus
distinguished from sporophores of P.
igniarius and others. The sporophores
\ • h ■ • vV' WW '•'^'^ ^'^^T frequent on cankered stems of
?\ rt-' t' S'SiV fir where the canker-spots afford easy

entrance for the spores.

The wood-destruction consists in a
white -rot. The wood becomes yellowish-
W'hite with clear spots and fine dark
lines, especially where in contact with
healthy parts. The mycelium is yellow-
ish, and consists of thick hyphae with
lateral branches forming tangled masses
which frequently fill up the cavity of
the bordered pits. This mycelium gives
off very fine branches which bore through
the cell-walls and dissolve them in such
a way that the middle lamellae disappear
first and leave the remainder of the wall-
thickening for a time isolated before it
too is used up. In this way large holes are formed in the
elements of the wood.

Polyporus sistotremoides (All), et Schw.) (P. Schiveinitzii
Fr. or P. mollu Fr. of II. Hartig)^ (Britain). Sporophores almost
circular with a short thick central stalk ; while young they
are light brown and spongy, luit when older become dark brown
and corky. The upper surface is downy ; the hymenial layer
extends far down the stalk, when young it is yellowish green,

' R. Hartig, Ztrsetzunystrtichtinnn'jen, PI. IX.

Fig. -27

- r<ii

Harlifiii,

Destruction of wood of Silver Fir.
The decayed wood is yellow, but
shows dark points and black lines,
(v. Tubeuf phot.)

POLYPOKITS.

449

but later becomes brown, and, on being touched, deep red. The
spores are white, and various forms of hairs occur among the
basidia. Young sporophores appear as little brown cushions on
felled timber, also on living stems of pine, and, according to
Magnus, on Weymouth pine.

The disease generally makes its first
appearance in roots and lower parts of the
stem, spreading thence into higher parts.
Diseased wood has a characteristic odour of
turpentine ; it has a reddish-brown colour,
and, as destruction proceeds, it gradually
shrinks and disintegrates till it becomes so
soft as to be easily powdered between the
fingers. Where broken over, the wood is
often covered with a thin white coating of
mycelium incrusted in resin so as to appear
like chalk.

The mycelium penetrates the cell-walls
in all directions. A very characteristic
feature of this parasite is furnished by
shrinkage-fissures in the thick walls of the
tracheids of the summer- wood (Fig. 280).
These are numerous and run upwards from
ricfht to left extending through the whole
wall to the outermost layers. They differ
from the fissures in tracheids destroyed by
P. vaporarius, in that they run round the
whole circumference of the cell, instead of
being small and set vertically above each
other.

Polyporus (Fomes) pinicola (Sw.) (U.S.
America). Sporopliores thick, hoof-like or
Viracket-shaped, with a smooth dark-grey upper side and a bright
red rounded margin. The hymenial layer is smooth and yellowish,
the spore-powder white. In section the sporophores are white.
The species is frequent on living stems of spruce, pine, and fir,
also on birch and cherry.

Polyporus (Fomes) marginatus Fr. (U.S. America). Sporo-
phores with red margins, and otherwise very like those of the pre-
ceding species, yet generally much larger, and more extended.

2 F

Fio. :2S0. — Traeheid of
P<iiMS destroyed by Polyporus
■■iistoti-iidoidea. The cellulose
has been for the most part
extracted, aud the walls con-
sist of ligiiin (wood-gum).
Cracks occur in the dry
secondary wall, while the
wall (a, 0) remains intact.
The spiral structure of the
secondary wall causes cross-
ing of the fissures in the
walls of adjoining cells at
the bordered pits, c, and at
bore -holes, d, e ; where
neither pits nor holes are
present the fissures are
simple,/. (After R. Hartig.)

450

BASIDIOMYCETES.

The two species are held Ity many authors to be identical.
It occurs chieHy on stems of beech, also on oak and birch.
In rer;ard to its ])arasitisiii notliinii fnrtlici- is known.

Polyporus (Fomes) annosus Fr. (Trametes radiciperda
Hartig^) (Britain and U.S. America). The sporophores vary
much in form, according as they occur more above or more
below ground on tree stems, or on timber in mines. The
upper surface is brown and marked in zones, the margin being
lighter. The section through the woody sporophore is white.
The hymenial layer is also white. Spores ovoid and colourless,
germinating easily in water. In artificial cultures, Brefeld
states 2 that they produce only conidia.

Fio. 281. — Polyporun annosus Fr. (^Trametes radiciperda Havtig). Stool of a
forty-year Spruce, which has been dead for two or three years. The sporophoi e
i.s several years old. «, a, White open-pored layer forming over tlie dead basidial
layer, h, h; at c a narrow strip of wood still remains fii'm, the remainder is
completely destroyed and rotten. (After R. Hartig.)

This species was first investigated in detail by K. Hartig,^
and is described by him as the most dangerous of all parasites
in the conifer forest. It is most frequent on Conifers, cjj. pine,
Weymouth pine, spruce, silver fir, Douglas fir, balsam fir,
juniper, and Thuja; it also occurs on various broad-leafed trees,
e.g. beech ^ and hawthorn.

^R. Hartig, Zerset-Amriserschfiinnnijtn, PI. I. -IV. WichtUjf. Krankheiten, PL
III. Zei/.'^rhri/t f. Fork-xind Jaifd-iveaen, 1889, p. 428. Botan. CentrcJUatl^
XLii., 1890.

■^Brefeld, Schimmelpihe, Heft 8, 1889.

' Rostrup, Afhildniini oij Beskrivelse af de farluiMe Snylte-numpe, 1889.

POLYPORUS.

451

The mycelium penetrates both bast and rind causing a very
acute red-rot in the wood, so that death of the tree attacked
rapidly follows. The disease makes its appearance on plants
of all ages, and in forests of spruce or pine causes gaps
which rapidly extend in a centrifugal direction. The roots
and lower parts of the stem are generally the parts first
attacked. On the roots, the parasite is easily distinguished,
even in the absence of sporophores,
by the very delicate white mycelial
membranes formed between the
bark-scales. Destruction of the
wood becomes first evident by the
appearance of vertical dark lilac-
coloured stripes indicating the stage
when the parenchyma cells are
killed. At a later stage, the wood
becomes brown, and shows isolated
black spots' with white margins
(Fig. 282). These last con.sist of
coils of dark mycelium surrounded

by wood from which the inCrUSting FiG.2^2.—Pol»po;-ngannosus. Destmc-

' Til "^ tion of Spruce-wood. LoDgitudinal sec-

sub.stance has been dissolved away, tion showing white (ceiiniose) spots w-ith

, . , ,, - Ti T black (mycelium) centres, (v. Tubeuf

leaving only cellulose, readily dis- vhot.)
tinguished by turning blue on

treatment with chlor-zinc-iodine ; here too, the middle lamellae
are ultimately dissolved out, so that the elements become isolated.
A colourless mycelium may also be found in tlie other parts
of the wood, both inside the elements, and extending in all
directions through the cell-wall, leaving holes where it itself
has disappeared. Dissolution of the lignifying substance pro-
ceeds from the cell-cavity, the middle lamella remaining
intact till the last. The resin of the decayed wood passes over
into all healthy parts and flows from the bark of diseased
stems as a resin-flux.

The most effective method for combating the ravages of
this parasite is isolation of infected areas. In one case which
I investigated in Baden, several spots in the forest formed
very evident starting points, and sporophores were everywhere
present at the base of stems amongst the moss. Such spots
should be enclosed by ditches with vertical sides, and deep

452 I5ASIDI0MYCETKS.

eiiouj^h tu cut through all roots, care being taken to leave no
diseased stems or roots outside the circle ; after remaining open
for a time, the ditch must be refilled with soil to prevent
development of sporophores on the exposed roots. Diseased stems
should be felled, and, along with all root-remains, burned on
the spot, where there is no risk of forest fire ; failing this, they
and their stumps should be deeply covered over with soil, to
prevent development of sporophores.

The following species of Polijporus have been observed on
living trees, but details in regard to their parasitism and mode
of destruction are still wanting :

P. officinalis Fr. On larch, chiefly in Russia, but also in France and
Switzerland. The sporophores are white irregular masses, and at one time
were used in medicine. The mycelium forms bands in the wood similar
to those of r. sulpliureus.

P. albus (Corda), according to Ludwig' is a cause of a disease of Conifers,
which extends from the root upwards. (U.S. America.)

P. spumeus (Sow.). On apple trees. (Britain and U.S. America.)

P. fumosus(Pers.). On willow, ash, maple, and other broad-leaved trees.
{Britain and U.S. America.)

P. picipes Fr. On willow and other broad-leaved trees. (Britain and
U.S. America.)

P. (Fomes) cinnamomeus Frog. On cherry trees. (Britain.)

P. radiatus (Sow.). On alder (.1. iacana), birch, and beech. (Britain and
U.S. America.)

P. (Fomes) ribis(Fi.). On blackcurrant and gooseberry shrubs. (Britain
and U.S. America.)

P. (Polystictus) hirsutus Fr. (Britain and U.S. America). On living
hornbeam, alder, oak, birch, and service. A variety, scrnposits, is common
and injurious on cherry.

P. ulmarius Fr., is, according to Cavara,- parasitic on living elm near
Favia. (Britain and U.S. America.)

P. (Fomes) nigricans. On birch. (Britain and U.S. America.)

P. salicinus (Pers.). A dangerous enemy of willow.-' (Britain and U.S.
America.)

Rostrup* gives Corticium comedens as a wound-parasite of oak and
alder.

Hartig describes Fistulina hepatica, the liver-fungus, as causing a dark-
brown colour in oak-wood.

^ Lnclwig, Lehrbitch d. niederen Kryptoyameii.

-Cavara, Revue Mycol., 1891.

■'Tursky, Russian translation of R. Hartig's " Lehrhuch d. Baumkrankheiten."

^Rostrup, Forfsatfe Underso^/elser, 1883.

TRAMETES. 45 B

Trametes.

Sporophores as in Polyporus, except that the substance
between the pores does not differ from that of the rest of the
sporophore.^

Trametes pini (Brot.) Fr.- liing-scale of I'ine. This is a
dangerous forest parasite in Xorthern Germany ; also in Britain
and U.S. America. On the pine the sporophores develop from
branch-scars, and assume a bracket form. The fungus has also
been o1:»served on spruce in Bavaria and elsewhere, but in this
case, the sporophores are more frequently found as a coating
over the bark on the under side of a branch. Larch, silver
fir, and the Douglas fir (in America), have also been mentioned
as hosts.

The sporophores are brown and woody, and continue to form
annual hymenial zones for a numlier of years. The hymenial
layer consists of pore-tubes lined with basidia, between which
thick-walled cystidia are formed. The spores are elliptical, and
on germination penetrate into wounds or broken branches not
protected by an outflow of resin. The older branches of pine
and larch have a central heart-wood from which no resin is
secreted, and these branches, when broken over, offer the neces-
sary access to the germinating spores ; for this reason, infection
takes place most frequently in old plantations. The mycelium
spreads through branch and stem, particularly upwards and
downwards in the same year-ring. In this way longitudinal
stripes and peripheral zones are formed in the wood, giving rise
to the popular name " ring-scale." Single hyphae bore through
the cell- walls, and a ferment secreted by them dissolves
the incrusting substance, so that walls affected show the re-
actions for cellulose almost at once. A very characteristic
feature is the appearance of isolated white spots or holes, indi-
cating where the wood, after becoming cellulose, has been
dissolved out entirely. The middle lamellae are dissolved out
first in attacks of this fungus, the tertiary lamellae remaining
longest intact (Fig. 12). The dark centres of mycelium inside

^ The distinction between the genera Polyponix and Trametes is badly defined.
A reinvestigation of the systematic relationships of the whole group of Polyporeae
would in fact be advisable.

^R. Hartig, Zersefzuiir)-serschei7iunr/en, PI. V. and TI. ; ]Virktii/e Kranlheiteiu
PL III. ; Lehrhurh d. Baumkrankheiten, 1894 (English translation by 8omerville).

454

BASIDIOMYCETES.

white wood-spots, so characteristic of Polyporiis annmus {Tram,
radiciperda), appear only rarely in this species.

The destruction of spruce and fir goes on from pith to l)ark;
in the ])ine, however, it seems to be confined to the heart-wood,

Fig. -liii. - TrameUx jmu on Spruce (Picui
(xcdxa). Sporophoro on the stem beneath a
snag-branch, (v. Tubenf phot.)

Fu;. 284. — 'J'lO.iiKt's jiiai on Spruce.
Board showing the characteristic
white celhilose-spots in the wood.
(V. Tubeuf phot.)

and is prevented from entering the sap-wood by a firm zone
permeated with resin.

Kemedial measures are the removal of all diseased stems

TRAMETES. 455

at thinning: and the prevention of unnecessary injuries to living
branches or stems.

Trametes suaveolens (L.), common on dead wiUow, is also
reported as parasitic on living stems. (Britain and U.S. America.)

AGARICINEAE.

Agaricus.

Sporophores umbrella-shaped and tleshy, and decaying soon
after discharge of the spores. Hymenium on the under side
of the umbrella, and spread over a series of radiating gills or
lamellae, easily divisible in a longitudinal direction.

The genus is divided into sections and subgenera distinguished
by the colour of the spores ; the Coprinarii are black-spored ;
the spores of the Pratdli are dark purple, brownish-purple, or
dark brown ; of the Dcrmini brown, yellowish-ljrown, or orange ;
of the Hyporliodii rosy or salmon-coloured ; of the Lcucospori
white.

Agaricus (Armillaria) melleus Vahl.^ (Britain and U.S.
America.) The lioney-fungus or " hallimasch." The sporophores
are present in numbers towards the close of summer on tree-
stools of all kinds, and on the bark of dead or living Conifers ;
also on timber, and even on earth. The fleshy stalk is somewdrat
thickened tow'ards its base, and towards the upper part bears
the membranous yellowish annulus (Fig. 286). The cap sur-
mounting the stalk is honey-coloured or brownish with dark
scales. The .spores are white and bestrew^ adjacent ol)jects with
a mealy dust. The sporophores are edible.

The connection l)etween the sporophores and the rhizomorph-
strands was proved by Hartig. These rhizomorphs are very
common and vary much in form ; they occur as round brown
strands running through the earth from root to root of attacked
trees ; inside hollow stems and in wooden water-pipes, they
retain their rounded form, but under the bark of trees they
become dark brown flattened bands (Fig. 288). They are not
uncommon on timber : in mines they may be frequently
seen hanging from the woodwork as tangled clumps, w4th

1 R. Hartig, Wichtiije Kranlcheiten, PI. I. and II. ; Zersetzuixj-ier-^clieinunfjen,
PI. XI. De Bary, Botan. Zettuii;/, 1S.">9. Brefeld, Srhimmelpih.e , Heft, in., 1S77.

456

lUSlDIOMYdiTES.

uuiuerou.s branches like the runners of some hann;ing plant, e.g.
Aaron's IJeard (S((.iifr(((ja mrmciUosd). The rhizoniorphs live as
saprophytes and have been long known to emit phosphorescent
light. Sporophores are developed directly on them, and if one
sows the spores, a delicate hyphal tissue is produced, which,
under suitable conditions, passes gradually over into the rhizo-
morph-strand. Brefeld succeeded in raising rhizomorphs from
spores in artificial nutritive media.

^'-^^ "

Fio. 285.— Affarkus m(lleu>: near a Ueech-stool. (v. Tubcuf phot.)

The /^r/«r/6'?<s-mycelium forms fan-shaped snowy-white firm
membranous expansions under the bark of newly killed or still
living trees. They are quite distinct from the much more delicate
mycelial expansions of Polyporus annosus, and offer a particularly
easy means of distinguishing between the two species. Another
indication of Afjaricxs is the great outflow of resin from the bark
at the base of the stem and from roots, whereby hard, clumps of
earth are formed round the roots. The passage of the rhizomorphs
into the white membranous mycelium is easily observed. The

AGARICUS.

457

rhizomorphs distribute the fungus in the earth and other dead
substrata, as well as bore into the bark of healthy Conifers.

This parasite attacks not only the indigenous Conifers (spruce,
silver fir, pine, larch, and juniper),^ but also the introduced
forms — Weymouth pine, Douglas fir, Pinus rigida, Abies Pichta,
Picea sitchensis, various Cuirressincae, etc. It also seems to attack
broad-leafed trees, at least as a wound parasite.^

In regard to the interesting structure of the rhizomorphs,
and the characteristic mode of wood-destruction caused by

Fig. 2S6. — Agaricv.s mfUfv.s. Sporophore
developed from a rhizomorph-strand ; the
other branch bears arrested sporophores.
(After R. Hartig.)

Fig. 2S7. — Aria,-icv.i< ,iitlleu-i. Section
through a lamella, d, The hypliae forming
the substance of the lamella are much
bi'aiiched, and send twigs outwards which
end in club-shaped basidia, a ; on many of
these are developed sterigmata with apices
swollen into spores, l> ; c, isolated thread-
like arrested basidia projecting above the
hymenial layer. (After R. Hartig.)

this fungus, I give directly the account by Hartig in his
"Lehrbuch."^ "The pathological symptoms can only be ex-
plained in the light of the peculiar organization of the mycelial
growth that lives in the cortical tissues. The apex of the
rhizomorphs consists of delicate pseudoparenchyma, which,
elongating by the division and growth of the cells, produces
delicate hyphae on the inside at a certain distance from the

^I found it on juniper in tlie pine-forests near Eberswalde. (Aiitli.)

- The mycelium does not seem capable of penetrating uninjured broad-leaved

trees, but R. Hartig {Forst/.-)iafu7-iri.s.s. Zeitschrift, 1894, p. 428) mentions attack

and death of cut roots of healthy oaks.

" R. Hartig, Lehrhuck d. Bamnkrankheifen, 1889. The translation given

here is from Prof. Somerville's English edition of Hartig's text-book, p.

210. (Edit. )

458

BASIDIOMYCETES.

point, whereby a felted tissue, called the medulla, is produced
in the interior. The outer parts of the pseudoparenchyma, on
the other hand, coalesce to form the so-called rind, which when
young gives off numerous delicate hyphae, and these, taking
advantage of the medullary rays, penetrate the wood, and
especially the resin-ducts, should such be present. In the wood
the growth is upwards. This filamentous mycelium, which pro-
gresses much more rapidly in the interior of the wood than
the rhizomorphs which grow in the cortex, completely destroys

Ficj. 2S8. — Aparicus melleus. Rhizomori)hs in the form of dark anastomosing
bands, developed between the bark and wood of a tree. (v. Tubeuf phot.)

the parenchyma that exists in the neighbourhood of the resin-
ducts, and to all appearance this is accompanied by a partial
conversion of the cell-contents and the cell-walls into turpentine.
The turpentine sinks down under its own weight, and in the
collar, where the cortex is withered, having been killed by
rhizomorphs, it streams outward, pouring partly in between the
wood and the cortex, and partly into the surrounding soil at
places where the cortex has ruptured owing to drying. On
this account the disease was formerly called ' Eesin-flux ' or

AGARICUS. 459

' liesin-glut.' In the upper parts of the stem, where the cambium
and cortex are still sound, the turpentine also flows laterally,
by means of the ducts of the medullary rays, from the injured canals
towards the cambium and cortex. In the latter this accumulation
induces the formation of large resin-blisters. When, during the
summer, the cambium is forming a new ring, the plethora of
resin has the effect of causing the production of numerous resin-
canals, which are usually large and abnormally constructed, and
these impart to the wood-ring formed during the year of sick-
ness a very striking and characteristic appearance.

" The mycelium gradually spreads from the cells of the
medullary rays and from the resin-ducts into the vascular
elements of the wood, where it produces a form of decay which
may be termed a variety of white-rot. During the progress of
the decomposition from the surface of the stem inwards a certain
stage is reached, which is highly favourable to the development
of the mycelium. While previously it was simply filiform and
furnished with numerous lateral hyphae, it now develops large
bladder-like swellings, and at the same time the hyphae change
into a kind of large-meshed parenchyma, which, like the tyloses
in the vessels of many dicotyledonous trees, completely tills up
the luniina of the tracheides. On account of the mycelium
assuming a brown colour when in this condition, it makes the
portion of diseased wood which it infests appear, to the naked
eye, like a black line. As this kind of mycelium soon dies
off' and is dissolved, being replaced by a delicate filamentous
mycelium, it seldom happens that the zone which it occupies
exceeds the breadth of three to four tracheids. The walls of
the elements of the wood afterwards display a cellulose
reaction, and speedily dissolve from the lumen outwards.

" On account of the trees drying up, after the rhizomorphs
have spread from the point of infection on the roots into the
stem, and again from the stem into the hitherto sound roots,
decomposition of the stem usually ceases before the mycelium
has advanced from the alburnum into the duramen. It is only
in the stool and roots tliat decay rapidly spreads throughout
the whole of the wood."

Methods for exterminating this parasite are unknown, beyond
removal of diseased plants and collection of sporophores. It
would certainly be advisable not to plant young conifers on

460

BASIDIOMYCETES.

cleared forest-land where the fungus sporophores are numerous
on dead stools or I'oots.

Agaricus (Pholiota) adiposus Fr.' (I'.ritain and U.S.
America). Tliis is a conspicuous bright yellow or honey-yellow
toadstool, with a glistening slimy cap which, as well as the
stalk, is beset with concentric darker scales (Fig. 289). The
scales and delicate annulus become indistinct or disappear on
old sporophores or after much rain. The stalk is thick, fleshy,
and stiff, and while growing so changes its direction as to keep
the cap always in a horizontal position. The pileus or cap, at

Fio. 'JSit. — Aijariciix o.diposax. A, A mature and a very young spurophore grown
in the forest ; the other sporophores were raised on Fir-wood in a cellar. The
latter have longer thinner stalks, and a basal swelling beset with white down,
/i, Mature and germinating spores, (v. Tubeuf del.)

first globose, opens out cone-shaped or tiat with a diameter of
about 5 cm. Eemains of the velum adhere to the margin. The
underside of the cap is at first yellow, later mouse-grey.
The lamellae are of three sizes, the largest extending from
margin to stalk. From the lamellae arise the basidia, with
four sterigmata each giving off a single spore. The spores
fall at maturity, and cover neighbouring objects with a brown
dust. They are oval with a length of 7-1 0/x and a breadth
of o-G/W.

The sporophores spring up rapidly in large numbers on

^ V. Tubeuf, " F^ine iieue Kranklieit d. Weisstanue." Ziiltichr. f. Forsf ii. Ja;/'l-
wesen, 1890.

AGARICUS.

461

living stems of silver fir, beech, etc., and on felled wood.^ In
the forest, on newly erected piles of firewood, the yellow stools
may frequently be found in every stage of development growing
from the cut billets, while they are especially numerous on the
rotting useless timber left lying. In cellars or other moist

Fig. 290. — Agaricv.s adijiosus. Destruc-
tion of Fir-wood. The deeply-coiToded
oross-fissures contain white mycelium ; the
remainder of the wood is yellow, (v.
Tubeuf phot.)

.^.

^:.l

Fio. 2yl. — Ayaricus adiposus. Uestruc-
tion of Fir-wood. Later stage. The
corroded fissures no longer contain my-
celium, (v. Tubeuf phot.)

chambers, the sporophores may be abundantly produced till
Christmas, but out-of-doors, August is the time of fructification.
The mycelium forms felted masses under the bark or in cracks
of the wood, and thence tlie sporophores arise as little pale-
yellow buttons, which gradually unfold and become differentiated
into cap and stalk. While quite young, they show the darker

1 Previous to the publication of v. Tubeuf s investigation the fungus had only
been observed on living beech and felled wood.

462

BASIDI0MYCETE8.

scales arranf^ed regularly in concentric lines. Tlie stools break
out from living stems through cracks in the bark or from wounds,

e.f). those made by wood-peckers.

The fir-wood, normally white, assumes,
when diseased, a yellow or honey-colour,
more or less like the sporophore, while
here and there, parts may become light
brown. The hyphae grow in all direc-
tions, but especially as white strands up
and down the year-rings, while others
in horizontal and vertical direction break
up the wood into irregular patches
(Fig. 290). In the final stages of
destruction the wood will be found
laminated into its separate year-rings
and very much broken up into irregular
pieces (Fig. 2.91).

The sporophores of this Arjaricus are
not uncommon protruding from bark-
cankers caused by Accidium elntinvm,
and its mycelium assists in the destruc-
tion of the stem.

Fio. 2D2. — Agnricuii (idiposua
and Poli/porus Hdrtigii. Destruc-
tion of Fir- wood, the boundary
of the regions affected by the
two fungi is formed by a verj'
dark line of demarkation. To
the riglit the destruction is that
produced by Poli/porov.s Hiirtigii,
to the left by Agaricus adiposuK.
(v. Tubcuf phot.)

Agaricus (Pholiota) squarrosus (Miill.). On
living and dead stems of broad-leaved trees.
(Britain.)

Ag. (Ph.) destruens (Brond.). On living
and dead stems of poplar. (Britain.)
Ag. (Ph.) aurivellus (Batsch.). On liv'ing and dead stems of broad-leaved
trees. (Britain.)

" FUNGI IMPERFECT!."

The fungi placed here have life-histories which as yet have
not been completely investigated, most of them being known
only in the form of pycnidia or conidia. The number of species
was at one time much larger, but it is gradually being re-
duced as the forms are proved to be stages in the life
of some species of definite systematic position in the other
groups already considered.

The group may be divided into the provisional sub-groups,
the Spliaei'opsidcae, Melanconieac, and Hyphomycetes.

FUNGI IMPERFECTI. 463

I. SPHAEROPSIDEAE.

Conidia abjointed from conidiophores contained in clark-
colovrcd pycnidia somewhat spherical in form. The various
species are provisionally arranged in genera according to the
colour of the conidia and the number of cells contained in
them. The families here included are the Sj^haeriouh'ae, Ncc-
trioidcae, Lcptostromaceae, and Excipvlaceae.

I. FAM. SPHAERIOIDEAE.

Hyalosporae.

Phyllosticta.

Fvmgi with colourless spores, and producing sharply defined
spots on living leaves. They occur on all kinds of woody plants,
Ijut as a rule the injury caused is too slight to be called a disease.

From the long list given by Saccardo (Vols. III., IX., and x.)
the following have been selected :

Phyllosticta persicae Sacc. This produces on leaves of peach
brownisli-yellow spots, frequently marked by concentric zones.
The name " shot-hole fungus " has sometimes been applied to
this and other allied forms, l)ecause the leaves become more or
less perforated by the withered spots falling out. The pycnidia
on reaching maturity rupture the lower epidermis of the leaf
in a star-like manner. Briosi and Cavara do not regard this
parasite as very harmful, because leaves attacked by it remain
alive without serious prejudice to their function.

Ph. pirina Sacc. has been observed injurious to pear-trees at
Geisenheim (Germany).

Ph. prunicola Sacc. is the cause of spotting of leaves of
apple, plum, cherry, and apricot. (U.S. America./

Ph. cytisi Desm. On leaves of CytAsus Lahurnum in
Britain and Europe.

Ph. acericola Cook et Ellis. On various species of
maple {Acer dasycarpum, etc.). It is described by Galloway -

^The chief authorities for the occurrence of the " Fuugi imperfecti " in
Britain and North America are Massee {Br-ituh Fungus Flora, 1895), Farlow
and Seymour (Host-Index for U.S. America, 1891), and Saccardo [Sylloge
funqorum). Professor J. VV. H. Trail kindly revised the records for Britain.
(Edit.)

■^Galloway, "Report of sect, of Veget. Pathology for 1888." U.S.A. Dept.
of Agriculture, Washington.

4G4 FUNfJI IMPERFKCTl.

as injurious, especially in nurseries and groves where the trees
are grown in nunil)er.

Ph. sphaeropsoidea E. et E. is another American species
wliich has become prominent on account of its ravages in
nurseries of horse-chestnut. The disease appears about the end
of June, and Ijy August the foliage of attacked trees is almost
entirely dead.

Ph. grossulariae Sacc. On leaves of Rihes (Jrossularia in Italy and North
America.

Ph. vulgaris JJesm. A common species on leaves of species of Lonkera.
(Britain and U.S. America.)

Ph. sambuci Desm. On species of Santhucus. (Britain.)

Ph. cornicola (D.C.). On leaves of species of Cornux in America.

Ph. limbalis Pers. On oblong white spots on leaves of l)ox. (Britiiin.)

Ph. tiliae Sacc. et Speg. On leaves of Tilia. (Britain.)

Ph. maculiformis Sacc. is p,robahly a stage of SphaereUa maculiformis
Auersw. It is a dangerous parasite causing a leaf-spot on sweet chestnut
{Castanea) and other trees.

Ph. violae Desm. A source of considerable damage to violets in America ;
it also occurs in Europe and Britain.

Ph. althaeina Sacc. has been reported as dangerous to hollyhock in the
United States. '

Ph. phaseolina Sacc. appears occasionally as a parasite on leaves of
kidney beans. (U.S. America.)

Ph. viciae (Lib.). On Vicia sepium. (Britain.)

Ph. cirsii Desm. On leaves of Cirsmm. (Britain.)

Ph. apii Hals.' produces a leaf-spot on celery, and has caused con-
siderable loss in America.

Ph. tabaci Pass, occurs on leaves of tobacco in Italy.

Ph. bataticola Ell. et Mart., and others, have been recorded on sweet
potato in America.

Ph. betae Oud. occurs on leaves of sugar beet and mangel.

Ph. tabifica PnlL- Prillieux believes the disease of beet-
root known as "heart-rot," to be due to this Phyllostida. It is
probably a conidial form of Spliacrella tahijica Prill. The symp-
toms of disease are withering of the outer leaves, followed by
the appearance of whitish spots with withered ti.ssue filled up
with mycelium. Thence the disease spreads into the younger
parts and causes " heart-rot " of the root.

Frank is of opinion that " heart-rot " is caused by SjJoridcs-

^ X. J. Af/ric. Exptr. Station Report, 1891.

-Prillieux et Delacroix, Bullet, de la soc. mycol. de France, vii., 1891.

PHYLLOSTICTA. 465

miuvi putrefaciens Fuck. This is probably the cause of the
gradual blackening of the leaves, yet it does not appear to
lose its saprophytic nature.

Frank also gives Phoma hetac Fr. as one cause of the heart-
rot of the sugar beet (comp. Phoma).

It will thus be seen that the cause of the rotting of beet-
root, sugar beet, and mangold is still very obscure.^

Ph. g-aleopsidis Sacc. On leaves of Galeopsis Tetrahit. (Britain.)
Ph. atriplicis Desni. On leaves of Chenopodium and Atriphx in Europe
and Britain.

Ph. chenopodii Saec. has been found injurious to spinaeli in America.
Ph. podophyUi (Curtis). In leaves of Podophyllum peltatum in America.
Ph. primulicola Desm. On withering leaves of Primula. (Britain.)
Ph. ruscicola Dur. et Mont. On leaves of species of Ruscus. (Britain.)

Depazea.

A provisional genus including species of which the spores
or conidia are unknown, so that the forms included in it will
probably 1)6 found to be related to various groups. They live
in many cases on living leaves, causing discoloration. Some
of them are :

Depazea acetosae Op. On liv.mex Acetosa.

D. impatientis Kirchn. On Impatiens Noli-tangere.

D. geicola (Fries). On Geum urhaimm.

Phoma.

Conidia unicellular and colourless. Pycnidia black and em-
bedded, but having a distinct pore. The species produce spots
with ill-defined margins.

Phoma abietina Hartig - {Fusicoccuni cibietinum Prill, et
Delac). This parasite is a frequent cause of death to the
silver fir. The branches become brown, yet retain their needles^
hence when they occur isolated amongst neighbouring green
branches they are at once conspicuous. On close examination
of the dead or dying branches, areas of shrunk or con-

1 According to Karlson (Peii-owsk. Akad. f. Landwirthscha/t, 1S90) and Hell-
riegel {Zeitfch. des Verein f. Ruhenzuckerindustrie d. deutsch. Reiclies, 1890)
insects take no part m it.

- Hartig, Lehrbuch d. Baumkrankheiten, Ed. ii. (English Edition by W.
Somerville). Mer, E., Journal de Botanique, 1893.

2g

466

FUNGI IMPEKFECTI.

stricted tissue will be found extending quite round the twig
(Fig. 293). At these places the bark and cambium have been

killed, whereas the higher
portions of the twig have
continued to increase in
thickness. Numerous
small black pycnidia
break out on the bark
of diseased places and
give of!" small unicellular
spindle-shaped couidia,
which convey infection
to new hosts in August
or September. Killed
branches die and dry
up without casting their
needles.^

Ph. pithya Sacc.
causes a disease similar
to the preceding on the
Douglas fir {Pscudotsuga
Donrjlasii). The pycnidia
of the fungus are found
on dead constricted parts
of twigs, and they, as well
as other symptoms of the
disease, closely resemble
those of Phoma ahietina.
Eostrup"'^ defined and de-
scribed it as Ph. 'pitliya
Sacc, ]\Iagnus also re-
cords it on branches of
Pinus syhestris in Berlin
botanic garden.
Other species of Phoma frequent other conifers and broad-

Fio. 203. — Phoma ahietina. Twig of Silver Fir show
iiig the constriction characteristic of this disease
dotted over with pycnidia. (After R. Hartig.)

^ Buhm (Zeifsch. f. Forst- u. Jacjd-wesen, 1896, p. 1.54) describes .and figures
an attack of this parasite on Pseudotstuia Donglasii in North GermanJ^ One
cannot, however, avoid suggesting some confusion between this and Ph. pithya
described next. (Edit.)

-E. Rostrup Undersoeqtlser over Snyltes vampes Angreb paa Skovtraeer,
188.3-1888.

PHOMA.

467

leaved trees, but details in regard to their parasitism are
wanting.

Ph. Hennebergii Kiihn.^ Brown-spot of wheat-ears. This
produces, on the glumes of wheat, brown spots with projecting
pycnidia from which unicellular conidia emerge. The grains of
attacked ears shrivel up and become spotted, while the value
of the chaff as fodder is much diminished. Whole fields may
be attacked, showing marked discoloration, and producing but
few healthy ears."' The fungus may also
appear on the leaves and produce pycnidia.

Ph. lophiostomoides Sacc.^ Lopriore
regards this as a parasite on cereals, but
Cavara looks on it as saprophytic on the
dead plants.

Ph. ampelinum De Bary {Sphaccloma
amjjelinwm De Bary). Anthracnose of the
Vine.* The mycelium of this fungus can
penetrate into leaves, green bark, or fruit,
and kills the tissues. Spots are first pro-
duced, then enlargement of the neighbour-
ing tissues takes place, causing the spots
to appear as if sunk in depressions, and
reminding one of hail-wounds. On leaves
and grapes, the spots are sharply defined,
at first dark-brown, later with greyish
centres and dark-brown margins. In the
later stages the dried-up spots may drop out of the leaves.

Anthracnose, or " birds-eye rot," constitutes one of the dreaded
vine diseases of America and Europe, so that it has received
much attention, both as to its life-history and remedial measures ;
as yet however with but partial success. Copper sulphate
solutions seem to be fairly successful remedies, as shown from
results of the many experiments recorded in the Journal of

^ Klihn, Jfedyju/ia, 1877, p. 121; also in 'Rahenhovst's Fungi europ. No. 2261.
Frank, Zeitsch. fur PJianzenkrankheiten, in., 1893, p. 28.

-Eriksson {Mitthl. dtr k. Landh. Akad. Stockholm, 1890) records a case of
this kind, hut the conidia are drawn two-celled as in a Diplodina, whereas
Klihn's original drawings have only one-celled conidia.

^Cavara et Eriksson, Zeitncli. f. PJianzenkrankheiten, iii., p. 23.

* Goethe, MittJd. ich. den. schwarzen Brenner d. Rehen. Leipzig, 1878. Cornu,
Bullet, de la Soc. botan. de France, 1878. Prillieux {idem), 1879. Eathay, " Der
Black-rot," 1891. Scribner, Report of U.S. Amer. Dept. of Agricidlure, 1886.

Fig. 294. — Phoiiia alnpeli-
num. Brown concave spots
on shoot and berry of Vitis.
(V. Tabuuf del.)

468 FUNGI IMrERFECTI.

Mycology and the bulletins and reports of the American experi-
mental stations. ((compare also Gloeosporium ampcJojikdyum
(Pass.) p. 484.)

Ph. betae Frank.^ The younger leaves of well-developed
beet-root become black, and the disease extends into the root.
Mycelium fills the diseased parts and penetrates into healthy
tissues. Pycnidia are developed on the diseased spots. The
fungus is no relation of Sporidcsmium i^utrefacuns, a form to
which a root-rot is ascribed by Frank. It is however probably
identical with Prillieux's Phyllostida tahifica. Ivriiger found
the disease so connnon, that in many localities as many as 80 per
cent, of the plants were destroyed. Sorauer regards the root-rot
of beet to be sometimes caused by Phoma, sometimes l)y
Sporidcsmium, perhaps in some cases by both together.

Ph. sanguinolenta Eostr.^ attacks carrot plants in their first
year, causing greyish-brown depressed spots on the bulbs with-
out however appearing to be very injurious to them. When
the seedlings are planted out in spring, the mycelium
extends into the stem and causes the umbel to wither at
flowering so that no seed is formed. PyCnidia are developed
from all attacked spots and give off conidia as red tendril-like
bodies — hence the species-name. Certain varieties of carrot
appear to resist attack by this parasite better than others.

Ph. solani Hals. This causes damage to the egg-plant
{Solanum melongemt).^ Young plants die off on the hot-beds,
their stems dying near the earth and shrivelling up. The
pycnidia of this Phoma appear on the killed parts.

Ph. cydoniae Sacc. has been reported as injurious to quince
trees. (U.S. America.)

Many species cause leaf-spot diseases. Some of the more
important British and American species are :

Ph. pinastrella Sacc. On Pinus syJvestris and others. (Britain.)

Ph. strobi (B. et Br.). On Pinus Strohus. (Britain.)

Ph. taxi (Berk.). On yew. (Britain.)

Ph. Candollei (Berk, et Br.). On box. (Britain and U.S. America.)

Ph. sorbi (Lasch.). On leaves of Pijrus Aucuparia. (Britain.)

^ Frank, Zidtsch. f. PflanzenkrankhtUtn, ill., p. 90, and Deutftcht landw. Pr.
No. 89, 1893. Kriiger, ZeitHch. f. Pflanzenkrunkheititn, iv., 1894, p. 195.

^Described and figured l)y Halsted in Bulletin 91, X. J. Aijric. Exper.
Station. 1892.

PHOMA. 469

Ph. malvacearum West. On mallows and hollyhock in Europe.

Ph. longissima (Per.s.). In species of Umbelliferae and Clienopodiaceae
in Europe and America.

Ph. errabunda Desm. In stems of Verbascum. (Britain.)

Ph. cucurbitacearum (Fr.). On fruits of various species of t'ucur-
bitaceae in Europe and America.

Dendrophoma.

Pycnidia similar to Phoma, coniciiopliores however bearing
several coiiidia either on 1 tranches or little processes

Dendrophoma Marconii Cav. attacks Hemp (Cannahts saliva),
causing dark oblong spots on the green stem. Tlie pycnidia
are embedded and Itreak through the epidermis with a round
pore. The conidiophores are branched, with swollen ends
carrying little short rod -like unicellular conidia. In case of
attack, which generally occurs towards the close of the
vegetative period of the hemp, it is suggested to cut the
crop somewhat prematurely, and thereby prevent maturing and
spreading of the fungus.

D. convallariae Cav. j^roduces dark elonoated spots on leaves of Con-
vallaria majalis.

D. valsispora Penz. is recorded by Penzig on living leaves of Citrus
Limonujii (Lemon).

Sphaeronaema.

Pycnidia embedded, membranous, and long-beaked. Conidia
ovoid or oblong, unicellular, and almost colourless.

Sphaeronaema fimbriatum (Ell. et Hals.), {Ccratocystis
fimbriata Ell. et Hals.). Black rot or black shank of sweet
potato.^ The parasite shows itself as black depressed spots on
the lower parts of young plants, and these may extend over
the whole shoot. The disease is best recognized on the tubers,
where it consists of dark, somewhat greenish spots, varying
from ^ to 4 inches in diameter, and extending some distance
into the tissue. These spots when once seen cannot be mis-
taken, as they are sunk areas with distinct margins, like spots
burned into the potato with a piece of metal which has left
the skin uninjured. The mycelium consists of thick-walled
olive-brown hyphae, which cause death and destruction to the

^ Halsted and Fairohild, Jour, of Mycology, Vol. vii. , 1891, with Figures.

470 FUNGI IMPERFECT!.

cells of attacked tissues. There are three modes of spore pro-
duction: (1) brown luacro-conidia inside the tissues; (2) colour-
less micro-conidia on the spots ; (3) spherical pycnidia with long
necks ending in a fringed opening. A sclerotial form is also
strongly suspected, lieniedial measures recommended are, de-
struction of all diseased parts, change of crop on diseased fields,
and selection of healthy seed and strong sprouts.

Several other species of this genus are recorded from North
America, but details in regard to their mode of life are
wanting.

Asteroma.

Fungi forming star-like, dark-grey, mycelial patches on the
surface of plants. Pycnidia very small and containing tiny
ovoid or short cylindrical spores. Several species frequent
living leaves.^

Asteroma impressum Fuck. On Tussilago farfara.
A. prunellae Part. On leaves of Prunella vulgaris. (Britain.)
A. ulmi Klotscli. (Britain), and A. maculare End. On Ulimts.
A. padi (D.C.) causes a leaf-fall on I'runus Padus. (Britain.)
A. geographicum Desm. is found on the leaves of species of Crataegus.
Prunus, and Pyrus in Europe and America.

Pyrenochaeta.

Pycnidia emergent or sessile, beset witli bristles. Conidia
oblong, on liranched conidiopliores.

Pyrenochaeta rubi-idaei Cav. forms l^lack spots on leaves
of Ruhus Idacus. The pycnidia are spherical with a tuft of
bristles projecting from their terminal pore. The conidia are
little, oval, and with one or two cells ; they are produced from
slightly branched conidiophores.

Vermicularia.

Conidia unicellular, rarely bicellular, generally spindle-shaped ;
they are produced inside pycnidia, and are embedded amongst
brown septate hairs. The species are a frequent cause of leaf-
spot, but most of them have not yet been sufficiently investigated.

^ CicinobiiJiis Ccfafii l)e Barj-, allied to this genus, is a parasite on Oidiinn
Tuckeri, the dreaded vine-parasite.

VERMICULARIA. 471

Vermicularia trichella Fr. occurs on living leaves of ivy and other plants.
(Britain.)

V. ipomoearum Schw. On species of Ipomoea in America.

V. microchaeta Pasc. On living leaves of Camellia japonica in Italy.

V. circinans Berk. Onion rot in Britain and U.S. America.

Placosphaeria and Cytospora are genera containing forms
parasitic on living plants, but of little practical importance.

PHAEOSPORAli:.

Coniothyrium.

Pycnidia brown or black. Conidia brown, unicellular, spheroid
or ovoid, and borne on short conidiophores.

Coniothyrium (Phoma) diplodiella Sacc.^ White-rot of the
vine. I'his disease has a wide distribution in Hungary, and has
also been observed in France, Italy, and America. It has caused
considerable damage, especially in Xorthern Italy, where it was
for a long time regarded as the black-rot.

According to Mezey, this parasite is distinguished from
Lacdadia (black-rot) in the following points : — The pycnidia
and conidia are larger ; the mature pycnidia are greyish or
light brown (never black), the mature conidia are brownish.
The disease attacks the fruit only, causing it to fall ofi'. IJathay,
however, states that it also attacks young shoots, infection taking
place from the fruit. Diseased grapes become soft, rotten, and
wrinkled ; the ridges are beset with pycnidial pustules, as in
black-rot, but the grapes never become brittle and hard.

Yiala and Eavaz- have recently succeeded in rearing perithecia
from twigs and fruit-stalks set in sterilized moist sand. Xone
could be found on grapes. The perithecia are globular, enclosed
in a black covering several cells thick, and with a large crater-
like aperture. The asci and paraphyses arise only from the depth
of the perithecium, the latter being longer than the former and
frequently branched. The asci are club-shaped and short-stalked,
and contain eight spindle-shaped colourless or yellowish asco-
spores, divided by one to three cross-septa. They germinate and
produce one or more germ-tubes.

iRathay, "Der White-Rot," Die Weinlaube, 1892.

General description in Report 9, Xeio York Agric. Exper. Station, 1890.
^Viala and Ravaz, Compt. reml., cxix., 1894, p. 443.

472 FUNGI IMPERFECTI.

A new genus Charrinia, belonging to the .Sphaeriaceae of the
Ascomycetes, has been formed to receive tiiis species.

Sphaeropsis.

Pycnidia black and spherical, witli an aperture. Conidia ovoid
or oblong, unicellular, dark-coloured, and on stalk-like conidio-
phores.

Sph. malorum Peck. The cause of a disease in America,
known as the black-rot of apple and quince. The mycelium
permeates and destroys the skin of the fruit, which, in con-
sequence, becomes dried up and mummified. It also occurs in
Britain.

Other species attack plants of various Kosaceae.

Phaeodidymae.

Diplodia.

Pycnidia, small, spherical, and dark-coloured ; the conidia are
two-celled when mature.

Diplodia gongrogena Temine.^ Temme discovered a mycelium
and the pycnidia of this JDi^ilodia in aspen {Fojmlus tremulae)
exhibiting hypertrophied outgrowths of wood and rind. As yet
it has not been possible to artificially produce tliese malformations
on the aspen, nor other somewhat similar ones which occur on
the willow.

Other species of this genus attack many trees, e.g. holly, lilac,
horse-chestnut, mulberry, and various conifers.

Hyalodidymak.

Ascochyta.

Conidia ovoid or oblong, bicellular, and hyaline. The pycnidia
have a central aperture, and are embedded in discoloured portions
of leaves or twigs.

The following species are of practical importance :
Ascochyta pisi Lib. (Britain). Briosi and Cavara state that

1 Teinnie, Landiv'trth. Jahrhnch, 1887.
Thomas, Verhand. d. hotan. Verein. d. Proc. BrandenJmrg, 1874.

ASCOCHYTA.

473

tliis fungus is injurious to Pisum sativum, Phascolus vulgaris,
Vicia sativa, etc. It causes spots on leaves and pods, followed by
drying up of the former and deformation of the latter. The
pycnidia appear as tiny points on the spots, and give out bicellular
cylindrical conidia.

As. Boltshauseri Sacc.^
This species was first observed
in Switzerland on bean {Pha-
seolus vulgaris). Leaves of all
ages become brown -spotted,
and premature defoliation may
follow. The spots are marked
by concentric zones, and bear
pycnidia. The conidia are
two- to three-celled, being
distinguished in this and by
their larger size from the
preceding species.

The following species fre-
quent living leaves :

Ascochyta tremulae Thuiii. On
the aspen.

A. metulispora, B. et Br. On leaves of the ash in Scotland.

A. armoraciae Fuck. On Annoracia rusticana (Horse-radish).
(Britain.)

A. periclymeni Thlini. On Lonicera Periclymenum.

A. maculans Fuck. On Hedera Helix.

A. Ellisii Thiim. On Vitis Lahrusca in America.

A. brassicae Thiim. On Brassica oleracea.

A. dianthi (A.S.). On Dianthus. (Britain.)

A. pallor Berk. On Rubus Idaeus. (Britain.)

A. viciae Trail. On Vicia sepium, etc. (Britain.)

A. malvicola Sacc. On Malva sylvestris. (Britain.)

A. graminicola Sacc. On various grasses. (Britain.)

A. scabiosae Rabh. On Knautia arvensis.

A. nicotianae Pass. On Nicotixina Tahaccum.

A. digitalis Fuck. On Digitalis purpurea.

A. fragariae Sacc. has been found injiu'ious to the strawberry crop in the
United States.

A. aspidistrae given {Gardener's Chronicle, xvii., 1895) as a parasite on
Aspidistra in Britain.

Fig. 295. — Ascochyta pisi on Pea. Enlarged
section of pycnidia, and still more enlarged
conidia. (v. Tubeuf del.)

^ Boltshaiiser-Amri.sweil, Zeitschri/t /. PJlanzenkranhheittn, i., p. 1.35.

474 FUNGI IMI'E[{FKCTI.

Actinonema.

Pycnidia siiiiiU and .situated on a gossamer net of mycelium.
Conidia liyaline and divided by one or more eross-septa.

Actinonema rosae Lib. {A.strroma rddiostim Fr.). Tbis pro-
duces black radiating spots on rose-leaves, on vvbicli pycnidia
vvitb ].)icellular conidia are developed. A premature defoliation
takes place, vvbicli in turn causes tlie upper buds to unfold in
autumn before tbeir time. Tbe mycelium is distributed botb
inside tbe leaves and superficially. Timely removal of diseased
leaves and defoliated slioots migbt be recommended as remedial
measures.

A. tiliae Allescb. sbows itself in spotting of the leaves and
petioles of lime, and may bring aljout defoliation of the whole tree.

A. fagicola Allescb. produces white spots with dark margins
on living beech leaves, and causes gradual discoloration of the
whole leaf. According to Allescher,^ this disease brings about
premature defoliation of beech. As yet it has been observed only
in U})per Bavaria.

A. fraxini Alle.'^cli. On living leaves of the ash.

A. crataegi Per.s. attacks leaves of Pyrui^ Aria, P. toi'minalis, and
Vih^inmm Opulus.

A. podagrariae Alleseh. On living leaves of Aegopodinm Podagrana,
and Chaerophyllum hirsutinn.

Darluca.

Darluca genistalis (Fr.). On living leaves of Ci/tisus sagktalis. This may,
however, be only a parasite on Uromyces cytisi with which it is frequently
observed, just as Dar. Jilum occurs on several JJredineae.

Diplodina.

Similar to Diplodia, but having colourless conidia.
D. castaneae Prill, et Delac." produces canker-spots on the
stems of chestnut, and brings about death.

Phragmosporae.
Hendersonia.
Pycnidia formed under the host-epidermis, which is later
ruptured. Conidia brown, two- or more-celled.

1 Allescher, Iledwhjia, 1S94.

'^Prillieux et Delacroix, Hull. ■•^oc. mycol. cle France, 1893.

HENDERSONIA. 475

Hendersonia foliicola (IJerk.) (Britain and Europe). The
black globular pycnidia are produced superficially on leaves of
Jvnipcrus communis. The conidia are elliptical in shape, three- to
five-celled, and abjointed from filamentous conidiophores. (This
species is not identical with Podiosoma JunijJeri ^ minor Corda,
which is more like the needle-frequenting form of Gymno-
sporangium junijjerinum .y

Several species are found on living leaves :
H. cydoniae C et Ell. on quince in America.
H. mali Tliiim, on apple.

H. rhododendri Thiini, on Rhododeadron hirsv.tvm in Northern Italy and
Germany.

Cryptostictis.

Similar to Hendersonia, but having ciliate spores.
Cr, cynosbati (Fuck.). Sorauer" regards this as parasitic
on Eosa canina, and causing death of portions of the rind.

Stagonospora, Couturea, Asteromidium, and Camarosporium contain
species said to frequent living leaves of various plants.

SCOLECOSPORAE.

Septoria.

Spores generally multicellular and hyaline ; produced from
short conidiophores, contained in lens-shaped embedded pycnidia.

Septoria parasitica Hartig." This disease may be frequently
observed in young plantations and seed-beds of Spruce. The
symptoms are very like those following damage by frost, Ijrown
needles appearing in May towards the base or middle parts of
young shoots, and followed by a premature needle-cast. The
disease is most apparent on lateral shoots, which become sharply
bent downwards, the green needles hanging limply till they
wither and fall as the whole shoot shrivels up,

The pycnidia are little, black, and spherical : they are pro-
duced during the summer, particularly towards the lower end

^ K. V. Tubeuf, " Generations-wechsel (Tymnosporangium-Arten," Cenfralbl. f.
Bakteriolor/ie v. Parasilenkunde, 1891.

'■^ Handbudi d. Pflanzeiikrankheiten , ii., 1S76, p. 388.

■'R. Hartig, Z<dtich. f. Fomt. u. Jw/d-icesen, 1890; and Fo)'st/irh-natiu-wiss.
Zeitschri/t, 1893.

476

FUNGI IMI'ERFECTI.

of the shoots, and eitlier rupture tlie epidermis or grow out from
the leaf-scar cushions (Fig. 297). The conidia are abjointed
from filamentous conidiophores inside the pyenidia, and emerge
as tendril-like structures. They are two-celled, small, cylindrical,

and pointed at both ends.
Germination takes place
easily in water, and the
disease spreads rapidly over
the young developing shoots
during May. The mycelium
permeates the twig, living
both inside the cells and
between them.

The disease has been
observed on Picea ejxelsa
and P. Mcnzii'sii, not only
in nurseries and on young
trees, but also in pole-
forest, where it frequents
the upper crown and causes
death. At the beginning
of an attack the pruning
of diseased twigs in young
plantations should be at-
tended to.

Septoria rubi (Westend.).^ Blackberry leaf-spot. This is a
parasite of some economic importance in the United States, where
it interferes with the blackberry culture. It also occurs in Europe
and Britain.

S. ribis Desm. produces a somewhat similar disease on leaves
of currant and gooseberry.' (Britain and ILS. America.)

S. piricola Desm. occurs throughout all Europe, causing little greyish
spots on leaves of pear trees. It is probably a pycnidial form of Spliaerella
lucillae Sacc.

S. crataegi Kich. A common species on leaves of Crataegus in Europe.

S. cerasina Peck. On leaves of Primus serotina in the United States.

Many forms of Septoria infest cultivated vegetables :

S. petroselini Desm. is the cause of dry spots appealing on leaves of

Fio. 29(3. — S'ploria para-iUirti. «, Young diseased
shout of Spnice, with apex still fresh and green.
It, Needle diseased towards base, c, Apex of a two-
year-old shoot, into which the disease has extended
backwards from the .younger shoot ; the brown
discoloration of cortex and pith is iudicated by
shading. (After R. Hartig.)

' Uescription in Bulletin, No. fi, Ohio Ar/ric. Exper. Station, 1891.
-Description in Bulletin, No. 13, Iowa Agric. Exper. Statioii, 1891.

SEPTORIA.

477

cultivated parsley in Europe and Britain
enemy of celery in the United States.

S. armoraciae Sacc. On
horse-radish in America.

S. consimilis Ell. et Mart,
frequents lettuce in America.

S. lycopersici Speg. This
parasite, originally observed in
America, has recently been de-
scribed by Briosi and Cavara on
tomatoes in Italy. It causes
spots on leaves, stems, and
fruits, inflicting thereby con-
sidei'able loss on cultivators.

The following are im-
portant forms on other
cultivated plants :

S. graminum Desm.
causes light spots on leaves
of wheat, oats, and brasses.
It has been observed to
injure the cereal crop in
Italy,^ It is recorded for
Britain and U.S. America.

S. cannabis (Lasch.).
This on leaves of hemp pro-
duces spots, which are at
first whitish, then yellowish
with dark margins. The
pycnidia are embedded in
the upper side of the leaf.

The following species
have caused injury to
garden plants :

S. dianthi Desm. Car-
nation-spot,- The disease
appears on the leaves and
stems as rounded spots of

A variety {(ipii Br. et Cav.) is an

Fio. 297.— a, Leader-shoot of Spruce, partially
killed and defoliated, b, Pycnidia emerging from
the rind and the leaf -scars ( x o). c, Formation
of oonidia inside a pycnidium ( x 240). rf, Spores
germinating in water. . , Spores germinating in
nutritive gelatine. (After R. Hartig.)

1 Cavara (Zej7.sc/i. /. Pflauzenkrankheilen, in., p. 23) regards this and S. tritici
with its varieties, as forms of a single species ; also Eriksson {Om Nagra
sjukdomar d odlade Vdxter, 1890).

-Atkinson, " Carnation Diseases," at American Carnation Society, 1893.

478 FUNGI IMPEUFEOTI.

dirty white or brownish colour with a darker margin. The
pycnidia appear as black points on the sjDots, and rupture the
epidermis before giving off their septate spores.

S. anemones Desni. On Aiiemone. (Britain.)

S. lychnidis Desm. On Lijchnis dhirna. (Britain.)

S. epilobii West. On Epilohiura. (Britain.)

S. stachydis D. et R. On tStaclafs. (Britain.)

S. urticae D. et R. On Urtica dioica. (Britain.)

S. cyclaminis Dur. et Mont. This produces roundish sjwts with
concentric markings on the leaves of Cyclamen which then gradually
wither.

S. chrysanthemi Cav. causes a leaf -spot on Chrysanthe'fmim japonicum and
C. indicum.

S. exotica Speg. attacks cultivated New Zealand species of Veronica.

S. hydrangeae Bizz. causes injury to cultivated Hydrangea.

S. sedi West, injures Seduni under cultivation in the United States
and Britain.

Other species on many other herbs in Britain and America.

Many species of Septoria have been recorded on trees and
shrubs, e.g. :

S. rosae Desm. On roses. (Britain.)

S. hederae West. On ivy. (Britain.)

S. fraxini Desm. On the ash. (Britain.)

S. nigro-maculans Thum. 0" green walnuts, stunting their growth.

S. castaneae Lev. On the sweet chestnut.

S. aesculi (Lib.). On the horse chestnut. (Britain.)

S. pseudoplatani Rob. et Desm. On leaves of sycamore.

S. populi Desm. On leaves of poplar.

S. didyma Fuck. On Salic triandra and S. alba.

S. cornicola Desm. On leaves of Cornus sanguinea.

Phleospora.

True pycnidia are not formed, but the conidia are abjointed
from cavities in the stroma ; they are hyaline, rod- or spindle-
shaped, and consist of two or more cells.

Phleospora aceris (Lib.). On living leaves of Acer Pseudoplatanus.
(Britain.)

Phi. mori (Lev.). On living mulberry leaves ; probably related to
Sphaerella mori. (Britain.)

Phi. ulmi (Fr.). On living leaves of elm. (Britain and America.)

Phi. oxyacanthae (K. et S.). On living leaves of Crataegus Oxyacantha.
{Britain.)

DILOPHOSPORA. 479

Dilophospora.

Dilophospora graminis Desm. (Britain.) This attacks rye,
wheat, and various grasses. Oblong light spots are produced
and bear the pycnidia ; when these occur in the flower heads,
stunting of the grain takes place. (See also Dilophia, p. 222.)

2. FAM. NECTROIDEAE.

The fungi of this family are chiefly pycnidial forms of the
Ascomycetes, and as such have already been considered.

3. FAM. LEPTOSTROMACEAE.

Htalosporae.

Leptothyrium.

Pycnidia black and discoid. Spores ovoid or spindle-shaped,
unicellular, and hyaline,

Leptothyrium periclymeni (Desm.). On living leaves of
species of Lmxiccra. (Biitain.)

L. alneum (Lev.) produces roundish leaf-spots on species of
Alnv.s. (Britain and America.)

L. acerinum (Kunze) causes spotting of the leaves of Acer
campestre and A. 'p^citanoides. (Britain.)

Several other species occur both in Europe and America.

Melasmia.

The black pycnidia occupy black extended stromata. Conidia
simple and unicellular, borne on rod-like conidiophores.

Melasmia berberidis Thiim. et. Wint. On living leaves
of barberry. Brown spots are produced, bearing the pycnidia
as black points ; the spots cause total or partial death of the
leaves, frequently ending in defoliation of the shrubs.

M. empetri Magn. (Britain.) This species was observed by
Magnus ^ causing an epidemic disease on crowberry. The
symptoms were abnormal elongation of young twigs, and the
leaves remained smaller than usual. The rind of the stem was
found to be permeated by a mycelium which produced black

^ Berichte d. deutsch. hofan. GeselL, 1886. With illustratious.

480 FUNGI IMrERFECTI.

pustules bearing the pycnidiu of this Mdnsmia. The cells of
the cortex dried up, and the rind became detached from the wood
in the following year. The leaves were never found attacked.
(The species is not a Rhytisma; nor does any species of lihytisma
produce similar hypertrophy of its host.)

M. acerina, M. punctata, and M. salicina are now recognized only as
pyciiidia of the species of /t'/ti/f/s/mi Ix-ariug these .same specific names.

Leptostroma.

Pycnidia oblong, black, and Hattened. Conidia ovoid or
oblong, unicellular, and whitish.

Leptostroma punctiforme Wallr. Found on the leaves of
Salir, liosa, Bh.vus, Euphorhia, etc.

L. caricinum Fr. frequents leaves of Garex and Brio2)horum
in Europe and North America.

The parasitism of other species is uncertain,

Labrella and Discosia are genera whose species have not as yet pro-
(hiced diseases of any serious economic importance.

PHRAGMOSrORAE.

Entomosporium,

Entomospormm maculatum (D.C.) Lev.^ This fungus, under
the name of leaf-blight of pear and quince, is the cause of
considerable loss in the cultivation of these crops. Defoliation
takes place early in the season and young seedlings are forced
to form a new set of leaves, whereby their reserves of food are
exhausted. If this be repeated several times the plants become
exhausted and are killed off in winter. Stocks already budded
seem to remain immune if not already diseased. The leaves
are first attacked, but later the succulent growing apex of the
twigs may also succumb. The parasite hibernates on the bark
in small depressions containing the pycnidia ; thence it spreads
in early spring, so that pustules appear on the young leaves
before they are fully developed.

Spraying with Bordeaux mixture, or solution of copper acetate

1 Galloway and Southworth {Report for 1888 of Section of Vejctahh'. Pathohny,
Dept. of Agriculture, U.S. America) give a historical account of the fungus
and a bibliography. (Edit.)

ENTOMOSPORIUM, 481

(6 oz. in 26 galls, water) have both produced good results in
checking the disease.^

E. mespili (D.C.). (See Stigmatea mespili, p. 210.)

SCOLECOSPORAE.

Brunchorstia.

Brunchorstia destruens Erikss. {B. ijini Allesch.). In ISTor-
way almost all the plantations of Austrian black pine {Pin.u&
Laricio) from five to thirty years old have become diseased and
died out. Similar ravages have also been observed in Germany.
Brunchorst ascribes this to a parasitic fungus whose mycelium
may be found in all parts of diseased twigs and needles, and
whose pycnidia are formed on the killed remains. The disease
begins in young first-year twigs, the mycelium growing in
the cortex, pith, and wood. The needles are attacked in
summer, become brown from the base upwards, and the
pycnidia make their appearance under the scale-leaves.

Brunchorst ^ describes the fungus as follows : Pycnidia par-
tially embedded in the tissues of the host-plant ; the smaller
ones being simple, the larger divided by complete or partial
partitions. The inner wall as well as the partitions of the
pycnidium are closely beset with straight basidia, from the
apices of which stylospores with two to five septa are abjointed.
Paraphyses are never present. The perithecia are black, oblong
or rounded, slightly grooved, and 1-2 mm. in diameter; they
dehisce by one or more irregular pores in the wall. The
spores are very minute (30 — 40 = 3m), tapering, and rounded
at each end.

Schwarz considers Brunch orstia as a conidial form of Ccnan-
guim ahietis already described (p. 251).

It may be here mentioned that drying-up of pine-twigs may
be due to heating by the sun in frosty weather, or to frost
itself;^ these are, however, quite distinct from the disease just
described.

^Fairchild [Journal of Mycolorjy, Vol. vii.) gives results of treatment with
various fungicides on several varieties of pear and quince. (Edit.)

^ " Ueber eine neue Krankheit d. Schwarzfohre." Bergens Museum, 1889.

^R. Hartig, " Vei'trocknen u. Erfrieren d. Kiefernzweige," Forstlichnaturioiss.
Zeitschrift, 1892 and 1895.

2h

482 FUNia LMrEllFECTI.

4. FAM. EXCIPULACEAE.

The parasitic nature of the .species ul" this family lias iKtt as
yet been investigated to any extent.

II. MELANCONIEAE.
True pyenidia are not formed, but the conidia are developed
in clusters or aggregations covered over at first by the epi-
dermis of the host-plant, which is ultimately ruptured.

Hyalosporae.
Gloeosporium.

Conidial clusters colourless or grey, never black ; they rup-
ture the overlying epidermis and give off unicellular conidia,
one from each conidiophore.

Gloeosporium fructigenum Berk.^ (Britain and U.S. America).
Apple liot or Eipe-rot. This is a very serious disease for
American cultivators. It not only attacks apple, but also the
grape, pears, peaches, and egg-plants."^ On the apple it appears
first as brown spots which become more conspicuous as the
fruit enlarges. The spots on first sight look like decay, but
they are quite firm and soon bear pustules of a white or
pinkish colour turning to black. The attacked part of the apple
has an intensely bitter taste, and should be carefully removed
before eating the fruit. On grapes the fungus produces tiny
raised pustules, which on the white varieties are situated on
spots with a purple centre and a Ijrown margin : the pustules
when mature give off flesh-coloured conidia. The grapes
gradually shrivel up, but do not become black as in the case
of the black-rot, nor do they assume a bitter taste as the
apples do.

The apple bitter-rot makes rapid progress amongst stored
fruit, especially before it has been sorted out. Care should
therefore be taken that diseased apples are removed as soon
as possible.

The spraying of trees bearing young fruit with copper car-

^ Southworth, Journal of Mycoloijy, vi. , p. 164.
-Halsted, Bulletin of the Torrey Club, 1893, p. 109.
Miissee, Gardener's Chronicle, Vol. xiv., 1893.

GLOEOSPORIUM. 483

l)onate or potassium sulphide solutions has good efiects on the
yield of the orchards. In vineyards under treatment for black-
rot or mildew, there is little chance of the ripe-rot fungus
appearing.

It is probable that the species known as Gl. phomoides
Sacc. on tomato, Gl. 2n2yeratum E. et E. on peppers {Capsicum
anmawi), and Gl. mdangeac E. et Hals, on the egg-plant, are
identical with Gl. fructigenum. At least they very much
resemble each other, even on their widely ditiering substrata,
and cross-infections have Iteen carried out.

Gl. venetum Speg, {Gl. nccatur Ell. et Ev.) Anthracnose of
raspberry and blackberry.^ This disease appears on both canes
and leaves. On the young shoots it produces small reddish-
purple spots during early summer ; as the season advances the
spots run together into irregular blotches of more or less
greyish colour with a dark purple margin. The ripening fruit
remains small and shrivels up. Leaves may also bear spots,
but they more frequently remain smaller and have an unhealthy
look. The conidia are at first enveloped in a thin covering,
which becomes gelatinous when wet, so that they escape. The
mycelium is believed to perennate in stems or decayed remains,
and so to carry the parasite from season to season. Owing
to the delicate nature of raspberry foliage, fungicides must be
used with great care. Dilute Bordeaux mixture is said to be
safe and beneficial. The burning of diseased canes should
certainly be carried out each autumn.

Gl. ribis (Lib.). This attacks currant bushes throughout
Europe and America in much the same way as Gl. venetum.
The leaves wither and fall, so that the fruit-crop suffers.
(Britain.)

Gl. amygdalinum Brizi.- This has recently been described
as destructive to almond cultivation in Italy. The mycelium
inhabits twigs and fruits, and gives off tufts of conidiophores
bearing conidia ; as a result, wounds are produced in the
epidermis and stunting of the host-tissues takes place.

Gl. rosae Hals, is described as injurious to rose-culture in
America. It may be identical with some of the species of
Gloeosporium already mentioned as frequenting Eosaceae.

^ U.S. America Dept. of Agriculture, Bepoi't for 1889, contains a good account.
-Brizi, Zeitsch. f. Pjlanzenkrankheiten, 1896, p. 65,

484 FUNGI IMPKUFECTI.

Gl. ampelophagum (Pass.)^ l^lack-rot of tlie vine. This
disease is very injurious and has a wide distribution in Europe.
It is known under many names such as " Pock, Brand, Eost,
Jausch, l)russone, and Nebbia nera," thouf^di probably these
names include several distinct diseases. The identity of this
Gloeosporium is somewhat uncertain, and it may really be
identical with Plioma ampclinvm (p. 467). Rathay ascribes the
black rot to Bphacdoiiia {Phoma) o.mpelinvm, while Thiimen
regards Gloeosporium as the cause. Briosi and Cavara consider
the two species of fungi as distinct. Thiimen says that the
patches of Gloeosporium are for a considerable time disc-like
and of a light-grey rose colour ; those of Phoma, on the other
hand, are always depressed and brown. Piithay, however, de-
scribes the spots of Phoma as at first dark brown, and later
ashy grey with a brown margin.

The spots appear on green parts of the vines during April
and May. Those on the leaves frequently fall out, leaving
holes. On the grapes the spots are smaller and produce a
brown coloration extending deep into the fruit. The conidia
are small, hyaline, oval, and unicellular ; they are abjointed
from very short conidiophores arranged in little clusters. The
conidial patches rupture the host-epidermis, and the conidia are
liberated.

Thiimen suggests that the soil of vineyards should l)e kept
well cleaned, and that the stake mode of culture be used in pre-
ference to an overhead trellis ; he also recommends the washing
of all parts of suspected vines during winter with 10 to 15
per cent, solution of sulphate of iron. This treatment is said
to have been very beneficial in keeping many vineyards quite
healthy and free from fungi.

Gl. nervisequium." This parasite occurs on species of Platamcs
in Europe and America. Brown spots appear on the leaves,
especially on the veins ; these as they extend cause sudden
withering and fall of the leaves. Pustules containing a stroma
develop on the spots, and unicellular, ovoid, hyaline conidia are
abjointed from club-shaped conidiophores.

^Thiimen, Die Pocken an Wein n. Ohst. 1885; Die Bekdinpfunrj d. Pilzhravk-
heiten, 1886; De Bary, Annahn d. Oenologie., iv. ; Viala, Zes maladien de la Vigne ;
Briosi e Cavara, Funghi parasit., iii. ; E. Eathay, " Der Black-Rot," 1891.

^ U.S. America Department of Vegetahle Pathohr/y, Report for 1888, gives a
general account of this disease.

GLOEOSPORIUM. 485

Several fungi of very near relationship, if not actually identical,
occur on Platanus} All cause considerable disfiguration of the
foliage, so that a systematic destruction of all young diseased
branches is strongly recommended.

Gl. cingulatum Atks."-^ This is the cause of Anthracnose on
Privet {Lignstrum vulfjarc) in the United States. The following
is Atkinson's diagnosis : " Affected areas light brown, either
oblong on one side of the stem or completely girding it. Acer-
vuli 100 to 150 in diameter, rupturing tlie epidermis, in age
black from the dark stroma lying in the base or extending
irregularly up the sides, frequently forming a pseudopycnidium.
Basidia numerous, crowded, simple, hyaline, or when very old
perhaps faintly fuliginous. Spores oblong, or elliptical, straight
or little curved, usually pointed at the base. From pustules
on the stem they measure 10-20 by 5-7 ; in artificial cultures
they are frequently much larger, but when crowded in the media,
or when the nutrient substances are nearly exhausted, they may
be considerably smaller. On stems of Ligustrnm vnhjarc. '

" This is quite distinct from Gloeosporium ligustrinum Sacc."

Many species of Glocosjwrmm frequent broad-leaved trees
and cause more or less injury to the foliage.

Gl. rhododendri Br. et Cav. attacks the leaves of outdoor
cultivated rhododendrons in autumn, or indoor species in
winter. Large yellow spots marked with concentric zones
are formed, and bear the pycnidia ; finally the leaves dry up
and fall off.

Gl. violae B. et Br. attacks violets in Britain and U.S.
America.

Gl. vanillae Cke. et Mass. {Calospora vaniUae Massee.^)
This causes a dangerous disease on Vanilla 'planifolia and other
Orchideae in Mauritius and other parts of the tropics. Death
is brought about by the Gloeosporiwin (Hainsca) form of the
fungus, the higher reproductive organs only appearing when the
leaves are killed.

Other species are known, but their economic importance is not
great.

^ V. Tavel, Bofaii. Zeitumj, 1886 ; Leclerc du Sablon, Revue i/en. de Botaniqne,
1892.

-Atkinson, "A New Anthracnose of the Privet," Cornell Unir. Af/)Hc. Exper.
Station Bulletin, No. 49, 1892.

■'Massee, Ktio Bulletin, 1892, p. 111.

486 FUN(;i IMPKUFECTI.

Myxosporium.

Conidiii ovoid, hyaline, and al)j(jinted from rod-shuped basidia
situated in cavities of the cortical tissues of arboreous plants ;
a true pycnidiuni is not formed, and the reproductive mycelium is
only covered oN'cr by the epidermal layers of the host.

Myxosporium devastans IJostr.^ is said to attack and kill
young twigs of Bctida verrucosa. The conidial patches aie
developed in the killed rind, and give oiT unicellular colourless
conidia.

M. carneum Lil). is ]);irasitic (in twigs of beech.

M. laneola Sacc. et Roum. causes deatli of oak-twig.s.

The otlier known species have as yet been observed only as saprophytes.

CoUetotrichum.

Conidial patches surrounded by setae ; characters very like
GhieoKporiinn.

CoUetotrichum Lindemuthianum (Sacc. et Magn.)." This
disease, first observed by Lindeuiuth in 1875, has assumed
great importance as a disease of the kidney bean (Fhascolus
vulgaris) both in Europe and America. Young pods are most
frequently attacked, but neither stems nor leaves are exempt.
The pods show brown depressed spots with a distinct margin.
The unicellular and oblong conidia are given off from short
conidiophores developed on the spots. Germination takes place
at once, the germ-tube forming an adhesion-disc on the host-
epidermis, and from this a hypha penetrates into the tissues
to develop into a brown mycelium. Frank obtained brown
spots and mycelium on young l)eans twenty-four hours after
infection.

C. Lagenarium (Pass.) {C. oUgoeliaetum Cav.). This parasite
is very injurious to seedlings of water melon {Cuaimis citridlus),
melon {C. Mdo), and the gourd {Ciicurhita Lagenaria). Leaves
and fruits may be attacked, but it is the cotyledons' and stems
of the seedling plants which most frequently fall a prey. Spots

^ Rostrup, Tidsakri/t f. Skovraesen, 1898.

-For the relationship of this with the following species, as well as their
synonomy, see Halstcd in Biilltfiii of Torrty Bofaniral Cliih, 1893, p. 24G.
Description, treatment, and bibliography l^y Beach, " Bean-spot disease," Genera
A. Y. Ex2)er. Sfarion BuUditi, N(.. 48.

COLLETOTRICHUM.

487

appear on the leaves, and depressions on the stem, sometimes
extending so far round that the whole shoot dries up. The
conidial patches are very much the same on the different hosts,
and consist of short conidiophores from
which oval, unicellular, hyaline conidia
are abjointed.

0. lycopersici Chest, is the cause of
a spot-disease orx the fruit of tomato in
the United States.

C. spinaciae Ell. et. Hals, causes a
destructive disease on cultivated spinach.

C. malvarum Br. et Casp. {C. althaea e
Southw.^) produces a disease of cultivated
hollyhock. It is most injurious to the
seedling plants, and has caused great
loss in America and Sweden. The fungus
may attack any organ, and produces spots
which enlarge so rapidly that death of the
host may result.

C. gossypii Southw.- Anthracnose of
Cotton. This disease, although it may
be found on stems and leaves, is most
frequent and most conspicuous on the
fruits or " bolls " of the cotton-plant.
The first signs are tiny depressed spois
of a reddish-brown colour, and as these
enlarge they cause blackening of neigh-
bouring tissue. When the spores are developed the spots
become dirty grey, or perhaps pinkish if the spores are present
in large numbers. Fruit attacked in this way does not mature
well, and the yield of cotton is greatly prejudiced. Atkinson
found the cotyledons easy to infect with the disease. The
spores are oblong and tapering, with a shallow constriction in
the middle ; they are borne either on short colourless basidiu
or on long, olive-coloured, septate setae, both kinds of conidio-
phore being produced in acervuli or patches.

C. adustum Ell. is the cause of a leaf -spot on orange in Florida.

Fig. 208. — CoUetotrichum Lhxde-
rauthio.mnn on pod of Kidney
Bean. Enlarged pustule and
conidia.

iSouthworth, "A New Hollyhock Disease," Journal of Mycology, vi., 1890.
2 Southworth, Journal of Mycology, vi., 1890, p. 100.
Atkinson, Alabama Agric. Exptr. Station Bulletin, No. 41, 1892.

488

FUNGI IMPKRFECTI,

Faded spots appear on the leaves, becoming later greyish brown dotted
over with minute black points, the conidial patches.'

C. ampelinum (!av. causes little dry spots on the leaves of vine, fre-
quently ill such numbers that the whole leaf dries up.

C. kentiae Hals, attacks palm-seedlings so
tiiat their leaves do not unfold.

C. cyclameneae Hals, occurs on Cyclamen.

Scoleco-Allaxtosporae.

Cylindrosporium.

The white and shining conidial
cushions are embedded in the host-
plants. The conidia are filamentous,
frequently somewhat twisted.

Cylindrosporium Tubeufianum Alles-
cher. This attacks the living green fruit
of the bird-cheny, and causes the forma-
tion of brown spots from which pustules
lircak out ; the premature dropping of
diseased fruits follows. In the locality
where I observed this disease, numerous
trees were attacked and most of the fruii
on each was badly diseased. The my-
celium spreads through epicarp and
mesocarp, but does not penetrate into
the endocarp, so that the development
of the embryo is not directly interfered
with. The conidia originate in pycnidial
cavities without any special peridiuni ;
their shape is given in the annexed
diagnosis.^ The pycnidial cavities arise
under the epidermis which is afterwards ruptured and with the
cells underlying it becomes brown and dead.

^ This note is taken from Underwood, Journal of Myroloriy, vii.,but no
mention is made of it in the later paper by Webber and Swingle ("Diseases of
Citrous Fruits in Florida," U.S.A. Dept. of A[)rirul(nre Bulletin, 8, I896;i. (Edit.)

- AUescher gives the following diagnosis of this species : Pustulis primum
convpxis, epicarpio tectit, dein applanati'< ficutiformiliuxre, epicarpio rupto cinct.i'<,
.mbcircularihufi, saepe rae><pitosi.'i i-ef covfluentihun, luteo-brunneoUt, suhfurfuraceh:
acervuli.i, nu'uu/is, iunatis, erumpentihuf! ; conidik filiformihns, rnrrads rej flex-
uosU multiyuttulatis, hyalinis 40-60 = 2-3/;t. Hab. in fnictihun immaturis Pruni
Padi, quos necat.

Fl(i. 299. — Cylindrosporium
Tubi ujianum on fruits of Prunus
Padus. The unsh.aded parts re-
present parts still green and
living, although bearing pustules
here and there ; the remaining
parts are completely beset by
pustules, so that the cells are
killed and brown. 1 natural
size. (v. Tubeuf del.)

CYLINDROSPORIUM.

489

As yet the disease has beeu observed in quantity only in
the neighbourhood of Oberammergau (Upper Bavaria).

C. padi Karst. Leaf-blight of cherry and plum. This dis-
ease is most destructive in the nursery, causing premature
defoliation of young trees ; it may also cause severe injury to
fruit-bearing trees. The leaves become spotted and perforated
by holes caused by the falling out of withered spots. Spraying
with dilute Bordeaux mixture early in the season is said to
have good effects.^

Fig. 300.— a fruit from Fig. 299 (enlarged). A, Two pustules still further
enlarged. B, Pustules before and after rupture of the epidermis. C, Isolated
conidia. (v. Tubeuf del.)

C. filipendulae Tliiini. occurs on leaves of Spiraea Filipendula.

C. ficariae Berk. On leaves of Ranunculus Ficaria. (Britain.)

C. viridis E. et E., and C. minus E. et E. On leaves of Fraxinus ciridis
in the United States.

C. cercosporoides E. et E. On living leaves of tulip-tree.

C. saccharinum E. et E. On living leaves of Acer saccharinum in the
United States.

Cryptosporium.

Conidial cushions shaped like pycnidia. Conidia rod-like or
spindle-shaped.

Cryptosporium leptostromiforme Kiihn.- This fungus forms
rows of l.)lack stromata on the stems of lupines; in the stromata
are formed pycnidia-like cavities with several neck-like openings,
and in them conidia are given off from conidiophores. The
conidia are rods with rounded ends 7-8"5ya long and about
2^ broad : they emerge from the necks of the cavities as
long tendril-like chains, and may be continuou.sly given off

^ Fairchild [Journal of Mycoloi/y, vii., p. 249) gives results of remedial
treatment.

-J. Kiihn, Berirhte d. lancUnrth. InM., Halle, 1880.
Fischer, " Crypto-^poriu?n lei^tostromiformt." Breslau, 1893.

490 FUNGI IMrERFECTI.

throughout tlie whole summer. Fischer has proved experi-
mentally that the conidia germinate easily in water, that the
germ-tubes penetrate into living lupines, and produce a mycelium
which spreads through stems and leaves to develop stromata on
all the organs of the plant. The formation of l)oth pycnidia and
conidia goes on throughout the autumn and following spring on
dead plants, the fungus being capable of living as a saprophyte
and of hibernating. The disease may occur with great severity.
Fischer describes cases where more than the half of the plants in
a field were attacked and died before flowering or soon after.
There is thus a loss not only in lupine seed, but also in the good
effects which the crop has as a " green manure."

Fischer gives the following measures for keeping this pest
in check : " Where the fungus has obtained a footing, lupines
should not be planted till at least tlie year after next, and then
only as a catch-crop on stul)ble ; it would be still safer to keep
lupines off the land till the third or fourth year. After lupines
as a catch-crop, they may safely be sown again in spring as a
seed crop, after the lapse of a clear year. No lupines should
be cultivated near diseased fields. Instead of ploughing-in a
catch-crop of lupines directly, it should be dried and used as
litter for cattle, because the excrement has been found to kill
the fungus : the lupines after lying over winter in the manure-
heap could then be used as manure in spring. Similarly when
the lupines have been grown for seed, they should be closely
mowed down so that little stubble is left ; the straw may then
be used for litter."

This fungus has not as yet been observed on plants other than
lupines.

DiDYMOSI'ORAE.

Didymosporium.

Conidia brown, oval or spindle-shaped, bicellular, and not
produced in chains.

Didymosporium salicinum Vnill. Yuillemin reports this as
very destructive to the Osier cultivation in Bourgogne.

Marsonia.

Conidia transparent, two-celled, and not produced in chains.
The species live on leaves.

MARSONIA. 491

Marsonia juglandis (Lib.) produces on leaves of Juglans little
greyish yellow spots with brown margins ; thereon stromata are
formed, which rupture the epidermis and liberate the large sickle-
shaped conidia. (Britain.)

M. populi (Lib.). On leaves of species of Populus in Europe and Britain.

M. potentillae (Desm.). On species of Potentilla. (Britain.)

M. campanulae Bres. et All. On Campanula latifolia.

The following are North Ameincan species :

M. toxicodendri (Ell. et Mart.). On Rhus Toxicodendron.

M. quercus Peck. On Quercus ilicifolia.

Phragmosporae.

Coryneum.

The conidial patches are black and disc-like, and rupture the
host-epidermis. The conidia are oblong or spindle-shaped,
yellowish, and pluriseptate ; they are abjointed from short
conidiophores.

Coryneum Beyerinkii Oud.^ This is stated by Beyerink to
1)6 the cause of a " gum-tiux " of cherry and allied species of
Rosaceae. It is the conidial form of AscosjMra (see p. 211).

C. camelliae Mass.'^ occurs on living Camellia leaves at Kew.
(Britain.)

Pestalozzia.

Conidia spindle-shaped, with two or more brown median cells
and hyaline terminal cells, the one at the free end carrying
several ciliate processes.

Pestalozzia Hartigii Tub.^ The external effects of this
disease have been long known, although the fungus causing it
has only been recently detected. It attacks young plants of
various trees and shrubs. The symptoms are yellow discoloration
of the foliage, and constriction of the stem just above the level
of the soil, followed by death of the whole plant. At the
constriction of the stem the rind gradually dries up, whereas
neighbouring portions continue to grow in thickness till finally
the bark is ruptured (Fig. 302). In the living part of the

^ Oudemans, Bediciijia, 1883.
2 Cooke, Grevillea, xx., p. 8, 1891.

^v. Tubeiif, Beitriifje zur Kenntniss d. Bmtmkrankheifen, 1888; and ForsfUrh-
naturiviss. Zeltschrift, 1892.

Fig. 301.— Pestalozzia UaHigii. Young Spruce Fio. ZQZ.—Peslalozzia Hartigii. Conidia and coni-

showing constriction just over the surface of the diophores on part of stroma. (After v. Tnbeuf.)

soil. (After v. Tubeuf.)

PESTALOZZIA.

493

rind of young plants of spruce and silver fir, I succeeded in
finding near the place of constriction, a delicate mycelial stroma
enclosing some cavities (pseudopycnidia). Conidia were formed
inside these cavities and emerged to the exterior. They belong to
the genus Pcstalozzia, and have two brown median cells, a trans-
parent stalk-cell to which the long stalk is attached, and a
transparent terminal cell carrying two or three transparent thread-
like appendages (Fig. 303). Germination resvdts in the emission
of a strong germ-tube from one of the three lower cells. If at
any time the conidia dry up, the two clear transparent cells

Fig. 304. — Pestalo-zia juncrea on Chamaecvparis MenzUsii. At the places
marked X cambium and rind have been killed, so that growth in thickness no
longer takes place ; the higher parts, however, have continued to thicken, but
are gradually dj-ing. (v. Tubeuf phot.)

collapse and the appendages easily fall off, so that on material
of this kind the conidia are only two-celled and brown. The
mycelium after cultivation in nutritive gelatine soon produces
conidia.

This fungus was found by Eostrup on Ijeech, producing much
the same effects as just described. On this host it has been
found very destructive in young naturally regenerated forest,
the loss in Bavaria and Wurtemburg within very recent years
having been estimated at 30 per cent. It also occurs on ash,
sycamore, and other trees.

P. funerea Desm. (Britain and U.S. America). The spores of

494 FUNGI IMFERFECTI.

this fungus were found by Boehm^ on diseased cypress trees, and
although investigations are not yet complete, it is believed that
this Pestalozzia is the cause of a well-known disease on cypress.
The symptoms on Chamaccypai'is Mcnziesii are local constriction
of stems and branches, and death of portions beyond. The rind
and cambium of constricted places are killed, the bark becomes
split, and the wood dries up. P. funerea is a well-known sapro-
phyte on twigs and needles of Ciipressus, JuniiJcrus, and other
Conifers ; its occurrence as a parasite has l)een suggested several
times.

P. gongrogena Temme" is said to cause the canker of willow.
In diseased willows Temme found an intercellular and an
intracellular mycelium with pycnidia and conidia of Pestalozzia,
but other pycnidia of unknown affinity were also present.

P. insidiens Zab. On bark of Ulmns americana. (U.S.
America.)

P. phoenicis Grev. causes a disease on indoor cultivated palms.

The following are some of the more important forms frequenting
living leaves :

p. Guepini Desm.^ (U.S. America). The conidia of this species
are found on large spots with dark margins on living leaves of
Camellia japoniea, Magnolia, Citrus, Phododcndron, and other
plants. Spore-patches appear on the epidermis, and give off
conidia embedded in a mucilaginous slime. The conidia have
three dark median and two hyaline terminal cells, the distal one
bearing the characteristic appendages. The leaves are permeated
with mycelium and fall prematurely.

P. inquinans C. et Hark. On Bucali/ptus in California.

P. stictica B. et C. On Flatanus occidentalis and Tilia in United States.

P. concentrica B. et Br. On leaves of Crataegus, Pyrus, Castanea, and
Quercus in North America.

P. suffocata E. et E., and P. discosioides E. et E. On cnltivated and
wild rose shrubs in America.

Pestalozzina.

Conidia similar to those of Pestalozzia, but all the cells
hyaline.

^ Zeitschri/t /. Foist, u. J ayd-wesen, 1894, p. 63.

^Thiel's landwirth. Jahrbuch, 1887; and Ber. d. deutsch. hotan. Ges., 1890.
'^ Annal. des Science natur., Ser. ii.. Vol. xiii., 1840; Briosi et Cavara, Funghi
parasit., vi.

PESTALOZZINA.

495

Pestalozzina Soraueriana Sacc.^ occurs on foxtail grass
{Alopecurus pratcnds). The conidial tufts develop on spots which
appear on the gradually withering leaves. The bristle-appendages
on the terminal cell of the conidia are lateral, only one being
terminal. This disease was first observed by Weinzierl at Vienna,

Fig. 305. — Sfptogloeum Bartif/kmum on Acer carivptstre. The dead twigs exhibit
black points and lines— the pycnidia of the parasite, (v. Tubeuf phot.)

and has not as yet l)een found out of that neighbourhood ; it
attacks the pure-culture seed-beds only.

Septogloeum.

Like Glocospormm, except that it has pluricellular conidia.
Septogloeum Hartigianum Sacc." Twigs of the common
maple {Acer campestre) are subject to a disease, which exhibits

^Sorauer, Zeitschrift f. PJlanzenkrankheiten, 1894, p. 213.
-R. Hartig, Forstlich-naturwiss. Zeitschrift, 1892, p. 289.

496 FUKGI IMPERFECTI.

itself in the drying-up of young twigs before their buds open
in spring. The older branches, however, assume their normal
foliage. Examination of diseased twigs reveals the mycelium
of a parasitic fungus living both inside and between the
cells of rind and wood. Conidial patches break through
the host's epidermis about May as long greyish-green lines.
The conidia are hyaline, three-celled, and cylindrical with
rounded ends ; the conidiophores are short thick rods. In May
and June the spores are capable of infecting new hosts, and
germinate in a few hours. Infection of twigs takes place in
summer, and the mycelium spreads through the first-year
shoots, without, however, giving any external indication of its
presence till the following spring, when the twigs dry up as
already described.

S. ulmi (Fr.) may be a form of Phyllachora ulmi. The
mycelium lives in parenchymatous cells, and causes the formation
of brownish-yellow spots on leaves of the elm. The conidial
patches form tiny points on the lower surface of the leaf; they
consist of pycnidia-like structures without a peridium, arising
from a stroma developed under the epidermis. The conidia are
spindle-shaped and pluricellular.

S. mori (Lev.) is stated by Briosi and Cavara to produce yellow
spots with brown margins on the leaves of Moms alba and M. nigra.
Death and premature defoliation of the host then take place.
The conidial patches develop under the epidermis, and rupture
it as the conidiophores emerge ; they have no real peridium,
hence the fungus cannot belong to the group Phleospora, as
Saccardo supposed. The conidia are long, cylindrical or fila-
mentous, and pluricellular.

Amongst the more important North American species are :

S. profusum (E. et E.). On living leaves of Corylus
amcricana.

S. fraxini Hark. On Fraxinus Orcgana.

S. apocyni Peck. On Apocymim cannahinum.

III. HYPHOMYCETES.

Conidia produced neither in pycnidia as in Sphaeropsideae,
nor from a special stroma as in Melanconideae, but free on
conidiophores given off from the mycelium.

HYPHOMYCETES. 497

The group is subdivided into the families of the Mucedineae,
Dematieae, Stilbeae, and Tuhercularicae}

I. FAM. MUCEDINEAE.
1. Sect. Amerosporae.
1. Suhsect. Micronemeae.

Oospora.

Conidia, transparent or only slightly coloured, globose or
ovoid, non-septate, and produced in regular chains from simple
short conidiophores ; they thus resemble the genus TorvXa in the
Dcraaticac.

Oospora scabies Thaxt.^ is said to cause the well-known
scab or scurf on beet and potato. This consists in portions of
the surface of the subterranean tubers swelling out as rough
brown excrescences. Other authors ascribe this disease to
bacteria.

Microstroma.

Conidia unicellular, transparent, oval, and shortly stalked.

Microstroma album (Desm.). This, although common on
living leaves of several species of Qiiercus, is not a serious
disease. The conidial patches on the under side of the leaves
are white and very thin. (Britain.)

M. juglandis (Bereng.) frequents the leaves of Juglans regict
and J. cinerca in Europe and Xorth America.

Monilia.

Conidia oval or spindle-shaped, and produced in chains from
branched conidiophores.

Monilia fructigena Pers. (Britain and U.S. America.) This
is the cause of certain widespread diseases — the brown-rot of
cherry and plum, the peach-rot, and a rot on apples and pears.
It has. been the subject of many papers since Thiimen first
described it in 1879.^ All parts of the host are attacked, and

^ This is the ai'rangement followed by Massee, "British Fungus Floi-a," Vol.
III.; there the characters of the various sub-divisions may be obtained. (Edit.)

'^Thaxter, Connecticut Agric. Exper. Station, Report, 1890.

^ Amongst the more important descriptions are : Thiimen, Fu7igi Pomicola,
1879; Smith (Worth. G.), Gardener's Chronicle, 1885, p. 52; Arthur, New York
Agric. Exper. Station, iv., 1885.

2i

498

FUNGI IMPERFECTI.

exhibit reddish or yellow spots ; therein the mycelium spreads
rapidly and gives off tufts of conidiophores which rupture the
epidermis. The conidiophores are septate, branched, and give
off chains of unicellular oval conidia. ^Meanwhile the affected
fruit becomes rotten and gradually shrivels up, it remains,
however, hanging on the tree throughout the winter. During

Fig. 306. — Monilia fructigena. A, Apple showing the grey conidial patches as
more or less concentric lines. B, Young Peach, shrivelled up in consequence of
attack, (v. Tubeuf del.)

next spring, when the fruit is again moist, further conidia are
given off. Infection takes place by wounds or even through
the epidermis of young leaves and blossoms. The conidia have

Fio. 307. — Monilia fructigena. Branched conidiophore with chains of conidia.
«, Branched hypha of Monitia in the tissue of an Apple, (v. Tubeuf del.)

been found to retain their vitality for two years. Smith ^
found that twigs were also affected by the disease, so that a
gummy degeneration took place in the soft bast and cambium.
As remedial measures, the gathering of all diseased fruit left
hanging over winter is strongly recommended. This, as well
as other diseased parts, should be burned as soon as possible.

^ Smith (Erwin), Journal of Mycology, vii., p. 36.

MONILIA. -499

Washing of stems with a solution of iron sulphate in spring
hefore the buds unfold is suggested, also spraying of young
foliage with dilute Bordeaux mixture.

Oidium.

Mycelium epiphytic on living plants. Conidia unicellular
and barrel-shaped, produced in chains on erect conidiophores.
Many have already been proved to be conidial forms of
Erysipheae.

Oidium erysiphoides Fr. frequents living leaves of hop,
clover, cucumber, etc., and is probably the conidia of species
of Erysiphe on these hosts. (Britain and U.S. America.)

0. Tuckeri Berk. On leaves and berries of the vine (see
Uncinula, p. 176).

0. leucogonium Desm. On roses; probably the conidial form
of Sphaerofltcca pannosa (see p. 172).

0. farinosum Cooke. On living leaves of apple-trees.
{Britain.)

0. chrysanthemi Eabh. On leaves of cultivated chrysan-
themum. (Britain.)

0. aceris Piabach. On leaves of Acer FseudoplcUanus. It is
probably the conidial stage of Uncinula bicornis. (Britain.)

0. mespilinum Thiim. On leaves of medlar. (Britain.)

0. destruens Peck. On Amclanchier canadensis and Prunvs
scrotina in America.

0. tabaci Thiim. On leaves of tobacco.

0. monilioides Link, probably the conidial stage of Erysiphe
(jraminis, occurs on living grasses over the whole world (see p. 175).

2. Sub-sect. Macronemeae.

Botrytis.

Mycelium grey. Conidia more or less spherical, and pro-
duced in aggregations on the ends of branched conidiophores.
Many of the species are saprophytes, others are parasitic on
plants or insects, and others form sclerotia ; the latter have
already been considered under Sclerotinia (see p. 267). The
following are known to be parasitic on plants :

Botrytis cinerea Pers. This enemy of many plants has already
been noticed as Sclerotinia Fuckcliana ; so also B. Douglasii Tubeuf.

500 FUNGI IMPERFECTI.

B. galanthina Sacc. occurs on the bulbs of Galanthus nivalis
in Ih-itain.

B. parasitica Cav. produces sclerotia and conidia on Tulipa
Gcsiicria/Ki in Italy {Sdcrotium tulipar).

B. vulgaris ¥r} This is a very common species, and includes
several well-marked varieties. It is said to be parasitic on
cultivated lettuce causing a " leaf-rot."

B. fascicularis Sacc. is reputed to be the cause of a " fruit-
mould " on the egg-plant (Solanum Mdongena) in the United
States.

A Botrytis is figured by Atkinson- as frequent on diseased
carnation-plants.

Ovularia.

Conidiophores simple except for tooth-like projections near
the apex on which the conidia are developed. Conidia uni-
cellular, colourless, solitary, rarely in chains.

" Closely allied to Ramnlaria, but distinguished by the one-
celled conidia " (IMassee).

Ovularia pulchella (Ces.). Briosi and Cavara distinguish this
as a disease of Loliiim italicum in Italy. The leaves become
black-spotted and permeated with an intercellular mycelium,
from which arise the erect, branched, septate conidiophores. The
more vigorous conidial patches have a delicate rose colour.

0. necans Pass, produces large spots on the foliage of quince
and medlar, so that the leaves gradually wither and dry up.
Conidia appear as a white powder on the dead remains. This
fungus is recorded from both Italy and France.

The following are British species occurring on leaves ; several
of them, however, are placed by Saccardo under Eamularia :

Ovularia lychnicola (Cke.) Mass. On Lychnis diurna.

O. senecionis (Sacc). On Senecio vulgaris.

O. lactea (Desm.). On species of Viola.

O. armoraciae (Fuck.). On cultivated horse-radish. It is reported as
somewhat destructive in the United States.

0. interstitialis (B. et Br.). On nnder surface of leaves of primrose^
forming yellow spots in the angles of the veins.

O. primulana Thuui. On leaves of Prinnda.

O. cochieariae (Cke.). On Cochlearia officinalis.

1 Wehmer on species of Botrytis, Zeitschrift f. Pflanzenhrankhntev , 1894.
2 Atkinson, "Carnation Diseases," at Amer. Carnation Society, 1893.

OVULARIA. 501

O. alnicola (Cke.). On Abuts glutinosa.

O. scelerata (Cke.). On Ranuncuhis sceleratus.

O. rosea (Fuck.) produces irregular brown spots on the leaves of
various species of willow.

O. asperifolii (Sacc). On Symphytiini ojficinalis.

O. veronicae (Fuck.). On spots on leaves of Veronica Chamaedrijs, etc.

O. lamii (Fuck.). On Lamium.

O. syringae (Berk.). On Syringa.

O. sphaeroidea Sacc. causes spots on leaves of Lotus.

O. carneola Sacc. On spots on leaves of Scrophularia nodosa.

O. bistortae (Fuck.). On spots on leaves of Polygonum Bistorta.

O. obliqua (Cke.). On leaves of Rumex.

2. Sect. Didymosporae.

Didymaria.

Couidia two-celled, colourless, and produced singly at the
extremity of simple erect conidiophores.

Didymaria prunicola Cav. Cavara states that this causes
raised roundish spots on the upper surface of leaves of plum ;
finally the leaves gradually dry up and fall off. Slender two-
celled conidiophores are produced, and give off' each a two-celled
obovoid conidium.

D. Ungeri Cord. On living leaves of Ranunculus repens. (Britain.)

D. astragali (Ell. et HoL). Found on leaves of Astragalus canadensis.

D. spissa Hark. On leaves of Solidago occidentalis ; both species in
North America.

Bostrichonema.

Conidiophores erect, spirally twisted, unhranched, and non-
septate. Conidia elliptic or oblong, two-celled, and hyaline.

Bostrichonema alpestre Ces. On living leaves of Polygonum
viviparam and P. Bistorta. (Britain.)

B. modestum (B. et B. White). On leaves of Alchcmilla
alpina. (Britain.)

3. Sect. Phragmosporae.

Ramularia.

Conidiophores emerging in tufts from the stomata ; they give
off" a terminal conidium, then bend over and produce a lateral
conidium, and so on they branch in a sympodial manner, pro-

502 FUNGI IMPEKFECTI.

duciiig conidia at the end of each brancli. Conidia septate
oval or cylindrical, and light-coloured.

" The parasitic habit, simple or sparingly branched hyphae,
denticulate and bearing the septate conidia at the tips, charac-
terize the genus, which differs from Orvlaria only in the
septate conidia " (Massee).

Ramularia cinarae Sacc. is said by Prillieux^ to have caused
great destruetitju in the cultivation of artichokes. The leaves
became spotted and died, so that no flower-heads were produced.

The followinii are British species :

Ramularia hellebori Fuck. On leaves of Hellehorus foetidus and H.
viridis.

R. epilobii (Schii.). On leaves of EpUohium.

R. ulmariae Cooke. On leaves of Spiraea Ulmaria. (U.S. America.)

R. gferanii Fuck. On under surface of leaves of various species of
Geraniiim.

R. lampsanae (Desni.). On Lampsana and Hypochoeris.

R. pruinosa Speg. On Senecio jacohea.

R. plantaginis El. et Mart. On leaves of Plantago major. (U.S. Am.)

R. variabilis Fuck. On leaves of Digitalis tiiuWerhascum. (U.S.America.)

R. calcea Ces. On leaves of Glechoma hederacea.

R. urticae Ces. On leaves of species of Urtica. (U.S. America.)

R. pratensis Sacc. On Rume.r Aretosa.

R. rufibasis (B. et Br.). On Mijrica Gale.

Some of the more important North American .species are :
Ramularia rufomaculans Peck. On the buckwheat (^Fagopyrum esculen-
turn), it has proved a somewhat injurious fungus.

R. albomaculata Peck. On leaves of Carya americana.

R. viburni E. et E. On leaves of Viburnum Lentago.

R. celtidis E. et K. On leaves Celtvi occidentalis.

R. desmodii Cnoke. On leaves of various species of Desriwdium.

R. brunnea Peck. On living Tussilago farfam.

R. areola Atks.- This causes spots on the foliage of cotton.
"Spots amphigenous, pale at first, becoming darker in age;
irregular in shape, limited by the veins of the leaf, conidia in
profusion giving a frosted appearance to the spots. Conidio-
phores fasciculate, in small clusters distributed over the spots.
Conidia oblong, usually abruptly pointed at the ends" (Atkinson).

R. Goeldiana Sacc. is said to kill leaves and twigs of Coffea
arahica in llrazil.

^"Maladie d. Artichauts," Bulletin de la soc. mycolog. de France, 1892.
2 Atkinson, Botanical, Gazette, xv. , 1890, p. 166.

PIRICULARIA.

503

Piricularia.

Conidia grey, pluricellular, somewhat pear-shaped, and pro-
duced from the apex of simple erect conidiophores.

Piricularia oryzae Br. et Cav. This species is described
by Briosi and Cavara as causing a disease of rice in Northern
Italy. The plants become spotted and reddish-brown in summer,
finally withering. The conidiophores arise on the spots on the
lower surface of the leaf, and bear light-grey three-celled

Fig. 308. — MoMi<josporiv.in album, (v. Tubeiif del.)

conidia. Diseased plants may be found bearing this fungus
only, frequently however it is in company with other fungi.

Cercosporella.

Conidia hyaline, similar to those of Ccrcospora, and produced
from simple or branched hyaline conidiophores.

Cercosporella persica Sacc. is parasitic on living leaves of
peach. In America it has been known .since 1890, and receives
the name of " frosty mildew." It causes yellow spots on the
lower surface of the leaf.

C. pastinacae Karst. occurs on living leaves of cultivated
parsnip.

504

FUNGI IMPKRFECTI.

Mastigosporium.

Conidia liyaline and lour-celled, frequently bristled.

Mastigosporium album Kiess. produces oblong dark spots
with light margins on leaves of living grass. The conidia
are produced on the margins of the spots (Fig. 308).

Fusoma.

Similar to Fusarium, but the mycelium is loose and not
aggregated into a tuft. Conidia spindle-shaped and septate.

Fig. 300. — Fusoma paranUicum. Dis-
eased Pine-seedlings, with, a, root killed ;
b, hypocotyl killed; c, first leaves and
plunmle killed. (After R. Hartig.)

Fig. 310. — Epidermis of a Pine-seedling
with a stoma. Some h3^ihae of Fusoma
have produced partial dissolution of cell-
walls. (After R. Hartig.)

Fig. 311. — Fusomo. parcuUicuui. Coni-
dia— immature, mature, and germinat-
ing. (After R. Hartig.)

Fusoma parasiticum Tub.^ is the cause of a disease of seed-
lings, particularly those of Conifers. The first symptoms are
dark patches on the seedlings, followed by their collapse. There-

' K. Hartig, Forstlich-naturtciss. Zeit-ichri/t, 1S93, p. 432.

FUSOMA. 505

after in moist weather or under artificial cultivation, a
light-grey mycelium appears bearing numerous slightly curved,
tapering, pluriseptate conidia (Fig. 311). In Bavaria and
Baden this parasite has caused great loss in the seed-beds of
conifers.

F. inaequale Hoyer. On living leaves of Tanuxtcum officinale.

Septocylindrium.

Conidia cylindrical, hyaline or pale-coloured, with two or
more septa, and produced in chains.

Septocylindrium aromaticum Sacc. occurs on living Acurus
Calamus, killing leaves and even plants. The mycelium grows
intercellularly and produces spots. The conidiophores emerge
in tufts from stomata included in the spots, and give off' long
thread-like, pluriseptate, hyaline conidia.

2. FAM. DEMATIEAE.
1. Sect. Amerosporae.

1. Suhsect. Micronemeae.

Many of the genera of this subsection contain species found
on the living leaves of plants, but none of them are yet of
economic importance.

2. Sabsect. Macronemeae.

Hormodendron.

Mycelium grey, epiphytic, and creeping. Conidiophores erect,
branched, and septate. Conidia spherical or ovoid, unicellular,
and produced in chains.

Hormodendron hordei Br.^ This produces a characteristic
spotting of the haulms and leaves of barley, accompanied by a
stunting of the whole plant and poor development of the ears.
This is not a true parasite, but when it appears in quantity
it has considerable effect, attacking whole fields and causing
great injury. The spots and conidia are found also on wild
Hordeum murinum on the margins of roads and fields.

^ Bnilme in Zopf's Btitraqe ;. Physio/, it. MorphoL nied. Organimien, iv.,
1894.

606 FUNGI LMPERFECTI.

2. Sect. Didymosporae.

1. Suhsect. Mirroneiiieae.

Dicoccum.

Conidia oblong, two-celled, and arising from short simple
conidi(>]>lior('s. ^lycelium subcuticular.

Dicoccum (Marsonia) rosae (Bon.) causes brown spots on
living leaves of roses, and a premature leaf-cast takes place.
Little mycelial stromata develop between the epidermal cells
and thcar cuticle, and give off two-celled hyaline conidia.

D. uniseptatum B. et Br. forms dark patches on twigs of
Cleriiafi>i cifidha. (Britain.)

D. lathyrinum Ell. et Gall. On living leaves of Lathyrus
ochroleucua in America.

Cycloconium.

Mycelium subcuticular. Conidia one- to three-celled.

Cycloconium oleaginum Cast.^ When this fungus is present,
the leaves of the olive show roundish light-brown spots with
dark margins, then becoming discoloured, they roll up and drop
off. The mycelium grows in the walls of the epidermal cells,
branching dichotomously ; branches of the hyphae break out
through the cuticle as sac-like cells, which become the conidio-
phores. The conidia consist of one to three cells. Kruch
states that Crrcosiwra dadosporioides is often present along with
this disease of the olive, and may take some part in causing it.

Feglion states that this or an allied species occurs on leaves
of Quercus Ilex.

2. Suhsect. Macronemeae.

Passalora.

Conidia oblong or spindle-shaped, two-celled, and borne on the
apex of greenish pluriseptate conidiophores, arising from an
olive-green mycelium.

Passalora bacilligera >\I. et Fr. occurs on living leaves of
Alnus glutinosa. (Britain.)

P. microsperma Fuck. This frequently covers the whole
lower surface of the leaves of Alnus incana with little tufts of

1 Kruch, Bulletin soc. hot. ilal., 1S92.
Boyer, Jiecherches .sur les maladies de I'Olivier, Montpellier, 1892.

PASSALORA.

507

brown septate conidiophores, bearing long, two- celled, obovate
conidia.

Fusicladmm.

Mycelium greenish and sparingly septate. Conidiophores in
tufts, short, erect, and bearing terminal conidia. Conidia ovoid
or clavate, and one or two-celled.

The species are conidial forms of Vcnturia, and have already
been considered. Some of the better-known forms are :

Fusicladium dendriticum Wallr. (Britain and U.S. America).
This attacks the leaves, shoots, and fruits of the apple (see p. 218).

Fig. 312. — Ventv.rin (Fusicladium) dendriticum forming brown .spots on an
apple ; those still in the earlier stages have a radiate margin and bear conidia.
The enlarged section shows two rows of large-celled parenchyma of the apple,
covered bv a stroma of pseudoparenchyma bearing conidiophores and conidia.
(v. Tubeu'f del.)

F. pirinum (Lib.) (U.S. America). This is a cause of
" spotting " on leaves and fruits of the pear, also of species of
Crataegus and Amektnchia\ The conidial patclies are brownish
in colour. Peglion states that this parasite forms sclerotia in
the bark of twigs. It is probaljly a conidial form of Venturia.
ditricha var. 2^P'i-

F. cerasi (Kabh.) attacks the cherry orchards with such
virulence that the crop may be rendered quite unsaleable.

F. eriobotryae Cav.^ Cavara states that this attacks the

^ Cavara, RiviMa di Pafoloyia Vegetale, 1892.

508 FUNGI IMrEHFKCTI.

leaves of Mrspilus (Eriohot/\i/a) japonica causing theMi to become
spotted and to wither. The hyphae live in the epidermis,
and form a stroma from which conidia are given off.

F. tremulae Frank. Frank ^ gives this as the cause of a
disease (jf the aspen {Populvs tremula). The leaves turn
brown and fall, the shoots in consequence soon drying up.
Conidia are developed on the surface of dead leaves and ger-
minate on living leaves of aspen, producing a germ-tube which,
after forming an adhesion-disc, penetrates into the cavity of
the epidermal cells.

F. depressutn B. et Br. is found on living leaves of Angelica sylvestris.
(Britain and U.S. America.)

F. praecox Rabh. On living leaves of Trayopogon orientalis.

F. sorghi Pass. On living leaves of Sorghum halepense.

The following are North American species :

F. caryogenum Ell. et Langl. On leaves of Carya olivaeformis.

F. effusum Wint. On leaves of Carpimis araericana.

F. destruens Peck. On living Avena satioa.

F. fasciculatum C. et E. On leaves and stems of Euphorbia.

Scolecotrichum.

Mycelium greenish. Conidia oblong or oval, produced both
terminally and laterally on the conidiophores.

Scolecotrichum melophthorum (Prill, et Del.).- This pro-
duces a melon disease in France known l)y the name " Xuile."
It consists in the fruits and stems becoming spotted, the tissue
being completely destroyed.

Sc. graminis Fuck. Occurs on grasses, especially on the oat.
Pammel^ reports it as also injurious on barley du-ring 1891,
in some parts of the United States : the diseased leaves were
marked with ])rown or purplish brown spots.

Sc. fraxini Pass. On living leaves of Fnudnus cvcehior
and F. Ornus.

Cladosporium.

Mycelium greenish. Conidia globose or ovoid, one to four-
celled, and of variable form. The species are mostly sapro-
phytes on substrata of all kinds.

^ Ber. d. deutxch. hotan. Gesell, 1883, p. 29.
- Bxdletin de la soc mycolofj. de Fraiire, 1891.
■Jourjiai of Myrolofjy, vii., p. 96.

CLADO8P0RIUM. 509

Cladosporium herbarum (Pers.). This species is found every-
where on dead plant remains, but it is also common on livino'
leaves of many plants. The first suggestion that this form
might occur as a parasite came from Haberlandt ^ and Frank.-
It possesses a dirty-grey, thick, septate mycelium, which may
be colourless when young or growing inside a substratum ; it
applies itself closely to the surface of plants and even pene-
trates through the stomata or cell-walls into the tissues. The
conidiophores are erect, otherwise variable in form : they give
off conidia from the apex or from lateral processes. The
conidia are oval and contain a variable number of cells. Organs
of plants attacked show grey spots, and withered parts if they
are still alive.

The following are some of the papers describing Cladosporium
herhcvntm as, in certain circumstances, a parasite. Prillieux and
Delacroix,^ on apple-trees and raspberry-bushes ; Cavara,* on
raspberry, cycads, agave, and other plants ; Sorauer,"^ on peas.
Lopriore "" describes this fungus as the cause of a " black "
disease on ears of wheat ; the results of infection were however
somewhat variable.

Ptitzema Bos reports it as producing disease, and in some
cases death, in fields of oats. Kosmahl and Nobbe '' found
that seedlings of Pinus rigida blackened and died suddenly in
the beginning of May, apparently from the attacks of this
fungus. Janczewski" states that this Cladosjjorium is a conidial
form of Bpliaevdla Tv.lasnei, a new species of Ascomycete
established l;)y him.^

CI. elegans Peuz. This causes on the orange a disease or
" scab," which has been injurious both in Southern Europe and
the Southern States of America.^ It attacks chiefly wild orange

^ Friihliiig's landicirth. Zeitunr/, 1878.

^Die Krankheiten der Pflanzen, 2nd Edit., 1896, ii., p. 292.
'^Bulletin de la soc. mycolorj. de France, vii.
* Revue mycologique, 1891.
^ Handhuch d. Pflanzmih-ankheiten, 1886.

^ Berkhte d. deutsch. botan. Gesell, 1892 ; Landicirth. Jahrhwh, 1894.
^ Extraits du Bulletin de VAcademie des sci. de Cracovie, 1892, 1893, 1894.
* Schostakowitsch (Flora, 1895 (ergzbd.) distinguishes Cladosporiuvi irom other
genera.

i^Scribner, Bidletin of Torrey Chd), xiii., 1886, p. 181. Underwood, Journal of
Mycology, vii., p. 34. Swingle and Webber, "Diseases of Citrous Fruits"
U.S.A. Dept. of Afjricidture Bidletin 8, 1896.

510 FUNOI IMPERFKCTF.

trees, more rarely the sweet orange and lemon. The disease
first appears as whitish or cream-coloured spots on leaves, young
twigs, or fruit. If the spots are numerous the leaves become
badly curled or twisted, and covered with wart-like eruptions.

CI. viticolum Ces. is regarded as a dangerous parasite of the
vine.

CI. carpophilum Thiim. This species has been found para-
sitic on plum and peach in the United States. Its mycelium
creeps over the surface of leaves and fruit, causing pale-coloured
spots which extend and run together, spoiling the appearance
of the fruit. The disease as yet does not appear to have a very
v^ide distribution, nor is it directly very injurious, but as
cracking of the ripe fruit occurs when it is present, the way is
opened for entrance of fruit-destroying fungi.

CI. condylonema Pass, also occurs on leaves of the plum.
It causes leaf-spot and leaf-curl. The mature conidia have
fine spines on their coat.

CI. fulvum Cooke. (Britain and U.S. America.) This is the
cause of a disease of tomato. It attacks leaves and shoots of
plants cultivated indoors, and soon causes their death. Prillieux
and Delacroix ^ have described a somewhat similar disease in
France, found, from artificial infection, to be produced by some
species of Cladospormm, but whether this particular species,
they did not state.

CI. cucumerinum Ell. et Arth.- causes a disease of cucumber
Frank ^ describes a disease which he found to be due to a
Cladospormm (CI. cucumeris n. sp.). This attacked the fruit of
both cucumbers and melons in cultivation under glass at Berlin,
and caused great damage ; brown rotten depressions appeared
on the fruits, and thereon the tufts of conidiophores.

CI. macrocarpum Preus. causes a " scab " disease of spinach in
the United States {N.J. Agric. Exper. Station Bulletin, 70, 1890).

Other species that may be parasitic are :

CI. pisi dig. et Mace. On living pods of Pisum sativum in Italy.
CI. epiphyllum Mart. On leaves of Quercus, Platanus, Populus, Hedera,
etc. (Britain and U.S. America.)

CI. juglandinum Cooke. On leaves of the walnut. (Britain.)

' Bulletin de la soc. mycolof/. de Finance, 1891.
-Description in ^fass. Agric. Exper. Station Report, 1892.
■^ Zeitschrifl f. PJlanzenkrankheiten, in., 1893.

CLADOSPORIUM. 511

CI. Scribnerianum Cav. (Jn leaves of Betula populifolia in America
and Italy.

CI. hypophyllum Fuck. On leaves of Ulmus campestris.

CI. tuberum Cooke. In the tubers of Batatas edulis in Carolina, U.S.A.

3. Sect. Phragmosporae.
1. Suhsect. Micronemeae.

Clasterosporium.

Conidia brownish, cylindrical or spindle-shaped, and consisting
of three or four cells.

Clasterosporium amygdalearum (Pass.) attacks the leaves of
almond, peach, apricot, cherry, and plum. An intercellular
mycelium has been found, and roundish dry spots with reddish
margins are formed. Thereon tufts of short conidiophores are
developed, bearing cylindrical, thick-walled, pluricellular conidia.

CI. glomerulosum Sacc. {Sporidcsmium glom. Sacc, 1878, and
Pleospora conglutinata Goebel, 1879). GoebeP first described
this species as a parasite on Juniperiis communis. A colourless
intercellular mycelium is present, and in consequence the
needles turn brown, die, and fall off
prematurely. On the upper side of
the needle the mycelium emerges
through the stomata, and forms
dark-grey coils from which the
grey, ovoid, pluricellular conidia are
given off.

Ceratophorum.

Conidia brownish, spindle-shaped
or cylindrical, three or more celled, cyu^ ^S^r'^S^'wi^^XL^d
the upper cell with terminal S'n'kaget" &trtiXne'r.)"^*' "'
bristles.

C. setosum Kirch. Dark spots occurring on the leaves,
petioles, and shoots of young plants of Cytisus Lahumum, etc.,
were found to enlarge and bring about death and defoliation.
Kirchner found the leaf-tissue permeated by a colourless septate
mycelium, which gives off conidia on both sides of the leaf.
The conidia resembled those of Pestalozzia, but their cell-number

^ Wurtemlmrg natia-wiss. Jahreshefte, 1879.
Zeitiichrift f. Pflanzenkrankhtiten, 1892, p. 324.

512 FUNGI IMPKRFECTI.

was variable, and the terminal cells, although lighter than the
median, were not quite hyaline. The terminal cell bore several
very long bristles.

C. ulmicolum E. et K. On living leaves of Ulmus fulva in
America.

Helminthosporium.

Conidia brown, cylindrical or spindle-shaped, and pluricellular.
Mycelium well-developed and brownish.

"Distinguished from Cladoqjorium by the conidia being more
than one-septate at maturity " (Massee).

Helminthosporium gramineum (liabenh.) ^ This causes a
disease on barley, both in Europe and the United States ; as yet,
however, it is not very common. It attacks generally the lower
leaves, producing long, narrow, dark-brown spots with yellow
margins. The leaves so attacked gradually wither, but do not
prejudice the yield of grain seriously. On the spots are
developed the black septate conidiophores, each with a large
black conidium with from two to eight cross-septa.

H. turcicum Pass, causes long spots on the leaves of Zea mais
both in Italy and America. The spots are yellow with indistinct
dark margins, and from them arise patches of grey septate
conidiophores. The conidia resemble those of the species last
described, so that some authorities regard the two forms as one.
Briosi and Cavara describe the mycelium as consisting of
branched septate hyphae, the cells of which frequently become
irregularly swollen. The young Indian corn leaves are killed,
and the crop may, in consequence, be seriously injured.

H, teres Sacc. This is a form of H. gramineum which
Briosi and Cavara distinguish as occurring on oats. Infection
takes place at the apex of the leaves, and the mycelium spreads
through the parenchyma causing elongated dry spots, so that
the leaf ultimately dries up and dies. The conidiophores are
developed singly, not in tufts, and the conidia are smaller than
those of H. gramineum. The conidia are greenish, thick-walled,
pluricellular, and produced terminally.

H. gracile (Wallr.) causes long margiuate spots on the leaves
of Iri.-^ germaniea.

1 Eriksson, Botan. Centralhlatt, xxix., 1887. Kirchner, Zeitschrift f. PJlanzen-
krankheiten, i., 1891, p. 24.

CERCOSPORA. 513

Cercospora.

Conidia elongated and slender, olive-green, and septate. My-
celium greenish.

" Distinguished by the vermiform sej)tate conidia " (Massee).

Cercospora circumscissa Sacc.^ This is a parasite which
occurs on cultivated almond, peach, and nectarine, as well as
on wild Prunus serotina in the United States. The leaves are
attacked while still young, and exhibit by reflected light a
yellowish spot with a dark centre. The conidia arise on the
spots as dark -green clusters, thereafter the diseased tissue shrinks,
becomes detached, and falls out, leaving " shot-holes " not
unlike those produced by species of Phyllostieta. Defoliation
may occur in severe cases of attack. As a result of the
injury to the foliage, the new wood does not mature well,
and second growth may take place during the same season ;
shoots of this kind will probably dry up during winter. The
fungus may also directly kill the tissue of twigs as far as the
cambium. The fruit is never attacked directly, but may be
seriously affected through the injury to leaves or twigs.

In order to minimize the disease, it is recommended to burn
all fallen foliage, and to turn the earth thoroughly below infected
trees. Pierce obtained a crown of very healthy foliage on almond
trees treated with (1) ammoniacal solution of copper carbonate,
and (2) modified eau celeste.

C. persicae Sacc. On leaves of peach. (U.S. America.)

C. acerina Hartig- appears on brown spots on the cotyledons,
young leaves, and stalks of young plants of Acer. The conidia
are grey, pluricellular, and slightly curved (Fig. 314). The
mycelium inhabits the intercellular spaces of the parts attacked,
and forms resting sclerotia in the tissues of dead leaves.

C. viticola (Ces.).^ This fungus is found in Europe and the
United States on Vitis vinifera and V. Labrusca. It causes
spots on the leaves, and from these arise close columns of
septate conidiophores which give off thick pluricellular conidia.

C. beticola Sacc.^ inflicts considerable injury on cultivated

1 Pierce, Journal of Mycology, vii., jd. 06 and p. 232.
^R. Hartig, Untersuchungen aus d. forstbotan. Institut, i., Munich.
^Description and treatment in Neio York Agric. Exper. Station Report for
1890, p. 324.

■•Thumeu, Die Behiimpfung d. Pilzkrankheittii vnserer Kidturqewdchse, 1886.

2k

514

FUNGI l.Ml'KHFECTI.

sugar beet and beet-root. It is easily recognized by the
numerous sharply defined spots produced on the leaves. The
conidia are very long and pluriseptate. In the United States
this is one of the most serious of beet diseases.^ As preventive
treatment, great care should be taken to destroy all infected
material. A long rotation sliould also prove a good remedy.

Fio. 314. — Ctfxonpora dccrinn. 2, Seedling of Acer, with a cotyledon brown and
withered, and a leaf partially so. 4, Section through a diseased cotyledon ; the
conldiophores (rf) emerge from the epidermis, and bear long tapering septate
conidia ; < , sclerotia formed inside the diseased tissues for hibernation. 5, Ger-
minating conidia. (After R. Hartig.)

C. apii Fres. Common on celery (Ajniim gravculens) and par-
snips {Pastinaca sativa) throughout all Europe and Xorth America.
It causes leaf-spots at first yellowish then enlarging and turn-
ing brown. The mycelium grows in the intercellular spaces of
the leaf, and gives oft' tufts of conidiophores through the
stomata. The conidia are long, tapering, obclavate bodies with
an attachment-scar at their larger end.-

C. asparagi Sacc. occurs on asparagus in Italy ; C. caulicola
Wint. frequents the same host in America.

C. Bloxami B. et Br. On Brassica in Britain.

C. armoraciae Sacc, On horse-radish.

iPammel. Iowa. Afjric. Exper. Station Bidletin, !.■>. 1891.
"Description in Xev; Jersey Aqric Exptr. Station Bxdletin '2, 1891.

CERCOSPORA. 515

C. resedae i'uck.^ This fungus is the cause of a garden
mignonette disease very common in America and Europe. It
causes little depressed spots with brownish or yellowish borders,
which begin as reddish discolorations of the leaf. The leaves
gradually wither and dry up, so that the flowers suffer. The
mycelium grows inside the leaves, and gives off tufts of conidio-
phores through the stomata. The conidia are elongated, septate,
and spindle-like or club-shaped. Spraying with Bordeaux
mixture was found to give good results.

C. cheiranthi Sacc. produces roundish leaf-spots on wall-
flower, and, if severe, causes death of the leaves and premature
defoliation of the plants.

C. rosaecola Pass. This causes leaf-spot on cultivated and
wild roses in the United States. The first indication of disease
is the appearance of black spots with reddish margins. The
conidiophores emerge from the stomata in tufts, and carry long
obclavate conidia.

0. angulata Wint. is one of the causes of leaf-spot on
currant, and occurs often in company with Scptoria ribis. (U.S.
America.)

C. violae Sacc. occurs on leaves of Viola odorata.

C. malvarum Sacc. On species of Malva.

C. althaeina Sacc. On hollyhock in the United States.

C. neriella Sacc. causes leaf-spot on Nerimn Oleander.

C. Bolleana (Thlim.) produces olive-brown spots on leaves and fruits
of the Fig, injuring the crop.

C. capparidis Sacc. On Capparis spinosa in Italy.

C. gossypina Cooke is given by Atkinson as a fungus frequently present
on diseased plants of cotton. -

Saccardo records over 230 species of Cercospora, most of which cause
spotting of living or fading leaves of many plants, e.g. Phaseolus, Lupimis,
Trifolium, Vicia, Gleditschia, Solanum nigrum. Datura, Riciniis, Ampelopsis,
Liriodendron, Tilia, Rosa, Potentilla, Ruhiis, Cydonia, Ptelea, Rhamnus,
Euonymits, Ailanthus, Rhus, Samhuciis, Viburnum, Olea, Syringa, Morus,
Fraxinus, Coffea, Ligustrum, Mercurialis, etc.

Heterosporium.

Conidiophores simple or branched. Conidia olive, oblong,
pluriseptate, and with a spiny or warty outer coat.

' Fairchild in Report of Section of Verjetable Pathology for 1889, U.S. Dept.
•of Agriculture.

-Botanical Gazette, 1891, p. 61.

516 FUNGI IMl'ERFEf'TI,

"liesembling JIrhmnfJiosj)oriu7n in general hal)it and structure,
in fact only distinguished by the minutely warted conidia "
(Massee).

Heterosporium echinulatum (Rerk.).^ (Britain and U.S.
America.) The " fairy ring spot " of Carnations. This is a
serious enemy of cultivated carnations, and causes great damage.
It was first described by lierkeley in 1870 as a carnation pest.
The symptoms are light-coloured spots on which are concentric
rings of dark-coloured conidiophores. These arise from dark-
coloured portions of the mycelium inside the leaf and give off
conidia with three or more cells. The conidia are at first
terminal, but after one has been formed the conidiophore
branches laterally and produces another conidium, repeating this
process for a considerable time. The spots are produced on
leaves, leaf-stalks, and sepals, causing them to wither." In
consequence the flowers do not unfold and the plants are
rendered unsightly.

Cultivation of the carnation in dry airy conditions is said
to keep this disease in check.

The following are British species occurring generally on
fading leaves :

H. variabile Cooke. On spinach.

H. ornithogali Klotzsch. On Ornithogalum, Convallarut, and other
species of Liliaceae.

H. typharum C. et M. On Typha angustifolia.

H. laricis C. et M. On larch needles.

H. asperatum Massee. ^ Occurs as a parasite on Smilacina stellata.

Napicladium.

Conidia oblong, three or more celled, and produced singly
on the end of short conidiophores.

" Somewhat resembling HchnintliosiJorium and Brachysporium,
but distinguished by the less rigid fertile hyphae and the
large solitary conidia " (Massee).

Napicladium (Helminthosporium) arundinaceum (Cord.).
(Britain.) This lives parasitic on the leaves of Phragmites
communis, and spreads rapidly from plant to plant. The leaves

^ Worth. (i. Smith, Gardener's Chronicle, xxvi., 1886, p. 244.

Atkinson, ^^ Carnation Diseases" at American Carnation Society, 189.3.
"Massee, American Journal of Microscopy, Fel>ruary, 1893.

NAPICLADIUM. 517

become coated with conidia and assume a leaden grey colour,
so that in many cases only the points remain green. Finally
the attacked leaves die and dry up.

4. Sect. Dictyosporae.

1. Suhsect. Micronemeae.

The forms included under genera of this group (e.g. Sporo-
dcsmium and Coniotlucium) have as yet been little investigated
in regard to their parasitic nature.

2. Subsect. Macronemeae.

Macrosporium.

Conidia grey, muriforra, and borne on the apex of simple or
branched conidiopliores.

Macrosporium sarcinaeforme Cav.^ Cavara describes a
browning and death of a whole field of red clover {Trifolium
'pratense), and ascribes it to this fungus. Minute spots were
produced, at first light-coloured, then brown, finally coalescing
so as to cause drying-up of the whole leaf The short thick
couidiophores were developed on the lower surface of the leaf,
and gave off pluricellular terminal conidia.

M. solani Ell. et Mart. This is described- as occurring along
with the " black-rot " of the tomato in the United States. It is
said to cause a rot in the fruit and a leaf-blight on both tomato
and potato. Along with this species there also occur a Fusarium
(p. 520) and frequently a Cladosporium ; as yet the relationships
of the different forms, and the part they take in causing the
diseases ascribed to them, is but imperfectly investigated.

Sorauer^ ascribes a disease on the potato in Germany to this
species or to an Alternaria {A. solani). He also believes that
it is the cause of the " early blight " of American potato crops,
but further investigation is still required.

Many other species of Macrosporium have been described on
plants of economic importance, yet most of them occur only on
parts somewhat faded or languid, so that they cannot be regarded

^Briosi and Cavara, Funghi parasif., v.

'Report of the Section of Vegetable Pathology for 1888, U.8. Department of
Agriculture.

■^ Zeitichrift f. Pfanzenkranl'heiten, 1896, p. 1.

518 FUNGI IMrHRFECTI.

as important parasites. Amongst tliese are the following British
and Xortli American species :

M. brassicae Ik-ik. On cabbajre, generally soinewliat decayed.

M. sarcinula Berk. On cucumber.

M. nobile Vi/.e. On Dianthus.

M. alliorum ( 'ke. et Mass. On onion.

M. ramulosum Sacc. On celeiy.

M. catalpae Ell. et Mart. On Catalpa Bignonioides.

M. nigricantium Atks. is a semi -parasite accompanying other diseases
of the cotton plant.

Mystrosporium.

"Allied to Macrosporium, but distingui.shed by the more rigid
and darker-coloured hyphae and conidia " (Massee).

Mystrosporium abrodens Neumann.^ This is described as
the cause of a disease which destroyed one-tenth of the total
wheat-crop in the Haute- Garonne of France. The fungus
attacked the nodes and leaves, forming dark patches ; the nodes
were weakened and frequently broke over, while the ears were
badly developed.

Alternaria.

Conidia grey, muriform-septate, flask-shaped, and borne on
short simple conidiophores.

" Distinguished by the clavate or flask-shaped muriformly
septate olive conidia being united in chains and connected
by narrow isthmus-like portions " (Massee).

Alternaria brassicae (Berk.) (Britain). This species causes
on leaves roundish black spots marked with concentric brown
zones. The mycelium lives in the leaf-parenchyma and gives
off tufts of conidiophores through the stomata. Briosi and
Cavara state that it causes considerable damage to Brassica
oleracea, Cochlearia ojfficiiialis, and Armoracia. (Probably the
same species as Polydesmus cxitiosiis Kuhn.)

Other diseases have been ascribed to species of Alternaria.

Septosporium.

Conidia brown, and muriform-septate. Conidiophores of two
kinds — short and fertile, or elongated and sterile.

Septosporium heterosporum Ell. et Gall, causes a leaf-

^ " Un nouveau parasite de ble." Soci6te de Biolog. a Toidoii-se, 1892.

SEPTOSPORIUM. 519

spot on Vitis calif arnica in California. The leaves become
quite black on the lower surface, brown on the upper. The
fungus has not as yet been reported on cultivated vines.

Fumago.

Conidia grey and two- or three-celled.

The species belong to Capnodium (see p. 181).

3. FAM. STILBEAE.

1. Ser. Hyalostilbeae.
Sect. Amerosporae.

Stysanus.

Conidia pale-coloured, more or less spherical, and developed
on a dark cylindrical or clavate erect stroma.

Stysanus veronicae Pass.^ This produces irregular spots on
the leaves of cultivated Veronica, longifolia in Italy, and causes
the plant to wither. The columnar stromata are produced on
the lower surface of the leaves, and give off unicellular conidia.

St. ulmariae M'W.^ On Spirca Ulmaria in Ireland.

Isaria.

Stroma erect, clavate, generally branched and bearing conidio-
phores all over. The conidia are abjointed from the apex of
the conidiophores, and are unicellular, hyaline, and rounded.

Isaria fuciformis Berk.^ This disease, first observed in
Australia, is described by Smith as occurring in England. It
attacks grasses, especially Festuca, during summer. The stems
and ears are "hied together bv the fungus-stroma, and conidia
are developed on all parts of the plants.

2. Ser. Phaeostilbeae.

Sect. Phrarpnosporae.

Isariopsis.

Conidia pale-coloured, cylindrical, and pluricellular.
Isariopsis griseola Sacc,'* produces spots on leaves of living

^ Hedwiijia, 1877, p. 123.

^M'Weeney, Irish XafuralUf, 1S9.5, p. 273.

^ Worth. G. Smith, Diseases of Fir Id and Llarden Crops, London, 1884, p. 55.

*Briosi and Cavara, Funrjhi parasit.

520 FUNGI IMPERFECTI.

cultivated kidney bean. The mycelium lives in the leaf-tissues
and forms stromata under the stomata, from which the conidio-
phores arise in tufts. The fungus often occurs along with
Uromyccs 2}haseoli.

Other species of Isariopsis are recorded on the living leaves
of various host-plants, e.g. Cerastium and StellaHa.

4. FAM. TUBERCULARIEAE.

Volutella.

The conidial patch or sporodochium is di.sciform, regular,
and fringed, or studded over with elongated spine-like hyphae.
Conidiophores simple or branched, and bearing elliptical or
oblong conidia.

The majority of the species of Volutella frequent only dead
plant remains. Atkinson,^ however, describes and figures a
widespread carnation-disease in North America, which is ascribed
to a species as yet unnamed. Fresh cuttings are most commonly
attacked, and exhibit dirty brown depressed areas, which soon
ruin the cutting for purposes of cultivation.

Fusarium.

Sporodochium more or less eft'used. Conidia spindle-shaped
or sickle-like, pluricellular when mature. The conidiophores
are branched, and give off' the . conidia from their apex.

Fusarium heterosporium Xees. Frank - found a field of
rye near Kiel completely destroyed, and the ears quite over-
grown by this fungus. I have found it on ears of Lolinm
perennc and Molinia coeriilea in Bavaria.

Species of Fusarium have been frequently described as causing
injury to cereal and grass-crops,^ in some cases to a serious
extent.

While most of the species of Fusariinii are found only on
dead or dying plant-remains, a parasitic mode of life has been
ascribed to some.

Fusarium lycopersici Sacc.^ The " Sleeping Disease " of

^ '' Caniation Diseases" in Keport of American Carnation Society, 1893.
-Jahrbuch d. deutsch. landwirth. Gesell., 1892.
=' Worth. G. Smith, Diseases of Crops, 1884, p. 208.
Rostrup [Fusarium avenaceum on Oat) Landhoslcrifter, v., 1893.

"•Massee, Gardener's Chronicle, xvii., 1895, p. 707. (Edit.)

FUSARIUM. 521

tomatoes. This tomato disease has proved very destructive
during recent years in Britain, particularly in the Isle of
Wisht and the Channel Islands. Plants are attacked when
quite young, but the disease seldom manifests itself outwardly
till the plant is full grown. The first symptom of disease
is drooping of the leaves, with or without discoloration. At
this stage the roots of attacked plants will be found to have a
yellowish brown colour in the wood region. The mycelium
of this fungus will be found in the vessels and other elements
of the root. They are believed to originate from resting-spores
which have hibernated in the soil and given off germ-tubes by
which young rootlets were infected. The mycelium makes its
way up the tomato stem, discolouring the vascular bundles as it
goes. The conidia are produced on all diseased organs as a
whitish bloom on the epidermis. The earlier conidia {Diplo-
eladium) are oval and one- or two-celled, but they are soon
replaced by pale orange crescent-shaped conidia of the true
Fusariuon type. The resting-spores are produced on the hyphae
in the tissues of the decaying host- stem ; after hibernation, they
germinate and produce hyphae which give off the Diplocladium
stage. Massee found that only the germ-tubes from resting-
spores were able to infect tomato planta The same author
does not consider fungicides of much avail on account of the
disease beginning from the roots. Careful removal and destruc-
tion of all infected material, and a liberal application of lime
to the soil are measures recommended.

Fus. limonis Briosi {tusisporinm limonis Briosi). This is
given by Briosi as the cause of " mal-di-gomma " of orange
and lemon trees in Italy and elsewhere ; ^ Webber and Swingle ^
ascribe the disease of the orange and lemon in Florida known
as " foot-rot " to the same fungus. In Florida the damage done
is great and much more serious than that caused by any other
disease of the same plants. It may be recognized by the
exudation of gum from patches near the base of the tree. The
patches enlarge and the disease spreads round the trunk and
down"wards into the roots, passing inwards from bark to cambium
and wood, killing the tissues as it goes. Other symptoms

'Briosi, "Mai di gomma," Memoria della R, Acad, dei Lincei, Rome, 1878.

-Webber and Swingle, "Diseases of citrous fruits in Florida."' U.S. America
Dept. of Acjricidture. Bnlletin, No. 8, 1896. (Edit.)

522 FUNGI IMPERFECTI.

are sparse foliage, small yellowish leaves, and death of the
smaller branches over the tree. Sweet seedling orange {Citrus
avrantium) and lemon (C limonum) are most subject to this
malady, the grape-fruit (C. decumana) is only slightly liable,
and the sour orange {C. higaradia) is almost wholly exempt.
For this reason sour orange stocks should be used on lowlands
and flatwoods, and grape-fruit stocks on the higher lands. The
most effective treatment is to remove the soil around the crown
roots by using a jet of water. Diseased bark should also be
cut away and the wounds painted over with carbolic acid or
sulphur wash. Good drainage to promote root aeration and
the avoidance of excessive use of nitrogenous manures are also
recommended.

Fus. vasinfectum Atks.^ A species found by Atkinson to
cause a cotton-disease known as " frenching." This consists in
a discoloration of the leaf from the margins inwards, at first
pale or yellow, but turning to brown. A mycelium was found
in the tissues of the stem, causing the vascular bundles to
assume a light brown colour. The host-plants are either killed
or so seriously affected that the crop is injured. The conidia
formed are of the pleuriseptate slightly curved Fusarium type.

Atkinson- in the course of his investigations on carnation
diseases found a Fusarium present in all cases of the " carnation
rosette." The stems remain short and stunted with their leaves
small and crowded together. A mycelium was present in the
tissues of the stem and caused discoloured spots.

II. THE PATHOGENIC SLIME-FUNGI.

MYXOMYCETES.

The Myxomycetes^ rank amongst the lowest of plant-forms.
They show so close relationship to the lowest animals that
certain groups {Monadina) receive greater consideration from
the zoologist than from the botanist. They exhibit in their

^Atkinson, "Cotton Diseases," Alabama Aqrk. Exper. Station BuUetm, No.
41, 1892. (Edit.)

^^^ Carnation Diseases" at American Carnation Society, 1893.

^The more important literature dealing with this family will be found in:
De Bary, Morpholo<jy and Biolo<jy of the Fvinji (English Edition) ; Lister, The
Mycetozoa, London, 189.5; Zopf in Schenk's Handhuch der Botanik, in., 1887;
Schroeter, " Myxomycetes " in Die natibiich. Pflanzenfamilitn, i., 1892.

THE PATHOGENIC SLIME-FUNGI. 523

mode of reproduction a close resemblance to the Fungi, and as
a result of their lack of chlorophyll, they share with Bac-
teria and Fungi the peculiarities of saprophytic and parasitic
nutrition.

The vegetative body of the Slime-fungi consists of naked
protoplasm without a firm membrane. ^Multiplication is effected
chiefly by spherical spores with the same external appearance
as the usual fungus-spore. Immediately on reaching maturity
the spores germinate in water and burst, setting free a mass of
plasma provided with a nucleus and vacuoles, and in which an
outer movable hyaloplasma can be distinguished from an enclosed
granular plasma. The hyaloplasma gives off delicate pseudopodia
capable of extension and retraction, it may also take the form
of a flagellum or of cilia. The organism is enabled by means
of the pseudopodia to creep over firm objects as an " amueba " ;
by the cilia it can propel itself through water, as a •' swarmer "
or " zoospore." A zoospore in the course of its development
generally loses its cilia and becomes an amoeba, and both
forms can multiply by division. The amoebae creep together
in large numbers, and either coalesce completely into masses,
or remain simply in contact as aggregations. In this w^ay
Plasmodia are formed, fretpiently of considerable size and of
conspicuous colour. The plasmodia maintain a constant move-
ment, both as a whole and in the form of internal streamings.
Eesting stages have been observed at each motile stage of
the life-history ; thus swarm-spores rest as microcysts, young
Plasmodia as thick-walled cysts, and mature plasmodia as multi-
cellular sclerotia.

^Multiplication of the Myxomycetes also takes place by spore-
formation. In the Acrasieae and Phytomyxinae the spores are
developed freely from the plasma. The Exosporeae, a very
small division, have their spores developed on the outside
of sporophores. In the greater number (Endosporeae) the
spores are formed in special enclosures, which may be a spor-
angium produced from a single plasmodium, or an aethalium — a
cushion-like structure consisting of numerous imperfectly defined
sporangia. The sporangia are often of considerable size, some-
times not unlike the sporocarps of the Gasteromycetes, spherical
or pear-shaped and stalked. Sporangia of this highly developed
kind may even exhibit a certain differentiation into a wall or

524 TlIK I'ATIIOGENIC SLIME-FUNGI.

riiid of compact plasma enclosing the spores, and frequently a
supporting skeleton or capillitium is present consisting of
numerous filaments of hardened plasma.

Schroeter divides the Myxomycetes into three divisions, the
Acrasieae, Pliytomyxinae, and Myxogasteres (including the Exos-
poreae and Endosporeae). Parasitic forms occur only in the
second of these groups. If, however, all the forms included
by Zopf in his group of Mycetozoa be taken into account
many of them will be found to act as parasites and to cause
frequent epidemics amongst algae and lower fungi.

We shall here consider only the genera Plasmodiophora,
Tetramyxa, and Sorosphaera. The genus Phytomyxa of Schroeter,
containing those micro-organisms which cause the root-tubercles
of Leguminosae, has already been considered in our general
part (see p. 101).

Plasmodiophora.

Spores spherical and developed inside the host-cells. This
genus causes diseases of considerable economic importance.

Plasmodiophora brassicae Wor.^ This species attacks all
kinds of cabbage, kale, turnip, kohl rabi, and other varieties of
Brassica Rapa, B. Napus, B. olcracea, and other edible Cruciferae;
also other plants from the same order, such as Iberis nmhrUata,
Capsella bm'sa-pastoris, Mathiola incami, etc.

The symptoms of the disease are manifold swelling, out-
growth, and branching of the roots at all stages of growth,
with a more or less marked stunting of the foliage, according
to the season of attack (Fig. 315). The forms assumed by
deformed roots are very variable and have gained the disease
many designations. In Britain it is known as " finger and
toe disease," " club-root," " clubbing," and " anbury " ; in Bel-
gium as " maladie digitoire " or " Vingerziekte " ; in Germany
as "Kropf" or " Kohlhernie."

The disease was first recorded in Scotland about 1789, but
now it has a very wide distribution, appearing in all places
where cabbage, turnips, and allied vegetables are cultivated on
a large scale. The roots after swelling become rotten and

MVoronin, Primj-ihdm >i Jahrbuch, xi. , 1S78, p. 548. Eycleshymer (Journal
of' Mt/coloijy, VII., p. 79) gives a good caccount of its distribution in America.
Massee, Transactions of Royal Sockty of London, lvii., 1895.

PLASMODIOPHORA.

525

decay, so that not only is the root itself worthless, but the
aerial shoot is badly developed. The destruction is greatly
favoured by moist rainy years.

The malformations of the root are the result of hypertrophy
of the host-cells due to a stimulus exerted by the plasniodium
of Plasmodiophora, not only on the contents of cells inhabited
by it, but also extending into the cells of the whole neigh-
bouring tissue. The cells so influenced enlarge in size and

y...?>-%^

?' r

Fig. 315. — Plasmodio'phoya brasslcae. Effects on Turnips grown in Scotland.
(v. Tubeuf phot.)

become divided up by new cell-walls. The plasmodium makes
its way from cell to cell by means of the wall-pits, and
by absorbing the contents it grows and fills the whole cell.
On exhaustion of food, and without previous enclosure in a
membrane, the plasmodium forms itself into spores, so that the
tissues of attacked roots become completely filled with thick-
walled spores, which are set free only after decay of the
surrounding tissues and cell-membranes. The spores hibernate,
and in spring niyxamoebae slip out, capable of infecting

526

T1II<; PATHOGENIC SLIME-FUNGI.

young roots of newly germinated cabbage, turnips, etc. They
do this by penetrating the cell-wall, probably that of a hair
to begin with, and the malformation ensues. The myxainoebae
possess a flagellum and pseudopodia, so that they are fitted for

Fio. 316. — Plasmodio'phora hro^x^iccK. Effects on Tiiniip grown in Russia.
(After Woronin.)

different modes of locomotion. When entrance into a host-cell
has been effected, a plasmodium is formed and growth proceeds
as just described.

Wakker^ describes, an enlargement of the attacked cells
and an irregular growth of the roots, associated with a rudi-

^ Prinysheiyn's Jahrbuch, 1892.

PLASMODIOPHORA.

527

mentary condition and twisted course of the vessels, and an
accumulation of transitory starch in the tissues.

[The methods at our disposal for combating this parasite all
work indirectly. Its spores seem to retain their vitality for two,
three, or more years, hence one very evident measure is not to
plant the same crop in succession on land which has been attacked.
As, however, all Cruciferae are liable to injury from this source,

Fig. 317. — Plasuwdiojihora bra-uicm. on Turnip. (After Worouin.)

neither would it be advisable to let say, turnips follow
cabbage or kohl rabi on infected land. For the same reason
weeds belonging to the order Cruciferae should not be allowed
to obtain a footing near land where plants liable to " finger and
toe " are under cultivation. In Scotland, where turnips are
necessary in all crop-rotations, a four-year rotation does not
give complete exemption from this disease, nor is five years

528

THE PATHOGENIC SLIME-FUNGI.

considered quite a safe interval, but seven years is, and with
good management the disease, though by no means uncommon,
only then attains serious dimensions in moist seasons, Massee
points out that the development of the fungus is favoured by
acids and checked by alkalis ; this explains the well-known
beneficial effects of dressings of lime or potash in keeping the
disease in check. With a six or seven-year rotation, and the
application of lime once in the rotation, the disease should

Fig. 318.— Hypertrophied cells from a Cabbage-root attacked by Plasmodiophora
brassicae. Several of the cells are filled with spores, (v. Tubenf del.)

never be very injurious. The direct application of farmyard
manure to the turnip crop should also be avoided, especially
if the stock which made the manure was fed on diseased turnips ;
this is necessary because it has been found that the spores are
not killed when eaten by animals.] (Edit.)

Plasmodiophora vitis Yiala et Sauv.^ This is said to
cause a Vine disease known as " Brunissure," which within
recent years has caused considerable loss in France, North
America, and Southern Paissia.^ The early symptoms are light-
brown star-shaped spots on the upper surface of the leaves
between the ribs. The spots enlarge and cause a premature fall
of the leaf, whereby the grapes are prevented from maturing.

' Viala et Sauvageau, Compt. rend., cxiv., 1892.

-Cooke (Gardcnpyii Cliroyncle, 1893) refers swellings found by him on roots of
the vine in England to the action of this fungus. (Edit.)

PLASilODIOPHORA. 529

The above-named investigators found plasmodia in various stages
of development in the palisade cells, and later in the spongy
parenchyma of diseased leaves. On treatment with " eau de
javelle " the plasmodia remained visible, whereas the contents
of healthy cells disappeared. Spore-formation has not as yet
been observed. The same parasite has been seen in vines in
the Ehine district.

Eecently Debray and Brive^ have, in consequence of their
researches on Brunissure, removed the fungus from the genus
Plasniodvyphora, and founded for it a new group Pseudocommis,
with a position near VampyreUa and Mycromycetes. This same
fungus they also found in a large number of plants from thirty
different natural orders.

Plasmodiophora californica Mala et Sauv.- is another vine
parasite which causes greater damage than the preceding species.
Eeddish leaf-spots are produced, and extend so rapidly that the
leaves may drop early in spring. The parasite also affects the
shoots to such a degree that an abnormal number of .shortened
branches are developed, the wood of which exhibits brown
stripes in autumn.

It has not as yet been quite proved that the plasma observed
in withered vme leaves really consists of plasmodia of the
above two species of Plasrnodioiiliora, nor have spores been
found. The true cause of the diseases has probably still to be
explained.

In cases of root-deformation in pear, Miiller-Thurgau^ obser^-ed
a slime-fungus in cells of the root-parenchyma.

Tetramyxa.

Spores united four together as tetrads and enclosed in a
delicate membrane.

Tetramyxa parasitica Goeb.^ First found by Goebel in
ditches of marshy meadows, causing tuberous balls of a whitish-
green to brown colour on leaves, flowers, and stalks of Rvppia
rostellata. Sections of the swellings showed the parenchyma
to be divisible into a dark brown central part consisting of

'^Compt. rendu., cxx., 1895; and " La Binmi<sii7-e," Bevuede Viticidture, 1895.
"^ Compt. rend., cxv., 1892, p. 67.
'^ Jahresberkht d. Vers. -Stat. Wcidensiceil, ii.
^Goebel, Flora, 1884. Identitied in Scotland by Prof. Trail.

2l

530 THE PATHOGENIC SLIME-FUNGI.

killed cells, and a lighter coloured peripheral part. The cells
of young tubercles contain niultinuclear plasmodia, which at the
time of spore-formation break up into portions round each
nucleus (spore-mother cells). These portions then divide into
four spores, each witii a nucleus. The spores remain enclosed
in a delicate membrane as spore-tetrads, the characteristic feature
of this species. The upper part of leaves containing galls
frequently died.

Sorosphaera.

Spores enclosed in large numbers in a delicate membrane,
and forming a single layer round a central cavity.

Sorosphaera veronicae Schroet.^ causes quill-like outgrowths
and malformations in the stems and leaf-petioles of species of
Veronica ( V. hederifolia, V. trvpliylla, V. chamacdrys). The galls
consist of enlarged parenchymatous cells containing numerous
spherical or elliptical light-brown balls about 15 or 22 ix broad.
The balls are enclosed in very delicate membranes, and consist
of a single layer of spores surrounding a small cavity. The in-
dividual spores are elliptical or oblong in shape, about 8-9iU
long and 4-4*5/u broad.

III. THE PATHOGENIC BACTERIA.

SCHIZOMYCETES.

Although the bacteria and allied forms included in this
group are the cause of many diseases of mankind and of
warm-blooded animals, yet very few diseases of plants are
ascribed to their agency. ' The true Fungi, on the other hand,
which we have seen to cause so many diseases amongst plants,
only very rarely appear as enemies of the higher animals. The
few cases in which bacteria have been stated to cause injury
to plants are all as yet incompletely investigated and uncertain
in two respects. Thus although a plant-disease undoubtedly
exists accompanied by the appearance of bacteria, these bacteria
may not be the cause of the disease ; nor need it follow
that the phenomena accompanying an attack l^y bacteria are
necessarily symptoms of disease. On this account we shall

' Schroeter, EiKjler-Prantl natiirUch. Pflanzenfamilien.

THE PATHOGENIC BACTERIA. 531

consider those phenomena, which have been described as
bacterial diseases of plants, very briefly and with a certain
reserve. This part of tlie work has been considerably facilitated
by the use of Ludwig's compilation of bacterial diseases/ and by
Migula's account of them from the bacteriological point of view.

Migula considers that only live diseases of plants have been
definitely proved to be due to bacteria, namely, pear or apple
blight, sorghum blight, the bacterial disease of the maize, the
bulb-rot of hyacinths, and the wet-rot of potatoes. AVe shall,
however, indicate briefly some other plant diseases wliich are
suspected to have a bacterial origin. The slime-fluxes of trees
have been already considered along with the genus Eiulomijces
(p. 141), so that we omit them here.

Pear and Apple Blight.

This destructive disease of the apple and pear in North
America has been proved by the investigations of Burrill -
and Arthur to be, without doubt, of bacterial origin. The
disease has been known for over 100 years, and occurs
with disastrous effects on fruit-trees in the orchards, as well
as on crabs and other wild species. Pear trees seem to suffer
most in the Eastern States, apple trees in Iowa and elsewhere,
while none of the species of Pyrus, Cydonia, and Sorhus are
exempt from attack.

The disease appears first on the bark as little dead spots ;
these, however, rapidly enlarge till death of twigs, branches, and
even stems may follow. As a result of death of twigs, the
leaves turn brown and fall, while a dark fluid exudes from the
diseased bark. Tlie presence of bacteria has been proved in
this exuded sap as well as inside the cells, and infections have
been successfully carried out from pure cultures. The name
Micrococcus amylovorous was given by Burrill to the organism.
It flourishes on the sour unripe fruit, and in the tissues of

' Lehrbuch der niederen KryjJtogamtn, 1892.
Migula, Kritische Uehertsicht d. Pflanzenkranl:heiten durch BaJcterien veruT'
sacht, 1892.

Prillieux et Delacroix. " Maladies baccillaires." Comptes rendu, 189-1.

-Burrill, The American JS^aturalist, 1881.

Arthur, Report of New York Afjric. Exper. Station, 1887.

Waite, Yearbook of U.S. Dept, of Acjricidture, 1895 ; description and
treatment.

532 THK PATHOGENIC I'.ACTKUIA.

diseased branches, and is one of those forms which does not
liquefy gelatine. One characteristic reaction is, that as destruc-
tion of the tree-rind proceeds, fermentation takes place with
production of carbon dioxide, hydrogen, butyric acid, and alcohol.
The bacterial colonies should be carefully cut out when
detected.

Bacteriosis of Carnations.

Artliur and Bolley have recently described a bacterial dis-
ease of carnations common in Xorth America.' It attacks the
leaves almost exclusively, causing pale spots which later become
whitish depressed areas. The plants are seldom killed outright
and the leaves remain attached, but they are stunted in size,
and the yield of flowers is prejudiced. The disease is favoured
by poor cultivation in moist surroundings, and is more prevalent
indoors. A very efficient remedy is to avoid watering the
foliage, except at long intervals ; by means of wire-netting it is
possible to water the roots without touching the foliage. (Edit.)

Twig-g-alls of the Olive" (" liogua or Loupe ").

Twigs of the olive are frequently beset with knots varying
from the size of peas to that of hazel-nuts. These consist
chiefly of parenchyma which begins to decay internally before
the gall has ceased growing ; finally the gall also dies. In this
way cavities in the twngs are formed in which Prillieux found
large masses of bacteria (Bacilli's vleac), to whose action he
ascribes the formation of the galls, as well as the decay of the
tissues. Infection from pure cultures is yet required to show
whether the galls are really due to the action of the bacteria,
and whether the above-mentioned BnciUus is the real cause.
I had the opportunity of personally inspecting the disease on
olives near Eiva, and found that the galls really contained
nests of bacteria, while death of twigs above the galls was
very frequent.

Similar symptoms of disease occur on willow, birch, pine,
and other trees, but they have not been investigated.

1 Arthur and Bolley, Piirdne University Ayric. Exper. Station, Bull., 59, 1896.

-Prillieux, " Les' tumeurs bacilles de TOlivier, etc.," Eevue gener. de
hotanique, 1889.

TVVIG-liALLS OF THE ALEPPO PINE. 533

Twig-galls of the Aleppo Pine.^

The galls occurring on the twigs and branches of Pinus
halejjensis are even larger than those on the olive ; they are
particularly common in the woods near Coaraze in the Maritime
Alps. The galls contain masses of bacteria situated in canals
and cavities in the parenchyma, and throughout the woody
tissues inside the galls. Prillieux regards bacteria as the cause
of the galls, and he believes that they penetrate the healthy
bark and form nests which kill the parenchyma. Experimental
infection has, however, not yet been carried out.

Canker of the Ash.

Sorauer^ regards the well-known ash-canker as the result
of the action of bacteria, but JSToack thinks this improbable.
Bacteria were found in the canker-spots only in summer, and
might easily have got there accidentally after the formation of
the galls. Galls of the ash caused by attacks of the insect
Phytoptus may frequently contain bacteria.

Canker of the Ivy.

Lindau-^ describes a cancerous formation on ivy-twigs, accom-
panied by death of portions of the leaves. The diseased places
contained slimy masses of bacteria, and the canker-spots, though
at first isolated by formation of wound-cork, continued to extend
till they reached the wood, which was ultimately killed. Pure-
culture and infection-experiments were not carried out, and the
author himself was unable to determine whether tlie bacteria
were primary agents in the canker- formation or only late arrivals.

Lilac Disease.

Sorauer'' observed masses of bacteria enclosed in cavities in
young twigs of lilac which after becoming black-spotted liad
in many cases broken over. The attack and the part taken in
it by the bacteria were not however investigated further.

^ Vuillemin, " Sur uiie tumem- du Pin d'Alep," Conipt. rend., cvii., 1888;
Prillieux {loc. cit.).

^Sorauer, Atla>i d. PJlauzenkrmikheiten ; Noack, " Der Eschenkrebs," Zeif,-
schrift f. Pjlaazenkrankheiten, 1893, p. 193.

'■^'L\m\a,\x, ZeitHchrift f. Pjlanzenkrankheiten, 1894, p. 1.

•*Sorauer, Zeitschri/t f. Pflanzenkraukheiten, 1891, p. 186, and 1892, p. 344.

534 THE pathogenic; TtACTKRIA.

Bacterial Disease of the Mulberry.^

Cavities containing bacteria have been found in brown spots
on diseased leaves and twigs of the mulberry. A form
" Bacterium mori " was isolated and found to reproduce the
disease when used to infect healthy leaves. I have myself
observed, in the arboretum of the forest experimental station
at Munich, most of the new twigs of an old niulljerry tree
beset with brown spots over the whole green tissue. The
leaves on such twigs were not spotted, but died off prematurely.
The spots indicated cavities filled with bacteria and a slimy
substance.

" Mai nero " of the Vine.

This name is given to certain diseases of the vine, the cause
of which has never been satisfactorily explained. Baccarini^
succeeded in obtaining all the symptoms of the disease after
infecting healthy twigs by grafting on diseased pieces. Prillieux
and Delacroix^ describe a similar disease prevalent in Tunis
and throughout France, with the name " Aubernage." The
wood when attacked exhibits black points which rapidly
enlarge and coalesce, causing it to decay. All diseased elements
were found to contain a brown gummy substance in which a
form of Leptothrix-hdiCteYiwYCi swarmed. Inoculation of healthy
vines produced the disease in the following year.

Certain diseases of the grape have also been ascribed to
bacterial action, and investigations are at present in progress.

Sorghum Blight.

A disease of species of Sorglutm has been long known in
America, especially on S. saccharatum, one of the sources of
sugar. The symptoms are red or black spotting of the leaves
and other parts of the plant. The disease may even be severe
enough to cause death of the host-plants. Burrill in 1886
found a bacterial form present in the spots, and named it
Bacilli's sordid. Kellermann and Swingle^ obtained pure cultures,

^ Boyer and Lambert, "Deux maladies du MArier," Compt. rend., cxvii., 1893.

^ Ma/pi(jhia, VI.; also Bullet . d. Soc. hotan. ItaL, 1894.

^"La gommose bacillaire d. Vignes," Comptes rend., cxviii., 1894.

* Report of botanical department of Kansas State Agrie. College, 1889.

SORGHUM BLIGHT. 535

and carried out successful experiments in infection of healthy
Sorghum.

Diseased fields should have the Sorgluim stubble burnt out,
and other crops cultivated on them for several years.

Bacterial Disease of Maize.^

From dark slimy spots on young maize-plants which had died
from some unknown disease, Burrill isolated Bacillus secales.
Pure cultures were obtained and minutely described, but no
record is given of its use in infection-experiments.

Red-coloration of Wheat.

This is a phenomenon not uncommon on wheat-grain, where
it may be epidemic. Prillieux- ascribes it to a Micrococcus
which he found associated with it ; as, however, neither pure
cultures were made nor any experiments in infection carried
out, the cause of the disease is still doubtful. Examination of
diseased grain showed that the starch-grains and even cell-walls
had been dissolved.

Mosaic Disease of Tobacco.

This disease of the tobacco is well known in the Nether-
lands. It makes its appearance as a mosaic-like pattern on
the leaf, due to isolated spots becoming light-green, then dying.
Mayer ^ ascribes the disease to the influence of bacteria, although
infection-experiments have hitherto failed ; other observations
on the disease do not confirm this conclusion.

Potato-Rot.^

Kuhn described a dry-rot or tuber-rot of the potato which
had been known since 1830. The disease appears generally
after harvest and lasts till spring. The tubers shrivel up and
become very brittle.

^Burrill, Agric. Exper. Station, Univ. of Illinois, 1889.

^Annale-f d. sci. natar., Ser. vi. , 8, 1878, p. 248.

"* " Ueber die Mosaik-krankheit des Tabaks," Versuchs-slation, Vol. 32, 1886.

■* Kiihn, Die Krcml-Jieiten d. Kulturgeiruchse, 1858.

The text-books of Frank and Sorauer.

Reinke and Berthold, Die Zersetzunr/ d. Kartoffel durch Pilze, 1879.

Kramer, Oesterreirli. landvnrth. Centralhlatt , 1891.

53G THE PATHUCJENIC BACTERIA.

Another disease of potato-tubers quite distinct from the
above is " wet-rot," which is widely distributed, and has been
known since 1845. It appears on the field and shows itself
by a putrefaction of the tubers. Kramer investigated tubers
whose contents had liquefied inside the swollen skin. They
contained unaltered starch-grains, remains of the protoplasm,
and numerous bacteria. The mass in the earlier stages was
acid, later it became alkaline, and smelt strongly of butyric
acid. Kramer obtained pure cultures of the bacteria and infected
potato tubers in various ways, obtaining in every case the
characteristic rot. The Bacillus was obtained in the form of
rods with rounded ends, or as long wavy filaments, or as
spores. On nutritive agar-agar, the colonies form little dirty-
white slimy drops with a distinct margin and a brownish
centre. On gelatine the margin of each colony makes a groove
or funnel in which the colony lies, and liquefaction of the
gelatine proceeds rapidly. This Bacillus is aerobic, in this
respect differing from Clostridium hutyricum Prazm, which is
anaerobic. It also differs from Bacillus hutyricus Hueppe, in
that it is able to decompose milk. It appears quickly on
wounds of all kinds, and infection can easily be performed
artificially by pricking or otherwise wounding the periderm.
Infection also takes plae^e through uninjured skin, and in
this case the Bacillus must enter by the lenticels of the
tuber.

The disease begins with the formation of a soft spot under
the periderm of the tuber. This extends rapidly, the tissue
being completely destroyed, and leaving great cavities containing
the almost uninjured starch-grains. At this stage carbonic
acid and butyric acid are formed, so that the reaction to lit-
mus is acid ; later the decomposing fluid becomes alkaline
from formation of ammonia, methylamine, and trimethylamine.
Various putrefactive bacteria and fungi make their appearance
in the later stages of decomposition after the periderm has
been ruptured.

A somewhat similar disease is reported by Halsted ^ from
the Southern States of America. Diseases of a similar nature
are also reported on tomato, cucumber, and melon.

^ Ztitsrhri/l f. PJlanztnl-rankheiten, 1895, p. .3.37.

POTATO-SCAB. 537

Potato-Scab.

The symptoms of this common disease consist in the formation
of areas of dry corky tissue on the surface of the tubers.
These soon fall a prey to bacterial forms, and rotting takes
place, soon, however, to be cut off from the healthy tissue by
a layer of cork. The disease continues to spread deeper into the
tuber, till the reserve materials are used up or rendered viseless.
Bolley ^ ascribes the disease to a particular Bacterium which he
isolated and used to carry out infections on healthy tubers.
Without doubt this Bacteriuiii is common in tubers exhibiting
" scab," but other conditions may have caused the disease in the
first instance.

Thaxter^ believes that the scab-disease of both potato and
beetroot is caused Ijy a fungus Oospora scabies (p. 497).

Schilberszky ^ in investigating a potato-scab, found a fungus
which he places amongst the Chytridiaceae ; its life-history has
not as yet been followed out.

Bacterial Diseases of Beetroot.

Beetroot and sugar beet have shown themselves very liable
to diseases which have been ascribed to bacterial agency. Thus
in sugar beet which yielded a low proportion of sugar, Arthur and
Golden * found the cells inhabited by a multitude of bacteria.
These inhabited both roots and leaves, without, however, giving
any external evidence of their presence.

Hiltner^ observed that beetroot died in consequence of loss
of its root-hairs. This loss was traced to bacteria, and, after
these had been killed by disinfection, the same roots again
produced normal root- hairs and grew well.

More recently Sorauer " describes a disease of these crops
in Germany. The lower ends of the plants become black, while
from the undiseased portions of the surface there exuded a
gummy fluid containing bacteria, yeasts, and fungi. He considers

'Bolley, "Potato-Scab."' Agricultural Science, 1890.

- Thaxter, BcporfH of the Connertirut Agric. Exper. Station, 1890 and 1891.
" .Schilberszk}', Vorlauf. Mittheilung, Ber. d. deutsch. botan. Ges., 1896, p. 36.
* " Diseases of the Sugar Beetroot." Indiana A<jric. Exper. Station, Bull. 39, 1892.
■' Hiltner, Sdchxi-ich. landirirth. Zeitnng, 1894.

'^ Blatter f. Zuckerruhenhau, 1894; also Ctntralhlatt f. Bakteriolo<jie und Para-
■sitenkiinde, xviii. , 189.5, p. 29,").

538 THE PATHOGENIC BACTERIA.

that the disease was in the first instance due to bacterial action.
Other diseases have already been noticed amongst the " Fungi
Imperfecti " (p. 464).

Gummosis of Plants.

There are many diseases characterized by a gummy outflow
from the diseased parts or from their neighbourhood. Amongst
plants exhibiting this are trees like the mulberry, olive, vine,
fig, and vegetables like potatoes, turnips, beetroot, and many
others. As yet, however, no investigations have been carried out
carefully enough to give satisfactory explanations of them. It is,
however, probable that they are primarily due to errors in
cultivation, while the bacteria which are always found associated
with them are of secondary importance as disease-producers.

Bacteriosis of Bulbs.

Hyacinth-bulbs, when stored up, are liable to several
diseases which bring about rot and decay. Bacteria have
been found in the earlier stages of the rot by several
observers. One of these bacterial forms described by Wakker ^
occurs as yellow masses, particularly in the decaying fibro-
vascular bundles of the bulbs ; it has been named Bacillus
hyacinthi Wakk. "Wakker succeeded in carrying out infections
with it, and it seems to be a definite bacterial disease. The
external symptoms were yellow lines on the leaves, due to yellow
masses of the Bacilli's in the vascular bundles and intercellular
spaces of the parenchyma.

Another bacterial disease of hyacinth and other bulbs was
investigated by Heinz.^ The disease starts from the bulb, and
rapidly extends into the leaves and inflorescences, so that the
leaves wither and the flower-buds drop off. Shortly afterwards
the diseased tissues break up and become a foul-smelling slime
containing an almost pure culture of a bacterial form which
Heinz named Bacillus hyacinthus sqjficus. The Bacillus is easily
cultivated on gelatine, which it does not liquefy. When applied
to the base of the leaves it easily infects them, penetrating in

Wakker, Botan. Cenfralblatt , xiv., 188.3; Wakker, "Onderzoek d. Ziekten
van Hyacinthen, etc.," Abjem. Vereenig. voor BloembollenktiKur, 1883, 84, 85.
-Heinz, Ctntralhlatt fnr BaJcttriologie und Parasitenkiinde, 1889, p. 535.

BACTERIOSIS OF BULBS. 539

twenty-four hours to a distance of 5-10 cm. through the leaf-
tissue. Infection of leaves and bulbs of common onion with
the same Bacillus was also successfvilly carried out, and the same
symptoms of disease followed.

Sorauer, in his " Handbuch." describes a bulb-rot said to be
due to bacteria ; but whether it be the same disease as this
or not we cannot say.

Bacterial Disease of Beans.

Halsted ^ describes a disease on cultivated beans, which caused
considerable loss in the United States. Bacteria were present in
large numbers in all diseased parts, but to what extent they
were responsible for the disease could not be exactly determined.

IV. THE PATHOGENIC ALGAE.

The Cyanophyceae or Schizophyceae, though generally placed
with the Bacteria in the group of the Schizophytes, are here
included with the true Algae on account of the great resemblance
in their mode of life when they play the part of symbiotes
or parasites.

The Diatomaceae contain no endophytic species.
The Algae differ from the groups of the Fungi, Myxomycetes,
and Schizomycetes, in their possession of chlorophyll and their
power of assimilation. The relationship of the Algae to other
living organisms may be expressed under the following heads :
I. Symbiosis of Algae with Fungi. (Lichens.)
11. Symbiosis of Algae with animals.
III. Symbiosis of Algae witli chlorophyllous plants.
{a) Epiph} tes.
(&) Endophytes.

1. Inhabitants of free spaces in other plants.

2. Inhabitants of domatia.

IV. Parasitism of the endophytic Algae.
{a) In relation to animals.
(&) In relation to plants.

1. Inhabitants of the cell wall.

2. Inhabitants of the cell cavity.

3. Destroyers of tissues as a whole.

1 New Jersey Agric. Exper. Station, Beport, 1892.

540 THE PATHOOKNKJ AlAiAK.

The lichen-symbiosis is the most marked example of mutual
symbiosis we know. Amongst the partnerships of Algae with
animals every form exists from mutual symbiosis to true
parasitism or to typical epiphytism. The last condition is, how-
ever, more frequently met with amongst Algae or Liciiens
epiphytic on other chlorophyllous plants. The phenomenon
of " shelter-parasitism " is also a frequent one, the Algae
inhabiting cavities already present in the host, or " domatia "
— places of abode formed with the assistance of the Algae.

The full discussion of these and other symbiotic relationships
may be had by reference to the works dealing with subject ;
some of the more important of these are given :

De Bary, Die Ersrheinung der Symhiose, 1879.

O. Hertwig, Die Symhiose im Thierreich, 1883.

Klebs, " Symbiose ungleichartiger Organisnien." Biolog. Centrcdblatt,
1882.

Klebs, " Beitriige yaw Keiintniss niederer Algeiiforinen," Dotan. Zeitang,
1881.

Geza Entz, " Das Koiisortialverhaltniss von Algen uiid Tliieren," Biolog.
Centralblatt, 1882.

Brandt, " Die raorphologische und physiologische Bedeutung des Chloro-
phylls bei Thieren." Mittheil. d. Zoolog. Station Xeapel., 1883.

Van Beneden, Animal parasites and Messmates. (English Edition),
International Scientific Series.

(])nly these algae which are parasitic on the higher plants
come, strictly speaking, within the limits of the present work ;
we shall, however, also take into consideration the interesting
symbiotic adaptations presented by several algae which live
endophytic, but not truly parasitic, in higher plants.^

There is a distinct resemblance between the parasitism of
algae and that of parasitic fungi. Some parasitic algae live
in the intercellular spaces of their host, others inside the
host's cells, and many of them inhabit algae and other aquatic
plants. A large number of algae live as endophytes, many
of them in cavities occurring naturally in other plants ; such
we can hardly regard as parasites ; nor those which cause the
formation of " domatia " on their hosts, since these structures
are an indication of a symbiotic rather than of a parasitic

^Altmann (Botan. Zeifnuf/, 1894, p. 207) describes a number of marine algae
parasitic ou Facaceae ; Moebius, " Endophyte Algen," Biolo(j. CentraU>{att, 1891 ;
also Conspecttis algarum endoph/tarum, etc., 1891, with complete bibliography.

THE CYANOPHYCEAE. 541

relationship. The manner in which tyijieal chlorophyllous plants
gradually become shelter-parasites, and pass from this into the
condition of true parasites, is well demonstrated amongst the
algae. Few of the parasitic algae can be said to affect their
host injuriously by causing death of its tissues ; PhyllosipJion is
the most marked case of this kind.

A. THE CYANOPHYCEAE.

These, the blue-green algae, possess a homogenous bluish
green plasma, with a colouring matter consisting of phycocyan
and chlorophyll. Multiplication takes place only by cell-
division ; sexual reproduction does not occur. Many of the
forms are adapted to a symbiotic life, yet without prejudice to
their ability to live as independent organisms. Numerous
species form lichens. They are in many cases capable of long
resistance to drought.

The Cyanophyceae are common both as endophytes and
epiphytes on other algae and on higher plants. Amongst them
will be found examples of purely shelter-parasitism, of true
parasitism, and all intermediate stages, yet no cases are known
of real injury or death to host-plants resulting from members
of this group. Amongst forms endophytic in Phanerogams may
be noticed Nostoc gunnerae in Angiosperms, and Anahaena
cycadearuin in Gymnosperms ; in Pteridophyta only Anahaena
azollae is known, and in Bryophyta, Nostoc lichenoides. In every
case the Nostoc penetrates as a shelter-parasite into fissures or
cavities already existing in the host, and becomes as a rule
entangled in a slime occupying the cavity. The Nostoc in
GvMnera becomes parasitic at a later stage, and makes its way
into the cavity of cells. The other species are never endophytic
in the host-cells, though they may affect the cells surrounding
a cavity and stimulate them to further growth, apparently,
however, without any injurious effect on the host-plant.

Nostoc punctiforme (Kutz.) P. Hariot ^ {Nostoc {Scytonema)
gunnerae Eeinke).^ This occurs in various species of G^innera,
natives of South Africa, New Zealand, and South America ; or
cultivated frequently in Europe. The occurrence of the Nostoc
is in every case the same, its presence being indicated to the

1 Hariot, Compt. rend, ex v., 1892.

-Reinke, Morphologische Ahhandlungen, Leipsic, 1873.

542

THK I'ATHOGENIC ALGAE.

naked eye by bluisli-green spots on sections of stems and

rhizomes of the host (Fig. 319).

These originate as follows : the
species of Gunncra possess charac-
teristic mucilage-secreting organs, in
the form of fissures of the leaf-tip,
collaters on the leaves, and glands
on the stems. Merker ^ found that
these glands originated endogenously
in the growing point between each
pair of leaves. The mature glands
are covered only by the epidermis,
and when activity commences the
uppermost cells of the gland-tip,
after swelling, become detached and
converted into slime (Fig. 320).
Ultimately the epidermis is ruptured
by the pressure of the slime, and

the remaining glandular cells are in turn rapidly transformed

into the same substance.

Via. 31'.i. — No.'<toc fit'.nnerae. Longi-
tudinal .section through the apex of a
stem of (liumtra niauirata. The punc-
tated spots indicate the position of
^ostO''-colonies. (v. Tubeuf del.)

Pio. 320. — Nosstoc gunnerae. Longitudinal sections through a gland in stem of
Gunnera macrophylla. c. Epidermis ; .?, slime-canal ; no, colony of Xostoc.
(After Merker.)

The Nostoc finds its way into the gland as soon as the
epidermis is broken, apparently attracted there by some
secretion. Merker found that the Nostoc filaments pass down

^Merker, " Gunnera viucropJujlla ," Inaugural Dissertation, 1888.

NOSTOC.

543

the slime-canal into the gland itself, and there occupy the
space left by the glandular cells on their conversion into slime.
Thence the filaments find their way into the intercellular spaces
of the starch-containing parenchyma surrounding the gland, and
become closely applied to the cell-walls. The Nosfoc then Ijores
through or dissolves the cell- wall, absorbs the starch, and grows
vigorously till it fills the whole cell. In this manner the
Nostoc spreads through the cortical parenchyma of the Gunncra
stem from cell to cell. The stem glands in course of time
become inactive and the canal closes up, so that the Nostoc is

Fig. 321. — Aiiobaena cyciuUarum. A , Coral-like surface-roots of Ci/ca.i. B, Trans-
verse and longitudinal sections of A ; the double line indicates the distribution
of the Nogtoc. (v. Tubeuf del.)

completely siiut in. In this condition it is absolutely de-
pendent on nourishment derived from the host-cells, and seems
to thrive on it. Xo outward symptoms of disease can be
observed on Gunnera with enclosed Nostoc, the local destruction
of the cell-contents, the loss of starch, and the filling up of
the tissues with filaments of Nostoc having apparently no
effect. The species of Gunnera have a very short stem with
a growing point hardly raised above the level of the soil, so
that the Nostoc easily finds its way there. Xo algae have
Ijeen found in the petiole and lamina of the gigantic leaves.
Gunnera may easily be cultivated although it contains no
Nostoc.

Jonsson^ regards Nostoc gunncrac as identical with N. puncti-

ijonsson, Botan. Notistr, 1894.

544

THE I'ATHOGENIC ALGAE.

forme (the earlier name) ; he also believes that it exists on
damp soil and independently of (ritnncra.

Anabaena cycadearum (Reinke).^ [Nostoc commune
(Sclmeider)."] The IVtllovving account of this species is taken
from De l^ary.^ Seedlings of Cycadeae have a thick tap-root
which branches in the soil ; from the proximal end of the
primary root a few pairs of root-branches grow up perpen-
dicularly, and, after forking once or twice, their ends swell to
form tubercles (Fig. 321). Similar clumps of forked twigs

Fig. 322. — Anabaena ri/rndiarum. Sectiun of a Cj'cad-root, as in Fig. .'521 A,
and in the condition shown in the upper transverse section B of that figure.
The iVo.sioc-iilaments crowd the intercellular spaces and cause alteration in shape
and growth of the .adjacent cells as shown, (v. Tubeuf del.)

arise later on other branches which arise from the tap-root
and spread over the surface of the ground.

It is into these forked twigs that the JVostoc makes its way
and causes the following characteristic alteration in their
structure. A layer of parenchyma, which in normal roots does
not differ from the surrounding compact polygonal tissue, becomes
in attacked roots a definite zone round the axile vascular bundle.
The zone consists of parenchymatous cells much elongated in one
direction, and with their interspaces filled with masses of algal
filaments (Fig. 322). In cross-sections of attacked roots the Nostoc

iReinke, Botan. Ztitung, 1879, and Ahhandlungen, 1873.

- Schneidei-, Botanicnl Gazette, 1894, p. 25.

^De Bary, Die Ersclieinunij der Si/nihiose, 1879, p. 14.

ANABAENA. 545

zone generally forms a circle; in longitudinal section the cylinder
of blue-green algae does not extend quite up to the growing-
point. According to Eeinke, the alga penetrates into the
newly-formed intercellular spaces of the developing periblem-
cortex, and remains confined to the zone which it has first
excited to increased growth. It is not certain whether the
Nostoc penetrates only into injured places or into natural
fissures.

The branched aerial masses of tubercles on Cycad-roots are
produced independently of the Nostoc} but their function is
unknown beyond a suggestion that they are organs of respira-
tion. They certainly receive no injury from invasion by the
Nostoc. Since the Nostoc lives completely cut off from the outer
world and frequently in subterranean roots, we must assume
that it receives nourishment from the host.

Eeinke found Anabacna in roots of Cycas, Ccratozainia, Dioon,
and Eiicc])]ialartos.

Eeinke has also found very fine fungal mycelia in the roots
of Cycads. Schneider observed intracellular bacteria in root-
tubercles free from Nostoc.

Anabaena azollae Strasb.^ This endophyte is never absent
from Azolla, neither A. caroliniann so much cultivated in hot-
houses, nor the wild species found in America, Africa, Asia,
and New Holland. The algal filaments are present even in
the neighbourhood of the vegetative point and in the closed
indusia of the sporangia. They are, however, most abundant
in the cavities formed in the epidermis of the fieshy floating
leaves.^ The Anabaena filaments do not enter the cavity by
the opening found in the completed structure, but find their
way in during the formation of the cavity, and probably influence
its development. As the cavity becomes filled with Anahaena,
some cells of its inner walls grow out as segmented branched
filaments amongst the coils of the alga, probably in consequence
of a stimulus exerted by the Anabaena.

No endophytic Schizophyceae are known in the true mosses,

^ Moebius (Joe. rit.) states that the roots of Cycads at the Botanic Garden.
Heidelberg, never contain Anabaena.

- Strasburger, Ueber Azolla, Jena, 1873 ; also Practical Botany (English Edition
by Hillhouse, 1889).

'The leaves of Azolla are divided into two parts, the upper fleshy one of
which doats on the water, the under membranous one being submerged.

2m

il46 THE I'ATHOGENIC ALGAK.

but several inhabit nqxUicae, chiefly species of Anthoccros, Blasia,
Pellia, Ancura, Diplolaena, Sauteria, and Riccia.

Nostoc lichenoides Vauch.^ is a common endophyte in tlie
unu'ilane-caviliu.s of ^inthoccros laevis. The motile ak'al filaments
gain admission through the stomata or mucilage-fissures on the
lower side of the thallus. Only one filament is admitted into
each cavity, then the opening is closed by an increased turgescence
and growth of the guard-cells ; tlie imprisoned Nostoc nmltiplies
to form a colony.

Leitgeb states that after infection has successfully taken place,
and frequently before the stoma has quite closed, the guard-

Fio. 323. — Anabaena azollae. Longitudinal section through the posterior lobe
of a floating leaf of AzoUa cnroliniana. The cavity is filled with i\'o.<(o<;-filaments
and septate hairs.

1, A septate hair, and a filament of Anahoxnn. (v. Tubeuf del.)

cells divide and ultimately form a three-layered covering of
cells over the intercellular space. Simultaneously all the thallus-
cells round the infected cavity undergo radial division and grow
into the cavity, first as papillae, then as much-branched and
septate tubes of various lengths ; the space left between them
becomes meanwhile filled with the Nostoc. In the case of
Anthoccros laevis the tubes form a kind of pseudoparenchyma

^Bibliography: Janczewski, Botan. Zeitunfj, 1872, and Annates d. sci.
7iatur., Ser. ^, XVI. 'Milde, Botan. Zeitung, 1851. Ijeitgeh, Akadetnie d. Wissen-
schaften in Wie/i, 1878; also Untersuchungen ilher Leber moose, i. Goebel, "Die
-Muscineen," in Schenk's Handhuch d. Botanik, 1882.

NOSTOC. 547

with interspaces filled with Nostoc. If other algae, e.g. Oscillaria,
enter the cavities, the opening is neither closed nor do the walls
grow out as processes. Infection by Nostoc only occurs when
tlie mucilage-cavities lie near the apex of the thallus and are
secreting mucilage, the substance which evidently stimulates the
Nostoc to enter.

Leitgeb found many Anthoceroteae {Demlroceros, Nototylas,
Anthoccros) with mucilage-cavities containing Nostoc, not sunk
in the thallus as w4th Anthoccros lacvis, but forming warty pro-
jections above it. In the case of Denclroceros these occurred on
the upper side of the thallus as well as on the lower. The
openings of the cavities of Notothylas do not close after infection,
but distinctly open wider.

Janczewski observed that chlorophyllous cells of Hepaticae,
though at first uninfluenced by the intruding alga, afterwards
lose their chlorophyll and plasma ; hence he assumed that the
imprisoned Nostoc begins in time to live a parasitic life, and to
kill the host-cells. This, however, is not supported by other
authorities. Goebel, on the other hand, believes that the Nostoc,
Jike the mucilage amongst which it grows, is useful to the
thallus, and that it ultimately completely replaces the mucilage.
Prantl held that the alga assimilated free nitrogen, giving
up the product to the hairs in the cavity ; but this is ex-
tremely unlikely, especially when the Nostoc is completely enclosed
in its host.

Nostoc lichenoides is also very frequent in the leaf-auricles on
the under side of the thallus of Blasia pusilla. The auricles
contain mucilage, which probably induces the Nostoc to enter. As
a result of the Nostoc invasion the auricle enlarges and continues
to live, whereas without this it would soon have died off.
Branched filamentous processes are produced from the inner wall
of the auricle and grow amongst the Nostoc}

B. THE TRUE ALGAE.
In these Algae the green chlorophyll is limited to certain
portions of the plasma, the chromatophores. The true Algae
are capable of sexual reproduction. They are all more or less
adapted to an aquatic life. Many of them live in symbiosis,
some are true parasites.

^ Waldner, Akad. d. Wissenscha/ten in Wien, 1S7S.

548 THK I'ATII0(;KNIC algak.

The true Algae may be grouped as follows: (1) Cotjiujaiac;
(2) GldoroiJhyccae ; (3) Rhudcyphyccae ; (4) Phae(yphyceae \ (5)
Characcae.

Of these the Ckuracecu' includes no endophytes, the Conjiujatac,
Phaeophyceac, and Rliodojthyceae only species endophytic in other
algae or in animals. The Chloroiiliyceae, however, include a
large number of species which live as " aerial algae " endophytic
in Phanerogams, either as shelter-parasites or as true parasites.

I. CHLOROPHYCEAE.

These are divided into three groups : ^

1. Protococcoideae including the families Volvocaccac, Tctra-
sporaccae, Chlorosphacraccae, Pleurococcaceae, Protococcaceae {Endos-
l^liaeraceac , Cliaracicae, Sciadiaccac), and Hydrodictyaccae.

2. Confervoideae including the families Ulvaceac, Ulothrichaceae,
Chaetophoraccac Mycoideaceae, Cylindrocapsaceae, Oedogoniaccae,
Coleocliadaccar , Cladoj^horacear, Goviontiaccac, and Bpliaero'pleaccac.

3. Siphoneae including the families Botrydiaccac, Phyllo-
sipJionaceae, Derbesiaceac, Vaucheriaceae, Bryopsidaceae, Cmder-
paceac, Codinccae, Valoviacear and Dasycladaceae.

Chlorosphaeraceae.

Chlorosphaera endophyta Klebs. This is found between
the living epidermal cells of Lemnci minor, and produces there
spherical cell-masses visible to the naked eye as wart-like
swellings. According to Frank, this is related to Endodonium
p)olym orph u m Fra nk.

Entophysa charae Mob. This lives under the cuticle of
the epidermal cell-wall of Ohara Hornemanni in Brazil.

Endosphaeraceae.

Most of the species can penetrate into living organs, but they
may also live as saprophytes or vegetate as independent organ-
isms. That all the Endosp)haeraceae are injurious to their host
has not as yet been proved.

Chlorocliytrium includes eight European species all endophytic
in living plants.

^ The arrangement used by Wille in Enriler-Prantl. natur. Pflanzen-familien.

CHLOROCHYTRIUJt.

549

Chlorochytrium lemnae Cohn.^ The zygozoospores have
four cilia and swarm for a short time in water. On plants of
Lemma trisulca, the ciliated end becomes apj)lied to the epidermis
at the place where two cells are in contact, the zoospore becomes
spherical, forms a membrane, and comes to rest (Fig. 324). It
remains resting for a day or two, and assimilates so that a
starch-grain is formed inside it. Next, a transparent process is
given off which finds its way between the epidermal cells, widens
out, and absorbs the cell-contents, while the portion of the algal

Fig. 324. — Chlorocliytrlum lemnae. u, h, c, Ger-
minating spores pcnetr.ating through the epi-
dermis and between the cells of the parenchyma.
A surface view shows the germinating spores
from above. (After Cohn.)

Fig. 325. — Chlorochytrium lemnae
in Ltmna trisulca. a, Mature ; b,
young ; c, discharged sporangia.
(After Klebs.)

cell remaining outside becomes filled with cellulose antl forms a
firm button-like process. The young alga continues to make
its way between the cells into the intercellular spaces of the
subepidermal layers of parenchyma, preferably taking up its
quarters in the thin anterior margin of the thalloid shoot,
and avoiding the larger air-spaces. The zoospores are formed
by repeated division of the plasma of the original cell ; they
are enclosed in a gelatinous mass which swells and ruptures
the membranes of the alua as well as the tissue of the Lemna.

^ Cohn, BaUratje zur Biologie d. nied. Orr/anismen ; Klebs, Botan. Zeituvij, 1881.

550

THE PATHOGENIC ALOAE.

The zoospores (gametes) coi)ulate in the gelatinous mass which
escapes, and break out from it as free swarming zygozoospores.
When the Lemna falls to the bottom in autumn, or when it
dries up, the cells of the alga become resting-cells capable of
sustaininrc drought. I'lants of Lcmna seem to be little
disturbed by attacks of the endophyte, and develop their
flowers normally.

Chi. Knyanum Kirch n. Frequents Lcmna minor and L. (jihha,
Cn-atophyllvm demersum, Elodea canadensis, but not Lemna
trisulca. It forms zoospores only, and these on penetrating
into a host do not produce a cellulose button like the species
just described. They appear to be able to enter the host only
by the stoniata.

Chi. pallidum Klebs. Grows in the intercellular spaces of
Lemna trisulca.

Chi. viride Schroet. Found in the respiratory cavity of
liumcx ohtusif alius.

Other species occur in dead Phanerogams or in Algae.

Stomatochytrium limnan-
themum Cunniugh. Inhabits
the respiratory cavity of leaves
of Limnanthemum indicum in
India.

Chlorocystis Cohnii Keinh.
Occurs as a " shelter-parasite "
in marine algae.

Scotinosphaera paradoxa
Klebs. Found between the
cells of dying leaves of Hypnum and Lcmna triscula.

Endosphaera biennis Klebs. The zygozoospores have four
cilia, and swarm in water till they reach a living leaf of
Potamocjeton lucens. They generally come to rest on the under-
side of a leaf at the boundary wall between two cells, and
become invested in a membrane. A process is next sent in
between the epidermal cells, and all the cell-contents pass over
into it, the outer portion dying away. The young alga now
makes its way into the intercellular spaces of the sub-epidermal
tissue and becomes a resting spore. In spring this spore
gives off' biciliate gametes, which, after copulating, become
zygozoospores. This shelter-parasite has not yet been observed

Fig. 326. — EnJo.ijihrn rn bimiiis in PotomoffetoH
lucens. Cell of the Alga, which has penetrated
through the epidermis a few weeks previously.
(After Klebs.)

ENDOSPHAERA.

551

to have an injurious effect on its host, beyond killing a few
isolated leaves.

End. rubra Schroet. occurs in leaves of Mentha aquatica and
Pcplis Portvla.

Phyllobium dimorphum Klehs. Found in leaves of Lysi-
macMa Nuramalaiia, Ajuga rcptans, Cldora serotina, Erytlivaca
Centaurium. This endophyte may either penetrate into living
leaves and there go through its life-history, or it may do so
in dead leaves. The zygozoospores have only two cilia, and
enter the leaves chiefly through the stomata of the lower
surface. Inside the leaf they form long filaments, which make
their way between the elements into the vascular bundles of
the leaf-ribs, and follow the course of the spiral vessels.
Eesting- spores are formed, and
give the veins of the leaf a
rosary -like appearance. Male
and female gametes are pro-
duced from the resting cells, and
copulate to form zygozoospores.
The host-plants are not injured
by this endophyte.

Chaetophoraceae.

Most of the species are aquatic
algae which live independent or
as epiphytes.

Endoclonium polymorphum
Frank (see C%lorosphaera cndo-
phyta Klebs). This form lives
endophytic and sometimes intra-
cellular in living or dead leaves
of Lemna.

Entoderma Wittrockii Wille
occurs inside the wall of Ectocarpus (Fig. 327).

Periplegmatium and Phaeophila live endophytic in living
algae.

Trentepohlia endophytica (Eeinsch). In living cells and,
intercellular spaces of Jungermanniaceae (e.g. FruUania dilatata)
and kills them.

Fig.

- Entoder

Wttti-ock-ii iu the

membraue of a species of Alga (Eitnrarjms).
A, A young one-celled plant just after pene-
tration into the alga. B, Plant composed of
several cells in the wall of Ertoco.,-pus. C,
Plant which has formed sporangia of swami-
spores, one of which Is discharged and
another is in the act. (After Wille.)

552

THK PATHOGENIC ALiiAE.

Mycoidaceae.

Cephaleuros Mycoidea, Xarsten ^ {Mijandm ^xirasitica,
Cuniiiii;j,.).- Tliis alga is epiphytic on the leaves of most trees
and' shrubs in the tropics. It varies considerably in its appear-

FlG. 328. — C'l phnliUi-oif MjK'o'ahn. Section through the epidermis of a leaf of C'amellw,
showing the thallus-like disc with haustoi-ia. (After Cunningham.)

ance, but generally forms flattened thalloid discs several layers
of cells thick and attached firmly to leaves by means of rhizoids
(Fig. 328). Hairs are produced from the thallus-discs, especially

Fio. 329. — CepIuUeuros Mycoideo.. Section through part of an attacked leaf of
Camellia. The epidermal layer has been ruptured, and haiistoria from the algal
disc penetrate to the tissues. The dark-shaded portion is that killed by the
alga. (xVfter Cunningham.)

the older ones ; in addition, sporangial structures are also developed
and give off biciliate swarm-spores. The discs form a kind of
cuticle which becomes completely fused with that of the leave.';.

1 Karsten, AunaJ^ dujardin. hotan. tie Buitenzonj, Vol. x., 1801.

-("unningham, Trans, of Linnean Soc. of London, 1880; H. M. Ward (idem),
1884.

MYCOIDACEAE. 553

Where this occurs, black patches are frequently formed so that
the leaves become spotted, but the injury to the host-plant is by
no means so severe as in the following species.

Ceph. parasiticus Karsten. This species is common on the
leaves of Calatlica and Panda nus at Buitenzorg. It spreads
through the whole leaf-tissue blackening and killing it. The
epidermis is blistered and its cells filled with the alga ; ultimately
the cuticle is ruptured and the stalked sporangia are pro-
duced. The swarm-spores germinate in the stomatal cavity,
or in the adjacent intercellular spaces.

Ceph, minimus Karsten is parasitic on leaves of Zizyiilms
Jujaha at Ikiitenzorg. It permeates the leaf-parenchyma and
kills it, the cells after death becoming completely occupied
by the alga.

Phyllosiphonaceae.

Phyllosiphon arisari Kuhn.^ This is a true parasite as yet
observed only on Arisarum vidgare. in Italy and the South of
France. It causes death of the leaves and is frequently very
abundant.

The tliallus consists of unicellular, non-septate, much branched
filaments containing chlorophyll, and filling up the intercellular
spaces of the spongy parenchyma of the host. The wall of
the filaments gives the reactions for cellulose and consists of an
outer and a later-formed inner layer, the latter capable of swelling
very much to assist in ejaculating the spores. The chlorophyll
corpuscles at first contain no starch, only oil, which, however,
decreases during spore-formation, while the starch increases.
The spores (aplanospores) are formed inside the algal threads,
and are ejected with great force from the extremities of filaments
which lie under stomata, and therefore in the position where least
resistance is offered to the swelling inner wall. Chlorophyll is
not present in the young filaments, but it appears in the older
parts, especially about the time of spore-formation, and seems
to be stored in the spores. The spores have a nucleus and
chlorophyll disc. They germinate to a filament which grows
between two epidermal cells into the intercellular spaces of the
leaf.

^ Kuhn, " Eine neue parasitische Alge," Sitzuiig-iber. d. naturforsch. Ges.,
Halle, 187S ; Just, Botan. ZtUiuKj, 1882 ; Schmitz {idem).

554

TKK PATHOfJENIC ALGAE.

Parts of the leaf and petiole inhabited by thi.s alga appear
externally as yellow spots. Only one individual alga inhabits
each spot, sending its numerous branches into the intercellular
spaces. Attacked leaf-cells lose their chlorophyll and starch,
the latter being at first replaced by oil. The cells, however,
remain alive and turgescent, even when deprived of almost
their whole content ; they die, when spores are produced in the
filaments. Cells undisturbed by the alga remain unaffected. A

i^fS^f

Fio. 330. — Phyllosiphon arisari on Ariso-ruui vulgare. A, Leaf with yellowish
s{)ot.s ; S, the branched alga isolated from a spot ; C, spore-formation in.side a
filament; 0, spores. (After Just and Engler-Prantl.)

single leaf may bear a large number of spots, and all the plants
of a locality are generally attacked. The spots were found by
Just only from December to April, then they disappeared,
indicating that the algal spores must have a resting-period
outside of the Arisarum, and return to young plants again in
autumn.

Phytaphysa Treubii Weber et v. Bosse. Forms characteristic
galls on a species of Filca in Java.

2. PHAEOPHYCEAE.

These algae live only in other living algae, and are not en-
dophytic in higher plants.

PHAEOPHYCEAE. 555

Streblonemopsis irritans Val. forms wart-like galls ou

Cystosira ojnmtioides.

Entonema grows between and into the cells of Rhodophyccae
and Mdanopliyccac.

3. RHODOPHYCEAE.

The Rhodophyccae or Floridcae occur endophytic only in other
algae ; e.g. Harveyella mirabilis (Eeinsch) vegetates in thalli of
Bhodomeleac and Polydphoncac, but reproduces itself outside
its host. Species of Chorcoeolax and other genera have a similar
mode of life.

I. INDEX OF PARASITES.

A

I'AGE

aegopodii, Caeoma, -

PAGE

- 419

abietina, Phoma, -

- 465

,, Puccinia,

- 359

abietiiuun, Aecidium,

- 377

aegra, Puccinia,

- 340

,, Fusicoccum,

- 465

aesculi, Aecidium, -

- 410

abietis, Cenangium,

- 251

,, Septoria, -

- 478

,, C'hrysomyxa,

,, Lophodermium, -

- 379

- 240

,, Taphrina, - - 147,
affinis, Thecaphora,

151, 153
- 324

abietis-pectinatae, Caeoma,

- 418

Agaricineae, . - - -

- 455

abrodens, Mystrospoiium,
abundans, Aecidium,

- 518

- 411

Agaricus, . . . .
aggregata, Soleroderris, -

5, 455
- 251

acaciae, Aecidium, -
acericola, Phyllosticta, -
,, Taphrina,

- 410

- 463
- 151, 154

Aglaospora, - - . -
agrimoniae, Melampsora,
,, Uredo,

- 226

- 370

- 420

acerina, Ceroospora,
,, Dermatea,-

- 513

- 253

agropyri, Puccinia,
,, Urocystis,

- 349

- 316

,, Melasmia, -

- 242, 480

agrostidis, Puccinia,

- 349

Taphrina, - - 147, 151, 153

albescens, Didymosphaeria, -

- 218

acerinum, Leptothyrium,
,, Rliytisma,

- 479

- 242

,, Puccinia,
albida, C'hrysomyxa,

- 341

- 380

aceris, Oidium,

- 499

albidum, Phragmidium, -

- 363

,, Phleospora, -

- 478

albomaculata, Ramularia,

- 502

,, Uncinula,
acetosae, Depazea, -

- 177

- 465

Albugo (see Cystopus), -
albulensis, Puccinia,

- 123

- 361

,, Puccinia, -

,, Uromyces,

actaeae, Aecidium, -

- 355

- 334

- 409

album, Mastigosporium,-

,, Microstroma,
albus, Polyporus, -

- 504

- 497

- 452

Actiiionema, -

- 474

alchemillae, Coleroa,

- 195

acutatus. Uromyces,
adiposus, Agaricus,
adoxae, Puccinia, -

- 337
5, 460

- 359

,, Uromyces, -

Algae,

alismatis, Doassansia,

- 337

539, 547

- 323

,, Ustilago, -

- 299

,, Pseudopeziza,

- 255

adusta, Sclerotinia,

- 262

alliatum, Aecidium,

- 349

adustum, Colletotrichum,

- 487

allii, Caeoma, - - - -

- 367

aecidioides, Melampsora,

- 367

,, Puccinia,

- 355

Aecidium-forms,

- 404

,, Rhizoctonia, -

- 202

I. INDEX OF PARASITES.

557

alliorum, Caeoma, -

,, Macrosporium,

alneuni, Leptothyrium, -
alni, Fraukia, -

,, Microsphaera, -

,, Sclerotinia,

„ Stigmatea,
alni glutinosae, Taphrina,

PAGE

- 419

- 518

- 479

- 101

- 176

- 262

- 211
150, 152, 157

alni incanae, Taphrina, 147, 150, 152, 157

alnicola, Ovularia, - - - - 501

alpestre, Bostrichonema, - - 501

alpina, Puccinia, . - - . 359

Taphrina, - 147, 149, 153, 161

alpinum, Synchytrium, - - - 112

alpinus, Uromyces, - - - 337

alsiuearum, Peronospora, - ■ 134

alta, Peronospora, - - - - 134

Alternaria, . - - . 517, 51S

althaeae, Colletotriclunn, - - 487

althaeina, Cercospora, - - - 515

,, Phyllosticta, - - - 464

Alveolaria, 403

ambiguus, Uromyces, - - - 337

amentorum, Exoascus, - - - 157

ampelinum, CoUetotrichum, - - 488

„ Phonia, - - - 467

,, Sphaceloma, - 12, 467

ampelophagum, Gloeosporium, - 484

amphigenum, Rhytisnia, - - 246

amygdalearum, Clasterosporium, - 511

araygdalinum, Gloeosporium, - - 483

amylovoroiis, Micrococcus, - - 531

Anabaena, . . - . . 544

anceps, Leptosphaeria, - - - 221

anchusae, Acciclium, - - - 347

Andersoni, Puccinia, - - - 359

androniedae, Coleroa, - - - 195

,, Exobasidium, - - 426

Rhytisma, - - - 246

,, Stigmatea,- - - 211

andropogonis-annulati, Ustilago, - 292

,, -tuberculati, Ustilago, 292

anemones, Septoria, - - - 478

,, Synchytrium, - - 112

,, Urocystis, - - - 316

anemones-virginianae, Puccinia, - 360

angulata, Cercospora, - - - 515

angustata, Puccinia, - - - 354

Anixia, ------ 178

annosus, Polyporus,
annularis, Puccinia,
anomala, Ustilago, -
anomalum, Synchytrium,
Antennaria, . . . -
Anthostoma, - - - - -
Anthostomella,
anthoxanthi, Puccinia, -
anthyllidis, Uromyces, -
apii, Cercospora,

,, Phyllosticta, -
Apiosporium, - . - -
apocyni, Aecidium,

,, Septogloeum, -
appendiculatus, Uromyces,
aquilegiae, Aecidium,
arborescens, Peronospora,
arctica, Melampsora,
,, Tilletia, -
arctostaphyli, Exobasidium, -
arenariae, Peronospora, -

,, Puccinia,

arenariicola, Puccinia,
areola, Ramiilaria, -
argentata, Puccinia,
ari, Aecidium,
ari-italici, Caeoma,
ariae, ^Melampsora,
aristidae-cyauthae, Ustilago, -
aristolochiae, Puccinia, -
Armillaria, - - - -
armoraciae, Ascochyta, -
,, Cercospora, -

,, Ovularia,

,, Septoria,

aromaticum, Septocylindrium,
Artliuri, Peronospora,
arundinaceum, Helminthospor
,, Napicladium, -

arundinellae, Ustilago, -
Asanuro, Caeoma, -
asarina, Puccinia, -
Aschersoniana, Schinzia,
Aschersonii, Entyloma, -
asclepiadeum, Croiiartium,
Ascoboleae, - . - ■
Ascobolus, - - - -
Ascochyta, . - -
Ascodesmus, - - -

PAGE

5, 450

- 361

- 298

- 112

- 181

- 226

- 226

- 354

- 337

- 514

- 464

- 181

- 411

- 496

- 334
349, 409

- 133

- 368

- 310

- 427

- 134

- 361

- 351

- 502

- 356
349, 410

- 419

- 370

- 294

- 341

- 455

- 473

- 514

- 500

- 477

- 505

- 134
516

- 516

- 294

- 418
32, 359

- 326

- 312

- 381

- 253

- 144

- 472

- 138

lum.

558

I. INDEX OF PARASITES.

rA<;K

Ascoidea,

- 1.S8,

141

Ascomyces,

-

146

Ascomycetes, -

136

Ascospora,

-

211

asparagi, Cercospora,

514

,, Puccinia,

341

aspeiatuni, Heterosporium,

516

Aspergillus,

179

asperifolii, Ovularia,

501

iispicUsttae, Ascochyta, -

473

Asterina,

179

asteris, Puccinia, -

-

361

Asteroma,

- 470,

474

Asteromiflium,

475

asteruni, Aecidiuin,

411

astragali, Didymaria,

-

501

,, Microsphaera,

-

176

,, Uromyces,

■

337

astrantiae, Fabraea,

255

astroidea, Piggotia,

230

atragenis, Puccinia,

-

358

atriplicis, Phyllosticta, -

-

465

aucupaiiae, Sclerotinia, -

-

260

aurautiaca, Thecaphora,

325

aurea, Taphrina, - 148,

ir>0, 154

166

Aureobasidium,

-

428

aureum, Synchytrium, -

111

Auricularieae,

421

aurivellus, Agaricus,

-

462

australe, Rhytisma,

-

246

australis, Peronospora, -

134

,, Puccinia,

349

,, Taphrina,

- 150

154

Auteupuccinia,

-

340

Autobasidiomycetes,

-

421

autuninale, Rhytisma, -

-

246

avenae, Ustilago, -

54

284

azaleae, Kxobasidium,

-

427

azoUae, Anabaena, -

-

545

B

baccarum, Sclerotinia, - - - 260
bacilligera, Passalora, - - - 506
Bacillus, .... 532-538

bacteriospermum, Taphrina, 147, 149, 153
Bacteria, . . . . . 530

Bacterium, - - 101, 143, 534, 537
Balansae, Peridermium, - - - 417
balsameum, Peridermium, - - 417

PAOE

balsamitae, Puccinia, - - - 355

banilnisae, Neovossia, - - - 31 1

barbareae, Aecidium, - - - 409

Barclayana, Neovossia, - - - 311

Barclayclla, 373

Barclayi, Phragmidiuvi, - - - 363

Bardanae, Aecidium, - - - 351

Bargellinia, 138

Barya, 184

Baryanum, Pythiuin de, - - 4, 116

Baryi, Puccinia, .... 354

basicola, Thielavia, - - - 182

Basidiomycetes, - - - - 421

Basidiophora, .... 127

batatas, Rliizoctonia, - - - 202

bataticola, Phyllosticta, - - 464

Batschiaua, Sclerotinia, - - - 270

Behenis, Uromyces, - - 337

bellidiastri, Puccinia, - - - 359

Beloniella, 255

berberidis, Aecidium, - • - 341

,, Melasmia, - - - 479

,, Microsphaera, - - 176

Berkeley!, Puccinia, - - - 356

betae, Phoma, .... 468

,, Phyllosticta, - - - 464

,, Rliizoctonia, - - - 202

,, Uromyces, - - - - 334

beticola, Cercospora, - - - 513

betonicae, Puccinia, - - - 359

Ustilago, - - - 298

betulae, Hormomyia, - - - 262

Sclerotinia, - - - 261

Taphrina, - 148, 149, 154

betulina, Dothidella, - - - 230

,, Melam psora, - - 366, 367

Taphrina, 147, 149, 152, 159

betuliniis, Polyporus, - - - 446

Beyerinckii, Ascospora, - - - 211

Coryneum, - - 211, 491

bicolor, Entyloma, - - - 312

Bidwellii, Laestadia, - - - 216

biennis, Endosphaera, - - - 555

biseptatum, Gymnosporangium, - 401

bistortae, Ovularia, - - - 501

,, Pseudopeziza, - - 256

,, Pseudorhytisnia, - - 255

,, Puccinia, - - - 355

,, Rhytisma, - - - 246

I. INDEX OF PARASITES.

559

bistortarum, Ustilago, -

Bivonae, Uncinula,-

bliti, Cystopus,

Bloxami, Cercospora,

BoUeana, Cercospora,

Boltshauseri, Ascochyta,

borealis, Exoascus,
,, Polyporus,

Bostrichonema,

Botrytis, - - 4,

boutelouae-humilis, Ustilago,

brachysporum, Lophodermiuni,

Brachypuccinia,

Brandegei, Aecidium,

brassicae, Alteruaria,
,, Asocliyta,
,, Chytridium, -
,, Macrosporium,
,, Olpidium,
, , Plasmodiopliora,

brassicicola, Sphaerella, -

Breniia, . - - - -

brexapes, Uromyces,

brevius, Peiidermium, -

bromivora, Ustilago,

Brunchorstia, - - - -

Brunchorstii, Frankia, -

brunnea, Ramularia,

bulborum, Sclerotina,

bulbosuni, Phragmidium,

Bulgaria, - . . .

buUata, Puccinia, -

Taphrina, - 148, 150,
,, Ustilago, -

bullatum, Tolyposporium,

bunii, Aecidium,
,, Puccinia,

Burillia, - . - - -

butomi, Cladochytrium, -

buxi, Laestadia,
,, Puccinia,

Byssothecium circinans, -

cacaliae, Uromyces,
Caeoma,

calamagrostidis, Tilletia,
calcea, Ramularia, -
caleudulae, Entyloma, -

PAGE

PAGE

- 298

californica, Plasmodiophora, -

• 529

- 178

Calonectria, - . - .

- 184

- 127

Calosphaeria, - - - -

- 2-26

- 514

calospora, Tilletia, -

- 310

- 515

calthae, Pseudopeziza, -

- 255

- 473

,, Puccinia, -

- 341

- 158

Calyptospora, -

- 370

439

Camarosporium,

- 47.->

- 501

camelliae, Coryneum,

- 491

267, 499

,, Meliola, -

- 182

- 299

campanulae, Coleosporium,

- 377

- 233

,, ^larsonia, -

- 491

- 353

,, Puccinia, -

- 359

- 411

cancellata, Pioestelia,

- 396

518

Candida, Peronospora,

- 134

- 473

candidus, Cystopus,

- 123

- 107

Candolleana, Sclerotinia,

- 266

- 518

CandoUei, Phoma, -

- 468

- 107

canescens, Entyloma,

- 312

- 524

cannabis, Septoria, -

477

- 215

capensis, Ustilago, -

- 294

- 131

Capnodium, - - - -

■ 181

- 337

capparidis, Cercospora, •

- 515

- 415

carbonarium, Phragmidium, -

- 363

- 292

caprearum, Melampsora,

- 368

- 481

cardui, Puccinia,

- 359

- 101

,, Ustilago, -

296

- 502

caricicola, Puccinia,

- 355

- 266

caricis, Cintractia, -

- 301

- 363

,, Puccinia, -

- 349

- 253

,, Ustilago,

- 301

- 353

cariciiium, Leptostroma,

- 480

154, 168

caries, Tilletia,

- 306

- 288

carnea, Taphrina, - 148, 149,

154, 167

- 306

carneola, Ovularia, -

- 501

355, 409

cameum, Myxosporium, -

- 486

- 356

carpinea, Dermatea,

- 253

- 322

carpini, Melampsora,

- 370

- 114

„ Taphrina, - 147, 150,

153, 162

- 217

Carpoasci, . . . -

- 168

- 361

carpophilum, Cladosporium, -

- 510

- 201

carthanii, Puccinia,

- 355

caryogenum, Fusicladium,

- 508

caryophyllinus, Uromyces,

- 336

- 337

Casparyana, Schinzia, -

- 326

364, 418

cassandrae, Exobasidium,

- 427

- 310

castagnei, Melampsora, -

- 368

- 502

,, Podosphaera, -

- 173

- 312

,, Puccinia,

- 355

560

castagnei, Spliaerotheca,
castaneae, Diploilina,

,, Septoiia,

catalpae, Macrosporiuni.-
catenulatum, Entyloma, -
caulicola, Cercospora,
cauliuni, Melanotaenium,
ceanothi, Aecidium,
oecidomophilus, Taphrina,
cedri, Periclermium,
celiulicola, Schinzia (Naegelia),
celtidis, Ivaimilaria,
celtis, Taphrina, - - 148,
Cenangium, -
ceuchri, Tolyposporium,
centaitreae, Aecidium, -

,, Pnccinia,

cephalanthi, Aecidium, -
Cephaleuros, -
Cephalotheca,
cepulae, Urocystis, -
cerasi, Fusicladium,

,, Puccinia.

,, Taphrina, 19, 147, 151,
cerasina, Septoria, -
cerastii, Aecidium, -

,, Melampsorella, -
cerastioruui, Fabraea,
Ceratocystis fimbriata, -
Ceratophorum,
cerealis, Gibellina, -
cerebrum, Periderniium,
Cercospora,
Cercosporella,

cercosporoides, Cylindrosporium,
Cesatii, Tuburcinia,
chaetomium, Coleroa,
Chaetophoraceae, -
Charrinia,

cheiranthi, Cercospora, -
chelidonii, Caeonia,
chenopodii, Phyllosticta,
,, Uromyces, -

Chlorochy triuni ,
Chlorocystis Cohnii,
Chloropliyceae,
Chlorosphaera endophyta,
Chlorosphaeraceae,
Choreocolax, -

NDEX Ol

' I'AUASITKS.

PAGE

i>a(;k

- 173

ohrysanthemi, Oidium, -

499

- 474

,, Septoria, -

478

- 478

Chrysochytrium, -

-

111

- 518

Chrysomyxa, - - - 20, 54

,377

- 313

chrysosplenii, P^ntyloma,

-

312

- 514

,, Puccinia, -

361

- 314

Chrysospora, - - - -

361

- 411

Chytridiaoeae,

11,

106

147, 152

Ciboria,

-

270

- 417

cichoriacearum, Krysiplie,

-

175

- 32f>

Cicinobolus Cesatii,

-

470

- 502

cicutae, Puccinia, -

-

355

149, 153

cinarae, Ramularia,

-

502

- 251

ciuerariae, Aecidium,

-

352

- 306

cinerea, Botrytis, - - 180,

267

499

- 351

,, Monilia, -

.

261

- 353

cingens, Melanotaenium,

.

314

- 411

cingulatum, Gloeosporium, -

-

485

- 552

cinnabarina, Nectria, - 8, 17, 71

185

- 178

cinnamomeus, Polyporus,

452

- 316

cinnamonea, Dermatea, -

253

- 507

Cintractia, ....

301

. 355

circaeae, Aecidium,

409

153, 163

,, Melampsora, -

370

- 476

,, Puccinia, -

361

- 410

circinans, Coleroa, -

195

- 370

,, Leptosphaeria,

201,

221

- 255

, , Vermicularia, -

471

- 469

circinata, Uncinula,

178

- 511

circumscissa, Cercospora,

513

- 220

cirsii, Phyllosticta,

-

464

- 414

,, I'uccinia,

-

340

- 513

citri, Capnodium, -

182

- 503

,, Meliola, -

181

- 489

Cladochytriaceae, -

113

- 322

Cladochytrium,

114

- 195

Cladosporium,

508

- 551

cladosporoides, Cercospora, -

506

- 472

Clasterosporium, -

-

511

- 515

clavariaeforme, Gymnosporangium,

384

- 419

Clavarieae, - . - .

-

431

- 465

clavellosum, Triphragmium, -

362

- 337

Claviceps, ....

191

- 549

clavipes, Gymnosporangium, -

402

- 550

claytoniae, Peronospora,

-

134

- 548

clematidis, Aecidium, -

349,

409

- 548

Clithris,

-

248

- 548

Cocconii, Tolyposporium,

-

306

- 555

cochleariae, Ovularia,

500

I. INDEX OF PARASITES.

561

PACK

coerulescens, Taphriua, 148, 150

154

167

coicis, Ustilago,

-

294

colchici, Urocystis,-

-

316

,, Uromyces,

-

338

Ooleopuccinia,

-

403

Coleosporium,

-

374

Coleroa, - - - - -

195

Colletotrichiim ,

486

Colpoma, . - - .

-

248

columnare, Aecidium, -

372,

409

comari, Doassansia,

-

324

commune, Nostoc, -

-

544

communis, Erysiphe,

-

175

Taphrina, 147, 151,

152

157

complanatum, Peridermlum, -

415,

416

compositarum, Aecidium,

-

409

concentrica, Pestalozzia,

-

494

condylonema, Cladosporium, -

-

510

confluens, Caeoma,

419

confusa, Taphrina, - - 147,

151

152

confusum, Gymnosporangium,

-

401

congesta, Graphiola,

-

326

conglomerata, Puccinia, -

359

conglutinata, Pleospora,-

-

511

conicum, Gymnosporangium, -

-

391

Coniothecium,

-

517

Coniothyrium,

471

conorum, Aecidium (Peridermium),

416

consimilis, Septoria,

477

controversa, Tilletia,

-

309

convallariae, Aecidium, -

-

410

, , Dendrophoma, •

469

convolvulacearum, Cystopus, -

127

convolvuli, Puccinia,

341

coralloides, Urocystis, -

-

319

Cordyceps, . . . -

-

184

cornicola, Phyllosticta, -

464

,, Septoria, -

478

cornu cervi, Taphrina, 29, 147

149

, 153

Cornuella, - . . .

-

322

Cornui, Peridermium,

381

415

cornuta, Roestelia, - - 385

391

, 392

coronata, Puccinia, -

-

346

coronifera, Puccinia,

-

346

Corticium comedens,

-

452

coruscans, Peridermium,

416

corydalis, Entyloma,

-

312

,, Perouospora, -

-

134

coryli, Gnomoniella,

224

PAGE

- 224

211, 491

- 475

- 292

- 312

- 474

- 476
147, 150, 153, 166

- 337

- 202

- 380

- 282

- 246

- 489

- 475
- 138, 170

- 134

- 510

- 510

- 428

- 469

- 206

- 204

- 188

coryli, Mamiania, -
Coryneum,
Couturea,

Crameri, Ustilago, -
crastophilum, Entyloma
crataegi, Actinonema,

,, Septoria, -

,, Taphrina
cristatus, Uromyces,
crocorum, Rliizoctonia, -
Cronartiura, -
cruenta, Ustilago, -
Cryptomyces, -
Cryptosporium,
Cryptostictis, -
Ctenomyces, -
cubensis, Peronospora, -
cucumerinum, Cladosporium,
cucumeris, Cladosporium,
,, Hypnochus, -

cucurbitacearum, Phoma,
Cucurbitaria, -
Cucurbitarieae,
cucurbitula, Nectria,
Cunninghamianum,Gymnosporangium403
cupulatum, Synchytrium, - - 111
cyani, Aecidium, - - . - 409
Cyanophyceae, . . - - 541
cycadearum, Anabaena, - ■ - 544
cyclameneae, Colletotrichum, - - 488
cyclaminis, Septoria, - - - 478
Cycloconium, - - - - 12, 506
cydoniae, Hendersonia, - - - 475
Phoma, - - - 468

Cylindrosporium, - - - - 488
cynodontis, Phyllachora, - - 229

,, Ustilago, - - - 294

cynoglossi, Peronospora,- - - 134
cynosbati, Cryptostictis, - - 475

cypericola, Schinzia, - - - 326
Cystopus, ... - 28, 123
,, haustoria, - - - 13

,, oogonia, - - - 47

,, spore-germination, 47, 60

cystosiphon, Pythium, - - - 117
cytisi, Diplodia, - - - - 209

,, Peronospora, - - - 133

„ Phyllosticta, - - - 463
Cytospora, - - - - - 471
N

562

D

Dacromycetes,

tlactylidis, Uroniycus,

Dailuca,

Dasyscypha,

Decaisneaua, Schroeteiia,

decipiens, Endomyces, -
,, Synchytriuin, -

,, Taphrina,
,, Tilletia, -

decolorans, Exobasidium,

deformans, Barclayella, -
,, Caeoma,

,, Peridenniuni,

,, Taphrina, 147,

,, Uromyces, -

Dehnii, Beloniella, -

Delastrina, Schroetei-ia, -

Dematieae,

Dematophora,

dendriticum, Fusicladium,
,, Venturia, -

Dendrophoma,

densa, Plasniopara,

densissima, Miciosphaera,

dentariae, Puccinia,

Depazea,

depazeaeformis, Sphaerella,

depressum, Fusicladium,

Dermatea,

Dermateaceae,

Dermatella,

desmodii, Kamularia,

destruens, Agaricus,

,, Biunchorstia,

,, Fusicladium, -

,, Oidium,

, , Ustilago,

devastans, Myxosporium,

devastatrix, Phragmidium,

Diachora,

dianthi, Ascochyta,
„ Septoria, -
,, Sorosporiuin,

Diatrypeae,

dicentrae, Aecidium,

Dicoccum,

dictyospermum, Pythium,

didyma, Septoria, -

147,

150,

[NDEX Ol'

PARASITES,

PAOE

PAOE

Didymaria,

- 501

- 422

Didyniosphaeria,

- 21H

- 3:^6

Didynidsporium,

- 490

- 474

digitalis, Ascochyta,

- 473

- 270

digitariae, Ustilago,

- 291

- 328

digitata, Schinzia, -

- 326

- 141

digraphidis, Puccinia,

- 349

- 109

Dilophia, ....

- 222

, 151, 153

Dilophospora,

- 479

- 310

Dimerosporium,

- 178

- 427

dioicae, Puccinia, -

- 351

- 373

Diorchidium, - - - -

- 361

30, 418

Diplodia, ....

- 472

- 416

diplodiella, Coniothyrium,

- 471

, 153, 165

Diplodina, ....

- 474

- 418

diplospora, Ustilago,

- 291

- 256

Dipodascus, - - ,-

- 138

- 328

dipsaci, Peronospora,

- 132

- 505

discoideum, Exobasidium,

- 427

- 202

Discomycetes,

- 240

218, 507

Discosia, ....

- 480

- 218

discosioides, Pestalozzia,

- 494

- 469

dispersa, Puccinia, -

347, 348

- 131

ditissima, Nectria, -

- 186

- 176

diversidens, Hydnum, -

- 431

- 359

Doassansia, ....

- 322

- 465

domestica, Ustilago,

- 298

- 215

Dothidea, ....

- 230

- 508

Dothideaceae,

184, 229

- 253

Dothidella, ... -

- 230

- 251

Dothiora, ....

- 249

- 252

Uouglasii, Botrytis, - 4,

269, 499

- 502

drabae, Aecidium, -

- 410

- 462

,, Puccinia, -

- 359

252, 481

dracontii, Aecidium,

- 410

- 508

dryadeus, Polyporus,

- 440

- 499

dryadis, Didymosphaeria,

- 218

- 289

Duriaeana, Ustilago,

- 297

- 486

Dyscomycopsis rhytismoides, -

- 245

■ 362

- 230

E

- 473

echinata, Ustilago,

- 294

- 477

echinatum, Triphragmium,

- 362

- 325

echinulatum, Heterosporium,-

- 516

- 226

Ectrogella, . - . -

- 107

- 410

effusa, Peronospora,

- 132

- 506

effusum, Fusicladium, -

- 508

- 117

Ehrenbergii, Sorosporium,

- 282

- 478

Elaphomyces, -

97, 183

I. INDEX OF PARASITES.

563

PAliE

PAGE

elatinum, Aecidiuin, - 18

72, 404

eriophori, Puccinia,

- 352

elegans, Clailosporiura, -

- 509

errabunda, Phoma,

- 469

Eleutheromyces,

- 184

ervi, Uromyces,

- 333

elliptica, Peronospora, -

- 13o

eryugii, Entyloma, -

- 312

Ellisii, Ascochyta, -

- 473

Erysiphe, ....

- 175

,, Entyloma, -

- 313

Erysipheae, ....

7, 170

,, Gymnosporangiuin,

- 402

,, liaustoria, -

-9, 10

elymi, Puccinia (Rostrupia), -

- 354

,, remedies, -

- 68

empetri, Caeoma, -

- 380

erysiphoides, Oidium, -

- 499

,, Chrysomyxa,

- 380

erythronii, Uromyces,

- 338

,, Melasmia,

- 479

erythrostoma, Gnomonia,

- 222

,, Pihytisina,

- 246

esculenta, Ustilago,

- 294

eudiviae, Puccinia, -

- 355

esculentum, Aecidium, -

- 410

Endocloniuin polymorphum. -

548, 551

euonymi, Caeoma, -

368, 419

eadogenum, Melanotaenium, -

- 314

, , Microsphaera, -

- 176

Endomyces, - - - -

- 141

Euj)ezizeae, . . . -

- 270

Endophyllum,

- 403

Euphacidieae, -

- 241

Endosphaera, - - - -

- 550

euphorbiae, Aecidium, -

24, 410

Endosphaeraceae, -

- 548

, , Peronospora,

- 135

Engelmanni, Peridcrmium,

- 417

,, Uromyces, -

- 834

Eiiglerianum, Aecidiuni,

- 409

euphorbiae-dulcis, Melampsora,

- 370

enormis, Puccinia, -

- 359

euphorbiae-sylvaticae, Endophy

Hum, 403

Entoderma Wittrockii, -

- 551

euphrasiae, Coleosporium,

- 376

Entomophthoreae, -

- 115

Eu-puccinia, ....

- 340

Entonaosporium,

- 4S0

Eurotium, ....

- 178

Entonema, . . . -

- 555

excavatus, Uromyces, -

- 337

Entophysa charae, -

- 548

Excipulaceae, - . - -

- 482

Eutorrhiza, . - - .

- 326

exitiosum, Polydesmus, -

221, 518

entorrhiza, Ustilago,

- 297

,, Sporidesmium,

- 221

entospora, Basidiophora,

- 127

Exoasceae, - - - 11, 41

, 52, 144

Entyloma, . - . .

- 311

galls, -

25, 29

ephedrae, Peridermium,

- 417

Exoascus (see Taphrina),

147, 152

Epichloe, ....

- 190

Exobasidiaceae,

- 423

epidermidis, Didymosphaeria,

- 218

Exobasidium, - - - - /

, 13, 423

epilobii, Plasmopara,

- 131

,, galls, - - '-

1, 25, 28

,, Ramularia,

- 502

exotica, Septoria, -

- 478

,, Septoria, -

- 478

expansa, Puccinia, -

- 359

,, Sphaerotheca, -

- 174

extensa, Taphrina, -

- 148

epiloljii-tetragonii, Puccinia, -

- 341

extensicola, Puccinia,

- 351

€piphylla, Taphrina, 20, 147, 150

152, 158

Tilletia, -

- 310

F

€piphyllum, Cladosporium, -

- 510

fabae, Uromyces, -

- 333

epitea, Melampsora,

- 368

Fabraea, ....

- 255

erectum, Aecidium,

- 349

fagi, Phytophthora,

- 117

Eremascus, ....

- 138

fagicola, Actinonema,

- 474

Eremothecium,

- 138

fallaciosa, Physalospora,

- 218

ericae, Hypoderma,

- 234

farinosa, Melampsora,

- 368

erigeronatum, Aecidium,

- 411

farinosum, Oidium,

173, 499

eriobotryae, Fusicladium,

- 507

Farlowii, Taphrina, - 147, 151,

152, 157

564

I. INDEX OF J'ARASITES.

fasciciilaris, Botrytis,
fasciciilata, Tai>lirjna, - I4S,
fasciculatum, Fusicladium,
Fenestella, ....
Fergussonii, Puccinia,
festucae, Puccinia,

,, Urocystis,
ficariae, Cylinclrosponuin,

,, Peronospoia,

,, • Uromyces, -
fici, Uredo, ....
ficuum, Usfcilago, -
filanientosum, Peridermiuin, -
filiciua, Ta2Dhrina, - - 148,

,, Uredinopsis,
filipendulae, Cylindrosporiuin,
., Triphragmium, -

,, Urocystis, -

filuni, Darluca,
fimbriata, Ceratocystis, -
,, Gnomoniella, -

,, Mamiauia,
fimbriatum, Sphaeronema,
firma, Puccinia,
Fischeri, Entyloma,

,, Peridermium, -

,, Tilletia, -

,, Ustilago, -
Fistulina hepatica, -
flaccidum, Cronartium, -
flammulae, Cladochytrium,
flava, Taphrina, - - 148,
Florideae, - - . .
flosculorum, Ustilago,
foeda, Chaetophoma,
foedum, Capnodium,
foliicola, Hendersonia, -
fomentarius, Polyporus, - 74

Fomes (see Polyporus).
fragariae, Ascochyta,

,, Sphaerella,
fragariastri, Phragmidiuni,
Frankia, ....

fraxini, Actinonema,
,, Aecidium, -
,, Hysterographium,
,, Scolecotrichum, -
,, Septogloeuni,
,, Septoria,

I'AOK

r)(»o

149

, 154

508

-

229

-

359

349

316

489

-

134

337

420

299

-

415

149

154

141

420

489

-

362

-

319

-

474

469

-

223

-

223

-

469

-

351

-

312

377

414

-

310

-

281

-

452

-

382

-

114

150

154

555

294,

295

-

181

-

181

-

475

, 84

435

473

-

214

-

363

-

101

-

474

410

232

-

508

-

496

-

478

fructigena, Monilia,

I'AfiB

261, 497

fructigenum, Gloeosporiuni, .

- 482

frustulosum, Stereum, -

- 4m

fuciforniia, Isaria, -

- 519

Fuckeliana, Sclerotinia,

- 267

fulgens, Synohytrium, -

- 109

fuliginosa, Scleroderris, -

- 251

fulvum, Cladosporium, -

- 510

,, Polystigma,

- 190

,, Sclerotiuni,

- 431

fulvus, Polyporus, -

447, 448

Fumago, ....

181, 519

fumariae, Caeoma, -

- 419

fumosus, Polyporus,

- 452

funerea, Pestalozzia,

- 493

Fungi, classification of, -

- 105

Fungi imperfecti, -

- 462

Fusarium, - - - 184,

189, 520

fusca, Puccinia,

- 356

fusco-violaceuni, Sistotrema, -

- 433

fuscum, Entyloma,

- 312

fuscus, Protomyces,

- 141

Fusicladium, - - . .

- 507

Fusicoccum abietinum, -

- 465

fusiforme, Phragmidiuni,

- 362

Fusispoi'ium,

- 521

Fusoma, ....

- 504

G

galanthi, Sclerotinia,

- 270

galanthina, Botrytis,

- 500

galeopsidis, Erj^siphe,

- 175

,, Phyllosticta,

- 465

galii, Melampsora,

- 370

,, Puccinia,

- 341

ganglioniformis, Peronospora,

- 131

Gasteromycetes,

- 422

geicola, Depazea, -

- 465

genistae, Didymosphaeria,

- 218

,, Uromyces,

- 337

genistalis, Darluca,

- 474

gentianae, Puccinia,

- 341

geographicum, Asteroma,

- 470

geranii, Plasmopara,

- 131

,, Puccinia, -

- 359

,, Ramularia,

- 502

,, Uromyces, -

- 334

,, Venturia, -

- 218

Gibbera, ....

- 204

I. INDEX OF PARASITES.

565

PAGE

Gibberella, . - . .

- 184

gibberosa, Puccinia,

346, 354

Gibelliana, Sphaerella, -

- 215

Gibellina, ....

- 220

giganteum, Peridermium,

- 416

giliae, Aecidium,

- 411

,, Puccinia,

- 355

gilvum, Lophodermium,

- 240

githagiuis, Magnusiella, 148,

151, 154

gladioli, Urocystis,

- 316

glaucum, Penicillium,

3, ISO

glechomatis, Puccinia, -

- 361

globosum, Gymnosporangium,

- 403

,, Synchytrium,

- 113

Gloeosporium,

- 482

glomerulata, Tilletia,

- 310

glomerulosum, Clasterosporiuni,

- 511

glumaruni, Puccinia,

- 348

,, Uredo, -

- 420

glycyrrhizae, Ui'omyces,

- 337

Gnomonia, ....

17, 222

Gnomoniella, ... -

- 223

Goeldiana, Eamularia, -

- 502

Goeppertiana, Calyptospora, -

- 370

,, Melampsora, -

- 370

,, Ustilago,

- 298

gongrogena, Diplodia,

- 472

,, Pestalozzia,

- 494

gossypii, Colletotrichum,

- 487

,, Uredo,

- 420

gossypina, Cercospora, -

- 515

,, Sphaerella, -

- 214

gracile, Helminthosporium, -

- 512

,, Phragmidium, -

- 363

,, Pythium, -

- 117

gramineum, Helminthosporium,

221, 512

gi-aminicola, Ascochyta,

- 473

,, Sclerospora,

- 131

graminicolum, Exobasidium, -

- 427

graminis. Dilophia,

- 222

,, Dilophospora, -

- 479

,, Erysiphe,

- 175

,, Ophiobolus,

- 222

,, Phyllachora, -

- 229

,, Puccinia,

75, 341

,, Scolecotrichum,

- 508

graminum, Septoria,

- 477

Typhula,

- 431

grammica, Ustilago,

- 294

PAGE

grandis, Ustilago, .... 293

Graphiola, 325

grisea, Peronospora, - - - 134

griseola, Isariopsis, - - - 519

grossulariae, Aecidium, - - - 409

,, Microsphaera, - - 176

Phyllosticta, - - 464

Guarinonii, Microsphaera, - - 176

Guepini, Pestalozzia, - - - 494

gunnerae, Nostoc, . . - - 541

guttata, Phyllactinia, - - - 178

Gymnoasci, - - - - - 137

Gymnoascus, .... 138, 170

Gymnosporangium, 48, 51, 74, 332, 383

,, deformations, 18, 43

H

Halstedii, Plasmopara, - - - 131

Harknessii, Peridermium, - - 415

Hartigianum, Septogloeum, - - 495

Hartigii, Melampsora, - - - 368

,, Pestalozzia, - - S3, 491

,, Polyporus, - - - 447

Harveyella mirabilis, - - - 555

hederae, Septoria, .... 478

hedericola, Sphaerella, - - - 215

hedysari-obscuri, Uromyces, - - 338

helianthi, Aecidium, - - - 340

,, Puccinia, - - - 340

Helicobasidium, ... - 429

helioscopiae, Melampsora, - - 370

hellebori, Eamularia, - - - 502

Helminthosporium, - - 512, 516

helosciadii, Entyloma, - - - 312

Helotieae, 256

Helvellaceae, 275

helvetica, Puccinia, - - - 353

Hemibasidii, . . - . - 275

Hemileia, .... 32, 361

Hemipuccinia, .... 353

Hendersonia, . . - - . 474

Hennebergii, Phoma, - - - 467

hepatica, Fistulina, - - - 452

hepaticae, Aecidium, - - - 409
herbarum, Cladosporium, - 4, 509
Herpotrichia, - - - 61, 83, 198

herpotrichoides, Leptosphaeria, - 220

hesperidearum, Pleospora, - - 221

Heteropuccinia, .... 341

666

T. TXDKX OF I'AKASITES.

I'AflK

heterogenea, Puccinia, - - - 360

heteroica, Sclerotinia, - - - 263

Hoterosphaeria, .... 249

Heterosporium, - . - - 51")

heterosporium, Fasarimn, - - 520

heterosponun, Septosporiuni, - 518

hieracii, Puccinia, .... 353

hiinalayonsis, C'hrysomyxa, - - 379

hippuriilis, Aecidium, - - - 33(5

hirsutum, Stereum, - - - 429

hirsutiis, Polyponis, - - - 452

hispidus, Polyponis, - - . 444

Holboelli, Puccinia, - - - 359

holostei, Ustilago, - . . - 297

hoi'dei, Horraodendron, - - 505

,, Tilletia, - - . - 310

,, Ustilago, - - - . 28S

Hormodendion, .... 505

hottoniae, Doassansia, - - - 324

hyacinthi, Bacillus, - - - 538

,, Pleospora, - - . 221

hyaliua, Theeaphora, - - - 324

Hydneae, 431

Hydnum, 431

hydrangeae, Septoria, - - - 478

hydropiperis, Sphacelotheca, - - 302

Hyinenomycetes, - - . . 422

hyoscyami, Peroiiospora, - - 134

hypericorum, Melampsora, - - 370

Hyphomycetes, . . - . 490

Hypnochaceae, . . . . 428

Hypnochus, ----- 428

Hypocreaceae, . - - . 184

Hypoderma, 233

Hypodermieae, . - . . 233

Hypodermella, - - - . 234

hypodytes, Ustilago, - - - 293

hypogaea, Niptera, - - - 254

Hyponiyces, 184

hypophyllum, Cladosporiuni, - - 511

Hysteriaceae, - - - - - 232

Hysterineae, 232

Hysterium, 237

Hysterographiuni, - - - - 232

I

igniarius, Polyporus,

35, 433, 441
pinuum, 447

I'AOE

impatientis, Depazea, - - 465

impressum, Asteroma, - - - 470

inaecpiale, Fusonia, - - 5(15

infestans, Phytophthora, - 7, 119

inflata, Pvhi/.ina, - . . - 273

inquinans, Bulgaria, - - - 253

,, Pestalozzia. - ■ - 494

insidiens, Pestalozzia, - - - 494

insititiae, Tapliriiia, 147, 151, 153, 164

intermedia, Doassansia, - - - 324

„ Ustilago, . - - 295

intermedium, Pythium, - - - 117

interstitialis, Ovularia, - - - 500

„ Puccinia, - - - 341

inulae, Coleosporium, - - - 376

ipomoeae, Coleosporium, - . 377

Nectria, - - - 189

,, Puccinia, - - - 356

ipomoearum, Vermicularia, - - 471

ipomoeae-panduranae, Cystopus, - 127

iridis, Aecidium, - - - - 411

,, Cladochytrium, - - - 114

,, Puccinia, . . - - 355

,, Uredo, 420

Irniischiae, Paipalopsis, - - - 322

Isaria, ....-- 519

Isariopsis, - - - - - 519

ischaemi, Ustilago, - - - 292

italica, Urocystis, - - - - 319

italicum, Penicillium, - - - 180

Jamesianum, Aecidium, - - - 411

Jenseni, Ustilago, - - - - 288

Johansonii, Taphrina, 147, 150, 152, 157

,, Urocystis, - - - 319

juglandinum, Cladosporiuni, - - 510

juglandis, Marsonia, . - - 491

,, Microstroma, - - - 497

junci, Puccinia, - . - - 354

,, Tolyposporiuni, - - - 305

., Urocystis, - - - - 319

,, Uromyces, - - - 336

juncicolum, Rhytisma, - - - 246

juniperi, Clithris, . - - - 248

,, Stigmatea, - - -211

juniperinum, Gymuosporangium, - 391

,, Lophodermiuni, - - 240

I. INDEX OF PARASITES.

567

PAGE

Kaufmanniana, Peziza, - - - 265

kentiae, Colletotrichiini,- - - 488

Kerneri, Sclerotinia, - - - 270

Klebahni, Peridermium, - 376, 414

Kmetiana, Urocystis, - - - 319

knautiae, Peronospora, - - - 132

Knyanum, Chlorochytrium, - - 550

Kochii, Strickeria, - - - - 205

Kolaczekii, Ustilago, - - - 292

KoUeri, Ustilago, - - - - 287

Koordersiana, Ustilago, - - - 298

Kriegerianum, Cladochytrium, - 114
Kruchii, Taphiiiia, - - 147, 150, 153

Ktihneana, Ustilago, - - - 298

Labrella, 480

laburni, Cucurbitaria, - - 6, 206

,, Physalospora, - - - 218

laceianum, Phragmidium, - - 363

lacerata, Roestelia, - - - 385

Lachnella, . . - - - 272

laciniata, Thelephora, - - - 429

lactea, Ovularia, ... - 500

lactiicae, Bremia, - - - . 131

Laestadia, - - - - - 216

laetum, Synchytriuni, - - - 111

laevigatas, Potyporus, - - - 445

laevis, Tilletia, - . - . 309

Lagenarium, Colletotrichum, - - 486

Lagerheimii, Leuconostoc, - - 143

Ustilago, - - - 299

lamii, Ovularia, . . - . 501

lampsanae, Puccinia, - - - 340

,, Ramularia, - - - 502

laneola, Myxosporium, - - - 486

lapponicus, Uromyces, - - - 337

laricina, Sphaerella, - - - 211

laricinnm, Leptostroma, - - - 212

,, Lopliodermium, - - 240

laricis, Caeoma, - - 366, 367, 419

,, Heterosporium, - - - 516

,, Hypodermella, - - - 234

Lasiobotrys, 182

lathyri, Thecaphora, - - - 324

lathyriimm, Dicoccum, - - - 506
Laurencia, Taphrina, 29, 148, 149, 153

laureolae, Sphaerella, - - - 215

PAGE

lauri, Exobasidium,

31

427

iedi, Chrysomyxa, -

-

378

,, Exobasidium, -

31,

427

,, Sclerotinia,

-

263

leguminosarum, Rhizobium, -

101

Leimbachii, Urocystis, -

-

317

lemnae, Chlorochytrium,

-

549

Cornuella, -

-

322

,, Olpidium, -

-

107

lepidii, Aecidium, -

410

lepigoni, Cystopus, -

-

127

leproides, Oedomyces,

-

313

leproidum, Entyloma,

-

313

Leptopuccinia,

359

leptosperma, Peronospora,

-

134

Leptosphaeria,

-

220

Leptostroma, - - - -

-

480

Leptostromaceae, -

-

479

leptostromiforme, Cryptosporiiim, -

489

Leptothyrium,

-

479

Letendraea, . - . -

184

leucanthemi, Aecidium, -

351

, 409

,, Puccinia, -

-

351

Leucochytrium,

-

112

leucogonium, Oidium,

499

Leuconostoc, - - - -

143

leucospermum, Aecidium,

409

lichenoides, Nostoc,

-

546

ligustri, Aecidium, -

409

,, Caeoma,

-

419

liliacearum, Puccinia,

356

limbalis, Phyllosticta,

-

464

limonii, Uromyces, -

-

334

limonis, Fusarium, -

-

521

limosae, Puccinia, -

-

351

limosellae, Doassansia, -

-

324

linariae, Entyloma,-

-

312

,, Peronospora,

-

134

Lindemuthianum, Colletotrichum, -

486

lineolatus, Uromyces,

336

Linhartiana, Monilia,

261

lini, Melampsora, -

369

,, Peronospora, -

134

lolii, Tilletia, - - -

310

longipes, Taphrina,- - 147

, 15

1, 152

longissima, Phoma,-

469

,, Puccinia,

- 354

,, Sphaerella, -

- 215

,, Ustilago,

- 293

568

1, INDEX OF 1'A11ASITE.S.

PAOK

lonicerae, Lasiobotrys, -

- 182

,, Microsphaera,-

- 176

lophanti, Peronospora, -

- 134

lophiostonioides, Phoma,

■ 4G7

Lophoilermium,

- 235

lucillae, Sphaerella,

- 476

Ludwigii, Saccharomyces, - 141, 143

luminatum, Caeoma,

- 419

lupini, Uromyces, -

- 337

lutescens, Taphrina (Magnusiella

,

148, 149, 154

luzulae, Urocystis, -

- 316

,, Ustilago, -

- 294

lychnicola, Ovularia,

- 500

lychnidis, Septoria,

- 478

lycii, Microsphaera,

- 176

lycopersici, Colletotrichum, -

- 487

,, Fusarium,

- 520

,, Septoria,

- 477

lycopi, Aecidium, -

- 411

M

niacrocarpum, Cladosporium,

- 510

macropiis, Gymuosporaiigium, 391, 402

macrosora, Uredo, -

- 420

Macrosporium,

- 517

macrosporum, Aecidium,

- 411

,, Hysterium,

- 237

,, Lophodermium,

?4, 237

macrosporus, Protomyces,

?1, 138

maculaeformis, Venturia,

- 218

maculaus, Ascochyta,

- 473

maculare, Asteroma,

- 470

maculatiim, Entomosporium,

- 480

maculiformis, Laestadia,

- 216

, , Phyllosticta,

- 464

Magelhaenicum, Aecidium, -

- 409

Magnusia, ....

- 178

Magnusiana, Puccinia, -

- 349

Magnusiella (see Taphrina), 146, 148, 151

Magnusii, Endomyces, -

- 143

,, Entyloma,

- 312

,, Puccinia,

- 350

major, Ustilago,

- 297

mali, Hendersonia,

- 475

malorum, Sphaeropsis, -

- 472

malvaceanim, Phoma,

- 469

,, Puccinia,

- 359

malvarum, Cercospora, -

- 515

I'AOK

malvarum, Colletotrichum, - - 487
malvicola, Ascochyta, - - - 473

Mamiania, 223

mammillata, Puccinia, - - - 355
Marconii, Dendrophoma, - - 469
marginalis, Ustilago, - - - 298
marginatus, Polyporus, - - - 449
Mariae-Wilsoni, Aecidium, - - 410
maritimus, Uromyces, - - - 336
Marsonia, .... 490, 506
Martianoffiana, Doassansia, - - 324
martii, Erysiphe, .... 175
Masseela, ..... 361
Mastigosporium, .... 504
maxima, Tuberculina, - - - 328
maximus, Cryptomyces, - - 246

maydis, Puccinia, - - - . 353
,, Ustilago, - - - 67,279
megalospora, Sclerotinia, - - 260

Melampsora, - - - 48, 53, 74, 303
Melampsorella, .... 370
melampyri, Aecidium, - - - 349
,, Coleosporium, - - 376

Melanconideae, .... 226
Melanconieae, .... 482

melangeae, Gloeosporium, - - 483
melanogramma, Schizonella, - - 305
Melanomeae, - - . - . 200
Melanospora, - - - - 8, 184
Melanotaenium, .... 313
Melasmia, . . . . . 479

Meliola, 181

melleus, Agaricus (Armillaria), 6, 455
melophthorum, Scolecotrichum, - 508
menthae, Puccinia, - - - 341

menyanthis, Cladochytrium, - - 114
mercurialis, Caeoma, - 366, 367, 419
,, Synchytrium, - - 113

Merulius lacrymans, - 40, 46, 442

Mesochytrium, - - - - 110
mespili, Entomosporium, - - 481

Morthiera, - - - 210

,, Stigmatea, - - - 210

mespilinum, Oidium, - - - 499
metulispora, Ascochyta, - - - 473
microcepliala, Claviceps, - - 194
microchaeta, Vermicularia, - - 471
Micrococcus, - - - 143, 531, 535
Micropuccinia, .... 356

I. INDEX OF PARASITES.

569

mierosora, Puccinia,
miciospeiTna, Passalora,
Microsphaera,
microsporiim, Entyloma,
Microstroma,
Microthyrium,
millefolii, Puccinia,
minimus, Cephaleuros, -
minor, Taphrina, - 147,

,, Uromyces, -
minus, Cylindrosporium,
mirabilis, Taphrina,
mirabilissima, Puccinia, -
mixta, Melampsora,
modestum, Bostrichonema,
moliniae, Neovossia,

,, Puccinia,
Mblleri, Ustilago, -
mollis, Polyporus, -
Mollisia,
Mollisieae,

Mompa, Helicoliasidium,
Monilia,

monilioides, Oidium,
monoicuni, Aecidium,
Monospora,

monotropae, Urocystis, -
montana, Puccinia,
morbosa, Plowrightia,
mori. Bacterium, -

,, Cladochytrium,

,, Phleospora, -

,, Septogloeum,

,, Sphaerella,
moricola, Gibberella,
mors-uvae, Sphaerotheca,
Morthieri, Mollisia,
,, Puccinia,

Mucedineae, -
Mucor, - - - -
Muelleri, Uredo,
mutila, Dothiora, -
Mycoidaceae,
Mycoidea,

Mycoidea, Cephaleuros, -

Mycomycetes,-

myosotidis, Aecidium, -

,, Peronospora,

,, Synchytrium,

PAGE

PAGE

- 355

myrtillina, Podosphaera,

-

175

- 506

Mystrosporiuni,

518

- 176

Myxomycetes,

135,

522

- 312

Myxosporium,

-

486

- 497

- 179

N

- 361

Naegelia, . . . .

-

.326

- 553

Naevia piniperda, -

-

238

50. 153, 164

nana, Taphrina, - 147, 149,

153,

161

- 338

napi, Pleospora,

-

221

- 489

Napicladium, - -

-

516

147, 151-153

neeans, Ovularia, -

-

500

- 340

necator, Gloeosporium, -

-

483

- 368

necatrix, Dematophora, -

-

202

- 501

Nectria, - - - - -

-

185

- 311

Nectriella, - . . -

-

184

- 349

Xectroideae, - - - -

-

479

- 298

neglecta, Ustilago, -

292

- 448

nelans, Ovularia, -

-

261

- 254

nemoralis, Puccinia,

-

349

- 253

Neovossia, . . . -

311

- 429

nepalense, Phragmidium,

363

- 261, 497

neriella, Cercospora,

-

515

- 175, 499

nervisequium, Gloeosf orium, -

229

484

- 410

,, Lophodermium,

-

239

- 138

nicotianae, Ascochyta, -

473

- 319

nidus-avis, Gymnospoi-angium,

-

403

- 340

Niesslii, Doassansia,

-

323

- 231

,, Sphaerotheca, -

-

174

- 534

nigra, Herpotrichia,

-

199

- 114

nigricans, Claviceps,

-

195

- 478

,, Polyporus, -

-

452

- 496

nigricantium, Macrosporium, -

518

- 215, 478

nigro-maculans, Septoria,

478

- 184

Niptera, ... -

-

254

- 173

nitens, Caeoma,

419

- 254

nivea, Plasmopara,

128

- 359

nobile, Macrosporium, -

-

518

- 497

Nostoc,

541

, 546

4, 180

nuda, Ustilago,

-

288

- 420

iiymphaeae, Entyloma, -

-

313

- 249

nymphaeoides, Aecidium,

351

, 410

- 552

- 552

0

- 552

obducens, Plasmopara, -

131

- 135

obliqua, Ovularia, -

501

- 411

oblongata, Puccinia,

-

.354

- 134

oblongisporium, Peridermium,

37c

, 414

- Ill

obscura, Puccinia, -

-

352

570

obscurum, Polystignia, -
obtusa, Puccitiia, -
occulta, Doassansia,

,, Urucystis, -
ochraceum, I'olystigina,
Ochrospora,

octolocularc, Phi-agmuliuin,
oenotherae, Aecidiuni, -

,, Puccinia,

officinalis, Polyporus,
Oidiuni, . - - . 144,
oleae. Bacillus,
oleaginum, Cycloconiuin,
Oleina, - . . . .
olida, Tilletia,

oligociiaetum, Colletotrichum,
olivacea, Ustilago, -
olivaceum, Penicillium, -
Olpidiaceae, - - . .
Olpidiopsis, - - . .
Olpidium, . - . .
omnivora, Phytophthora,
onobrychidis, Aecidium,

,, Diachora, -

Oomyces, ....

Ooniycetes, ....
Oospora, ....

Ophiobolus, - - . .

orchidis, C'aeoma, -
oreophila, .Sclerotinia,
oreoselini, Puccinia,
orientale, Peridermium, -
ornamentale, Aecidium,
ornithogali, Heterosporium, ■
,, Urocystis, -

,, Uromyces, -

,, Ustilago,

orobancbes, Urocystis, -
orobi, Uromj'ces,
oryzae, Piricularia,

,, Sclerotium,
Tilletia,

,, Ustilaginoidea, -
ossifragi, Entylonia,
ostryae, Taphrina, - 148,

Ovularia,
oxyacantbae, Phleospora,

, , Podospbaera,

oxybapbi, Peronospora, -

NDK.X ()!'

I'AltASITKS.

rAi;K

PAGE

100

oxycocci, Exobasidium, -

- 426

341

,, iSclerotinia,

- 259

-

3-24

oxyriae, Puccinia, -

- 355

-

315

oxystoma, Valsa, -

- 224

-

1!)0

-

300

P

-

363

pachydernius, Protomyces,

- 141

-

411

padi, Asteroma,

- 470

-

355

,, Cylindrosporium, -

- 489

-

452

,, Melampsora, -

- 370

175

490

,, Sclerotinia, -

- 261

-

532

Paipalopsis, - - . .

- 322

-

506

paliformis, Puccinia,

- 354

-

138

pallescens, Thecapbora, -

- 325

-

310

pallidum, Cblorocbytrium,

- 550

-

486

X)allidus, Uromyces,

- 338

-

294

pallor, Ascochyta, -

- 473

180

paludosa, Puccinia,

- 351

-

106

pandani, Melanconium, -

- 188

107

,, Nectria, -

- 188

-

106

panici-frumentacei, Ustilago, -

- 292

, 83

117

,, -leucophaei, ,,

- 291

410

,, -miliacei, ,,

- 289

-

230

pannosa, Spbaerotbeca, -

172, 499.

-

184

papillatum, Pbragmidium,

- 363

-

115

,, Syncbytrium,

- 109

-

497

parasitica, Botrytis,

- 500

-

222

,, Mycoidea,

- 552

368

419

,, Peronospora, -

- 133

-

259

,, Septoria,

- 475

-

353

,, Tetramyxa, -

- 529

-

415

, , Tricbospbaeria,

10, 196

-

410

parasiticum, Fusoma,

- 504

-

516

parasiticus, Cepbaleuros,

- 552

-

316

paridis, Puccinia, -

- 349

-

338

Parlatorei, Ustilago,

- 298

-

299

parnassiae, Aecidium,

- 352

-

319

,, Uromyces, -

- 334

-

333

paspalus-dilatati, Ustilago,

- 294

-

503

Passalora, ....

- 506

-

266

pastinacae, Cercosporella,

- 503

-

310

Patella, Heterospbaeria,-

- 249

-

311

Pazscbkei, Puccinia,

- 359

-

313

Peckiana, Puccinia,

341, 419

1.50

, 154

Peckii, Aecidium, -

- 411

201

500

,, Exobasidium,

- 427

-

478

,, Peridermium,

- 417

174

pedicillata, Tbelepbora, -

- 429

-

135

pedicularis, Aecidium, -

351, 410

I. INDEX OF PARASITES.

571

PAOE

Pellicularia, -

- 181

penicillariae, Tolyposporium,

- 306

penicillata, Roestelia, - 385, 389, 391

Penicillium, -

- 3, 4, 180

pentastemonis, Aecidiiim,

- 411

Penzigi, Meliola, -

- 181

perdix, Thelephora,

15, 429, 430

perennans, Ustilago,

- 288

periclymeni, Aecidium, -

- 349, 409

,, Ascochyta,-

- 473

,, Leptothyrium,

- 479

Peridennium, -

- 374, 411

Periphlegmatiuni, -

- 551

Perisporiaceae,

- 170

Perisporieae, -

- 178

Perisporium, -

- 179

Perouospora, -

- 132

Peronosporeae,

- 7, 13, 115

,, remedies,

■ 68

perplexans, Puccinia,

- 349

persicae, Cercospora,

- 513

,, Cercosporella, -

- 503

Phyllosticta, -

- 463

persicina, Tu-ljerculina, -

- 327

persistens, Puccinia,

- 349

Personii, Quateruaria,

- 226

Pestalozzia,

- 491

Pestalozzina, -

- 494

petasitidis, Coleroa,

- 195

Petersii, Aecidium,

- 410

petroselini, Septoria,

- 476

Pezicula (see Dermatea),-

- 253

Peziza, - - . .

- 271

Pezizeae, -

- 253

Phaciiliaceae, -

- 241

phacidioides, Sphaeronema,

- 255

Pliacidium,

- 241, 255

Pliaeopiiila,

- 551

Phaeophyceae,

- 554

Phakospora, -

- 361

phalaridis, Puccinia,

- 349

phaseoli, Phytophthora, -

- 122

,, Uromyces,

- 334

phaseolina, Phyllosticta,

- 464

phillyreae, Aecidium,

- 410

,, Uredo, -

- 420

phlei-pratensis, Puccinia,

- 348

Phleospora,

- 478

phoenicis, Graphiola,

- 325

PACE

phoenicis, Pestalozzia, -

- 494

Pholiota = Agaricus.

Phonia, - - - -

- 465

phomoides, Gloeosijoriuni,

- 483

Phragmidium,

- 362

phragmitis, Puccinia,

- 349

Phycomycetes,

- 106

Phyllachora, -

- 229

Phyllactiuia, -

- 178

Phyllobium dimorphuni,-

- 551

Phyllosiphon arisari.

- 553

Phyllosticta, -

- 463

Physalospora, -

- 217

Physoderma, -

- 114

Phytaphysa Treubii,

- 554

phj'teumatuni, Uromyces,

- 338

Phytomyxa, -

- 101, 524

Phytophthora,

- 117

piceae, Chrysomyxa,

- 380

,, Peridermium,

- 417

pic.ipes, Polyporus, -

- 452

picridis, Entyloma,

- 312

,, Puccinia, -

- 355

Piggotia astroidea, -

- 230

Pilacreae,

- 421

piliticum, Synchytrium, -

- Ill

pimpinellae, Puccinia,

- 340

,, Thecaphora,

- 325

pinastrella, Phoma,

- 468

pinastri, Lophodermium,

- 235

pinguicolae, Ustilago,

- 297

pini, Brunchorstia,

- 481

,, Lachnella,

- 272

,, Peridermium,

- 411, 415

,, Trametes,

38, 453

pinicola, Hypoderma,

- 234

,, Polyporus,

- 449

pinitorquum, Caeoma, -

- 364

pinophihim, Apiosporium,

- 181

piperatiim, Gloeosporium,

- 483

Piptocephalis,

- 11

pirata, Roestelia, -

- 391, 402

piricola, Septoria, -

- 476

Piricularia,

- 503

piriforme, Peridermium,

- 414

piriformis, Mucor, -

- 180

pirina, Phyllosticta,

- 463

pirinum, Fusicladium, -

- 218, 507

, , Venturia,

- 218

572

I. INDEX OF PARASITES.

pirolae, Chrysomyxa,
, , Melampsora,
pisana, Anthostoniella, -
pisi, Ascochyta,

,, Cladosporium,

,, Uroniyces,
pitliya, Phoina,
pityophila, Cticiii-bitaria,
Plaoosphaeria,
plantaginis, Aecidium, -
), Kamularia, -

Plasmodiophora,
Plasmopara, -
platani, Fenestella,
,, Fusarium, -
Pleolpidium, -
Pleonectria, -
Pleospora,
Pleosporeae, -
Pleotrachelus, - - 1,"),

Plowrightia, -
Plowrightii, Periderniiuni.
plumbea, Ustilago,
poae, Uromyces,
poarum, Puccinia, -
podagrai-iae, Actinonema,
,, Phyllachora,

Podiosoma juniperi,
Podocapsa,

podophylli, Pliyllosticta,
Podosphaera, -
polenionii, Aecidium,
polygoni, Peronospora, -
,, Puccinia,
,, Uroniyces,
polygonorum, Stigmatea,
polymorpha, Bulgaria, -
polypodii, Sphaerella, -

,, Uredo, -

Polyporeae, - - - ',
,, action on stai'ch,

,, remedies,

Polyporus,

polyspora, Taphrina, 148, 1
Polystictis,
Polystigma,
Polythrincium,
populi, Marsonia, -

,, Septoria,

I'A<iK

PAfiE

- 380

populina, Didymosphaeria,

- 218, 249

- 370

,, Melampsora, -

- 367

- 226

Poria-= Polyporus.

- 472

porri, Puccinia,

- 341

- 510

portulacae, Cystopus,

- 127

- 334

jiostunia, Peziza,

- 268

- 466

potentillae, Coleroa,

- 195

- 210

,, Magnusiella,

- 148

- 471

,, Marsonia,

- 195, 491

- 411

, , Peronospora,

- 134

- 502

,, Phragmidium,

- 363

- 524

,, Taphrina,

148, 151, 154

- 127

praecox, F'usicladium,

- 508

- 229

pratensis, Ramularia,

- 502

- 184

prenanthis, Puccinia,

- 340

- 107

priniulae, Puccinia,

- 341

- 184

,, Uromyces,

- 334

- 221,511

primulana, Ovularia,

- 500

- 217

primulicola, Phyllosticta,

- 465

. 25, 28, 107

,, Tuburcinia,

- 321

- 230

princeps, Calosphaeria, -

- 226

■ 376, 414

Pringsheimiana, Puccinia,

- 350

- 299

prcieminens, Uromyces, -

- 337

- 336

profusa, Aglaospora,

- 229

- 348

profusum, Septogloeum,

- 496

- 474

proserpinacae, Aecidium,

- 410

- 229

Prosti, Puccinia, -

- 359

- 465

Protobasidiomycetes,

- 421

- 138

Protomyces, -

- 7, 31, 138

- 465

pruinosa, Ramularia,

- 502

- 174

,, Sphaerotheca,

- 174

- 411

prunastri, Dermatella, -

- 252

- 135

,, Unciuula,

- 178

- 355

prunellae, Aecidium,

- 410

- 334

,, Asteroma,

- 470

- 211

l)runi, Puccinia,

- 355

- 253

,, Taphrina,

147, 151-154

- 215

prunicola, Didymaria, -

- 501

- 420

,, Phyllosticta, -

- 463

5, 6, 17, 433

pseudocerasus, Exoascus,

- 164

- 34

pseudocolumnare, Aecidium

- 409

70, 72

Pseudocommis,

- 529

- 433

pseudoigniarius, Polyporus,

- 440

51, 154, 168

Pseudolpidium,

- 107

- 452

Pseudopeziza,

- 254

7, 189

Pseudophacidieae, -

- 246

- 229

pseudoplatani, Septoria, -

- 478

- 491

Pseudorhytisma,

- 255

- 478

pseudotuberosa, Ciboria,

- 270

I. INDEX OF PARASITES.

573

pseudotuberosa, Sclerotinia,
psoraleae, Aecidium,
ptarmicae, Leptothyrium,
,, Schizothyrium,

pteleae, Aecidium, -
pteridis, Cryptomyces, -
,, Fusidium,-
,, Uredinopsis,
Puccinia,
Pucciniosira, -
Pucciniopsis, -
pulcliella, Ovularia,
pulicaris, Gibberella,
pulposum, Cladochytrium,
piilsatillae, Coleosporium,
pulverulenta, Puccinia, -
punctata, Melasmia,
punctatum, Aecidium, -
,, Khytisma, -

,, Synchytrium,

punctiforme, Leptostroma,

, , Nostoc,

punctiformis, Pliyllachora,
punctuni, Synchytrium, -
pupurascens, Taphrina, -
purpurea, Claviceps.
,, Puccinia,

,, Urocystis,

pusilla, Claviceps, -
, , Plasmopara,
pustulata, Burillia, -

,, Melampsora, -

putrefaciens, Sporidesmium
pychroa, Calonectria,
Pycnis, - - - -
Pycnochytrium,
pygmaea, Plasmopara, -
pymaea, Ravenelia,
Pyrenocliaeta,
Pyrenomycetes,
Pyroctonum, -
Pythium,

Q

quadrifidum, Aecidium, -

Quaternaria, -

quercina, Clithris, -
,, Colpoma,

„ Rosellinia,

PAGE

- 270

- 410

- 242

- 242

- 410

- 248

- 248

- 420

- 339

- 404

- 356

- 500

- 184

- 114

- 377

- 341

- 480

- 23, 409

- 244

- 112

- 480

- 541

- 241

- Ill
147, 151, 153

- 7, 29, 191

■ 319

- 195

- 130

- 322

- 370
, - 221, 465

- 184

- 226

- 109

- 130

- 403

- 470

- 183

- 114
4, 116

409
226
248
248
200

quercinum, Capuodium, -
quercus, Marsonia,

,, Uredo,
quercus-ilicis, Gnomonia,
quinqueloculare, Phragmidium,

R

Rabenhorstiana, Ustilago,
racemosus, Mucor, -
radiatus, Polyporus,
radiciperda, Trametes, -
radicola. Bacterium,
radicolus, Protomyces, -
radiosum, Asteroma,
Ramularia,

ramulosum, Macrosporium,
ranunculacearum, Aecidium, -
ranunculi, Entyloma,
,, Fabraea,

,, Stigmatea,

RauwenhofEi, Tilletia, -
Ravenelia, . - . .
Ravenelii, Peridermium,
Reessia, . - - - -
Reiliana, Ustilago, -
repandum, Phacidium, -
repentis, Melampsora, -
resedae, Cercospora,
rhamni, Aecidium, -
rhinanthi, Sclerotium, -
Rhizina, - - - - -
rliizipes, Taphrina, - 147,

Rhizobium, . . - -
Rhizoctonia, - - - -
rhizoides, Sclerotium,
rhizophora, Taphrina, 147, 150,
rhodiolae, Puccinia,
rhododendri, Apiosporium, -
, , Chrysomyxa,

,, Exobasidium, -

,, Gloeosporium, -

,, Hendersonia,

,, Sclerotinia,

Rhodomyces, - - - -
Rhodophyceae,

Rhytisma, - - - ■
rhytismoides, Dyscomycopsis,
ribesia, Scleroderris,
ribesii, Caeoma, - . -

PAGE

181
491
420
223
363

- 291

- 180

- 452

- 450

- 101

- 141

- 474

- 501

- 518

- 409

- 312

- 255

- 210

- 310

- 403

- 416

- 107

- 282

- 241

- 368

- 515

- 346

- 266

- 272

151, 152

- 101
201, 274

- 266

152, 157

- 359

- 181

- 377

- 427

- 485

- 475

- 262

- 143

- 555
71, 242

- 245

- 251

- 368

574

I, INDEX OF I'AKASITKS.

PACK

ribicolii, IMasiiiopara,

- 131

ribicoluni, (-"ronartium, -

- 382

ribis, Gloeosporiuin,

- 4S3

,, Polyporus,

- 452

,, Pucciiiia,

- .'^5!)

,, Septoria,

476, 515

robertiaiii, Stigmatea, -

- 210

robiniae, Dothiorella,

- 229

Ptobinsoniana, Taphriiia,

150, 152

rosae, Actinonema,

- 474

,, Dicoccuni,

- 50(i

,, Gloeosporium,

- 483

,, Marsouia,

- 50()

,, Septoria,

- 478

rosae-alpinae, Phragmidium, -

- 302

rosaecola, Cercospora,

- 515

rosea, Ovularia,

- 501

Roselliiiia, . . . .

- 200

rostratum, Urobasidiuin,

- 427

Rostrupia, - - - -

- 354

Rostrupiana, Taphrina, 147, 151

152, 156

Rostrupii, Peridermium,

- 377

Ronsseauana, Fabraea, -

- 255

Rouselliana, Nectria,

- 188

rubefaciens, Puccinia,

- 359

rubellum, Aecidium,

- 349

ruljescens, Asooidea,

- 141

rubi, Exosporium, -

- 195

,, Phragmidium,

- 363

,, Septoria,

- 476

,, -idaei, Phragmidium,

- 363

,, ,, Pyrenochaeta,

- 470

,, -miniatum, Phragmidium,

- 363

rubigo-vera, Puccinia,

- 347

rubra, Eiidosphaera,

- 551

rubrocinctum, Synchytrium, -

- 112

rubrum, Poly stigma,

- 189

rufibasis, Ramularia,

- 502

rufomaculans, Ramularia,

- 502

rumicis, Uromyces,

- 337

,, Venturia, -

- 218

rumicis-scutati, Puccinia,

- 355

ruscicola, Phyllosticta, -

- 465

S
sabinae, Gymnosporangium, -

74, 395

sacchari, Trichosphaeria,

- 198

,, Ustilago, -

- 284

,, -ciliaris, Ustilago, -

- 284

PA(iK

saccharinuni, Cylindrosporium, - 489
Saccharomyces, - - - 8, 143

Sadebeckianum, Pythiuni, - - 117
Sadebeckii, Taphrina, 148, 15(t, 154, 168
sagittariae, Doassansia, - - 322, .S23

salieina, Melampsora, - - - 'AQ7

,, Melasniia, - - - - 480

salicinum, Capnodium, - - - 181

,, Didymosporium, - - 490

,, Rhytisma, - - - 245

salicinus, Polyporus, - - - 452

salicis, Uncinula, - - - - 178

salicis-caprcae, Melampsora, - - 368

salicorniae, Uromyces, - - - 334

sambuci, Aecidium, - - - 411

Phyllosticta, - - - 464

sanguineum, Synchytrium, - - 109

sanguinolenta, Phonia, - - - 468

sanguisorbae, Phragmidium, ■ - 363

saniculae, Puccinia, - - - 341

saponariae, Sorosporium, - - 325

Saprolegniaceae, - - - - 115

sarcinaeformae, Macrosporium, - 517
sarcinula, Macrosporium, - -. 518

saxifragae, Caeoma, - - - 419

,, Puccinia, - - - 359

scabies, Oospora, .... 497

scabiosae, Ascochyta, - - - 473

Ustilago, - - - 294

scelerata, Ovularia,- - - - 501

Schachtii, Peronospora, - - - 132

Schiedermayeri, Hydnum, - - 433

Schinzia, ..... 326

Schinzianum, Exobasidium, - - 427

Schizomycetes, .... 530

Schizonella, ..... 305

Schizospora, - - - . . 361

Schizothyrium, .... 242

Schleideni, Peronospora, - - 132

Schneideri, Puccinia, - - - 359

Schoeleriana, Puccinia, - - - 350

Schroederi, Puccinia, - - - 359

Schroeteri, Uromyces, - - - 337

Schroeteria, ..... 328

Schroeteriaster, .... 337

Schweinfurthiana, Ustilago, - - 299

Schweinfurthii, Aecidium, - - 410

Schweinitzii, Polyporus,- - - 448

„ Ustilago, - - - 281

I. INDEX OF PARASITES.

575

scillae, Puccinia, - . - -
scillarum, Uromyces, . . .
scirpi, Puccinia, . . . -
Scleroderris, -----
Sclerosi^ora, -----
Sclerotiiiia, - 3, 7, 16, 29,

sclerotiorum, Peziza,

,, Sclerotinia,

Sclerotium,
Scolecotriclium,
scorzonerae, Ustilago,
Scotinosphaera paradoxa,
Scribnei'ianuni, Cladosporium,
scrophulariae, Uromyces,
scutellatiis, Uromyces, -
Scytonema, - - - -
secales, Bacillus,
secalis, Tilletia,

,, Ustilago,
sedi, Endophyllum,

,, Puccinia, - - " -

,, Septoria,
Selinia, - - - - -
seniinum, Ustilago,
sempervivi, Endophyllum,
senecionis, Coleosporium,
,, Ovularia,

,, Puccinia,

sentina, Sphaerella,
separata, Tilletia, -
septentrionalis, Puccinia,
Septocylindrium, -
Septogloeum, - - - -
Septoria, - - - -

Septosporium,
serotinum, Entyloma,
sesleriae, Puccinia, -
,, Tilletia, -
sessilis, Puccinia, -
setariae, Ustilago, -

,, Ustilaginoidea, -
setosum, Ceratophorum, -
setulosa, Claviceps,-
Sherardiana, Puccinia, -
sii latifolii, Aecidium,
silenes, Puccinia, -
,, Uromyces, -
simplex, Puccinia, -
simulans, Olpidium,

- 2, 4,
266, 431,

13,

PAGE

PAGE

359

singularis, Puccinia,

- 358

338

Sistotrema, - - - .

- 433

352

sistotremoides, Polyporus,

- 448

250

Slinie-fungi, - - - -

- 522

131

smilacis, Aecidium, -

- 411

256

smyrnii, Puccinia, -

- 356

263

solani, Alternaria, -

- 517

263

,, Hypnochus, -

- 428

500

,, Macrosporium,

- 517

508

,, Phoma,

- 468

296

,, Rhizoctonia,

- 202

550

,, Schinzia (Entorrhiza), -

- 326

511

soldanellae, Puccinia,

- 341

338

solidaginis, Uromyces, -

- 338

336

Sommerfeltii, Aecidium, -

- 352

541

sonchi, Coleosporium,

- 376

535

,, Puccinia,

- 355

310

Soraueri, Peridermium, -

376, 414

289

Soraueriana, Pestalozzina,

- 495

404

sorbi, Cucurbitaria,

- 210

359

,, Melampsora, -

- 369

478

,, Phoma, -

- 468

184

sordida, Peronospora,

- 134

297

sorghi, Bacillus,

- 534

404

,, Cintractia, -

- 302

374

,, Endothlaspis,

- 302

500

,, Fusicladium,

- 508

356

,, Puccinia, -

- 353

216

,, Uredo,

- 420

310

,, Ustilago,

- 284

352

Sorosphaera, . . - -

- 530

505

sorosporioides, Urocystis,

- 317

495

Sorosporium, - - . -

- 325

475

sparsa, Melampsora,

- 370

518

,, Peronospora,

- 133

312

sparsus, Uromyces,-

- 337

349

speciosum, Gymnosporangium,

- 403

310

,, Phragmidium,

- 362

349

spergulae, Puccinia,

- 361

291

Sphaceloma, - - - -

- 467

311

Sphacelotheca,

- 302

511

Sphaerella, - - . .

- 211

195

Sphaerelloideae,

- 210

360

Sphaeriaceae, - - - -

184, 195

336

Sphaerioideae,

- 463

340

sphaerogena, Ustilago, -

- 291

334

sphaeroidea, Dothidea, -

- 230

347

,, Ovularia, -

- 501

107

sphaeroides, Dothiora, -

218, 249

576

I. INDEX OF TAKASITES.

Sphaeronema, - - - -
iSpliaerophragmiiuii ,
Sphaeropsideae,
•Sphaeropsis, - - - -
sphaeropsoidea, Phyllosticta, -
Sphaerostilbe, -

Sphaerotheca, - - - -
sphagni, Tilletia,
spinaciae, CoUetotrichnm,
spinificis, Ustilago, -
spinulosus, Cystopus,
spiralis, Unciiuila, -
spissa, Didyniaria, -
splendens, Aecidium,
Sporidesmium,
Sporodesmium,
spumeus, Polyporus,
spurium, Sphaeronema, -
squamosus, Polyporus, -
squarrosus, Agaricus,
stachydis, Puccinia,
,, Septoria,

Stagonospora, - - - -
Stahlii, Peridermium,
stellariae, Syuchytrium, -
Stemphyliiim, - - - -
Stereum,- . - . .
stictica, Pestalozzia,
stictoides, Leptosphaeria,
Stigmatea, . . - -

Stilbeae,

stolonifer, ilucor, -
Stomatochytrium, -
straniinis, Pucciuia,
Straussii, Venturia,
Streblonemopsis irritans,
striaeformis, Puccinia, -
striatus, Uromyces,-
Strickeria, . . . .
striifornais, Tilletia,
strobi, Peridermium,

,, Phoma,
strobicola, Hypoderma, -
strobilinum, Aecidium, -
struthiopteris, Uredinopsis, -
Sfcysanus, ....

suaveolens, Puccinia,
,, Trametes,

subcorticium, Phragmidium, -

PAOF,

I'AOK

- 469

subinclusa, Cintractia, -

- 302

- 361

,, Ustilago,

- 301

- 463

subtccta, Leptosphaeria, -

- 221

■ 472

subtilis, Coleroa,

- 195

- 464

succisae, Synchytrium, -

.- 110

- 184

,, Ustilago, -

■ 296

- 171

suffocata, Pestalozzia,

- 494

- 310

suffulta, Phyllactinia,

- 178

- 487

sulcigena, Hypodermella,

- 234

- 299

sulphureus, Polyporus, -

6,437

- 127

sylvatica, Puccinia,

- 351

- 176

symmetricum, Rhytisma,

- 246

- 501

symphyti, Uredo, -

- 420

- 410

symploci, Exobasidium,

- 427

221, 511

synantherearura, Coleosporium,

- 377

- 517

Syncephalis, - - - -

11, 28

- 452

Synchytriaceae,

- 107

- 253

Synchytrium,

- 108

- 443

syringae, Ovularia.

- 501

- 462

- 356

T

- 478

tabaci, Oidium, - - - .

- 499

- 475

,, Phyllosticta,

- 464

376, 414

tabifica, Phyllosticta (Sphaerella)

, - 464

- Ill

taleola, Aglaospora,

- 226

- 182

,, Diaporthe, -

- 226

- 429

tanaceti, Puccinia, -

- 355

- 494

Taphria = Taphrina,

- 146

- 221

Taphrina, - - - 7, 29,

[46, 148

- 210

Taphrinopsis, - . - -

- 148

- 519

taraxaci, Puccinia,

- 353

- 180

,, Synchytrium, -

22, 108

- 550

taxi, Capnodium, -

- 181

- 347

,, Phoma, ... -

- 468

- 218

,, Sphaerella,

- 215

- 555

tenuistipes, Puccinia,

- 351

- 347

Tepperianus, Uromyces,

- 338

- 336

terebinthi, Uromyces, -

- 337

- 204

teres, Helminthosporium,

- 512

- 310

Tetramyxa, ....

- 529

382, 415

thalictri, Aecidium,

- 349

- 468

,, Entyloma,

- 312

- 233

,, Puccinia,

- 358

- 407

Thecaphora, ... -

- 324

- 420

Thecopsora, . . . -

- 370

- 519

thelebola, Aglaospora, -

- 226

- 353

,, Melanconium,

- 226

- 455

Thelephora, - . - -

- 429

- 362

thesii, Puccinia,

- 341

I. INDEX OF PARASITES.

577

P/.GE

PAGE

Thielavia,

-

182

trigonellae, Uromyces, -

- 337

Thielaviopsis,

-

183

Triphragraium,

- 361

thlaspeos, Puccinia,

-

361

tritici, Leptosphaeria,

- 221

Tilletia,

-

310

,, Tilletia,

- 306

tiliae, Actinonema,

-

474

,, Ustilago,

- 288

,, Phyllosticta,

-

464

trollii, Puccinia,

- 356

Tilletia, - - . .

46, 68

306

tropaeoli, Pleospora,

- 221

Tilletieae,

-

275

Tuberaceae, - - - -

- 183

Tolyposporium,

-

305

Tubercularieae,

- 520

Tomentelleae,

-

423

tuberculatum, Phragmidium,

- 362

tormentillae, Pliragmidium,

-

363

tuberculatus, Uromyces,

- 337

tortilis, Erysiphe, -

-

175

Tuberculina, - - - -

- 327

Torula, - - . -

- 143

181

tuberosa, Sclerotinia,

- 266

Tosquinetii, Taphrina, 147,

150, 153

166

tuberum, Cladosporium,

- 511

toxicodendri, Marsonia, -

-

491

Tubeufianum, Cylindrosporium,

- 488

Trabutiana, Ustilago,

-

299

Tuburcinia, - - - -

- 319

Trachyspora, -

-

337

Tuckeri, Erysiphe,

- 176

tragopogonis, Cystopus, -

-

127

,, Oidium, -

177, 499

,, Puccinia, -

-

356

Tulasnei, Ramularia,

- 214

,, Ustilago, -

-

296

,, Sphaerella,

- 509

Trailii, Puccinia, -

.

349

,, Uncinula,

- 178

„ Thecaphora,

-

324

,, Ustilago,

- 284

Trametes,

- 450

453

tulipae, Puccinia, -

- 359

Trematosphaeria circinans.

-

201

,, Sclerotium,

- 500

Tremellinae, -

.

421

,, Ustilago, -

- 299

tremelloides, Gymnosporangium, -

389

turcicum, Helminthosporium,

- 512

tremulae, Ascochyta,

-

473

turgida, Taphrina, 147, 150,

152, 159

,, Fusicladium, -

-

508

tussilaginis, Coleosporium,

- 376

,, • Melampsora, -

- 364

367

typharum, Heterosporium,

- 516

,, Napicladium, -

-

218

typhina, Epichloe, -

- 191

Trentepohlia endophytica.

-

551

Typhula, ... -

- 431

Treubii, Ustilago, -

30

299

,, Phytaphysa,

-

554

U

trichella, Vermicularia, -

-

471

Ulei, Urocystis,

- 316

trichophora, Ustilago,

-

291

,, Ustilago,

- 299

Tricliospliaeria,

- 61

195

uliginosa, Puccinia,

- 351

Trichosphaerieae, -

-

195

ulmariae, Ramularia,

- 502

Trichospora, -

-

403

,, Stysanus,

- 519

tridactyla, Podosphaera,

-

174

,, Triphragmium,

- 361

trientalis, Tuburcinia, -

-

319

ulmarius, Polyporus,

- 452

trifolii, Olpidium, -

-

107

ulmi, Apiosporium,

- 181

,, Phacidium,

-

255

,, Asteroma,

- 470

,, Phyllachora,

-

229

,, Dothidella, -

- 230

,, Polythrincium, -

-

229

,, Phleospora, -

- 478

,, Pseudopeziza,

-

255

,, Phyllachora, -

- 496

,, Synchytrium,

- 107

109

,, Pleospora,

- 221

,, Uromyces,

-

333

,, Septogloeum,

- 496

trifoliorum, Peronospora,

-

132

,, Taphrina, - - 148,

149, 154

,, Sclerotinia, -

-

265

ulmicolum, Ceratophorum,

- 51'2

2o

578

I. INDEX OF PAKASSITES.

PAOE

umbelliferarum, Erysiphe

- 175

,, Magiuisicllii

\,, 148,

151, 154

umbilici, Puccinia,

- 361

umboiiatum, Rhytisiua, -

- 246

Uncinula,

.

- 176

undulata, Rliizina, -

■ 272

Ungeri, Didymaria,

-

• 501

Ungeriamun, Eutyloma, -

-

- 312

uniseptatiun, Dicoccum,

-

- 506

Uredineae, - - 7,

13,21

, 48, 328

,, heteroecisni,

-

45, 51

Urediiiopsis, -

141, 420

Uredo-foriiis, -

-

■ 420

Urnula, Sclerotinia,

- 256

Urobasidium, -

- 427

Urocystis, - - . -

.

- 314

Uromyces,

- 333

Urophlyctis, -

- 113

Uropyxis,

-

- 361

urticae, Peroiiospora,

- 135

, , Ramularia,

-

- 502

,, Rliytisma, -

- 246

,, Septoria, -

-

- 478

Ustilagineae, 7, 13, 16,

21,28

47, 275

,, infection, -

-

52,54

,, remedies, -

- 65

Ustilaginoidea,

- 311

Ustilago,

-

- 276

ntriculosa, Ustilago,

-

- 298

uvicola, Phoma,

-

- 216

V

vaccinii, Exobasidium, -

- 423

,, Gibbera, -

- 204

,, Melampsora,

-

- 370

,, Sclerotinia,

-

- 256

,, Synchytrium, -

- 109

vagans, Fumago, -

- 181

Vaillantii, Ustilago,

- 299

valantiae, Puccinia,

- 361

Valerianae, Puccinia,

- 356

, , Uromyces,

-

- 334

Valsa, - - . -

.

- 224

Valseae, - - - -

-

- 223

valsispora, Dendroplioma,

-

- 469

vauillae, Calospora,

-

- 485

,, - Gloeosporium, -

- 485

vaporarius, Polyporus, -

-

6, 442

variabile, Heterosporium,

- 516

variabilis, Ramularia,
variiis, Exoascus, -
vasinfectum, Piisarium, -
vastatrix, Hemileia,
venetum, (jlloeosporium,
Venturia, ....
veratri, Puccinia, -

,, Uromyces,
Vermicularia,

vermiculariaeformis, Venturia,
vernalis, Endomyces,

,, Melampsora, -
veronicae, Ovularia,
,, Puccinia,

,, Sorosjjhaera, -

,, Stysanus,

veronicarum, Puccinia, -
verruculosum, Eutyloma,
Vialae, Uredo,
viburni, Plasmopara,

,, Ramularia,
viciac, Ascocbyta, -

,, Peronospora, - .

,, Phyllosticta,
vincae, Puccinia,
vinosa, Ustilago,
violacea, Rhizoctonia,

,, Ustilago, -
violaceum, Phragmidium,
violae, Cercospora, -

,, Gloeosporium,

,, Peronospora,

,, Phyllosticta,

,, Puccinia,

,, Urocystis, - - 16, 21
virgaureae, Puccinia,
virginica, Taphrina, - 148,
virgultorum, Dothidea, -
viride, Chlorochytrium, -
viridis, Cylindrosporium,
vitellinae, Melampsora, -
viticola, Cercospora,

,, Plasmopara,
viticolum, Cladochytrium,

,, Cladosporium,

vitigena, Leptosphaeria,
vitis, Aureobasidium,
,, Plasmodiophora, -
,, Sphaerella,

. 31,
150,

PAOE

502
152
522
361
483
218
355
337
470
218
143
370
501
361
530
519
361
312
420
131
502
473
132
464
356
298
201
297
363
515
485
134
464
340
317
359
154
230
550
489
368
513
128
114
510
221
428
528
215

I. INDEX OF PARASITES,

579

vitis, Uredo, -
Yolkensii, Ravenelia,
Volutella,

Vi-ieseana, Ustilago,
Vuijkii, Ustilago, -
vulgaris, Botrytis, -

,, Phyllosticta, -
vulpinae, Puccinia,

W

Warburgiana, Epichloe, -
Warmingii, Exobasidium,
Westeiidorpii, Thecaphora,
Willkommii, Dasyscypha,

PAGE

PAGE

420

Willkommii, Feziza,

- 6, 20, 271

403

Winteriana, Puccinia,

- 349

520

Wittrockii, Entoderma, -

- 551

299

294

X

500

xautlioxyli, Aecidinm, -

- 410

464

Xenodochus, -

- 363

351

xylostei, Anthostoma, -
Z

- 226

zonata, Tilletia,

- 310

191

Zopfia, - - - -

- 179

427

Zopfiella,

- 178

325

Zopfii, Puccinia,

- 341

271

Zygomycetes, -

- 114

IL GENEEAL INDEX
OF HOST-PLANTS, COMMON NAMES, Etc.

Abies, Aecidium, 404, 409
Agaricus, - 457, 461
Apiosporium, - 181

Caeoma, - - 418

Calyptospora, - 372
Lophodermium, - 239
Nectria,- - - 185
Periderinium, - 417

Pestalozzia, - - 493
Phoma, - - - 465
Polyporus, 439, 442, 448,
449, 450
Rhizina, - - 274

Sclerotinia, - - 270
Trametes, - - 453
Trichosphaeria, - 196
Abietineae, Mycorhiza, 96
Acacia, Aecidium, - 410
Pavenelia, - - 403
Uromyces, - - 338
Acer, Cercospora, - 513
Cylindrosporium, - 489
Dermatea, - - 253
Dyscomycopsis, - 245
Leptothyrium, - 479
Melasmia, - 242, 480
Nectria, - - - 185
Oidium, - - - 499
Pestalozzia, - - 493
Pezicula, - - 253
Phleospora, - - 478
Phyllosticta, - - 463
Polyporus, 435, 444, 452

PAGE

Rhytisma, - 242, 244
Septogloeum, - 495

Septoria, - - 478
Taphrina, 151-154, 168
Uucinula, - 177, 178

Achillea, Cystopus, - 127
Leptothyrium , - 242
Protomyces, - - 141
Puccinia, - - 361
Schizothyrium, - 242
Synchytrium, - 113

Aconitum, Puccinia, - 356
Urocystis, - - 316

Acorus,

Septocylindrium, - 505

Actaea, Aecidium, - 409
Urocystis, - - 316

Adenostyles, Aecidium, 348
Coleosporium, - 377

Niptera, - - - 254
Puccinia, - 348, 359
Uromyces, - - 337

Adliesion-discs = appres-
soria.

Adonis, Urocystis, - 317

Adoxa, Puccinia, 341, 359
Synchytrium, - 1 12

Ustilago, - - 299

Aecidium, Tuberculina, 327

Aegopodium,

Actinonema, - - 474
Caeoma, - - - 419
Pliyllachora, - - 229
Protomyces, - - 138

PAGE

Puccinia, - - 359

Aesculus, Aecidium, - 410

Diplodia, - - 472

Nectria,- - - 185

Phyllosticta, - - 464

Polyporus, - - 444

Septoria, - - 478

Slime-flux, - - 143

Taphrina, - 151, 153

Aethusa, Puccinia, - 353

Agaricus, Endomyces, 141

Agave, Cladosporium, 509

Agrimonia, Melampsora,370

Uredo, - - - 420

Agropyrum (see also

Triticum )

Puccinia, - 345, 349

Ustilago, - - 293

Agrostemma,

Taphrina, - 151, 154

Agrostis, Puccinia, 345-349

Tilletia, - - - 310

Ailantbus, Cercospora, 515

Aira, Entyloma, - 313

Puccinia, - - 345

Ustilago, - - 294

Ajuga, Phyllobium, - 551

Albizzia, Uromyces, - 338

Alcbemilla,

Bostrichonema, - 501
Coleroa, - - - 195
Uromyces, - - 337
Alder, black = Alnus
glutinosa.

II. GENERAL INDEX.

581

PAGE

Alder, \vhite=Alnus incana.

Aletris, Physalospora, 218

Algae, Chlorocystis, - 550
Entoderm a, - - 551
Entonema, - - 555
Hai'veyella, - - 555
Olpidium, - - 107
Periphleginatium, - 551
Phaeophila, - - 551
Pythium, - - 117
Streblonemopsis, - 555
,, blue-greeu, - - 541
., 2:>athogenic, 539, 547

Alisma, Cladochytrium, 114
Doassansia, - - 323
Pseudopeziza,- - 255

Allium, Aecidium, - 349
Bacteriosis, - - 539
Caeoma, - - 367,419
Cladochytrium, - 114
Macrosporium, - 518
Peronospora, - - 132
Puccinia, - 341, 355
Rhizoctoiiia, - - 202
Sclerotinia, - - 266
Urocystis, - - 316
Uromyces, - 337, 338
Vermicularia, - 471

Almond (see Amygdalus)

Alnus, Corticium, - 452
Frankia, - - 101

Leptothyrium, - 479
Microsphaera, - 176

Mycodomatia, - 99

Mycorhiza, - - 99
Ovularia, - - 501
Passalora, - - 506
Polyporus, 433, 439, 452
Sclerotinia - - 262
Stigmatea, - - 211
Taphrina, 150, 157, 158,
166, 168
Valsa, - - - 224

Alopecurus,

Pestalozzina, - - 495
Puccinia, 345, 346, 349
Tilletia, - - - 310

Alpine-rose (see Rho-
dodendron)

PAGE

Alsineae, Puccinia, - 361

Althaea, Cercospora, - 515
Colletotrichum, - 487
Phoma, - - - 469
Phyllosticta, - - 464
Puccinia, - - 360

Amarantaceae,

Cystopus, - - 127

Amelanchier,

Fusicladium, - - 507
Gymnosporangium, 385,
391, 401, 402, 403
Oidium, - - - 499
Podosphaera, - - 173
Pvoestelia, 385, 391, 402

Ampelopsis, Cercospora, 515

Amphicarpaea,

Synchytrium, - 109

Amygdalus (see also
Prunus)
Ascospora, - - 211
Cercospora, - - 513
Gloeosporium, - 483

Polystigma, - - 189
Taphrina, 150, 153, 165

Anbury, - - - 524

Ancliusa, Aecidium, - 347

Andromeda, Coleroa, 195
Exobasidium, 426, 427
Rhytisma, - - 246
Stigmatea, - - 211

Andropogon, Claviceps, 195
Puccinia, - 345, 354
Tilletia, - - - 310
Ustilago, - - 292

Androsace,

Peronospora, - - 134

Anemone, Aecidium, 23,409
Coleosporium, - 377

Protomyces, - - 141
Puccinia, 356, 358, 360
Sclerotinia, - - 266
Septoria, - - 478
Synchytrium,- - 112
Urocystis, - - 316

Anethum, Puccinia, - 353
Heterosphaeria, - 249

Angelica, Fusicladium, 508
Puccinia, - - 340

PAGE

Anthoceros, Nostoc, - 546

Anthoxanthum,

Puccinia, - 345, 354
Tilletia, - - - 310

Anthracnose,

Blackberry, - - 483
Cotton, - - - 487
Privet, - - - 485
Raspberry, - - 483
Vine, - - - 467

Anthriscus, Plasmopara, 128
Puccinia, - - 340

Anthyllis, Uromyces, 337

Apium, Cercospora, - 514
Entyloma, - - 312
Macrosporium, - 518
Phyllosticta, - - 464
Puccinia, - 353, 355
Septoria, - - 477

Apocynum, Aecidium, 411
Septogloeum, - - 496

Apple (see Pyrus Mains)
-blight, - - - 531
-rot, - - - 482
powdery mildew, - 174

Appressoria, - - 9

Apricot (see Prunus)

Aquilegia,

Aecidium, - 349, 409

Arabis, Aecidium, - 410
Puccinia, - 359, 361
Ustilago, - - 297

Aralia, Triphragmium, 362

Arctium, Aecidium, - 351

Arctostaplaylos,

Exobasidium,- - 427
Melampsora, - - 370

Arisarum, Phyllosiphon,553

Aristida, Ustilago, - 294

AristolocMa, Puccinia, 341

Armeria, Uromyces, - 334

Armoracia, Ascochyta, 473
Alternaria, - - 518
Cercospora, - - 514
Cystopus, - - 126
Ovularia, - - 500
Septoria, - - 477

Arnica, Entyloma, - 312

Arnoseris, Entyloma,- 312

582

II. GENERAL INDEX.

TAOK

Aronia,

(Jymnosporangiuni, ."lOl
Roestelia, - - .302

Arrhenatherum,

Exobasiclium, - 427

Puccinia, - - 345
Tilletia, - - - 310
Urocystis, - - 316
Ustilago, - - 288

Arrowroot (see Maranta)

Artemisia. Peronospora, 1.34
Puccinia, - - 361

Artichoke (see Cynara)
,, Jerusalem (see
Heliaiithus)

Arum, Aecidium, .349, 410
Caeoma, - - - 419
Ustilago, - - 299

Arundinaria, Ustilago, 293

Anmdinella, Ustilago, 294

Asarum, Puccinia, 32, 359

Asclepias, Aecidium, - 411

Ash (see Fraxinus ex-
celsior)

Ash-canker, - - 533

Asparagus, Cercospora, 514
Puccinia, - - 341
Rhi^octonia, - - 202

Aspen (see Populus
tremula)

Asperula, Phacidium, 241
Puccinia, - .341, .353

Aspidistra, Ascochyta, 473

Aspidium )

Asplenium

Aster, Aecidium, 351, 411
Basidiophora, - 127

Puccinia, - - 361

Astragalus, Didymaria, 501
Microsphaera, - 176

Polystigma, - - 190
Thecaphora, - - 324
Uroniyces, - - 337

Astrantia, Fabraea, - 255
Puccinia, - - 359

Athamantha, Puccinia, 340

Atragene, Puccinia, - .358
Urocystis, - - 316

Atriplex,Cladochytrium,l 14

(see Ferns)

PAOK

Phyllosticta, - - 465

Atrophy, - - 22, 26

Aubernage, - 202, 534

Autoecism, - - 45

Avena, Cladosporium, 509

Erysiphe, - - 175

Fusarium, - - 512

Fusicladium, - - 508

Helminthosporium, 512

Phoma, - - - 467

Puccinia, 345, .346, 348

Scoleootrichum, - 508

Septorla, - - 477

Uromyces, - - ,336

Ustilago, - 284, 287

AzoUa, Anabaena, - 545

B

Bacterial diseases or

Bacteriosis, - - 530
Bacteroids,- - - 102
Bamhusa, Neovossia, 311
Puccinia, - - 354
Barbarea, Aecidium, 409
Barberry (see Berberis)
Barley (see Hordeum)
Bartsia, Coleosporium, 376
Batatas, Ceratocystis, 469
Cladosporium, - 511
Cystopus, - - 127
Nectria, - - 189

Phyllosticta, - - 464
Rhizoctonia, - - 202
(see also Ipomoea)
Bean (see Vicia)

,, Kidney (see Phaseolus)
Beech (see Fagus)
Beet-root and Sugar Beet

(see Beta)
Beet, heart rot, - - 464
,, -scab, - 497, 537

Bellidiastrum,

Aecidium, - - 351
Entyloma, - - 312
Puccinia, - - 359
Bellis, Aecidium, - 352
Berberis, Aecidium, 341, 409
Didymosphaeria, - 218
Melasmia, - - 479

PAOB

Microsphaera,

- 176

Puccinia,

- 340

Beta, Bacteria, -

- 537

Cercospora, -

- 514

Entyloma,

- 313

Oospora,

- 497

Peronospora,

- 1.32

Phoma,

- 468

Phyllosticta, -

- 464

Pythium,

- 116

Rhizoctonia, -

- 202

Sclcrotinia, -

- 264

Sporidesmium,

- 221

Uromyces,

- 334

Betonica, Puccinia,

- 359

Ustilago,

- 298

Betula, Cladosporium, 511
Dothidea, - - 230
Dothidella, - - 2.30
Hormomyia, - - 262
Melampsora, - 366, 367
Microsphaera, - 176

Myxosporium, - 486
Phyllactinia, - - 178
Polyporus, 446, 449-4.")2
Sclerotinia, - - 261
Slime-flux, - - 143
Taphrina, 149-154,

159-161, 167

Twig-galls, - - 532

Uncinula, - - 178

Bilberry (see Vaccinium

Myrtillus)

Birch (see Betula alba, etc.)

Bitter-rot,- - - 482

Black-knot, - - 231

,, -rot, Vine, 216, 484

,, -rust, - 341, 419

,, -shank, - - 469

Bladder-plums, - - 155

Blanc des Racines, - 202

Blight, a common name for

diseases
Boragineae, Erysiphe, 175
Puccinia, - 347, 348
Borage, Entyloma, - 312
BordeaiTx mixture, 69, 172
Bouillie-Bordelaise, - 69
Bouteloua, Ustilago, 299

II. GENERAL INDEX.

583

Brachypodium,

Puccinia, - 346, .354

Tilletia, - - 310

Uromyces, - - 336

Bramble (see Rubus)

Brand, Vine, - - 4S4

Brands (see Ustilagineae)

Brassica, Ascochyta, 473

Alternaria, - - 518

Cercospora, - - 514

Cystopiis, - - 126

Macrosporium, - 51S

Olpidium, - - 107

Peronospora, - - 133

Plasmodiophora, - 524

Pleospora, - - 221

Sclerotinia, - - 264

Sphaerella, - - 215

Sporidesmium, - 221

Briza, Puccinia, - 345

Tilletia, - - 310

Bromus, Exobasidium, 427

Puccinia, - 345, 347

Sphaerella, - - 215

Tilletia, - - 310

Urocystis, - - 316

Ustilago, - 292, 293

Brown-rot, - - 497

Brown -rust, - - 347

Brunissure, - 114, 528

Brusone, Rice, - - 266

Brussone, Vine, - 484

Bryzopyrum, Puccinia, 345

Buckwheat (seeFagopyrum)

Buds, premature, - 20

Bulb-bacteriosis, - 538

Bunt (see Tilletia)

Butomus,

Cladochytrium, - 113

Doassansia, - - 323

Buxus, Laestadia, - 217

Leptostroma, - - 480

Nectria, - - 188

Phoma, - - - 468

Phyllosticta, - - 464

Puccinia, - - 361

C
Cabbage (see Brassica)

PAGE

Cacalia, Coleosporiuin, 377
Uromyces, - - 337

Cactus, Phytophthora, 118

Caeoma, Tuberculina, .327

CalamagTostis,

Puccinia, - - 346
Sclerotium, - - 266
Tilletia, - - 310

Ustilago, - - 293

Calatbea, Cephaleuros, 553

Calcium oxalate and fungi,
35

Calendula, Entyloma, 312

Caltha, Faljraea, - 255
Pseudopeziza, - 255

Puccinia, - - 341

Camellia, Cephaleuros, 552
Coryneum, - - 491
Meliola, - - 182

Pestalozzia, - - 494
Vermicularia, - 471

Campanula,

Coleosporiuin, - 377

Marsoi:ia, - - 491
Puccinia, - - 359

Cankers (see under Hosts)
Nectria, Aecidium, etc.

Cannabis,

Dendrophoma, - 469
Peziza, - - - 265
Septoria, - - 477

Caper = Capparis spinosa
Cercospora, - - 515
Cystopus, - - 126

Capsella, Cystopus, - 126
Peronospora, - - 133
Plasmodiophora, - 524

Capsicum,

Gloeosporium, - 483

Caragana, Uromyces, 337

Carduus,

Puccinia, 340, 353, 359
Thecaphora, - - 324
Ustilago, - - 296

Carex, Cintractia, - 302
Leptostroma, - 480

Phyllachora, - - 229
Puccinia, 349-351, 355
Schizonella, - - 305

PAGE

Tilletia, - - 310

Tolyposporiuni, - 306

Ustilago, - 27, 294

Carlina, Puccinia, - 353

Carnation (see Dianthus)

bacteriosis, - - 532

fairy ring spot, - 516

rosette, - - - 522

rust, - - - 336

spot, - - - 477

Carpinus, Dermatea, 253

Fusicladium, - - 508

Gnomoniella, - - 223

Mamiania, - - 223

Melampsora, - - 370

Pezicula, - - 253

Phyllactinia, - - 178

Polyporus, - 447, 452

Slime-flux, - - 143

Taphrina, 150-154, 162

Carrot (see Daucus)

Carthamus, Puccinia, 355

Carum, Cladochytrium, 114

Puccinia, - - 356

Carya, Fusicladium, - 508

Ramularia, - - 502

Cassandra,

Exobasidium, - 427

Castanea, Diplodina, - 474
Pestalozzia, - - 494
Phyllosticta, - - 464
Polyporus, - - 439
Septoria, - - 478

Slime-flux, - - 143
Urocystis, - - 319
Castration of flowers, 27
Catalpa, Macrospo-
rium, - - - 518
Ceanothus, Aecidium, 411
Cedar-apples, - - 402

Cedrus, Peridermium, 417
Celery (see Apium)
Cell-contents and fungi, 31
Cell-sap and fungi, - 33
Cell-walls and fungi, 36
Cellulose-destroying fungi,
35, 38
Celtis, Ramularia, - 502
Taphrina, - 149, 153

584

II. GENERAL INDEX.

PAGE

PAOE

PAGE

Cenchrus,

Cherry, Bird (see

Prunus

Dicoccum,

506

Tolyposporium,

- 306

Padus)

Clover (see Trifolium)

Centaurea,

Chervil (sec Antlniscus

)

Clover-rust,

333

Accidium,

351, 409

Chestnut, horse (

see

Club-root, -

524

ruccinia,

.340, 353

Aesculus)

Cochlearia,

Centranthus, Puccinia, SoG

Chestnut, sweet (

see

Alternaria,

518

Cephalanthus,

Castanea)

Cystopus,

126

Accidium,

- 411

Chives (see Allium

)

Ovularia,

500

Cerastium, Accidium, 410

Chlora, Piiyllobium, -

551

Coffea, Ceroospora, -

515

Fabraea,

- 255

Ciiloranthy,

3.^

t, 90

Hemileia,

361

Isariopsis,

- 520

Chloris, Ustilago,

299

Pellicularia, -

181

Melampsorella,

- 370

Cldorosis, -

32

Raniularia,

502

Peronospora, -

- 1.34

Chrysanthemum,

Coix, Ustilago, -

294

Sorosporium, -

- 325

Accidium,

351

409

Colchicum, Urocystis,

316

Ustilago,

- 297

Oidium, -

499

Uromyces,

3.38

Ceratopliylluin,

Septoria,

478

Colutea, Uromyces, -

337

Chlorochytrium,

- 550

Chrysosplenium,

Comarum, Doassansia,

324

Cereals (under Avena, Hor-

Entyloma,

312

Compositae, Aecidium,

409

deum, Secale,Triticum)

Puccinia,

361

Bremia, -

132

Cereal-rust,

82, 84

Cichorium,

Cystopus,

127

Chaerophyllum,

Puccinia,

353

355

Erysiphe,

175

Actiiionema, -

- 474

Sclerotinia, -

-

264

Peronospora, -

1,34

Caeoma,

- 419

Cicuta. Puccinia,

-

355

Plasmopara, -

131

Protomyces, -

- 138

Cineraria, Aecidium,-

352

Protomyces, -

141

Puccinia,

340, 359

Bremia, -

132

Puccinia,

353

Cliamaecyparis,

Circaea, Aecidium

409

Sphaerotheca,

173

Gymnosporangiu

m,

Melampsora, -

-

370

Synchytrium,

109

401, 402

Puccinia,

-

,361

Conifers, Agaricus, -

457

Pestalozzia, -

- 494

Clrsium, Aecidium

, -

,351

Botrytis,

268

Chamerops,

Cystopus,

127

Diplodia,

472

Anthostomella,

- 226

Phyllosticta, -

-

464

Fusoma,

504

Giapliiola,

325, 326

Puccinia,

353,

.361

Pestalozzia, -

494

Chamomilla, Cystopus, 127

Synchytrinm,-

-

109

Phytophthora,

117

Champignon blanc

- 202

Citron (see Citrus

tnedi

ca)

Polyporus, - 450

452

Chara, Entophysa,

- 548

Citrus, Capnodium

, -

182

Rhizina, -

273

Cheiranthus,

Cladosporium,

-

509

Conium, Puccinia,

353

Ceroospora, -

- 515

Colletotriclium,

487

Conopodium, Aecidium

,409

Cystopus,

- 126

Pendrophoma,

-

469

Puccinia,

355

Peronospora, -

- 133

Fusarium,

-

521

Conservation of Host,

21

Chelidonum, Caeoma, 419

Fusisijorium, -

521

Convallaria,

Chenopodiaceae,

Meliola, -

-

181

Aecidium, - ,349

410

Peronospora, -

- 132

Penicillium, -

-

180

Dendi'ophoma,

469

Phoma, -

- 469

Pestalozzia, -

494

Heterosporium,

516

Clienopodium,

Pleospora,

-

221

Convolvulaceae,

Cladochytrium,

- 114

Sphaerella, -

-

215

Cystopus,

127

Piiyllosticta, -

- 465

Sporidesmium,

-

221

Convolvulus, Puccinia,

341

Uromyces,

- 337

Claytonia, Peronospora

1,34

Thecaphora, -

324

Cherry (see Prunus avium

Clematis,

Copper salts as Fungi-

and Prunus Cerasus)

Aecidium,

,349,

409

cides. 66, 69, 1 22, 1 7 1

,467

II. GENERAL INDEX.

585

PAGE

Coralliorliiza,Mycorhiza, 97

Cork (see Wound-cork)

Cornus, Cryptomyces, 2-iS

Erysiplie, - - 175

Phyllosticta, - - 464

Septoria, - - 478

Corydalis, Aecidiuni,- 410

Caeoma, - - 419

Entyloina, - - 312

Peronospoi'a, - - 134

Corylus, Gnomoniella, 224

Mamiania, - - 224

Phyllaotinia, - - 178

. Polyporus, - 439, 444

Septogloeiim, - - 496

Cotoneaster,

Sclerotinia, - - 261
Cotton (see Gossypium)

,, frenching, - 522
Cottonwoods (see Populus)
Couch-grass (see Triticum)

cowberry I (geeVaccmium)

Cranberry J

Crataegus, Asteroma, 470
Fusicladium, - - 507
Gy miiosporangiuni ,

385, 391, 397, 401-403
Pestalozzia, - - 494
Phleospora, - - 478
Podosphaera, - - 174
Polyporus, - - 450
Eoestelia, 385, 397, 402
Septoria, - - 476

Taphrina, 150, 153, 166

Crepis, Puccinia, - 353
Synehytrium, - 109

Cress (see Lepidium)

,, water (see Nasturtium)

Croton, Aecidiuin, - 410

Crowberry (see Empetrum)

Cruciferae, Cystopus, 124
Erysiphe, - - 175
Peronospora, - - 133
Plasmodiophora, - 524
Pythium, - - 116

Cucumber (see Cucumis)

Cucumis, Bacteria, - 536
Cladosporium, - 510
Colletotrichum, - 486

PAGE

Erysiphe, - 175, 499

Hypnochtis, - - 428

Macrosporium, - 518

Peronospora, - - 134

Pythium, - - 117

Scolecotrichum, - 508

Cucurbita, Bacteria, - 536

Colletotrichum, - 486

Peronospora, - - 134

Cucurbitaceae, Phoma, 469

Sclerotinia, - - 265

Sphaerotheca, - 173

Cupressus, Agaricus, 457

Gymnosporangium, 403

Pestalozzia, - - 494

Cupuliferae,

Mycorhiza, - 93, 94

Cycads, Anabaena, - 544

Cladosporium, - 509

Cyclamen,

Colletotrichum, - 488

Septoria, - - 478

Thielavia, - - 183

Cydonia, Bacteria, - 531

Cercospora, - - 515

Entomosporium, - 480

Gymnosporangium, 385,
391, 401, 403

Hendersonia, - - 475

Ovularia, - - 500

Phoma, - - - 468

Roestelia, - - 391

Sphaeropsis, - - 472
Taphrina, 150, 154, 168

Cynancbum,

Cronartium, - - 381

Cynara, Raniularia, - 502

Cynodon, Phyllachora, 229

Tilletia, - - - 310

Ustilago, - - 294

Cynoglossum,

Peronospora, - - 134

Cyperus, Schinzia, - 326

Cjrtisus, Ceratophorum, 511

Cucurbitaria, - - 206

Darluca, - - 474

Diplodia, - - 209

Microsphaera, - 176

Peronospora, - - 133

PAGE

Phyllosticta, - - 463
Phj'salospora, - 218

Uromyces, - 337, 338

D

Dactylis, Entyloma, - 312

Epichloe, - - 191

Puccinia, - 345, 346

Sclerotium, - - 266

Tilletia,- - - 310

Uromyces, - - 336

Dahlia, Sclerotinia, - 264

Dammara,Peridermium,417

Damping-off, - - 116

Dandelion (see Taraxacum)

Daphne, Sphaerella, - 215

Datura, Cercospora, - 515

Daucus,Heterosphaeria,249

Phoma, - - - 468

Plasmopara, - - 128

Polydesmus, - - 221

Protomyces, - - 138

Ehizoctonia, - - 202

Sclerotinia, - - 264

Sporidesmium, - 221

Desmodium,

Microsphaera, - 176

Ramularia,, - - 502

Dentaria, Puccinia, - 359

Dianthus, Ascochyta, 473

Bacteriosis, - - 532

Botrytis, - - 500

Fusarium, - - 522

Heterosporium, - 516

Macrosporium, - 518

Puccinia, - - 361

Septoria, - - 477

Sorosporium, - - 325

Urocystis, - - 319
Uromyces, 334, 336, .337

Ustilago, - - 297

Volutella, - - 520

Dicentra, Aecidium, - 410

Peronospora, - - 134

Digitalis, Ascochyta, 473

Piamularia, - - 502

Digitaria (see Panicum)

Dill (see Anethum)

Diplachne, Ustilago, - 293

586

II. GENERAL INDEX.

PAOE

Dipsacus, Peronospora, 1.32
Disposition : Cliap. V.
Doiiiatia, - ():i, 99, 540

Doronicum, T'lictinia, .361
Doubling of B^lowers, 2S
Douglas Fir (see Pseudo-

tsuga)
Draba, Aecidium, - 4i(i
Puccinia, - . 359
Dracaena, Ustilago, - 299
Dry-rot = Merulius.
Dryas, Didyjnosphaeria,218
Synehytrium, . m

Durra (see Sorghum)

E
Eau celeste, - . qq
Echeveria,

Endophyllum, - 404
Echinocystis,

Peronospora, - - 134
Echinospermum,

Peronospora, - 134

Ectotrophicmycorliiza, 94
Egg-plant (see Solanum

Melongena)
Elder (see Sambucus)
Eleagnaceae, Mycorhiza, 99
Elm (see Ulnnis)

Elodea,Chlorochytrium, 550
Elymus,

Puccinia, 345, 348, 354

Ustilago, - . 293

Empetraceae, Mycorhiza, 98

Empetrum, Caeonia, - 380

Chrysoniyxa, - - 380

Melasmia, - . 479

Podosphaera, - - 175

Rhytisma, - . 246

Sclerotinia, - . 260

Endophytes, - - 8 II

Endotrophic, Mycorhiza, 93

Enzymes, - - 35, 37

Epacrldeae, Mycorhiza, 98

phedra, Peridermium, 417

Epilobium,

Melampsora, - - 370
Plasmopara, - - 131
Puccinia, - . 341
Ramularia, - - 502

PAOE

Septoria, - . 478

Spiiaerotheca, - 1 74

Uredo, - - . 42()
Venturia, - - 218

Kpipliytes, - - 8, 10

Epipogon, Mycorhiza, 97
Equisetum, Pythium, 116
Eranthis, Aecidium, 409
Urocystis, . . 316
Ergot (see Claviceps)
Ergotism, symptoms, 193
Erica, Hypoderma, - 2.34
Leptosphaeria, - 221
Venturia, - - 218
Ericaceae,

Exobasidium, 423, 427

Mycorhiza, - . 98

(see also Vaccinium)

Erigeron, Aecidium, - 411

Basidiophora, - 127

Entyloma, - . 312

F>rikssoa on Cereal-rusts,

82, 332, 345
Eriophorum,

Leptostroma, - - 480
Puccinia, - 352, 354

Eryngium, Entyloma, 312
Puccinia, - . 340

Erythraea, Phyllobium, 551

Eucalyptus,

Didymosphaeria, - 218
Pestalozzia, - - 494
Ustilago, - . 299

Euonymus.Caeoma, 368,419

Cercospora,

Microsphaera,

Venturia,
Euphorbia,
I Aecidium,

Endophj'llum,

Fusicladium, -

Leptostroma, -

Melampsora, -

Peronospora, -

Ravenelia,

Uromyces, 334, 336, 337
Euphrasia,

Coleosporium, - 376

Tuburciuia, - - 321
Exoasceae, parasitic, 144

Fagopyrum,

Pliytojihchora, - II7

Ramularia, - - r)02

Fagus, Actinonema. - 474

Agaricus; - . 461

Hydnurn, - . 432

Myxosporium, - 486

Xectria, ■ - - 186

Pestalozzia, - . 493

Phyllactinia, - - 178

Phytophthora, - II7

Polyporus, 435, 444, 4.30

452

Quaternaria, - - 226

Slime-flux, - I43, 144

Fennel, Rhizoctonia, - 202

Ferments, - 2, 16, 35, 37

Ferns, Cryptomyces, 248

Sphaerella, - - 215

Taphrina, 29, 149, 153

Uredinopsis, - 141, 420

Urobasidium, - 427

Festuca, Isaria, - - 519

Puccinia, 345-349, 354

515

- 170

- 218

24, 410

480
370
135
403

Tilletia,

Uroc5'stis,

Ustilago,

Ficus, Cercospora,

Uredo, -

Ustilago,

" Finger and Toe," -

Fir, silver (see Abies)

Flax (see Linum)

Flower-hypertrophy,

Flowering, premature,

Flux of Trees, -

Fly-wood, -

403 I Forests, close and mixed, 80

508 Fragaria, Ascochyta, 473

Peronospora, - - 134

Ramularia, - . 214

Sphaerella, - - 214

Synchytrium, - m

Thecaphora, - . 325

Fraxinus, Actinonema, 474

Aecidium, - . 4l(>

Ascochyta, - . 473

Bacteria, - - 533

310
316
288
515
420
299
524

26

20
142
4.30

II. GENERAL INDEX.

587

Cereospora, -

515

Cylindrosporium, -

4S9

Hysterographmm,

233

Pestalozzia, -

493

Ph3'llactinia, -

178

Polyporus, 439, 444,

445,

452

Scolecotrichum,

50S

Septogloeum,

496

Septoria,

478

Fritillaria, Uromyces,

338

Fiuit-i'ot, - 58, 115

179

Fungi, pathogenic,

104

,, classification, -

105

,, heteroecious, 45

, 74,

331

,, in fodder, 85

306

,, sexuality, 104

135

Fungicides,

68

Fungus-digesting plants,

9-2, 97

,, - -galls, 15, -lo, 32

,33,

40

300

,, -roots, -

93

,, -traps, - 9:

2,97

G

Gagea, Puccinia,

356

Synchytriuni,

111

Uromyces,

338

Ustilago,

299

Galanthus, Botrytis, -

500

Caeoma,

368

Sclerotinia, -

270

Galega, Uromyces, -

337

Galeopsis, Phyllosticta

465

Galium, Melampsora,

370

Melanotaenium,

314

Phacidium,

241

Puccinia, ,341, 359

361

Synchytriuni,

113

Gaultheria,

Synchytriuni,

109

Genista,

Didymosphaeria, -

218

Ehizobium, -

101

Uromyces,

337

Gentiana, Botrytis, -

268

Cronartium, -

381

PAGE

Heterosphaeria, - 249

Mycorhiza, - - 97

Puccinia, - - 341

Sclerotinia, - - 268
Geraniaceae,

Sphaerotheca, - 173

Geranium, Botrytis, - 269

Coleroa, - - 195

Plasmopara, - 130, 131

Puccinia, - - 359

Ramularia, - - 502

Stigmatea, - - 210

Synchytrium, - 109

Tuburcinia, - - 322

Uromyces, - - 334

Venturia, - - 218

Geum, Uepazea, - 465

Peronospora, - - 134

Gilia, Aecidium, - 411

Puccinia, - - 355

Gladiolus, Urocystis, - 316

Glaux, Aecidium, - 336

Glechoma, Puccinia, - .361

Ramularia, - - 502

Gleditschia, Cereospora, 515

Glyceria,

Cladochytrium, - 114

Claviceps, - - 194

Ustilago, - 293, 294

Glycyrhiza, Uromyces, 337

Gnaphalium, Entyloma, 312

Golilen-rust, - - 348

Goodyera, Mj-corhiza, 97
Gooseberry (see Ribes)

-mildew, - - 173

Gossypium, Cereospora, 515

CoUetotrichum, - 487

Fusarium, - - 522

Macrosporium, - 518

Ramularia, - - 502

Sphaerella, - - 214

Uredo, - - - 420

Gourd (see Cucurbita)

Grain-smuts, - 65, 221

(see also Ustilagineae)

Gramineae, Ascochyta, 473

Claviceps, - - 191

Dilophia, - - 222

Dilophospora, - 479

PAGE

191
175
427
520
519
504
499
222
229
-349
508
477
306

Epic?doef

Erysiphe,

Exobasidium,

Fusarium,

Isaria, -

Mastigosporium,

Oidium, - 175,

Ophiobolus, -

Phyllachora, -

Puccinia, - 341

Scolecotrichum,

Septoria,

Ustilago, - 288,

Grape (see Vitis)
Grape-fruit (see Citrus)
Grasses (see Gramineae)
Grass-mildew, - - 175
Gumming, 211, 491, 538
Gunnera, Xostoc, - 541

H

Habitat-races, - - 332

Hail-wounds, - 61, 78

Hallimasch, - - 455

Hartig's, R., chief works, 37

Haustoria, - 8, 10, 12

Hawthorn (see Crataegus)

Hazel (see Corylus)

Heart-wood, antiseptic, 5, 76

Hedera, Ascochyta, - 473

Bacteria, - - 533

Cladosporium, - 510

Septoria, - - 478

Sphaerella, - - 215

Vermicularia, - 471

Hedysarum, Uromyces, 338

Heleocharis, Claviceps, 195

Helianthus, Plasmopara, 131

Puccinia, - - 340

Ramularia, - - 502

Sclerotinia, - - 264

Helichrysum, Entyloma, 312

Helleborus, Ramularia, 502

Urocystis, - - 316

Helosciadium (see Apium)

Entyloma, - - 312
Hemi-parasite, - 3, 4, 6
Hemi-saprophyte, - 3, 4
Hemp (see Cannabis)

588

II. GENERAL INDEX.

PACE

Hemp-canker, - - 'iOS
Hepaticae, Nostoc, - 547
Seliizophyceae, - 546
Heracleum,

Heterosphaeria, - 249

Protomyces, - - 138

Puccinia, - - 340

Taphrina, - 151, 154

Heteioecism, - 45, 331

Hieracium, Entyloma, 312

Puccinia, - - .353

Hippuris, Uromyces, 336

Holcus, Puccinia, - 346

Tilletia, - - 310

Hollyhock (see Althaea)

Holosaprophytes, - 3

Holosteum, Ustilago, 297

Homogyne, Puccinia, 359

Honey-dew, - 181, 193

Honey-fungus, - - 455

Honeysuckle (see Loni-

cera)
Hop (see Humulus)
Hop-mildew, - - 173
Hordeum, Erysiphe, 175
Helminthosporium,

221, 512
Hormodendron, - 505
Phoma, - - - 467
Puccinia, - 345, 348
Tilletia, - - 310

Ustilago, - - 288
Hornbeam (see Carpinus)
Horse-radish (see Armor-

acia)
Hottonia, Doassausia, 324
Hot-water sterilization, 66
Humulus, Capnodium, 181
Oidium, - - 499

Sphaerotheca, - 173
Hyacinth (see Scilla)
Hydrangea, Septoria, 478
Hjrpericum,

Melampsora, - - 370
Hypnum,

Scotinosphaeria, - 550
Hypochoeris,

Ramularia, - - 502
Hypopitys, Mycorhiza, 93

J PAGE

Iberis, Plasmodiophora, 524

Ilex, Diplodia, - - 472

Impatiens, Depazea, 465

Plasmopara, - - 131

Puccinia, - - 356

Imperata, Ustilago, - 299

Indian Com (see Zea)

Individuation, - - 87

Infection methods, 53, 56

Insect diseases, - 8, 115

Inula, Coleosporium, 376

Ipomoea, Coleosporium, 377

Puccinia, - - .356

Vermicularia, - 471

Iris, Aecidium, - - 411

Cladochytrium, - 114

Helminthosporium, 512

Puccinia, - - 355

Schinzia, - - 326

Uredo, - - - 420

Isopyrum,

Synch j'trium, - 112

Ivy (see Hedera)
Ivy-canker, - - 533

Jasione, Puccinia, - 359

Jausch, - - - 484

Jensen's method, - 66

Juglans, Botrytis, - 180

Cladosporium, - 510

Entorrhiza, - - 326

Marsonia, - - 491

Microstroma, - - 497

Penicillium, - - 180

Septoria, - - 478

Juncus, Puccinia, - 354

Rhytisma, - - 246

Schinzia, - - 326

Tolyposporium, - 305

Urocystis, - - 319

Uromyces, - - 336

Ustilago, - - 294

Jungermanniaceae,

Trentepohlia, - 551

Juniperus, Agaricus, 357

Botrytis, - - 270

Clasterosporium, - 511

PAGE

Clithris, - - 248

Dothidea, - - 2.30

Gyranosporangiura, 384,
389, .391, .395, 401-403

Hendersonia, - - 475

Herpotrichia, - - 199

Lophodermium, - 240

Pestalozzia, - - 494

Pleospora, - - 511

Polyporus, - - 450

Stigmatea, - - 211

K

Kalmia, Synchytrium, 109

Enautia, Ascochyta, 473

Peronospora, - 28, 132

Ustilago, - - 294

Koeleria, Puccinia, - 354

Kohlhernie, or Kropf, 524

L

Labiatae, Erysiphe, - 175
Puccinia, - - 341

Laburnum (see Cytisus)

Lactuca, Botrytis, - 500
Bremia, - - - 132
Puccinia, - - 340
Septoria, - - 477

Lamium, Ovularia, - 501

Lampsana, Puccinia, - 340
Ramularia, - - 502

Larch (see Larix)

-canker, - - - 271

Larix, Agaricus, - 457

Caeoma, - 366, 367, 419
Dasycypha, - - 271
Heterosporium, - 516
Hypodermella, - 234
Leptostroma, - - 212
Lophodermium, - 240
Nectria, - - 188

Peziza, - - 20, 271
Polyporus, - 439, 452
Sphaerella, • - 211
Trametes, - - 453

Lathyrus, Diachora, - 230
Dicoccum, - - 506
Peronospora, - - 132
Thecaphora, - - 324
Uromyces, - 333, 334

II. GENERAL INDEX.

589

PAGE

Laurus,

Exobasidium, 31, 427
Leaf-cast, - - - 236
Ledum, Chrysomyxa, 379

Exobasidium,

427

Sclerotinia,

-

263

Leguminosae,

Erysiphe,

-

175

Mycodomatia,

101,

524

Mycorhiza,

-

99

Ravenelia,

-

403

Lemna,

Chlorochytrium,

549,

550

410
126
133

401
86

Chlorosphaera, - 548
Cornuella, - - 322
Eudoclonium, - 551

Olpidium, - - 107
Pythium, - - 117
Scotinosphaera, - 550

Lemon (see Citrus)

Lepidium, Aecidium,
Cystopus,
Peronospora, -

Lettuce (see Lactuca)

Libocedrus,

Gymnosporangium,

Lichen-symbiosis,

Lignificationof cell-walls, 37

Lignin-destroying fungi, 38

Ligustrum, Aecidium, 409
Caeoma, - - 419

Cercospora, - - 515
Gloeosporium, - 485

Lilac (see Syringa)

Lilium, Aecidium, 349, 410
Botrytis, - - 268

Peronospora, - - 135
Sclerotinia, - - 268
Uromyces, - - 338

Lima bean (see Phaseolus)

Lime or Linden (see Tilia)

Limnantliemum ,

Aecidium, - 352, 410
Stomatochytrium, - 550

Limosella, Doassansia, 324

Linaria, Entyloma, - 312
Melanotaenium, - 314
Peronospora, - - 134

Linum, Melanipsora, - 369

PAGE

Peronospora, - - 134

Liriodendron,

Cercospora, - - 515

Cylindrosporium, - 489

Leptosphaeria, - 221

Lithospermum,

vSynchytrium, - 111

Lolium, Fusarium, - 520

Ovularia, - - 500
Puccinia, - 345, 346

Thecaphora, - - 325

Tilletia, - - - 310

Ustilago, - - 288

Lonicera, Aecidium, 349, 409

Anthostoma, - - 226

Ascociiyta, - - 473

Didymosphaeria, - 218

Lasiobotrys, - - 182

Leptothyrium, - 479

Microsphaera, - 176

Nectria, - - - 185

Phyllosticta, - - 464

Venturia, - - 218

Lophantlius,

Peronospora, - - 134

Lotus, Ovularia, - 501

L'romyces, - - 336

Lucerne (see Medicago)

Lupinus, Cercospora, 515

Cryptosporium, - 489

Erysiphe, - - 175

Pythium, - - 117

Thielavia, - - 182

Uromyces, - - 337

Luzida, Phyllachora, - 229
Puccinia, - 352, 354

Urocystis, - - 316

Ustilago, - - 294

Lychnis, Ovularia, - 500

Puccinia, - - 340

Septoria, - - 478

Sorosporium, - - 325

Uromyces, - - 337
Ustilago, - 27, 297

Lycium, Microsphaera, 176

Lycopodium, Pythium, 116

Lycopus, Aecidium, - 411

Lysimachia, Aecidium, 351

Phylloliium, - - 551

Synchytrium, - 111

M

Magnolia, Pestalozzia,

494

Mahonia, Aecidium, -

341

Maize (see Zea)

Majanthemum,

Aecidium,

349

Malachium, Ustilago,

297

Maladie digitoire,

524

Mal-di-gomma, -

521

Mallow (see Malva)

Mai nero, - - 202

534

Malva, Ascochyta, -

473

Cercospora, -

515

Phoma, -

469

Puccinia, - 359

360

Mandarin (see Citrus)

Mangel Wurzel (see Bel

a)

Mangold (see Beta)

Manure and Fungi, 67

279

,, Plasmodiophora,

528

Maple (see Acer)

Maranta, Epichloe, -

191

Matthiola,

Plasmodiophora, -

524

Medicago,

Peronospora, -

133

Pseudopeziza,

255

Rhizoctonia, -

201

Sclerotinia,

265

Tilletia, -

310

Uromyces,

336

Medlar (see Mespilus

and

Amelanchier)

Melampyrum, Aecidium, 349

Coleosporium,

376

Melica, Puccinia,

346

Melon (see Cucumis)

,, water (see Cucumis)

Mentha, Cladochy trium

114

Endosphaera,

Puccinia,
Menyanthes,

Cladochy trium,
Mercurialis,

Caeoma, -

Cercospora, -

Synchytrium,
Mespilus,

Fusicladium, -

551
341

114

367, 419

- 515

- 113

- 508

590

II. GENERAL INDJiX.

PAOK

Mespilus,

Gyiuuosjjorangium,

391, 397
Mucor, - - - 180
Oidium, - - - 499
Ovularia, - 261, 500
Penicillium, - - ISO
Podospliaera. - - 174

Meum, Triphraginium, 3(32
Mignonette (see Reseda)
Mildew, powdery (see Ery-
sipheae)
,, false (see Perono-
sporeae)
Milium, Puccinia, - 345
Tilletia, - - - 310
Millardet's vines, - 82
Millet (see Panicum and

Sorghum)
Mint (see Mentha)
Mistletoe, - - 18, 64

Molinia, Claviceps, - 194
Fusarium, - - 520
Neovossia, - - 311
Puccinia, - - 349

Monotropa,

Mycorhiza, - 87, 93

Urocystis, - - 319

Monoxeny, - - 45

Morbe bianco, - - 202

Morus, Bacteria, - 534

Cercospora, - - 515

Cladochytrium, - 114

Diplodia, - - 472

Gibberella, - - 184

Helicobasidium, - 429

Nectria, - - - 185

Phleospora, - - 478

Polyporus, - - 445

Septogloeum, - - 496

Sphaerella, - 215, 478

Mountain Ash (see Pyrus

[Sorb us] Aucuparia)

Mucilage flux, - - 142

Mulberry (see Morus)

Mulgedium, Puccinia, 340

Mummification of fruits, 29

Musa, Physalospora, - 218

Muscari, Urocystis, - 316

■A(JE

338
299

Uromyces,

Ustilago,
Mycocecidia,
Mycodomatia, - 93

Mycorliiza, - 32,

Myosotis, Aecidium, -

Kntyloma,

Peronospora, -

Syiichytrium, 111,
Myosurus, Peronospora,
Myrica, Ramularia, -

Frankia,
Myricaceae,

Mycodomatia,
Myricaria,

Didymosphaeria,
Myrrhis, Puccinia,

N
Narcissus, Puccinia, -
Nardus, Claviceps,
Narthecium, Entyloma,
Nasturtium, Oystopus,
Nebbia nera,
Needle-cast, 211, 236,
Neottia, Mycorhiza, -
Nepeta (see Glechoma)
Nephrodium (see Ferns)
Nerium, Capnodium, -

Cercospora, -
Nicotiana, Ascochyta,

Bacteria,

Erysiphe,

Oidium, -

Peronospora, -

Phyllosticta, -
Nucleus-parasites.
Nuile,

Nuphar, Aecidium, 352,
Nutricism, - 88-

Nyctaglnaceae,

Peronospora, -
Nymphaea,

Aecidium, - 352,

Entyloma,

O

Oak (see Quercus)
Oak-root fungus, - 200

, 99
, 93
411
312
134
113
134
502
101

99

21S
340

359
194
313
126

484

481

97

181
515
473
535
175
499
134
464
32
508
410
, 92

135

410
313

PAOK

Oat (see Avena)

Oenothera, Aecidium, 411

Peronospora, - - 134

Puccinia, - - 355

Synchytrium,- - 109

Olea, Cercospora, - 515

Cycloconium,- - 506

Polyporus, - - 447

Twig-galls, - - 532

Oleaceae,

Hysterograpliium, - 232

Oleander (see Nerium)

Olive (see Olea)

Rogna or Loupe, - 532

Onion (see Allium)

Onion-rust, - 341, 355

Onobrychis, Diachora, 230

Thielavia, - - 183

Uromyces, - - 337

Orange (see Citrus)

foot-rot,- - - 521

mal-di-gomma, - 521

sooty mould, - - 182

Orchideae, Aecidium, 349

Caeoma,- - 368, 419

Gloeosporium, - 485
Mycorhiza, - 97, 99

Ornithogalum,

Heterosporium, - 516

Puccinia, - - 356

Urocystis, - - 316

Uromyces, - - 338

Ustilago, - - 299

Orobanche, Urocystis, 319

Oryza, Piricularia, - 503

Sclerotium, - - 266

Tilletia, - - - 310

Ustilaginoidea, - 311

Ostrya, Taphrina, 150, 154

Oxalis, Sphaerella, - 215

Oxyria, Puccinia, - 355

Ustilago, - - 298

Paeonia, Cronartium, 382

Palms, Colletotrichum, 488

Graphiola, - - 325

Pestalozzia, - - 494

Thelephora, - - 429

II, GENERAL INDEX.

591

PAGE

Pandanus, Cephaleuros, 553
Nectria,- - - ]88

Panicum, Pythium, - 116
Tolyposporium, - 306
Ustilago, 289, 291, 293

Papaver, Entyloma, - 312
Peronospora, - - 133

Papilionaceae,Ei'ysiphe,175
Peronospora, - - 132

Parasites, - - 1-3, 7, 14
classification, - - 3
mode of life, - - 7

Paris, Aecidium, 349, 410
Mycorbiza, - - 32
Tubnrcinia, - - 321
Urocystis, - - 316

Parnassia, Aecidium, 352
Uromyces, - - 334

Parsley (see Petroselinum)

Parsnip (see Pastinaca)

Partridge-wood, - 431

Paspalus, Ustilago, - 294

Pastinaca, Cercospora, 514
Cercosporella, - 503

Heterosphaeria, - 249

Pea (see Pisum)

Pea-rust, - - - 334

Peach (see Persica)

-curl, - - - 165
frosty mildew, - 503
-rot, - - - 497

Pear (see Pyrus communis)
-blight, - - - 531

Pedicularis,

Aecidium, - 351, 410

Penicillaria,

Tolyposporium, - 306

Pennisetum, Neovossia, 31 1

Pentstemon, Aecidium, 411

Peplis, Endospbaera, 551

Peridermium,

Tuberculina, - - 327

Persica (see also Prunus)
Cercospora, - - 513
Cercosporella, - 503

Cladosporium, - 510

Clastcrosporium, - 511
Gloeosporium, - 482
Monilia, - - 497

PAGE

PAOE

Pbyllosticta, -

463

Picea, Aecidium,

377,

Puccinia,

355

379

, 407, 416

Spbaerotbeca,

172

Agaricus,

- 457

Taphrina, 150, 153

165

Barclayella, -

- 373

Petasites, Aecidium, -

348

Chrysomyxa, -

379, 380

Coleosporium,

377

Herpotrichia, -

- 199

Coleroa, -

195

Lopbodermium,

237, 240

Petroselinum,

Mycorbiza,

- 95

Heterosphaeria,

249

Naevia, -

- 238

Plasmopara, -

128

Nectria, -

- 188

Puccinia,

353

Peridermium,

416, 417

Septoria,

477

Pestalozzia, -

- 493

Petunia,

Polyporus,

440-450

Pbytophtbora,

122

Septoria,

- 475

Sclerotinia, -

264

Trametes,

- 453

Peucedanum,

Tricbospbaeria,

- 197

Puccinia, - 353

, 359

Picris, Entyloma,

- 312

Taphrina, - 151

, 154

Puccinia,

- 355

Phalaris,

Pilea, Phytaphysa

- 554

Cladochytrium,

114

Pimpinella,

Puccinia, - 346

349

Puccinia,

340, 356

Sclerotium, -

266

Thecapbora, -

- 325

Ustilago,

294

Pine (see Pinus)

Phaseolus, Ascocbyta,

473

,, Cembran (see

Pinus

Bacteria,

539

Cembra)

Cercospora, -

515

, , Mountain (see Pinus

CoUetotrichum,

486

montana)

Isariopsis,

520

,, Scots (see

Pinus

Pbyllosticta, -

464

sylvestris)

Pbytophtbora,

122

, , Weymouth (see Pinus

Sclerotinia,

264

Strobus)

Uromyces,

334

Pine-twister,

- 364

Phegopteris (see Ferns)

Pinguicula, Ustilago,- 297

Pbillyrea, Aecidium, -

410

Pinus, Agaricus,

- 457

Uredo, -

420

Brunchorstia,-

- 481

PWeum, Epicbloe,

191

Caeoma, -

- 364

Puccinia, - 345,

348

Cenangium, -

251, 481

Phlox, Aecidium,

411

Cladosporium,

- 509

Puccinia,

355

Cucurbitaria, -

- 210

Phoenix (see Palms)

Elapbomyces,

- 183

Phrag-mites, Claviceps,

194

Gymnosporangium, 396

Helmintbosporium,

516

Lopbodermium,

- 240

Napicladium,-

516

Melani psora, -

- 364

Puccinia,

349

Mycorbiza,

- 96

Ustilago,

293

Peridermium,

- 376,

Phyllanthus, Ravenelia

403

382

411-416

Phyteuma,

Pboma, -

466, 468

Coleospoi'ium,

377

Polyporus,

449, 450

Uromyces,

338

Rhizina,-

- 273

692

II. GENERAL INDEX.

PAGE

Pinus, Sistotrema, - 433
Trametes, - - 453
Twig-galls, - 532, 533
drying up of twigs, 481

Plnus Cembra,

Cucurbitaiia, - - 210
Nectria, - - - 188
Perideriniuni,- 382, 415

Flnus montana,

Herpotrichia, - - 199
Hypoderiuella, - 234
Melampsora, - - 364
Peridermium,- - 411

Pinus sylvestris,

Agaricus, - - 457
Caeoma, - - - 364
Hypoderma, - - 234
Hypodermella, - 234
Lachnella, - - 272
Lophodermiutn, - 235
Melampsora, - - 364
Peridermium,- 374, 376,
377, 381, 411, 414, 415
Phoma, - - 466, 468
Polyporus, - - 450
Trametes, - - 453

Pinus Strobus, Agaricus, 457
Hypoderma, - - 233
Peridermium, 382, 415
Phoma, - - - 468
Polyporus, - 449, 450
Tuberculina, - - 328

Piptatherum, Puccinia, 346

Pistacia, Uromyces, - 337

Pisum, Ascochyta, - 473
Cladosporium, 509, 510
Erysiphe, - - 175
Peronospora, - - 132
Pythium, - - 117
Thielavia, - - 183
Uromyces, - - 334
Ustilago, - - 297

Plane (see Plataniis)

Plantago, Aecidium, - 411
Peronospora, - - 134
Eamularia, - - 502
Synchytrium,- - 111
Tilletia, - - - 310

Platanus, Calonectria, 184

Cladosporium,
Fenestella,
Gloeosporium,
Pestalozzia, -
Polyporus,

PAGE

510
229
484
494
445

Plum (seePrunus domestica)

Plums, pocket, - 154, 156

Plum-rust, - - 355

Poa, Claviceps, - - 195

Entyloma, - - 312

Epichloe, - - 191

Puccinia, - 345, 348

Tilletia, - - - 310

Urocystis, - - 316

Uromyces, - - 336

Pock of Vine, - - 484

Podopbyllum,

Phyllosticta, - - 465
Podospermum, Puccinia, 356
Polemonium, Aecidium, 411
Polygonatum,

Aecidium, - 349, 410
Polygoneae, Puccinia, 355
Polygonum,

Bostrichonema, - 501
Ovularia, - - 501
Peronospora, - - 135
Pseudopeziza, - 255

Pseudorhytisma, - 255
Puccinia, - 352, 355
Rhytisma, - - 246
Sphacelotheca, - 302
Stigmatea, - - 211
Uromyces, - - 334
Ustilago, - 298, 299
Polypodium (see Ferns)
Polj'xeny, - - - 45
Poplar (see Populus)
Poppies (see Papaver)
Populus, Agaricus, - 462
Ascochyta, - - 473
Capnodium, - - 181
Cladosporium, - 510
Didymosphaeria, - 218
Diplodia, - - 472
Dothiora, - 218, 249
Fusicladium, - - 508
Marsonia, - - 491
Melampsora, - 364, 367

PAOB

Mycorhiza, - - 96

Polyporus, - 439, 447

Septoria, - - 478

Slime-flux, - - 143

Taphrina, 150-154, 157,

166

Uncinula, - - 178

Portulaca, Cystopus, - 127

Potamogeton,

Uoassansia, - - 324

Endosphaera, - - 550

Potassium sulphide, 1 73, 483

Potato (see Solanum

tuberosum)

-disease,- - - 119

early blight, - - 517

-rot, - - - 535

-scab, - - - 537

Potato, sweet (see Batatas)

Potentilla, Beloniella, 256

Cercospora, - - 515

Cladochytrium, - 114

Coleroa, - - - 195

Marsonia, - - 491

Peronospora, - - 134

Phragmidium, - 363

Synchytrium, - 111

Taphrina, - 151, 154

Pourriture of Vine, - 202

Powdery mildew (see

Erysipheae)

Prenanthes, Puccinia, 340

Primula, Ovularia, - 500

Phyllosticta, - - 465

Puccinia, - - 341

Tuburcinia, - - 321

Uromyces, - 21, 334

Primulaceae,

Peronospora, - - 134

Privet (see Ligustrum)

Proserpinaca, Aecidium, 410

Prunella, Aecidium, - 410

Asteroma, - - 470

Pruning, - - - 77

Prunus, Ascospora, - 211

Asteroma, - - 470

Botrytis, - - 269

Cercospora, - - 513

Clasterosporium, - 511

II. GENERAL INDEX.

593

PACE

PAGE

PACE

Coryneum,

211,

491

Melampsora, -

370

Gymnosporangium,

Dermatella, -

-

252

Monilia, -

261

385, 391, 396,

401

403

Gloeospoi'iuni,

482

Polystigma, -

190

Monilia,

-

497

Monilia, -

-

497

Sclerotinia,

261

Morthiera,

210

Oidium, -

499

Taphrina, 151, 152,

154

Mucor, -

-

180

Phyllosticta, -

463

Psamma, Ustilago, -

293

Penicillium, -

-

180

Podosphaera, -

174

Pseudotsuga, Agaricus,

457

Phyllosticta, -

-

463

Puccinia,

355

Botrytis,

269

Plasmodiophora

-

529

Septoria,

-

476

Phoma, -

466

Plowrightia, -

-

231

Sphaeronema,

253

Polyporus,

450

Podosphaera, -

174

Sphaerotheca,

-

172

Trametes,

453

Polyporus,

439

444

Taphrina, 150-157

164

Psoralea, Aecidium, -

410

Roestelia,

385

396

Uncinula,

178

Ptelea, Aecidium,

410

Septoria,

-

476

Prunus avium and

P.

Cercospora, -

515

Sphaerella,

216

476

Cerasus, Ascospom

,211

Pteris (see Ferns)

Stigmatea,

-

210

Calosphaeria, -

-

226

Pulicaria, Uromyces,-

236

Taphrina, 150,

154

168

Clasterosporium,

-

511

Pulsatilla(see also Anemone)

Venturia,

-

218

Coryneum,

211,

491

Puccinia,

356

Pyrus Malus, Bacteria,

531

Cjdindrosporium

, -

489

Urocystis, - 316

317

Cladosporium,

590

Fusicladium, -

-

507

Pyrola, Chrysomyxa,-

380

Fusicladium, -

218

507

Gnomonia,

222

Melampsora, -

370

Gloeosporium,

482

Monilia, -

261,

497

Pyrus, Actinonema, -

474

Gymnosporangium,

Penicillium, -

180

Asteroma,

470

385, 389, 391,

402

403

Phyllosticta, -

463

Bacteria,

531

Hendersonia, -

475

Plowrightia, -

231

Gymuosporangium,

Hydnum,

-

433

Podosphaera, -

-

174

385, 391

402

Monilia, -

-

497

Polyporus, 439,

449

452

Hydnum,

433

Mucor, -

-

180

Puccinia,

355

Melampsora, - 369

370

Nectria, -

186

Taphrina, 151,

153,

163

Nectria, -

185

Oidium, -

173

499

Prunus domestica,

Pestalozzia, -

494

Penicillium, -

180

Calosphaeria, -

-

226

Polyporus, - 445

452

Phyllosticta, -

-

463

Cladosporium,

-

510

Poestelia, 385, 391,

Podosphaera, -

-

174

Clasterosporium,

-

511

392, 397

402

Polyporus, 433,

445,

452

Cylindrosporium

, -

489

.Sphaerotheca,

174

Roestelia, 385,

391

402

Dermatella, -

252

Pyrus (Sorbus) Aucuparia,

Slime-flux,

143

Didymaria,

501

Cucurbitaria, -

210

Sphaeropsis, -

472

Monilia, -

-

497

Gymuosporangium,

Sphaerotheca,

173

Mucor, -

180

385

391

Thelephora, -

429

Penicillium, -

-

ISO

Melampsora, -

369

Venturia,

218

Phyllosticta, -

-

463

Phoma, -

468

Plowrightia, -

-

231

Podosphaera, -

174

Q

Podosphaera, -

174

Polyporus,

444

Quercus, Agaricus

-

457

Polyporus,

-

447

Roestelia,38o,389,391,392

Aglaospora, -

226

Poly stigma, -

189

Sclerotinia, -

260

Bulgaria,

253

Puccinia,

355

Pyrus communis.

Capnodium, -

-

181

Taphrina, 151

-154

164

Bacteria,

531

Ciboria, -

-

270

Uncinula,

-

178

Entomosporium,

480

Cladosporium,

-

510

Prunus Padus, Asteroma,470

Fusicladium, - 218

507

Clithris, -

-

248

Cylindrosporium

. -

488

Gloeosporium,

482

Colpoma,

-

248

594

II. genki:al indkx.

l'A(;li

I'AIlK

I'AOE

Quercus, Corticium, -

452

Raphanus, Cystopus,-

126

Scleroderris, -

251

('ycloooniuin, -

50G

Peronospora, -

133

Septoria,

476

Deriiiiitea,

253

Raspberry (see Ru

l>us)

Spliaerotheca,

173

Diaporthe,

226

Red lot (due to Po

lyporeae)

Rice (see Oryza)

Kistulina,

452

Reed (see I'hragnii

tes)

Ricinus, Cereospora, -

515

(Juoiiionia,

223

Reseda, Cereospora, -

515

Ring-scale,

453

Hydnum,

432

Peronospora, -

133

Robinia, Aglaospora, -

229

Marsonia,

491

Resin,

62

, 75

Uothiorella, -

229

Microsphaeia,

176

,, collecting,

78

Nectria, -

185

Microstroma, -

497

,, -flux.

44,

458

Polyporus,

439

Myxosporium,

486

Rhamnus,

Rhizobium, -

102

Pestalozzia, -

494

Aecidium, 346

,349

387

•Strickeria,

204

Pezicula,

253

(;!ercospora, -

515

Root-hypertrophy,

26

Pliyllactinia, -

178

Microsphaera,

-

176

,, tubercles, 99, 101,52

S,544

I'olyporiis, 433,

439,

440,

Rheum, Aecidium

349

Rosa, Actinonema, -

474

444

450

452

Rhinanthaceae,

Cereospora, -

515

Rosellinia,

200

Scleroderris, -

-

251

Cryptostictis,-

475

Sclcrotiiiia, -

266,

270

Rhinanthus,

Dicoccuni,

506

iSlime-llux,

142,

143

Coleosporiiim,

376

Gloeosporium,

483

iStereuin,

429,

430

Sclerotium, -

266

Leptostroma, -

480

Taphriua, 150,

153,

167

Rhizoctonia,

200

Marsonia,

506

Thelephora, -

429,

430

Hhizomorphs,

210,

457

Peronospora, -

133

Ureilo, -

-

420

Rhododendron,

Pestalozzia, -

494

Quince (see Cydonia)

Ajjiosporium, -

181

Phragmidium,

362

-rust (see Roestelia)

Chrysomyxa, -

377,

379

.Septoria,

478

leaf-blight, -

-

480

Exobasidium,

-

427

Sphaerotheca,

172

black rot,

472

Gloeosporiuni,

-

485

Rosaceae, Oidium,

499

Hendersonia, -

475

Peronospora, -

134

R

Pestalozzia, -

494

Phragmidium,

362

Radish (see Raphanus)

Sclerotinia,

262

Sphaeropsis, -

472

Radish, horse (see

Synehytriuni,

109

Sphaerotheca,

173

Annoracia)

Rhodophyceae,

Rose-Mildew, -

172

Ranunculaceae,

Entonema,

-

555

Rost of Vine,

484

Erysiphe,

175

Rhus, Cereospora,

515

Rowan (see Pyrus

Plasmopara, -

-

130

Marsonia,

491

Aucuparia)

Ranunculus,

Sphaerotheca,

-

174

Rutaiaceae, Phacidium

241

Aecidium,

349

409

Taphrina,

151,

153

Rubus, Ascochyta, -

473

Cladocliytrium,

-

114

Uromyces,

-

337

Caeoma,

419

Cylindrosporiiim, -

489

Ribes, Aecidium,

350,

409

Cereospora, -

515

Didyniaria, -

501

(/aeoma,-

368,

419

Chrysomyxa, -

380

Entyloma,

312

Cercospora, -

-

515

Cladosporium,

509

Fabraea,

255

Cronartium, -

382

Coleroa, -

195

Ovularia,

-

501

Gloeosporium,

-

483

Gloeosporium,

483

Peronospora, -

134

Leptosphaeria,

221

MoUisia,

254

Stigmatea,

210

Microsphaera,

176

Phragmidium,

363

Syncliytrium,

112

Phyllosticta, -

464

Puccinia,

341

Urocystis,

-

316

Plasmopara, -

-

131

Pyrenochaeta,

470

Uromyces,

336

337

Polyporus,

-

452

Septoria,

476

Rape (see Brassica)

Puccinia,

359

Uredo, -

420

II. GENERAL INDEX.

595

P.^OE

PACK

PAGE

Rumea, Ustilago,

299

Didymosphaeria

, -

218

Sedum, Aecidium,

349

Rumex, Aecidium,

349

Nectria, -

185

Endophyllum,

404

Chlorochytrium,

550

Phyllosticta, -

-

464

Puccinia,

359

Cladochytriiim,

114

Sanguisorba,

Septoria,

478

Depazea,

465

Phragmidium,

-

363

Seed-control stations.

65

Ovularia,

501

Sanicula, Fabraea,

255

Seed-sterilization,

65

Puccitiia,

355

Puccinia,

-

341

Seedling-diseases,

Ramularia,

502

Saponaria, Sorospo

rium,325

Fusoma,

540

iSynchytriuni,

113

Ustilago,

28

297

Peronosporeae, 116

,117

Uromyces, - 334

,337

Saprophytes,

-

1-3

Selection against dis-

Ustilago,

298

Saxifraga, Caeoma

, -

419

ease, -

81

Venturia,

218

Exobasidium,-

427

Selinum, Puccinia,

353

Ruppia, Tetramyxa, -

529

Melampsora, -

370

Sempervivum,

Ruscus, Phyllosticta,-

465

Puccinia,

-

359

Endophyllum,

403

Rust or Uredineae, -

328

Syncliytrium,-

-

112

Phytophthora,

118

Rust in Australia, etc.

, 85

Scabiosa, Peronospora,

1.32

Senecio, Aecidium, 350

, .351

Rust, white,

123

Puccinia,

-

361

Coleosporium, 374

377

Rye (see Secale)

Synchytrium,-

110

Ovularia,

500

Ustilago,

294-296

Puccinia, - 356

359

S

Scilla, Bacteriosis,

538

Ramularia, -

502

Saccharum,

Pleospora,

221

Thielavia,

183

Thielaviopsis,

183

Puccinia,

356

359

Seseli, Puccinia,

353

Trichosphaeria,

198

Sclerotinia,

-

266

Sesleria, Puccinia,

349

Ustilago,

284

Urocystis,

-

316

Tilletia, -

310

SaflFron, Rhizoctonia, -

202

Uromyces,

-

338

Setaria, Sclerospora, -

131

Sagittaria, Burillia, -

322

Ustilago,

-

299

Ustilago,

292

Doassaiiia, - 323

324

Scirpus, Cladochyt

riun"

,114

Ustilaginoidea,

311

Sainfoin (see Onobrychis)

Claviceps,

195

Shelter-parasitism, -

540

Salicornia, Uromyces,

334

Puccinia,

352

354

Shepherds Purse (sec

Salix, Capnodium,

181

Uromyces,

336

Capsella)

Cryptomyces,-

246

.Sclerotium-diseases

, 29

256

Shot-hole fungi, 463, 461

,513

Didyniosphaeria, -

218

Scorzonera, Cystopus,

127

Sicyos, Peronospora, -

134

Didymosporium, -

490

Puccinia,

353,

356

Silaus, Cladochytrium,

114

Leptostroma, -

480

Ustilago,

-

296

Silene, Peronospora, -

134

Melampsora, - 367

368

Scropliularia, Ovularia

501

Puccinia, - 340

361

Melasmia,

480

Peronospora, -

134

Sorosporium, -

325

Ovularia,

501

Ui'omyces,

338

Uromyces, - 334

337

Pestalozzia, -

494

Scropliularineae,

Ustilago,

297

Polyporus, 433, 439,

444,

Plasmopara, -

131

Silver Fir (see Abies

452

Secale, Claviceps,

191

pectinata)

Rhytisma, - 245

246

Dilophia,

-

222

Silybum, Ustilago, -

296

Scleroderris, -

251

Dilophospora,

-

479

Slum, Aecidium,

336

Septoria,

478

Fusarium,

520

Cladochytrium,

114

Trametes,

455

Hel m inthosporiu m ,

221

Slime-flux of trees, -

142

Twig-galls,

532

Leptosphaeria,

-

220

Slime-fungi,

522

Uncinula,

178

Puccinia, 345,

347,

348

Sloe (see Prunus)

Salvia, Puccinia,

341

Tilletia, -

-

310

Smilacina,

Sambucus, Aecidium,

411

Urocystis,

315

Heterosporium,

516

Cercospora,

515

Ustilago,

289

Smilax, Aecidium,

411

596

II. GENERAL TNDKX.

VAG t

Smuts or Ustilagineae

275

Smuts, stinking (see

Tilletia)

Smymium, Puccinia, -

356

Snag-pruning, -

77

Solanum, Cercospora,

515

I'liytophthoi-a,

120

Solanum Lycopersicum

,

Bacteria,

536

Cladosporium,

510

CoUetotrichum,

487

Fusarium,

520

Gloeosporium,

483

Macrosporium,

517

Phytophthora,

119

Septoria,

477

Solanum Melongena,

Botrytis,

500

Gloeosporium, 482

483

Nectria, -

189

Plioma, -

468

Solanum tuberosum,

Alternaria,

517

Bacteria, - 535

537

Botrytis,

268

Entorrhiza, -

326

Hypnochus, -

428

Macrosporium,

517

Oospora,

497

Peziza, -

268

Phytophthora,

119

Pythium,

116

Rhizoctonia, -

202

Schinzia,

326

Sclerotinia,

264

Soldanella, Puccinia, -

341

Solidago, Aecidium, -

411

Basidiophora, -

127

Didymaria, -

501

Puccinia,

359

Uromyces,

338

Sonchus, Bremia,

132

Coleosporium,

377

Puccinia,

355

Synchytrium,

113

Sorbus (see Pyrus)

Sorghum, Bacteria, -

534

Cintractia,

302

Endothlaspis,-

302

PAOE

Fusicladium, - - 508

Puccinia, - - 353

Uredo, - - - 420

Ustilago, - 282, 284

Spergula, Puccinia, - 361

Spergularia, Cystopus, 127

Uromyces, - - 337

Spermatiaand Spermo-

gonia, - 55, 137, 32S

Sphagnum, Tilletia, - 310

Spinach (see Spiuacia)

Spinacia, Cladosporium, 510

CoUetotrichum, - 487

Entyloma, ■ - 313

Heterosporium, - 516

Peronospora, - - 132

Phyllosticta, - - 468

Spinifex, Ustilago, - 299

Spiraea,

Cylindrosporium, - 489

Podosphaera, - - 174

Ramularia, - - 502

Sphaerotheca, - 1 73

Stysanus, - - 519

Triphragmium, 361, 362

Urocystis, - - 319

Spore, distribution, - 53

,, germination, - 46

Sporobolus, Tilletia, - 310

Spraying of Plants, - 69

Spruce (see Picea)

Spiirge (see Euphorbia)

Stachys, Puccinia, 356, 359

Septoria, - - 478

Starch and fungi, - 33

Statice, Uromyces, - 334

Steeps for fungi, - 65

Stellaria, Isariopsis, - 520

Melampsorella, - 370

Sorosporium, - - 325

Synchytrium, - 111

Uromyces, - - 337

Ustilago, - - 297

Stenactis (see Erigeron)

Stiftia, Protomyces, - 141

Stipa, Ustilago, - 293

Strawberry (see Fragaria)

Streptopus, Aecidium, 349

Struthiopteris, (see Ferns)

I'A(;K

Sugar-cane (see Saccharum)

Sulphur for Mildew

68

,170

Sulphur-purt',

-

171

Summer-rust, -

-

341

Sunflower (see Helianthus)

Sunflower-rust, -

-

340

Sycamore (see Acer

Symphoricarpus,

Aecidium,

411

Symphytum,

Cladochytrium,

114

Entyloma,

-

312

Ovularia,

-

.501

Uredo, -

-

420

Symplocos, Exobasii

um

,427

Syringa, Bacteria,

-

533

Cercospora, -

-

515

Uiplodia,

-

472

Ovularia,

.501

T

Tanacetum, Puccin

a.

355

Taraxacum, Aecidium,

351

Fusoma, -

-

505

Olpidium,

107

Protomyces, -

141

Puccinia,

-

353

Synchytrium, -

22.

108

Tare (see Vicia)

Tarring of Wounds,

77

,201

Taxus, Capnodium,

-

181

Phoma, -

-

468

Sphaerella,

-

215

Teucrium, Puccinia

361

Thalictrum,

Aecidium, - 349,

352

Entyloma,

312

Puccinia, - 356,

358

Synchytrium,

-

112

Urocystis,

317

Thesium, Puccinia,

-

341

Thlaspi, Puccinia,

.361

Tilletia, -

310

Thuja, Polyporus,

450

Thujopsis, Caeoma,

30

419

Thymus, Puccinia,

-

.359

Tilia, Actinonema,

474

Cercospora, -

-

515

Nectria, -

-

185

II. GENERAL INDEX.

597

Pestalozzia,
Phyllosticta,
Polyporus,
Tinder-fungus,

PAGE

- 494

- 464

- 444

- 435
Tobacco (see Nicotiana)
Tomato (see Solanum Lyco-

persieum)
Sleeping disease, - 520

Topinambur,Sclerotinia,264

Tragopogon,

Fusicladium, - - 508
Puccinia, - - 356
Tstilago, - - 296

Trientalis, Tuburcinia, 319

Trifolium, Cercospora, 515
Erysiphe, - 175, 499
Macrosporium, - 517
Peronospora, - - 133
Phacidium, - - 255
Phyllachora, - - 229
Polythrincium, - 229
Pseudopeziza, - 255

Pythium, - - 116
Rhizoctonia, - - 201
Sclerotinia, - - 2Go
Sphaeronema, - 255

Synchytriuni, 107, 109
Uromyces, 333, 336, 338

Trigonella, Thielavia, 183
Uromyces,

Triticum, Bacteria,
Cladosporium,
Dilophia,
Dilophospora,
Erysiphe,
Gibellina,
Leptosphaeria,
My strosporium ,
Ophiobolus, -
Phoma, -
Puccinia,
Pyroctonum, -
Sclerotium, -
Septoria,
Tilletia, -
Typhula,
Urocystis,
Ustilago,

Trollius, Puccinia,

- 337

- 535

- 509

- 222

- 479

- 175

- 220

- 221

- 518

- 222

- 467
345-349

- 114

- 431

- 477
306, 309, 310

- 431

- 316
- 28S, 293

356

Tropaeolum, Pleospora, 221

Tsuga, Peridermiuni, 417

Trichosphaeria, - 197

Tulipa, Botrytis, - 500

Puccinia, - - 359

Sclerotium, - - 500

Ustilago, - - 299

Turnip (see Brassica)

Turritis (see also Arabis)

Urocystis, - - 319

Tussilago, Asteroma, 470

Coleosporium, - 376

Puccinia (Aecidium), 348

Ramularia, - - 502

Twig-galls, - - 532

Tyloses, - - - 76

Typha, Heterosporium, 516

Ustilago, - - 293

U

Ulmaceae, Taphrina, - 149

Ulmus, Apiosporium, 181

Asteroma, - - 470

Ceratophorum, - 512

Cladosporium, - 511

Dothidella, - - 230

Nectria, - - - 185

Pestalozzia, - - 494

Phleospora, - - 478

Phyllachora, - - 496

Piggotia, - - 230

Pleospora, - - 221

Polyporus, 435, 444, 445,

452

Septogloeum, - - 496

Slime-flux, - - 143

Taphrina, - 149, 154

Uncinula, - - 178

Umbelliferae, Erysiphe, 1 75

Heterosphaeria, - 249

Phoma, - - - 469

Protomyces, - - 138

Puccinia, - 353, 359

Umbilicus, Puccinia, - 361

Uredineae, Darluca, - 474

Tuberculina, - - 327

Uromyces, Darluca, - 474

Urtica, Aecidium, - 349

Ramularia, - - 502

PAOK

Rhytisma, - - 246

Septoria, - - 478

Thecaphora, - - 325

Urticaceae, Peronospora, 1 35

V

Vaccinium,

Calyptospora, - 370

Exobasidium,- 423, 426

Gibbera, - - 204

Melampsora, - - 370

Podosphaera, - - 175

Sclerotinia, 256-260, 263

Synchytriuni,- - 109

Valeriana, Puccinia, - 356

Uromyces, - - 334

Vanilla, Gloeosporium, 485

Veratrum,

Heterosphaeria, - 249

Puccinia, - - 355

Uromyces, - - 337

Verbascum, Phoma, - 469

Ramularia, - - 502

Uromyces, - - 338

Veronica, Ovularia, - 501

Peronospora, - - 134

Puccinia, - - 361

Schroeteria, - - 328

Septoria, - - 478

Sorosphaera, - - 530

Stysanus, - - 519

Vetch-rust, - - 333

Viburnum, Actinonema, 474

Cercospora, - - 515

Microsphaera, - 176

Plasmopara, - - 131

Ramularia, - - 502

Vicia, Ascochyta, - 473

Cercospora, - - 515

Erysiphe, - - 175

Peronospora, - - 132

Phyllosticta, - - 464

Uromyces, 333, 334, 336

Vinca, Puccinia, - 356

Vine (see Vitis)

bird's eye rot, - 467

black rot, - 216, 484

false mildew, - 129

598

ir. GENERAL INDEX.

Vine, mildew, -
root-fungus, -
vine-epidemics,
white rot,

- 176

- 20'2
SI, 84

- 471

Vines, American iiybrid, 81

Vingerziekte, - - 524

Viola, Aecidium, - 410

Cercospora, - - 515

Gloeosporium, - 485

Ovularia, - - 500
Peronospora, - - 134

Phyllosticta, - - 464

Puccinia, - 340, 359

Synchytrium,- 112, 113

Urocystis, 16,21, 31,317
Violet-rust, - - 340
Viscaria (see Lychnis)
Vitis, Ascochyta,

Aureobasidium,

Bacteria,

Botrytis,

Cercospora,

Cladochytrium,

Cladosporium,

Colletotrichu7ii,

Coniothyrium,

Dematophora,

Gloeosporium,

Laestadia,

Leptosphaeria,

Oidium, - - 1"

Penicillium, -

- 473

- 428

- 534
180, 267

- 513

- 114

- 510

- 488

- 471

- 202
484
216
221
499
180

482,

PAOK

Phoma, - - 216, 467
Plasmodiophora, 528, 529

Plasmopara, - 81, 128

Pseudocommis, - 529

Sclerotinia, - - 267

Septosporium, - 519

Sphaceloma, - - 467

Sphaerella, - - 215

Uncinirla, - - 176

Uredo, - - - 420

W

Wallflower (see Cheiranthus)
Walnut (see Juglans)
Weinstockfaule, - 202

Weymouth Pine (see

Pinus iStrobus)
Wheat (see Triticum)
White-rot of timber
(due to Polyporeae)
Willow (see Salix)
Witches' Broom, due to
Aecidium, 18, 24, 72, 88,
404, 410
Caeoma, - - - 418
Exoasceae, 19, 24,52, 145,
158, etc.
Ravenelia, - - 403
Wood-destroying fungi,

5, 34, 36, 62, 72
(see also Polyporeae,
Agaricus, Nectria, etc.)

I'AOE

Wound-cork, - 42, 76

,, -duramen, - 76

,, -infection, - 75

,, -parasites, 5, 17, 72,

75, 142

(see also Polyporeae,

Nectria, etc.)

,, -treatment, - 75

Wounds from animals, 78

X

Xanthoxylum,

Aecidium,

410

Yeast (see Saccharomyces)
Yew (see Taxus)

Zea, Bacteria, -

5,35

Helminthosporium,

512

Puccinia,

353

Pythium,

116

Tilletia, -

310

Uredo, -

420

Ustilago, 279, 281

282

Zinnia, Sclerotinia, -

264

Zizania, Ustilago,

294

Zizyphus, Cephaleuros,

553

Zoocecidia,

25

THE END.

i8m 97

^•-<. ..^;■■''■^V■.>■■

■■■' ^"."V^

■■•lx<fc^

}i'

n

hr> "

utu -

3 fttb'U

• V :•.:• ■■■•'.,. - > ^'''. "1^' '■■•'-,■■ si ^ ''-'.• ^ ' . '

'-»>»■ ..=ilV->>«i

*J ■/!"

5-^~

-■■ -. ■- '

0^^

R'*

'W

j^.

•'1^2^

SP

m

»^

m

t-^^m

":^v

" .'fit:

'M'^''

lAGRIGULTWRl
-"FORESTRY
■ Lte^ARY

n