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Eruin F. Smith.
Dean of American plant pathologists.

An Outline

of the

History of Phytopathology

BY

Herbert Hice Whetzel

Professor of Plant Pathology at Cornell University
Ithaca, New York

With 22 Portraits

Philadelphia and London

W. B. Saunders Company

1918

Copyright, 1918, by W. B. Saunders Company

PRINTED IN AMERICA

PRESS OF

W. B. 8AUN0ERS COMPANY

PHILADELPHIA

TO
THE MEMORY OF

ittason $?. Cfjotnag

A GREAT TEACHER AXD A TRUE FRIEND

THIS LITTLE VOLUME IS GRATEFULLY

DEDICATED

PREFACE

This booklet is to be regarded as in no sense a com-
plete history of the science of plant pathology. The
author has endeavored only to set forth in outline what
appear to be the most outstanding features in the evo-
lution of the science, and to indicate the proper rela-
tion thereto of the men who have chiefly shaped its
progress.

The literature upon which a complete history of plant
pathology must be based is here largely brought to-
gether for the first time. It is hoped that this sketch
may be elaborated later into a more complete and critical
presentation of the subject.

The author desires to express his appreciation of the
assistance of numerous friends and colleagues in the
preparation of this book; to a number of them, and
especially to Dr. Erwin F. Smith, for photographs, im-
portant historic data, and a final criticism of the com-
pleted text; to Dr. L. R. Hesler and Dr. C. H. Kauff-
mann for critical reading of the manuscript.

H. H. Whetzel.

Cornell University, Ithaca, X. Y.
May, iqi8.

CONTENTS

PAGE

Introduction 11

The Ancient Era (from Earliest Times to End of 5th Century
A.D.):

Hebraic Period (to about 500 B. C.) 14

Theophrastian Period (500 to 320 B. C.) 14

Plinian Period (320 B. C. to 476 A. D.) 17

Summary 18

The Dark Era (6th to 16th Centuries Inclusive) 20

The Premodern Era (1600 to about 1850) 22

The Renaissance Period (17th Century) 22

Summary 24

The Zallingerian Period (18th Century) 25

Characteristic Features 32

The Ungerian Period (1807 to 1853) 33

Characteristic Features 40

The Modern Era (1853 to about 1906) 41

The Ktihnian Period (1853 to 1883) 44

Summary 57

The Millardetian Period (1883 to about 1906) 58

Discovery of Bordeaux Mixture 58. 63

Rise and Development of Plant Pathology in America .... 59
Discover)' of Bacterial Etiology of Certain Plant Diseases . . 61
Discovery and Establishment of Causal Relation of Bac-
teria to Plant Diseases 66

Pathogenetists and Predispositionists 71

The Present Era (1906 ) 108

Establishment of Chairs of Plant Pathology in Universities and

Colleges of Agriculture 109

Discovery of the Cause and Nature of Crown Gall 109

Establishment of the American Phytopathological Society. ... 110

The United States Quarantine Act of 1912 Ill

The Introduction of Sulfur as a Substitute for Copper in Fun-
gicides 112

Development of Disease-resistant Crops 113

The Epiphytotic of Chestnut Blight 114

Bibliography 116

Index 127

9

AN OUTLINE

OF THE

HISTORY OF PHYTOPATHOLOGY

INTRODUCTION

The science of phytopathology, like all natural sciences,
had its beginning in the dawn of man's civilization.
All wild plants have diseases, and from the time that man
began to domesticate by cultivation those of the wild
species that suited his needs, he must necessarily have
observed and considered the diseases that robbed him of
part or all of the fruits of his labor. Not until he acquired
the art of writing, however, could he record his observa-
tions and opinions with respect to the maladies which
affected his crops. Even long thereafter, records of plant
diseases were but fragments woven here and there into
his historic or religious writings. Later, as he began to
seek for order in the multitudinous facts of nature, his
observations on plant diseases were segregated more or
less along with the related facts and data into his writ-
ings on botany and agriculture. Only in relatively
modern times have there been attempts to organize
the facts and phenomena of disease in plants into a
separate science of plant pathology.

A history of the science of phytopathology has not yet
been written. Such a history must be based on the ob-

11

12 BISTORY (»l PHYTOPATHOLOGY

servations and interpretations of phytopathologic phe-
nomena as found in the preserved writings of the race.
There are, to be sure, a number of short papers or
chapters in books dealing with the subject, but they are
not at all comprehensive. One of the best is to be found
in the first volume of Sorauers Handbuch der Pflanzen-
krankheiten (1909), a recent translation of which by
Miss Dorrance (1914) makes it available to the English
reader. Another interesting paper is that by Arthur
(1906), which gives one a very good notion of the ideas
of some of the earlier writers who undertook the organiza-
tion of our science. Count Filippo Re, in the introduc-
tion to his essay on diseases of plants (1807), gives an
interesting list of phytopathologic writings prior to his
day. A preliminary survey of the field has been made
by Jensen (1909) in a thesis presented at Cornell Uni-
versity.

We can best approach the subject through a chrono-
logic survey of the available data. This will insure a
logical consideration of the landmarks in the evolution
of the science and a sequential introduction of the men
who have shaped its progress.

The history of phytopathology divides itself into eras,
and these again into periods. Each era is characterized
by a general and dominating point of view regarding the
nature, cause, and control of diseases in plants; the begin-
ning of each is marked by an epochal change in this point
of view. These changes from one era to the next come
as the result not only of accumulation and organization
of phytopathologic facts and theories, but are profoundly
affected, in fact often largely determined, by revolution-
ary discoveries in the fundamental sciences on which

INTRODUCTION 13

plant pathology is based. That these eras in our science
are often almost coincident with great historic epochs is
also significant. So sharp usually has been the change
from one era to the next that we may wifh considerable
accuracy designate the year, or decade at least, which
marks the passing of one and the inauguration of another.
I shall designate these eras as follows: (1) the Ancient
Era; (2) the Dark or Middle Era; (3) the Pre-modern or
Autogenetic Era; (4) the Modern or Pathogenetic Era,
and (5) the Present Era.

Each era divides itself more or less sharply into periods
— phases in the development and crystallization of the
prevailing point of view of the epoch. Since the thought
of each period, in the development of this, as of other
sciences, has been strongly influenced, in fact often
molded, by the life and works of some one man, I shall,
as far as practicable, designate each period by a name
indicating its dominating personality, following in general
the nomenclature used by Jensen (1909).

THE ANCIENT ERA

This may be said to begin with the earliest records of
plant diseases (to be found chiefly in ancient religious
writings, especially the Bible), and extending down to
about the time of the fall of the Roman Empire in the
fifth century (476 A. D.). It falls naturally into three
periods: the Hebraic, the Theophrastian, and the Plinian.

HEBRAIC PERIOD

The Hebraic period includes the centuries covered by
the Old Testament down to the rise and development of
ancient Greece, about 500 B. C, when the Jews as a free
people ceased to exist.

The data recorded by Hebrew writers consist largely of
mention of blightings, blastings, rusts, mildews, and
smuts of the crops of this ancient people. The cause of
these maladies was laid to the Deity, of whose wrath or
disfavor they were regarded as an expression. The
general character of these records will be seen by consult-
ing the following Biblical references: Genesis 41 : 23;
lKings8:37;Deut.28 : 22; Amos 4 :9;Haggai2 : 16, 17;
2 Chron. 6 : 28.

THEOPHRASTIAN PERIOD

The Theophrastian or Greek period covers the time
from the rise of the Greek peoples, about 500 B. C, to the
end of the Macedonian supremacy about 320 B. C.
The recorded observations on plants and plant diseases

14

THEOPHRASTIAN PERIOD 15

made by the Greeks during this period are to be found in
the writings of their great philosophers, Aristotle and
Theophrastus. According to E. L. Greene (1909 : 49)
the first plant pathologist was a Greek, one Cleidemus, a
rhizotimos whose observations on the diseases of the
fig, the olive, and the vine are quoted by Aristotle.

Theophrastus of Eresus was the first great botanist
of whom we have authentic records. He lived at about
the same time as Aristotle (370-286 B. C), whose pupil
he was, and to whom the great philosopher, dying,
bequeathed his library and botanical garden at Athens.
Theophrastus is generally regarded as the Father of
Botany. Chapter II in Greene's "Landmarks in Botan-
ical History" (1909) gives a very clear picture of the life
and works of this greatest of all ancient botanists. His
works abound with references to plant diseases. Some
excerpts from his Historia Plantarum1 will indicate the
breadth of his knowledge and the accuracy of his ob-
servations :

"As to diseases — they say that wild trees are not liable
to diseases which destroy them. Cultivated kinds,
however, are subject to various diseases, some of which
are, one may say, common to all or to most, while others
are special to particular kinds. General diseases are
those of being worm-eaten, of being sun-scorched, and
rot."

"The olive, in addition to having worms (which destroy
the fig too by breeding in it), produces also a 'knot'

1 Hort, Sir Arthur: Theophrastus' enquiry into plants; and minor
works on odors and weather signs, with an English translation, 1 : I-
XXYIII + 1-475; 2 : 1-IX + 1-499. 1916. (Greek and English text
on opposite pages.) See especially 1 : 391-413; 2 : 201-209.

16 HISTORY OP PHYTOPATHOLOGY

(which some call a fungus, others a bark blister), and it
resembles the effect of sun-scorch. The fig is also
liable to scab."

"The fig is also often a victim to rot and to krados."
"Scab chiefly occurs when there is not much rain, after
the rising of the Pleiad."

"Moreover, there are certain affections, due to season
or situation, which are likely to destroy the plant, but
which one would not call diseases; I mean such affections
as freezing and what some call scorching."

"As to diseases of seeds — some are common to all, as
rust, some are peculiar to certain kinds; thus chick-pea
is alone subject to rot." "Some again are liable to canker
and mildew, as cummin. But creatures which do not
come from the plant itself but from without do not do so
much harm."

"Generally speaking, cereals are more liable to rust than
pulses, and among these barley is more liable to it than
wheat; while of barleys, some are more liable than others,
and most of all, it may be said, the kind called 'Achillean.'
Moreover, the position and character of the land make no
small difference in this respect ; for lands which are ex-
posed to the wind and elevated are not liable to rust,
or less so, while those that lie low and are not exposed
to wind are more so. And rust occurs chiefly at full
moon."

Aristotle incidentally records the epiphytotic occur-
rence of rusts, but Theophrastus appears to have made a
careful study of these diseases in cereals as they occurred
in his day in ancient Greece. So frequent and destruc-
tive were these diseases that the ancient Greek farmer
regularly besought Apollo or some other of his numerous

PLIXIAX PERIOD 17

gods to shield his fields from the pestilence (Eriksson and
Henning. 1896 : 7-9). Thus did the Greek philosophers
shrewdly speculate as to the cause of these diseases,
while the husbandman dedicated such pests to special
gods (Ward. 1901 : 86). (See also Sorauer. 1909 : 38, 39.)

PLINIAN PERIOD

The Plinian or Roman period extends from 320 B.C.
to about the time of the fall of the Roman Empire in the
fifth century (476 A. D.). This period is named for the
great Roman encyclopedist, Plinius Secundus, who lived
from 23 to 79 A. D., and who brought together in his
writings the knowledge of his day on natural history
(E. L. Greene, 1909 : 155). The ancient Romans
placed responsibility for diseases and injuries to their
crops, along with their other misfortunes, on the gods or
the stars. To quote Pliny, "The evil influence of the
stars depends entirely upon the Heavens; on this account
there must be included among the effects, hail as well
as blight and the injury caused by white frost. The
blight especially attacks tender plants, if, enticed by the
warmth of spring, they venture to break through the
ground, and it singes the juicy buds of germinating plants.
In blossoms this is called blasting" (Sorauer Transl.,
1914 :43).

There is abundant evidence in the writings of Pliny
and other Roman authors of this period that plant dis-
eases were not only common and destructive but also
subjects of study by philosophers and of prayer by far-
mers. Pliny's observations on the relative severity of the
rust on wheat and barley in ancient Rome were just the
opposite from those of Theophrastus in Greece. He holds

18 HISTORY OP PHYTOPATHOLOGY

the wheat to be the more seriously affected. lie also
absolves the sun from all responsibility in bringing on the
disease. He regards the rust as the most destructive of
all cereal crop diseases. He recommends two methods of
control: early sowing of the grain so that it will ripen
before the rust comes on; and the sticking of laurel
branches in the soil throughout the field, so that the rust
may go over on these. Columella, another Roman
writer, recommends that great piles of chaff be distributed
about fields and vineyards and that these be fired when
frost threatens, thus preventing frost injury and rust. So
important a part did the rust play in Roman agriculture
that a special rust-god pair, Rubigus and Rubigo, were
evolved and an annual festival to propitiate them was
instituted. A Roman legend explains the rust to be a
curse sent on farmers as the result of the act of a wicked
boy, who burned a fox which he caught robbing his
father's hen roost (Eriksson and Henning, 1896 : 9-11).
Summary. — This ancient era comprises within itself a
very distinct unit in human progress. Particularly is this
true of all science and learning. For centuries to follow
little or nothing was to be added to the sum of scientific
knowledge; what had been gained by the observation and
studies of the ancient philosophers was to be all but lost
in the darkness of the Middle Ages. This is strikingly
true of phytopathologic learning. A careful review of
such records as are left to us from this era indicates that
considerable advances in an understanding of the fun-
damental features of phytopathology had been made.
(1) Of the nature of disease in plants little of our modern
conception is to be discovered in the philosophies of this
epoch. On the other hand, the observations on immunity

PLINIAN PERIOD 19

and susceptibility and the explanations offered therefor
fall not so far short of present-day progress in this direc-
tion. (2) The etiology of disease in plants was largely
shrouded in mystery and supersitition. Of the causal
relation of living organisms to disease in plants, the most
advanced of these ancient thinkers appear to have had
not the slightest suspicion. On the other hand, they
seem to have had an accurate conception of the causal
relation of such factors as drought, freezing, and winds.
(3) Their conclusions and recommendation respecting
control are odd mixtures of accurate reasoning and blind
superstition, as witness the two methods suggested by
Pliny for the control of the wheat rust and the smudging
urged by Columella for protection of the vine against
frost and of the grain against rust.

THE DARK ERA

The Dark or Middle Era includes what is known in
civil history as the dark ages, covering roughly the period
from the fall of the Roman Empire (476 A. D.) until the
beginning of the seventeenth century. The writings
of this period show little that is new regarding plant
diseases. This was the period when science and learning
may be said to have slumbered, hence it is not strange
that so fragmentary and unorganized a body of knowledge
as was phytopathology at that time should have had few
additions even in the form of isolated observations.

There is, however, one bright spot in the all but
universal darkness. This is the work of the Arabian
country gentleman and agricultural encyclopedist, Ibn-
al-Awam. He lived and wrote during the tenth century
at Seville, Spain. Thoroughly familiar with the writings
of Theophrastus, Pliny, and other ancient writers on
agriculture, including those of ancient India, he was
nevertheless an independent observer and thinker.
His phytopathologic comments are almost entirely on the
diseases of trees and the vine. He describes the symp-
toms of many diseases briefly but with accuracy and gives
extensive consideration to their control (Savastano,
1890-91 :16, 17, 70).1

1 Clement-Mullet, J. J.: Le livre de l'agriculture d'Ibn-al-Awam
(Kitab-al-Felahah). Traduit de l'Arabe, 1 : 1-100 (Preface) + 1-657
+ Index 1-24, 1864; 2:1: 1-460, 1866; 2:2: I-X + 1-293, 1867.
For his treatment of diseases of trees and other plants see vol. 1, ch.
14, pp. 543-597. Savastano (1890-91 : 16) in citing this translation
20

THE DARK ERA 21

The revival of interest in ancient Greek and Roman
literature which began in the fourteenth century and
became so general and enthusiastic throughout Europe
in the fifteenth century, brought to the attention of the
scientist and layman the observations and philosophies
of Theophrastus and Pliny regarding the diseases of
plants. But the statements of these philosophers were
blindly accepted and no attempts were made to verify
or disprove them by actual observation. The few
writers on agriculture during the latter part of this dark
era contented themselves for the most part with repeating
merely the statements of the ancients (Sorauer Transl..
1914 :45).

gives volume 3 as the one in which data on diseases of plants is to be
found. This appears to be an error, as I am unable to discover any
"volume 3." Part 2 of the second volume, which might have been
meant, deals with diseases of animals.

THE PREMODERN ERA

This era may be said to begin with the seventeenth
century and extend to about the middle of the nineteenth.
It was ushered in by the first recorded observations on
plant diseases and their control since the days of the
ancient Greeks, Romans, and Arabians. An epoch
during which observations and classification dominated
natural science in all lines, we find here for the first time
attempts at the classification of the phenomena of plant
diseases. During this era were written the first books on
plant diseases. Since of all the applied sciences, human
pathology was in this age the most powerful and re-
spected, it is not surprising that the sister science, plant
pathology, should have been largely influenced, in fact
dominated thereby, particularly in its nomenclature and
philosophy. Imbued with the dogma of spontaneous
generation, the phytopathologic philosophers of this era
brought to its perfection the theory of the autogenetic
origin and nature of disease in plants.

This epoch may be divided into three periods: the
Renaissance, the Zallingerian, and the Ungerian.

THE RENAISSANCE PERIOD

This period embraces, roughly speaking, the seven-
teenth century and may be said to have opened with the
publication in 1600 of the Oeconomia and Haussbuch by

22

THE RENAISSANCE PERIOD 23

Coler,1 in which is included information on diseases of
plants. This work consists largely, however, of repeti-
tion of the statements of ancient writers. The evil in-
fluence of the stars is soberly set forth. Peter Laurem-
berg,2 in his Horticultura published in 1631, "relates
that certain stars like Orion, the Pleiades, and others
exert an especially injurious influence from which the
so-called 'secret evils' arise, among which belong rust,
carbuncle, and mildew" (Sorauer Transl., 1914:45).
It is interesting that the practical growers, especially
educated gardeners, had more to do with the revival of
interest in the study of plant diseases than did the
botanists or other scientists of this period. Observa-
tions on the symptoms of diseases and details of so-called
practical methods of control appeared in books on garden-
ing. The general character of the better writers on plant
maladies during this time may be illustrated by the point
of view of Heinrich Hesse3 in his Neue Gartenlust (1690)

1 * Coler, Johannis: Oeconomia, oder Hausbuch. Ander Theil.
Buch V, Kap. 12, 1600. This date is the one given by Sorauer, Hand-
buch d. Pflanzenkr. 1 :41, 1909. I was unable to see the original.
Haller, Bibliot. Bot. 1 : 387, gives but two editions of the "Ander
Theil," 1595 and 1598. The work was issued in six parts and these
were frequently reprinted, separately and together, throughout the
17th century.

2 Lauremberg, Petrus: Rostochiensis horticultura. Libris II. com-
prehensa; huic nostro coelo et folo accomodata; regulis, observationibus,
experimentis et figuris novis instructa; in qua quicquid ad hortum pro-
ficue colendum et eleganter instruendum facit, explicatur, pp. 1-196.
Francfurti, 1631. See especially caput XXXV, "De avertendis et
corrigendis aeris iniuriis."

3 * Hesse, Heinrich: Xeue Gartenlust d. i. griindliche Vorstellung wie
ein Lust-, Kuchen-, und Baumgarten unter unsern Climate fiiglich
anzurichten, u. s. w., pp. 1^116. 10 Kpf. Leipzig, 1690.

* References marked with an * have not been seen by the author.

24 HISTORY ()F PHYTOPATHOLOGY

in which he gives as the three chief causes of the blighting
of trees: (1) superfluous sap with inflammation of the
sap; (2) resetting a tree in a position different from that
in which it originally stood (he preserved trees thus
reversed by coating the south side of the body with a
mixture of cow manure, oat chaff, glue, and ashes);
(3) using a bread knife in grafting a tree. He subscribes
to the ancient superstitions to a marked degree as is
evidenced by his opinion that cankers on trees result
from grafting the tree at the time when the moon lies in
the sign of the crab or scorpion. He says, "This disease
may be recognized by the fact that here and there the
bark throws up little hummocks under which the tissue
is dead and black. This spreads further and further,
ultimately infecting the whole trunk. Many scattered
causes of canker have been brought forward, but the one
given above is the most probable of all" (Sorauer Transl.,
1914:45,46).

Reference to the common and destructive occurrence
of rusts and smuts in cereal crops again appears in writ-
ings on agriculture. Especially in England where these
diseases were known under the names of blight and mil-
dew they were reported as very destructive during this
period. It is interesting that the first law, so far as
records show, directed toward the control of a plant dis-
ease, was enacted during this period. It was in Rouen in
France in 1660 that a decree was promulgated directing
the grubbing out and destruction of all barberry plants,
as they were held to bear some mysterious relation to
epiphytotics of wheat rust (Eriksson and Henning,
1896 : 12).

Summary. — The Renaissance period of the pre-modern

THE ZALLINGERIAN PERIOD 25

era is characterized : (1) by the revival of general in-
terest in plant diseases as is seen from the numerous
records in the agricultural literature of the 17th century;
(2) by the evidence that this interest was especially pro-
nounced among the educated agriculturists and garden-
ers; (3) by the fact that with respect to the cause of these
diseases opinion was largely dominated by the philoso-
phies of the ancients and by superstition; (4) by the
attempts to develop practical methods of controlling
diseases in plants, and (5) by the enactment of the first
law directed toward plant disease control.

THE ZALLINGERIAN PERIOD

The Zallingerian or taxonomic period covers the
18th century. It is characterized by attempts to name
and classify the diseases of plants much after the fashion
of naming and classifying plants themselves. The names
of the various plant diseases are copied from or fashioned
after those employed in human medicine for supposedly
similar diseases, and the classifications employed are
largely adaptations from those used in classifying
the diseases of man and animals. The period was
ushered in during the time of the revival of interest
in systematic botany, which culminated in the publica-
tion of Linnaeus' system of nomenclature (in Species
Plantarum) in 1753. Naming and classifying was the
order of the day and this early period of modern plant
pathology was largely dominated by the taxonomic mode
of thinking which prevailed among the scientific men of
that time.

Phytopathologic thought and writings during the early
part of this period were, however, to be influenced not

26 HISTORY OF PHYTOPATHOLOGY

only by the taxonomic philosophers and medical men
hut also by the practical gardeners, evidences of whose

influence we have already noted in the writings of the
previous period. We thus discover during the premodern
era two points of view in plant pathology, the philosophic
and the practical, clearly marked, at least as far as the
writers on the subject are concerned. Xot until the
middle of the nineteenth century are we to see these two
points of view united by Julius Kiihn. the first real plant
pathologist who effectively applied the scientific knowl-
edge of his day to the practical solution of plant disease
problems.

This period may be said to begin with the presentation
in 1705 of a paper by that noted French botanist Joseph
Pitton de Tournefort, under the title: Observations on
the maladies of plants.1 It is worthy of note that
Tournefort's classification was the first to present the
division of all plant diseases into two great groups,
viz., (a) those due to external causes, and (b) those due to
internal causes, a division very similar to that em-
ployed by some pathologists of more modern times.
Tournefort's work on plant pathology has had little
recognition, as his fame rests on his work as a taxonomic
botanist.

Following Tournefort's treatise appeared a number of
works on plant diseases, all more or less systematic in
character. Among these may be mentioned the following :

Christian Sigismund Eysfarth,2 a German, presented

1 Tournefort, J. P. de: Observations sur les maladies des plantes,
Mem. Mat. et Phys. tirez des registres Acad. Roy. Sci. de Fanne 1705:
.112-345, Paris, 1730.

2 * Eysfarth, Christian Sigismund: Dissertationem physicam de
morbis plantarum, pp. 1-48, Lipsiae, 1723.

THE ZALLIXGERIAX PERIOD 27

as a thesis for his doctorate at Leipzig, in 1723, a dis-
sertation on the physiology of the death of plants, in
which he classifies diseases according to the period of the
plant's life in which they appear, thus, (1) diseases of
the germinating period, (2) diseases of the vegetative
period, and (3) diseases of the fruiting period (Sorauer,
1909 :45).

Johann Christian' Fabricius.
The first pathogenetist. (After an engraving in Lind's "Danish Fungi.")

Johann Christian Fabricius, the first Dane to write on
plant pathology, published his complete classification in
1774 in his Essay on phytopathology,1 in which he
presents views far in advance of his day. He holds, for

1 Fabricius, Joh. Christ. : Forsog til en Afhandling om Planternes
:Sygdomme. In Det Kongl. Xorske. Vidensk. Selsk. Skriften, 5 : 431—
492, Kiobenhavn, 1774. What appears to be this same thing is cited
by Boehmer in his Handbuch der Xaturgeschichte, 3:1: 523, thus:
"Joh. Chr. Fabricius de morbis plantarum; in Act. Soc. Scient. Xonveg.
'To. 5. p. 431." Xo date is given.

28 HISTORY 01 PHYTOPATHOLOGY

example, that fungi found associated with disease lesions
are distinct organisms and not morbid plant tissues, a
view which was not to be generally accepted until more
than seventy-five years later. He was primarily an
entomologist and his phytopathologic writings had little
influence on contemporary phytopathologic thought.
His name is nevertheless not to be forgotten, for he stands
forth as one of those geniuses whose misfortune it was to
have lived and thought long before the world was able
to understand them (Lind, 1913 : 19, 20).

Michel Adanson, another noted French botanist of
this period, also contributed a chapter to the maladies of
plants in his work on Families des Plantes.1 He follows
Tournefort and Fabricius in classification and terminol-
ogy (Sorauer, 1909 :46).

The most striking phytopathologic publication of this
period is that by Johann Baptista Zallinger, De morbis
plantarum, a German translation of which appeared in
1779.2 In this work the attempt to utilize the terminology
of animal pathology reached its climax. Zallinger made
five general classes of plant diseases, viz. : ( 1 ) Phlegmasia?,
or inflammatory diseases, (2) paralysis or debility, (3)
discharges or draining, (4) cachexia, or bad constitution,
and (5) chief defects of different organs. Zallinger
strongly upheld the idea that fungi found associated

1 Adanson, Michel: Maladies des plantes. In Families des plantes,
1 : 42-53, 1763.

2 Zallinger, J. B.: De morbis plantarum cognoscendis et curandis dis-
sertatio exphaenomensis deducta. (Diss.), pp. 1-137 + apx. Oemponti,
1773. Translated into German by Johann Grafen von Auersberg under
the title Abhandlung iiber die Krankheiten der Pflanzen. ihrer Kenntniss
und Heilung; aus dem Lateinischen ubersetzt, pp. 1-6 + 1-143, Augs-
burg, 1779. According to Berkeley (Gard. Chron., 1854 : 20) a German
translation of this appeared as late as 1809.

THE ZALLIXGERIAX PERIOD 29

with disease in plants are but abnormal structures of the
plants themselves resulting from, rather than the cause
of, the diseased condition, and this theory with respect
to one of the most fundamental facts of modern pathology
was to dominate the thought of the following period
(Sorauer Transl., 1914 : 50).

The prevailing ideas regarding the etiology of diseases
in plants were still largely those of the ancients. Belief
in the role of the supernatural in the production of disease
was, of course, less marked than in the preceding period,
but it was still generally entertained. The causal nature
of such environmental factors as drought, drying winds,
hail, freezing, unfavorable soil, and the like was especially
put forth and emphasized. The idea of the autogenetic
origin of disease within the plant itself which was to pre-
vail during the succeeding period was taking form in the
minds of the contemporaries of Zallinger, as witness the
statement of Ritter von Ehrenfels that "even at times the
tendency to blight lies in the disposition of the tree itself —
a disposition which the trees obtain from the soil in
which they grow, from their descent, and from an unwise
cultivation" (Sorauer Transl., 1914 : 52).

The practical gardeners and horticulturists were ac-
cumulating facts and observations on the diseases of
plants with which they worked and were endeavoring to
explain them in the light of the ancient theories and
superstitions with regard to such phenomena, rather
than in that of the scientific thought of their day. They
were nevertheless beginning to devise treatments for
these diseases and to test them through crude experi-
ments. Their observations, theories, and remedies they
set down in their books and articles on practical garden-

30 HISTORY OP PHYTOP \ I BOLOGY

ing and horticulture. The "practical" writings of this
period differed strikingly from those preceding in the
greater emphasis placed upon the treatment. Some
of these recommendations sound very modern. For
example. Riedel,1 in his Garten Lexicon, 1751, gives as a
remedy for canker, cutting out the diseased places and
coating with grafting wax. On the other hand, his sug-
gestion that trees be bled by boring a hole or splitting a
root to relieve them of superfluous sap sounds ridiculous
(Sorauer, 1909 :43).

An English gardener, Stephen Hales, 1731, refers to the
transmission of canker diseases in budding as evidence of
the circulation of sap (Sorauer, 1909 :44). Hales also
offers an interesting explanation of the cause of hop
mildew and records an epiphytotic of this malady in 1731.2

These studies of the practical horticulturists reached
their climax in the discovery by William Forsyth in
1791 of a so-called "composition" or tree cement for the
treatment of lesions on trees.3 This was widely ad-

1 * Riedel, J. Christ. : Kurz abgefasstes Gartenlcxikon nebst einem
Garten-Calender, pp. 1-420, Nordhauscn, 1751.

2 Hales, Stephen: Statical essays; containing vegetable staticks;
or an account of some statical experiments on the sap in vegetables,
being an essay toward a natural history of vegetation; of use to those
who are curious in the culture and improvement of gardening, etc.,
1 :I-XII -f- 1-376, London, 1731. (Canker transmission, p. 147; hop
mildew, p. 33.) The earliest edition of this appears to have been that
of 1727. There were later editions, including a fourth, issued in two
volumes in 1769.

! Forsyth, William: Observations on the diseases, defects, and in-
juries in all kinds of fruit and forest trees; with an account of a peculiar
method of cure, pp. 1-71, London, 1791. This was translated twice
into German, twice into French, once into Italian, and once into Danish.
"A new and improved edition" of the above is to be found in the fourth
edition of "A treatise on the Culture and Management of Fruit Trees,"
London, 1806, by the same author, pp. 407-484.

THE ZALLINGERIAN PERIOD 31

vertised and, of course, overestimated, but had the
effect of calling more general attention to the economic
importance of plant diseases and created a demand for
semi-technical works on the subject. Such were immedi-
ately forthcoming. Three books of this type appeared
in the years 1794 and 1795 alone.

Perhaps the most important of these is that by
Plenck, on the physiology and pathology of plants.1
The author attempts to treat the diseases of all cultivated
plants of importance at that time. This work is valuable
because based apparently on thorough observation. The
two others are: Schregers Introduction to a correct
understanding of the diseases of trees2; and Ritter von
Ehrenfels' Diseases and injuries of fruit and garden
trees.3 Both give good descriptions of cankers, especially
of the Nectria canker still so destructive in Europe.
They attribute most of the ailments of plants to
unfavorable soil conditions, climate, or the inherent
disposition of the plant to become diseased (Sorauer,
1909:48). Writings dominated by the theories and
dogmas of this period continued to appear far into the
nineteenth century and were numerous during the early

1 Plenck, Joseph Jacob von: Physiologia et pathologia plantarum,.
pp. 1-192, Veinnae, 1794. (Pages 123-184 only, deal with pathology
including insect injuries.) This was translated into Italian by G.
Pagani in 1804 under the title: Fisiologia e patologia delle piante.

2 * Schreger, B. X. G.: Erfahrungsmassige Anweisung zur richtigen
Kenntniss der Krankheiten der YVald- und Gartenbaume, der Getreidear-
ten, Futterkrauter, Kiichengewachse und Blumen, nebst den bewahrtesten
Mitteln dagegen; fur Forstbediente, Oekonomen und Gartenliebhaber,
pp. 1-518, Leipzig, 1795.

3 * Ehrenfels (J. M.), Ritter von: Uber die Krankheiten und Ver-
letzungen der Frucht und Gartenbaume, pp. I-XX + 1-232, Breslau.,
1795.

32 HISTORY OF PHYTOPATHOLOGY

years of the Ungerian period, which is next to be con-
sidered. They were of little influence, however, and to
be considered only as echoes of a point of view already
on its way to the limbo of scientific rejecta. Sorauer
(1909 : 49) refers to one such published in 1818.1

The publication in 1807 by Freiherr von Werneck of
his Investigations in plant pathology and therapy,2
and the Essay, theoretical and practical, on diseases of
plants,3 by the Italian Filippo Re, mark the close of this
period. Both were philosophical rather than practical,
following much the same lines as those of their contem-
poraries.

The characteristic features of the Zallingerian period
may be summarized as follows: (1) Phytopathologic
thought and writings were distinctly taxonomic; (2)
the basis of classification was symptomologic ; (3) modern
practices in plant disease control had their beginnings
in this period; (4) the cause of disease in plants was gener-
ally attributed to occult influences or to the effects of
the elements, especially unfavorable soil, winds, low
temperatures, and the like, but the theory of the auto-
genetic nature of disease was beginning to take form.

1 * Burdach, Heinrich: Systematisches Handbuch der Obstbaum-
krankheiten, Berlin, 1818.

2 * Werneck (L. F. F.), Freiherr von: Veisucb einer Pflanzen Patho-
logie und Therapie; ein Beitrag zur hohern Forstwissenschaft, pp. 1-60,
Mannheim, 1807.

3 Re, Filippo: Saggio teorico pratico sulle malattie delle piante, pp.
1-437, Venice, 1807. A second edition appeared in 1817 from Milan,
pp. 1-331. An English translation of this appeared in Gard. Chron., 1849,
p. 211, and running throughout the numbers for nearly two years. An
earlier work of the same sort, under the title: * Saggio di nosologia
vegetabile, Mem. di Mat. e di Fisica Soc. Ital. delle Sci., 12 : 2 : 225 -255.
appeared in 1805.

THE UNGERIAN PERIOD 33

This period saw the early attempts of scientists to
assemble and organize the scattered and apparently
unrelated facts and phenomena of disease in plants.
The writings of the period constitute the record of the
real beginnings of the science. From these pioneer
attempts was to develop with astounding rapidity the
phytopathology of the present, which is even yet to
some degree in the process of delimitation and crystal-
lization. In the periods to follow we shall see something
of the lines along which and of the great minds by which
this development has been effected.

THE UNGERIAN PERIOD

The Ungerian period extended from about 1807 to
1853. This period might well be designated the physi-
ologic or autogenetic period, since the theories and in-
vestigations on plant nutrition, sexuality, and irritability
largely dominated botanical thought, eclipsing to a
marked extent the taxonomic point of view of the pre-
ceding period. This is strikingly brought out by the
fact that the most important works on plant pathology
were written by men primarily plant physiologists, and
those too among the greatest of their day. It is also
worth noting in passing that they were all doctors of
medicine and practised their profession at the beginning
of their careers. During the early part of the period no
contributions of marked worth appeared. The men who
were to express the ideas and shape the evolution of our
science during this time were getting the training and
experience which was finally to appear in the distinctive
contributions of their day.

Among the botanists whose work strongly influenced
3

34 HISTORY OF PHYTOPATHOLOGY

the writers on plant pathology <>l this period were the
elder De Candolle, the noted French savant, and the
German writers, Schleiden and Sprengel. Sachs, in his
History of Botany, characterizes this period (1800-60)
as the one in which "botanical science developed from
one founded on misinterpreted observation and natural
philosophy to a real science founded on investigation
and research." While this characterization could
scarcely apply to the plant pathology of this period,
it certainly does to that of the following period. Never-
theless this revolution in botanical thought influenced
powerfully and made possible a similar revolution in
phytopathologic thought during the last half of the
19th century.

The first and most characteristic work of the Ungerian
period is that by Franz Unger, after whom the period is
named. Franz Joseph Andreas Nicholas Unger1 was
born at Leutschach, South Germany, in 1800, and died
in 1870. He took his degree of doctor of philosophy in
law at the age of twenty; studied and practised medicine
for the next fifteen years at Vienna and in the Tyrol.
While stationed as army surgeon at the latter place he
gave much of his time to botany and plant pathology,
publishing as a result of his studies among other things
the work referred to above. It was here that he main-
tained a plant disease garden, probably the first of its
kind. He devoted the remainder of his life to the teach-
ing of botany, being for fifteen years professor of vege-
table physiology at the University of Vienna, from where
he wrote several books on plant physiology.

1 Wittrock, in Acta Horti Bergiani, 3 : 3 : 86 and tabic 56, gives his
name as Franz Xavcr Unger.

THE UXGERIAX PERIOD

35

In his book, Exantheme der Pflanzen,1 published in
1833, Unger devotes 20 pages to the relation of fungi to
the plants on which they live. He calls them entophytes
or "disease organisms," not parasites,2 holding firmly
to the idea of the previous period that they originate
from the diseased host tissues, but at the same time he

Franz Uxgee.

The greatest autogenetist. (After a portrait in Wittrock's "Acta Horti

Bergiani.")

recognizes them as distinct organisms, worthy of names
and classification.

1 Unger, Franz: Die Exantheme der Pflanzen und einige mit diesen
verwandete Krankheiten der Gewachse, pathologisch und nosographisch
dargestellt, pp. 1-421, Wien, 1833.

2 Unger, Franz: Originare Bildung der Krankheitsorganismen. In
Beitrage z. Yergleichenden Pathologic Sendschreiben an Herrn Pro-
fessor Schonlein, pp. 39, 40, Wien, 1840.

36 HISTORY OF PHYTOPATHOLOGY

He believes diseases to be conditions brought about
through internal disorganization of the nutrition proc-
esses; that they have their origin in a lack of certain
chemical constituents of the sap. He observed, however,
that '"entophytes," the fungi, protrude their structures
from the stomates of the diseased plant (see his sketches)
and concludes that they must be the transformed sap
of diseased tissues. His theory is that this morbid sap
exuded into the substomatal cavities and intercellular
spaces is converted, under the influence of the still living
cells of the host, into fungous structures, i. e., conidio-
phores and spores. Of mycelium he seems to have had
no true conception, as may readily be gathered from
his drawings of cross-sections of diseased leaves. The
theory of spontaneous generation, generally accepted by
the scientific men of his time, was also for Unger a fun-
damental conception, hence his idea of the relation
of pathogene to host was but a natural and logical
deduction. Nevertheless, mycologists of the period
were collecting and studying fungi, observing the char-
acter of their spores and their manner of germination.
Some were even contending that the entophytic forms
were entirely distinct from their host plants. Their
observations and deductions were not to materially in-
fluence during the Ungerian period the generally accepted
explanation of the relation of the fungus to the plant on
which it grew. Their work and their ideas were, however,
to profoundly affect the phytopathologic thought of the
next period, as we shall see.

Unger dominated the phytopathologic thought of his
time, as is strikingly shown in the work of Arend Joachim
Friedrich Wiegmann, whose book on "The diseases and

THE UNGERIAN PERIOD 37

disease abnormalities of plants"1 appeared in 1839.
Wiegmann accepts Unger's explanation of the nature of
disease in plants and the relation of the fungi found as-
sociated with the lesions. He cites Unger's book exten-
sively, setting forth in much simpler language, however,
the autogenetic doctrine of disease in plants. Wieg-
mann's book differs distinctly from that of Unger in
that it purports to be a handbook for farmers and garden-
ers rather than a scientific treatise. He covers much
the same ground as Unger, but adds a discussion of
means of control, a phase of the subject not considered
by Unger. Wiegmann claims to have thoroughly tried
out the various remedies he recommends.

Next to Unger, the most dominating personality in
the phytopathologic thought of the Ungerian period was
Meyen, a remarkable young botanist who at his death
was professor of botany at the Imperial University at
Berlin.

Franz Julius Ferdinand Meyen was born at Tilsit in
Posen in 1804. He was the son of a bookkeeper in a
small store. Leaving the gymnasium early, he began
to study pharmacy, but eventually studied medicine,
taking his degree in 1826. He practised four years and
then went for a botanizing trip around the world. Re-
turning, he was made professor of botany at Berlin,
where he remained until his death at the age of thirty-
six. Meyen was one of the most brilliant and productive
botanists of this period. His writings cover the whole

1 Wiegmann, A. F. sen.: Die Krankheiten und krankhaften Miss-
bildungen der Gewachse. Ein Handbuch fur Landwirthe, Gartner,
Gartenliebhaber und Forstmanner, pp. I-XII + 1-176, Braunschweig,
1839.

38 HISTORY 01 PHYTOPATHOLOGY

field of botany, but more especially plant physiology
(Ratzenburg, 1843).

M even's book on Plant Pathology1 which appeared
the year following his death is, next to lingers Exan-
theme der Pflanzen, the most important contribution
of this period. This work was intended to constitute
the final contribution to a series of works by the author

Franz Julius Meyen.
(From an engraving in the Kaathoven collection. Courtesy of the
Library of the U. S. Surgeon General's Office. I

on botany, of which his three-volume work on Xeuen
System der Pflanzen-Physiologie is the most remarkable
and important. It was to consist of two volumes, the
second to be on teratology, and was to appear under the
general title of Handbuch der Pflanzen-Pathologie und

1 Meyen, F. J. F.: Pflanzen-Pathologie. Lehre von dem kranken
Leben und Bilden der Pflanzen, pp. I-XII + 1-330, Berlin. 1841.

THE UXGERIAX PERIOD 39

Pnanzen-Teratologie. The manuscript for the first
volume was largely completed before his death and was
published a year later by his friend. Xees von Esenbeck
(see Yorerinnerung in same. Y-YIII .

Eleven's Pflanzen Pathologie is really only a careful
classification and description of a large number of dis-
eases. There is wanting in the book those general or
introductory chapters in which authors are wont to set
forth their generalizations and philosophies. We do not
have, therefore, a summarized or organized statement
of his ideas with respect to the nature of disease, the
relation of the fungi found associated with disease lesions,
and other fundamental pathologic theories so extensively
set forth by Unger and even by Wiegmann. His early
death is doubtless responsible for these omissions. The
book gives one the impression of incompleteness. From
his description of the smuts, the rusts, and the mildews
it is. however, readily seen that his philosophy of disease-
in plant? is not materially different from that of his
phytopathologic contemporaries. His philosophy of
disease, the nature of parasitic fungi, and their relation
to their host plants is clearly indicated in a short paper
on the development of smut in the maize plant.1 He
says it is an established fact that the cereal smut is not
an infectious disease, but is one due to a stagnation of
sap brought about by excessive and unnatural fertilizing.
He describes and figures the formation of the spores as
taking place within the host cells, and calls them pseudo-
organisms, the product of abnormal nutrition. His

1 Meyen. F. J. F. : Beitrage zur Pnanzenphysiologie. I. Uber die
Entwickelung des Getreidebrandes in der Mays Pnanze, Archiv. f.
Natmgesch., 1 : 417-421. 1837.

40 HISTORY OF PHYTOPATHOLOGY

book shows in its detailing of facts and observations the
marked influence of the mycologic discoveries of his age.
Brilliant man though he was, he failed to understand
their true significance and sought to explain them with
the philosophy of Zallinger and his school of the 18th
century.

Summarizing the characteristic features of the Unger-
ian period, we see that : (1) phytopathologic thought
was distinctly physiologic, with a marked tendency
toward the mycologic near the end of the period; (2)
the basis of classification of plant diseases was etiologic,
that, too, in spite of the fact that pathologists would
not admit the causal relation of the associated fungi;
(3) the influence of the practical gardener on the phyto-
pathologic writings of the period was overshadowed by
the researches and activity of scientists; (4) the influence
of human medicine was still strongly marked; (5) the
cause of disease in plants was held to be autogenetic.
Increasing observations of the very general association
of fungi with disease lesions was constantly raising the
question whether these must not be the cause rather
than the result of the diseased condition.

This was the transition period from old, long held,
and firmly rooted beliefs and theories with respect to
plant diseases to the modern ideas and point of view.

THE MODERN ERA

The doctrine of the autogenetic origin of disease in
plants reached its high-water mark in the philosophy of
Franz Unger, as we have already seen. The end of the
eighteenth and the early days of the nineteenth century
saw a growing school of mycologists whose observations
and studies convinced them that the spore-like structures
of the entophytic fungi were, in reality, reproductive
bodies; that they germinate and hence must serve to
propagate their kind; and finally that these entophytes
must be independent organisms causing the diseased
conditions with which they are constantly found associ-
ated and not the result thereof. To this school belonged
such noted mycologists as Bulliard, DeCandolle, Link,
Tulasne, Leveille, and others (de Bary, 1853 : 107).
Positive proof in the form of carefully checked infection
experiments were, however, largely wanting

The brilliant and classic studies of the Tulasne1
brothers on the life history of such parasitic fungi as
Claviceps, the Erysiphaceae, the Uredinales, and the
Ustilaginales had unfolded the fact of polymorphism in

tulasne, L. R. et Ch.: Memoire sur les Ustilaginees comparees
aux Uredinees, Ann. Sci. Nat., 3:7: 12-127, 1847; and the following
by L. R. Tulasne alone: Memoire sur l'Ergot des Glumacees, Ann.
Sci. Nat., 3 : 20 : 5-56, 1853; Second Memoire sur les Uredinees et les
Ustilaginees, Ann. Sci. Nat., 4:2: 75-196, 1854; and finally that extra-
ordinary work by the Tulasne brothers, Selecta fungorum carpologia, ea
documenta et icones potissimum exhibens quae viria fructuum et
seminum genera in eodem fungo simul aut vicissim adesse demonstrentr
1 :I-XXVlII + 1-242, 1861; 2 : 1-XIX + 1-319, 1863.

41

42 HISTORY OF PHYTOPATHOLOGY

these forms. Zoologic investigations1 had established
the facts of heteromorphism among insects, notably in
the case of aphids. The true relation of gall wasps, tape-
worms, and other parasitic animals to their hosts was
becoming increasingly clear to scientific workers.

Nevertheless, the deep-rooted theory of spontaneous
generation still dominated to a great extent the doctrines
on reproduction. Accumulating evidence against it
and a growing understanding of the significance of this
evidence were of themselves powerless to overcome the
handicap which centuries of established acceptation
gave to the prevailing dogma. The overthrow of this
ancient superstition awaited the magic power of master
minds. The middle of the nineteenth century saw their
entrance upon the scientific stage. The brilliant re-
searches and convincing demonstrations of that noted
French savant, Louis Pasteur,2 swept away the nebu-
lous foundations of spontaneous generation. Kiichen-

1 For classic works on this subject see —

Steenstrup, Johann Japetus Smith: Om Fortplantning og Udvikling
gjennem vexlende Generationsvrikker en saeregen Form for Opfostringen
i de lavere Dyrklassen, pp. I-IY -f 1-76, Kjobenhavn. 1842. A German
translation by Lorenzen appeared in 1842 and from this an English trans-
lation by Rusk in 1845 under the title: On the alternation of generation;
or the propagation and development of animals through alternate
generations.

Owen, Richard: On parthenogenesis or the successive production of
procreating individuals from a single ovum, pp. 1-76, London. 1849.

Siebold, Carl Theodor Ernst von: On a true parthenogenesis in
moths and bees; a contribution to the history of reproduction in animals.
Translated from the German by William L. Lallas, pp. I-YIII + 1-110,
1857, The original appeared in 1856.

2 Frankland, P., and Frankland, Mrs. P.: Pasteur, pp. 1-224, New
York, 1898. See especially ch. 5, and Yallery-Radot's, The Life of
Pasteur, in two volumes, 1902, vol. 1, ch. 5.

THE MODERN ERA 43

meisterV work on the animal parasites of man revolu-
tionized the theories on animal parasitism. Darwin's
painstaking researches into the origin of species2 freed
the biologic sciences of the deadening dogmas of special
creation and fixity of forms. The wonderfully exact
and extensive studies of that master mycologist, Anton
de Bary, so completely established the independent na-
ture of entophytic fungi that the theory of their meta-
morphosis from the sap of diseased plants was no longer
tenable.

The wide-spread and destructive epiphytotics of the
Phytophthora blight which swept the potato fields of
Europe in 1844 and 1845, 3 resulting in famine in some
sections, suddenly impressed everyone, layman and
scientist, with the importance of plant diseases in the
economic welfare of mankind. The most noted scientists
of the time turned their attention to the solution of the
problem thus presented. Learned societies and even
governments appointed commissions to investigate the
cause of the disease. This intensive investigation led
naturally to a more general and critical examination of

1 Kuchenmeister, Friedrich: Die in und an dem Korper des lebenden
Menschen vorkommemden Parasiten. Ein Lehr- und Handbuch der
Diagnose und Behandlung der thierischen und pflanzlichen Parasiten des
Menschen, Abt. 1 : 1-XVI + 1-486; Abt. 2 : 1-X + 1-148, Leipzig,
1855. An English translation appeared in 1857 under the title: On
animal and vegetable parasites of the human body. A manual of their
natural history, diagnosis and treatment, 1 : 1-XIX -f- 1-443; 2 : 1-XVI
+ 1-287.

2 Darwin, Charles: On the origin of species by means of natural selec-
tion, or the preservation of favored races in the struggle for life, pp. I-IX
+ 1-502, 1859.

3 Jones, L. R.: Investigations of the potato fungus Phytophthora
infestans, U. S. Dept. Agr. Bu. PI. Ind. Bui.. 245 : 19-24, 1912.

44 HISTORY OF PHYTOPATHOLOGY

other diseases equally common though less strikingly
destructive. This was especially true of the rusts and
smuts of cereals.

Thus the middle of the nineteenth century saw the
beginning of a new era in the science of phytopathology.
In the establishment of the pathogenic nature of fungi,
the autogenetic theory of disease in plants received a
staggering blow. The day of the autogenetists had
passed, and for the next half-century or more a new
school, the pathogenetists, and the etiologic phases of
phytopathology were to dominate the science.

The era falls naturally into two periods of approxi-
mately a quarter century each, the Kiihnian and the Mil-
lardetian. The first of these is characterized by an al-
most complete devotion to the study of the causal rela-
tions of fungi to the diseases with which they are found
associated; the second period saw a marvelous develop-
ment and general application of methods of disease
control. Together they constitute an era unparalleled
in the history of plant pathology.

THE KUHNIAN PERIOD

This period (1853-83) will always stand out as one of
the greatest in the history of plant pathology. It is
characterized chiefly by the discoveries which have
firmly established the causal nature of fungi associated
with plant diseases. As fungi are now generally recog-
nized to be responsible for most of our plant diseases, the
importance of the pioneer work of this period cannot be
overestimated.

The phytopathologists of this period were powerfully
influenced in their thought and theories by the works of

THE KUHNIAN PERIOD 45

three great scientists. None of them were plant pathol-
ogists, though all made investigations and discoveries
not only epoch making in their respective fields, but fun-
damental to related sciences and to none more than phyto-
pathology. I refer to the great German botanist and
mycologist, Anton de Bary, who lived and worked from
1831 to 1888; the equally noted chemist, Justus Freiherr
von Liebig, 1803-73, the father of agricultural chemistry;
and the famous French chemist and bacteriologist, Louis
Pasteur, 1822-95.

The opening of this period is marked by the publica-
tion in 1853 of that classical work of de Bary's, Die Brand
Pilze, in which the young investigator (then twenty- two
years old) established beyond doubt the causal nature of
the fungi found associated with rust and smut diseases.
In 18611 he published his investigation on the cause and
nature of the late blight of potatoes in which he proved
the causal relation of Phytophthora injestans. In 18652
he published his work, establishing the relation of the
aecidium on barberry to the rust fungus on wheat. These
are but a few of the striking pieces of work of an almost
endless number of similar investigations on the nature of
the relation of fungi to different diseases. One should
read the list of his contributions in the Lindau and
Sydow Thesaurus, Vol. I.

Heinrich Anton de Bary was born at Frankfurt-am-
Main. He became interested in botany while still in the

1 de Bary, A.: Die gegenwartig herrschende Kartoffelkrankheit, ihre
Ursache and ihre Yerhutung, pp. 1-75, Leipzig, 1861.

2 de Ban-, A.: Neue Untersuchungen iiber die Uredineen, insbeson-
dere die Entwickelung der Puccinia graminis und den Zusammenhang
derselben mit Aecidium Berberidis, Monatsber. d. Kon. Preuss. Akad.
der Wiss. aus dem Jahre 1865 : 15-50, Berlin, 1866.

46 history OB PHYTOPATHOLOGY

gymnasium, but fitted himself for the practice of medi-
cine, taking his degree in 1853, the same year in which he
published the investigations on smut fungi, which, as we
have already seen, marks the opening of this period.
He practised medicine for two years in his native city,
but abandoned it for research in botany. He began as in-

AXTUX DE BARY.

Founder of modern mycology. His studies on the parasitism
of fungi gave rise to the school of pathogenetists. (From a photograph,
courtesy of Dr. Envin F. Smith. I

structor in the University of Tubingen, becoming two
years later professor at Freiburg until 1867. He then
went to Halle, and finally in 1872 to Strassburg. where he
remained until his death in 1888. Xo less than sixty-
eight men afterward noted for work in science studied
under him in his laboratories in Strassburg.

THE KUHNIAN PERIOD 47

De Bary has been regarded by some as the father of
modern plant pathology. Though there can be no doubt
of the molding and dominating influence of his work on
the plant pathology not only of this but of the succeeding
period, still he was a botanist, a mycologist. He did not
assume to be a plant pathologist. He did not concern
himself extensively with the pathology of the diseases
with which he worked, except from the point of view of
the physiologist undertaking to discover the nature of the
life of the parasite, its mode of attack, its method of
feeding, and its life history. With the many other
aspects of the disease, especially the economic, he con-
cerned himself little. He wrote no books on plant
pathology. To Julius Kiihn, a countryman of de Bary,
belongs, in my opinion, the title of Father of Modern
Plant Pathology.

Julius Gotthelf Kuhn was born in Pulsnitz, in Saxony,
not far from Dresden, in 1825. His father was a land
owner and it was the son's ambition to become an expert
agriculturist. He received his elementary and gymna-
sium education, as well as some technical training, very
largely in the schools of Dresden. In 1841 he returned
to his father's estate to take up practical training as a
"Landwirt." Six months later he became assistant to
the manager of a large estate in Saxony. Here he spent
two and a half years. The manager was a hard and
exacting master but an excellent teacher, and Kiihn did
so well that in 1844, after three months as assistant
manager on the estate of Graf Kospoth in Halbau, he was
made administrator. For the next four years he was
manager of different large estates; finally at the age of
twentv-three (1848) he took charge as Amtmann (farmer

48 HISTORY OF PHYTOPATHOLOGY

of a crown domain) of the large estate of Gross- Krausche
by Bunzlau in Silesia, remaining eight years. Here he
began in earnest his agricultural investigations. In-
fluenced by the writings of Liebig, he tested out the value
of commerical fertilizers on a large scale. He tried out
and introduced the drilling of grain and made extensive
use of tile drainage. Through his activities along these
lines he became known to his colleagues as the micro-
scope farmer.

For us, however, his work on the diseases of his crops on
this estate is of most interest. Here he not only gathered
his fundamental training along these lines, but laid by
extensive and exact experiments the foundation for his
book on plant diseases to appear a few years later. His
interest in plant diseases appears to have begun with some
studies on Sporodesmium exitosum, the cause of a serious
disease of rape. He studied and named the pathogene.
His work attracted the attention of such men as Ferdi-
nand Cohn, Goppert, and Rabenhorst. These years of
practical study and experiment aroused in Kiihn the
desire for further training at some agricultural academy
or some university.

The Agricultural Academy at Poppelsdorf loosely
associated with the University of Bonn was at that time
the most noted in Germany. Thither the young Amt-
mann turned his steps at the age of thirty in the autumn
of 1855. Unfortunately, the teachers at Poppelsdorf had
little new to offer this well-read and experienced farm
manager, but in the University he had the chance to com-
plete and round out his scientific training in the two
semesters that he spent there. It was here at Bonn
also that he conceived the idea that agricultural educa-

Julius Kuhx.

Father of modern phytopathology. (After a portrait in the Deutsche

Landwirtschaftliche Presse. vol. xxii.)

49

THE KXHXIAX PERIOD 51

tion could be best conducted as a department or faculty of
a university rather than in a separate institution. This
idea he himself was to be the first to work out in a most
practical manner a little later in the University of Halle.

In the summer of 1856 on the basis of his work in plant
pathology Ktihn took his doctorate at Leipzig, and passed
the examination for lecturer at the Agricultural Academy
at Proskau. After one term there he again returned to
the land, taking the management of a large estate near
Gross-Glogau in lower Silesia. It was from here in 1858
that he published the first edition of his text-book on
plant diseases. He remained on this estate until 1862,
when he was called to the chair of Agriculture in the
University of Halle, to begin his career as a university
professor at the age of thirty-seven. Kiihn married at
the age of thirty-two and was the father of five children
(Wohltman and Holdefleiss, 1905).

Rutin's first and only text-book on plant pathology
appeared, as has been indicated, in 1858. So great was
the demand for it that a second unaltered edition was
published the next year. Although he wrote numerous
articles on plant diseases from time to time until his
death, he contributed more largely along other lines of
agriculture. One of his best known works is that on
cattle feeding,1 which, first published in 1861, ran through
many editions.

The full title of Kiihn's book2 on plant diseases is,
Die Krankheiten der Kulturgewachse, ihre Ursachen und

1 Kiihn, J.: Die zweckmassigste Ernahrung des Rindviehs vom
wissenschaftlichen und praktischen Gesichtspunkte, Dresden. 1861.

2 Kiihn, J.: Die Krankheiten der Kulturgewachse. ihre Ursachen und
ihre Yerhiitung, pp. I-XXII + 1-312, Berlin, 1858.

52 HISTORY OF PHYTOPATHOLOGY

ihre Verhiitung (The diseases of cultivated plants, their
cause, and their prevention). It is in several respects an
epoch-making book. It is the first phytopathologic
text to appear based upon the remarkable and far-
reaching discoveries and researches of de Bary, the
Tulasne brothers, Pasteur, and other workers of the first
half of the 18th century in the field of parasitology. Here
for the first time in a phytopathologic text (excepting the
little paper of Fabricius the Dane) is adopted the funda-
mental fact of the causal nature of fungi as pathogenes in
the diseases of plants. With a fine grasp of the entire
field of etiologic phytopathology Kiihn, while recognizing
the new factor, pathogenic fungi, did not deny the old
and generally accepted factors of weather, soil conditions,
animals, and parasitic flowering plants as producers of
disease in plants. He accepted them, but gave them
their proper place and value in his treatment of the sub-
ject. A brief of the table of contents of this the first of
modern texts on plant diseases will best indicate the
tremendous advance in the science during the first half
of the 19th century:

First Part
General considerations with respect to plant diseases.
Introduction.

Nature and types of disease in plants.
Cause of disease:

Unfavorable climatic and soil conditions.
Diseases due to the influences of animals.
Diseases due to parasitic plants:
Phanerogamic parasites.
Cryptogamic parasites.

the kuhnian period 53

Second Part
Special investigations on diseases of cultivated plants.
The smuts of cereals.
The rust.
The ergot.

The mildew, sooty mold, and honey dew.
The leaf blight or leaf spot disease.
The disease of rape and rape seed.
The seed rot of Fullers' teasel and the gout or cockle

disease of wheat.
The diseases of tuber and root crops.

Appendix
The microscope as a household utensil for the farmer.

In the case of those diseases especially investigated (as
above indicated) methods of control based on a proper
conception of the causal factors involved and thoroughly
tested in actual practice by the author are recorded.
This book is a model of conciseness and accuracy that has
not been excelled by any of the numerous pathologists
who have written books since that time. This is the
great achievement of the father of modern plant pathol-
ogy that he was the first to apply the scientific knowledge
of his day to the practical solution of plant disease
problems, and so fundamental has been this contribution
of Kiihn's that it has remained to the present time the
vitalizing factor in the wonderful growth and develop-
ment of the science.

In 1868 appeared the text-book "Phytopathologie,"1

1 Hallier, E.: Phytopathologie. Die Krankheiten der Culturge-
wachse fur Land- und Forstwirthe, Gartner und Botaniker, pp. I-X +
1-373, 1868.

54 BISTOITS OP PHYTOPATHOLOGY

by Ernst Hallier. This was the first text-book of any

importance to follow that of kiilm'>. As thi> was the
only edition which he published, Hallier may, therefore
be said to have belonged to this period alone; in fact, as
we shall see, he retired from active work about the end of
the period.

Ernst Hallier lived from 1831-1904. Beginning as
assistant gardener in the Botanical Gardens at Jena in
1848, he later studied at the University of Berlin, taking
his degree in 1858. He then became assistant to his
uncle, Professor Schleiden, the botanist at Jena. Here
in 1866 he was promoted to assistant professor, in which
capacity he served for nineteen years, retiring on account
of ill health in 1884. He is perhaps best known for his
antagonism to and attacks upon de Bary, whom he hated.
His failure to obtain a full professorship he blamed chiefly
on de Bary, who, however, does not appear to have been
responsible except perhaps indirectly as an opponent of
his peculiar scientific ideas. Hallier's book was far more
comprehensive and extensive than that of Kiihn, but
lacked the sound scientific and practical experimental
basis of that master's work. The peculiar and erroneous
ideas of the author with respect to the genetic relation
of bacteria to fungi brought discredit upon the book among
the scientific workers of his day. He believed that bac-
teria developed into fungi. His work, therefore, did not
have a great influence on plant pathology.

Anders SandflSe Orsted, the most noted Danish plant
pathologist before Rostrup, belongs to this period. He
lived from 1816 to 1872. His contributions to the science
began about 1862. Working with species of Gymnospo-
rangium, he discovered hetercecism at about the same

THE KUHNIAN PERIOD 55

time and independently of de Bary. He is the author of
several books and papers on the diseases of cultivated
plants (Lind, 1913 : 18, 605, 606).

England made her first real contribution to the ranks
of plant pathologists during the Kiihnian period in the
person of M. J. Berkeley. Receiving his inspiration and
enthusiasm for the study of plants and their maladies
largely from gardeners and horticulturists, his contribu-
tions to the science are largely addressed to the practical
growers rather than to the scientists of his time. To
the latter he was well known, however, as the leading
English authority on fungi, and is generally held to
be the founder of British mycology (Thiselton Dyer,
1897).

Miles Joseph Berkeley, born 1803, was one of the fa-
mous family of Berkeley. He was educated at Christ's
College, Cambridge, from which he graduated in 1825.
In spite of his inclination for the natural sciences, he
entered the then slightly more lucrative profession of the
ministry, in which he continued until his death in 1889.
He devoted all of his leisure to biologic studies and re-
search, especially on fungi and plant diseases. Aside
from numerous short papers on different plant diseases,
his chief contribution to the science is that on vegetable
pathology,1 which appeared in the Gardener's Chronicle
throughout the years 1854 to 1857 inclusive. This ex-
tensive paper sets forth in much detail the ideas and the-
ories with respect to diseases in plants held by English
gardeners and scientists of that period. The chapter

1 Berkeley, M. J.: Vegetable Pathology, Gard. Chron., 1854-1857,
continued weekly throughout these years. See especially 1854 : 4, 20:
36, 52, 68, 708, 740; 1857 : 644, 660, and the index, 676, 677.

56 JIISIDRY OF PHYTOPATHOLOGY

on Diseases caused by fungi in his Outlines of British
fungology1 gives an excellent picture of British knowl-
edge of the subject at the opening of the Kiihnian period.

Miles Joseph Berkeley.

First noted English plant pathologist. (From a photograph, courtesy

of Dr. L. R. Hcsler.)

One of the best of his contributions, aside from those
mentioned, is his paper on potato murrain2 which had

1 Berkeley, M. J.: Outlines of British fungology containing characters
of above a thousand species of fungi and a complete list of all that have
been described as natives of the British Isles, pp. I-XY + 1-442, London,
1860.

2 Berkeley, M. J.: Observations, botanical and physiological, on the
potato murrain, Jour. Roy. Hort. Soc. of London, 1 : 9-.U, 1846.

THE KUHNIAN PERIOD 57

appeared in 1846. Berkeley is better known as a mycol-
ogist because of his numerous contributions in that field.
He was always interested in the practical application of
his knowledge, being for ten years editor of the journal
of the Royal Horticultural Society.

Toward the end of this period appeared a number of
books on plant pathology, for the most part the maiden
efforts of young pathologists whose works and writings
were to mold and direct in many ways the phytopath-
ologic thought of the early part of the next period.
The most important were: Important diseases of forest
trees, 1874,1 by Robert Hartig; Handbook of plant dis-
eases, 1874,2 and Fruit tree diseases, 1879, 3 by Paul
Sorauer; and Diseases of plants, 1880,4 by A. B. Frank.
These men and their works will be discussed under the
next period.

Summarizing as for the previous periods, we may say
of the Kiihnian period: (1) the thought and works of
the time were decidedly mycologic; (2) the basis of
classification was now entirely etiologic. This is char-
acteristic of all the books on plant diseases published
during this period; (3) the influence of the gardener,
forester, and farmer was decidedly marked and was due
primarily to the investigations of the farmer-scientist

1 Hartig, R. : Wichtige Krankheiten der Waldbaume, pp. I-VIII +
1-127, Berlin, 1874.

2 Sorauer, P.: Handbuch der Pflanzenkrankheiten, pp. I-VIII +
1-406, Berlin, 1874. This is the first edition, followed later by two en-
larged revisions, the third in three volumes. (See footnote 1, page 100.)

3 Sorauer, P.: Die Obstbaumkrankheiten, pp. 1-VTI + 1-204,
Berlin, 1879.

4 Frank, A. B.: Die Krankheiten der Pflanzen, pp. I-VH + 1-844,
Breslau, 1880.

58 HISTORY OF PHVTOI'ATHOl.nOV

Kiihn. The attempt to serve this class of reader- is
indicated in the title of the books published; (4) the
theory of the autogenetic origin of disease was almost
completely discredited by the epoch-making discovery
and demonstration of the causal nature of endophytic
organisms, especially fungi, found associated with dis-
ease lesions. This doctrine of pathogene responsibility
thus firmly established by the work of Pasteur, de Bary,
Kiihn, Hartig, and others was to inspire and shape the
remarkable developments of the science during the suc-
ceeding period. Hallier sought in his treatment of the
subject to counteract this to some extent by emphasizing
the influence of soil, climate, and predisposition of the
plant. Hallier 's doctrine of predisposition was to be
more ably developed by Sorauer during the next period,
as we shall see; (5) control of plant diseases was for the
first time placed upon a sound basis, made possible, of
course, by the recognition of the true relation of fungi
to plant diseases. Ktihn's work on seed disinfection
was the great achievement in this direction.

THE MILLARDETIAN PERIOD

The Millardetian or economic period extends from
1883 to about 1906. This period is characterized by
the emphasis that was placed upon the economic
features of plant pathology. It was ushered in by a
number of remarkable and far-reaching events and dis-
coveries.

Discovery of Bordeaux Mixture. — A French patholo-
gist, Millardet, with whose name this period is desig-
nated, began his experimental work with bordeaux

THE MILLARDETIAN PERIOD 59

mixture in 18831 (Lodeman, 1896:27). Through his
efforts its use was introduced throughout the vineyards
of France, and the wine industry, threatened by the
ravages of the American mildew fungus, was saved.
This fungicide was shortly after introduced into America
to be used for the same purpose, and also against the
Phytophthora fungus on potatoes and the scab parasite
of the apple. It soon became the universal fungicide,
which place it held until the recent introduction of
lime-sulfur as a summer spray. It still remains for the
vine and potato as well as for many other plants the
best and safest fungicide. The discovery and introduction
of this mixture more than any other one thing influenced
and shaped the development of the science of plant
pathology during the quarter century following its dis-
covery.

Rise and Development of Plant Pathology in America.
— The national government had for some years main-
tained a Commissioner of Agriculture under whose direc-
tion were several sections or divisions, among them one
known as the Botanical Division. On July 1, 1885, a
Section of Mycology of the Botanical Division of the
U. S. Department of Agriculture was established and
F. Lamson Scribner appointed as the mycologist. Erwin
F. Smith was called to be his assistant the following
year, 1886. This represents the first government recog-
nition of the science of phytopathology in this country,

1 The discovery itself was made in October, 1882, in a vineyard of St.
Julian in Medoc. (See Jour. d'Agr. Prat., 1885, pp. 707-710, and also
801-805. There is a translation of the same article, U. S. Dept. Agr.
Bot. Div. Sec. PI., Path. Bui. 2, Appendix C, p. 94, 1886.) The first re-
port of the discovery appears to have been made by Millardet in the
Annales de la Societe d'Agriculture de la Gironde, 1885, p. 73.

60 history OF PHYTOPATHOLOGY

for the work had to do almost entirely with diseases in
plants. In 1887 the name of this section was changed
to that of Vegetable Pathology, Scribner continuing as
chief. Scribner's reports for the years 1886 and 18871
indicate the unorganized and dependent state of American
phytopathology at that time. On November 1, 1888,
there was appointed to this recently established section
a young botanist who. under the stimulating influence
of the discoveries of Millardet and of his own country-
men, was to stand forth as a leader in the development
of phytopathology in America; I refer to B. T. Galloway,
who succeeded Scribner in 1889.- Galloway gathered
about him gradually a staff of the most competent and
enthusiastic young botanists of this country. Many of
these became pathologists whose names and works are
known today not only in their own country but in all
foreign lands. One needs mention but a few of these
to show the type: Erwin F. Smith, Merton B. Waite,
David G. Fairchild, Mark A. Carleton, Walter T. Swin-
gle, Herbert J. Webber, O. Ff. Dorsett, Newton B. Pierce,
Albert F. Woods, and others. The influence of this
division and its corps of workers upon the development
of phytopathologic investigations in the various experi-
ment stations of the different states was most potent.
To their efforts was also due the founding of the present

1 Scribner, F. L.: Report of the mycologist for the year 1886. In,
U. S. Dept. Agr. Ann. Report for the year 1886 : 95-138, 1887; also
report of the chief of the section of vegetable pathology for the year
1887. In, U. S. Dept. Agr. Ann. Report for the year 1887 : I-V + 323-
397, 1888.

2 Galloway, B. T.: Report of the chief of the section of vegetable
pathology for the year 1888. In, U. S. Dept. Agr. Ann. Report for the
year 1888 : 1-IV + 325-404, 1889 (see p. 325).

THE MILLARDETIAN PERIOD 61

Bureau of Plant Industry of the U. S. Department of
Agriculture. At present nearly every experiment station
in the United States has a man or a number of men de-
voting a part or all of their time to plant disease investi-
gation (Galloway, 1900 : 194-197).

Discovery of the Bacterial Etiology of Certain Plant
Diseases. — During the years from 1878 to 1884 Burrill,
in Illinois, working on the well-known fire blight of
apples and pears, discovered that it was caused by bac-
teria.1 Wakker, a young Dutch pathologist, working
on the so-called yellow disease of hyacinths, proved it to
be caused by bacteria. He published his results from
1883-89. 2 These studies were the beginning of a series
of most remarkable discoveries of bacterial diseases in
plants. Particularly numerous have been these dis-
coveries in America, where this class of plant diseases
has been brought to the fore through the remarkable
investigations of Dr. Erwin F. Smith, who took up this
line of work in 1893, publishing his first observations
(on wilt of cucurbits) in that year.3

The first of these events forecasted the general char-
acter of the work and investigations of the Millardetian

1 For a complete list of Bun-ill's publications on blight during this
period, see bibliography in New York (Cornell) Agr. Exp. Sta. Bui.
329 :369, 1913.

2 Smith, E. F. : The bacterial diseases of plants; a critical review of the
present state of our knowledge, Amer. Xat., 30 : 797-804, 912-924,
1896. Uncompleted. (Gives an extended abstract of Dr. Wakker's
papers.)

3 Smith, E. F.: Two new and destructive diseases of cucurbits: 1.
The muskmelon Alternaria. 2. A bacterial disease of cucumbers,
cantaloupes, and squashes, Proc. Amer. Ass. Adv. Sci. for 1893, 42 : 259,
1894. Abstract Bot. Gaz., 18 : 339, 1893. For further contributions on
cucumber wilt, see Bacteria in relation to plant diseases, 2 : 299, 1911.

62 HISTORY OF PHYTOPATHOLOGY

period. It was to be the economic period; the period
in which the emphasis was to be especially placed upon
the control of plant diseases. The importance of this
phase of the science had been foreshadowed in the work
and investigation of Kiihn. Its importance during the
kiihnian period was overshadowed by the researches
and discoveries on the etiologic aspects of the science,
as we have already seen. The economic importance of
plant diseases became the dominating and vitalizing
force in phytopathology during the Millardetian period.
To the stimulating influence of the discovery of bordeaux
mixture was added in the United States the stimulus of
governmental sanction and support in the establishment
in the U. S. Department of Agriculture of the section of
Vegetable Pathology referred to above. Governmental
espousal of scientific investigation always has been, and
doubtless will be for many decades to come, based upon
the economic value of the same. The etiologic phase of
phytopathology which dominated the Kiihnian period
had its continuation and perpetuation during the Mil-
lardetian period chiefly in the discovery and unfolding
of the causal relation of bacteria to plant diseases. While
investigation and discovery in the realm of mycologic
etiology was not halted or diminished, was, in fact, stim-
ulated and expanded, nevertheless progress along these
lines contributed largely to and was overshadowed by the
progress in the control of the diseases of crops. The
influence of bacterio-phytopathology on this progress
and expansion was most marked and most healthful.
Bacteriologic methods and technic were widely adopted
and applied in the study of fungous pathogenes. Thus
it appears that these three factors — (a) discovery of the

THE MILLARDETIAN PERIOD 63

fungicide, bordeaux mixture; (b) governmental espousal
of the science, and (c) discovery of the bacterial nature of
some of our most destructive plant diseases — combined
to initiate a new epoch in the history of plant pathology.

A clear and comprehensive view of this period may
best be obtained, perhaps, by a brief consideration,
first, of the epoch-making discoveries and the men who
made them, and, second, of the life and works of those
phytopathologists who largely dominated the thought
and teaching of the time.

The discovery of bordeaux mixture, as already pointed
out, was the most potent factor in the development of the
economic phase of plant pathology. It gave to the plant
pathologist a means of control of wide application and
remarkable efficiency. It became the universal fungicide.
The active principle of this fungicide is copper. Numer-
ous other copper fungicides were rapidly devised and
exploited, such as ammonium copper carbonate, soda
bordeaux, and eau celeste, but none of these were found
to compare, in safety to the plants and in effectiveness
against the fungi, with the bordeaux mixture originally
devised by Millardet. As regards the control of plant
diseases, this may well be regarded as the "copper"
period. Of the man who first properly appreciated the
fungicidal value of the copper salts, a few words are now
in place.

Pierre Marie Alexis Millardet was born December 13,
1838, at Montmerey-la-ville in the department of Jura,
and died December 15, 1902. Born of intellectual
parents of old and honorable families, he was well taught
and educated. He first studied medicine, but soon
abandoned it for the more enticing pursuit of botany.

64 HISTORY OF PHYTOPATHOLOGY

Giving up the Inheritance of the good medical practice
of his uncle, he went to Germany to study botany first
under Hofmeister at Heidelberg and then under de Bary
at Freiburg. He was a profound student and an ac-
complished artist, his drawings being the admiration and
envy of his fellow-students. Returning to France he

Alexis Millardet.

Discoverer of bordeaux mixture. (From a photograph, courtesy of

Dr. Envin F. Smith.)

took his doctorate in medicine and also in science. Im-
mediately thereafter, 1869, he was made assistant profes-
sor of botany in the University of Strassburg. The
breaking out of the Franco-Prussian War the next year
interrupted his work, and after serving in the army as
surgeon he became professor of botany at Nancy in 1872.
and finally professor of botany at Bordeaux in 1876,

THE MILLARDETIAX PERIOD 65

where he remained until his retirement in 1899, and
where a monument has now been erected to his
memory.

The early years of his professional life were given
entirely to pure science. His later years and maturer
judgment were devoted to the economic or applied phases
of botany. This change in Millardet's line of thought
and effort was determined by the introduction into
France of two vine pathogenes from America, viz.. the
phylloxera and the down}- mildew fungus. Plasmopara
viticola. The former he had early studied to some
extent in the laboratories of de Bary in Freiburg. The
latter he discovered in France in 1878 at about the same
time that a colleague. Planchon, found it in another part
of the same country. Both these pathogenes spread
rapidly and became so destructive as to threaten the
wine industry of France. Millardet. already one of the
most noted botanists of France, was commissioned to
investigate and combat these two threatening pests.
By the introduction of resistant American vines as stock
for the grafting of the European varieties he saved the
vineyards from the phylloxera. Accidently observing
the prophylactic effects against the mildew of a mixture
of copper sulphate and lime sprinkled on grapevines
along the road to prevent pilfering of the fruit, he dis-
cerned the possibilities of copper as a fungicide. He at
once undertook the investigation of this mixture of lime
and copper sulfate for the control of the devastating
mildew and developed the bordeaux mixture (Lodeman,
1896 : 25). This mixture has remained for a quarter of a
century the most efficient and most universally applicable
fungicide known.

66 HISTORY OP PHYTOPATHOLOGY

The discovery and establishment of the causal relation
of bacteria to plant diseases, made during the first years
of this period, was in many ways of even greater signifi-
cance and importance than the discovery of the fungi-
cidal value of copper. It is the greatest contribution to
phytopathologic etiology since the epoch-making dis-
coveries of de Bary and his contemporaries on the causal
relation of fungi to plant diseases. The credit for this
great discovery belongs to an American, Thomas J.
Burrill. In justice to our European colleagues it must
be recorded that working only a little later and inde-
pendently a Dutch plant pathologist, J. H. Wakker,
made a similar discovery (see footnote 2, page 61). Bur-
rill, however, published his discovery first.

Thomas Jonathan Burrill, born in 1839 in Massa-
chusetts, was educated at Illinois State Normal School.
He held the honorary degree of Ph.D. from Chicago
University (1881) and later the LL.D. from the North-
western University. For man}' years he filled the chair
of botany at the University of Illinois, and from 1879
until his retirement in 1913 was Vice-President of the
University. He died in 1916. The discovery of the
bacterial nature of the fire blight of pears and apples is
but one, though unquestionably the greatest, of his
several contributions to American botany and plant
pathology. The details of his observations and experi-
ments on the cause of fire blight are to be found largely
in the papers he presented and the discussions in which
he engaged before the Illinois Horticultural Society during
the years from 1878-84 (see footnote 1, page 61). The
reports of this society for these years will repay perusal.
Of such great importance is this disease that following

THE MILLARDETIAN PERIOD 67

the pioneer investigations of Burrill, more extensive and
detailed studies of the pathogene were undertaken by J.
C. Arthur, at that time, 1885, botanist of the N. Y.
(Geneva) Experiment Station,1 and by M. B. Waite of the
U. S. Department of Agriculture.2 Many other workers
in all parts of the United States and Canada have since

Thomas J. Burrill.
Discoverer of bacterio-phytopathogenesis. (From a photograph, cour-
tesy of Dr. Erwin F. Smith.)

worked on the disease, so that we now possess a more
extensive and better knowledge of the first recognized
bacterial disease of plants than of almost any of the other
numerous bacterial maladies since brought to light.

1 For a list of Arthur's papers on pear blight, see New York (Cornell)
Agr. Exp. Sta. Bui. 329 : 368. 1913.

2 Waite, M. B.: Cause and prevention of pear blight, U. S. Dept.
Agr. Year Book 1895 : 295-300, 1896.

68 HISTORY OF PHYTOPATHOLOGY

Although the discover}' by the Dutch pathologist,

Wakker, of the bacterial nature of the yellow disease of
hyacinths was announced shortly after the discoveries of
Burrill on the fire blight, it appears to have had little
attention from his European contemporaries, and the
bacterial nature of plant diseases was an idea long un-
accepted and vigorously combated by European botanists
(Smith, Bacteria in relation to plant diseases, 2 :9-22).
At the time of his researches and discoveries on the yellow
disease of hyacinths, Wakker was a young enthusiastic
investigator in the University of Amsterdam. He had
been especially employed by the bulb growers' association
of Haarlem, Holland, to investigate this and other dis-
eases at that time devastating their crops. Later he did
some other excellent phytopathologic work, but failing of
expected promotion at the University of Amsterdam, he
foreswore botanical science and its devotees entirely,
and sought solace in the teaching of mathematics in a
secondary school. The loss to phytopathologic science of
so brilliant and promising a worker is much to be de-
plored. His work, dealing with the yellow disease of
hyacinths, has been carefully repeated and reviewed by
Dr. Erwin F. Smith, and pronounced accurate and clas-
sical to a degree scarcely to be expected of the day in
which Wakker worked. (See Smith, Bacteria in relation
to plant diseases, 2 : 336-337, and U. S. Dept. Agr. Div.
Veg. Phys. and Path. Bui. 26 : 9, 10.)

Great and epoch making as were these two discoveries,
bordeaux mixture and bacterial phytopathogenes, the
men who made them contributed but little else to the
great progress and development of the science during
this period. Millardet made some careful investigations

THE MILLARDETIAN PERIOD 69

on Plasmopara viticola, and Burrill described one or more
other bacterial diseases of plants, and made some worthy
contributions to our knowledge of fungous pathogenes.
Neither his training nor facilities permitted Burrill to
develop and lead in the field of research on bacterial
diseases of plants. This leadership, as we shall see, soon
passed to another American. Moreover, both Burrill
and Millardet devoted too great a portion of their time
and efforts to teaching and administration to enable them
to contribute largely to research in the field which their
historic discoveries have so mightily influenced. Wakker's
early self-elimination from the field we have already
noted. These discoveries, however, together with govern-
mental espousal of plant disease work inspired and stimu-
lated a host of young men both in America and in Europe
to take up phytopathology as a life work. The Mil-
lardetian period surpassed without doubt all previous
periods in the number of workers and in the scope and
variety of their efforts.

In America the beginning of this period found but very
few old and well-trained botanists who were at all inclined
to phytopathologic research. A few great teachers of
botany, like Bessey, in Nebraska, Farlow, of Harvard,
Burrill, of Illinois, Spaulding and Beal, of Michigan, and
Tracy, of Missouri, recognizing the signs of the times,
turned the eyes of their students to the opportunities in
this direction. A little later to these were added the
students of Atkinson, of Cornell, Thomas, of Wabash,
Jones, of Vermont, and others who saw the economic
trend and espoused it with enthusiasm. These young
scientists with the pioneer spirit and enthusiasm of their
fathers plunged into the problems with a vigor and

70 HISTORY OF PHYTOPATHOLOGY

earnestness that in twenty-five years has placed this
country in the forefront of phytopathologic thought.

research, and teaching.

In Europe the opening of this period found a consider-
able number of men, young but well trained, and already
enlisted in the scientific work of phytopathology. As we
have seen, some of these, like Hartig, Frank, and Sorauer,
had during the last years of the Kiihnian period made
their first contributions to the science in monographs,
manuals, and text-books. They brought to the new
period minds trained and experienced in the field in which
the problems were to be solved. They also brought with
them the points of view and the prejudices of the pre-
vious period. They could not, from the very nature of
the conditions under which they were trained and under
which they worked, bring to their problems the enthusi-
asm and unbiased judgment of their American contem-
poraries. They were the direct inheritors of all the
learning, the discoveries, and the dogmas in this field.
Prior to 1880 plant pathology had been wholly European,
one might almost say German. This inheritance was
their handicap. Free from prejudice and dogma, un-
hampered by text and training, with all the problems be-
fore him new and untouched, the young pathologist of
America delved with the energy and delight, and often, it
must be admitted, with the recklessness and ill-prepared-
ness of the pioneer. Much that was done was super-
ficial, some of it was worthless. Yet so much of thor-
oughly substantial and creditable research was ac-
complished as to force from some of our European con-
temporaries the not too ready or hearty acknowledgment
of American leadership.

THE MILLARDETIAX PERIOD 71

Before passing to a brief consideration of the men whose
work and researches stand forth from among the multi-
tudinous contributions of this period, it may be pointed
out that the Millardetian period saw the beginning of
specialization within the science. From the general field
were developed and split off in more or less independent
lines of development forest pathology and bacterio-
phytopathology. Within the general field a tendency
toward splitting up along crop group lines is also dis-
cernible, as, for example, diseases of fruit crops, diseases
of citrus crops, diseases of field and garden crops, etc.
This will be brought out more clearly in the discussion
of the pathologists and their writings.

Modern pathologists may be divided, for the most part,
into two philosophic schools, the pathogenetists and the
predispositionists. The latter are the philosophic de-
scendants of the autogenetists, of which Franz Unger and
his period represent the highest development. The doc-
trine of this school collapsing before the revolutionary
discoveries of de Bary, Kiihn, and Pasteur, was main-
tained and somewhat readjusted to the new facts by
Hallier during the Kiihnian period. The pathogenetists
and their doctrine of pathogene responsibility in plant
disease production were distinctly the products of the
Kiihnian period. It will be recalled that, in reality, the
first of these, Fabricius the Dane, had lived and an-
nounced the doctrine more than seventy-five years
before the appearance of de Bary's classic work on the
pathogenic nature of the smut fungi. But phytopatho-
logic thought was at that time unprepared to under-
stand and accept so revolutionary a doctrine. It re-
mained for de Bary and Kiihn to revive and prove it

72 HISTORY OF PHYTOPATHOLOGY

and to present it to a scientific public ready to re-
ceive it.

It is, therefore, not surprising that this doctrine so
vitalizing and fruitful during the quarter century pre-
ceding should have seen a greater increase in its devotees
during the Millardetian period. The discovery of so
promising a fungicide as bordeaux mixture must need- be
utilized. Known fungous pathogenes had to be more care-
fully studied. New ones were sought in connection with
every disease of unknown etiology. The pathogenetists
flourished. They dominated both as to numbers and
influence in every land where plant diseases claimed at-
tention. They were supported and strengthened by a
host of enthusiastic mycologic contemporaries who had
arisen as a result of de Bary's stimulating discoveries
and teaching.

In Germany, the cradle of modern phytopathology,
the most distinguished and influential of the pathogene-
tists were Hartig, Frank, Kirchner, Brefeld, and Klebahn.
They entered the period as young but trained and sea-
soned recruits to the Kuhnian standards. Of these,
Hartig is the most renowned because of his pioneer and
classic researches on the diseases of trees. He will live
in the history of our science as the father of forest path-
ology. Of predispositionists, Sorauer stands forth with-
out a peer, exceptirg only H. Marshall Ward of England.

Heinrich Julius Adolph Robert Hartig was born May
30, 1839, in Braunschweig, Germany. He was the last
of an illustrious line of scientists. His grandfather,
Georg Ludwig Hartig, chief forester of Prussia, laid the
foundations of modern silviculture. His father, Theodor
Hartig, a great forester of his time, was a botanist as

THE MILLARDETIAN PERIOD 73

well, and a student of tree diseases, especially wood
decay. Living in the time and under the influence of
the Ungerian period he misinterpreted the relation of
the fungus mycelium to the decayed wood in which he
was the first to record its occurrence. It remained for
his son to make the correct interpretation. Robert
Hartig received his early schooling in Braunschweig,

fc**

Robert Hartig.
Father of forest pathology. (From a portrait in "Phytopathology,'*

vol. v.)

spending much time with his father who was at that time
in the forest service there. Trained as a professional
forester, he was given his bachelor's degree at the age
of twenty. He traveled through the forests of Germany
for two years, served one year in the army, and finally
went to the University of Berlin in the autumn of 1865.
Two vears later he took his doctor's degree from the

74 HISTORY OF PHYTOPATHOLOGY

[Jnivcrsity of Marburg. lb- served in various positions
in the Forest Service. In 1866 he was called to lecture on
botany and zoology at the Forest Academy at Ebers-
walde, where he remained until 1878, having been made
professor of botany in 1871. From Eberswalde he was
called in 1878 to the chair of botany in the royal For-
estry Experiment Station at Munich, where he remained
until his death, October 9, 1901, at the age of sixty-two.
The beginning of the Millardetian period found Ffar-
tig already firmly established in his life work. Two of
his most classical contributions to our science had al-
ready appeared, viz., Wichtige Krankheiten der Wald-
baume (1874) and Zersetzungserscheinungen des Holzes
der Nadelholzbaume und der Eiche in forstlicher, chem-
ischer, und botanischer Richtung (1878). The first
edition of his Lehrbuch der Baumkrankheiten appeared
the year of Millardet's famous discovery. Hartig
appears to have been but little if at all influenced in
his work and philosophy by the fungicidal trend and
discoveries of the period. An etiologist of the de Ban-
school, he was little inclined to emphasize control. To
the Millardetian period he gave rather than received;
a product of the previous period, he became a molder
of the etiologic thought of the new. He brought to
this phase of our science a biologic and ecologic point
of view of great worth and influence. Being a practical
forester, he became a field pathologist. In the forest
the numerous ecologic factors influencing disease phe-
nomena are most in evidence. There he laid out his
experiments and there he measured his results. His
contributions from 1883 until his death eighteen years
later are very numerous and important. He was a

THE MILLARDETIAX PERIOD 75

productive as well as an accurate, painstaking investi-
gator. These contributions, while in large part phyto-
pathologic, cover a wide range of forestry and botanical
subjects, especially physiology and histology. Two
new editions of his Lehrbuch appeared, the final one in
1900. Two translations of the earlier edition appeared
in 1894, one in English and one in Russian. A French
translation had been published in 1891. A classical
work on the dry rot fungus of structural timbers (Der
achte Hausschwamm, Merulius lacrymans) appeared
in 1885; another on smoke injury (Die Beschadigung
der Nadelwaldbaume durch Hlitten und Steinkohlen-
rauch) in 1896. He was engaged on a monographic
study of lightning injury at the time of his death (Tu-
beuf, 1903 : (22)).

Of the pathogenetists ranging the general field of
phytopathology during this period in Germany, perhaps
none is better known or had a wider influence, especially
in Germany, than Frank. Trained as a plant physiolo-
gist, his early work was along the lines of physiologic
biology. He made extensive studies on the biology of
the legume organism and was the pioneer in the investi-
gations of mycorrhizal fungi.

Albert Bernhard Frank was born January 17, 1839, in
Dresden, where he received his early training in the
Realschule and Gymnasium. In 1861 at the age of
twenty- two he matriculated in the University of Leipsig,
studying medicine and botany. He took his doctor's
degree from Leipsig in 1865, at which time he was made
curator of the herbarium, becoming shortly thereafter
privatdocent, and finally in 1878 assistant professor of
botany. Called to the chair of botany in the Agricul-

76 HISTORY OF PHYTOPATHOLOGY

tural College in Berlin in 1881, he remained there for
eighteen years until his death, September 27, 1900. Born
the same year as Hartig, he lived but one year less. Both
were outstanding German pathogenetists of their time.

Frank's chief contributions to phytopathologic research
were: (1) his discovery of the true cause of the leaf
scorch of cherries,1 a disease which became epiphytotic in
Germany about 1880 and threatened the destruction of
all sweet cherry trees. He showed this to be due to the
ascomycete Gnomonia erythrostoma which winters over
on the leaves hanging to the tree. With German
soldiers placed at his disposal he picked all these leaves
for two seasons, claiming to have thereby effected the
control of the disease; (2) his discovery of the cause of the
heart and dry rot of sugar beets.2 This disease so threat-
ening to the sugar-beet industry he showed to be due to
the fungus Phoma beta.

Frank's career as a plant pathologist really began with
his call to the chair of plant physiology in the Koniglichen
Landwirtschaftlichen Hochschule in Berlin in 1881, al-
though the first edition of his text-book on plant diseases
had appeared the year previous. The second edition of
this text-book appeared in three volumes in 1 895-96. 3

1 Frank, A. B.: Uber Gnomonia erythrostoma, die Ursache einer
jetzt herrschenden Blattkrankheit der Siisskirschen im Altcnlande.
nebst Bemerkungen liber Infection bei blattwohnenden Ascomyceten
der Baume uberhaupt, Ber. Deut. Bot. Ges., 4 : 200-205, 1886; also,
Uber die Bekampfung der durch Gnomonia erythrostoma verursachten
Kirchbaumkrankheit im Altenlande, Ber. Deut. Bot. Ges., 5 : 281-286,
1887.

2 Frank, A. B.: Phoma Betae, ein neuer Riibenpilz, Zeitschr. Pflanz-
enkr, 3 : 90-92, 1893.

3 Frank, A B.: Die Krankheiten der Pflanzen, 1 : 1-XII + 1-344,
1895; 2 : 1-XI + 1-574, 1896; 3 : 1-IX + 1-363, 1896.

THE MILLARDETIAX PERIOD 77

Like Hartig, he was a product of the Ktihnian period.
As a professor in the agricultural college at the national
capitol he was much in demand as lecturer before
agricultural societies (Landwirtschaf tliche Vereinen) . He
was vice-president of the Special Committee of the Im-
perial Government on plant protection. He was, on the
whole, a teacher rather than an investigator. He is the
author of no less than eleven text-books on botany,
plant physiology, and plant pathology. He was secretary
of the Deutschen Botanischen Gesellschaft from its
foundation. He gave much of his time to what we would
now designate as extension work. Frank's influence was
greatest during his lifetime and in his own country.
His work lacks that accuracy, finish, and touch of genius
so characteristic of his countryman and contemporary,
Robert Hartig.

Oskar Kirchner, the third German pathogenetist who
belongs distinctly to the Millardetian period, still lives
and works at his post in the agricultural college at
Hohenheim in the hills to the south of Stuttgart in
Wurtemberg, south Germany. A da}' with him in his
laboratory and home during the winter of 1913 revealed
something of his character and relation to phytopatho-
logic science. A fine old man of perhaps sixty-five, with
white hair and beard, he nevertheless exhibits every
evidence of vigor and energy. A personality at once
impressive and cordial, one sees in him the teacher
rather than the investigator, but he is both. Like
Frank, Kirchner emphasizes the practical applications
rather than the scientific aspects of the science. His
chief contributions to plant pathology are two: his
text-book on the diseases of cultivated plants; and an

78 HISTORY OF PJIYI'iPUHOLOGY

atlas of colored plates illustrating the diseases and in-
juries of cultivated plants. The text-book, first published
in 1890, 1 is designed primarily for farmers and gardeners.
It is unique in the arrangement of its data, being, in
short, an annoted key to the fungous diseases and insect
injuries of plants, based on the symptoms exhibited.

OSKAR KlRCHXKR.

A noted German pathogenetist. (From a photograph.)

The primary grouping of the diseases, is however, on
the crop basis. There are ten groups or classes of
these, as follows: 1. Cereals. 2. Edible-seeded legumes.
3. Fodder grasses. 4. Fodder legumes. 5. Root crops.

1 Kirchner, Oskar: Die Krankheiten und Beschadigungen unserer
landwirtschaftlichen Kulturpflanzen, pp. I-X + 1-637, 1890. A second
completely revised edition appeared in 1906.

THE MILLARDETIAX PERIOD 79

6. Trade crops. 7. Vegetable and garden crops. 8. Tree
fruits. 9. Small fruits. 10. Grapes. These are again di-
vided into the individual crops composing each crop
group and under each plant, according to the parts
affected, as, for example, wheat: I. Diseases and pests
of the heads. II. Diseases and pests of the leaves and
haulms. III. Diseases and pests of the seedling. IV.
Diseases and pests of the roots. V. Diseases and pests
of the ripe seed. Finally, under each of these the diseases
are arranged according to the chief symptoms exhibited.
The atlas published in collaboration with H. Boltshauser
has appeared in several series beginning in 1896. l Each
colored plate, reproduced from large hand-painted charts,
many of which he showed me with much pride, is ac-
companied by a brief text of description or explanation.

Germany produced during this period another patho-
genetist of marked ability and who fortunately is still
living and contributing to the etiologic phase of the
science. I refer to Heinrich Klebahn, botanist of the
Hamburg Botanical Institute. He is best known for
his contribution to our knowledge of the hetercecious
rusts.2 His first paper, published in 1887. deals with a
rust fungus. Since 18923 he has published almost annu-
ally reports of his cross inoculation work with hetercecious

1 For a list of these series see Lindau and Sydow, Thesaurus, 1 : 767.
They appeared under the general title of Atlas der Krankheiten und
Beschadigungen unserer landwirtschaftlichen Kulturpflanzen. Each
series deals with the diseases and pests of some crop group, as, for ex-
ample, "Krankheiten und Beschadigungen der Getreidearten."

2 Klebahn, H.: Die wirtswechselnden Rostpilze. Versuch einer
Gesamtdarstellung ihrer biologischen Yerhaltnisse, pp. I-XXXVII +
1^47, Berlin, 1904.

3 Klebahn. H. : Kulturversuche mit heterocischen Uredineen, Zeitschr.
Pflanzenkr., 2 : 258-275, 332-343, 1892.

80 HISTORY OF PHYTOPATHOLOGY

rusts. These reports have appeared in the Zeitschrift
fur Prlanzenkrankheiten. He stands in much the same
relation to rust work in Germany that Dr. J. C. Arthur
does to rust work in America. It is interesting to note in
passing that not only are their contributions to phyto-
pathology of a very similar type, but their personal
resemblance to each other is marked. Klebahn's con-
tributions, however, have not been confined to the rust
diseases. He has done pioneer work on the diseases of
tulips, lilacs, and celery due to other forms of fungi.
An examination of the very extensive lists of his publica-
tions as given by Lindau and Sydow in Thesaurus 1 and
3 will best serve to impress one with the range and
volume of this man's contributions to the phytopatho-
logic thought of his time. His text-book on the Basis
of general phytopathology appeared in 1912. y In the
point of view therein expressed and in its treatment of the
material it is distinctly of the Millardetian period.

Of the life and training of Klebahn no data have been
available to the writer. A morning spent with him in his
laboratories and gardens in Hamburg in the spring of
1914 has left a most pleasant impression of the person-
ality, ability, and scientific spirit of the man. He is
wholly an investigator, keen, and as critical of his own
work as he is of that of his contemporaries.

There are numerous other German workers of the
pathogenetist school belonging to the Millardetian
period. Space permits the mention of but one other,
Oskar Brefeld. While perhaps more truly a mycologist
than any of his countrymen above discussed, his work

1 Klebahn, H.: Grundziige der allegemeinen Phytopathologie, pp.
1-147, Berlin, 1912.

THE MILLARDETIAN PERIOD 81

has nevertheless a marked phytopathologic character.
His most noteworthy contributions to mycology began
to appear about 1872 under the general title of Unter-
suchungen aus dem Gesammtgebiet der Mykologie
(See Lindau and Sydow, 1 : 196; 3 : 120). Among the
studies detailed in the fourteen quarto volumes which
have appeared up to 1908, those dealing with the smut
fungi are of the most value to phytopathologic science.
Of special importance have been the studies on corn
smut and on blossom infection by the loose smut fungi
of cereals. So far as the writer is aware, Brefeld still
lives, and there is no data at hand for a biographic
sketch. A chronologic arrangement of his contributions
indicate clearly that he belongs to the Millardetian
period. His relation to plant pathology is much the
same as that of de Bary, a builder of one of the funda-
mental foundations of that science rather than of the
superstructure itself.

Other European countries contributed pathogenetists
to this period less in number, but equally eminent with
those of Germany.

One of the most interesting of the non-German patho-
genetists is the Danish botanist, Rostrup. He was one
of the most diligent, broad-minded, and successful plant
pathologists of this period. Because he wrote almost
wholly in Danish his work is little known outside of the
Scandinavian countries. Lind (1913 : 25) calls him the
"first phytopathologist of Denmark." For years a
teacher of mathematics and natural history in a second-
ary school, he trained himself in botany and mycology
during leisure hours, so that at the age of forty he was
the accepted authority on the flowering plants and fungi
6

82 IllSTDRY OF !*H\ l< 'I'M BOLOG"X

of Denmark. Naturally inclined to the practical appli-
cations of his scientific knowledge, he then turned his
attention to the diseases produced by Fungi in plants,
and during the next thirty years of his life won for him-
self and his little country an enviable place in the history
of plant pathology. As a mycologist his name is per-
petuated in a gigantic collection of over 30,000 specimens
of Danish fungi, now preserved in the botanical museum
of the University of Copenhagen. The one thing to
make this monument complete we now have — the fine
volume (in English) on Danish Fungi by J. Lind, which
is based upon this collection. As a phytopathologist
his great contribution to literature is his comprehensive
w7ork, Plantepatologi,1 published in his seventy-second
year, a text-book of phytopathology based on the study
and experience of over thirty years devoted to the sub-
ject of plant diseases. Ravn says of this book: "It is
a book the distinctive exterior of which bespeaks the
sterling and personal character of its contents. The
series of different disease types stand sharply forth with
exact clearness. One feels that he has here to do with
proved experience. The work shows throughout the
characters of reliability. It takes a prominent position
in the world's literature" (1909 : 50).

Frederick George Emil Rostrup was born January 28,
1831, on the island of Lolland. Ravn's brief statement
of his early life and boyhood training reads wonderfully
like that of Julius Kiihn. The son of a farm-manager
of a large estate, he received his early education in the
public schools. Fond of hunting, he soon became inter-

1 Rostrup, E. : Plantepatologi, Haandbog i Leren om Plantesygdomme
for Landbrugere, Havebrugere og Skovbrugere, pp. I-V -f 1-640. 1902.

THE MILLARDETIAN PERIOD 83

ested in the natural history of the game he sought, espe-
cially birds. After a year as secretary to his father he
went, at the age of nineteen, to Copenhagen, where he
studied natural history and mathematics in the Poly-
technical School and in the University. Here for seven
years he studied, getting the best the University had to

Emil Rostrup.

The most noted Danish phy topathologist. ( From a portrait in "Botanisk

Tidiskrift," vol. xxviii.)

offer in mathematics and natural history, especially
botany and agriculture. Having passed his final exam-
inations, he accepted, at the age of twenty-six, the posi-
tion of teacher in mathematics and natural history at the
public seminary at Skaarup in southern Fiinen. Here
he lived and taught for twenty-five years. It was during
the leisure of these years that he made himself both a

84 HISTORY OF PHYTOPATHOLOGY

phaneogamic botanist and a mycologist of renown. His
interest in mycology dates from August 31, 1860, the

date of his first collection of fungi. In I860 he published
the first edition of his Flora of Denmark (including only
flowering plants), which has already gone through ten
editions, and is to Danish botanists what Gray's Manual
is to Americans. In 1869 he published a second volume
of this flora dealing with the Cryptogames (Ravn. 1909 :
47-55).

His interest in phytopathology as such dates from IS 70.
The works of Kiihn, de Bary, and Tulasne were the
sources of his inspiration and teachings, while the wealth
of his knowledge and experience with the flowering
plants and fungi made these teachings more fruitful
than usual. His first publications on the diseases of
cultivated plants began to appear in 1870-71. Becom-
ing especially interested in diseases of trees, he became
an intimate correspondent and contemporary worker
with Robert Hartig. His greatest contributions are,
according to Ravn (1909 :49), in the field of forest
pathology.

During the decade 1870 to 1880 Rostrup's phyto-
pathologic work developed and attracted such general
attention throughout Denmark, especially among far-
mers, that in 1883 he was called to the Agricultural
College as instructor in plant pathology and chief con-
sulting plant pathologist for the national government.
In 1889 he was made lecturer, and finally in 1902 pro-
fessor, at the age of seventy-two. He died January 16,
1907, at the age of seventy-six. Probably no one man
has so completely dominated by his life and works the
botanical and agricultural thought of an entire country.

THE MILLARDETIAN PERIOD 85

It will be seen from the above that Rostrup, the phyto-
pathologist, was distinctly of the MUlardetian period,
though, like his European contemporaries, Hartig,
Sorauer, and Frank, he brought to his work a training
and point of view fashioned and fixed in the atmosphere
of the Kuhnian period. He began officially his profes-
sional career as a pathologist in that year which marks
the beginning of the MUlardetian period. His text-
book on plant pathology appeared during the very last
years of the period (1902).

Rostrup's contributions to phytopathologic science
consist not alone in published papers. He has left behind
a corps of enthusiastic and well-trained young patholo-
gists, his students, who are carrying forward with re-
markable energy and brilliancy the work he has so well
established. The most noted of these is his successor at
the agricultural college of Copenhagen, F. K^lpin Ravn.

There were during this period but two other plant
pathologists in Denmark who, according to Lind
(1913:25), deserve to be mentioned with Rostrup.
These are P. Nielson and J. L. Jensen. Both were
noted for their practical applications of Rostrup's ideas
to the control of plant diseases. Jensen is especially
noted for his investigations on the control of cereal
smuts by the hot-water method and on the control of
the late blight of potatoes (Ravn, 1917 : 1-4).

Scandinavia produced during this period another
plant pathologist of eminence and a striking type of
pathogenetist in Jakob Eriksson of Sweden. As he is
still living the facts regarding his early life and training
are not available in a published biography. His contri-
butions show, however, that he was a contemporary of

86 HISTORY OF PHYTOPATHOLOGY

Rostrup. Prominent in the agricultural activities of his
country, he was for many years professor and director
of the Botanical Division of the Swedish Central Station
for Agricultural Experiments in Stockholm. He has
recently retired.

Eriksson has devoted himself primarily to the diseases
of cereal crops, especially the rust diseases; his most

Jakob Eriksson.

Most noted Swedish phytopathologist. (From a portrait in Wittrock's

"Acta Horti Bergiani.")

important contribution along this line being the work on
cereal rusts, published in 1896 with E. Henning as co-
author.1 It is a volume of 464 pages with fine colored plates.
To Eriksson belongs the credit of having discovered

1 Eriksson, J., and Henning. E.: Die Getreideroste. ihre Geschichte
und Xatur, sowie Massregetn gegen dieselben. pp. I-YIII -f 1-4(4.
Stockholm. 1896. This was first published in 1894 in Xo. 38 Med-
delanden fran Kongl. Landtbruks Akademiens Experimentalfiilt. It
was translated from the Swedish into German by C. ( >. Xordgren.

THE MILLARDETIAX PERIOD 8/

biologic races or "special forms," as he called them, within
morphologic species of rusts.1 This has been one of the
very fruitful discoveries in phytopathologic etiology
during the Millardetian period and has been extended
to other groups. Eriksson is widely known as the author
of the mycoplasm theory. This theory is one of the
most extraordinary and ingenious modifications of the
idea of symbiosis which any botanist has proposed.
The gist of the mycoplasm theory is that the naked
protoplasm of the pathogene lives for a time mingled in
indistinguishable combination with that of the host.
This mixed plasm Eriksson designates as mycoplasm.
He holds that at certain stages in the host's development
the pathogene protoplasm separates itself from that of
the host, migrates through the cell walls out into the
intercellular spaces, at first a naked nucleated mass not
unlike a plasmodium. Gradually this takes on a thread-
like shape, secretes a cell wall, and sends haustoria into
the adjacent cells, and the pathogene mycelium is
formed. From this internal mycelium, present through-
out the plant, spore bodies arise beneath the epidermis
simultaneously. Thus he accounts for the sudden and
general outbreaks of rusts. The pathogene reverts to
the mycoplasmic condition in the next crop of seeds and
is thus perpetuated.2 Eriksson has persisted in main-

1 Eriksson, J. : Ueber die Specialisirung des Parasitismus bei den
Getreiderostpilzen, Ber. Deut. Bot. Ges., 12 : 292-331, 1894; also
Neue Untersuchungen iiber die Specialisirung, Verbreitung und Herkunft
des Schwartzrostes (Puccinia graminis Pers.), Jahrb. Wiss. Bot., 29 : 499-
524, 1896.

2 Eriksson, J. : Uber die Mykoplasmatheorie, ihre Geschichte und
ihren Tagesstand, Biol. Centralbl., 30 : 618-623, 1910. (A concise
review of the matter with numerous references to the literature of the
subject.)

88 HISTORY OF PHYTOPATHOLOGY

taining his theory in the face of withering attacks upon
it by the English mycologist, H. Marshall Ward,1 and
by others. He has recently sought to strengthen his
position by an extensive study of the hollyhock rust,
Pucciniti malvacearum, in which he assumes to haw-
discovered another marked case of rust inheritance
through mycoplasm.2 Eriksson is the author of a text,
on the fungous diseases of field crops, the first of a pro-
jected series on the fungous diseases of the cultivated
plants of Sweden.3

Russia's contribution to the ranks of the pathogen e-
tists was Woronin. He was a mycologist rather than a
pathologist. A single contribution, his studies on the
club root of cabbage,4 alone sufiices, however, to give
him a place among plant pathologists.

Michael Stepanovitch Woronin was born in St. Peters-
burg June 21, 1838, a year after the birth of Hartig.
Born of wealthy parents, he was not only well educated
but also inherited wealth which made him independent
throughout a life almost entirely devoted to investiga-
tion. Entering the University of St. Petersburg at the

1 Ward, H. M.: II. On the hbtology of Uredo dispersa Erikss. and
the "mycoplasm" hypothesis, Phil. Trans. Roy. Soc, London, B: 196 :
29-46, 1904. (Read March, 1903.)

2 Eriksson, J.: Der Malvenrost (Puccinia malvacearum Mont.),
seine Verbreitung, Natur und Entwickelungsgeschichte, Kungl. Svcnska
Vetenskapsakademiens Handlingar, 47 : 2 : 1-125, 1911.

3 Eriksson, Jacob: Landtbruksvaxternas Svampsjukdomar, pp.
I-XII + 1-210, Stockholm, 1910. This is the first part of his Vara
Kulturvaxters Svampsjukdomar (Diseases of our cultivated plants).
An English translation of this by Anna Molander was published in 1912
under the title : Fungoid diseases of agricultural plants. A German
translation by A. Y. Grevillius appeared in 1913.

4 Woronin, M.: Plasmodiophora Brassicae. Urheber der Kohl-
pflanzen-Hernie, Jahrb. Wiss. Bot., 11 : 548-574. 1878.

THE MILLARDETIAX PERIOD

89

age of sixteen, he took his bachelor's degree in four
years, after which he studied in Germany under de Bary,
from whom he received his greatest inspiration and his
tendency toward mycologic studies. Xot caring to seek
a Ph.D., it was thrust upon him eventually in 1874 by
the University of Odessa, honoris causa. From 1869

Michael Wuruxix.

The greatest of Russian phytopathologists. (Frcm a photograph,

courtesy of Dr. Envin F. Smith.)

until his death. February 20, 1903, he lived in St. Peters-
burg, teaching mycology and cytology for a time, but
devoting himself during his latter years entirely to re-
search as a member of the Royal Academy of Sciences.
A man of rare ability and attainments, he was pos-
sessed of a fine and lovable personality. Famintizen,
his colleague and biographer, says of him: "Vanity,

90 HISTORY OF PHYTOPATHOLOGY

egotism, and human malice, the traits common to most
of us, were unknown to him" (Smith, 1912 : 4). His
bedroom was ever his laboratory. His microscope, a
few simple tools, his pencil and paper, on a small table
by the window near his bed, sufficed as equipment with
which he turned out those classical monographs which
have made him famous throughout the botanic and
mycologic world. These studies were, like those of de
Bary, of fundamental significance for phytopathologic
science. The most important of these, aside from the
one already mentioned, are his studies. on Sclerotinial
diseases of fruits, especially the one on Sclerotinia cinerea
and Sclerotinia fruciigena,1 and on the sunflower rust
pathogene, Puccinia Helianthi.2

Phytopathology in Holland during the Millardetian
period was represented chiefly by the pathogenetist,
J. Ritzema Bos. He was the first director of the privately
endowed Wille Commelin Scholten Phytopathological
Laboratory, established in Amsterdam in 1895 (Riztema-
Bos, 1906 : 28-58). In 1906 he was called to take the direc-
torship of the Government Institute for Phytopathology at
Wageningen, of which he is still the active head (Ritzema-
Bos, 1906 : 17-27). He is perhaps best known as the editor
of the Dutch journal on plant diseases, Tijdschrift over
Plantenziekten,3 the first issue of which appeared in 1895.

1 Wbronin, M.: Uber Sclerotinia cinerea und Sclerotinia fructigena,
Mem. Acad. Imp. Sci., St. Petersbourg, VIII. Ser. Phys. Math. CI.,
10 : 5 : 1-38, 1899.

2 Woronin, M.: Untersuchungen uber die Entwickelung des Rostpil/.e-
(Puccinia helianthi), welcher die Krankheit der Sonnenblume verursacht,
Bot. Zeit, 30 : 677-683, 693-697, 1872.

3 Tijdschrift over Plantenziekten. edited 1895-1903 by J. Ritzema
Bos and G. Staes; 1904 to date, by J. Ritzema Bos alone.

THE MILLARDETIAX PERIOD

91

England contributed to this period but two plant
pathologists of note — H. Marshall Ward and D. Mc-
Alpine. Ward, because of his physiologic training and
point of view, is to be classed with Sorauer as a pre-
dispositionist. McAlpine, on the other hand, is shown
by his work to be an orthodox pathogenetist.

Daniel McAlpixe.
Noted Australian plant pathologist. (From a photograph.;

Daniel McAlpine, vegetable pathologist to the Depart-
ment of Agriculture of Victoria, Australia, though trained
in England, has made his reputation entirely through
his lifelong labors in the Australian commonwealth. His
work on the fungous diseases of Australian crops and
native plants, especially his monographs of the rusts and
the smuts, are well known to his contemporaries through-

92 HISTORY OF PHYT()PATHOL()<;\

out the world.1 He has recently completed the fifth
volume of a most extensive investigation on the nature
and control of the bitter pit (stippin) of the apple- This
work, undertaken in 1911, is of a type very different from
that of his previous contributions. It is distinctly phys-
iologic, being in sharp contrast to the mycologic charac-
ter of his earlier contributions. This work on bitter pit
will doubtless give McAlpine a place in the present era.
Born in Scotland and educated in London University, he
went, in 1884 at the very beginning of the Millardetian
period, to Australia, where he held the position of
lecturer in biology in Ormond College and at the same
time a similar position in botany in the College of Phar-
macy in Melbourne until 1890, when he was appointed to
his present position.

The most noted Hungarian phytopathologist of the
Millardetian period is Gyula de Csik Madejalva Istvanffi,
director of the Royal Central Institute for Viticulture at
Budapest. He has made extensive studies of the more
common diseases of the grape.3 He is still living, hence

1 McAlpine, D.: The rusts of Australia, pp. 1-349, 1906; and The
smuts of Australia, pp. 1-285, 1910. He has to his credit a total of over
220 scientific books and papers, of which 15 are scientific contributions
of special merit. For an extensive list of his contributions see, List of
Scientific Works, Papers, and Bulletins by D. McAlpine, government
vegetable pathologist 1877-1916, in an unnumbered pamphlet, pp. 1-12,
1916. Published by Department of Agriculture of Victoria, Melbourne,
Australia.

2 McAlpine, D.: Bitter pit investigations, Reports 1-5, 1911 to 1916.

3 Among Istvanffi's most important papers on grape diseases may be
mentioned, Etudes microbiologiques et mycologiques sur le rot gris de
la vigne (Botrytis cinerea, Sclerotinia Fuckeliana), pp. 183-360, 1905;
Etudes sur le rot livide de la vigne (Coniothyrium Diplodiella), pp. 1-
88, 1902; Etudes sur le mildiou de la vigne, pp. 1-125. 1913; all published
in the Annates de lTnstitute Central Ampelologique Royal Hongrois.

THE MILLARDETIAN PERIOD 93

little biographic data is available. His contributions
show him to belong to the dominating school of the
Millardetian period.

The Latin races have had much less influence on phyto-
pathology than have the Teutonic and Anglo-Saxon.
Nevertheless, during the Millardetian period, France and
Italy produced plant pathologists of note. They are
chiefly pathogenetists. Most of these are still living.

In France, aside from Millardet, the most noted patho-
genetists of this period are Delacroix, Prillieux, and Viala.
These men all began their work in the field of plant
pathology about the opening of the period. Prillieux
had already made some contributions to the science as
early as 1872. Viala, whose first paper appeared in 1883,
has devoted himself almost entirely to diseases of the
vine. (See list of his papers in Lindau and Sydow,
2 : 692-695.)

Edouard Ernest Prillieux has made perhaps the most
numerous and varied contributions to French literature
on plant diseases. He was for many years professor of
botany at the Institute Agronomique in Paris. He died
in 1915 at the advanced age of eighty-seven. He was a
senator and the first director of the laboratory for vege-
table pathology in Paris. Prillieux is regarded by his
French contemporaries as the founder of phytopathology
in France. He is the author of a two-volume work on
diseases of agricultural plants, published in 1895 and
1897. l Many of his papers were published in co-author-
ship with Georges Delacroix. Upon his election as

1 Prillieux, E. : Maladies des plantes agricoles et des arbres fruitier*
et forestiers causees par des parasites vegetaux, 1 : I-XYI -f- 1-421,
1895; 2 : 1-592, 1897.

94 HISTORY OF PHYTOPATHOLOGY

Senator in 1897 he was forced to give up the (hair of
botany which he had occupied since its creation.

George Delacroix was horn in 1858 in Paris. The
second of six children of a poor family, he suffered great
hardships and privations in his struggle to get an educa-
tion and fit himself for the profession of medicine. While
still a student he exhibited a great interest in botany and

Edouard Prillieix.
Founder of phytopathology in France. (Froin a portrait in "Bulletin
de la Societe Mycologique de France." vol. xxxii.)

was able during the years of his struggle as a young
physician to find time for botanical excursions with the
noted mycologist Boucher. In this way he acquired an
extensive knowledge of the fungi. In 1888 he was offered
a position with Prillieux as assistant in the laboratory of
Plant Pathology in the Institut Agronomique, which he
accepted. On the retirement of Prillieux in 1897 he was

THE MILLARDETIAX PERIOD

95

made director of the newly established Station of Plant
Pathology, in which position he continued until his death.
He is especially noted for his studies on the diseases of
tobacco. He also gave much attention to the diseases of
tropical plants, material of which came to him from the
French colonies. In addition to his numerous papers on
various diseases of plants, Delacroix is the author of

Georges Delacroix.

A noted French pathogenetist. (From a portrait in "Bulletin de la

Societe Mycologique de France,'- vol. xxiv.)

several text-books. The first of these, a small booklet
on diseases of cultivated plants, appeared in 1902. 1 A
book on non-parasitic diseases of plants was given to the
public in 1908 after his death.2 He wrote the final pages

1 Delacroix, G.: Maladies desplantes cultivees, pp. 1-73, Paris, 1902.

2 Delacroix, G.: Maladies des plantes cultivees. Maladies non-parasi-
taires. pp. I-XII + 1-431, Paris. 1908.

96 HISTORY OF PHYTOPATHOLOGY

of this work the evening before he died. His most pre-
tentious text, that on the diseases of plants of the tropics,1
was completed by his successor, Maublanc, from notes
and manuscripts which he left.

Italy produced several plant pathologists of note dur-
ing this period. Orazio Comes, born in 1848, was at the
opening of the period the most mature and best known.
He had already published numerous papers on pathogenic
fungi, including an extensive text on the cryptogamic
parasites of agricultural plants.2 A second book on the
same subject appeared in 1891.3 He has written exten-
sively on the diseases of the vine. His most recent con-
tributions to the literature is a text on the control of
plant diseases.4 He is one of the most productive teachers
of phytopathology in Italy, his students occupying many
positions throughout the kingdom. Formerly professor
of botany in the Royal School of Agriculture at Portici,
he is now director of that institution.

Of the Italian plant pathologists of the Millardetian
period, perhaps the most noted is Luigi Salvatore Savas-
tano, whose first papers appeared about 1881. He was
born in Naples in 1853 and is still living. He was for
some years professor of arboriculture and applied vege-
table pathology in the Superior School of Agriculture

1 Delacroix, G.: Maladies des plantes cultivees dans les pays chauds,
pp. I-IX + 1-595, 1911.

2 Comes, ().: Le Crittogame parassite delle piante agrarie. Lezioni
tenute nella R. Scuola Sup. die Agric. di Portici nell'anno 1882 : 1-580,
Napoli, 1882. This consists of a collection of his lectures, reproduced
in script from a copy made by his students, R. de Netto and F. de Rosa;
illustrated by another student, L. de Luise.

3 Comes, O.: Crittogamia agraria, pp. 1-600, Napoli, 1891.

4 Comes, O.: La profilassi nella patologia vegetale, pp. 1-172. Napoli,
1916.

THE MILLARDETIAN PERIOD 97

at Portici. He is at present director of the Royal Experi-
ment Station for the culture of citrus and other fruits
at Acireale. Among his numerous contributions to
phytopathology the following merit special mention:

(1) various papers on the olive knot, a bacterial gall1;

(2) a book on the diseases of trees2; and his essay on the
phytopathology of the Greeks, Romans, and Arabs.3

Fridiano Cavara, director of the Royal Botanical
Gardens at the University of Naples, has made many
contributions since 1888 to Italian phytopathologic
literature. According to Smith,4 Cavara was the first
to isolate the crown gall organism and make successful
inoculations with it. These investigations were made on
the crown gall on grapes and published in 1897. 5

Augusto Napoleone Berlese is another Italian patho-
genetist of this period who deserves mention. His first
publication on fungi appeared in 1883 (Lindau and Sydow,
Thesaurus, 1 : 135). He is perhaps best known as one
of the editors of Rivista di Patologia Vegetale, which
began to appear in 1892. He died in 1903.

We must now turn to a consideration of that other

1 Savastano, Luigi: Tuberculosi, iperplasie e tumori dell'olivo.
I-II Memoria, Ann. R. Scuola Sup. Agr. in Portici 5 : 1-131, 1887.
See also Smith, Envin F., Recent studies of the olive tubercle organism,
U. S. Dept. Agr. Bu. PI. Ind. Bui. 131 : 25-43, 1908.

2 Savastano, Luigi: Patologia arborea applicata; lezioni, pp. I-XI +
1-666, Napoli, 1910.

3 Savastano, Luigi: La patologia vegetale dei Greci, Latini ed Arabi;
memoria, pp. 1-75. Portici, 1890; from Scuola Sup. Agric. Portici Ann.,
VI, 1890-91.

4 Smith, Envin F., et al: Crown gall of plants; its cause and remedy,
U. S. Dept. Agr. Bu. PL Ind. Bui. 213: 15, 16, 1911.

5 Cavara, F.: Tubercolosi della vite. In, Intorno alia eziologia di
alcune malattie di piante coltivate nota, Sta. Sperim. Agr. Italiane,
30 : 483-487, 1897.

7

98 HISTORY OF PHYTOPATHOLOGY

school of phytopathologists, the predispositionists. The
Kiihnian period had produced but one predispositionist
of note, Ernst Hallier, whom I have already mentioned.
The Millardetian period was but little more fortunate
as to the number of disciples of this doctrine. On the
other hand, the great predispositionists of this quarter-
century were to far outshine in ability and success their
predecessor of the earlier period. This doctrine so
inauspiciously launched by Hallier was to find master
champions in Sorauer of Germany and Ward of Eng-
land.

Paul Carl Moritz Sorauer was born in 1839 and died
January 9, 1916, at the age of seventy-seven.1 Of his
early life and training I am unable to write. His biog-
raphy is not as yet available to us. Like his German
contemporaries of this period, he was already trained
and had made some contributions to the science before
the advent of the Millardetian period. The most note-
worthy of his pre-Millardetian writings is the first edition
of his handbook and his book on fruit diseases. (See
footnotes 2 and 3, page 57.)

Sorauer, unlike Hallier, was largely free from the
theories and dogmas incompatible with the scientific
progress of his time. He was, nevertheless, an uncom-
promising predispositionist, and it is safe to assert that
the modern interpretation of the doctrine of predispo-
sition as set forth by Sorauer has much in it for thought-
ful consideration by pathogenetists. That external fac-
tors, such as temperature, moisture, and nutrition, may
gravely affect the constitution of the individual plant as

1 A notice of Sorauer's death is to be found in Hedwigia, Beibl.
57 : 151, 1916.

THE MILLARDETIAN PERIOD 99

regards its relation to the attacking pathogene is now
held by many plant pathologists.

Sorauer's most noted contribution to phytopathology
in the way of publications are the three editions of his
text-book, Handbuch der Pflanzenkrankheiten. The
first edition, a single volume written in 1874 while he
was director of the Experiment Station for Plant Phys-

Paul Sorauer.

The great German predispositionist. (From a photograph, courtesy of

Dr. Erwin F. Smith.)

iology at the Imperial Cider Institute of Proskau
(Nature, 96 : 600), seems to have been his first contribu-
tion to the science (see footnote 2, page 57). The second
edition appeared in two volumes in 1886 while he was
still attached to the Pomological Institute at Proskau.
The first volume, dealing with non-parasitic maladies,
is twice the size of the second, dealing with the parasitic

100 HISTORY OF PHYTOPATHOLOGY

diseases. Thus is indicated, both by order and size,
his predispositionist attitude'. A third edition, com-
pletely revised, appeared in 1908-13. l Sorauer is also
well known as the founder and editor of the German
phytopathologic journal. Zeitschrift ftir Pflanzenkrank-
heiten. He continued to write on phytopathologic sub-
jects until his death, and was always much interested
in international efforts to restrict the spread of plant
pathogenes.

Harry Marshall Ward was undoubtedly the greatest
of English phytopathologists. His work and influence,
even more than that of Sorauer, has shaped our current
ideas and researches on predisposition. Trained in the
English University of Cambridge, he went abroad after
taking his bachelor's degree, studying under Sachs and
de Bary. From the latter he received his inclination
toward the study of fungi, and from the former his phys-
iologic point of view. His advent into the field of phy-
topathology came with his call in 1881, while still study-
ing in Germany, to investigate the coffee disease then
devastating the plantations of the island, of Ceylon.
This commission was executed with energy and brilliancy.
His study of the pathogene, Hemeleia vastatrix,2 made

1 The third edition appeared in three volumes. The first volume of
891 pages on non-parasitic diseases was written by Sorauer himself
(issued in parts from 1905-09); the second volume of 550 pages on
diseases caused by parasitic plants was prepared by G. Lindau (issued in
parts from 1905-08); the third volume of about the same size on insect
pests of plants was written by L. Reh (issued in parts from 1906-13).

-Ward, H. M.: On the morphology of Hemeleia vastatrix Berk,
and Br. (the fungus of the coffee disease of Ceylon), Quart. Jour. Micro-
scop. Soc. n. s., 22 : 1-11, 1882; also, Researches on the life history of
Hemeleia vastatrix, the fungus of the "coffee-leaf disease," Jour. Linn.
Soc, London, 19 : 299-335, 1882.

THE MILLARDETIAN PERIOD

101

him a predispositionist. After two years in Ceylon he
returned to England, where after three years as Fellow
at Owen College, Manchester, he was called to the chair
of botany in the Forestry Department of the Royal
Indian Engineering College at Coopers Hill. While
here he naturally interested himself in forest botany.

H. Marshall Ward.

The greatest English phytopathologist. (From a portrait in "Makers

of British Botany.")

His chief pathologic contributions during this time were
his book, Timber and some of its diseases1; Diseases of
plants2 (translated into Russian in 1891); and funda-

1 Ward, H. M.: Timber and some of its diseases, pp. I-VIII + 1-295,
1909.

2 Ward, H. M.: Diseases of plants, pp. 1-196, 1896. (Published by
Society for Promoting Christian Knowledge, in the Romance of Science
Series.) What appears to be a first edition of this appeared in 1889
under the same title and from the same publishers.

102 HISTORY OF PHYTOPATHOLOGY

mental studies on the life histories of several pathogenes,
namely, Phytophthora infestans, Entyloma Ranunculi,
Puccinia graminis, and the Botrytis sp. of lily. (See
Lindau and Sydow, 1909, 2 : 723-725.) In 1895 he
was made professor of hot any at the University of Cam-
bridge, where he remained until his death in 1906 at the
age of fifty-two. His years at Cambridge were full of
activities along many lines of botany, both research and
teaching, and were exceptionally fruitful. His chief
pathologic papers during the last eleven years of his
life were: Disease in plants,1 and his numerous classic
studies from 1899 to 1905 on parasitism as exhibited in
the rusts and other fungi.2 His studies in parasitism
may be said to have laid the foundation for all later

1 Ward, H. M.: Disease in plants, pp. I-XIV + 1-309, 1901.

2 Ward, H. M.: On some relations between host and parasite in certain
epidemic diseases of plants, Proc. Roy. Soc, London, 47 : 393-443, 1890.

— Symbosis, Ann. Bbt., 13 : 549-562, 1889. (With extensive
bibliography.)

On the question of "predisposition" and ''immunity" in

plants, Proc. Cambridge Phil. Soc, 11 : 307-328, 1902.

— On the relations between host and parasite in the Bromes
and their brown rust, Puccinia dispersa (Eriks.), Ann. Bot., 16 : 233-315,
1902.

— Experiments on the effect of mineral starvation on the parasit-
ism of the uredinc fungus, Puccinia dispersa, on species of Bromus, Proc.
Roy. Soc, London, 71 : 138-151, 1902.

— On pure cultures of a Uredine, Puccinia dispersa (Eriks.),
Proc. Roy. Soc, London, 69 : 451-466, 1902.

Further observations on the brown rust of the Bromes, Puc-
cinia dispersa (Eriks.), and its adaptive parasitism, Ann. Mycol., 1 : 132—
151, 1903.

— On the histology of Uredo dispersa Eriks., and the "Myco-
plasm" hypothesis, Phil. Trans. Roy. Soc, London, B : 196 : 29-46, 1904.

— Recent researches on the parasitism of fungi, Ann. Bot.,
19 : 1-54, 1905.

THE MILLARDETIAN PERIOD 103

investigations into the nature of susceptibility and im-
munity in plants. His last paper, Recent researches
on the parasitism of fungi, appeared in the Annals of
Botany in 1905.

Only the most noted pathologists of foreign countries
of the Millardetian period have been mentioned. This
period saw the rise and development of the science in

Beverly T. Galloway.
First chief of the U. S. Bureau of Plant Industry. (From a photo-
graph.)

America. The men who were active in organizing and
developing the work in the United States are almost
without exception still living and contributing to its
progress and growth. Future history may judge them
as more of the following than of the Millardetian period.
Certain of them, however, will doubtless stand forth as
prominent figures of Millardetian times. I may be
permitted to name those who in my judgment will be

104 IIIMnkY OF PHYTOPATIKM u.,\

so known: F. L. Scribner, first federal phytopathologisl :
B. T. Galloway, first chief of the Bureau of Plant Industry
in the United States Department of Agriculture; Erwin
F. Smith, the dean of American phytopathologists and
father of the science of bacterio-phytopathology1; J. C.
Arthur, our greatest rust specialist-'; T. J. Burrill, dis-
coverer of bacterial phytopathogenesis; G. F. Atkinson,
a noted American botanist, and author of several classics
in phytopathology3; L. R. Jones, noted for his studies
on the etiology and control of potato blights,4 his inves-

lA complete list of Smith':- paper- on bacteria] diseases of plants
would be too extensive for these pages. His pre-eminence in the field
of bacterio-phytopathology has been full}' established by bis epoch-
making studies on the crown gall, a plant cancer, and by his mono-
graphic work on bacterial diseases of plants, Bacteria in relation to plant
diseases, three volumes of which have appeared, the first in 1905, the
second in 1911, and the third in 1914.

2 Besides many papers on various taxonomic phases of the rust prob-
lem, of which the most important to plant pathology are perhaps those
detailing his cultural studies, Arthur is also the author of the rust section
of the North American Flora.

3 Among the more important may be cited: (Edema of the tomato,
X. Y. (Cornell) Agr. Exp. Sta. Bui. 53 : 77-108, 1893; Leaf curl and
plum pockets. Contribution to the knowledge of the prunicolous
exoasceae of the United States. N. Y. (Cornell) Agr. Exp. Sta. Bui.
73 : 319-355, 1894; Damping off, N. Y. (Cornell) Agr. Exp. Sta. Bui.
94 : 233-272, 1895; Studies of some shade tree and timber destroying
fungi, X. Y. (Cornell) Agr. Exp. Sta. Bui. 193 : 199-235. 1901 ; Carnation
diseases, Amer. Florist, 8 : 720-728, 1893 (reprinted in the Amer.
Florist, 24 : 16-24, 1905).

4 His investigations on the potato blight and its control conducted at
the Vermont Station extend over a period of twenty years, beginning in
1890. This work is concisely reviewed by B. F. Lutman, Twenty years'
spraying for potato diseases, Vermont Agr. Exp. Sta. Bui. 159. For
other important contributions to this subject, see Jones, L. R., et al.
Investigations of the potato fungus Phytophthora infestans. U. S. Dept.
Apr. Bu. PI. Ind. Bui. 245, especially the list of Jones' papers, pp.
89, 90.

THE MILLARDETIAX PERIOD 105

tigations on the etiology and nature of soft rots in vege-
tables,1 and for his work on wilt resistance in cabbage2;
B. D. Halstead, for many years botanist of the New

George F. Atkinson.
Noted American botanist and plant pathologist. (From a photograph.)

Jersey Experiment Station ; H. L. Bolley, botanist of the
Xorth Dakota Experiment Station. He was the first

1 Jones, L. R.: A soft rot of carrots and other vegetables, caused by
Bacillus carotovorus, Jones, Vermont Agr. Exp. Sta. Rep. 13 : 299-
332, 1901. See also his paper on, Pectinase, the cytolytic enzyme pro-
duced by Bacillus carotovorus and certain other soft-rot organisms. New
York (Geneva) Agr. Exp. Sta. Tech. Bui. 11:2: 289-368, 1909.

2 Jones, L. R.: The control of cabbage yellows through disease re-
sistance, Wisconsin Agr. Exp. Sta. Research Bui. 38 : 1-70, 1915
(see especially list of papers by Jones, p. 69); also. Fourth progress
report on Fusarium resistant cabbage. Abstract in Phytopath.,
6 : 102, 1916.

106 HISTORY OF PHYTOPATH<>L<h,\

to make practical use of the fungicidal properties of
formaldehyd,1 and is widely known as the advocate of
the seed and soil infestation theory for the explanation
of the decreasing yields on western flax and wheat lands2;
F. C. Stewart, botanist of the New York (Geneva)
Experiment Station, noted for the great variety of his
studies on plant diseases3 and his ten-year experiments
in potato spraying,4 and A. D. Selby, botanist of the
Ohio Experiment Station. There are numerous others
who in their earlier years contributed much to the ad-
vancement of the science, but who later passed into ad-

1 Bolley, H. L.: New studies upon the smut of wheat, oats, and
barley, with a resume of treatment experiments for the last three years,
North Dakota Agr. Exp. Sta. Bui. 27 : 109-162, 1897. For excellent
bibliography of early papers on formalin as a disinfectant, see Arthur,
J. C, Formalin for prevention of potato scab, Indiana Agr. Exp. Sta.
Bui. 65 : 1-35, 1897.

2 Bolley, H. L.: Wheat, North Dakota Agr. Exp. Sta. Bui. 107 : 1-94,
1913. See also Conservation of the purity of soils in cereal cropping,
Science, n. s., 32 : 529-541, 1910; and, Plant diseases and crop rotation,
The Northwestern Miller, 89 : 565-566, 585, 623, 624, 641, 642, 1912.

The main facts and the economic significance of soil infestation by
phytopathogenes appears to have been first clearly set forth by Erwin
F. Smith as a result of his studies on the Fusarium diseases of water-
melons, cowpeas, cotton, tomatoes, sweet potatoes, and cabbage. The
matter is admirably set forth by him in a paper under the title: The
fungous infestation of agricultural soils in the United States, which
appeared in The Scientific American, Supplement, No. 1246, pp. 19981,
19982, November 18, 1899.

3 Stewart, F. C: Botanical investigations. In, Twenty-fifth
Anniversary Report 1882 to 1907, New York (Geneva) Agr. Exp. Sta.
Ann. Rep. 26 : 3 : 119-162, 1908. Published also as reprint, pp. 1-44,
1908. This is a summary of botanical work at the station during these
twenty-five years. For later papers by Stewart, see bulletins and reports
of N. Y. (Geneva) Experiment Station since 1908.

4 Stewart, F. C., et al: Potato spraying experiments, 1902-11, New
York (Geneva) Agr. Exp. Sta. Bui. 349 : 99-139, 1912.

THE MILLARDETIAX PERIOD 107

ministration or other lines of botanical or agricultural
work. Material for a fuller treatment of the lives and
contributions of American phytopathologists is not vet

L. R. Jones.

A noted American investigator and teacher of plant pathology. (From

a photograph, courtesy of Dr. W. A. Orton.j

assembled and put into form for presentation. May
they all live to see such a survey of their work available
as an inspiration to the rising generation of workers in
plant pathology.

THE PRESENT ERA

The years from 1906 to 1912 mark, in my opinion, the
beginning of a new era in the history of plani pathology.
During these six years several events of special signifi-
cance for the science occurred. These epoch-making
events took place chiefly in America, indicating most
definitely the transfer of the fate of phytopathologic
science from the Old to the New World. Science, like
empire, marches ever westward. Of these events, those
most significant would seem to be: (a) The establishment
of the first chairs of plant pathology in American Univer-
sities; (b) the discovery of the cause of crown gall and the
beginning of Smith's classic investigations into the simi-
larity of this disease to human cancer; (c) the founding of
the American Phytopathological Society and its journal,
Phytopathology; (d) the enactment of the United States
Quarantine Act of 1912; (e) introduction of sulfur as a
substitute for copper in fungicides; (/) the development,
by selection and breeding, of crops resistant to patho-
genes, and (g) the outbreak of the destructive epiphytotic
of chestnut blight which is fast wiping out the chestnut
in eastern United States. These events constitute a
combination as important in their bearing and as far
reaching in their effects upon the science as those in-
troducing the Millardetian period. Moreover, the decade
from 1900 to 1910 saw the passing away of many of those
figures whose personality and work strongly influenced
our science during their time — Millardet in 1902, Hartig
108

THE PRESENT EM 109

in 1901, Frank in 1900, Ward in 1906, Delacroix in 1907,
Rostrup in 1907. A few remain, veterans of the past,
riving inspirations for the future. Thus did the last
decade of the Millardetian period presage the inaugural
events of a new.

The Establishment of Chairs of Plant Pathology in
Universities and Colleges of Agriculture. — Until very
recent years plant pathology has been considered as
simply a phase of botany or as applied mycology. A
brief course in mycology masquerading under the name
of plant pathology has in most cases sufficed to dispose of
the subject. Even the so-called plant pathologists of the
present day are in large part only mycologists with little
of the true phytopathologic point of view. The first
distinct department of plant pathology to be established,
so far as I know, was the one at Cornell University in the
autumn of 1907. Shortly thereafter (1909) the one at the
University of Wisconsin, with Professor Jones at its head,
was announced. Since that time several other state
institutions have established teaching departments of
plant pathology either independently or as a division of
the botanical department. Minnesota, Illinois, and Iowa
are examples of the latter.

Discovery of the Cause and Nature of Crown Gall. —
This disease, so common to our cultivated fruit trees, had
long been an object of investigation by pathologists in
this country. The cause of the disease remained a mys-
tery in spite of the evidence presented by Tourney1 to
show that it was myxomycetous in nature. It remained
for Dr. Erwin F. Smith, as perhaps the greatest single

1 Toumey, J. W. : An inquiry into the cause and nature of crown gall,
Arizona Agr. Exp. Sta. Bui. 33 : 1-64, 1900.

110 HISTORY OP PHYTOPATHOLOGY

contribution of his eminent career, to discover, in col-
laboration with his fellow-workers Townsend and Brown,
the true cause of this interesting disease. Evidence of its
bacterial nature was first set forth in Science1 in 1907.
Following this there has appeared from the hand of
Smith a series of most brilliant researches2 in which he has
clearly shown the striking similarity in structure of this
plant tumor to that of the cancer in man and animals.

The Establishment of the American Phytopathological
Society. — The establishment of this society at the Balti-
more meeting of the American Association for the Ad-
vancement of Science in 19093 marks the beginning of
another important development in American phyto-
pathology, if not in that of the world. Within two years
the society's membership exceeded 200, and at present
totals approximately 350. At the beginning of its third
year, 1911. it undertook the publication of a journal,4
Phytopathology, designating it as the official organ of the

1 Smith, Envin F., and Townsend, C. O.: A plant tumor of bacterial
origin, Science, n. s., 25 : 671-673, 1907. (The pathogene named and
briefly characterized.)

2 For later papers on the same subject see: Crown gall of plants,
Phytopath., 1 : 7-11, 1911; Crown gall of plants, its cause and
remedy, U. S. Dept. Agr. Bu. PI. Ind. Bui. 213. 1911; Crown gall
and sarcoma, U. S. Dept. Agr. Bu. PI. Ind. Circ. 85, 1911; The
structure and development of crown gall, a plant cancer, U. S. Dept.
Agr. Bu. PI. Ind. Bui. 255, 1912; Mechanism of tumor growth in crown
gall, Jour. Agr. Research, 8: 165-186. pis. 4-65. 1917; Mechanism of
overgrowth in plants, Proc. Am. Phil. Society, 56 : 437-444, 1917;
Embryomas in plants (produced by bacterial inoculations). The
Johns Hopkins Hospital Bull., 28 : 276-294, Sept., 1917. For list of
other papers by this author see bibliography in last three papers.

3 The .American Phytopathological Society. (Report of first annual
meeting.) Science, n. s., 31 : 746-757, 1910.

4 For data on establishment of the journal, see Science, n. s., 31 : 746,
1910; 33 : 155. 156, 1911; and Phytopath., 1 : 38 and 67, 1911.

THE PRESENT ERA 111

society. This journal, under the editorship of L. R.
Jones, of the University of Wisconsin, and later Donald
Reddick, of Cornell University, has been from the begin-
ning a marked success. In it appears from year to year
the first reports on new discoveries by American pathol-
ogists as well as contributions from foreign members.
The journal has obtained a wide circulation abroad and
has created a most favorable impression upon our foreign
colleagues. This society and the journal it publishes has
done more to stimulate and unify the phytopathologic
work and workers of this country than any other one
thing.

The United States Quarantine Act of 1912. — Congress-
man Simmons of New York introduced into the Sixty-
second Congress at its second session a bill to regulate
the importation by the national government of nursery
stock. This finally became a law in the form of the
National Quarantine Act of 1912. l This was the first
national enactment aimed at the exclusion, from this
country, of insect pests and plant diseases. Other coun-
tries for years had various laws of this type, for the most
part ineffective. The enactment of this measure, to-
gether with the establishment of a Federal Horticultural
Board, marks a new period in the plant pathology not
only of this country but of other countries as well. The
exclusion of potatoes and certain nursery stock to protect

1 The text of this act may be found in Circular 41 : 7-11, office of the
secretary, U. S. Department of Agriculture, issued September 25, 1912,
under the title: Rules and regulations for carrying out the plant quaran-
tine act. Also in revised edition of Circular 41 of December 20, 1912;
in Circular 44 : 12-15, May 26, 1913, text as amended March 4, 1913;
and in unnumbered circulars issued by the Federal Horticultural Board,
one of July 1, 1914.

112 IlISTnkY OP PHYTOPATHOLOGY.

our growers from the introduction of dangerous patho-
genes and pests aroused great antagonism abroad at
first as well as some at home. It has, however, resulted
in a marked improvement of foreign inspection and in
extraordinary activity of our domestic inspection servii e.
The Introduction of Sulfur as a Substitute for Copper
in Fungicides.- — Lime-sulfur has long been known and
used as an insecticide and to a very limited extent as a
fungicide in cases where disinfection of dormant trees is
desirable, as in the case of the peach leaf curl.1 Cordley of
Oregon in 1906 discovered that much diluted solutions of
lime-sulfur might be used with safety and efficiency as a
summer spray for apple scab.2 Scott in 1907 devised and
tested out the so-called self-boiled lime-sulfur mixture/1
He showed that it could be used successfully in the control
of the scab and brown rot of peaches, without at the same
time causing injury to the tender foliage of the peach,
such as results from the use of copper sprays or of solu-
tions of calcium sulfids. These discoveries were soon

1 The earl}- history of the use of sulfur solutions for the control of
peach leaf curl is set forth in detail by X. B. Pierce in, Peach leaf curl,
its nature and treatment, U. S. Dept. Agr. Div. Veg. Path, and Phys.
Bui. 20 : 46-66, 1900. Long before this, however, dilute solutions of
lime-sulfur concentrate had been recommended as a spray for grapes
to control the powdery mildew. (Regel, E. Die Schmarotzergewachse
und die mit denselben in Yerbindungstehenden Pflanzenkrankheiten,
pp. Ill, 112, 1854.)

2 See Cordley, A. B.: Lime-sulfur spray as a preventive of apple
scab, Rural New Yorker. March 1. 1908:202; Oregon Agriculturist.
March 1, 1908 : 178, or Better Fruit, September, 1908 : 26; also. Whetzel,
H. H., Summer use of concentrated lime-sulfur, X. Y. State Fruit
Growers' Assoc. Ann. Rep., 9 :31-33, 1910.

3 Scott, W. M.: Self-boiled lime-sulfur mixture as a promising
fungicide, U. S. Dept. Agr. Bu. PI. Ind. Circ. 1 : 1-18. 1908; also, Circ.
27 : 1-17, 1909.

THE PRESENT ERA 113

heralded throughout the United States and Canada,
receiving a most cordial reception from growers and some
pathologists, as promising substitutes for bordeaux mix-
ture, so frequently injurious to fruit and foliage. Within
half a decade lime-sulfur almost completely replaced bor-
deaux mixture for apples and some other crops. It has
not proved a satisfactory substitute, however, in the case
of grapes and potatoes.1 Studies soon indicated that it is
the finely divided sulfur on the foliage which is the effec-
tive agent. Following this idea, dusting with finely ground
sulfur has been carefully investigated by Blodgett,2 Red-
dick,3 and Stewart4 of Cornell, who have conclusively
shown that dry sulfur may safely and profitably replace
the liquid sprays for the control of some of our most
common and destructive diseases. Our day is to see
sulfur the chief fungicide as against the copper of the
Millardetian period.

Development of Disease-resistant Crops. — The extra-
ordinary progress which is now being made in this direc-
tion is the logical outgrowth of the pioneer labors of an

1 For the results on grapes, see Reddick, D., et al: Spraying for black
rot of the grape in a dry season, New York (Cornell) Agr. Exp. Sta. Bui.
296 : 586, 587, 1911; and for those on potatoes, see Stewart, F. C, and
French, G. T. : Lime-sulfur vs. Bordeaux mixture as a spray for potatoes.

I. New York (Geneva) Agr. Exp. Sta. Bui. 347. 1911; Munn, M. T.,

II. Bui. 352, 1912; III. Bui. 397, 1915; IV. Bui. 421, 1916.

2 Blodgett, F. M.: Hop mildew, Xew York (Cornell) Agr. Exp. Sta.
Bui. 328, 1913; and, Further studies on the spread and control of hop
mildew, Xew York (Geneva) Agr. Exp. Sta. Bui. 395, 1915.

3 Reddick, D., and Crosby, C. R.: Dusting and spraying experiments
with apples. Xew York (Cornell) Agr. Exp. Sta. Bui. 369, 1916.

4 Stewart, Y. B.: Dusting and spraying nursery stock. Xew York
(Cornell) Agr. Exp. Sta. Bui. 385, 1917.

114 HISTORY OF PIIYTOI'ATHOI.OOY

eminent AmericaD pathologist, W. A. Orton.1 During the
decade from 1899 to 1909 he obtained by selection and
breeding strains of cotton, melons, and cowpeas resistant
to Fusarium wilt fungi. His results at once stimulated
wide-spread search for disease-resistant strains in many
other of our cultivated crops.

The Epiphytotic of Chestnut Blight. — This, the most
devastating disease of modern times, was first observed in
New York City abut 1904. At this time it was found to
be thoroughly established on Long Island and the im-
mediate vicinity of New York City. It then spread
rapidly in all directions from this center, and by 1914 had
extended throughout the southern New England States,
southern Vermont, New Hampshire, the Hudson Valley
and the eastern half of Pennsylvania, as well as south
through New Jersey, Delaware, eastern West Virginia,
Maryland, and northern Virginia. Its ravages aroused
general alarm among laymen as well as pathologists.
Large sums of money were appropriated both by the
Federal Government and by several of the states for
the purposes of investigation and control. While all
efforts to stay its progress have failed, it has served to
impress upon the people of the United States the danger
from such destructive plant diseases, and has resulted in a

1 The following papers by Orton should be consulted: The wilt disease
of cotton and its control, U. S. Dept. Agr. Div. Veg. Phys. and Path.
Bui. 27 : 1-15, 1900; Some diseases of the cowpea, U. S. Dept. Agr.
Bu. PI. Ind. Bui. 17 : 1-36, 1902; On the breeding of disease- resistant
varieties, Hort. Soc. New York, Mem., 1 : 41-52, 1902; Plant breeding as a
factor in controlling plant diseases, Amer. Breeders' Assoc, 1 : 69-72,
1905; On the theory and practice of breeding disease-resistant plants.
Amer. Breeders' Assoc, 3 : 144-156, 1908; The development of disease-
resistant varieties of plants, IV Conference Internat. de genetique, Paris,
1911, Comp. Rend, et Rapports, pp. 247-261. 1913.

THE PRESENT ERA 115

keen appreciation of the necessity for more intelligent
legislation and efforts in meeting similar danger to other
crops. It has been, like the potato blight epidemics of
the early forties, a potent factor in giving to the lay mind
a proper appreciation of the importance of phytopathol-
ogy in the economics of crop production. The history
of this epiphytotic has been accurately outlined bv
Anderson and Rankin.1

I have intentionally refrained from an attempt to
analyze in more detail the trend of phytopathologic
thought and development in the present era. We are
too near to it, being in the midst of it, to justly weigh the
relative importance of passing events and current contri-
butions. Those who are making the history of our sci-
ence are our friends and our colleagues. Their scientific
faults and virtues are likely to loom up quite out of pro-
portion to their real significance in the evolution of
plant pathology. My verdict on the makers of the
Alillardetian period is doubtless more or less invalidated
for the same reason. Some of them still stand forth in
the flesh to challenge or accuse me; those whom I have
named and those whom I have refrained from naming.
To each his consolation; to the former, that he stands
among the founders of the science in this country; to the
latter, that somewhere in the annals of plant pathology
future historians must give him a place.

1 Anderson, P. J., and Rankin. W. H.: Endothia canker of Chest-
nut, New York (Cornell) Agr. Exp. Sta. Bui. 347 : 538-545, 1914.

BIBLIOGRAPHY

HISTORIC

Arthur, J. C: History and scope of plant pathology, Cong. Arts and

Science, St. Louis, 5 : 140-164, 1906.
de Bary, Anton: Untersuchungen iiber die Brandpilze und die 'lurch sie

verursachten Krankheiten der Pflanzen, mit Riicksicht auf das

Getreide und andere Nutzpflanzen, pp. I \'1 1 1 + 1-144, Berlin, 1853.
Bullcr, A. H. R.: The fundus lore of the Creeks and Romans. British

Myc. Soc. Trans., 5 : 30-33, 1915.
Dugger, B. M.: Fungous diseases of plants, pp. 2-4, 1909.
Eriksson, J., and Henning, E.: Die Getreideroste, ihre Geschichte und

Natur, sowie Massregeln gegen dieselben, pp. 7-24, 1896.
Farlow, W. G. : The change from the old to the new botany in the United

States, Science, n. s., 37 : 79-86, 1913.
Galloway, B. T.: Progress in the treatment of plant diseases in the

United States, U. S. Dept. Agr. Year Book for 1899 : 191-200, 1900.

Twenty years' progress in plant pathology, Proc. Soc. Prom.

Agr. Sci. Ann. Meeting 21 : 90-102, 1900.

Greene, E. L.: Landmarks of botanical history. A study of certain
epochs in the development of the science of botany. Part 1. —
Prior to 1562 A. D. Smithsonian Miscell. Coll., 54 : 1 : 1-329, 1909.

Green, J. Reynolds: A history of botany, 1860-1900, being a continua-
tion of Sachs' History of Botany, 1530-1860. pp. 1-543, Oxford, 1909.

A history of botany in the United Kingdom, from the earlier

times to the end of the 19th Century, pp. I-XII + 1-648, London
and Toronto, 1914. (Published after the author's death.)

Hartig, R. : Text-book of the diseases of trees. (Transl. by Wm. Sommcr-

ville), pi>. X-XVTJ and 1-4, 1894.
Hollrung, M.: Die Mittel zur Bekampfung der Pflanzenkrankheiten. pp.

1-3, 1914.
Jensen, C. N.: Resume of publications on plant pathology, Thesis,

Cornell University, pp. 1-69, 1909.
Jones, L. R.: Problems and progress in plant pathology, Amer. Jour.

Bot., 1 : 97-111, 1914.

1 Only those pages containing data of historic interest are given for

these references.
116

HISTORIC 117

Klebahn, H.: Die wirtswechselnden Rostpilze. Versuch einer Gesamt-
darstellung ihrer biologischen Verhaltnisse, pp. 5-12, 1904.

Lind, J.: Danish fungi as represented in the herbarium of E. Rostrup,
pp. 1-9, 19-25, 1913.

Berberisbusken og Berberisloven. Tids. Planteavl., 22 : 729-

780, 1915.

Lodeman, E. G.: The spraying of plants, pp. 1-114, 181-207, 1896. (See
same pages in the 1906 edition.)

McAlpine, D.: The smuts of Australia, pp. 4-7, 1910.

Meyer, E. H. F.: Geschichte der Botanik, 1 : 1-X + 1-430, 1854;
2 :I-X + 1-430, 1855; 3 : 1-XVI + 1-455, 1856; 4 : 1-VIII +
1-451, 1857

Potter, M. C.: Bacteria in their relation to plant pathology, British Myc.
Soc. Trans., 3 : 150-168, 1910. (Gives extensive bibliography.)

Re, Count Philippo: Essay theoretical and practical on the diseases of
plants. (Translated from the Italian.) Gard. Chron., 1849 : 211,
228-229, 1849. The original was published in 1807. (See foot-
notes, page 32.) This translation is from the second edition, 1817.

Ritzema-Bos, J.: Instituut voor phytopathologie, verbonden aan de
Rijks Hoogere Land- ,Tuin- ,en Boschbouwschool te Wageningen.
Tijds. over Plantenz., 12 : 17-27, 1906. He here describes the
establishment of the first royal phytopathological institute in Hol-
land.

Het phytopathologisch laboratorium Wille Commelin Scholten

van 1895 tot 1906. Tijds. over Plantenz., 12 : 28-58, 1906. He
reviews the history of the foundation and development of this
privately endowed phytopathological institute in Amsterdam.

Rostrup, E.: Plantepathologi, pp. 1-9, 1902.

Sachs, Julius: Geschichte der Botanik vom 16 Jahrhundert bis 1860,

pp. I-XII + 1-612, 1875; also the English translation by Garnsey

and Balfour, pp. I-XV + 1-568, 1900.
Savastano, L.: La patologia vegetale die Greci, Latini ed Arabi,

Memoria, pp. 1-75, Portici, 1890-91.
Selby, A. D.: The future of vegetable pathology, Science, n. s., 15 : 736-

740, 1902.
Smith, Annie L.: Microfungi: a historical sketch, British Myc. Soc.

Trans., 3 : 18-25, 1908.
Smith, Envin F.: Plant pathology: a retrospect and prospect, Science,

n. s., 15 : 601-612, 1902.

Bacteria in relation to plant diseases, 2 : 7-22, 1911. He gives

here an historical review of the rise and development of bacterio-
phytopathology.

118 HISTORY OF PHYTOPATHOLOGY

Sorauer, P.: Handbuch der Pflanzenkrankheiten, 1 :37 68, L909; also
the translation by Frances Dorrance tinder the title: Manual of
plant diseases, 1 : 41 71, 1914.

Stevens, F, I..: The science of plant pathology, Jour, Elisha Mitchell Sci.
Soc, 20 : 61-75, 1904. (Reprinted from Popular Science Monthly,
September, 1905.)

Stevens, F. L., and Hall, J. ('•.: Diseases of economic plants, pp. 3 12,
1910.

Ward, II. Marshall: Disease in plants, pp. 85-90, 1901.

Recent researches on the parasitism of fungi, Ann. Hot., 19 : 1-54.

1905.

Westerdijk, Johanna: De oieuwe wegen van het phytopathologisch
onderzoek. Rede uitgcsproken bij het aanvaarden van hut ambt
van buitengewoon hoogleeraar aan de Universiteit te Utrecht, op
Zaterdag, 10 February, pp. 1-38, Amsterdam, 1917.

BIBLIOGRAPHIC

Boehmer, George Rudolph: Bibliotheca scriptorum historiae naturalis
oeconomiae aliarum ac scientiarum ad illam pertinentium realis
systematica. Pars III, Phytologi 1 : 1-808, 1787. On pages 522-
546 will be found an extensive list of references on diseases of plants.
See pages 459-470 for references on frost and weather injury; and
pages 514-522 for references on teratology.

Jackson, B. D.: Guide to the literature of botany, pp. 102-105, 1881.

Lindau, G., and Sydow, P.: Thesaurus litteraturae mycologicae et
lichenologicae, 1^4, 1908-15.

Pritzel, G. A.: Valetudo et morbi plantarum. In, Thesaurus literaturae
botanicae, pp. 526, 527, 1872; also 2d ed., pp. 526, 527, 1877.

Rehder, A.: The Bradley Bibliography. A guide to the literature of the
woody plants of the world, published before the beginning of the
twentieth century, 1:1: 206-216, 1911; 3 : 178-186, 193-198, 1915;
4 : 65, 66, 188-196, 210-212, 1914.

BIOGRAPHIC

General

Michaud, J. F. and L. G.: Biographie universelle, ancienne et moderne,
1-52, 1811-62.

Saccardo, P. A.: La botanica in Italia. [Reprinted from] Mem. Reale
Inst. Veneto Scienze, Letterc ed Arti, 25 : 1-236, 1895; part 2:
I-XV + 1-172, 1901. The latter is an addendum. These give
brief biographical notes on Italian botanists both living and dead.

BIOGRAPHIC 119

Wittrock, V. B.: Catalogus illustratus iconotheca botanicae horti Ber-
giani Stockholmiensis natulis biographicis adjectis. Acta Horti
Bergiani, 3:2: 1-198, tab. 1-37, 1903; 3 :3 : 1-XCIII + 1-245,
tab. 1-150, 1905. (Half-tones and biographic sketches of ancient
and modern botanists.)

Individual
Adanson, Michel

Cuvier, Baron [G.] : Biographical memoir of Michel Adanson. Read
to the institute of France, Edinburgh New Phil. Jour. n. s., 3 : 1-21,
1827. This is a translation from the French, Eloge historique de
Michel Adanson, Mem. classe Sci. Mat. e. Phys. Inst. National
France [Acad. Sci.], 1806 : 2 : 159-188, 1907.

Anonymous: Xekrolog. Michel Adanson, Mitglied der ehemaligen
Akademie der Wissenschaften und des Xational-Instituts, u. s. \\\,
geboren 1727, gestorben 1806. Intelligenzblatt Allgem. Litteratur
Zeit., 1806 : 1257-1260, 1806.

de Bary, Heinrich Anton
Balfour, B.: Professor Heinrich Anton de Bary. Trans. Bot. Soc.

Edinburgh, 17 : 350-354, 1889. (Chiefly a list of his publications.)
Farlow, W. G.: Professor Anton de Bary, Garden and Forest, 1 : 15, 16,

1888.
Murray, G.: Heinrich Anton de Bary, Jour. Bot.. 26 : 65-67, 1888.

See also Ann. Bot., 2 : 393-397, 1889. (Short biographical sketch

with list of publications.)
Prantl, K.: Anton de Bary, Hedwigia, 27 : 77-86, 1888. (Portrait and

bibliography.)
Rees, M.: Anton de Bary, Ber. Deut. Bot. Ges., 6 : YIII-XXYI.

1888. (Portrait and list of publications.)
Smith, Erwin F.: Anton de Bary, Phytopath., 1 : 1, 2, 1911. (Portrait.)
Wilhelm, K.: Xekrologe. Anton de Bary, Ein Xachruf, Bot. Centralbl..

34 .93, 94. 156-158, 191, 192, 221-224, 252-256, 1888. (List of

publications.)

Berkeley, Miles Joseph

Baker, J. G.: The Rev. M. J. Berkeley, Xature, 40 : 371, 372 ,1889.

Cooke, M. C: The Rev. M. J. Berkeley, Grevillea, 18 : 17-19, 1889;
for portrait see Grevillea, 1 : frontispiece, 1872.

Druce, G. C, and Taylor, J.: Xorthamptonshire obituaries: The Rev.
Miles Joseph Berkeley, M. A., F. R. S., F. L. S., Xorthamptonshire
Notes and Queries, 4 : 25-37, 221-224, 1892. (Portrait and com-
plete list of publications.)

120 history OF PHYTOPATHOLOGY

Farlow, \V. (.',.-. Miles Josepb Berkeley, Garden and Forest, 2 : 410. 41 1.

1889.
I Ireen, J. Reynolds: Berkeley, hi, A history of botany in the United

Kingdom from the earliest limes to tin- end of the 19th Century, i >i >-

445-447. 1914.
Hooker, J. D.: The Rev. Miles Josepb Berkeley, Proc. Roy.

London, 47 : IX-XII, 1890.
Lloyd. C. (I.: Rev. M. J. Berkeley, hi. Synopsis of the stipitate

Stereums, p. 14. 1913. (Portrait with note.)
[Morrens, E.]: Prologue en l'honncurde Rev. M. J. Berkeley, membre

de la Societe Linnee de Londres, La Belgique Hort. Ann. Hort.

Beige, et Etrangere, 22 : 5-9, 1872. (Portrait.)
Ma^see, Geo.: Miles Joseph Berkeley, 1803-89. hi, Makers of British

Botany by Oliver, pp. 225-232, 1913. (Portrait.)
[.Murray. Geo., and Editors]: The Rev. M. J. Berkeley, M. A., F. R.

S., Jour. Bot, 27 : 305-308, 1889; also, Miles Joseph Berkeley,

Ann. Bot., 3 : 451-456, 1890. (Consist chiefly in a long list of his

published papers.)
Thiselton-Dyer, W. T.: Miles Joseph Berkeley. Born 1803. Died

1889. Ann. Bot., 11 : IX-XI, 1897. (Portrait.)
Anonymous: Obituary. Miles Joseph Berkeley, Gard. (limn..

3:6: 141, 142, 1889. (Portrait, p. 135.)

Berlese, Augusto Napoleone

Berlese, A.: Augusto Xapoleone Berlese. 21 Ottobre, 1864-26 Gennaio,

1903, Riv. Pat. Veg., 10 : 347-394, 1904. (Portrait and copies of

obituary notices published in other journals, with a complete list of

titles of his published papers.)
Cavara, Fr.: A. X. Berlese (Xekrologe). Ann. Myc. 1 : 178-180,

19(13.
Saccardo, P. A.: Augusto Xapoleone Berlese. Cenno necrologico,

Malphigia, 17 : 117-126, 1903.

Burrill, Thomas Jonathan

Davenport, E.: Dr. Thomas Jonathan Burrill. Memorial address,

Trans. 111. Hort. Soc, n. s., 50 : 67-97, 1917. (Portrait and list of

publications.)
Forbes, S. A.: Thomas Jonathan Burrill. Alumni Quarterly and

Fortnightly Xotes, University of Illinois, July 15, 1916.
Smith, Erwin F.: In memoriam of Thomas J. Burrill, Jour. Bact.,

1 : 269-271, 1916. (Portrait.)
Trelease, Wm.: Thomas Jonathan Burrill, April 25, 1839-April 14,

1916, Bot. Gaz., 42 : 153-155, 1916.

BIOGRAPHIC 121

Belacrois, Georges
Prillieux, E. E.: Notice sur la vie et les travaux de Georges Delacroix,

Bui. Soc. Myc. France, 24 : 48-67, 1908. (Portrait.
Fabricius, Johann Christian

Lind, J.: Danish fungi as represented in the herbarium of E. Rostrup,

pp. 19, 20, 1913. (Portrait.)
Latreille, M.: Notice biographique. Sur Jean Chretien Fabricius,

conseiller d'etat du roi de Dannemarck, professeur d'histoire natu-

relle et d"economie rural a Kiell, et membre d'un grand nombre

d'academies. Ann. Mus. Hist. Nat., 11 : 393-404. 1808.
Forsyth, William
Anonymous: Early writers on English gardening. William Forsyth,

Jour. Hort. Cottage Gardner and Country Gentleman ('old ser. 56),

n. s.. 31 : 147. 1876. (Portrait.)
Anonymous: Centenary of the horticultural society. The Founders:

William Forsyth, Gard. Chron., 3 : 35 : 147, 148, 1904.
Frank, Albert Bernhard

Kriiger, F.: Albert Bernhard Frank. Ber. Deut. Bot. Ges.. 19 : (10)-

(36). 1902. (Complete bibliography of his works.)
Lopriore, G.: A. B. Frank, Malphigia. 14 : 387^10, 1900. (Portrait

and list of his publications.)
Xobbe, F.: Albert Bernhard Frank, Landw. Vers. Stat., 55 : 159, 160,

1901.
Anonymous: Biographische Mittheilungen. Albert Bernhard Frank,

Leopoldina, 36 : 170, 171, 1900.
Hales, Stephen
Darwin. F.: Stephen Hales. 1677-1761. /», Makers of British Botany

by Oliver, pp. 65-83, 1913. (Portrait.)
Green. J. Reynolds: Stephen Hales. In, The history of botany in

the United Kingdom from the earliest times to the end of the 19th

Century, pp. 198-206. 1914.
Anonymous: British botanists: Stephen Hales, Gard. Chron., 3 : 49 :

88, 89, 1911. (Portrait.)
Hallier, Ernst
Anonymous: Hallier, Ernst: Brockhaus' Konver.-Lexik., 8 : 684,

4th ed.. 1894.
Anonymous: Biographische Mittheilungen. Ernst Hallier, Leopold-
ina, 41 : 38, 1905.
For a notice of his death, see Bot. Centralbl.. 98 : 32. 1905.
Hartig, Heinrich Julius Adolph Robert

Cieslar, R.: Robert Hartig, Centralbl. Gesamte Forstw., 28:37-46.

1902. (Portrait.)

122 HISTORY OF PHYTOPATHOLOGY

Meinecke, I'.. P.: Roberl Hartig. Ein Nachruf. Allegm. Forst.-u.-
Jagd. Zcii., 78:129 131, 1902; also, Robert Hartig (1839-1901).

I'liytopath., 5 : 1-3, 1915. (Portrait.)
Tubeuf, Carl von: R. Hartig, Nekrolog. Ber. Deut. Bot. Ges., 20 : (8)-

(28), 1903.
Anonymous: Dr. Robert Hartig, Proc. Linn. Soc., London., 114 : 35-
37,1902.

Anonymous: Biographische Mittheilungen. Robert Hartig, M. N. A..

Leopoldina, 37 : 94-95 (also 90), 1901.
Ibn-al-Awam (Yah'ya Ibn Muh'ammad or Abu Zakariya)

Meyer, E. H. F.: Ibu-al-Awam. In, Geschichte der Bontanik.

3 : 260-266, 1856.
Jensen, Jens Ludvig

Ravn, F. K</>lpin: Jens Ludvig Jensen (1836-1904), Phytopath.,

7 : 1-4, 1917. (Portrait.)
Lind, J: Jensen, Jens Ludwig. In, Danish Fungi as represented in the

herbarium of E. Rostrup, p. 31, 1913. (Portrait.)
Anonymous: Personalia Direkter Jens Ludwig Jensen, fodt, 1836.

Aarsb. Kong. Dansk. Landh.-Skab., 1904-05 : 288, 1905. (Portrait.)
Kiihn, Julius Gotthelf

Holdefleiss, P.: Julius Kiihn, Nachruf. Naturw. Rundschau, 25 : 297-

299, 1910.
Wohltmann, F., and Holdefleiss, P.: Julius Kiihn, sein Leben und

Wirken. Festschrift zum 80 Geburtstag am 23. Oktober, 1905. pp.

1-56, Berlin, 1905. (Portrait.)
Anonymous: Die Julius Kiihn-Ehrung am 15. Juni ds. Js., Deut.

Landw. Presse, 28 : 444, 445, 1901. (With photographs of the

gathering.)
Anonymous: Zum 70. Geburtstag Julius Kiihns. Aus dem Lebensgang

Julius Kiihns. Deut. Landw. Presse, 22 : 767, 1895. (With ex-
cellent full-page portrait.)
McAlpine, Daniel
Anonymous: A prominent fruit expert: Professor D. McAlpine. /;;,

The Fruit World of Australia, August 1, 1915, p. 255.
Meyen, Franz Julius Ferdinand

Ratzeburg, J. T. C: Meyen's Lebenslauf, Verb.. Kais. Leopol.-Carol.

Akad. Naturforscher, Erstes Suppl., 19 : XIII-XXXII, 1843.
Millardet, Pierre Marie Alexis
Bornet, E.: Necrologie Millardet (Pierre-Marie- Alexis), Bui. Soc. Bot.

France, 49 : 318, 1902.
Galloway, B. T.: Pierre-Marie-Alexis Millardet (1838-1902), Phyto-
path., 4 : 1-4, 1914. (Portrait.)

BIOGRAPHIC 123

Gayon, U., and Sauvageau, C: Notice sur la vie et les travaux de A.

Millardet (1838-1902), Mem. Soc. Sci. Phys. et Nat. Bordeaux,

6:3 :IX-XLVII, 1903. (Portrait and list of publications.)
Magnus, P.: Millardet, Ber. Ueut. Bot. Ges., 22 : (10)-(14), 1905.
0rsted, Anders Sandbe

Brown, R.: Life and labors of Professor 0rsted, Trans. Bot. Soc,

Edinburgh, 11 : 426-435, 1873.
Lind, J.: Anders Sandoe <#rsted. In, Danish fungi as represented in

the herbarium of E. Rostrup, pp. 17, 18, 1913. (Portrait.)
Pliny the Second
Greene, E. L.: Caius Plinius Secundum (A. D. 23-79). In, Landmarks

of Botanical History, Smithsonian Miscell. Coll., 54 : 1 : 155-159,

1909.
Prillieux, Edouard Ernest

Berthault, P.: Mort de M. Edouard Prillieux, Jour. Agr. Prat..

79 : 583, 584, 1915; also, *Edouard Prillieux, Rev. Gen. Bot., 28 :

193-203, 1916.
Bois, D., and Grignan, G. T.: Necrologie — M. Ed. Prillieux. Rev.

Hort.,87 : 580, 1915.
Pinoy, E.: Ed. Prillieux, Bui. Soc. Myc, France, 32 : 7-16, 1916.

(Portrait and bibliography of his works.)
Notices of his death are to be found in: Revue Gen. Bot., 27 : 352,

1915; Gard. Chron., 3 : 58 : 282, 1915; and Jour. Soc. Nat. Hort.,

France, 16 : 152, 1915.

Re, Filippo

Saccardo, P. A.: In, La Botanica in Italia (Mem. Reale Inst. Veneto
Sci., Lett, e Arti, 25 : 135, 1895), gives the following facts: Born
March 20, 1763; died March 25, 1817. Professor of agriculture in
the University of Bologna; afterward Professor of agriculture and
botany at Modena. Then follows references to biographies from
Italian sources. (See also part II of the above, p. 89, 1901.)
Rostrup, Fredrick George Emil

Lind, J.: [Biographical data]. In, Danish fungi as represented in the
herbarium of E. Rostrup, pp. 1-9, 1913.

Ravn, F. K>lpin: E. Rostrup (Nekrolog.), Ber. Deut. Bot. Ges.,
26a : (47)-(55), 1909.

Rosen vinge, L. Kolderup: Emil Rostrup. En Levnedsskildring, Bot.
Tidssk., 28 : 185-198, 1908. (Portrait.)
Sorauer, Paul Carl Moritz

[Notice of his death.] Hedwigia, 57 : (150), Beibl. fur December, 1915,
1916; a fuller note is to be found in Nature, 96 : 600, 1916.

124 HISTORY OF PIIYTOPATIIOLOOY

Theophrastus of Eresus
Greene, E. I..: Theophrastus of Eresus, B. C. 370 286 (or 262). In,

Landmarks of Botanical History, Smithsonian Miscell. Coll., 54 : 1 :

S2 142, L909.
Hort, Sir Arthur: Theophrastus' life and work-. In, Theophrastus,

Enquiry into Plants, 1 :XVTJ XXIII. 1016.

Tournefort, Joseph Pitton de

Lauthier, II. M.: The life of M. Tournefort; in a letter to M. Begon,
Intendant of the Marine at Rochefort, etc. hi. Tournefort's, A
voyage into the Levant, 1 :V XXXVI, London. 1741. Following
this in tin.' same volume is, The elogium of M. Tournefort, By M.
Fontenelle, perpetual secretary of the Royal Academy and one of
the Forty of the French Academy, pp. XXXVUI-XLIX.

Lcfebure, E. F. H.: Eloge de Tournefort, Mem. Soc. Linn., Paris,
1 : 639-648, 1822.

Anonymous: Eloge de M. Tournefort. Hist. Acad. Roy. Sci. annee
1708 : 143-154, 1730.

Unger, Franz Joseph Andreas Nicholas
Leitgeb, II.: Zur Errinnerung an Franz Unger, Bot. Zeit., 28 : 241-257.

Yerzeichnessdergedruchten Schriften F. Unger's. pp. 257-264. 1870;

also, Franz Unger, Mitth. Xaturw. Vereins f. Steiermark, 2 : 270-

286, 1870. (Portrait in front of volume.)
Xeilreich, A.: Gallerie osterreicher Botaniker. Franz Unger, Oester.

Bot. Zeitsch., 14 : 1-9, 1864. (Portrait.)
* Reyer, Alex.: Leben und Wirken des Naturhistorikers, Dr. Franz

Unger, Professor der Pflanzen-Anatomie und Physiologic, p. 4

unnumbered + 1-100, Gratz, 1871. An abstract of this is to be

found in Flora, 54 : 361-366, 1871.
Anonymous: Dr. Franz Unger. Anthropol. Rev. (Jour. Anthropol.,

October, 1870), 8 : 227-232, 1870. (Portrait.)
Anonymous: Obituary of Dr. Franz Unger, Jour. Hot., 8 : 192-203,

1870. (Portrait and list of publications.)
Ward, Harry Marshall
Balfour, I. B.: Harry Marshall Ward, Trans, and Proc. Bot. Soc,

Edinburgh, 23 : 218-232, 1908. (Chronology and bibliography.)
Boodle, L. A.: H. Marshall Ward, Bui. Misc. Information Lew.

1906 : 281, 282, 1906.
Lower, F. O.: Harry Marshall Ward. F. R. S., Jour. Bot., 44 : 422-425,

1906.
Freeman, E. M.: Harry Marshall Ward (1854-1906), Phytopath.,

3:1,2, 1913. (Portrait.)

BIOGRAPHIC 125

Jackson, B. D.: Harry Marshall Ward, Proc. Linn. Soc, London,
119 : 54-57, 1907.

Johnson, T.: H.Marshall Ward, Ber. Deut. Bot. Ges., 26a : (10)-(12),
1909.

Thiselton-Dyer, W. T.: Harry Marshall Ward, 1854-1906, Proc. Roy.
Soc, London, B : 83 : I-XIY, 1911; see also New Phytol., 6 : 1-9,
1907; and Makers of British Botany by Oliver, pp. 262-279, 1913.
(Portrait.)

Vines, S. H.: Professor H. Marshall Ward, Nature, 74 : 493-495, 1906;
see also, Ann. Bot., 21 : IX-XIII, 1907; and, Bot. Centralbl., 102 :
367, 368, 1906.

Anonymous: Two leaders in science, Gard. Chron., 3 : 40 : 164, 1906.
Weigmann, Arend Joachim Friedrich

No published biography of Wiegmann has been found. The following
facts have been gathered from several sources, but chiefly from a
seminary paper presented by Charles Chupp before the department
of plant pathology of Cornell University in 1913. A copy of this
paper is to be found in the library of Cornell University. Wiegmann
was born 1771; died 1853 in Braunschweig. He was examined for
assistant chemist by the Imperial College in Braunschweig in 1795,
and appointed associate pharmacist to the chief apothecary there.
From 1821 on he lived as a private druggist in Braunschweig, but
having taken his medical degree in 1827, he was appointed to a pro-
fessorship there. He began his studies in plant pathology in 1798,
his first contribution in this field being apparently his, Yersuch einer
Krankheitslehre der Gewachse, which appeared in the first three
volumes of Sprengel's, Land- und Forstwissenschaftliche Zeitschrift,
which formed the basis of his text-book issued in 1839 (see footnote
1, p. 37). He also interested himself in, and wrote papers on, plant
hybridization; the nature and origin of peat; and the inorganic
constituents of plants. The following references give some few
facts regarding him: Ascheron, P., and Graebner, P., Synopsis der
Mittel-Europaischen Flora, 6:2: 1086, footnote, 1910; Flora,
36 : 288, 1853; Bot. Zeit. 11 : 279, 280, 1853. A fine lithograph
portrait is to be found in the Van Kaathoven collection of medical
men in the library of the Surgeon General's office, Washington, D. C.
Woronin, Michael Stepanovitch

Famintzin, A. S.: M. S. Woronin (Nekrolog), Trav. Imp. Soc. Nat.,
St. Petersburg, 34 : 210-222, 1903. (Portrait.) In Russian.

Nawaschin, S.: Michael Woronin, Ber. Deut. Bot. Ges., 21 : (35)-(47),
1903.

Smith, Erwin F.: Woronin, Phytopath., 2 : 1-4, 1912. (Portrait.)

126 BISTORT OP PHYTOPATHOLOGY

Zallinger, Johann Baptista

Zallinger (Jean-Baptiste de Thurn). In, Biogr. Univers.,^52 :

55, 56, 1828.
Poggendorff, S. C: Zallinger zum Thurn. In, Biogr. Liter. Hand-

worterbuch,2 : 1390, 1863.

INDEX

Adanson, 28

America, rise and development of
phytopathology in, 103

American Phytopathological Soci-
ety, establishment of, 110

Ancient era, 14

Anderson and Rankin, 115

Apple, bitter pit of, McAlpine on,
92

Arthur, 12, 67, 104

Atkinson, 104

Bacteria and plant diseases, causal
relation, discovery and establish-
ment of, 66

Berkeley, 28, 55

Berlese, 97

Bibliography, 116-126
bibliographic, 118
biographic, 118
historic, 116

Bitter pit of apple, McAlpine on, 92

Blight, chestnut, epiphytotic of, 114
fire, Burrill on, 66

discovery of cause, 61
potato, De Bary on, 45

Blighting, Hesse on, 24
von Ehrenfels on, 29

Blodgett, 113

BoUey, 105

Bordeaux mixture, discovery of, by
Mfflardet, 58, 63

Bos, 90

Botrytis sp. of lily, Ward on, 102

Brefeld, 80
Bulliard, 41
Burdach, 32
Burrill, 61, 66, 104

Canker, Hales on, 30
Riedel on, 30
Schreger on, 31
von Ehrenfels on, 31

Carleton, 60

Cavara, 97

Chestnut blight, epiphytotic of, 1 14

Cleidemus, 15

Clement-Mullet, 20

Coler, 23

Columella, 18

Comes, 96

Copper, substitution of sulfur for,
as fungicide, 112

Cord ley, 112

Crops, disease-resistant, develop-
ment of, 113

Crown gall, discovery of cause and
nature, 109
Smith on, 109

Dark era, 20
Darwin, 43
De Bary, 45
De Candolle, 34, 41
De Tournefort, 26
Delacroix, 94

Disease-resistant crops, develop-
ment of, 113

127

128

i\Di.\

Dorrance, 12 Hort, IS

Dorsett, 60 Hyacinths, yellow disease of, Bur-

Dry n>t of sugar beet, Frank on, 76 rill on, 61

Entophytes, (Tnger on, 35

Entyloma Ranunculi, Ward on, 102
Epiphytotic of chestnut blight, 114
Era, Ancient, 14

Dark, 20

.Middle. 20

Modern, 41

Premodern, 11

Present, 108
Eriksson, 85
Evils, secret, 23
Eysfarth, 26

Fabricius. 27
Fairchild, 60

Fire blight, Burrill on, 66
discovery of cause, 61
Forsyth, 30
Frank. 57, 75
Frankland, 42
Fungi, parasitic. Tulasne on, 41

Gall, crown, discover}- of cause
and nature, 109
Smith on, 109
Galloway, 60, 104
Gnomonia erythrostoma. Frank on,

76
Greene, 15, 17

Hales, 30

Hallier, 54

Halstead, 105

Hartig, 57, 72

Hebraic period, 14

Hemeleia vastatrix, Ward on, 1C0

Hesse, 23

Hollyhock rust. Eriksson on, 88

[bn-al-Awam, 2(i
Istvanffi, 62

Jensen, 12, 85
Jones; 43, 104

KlRC'HNEK. 77

Klebahn, 76
Kuchenmeister, 42
Kiihn. 26, 47
Kuhnian period, 44
summary. 57

Laurembkrg, 23

Leveille, 41

Lily, Botrytis sp. of, Ward on. 102

Lind, 28

Link, 41

Linmeus, 25

Lutman, 104

McAlpixe, 91

Meyen, 37

Middle Era, 20

Millardet. 58, 63

Millardetian period, 58

Mixture, bordeaux, discovery of,

by Millardet, 58, 63
Modern Era, 41

Xielsox, 85

''/'rsted. 54
Orton, 114
Owen. 42

Parasitic fungi, Tulasne on. 41
Pasteur, 42. 45

INDEX

129

Pathogenetist school, 71

origin of, 44
Pathology, plant. See Phytopath-
ology.
Period, Hebraic, 14

Kiihnian, 44
summary, 57

Millardetian, 58

Plinian, 1 7

Renaissance, 22

Roman, 17

taxonomic, 25

Theophrastian, 14

I ngerian, 33

Zallingerian, 25

characteristic features, 32
Phoma beta?, Frank on, 76
Phylloxera, introduction into

France, 65
Phytopathological Society. Amer-
ican, establishment of, 110
Phytopathology, 1 1

ancient era, 14

classification in, Fabricius', 27
Tournefort's, 26
Zallinger's, 28

Dark era, 20

establishment of chairs in uni-
versities, 109

Hebraic period, 14

Kiihn's work on, synopsis of, 52

Kiihnian period, 44

Millardetian period, 58

Modern era, 41

Plinian period, 17

Premodern era, 22

Present era, 108

Renaissance period, 22

rise and development of, in Amer-
ica, 59, 103

Theophrastian period, 14

Ungerian period, 33
9

Phytopathology, United States
Government sanction of, 62
Zallingerian period, 25
Phytophthora infestans, De Ban-
on, 45
Ward on, 102
Pierce, 60
Planchon, 65

Plant diseases, bacterial etiology,
discovery of, 61
organisms of, Unger on, 35
Industry, United States Bureau

of, founding of, 60
pathology. See Phytopathology.
Plants, physiology of death of,

Eysfarth's, 27
Plasmopara viticola, introduction

into France, 65
Plenck, 31
Plinian period, 17
Plinius Secundus, 17
Potato blight, De Bary on, 45
Predispositionist school, 71
Premodern era, 22
Present era, 108
Prillieux, 93

Puccinia graminis, Ward on, 102
Helianthi, Woronin on, 90
malvacearum, Eriksson on, 88

Quarantine Act of 1912, United
States, 111

Rankin and Anderson, 115

Ravn, 85

Re, 12, 32

Reddick, 113

Renaissance period, 22

Riedel, 30

Roman period, 17

Rostrup, 81, 82

Rust, hollyhock, Eriksson on, 88

130

INDEX

Rust, Pliny on, 17
Tbeophrastus on, IS

S.W \ST\MI. 2<), 96

Schleiden, 34

Schreger, 31

Sclerotinia cinerea, Woronin on, 90

fructigena, Woronin on, (>0
Scott, 112
Scribner, 59, 104
Secret evils, 23
Selby, 106
Siebold, 42
Smith, 60, 61, 104
Sorauer, 37, 98
Sporodesmium exitosum, Kiihn on,

48
Sprengel, 34
Steenstrup, 42
Stewart, 106, 113

Sugar-beet, dry rot of, Frank on, 76
Sulfur, substitution for copper as

fungicide, 112
Swingle, 60

Taxonomic period, 25
Theophrastian period, 14
Theophrastus of Eresus, 15
Tree cement, Forsyth's, 30
Tulasne, 41

[JNGER, 34
Ungerian period, 33

characteristic features, 40
United States Bureau of Plant In-
dustry, founding of, 60
Government sanction of phy-
topathology, 62
Quarantine Act of 1(>12, 111

VON A.TJESSBERG, 28

von Ehrenfels, 2l), 31
von Liebig, 45
von Werneck, 32

Watte, 60,67
Wakker, 61, 68
Ward, 17, 88, 100
Webber, 60
Wiegmann, 36
Woods, 60
Woronin, 88

YELLOW disease of hyacinths, Bur-
rill on, 61

Zallinger, 28
Zallingerian period, 25

characteristic features, 32

MORA

c m I

University of British Columbia Library

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