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INTRODUCTION

BOTANY.

London :

Printed by A. & R. Spottiswoode,

New-Street- Square.

AN

INTRODUCTION

B O T A N

BY

JOHN LINDLEY, F.R.S. L.S. G.S.

MEMBER OF THE IMPERIAL ACADEMY NATURES CURIOSORUM J OF THE
BOTANICAL SOCIETY OF RATISBON J OF THE PHYSIOGRAPHICAL SOCIETY
OF LUND; OF THE HORTICULTURAL SOCIETY OF BERLIN J HONORARY
MEMBER OF THE LYCEUM OF NATURAL HISTORY OF NEW YORK; AS-
SISTANT SECRETARY OF THE HORTICULTURAL SOCIETY OF LONDON,
ETC. ETC. J

AND PROFESSOR OF BOTANY IN THE UNIVERSITY
OF LONDON.

aiaUitf) &tjc eropper^lPIates ant) numeroiw 2ia3o<rt>-<I£nGratomg0.

LONDON:

PRINTED FOR

LONGMAN, REES, ORME, BROWN, GREEN, & LONGMAN,

PATERNOSTER-ROW.
1832.

>

PREFACE.

A. wo hundred and ninety years have now elapsed
since one of the earliest introductions to Botany
upon record was published, in four pages folio, by
Leonhart Fuchs, a learned physician of Tubingen.
At that period Botany was nothing more than the
art of distinguishing one plant from another, and
of remembering the medical qualities, sometimes real,
but more frequently imaginary, which experience, or
error, or superstition, had ascribed to them. Little
was known of Vegetable Physiology, nothing of Vege-
table Anatomy, and even the art of arranging species
systematically had still to be discovered; while
scarcely a trace existed of those modern views which
have raised the science from the mere business of
the herb-gatherer to a station among the most intel-
lectual branches of natural philosophy.

It now comprehends a knowledge not only of the
names and uses of plants, but of their external and
internal organisation, and of their anatomy and phy-
siological phenomena ; it embraces a consideration
of the plan upon which those multitudes of vegetable
forms that clothe the earth have been created, of the
skilful combinations out of which so many various
organs have emanated, of the laws that regulate the
dispersion and location of species, and of the influ-
ence that climate exercises upon their developement ;

A 3

PREFACE.

and, lastly, from botany as now understood, in its
most extensive signification, is inseparable the know-
ledge of the various ways in which the laws of vege-
table life are applicable to the augmentation of the
luxuries and comforts, or to the diminution of the
wants and miseries of mankind. It is by no means,
as some suppose, a science for the idle philosopher in
his closet ; neither is it merely an amusing accom-
plishment, as others appear to think ; on the con-
trary, its field is in the midst of meadows, and
gardens, and forests, on the sides of mountains, and
in the depths of mines, — wherever vegetation still
flourishes, or wherever it attests by its remains the
existence of a former world. It is the science that
converts the useless or noxious weed into the nutri-
tious vegetable ; which changes a bare volcanic rock,
like Ascension, into a green and fertile island ; and
which enables the man of science, by the power it
gives him of judging how far the productions of one
climate are susceptible of cultivation in another, to
guide the colonist in his enterprises, and to save him
from those errors and losses into which all such per-
sons unacquainted with Botany are liable to fall. This
science, finally, it is which teaches the physician how
to discover in every region the medicines that are
best adapted for the maladies that prevail in it ; and
which, by furnishing him with a certain clue to the
knowledge of the tribes in which particular proper-
ties are or are not to be found, renders him as much
at ease, alone and seemingly without resources, in a
land of unknown herbs, as if he were in the midst of
a magazine of drugs in some civilised country.

The principles of such a science must necessarily
be extremely complicated, and in certain branches,
which have only for a short time occupied the atten-

PREFACE. Vll

tion of observers, or which depend upon obscure and
ill-understood evidence, are by no means so clearly
defined as could be wished. To explain those prin-
ciples, to adduce the evidence by which their truth
is supposed to be proved, or the reasoning upon
which they are based in cases where direct proof is
unattainable ; to show the causes of errors that are
now exploded, and the insufficiency of the arguments
by which doubtful theories are still defended, — in
fine, to draw a distinct line between what is certain
and what is doubtful, — are some of the objects of this
publication, which is intended for the use of those
who, without being willing to occupy themselves
with a detailed examination of the vast mass of evi-
dence upon which the modern science of botany is
founded, are, nevertheless, anxious to acquire a dis-
tinct idea of the nature of that evidence. Another
and not less important purpose has been to demon-
strate, by a series of well-connected proofs, that in no
department of natural history are the simplicity and
harmony that pervade the universe more strikingly
manifest than in the vegetable kingdom, where the
most varied forms are produced by the combination
of a very small number of distinct organs, and the
most important phenomena are distinctly explained
by a few simple laws of life and structure.

In the execution of these objects, I have followed
very nearly the method recommended by the cele-
brated Professor De Candolle, than whom no man is
entitled to more deference, whether you consider the
soundness of his judgment in all that relates to order
and arrangement, or the great experience which a
long and most successful career of public instruction
has necessarily given him.

I have begun with what is called Organography
a 4

VIU PREFACE.

(Book I.) ; or an explanation of the exact structure of
plants; a branch of the subject which comprehends
all that relates either to the various forms of tissue of
which vegetables are constructed, or to the external
appearance their elementary organs assume in a state
of combination. It is exceedingly desirable that
these topics should be well understood, because they
form the basis of all other parts of the science. In
physiology, every function is executed through the
agency of the organs : systematic arrangements de-
pendjupon characters arising out of their consider-
ation ; and descriptive Botany can have no logical
precision without the principles of Organography
being first exactly settled. Great difference of opi-
nion exists among the most distinguished botanists,
upon some points connected with this subject, so
that it has been found expedient to enter occasionally
into much detail, for the purpose of satisfying the
student of the accuracy of the facts and reasonings
upon which he is expected to rely.

To this succeedsVEGETABLE.PH ysiology (BooklL);
or the history of the vital phenonema that have been
observed both in plants in general, and in particular
species, and also in each of their organs taken sepa-
rately. It is that part of the science which has the
most direct bearing upon practical objects, and with
which the enquirer who would occupy himself more
with the utile than the dulce is most likely to be inter-
ested. Its laws, however, are either unintelligible, or
susceptible of no exact appreciation, without a pre-
vious acquaintance with the more important details of
Organography. Much of the subject is at present
involved in mystery, and the accuracy of many of the
conclusions of physiologists is inferred rather than
demonstrated ; so that it has been found essential

l'KEFACE. ix

that the grounds of the more popularly received
opinions, whether admitted as true or rejected as
erroneous, should be given at length. No particular
chapter is assigned to the practical application of
physiological principles, because this has been con-
stantly taken as illustrative of the separate functions
of individual parts.

Next follows Taxonomy (Book III.); or some
account of the Principles of Classification ; — a very
important subject, comprehending not only an account
of the various methods of arrangement employed by
botanists in their systematic works, but an explan-
ation of the principles by which the limits of genera
and species are determined. It also explains the mode
of obtaining a correct view of vegetation, of con-
ducting the examinations of unknown plants with
precision, of avoiding errors in consequence of acci-
dental aberrations from the ordinary structure, and
of forming a just estimate of the mutual relation that
one part of the vegetable kingdom bears to another.

After this I have taken Glossology (Book IV.) ;
or, as it was formerly called, Terminology ; restrict-
ing it absolutely to the definition of the adjective
terms, which are either used exclusively in Botany,
or which are used in that science in some particular
and unusual sense. The key to this book, and also
to the substantive terms explained in Organography,
will be found in a copious index at the end of the
volume.

These four topics exhaust the science considered
only with reference to first principles ; there are, how-
ever, a few others which it has been thought advis-
able to append, on account of their practical value.
These are, firstly, Phytography (Book V.) ; or an
exposition of the rules to be observed in describing

X PREFACE.

and naming plants. As the great object of descrip-
tions in natural history, is to enable every person to
recognise a known species, after its station has been
discovered by classification, and also to put those
who have not had the opportunity of examining a
plant themselves into possession of all the facts
necessary to acquire a just notion of its structure
and affinities ; it is indispensable that the principles
of making descriptions should be clearly understood,
both to prevent their being too general to answer the
intended purpose, or more prolix than is really
requisite. It is the want of a knowledge of these
rules that renders the short descriptions of the classical
writers of antiquity, and the longer ones of many a
modern traveller, equally vague and unintelligible.
In this place are inserted a few notes upon the form,
ation of an herbarium.

After this, has been introduced (Book VI.) a
summary of the little which is known of the laws
that regulate the distribution of plants upon the
surface of the earth ; a question which, however
indefinite and unsatisfactory our information may at
present be, has begun to assume such an appearance
as to justify the expectation, that future discoveries
will explain the causes of the characters of vegetation
being determined, as they surely are, by climate.

Finally, the work is concluded by an exposition of
what is called Morphology ; a subject which is in
the vegetable what Comparative Anatomy is in the
animal kingdom, and which is by far the most im-
portant branch of study after Elementary Anatomy
and Vegetable Physiology. Organography itself is
in all respects an exposition of thg doctrines of Mor-
phology ; but the novelty of the subject, and a per-
suasion that it would be better understood if treated

PREFACE. xi

separately, has induced me to make it the subject of
particular consideration. Unknown before the time
of Linnaeus, and first placed in its true light by the
venerable poet Gothe, it lay neglected for nearly
thirty years, until, having been revived by Du Petit
Thouars, De Candolle, Brown, and others, it has
come to be considered the basis of all scientific
knowledge of vegetable structure.

It has been my wish to bring every subject that I
have introduced down, as nearly as possible, to the
state in which it is found at the present day; but,
alas ! tasks that are infinite can never be accomplished
by finite means. While the MSS. has been going-
through the press, my table has been covered with
works illustrating the fundamental principles of the
science, of scarcely any of which has it been possible
to make the slightest use. This I regret the more,
as some of them are of high interest*, especially with
regard to Vegetable Anatomy.

In the statements I have made, I have uniformly
endeavoured to render due credit to all persons for
the discoveries by which they may severally have
contributed to the advancement of the science ; and

* The more important of these works are, —

Agardh, C. A., Lehrbuch der Botanik. Copenhagen, 1831.

Kunth, K. S., Handbuch der Botanik. Berlin, 1831.

Meyer, F. J. F., Phytotomie. Berlin, 1830.

De Candolle, A. P., Physiologie Vegetale, &c. Paris, 1832.

Martius, Palmae. The part containing the Anatomy.

Arnott, G. W. The article Botany in the Edinburgh Encyclo-
paedia.

Bischoff, G. W., Handbuch der Botanischen Terminologie und
Systemkunde. Nuremberg, 1830.

Annales des Sciences Naturelles, par MM. Audouin, Ad.
Brongniart, et Dumas. Several Numbers.

Mirbel, C.B.. Memoire sur le Marchantia. Paris, 1832.

I'll E FACE.

if I have on any occasion either omitted to do so, or
assumed to myself observations which belong to
others, it has been unknowingly or inadvertently. It
is, however, impracticable, and if practicable it would
not be worth while, to remember upon all occasions
from what particular sources information may have
been derived. Discoveries, when once communi-
cated to the world, become public property : they
are thrown into the common stock for mutual benefit;
and it is only in the case of debatable opinions, or
of any recent and unconfirmed observations, that it
really interests the world that authorities should be
quoted at all. In the language of a highly valued
friend, when writing upon another subject : — " The
advanced state of a science is but the accumulation
of the discoveries and inventions of many : to refer
each of these to its author is the business of the
history of science, but does not belong to a work
which professes merely to give an account of the
science as it is j all that is generally acknowledged
must pass current from author to author." *

London, Sept. 10. 1832.

* Brett's Principles of Astronomy, p. v.

CONTENTS.

BOOK I.

Page

Organography; or, of the Structure of Plants I

Chap. I. Of the Elementary Organs - - - - ib.

1. Of Cellular Tissue - - 3

2. Of Woody Fibre - - - - 12
5. Of Vascular Tissue - - - - 17
4. Of Spurious Elementary Organs :

1. Intercellular Passages - - -26

2. Receptacles of Secretion - - - 27

3. Air Cells - - ib.

4. Raphides - - 29

Chap. II. Of the Compound Organs in Flowering Plants - - 31

1. Of the Cuticle and its Appendages:

1. Cuticle - - ib.

2. Stomata - ------33

3. Hairs - - - - - - 38

4. Scales - - - - 41

5. Glands - - - - 42

6. Prickles - - 44

2. Of the Stem or Ascending Axis :

1. Of its Parts - ----- 45

2. Of its External Modifications - - 54

3. Of its Internal Modifications - - - 58

1. Of the Exogenous Structure - - 59

2. Of the Endogenous Structure - - 72

3. Of the Root or Descending Axis - - 76

4. Of the Appendages of the Axis - 78

1. Leaf - - 79

2. Stipulae - 98

3. Bracteae - - - - - 100

XIV CONTENTS.

Page

4. Flower - - - - - - 105

5. Inflorescence - - - - - 106

6. Calyx - 112

7. Corolla - - - - - - 117

8. Stamens - - - - - 122

9. Disk - - - - - - 137

10. Pistillum - - - - - - 138

11. Receptacle - - - - 152

12. Ovulum - - - - - 153

13. Fruit - - - - - - 160

14. Seed - - - ... 181

15. Naked Seeds ... .... 194

CHAr. III. Of the Compound Organs in Flowerless Plants - - 195

1. Ferns ... _ j£,

2. Equisetaceae - - -- --197

3. Lycopodiacese - - - - - ib.

4. Marsileaceas - - - - 198

5. Mosses ------ 200

6. Hepaticae - 202

7. Lichens - - - ... 204

8. Algae ------ 206

9. Fungi - ----- 208

BOOK II.

Physiology ; or, Plants considered in a State of Action - 210

Chap. I. Elementary Organs ----- 221

II. Root - - - - 227

III. Sap ... ... . 230

IV. Pith, Wood, and Bark - - - - 239
V. Leaves - - - 247

VI. Bracteae, Calyx, Corolla, and Disk - - - 257

VII. Stamens and Pistillum - - - - - 262

VIII. Fruit - - - - - 266

IX. Seeds ------- 270

X. Colour, Smell, and Taste - 274

XL Directions - - - - - 277

XII. Irritability - - - - - 288

XIII. Poisons ... - . 293

XIV. Diseases - ..... 297
XV. Hybrid Plants - - - - - - 501

XVI. Flowerless Plants ..... 305

CONTENTS. XV

BOOK III.

Taxonomy; or, of the Principles of Classification.

Pago

Chap. I. General Objects of Classification - - 306

II. Artificial Arrangements - ... 509

III. Natural System .... 31s

IV. Speculative Modes of Arrangement - - - 324
V. Value of Characters ..... 549

VI. Species, Varieties, Genera, Orders, and Classes - - 365

BOOK IV.

Glossology ; or, of the adjective Terms used in Botany - 369

Class I. Of Individual Terms - - - - 371

1 . Of Individual Absolute Terms : - - - 572

1. Figure - ib.

2. Division ..... 586

3. Surface ..... 593

4. Texture or Substance ... 397

5. Size - - - - - 599

6. Duration ..... 401

7. Colour ..... 402

8. Variegation or Marking ... 407

9. Veining - . - - ... 408

2. Of Individual Relative Terms :

1. ^Estivation - - - - 409

2. Direction - - - - - -411

5. Insertion, or Origin - - 415

Class II. Of Collective Terms :

1. Of Arrangement - - - - 417

2. Of Number ... . 420

Class III. Of Terms of Qualification - - 422

Signs - - - ib-

Abbreviations - ... 425

XVI tONTENTS.

HOOK V.

Page
Phytography; on. of the Rules to be observed in describing

AND NAMING Pl.ANTS ...... 432

Chap. I. Diagnoses ; or, Generic and Specific Characters - 433

II. Descriptions - ... 440

III. Punctuation - - 4.52

IV. Nomenclature and Terminology - - - 454
V. Synonyms - - - - - 460

VI. Herbaria - - 463

VII. Botanical Drawings - 469

BOOK VI.

Geografhy; or, the Distribution of Plants upon the Surface

of the Globe - - - - . 470

BOOK VII.

Morphology; or, of the Metamorphosis of Organs - - 504

Chap. I. Regular Metamorphosis .... 509

II. Irregular Metamorphosis - - - - 521

Explanation of the Plates - ... 527

Index :

1. Substantives - - . . 537

2. Adjectives - 546

INTRODUCTION

TO

BOTANY.

BOOK I.

ORGANOGRAPHY ; OR, OF THE STRUCTURE OF PLANTS.

CHAPTER I.

OF THE ELEMENTARY ORGANS.

If plants are considered with reference to their internal
organisation, they appear at first sight to consist of a vast
multitude of exceedingly minute cavities, separated by a
membranous substance ; more exactly examined, it is found
that these cavities have a variety of different figures, and
that each is closed up from those that surround it; and if the
enquiry is carried still farther, it will be discovered that the
partitions between the cavities are all double, and that by
maceration in water, or by other processes, the cavities with
their enclosing membrane may be separated from each other
into distinct bodies. These bodies constitute what is called
Vegetable Tissue, or Elementary Organs : they are the Simi-
lar^ parts of Grew; the Tissu organique of Mirbel ; and the
Parties elementaires, or Parties similaires, of De Candolle.

The chemical basis of the elementary organs has been
found to be oxygen, hydrogen, and carbon, with occasionally
a little nitrogen or azote, combined in various proportions :
their organic basis is membrane and fibre. The latter only
are here to be considered.

2 ORGANOGRAPHY'. BOOK I.

It is a common opinion that membrane only is the basis of
the tissue of plants, and that fibre is itself a form of mem-
brane. But as we find both developed in many of the most
imperfectly organised plants, such as Scleroderma and other
fungi ; and as it is difficult to conceive how that can be a
mere modification of membrane which is generated inde-
pendently of it, which has no external resemblance to it, and
which is obviously something superadded, it will be better to
consider both membrane and fibre as the organic bases of
vegetable tissue, rather than the former only.

The membrane varies in degree of transparency, being
occasionally so exceedingly thin as to be scarcely discover-
able, except by the little particles that stick to it, or by its
refraction of light, and sometimes having a perceptible green
colour, and a thickness which is considerable if compared
with the diameter of the cavity it encloses. It generally tears
readily, as if its component atoms do not cohere with greater
force in one direction than another ; but I have met with a
remarkable instance to the contrary of this in Bromelia nudi-
caulis, in which the membrane of the cuticle breaks into little
teeth of nearly equal width when torn. (Plate I. fig. 6.)
It is in almost all cases destitute of visible pores ; although
as it is readily permeable by fluids, it must necessarily be
furnished with invisible passages. An opinion to the contrary
of this has been held by some botanists, who have described
the existence of holes or pores in the membrane of tissue,
and have even thought they saw a distinct rim to them ; but
this idea, which probably originated in imperfect observation
with ill-constructed glasses, is now generally abandoned. The
supposed pores, with their rim, have been ascertained to be
nothing but grains of semi-transparent matter sticking to the
membrane : this has been proved by Dutrochet, who found
that boiling them in hot nitric acid rendered them opaque,
and that dipping them in a solution of caustic potash re-
stored their transparency, — a property incompatible with
a perforation ; and any one furnished with a good modern
microscope may satisfy himself upon the point, without going
through Dutrochet's process ; by simple movement in water
the grains may be often detached. It however occasionally

CHAF. I. OF THE ELEMENTARY ORGANS. 3

happens that holes do exist in the membrane, of which men-
tion will be made hereafter.

Fibre may be compared to hair of inconceivable fineness,
its diameter often not exceeding the -j^o of an inch. It
has frequently a greenish colour, but is more commonly trans-
parent and colourless. It appeal's to be sometimes capable
of extension with the same rapidity as the membrane among
which it lies, and to which it usually adheres ; but occasionally
elongates less rapidly, when it is broken into minute portions,
and carried along by the growing membrane. In direction
it is variable (Plates I. and II.) ; sometimes it is straight,
and attains a considerable length, as in some fungi ; some-
times it is short and straight, but hooked at the apex, as in
the lining of the anther of Campanula; occasionally it is
straight, and adheres to the side of membrane, as in the same
part in Digitalis purpurea ; but its most common direction is
spiral. Whether it is solid or hollow has not been fully de-
monstrated ; Dr. Purkinje asserts that it is hollow, as will be
hereafter mentioned ; but there can be no doubt that it is also,
at least sometimes, solid, as in the fibrous cellules of the leaf
of Oncidium altissimum ; it is the opinion of many that it is
hollow in the case of spiral vessels. Fibre has a constant
tendency to anastomosing, in consequence of which reticulated
appearances are occasionally found in tissue.

The forms under which the elementary organs are seen
are, — 1. Cellular tissue; 2. Woody Jibre ; and, 3. Vascular
tissue.

Sect. I. Of Cellular Tissue.

Cellular tissue [Contextus cellulosus or Tela cellulosa, Lat. ;
Ptdpa, Parenchyma, or pithy part, of old writers; Zellcngcwebe,
Germ.;) generally consists of little bladders or vesicles of
various figures, adhering together in masses. Occasionally it
is composed of fibre only, unconnected by membrane. It is
transparent, and in all cases colourless : when it appears
otherwise, its colour is always caused by matter contained
within it.

n 2

ORGANOGRAPHY.

BOOK I.

If a thin slice of the pith of elder, or any other plant, be
examined with a microscope, it will be found to have a sort of
honeycomb appearance, as if there were a number of hexagonal

l

cavities, separated by partitions {fig. 1.). These little cavities
are the inside of cellules of cellular tissue ; and the partitions
are caused by the cohesion of their sides, as may be easily
proved by boiling the pith a short time, when the cellules
readily separate from each other. In pulpy fruits, or in those
which have their cellular tissue in a loose, dry state when ripe,
the cellules may be readily separated from each other without
boiling. It was formerly thought that cellular tissue might
be compared to the air bubbles in a lather of soap and
water, while by some it has been supposed to be formed
by the doublings and foldings of a membrane in various di-
rections : on both these suppositions, the partitions between
the cells would be simple, and not composed of two mem-
branes in a state of cohesion. But the facility with which, as
has been just stated, the cellules may be separated, sufficiently
disproves these opinions. It is probable, however, that al-
though the double nature of the partitions in cellular tissue
may be demonstrated, yet that the cellules usually grow so
firmly together, that their sides really form in their union but
one membrane.

Cellules are destitute of all perforation or visible pores,
so that each is completely closed up from its neighbour, as
far as we can see ; although, as they have the power of filter-
ing fluids with rapidity, it is certain that they must abound in
invisible pores, and that they are not impermeable, as if they
were made of glass. An opinion different from this has been
and is still entertained by some observers, who have described
and figured perforations of the membrane in various plants.

CHAP. I. OF THE ELEMENTARY ORGANS. 5

Mirbel states that " the sides of the cellules are sometimes
2 riddled full of holes (Jig. 2.), the aperture of which

does not exceed the -jfo of a millimetre (or of
half a line) ; or are less frequently pierced with
transverse slits, which are occasionally 3
so numerous as to transform the cellules
into a real articulated tissue, as in the
pith of the Nelumbium (fig. 3.)." This
statement is now so well known to have
been founded upon inaccurate observation, and such
pores or slits are so universally admitted to be small portions
of amylaceous matter sticking to the walls, that no additional
disproof seems necessary. A good microscope is alone suf-
ficient, generally, to show the real nature of these supposed
pores, or if not, the test used by Dutrochet, and mentioned at
page 2., is in all cases sufficient.

It may also be observed, that cellules often contain air-
bubbles, which appear to have no direct means of escape, and
that the limits of colour are often very accurately defined in
petals, as, for instance, in the stripes of tulips and carnations,
which could not be the case if cellular tissue were perforated
by such holes as have been described ; for in that case colours
would necessarily run together.

One of the most striking instances with which I am ac-
quainted, of cellular tissue having the appearance of pores is
in Calycanthus, where it was pointed out to me by Mr. Va-
renne. (Plate I. fig. 1.) But even in this, a careful ex-
amination with glasses of different magnifying powers shows
that the apparent pores are certainly not so, but composed of
a solid subsance which may be distinctly seen by varying the
direction of the rays of the transmitted light with which it
is viewed. Sometimes they appear like luminous points ; by
a little alteration of light they acquire a brownish tint ; and if
seen with the highest powers of a compound microscope, where
there is a great loss of light, they become perfectly opaque.

Cellular tissue is always transparent and colourless, or at
most only slightly tinged with green. The brilliant colours
of vegetable matter, the white, blue, yellow, scarlet, and other
hues of the corolla, and the green of the bark and leaves, is

b 3

6 ORGANOGRAPHY. BOOK I.

not owing to any difference in the colour of the cellules, but
to colouring matter of different kinds which they contain.
In the stem of Impatiens balsamina, a single cell is frequently
red in the midst of others that are colourless. Examine the
red cellule, and you will find it filled with a colouring matter
of which the rest are destitute. The bright satiny appearance
of many richly coloured flowers depends upon the colourless
quality of the tissue. Thus, in Thysanotus fascicularis, the
flowers of which are of a deep brilliant violet, with a remark-
able satiny lustre, that appearance will be found to arise from
each particular cellule containing a single drop of coloured
fluid which gleams through the white shining membrane of
the cellules, and produces the flickering lustre that is per-
ceived. The colouring matter of the cellular tissue is fre-
quently fluid, but is in the leaves and other parts more
commonly composed of granules of various sizes ; this is
particularly the case in all green parts ; in which the granules
lie amongst greenish liquid, the latter of which, as they grow
older, dries up, while the granules themselves gradually change
to olive green, and finally to brown.

Kieser distinguishes three sorts of globules among tissue :
— 1. Round extremely transparent bodies, of a more or less
regular figure, found principally in young plants and in coty-
ledons, and soluble in boiling water : it is these that constitute
starch or faecula. 2. Globules of a small size, a more irre-
gular figure, and coloured either green or some other tint.
They are not soluble in water, but are so in alcohol; but
when dissolved, their matter is not precipitated by the addition
of water, on which account they are distinguishable from
resinous substances. 3. Extremely small round bodies, vary-
ing in colour, and found floating in the proper juices of
vegetables.

The green granules are what M. Turpin calls Globuline.
He believes them to be young cellules, and that it is from
them that new tissue is developed. There does not, however,
appear to be any evidence of this, which must be considered,
at present, a gratuitous hypothesis, if, indeed, it were not
rather said to be an untenable one. No one has ever seen
the granules passing through the sides of the cellules ; no

CHAP. I. OF THE ELEMENTARY ORGANS. 7

rupture of the sides of the cellules, caused by such a passage,
has ever been detected ; and yet it seems inconceivable how
the granules are to be constantly developing as new tissue,
without some such trace of their passage being observable.
Those who are curious to know the exact nature of this
speculation, should consult the memoir of the author, in the
Memoir rs du Museum, vol.18, p. 212. The mode in which
cellular or any other tissue is really formed, is buried in
mystery. It has been suspected by Mr. Valentine, and I be-
lieve the same idea has also occurred to Mr. Bauer, that it
may be caused by the extrication of gaseous matter among
mucus ; but it is obvious that there are many difficulties in
the way of this supposition. Amici says the cellules pullulate.

The cellules develope, in some cases, with great rapidity. I
have seen Lupinus polyphyllus grow in length, at the rate of an
inch and a half a day. The leaf of Urania speciosa has been
found by Mulder to lengthen at the rate of from one and a
half to three and a half lines per houi', and even as much as from
four to five inches per day. This may be computed to equal the
developement of at least 4000 or 5000 cellules per hour. But
the most remarkable instances of this sort are to be found in the
mushroom tribe, which in all cases develope with surprising ra-
pidity. It is stated by Junghuns, that he has known the Bovista
giganteum, in damp warm weather, grow in a single night from
the size of a mere point to that of a huge gourd. We are not
further informed of the dimensions of this specimen ; but sup-
posing its cellules to be not less than the ^o? of an inch in
diameter, and I suspect they are nearer the ^o* it may be
fairly estimated to have consisted, when full grown, of about
47,000,000,000 cellules ; so that, supposing it to have grown in
the course of twelve hours, its cellules must have developed
at the rate of near 4,000,000,000 per hour, or of more than
sixty-six millions in a minute.

The cellules of cellular tissue are always very small, but are
exceedingly variable in size. The largest are generally found
in the gourd tribe (Cucurbitaceae), or in pith, or in aquatic
plants ; and of these some are as much as the 3-V of an inch in
diameter ; the ordinary size is about the ^foj or the ^J^, and
they are sometimes not more than the tt)W» Kieser has

b 4

8 ORGANOGRAPHY. BOOK I.

computed that in the garden pink more than 5,100 are con-
tained in half a cubic line.

Cellular tissue is found in two essentially different states,
the membranous and the Jibrous.

Membranous Cellular Tissue is that in which the sides
consist of membrane only, without any trace of fibre ; it is
the most common, and was, till lately, supposed to be the
only kind that exists. This sort of tissue is to be considered
the basis of vegetable structure, and the only form indispen-
sable to a plant. Many plants consist of nothing else ; and
while numberless vegetables are destitute of all other kinds
of tissue, the membranous cellular tissue is never absent. It
constitutes the whole of Mosses, Algae, Fungi, Lichens, and the
like ; it forms all the pulpy parts, the parenchyma of leaves,
the pith, medullary rays, and principal part of the bark, in
the stem of exogenous plants, the soft substance of the stem
of endogenous plants, the delicate membranes of flowers and
their appendages, and both the hard and soft parts of fruits
and seeds.

It appears that the spheroid is the figure which should be
considered normal or typical in this kind of tissue ; for that is
the form in which cellules are always found when they are
generated separately, without exercising any pressure upon
each other ; as, for example, is visible in the leaf of the white
lily, and in the pulp of the strawberry or of other soft fruits,
or in the dry berry of the jujube. All other forms of the
cellules are considered to be caused by the compression or
extension of such spheroids.

When a* mass of spheroidal cellules is pressed together
equally in all directions, rhomboidal dodecahedrons are pro-
duced, which, if cut across, exhibit the appearance of hexa-
gons. (Plate I. fig. 12.) This is the state in which the tissue
is found in the pith of all plants ; and the rice paper, sold in
the shops for making artificial flowers, and for drawing upon,
which is really the pith of a Chinese plant, is an excellent
illustration of it. If the force of extension or compression be
greater in one direction than another, various other forms are
produced, of which the following have been observed : —

1. The oblong ; in the stem of Orchis latifolia, and in the
inside of many leaves. (Plate I. fig. 9.)

CHAP. I. OF THE ELEMENTARY ORGANS. 9

2. The lobed (Plate I. fig. 2.f) ; in the inside of the leaf of
Nuphar luteum, Lilium candidum, Vicia Faba, &c. : in this form
of cellular tissue the vesicles are sometimes oblong with a
sort of leg or projecting lobe towards one end ; and some-
times irregularly triangular, with the sides pressed in and the
angles truncated. They are well represented in the plates of
M. Adolphe Brongniart's memoir upon the Organisation of
Leaves, in the Annales des Sciences, vol. xxi.

3. The square ,• in the cuticle of some leaves, in the bark of
many herbaceous plants, and frequently in pith. (Plate I.
fig. 13.)

4. The prismatical ; in some pith, in liber, and in the vicinity
of vessels of any sort. (Plate 1. fig. 6.)

5. The cylindrical (Plate I. fig. 8. a) ; in Chara; this has
been seen by Amici so large, that a single cellule measured
four inches in length and one third of a line in diameter.
(Ann. des Sciences, vol. ii. p. 246.)

6. The fusiform or the oblong pointed at each end ; in
wood, and in the membrane that surrounds the seed of a
Gourd. These are what Dutrochet calls clostres. (Plate II.
fig. 19. 8.; Plate I. fig. 5.)

7. The muriform ; in the medullary rays. This consists of
parallelopiped cellules compressed between woody fibre or
vessels, with their principal diameter horizontal, and in the
direction of the radii of the stem. It is so arranged that
when viewed laterally it resembles the bricks in a wall ;
whence its name. (Plate I. fig. 7.)

8. The compressed; in the cuticle of all plants. The cellules
are often so compressed as to appear to be only a single
membrane. (Plate I. fig. 2. a; Plate III. fig. 3, 4, &c.)

9. The irregular : in the testa of many seeds, as Casuarina :
here the form of the cellules is so very irregular that they
can be reduced to no certain form.

10. The sinuous ; in the cuticle, and also sometimes beneath
it, as in the leaf of Lilium candidum. (Plate III. fig. 5.)

Cellular tissue is frequently called Parenchyma. Professor
Link distinguishes both Parenchyma and Prosenchyma ; re-
ferring to the former all tissue in which the cellules are
applied by their plane faces (Plate I. fig. 1. 3. 6, 7, &c), and

10 ORGANOGRAPHY. BOOK I.

which consequently have truncated extremities ; and to the
latter, forms of tissue in which the cellules taper to each end,
and, consequently, overlap each other at their extremities.
(Plate II. fig. 8. 19.)

Fibrous cellular or Fibro-cellular Tissue is that in
which the sides are composed either of both membrane and
fibre together, or of fibre only.

It is only lately that this kind has been recognised. The
first observation with which I am acquainted is that of Mol-
denhauer, who, in 1779, described the leaves of Sphagnum as
marked by fibres twisted spirally. (Fig. 1. a, p. 4.) Link
afterwards stated, that the supposed fibres were nothing but
the lines where small cells contained in a larger one unite to-
gether ; and his opinion was received. It is nevertheless cer-
tain, that the tissue of Sphagnum is as Moldenhauer described
it. In November, 1827, I described the tissue of Maurandya
Barclayana as consisting of cellules formed of spiral threads
crossing each other, interlaced from the base to the apex, and
connected by a membrane. A few other solitary cases of
the observation of this kind of tissue had subsequently oc-
curred, when the admirable investigation of a modern anato-
mist suddenly threw an entirely new light upon the subject,

Instead of being very rare, cellular tissue of this kind
appears to be found in various parts ; it has been already
mentioned as existing in the leaves of Sphagnum ; it is also
found in the pith of Rubus odoratus. I originally discovered
it in the parenchyma of the leaves of Oncidium altissimum,
and in the testa of various seeds. Mr. Griffiths has detected
it abundantly in the aerial roots of Orchideous plants, observ-
ations since confirmed by Mr. Brown ; and Dr. Purkinje has
shown, by a series of excellent observations and drawings, that
it forms the lining of the valyes of almost all anthers. The
forms under which it exists in these parts are far more various
than those of membranous cellular tissue. The principal
varieties are these : —

A. Membrane and Fibre combined.

1. Fibres twisted spirally, adhering to a spheroidal or angu-
lar membrane, and often anastomosing irregularly, without the

CHAP. I. OF THE ELEMENTARY ORGANS. 11

spires touching each other. (Plate I. fig. 12.) This is what
is found in Oncidium altissimum leaves, in the aerial roots of
some Orchideous plants, in the lining of many anthers, and is
what Mohl has figured ( Ueber die Poren, <$~c. tab. i. fig. 9.), from
the pith of Rubus odoratus. It approaches very nearly to the
nature of spiral vessels, hereafter to be described, and ap-
pears only to be distinguishable by the spires of the fibres
not being in contact, being incapable of unrolling, having no
elasticity or tenacity ; and by not being cylindrical and taper-
ing to each end, but spheroidal.

2. Fibres crossing each other spirally, and forming a reticu-
lated appearance by their anastomosing in oblong or botuli-
form cells. Of this nature are the reticulated cells of the
testa of Maurandya Barclayana, Wightia gigantea, and the
like. (Plate I. fig. 1 1.)

3. Fibres running straight along the sides of truncated
cylindrical cells in the anthers of Calla eethiopica and many
other plants. (Plate I. fig. 13.)

4. Fibres running transversely in parallel lines round three
of the sides of prismatical right-angled cells, in the anthers
of Nymphseaceae, &c.

5. Fibres very short, attached to the sides of cells of various
figures, to which they give a sort of toothed appearance, as in
the anther of Phlomis fruticosa and other Labiatae. (Plate I.
fig. 15.)

The last three were first noticed by Dr. Purkinje.

6. The fibre twisted spirally, in the open membranous
tubes that form the elaters of Jungermannia, apparently con-
stitutes another form of tissue of this order. (Plate I. fig. 17.)

B. Fibre tsoitJiout Membrane.

7. Spiral fibres repressed by mucus, but having sufficient
elasticity to uncoil when the mucus is dissolved, and then
breaking up into rings. (Plate I. fig. 16.) These are what
are found in the testa of Collomia linearis. They approach
spiral vessels so very nearly, that when I originally discovered
them I mistook them for such. They are known by their
roundish or depressed figure when at rest, and by the want
<>f an inclosing membrane, and by their brittleness when un-
coiled.

I '2 ORGANOGRAPHY. BOOK I.

8. Fibres short, straight, and radiating, so as to form little
starlike appearances, found in the lining of the anthers of
Polygala Chamaebuxus, &c. by Dr. Purkinje. (Plate I.
fig. 19.)

9. Fibres originating in a circle, curving upwards into a
sort of dome, and uniting at the summit, observed by the
same anatomist in the anthers of Veronica perfoliata, &c.

10. Fibres standing in rows, each distinct from its neigh-
bour, and having its point hooked, so that the whole has some
resemblance to the teeth of a currycomb, in the anthers of
Campanula; first noticed by Dr. Purkinje. (Plate I. fig 18.)

1 1. Fibres forming distinct arches, as seen in the anthers of
Linaria cymbalaria, &c. by Dr. Purkinje. (Plate I. fig. 4.)*

In the centre of some of the cellules of the cellular tissue of
many plants there is a roundish nucleus, apparently consisting
of granular matter, the nature of which is unknown. It was
originally remarked by Mr. Francis Bauer, in the cellules of
the stigma of Phaius Tankervilliae. A few other vegetable
anatomists subsequently noticed its existence ; and Mr. Brown,
in his recent Memoir on the mode of impregnation in Orchi-
deae and Asclepiadeae, has made it the subject of more ex-
tended observation. According to this gentleman, such nuclei
not only occasionally appear on the cuticle of some plants
(Plate III. fig. 9.), in the pubescence of Cypripedium and
others, and in the internal tissue of the leaves, but also in the
cells of the ovulum before impregnation. It would also seem
that Mr. Brown considers stomata to be formed by the juxta-
position of two of these nuclei.

Sect. II. Of Woody Fibre.

This (Vasa fibrosa, Lat. ; Petits tubes, Mirb. ; Tissu cellu-
laire allonge or ligneiuc, Fr. ; Vaisseaux propres fasciculaires,
Mirb. ; Lignecsfistulce, Malpighi ; Fasergefdsse, or Bastrbhren,

* According to the last mentioned author, the fibres themselves are
generally tubular, and either perfectly round or somewhat compressed, or
even three or four sided. He considers it proved, that they are hollow, by
their appearance when compressed, by their occasionally containing bubbles
of air, and by the difference between their state when dried and when
recent.

CHAP. I. OF THE ELEMENTARY ORGANS. l^J

Germ.; perhaps the Vital vessels of Schultz;) consists of
very slender transparent membranous tubes, tapering acutely
to each end, lying in bundles, and, like the cellular tissue,
having no direct communication with each other, except by
invisible pores. (Plate II. fig. 1. a, b ,■ 2. 5. a, &c.)

Many vegetable anatomists consider it a mere form of
cellular tissue, in an elongated state; but scarcely with justice;
for if this mode of viewing the subject were pushed a little
farther, it would be necessary to refer every modification of
tissue to the cellular, which would be obviously improper.*
Woody fibre may be at all times known by its elongated
figure and extremely attenuated character ; usually it has no
sort of markings upon its surface, except occasionally a par-
ticle or two of greenish matter in its inside ; but sometimes it
is covered with spots that have been mistaken for pores, and
that give it a peculiar character (Plate II. fig. 3. and 4.);
and I have remarked an instance, in Oncidium altissimum, of
its having tubercles on its surface. (Plate II. fig. 2.) Gene-
rally, while cellular tissue is brittle, and has little or no cohe-
sion, woody fibre has great tenacity and strength ; whence its
capability of being manufactured into linen. Every thing pre-
pared from flax, hemp, and the like, is composed of woody
fibre.

That even the most delicate of it consists of tubes, may be
readily seen by examining it with a high magnifying power,
and also by the occasional detection of particles of greenish
matter in its inside. (Plate II. fig. 2. b.) A very different
opinion has nevertheless been held by some physiologists,
who have thought that the woody fibre is capable of endless
divisibility. " When," says Duhamel, " I have examined
under the microscope one of the principal fibres of a pear tree,
it seemed to me to consist of a bundle of yet finer fibres ; and
when I have detached one of those fibres, and submitted it to
a more powerful magnifying power than the first, it has still

* The distinction between cellular tissue and woody fibre is more pro-
nounced in the long club-shaped aerial radicle of Rhizophora Candelaria,
than in any plant with which I am acquainted. It there consists of large,
very long, transparent tubes, lying imbedded in fine brownish granular
matter, which is minute cellular tissue.

14 ORGANOGRAPHY. BOOK I.

appeared to be formed of a great number of yet more delicate
fibres." {Physique des Arbres, i. 57.) To this opinion
Du Petit Thouars assents, conceiving the tenuity of a fibre
to be infinite, as well as its extensibility. (Essais sur la
Vegetation^ p. 150.) These vjjews have doubtless arisen from
the use of very imperfect microscopes, under low powers of
which such appearances as Duhamel describes are visible ;
but with modern glasses, and after maceration in nitric acid,
or even in pure water, each particular fibre can be separated
with the greatest facility. Their diameter is often very much
less than that of the finest human hair ; the tubes of hemp,
for example, when completely separated, are nearly six times
smaller. It must, however, be observed, that the fibres of
this plant, as used in linen making, are by no means in a
state of final separation, each of the finest fibres that meet
the naked eye being in reality a bundle of tubes. While,
however, some are of this extremely small size, others have
a diameter as considerable as that of ordinary cellular tissue
itself; in Coniferae the tubes are often ybts or -j^-q of an inch
in diameter, and in the Lime they average about tto« Link
states (Elementa, p. 85.) that they are very large in trees of
hot countries, as, for instance, the Brazilian coffee.

It has been asserted by some writers, that the tubes of the
woody fibre are occasionally divided internally by transverse
septa or partitions ; but the fact is denied by Link, who de-
clares that " ejusmodi septa non existunt." It is no doubt
true that, in general, there is no trace of such septa ; but I
think it is impossible to deny their existence in the tissue of
the Lime tree, at least.

There are three distinct kinds of woody fibre : —

1. That in which the walls are not occupied with either
granules or glands sticking to them, or in which the former
are of very rare occurrence. (Plate II. fig. 1.) This is the
finest and the commonest of all ; and is also the most genuine
state of woody fibre.

2. That in which the walls have uniformly considerable
numbers of granules of regular size sticking to them in a
scattered manner. (Plate II. fig. 3, 4, 5.) These granules
have been, and are still considered by many anatomists as

CHAP. I. OF THE ELEMENTARY ORGANS. 15

pores in the sides of the tissue. They have been, in parti-
cular, so described and represented lately by Mons. Brong-
niart in Cycadese, in which the tubes are large, and the
appearance very conspicuous. (Annates des Sciences, vol. xvi.
tab. 21.) But I think it possible to demonstrate that this
is an optical deception, and that the supposed perforations
are of the same nature as the similar punctuations in cel-
lular tissue, viz. semitransparent granules. In the first place,
no colourless light passes through the supposed pores in
any case ; on the contrary, they are dark, and have a solid
appearance at all times, except when, at a certain distance
out of the focus of the microscope, they become luminous.
Secondly, if they were holes, they would, at least, be seen
open when the tissue is dry and contracted, although they
might close up when it becomes swollen with moisture. That,
however, they never are: on the contrary, they are more
opaque when dry than when wet. Thirdly, they be-
come more and more opaque as the magnifying power with
which they are viewed is increased ; a circumstance which
seems incompatible with perforations. Finally, and it is this
which will possibly be regarded most conclusive, if the tissue
of Zamia be allowed to remain macerating for some time in
dilute nitric acid, the apparent pores disappear : that is to
say, the granules that cause the appearance of perforations
are dissolved. It has been thought that such appearances as
these were confined to Cycadese and Coniferae ; but I suspect
that they are far from uncommon in other families. Such
tissue constitutes a considei'able part of the wood of Calycan-
thus (Plate II. fig. 4.), as has been already noticed ; and it is
abundant in an East Indian genus allied to Trichopus. This
kind of tissue might be called granular xwody Jibre : it ap-
proaches very nearly to the character of ducts, into which,
in Zamia, it seems to pass by almost insensible transitions.
It may, however, be known from dotted ducts, either by its
very acuminated extremities, or by its granules not being
arranged in a spiral manner.

2. The third kind of woody fibre is the glandular. This
has hitherto only been noticed in Conifers, in which it is
uniformly found in every species. Its dimensions are more
considerable than that of either of the last-mentioned forms;

16

ORGANOGRAPHY.

BOOK f.

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and, like the second, it has been described as perforated with
pores. It differs from granular woody fibre in the markings
of the tube being vesicular, and usually transparent, with a
darkened centre (Plate II. fig. 5, 6. 8.), which last is what has
been described as a pore, the vesicle itself being considered a
thickened rim. Kieser figures the glands as pores, both in Pine

wood (Jig. 4.),
and in Ephedra
{fg- 5.), and in
other cases also.
They may be
most conveni-
ently found by examining a thin shaving of Pinus Strobus
with a microscope, when they will be seen in the form of
transparent globules, having a dark centre, and placed upon
the walls of the tissue. That these globules are not pores,
seems to me to be proved thus : they are flaccid when dry,
and distend when moistened, which is not the property of a
pore ; their centre is more generally opaque than transparent,
which is also not the property of a pore ; they may be torn
through the middle without any hole becoming visible ; and,
finally, they may sometimes be detached from the tissue
(Plate II. fig. 7.), or fall away spontaneously. In the latter
case they leave a hole in the tissue at the place where they
grew ; and holes thus occasioned misled Kieser into the belief
that the woody fibre of Ephedra was really pierced with pores
of considerable magnitude. An illustration of the manner in
which these perforations are caused will be found in Plate II.
fig. 7.

M. Adolphe Brongniart has rightly stated, that there
exists in Gnetum Gnemon a form of tissue exactly the same
as in Coniferae. (Voyage de Freycinet.) In a species of that
genus collected in Tavoy by Dr. Wallich, the glands are only
different from what we commonly meet with in Coniferae, in
being arranged side by side, instead of being placed in single
rows irregularly one above the other. (Plate II. fig. 5.)

Woody fibre constitutes a considerable proportion of the
ligneous part of all plants ; it is common in bark, and it forms
the principal portion of the veins of leaves, to which it gives
stiffness and tenacity.

CHAP. I.

OF THE ELEMENTARY ORGANS.

17

Of Vascular Tissue.

Vascular tissue consists of simple membranous tubes ta-
pering to each end, but often ending abruptly, either having
a fibre generated spirally in their inside, or having their walls
marked by dots or transverse bars arranged in a spiral
direction.

Such appears to me to be the most accurate mode of de-
scribing this kind of tissue, upon the exact nature of which
anatomists are, however, much divided in opinion ; some be-
lieving that the fibre coheres independently of any membrane,
others doubting or denying the mode in which the vessels ter-
minate ; some describing the vessels as ramifying ; and a fourth
class ascribing to them pores and fissures, as we have already
seen has been done in cellular tissue and woody fibre. It will
be most convenient to consider all these points separately,
along with the varieties into which vascular tissue passes.

There are two principal kinds of vascular tissue ; viz. spiral
vessels (Plate II. fig. 9. 11.), and ducts (Plate II. fig. 13. 15,
1G. 18. 20.).

Spiral vessels (Jig.6,7.) {Vasa spiralia, Lat. ; Trachea of
many ; Fistula spirales of Malpighi ; Spiralgefdsse or Schrcm-
be?igcfasse, Germ. ;) are membranous tubes with conical extre-
mities; their inside being occupied by a fibre twisted spirally,
and capable of unrolling with elasticity. To the eye they, when
at rest, look like wire twisted round a cylinder that is after-

c

18 ORGANOGRAPHY. BOOK I.

wards removed. For the purpose of finding them for examin-
ation, the stalk of a strawberry leaf, or a young shoot of the
Cornus alba (common dogwood) may be conveniently used ;
in these they may be readily detected by gently pulling the
specimen asunder, when they unroll, and appear to the naked
eye like a fine cobweb.

Very different opinions have been entertained as to the
exact structure of spiral vessels. They have been considered
to be composed of a fibre only, twisted spirally, without any
connecting membrane ; or to have their coils connected by an
extremely thin membrane, which is destroyed when the vessel
unrolls ; or to consist of a fibre rolled round a membranous
cylinder ; or even, and this was Malpighi's idea, to be formed
by a spiral fibre kept together as a tube by interlaced fibres.
Again, the fibre itself has been by some thought to be a flat
strap, by others a tube, and by a third class of observers a
kind of gutter formed by a strap having its edges turned a
little inwards. Finally, the mode in which they terminate,
although formerly stated by Mirbel to be continuous with the
cellular tissue, is so little known, that the learned M. De Can-
dolle, in his Organographies published in 1827, remarks,
" Personne jusqu' ici n'a vu d'une maniere claire, ni I'origine,
ni la terminaison d'un vaisseau." (P. 58.) As doubts upon
these points arise from the extreme minuteness of the vessels,
and from the different degrees of skill that observers employ
in the use of the microscope, I can scarcely hope that any ob-
servations of mine will have much weight. Nevertheless I
may be permitted to state briefly what arguments occur to
me in support of the definition of the spiral vessel as given
above.

With regard to the presence of an external membrane
within which the spiral fibre is developed, it must be con-
fessed that direct observation is scarcely sufficient to settle
that point. It is easy to prove the existence of a membrane,
but it is difficult to demonstrate whether it is external or
internal with respect to the fibre. The best mode of examin-
ation is to separate a vessel entire from the rest of the tissue,
which may be done by boiling the subject, and then tearing it
in pieces with the points of needles or any delicate sharp

CHAP. I. OF THE ELEMENTARY ORGANS. 19

instrument ; the real structure will then become much more
apparent than if the vessel be viewed in connection with the
surrounding tissue. From some beautiful preparations of
this kind by Mr. Valentine and Mr. Griffiths, it appears that
the membrane is external : in the root of the Hyacinth, for
example, the coils of the spiral vessel touch each other,
except towards its extremities ; there they gradually separate,
and it is then easy to see that the spiral fibre does not project
beyond the membrane, but is bounded externally by the latter,
which would not be the case if the membrane were internal :
a representation of such a vessel is given at Plate II. fig. 9.
Another argument as to the membrane being external may not
unfairly be taken from the manifest analogy that a spiral
vessel bears to that form of cellular tissue (p.l I.), in which a
spiral fibre is generated within a cellule : it is probable that
the origin of the fibre is the same in both cases, and that its
position with regard to the membrane is also the same.

It is much more difficult to determine whether the fibre is
solid, or tubular, or flat like a strap ; and Amici has even
declared his belief that the question is not capable of solution
with such optical instruments as are now in use. When
magnified 500 times in diameter, a fibre appears to be
transparent in the middle, and more or less opaque at the
edges ; a circumstance which has no doubt given rise to
the idea that it is a strap or riband, with the edges either
thickened, according to M. De Candolle* or rolled inwards
according to Mirbel. But it is also the property of a trans-
parent cylinder to exhibit this appearance when viewed by
transmitted light, as any one may satisfy himself by examin-
ing a bit of a thermometer tube. A better mode of judging
is, perhaps, to be found in the way in which the fibre bends
when the vessel is flattened. If it were a flat thread, there
would be no convexity at the angle of flexure, but the external
edo-e of the bend would be straight. The fibre, however,
always maintains its roundness, whatever the degree of pres-
sure that I have been able to apply to it. (Plate II. fig. 10.)
This I think conclusive as to the roundness of the fibre ; but
it does not determine the question of its being tubular or
solid. I should have been induced to think, with Dr. Bischoff,

c 2

20 ORGANOGRAPHY. BOOK I.

who has investigated the nature of spiral vessels with singular
skill [De vera Vasorum Plantarum spiralium Stmctura et Fwic-
tione Commentation 1829) that it is solid, if it did not appear
to have been ascertained by Hedvvig that, when coloured
fluids rise in spiral vessels, they follow the direction of the
spires. This fact may, however, be explained upon the sup-
position that they rise in the channels formed by the approxi-
mation of cylindrical fibres, and not in the fibres them-
selves ; in which case there could be little doubt that the
fibres are really solid.

The nature of the termination of spiral vessels is now
placed beyond all doubt, by the preparations of Mr. Valentine,
above alluded to, and by some observations of my own.
It is stated by Professor Nees von Esenbeck, in his Handbuch
der Botanik, published in 1820, that they terminate in a
conical manner; and in 1824 M. Dutrochet asserts, that
they end in conical spires, the point of which becomes very
acute ; but one would not suppose, judging from the figure
given by the latter writer, that he had seen the terminations
very clearly. It is, however, certain that the statement
of Nees von Esenbeck is correct, and that the spiral vessel
generally terminates in a cone. If the point of such a vessel in
the Hyacinth (Plate II. fig. 9.) be examined, it will be seen
that the end of the spiral fibre lies just within the acute
point of the vessel, and that the spires become gradually
more and more relaxed as they approach the extremity, as if
their power of extension gradually diminished, and the mem-
brane acquired its pointed figure by the diminution of elasti-
city and extensibility in the fibre. It is not, however, always
in a distinct membrane that the spiral vessel ends. In Ne-
penthes the fibres terminate in a blunt cone, in which no
membrane is discoverable. (Plate II. fig. 11.)*

* A singular change occurs in the appearance of the spiral vessels of
Nepenthes, after long maceration in dilute nitric acid, or caustic potash ;
the extremities cease to be conical and spirally fibrous, but become little
transparent oblong sacs, in which the spires of the fibres gradually lose
themselves. This alteration, which is a very likely cause of deception, is
perhaps owing to the extremities of the vessels being more soluble than the
other part, the sac being the confluent dissolved fibres. This is in some
measure confirmed by the subsequent disappearance of all trace of fibres
in any part of the vessels, under the influence of those powerful solvents.

CHAP. I. OF THE ELEMENTARY ORGANS. 21

A spiral vessel is formed by the convolutions either of a
single spire, or of many. In the former case it is called
simple, in the latter compound. The simple is the most com-
mon. (Plate II. fig. 9.) Kieser finds from two to nine fibres
in the Banana ; M. de la Chesnaye as many as twenty-two in
the same plant. There are four in Nepenthes. (Plate II. fig. 11.)
In general, compound spiral vessels are thought to be almost
confined to Monocotyledonous plants, where they are very
common in certain families, especially Marantaceae, Scitami-
neae, and Musaceae ; but their existence in Nepenthes, and,
according to Rudolphi, in Heracleum speciosum, renders it
probable that future observations will show them to be not
uncommon among Dicotyledons also.

In Coniferae the spiral vessels have in some cases their
spires very remote, and even have glands upon their mem-
brane between the spires. (Plate II. fig. 6.)

In size, spiral vessels, like other kinds of tissue, are vari-
able; they are generally very small in the petals and filaments.
Mirbel states them to be sometimes as much as the 288th
of an inch in diameter ; Hedwig finds them, in some cases, not
exceeding the 3000th ; a very common size is the 1000th.

An irritability of a curious kind has been noticed by Mal-
pighi in the fibre of a spiral vessel. He says (Anat. p. 3.)
that in herbaceous plants and some trees, especially in the
winter, a beautiful sight may be observed, by tearing gently
asunder a portion of a branch or stem still green, so as to
separate the coils of the spires. The fibre will be found to
have a peristaltic motion which lasts for a considerable time.
An appearance of the same nature has been described by
Mr. Don in the bark of Urtica nivea. These observations
are, however, not conformable to the experience of others.
M. De Candolle is of opinion that the motion seen by Mal-
pighi is clue to a hygroscopic quality combined with elasticity;
and as spiral vessels do not exist in the bark of Urtica nivea,
it seems that there is some inaccuracy in Mr. Don's remark.

The situation of spiral vessels is in that part of the axis of
the stem surrounding the pith, and called the medullary sheath,
and also in every part the tissue of which originates from
it ; such as the veins of leaves, and petals ; and of all other

c 3

22 ORGANOGRAPHY. BOOK I.

modifications of leaves. It has been supposed that they are
never found either in the bark, the wood, or the root ; and
this appears to be generally true. But there are exceptions
to this : Mirbel and Amici have noticed their existence in
roots; and Mr. Valentine and Mr. Griffiths have both ex-
tracted them from the root of the Hyacinth ; they do not, how-
ever, appear to have been hitherto seen in the roots of Dicoty-
ledonous plants. I know of no instance of their existence in
bark, except in Nepenthes, where they are found in prodigious
quantities, not only between the alburnum and the liber, em-
bedded in cellular tissue, as was first pointed out to me by
Mr. Valentine, but also sparingly both in the bark and wood.
They have been described by myself as forming part of the
testa of the seed of Collomia, and Mr. Brown has described
them as existing abundantly in that of Casuarina. In the
former case, the tissue was rather the fibro-ce] hilar, as has
been already explained (p. 11.); in the latter, they are appa-
rently of an intermediate nature between the cellular -fibrous
and the vascular; agreeing with the former in size, situation,
and general appearance, but differing in being capable of un-
rolling. In the stem of Monocotyledonous plants, spiral
vessels occur in the bundles of woody tissue that lie among its
cellular substance ; in the leaves of some plants of this de-
scription they are found in such abundance, that, according to
M. de la Chesnaye, as quoted by De Candolle, they are col-
lected in handfuls in some islands of the West Indies for
Amadou. The same author informs us, that about a drachm
and a half is yielded by every plantain, and that the fibres may
be employed either in the manufacture of a sort of down, or
may be spun into thread. In Coniferous plants they are few and
very small, and in Flowerless plants they are for the most part
altogether absent ; the only exceptions being in Ferns and
Lycopodiaceae, orders occupying a sort of middle place be-
tween flowering and flowerless plants : in these thev no doubt
exist. My friend Mr. Griffiths has succeeded in unrolling
them in the young shoots of Lycopodium denticulatum.

Some have thought that the spiral vessels terminate in those
little openings of the cuticle called stomata ; but there does
not seem to be any foundation for this opinion*

CHAP. I. OF THE ELEMENTARY ORGANS. 23

Ducts {Jig. 8, 9, 10, 11,12.) (Fausses trachees, Fr.; Saft-
rohren, Germ ; Tubes corpuscidiferes of Dutrochet, Lymph de-
ducts, or Sap>-vessels of Grew and others ; Vaisseaux lympha-
tiques of De Candolle, Vaisseaux pneumatiques of others ;) are
membranous tubes, with conical or rounded extremities ; their
sides being marked with transverse lines, or rings, or bars, or
dots arranged spirally, and being incapable of unrolling.

In some states these approach so nearly to the spiral vessel,
that it is impossible to doubt their being a mere modification
of it, as is the case in the annular duct (Plate II. fig. 13.);
but in other states, as in the dotted duct, it is impossible to
trace the transition from the one form to the other. Some
writers confound all the forms under the common name of
spiral vessels, but it is more convenient to consider them as
distinct, not only because of their peculiar appearances, but
because they occupy a station in plants in which true spiral
vessels are not found ; and it is therefore probable that their
functions are different.

All the forms of the duct seem reducible to the following
varieties : —

1. The Annular (Jig.ll., and Platell. fig. 1 3.). These are well
described by BischofFas being formed of fibrous rings, placed
at uncertain intervals ; or, to speak more accurately, they, like
spiral vessels, are formed of a spiral thread, but it is broken
at every coil, so as to separate into a number of distinct
rings. These rings are included within a membranous tube,
by which they are held together. When the rings are distant
from each other (Plate II. fig. 1. b), the duct has a very
peculiar appearance ; when the rings are packed together, so
as to touch each other (Plate II. fig. 18.), the external
appearance is exactly that of a spiral vessel, from which they
are known by being incapable of unrolling. Both these
forms are common in the soft parts of plants, particularly in
the root, and also in Ferns and Lycopodiaceae among flower-
less plants.

2. The Jleticidated (fig. 10. 12., and Plate II. fig. 1 3. a.). In
these the spiral fibre, instead of separating into a number of
distinct rings, is continuous in some places, anastomoses in
others, so as to form a sort of netted appearance, or even

c 4

24 ORGANOGRAPHY. BOOK I.

breaks into short lengths, which, adhering to the sides of the
membrane, give the vessel the appearance of having transverse
bars. It is these appearances that have given rise to the
notion of cracked, or pierced ducts {fig. 10.) existing in plants;
the membrane between the spires, or bars, having been mis-
taken for pores ; hence the term vaisseaufendu, used by Mirbel
and others. Vessels of this kind are found in the stem of some
herbaceous plants ; as, for example, the Impatiens Balsamina,
in which they may be found in a great variety of states.

3. The Dotted {fig. 9.). Ducts of this kind are tubes having
their sides marked with numerous dots, arranged in a more or
less spiral manner, and being divided internally by transverse
partitions. Usually, in addition to the dots, there is distinctly
visible an oblique or annular transparent line upon the walls
of the vessel. (Plate II. fig. 15. 17.) Hence Kieser con-
sidered them as spiral vessels, the spires of which, when
old, elongate, and become connected by a dotted membrane.
Bischoff, on the contrary, considers the dots to be caused by
the separation of a spiral fibre into extremely minute portions ;
and he gives a figure (Plate II. fig 16.) of the manner in
which he considers this change to occur.

It is certain, however, that the dotted duct is really an en-
tirely distinct kind of vessel, or at least a modification of
cellular rather than of vascular tissue, as has been asserted by
Du Petit Thouars {Ann. des Sciences, vol. xxi. p. 224.) ; for
the following reasons : — If it were such a modification of the
spiral vessel as Kieser supposes, it would have none of those
internal septa by which it is particularly known. The same
remark applies to the theory of Bischoff, which is also im-
perfect, in not accounting for the nature of the transverse
transparent lines that mark the sides of dotted ducts.
Besides, the dotted ducts always terminate abruptly, not in
acute cones, as has been seen by myself, and well represented
by Mr. Griffiths, in his excellent illustrations of the anatomy
of Phytocrene (Plate II. fig. 19. 20.), and they readily separate
at the septa ; none of which properties are those of a spiral
vessel. That the partitions above alluded to really exist, as
has been correctly stated by Dr. Dutrochet, there can be no
doubt, notwithstanding the denial of the fact by Link and

CHAI\ I. OF THE ELEMENTARY ORGANS. 25

others. They may be seen with the naked eye in the ducts
of the Cane, the Bamboo, and many other plants.

While, therefore, I conform to the general practice of
classing this kind of duct among vascular tissue, I would
suggest that it should rather be considered as made up of
cylindrical cells, the sides of which are covered with oblong
granules, arranged with their principal axis across the tube,
and the united ends of which cause the partitions discover-
able upon a longitudinal section. It is these partitions that
cause externally the appearance of transverse transparent
lines.

Dotted ducts are the largest of all kinds of tissue. The
holes which are so evident to the naked eye, in a transverse
section of the oak or the vine, are the mouths of dotted ducts;
and the large openings in the ends of the woody bundles of
Monocotyledonous stems, as in the Cane, are also almost always
caused by the section of a dotted duct. The stem of Arundo
Donax, or of any large grass, is an excellent subject for
seeking them in ; they can be readily extracted from it when
boiled.

Vascular tissue always consists of tubes that are unbranched.
They have been represented by Mirbel as ramifying in some
cases ; but this opinion has undoubtedly arisen from imperfect
observation. When forming a series of vessels, the ends of
the tubes overly each other, as represented in Plate II.
fig. 18.

Some anatomists have added to the varieties above enumer-
ated, what they call moniliform, or necklace-shaped, or stran-
gulated vessels (jfg> 8.) (vaisscaux en chapelet or Strangles, vasa
moniliformia, corpuscula vermiformia). These are rightly de-
termined by BischofF to be mere accidental forms, caused by
their irregular compression, when growing in knots or parts
that are subject to an interrupted kind of developement. They
may be found figured in Mirbel's Elemens, tab. x. fig. 15.;
and in Kieser, fiff. 56. and 57.

26 ORGANOGRAPHY. BOOK I.

Sect. IV. Of spurious elementary Organs ; such as Air Cells,
Receptacles of Secretion, Glands, fyc. fyc.

. The kinds of tissue now enumerated are all that have as
yet been discovered in the fabric of a vegetable. There are.
however, several other internal parts, which although not
elementary, being themselves made up of some one or other
of the forms of tissue already described, nevertheless have
either been sometimes considered as elementary, or at least
are not referable to the appendages of the axis, and can be
treated of more conveniently in this place than elsewhere.
These are, 1 . Intercellular passages ; 2. Receptacles of secre-
tion ; 3. Air cells ; 4. Raphides.

1. Of Intercellular Passages.

As the elementary organs are all modifications of either the
spherical or cylindrical figure, it must necessarily happen that
when they are pressed together, spaces between them will
remain, which will be more or less considerable in proportion
as the tissue departs in a greater or less degree from the
cylindrical or spherical form. When the pressure has been
very uniform, as in the case of the tissue of the cuticle, and in
many states of cellular substance, no spaces will exist. When
they do exist, they are called Intercellular passages [meatus or
ductus intercellulares, canaux entrecellidaires). They neces-
sarily follow the course of the tissue, being horizontal, ver-
tical, or oblique, according to the direction of the angles of
the tissue by which they are formed. Their size varies
according to the size of the tissue, and the quantity of sap.
In plants of a dry character, they are frequently so small as
to be scarcely discoverable ; while in succulent plants they are
so large as to approach the size of cellules, as in the stem
of Tropaeolum majus. (Plate II. fig. 14-.) They are con-
tinually filled with fluid, so long as the part of the plant in
which they are situated performs its vital functions, and only
become dry when it has ceased to live, as in dry pith.

CHAP. I. OF THE ELEMENTARY ORGANS. 2/

2. Of Receptacles of Secretion.

But it frequently occurs that the simple intercellular pas-
sages are dilated extremely by the secretions they receive,
and either increase unusually in size, or rupture the coats of
the neighbouring tissue; by which means cavities are formed
replete with what is called the proper juice of the plant; that
is to say, with the sap altered to the state which is peculiar to
the particular species of tree producing it. Cavities of this
nature are often called vasa propria ; they are the receptacula
sued of Link; the vaisseaux propres of Kieser and De Can-
dolle ; and the reservoirs du sue propre of the last author.
To this class also are to be referred the turpentine vessels, and
the milk vessels of Grew ; the reservoirs accidentels of M. De
Candolle ; and also the reservoirs en caecum of the latter, which
latter are the clavate vessels filled with oily fluid that are
found in the coat of the fruit of Umbelliferae, and which are
commonly called vittce. Although the receptacles of secretion
have no proper coat, yet they are so surrounded by cellular
tissue, that a lining or wall is formed, of perfect regularity and
symmetry. The tissue of this lining is generally much smaller
than that of the neighbouring parts. In figure the receptacles
are extremely variable, most commonly round, as in the
leaves of the Orange and of all Myrtacese, where they are
called crypta, or glandulce impresses, or reservoirs vesicidaires, or
glandes vesiculates, or receptacles of oil. In the Pistacia Te-
rebinthus the receptacles are tubular ; in Coniferas they are
very irregular in figure, and even position, chiefly forming
large hollow cylindrical spaces in the bark. Those in the
rind of the orange and lemon are little oblong or spherical
cysts; their construction, which is very easily examined,
gives an accurate idea of that of all the rest. (Plate II.
fig. 21.)

3. Of Air Cells.

Besides the common intercellular passages, and the recep-
tacles now described, there is another and a very remarkable

28 ORGANOGRAPHY. BOOK I.

sort of cavity among the tissue of plants. This is the air
cell ; the lacuna of Link, the reservoir d'air and cellule d 'air of
Kieser, and the luftbeh'dlter of the Germans. Like the re-
ceptacles of secretion, the air cells are built up of tissue, but
have no proper membrane of their own ; and this sometimes
takes place with a truly wonderful degree of uniformity and
beauty. Each cell is often constructed so exactly like its
neighbour, that it is impossible to regard them always as mere
accidental distensions of the tissue; on the contrary, they are,
in those plants to the existence of which they are necessary,
evidently formed upon a plan which is uniform in the species,
and which has been wisely contrived by Providence in that
manner which is most suitable to the purpose for which they
are destined.

They differ from receptacles of secretion in containing
air only, and not the proper juice of the plant ; a peculiarity
which is provided for by a curious contrivance of Nature.
In receptacles, the orifices of the intercellular passages through
which the fluid that is to be deposited drains, are all open ;
but, to prevent any discharge of fluid into the air cells, the
orifices of all the intercellular passages that would otherwise
open into them are closed up.

Air cells are very variable in size, figure, and arrangement.
In the stems of fistular plants, as Allium, they from a cavity
from the base to the summit ; in the stem of the Rush
(Juncus articulatus), they consist of a number of tubular ca-
vities placed one above the other, and separated by mem-
branous partitions composed of a combination of minute
cellules; in some aquatic plants they are very small, as in
Butomus umbellatus. In form they are either cylindrical,
or they assume the figure of the cellules by which they are
formed, as in Limnocharis Plumieri (Plate III. fig. 1. and 2.),
in which the structure of the air cells and their coats forms
one of the most beautiful of microscopical objects.

The inner surface of the air cells, when they are essential
to the life of a plant, is smooth and uniform ; but in grasses,
umbelliferous plants, and others where they are not essential,
they seem to be caused by the growth of the stem being

CHAP. I.

OF THE ELEMENTARY ORGANS.

29

more rapid than the formation of the air cells ; so that the
tissue is torn asunder into cavities of an irregular figure and
surface. Kieser was the first to observe that in many plants
in which the air cells of the stem are regularly separated
by partitions, the intercellulary passages of the cellules form-
iiirr- the partitions are sometimes left open, so that a free
communication is maintained between all the tiers of air cells.
(Plate II. fig. 2.)

4. Of Raphides.

14

15

Among the tissue, and particularly in the intercellular
passages° of Monocotyledonous plants, are found certain
needle-shaped transparent bodies, lying either singly or in
bundles, and called raphides. They were first discovered by
Rafa, who found them in the milky juice of Euphorbias ;
afterwards they were met with by M. Jurine, in the leaves of
Leucojum vernum, and elsewhere; and they are now well
known to all vegetable anatomists. It is probable that the
first discoverers considered them a kind of special organ ;
but they have subsequently been recognised to be crystals of
extreme minuteness, and, according to M. Raspail, of oxalate
of lime. If a common Hyacinth is wounded, a considerable
discharge of fluid takes place, and in this myriads of raphides
are found floating ; or if the cuticle of the leaf of Mirabilis
Jalapa is lifted up, little whitish spots are observable, which
are composed of them; all these are acicular in form, whence
their name. But in the Cactus peruvianus they are, according
to M. Turpin, found in the inside of the vesicles of cellular
tissue, and, instead of being needle-shaped, have the form of

30 ORGANOGRAPHY. BOOK I.

extremely minute conglomerated crystals, which are rectangular
prisms with tetraedral summits, some with a square, others
with an oblong base. Crystals of a similar figure have been
remarked by the same observer in Rheum palmatum ; and
their presence, according to him, is sufficient to distinguish
samples really from China and Turkey, from those produced
in Europe. The former abound in these crystals, the latter
have hardly any.

In the above figure, 15 represents the raphides of Aloe
verrucosa (from Kieser); 14, those of Cactus peruvianus; 13,
those of Rheum palmatum : the two latter from Turpin.

31

CHAPTER II.

OF THE COMPOUND ORGANS IN FLOWERING PLANTS.

Having now explained the more important circumstances
connected with modifications in the elementary organs of
vegetation, the next subject of enquiry will be the manner in
which they are combined into those masses which constitute
the external or compound organs, or in other words the parts
that present themselves to us under the form of roots, stems,
leaves, flowers, and fruit, and that constitute the apparatus
through which all the actions of vegetable life are performed.
In doing this, I shall limit myself in the first place to Flower-
ing Plants {Introduction to the Natural System, p. 1.); reserv-
ing for the subject of a separate chapter the explanation
of some of the compound organs of Flowerless plants [Ibid.
p. 307. ), which differ so much in structure from all others, as
to require in most cases a special and distinct notice.

Sect. I. Of the Cuticle and its Appendages.

1. Of the Cuticle.

Vegetables, like animals, are covered externally by a thin
membrane or cuticle, which usually adheres firmly to the
cellular substance beneath it. To the naked eye it appears
like a transparent homogeneous pellicle, but under the mi-
croscope it is found to be traversed in various directions by
lines, which, by constantly anastomosing, give it a reticulated
character. In some of the lower tribes of plants, consisting
entirely of cellular tissue, it is not distinguishable, but in all
others it is to be found upon every part, except the stigma
and the spongioles of the roots. Its usual character is that
of a delicate membrane, but in some plants it is so hard as
almost to resist the blade of a knife, as in the pseudo-bulbs of

32 ORGANOGRAPHY. BOOK I.

certain Orchideous plants. The most usual form of the
reticulations is the hexagonal (Plate III. fig. 11.) : sometimes
they are exceedingly irregular in figure; often prismatical ;
and not unfrequently bounded by sinuous lines, so irregular
in their direction as to give the meshes no determinate figure
(fig. 5.).

Botanists have not agreed as to the exact nature of the
cuticle ; while the greater number incline to the opinion
that it is an external layer of cellular tissue in a dry and
compressed state; others, among whom are included both
Kieser and Amici, consider it a membrane of a peculiar nature,
transversed by veins, or vasa lymphatica.

By the latter it is contended, that the sinuous direction of
the lines in many cuticles is incompatible with the idea of
any thing formed by the adhesion of cellular tissue; that
when it is once removed, the subjacent tissue dies, and does
not become cuticle in its turn, and that it may often be torn
up readily without laceration.

On the other hand, it is contended, that the reticulations of
the cuticle are mostly of some figure analogous to that of
cellular tissue, and that the sinuous meshes themselves are
not so different as to be incompatible with the idea of a mem-
brane formed of adhering cellules. We are accustomed to
see so much variety in the mere form of all parts of plants,
that an anomalous configuration in cellular tissue should not
surprise us. The lines, or supposed vasa lymphatica, are
nothing more than the united sides of the cellules, and are
altogether the same as are presented to the eye by any section
of a mass of cellular substance. It is certain that the cuticle
cannot be removed without lacerating the subjacent tissue,
with however much facility it may be sometimes separable:
on the under surface of the leaf of the Box, for instance, there
has plainly been some tearing of the tissue, before the cuticle
acquired the loose state in which it is finally found. If the
subjacent epidermis never becomes cuticle when the latter is
removed, this is no reason why the cuticle itself should not be
composed of cellular tissue ; for it is an axiom in vegetable
physiology, that a part once fully formed is incapable of any
subsequent change. Thus, pith never alters its dimensions,

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 33

after the medullary sheath that encloses it has been once
completed, and a zone of wood never contracts or expands
after it has been deposited : new matter may be added to
any part, but the arrangement of the tissue, once fixed, re-
mains unchangeable.

The principal argument, however, in favour of cuticle being
compressed cellular tissue, is, that in the cuticle of many
plants the cellular state is distinctly visible upon a section
(Plate I. fig. 2. a) ; that it even consists occasionally of several
layers of cellules, as in many epiphytes of the Orchis tribe;
and that, as there is no reason to doubt that Nature is as uni-
form in the plan upon which cuticle is constructed as in all
her other works, in those cases in which the cellular structure
is less distinctly visible, we are nevertheless ' istified by sound
philosophy in recognising it; while, on the other hand, it
would be highly unphilosophical to suppose that the cuticle
is formed in some plants upon one plan, and in others upon
a totally different one. It may be farther remarked, that
separable cuticle may often be traced into that which, being
younger, is both inseparable and undistinguishable from the
other cellular substance with which it is in contact, and from
which it possesses no organic difference.

There is some reason to suppose that there is occasionally
present, on the outside of the cuticle, a transparent, very deli-
cate membrane, having no organic structure, as far as can be
discovered with the most powerful microscopes. Something
of this kind has been noticed by M. Adolphe Brongniart in
the Cabbage leaf, and an analogous structure has been re-
marked by Professor Henslow in the Digitalis.

2. Of Stomata.

In many plants the cuticle has certain openings of a very
peculiar character, which appear connected with respiration,
and which are called Stomata. (Plate III. passim.)

Stomata [Pores of the epidermis ; Pores corticaux, allonge's,
evajioratoires, or grands pores •, Glands corticales, miliaires, or
epidermoi dales ; Gland/da? cutanea? ,■ Oejfnungen ,■ Stomal ia ,•)
are passages through the cuticle, having the appearance of

D

34. ORGANOGRAPHY. BOOK I.

areolae, in the centre of which is a slit that opens or closes
according to circumstances, and lies over a cavity in the sub-
jacent tissue.

There is, perhaps, nothing in the structure of plants upon
which it is more difficult to form any satisfactory opinion
than these stomata. Malpighi, and Grew, who seems first to
have figured them {see his plate xlviii. fig. 4.), call them
openings or apertures, but had no exact idea of their struc-
ture. Mirbel also, for a long time, considered them pores, and
figured them as such ; admitting, however, that he suspected
the openings to be an optical deception. M. De Candolle
entertains no doubt of their being passages through the cu-
ticle. He says their edge has the appearance of a kind of
oval sphincter, capable of opening and shutting. The mem-
brane that surrounds this sphincter is always continuous with
those which constitute the network of the cuticle : under the
latter, and in the interval between the pore and the edge of
the sphincter, are often found molecules of adhesive green
matter {Organogr.'i. 80.); and recently M. Adolphe Brong-
niart, in his beautiful figures of the anatomy of leaves, would
seem to have settled the question beyond all dispute. {Annales
des Scie?ices, vol. xxi.) Nevertheless, there are anatomists
of high reputation who entertain a directly opposite opinion ;
denying the existence of passages, and considering the sto-
mata rather in the light of glands. Nees von Esenbeck
and Link deny the existence of any perforation in the sto-
mata, and consider that the supposed opening is a space more
pellucid than the surrounding tissue, and that what seems a
closed up slit is the thickened border of the space. Link
further adds, that the obscuration of the centre of the stomata
is caused by a peculiar secretion of matter, as is plainly
visible in Baryosma serratum. {Elementa, p. 225.) To the
views of these writers is to be added the testimony of Mr.
Brown {Suppl. prim. Prodr. p. 1.), who describes the stomata
as glands which are really almost always imperforate, with a
disk formed by a membrane of greater or less opaqueness, and
even occasionally coloured ; at the same time he speaks of
this disk being, perhaps, sometimes perforated.

In the midst of such conflicting testimony, an observer

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 35

necessarily finds much difficulty in fixing his opinion. I shall
take the liberty of stating what I myself have seen, without,
however, supposing that my humble authority can in any
degree contribute to the determination of the question. In
no plants are stomata larger than in some Monocotyledons ;
they are, therefore, the best subjects for examination for
general purposes. In Crinum amabile they evidently consist
of two kidney-shaped bodies filled with green matter, lying
upon an area of the cuticle smaller than those that surround
it, and having their incurved sides next each other. In some,
at the part where the kidney-shaped bodies come in contact,
there is an elevated ridge, dark, as if filled with air, and
having its principal diameter distinctly divided by a line.
(Plate III. fig. 11.) In this state the stoma is at rest: but
in others the kidney-shaped bodies are much more curved ;
their sides are more separated from each other ; and there is
no elevated ridge : at their former line of contact there is an
opening so distinct and wide as to be equal to half the diameter
of one of the kidney -shaped bodies; this, I presume, is the
stoma open. That what is described to be an opening, is
really so, seems to be demonstrated by the following tests : —
1. It is more transparent than any part of the most trans-
parent portion of the cuticle ; 2. It admits transmitted light
without interruption ; as is seen by gradually augmenting the
magnifying power by which it is viewed, when the opening
continues transparent, notwithstanding the great loss of light
that attends the use of very high powers in compound mi-
croscopes; and, 3. None of those arts which the microscopic
observer knows so well how to employ, such as shifting,
augmenting or decreasing the light, interposing moveable
shadows between the mirror and the object, and the like, give
the least indication of the presence of any membrane across
the orifice of the stoma. I therefore conclude, that, in the
Crinum amabile, the stomata are formed by two elastic reni-
form cellules, lying over an opening in the centre of a con-
tracted area of cuticle ; that these cellules, when expanded,
meet, and press powerfully against each other, like two
opposing springs ; thus causing the elevated ridge-like ap-
pearance visible in the axis of the stoma in the figure above

d 2

36 ORGANOGRAPHY. BOOK I.

referred to ; and that, when contracted, they curve in an oppo-
site direction, separating from each other, and ceasing to
close up the aperture over which they lie. If it were possible
to be absolutely certain of the accuracy of this description, the
structure of the stoma in Crinum amabile might be safely
taken as the type of all others ; for, no doubt, they are all
constructed upon a similar plan. Without actually asserting
so much as this, I may venture to state, that, of many hun-
dreds of observations I have made upon this subject, I have
not met with any thing that has led me to doubt the uni-
formity of their nature, or their general accordance with what
is found in Crinum amabile, whatever that may be. Or at
least, the only difference is this, that while the two cellules
that form the edges of the aperture are distinctly separated at
their extremities in this plant, they are often confluent in
others, as in Caladium esculentum. (Plate III. fig. 9.) Several
varieties are represented at Plate III. ; besides which, they
have been noticed by Link to be occasionally quadrangular,
as in Yucca gloriosa (Plate III. fig. 10.), and Agave ameri-
cana, and by Mr. Brown to be very rarely angular, of which,
however, no instance is cited by that botanist. The former
case is one in which the quadrangular figure is caused by the
cellules being straight ; I am not aware if Mr. Brown means
the same thing.

I have never been so fortunate as to discover the mem-
brane which Mr. Brown describes as generally overlying the
apertures ; nor do I know of any other botanist having con-
firmed that observation.

Stomata are not found in Mosses, Hepaticae, Fungi, Algas,
or Lichens (see Introduction to the Natural System)', in no
submersed plants, or submersed parts of amphibious plants ;
it is also said, not in Monotropa hypopithys, Neottia nidus
avis, and Cuscuta europaea. They are not formed in the
cuticle of plants growing in darkness ; are very small in
trees and shrubs, particularly evergreens, and more espe-
cially in such as have coriaceous leaves, and acrid or aromatic
juices. {Iiudolphi.) They are not present upon roots, or
the ribs of leaves. It also frequently happens that they are
found upon one surface of a leaf, but not on another, and

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 37

generally in most abundance on the under side. In suc-
culent plants, or in the succulent parts of other plants, they
are either rare, or wholly wanting. They may be generally
seen upon the calyx ; often on the corolla ; and rarely, but
sometimes, upon the filaments, anthers, and styles. In fruit,
they have only been noticed upon such as are membranous,
and never upon the coat of the seed ; they exist, however,
upon the surface of cotyledons.

Mr. Brown thinks that the uniformity of the stomata, in
figure, position, and size, with respect to the meshes of the
cuticle, is often such as to indicate the limits, and sometimes
the affinities, of genera, and of their natural sections. He
has shown, with his usual skill, that this is the case in Pro-
teaceae. He also remarks, that on the microscopic character
of the equal existence of stomata on both surfaces of the leaf
depends that want of lustre which is so remarkable in the
forests of New Holland. {Journal of the Royal Geogr. Society,
i. 21.)

The same botanist is of opinion, that the two glands, or cel-
lules, of which a stoma is composed, are each analogous to the
single cellules found occupying the inner face of the meshes
of the cuticle. (Plate iii. fig. 9.) See the Memoir on the
Impregnation of Orchidece.)

The surface of the cuticle is either perfectly smooth, or
furnished with numerous processes, consisting of cellular tissue
in different states of combination, which may be arranged
under the heads of hairs, scales, glands, and jnnckles. All
these oi-iginate either directly from the cuticle, or from the
cellular substance beneath it ; never having any communication
with the vascular or ligneous system.

In Nepenthes the cuticle in the inside of the pitchers is
pierced by a great number of holes, each of which is closed
up by a firm thick disk of small cellular tissue, deep brown in
colour, and connected with the cavernous parenchyma of the
pitcher. Besides these, Nepenthes has also stomata.

Nerium oleander and some other plants have, in lieu of
stomata, cavities in the cuticle, curiously filled up or protected
by hairs. (See Annales des Sciences, xxi. 438.)

D 3

38 ORGANOGRAPHY. BOOK I.

3. Of Hairs.

These (Jig.16.) are minute,
transparent, filiform, acute
processes, composed of cel-
lular tissue more or less elon-
gated, and arranged in a single row. They are found occasion-
ally upon every part of a plant, even in the cavities of the
and stem, as in Nymph ae a and other aquatic plants. In
the Cotton Plant (Gossypium herbaceum, &c.) they form the
substance which envelopes the seeds, and is wrought into linen;
in the Cowhage (Mucuna urens and pruriens), it is they that
produce the itching; and in the Palm tribe they are the long,
entangled, soft, strangulated filaments that are used for Ama-
dou. They vary extremely in length, density, rigidity, and
other particulars ; on which account they have been distin-
guished by the following names : —

Down or Pubescence (pubes, adj. pubescens), when they form
a short soft stratum, which only partially covers the cuticle, as
in Geranium molle.

Hairiness (hirsuties, adj. hirsutus), when they are rather
longer and more rigid, as in Galeopsis Tetrahit.

Pili (pilus, adj. pilosus), when they are long, soft, and erect,
as in Daucus Carota.

Villus (adj. villosus), when they are very long, very soft,
erect, and straight, as in Epilobium hirsutum. Crini (adj.
crinitus) are this variety in excess.

Velvet (velumen, adj. vehrfinus), when they are short, very
dense and soft, but rather rigid, and forming a surface like
velvet, as in many Lasiandras.

Tomentum (adj. totnentosus), when they ai'e entangled, and
close pressed to the stem, as in Geranium rotundifolium.

Cilice (adj. ciliatus), when long, and forming a fringe to a
margin, like an eyelash, as in Sempervivum tectorum.

Bristles (setce, adj. setosus), when short and stiff, as on the
stems of Echium.

Stings (stimuli, adj. stimulans; pili subulati of De Candolle),

CHAP. II. COMPOUND ORGANS IN FLOWERING TLANTS. 39

when stiff and pungent, giving out an acrid juice if touched,
as in the Nettle.

Glandular hairs (pili capitati), when they are tipped with
a glandular exudation, as in Primula sinensis. These must
not be confounded with stalked elands.

Hooks (hami, unci, roslella), when curved back at the point,
as in the nuts of Myosotis Lappula.

Barbs (glochis, adj. glochidatus), if forked at the apex, both
divisions of the fork being hooked, as in the nuts of the same
plant.

Hairs also give the following names to the surface of any
thing : —

1. Silhj (scriceus), when they are long, very fine, and
pressed closely to the surface, so as to present a sublucid silky
appearance ; ex. Protea argentea.

2. Arachnoid, when very long, and loosely entangled, so as
to resemble cobweb : ex. Calceolaria arachnoidea.

3. Manicate, when interwoven into a mass that can be
easily separated from the surface : ex. Cacalia canescens,
Bupleurum giganteum.

4. Bearded {barbatus), when the hairs are long, and placed
in tufts : ex. the lip of Chelone barbata.

5. Bough (asper), when the surface is clothed with hairs,
the lower joint of which resembles a little bulb, and the upper
a short rigid bristle : ex. Borago officinalis.

Hairs are either formed of a single cell of cellular tissue
(Plate I. fig. 8. b), or of several placed end to end in a single
series (Plate I. fig. a, b.), whence, if viewed externally, they
have the appearance of being divided internally by transverse
partitions. They are sometimes divided into two or three
forks at the extremity, as in Alyssum, some species of Apargia,
&c. Occasionally they emit little branches along their whole
length : when such branches are very short, the hairs are said
to be toothed or toothleted, as in the fruit of Torilis Anthris-
cus ; when they are something longer, the hairs are called
branched, as in the petioles of the gooseberry ; if longer and
finer still, the term is pinnate, as in Hieracium Pilosella; if the
branches are themselves pinnate, as in Hieracium undulatum,

d 4

40 ORGANOGRAPHY. BOOK I.

the hairs are then said to be plumose. It sometimes happens
that little branchlets are produced on one side only of a
hair, as on the leaves of Siegesbeckia orientalis, in which case
the hair is called one-sided {secundatus) ; very rarely they appear
upon the articulations of the hair, which in that case is called
ganglioneous. (Plate I. fig. 9. Verbascum Lychnitis) : \\~\e poils
en goupillon of De Candolle are referable to this form. Be-
sides these, there are many other modifications. Hairs are
conical, cylindrical, or moniliform, thickened slightly at the
articulations (torulose), as in Lamium album, or much en-
larged at the same point (nodulose), as in the calyx of Achy-
ranthes lappacea.

Hairs are sometimes said to be Jixed by their middle
(Plate I. fig. 10. c) ; a remarkable structure, common to many
different genera; as Capsella, Malpighia, Indigofera, &c.
This expression, however, like many others commonly used
in botany, conveys a false idea of the real structure of such
hairs. They are in reality formed by an elevation of one cel-
lule of the cuticle above the level of the rest, and by the
developement of a simple hair from its two opposite sides.
Such would be more correctly named divaricating hairs.
When the central cellule has an unusual size, as in Malpighia,
these hairs are called poils en navette (pili Malpighiacei) by
M. De Candolle ; and when the central cellule is not very
apparent, poils en fausse navette (pili pseudo-Malpighiacei,
biacuminati), as in Indigofera, Astragalus, Asper, &c. In
many plants the hairs grow in clusters, as in Malvaceae, and
are occasionally united at their base : such are called stellate,
and are frequently peculiar to certain natural orders. (Plate I.
fig. 10. a.)

All these varieties belong to one or other of the two prin-
cipal kinds of hairs ; viz. the Lymphatic and the Secreting.
Of these, lymphatic hairs consist of tissue tapering gradually
from the base to the apex ; and secreting, of cellules visibly
distended either at the apex or base into receptacles of fluid.
Malpighiaceous and glandular hairs, stings, and those which
cause asperity on the surface of any thing, belong to the latter;
almost all the other varieties to the former.

When hairs arise from one surface only of any of the

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 41

appendages of the axis, it is almost always from the under
surface ; but the seed leaves of the nettle, and the common
leaves of Passerina hirsuta, are mentioned by M. De Candolle
as exceptions to this rule : certain states of Rosa caniua
might also be mentioned as exhibiting a similar phenomenon.
When a portion only of the surface of any thing is covered
by hairs, that portion is uniformly the ribs or veins. According
to M. De Candolle, hairs are not found either upon true roots,
except at the moment of germination, nor upon any part of
the stem that is formed under ground, nor upon any parts
that grow under water.

4. Of Scales.

Scales are thin flat membranous processes, formed of
cellular tissue springing from the cuticle. They may be con-
sidered as hairs of a higher order, — as organs of the same
nature, but more developed ; for they differ from hairs only in
their degree of composition. They are of two kinds, Scales
properly so called, and Momenta. Care must be taken not to
confound scales of this description with scales of the stem, to
be described hereafter : those now under consideration being
mere processes of the cuticle ; those to be noticed hereafter
being peculiar modifications of leaves.

Scales, properly so called, are the small, roundish, flattened
particles which give a leprous appearance to the surface of
certain plants, as the Elaeagnus and the Ananassa. (Plate I.
fig. 10. b.) They consist of a thin transparent membrane,
attached by its middle, and, owing to the imperfect union
towards its circumference, of the cellular tissue of which it is
composed, having a lacerated irregular margin. A scale of
this nature is called in Latin composition lepis, and a surface
covered by such scales lepidotus, and not squamosus, which is
only applied to a surface covered with the rudiments of leaves.
Scales are the jjoils en ecusson {pill scutati) of De Candolle.

Ramenta (Vaglnella:) are thin, brown, foliaceous scales,
appearing sometimes in great abundance upon young shoots.
They are particularly numerous, and highly developed,
upon the petioles and the backs of the leaves of Ferns.
They consist of cellular tissue alone, without any vascular

42 ORGANOGRAPHY. BOOK I.

bundles, and are known from leaves not only by their anato-
mical structure, but also by their irregular position, and by the
absence of buds from their axillae. The student must particu-
larly remark this, or he will confound with them leaves having
a ramentaceous appearance, such as are produced upon the
young shoots of Pinus. Link remarks, that they are very
similar in structure to the leaves of mosses. The term striga
has occasionally been applied to them (Dec. Theor. Elan.
ed. 2. 376. Link, Elcm, 240.) ; but that word was employed
by Linnaeus to designate any stiff bristle-like process, as the
spiiies of the Cactus, the divaricating hairs of Malpighia, and
the stiff stellated hairs of Hibiscus. So vague an application
of the term is very properly avoided at the present day, and
the substantive is rejected from modern glossology ; the ad-
jective term strigose is, however, occasionally still employed
to express a surface covered with stiff hairs.

5. Of Glands.

Glands are elevated spaces in the stratum of parenchyma
lying immediately below the cuticle, in which they cause pro-
jections. They are of several kinds.

Stalked glands are elevated on a stalk which is either sim-
ple or branched : they secrete some peculiar matter at their
extremities, and are often confounded with the glandular
hairs above described, from which they have been well dis-
tinguished by Link. According to that botanist, they are
either simple or compound ; the former consisting of a single
cell, and placed upon a hair acting as a simple conduit, oc-
casionally interrupted by divisions ; the latter consisting of
several cells, and seated upon a stalk containing several con-
duits, formed by rows of cellular tissue. They are common
upon the rose and the bramble, in which they become very
rigid, and assume the nature of aculei. For the sake of dis-
tinguishing them from the latter, they have been called sctce
by Woods and myself, but improperly ; they are also the
aigxdllons of the French. In Hypericum they abound on the
calyx and corolla of some species, but do not give out any
exudation ; they contain, however, a deep red juice within

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 43

their cells. In some Jatrophas they are much branched ; in
many Diosmeee they form a curious humid appendage at the
apex of the stamens.

Sessile glands are produced upon various parts, and are
extremely variable in figure. In Cassias, they are seated
upon the upper edge of the petiole, and are usually cylin-
drical or conical; in Cruciferous plants they are little roundish
shining bodies, arising from just below the base of the ova-
rium ; in the leafless Acacias, they are a little depressed, with
a thickened rim, and placed on the upper edge of the phyllo-
dium ; they are little kidney-shaped bodies upon the petiole
of the Peach and other drupaceous plants ; and they assume
many more appearances.

Verruca, or warts, are roundish excrescences, formed of
cellular tissue filled with opaque matter, and are situated
upon various parts. They are common upon the surface of
the leaves of the Aloe, where they are very large ; upon the
stem, as in Euonymus verrucosus ; upon the petiole, as in
Passiflora; they are also found upon the calyx, as in some
species of Campanula, and at the serratures of the leaves,
when they are considered by M. Roper (De Floribus Bal-
saminearum, p. 15.) to be abortive ovula. They also appear
upon the pericarpium and the testa of the seed; in the latter
case they are called spongioid: seminales by De Candolle.
They are round, oblong, or reniform, and occasionally cupu-
late, when they receive the name of glandes a godet (glan-
didte urceolares) from some French writers. Verrucas are the
glandes ccllulaiTes of Mirbel ; but they must not be confounded
with the glandes vasculaires of the same writer, which are not
mere excrescences of the epidermis, but modifications of
well known organs. (See Discus, further on.) The presence
of minute verrucas upon the surface of a leaf gives rise to a
peculiar kind of roughness which is called scabrities, and such
a surface is then said to be scabrous (scaber) : this must not
be confounded with asperity.

Papilla; {Glandidce idriculaires of Guettard) are minute
transparent elevated points of the cuticle, filled with fluid, and
covering closely the whole surface upon which they appear.
In other words, they are elevated, distended cellules of the

44< ORGANOGRAPHY. BOOK I.

cuticle. The presence of papillae upon the leaves of the
ice plant gives rise to the peculiar crystalline nature of its
surface; they also cause the satiny appearance of the petals,
upon which they almost always exist in great quantities.
Link remarks, that the petals of Plantago, which are destitute
of papillae, are also without the usual satiny lustre of those
organs. When the papillae are much elongated beyond the
surface, as in many stigmas, of which they form the collecting
fringes, they receive sometimes the name of papulce. It
should be observed, that in M. De Candolle's Theorie Elemen-
taire, these two terms are transposed, each having received
the definition belonging to the other.

Lenticular glands (Lenticelles of De Candolle ; Glandes
lenticulaires of Guettard ;) are brown oval spots found upon
the bark of many plants, especially willows : they indicate the
points from which roots will appear if the branch be placed
in circumstances favourable to their production. They are
considered by M. De Candolle to bear the same relation to
the roots that buds bear to young branches. (De Candolle^ Pre-
mier Mem. sur les Lentic., in the Ann. des Sciences Nuturellcs.)

6. Of Prickles.

Prickles (aculei) are rigid, opaque, conical processes,
formed of masses of cellular tissue, and terminating in an
acute point. They may be, not improperly, considered as very
compound indurated hairs. They have no connection with
the woody fibre, by which character they are obviously distin-
guished from spines, of which mention will be made under
the head of branches, of which spines are an abortion.
Prickles are found upon all parts of a plant, except the sti-
pulae and stamens. They are very rarely found upon the
corolla, as in Solanum Hystrix ; their most usual place is
upon the stem, as in Rosa, Rubus, &c.

Sect. II. Of the Stem or Ascending Axis.

When a plant first begins to grow from the seed, it is a
little body called an embryo, with two opposite extremities, of

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 45

which the one elongates in the direction of the earth's centre,
and the other, taking a direction exactly the contrary, extends
upwards into the air. This disposition to develope in two
diametrically opposite directions is found in all seeds, pro-
perly so called, there being no known exception to it; and the
tendency is moreover so powerful, that, as we shall hereafter
see (Book II.), no external influence is sufficient to overcome
it. The result of this developement is the axis, or centre,
round which the leaves and other appendages are arranged.
That part of the axis which forces its way downwards, con-
stantly avoiding light, and withdrawing from the influence of
the air, is the descending axis, or the root ; and that which
seeks the light, always striving to expose itself to the air, and
expanding itself, to the utmost extent of its nature, to the solar
rays, is the ascending axis, or the stem. As the double elonga-
tion just mentioned exists in all plants, it follows that all plants
must necessarily have, at an early period of their existence at
least, both stem and root ; and that, consequently, when plants
are said to be rootless, or stemless, such expressions are not
to be considered physiologically correct.

The Stem has received many names ; such as candex
asce?ide?is, caudex intermedins, cidnms, stipes, truncus, and
truncus ascendens. It always consists of bundles of vascular
and woody tissue, embedded in cellular substance in various
ways, and the whole enclosed within a cuticle. The manner
in which these parts are arranged with respect to each other
will be explained hereafter. The more immediate subject of
consideration must be the parts that are common to all
stems.

1. Of its Parts.

Where the stem and root, or the ascending and descend-
ing axes, diverge, there commences in many plants a differ-
ence of anatomical structure, and in all a very essential
physiological dissimilarity ; as will be hereafter seen. This
portion of the axis is called the neck or collum, (coarclure
of Grew, nceud vital of Lamarck, limes cojjummis, or fundus
planter, of Jungius,) and has been thought by some to be the

46 ORGANOGRAPHY. BOOK X.

seat of vegetable vitality ; an erroneous idea, of which more
will be said in the next book. At first it is a space that we
have no difficulty in distinguishing, so long as the embryo, or
young plant, has not undergone any considerable change ;
but in process of time it is externally obliterated ; so that in
trees of a few years' growth its existence becomes a matter of
theory, instead of being actually evident to our senses.

Immediately consequent upon the growth of a plant is the
formation of leaves. The point of the stem whence these
arise is called the nodus (geniculum, Jungius; nceud, Fr. ;) and
the space between two nodi is called an internodium (en-
trenceud Fr.; merithallus, Du Petit Thouars). In internodia the
arrangement of the vascular and fibrous tissue, of whatever
nature it may be, of which they are composed, is nearly
parallel, or, at least, experiences no horizontal interruption.
At the nodi, on the contrary, vessels are sent off horizontally
into the leaf; the general developement of the axis is mo-
mentarily arrested while this horizontal communication is
effecting, and all the tissue is more or less contracted. In
many plants this contraction, although it always exists, is
scarcely appreciable ; but in others it takes place in so re-
markable a degree as to give their stems a peculiar character;
as, for instance, in the Bamboo, in which it causes diaphragms
that continue to grow and harden, notwithstanding the pow-
erfully rapid horizontal distension to which the stems of that
plant are subject. In all cases, without exception, a leaf-bud
or buds is formed at a nodus immediately above the base of
the leaf; generally such a bud is either sufficiently apparent to
be readily recognised by the naked eye, or, at least, it becomes
apparent at some time or other : but in certain plants, as
Heaths, the buds are often never discoverable ; nevertheless,
they always exist, in however rudimentary a state, as is proved
by their occasional developement under favourable or uncom-
mon circumstances. By some writers nodi, upon which buds
are obviously formed, are called compound, or artiphyllous •
and those in which no apparent buds are discoverable, are
named simple, or plci plujilous : they are also said to be divided,
when they do not surround the stem, as in the apple and
other alternate-leaved genera; or entire, when they do surround

CIlAr. II. COMPOUND ORGANS IN FLOWERING PLANTS. 47

it, as in grapes and umbelliferous plants : they are further
said to he pervious, when the pith passes through them without
interruption, or closed, when the canal of the pith is inter-
rupted, as if by a partition. Pervious and divided, and closed
and entire nodi usually accompany each other. For other
remarks upon this subject, see Link's Elementa.

All the divisions of a stem are in general terms called
branches {rami) ; but it is occasionally found convenient to ex-
press particular kinds of branches by special names. Thus, the
twigs, or youngest shoots, are called ramuli or branchlets
{brindilles or ramilles, Fr.), and by the older botanists Jlagclla :
the assemblage of branches which forms the head of a forest
tree is called the coma : cyma is sometimes used to express
the same thing, but improperly.

Shoots which have not completed their growth have re-
ceived the name of innovations, a term usually applied to
mosses. When such a shoot is covered with scales upon its
first appearance, as the Asparagus, it is called turio : by the
old botanists all such shoots were named asparagi. When a
shoot is Ions and flexible, it receives the name of vimcn. This
word, however, is seldom used ; its adjective being employed
instead : thus, we say, rami viminei, or caulis vimineus ; and not
vimen. From this kind of branch, that called a virgate stem,
caulis virgatus, differs only in being less flexible and more
riend. A vounsr slender branch of a tree or shrub is some-

© Jo

times named virgultum. When the branches diverge nearly
at right angles from the stem, they are said to be brachiate.
Small stems, which proceed from buds formed at the neck of
a plant without the previous production of a leaf, are called
cauliculi.

Besides these terms, Du Petit Thouars employed cer-
tain French words in a way peculiar to himself. The first
young shoot produced during the year by a tree, he named
scion ; any subsequent shoots formed by the scion, he termed
ramilles ; the shoot that supports the scion was a ramcau; that
which supports the rameau a branche ; and the trunk which
bears the whole the tronc. Professor Link calls a stem
which proceeds straight from the earth to the summit, bearing
its branches on its sides, as Pinus, a caidis excurrens, and a

48 ORGANOGRAPHY. BOOK I.

stem which at a certain distance above the earth breaks out
into irregular ramifications, a caidis deliquescens.

From the constitution and ramifications of their branches,
plants are divided into trees, shrubs, and herbs. When the
branches are perennial, and supported upon a trunk, a tree
(arboy-) is said to be formed ; for a small tree, the term arbus-
culus is sometimes employed. When the branches are peren-
nial, proceeding directly from the surface of the earth without
any supporting trunk, we have a shrub (frutex or arbustum,
Lat., and arbrisseau, Fr.), which occasionally, when very small,
receives the diminutive name of fruticulus. If a shrub is low,
and very much branched, it is often called dumosus (subst.
dumas) : this kind of shrub is what the French understand by
their word buisson. The suffrutex, undcr-shrub, or sous-arbris-
sean, differs from the shrub, in perishing annually, either
wholly or in part ; and from the herb, in having branches of a
woody texture, which frequently exist more than one year :
such is the Mignonette (Reseda odorata) in its native country,
or in the state in which it is known in gardens as the Tree
Mignonette. The under-shrub is exactly intermediate between
the shrub and the herb. All plants producing shoots of
annual duration from the surface of the earth are called
herbs.

Some botanists distinguish two sorts of stems, the characters
of which are derived from their mode of growth. When a
stem is never terminated by a flower-bud, nor has its growth
stopped by any other organic cause, as in Veronica arvensis,
and all perennial and arborescent plants, it is said to be
indeterminatus ; but when a stem has its growth uniformly
stopped at a particular period of its existence by the production
of a terminal bud, or by some such cause, it is called determi-
natiis. The capitate and verticillate species of Mint owe their
differences to causes of this nature; the stem of the former
being determinate, the latter indeterminate.

Some branches are imperfectly formed, lose their power
of extension, become unusually hard, and acquire a sharp
point. They are then called spines (spina), and must not be
confounded with prickles, already described, from which
they are distinguishable by their woody vascular centre.

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS.

49

Occasionally, as in the Whitethorn, they bear leaves. In do-
mesticated plants they often entirely disappear, as in the Apple
and Pear, the wild varieties of which are spiny, and the culti-
vated ones spineless.

The point whence two branches diverge is called the axilla,
or, in old botanical language, the ala.

Leaf-buds {Gemma, Linn. Bourgeon, Fr.), being the rudi-
ments of young branches, are of great importance in regard
to the general structure of a plant. They consist of scales

17 18

imbricated over each other, the outermost being the hardest
and thickest, and surrounding a minute axis which is in direct
communication with the woody and cellular tissue of the stem.
Linnaeus called this bud Hybemacidum, because it serves for
the winter protection of the young and tender parts ; and dis-
tinguished it into the Gemma, or leaf-bud of the stem, and
the Bulb, or leaf-bud of the root.

The leaf-bud has been compared by Du Petit Thouars and
some other botanists to the embryo, and has even been de-
nominated a Jixed embryo. This comparison must not, how-
ever, be understood to indicate any positive identity between
these two parts in structure, but merely an analogous func-
tion, both being formed for the purpose of reproduction ;
both in origin and structure they are entirely different. The
leaf-bud consists of both vascular and cellular tissue, the
embryo of cellular tissue only: the leaf-bud is produced
without sexual intercourse, to the embryo this is essential :

50

ORGANOGRAPHY.

BOOK I.

finally, the leaf-bud perpetuates the individual, the embryo
continues the species.

The usual, or normal, situation of'leaf-buds is in the axillae
of leaves; and all departure from this position is either irre-
gular or accidental. Botanists give them the name of regular
when they are placed in their normal station, and they call all
others latent or adventitious. The latter have been found in
almost every part of plants; the roots, the internodia, the
petiole, the leaf itself, have all been remarked producing them.
On the leaf they usually proceed from the margin, as in Malaxis
paludosa, where they form minute granulations, first deter-
mined to be buds by Professor Henslovv, or as in Bryophyl-
lum calycinum and Tellima grandiflora ; but they have been
seen by M. Turpin proceeding from the surface of the leaf
of Ornithogalum. (fig. 19.)

We are wholly unacquainted with the cause of the form-
ation of leaf-buds ; all we know is, that they appear to pro-
ceed from woody or vascular, and not from cellular tissue.
There is, indeed, an opinion, which I believe is that of Mr.
Knight, that the sap itself can at any time generate buds
without any previously formed rudiment ; and that they de-
pend, not upon a specific alteration of the arrangement of
the vascular system, called into action by particular circum-
stances, but upon a state of- the sap favourable to their
creation. In proof of this it has been said, that if a bud of
the Prunus Pseudo-cerasus, or Chinese Cherry, be inserted
upon a cherry stock it will grow freely, and after a time will
emit small roots from just above its union with the stock ;

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 51

at the time when these little roots are formed, let the shoot
be cut back to within a short distance of the stock, and the
little roots will then, in consequence of the great impulsion of
sap into them, become branches emitting leaves.

The leaf-buds of the deciduous trees of cold climates are
covered by scales, which are also called tegmenta ; these afford
protection against cold and external accidents, and vary much
in texture, thickness, and other characters. Thus, in the
Beech, the tegmenta are thin, smooth, and dry ; in many Wil-
lows they are covered with a thick down ; in Popidus balsa-
mifera they exude a tenacious viscid juice. In herbaceous
plants and trees of climates in which vegetation is not exposed
to severe cold, the leaf-buds have no tegmenta ; which is also,
but very rarely, the case in some northern shrubs, as Rham-
nus Frangula.

The scales of the bud, however dissimilar they may be to
leaves in their ordinary appearance, are nevertheless, in reality,
leaves in an imperfectly formed state. They are the last
leaves of the season, developed at a period when the current
of vegetation is stopping, and when the vital powers have
become almost torpid. That such is really their nature is
apparent from the gradual transition from scales to perfect
leaves, that occurs in such plants as Virburnum prunifolium,
Magnolia acuminata, Liriodendron tulipifera, and iEsculus
Pavia ; in the latter the transition is, perhaps, most satisfac-
torily manifested. In this plant the scales on the outside are
short, hard, dry, and brown ; those next them are longer, and
greenish, and delicate ; within these they become dilated, are
slightly coloured pink, and occasionally bear a few imperfect
leaflets at their apex ; next to them are developed leaves of
the ordinary character, except that their petiole is dilated and
membranous like the inner scales of the bud ; and, finally,
perfectly formed leaves complete the series of transitions.

Among the varieties of root is sometimes classed what
botanists call a bulb ,• a scaly body, formed at or beneath the
surface of the ground, emitting roots from its base, and pro-
ducing a stem from its centre. Linnaeus considered it the
leaf-bud of a root; but in this he was partly mistaken, roots
being essentially characterised by the absence of buds. He

f. 2

52

ORGANOGRAPHY.

BOOK I.

was, however, perfectly correct in identifying it with a leaf-
bud. A bulb has the power of propagating itself by deve-
loping in the axillae of its scales new bulbs, or what gardeners
call cloves, ( Cayeu, French ; Nucleus and Adnascens of the
older botanists ; Adnatum of Richard ;) which grow at the ex-
pense of their parent bulb, and eventually destroy it. Every
true bulb is, therefore, necessarily formed of imbricated
scales, and a solid bulb has no existence. The bulbi solidi, as
they have been called, of the Crocus, the Colchicum, and
others, are, as we shall hereafter see (see Cormus), a kind of
ubterranean stem : they are distinct from the bulb in being
not an imbricated scaly bud, but a solid fleshy stem, itself
emitting buds. It has been supposed that they were buds,
the scales of which had become consolidated; but this hypo-
thesis leads to this very inadmissible conclusion, — that as the
cormus or bulbus solidus of a Crocus is essentially the same,
except in size and situation, as the stem of a Palm, the stem
of a Palm must be a bulbus solidus also, which is absurd. In
truth, the bulb is analogous to the bud that is seated upon the
cormus, and not to the cormus itself; a bulb being an enlarged
subterranean bud without a stem, the cormus a subterranean
stem without one enlarged bud.

Of the bulb, properly so called, there are two kinds.

1. The tunicated bulb (fig. 21.), of which the outer scales are
thin and membranous, and cohere in the form of a distinct
covering, as in the onion ; and, 2. the naked bulb [Bulbus

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 53

squamosus) (fig. 23. 22.), in which the outer scales are not mem-
branous and coherent, but distinct and fleshy like the inner
scales, as in Lilium. The outer covering of a bulb of the first
kind is called the tunic.

Besides the bulbs properly so called, there are certain
leaf-buds, developed upon stems in the air, and separating
spontaneously from the part that bears them, which are alto-
gether of the nature of bulbs. Such are found in Lilium
tigrinum, some Alliums, &c. They have been called bulbilli,
propagines, sautilles, bacilli, &c. Care must be taken not to
follow some botanists, in confounding with them the seeds of
certain Amaryllideae, which have a fleshy testa; but which,
with a vague external resemblance to bulbs, have in every in-
spect the structure of genuine seeds.

The tegmenta, or scales of the bud, have received the fol-
lowing names, according to the part of the leaf of which they
appear to be a transformation ; such terms are, however, but
seldom employed : —

1. Foliacea, when they are abortive leaves, as in Daphne
Mezereum.

2. Petiolacea, when they are formed by the persistent base
of the petiole, as in Juglans regia.

3. Stipulacea, when they arise from the union of stipulae,
which roll together and envelope the young shoot, as in Car-
pinus, Ostrya, Magnolia, &c.

4. Fulcracea, when they are formed of petioles and stipules
combined, as in Prunus domestica, &c. — [Rich. Nouv. Elem.
134. ed. 3.)

The manner in which the nascent leaves are arranged with-
in the leaf-bud is called foliation or vernation. The names
applied to the various modifications of this will be explained
in Glossology. They are of great practical importance
both for distinguishing species, genera, and even natural
orders; but have, nevertheless, received very little general
attention. The vernation of Prunus Cerasus is conduplicate ;
of Prunus domestica, convolute; of Filicesand Cycadeae,
circinate. and so on.

e 3

54-

ORGANOCiltAPHY.

BOOK I.

2. Of its External Modifications.

It has already been stated, that the first direction taken by
the stem immediately upon its developement is upward into
the air. While this ascending tendency is by many plants
maintained during the whole period of their existence, by others
it is departed from at an early age, and a horizontal course is
taken instead ; while also free communication with light and
air is essential to most stems, others remain during all their
lives buried under ground, and shun rather than seek the
light. From these and other causes, the stems of plants
assume a number of different states, to which botanists attach
particular terms. It will be most convenient to divide the
subject into the consideration of the varieties of —

1 . The subterranean stem ; and,

2. The aerial stem.

The subterranean stem, often called soucheby the French,
was confounded by all the older botanists, as it still is by the
vulgar, with the root, to which it bears an external resem-
blance, but from which it is positively distinguished both
by its ascending direction, and by its anatomical structure.
(See Root.)

24 25

The following are the varieties which have been distin-
guished : —

The Cormns, fig. 24. (Lecus of Du Petit Thouars, Plateau
of De Candolle), is the dilated base of the stem of Monocoty-

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 55

ledonous plants, intervening between the roots and the first
buds ; and forming the reproductive portion of the stem of such
plants when they are not caulescent. It is composed of cellular
tissue, traversed by bundles of vessels and woody fibre, and
has the form of a flattened disk. The fleshy root of the
Arum, that of the Crocus and the Colchicum, are all differ-
ent forms of the Cormus.

It has been called bulbo-tuber by Mr. Ker, and bulbus
solidus by many others ; the last is a contradiction in terms.
(See Bulb.)

The stems of Palms have by some writers been considered
as an extended cormus, and not a true stem, but this seems an
extravagant application of the term ; or rather an application
which reduces the signification of the term to nothing. A
cormus is a depressed subterranean stem of a particular kind;
the trunk of a Palm is, as far as its external character is con-
cerned, as much a stem as that of an oak. M. De Candolle
applies the name cormus only to the stems of Cryptogamous
plants, and refers to it the Anabices of Necker.

The Tuber, fig. 25. (Tuberculum if very small), is an
annual thickened subterranean stem, provided at the sides
with latent buds, from which new plants are produced the
succeeding year, as in the Potato and Arrow root. A tuber
is, in reality, a part of a subterranean stem, excessively en-
larged by the developement to an unusual degree of cellular
tissue. The consequences frequently attendant upon a state
of anamorphosis, as this is called, take place; the regular
and symmetrical arrangement of the buds is disturbed,
the buds themselves are sunk beneath the surface, or half
obliterated, and the whole becomes a shapeless mass. Such
is not, however, always the case ; the enlargement sometimes
occurs without being accompanied by much distortion. In
most, perhaps all, tubers, a great quantity of amylaceous matter
is deposited, on which account they are frequently found to
possess highly nutritive properties.

The Creeping stern, fig. 26. (soboles), is a slender stem, which
creeps along horizontally below the surface of the earth, emit-
ting roots and new plants at intervals, as in the Triticum repens.

e 4

56

ORGANOGRAPHY.

BOOK I.

This is what many botanists call a creeping root. It is one
of those provisions of nature, by which the barren sands that
bound the sea are confined within their limits ; most of the
plants which cover such soils being provided with subterranean
stems of this kind. Jt is also extremely tenacious of life, the
buds at every nodus being capable of renewing the existence
of the individual ; hence the almost indestructible properties
of the Couch grass, Triticum repens, by the ordinary opera-
tions of husbandry ; divisions of its creeping stem by cut-
ting and tearing, producing no other effect than that of
calling new individuals into existence as fast as others are
destroyed. The term soboles is applied by Link and De
Candolle to the sucker of trees and shrubs. (See Surculus.)

Of the aerial stem, the most remarkable forms are the
following : —

The term stem (caulis) is generally applied to the ascending
caudex of herbaceous plants or shrubs, and not to trees, in
which the word truncus is employed to indicate their main
stem ; sometimes, however, this is called caulis arboreus.
From the caulis, Linnaeus, following the older botanists,
distinguished the culmus or strata (Chawne, Fr.), which is
the stem of Grasses; and M. De Candolle has further
adopted the name Calamus (Chalumeau, Fr.) for all fistulous
simple stems without articulations, as those of Rushes ; but
neither of these differ in any material degree from common
stems, and the employment of either term is superfluous.

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 57

This has been already remarked with respect to Culmus by
Link, who very justly enquires (Linnaea, ii. 235.) "cur Gra-
minibus caulem denegares et culmum diceres?"

The Runner, fig. 27. (sarmentum of Fuchsius and Linnaeus,
coulant of the French,) is a prostrate filiform stem, forming at
its extremity roots and a young plant, which itself gives birth to
new runners, as in the Strawberry. Rightly considered it is a
prostrate viviparous scape ; that is to say, a scape which pro-
duces roots and leaves instead of flowers. It has been called
flagellum by some modern botanists, but that term properly
applies to the trailing shoots of the vine.

The Sucker, fig. 29. (surculus), called by the French Dragon
or Surgeon, is a branch which proceeds from the neck of a
plant beneath the surface, and becomes erect as soon as it
emerges from the earth, immediately producing leaves and
branches, and subsequently roots from its base, as in Rosa
spinosissima, and many other plants. Link applies the term
soboles to this form of stem. From this has been distinguished
by some botanists the Stole, {Stolo, Lat. ; and Jet, French ;)
which may be considered the reverse of the sucker, from
which it differs in proceeding from the stem above the surface
of the earth, into which it afterwards descends and takes root,
as in Aster junceus ; but there does not appear to be any ma-
terial distinction between them. Willdenow confines the term
surculus to the creeping stems of Mosses. By the older bota-
nists a sucker was always understood by the word Stolo, and
Surculus indicated a vigorous young shoot without branches.

The shoots thrown up from the buried stems of Monocoty-
ledonous plants, as the Pineapple for example, (the Adnata,
Adnascentia, or Appendices of Fuchsius,) are of the nature of
suckers.

It may be here remarked, that Stolo. has given rise to the
name Stool, which is applied to the parent plant, whence
young individuals are propagated by the process of laying, as
it is technically called by gardeners. The branch laid down
was termed Propago by the older botanists, and the layer was
called Malleolus, which literally signifies a hammer, and which
was thus applied, because when the layer is separated from its

58 ORGANOGRAPHY. BOOK I.

parent, its lower end resembles a hammer head, of which the
new plant represents the handle.

The Offset, fig. 30. {propaadum, Link), is a short lateral
branch in some herbaceous plants, terminated by a cluster of
leaves, and capable of taking root when separated from the
mother plant, as in Sempervivum. It differs very little from
the runner.

The Rootstock, fig. 28. (rhizoma), is a prostrate thickened
rooting stem, which yearly produces young branches or plants.
It is chiefly found in Irideae and epiphytous Orchideae, and is
often called Caudex repens. Link considers it scarcely dis-
tinct from the sucker or stole. The old botanists called it
Cervix, — a name now forgotten.

The Vine, fig. 31. (viticula, Fuchs.), is a stem which trails
along the ground without rooting, or entangles itself with
other plants, to which it adheres by means of its tendrils, as
the Cucumber and the Vine. This term is now rarely em-
ployed. M. De Candolle refers it to the runner or sarmentum ;
but it is essentially distinct from that form of stem.

If a plant is apparently destitute of an aerial stem, it is
technically called stemless [acaulis) ; a term which must not
however be understood to be exact, because it is, from the
nature of things, impossible that any plant can exist without
a stem in a greater or less degree of developement. All that
the term acaulis really means, is that the stem is very short.

The Pseudobulb is an enlarged aerial stem, resembling a
tuber, from which it scarcely differs, except in its being formed
above ground, in having a dliticle that is often extremely hard,
and in retaining upon its surface the scars of leaves that it
once bore. This is only known in Orchideous plants, in
which it is very common: the tuber of Arrow root is inter-
mediate between the Pseudobulb and the genuine tuber.

3. Of its Internal Modifications.

The internal structure of the stems of Flowering plants, is
subject to two principal and to several subordinate modifica-
tions. The former are well illustrated by such plants as the Oak

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 59

and the Cane, specimens of which can be easily obtained for
comparison. A transverse slice of the former exhibits a cen-
tral cellular substance or pith, an external cellular and fibrous
ring or bark, an intermediate woody mass, and certain fine
lines radiating from the pith to the bark, through the wood,
and called medullary rays ; this is called Exogenous structure. In
the Cane, on the contrary, neither bark, nor pith, nor wood,
nor medullary rays, are distinguishable; the transverse section
exhibits, on the contrary, a large number of hard spots caused
by the section of bundles of woody tissue, and a mass of
cellular substance in which they lie imbedded. This kind of
structure is named Endogenous.

In both cases there is a cellular and vascular system distinct
from each other ; by a diversity in the respective arrangement
of which the differences above described are caused. In de-
scribing in detail the peculiar structure of Exogenous and
Endogenous stems, it will be more convenient to consider them
with reference to those two systems, than to follow the usual
method of leaving the fact of there being two distinct systems
out of consideration.

§ 1. Of the Exogenous Structure.

The Cellular system in an Exogenous stem chiefly occupies
the centre and the circumference, which are connected by thin

60

ORGANOGRAPHY.

BOOK I.

vertical plates of the same nature
as themselves. The central part
(a fig. 33.) is the pith, that of the
circumference (b) is the bark, and
the connecting vertical plates (c) are
medullary rays.

The pith is a cylindrical or an-
gular column of cellular tissue,
arising at the neck of the stem
and terminating at the leaf-buds,
with all of which, whether they are lateral or terminal,
it is in direct communication. Its tissue, when cut through,
almost always exhibits an hexagonal character, and is
frequently larger than in any other part. When newly
formed, it is green, and filled with fluid ; but its colour
gradually disappears as it dries up, and it finally becomes
colourless. After this it undergoes no further change, un-
less by the deposition in it, in course of time, of some of the
peculiar secretions of the species to which it belongs. It
has been contended, indeed, by some physiologists, that it is
gradually pressed upon by the surrounding part of the vas-
cular system, until it is either much reduced in diameter or
wholly disappears ; and in proof of this assertion, the Elder has
been referred to, in which the pith is very large in the young
shoots, and very small in the old trunks. Those, however,
who entertain this opinion, seem not to consider that the
diameter of the pith of all trees is different in different shoots,
according to the age of those shoots; — that in the first that
arises after germination, the pith is a mere thread, or at least
of very small dimensions — that in the shoots of the succeeding
year it becomes larger — and that its dimensions increase in
proportion to the general rapidity of developement of the
vegetable system : the pith, therefore, in the first-formed
shoots, in which it is so small compared with that in the
branches of subsequent years, is not so because of the pressure
of surrounding parts ; it never was any bigger.

The pith is always, when first forming, a uniform compact
mass, connected without interruption in any part; but the
vascular system sometimes developing more rapidly than

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 61

itself, it occasionally happens that it is either torn or divided
into irregular cavities, as in the Horse Chestnut, the Rice-paper
plant, and many others ; or that it is so much lacerated as to
lose all resemblance to its original state, and to remain in the
shape of ragged fragments adhering to the inside of the vas-
cular system : this is what happens in Umbelliferous and other
fistular-stemmed plants.

Sometimes the pith is much more compact at the nodi than
in the internodia, as in the Ash ; whence an idea has arisen that
it is actually interrupted at those places : this is, however, an
obvious mistake; there is no interruption of continuity, but a
mere alteration in compactness.

It very seldom happens that any part of the vascular system
intermixes with the pith, which is almost always composed of
cellular tissue exclusively ; but in Ferula and the Marvel of
Peru, it has been proved by Messrs. Mirbel and De Candolle,
that bundles of woody fibre are intermixed ; and in the Ne-
penthes there is a considerable quantity of spiral vessels
scattered among the cellular tissue of the pith.

The Bark is the external coating of the stem, lying imme-
diately over the wood, to which it forms a sort of sheath, and
from which it is always distinctly separable. When but one
year old, it consists of an exterior coating of cellular substance,
called the cellular integument or the epidermis, and of an in-
terior lining of woody fibre, called the liber or inner bark : if
more than one year old, then it is composed of as many layers
of cellular integument and woody fibre as it is years old, the
former being invariably external, and the latter internal, in
each layer ; and every layer being formed beneath the previous
one, and therefore next the wood. In consequence of the
new bark being continually generated within that of the pre-
vious year, it is necessary that the latter, which is pushed
outwards, should be extensible ; and in many plants this ex-
tensibility takes place to a considerable degree. In the Apple,
several successive zones of bark are formed without any
appearance of a dislocation or disruption of the tissue of
the outside; and in the Daphne Lagetto, the fibres of the
liber are so tenacious that, instead of being ruptured by

62 ORGANOGRAPHY. BOOK I.

the force of the inward growth, they are separated into
lozenge-shaped meshes, arranged in such beautiful order,
as to have acquired for the plant itself the name of the Lace
Bark Tree. There exists, however, in all cases, a limit to the
extensibility of the old layers of bark ; and when this ceases,
the outer bark either splits into deep fissures, as in the Oak,
the Elm, the Cork, and most of our European trees, or it falls
away in broad plates, as in the Plane, or it peels off in long
thin ribands, as in the Birch.

As there is a double layer of cellular integument and woody
fibre formed every year, it follows that the age of a tree ought
to be indicated by the number of such deposits contained in
its bark. But the arrangement of the zones is so very soon
disturbed, and the distinction between them becomes so im-
perfect, that even when the outermost coating is still entire,
it is scarcely practicable to count the zones; and as soon
as the outside begins to split or peel off, all traces of their
full number necessarily disappear.

That the bark really increases by constant deposits of new
matter between it and the wood, is demonstrated by intro-
ducing a piece of metal into the liber of a tree, and watching
it subsequently : in process of time it will be protruded to the
outside, and will finally fall away.

Notwithstanding the fibrous character of a certain portion
of the bark, it is generally so brittle as to be capable of
breaking in all directions with a clean fracture, as soon as it
becomes dry and ceases to live ; but in many plants, when
young, it is so tough as to be applied to different economical
purposes. For instance, the Russia mats of commerce are
prepared from the liber of two or three species of Tilia, that
of many Malvaceae is manufactured into cordage, and similar
properties are found in that of many other plants.

When stems are old, the bark usually bears but a small
proportion in thickness to the wood ; yet in some plants its
dimensions are of a magnitude that is very remarkable. For
instance, Pinus Douglasii specimens have been brought to
Europe twelve inches thick, and these are said not to be of
the largest size.

Lacunae and Vasa propria are exceedingly common in the

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 63

bark, but there is no well authenticated instance of any spiral
vessels having been found in it; except in Nepenthes, in
which they are found in almost every part, and exist in no
inconsiderable numbers in the bark. Mr. Don states that
spiral vessels abound in the bark of Urtica nivea, but I have
not succeeded in discovering them there.

Beneath the bark and above the wood is interposed in the
spring a mucous viscid layer, which, when highly magnified,
is found to consist of numerous minute transparent granules,
and to exhibit faint traces of a delicate cellular organization.
This secretion is named the Cambium, and appears to be
exuded both by the bark and wood, certainly by the latter.

The cellular system of the pith and that of the bark are, in
the embryo, and youngest shoots, in contact ; but the vascular
system, as it forms, gradually interposes between them, till
after a few weeks they are distinctly separated, and in very awed
trunks are sometimes divided by a space of several feet ; that
is to say, by half the diameter of the wood. But whatever
may be the distance between them, a horizontal communi-
cation of the most perfect kind continues to be maintained.
When the vascular system is first insinuated into the
cellular system, dividing the pith and bark, it does not
completely separate them, but pushes aside a quantity of
cellular tissue, pressing it tightly into thin vertical radiating
plates ; as the vascular system extends, these plates in-
crease outwardly, continuing to maintain the connection
between the centre and the circumference. Botanists call
them medullary rays (or plates) ; and carpenters, the silver
grain. They are composed of muriform cellular tissue
(Plate I. fig. 7.), often not consisting of more than a single
layer of cellules ; but sometimes, as in Aristolochias, the
number of layers is very considerable (Plate II. fig. 12. a).
In horizontal sections of an Exogenous stem, they are seen as
fine lines radiating from the centre to the circumference ; in
longitudinal sections they give that glancing satiny lustre
which is in all discoverable, and which gives to some, such as
the Plane and the Sycamore, a character of remarkable
beauty.

No vascular tissue is ever found in the medullary rays,

64 ORGANOGRAPHY. BOOK I.

unless those curious plates described by Mr. Griffith in the
wood of Phytocrene gigantea, in which vessels exist, should
prove to belong to the medullary system.

The vascular system in an Exogenous stem is confined to
the space between the pith and the bark, where it chiefly
consists of ducts and woody fibre collected into compact
wedge-shaped vertical plates (fig. 33. d), the edges of which
rest on the pith and bai'k, and the sides of which are in
contact with the medullary rays.

That portion of the vascular system which is first generated
is in immediate contact with the pith, to which it forms a
complete sheath, interrupted only by the passage of the
medullary rays through it. It consists of spiral vessels and
woody fibre intermixed, and forms an exceedingly thin
layer, called the medullary sheath. This is the only part of
the vascular system of the stem in which spiral vessels are
ordinarily found ; the whole of the vessels subsequently depo-
sited over the medullary sheath being ducts, and mostly
dotted ones, with a few exceptions. The medullary sheath
establishes a connection between the axis and all its append-
ages, the veins of leaves, flowers, and fruits, being in all cases
prolongations of it. It has been remarked by Senebier, and
since by M. De Candolle, that it preserves a green colour
even in old trunks, which proves that it still continues to
retain its vitality when that of the surrounding parts has
ceased.

The vascular system of a stem one year old consists of a
zone of wood lying between the pith and the bark, lined in
the inside by the medullary sheath, and separated into wedge-
shaped vertical plates by the medullary rays that pass through
it. All that part of the first zone which is on the outside of
the medullary sheath is composed of woody fibre and ducts
intermixed in no apparent order ; but the ducts are generally
either in greater abundance next the medullary sheath, or
confined to that side of the zone, and the woody fibre alone
forms a compact mass on the outside. The second year
another zone is formed on the outside of the first, with which
it agrees exactly in structure, except that there is no medul-
lary sheath ; the third year a third zone is formed on the

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 65

outside the second, in all respects like it; and so on, one
zone being deposited every year as long as the plant con-
tinues to live. As each new zone is formed over that of the
previous year, the latter undergoes no alteration of struc-
ture when once formed : wood is not subject to distension
by a force beneath it, as the bark is , but, whatever the first
arrangement or direction of its tissue may be, such they re-
main to the end of its life. The formation of the wood is,
therefore, the reverse of that of the bark ; the latter increas-
ing by addition to its inside, the former by successive de-
posits upon its outside. It is for this reason that stems of
this kind are called Exogenous (from two Greek words, sig-
nifying to grow outwardly). According to M. Dutrochet,
each zone of wood is in these plants separated from its neigh-
bour by a layer of cellular tissue, forming part of the system
of the pith and bark.

After wood has arrived at the age of a few years, or some-
times even sooner, it acquires a colour different from that
which it possessed when first deposited, becoming what is
called heart-wood, or duramen. For instance, in the beech it
becomes light brown, in the oak deep brown, in Brazil wood
and Guaiacum green, and in ebony black. In all these it
was originally colourless, and owes its different tints to matter
deposited at first in the ducts, and subsequently in all parts of
the tissue ; as may be easily proved by throwing a piece of
heart-wood into nitric acid, or some other solvent, when the
colouring matter is discharged, and the tissue recovers its
original colourless character. That part of the wood in which
no colouring matter is yet deposited, and consequently that
which, being last formed, is interposed between the bark and
duramen, is called alburnum. The distinction between these
is physiologically important, as will hereafter be explained.

Each zone of the vascular system of an Exogenous stem
being the result of a single year's growth, it should follow
that to count the zones apparent in a transverse section is
sufficient to determine the age of the individual under ex-
amination ; and further, that, as there is not much difference in
the average depth of the zones in very old trees, a certain
rate of growth being ascertained to be peculiar to particular

F

66 ORGANOGRAPHY. BOOK I.

species, the examination of a mere fragment of a tree, the
diameter of which is known, should suffice to enable the botanist
to judge with considerable accuracy of the age of the indivi-
dual to which it belonged. It is true, indeed, that the zones
become less and less deep as a tree advances in age ; that in
cold seasons, or after transplantation, or in consequence of
any causes that may have impeded its growth, the formation
of wood is so imperfect as scarcely to form a perceptible zone :
yet the learned M. De Candolle has endeavoured to show, in
a very able paper Sur la Longevite des Arbres, that the
general accuracy of calculations is not much affected by such
accidents ; occasional interruptions to growth being scarcely
appreciable in the average of many years. This is possibly
true in European trees, and in those of other cold or temperate
regions in which the seasons are distinctly marked ; in such
the zones are not only separated with tolerable distinctness,
but do not vary much in annual dimensions. But in many
hot countries the difference between the growing season and
that of rest, if any occur, is so small, that the zones are as it
were confounded, and the observer finds himself incapable of
distinguishing with exactness the formation of one year from
that of another. In the wood of Guaiacum, Phlomis fruticosa,
Metrosideros polymorpha, and many other Myrtaceae, for
instance, the zones are extremely indistinct ; in some Bauhi-
nias they are formed with great irregularity ; and in Holbollia
latifolia, some kinds of Ficus, certain species of Aristolochia,
as A. labiosa, and many other plants, they are so confounded,
that there is not the slightest trace of annual separation.

With regard to judging of the age of a tree by the inspection
of a fragment, the diameter of the stem being known, a little
reflection will show that this is to be done with great caution,
and that it is liable to excessive error. If, indeed, the zones
upon both sides of a tree were always of the same, or nearly the
same, thickness, much error would, perhaps, not attend such
an investigation ; but it happens that, from various causes, there
is often a great difference between the growth of the two sides,
and consequently, that a fragment taken from either side must
necessarily lead to the falsest inferences. For example, I have
now before me four specimens of wood, taken almost at

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 67

hazard from among a fine collection, for which I am indebted
to the munificence of the East India Company. The mea-
surements of either side, and their age, as indicated by the
number of zones they comprehend, are as follows : —

Cornus capitata
Pyrus foliolosa
Magnolia insignis -
Alnus napalensis -

Diameter of
Side A. Side B.

9 lines.

8 lines.
1 1 lines.
1 1 lines.

36 lines.

22 lines.
20 lines.

23 lines.

Total.

45 lines.

30 lines.

31 lines.
34 lines.

Real

Age, or

No. of Zones.

40
36
17

Now, in the first of these cases, suppose that a portion of the
side A. were examined, and the observer were told that the
diameter of the whole stem was 45 lines, he would find that
each zone was 0.45 of a line deep, and that, consequently, the
tree had been twenty years forming a radius of 9 lines, or in-
creasing 18 lines in diameter: the total diameter being 45
lines, he would necessarily infer that the age of the tree was
one hundred years ; its real age being only forty, as indicated
by its zones. And so of the rest.

When we hear of the Baobab trees of Senegal being 5150
years old, as computed by Adanson, and the Taxodium dis-
tichum still more aged, according to the calculations of the
ingenious M. Alphonse De Candolle, it is impossible to avoid
suspecting that some such error as that just explained has
vitiated their conclusions.

To the characters above assigned to the stem of Exogenous
plants there are several remarkable exceptions, some of which
have been described by botanists ; others are mentioned now
for the first time. M. Mirbel has noticed the unusual structure
of Calycanthus, (Annates des Sciences, vol. xiv.) in the bark
of which, at equal distances, are found four minute extremely
eccentrical woody axes, the principal diameter of which is
inwards ; that is to say, next the wood. The existence of
this structure, noticed by the discoverer only in C. floridus,
I have since ascertained in all the other species, and also in
Chimonanthus.

f 'J

68

ORGANOGRAPHY

BOOK I.

In Coniferous wood {fig. 34?.) there is
scarcely any mixture of ducts among
woody fibre, as in other exogenous plants ;
in consequence of which a cross section
exhibits none of those open mouths which
are caused by the division of ducts, and
which give what is vulgarly called po-
rosity to wood. Instead of this, the
vascular system generally consists exclu-
sively of that kind of woody fibre which
has been described at p. 15., under the
name of glandular, with the exception of
the medullary sheath, in which spiral vessels are present in
small numbers. The Yew is the principal exception : in this
plant the woody fibre is the same as that of other Coniferae ; but
many tubes have a great quantity of little fibres lying obliquely
across them at nearly equal distances, sometimes arranged with
considerable regularity, — sometimes disturbed as it were, so
that the transverse fibres, although they retain their obliquity,
are not parallel, — and sometimes, but more rarely, so regular
as to give to the tubes of woody fibre the appearance of spiral
vessels, the coils of which are separated by considerable
intervals. The latter only is represented by Kieser, at his
tab. xxi. fig. 103, 104?.; but the former is by far the most
common appearance.

In Cycadeae the vascular system is destitute of ducts, as
in Coniferae ; their place being supplied by such woody fibre
as has been already described at p. 14. But the zones of
wood are separated by a layer of cellular substance resembling
that of the pith, and often as thick as the zones themselves.
This structure is represented by M. Adolphe Brongniart, in
the 16th volume of the Annales des Sciences.

My friend Mr. Griffith has beautifully illustrated the struc-
ture of a plant called Phytocrene {Jig. 35.), in Dr. Wallich's
Plantse Asiatics?, vol. iii. t. 216. In this curious produc-
tion, the wood consists of vessels encompassed by woody
fibre ; and in the place of medullary rays are thick plates, con-
nected neither with the medulla nor with the bark, nor even
with each other in different zones. When the wood is dry,

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS.

69

these plates separate from the wood, in which they finally
lie loose ; and, what is very remarkable, they contain vessels.

35

In Nepenthes distillatoria the pith contains a great quantity
of spiral vessels; the place of the medullary sheath is occu-
pied by a deep and very dense layer of woody fibre, in which
no vessels, or scarcely any, are discoverable ; there are no
medullary rays; the wood has no concentric zones; between
the bark and the wood is interposed a thick layer of cellular
tissue, in which an immense quantity of very large spiral ves-
sels is formed ; on the outside of this layer is a thinner
coating of woody fibre, containing some very minute spiral
vessels ; and, finally, the whole is enclosed in a cellular inte-
gument, also containing spiral vessels of small size. In this
singular plant the outer layers are, it is to be presumed, liber
and epidermis; and the cellular deposit between the former
and the wood is analogous to cambium in an organised state,
belonging equally to the wood and the bark. What is so
exceedingly remarkable is the complete intermixture of the
vascular and cellular systems, so that limits no longer exist
between the two.

I have a specimen of the twisted compressed stem of a
Bauhinia from Colombia (Jig. 36.), in which there are no con-
centric circles, properly so called ; but in which there are cer-
tain irregular flexuous zones, consisting of a layer of cellular
tissue coated by a stratum of woody fibre, enclosing, at irre-

w 3

70

ORGANOGRAPHY.

BOOK I.

gular distances from the centre, very un-
equal portions of the vascular system.
The pith is exceedingly eccentrical ; and
the medullary rays, which are very im-
perfectly formed, do not all radiate from
the pith, but on the thickest side form
curves passing from one side of the stem
to the other, their convexities turned to-
wards the pith.

In the stem of an unknown climber in
my possession from Colombia {Jig. 37.),
the vascular system is divided into four

37

In Hollbollia latifolia
(Jig. 38.), which has atwin-
ing stem, there are no con-
centric circles, and the me-
dullary rays are curved,
part from right to left, and
part from left to right, di-
verging at one point and

nearly equal parts, by four short
thick plates radiating from the
pith, and consisting of woody
fibre with a very few ducts. These
plates are not more than one third
the depth of the wood; so that
between their back and the bark
there is a considerable vacancy,
by which the four divisions of
the vascular system are separated.
This vacancy is nearly filled with
bark, which projects into the
cavity.

38

converging at another

bark is
tensive
fo rations.

pier

ced

longitudinal

the
with ex-
per-

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 71

In Euonymus tingens (fig.
39.) the vessels near the centre
of the stem are arranged in con-
centric interrupted circles, but
towards the bark there is no
trace of such circles; and the
vessels are all confounded in an
uniform mass.

InMenispermum laurifolium
(fig. 40.) the concentric lines
evidently belong to the medullary sys-
tem; they are extremely interrupted
and unequal, often only half encir-
cling the stem, or even less, and they
anastomose in various ways ; the me-
dullary rays are unusually large, and
lie across the wood like parallel bars ;
and, finally, the plates of which the
wood consists each contain but one
vessel, which is situated at the ex-
ternal edge of the plate.

None of the anomalous forms of

41

Exogenous stems are, however, so
remarkable as an unknown Burmese
p tree ( fig. 41.), for a specimen of which I
* am indebted to my friend Dr. Wallich.
In a section of this the general ap-
pearance is so much that of an Endo-
genous stem, that without an attentive
examination it might be actually mis-
taken for one. The diameter of this
stem is two inches seven lines ; it is
nearly perfectly circular, and has a very thin but distinct
bark, with a central pith surrounded by very compact woody
fibre. There are neither zones nor medullary rays ; but the
vascular system consists of an uniform mass of ducts and
woody fibre, disposed with great symmetry, and of the
same degree of compactness at the circumference as well
as in the centre. Amongst his wood are interspersed, at

f 4

ORGANOGRAPHY.

BOOK I.

the distance of about half a line, with very great regularity,
passages containing loose cellular tissue. These passages are
convex at the back and rather concave in front, run parallel
with the ducts, and do not seem to have any kind of com-
munication with each other. They, no doubt, represent the
medullary rays of the cellular system of this highly curious
plant. It must be remarked, that the resemblance borne by
this stem to that of an Endogenous plant is more apparent
than real ; for whilst, in the latter, the vascular system is
separated into bundles surrounded by the cellular system, in
this, on the contrary, the cellular system consists of tubular
passages surrounded by masses of the vascular system.

These examples of anomalous structure will show the stu-
dent that it is neither medullary rays nor concentric zones in
the wood that are the certain indications of Exogenous
growth ; both the one and the other being sometimes absent ;
but that the presence of a central pith, and a greater degree
of hardness in the centre than in the circumference, are
the signs from which alone any absolute evidence can be
derived.

§ 2. Of the Endogenous Structure.

42

Plants of an arborescent habit having this structure being
almost exclusively extra-European, and most of them being

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 73

natives only of the tropics, botanists have had much fewer
occasions of examining them, and, consequently, their know-
ledge concerning them is far more limited. It is, therefore,
probable that in this department of the subject there will be
hereafter much to add and much to correct. In the mean
while it must suffice, that what has been published concerning
Endogenous plants is given with such corrections and additions
as my own experience may have suggested.

In Endogenous plants the vascular
and cellular systems are as distinct as
in Exogenous, but they are differently
arranged. The cellular system, instead
of being distinguishable into pith, bark,
and medullary rays, is a uniform mass,
in which the vascular system lies im-
bedded in the form of thick fibres;
and the vascular system itself has no tendency to collect into
zones or wedges resembling wood, but in all cases retains the
form of bundles resembling fibres. These bundles consist of
woody fibre, enclosing spiral vessels or ducts ; most commonly
the latter.

The diameter of an Endogenous stem is increased by the
constant addition of fibrous bundles to the centre, whence
the name. Those bundles displace such as are previously
formed, pushing them outwards; so that the centre, being
always most newly formed, is the softest; and the outside,
being older, and being gradually rendered more and more
compact by the pressure exercised upon the bundles lying
next it by those forming in the centre, is the hardest. In
Endogenous plants that attain a considerable age, such as
many Palms, this operation goes on till the outside becomes
sometimes hard enough to resist the blow of a hatchet. It
does not, however, appear that each successive bundle of
fibres passes exactly down the centre, or that there is even
much regularity in the manner in which they are arranged in
that part: it is only certain that it is about the centre that
they descend, and that on the outside no new formation takes
place. This appears from the manner in which the bundles
cross and interlace one another, as is shown in the figure of

74 ORGANOGRAPHY. BOOK I.

Pandanus odoratissimus given by M. De Candolle in his
Organographie (tab. vi.), or still more clearly in the lax tissue
of the inside of the stems of Dracaena Draco.

The epidermis of an Endogenous stem seems capable of
very little distension. In many plants of this kind the
diameter of the stem is the same, or not very widely different,
at the period when it is first formed, and when it has arrived
at its greatest age : Palms are, in particular, an instance of this ;
whence the cylindrical form that is so common in them. That
the increase in their diameter is really inconsiderable, is
proved in a curious, and at the same time very conclusive,
manner by the circumstance of gigantic woody climbing
plants sometimes coiling round such stems, and retaining
them in their embrace for many years, without the stem thus
tightly wound round indicating in the slightest manner, by
swelling or otherwise, that such ligatures inconvenience it.
A specimen illustrative of this is preserved in the Museum
of Natural History at Paris, and has been figured both by
M. Mirbel in his Elemens (tab. xix.), and M. De Candolle in
his Organographie (tab. iv.). We know, from the effect of
the common Bindweed upon the Exogenous plants of our
hedges, that the embrace of a twining plant is, in a single
year, destructive of the life of every thing that increases in
diameter; or at least produces, above the strangled part,
extensive swellings that always end in death.

It is, however, certain that other Exogenous plants do
increase extensively in diameter up to a certain point; but this
is effected with great rapidity ; and the horizontal growth once
stopped appears never to be renewed. Thus, in the Bamboo,
stems are sometimes found as much as two feet in circum-
ference, which were originally not more than half an inch in
diameter. Others would seem to have an unlimited power of
distension. In the Dracaenas, called in French colonies in
Africa Bois-chandelles, the first shoot from the ground is a
Turio (sucker), an inch in diameter, and perhaps fifteen feet
high ; but in time it distends so much that sometimes two
men can scarcely embrace it in their extended arms. ( TJwu-
ars, Essais, p. 3.)

As Endogenous stems contain no concentric zones, there is

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 75

nothing in their internal structure to indicate age ; but, in the
opinion of some botanists, there are sometimes external cha-
racters that will afford sufficient evidence. It is said that the
number of external rings that indicate the fall of leaves from
the trunk of the Palm tribe coincide with the number of
years that the individual has lived. There is, however,
nothing like pi'oof of this at present before the public ; such
statements must therefore be received with great caution. It
may further be remarked, with reference to this subject, that
in many Palms these rings disappear after a certain number
of years.

In arborescent Endogenous plants, it usually happens that
only one terminal leaf-bud developes ; and in such cases the
stem is cylindrical, or very nearly so, as in Palms. If two
terminal leaf-buds constantly develope, the stem becomes
dichotomous, but the branches are all cylindrical, as in Pan-
danus and the Doom Palms of Egypt; but if axillary leaf-
buds are regularly developed, as in the Asparagus, Dracaena
Draco, or in arborescent grasses, then the conical form that
prevails in Exogenous plants uniformly exists in Endogenous
ones also.

Besides the difference now mentioned, there is one other
form of the Endogenous stem that it is necessary to describe ;
viz. that of Grasses. In those plants the stem is hollow ex-
cept at the nodi, where transverse partitions intercept the
cavity, dividing it into many cells. In the Bamboo these cells
and partitions are so large that, as is well known, lengths of
that plant are used as cases to contain papers. In consequence
of this great apparent deviation from the usual structure, a
celebrated Swedish botanist has remarked, that Grasses are
the least Endogenous of all Endogenous plants.

But if the gradual developement of a grass be attentively
observed, it will be found that the stem is originally solid ;
that it then becomes hollow in consequence of its increasing
in diameter more rapidly than new tissue can be formed ; and
that, finally, in old arborescent stems, it again becomes solid
by the constant addition of matter to its inside; so that its
deviation from the ordinary characters of Endogenous structure
i> much less considerable than it seems to be at first sight.

76 ORGANOGRAPHY. BOOK I.

Sect. III. Of the Root, or descending Axis.

At or about the same time that the ascending axis seeks
the light and becomes a stem, does the opposite extremity of
the seed or bud bury itself in the earth and become a root,
with a tendency downwards so powerful, that no known force is
sufficient to overcome it. Correctly speaking, nothing can be
considered a root except what has such an origin ; for those
roots which are emitted by the stems of plants, are in reality
the roots of the buds above them, as will be hereafter explained.
Nevertheless, nothing is more common than even forbotanists
to confound subterranean stems or buds with roots, as has
been already seen. (See Bulb, Tuber, Soboles, &c. &c.)

Independently of its origin, the root is to be distinguished
from the stem by many absolute characters. In the first
place, its ramifications occur irregularly, without any sym-
metrical arrangement: they do not, like branches, proceed
from certain fixed points (buds), but are produced from all
and any points of the root. Secondly, a root has no leaf-buds,
unless indeed, as is sometimes the case, it has the power of
forming adventitious ones ; but, in such a case, the irregular
manner in which such are produced is sufficient evidence of
their nature. Thirdly, roots have no scales, leaves, or other
appendages ; neither do they ever indicate upon their surface,
by means of scars, any trace of such : all underground bodies
upon which scales have been found are stems, whatever they
may have been called ; the only appendages they ever have
are such things as the little hollow floating bladders found in
Utricularia. A fourth distinction between roots and stems is,
that the former have never any stomata upon their cuticle ;
and, finally, in Exogenous plants, the root has never any pith.
It has been also said that roots are always colourless, while
stems are always coloured ; but aerial roots are often green,
and all underground stems are colourless.

The body of the root is sometimes called the caudex ; the
minute subdivisions have been sometimes called radicular — a
term that should be confined to the root in the embryo;
others name them Jibrillcc, a term more generally adopted ;
while the terms rhizina and rhizula have been given by Pro-
fessor Link to the young roots of mosses and lichens.

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 77

Kjibrilla is a little bundle of annular ducts, or sometimes
of spiral vessels, encased in woody fibre, and covered by a lax
cellular integument : it is in direct communication with the vas-
cular system of the root, of which it is, in fact, only a sub-
division; and its apex consists of extremely lax cellular tissue
and mucus. This apex has the property of absorbing fluid
with great rapidity, and has been called by M. De Candolle
the Spongiole. It must not be considered a particular organ ;
it is only the newly formed and forming tender tissue. In
Pandanus the spongioles of the aerial roots consist of numerous
very thin exfoliations of the epidermis, which form a sort of
cup fit for holding water in.

The proportion borne by the root to the branches is ex-
tremely variable : in some plants it is nearly equal to them,
in others, as in Lucerne (Medicago sativa), the roots are
many times larger and longer than the stems ; in all succu-
lent plants and Cucurbitaceae they are much smaller. When
the root is divided into a multitude of branches and fibres,
it is cal \edji brous : if the fibres have occasionally dilatations at
short intervals, they are called nodulose. When the main root
perishes at the extremity, it receives the name of prcemorse, or
bitten off: frequently it consists of one fleshy elongated centre
tapering to the extremity, when it is termed fusiform (or tap-
rooted by the English, and pivotante by the French) ; or it
dilates immediately below the surface of the earth into a
globose form, when it is named turnip-shaped ', as in the
common turnip ; if it is terminated by several distinct buds,
as in some herbaceous plants, it is called many-headed
{midticeps).

The roots of many plants are often fleshy, and composed
of lobes, which appear to serve as reservoirs of nutriment to
the fibrillse that accompany them ; as in 44

many terrestrial Orchideous plants, Dahlias,
&c. These must not be confounded either
with tubers or bulbs, as they have been by
some writers, but are rather to be con-
sidered a special form of the root, to which
the name of Pseudo-tuber {Jig. 44.) would"
not be inapplicable. In Orchis the pseudo-
tubers are often palmated or lobed ; in the

78 ORGANOGRAPHY. BOOK I.

Dahlia, and many Asphodeleae, they hang in clusters, or are
fasciculated.

In internal structure the root differs little from the stem,
except in being often extremely fleshy ; the cellular system
being subject to an unusually high degree of developement in
a great many plants, as the Turnip, the Parsnep, and other
edible roots. In Endogenous plants, the mutual arrange-
ment of the cellular and vascular systems of the root and stem
is absolutely the same; but in Exogenous plants there is
never any trace of pith in the root.

Sect. IV. Of the Appendages of the Axis.

From the outside of the stem, but connected immediately
with its vascular system, arises a variety of thin flat expan-
sions, arranged with great symmetry, and usually falling off
after having existed for a few months. These are called, col-
lectively, appendages of the axis ; and, individually, scales,
leaves, bracteae, flowers, sexes, and fruit. They must not be
confounded with mere expansions of the cuticle, such as ra-
menta, already described (p. 41.), from which they are known
by having a connection with the vascular system of the axis.
Till lately, botanists were accustomed to consider all these as
essentially distinct organs ; but, since the appearance of an
admirable treatise by Goethe in 1790, On the metamorphosis
of plants, proofs of their being merely modifications of
one common type, the leaf, have been gradually discovered ;
so that that which, forty years ago, was considered as the
romance of a poet, is now universally acknowledged to be an
indisputable truth. It is not my intention to enter into much
separate discussion of this doctrine ; proof of it will be more
conveniently adduced as the different modifications of the
appendages of the axis come separately under consideration.
The leaf, as the first that is formed, the most perfect of them
all, and that which is most constantly present, is properly
considered the type from which all the others are deviations,
and is that with the structure of which it is first necessary to
become acquainted.

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 79

45

§ 1. Of the "Leaf.

46 47

The leaf is an expansion of the bark at the base of a leaf-
bud, prior to which it is developed. In most plants it con-
sists of cellular tissue filling up the interstices of a net-work
of fibres that proceed from the stem, and ultimately separating
from the bark by an articulation ; in many Monocotyledonous
plants, Ferns, and Mosses no articulation exists, and the base
of the leaf only separates from its parent stem by rotting
away.

This difference of organisation has given rise to a distinc-
tion, on the part of Oken, between the articulated leaves of
Dicotyledones and the inarticulated leaves of Monocotyledones
and Acotyledones : the former he calls true leaves, and dis-
tinguishes by the name of Lcinb ; the latter he considers
foliaceous dilatations of the stem, analogous to leaves, and
calls Blatt.

A leaf consists of two parts; namely, its stalk, which is
called the petiole (fg. 46. a), and its expanded surface, which
is called the lamina (fg. 46. c, b, d) : in ordinary language the
latter term is not employed, but in very precise descriptions
it is indispensable.

The point where the base of the upper side of a leaf joins
the stem is called the axilla ; any thing which arises out of
that point is said to be axillary. If a branch or other process
proceeds from above the axilla, it is called supra-axillary ,• if
from below it, infra- axillary.

80 ORGANOGRAPHY. BOOK I.

The scar formed by the separation of a leaf from its stem
is called the cicatricula. The withered remains of leaves,
which, not being articulated with the stem, cannot fall off,
but decay upon it, are called reliquiae or induvice (debris, Fr.),
and the part so covered is said to be induviatus.

When leaves are placed in pairs on
opposite sides of a stem (j%.51.), and
on the same plane, they are called op-
posite : if more than two are opposite,
they then form what is called a whorl,
or verticillus, and are said to be whorled,
or verticillate: but if they arise at re-
gular distances from each other round
the stem, and not from the same plane>
they are then called alternate.

In plants having Exogenous stems,
the first leaves, — namely, those which are present in the
embryo itself (cotyledons), — are uniformly opposite; but those
subsequently developed are either opposite, verticillate, or
alternate in different species : on the contrary, in Endogenous
plants, the embryo leaf is either solitary, or, if there are two,
they are alternate ; and those subsequently developed are
usually alternate also, but few cases occurring in which they
are opposite.

Hence some have formed an opinion that the normal
position of the leaves of Exogenous plants is opposite, or
verticillate ; and that when they are alternate, this arises
from the extension of a nodus ; while that of Endogenae is
alternate, the verticilli being the result of the contraction of
internodia.

But it seems more probable that the normal position of
all leaves is alternate, and their position upon the stem an
elongated spiral, as is in many cases exceedingly apparent,
as, for instance, in the genus Pinus, in Pandanus, which is
actually named Screw-pine, in consequence of the resem-
blance its leaves bear to a screw, and in the Pine apple ; the
Apple, the Pear, the Willow, the Oak, will also be found to
indicate the same arrangement, which is only less apparent
because of the distance between the leaves, and the irregu-

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 61

larity of their direction. If, in the Apple tree, for instance, a
line be drawn from the base of one leaf to the base of another,
and the leaves be then broken off, it will be found that a per-
fectly spiral line will have been formed. Upon this supposition,
opposite or verticillate leaves are to be considered the result of
a peculiar contraction or non-developement of internodia, and
the consequent confluence of as many nodi as there are leaves
in the whorl. The Rhododendron ponticum will fuiuiish the
student with an illustration of this : on many of its branches
the leaves are some alternate and some opposite ; and many
intermediate states between these two will be perceivable.
In many plants, the leaves of which are usually alternate,
there is a manifest tendency to the appi-oximation of the nodi,
and consequently to an opposite arrangement of the leaves, as
in Solanum nigrum, and many other Solaneae * ; while, on the
other hand, leaves that are usually opposite separate their
nodi and become alternate, as in Erica mediterranea : but this
is more rare.

The best argument in support of the hypothesis that all
verticilli arise from the contraction of internodia and con-
fluence of nodi, is, however, to be derived from flowers, which
are several series of verticilli, as will be seen hereafter. In
plants with alternate leaves, the flowers often change into
young branches, and then the verticilli of which they consist
are broken, the nodi separate, and those parts that were
before opposite become alternate; while, in monstrous Tulips,
the verticilli of which the flower consists are plainly shown
to arise from the gradual approximation of leaves, that in their
unchanged state are alternate.

In this normal state leaves are obviously distinct, both from
each other and from the stem. But, in some cases, adhesions
of various kinds occur, and give them a new character. Thus,
in Cardui, and many other thistle-like plants, the elongated
bases of the leaves adhere to the stem, and become what is
called decurrent. In Bupleurum perforatum the lobes of the
base of the leaf not only cohere with the stem, but, projecting
beyond it, grow together, so as to resemble a leaf through

Introduction to the Natural S3 stem of Botany, p. 231.
G

82 ORGANOGRAPHY. BOOK I.

which the stem has pierced : this is called being -perfoliate.
Frequently two opposite leaves grow together at the base, as
in Caprifolium perfoliatum ; to this modification the latter
term is often also applied, but that of connate is what more
properly belongs to it.

The anatomical structure of the leaf is this: — From the
medullary sheath diverges a bundle of woody tissue, accom-
panied by spiral vessels : this passes through the bark, and
proceeds, at an angle more or less acute, to a determinate
distance from the stem, branching off at intervals, and, by
numerous ramifications, forming a kind of net-work. At the
point of the stem whence the bundle of fibrovascular tissue
issues, the cellular tissue of the bark also diverges, accom-
panying the fibrovascular tissue, expanding with its ramifi-
cations, and filling up their interstices. The tissue that
proceeds from the medullary sheath, after having passed from
the origin of the leaf to its extremity, doubles back upon
itself, forming underneath the first a new layer of fibre,
which, upon its return, converges just as the first layer
diverged, at length combines into a single bundle, corre-
sponding in bulk and position to that which first emerged,
and finally discharging itself into the liber. If, therefore, a
section of the leaf and stem be carefully made at a nodus, it
will be found that the bundle of woody tissue which forms the
frame-work of the leaf communicates above with the medullary
sheath, and below with the liber. This is easily seen in the
spring, when the leaves are young; but is not so visible in
the autumn, when their existence is drawing to a close. The
double layer of fibrovascular tissue is also perceptible in a leaf
which has laid during the winter in some damp ditch, where
its cellular substance has decayed, so that the cohesion between
the upper and lower layers is destroyed: they can then be
easily separated. The curious Indian leaves which have the
property of opening, upon slight violence, like the leg of
a silk stocking, so that the hand may be thrust between
their upper and lower surfaces, derive that singular separa-
bility from an imperfect union between the layer of excurrent
and recurrent fibre. M. De Candolle remarks, that when the
fibres expand to form the limb of a leaf, they may (whether
this phenomenon occurs at the extremity of a petiole, or at

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 83

the point of separation from the stem,) do so after two different
systems : they may either constantly preserve the same plane
when the common flat leaves are formed ; or they may expand
in any direction, when cylindrical, or swollen, or triangular
leaves are the result. (Organogr. p. 270.)

The cellular tissue of which the rest of the leaf is composed
is parenchyma, which Link then calls diachijma, or that im-
mediately beneath the two surfaces cortex, and the intermediate
substance diploe. M. De Candolle calls these two, taken to-
gether, the mesaphyllum. The whole is protected, in leaves
exposed to air, by a coating of cuticle, furnished with stomata ;
but in submersed leaves the parenchyma is naked, no cuticle
overlaying it.

The general nature of the parenchymatous part of leaves
has been very well explained, both by Link and others, and
figured by Dr. Mohl, in 1828. (Uber die Poren des Pflanzcn-
zellgewebes, tab. i. fig. 4, &c.) But the most complete a°count
is that of M. Adolphe Brongniart, in 1830 (A/males des Sc.
vol. xxi. p. 420.), of which the principal part of what follows
is an abstract.

The cuticle is a layer of cellules adhering firmly to each
other, and sometimes but slightly to the subjacent tissue, from
which they are entirely different in form and nature : in form,
for the cellules are depressed, and, in consequence of the variety
of outline that they present, form meshes either regular or
irregular ; and in nature, because these cellules are perfectly
transparent, colourless, and probably filled with air, — for the
manner in which light passes through them proves that they
do not contain dense fluid. They scarcely ever contain any
organic particles, and are probably but little permeable either
to fluids or gaseous matter; while, on the other hand, the
cellules of the subjacent parenchyma are filled with the green
substance that determines the colour of the leaf. The cuticle
is not always formed of a single layer of cellules, but in some
cases consists of two, or even three. No trace whatever is
discoverable of vessels either terminating in or beneath the
cuticle; M. Brongniart states this most explicitly, and my
own observations are entirely in accordance with his : an
opinion, therefore, which some distinguished botanists have

g 2

84- ORGANOGRAPHY. BOOK I.

entertained, that spiral vessels terminate in the stomata (D. C.
Omanogr. p. 272, &c), must hereafter be abandoned. At the
margin of a leaf the cuticle is generally harder than elsewhere,
and sometimes becomes so indurated as to assume a flinty
texture, as in the Aloe, and many other plants.

Stomata (p. 33.) are found upon various parts of the cuti-
cle : in some plants only on that of the under side of leaves,
in others on the upper also ; in floating leaves upon the latter
only. When leaves are so turned that their margins are
directed towards the earth and the heavens, the two faces are
then alike in appearance, and are both equally furnished with
stomata. In succulent leaves they are said to be either alto-
o-ether absent or very rare ; but this is a statement that requires
confirmation. According to the observations of M. De Can-
dolle (Organogr. p. 272.), they are, in the Orange and the
Mesembryanthemum, as ten in the former to one in the latter.

The parenchyma is, if casually examined, or even if viewed
in slices of too great thickness, apparently composed of heaps
of little green cells, arranged with little order or regularity ;
but, if very thin slices are taken and viewed with a high mag-
nifying power, it will be seen that nothing can be more
perfect than the plan upon which the whole structure is con-
trived, and that, instead of disorder, the most wise order
pervades the whole. Upon this subject I extract the words
of M. Adolphe Brongniart : — " There exists beneath the
upper cuticle two or three layers of oblong blunt vesicles,
placed perpendicular to the surface of the leaf, and generally
much less in diameter than the cells of the cuticle; so that
they are easily seen through it. These vesicles, which appear
specially destined to give solidity to the parenchyma of the
leaf, have no other intervals than the little spaces that result
from the contact of this sort of cylinder: nevertheless, in
plants that have stomata on the upper surface of their leaves,
as is the case in most herbaceous plants, and in such as float
on the surface of water, there exist here and there among
the vesicles some large spaces, through which the stomata
communicate with the interior of the leaf.

This parenchyma is entirely different from what is found
beneath the cuticle of the lower side. There, instead of con-
sisting of regular cylindrical vesicles, it is composed of irre-

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 85

gular ones, often having two or three branches, which unite
with the limbs of the vesicles next them, and so form a reticu-
lated parenchyma; the spaces between whose vesicles are
much larger than the vesicles themselves.

It is this reticulated tissue, with large spaces in it (to which
the name of cavernous or spongy parenchyma might not im-
properly be applied), that, in most cases, occupies at least
half the thickness of the leaves between the veins. The
arrangement of the vesicles is very obvious if the lower cuticle
of certain leaves be lifted up with the layer of parenchyma
that is applied against it; it may then be seen that these
anastomosing vesicles form a net with large meshes, — a sort of
grating inside the cuticle. It must not, however, be supposed
that this structure, which I have remarked in several ferns,
and in a great many dicotyledonous plants, is without ex-
ception. In many monocotyledonous and succulent plants we
have some remarkable modifications of this structure. Thus,
in the Lily, and several plants of the same family, the vesicles
of parenchyma that are in contact with the lower cuticle are
lengthened out, sinuous, and toothed, as it were, at the sides :
these projections join those of the contiguous vesicle ; and a
number of cavities is the consequence, which render this sort
of parenchyma permeable to air. An analogous arrangement
exists in the lower parenchyma of Galega. In the Iris, there
is scarcely any space between the oblong and polyedral vesi-
cles which form the parenchyma ; but it is remarked, that the
subjacent parenchyma is wanting at every point where the
cuticle is pierced by a stoma. In such succulent plants as I
have examined, the spaces between the cellules of parenchyma
are very small ; but, nevertheless, here and there, there are
often larger cavities, which either correspond directly with
the stomata, or are in communication with them. The same
thino- happens in plants with floating leaves, where the stomata
placed on the upper surface correspond with the layer of
cylindrical and parallel vesicles ; in such case there are, here
and there, between these vesicles, empty spaces which almost
always correspond to the points where the stomata exist, and
which permit the air to penetrate between the vesicles as far
as the middle of the parenchyma of the leaf.

G 3

86 ORGANOGRAPHY. BOOK I.

Thus much M. Brongniart; who adds, that in submersed
leaves there is no cuticle, but the whole consists of solid
parenchyma alone, in which there are no other cavities than
such as are necessary to float the leaves.

The veins, being elongations of the medullary sheath, neces-
sarily consist of woody fibre and spiral vessels, to which are
sometimes added annular ducts. In submersed leaves spiral
vessels are often wanting, the veins consisting of nothing but
woody fibre. In these veins M. Schultz finds what he calls
vessels of the latex, or of the nutritive fluid ; but it is difficult
to understand, either from his figures or descriptions, which
kind of tissue in particular he means to designate by that
name. M. Adolphe Brdngniart says, the latex vessels are the
vasa propria; but what are the vasa propria of leaves, in
which there is nothing but woody fibre, spiral vessels, and

ducts ?

Such are the general anatomical characters of leaves; but
it must be borne in mind, that, in different species, they
undergo a variety of remarkable modifications. These arise
either from the addition of parenchyma when leaves become
succulent, or from the non-developement of it when they
become membranous, or from the total suppression of it, and
even of the veins also in great part, as in those which are
called ramentaceous, such as the primordial leaves of the
genus Pinus.

I have dwelt thus much at length upon the structure of the
leaf, because it is by far the most important part of a plant,
and that of which the functions are the best ascertained. Let
us now turn our attention to the modifications of the leaf. It
has already been seen that a leaf may consist of two distinct
parts ; the petiole, or stalk, and lamina, or leaf itself: both of
these demand separate consideration.

The lamina, or limbus, as it is called by some, is subject to
many diversities of figure and division ; most commonly it
forms an approach to oval, being longer than broad. When
speaking of the leaf, it is usual to take the opportunity of
explaining the terms employed by botanists to distinguish
varieties of figure ; but, as those terms are equally applicable
to any other part with a similar dilated surface, it has appeared

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 87

to me expedient to include them in Glossology, where they
will accordingly be found.

That extremity of the lamina which is next the stem is
called its base ; the opposite extremity, its apex ; and the line
representing its two edges, the margin or circumscription.

If the lamina consists of one piece only, the leaf is said to
be simple, whatever may be the depth of its divisions : thus,
the entire lamina of Box, the serrated lamina of the Apple,
the toothed lamina of Coltsfoot, the r uncinate lamina of
Taraxacum, the pinnatifid lamina of Hawthorn (which is
often divided almost to its very midrib), are all considered
to belong to the class of simple leaves. But if the petiole
branches out, separating the cellular tissue into more than
one distinct portion, each forming a perfect lamina by itself,
such a leaf is often said to be compound, whether the divisions
be two, as in the conjugate leaf of Zygophyllum, or inde-
finite in number, as in the many varieties of pinnated leaves.
Nevertheless, a more accurate notion of a compound leaf is
found to consist in its divisions being articulated with the
petiole, by which it is much better distinguished from the
simple leaf than by the number of its divisions. Thus, the
pinnated leaf of a Zamia, and the pedate leaf of an Arum,
both in this sense belong to the class of simple leaves ; while
the solitary lamina of the Orange, the common Berberry, &c.
are referable to the class of compound leaves. This distinction
is of some importance to the student of natural affinities ; for,
while division, of whatever degree it may be, may be expected
to occur in different species of the same genus or order (pro-
vided there is no articulation), it rarely happens that truly
compound leaves, — that is to say, such as are articulated with
their petiole, — are found in the same natural assemblage with
those in which no articulation exists.

In speaking of the surface of a leaf it is usual to make use
of the word pagina. Thus, the upper surface is called pagina
superior ; the lower surface, pagina inferior. The upper surface
is more shining and compact than the under, and less generally
clothed with hairs; its veins are sunken; while those of the
lower surface are usually prominent. The cuticle readily
separates from the lower surface, but with difficulty from the

g 4

88 ORGANOGRAPHY. BOOK I.

upper. There are frequently hairs upon the under surface
while the upper is perfectly smooth ; but there is scarcely any
instance of the upper surface being hairy while the lower is
smooth.

The ramifications of the petiole among the cellular tissue of
the leaf are called veins, and the manner of their distribution
is termed venation. This influences in a great degree the
figure and general appearance of the foliage, and requires a
more careful consideration than it generally receives in ele-
mentary works.

The vein which forms a continuation of the petiole and the
axis of the leaf is called the midrib or costa : from this all the
rest diverge, either from its sides or base. If other veins
similar to the midrib pass from the base to the apex of a leaf,
such veins have been named nerves; and a leaf with such an
arrangement of its veins has been called a nerved leaf. If the
veins diverge from the midrib towards the margin, ramifying
as they proceed, such a leaf has been called a venous or reticu-
lated leaf. This is the sense in which these terms were used
by Linnaeus ; but Link and some others depart from so strict
an application of them, calling all the veins of a plant nerves,
whatever may be their origin or direction.

Till within a few years the distribution of veins in the leaf
had not received much attention; the terms just mentioned
had been contrived to express certain of the most striking
forms of venation ; but the application of these was far from
being sufficiently precise. Many improvements have been pro-
posed by modern botanists ; it however appears to me that the
whole nomenclature of venation is essentially defective, and
requires complete revision. My ideas upon this subject have
been already laid before the public in the Botanical Register
for Sept. 1826, page 1004.; and, as I am not aware that any
objection to them has yet been taken, I shall repeat them here,
in a form better adapted to an elementary work than that
under which they first appeared.

The objections that I take to the present modes of distin-
guishing veins are these: — 1st, That the veins are very im-
properly, as I think, called nerves, either in all cases, as by
Link, which is bad, or in certain cases only, when they have

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 89

a particular size or direction, as by Linnaeus and his followers,
which is worse. Nothing is more destructive of accurate
ideas in natural history than giving names well understood in
one kingdom of nature to organs in another kingdom of an
entirely different kind, unless it is the, perhaps, more repre-
hensible practice of giving two names conveying totally differ-
ent ideas to the same organ in the same kingdom of nature.
Thus, when the veins of a plant are termed nerves, it is neces-
sarily understood that they exercise functions of a similar
nature to those of the nerves of animals : if otherwise, why are
they so called ? But they exercise no such functions, being,
beyond all doubt, mere channels for the transmission of fluid.
Again, if one portion of the skeleton of a leaf is called a vein,
and another portion a nerve, this apparently precise mode of
speaking leads yet more strongly to the belief (especially when
such a distinction is seen admitted into works which are said
to be of the highest authority in science), that the structure
and function of those two parts are as widely different as the
structure and function of a vein and a nerve in the animal
economy ; else why should such nice caution be taken to dis-
tinguish them ? But it must be confessed that there is no
difference whatever, except in size, between the veins and
nerves of a leaf. Let us, then, abandon a term which is one of
those relics of a barbarous age, which it is the duty of modern
science to expel. My second objection is caused by the vague
manner in which the veins of leaves are at present described ;
whence it happens that no precise idea can be attached to the
different terms that have been contrived to designate particular
forms of venation. A third objection is this, — that, while slight
modifications in the arrangement of the veins have received
distinctive names, others of much greater importance, and of a
more decided character, have received no distinctive appellation
whatever. For these reasons, the practical weight of which I
have long experienced, it has occurred to me that the follow-
ing changes in the language used in speaking of venation will
be found better, at least, than that for which they are sub-
stituted, if they are not entirely what could be desired.

It has been usual to call that bundle of vessels only which
passes directly from the base to the apex of a leaf the costa, or

90

ORGANOGRAPHY.

BOOK I.

midrib. This term I would extend to all main veins which
proceed directly from the base to the apex, or to the points of
the lobes. There is no difference in size in these costae ; and
in lobed leaves, which may be understood as simple leaves,
approaching composition, each costa has its own particular
set of veins.

The costa (jig. 52, 7.) sends forth, alternately right and left
along its whole length, ramifications of less dimensions than
itself, but more nearly approaching it than any other veins:

52 53

^7

these I would call vencs primaries (jig- 52, 3.). They diverge
from the costa at various angles, and pass to the margin of
the leaf, curving towards the apex in their course, and finally,
at some distance within the margin, forming what is called an
anastomosis, or junction, with the back of the vena primaria,
which lies next them. That part of the vena primaria which
is between the anastomoses thus described, having a curved
direction, may be called the vena arcuata. Between this latter
and the margin, other veins, proceeding from the venae arcuatae,
with the same curved direction, and of the same magnitude,
occasionally intervene : they may be distinguished by the name
of venae externa ( jig. 52, 1 .). The margin itself and these last
are connected by a fine net-work of minute veins, which I
would distinguish by the name of venules marginales. From
the costa are generally produced, at right angles with it, and
alternate with the vena? primariae, smaller veins ; which may
be considered imperfect venae primariae, and may not im-
properly be named vence costales (jig. 52, 5.). The venae
primariae are themselves connected by fine veins, which anas-

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 91

tomose in the area between them. These veins, when they
immediately leave the venae primariae, I call venules pro-
price {Jig. 52, 4.); and where they anastomose, venules com-
munes. The area of parenchyma, lying between two or more
veins or veinlets, I name with the old botanists intervenium.

These distinctions may to some appear over-refined ; but I
am convinced that no one can accurately describe a leaf
without the use of them, or of equivalent terms yet to be
invented. Upon these principles leaves may be conveniently
divided into the following kinds : —

1. Veinlcss (avenium), when no veins at all are formed,
except a slight approach to a costa, as in Mosses, Fuci, &c.
Leaves of this description exist only in the lowest tribes of
foliaceous plants, and must not be confounded with the fleshy
or thickened leaves common among the higher orders of
vegetation, in which the veins are by no means absent, but
only concealed within the substance of the parenchyma. (See
No. 10.) Of this M. De Candolle has two forms, — first, his

folia nullinervia, in which there is not even a trace of a costa,
as in Ulva ,• and second, his folia fahinervia, in which a trace
of a costa is perceptible. These terms appear to me unneces-
sary ; but, if they be employed, the termination nervia must be
changed to venia.

2. Equal-veined {ceqnalivenium\ when the costa is perfectly
formed, and the veins are all of equal size, as in Ferns.
This kind of leaf has not been before distinguished : it may be
considered intermediate between those without veins and those
in which vena3 primariae are first apparent. The veins are
equal in power to the venulae propriae of leaves of a higher
class.

3. Straight-veined (rectivenium). In this the veins consist
only of venae primariae, generally very much attenuated, and
arising from towards the base of the costa, with which they
lie nearly parallel : they are connected by venulae propriae ;
but there are no venulae communes. The leaves of Grasses
and of Palms and Orchideous plants are of this nature. This
form has been called by Link paralleli and convergenti-nervo-
sum, according to the degree of parallelism of the venae pri-
mariae ; and to these two he has added what he calls venuloso-

92 ORGANOGRAPHY. BOOK I.

nervosum, when the venae primariae are connected by venulae
propriae: but as this is always so, although it is not in all
cases equally apparent, the term is superfluous. Ach. Richard
calls this form later inervium, and De Candolle rectinervium ;
from which I do not find it advisable to distinguish his rupti-
nervium, which indicates the straight-veined leaf, when the
veins are thickened and indurated, as in the Palm tribe.

4. Curve-veined (curvivenium). This is a particular modifi-
cation of the last form, in which the venae primariae are also
parallel, simple, and connected by unbranched venulae pro-
priae; do not pass from near the base to the apex of the
leaf, but diverge from the costa along its whole length, and
lose themselves in the margin. This is the folium hinoideum
and venuloso-hinoideum of Link, the f penninervium of A.Rich-
ard, and they, curvinervium of De Candolle. It is common
in Scitamineae. It is not improbable that both this and the
last ought to be regarded as peculiar modifications of petiole
(a kind of phyllodia), rather than as true leaves analogous to
those next to be described.

5. Netted (reticulatum). Here the whole of the veins that
constitute a completely developed leaf are present, arranged
as I have above described them, there being no peculiar com-
bination of any class of veins. This is the common form of
the leaves of Dicotyledones, as of the Lilac, the Rose, &c. It
is the folium venosum of Linnaeus, the^ indirecte vcnosum of
Link, they! mixtinervium of A. Richard, and the^ retinervium
of De Candolle. If the venae externae and venulae margi-
nales are conspicuous, Link calls this form combinate venosum,-
but if they are indistinct, he calls it evanescente venosum.

6. Ribbed (costaticm). In this three or more costae proceed
from the base to the apex of the leaf, and are connected by
branching venae primariae of the form and magnitude of
venulae propriae, as in Melastoma. This must not be con-
founded with the straight -veined leaf, from which it may in all
cases of doubt be distinguished by the ramified veins that
connect the costae. This is a very material difference, which
has never been properly explained. Linnaeus and his followers
confound the two forms ; but modern writers separate them :
although it must be confessed that it is difficult to discover

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 93

their distinctions from the characters hitherto assigned to
them. Link calls these leavesj^ ncrvata, A. Richard f. basi-
nervia, and De Candolle f. triplinervia and f. quintupli-
nervia. If a ribbed leaf has three costae springing from the
base, it is said to be three-ribbed (tri-costatum, trinerve of
authors) ; if five, Jive-ribbed^ and so on. But if the ribs do
not proceed exactly from the base, but from a little above it,
the leaf is then said to be triply-ribbed (triplicostatiwi), as in
the Helianthus.

7. Falsely ribbed (pseudocostattim), is when the venae arcuatae
and venae externae, both or either, in a reticulated leaf, become
confluent into a line parallel with the margin, as in all Myr-
taceae. This has not been before distinguished.

8. Radiating (radiatum), when several costae radiate from
the base of a reticulated leaf, to its circumference, as in
lobed leaves. This and the following form the f. directe
venosum of Link : it is the f. digit inervium of A. Richard.
Hither I refer without distinguishing them the f. pedali-
nervia, palminervia, and peltinervia of M. De Candolle ; the
differences of which do not arise out of any peculiarity
in the venation, but from the particular form of the leaves
themselves.

9. Feather-veined (penniveniam), when the venae primariae
of a reticulated leaf pass in a right line from the costa to the
margin, as in Castanea. This has the same relation to the
radiating leaf that the curve-veined bears to the straio-ht-
veined ; it is the folium pennivenium of M. De Candolle.

10. Hidden-veined (introvenium). To this I refer all leaves
the veins of which are hidden from view by the parenchyma
being in excess, as in the Hcn/a, and many others. Such a
leaf is often inaccurately called veinless. M. De Candolle
calls a leaf of this nature, in which the veins are dispersed
through a large mass of parenchyma, as in Mesembryanthe-
raum, vaginervium.

It is often necessary to explain the direction that the venae
primariae take when they diverge from the costa: this may
be denoted by measuring the angle which is formed by the
costa and the diverging vein, and can either be stated in
distinct words, or by applying the following terms thus : — if

94-

ORGANOGRAPHY.

BOOK I.

the angle formed by the divergence is between 10° and 20°,
the vein may be said to be nearly parallel (subparallela) ; if
between 20° and 40°, diverging ; between 40° and 60°, spread-
ing,- between 60° and 80°, divaricating; between 80° and 90°,
right-angled; between 90° and 120°, oblique; beyond 120°,
reflexed (retrqflexa).

The petiole {Jig- 55 a — b.) is the part which connects the la-
mina with the stem, of which it
was considered by Linnaeus as a
part. It consists of one or more
bundles of fibrovascular tissue
surrounded by cellular tissue.
Its figure is generally half cy-
lindrical, frequently channelled
on the surface presented to
the heavens ; but in most mo-
nocotyledonous plants it is
perfectly cylindrical. If the
petiole is entirely absent, which is often the case, the leaf is
then said to be sessile. Generally the petiole is simple, and con-
tinuous with the axis of the leaf; sometimes it is divided into
several parts, each bearing a separate leaf or leaflet (Jbliolus) :
in such case it is by some said to be compound: each of the
stalks of the leaflets being called petiolules (ramastra, Jungius).
In all simple leaves the petiole is continuous with the axis of
the lamina, from which it never separates ; in all truly com-
pound leaves the petiole is articulated with each petiolule; so
that when the leaf perishes, it separates into as many portions
as there are leaflets, as in the Sensitive plant : hence, when-
ever an apparently simple leaf is found to be articulated with
its petiole, as in the Orange, such a leaf is not to be considered
a simple leaf, but the terminal leaflet of a pinnated leaf, of
which the lateral leaflets are not developed. This is a most
important difference, and must be borne constantly in mind
by all persons who are engaged in the investigation of natural
affinities. It is an occult sign which must never be neglected.

At the base of the petiole, where it joins the stem, and
upon its lower surface, the cellular tissue increases in quan-
tity, and produces a protuberance or gibbosity, which Ruellius,

CHAF. II. COMPOUND ORGANS IN FLOWERING PLANTS. 95

and after him Link, called the pulvinus, and M. De Candolle
coussinet {%fig. 55, a.). At the opposite extremity of the petiole,
where it is connected with the lamina, a similar swelling is often
remarkable, as in Sterculia, Mimosa sensitiva, and others: this
is called the struma, or, by the French, bourrelet (>y%. 55, b.).

Occasionally the petiole embraces the branch from which
it springs, and in such case is said to be sheathing ,- and is even
called a sheath or vagina, as in grasses {Jig- 54>, a.). When the
lower part only of the petiole is sheathing, as in Umbelliferse,
that part is sometimes called the jpericladium. In grasses there
is a peculiar membranous process at the top of the vagina,
between it and the lamina, which has received the name of
ligula {Jig- 54, b.) (languette, Fr. ; collare, Rich.) ; the nature of
this process has not yet been determined. In the Asparagus,
the petiole has the form of a small sheath, is destitute of
lamina, and surrounds the base of certain small branches
having the appearance of leaves : such a petiole has been
named hypophijllium by Link. In Trapa natans, Pontedera
crassipes, and other plants, the petiole is excessively dilated
by air, and acts as a bladder to float the leaves : except in
this state of dilatation, it differs in no wise from common
petioles : it has, nevertheless, received the name of vesicula
from M. De Candolle, who considers it the same as the
bladdery expansions of Fuci. The petiole is generally straight :
occasionally it becomes rigid and twisted, so that the plant can
climb by it.

It has been said that the figure of the petiole usually ap-
proaches more or less closely to the cylindrical : this, however,
is not always the case. In many plants, especially of an herba-
ceous habit, it is very thin, with foliaceous margins ; it is then
called winged. There are, moreover, certain leafless plants,
as the greater number of species of Acacia, in which the
petiole becomes so much developed as to assume the appear-
ance of a leaf, all the functions of which it performs. Petioles
of this nature have received the name of Phyllodia [Jig. 56.).
They may always be distinguished from true leaves by the fol-
lowing characters : — 1. If observed when the plant is very
young, they will be found to bear leaflets. 2. Both their sur-
faces are alike. 3. They very generally present their margins

96 ORGANOGRAPHY. BOOK I.

to the earth and heavens, — not their surfaces. 4. They are
always straight-veined ; and, as they only occur among dico-
tyledonous plants which have reticulated leaves, this peculiarity
alone will characterise them.

But, besides the curious transformation undergone by the
petiole when it becomes a phyllodium, there are several others
still more remarkable : among these the first to be noticed is
the tendril ( Vrille, Fr.; Cirrhus, Linn.; Capreolus and Clavicula
of the old botanists). It is one of the contrivances employed
by nature to enable plants to support themselves upon others
that are stronger than themselves. It was included by Lin-
naeus among what he called fulcra ,- and has generally, even
by very recent writers, been spoken of as a peculiar organ.
But, as it is manifestly in most cases a particular form of the
petiole, I see no reason for regarding it in any other light. It
may, indeed, be a modification of the inflorescence, as in the
Vine ; but this, I conceive, is an exception, showing, not that
the cirrhus is not a modification of the petiole, but that any
part may become cirrhose.

In some cases, the petiole of a compound leaf is elongated,
branched, and endowed with the power of twisting round any
small body that is near it, as in the Pea : it then becomes what
is called a cirrhus petiolaris. At other times, it branches off on
each side at its base below the lamina into a twisting ramifica-
tion, as in Smilax horrida ; when it is called a cirrhus peduncxi-
laris. At other times it passes, in the form of midrib, beyond
the apex of a simple leaf, twisting and carrying with it a portion
of the parenchyma, as in Gloriosa superba ; when it is said to be
a cirrhus foliar is. M. De Candolle refers to tendrils the acu-
minate, or rather caudate, divisions of the corolla of Strophan-
thus, under the name of cirrhus corollaris ,• but these do not
appear to me to possess any of the requisites of a tendril.

As another modification of the petiole, I am disposed to
consider, with Link (Elem. 202.), the singular form of leaf in
Sarracenia and Nepenthes, which has been called Ascidium or
Vasculum {outre De Candolle). This consists of a fistular green
body, occupying the place and performing the functions of a
leaf, and closed at its extremity by a lid termed the operculum.
To me it appears that the ascidium itself, or fistular part, is

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 97

57

the petiole, and the operculum the lamina of a leaf in an
extraordinary state of transformation. Look, for example, at
Dionsea muscipula; in this plant the leaf consists of a broad
winged petiole, articulated with a collapsing lamina, the mar-
gins of which are pectinate and inflexed. Only suppose the
broad winged petiole to collapse also, and that its margins»
when they meet, as they would in consequence of collapsion,
cohere; a fistular body would then be formed, just like the
ascidium of Sarracenia ; and there would be no difficulty
in identifying the acknowledged lamina of Dionaea with
the operculum of Sarracenia also. From Sarracenia the
transition to Nepenthes would perhaps not be considered
improbable.

58

98

ORGANOGRAPHY.

BOOK I.

The student must not, however, suppose that all pitchers
are petioles, because those of Nepenthes and Sarracenia are
so. Those of the curious Dischidia Rafflesiana (Jig. 58.),
figured by Dr. Wallich in his Plantce Asiatics Rariores,
are leaves, the margins of which are united. The pitchers
of Marcgraavia and Norantea (fg. 59.) are bracteae in the
same state.

Spines of the leaves are formed either by
an elongation of the woody tissue of the
veins, or by a contraction of the paren-
chyma of the leaves : in the former case
they project beyond the surface or margin
of the leaf, as in the Holly (Ilex aquifolium) :
in the latter case they are the veins them-
selves become indurated, as in the palmated
spines of Berberis vulgaris. The spiny pe-
tiole of many Leguminous plants is of the
same nature as the latter. So strong is the
tendency in some plants to assume a spiny
state, that in a species of Prosopis from
Chili, of which I have a living specimen
now before me, half the leaflets of its bi-
pinnate leaves have the upper half converted into spines.

2. Of Stipulae.

f

CHAP. II. COiMPOUND ORGANS IN FLOWERING PLANTS. 99

At the base of the petiole, on each side, is frequently seated
a small appendage, most commonly of a texture less firm than
the petiole, and having a subulate termination. These two
appendages are called stipulce. They either adhere to the
base of the petiole or are separate ; — they either endure as
long as the leaf, or fall off before it ; — they are membranous,
leathery, or spiny ; — finally, they are entire or lacineated.
By Link they have been called Paraphyllia ,• an unnecessary
term. When they are membranous, and surround the stem
like a vagina, cohering by their anterior margins, as in Poly-
gonum ( Jig. 60.), they have been termed ocJirea by Willdenow.
Of this the fibrous sheath at the base of the leaves of Palms,
called reticulum by some, may possibly be a modification. In
pinnated leaves there are often two stipulae at the base of each
leaflet as well as at the base of the common petiole : stipulae,
under such circumstances, are called stipcllcc.

The exact analogy of stipulae is not well made out. M. De
Candolle seems, from some expressions in his Organographies
to suspect their analogy with leaves ; while, in other places
in the same work, it may be collected that he rather con-
siders them special organs. I am clearly of opinion that,
notwithstanding the difference in their appearance, they are
really accessory leaves : first, because occasionally they are
transformed into leaves, as in Rosa bracteata, in which I have
seen them converted into pinnated leaves ; secondly, because
they often are undistinguishable from leaves, of which they
obviously perform all the functions, as in Lathyrus, Lotus,
and many other Leguminosae : and, finally, because there are
cases in which buds develope in their axilla, as in Salix ; a
property peculiar to leaves and their modifications. M. De
Candolle, in suggesting, after Seringe, that the tendrils of Cu-
curbitaceae are modified stipulae, assigns the latter a tendency
to a transformation exclusively confined either to the midrib
of a leaf, or to a branch ; and they cannot be the latter.

It is sometimes difficult to distinguish from true stipulae,
certain membranous expansions, or ciliae, or glandular append-
ages of the margin of the base of the petiole, such as are
found in Ranunculaceae, Apocyneae, Urn bell iferae, and many
other plants. In these cases the real nature of the parts is

h 2

100

ORGANOGRAPHY.

BOOK I

only to be collected from analogy, and a comparison of
them with the same part differently modified in neighbouring
species.

M. De Candolle remarks, that no Monocotyledonous plants
have stipulae; but they certainly exist, at least in Fluviales
and Aroideae. The ligula of grasses, a membranous appendage
at the apex of their sheathing petiole, which some have con-
sidered stipulae, should rather be understood as a membranous
expansion analogous to the corona of some Caryophylleae,
such as Silene.

It has been already noted, that when they surround the
stem of a plant they become an ochrea ,• in this case their
anterior and posterior margins are united by cohesion ; a
property that they possess in common with all modifications
of leaves, and of which different instances may be pointed out
in Magnoliaceae, where the back margins only cohere, in cer-
tain Cinchonaceae, in which the anterior margins of the stipulae
of opposite leaves are united, and in a multitude of other
plants,

Of Bracteae.

65

All the parts that have hitherto been subjects of enquiry
are called orgems of vegetation ,• their duty being exclusively
to perform the nutritive parts of the vegetable economy.
Those which are about to be mentioned are called organs of
fructification ■, their office being to reproduce the species by a
process in some respects analogous to that which takes place

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 101

in the animal kingdom. The latter are, however, all modifi-
cations of the former, as will hereafter be seen : and as the
subject of this division is in itself a kind of proof; bracteae not
being exactly organs either of vegetation or reproduction, but
between the two.

Botanists call Bractca either the leaf from the axilla of
which a flower is developed, such as we find in Veronica
agrestis ; or else all those leaves that are found upon the inflo-
rescence, and are situated between the true leaves and the
calyx. There are, in reality, no exact limits between bracteae
and common leaves ; but in general the former may be known
by their situation immediately below the calyx, by their
smaller size, din°ex*ence of outline, colour, and other marks.
They are generally entire, however much the leaves may be
divided; frequently scariose, either wholly or in part; often
deciduous before the flowers expand ; but rarely very much
dilated, as in Origanum, Dictamnus, and a few other plants.
It is often more difficult to distinguish bracteae from the sepals
of a polyphyllous calyx than even from the leaves of the
stem. In fact, there is in many cases no other mode than
ascertaining the usual number of sepals in other plants of the
same natural order, and considering every leaf-like appendage
on the outside of the usual number of sepals as bracteae. In
Camellia, for example, if it were not known that the normal
number of sepals of kindred genera is five, it would be im-
possible to determine the number of its sepals. When the
bracteae are very small, they are called bracteola ; or if they
are of different sizes upon the same inflorescence, the smallest
receive that name. It rarely occurs that an inflorescence is
destitute of bracteae. In Cruciferae this is a frequent cha-
racter, and is observed by Link to indicate an extremely
irregular structure. When bracteae do not immediately sup*
port a flower or its stalk, they are called empty {vacua).
As a general rule, it is to be understood, that whatever inter-
venes between the true leaves and the calyx, whatever be
their form, coloui', size, or other peculiarity, comes within the
meaning of the term.

Under particular circumstances bracteae have received the
following peculiar names : —

h 3

102 ORGANOGRAPHY. BOOK I.

When they are empty, and terminate the inflorescence, they
form a coma, as in Salvia Horminum, In this case they are
generally enlarged and coloured.

If they are verticillate, and surround several flowers, they
constitute an involucrum. In Umbelliferous plants, the bracteae
which surround the general umbel are called an universal
involucrum ; and those which surround the umbellules a partial
involucrum, or involucellum. In Compositae, the involucrum
often consists of several rows of imbricated bracteae, and has
received a variety of names, for none of which does there
appear to be the least occasion. Linnaeus called it calyx
communis, Necker perigynavdra communis, Richard periphor-
anthium, Cassini periclinium. There is often found at the
base of the involucrum of Compositae an exterior rank of
bracteae, which Linnaeus called calyculus ,• and such involucra
as were so circumstanced calyx calyculatus. M. Cassini re-
stricts the term involucrum to this; but it seems most con-
venient to call these exterior bractese bracteolce, and to say
that an involucrum in which they are present is basi bracteo-
latus, bracteolate at the base.

Another and very remarkable form of the involucrum is the
cupula {Jig. 66.). It consists of bracteae not developed till after
flowering, when they cohere by their bases, and form a kind
of cup. In the Oak the cupula is woody, entire, and scaly,
with indurated bracteae: in Fagus it forms a sort of coriaceous
valvular spurious pericarpium : in Corylus {Jig. 64.) it is folia-
ceous and lacerated : in Taxus it is fleshy and entire, with no
appearance of bracteae.

The name squama or scale is usually applied to the bracteae
of the amentum ; it is also occasionally used to indicate any
kind of bracteae which has a scaly appearance.

The bracteae which are stationed upon the receptacle of
Compositae, between the florets, have generally a membranous
texture and no colour, and are called palece, Englished by
some botanists chaff of the receptacle. The French call this
sort of bracteae paillette, Cassini squamelles {Jig. 63.).

In Palms and Aroideae there are seated, at the base of the
spadix, large, coloured bracteae, in which the spadix is in
aestivation wholly enwrapped, and which may perhaps perform

CHAP. U. COMPOUND ORGANS IN FLOWERING PLANTS. 103

in those plants the office of corolla. This is called the
spat/ia {Jig. 84.). Link considers it a modification of the
petiole ! (Elemeiita, p. 253.)

67

The most remarkable arrangement of bracteae takes place
in Grasses, in which they occupy the place of calyx and
corolla, and have received a great variety of names from
different systematic writers. In order to explain distinctly
the application of these terms, I must describe with some
minuteness the structure of a locusta or spicula, as the partial
inflorescence of Grasses is denominated. Take, for example,
any common Bromus ; each locusta will be seen to have at its
base two opposite empty bracteae (Jig. 67, b.), one of which is
attached to the rachis a little above the base of the other:
these are the gluma of Linnaeus and most botanists, the gluma
exterior or calycinalis of some writers, the tegmen of Palisot
de Beauvois, the lepicena of Richard, the ccetonium of Trinius,
and, finally, the jperistachyum of Panzer. Above the gluma are
several florets sitting in denticulations of the rachis (Jig. 67, c):
each of these consists of one bractea, with the midrib quitting
the lamina a little below the apex, and elongated into a bristle
called the wwn, beard, or arista, and of another bractea facing
the first, with its back to the rachis, bifid at the apex, with no
dorsal vein, but with its edges inflexed, and a rib on each side
at the line of inflexion (Jig. 67, a.). These bracteae are the
corolla of Linnaeus, the calyx of Jussieu, the pierianthium of
Mr. Brown, the gluma interior or corollina and perigonium of
some, the stragulum of Palisot de Beauvois, the gluma of

h 4

104 ORGANOGRAPHY. BOOK I.

Richard, the bale or Glumella of De Candolle and Desvaux,
the palecc of others. When the arista proceeds from the very
apex of the bracteae, and not from below it, it is denominated
in the writings of Palisot a seta. Within the last-mentioned
bracteae, and opposite to them, are situated two extremely
minute colourless fleshy scales {Jig. 67, e.), which are some-
times connate : these are named corolla by Micheli and
Dumortier, nectarium by Linnaeus, squamula by Jussieu and
Brown, glumella by Richard, glumellula by Desvaux and De
Candolle, lodicula by Palisot de Beauvois. Amidst these
conflicting terms it is not easy to determine which to adopt.
I recommend the exterior empty bracteae to be called glumce-,
those immediately surrounding the fertilising organs palece ;
and the minute hypogynous ones, scales or squamidce.

The pieces of which these three classes of bracteae are
composed are called valves or valvulce by the greater part of
botanists ; but as that term has been thought not to convey an
accurate idea of their nature, Desvaux has proposed to sub-
stitute that of spathella, which is adopted by M. De Candolle.
Palisot proposed to restrict the term gluma to the pieces
of the gluma, and to call the pieces of the perianthium palcce.
Richard called the pieces of both gluma and perianthium
palece, and the squamulae paleolce. It seems to me most con-
venient to use the term valvula, because it is more familiar to
botanists than any other, and because I do not see the force
of the objection which is taken to it.

In the genus Carex two bracteae (j%. 67, e, //..) become con-
fluent at the edges, and enclose the pistillum, leaving a passage
for the stigmata at their apex. They thus form a single urceo-
late body named urceolus or perigynium. M. De Candolle justly
observes, in his Theorie, that some botanists call this nec-
tarium, although it does not produce honey ; others capsula,
although it has nothing to do with the fruit ; but he does not
seem to me more correct than those he criticises in arranging
the urceolus among his miscellaneous appendages of the floral
organs, which are " ni organes genitaux ni tegumens." I
believe I was the first who explained the true nature of the
urceolus, in my translation of Richards's Analyse du Fruity
printed in 1819. (p. 13.)

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 105

At the base of the ovarium of Cyperaceae are often found
little filiform appendages, called hypogynous setce by most
botanists. These are probably of the nature of the squamulae
of Grasses, and have been named perisporwn by some French
writers.

Bracteae are generally distinct from each other, and imbri-
cated or alternate. Nevertheless, there are some striking
exceptions to this ; as remarkable instances of which may be
cited Althaea and Lavatera among Malvaceae, all Dipsaceae,
and some Trifolia, particularly my Tr. cyathiferum {Hooker,
Fl. Borcali-Amcr.), in all which the bracteae are accurately
verticillate, and their margins confluent, as in a true calyx.

4. Of the Flower.

69 70 71

The Flower is a terminal bud enclosing the organs of
reproduction by seed. By the ancients the term flower was
restricted to what is now called the corolla; but Linnaeus
wisely extended its application to the union of all the organs
which contribute to the process of fecundation. The flower,
therefore, as now understood, comprehends the calyx, the
corolla, the stamens, and the pistillum, of which the two last
only are indispensable. The calyx and corolla may be wanting,
and a flower will nevertheless exist ; but if neither stamens
nor pistillum nor their rudiments are to be found, no assem-
blage of leaves, whatever may be their form or colour, or how
much soever they may resemble the calyx and corolla, can
constitute a flower.

106 ORGANOGRAPHY. BOOK I.

The flower, when in the state of a bud, is called the alabas-
trus [bouton of the French), a name used by Pliny for the
rose-bud. Some writers say alabastrum, forgetting, as it
would seem, that that term was used by the Romans for a
scent-box, and not for the bud of a flower. Link calls the
parts of a flower generally, whether united or connate, ?noria,
whence a flower is bi-polymorious (Elem., 243.) ; but I know of
no writer who employs these terms, which indeed are quite
superfluous.

The flowers of an anthodium, which are small, and some-
what different in structure from ordinary flowers, are called
Jlorets (Jfosculi ; elytriculi of Necker ; Jleuron of the French).

The period of opening of a flower is called its anthcsis; the
manner in which its parts are arranged with respect to each
other before opening is called the cestivation. ^Estivation is
the same to a flower-bud as vernation (p. 53.) is to a leaf-
bud : the terms expressive of its modifications are to be sought
in Glossology. This term aestivation is applied separately to
the parts of which a flower may consist ; thus, we speak of the
aestivation of the calyx, of the corolla, of the stamens, and of
the pistillum ; but never of the aestivation of a flower, col-
lectively.

5. Of the Inflorescence.

Inflorescence is a term contrived to express generally the
arrangement of flowers upon a branch or stem. The part
which immediately bears the flowers is called the peduncidus
or peduncle, and is to be distinguished from any portion of
a branch by not producing perfect leaves; those which are
found upon it called bractecc being much reduced in size and
figure from what are borne by the rest of the plant.

The term peduncle, although it may be understood to apply
to all the parts of the inflorescence that bear the flowers, is
only made use of practically, to denote the immediate support
of a single solitary flower, and is therefore confined to that
part of the inflorescence which first proceeds from the stem.
If it is divided, its principal divisions are called branches ; and
its ultimate ramifications, which bear the flowers, are named
pedicels. There are also other names which are applied to
modifications of the peduncle.

CHAP. II. COMPOUND ORGANS IN FLOWERING TLANTS.

107

In plants which are destitute of stem, it often rises above
the ground, supporting the. flowers on its apex, as in the
Cowslip. Such a peduncle is named a scape (hampe, Fr.).
Some botanists distinguish from the scape the pedunculus radi-
calism confining the former term to the peduncle which arises
from the central bud of the plant, as in the Hyacinth ; and
applying the latter to a peduncle proceeding from a lateral
bud, as in Plantago media.

When a peduncle proceeds in a nearly right line from the
base to the apex of the inflorescence, it is called the rachis, or
the axis of the inflorescence. This latter term was used by
Palisot de Beauvois to express the rachis of Grasses, and is
perhaps the better term of the two, especially as the term
rachis is applied by Willdenow and others, without much
necessity it must be confessed, to the petiole and costa of
Ferns. In the locustae of Grasses the rachis has an unusual
toothed flexuose appearance, and has received the name of
scobina from M. Dumortier. If it is reduced to a mere bristle,
as in some of the single-flowered locustae, the same writer then
distinguishes it by the name of acicida. I mention these and
similar terms, in order that nothing which can even remotely
lead to information may be omitted ; but I cannot recommend
their adoption.

When the part which bears the flowers is repressed in its de-
velopement, so that, instead of being elongated into a rachis, it
forms a flattened area on which the flowers are arranged, as in
Compositae, it becomes what is called a receptacle; or, in the lan-
guage of some botanists, the receptacle of the Jloisoer (Jig. 72.).

108

ORGANOGRAPHY.

BOOK I.

When the receptacle is not fleshy, but is surrounded by
an involucrum, it is called the clinanthium (the thalamus of
Tournefort), as in Compositae, or, in the language of M.
Richard, phoranthium ; the former term is that generally
adopted. But if the receptacle is fleshy, and is not enclosed
within an involucrum, as in Dorstenia and Ficus (Jig. 73.),
it is then called by Link Hypanthodium ; the same writer
formerly named it Amphanthium, a term now abandoned.

According to the different modes in which the inflorescence
is arranged, it has received different names, the right applica-
tion of which is of the first importance in descriptive botany.
If flowers are sessile along a common axis, as in Plantago, the
inflorescence is called a spike (e*pi, Fr.), (Jig. 76.) ; if they are
pedicellate, under the same circumstances, they form a raceme
(grappe, Fr.), (Jig. 77.) as in the Hyacinth : the raceme and
the spike differ, therefore, in nothing, except that the flowers
of the latter are sessile, of the former pedicellate. These are
the true characters of the raceme and spike, which have been
confused and misunderstood in a most extraordinary manner
by some French writers.

79, a.

CHAP. IJ. COMPOUND ORGANS IN FLOWLIUNG PLANTS. 10.0
80 81 82

83 84 85 86

When the flowers of a spike are destitute of calyx and
corolla, the place of which is taken by bracteae, and when
with such a formation the whole inflorescence falls off" in a
single piece, either after flowering or ripening the fruit, as in
Cory 1 us, Salix, &c, such an inflorescence is called an amentum
or catkin [chaton, Fr. ; Catuhis, lulus, nucamentum, of old
writers), [Jig. 8 1 .) Linnaeus considered the catkin to be an
elongated filiform receptacle, analogous to that of Compositae,
in which he is followed by Sir James Edward Smith, Link,
and others. This opinion arises from a distinction being
drawn between the axis of a spike and the receptacle of
Compositae ; but, as I have already stated, the latter can be
considered in no other light than that of a depressed axis or
rachis : so that, when the amentum is said not to be a true
axis, but an elongated receptacle, a difference is drawn between
words rather than tilings ; for if a receptacle is only a depressed
axis, an elongated receptacle is necessarily a return to the
common form of the axis.

If a spike consists of flowers destitute of calyx and corolla,
the place of which is occupied by bractaea, supported by other
bracteae which enclose no flowers, and when with such a form-
ation the rachis, which is flexuose and toothed, does not fall
off with the flowers, as in Grasses, each part of the inflo-
rescence so arranged is called a spicula or locust a {ejnllet, Dec;
jiaquct, Tournefort). Link is of opinion that the rachis of a
spicula, as well as that of the amentum, is a kind of receptacle.

110 ORGANOGRAPHY. BOOK I.

When the flowers are closely arranged around a fleshy
rachis, which is enclosed in the kind of bracteae called a
spatha (see p. 103.), the inflorescence is termed a spadix
(spa dice or poi?ifo?i, Fr.), (Jig. 84-.). This is only known to
exist in Aroideae and Palms.

The raceme has been said to differ from the spike only in
its flowers being pedicellate: to this must be added, that the
pedicels are all of nearly equal length ; but in many plants, as
Alyssum saxatile, the lower pedicels are so long that their
flowers are elevated to the same level as that of the upper-
most flowers ; a corymbus is then formed (Jig. 86.). This term
is frequently used in an adjective sense, to express a similar
arrangement of the branches of a plant or of any other kind
of inflorescence : thus, in Stevia, the branches are said to be
corymbose; in others, the panicle is said to be corymbose;
and so on. When corymbose branches are very loose and
irregular, they have given rise to the term muscar'mm ; a name
formerly used by Tournefort, but not now employed.

If the expansion of an apparent corymb is centrifugal, in-
stead of centripetal ; that is to say, commences at the centre,
and not at the circumference, as inDianthus Carthusianorum,
we then have the fasciculus (Jig. 82.); a term which may not
incorrectly be understood as synonymous with compound co-
rymbus. The modern corymbus must not be confounded with
that of Pliny, which was analogous to our capihdum.

When the pedicels all proceed from a single point, as in
Astrantia, and are of equal length, or corymbose, we have what
is called an umbel (Jig. 79.). If each of the pedicels bears a single
flower, as in Eryngium, the umbel is said to be simple (fg. 79, a.) ;
but if they divide and bear other umbels, as in Heracleum,
the umbel is called compound; and then the assemblage of
umbels is called the umbella universalis, while each of the
secondary umbels, or the umbellules, is named an umbella
partialis. The peduncles which support the partial umbels
are named radii. The late M. Richard confined the word
umbel to the compound umbel, and named the simple umbel
sertulum (bouquet); but this was an unnecessary change.

Suppose the flowers of a simple umbel to be deprived of
their pedicels, and to be seated on a receptacle or enlarged

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. Ill

axis, and we have a capitulum or head, named glomus by some,
glomerulus by others. If this is flat, and surrounded by an
involucrum, the compound flower, as it is inaccurately called
by the school of Linnaeus, of Compositae, is produced; which
is often named by modern botanists anthodium; a term
invented by Ehrhart, and to which there seems to be no
objection. It was called cephalanthium by Richard, and
calathidium by Mirbel. The flowers or florets borne by the
anthodium in its circumference are usually ligulate, and differ-
ent from those produced within the circumference. Those in
the former station are called Jlorets of the ray, and those in
the latter Jlorets of the disk.

I have said that the school of Linnaeus inaccurately calls the
anthodium a compound flower, from which opinion I should
think that few persons would at the present clay dissent,
unless they applied the same term to the umbella, the spica,
and all other forms of inflorescence, of which the anthodium
is palpably a mere modification. Professor Link, however,
has in a late work defended the nomenclature of Linnaeus ;
urging, that the rays of an anthodium may be considered
a sort of corolla, the florets of the disk a representation of the
stamens and pistillum ; and that this mode of viewing the
subject is much confirmed by the property possessed by the
rays of many Compositae, of closing at night, or in cloudy or
rainy weather. What this sort of argument may be worth, I
profess not to understand ; but it seems to me that we may as
well call a branch clothed with leaves a compound leaf, or a
flock of sheep a compound sheep, as the cluster of flowers of
an anthodium a compound flower.

All the forms of inflorescence which have been yet men-
tioned are to be considered as reductions of the spike or
raceme. Those which are now to be described are decom-
positions, more or less irregular, of the raceme.

The first of these is the panicle and its varieties. The
simple panicle differs from the raceme in bearing branches of
flowers where the raceme bears single flowers, as in Poa
(fg. 80.); but it often happens that the rachis itself separates
into irregular branches, so that it ceases to exist as an axis, as
in some Oncidiums. This is called by Willdenow a deliquescent

112 ORGANOGRAPHY. BOOK I.

panicle. When the panicle was very loose and diffuse, the
older botanists named it a juba; but this is obsolete. If the
lower branches of a panicle are shorter than those of the
middle, and the panicle itself is very compact, as in Syringa,
it then receives the name of thyrsus.

Suppose the branches of a deliquescent panicle to become
short and corymbose, with a centrifugal expansion indicated
by the presence of a solitary flower seated in the axillae of the
dichotomous ramifications, and a clear conception is formed of
what is called a cyme. This kind of inflorescence is found in
Sambucus, Viburnum, and other plants (<fig- 83.).

If the cyme is reduced to a very few flowers, and those few
become corymbose, such a disposition has been called a verti-
cillaster by Hoffman segg. (Verzcicluiiss z. Pflanz. Cult., ii. 203.)
It constitutes the normal form of inflorescence in Labiatae, in
which two verticillastri are situated opposite to each other in
the axillae of the opposite leaves. By Linnaeus, the union of
two such verticillastri was called a verticillus or whorl; and by
others, with more accuracy, a verticillus spurius or false
whorl. Link terms this inflorescence a thyrsula ; but Hoff-
mansegg's name seems preferable.

It occasionally happens, as in the Vine, that the rachis of
some of the masses of inflorescence lose their flowers, but at
the same time acquire the property of twining round any
body within their reach, and so of supporting the stem, which
is too feeble to support itself. Such rachises form what is
called a spurious cirrhus, or a cirrhus peduncularis, and are a
striking exception to the general law that the cirrhus takes its
rise from the petiole or costa.

6. Of the Calyx.

The calyx is the most exterior integument of the Flower,
consisting of several verticillate leaves, either united by their
margins or distinct, usually of a green colour, and of a ruder
and less delicate texture than the corolla.

Authors have long disputed about the definition of a calyx,
and the limits which really exist between it and the corolla:
the above, which is copied from Link, seems to be the only

CHAP. II. COMPOUND OROANS IN FLOWERING PLANTS. IIS

one that can be considered accurate. The fact is, that in
many cases they pass so insensibly into each other, as in Caly-
canthus and Nymphsea, that no one can say where the calyx
ends and the corolla begins, although it is evident that both
are present. Linnaeus, indeed, thought that it was possible
to distinguish them by their position with regard to the
stamens, asserting that the divisions of the calyx are opposite
those organs, of the corolla alternate with them ; but, if this
distinction were admitted, the corolla of the Primrose would
be an inner calyx, which is manifestly an absurdity. Jussieu
defines a calyx by its being continuous with the peduncle,
which the corolla never is ; and this may seem in some cases
a good distinction ; but there are plenty of true calyxes, of all
Papaveraceous and Cruciferous plants, for instance, in which
the calyx is deciduous, and not more continuous with the
peduncle than the corolla itself. The only just mode of dis-
tinguishing the calyx seems to me to be to consider it in all
cases the most exterior verticillate series of the integuments
of the flower within the bractese, whether it be half-coloured,
deciduous, and of many pieces, as in Cruciferee ; membranous
and wholly-coloured, as in Mirabilis ; green and campanulate,
or tubular, as in Laurus and Lythrum. Upon this principle,
whenever there is only one series of floral integuments, that
series is the calyx. A calyx, therefore, can exist without a
corolla; but a corolla cannot exist without a calyx.

In some elementary works the term Perianthium is given as
synonymous with that of calyx ; but this is an error.

The word Perianthium signifies the calyx and corolla com-
bined, and is therefore strictly a collective term. It should
only be employed to designate a calyx and corolla, the limits
of which are undefined, so that they cannot be satisfactorily
distinguished from each other, as in most Monocotyledonous
plants, the Tulip and the Orchis for example. But since,
even in such plants as these, there can be no reasonable doubt
that the three outer floral leaves are the calyx, and the three
inner the corolla (as is shewn both by Tradescantia and its
allies, in which the usual limits between calyx and corolla
exist, and by the usual origin of those parts in two distinct
whorls), the utility of the term Perianthium is rendered ex-

i

114 ORGANOGRAPHY. BOOK i,

tremely doubtful. It is, in reality, an evasion of the task of
ascertaining the exact nature of the floral envelopes in doubtful
cases. Some writers, among whom are Link and De Can-
dolle, have substituted Perigonium for Perianthium ; but the
latter is in most common use, its application is perfectly well
understood, and there is no good reason for its being changed.
Ehrhart, with whom the name Perigonium originated, called
it double when the calyx and corolla are evidently distinct,
and single if they are not distinguishable ; but this use of terms
is obsolete.

The divisions of a calyx are called its sepals (sepala) ; a
term first invented by Necker, and recently revived by M. De
Candolle. Botanists of the school of Linnaeus call them the
leaflets or foliola. Link says the word sepalum is barbarous,
and proposes to substitute phyllum. The sepals are generally
longer than the corolla in aestivation, and during that period
act as its protectors : during flowering they are mostly shorter.

The calyx, if deciduous, falls off from the peduncle by its
base. In many cases the sepals drop off separately, as leaves
fall from the stem ; but occasionally they cohere firmly into a
sort of cap or lid, which is pushed off entire by the increase
of the corolla and stamens : in these cases the calyx is said to
be operctilate, if it falls off without any lateral rupture of its
cap, as in Eucalyptus; and calyptrate, if at the period of
falling it bursts on one side, as in Eschscholtzia. In the
former of these two cases, the cohesion between the sepals is
complete and never destroyed ; in the latter, two of the sepals
separate, the cohesion between the remainder continuing
complete.

The calyx of Compositoe is so very different in appearance
from the calyx of other plants, that it is known by the par-
ticular name of pappus. It usually consists of hair-like pro-
cesses proceeding from the apex of the ovarium, in which
case it is said to be pilose: if those hairs are themselves
divided it is plumose ; if they are very unusually stiff, it is
setose, in which case the setae are often reduced in number to
two, or even one ; if the divisions of the pappus are broad and
membranous it is said to be paleaceous : finally, it is sometimes
reduced to a mere rim ; in which case it is usually said either

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 115

to be marginate, or to be none, or to have no existence. If
the pappus is in two rows, which it occasionally is, the inner
circle only is to be understood as calyx : the exterior must
then be accounted bracteae or paleae of the receptacle con-
fluent with the ovarium.

In such cases as those above mentioned, when the calyx is
altogether obsolete, the definition of that organ, as the most
external of the floral envelopes, appears to be destroyed ; but
there can be no doubt that it is present in the form of a mem-
brane adhering to the side of the ovarium, although it is not
visible to our eyes. The same may be said of such plants as
those Acanthaceae [Introduction to the Nat. Syst., p. 233.), in
which, although the calyx is reduced to a mere ring, yet it
does exist in the shape of that ring.

The Calyx being composed of leaves analogous to those of
the stem, but reduced in size and altered in appearance, it
will follow that it is subject to the same laws of developement
as stem-leaves ; and, as the latter, in all cases, originate imme-
diately from the axis, below those that succeed them in the
order of developement, so the calyx must always have an
origin beneath those other organs which succeed it in the
form of corolla, stamen, and pistillum or ovarium. Hence
has arisen the axiom in botany, that whatever the apparent
station of the calyx may be, it always derives its origin from
below the ovarium : nevertheless, it is often said to be su-
perior.

If it is distinct from the ovarium, as in Silene, it is said to
be hiferior ( calyx hiferus, or liberies) ; and the ovarium is then
called superior {ovarium superum, or liberum) (Plate V. fig. 3.);
but if it is firmly attached to the sides of the ovarium, so that
it cannot be separated, as in Myriophyllum, it is then called
superior [calyx superus), and the ovarium hiferior [ovarium in-
ferum) (Plate V. fig. 7. 9.). From what has been said of
pappus it will be obvious that it is a superior calyx.

The general opinion of botanists, in regard to the real
nature of the superior calyx, is such as I have stated ; and
the accuracy of it in the majority of cases is indisputable.
But it is by no means certain that, in some instances, what is
called the tube of the calyx is not, as I have elsewhere stated

i 2

llfi ORGANOGRAPHY. BOOK I.

{Introduction to the Natural System, p. 26.), " sometimes a
peculiar extension or hollowing out of the apex of the pedicel,
of which we see an example in Eschscholtzia, and of which
Rosa and Calycanthus, and, perhaps, all supposed tubes with-
out apparent veins, may also be instances." And if this be
so, the superior calyx may be so in consequence of the
cohesion of the ovarium with the inside of an excavated
pedicel, and not with the calyx itself.

When the sepals cohere by their contiguous edges into a
kind of tube or cup, the calyx is said to be monophyllous ; an
inaccurate term, which originated in what may be called the
dark age of botany, when the real nature of organs was
unknown, and when a monophyllous calyx was thought to
consist really of a single leaf, clipped into teeth at its margin.
To avoid this inaccuracy, the word gamosepalous has been
proposed. But as the real nature of a monophyllous calyx is
now understood, changing the term is more embarrassing to
the student than profitable to science.

Various terms are employed to express the degree in which
the sepals of a monophyllous calyx cohere : they will be ex-
plained in Glossology. When no cohesion whatever takes place
between the leaves of a calyx, the term sepalous is employed with
that Greek numeral prefixed, which is equivalent to the number
of pieces ; as, for example, if they are two, the calyx is dise-
palous ; if three, trisepalous ; if four, tetrasepalous, and so on.

Sometimes the calyx has certain expansions or dilatations,
as in Scutellaria and Salsola. These are generally named
appendages, and such a calyx is said to be appendicidate ; but
Mcench has proposed a particular term for them, peraphyllum,
which is, however, never used.

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 117

87

7. Of the Corolla.

88 89

That envelope of the flower which forms a second whorl
within the calyx, and between it and the stamens, is called the
corolla. Its divisions always, without exception, alternate
with those of the calyx, and are called petals. Like the
sepals, they are either united by their margins, or distinct;
but, unlike the calyx, they are rarely green, being for the most
part either white, or of some colour, such as red, blue, or
yellow, or of any of the hues produced by their intermixture.
The corolla is generally also much larger than the calyx.

Necker called the corolla perigynandra interior^ and Lin-
naeus occasionally gave it the name of Aula urn, which literally
signifies the drapery of a room.

The alternation of the segments of the corolla with those
of the calyx is a necessary consequence of their both being-
modifications of verticilli of leaves, and therefore subject to
the same laws of arrangement. If two verticilli of leaves are
examined, those of Galium, for example, they will always be
found to be mutually so arranged, that if the internodium
that separates them were removed, they would exactly alter-
nate with each other ; and as there are no known exceptions
to this law in real leaves, it is natural that it should not be
departed from in any modifications of them.

When the petals of a corolla are all distinct, then the
corolla is said to be polypetalom ; but if they cohere at all by
i 3

118 ORGANOGRAPHY. BOOK I.

their contiguous margins, so as to form a lube, it then be-
comes what is called monopetalous ; an inaccurate term of the
same origin as that of monophyllous, in regard to calyx (see
p. 1 16.)» and for which that of gamopetalous has been some-
times substituted.

If the petals adhere to the bases of the stamens, so as to
form a sort of spurious monopetalous corolla, as in Malva
and Camellia, such a corolla has been occasionally called
catapetalous ; but this term is never used, all such corollas
being considered polypetalous.

When the petals are confluent into a monopetalous corolla,
the unguis form what is called a tube ; the orifice of which is
the faux or throat. The principal forms of such a corolla
are rotate (Jig. 93.), hypocrateriform (Jig. 91.), infundibu-
liform (Jig. 94.), campanulate (Jig. 68.), and labiate (Jig. 92.).
When the divisions of a monopetalous corolla do not spread
regularly round their centre, as in Campanula, but part
take a direction upwards, and the remainder a direction
downwards, as in Labiatae, the upper form what is called
the upper lip, and the lower, the lower lip, or labellum ;
the latter term is chiefly applied to the lower lip of Or-
chideous plants. If the upper lip is arched, as in Lamium
album, it is termed the galea or helmet. When the two lips are
separated from each other by a wide regular orifice, as in
Lamium, the corolla is said to be labiate or ringent ; if the
upper and lower sides of the orifice are pressed together, as
in Antirrhinum, it is personate or masked, resembling the face
of some grinning animal. In the latter, the lower side of the
orifice is elevated into two longitudinal ridges, divided by a
depression corresponding to the sinus of the lip ; this part of
the orifice is called the palate. In ringent and personate
corollas the orifice is sometimes named the rictus ; but this
term is superfluous and little used.

A petal consists of the following parts : — the limbus or
lamina (lame, Fr.) ; and the unguis or claw (onglet, Fr.).
The unguis is the narrow part at the base which takes the
place of the foot-stalk of a leaf, of which it is a modification ;
the limbus is the dilated part supported upon the unguis, and
is a modification of the lamina of a leaf. In many petals
there is no unguis, as in Rosa ; in many it is very long, as in

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 119

Dianthus. When the unguis is present, the petal is said to
be unguiculate. In some unnaturally deformed flowers the
limbus is absent, as in the garden variety of Rosa, called
R. QEillet, in which the petals consist wholly of unguis.

According to the manner in which the petals of a polype-
talous corolla are arranged, they have received different names,
which are thus defined by Link : — the rosaceous corolla (Jig. 96.)
has no unguis, or it is very small ; the liliaceous (Jig- 71.) has
its ungues gradually dilating into a lamina, and standing side
by side ; a caryophyllaceous has long, narrow, distant ungues ;
the alsinaceous has short distant ones ; the cruciate flower has
four valvaceous sepals, four petals, and six stamens, of which
two are shorter than the rest, and placed singly in front of the
lateral sepals, and four longer, and standing in pairs opposite
the two other sepals. If the corolla is very irregular, with one
petal very large and helmet-shaped, or hooded, as in Aconitum,
it is sometimes called cassideous ,• if it resembles what is called
labiate in gamopetalous corollas, it is termed labiose. The
corolla of the Pea, and most Leguminous plants, has re-
ceived the fanciful name of papilionaceous
or butterjly-shaped (Jig. 97, 98.); in this
there are five petals, of which the upper
is erect and more expanded than the
rest, and is named the vexillum or stand-
ard, (etendard, Fr.) ; the two lateral are
oblong, at right angles with the vexillum,
and parallel with each other, and are
called the alee or wings (ailes, Fr.) ; and
the two lower, shaped like the alas and
parallel with them, cohere by their lower
margin, and form the carina or keel
(carene or nacelle, Fr.). The alae were
formerly called talarcc by Link, and the carina scaphium by
the same author.

When the corolla is very small, or when it forms a part of
an anthodium, it is called corollula : that of a floret is so
called.

If the flower has no corolla, it is said to be apetalous.

Sometimes a petal is lengthened at the base into a hollow

i 4

120 ORGANOGRAPHY. BOOK I.

tube, as in Orchis, &c. : this is called the spur or calcar, and
by some nectarotheca.

In Umbelliferae the petal is abruptly acuminate ; and the
acumen is inflexed. The latter is named the lacinula.

A corolla is said to be regular when its segments form
equal rays of a circle supposed to be described, with the axis
of the flower for a centre. If they are unequal, the corolla is
called irregular. Equal and unequal are occasionally substi-
tuted for regular and irregular.

In anatomical structure, the petal should agree with a
leaf, of which it is a mere modification ; and, in fact, it does
so in all that it is important, its differences consisting chiefly
in an attenuation and coloration of the tissue, with a suppres-
sion of woody fibre. Like a leaf, they consist of a flat plate
of parenchyma, articulated with the stem, traversed by veins,
and frequently having stomata upon its surface. Their veins
consist almost entirely of delicate spiral vessels, upon which
the parenchyma is immediately placed. It is therefore by
mistake that the learned M. De Candolle has stated [Organogr.
p. 454.) that stomata and spiral vessels are usually absent.
The latter may be very readily seen in the corolla of Anagallis,
where they form a beautiful microscopical object, as I first
learned from Mr. Solly.

The petals are usually deciduous soon after flowering, or
even at the instant of expansion ; a very rare instance of their
persistence and change from minute colourless bodies into
leafy, richly coloured expansions, occurs in Dr. Wallich's
Melanorrhaea usitatissima.

Their colours are due to the secretion within the cellules
of their parenchyma of a peculiar substance : even white petals
are so in consequence of the deposit of an opaque white sub-
stance, and not because of the absence of colouring matter.

In most corollas the petals, in their natural state, form but
one verticillus within that of the calyx : but instances exist in
which they naturally are found in several whorls, as in Nym-
phaea, Nuphar, Magnolia, &c. It sometimes happens that, if
there is more than one row of petals, all within the first row
assume a different appearance from the first ; the filamentous
processes of the crown of Passiflora are also apparently of this
nature.

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 121

The petals are often furnished with little appendages
(Jig. 104.), which are either inner rows of petals in a state of
adhesion to the first row, or modified stamens ; which it is
sometimes difficult to ascertain, but always certainly one of
the two. Many of these enter into Linnseus's notion of nec-
tarium, although nearly the whole of them are destitute of
any power of secreting nectar or honey.

99 100 101

102 103 104

The most common form of appendage is the coro?ia, which
proceeds from the base of the limb, forming sometimes an undi-
vided cup, as in Narcissus (Jig. 103.), when it becomes the
scyphas of Haller ; sometimes dividing into several foliaceous
erect scales, as in Silene and B rod iaea, when it forms the lamella
of some writers; occasionally appearing as cylindrical or clavate
processes, as in Schwenckia and Tricoryne, where they are
manifestly modified stamens : and even in some instances
forming a thick solid mass covering over the ovarium, and
adhering to the stamens, as in Stapelia ; when it is called the
orbiculus. Parts of this last form of corona bear several
names, which are found useful in avoiding repetition in de-
scribing the complicated structure of this kind of appendage.
The whole mass of the corona is the orbiculus, or saccus, or
stylotegium ; certain horn-like processes are cornua, or horns ;
the upper end of these is the beak, or rostrum, and their back,
if it is dilated and compressed, is the ala, or appendix,-
occasionally there is an additional set of horns proceeding
from the base of the orbiculus, and alternate with the horns,
these are ligulcc ; the circular space in the middle of the top

122

ORGANOGRAPHY.

BOOK I.

of the orbiculus is the scutum. Mr. Brown names the orbi-
culus corona stcwihiea, and its divisions foliola, or leaflets.

In some plants, as Cynoglossum, the lamellae are very
small, scale-like, and overarch the orifice of the tube ; such
have received the name of fornix.

Link calls every appendage which is referable to the corolla
a paracorolla ; or, if consisting of several pieces, parapet alwn ;
and every appendage which is referable to the stamens a
parastemon. The filiform rays of the corona of Passiflora the
same author calls paraphyses or parastades.

Mcench names such appendages of the corolla as the fila-
mentous beard of Menyanthes perapetalum, and Sprengel calls
the same thing nectarilyma.

In Ranunculus there exists at the base of each petal a little
shining, sometimes elevated, space which secretes honey.
This is the true nectarium or nectarostigma of Sprengel. By
some writers it has been considered a kind of reservoir, in
which there is much plausibility ; but it seems to me, from
analogy, to be a barren stamen, united with the base of the
petal, and to be of the same nature as the lamella of other
plants.

105 106

107

108

8. Of the Stamens.
109 no

114

113

112

Next the petals, in the inside, are seated the organs called
Stamens — the Apices of old botanists. These constitute the
male apparatus of the flower, like the calyx and corolla are
modifications of leaves, and consist of the filament, the anthera,
and the pollen, of which the two latter are essential: the first is

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 123

not essential ; that is to say, a stamen may exist without a
filament, but it cannot exist without an anther and pollen.
All bodies, therefore, which resemble stamens, or which occupy
their place, but which are destitute of anthera, are either
petals, or appendages of the petals, or abortive stamens.

As the petals are naturally alternate with the sepals, so the
natural station of the stamens, if of equal number with the
petals, is alternately with them ; and all deviations from this
law are to be understood as irregularities arising from the
suppression or addition of parts. Thus, when in Primula
we find the stamens opposite the segments of the corolla,
and equal to them in number, it is to be supposed that those
stamens which are present constitute the second of two rows
of which the exterior is not developed ; and when in Silene
we find the stamens ten, while the petals are five, the former
are to be considered to consist of two rows, although appear-
ing to consist of one. This may be understood by examining
Oxalis, in which the stamens are all apparently in one row,
but are alternately of different lengths. When the number
of stamens exceeds twice that of the petals, they will still be
divisible by the number of which they were at first a mul-
tiple, until their number is excessively increased, when they
seem to cease to bear any kind of proportion to the petals.

The stamens always originate from the space between the
base of the petals and the base of the ovarium. But botanists
are nevertheless in the habit of saying that they are inserted
into the calyx or corolla {Jig. 119.) (perigynous), or under the
pistillum (Jig. 1 1 7.) (hypogynous), or into the pistillum (Jig. 118.)

115 116

124? OHGANOGRAPHY. BOOK I.

(epigynous), all expressions inaccurate and leading to erroneous
notions of structure. The student, therefore, must understand,
that when in Primula the stamens are said to be inserted into
the faux of the corolla, it is meant that they cohere with the
corolla as far as the faux, where they first separate from it ; when
in Rosa they are said to be inserted into the calyx, it is meant
that they cohere with the calyx up to a certain point, where
they separate from it; when in Arabis they are said to be
inserted under the pistillum, it is meant that they cohere
with neither calyx nor corolla, but stand erect from the point
which immediately produces them ; and finally, when in
Orchis or Heracleum they are said to be inserted into the
pistillum, such an expression is to be taken as meaning that
they cohere with the pistillum more or less perfectly. For
excellent arguments in support of this hypothesis, see Conside-
rations sur la Nature et les Rapports de quelques uns des Organes
de la Fleur ; by Mons. Dunal. Montpellier, 1829, 4to. I
do not use them, or any such, here, because it seems to be so
self evident a fact, when once pointed out, as to require no
demonstration.

When their filaments are combined into a single mass, the
mass is said to be a brotherhood or an adelphia : if there is
one combination, as inMalva, they are monadelpJwus (^.113.);
if two, as in Fumaria or Pisum, diadelphous ,■ if three, as in
some Hypericums, triadelphous ; if several, as in Melaleuca,
polyadelphous {tfig. 111.). The tube formed by the union of
the filaments in a monadelphous combination is called, by
Mirbel, androphorum.

If the stamens are longer than the corolla they are exserted;
if shorter, they are called included ; when they all bend to one
side, as in Amaryllis, they are decimate ; if two out of four are
shorter, they are didynamous ,• if two out of six are longest, they
are tetradynamous.

The number of stamens is indicated by a Greek numeral
prefixed to the word androus, which signifies male, thus: —

One stamen is Monandrous.
Two — Diandrous.
Three — Triandrous.

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 125

Four stamens, Tetrandrous.

Five — Pentandrous.

Six — Hexand rous.

Seven — Heptandrous.

Eight — Octandrous.

Nine — Enneandrous.

Ten — Decandrous.
Eleven or twelve stamens, Dodecandrous.
Twelve to twenty — Icosandrous.
Above twenty — Poly and rous, or Indefinite.

Thejilament (Plate III.) (capillamentum,ov pediculusoi some)
is the part that supports the anther. It consists of a bundle
of delicate woody fibre and spiral vessels, surrounded by cel-
lular tissue, and is in all respects the same as the petiole of a
leaf, of which it is a modification, except that its parts are
more delicate. As the petiole is unessential to the leaf, so
is the filament to the anther, it being frequently absent, or at
least so strictly united to the sides of the calyx or corolla as
to be undistinguishable. Its most common figure is filiform
or cylindrical (Plate III. fig. 12, 13. 20, 21.), and it is almost
always destitute of colour ; but there are exceptions to both
these characters. In Fuchsia, for instance, the filaments are
red like the petals ; in Adamia they are blue ; in CEnothera
they are yellow ; and a return to the foliaceous state of which
they usually are a distinct modification is by no means rare.
(Plate IV. fig. 6. 8.) Thus the filament in Canna is undis-
tinguishable from petals except by its having an anther;
in the same genus and its allies, and in all Scitamineas, the
inner series of what seem to be petals are modifications of
filaments (See Introduction to the Nat. Syst. p. 265.): and this
is a very common circumstance in sterile stamens.

The filament also varies in other respects : in Thalictrum
it is thickest at the upper end, or clavate (Plate III. fig. 23.) ;
in Mahernia geniculate (Plate III. fig. 25.), in Hirtella
spiral, in Crambe bifurcate, in Anthericum bearded or stuposc.
In some plants the filaments are combined into a solid body
called the columna, as in Stapelia, Stylidium (Plate 4% fig. 1,

126 ORGANOGRAPHY. BOOK I.

2, 3.), Rafflesia, and others : this has in Orchideae received
from M. Richard the name of gynostemium.

Care must be taken not to confound the pedicel and single
stamen of the naked male flowers of Euphorbia with a fila-
ment, as was done by all writers, until Mr. Brown detected
the error; and as is still done by some botanists from whom
better things might be expected. For modifications of fila-
ments see Plates III. and IV.

The Anther ( Theca of Grew ; Capsula, Malpighi ; Apex,
Ray; Test iculus or Testis, Vaillant; Capitulum, Jungius; Sper-
matocystidium, Hedwig) is a body generally attached to the
apex of the filament, composed of two parallel lobes or cells
{theca, or coniothecce, or loculi), containing pollen, and united
by the connectivum. It consists entirely of cellular tissue,
with the exception sometimes of a bundle of very minute
vascular tissue, which diverges on each side from the filament,
and passes through that part of the anther from which the
pollen has been incorrectly supposed to separate, and which
is called the receptacle of the pollen by some, the trophopollen
by Turpin, and the raphe by Link, but with greater propriety
the septum of the anther. Its coat is called by Purkinje
exothecium.

In the most common state of the anther the cells are parallel
with each other (Plate III. fig. 14.), and open with two
valves (Plate III. fig. 13. a), by a longitudinal fissure from
the base to the apex ; in Labiatae and Scrophularineae the
cells diverge more or less at the base (Plate III. fig. 15. 18.),
so as in some cases to assume the appearance of a one-celled
horizontal anthei*, especially after they have burst. In Cu-
curbitacese the lobes are very long and narrow, sinuous and
folded back upon themselves (Plate III. fig. 24.). In Salvia
the connectivum divides into two unequal portions, one of
which supports a cell and the other is cell-less ; in this case
the connectivum has been called by Richard, distractilc.
Lacistema (Plate IV. fig. 7.), affords another instance of a
divided connectivum. In many of the cases of excessive
divergence of the cells the line of dehiscence of the anther
is changed from longitudinal to vertical (Plate III. fig. 20.
17.), and has actually been supposed to be really trans-
14

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 127

verse; an error which in most cases has arisen from not un-
derstanding the real structure of the anther. Some anthers,
however, no doubt have cells that burst transversely, as Lemna,
Alchemilla arvensis, Securinega, &c. (See Plate III., fig. 12.
16. 30.)

All anthers are not two-celled, their internal structure
being subject to several modifications. It sometimes happens
that the septum, instead of being very obscurely formed, pro-
jects forwai'd into the cavity of the anther, till it meets the
inflexed lips of the fissure : in such a case the anther is spu-
riously four-celled, as in Tetratheca. In Epacris the two
parallel cells become confluent into one, and the anther is
therefore one-celled. In Maranta and Canna only one cell
is produced, the other being entirely suppressed. In most
Amarantaceae, and some other plants, the anther seems to be
absolutely one-celled. (Plate IV. fig. 8.)

Other deviations from the normal form of anther occur,
which are less easy to reconcile with the idea of a two-celled
type. In some Laurineae the anther is divided into four cells,
one placed above the other in pairs ; in iEgiceras it consists
of numerous little cavities ; and in the singular genus RafHesia
the interior is separated into many cellules of irregular figure
and position, described by Mr. Brown as " somewhat con-
centrical, longitudinal, the exterior ones becoming connivent
towards the apex, sometimes confluent, and occasionally in-
terrupted by transverse partitions." In these instances the
septa may be understood to arise from portions of the cellular
tissue of the anther remaining unconverted into pollen, and
may be considered of a nature analogous to that of the fruit
of Diplophractum.

With regard to the deviations from the usual mode of de-
hiscence, Mr. Brown observes (Linn. Trans, xiii. 214.), "that
they are numerous : in some cases consisting either in the
aperture being confined to a definite portion, — generally the
upper extremity of the longitudinal furrow, — as in Dillenia
and Solanum ; in the apex of each theca being produced
beyond the receptacle of the pollen into a tube opening at
top, as in several Ericineae (Plate III. fig. 22.) ; or in the
two thecae being confluent at the apex, and bursting by a

128 ORGANOGRAPHY. BOOK I.

common foramen or tube, as in Tetratheca (See Plate IV.
fig. 4.). In other cases a separation of determinate portions
of the membrane takes place, either the whole length of the
theca, as in Hamamelideae and Berberideae, or corresponding
with its subdivisions, as in several Laurineae, or lastly, having
no obvious relation to internal structure as in certain species
of Rhizophora. In Laurineae and Berberideae the anthers are
technically said to burst by valves (Plate IV. fig. 10, 11.),
that is to say, the dehiscence does not take place by a cen-
tral line, but the whole face of the cell separates from the
anther, and curls backwards, adhering to it only at the apex
to which it is, as it were, hinged.

The cells of the anther have frequently little appendages,
as in different species of Erica, where they resemble setae,
aristae, or crests. (Plate III. fig. 29.).

The anthers are attached to the filament either by their
base, when they are called innate (Plate III. fig. 27. 21. 23.),
or by their back, when they are adnate (Plate III. fig. 13.),
or by a single point of the connectivum from which they
lightly swing : in the latter case they are said to be versatile.
This form is common to all true Grasses.

When the line of dehiscence is towards the pistillum, the
anthers are called by Mr. Brown anticte, but by other bota-
nists introrsce, or turned inwards : when the line is towards
the petals they are said by Mr. Brown to be postictc, and by
other botanists to be extrorsce, or turned outwards.

The connectivum is usually continuous with the filament,
and terminates just at the apex of the anther; but in some
plants, as Compositae, it is articulated with the filament
(Plate IV. fig. 5.) In others it is elongated far beyond the
apex (Plate IV. fig. 6. 9.), now into a kind of crest, as in many
Scitamineae ; now into a sort of horn, as in Asclepiadeae ; now
into a kind of secreting cup-like body articulated with the
apex, as in Adenostemon. Very frequently it is enlarged in
various ways. For cases of this kind see Plates III. and IV.
Its being sometimes two-lobed, or forked, has been already
noticed (Plate IV. fig. 7.). The lining of the anther has
received particular illustration from M. Purkinje, who calls
it endothecium, and who has found that it consists of that

13

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 129

very remarkable kind of tissue which has been already described
under the name of fibrous cellular (p. 10.). According to that
botanist the forms of this tissue are extremely variable, the
cells being sometimes oblong, sometimes round, frequently
cylindrical, usually fully developed, or, in some cases, merely
rudimentary ; the cellules are in some species erect, in others
decumbent ; but in all cases more or less fibrous. (See Plate I.
figs. 4. 13, 14, 15. 18, 19, 20.) For an elaborate treatise on
the subject see Joh. Ev. Purkinje de Cellulis Anther amm
Fibrosis. Vratislavias, 1830. 4to. with 18 plates.

The pollen is the pulverulent substance which fills the cells
of the anthers : it consists of a multitude of little grains,
most commonly called granules, or sometimes ulriculi.

The origin of the granules is still involved in some mystery.
The best account of it has been given by M. Adolphe Bron-
gniart, in the Annales des Sciences, vol. 12. Gleichen con-
sidered it to take its origin in the midst of a mucilaginous
mass, occupying the cells of the anther, and merely becoming
indurated and solidified towards maturity. Mr. Brown, in
the year 1820, without entering into any details on the sub-
ject, described it {Linn. Trans, xiii. 211.) as produced on
the surface or in the cells of a pulpy substance with which
the thecaa are filled. But this hypothesis is objected to by
Link (Elem. 29t). M. Guillemin (Recherches p. 5.) declares
that the granules are always arranged in regular rows, and
generally in the direction of the valves, and that they are
always distinct, at first floating in a viscid liquid, but finally
quite separate from it. M. Brongniart concludes, from a
series of very interesting observations, " that the pollen is
formed in the interior of the cellules of a single and distinct
cellular mass, which fills each cell of the anther without ad-
hering to its walls, and consequently without being a continu-
ation of the parenchyma of that organ, from which it also
differs in the size and form of the cellules that compose it ;
that sometimes these cellules, which are at first in close
cohesion, separate from each other, when each becomes a grain
of pollen ; and that sometimes the cellules contain an uncer-
tain number of grains of pollen, which, at the time of their
perfect developement, rupture and almost entirely destroy their

K

130 ORGANOGRAPHY. BOOK I.

membrane, some remains of which may sometimes be found
among the grains of pollen.

In 1831, Mr. Brown speaks thus of the evolution of the
pollen of Tradescantia virginica. " In the very early stage
of the flower bud, while the antherae are yet colourless, their
loculi are filled with minute lenticular grains, having a trans-
parent flat limb, with a slightly convex and minutely granular
semi-opake disk. This disk is the nucleus of the cell, which
probably loses its membrane or limb, and, gradually enlarging,
forms in the next stage a grain also lenticular, and which is
marked either with only one transparent line, dividing it into
two equal parts, or with two lines crossing at right angles, and
dividing it into four equal parts. In each of the quadrants a
small nucleus is visible : and even where one transparent line
only is distinguishable, two nuclei may often be found in each
semicircular division. These nuclei may be readily extracted
from the containing grain by pressure, and, after separation,
retain their original form. In the next stage examined, the
greater number of grains consisted of the semicircular di-
visions already noticed, which had naturally separated, and
now contained only one nucleus, which had greatly increased
in size. In the succeeding state the grain apparently con-
sisted of the nucleus of the former stage, considerably enlarged,
having a regular oval form, a somewhat granular surface, and
originally a small nucleus. This oval grain continuing to in-
crease in size, and in the thickness and opacity of its mem-
brane, acquires a pale yellow colour, and is now the perfect
grain of pollen." (On Orchid, and Asclep. p. 21.)

The granules of pollen are commonly distinct from each
other. They are, nevertheless, in certain cases, found in
various states of cohesion. In many plants they cohere in
threes or fours, as in many Orchidese; or in clusters of many
grains, as in Acacia (Plate IV. fig. 28.). In some, as the
Fuchsia, GEnothera, &c, they hang together by a sort of
cobweb substance, which is the remains of the cellular matter
in which they were engendered. In other cases they coalesce
in masses, having a waxy texture and colour, and occupying
the whole cavity of a cell of the anther, as in Asclepiadeae.
But the most curious instances of the cohesion of the grains

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 131

of pollen is to be found in Orchideae ; in which some genera
have the pollen in its common pulverulent state, with no
remains of the cellular substance in which it was developed ;
others have the granules held together by some of this cellular
substance in an elastic state, and forming a distinct appendage
to the pollen called the caudicula ,- while others have the grains
united either by threes or fours, or in wedge-shaped masses,
or in a hard, dry, solid body. It appears from Mr. Fran-
cis Bauer's observations, that the masses of pollen of both
Asclepiadeae and Orchideee, in the most solid state, are really
cellular, the grains of pollen being contained in cavities, the
walls of which are either separable from each other as in some
Orchideae, or are ruptured without a separation of the cavities
as in Asclepiadeae. (See the Observations on Orchideae and
Asclepiadeae before referred to.)

The granules are generally discharged at once, upon the
dehiscence of the anther, or at least are at that time wholly
formed. But in some Aroideae, which emit their pollen by a
hole in the apex of their anther, the formation or developement
of pollen must be going on for a considerable time after the
first emission. A single anther continues to secrete and dis-
charge pollen, till, as Mr. Brown remarks, the whole quantity
produced greatly exceeds the size of the secreting organ.

The surface of the pollen is commonly smooth. In some
plants it is hispid, as in the Gourd and Ipomaea purpurea ; in
others it is covered with strong points, as Hibiscus syriacus;
and in all cases, when there are asperities of the surface or
angles in its outline, it is asserted by M. Guillemin to have a
mucous surface, which was first observed in Proteaceae by
Mr. Brown.

The Jigwe of the granules is very various ; most frequently
it is spherical or slightly oblong. Many other forms have,
however, been described. The cylindrical exists in Anethum
segetum, and in a very remarkable degree in Tradescantia
virginica, where the grains become curved. In Colutea arbor-
escens, it was observed by M. Guillemin to be nearly square;
in Lavatera acerifolia to be oval, much attenuated to each
end. In CEnothera it is triangular, with the angles so much

k 2

132 ORGANOGRAPHY. BOOK I.

dilated as to give the sides a curved form. In Jacaranda
tomentosa I have remarked it to be spherical, with three
projecting ribs tapering to either apex. In the Chicoraceee
of Jussieu the granules are spherical with facettes ; in Dip-
saceae they are a depressed polyedron ; in Scabiosa caucasica
patelliform and angular. (For other Modifications see
Plate IV. fig. 12. to 37.)

In most spherical or elliptical pollen, with a smooth surface,
a line is observable along the axis of the granules, when they
are dry, which disappears upon the application of moisture.
This was long ago remarked by Malpighi, who compared
granules of pollen of this kind to grains of wheat, one side of
which is convex and the other furrowed. M. Guillemin is of
opinion that this supposed furrow exists on both sides of a
grain of pollen, because, let there be never so many of this
description examined at the same instant, the appearance
will be visible in all. But it is probable that the strong
transmitted light which is used in microscopical examinations
of minute objects would render the furrow visible on both
sides of a grain although it really existed only in one.

As to the nature of this supposed furrow, nothing positive
is known. M. Guillemin supposes it to be a slit intended to
facilitate the admission of water into the interior of the era-
nules and the emission of their fovilla, and he further com-
pares it to the line of dehiscence of each lobe of the Anthera.
In Passiflora a curious contrivance exists for the emission of
the contents of the pollen. Each spherical grain has on its
surface three equidistant circles, which indicate the lines of
dehiscence : at the proper time those parts of the coat of the
grain contained within the circles separate from the rest like
little lids, and allow the contents of the pollen to escape.
This economy is well represented by Purkinje.

Many botanists are of opinion that the coat of the pollen is
a simple cellular substance ; others think it a solid membrane ;
and a third class of writers insist upon its consisting of two
integuments, the outer of which is cellular, the inner mem-
branous and extensible : the last of these opinions is enter-
tained by M. Adolphe Brongniart and Amici. Mr. Brown
says that the existence of an inner membrane is manifest in

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 133

several Coniferae, in which the outer coat regularly bursts
and is deciduous ; and further, he considers that the struc-
ture in Asclepiadeae, as discovered by Mr. Francis Bauer,
furnishes the strongest argument in support of the opinion
of the existence of two membranes. In parts of such extreme
minuteness and delicacy of structure, a point of this kind can-
not be determined by sections ; for the sharpest knives in the
most skilful hands will only crush the grain of pollen into a
shapeless mass. The evidence of the existence of an internal
membrane is derived from the appearance of a thin transparent
coating round the fovilla when it is emitted upon the stigma,
and which is sometimes extended to a considerable length.
Its existence having been called in question, M. Adolphe
Brongniart was induced, in his examination of the anther,
to pay particular attention to the circumstance ; and he de-
clares that, " in all the pollen that he has examined with
care, after it had been a greater or less space of time upon
the stigma, he has found a tubular appendage, of variable
length, formed of an extremely thin and transparent mem-
brane, which evidently proceeded from the interior of the
grain of pollen, either through an accidental opening, or
through a special passage formed in the external membrane.'*
(See Plate IV. figs. 34. to 38.) He calls this appendage the
boyau or intestine. Notwithstanding the precise manner in
which this is stated, it has nevertheless been doubted by some
whether the boyau or pollen-tube is any thing more than mu-
cus surrounding the fovilla when emitted. Mr. Brown, in
1828, declared his difference in opinion from M. Brongniart
as to the existence of a membrane forming the coat of the
pollen-tube; but, in 1831, he states, in another place, that seve-
ral arguments may be adduced in favour of M. Brongniart's
opinion that the pollen-tubes belong to the inner membrane
of the grain ; and he particularly cites the structure in Ascle-
piadeae as favourable to the opinion. For my own part I can
only state that I have not succeeded in discovering two mem-
branes in any really simple pollen that I have examined ; and
that in some, particularly in Gesneria bulbosa (Plate IV.
fig. 32.) there is incontestibly but one membrane, the ex-
tension of which forms the pollen-tube. That the pollen-

K 3

I.H ORGANOGRAPHY. BOOK I.

tube itself lias not been found by some observers, has pro-
bably arisen from its having been looked for in pollen made
to burst on the field of the microscope, immersed in water,
when the pollen-tube is scarcely ever emitted. The vital
action that causes the emission seems to depend upon contact
with the secretion of the stigmatic surface. The pollen-tube
is, therefore, only to be sought in pollen that has been some
time upon the stigma.

The colour of pollen is chiefly yellow. In Epilobium an-
gustifolium it is blue, in Verbascum it is red, and it occa-
sionally assumes almost every other colour, except green,
According to Messrs. Fourcroy and Vauquelin, the pollen of
the Date tree consists of malic acid, phosphate of magnesia, and
lime, and also an insoluble animal matter intermediate between
gluten and albumen. M. Macaire Prinsep has ascertained that
the pollen of the Cedar contains acid, malate of potass, sul-
phate of potass, phosphate of lime, silica, sugar, gum, yellow
resin, and a substance which by its characters approximated to
starch. Being analysed as a whole, it gave, per cent., 40
carbon, 11.7 hydrogen, and 48.3 oxygen, but no azote. —
Bill. Univers. 1830. 45.

The matter contained in the granules is called the fovilla.
Under common magnifiers it appears like a turbid fluid ;
under glasses of greater power it has been found to consist
of a multitude of particles moving on their axes with activity,
of such excessive minuteness as to be invisible, unless viewed
with a magnifying power equal to 300 diameters, and mea-
suring from the 4000th or 5000th to the 20,000th or 30,000th
of an inch in length. This motion was first distinctly noticed
by Gleichen ; but it seems to have escaped the recollection of
succeeding botanists until the fact was confirmed by Amici,
who some time before 1824 saw and described a distinct,
active, molecular motion in the pollen of Portulaca oleracea.
In 1825 the existence of this motion was confirmed by
M. Guillemin, who ascertained its presence in other species.
In June 1827 I was shown the motion by Mr. Brown, who
subsequently published some valuable observations upon the
subject, without however noticing those of either Amici or
Guillemin. The most important addition that was made by

CHAP. II. COMPOUND OKGANS IN FLOWERING PLANTS. 135

Mr. Brown to the knowledge that previously existed, consisted
in the discovery of the presence of two kinds of active particles
in pollen, of which one is spheroidal, extremely minute, and
not distinguishable from the moving ultimate organic particles
common to all parts of a vegetable, the other much larger,
often oblong, and unlike any other kind of particle hitherto
detected in plants.

The supposed functions of these particles will be explained
hereafter. For the present it will be sufficient to remark,
that some of the best subjects in which to witness their mo-
tions are Clarkia pulchella, Mirabilis jalapa, and Lolium
perenne.

The stamen deviates in a greater degree than any other
organ from the structure of the leaf, from a modification of
which it is produced ; and, at first sight, in many cases, it
appears impossible to discover any analogy between the type
and its modification; as, for instance, between the stamen and
leaf of a Rose. Nevertheless, if we watch the transitions that
take place between the several organs in certain species, what
was before mysterious or even inscrutable, becomes clear and
intelligible. In Nymphaea alba the petals so gradually change
into stamens, that the process may be distinctly seen to depend
upon a contraction of the lower half of a petal into the fila-
ment, and by a development of yellow matter within the sub-
stance of the upper end of the same petal on each side into
pollen. A similar kind of passage from petals to stamens
may be found in Calycanthus, Illicium, and many other
plants. Now, as no one can doubt that a petal is a modified
leaf, it will necessarily follow, from what has been stated, that
a stamen is one also. But it is not from parts in their nor-
mal state that the best ideas of the real nature of the stamen
may be formed ; it is rather by parts in a monstrous state,
when reverting to the form of that organ from which they
were transformed, that we can most correctly judge of the
exact nature of the modification. Take for example that well-
known double Rose, called by the French R. CEillet. In
that very remarkable variety, the unguis of the petals may

at all times be found in every degree of gradation from its

k 4

136 ORGANOGRAPHY. BOOK II.

common state to that of a filament, and the lamina some-
times almost of its usual degree of developement, — sometimes
contracting into a lobe of the anther on one side, or perhaps
on both sides, — now having the part assuming the character of
the anther merely yellow, — now polliniferous, — and finally
acquiring, in many instances, all the characters of an un-
doubted though somewhat distorted stamen. Double Paeo-
nies, Double Tulips, and many other monstrous flowers,
particularly of an icosandrous or polyandrous structure,
afford equally instructive specimens. It is for these reasons
that it is stated in the Outlines of the first Principles of Bo-
tany, 307., that " the anther is a modification of the lamina,
and the filament of the petiole."

Such is the structure of the stamens in their perfect state.
It often, however, happens that, owing to causes with which
we are unacquainted, some of the stamens are developed
imperfectly, without the anther and pollen. In such cases
they are called sterile stamens, and are frequently only to be
recognised by the position they bear with respect to the other
parts of the flower. Botanists consider every appendage, or
process, or organ, that forms part of the same verticillus of
organs as the true stamens, or that originates between them
and the pistillum, as stamens, or as belonging to what
Roper calls the androccenm, namely, to the male system ,•
and every thing on the outside of the fertile stamens is in
like manner usually referred to modifications of petals; a
remarkable instance of which is exhibited by Passiflora.
The appearances assumed by these sterile stamens are often
exceedingly curious, and generally extremely unlike those of
the fertile stamens : thus in Canna they are exactly like the
petals ; in Hamamelis they are oblong fleshy bodies, alter-
nating with the fertile stamens : in Pentapetes they are fili-
form, and placed between every three fertile ones; in Sci-
tamineae they are minute gland-like corpuscles, a very
common form (Plate IV. fig. 10. c) ; in Brodiaga they are
bifid petaloid scales ; and in Asclepiadeae they undergo yet
more remarkable transformations. M. Dunal calls these
sterile stamens lepals {lepala) ; a term which has not yet
been adopted.

CHAP. II. COMPOUND ORGANS IN FLOAVF.RING PLANTS. 137

9. Of the Disk.

By this term are meant certain bodies or projections, situ-
ated between the base of the stamens and the base of the
ovarium, but forming part with neither ; they are referred by
the school of Linnaeus, along with other things, to nectarium :
Link calls them sarcoma and pcrigynium ; and Turpin, phycos-
tcmones. The most common form is that of a fleshy ring,
either entire or variously lobed, surrounding the base of the
ovarium (Plate V. fig. 4. e, 8. d), as in Lamium, Cobaea, Gra-
tiola, Orobanche, &c. ; in Gesnerieae and Proteaceae the disk
consists of fleshy bodies of a conical figure, which are
usually called glandulcc hypogyncc. It occasionally assumes
the appearance of a cup, named by M. De Candolle in Paeo-
nias and Aconites lepisma, a bad term, for which it is better
to say discus cyathiformis. In flowers with an ovarium in-
ferum (Plate 5. fig. 9. c. 7. c) the discus necessarily ceases to
be hypogynous, and generally also to appear in the form of
scales. In Compositse it is a fleshy solid body, interposed
between the top of the ovarium and the base of the style;
and has given rise, when much enlarged, to the unfounded
belief in the existence of an ovarium superum in that order,
as in Tarchonanthus. In Umbelliferae it is dilated and
covers the whole summit of the ovarium, adhering firmly to
the base of the styles ; by Hoffman it is then called stylopo-
dium, a word which is seldom used.

Besides these forms of discus there is still another, called
thegynobasis, a term which is used when the discus is enlarged,
and as it were inserted under the ovarium to which it forms
a sort of receptacle (Plate V. fig. 3. a). It occurs in Labiatae,
and Boragineae, and especially in Ochnaceae ; and in many
other orders. It ought, perhaps, to be considered a com-
bination of the discus and receptacle.

It is an opinion that daily gains ground, that the discus is
really only a rudimentary state of the stamens ; and it is
thought that proofs of the correctness of this hypothesis are
to be found in the frequent separation of the cyathiform disk
into bodies alternating with the true stamens, as in Gesneria;
in its resemblance in Parnassia to bundles of polyadelphous

138 ORGANOGRAPHY. BOOK I.

stamens, and particularly in the fact noticed by Mr. Brown,
that an anther is occasionally produced upon the highly
developed disk of Paeonia Moutan. To which may be added
the observation of Dunal, that half the disk of Cistus vagi-
natus occasionally turns into stamens. [Considerations, &c.
p. 44.)

Like the petals, sepals, and stamens, the disk always ori-
ginates from below the pistillum ; but it often contracts an
adhesion with the sides of the calyx, when it becomes pcrigy-
?ious, as in Amygdalus ; or with both the calyx and the sides of
an inferior ovarium, when it becomes cpigynous, as in umbel-
liferous plants.

10. Of the Pistillum.

The last organ to enumerate in the flower is that which
constitutes the female system, or gynceceum of Roper, and
which is usually called the pistillum. In all cases it occupies
the centre of the flower, terminating the axis of growth of the
peduncle ; and is consequently the part around which every
other organ without exception is arranged.

It is distinguished into three parts ; viz. the ovarium
(Plate V. fig. 7. a), the style (fig. 7../), and the stigma (fig.7.g").

The ovarium, called germen by Linnaeus, is a hollow case
placed at the base of the pistillum, enclosing the ovula, and
often containing two or more cells or cavities. It is the part
which ultimately becomes the fruit ; and consequently, what-
ever may be the structure of the ovarium such must neces-
sarily be that of the fruit ; allowance being made, as will
hereafter be explained, for changes that may occur during the
progress of the ovarium to maturity.

Notwithstanding what has been stated of the pistillum con-
stantly occupying the centre of the flower, and being the part
around which all the other parts are arranged, an apparent
exception exists in those flowers, the calyx of which is said to
be superior (Plate V. fig. 7. &9.), as the Apple blossom. In
this instance the ovarium seems to originate below the calyx,
corolla, and male system ; on which account it is said to be
inferior in such cases, while in the opposite state it is called

CHAP. II. COMPOUND ORGAN'S IN FLOWERING PLANTS. 139

superior. But in reality, the inferior ovarium is only so in
consequence of the tube of the calyx contracting an adhesion
ivith its sides ; and such being the case, the exactness of the
description of the constant place of the pistillum as above, is
unshaken. This is proved in many ways. In Saxifrageae,
the genus Leiogyne has the ovarium superior ; in Saxifraga
itself the calyx partially adheres to the sides of the ovarium,
which then becomes half inferior, while in Chrysosplenium
the union between the calyx and ovarium is complete, and
the lattter is wholly inferior. Again, in Pomaceae, the ovaria
partially cohere with the calyx in Photinia, completely in
Pyrus, and by their backs only in Cotoneaster ; whence the
ovarium is half superior in the first instance, quite inferior in
the second, and what is called parietal in the third. Botanists
call any thing parietal which arises from the inner lining or
wall of an organ ; thus in Cotoneaster the ovaria are parietal,
because they adhere to the inner lining of the calyx, and in
Papaver the placentas are parietal, because they originate in
the inner lining of the fruit.

Sometimes the ovarium, instead of being sessile, as is usually
the case, is seated upon a long stalk ; as in the Passion flower
and the genus Cleome. This stalk is often called the theca-
phore or gynophore ; but it is obviously analogous to the
petiole of a leaf, as will hereafter be seen, and the application
of a special term to it appears unnecessary. M. Cassini calls
the elongated apex of the ovarium of some Compositae le
plateau.

That part of the ovarium from which the ovula arise is
called the placenta (Trophospermium, Richard; Spermaphorum,
Colum, lieceptacle of the Seeds). It generally occupies the
whole or a portion of one angle of each cell (Plate V. fig. 1. e,
2. ct &c.)> and will be spoken of more particularly hereafter.
It is sometimes elongated in the form of a little cord, as in
the Hazel nut, and many Cruciferae : such a part is called
the umbilical card [funiculus umbilicalis, podospermium).

The swelling of the ovarium after fertilisation is termed
grossijication.

The style {tuba of old authors) is that elongation of the
ovarium which supports the stigma (Plate V. fig. l.f). It is

140 ORGANOGRAPHY. BOOK I.

frequently absent, and then the stigma is sessile : it is not
more essential to a pistillum than the petiole to a leaf, or the
unguis to a petal, or the filament to a stamen. Anatomically
considered, it consists of a column of one or more bundles of
vascular tissue, surrounded by cellular tissue ; the former com-
municating on the one hand with the stigma, and on the
other with the vascular tissue of the ovarium. It is usually
taper, often filiform, sometimes very thick, and occasionally
angular: rarely thin, flat, and coloured, as in Iris and in
Canna. In some plants it is continuous with the ovarium,
the one passing insensibly into the other, as in Digitalis; in
others it is articulated with the ovarium, and falls off, by a
clean scar, immediately after fertilisation has been accom-
plished, as in the Scirpus. Its usual point of origin is from
the apex of the ovarium ; nevertheless, cases occur, in which
it proceeds from the side, as in Alchemilla, or even from
the base, as in Labiatae and Boi'agineas. In these cases, how-
ever, it is to be understood that the geometrical and organic
apices are different, the latter being determined by the origin
of the style. For this reason, when the style is said to pro-
ceed from the side or base of the ovarium, it would be more
correct to say that the ovarium is obliquely inflated or dilated,
or gibbous at the base of the style.

The surface of the style is commonly smooth ; but in Com-
positse, Campanulaceas, and others, it is often densely covered
with hairs, called collectors, which seem intended as brushes
to clear the pollen out of the cells of the anthers. In Lobelia
these hairs are collected in a whorl below the stigma ; in
Goodenovise they are united into a cup, in which the stigma is
enclosed, and which is called the indusium (Plate V. fig. 13.6.).
Many styles which appear to be perfectly simple, as for
instance those of the Primrose, the Lamium, the Lily, or the
Borage, are in reality composed of several grown together ; as
is indicated by the lobes of their stigma, or by the number
of cells or divisions of their ovarium. In Malva an example
may be seen of a partial union only of the styles, which are
distinct upwards, but united below. In speaking of styles in
this latter state, botanists are apt to describe them as divided

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 141

in different ways, which is manifestly an inaccurate mode of
expression.

The stigma is the upper extremity of the style, without a
cuticle; in consequence of which it has almost uniformly
either a humid or papillose surface. In the first case it is so
in consequence of the fluids of the style being allowed to flow
up through the intercellular passages of the tissue, there
being no cuticle to repress and conceal them ; in the latter
case the papillae are really the rounded sides of vesicles of
cellular tissue. When perfectly simple, it is usually notched
on one side, the notch corresponding with the side from which
the placenta arises : see the stigma of Rosa, Prunus, Pyrus,
and others. If it belongs to a single carpellum (p. 143.), it is
either undivided, or its divisions, if any, are all placed side by
side, as in some Euphorbiaceas, Crocus, &c. ; but if it is
formed by the union of the stigmas of several carpella, its
lobes are either opposite each other, as in Mimulus, or placed
in a verticillus, as in Geranium. Such being the case, it is
always to be understood that an apparently simple ovarium,
to which two or more opposite stigmata belong, is really of a
compound nature, some of its parts being abortive, as in
Compositae.

Nothing is, properly speaking, stigma, except the secreting
surface of the style : it very often, however, happens, that the
term is carelessly applied to certain portions of the style.
For example, in the genus Iris the three petaloid lobed styles
in the centre are called stigmata ; while the stigma is in
reality confined to a narrow humid space at the back of each
style ; in Labiatse, my friend Mr. Bentham has shown that
what is called a two-lobed stigma is a two-lobed style, the
points only of the lobes of which are stigmatic : and in
Lathyrus, and many other Papilionaceous plants, Linnaean
botanists call the hairy back of the style the stigma ; while, in
fact, the latter is confined to the mere point of the style.

Nevertheless, there are certain stigmata in which no
denuded or secreting surface can be detected. Of this nature
is that of Tupistra, in which the apparent stigma is a fungous
mass with a surface of the same nature as that of the style ;

14-2 ORGANOGRAPHY. BOOK I.

in such a stigma the mode of fertilisation forms a very inte-
resting problem, which botanists have yet to solve.

In almost all cases the stigmata are perfectly distinct
from all surrounding bodies, and are freely exposed to the
influence of the pollen ; but in Asclepiadeae they adhere to
the anthers in a solid mass, of which the angles only that
are in contact with the cells of the anther are free and sus-
ceptible of fertilisation.

The centre of a stigma consists of tissue of a peculiar
character, which communicates directly with the placenta,
and which is called the stigmatic tissue. It is more lax than
that which surrounds it, and serves for the conveyance of the
fertilising matter of the pollen into the ovula.

Such is a general view of the more remarkable peculiarities
of the female system. This part, however, bears so important
an office in the functions of vegetation, is so valuable as a
means of scientific arrangement, and is liable to such a great
variety of modifications, that it will be necessary now to con-
sider it in another and more philosophical point of view. For
we have yet to consider the structure of the compound pis-
tillum, and to learn to understand the exact nature of its
cells, and dissepiments, and placentae, and the precise relation
that these parts bear to each other; and also to prove that
the necessary consequence of the laws under which pistilla
are constructed is, that they can be subject to only a parti-
cular course of modification, within which every form must
absolutely, and without exception, fall. This enquiry would,
perhaps, be less important if none but structure of a very
regular and uniform kind were to exist ; but, considering the
numberless anomalies that the pistillum exhibits, it becomes
at once one of the most difficult and most essential parts of a
student's investigation.

In the days of Linnaeus and Gasrtner, and even in those of
the celebrated L. C. Richard, nothing whatever was known
of this matter, and consequently the writings of those car-
pologists are a mere tissue of ingenious misconceptions. Nor
did the subject become at all intelligible until the admirable
Treatise upon Vegetable Metamorphosis, which had been
published by Goethe in 1 790, but which had long been neg-

*3

CHAP.IT. compound organs in flowering plants. 143

lected, was again brought into notice, and illustrated by the
skilful demonstrations of De Candolle, Turpin, Du Petit
Tho uars, and others.

120 121

According to these writers, the pistillum is either the
modification of a single leaf, or of one or more whorls of such
leaves, which are technically called carpella. Each carpellum
has its own ovarium, style, and stigma, and is formed by a
folded leaf, the upper surface of which is turned inwards, the
lower outwards, and the two margins of which develope one
or a greater number of buds, which are in a rudimentary
state, and are called the ovules.

A very distinct idea of the manner in which this occurs
may be obtained from the carpellum of a double cherry, in
which the pistillum loses its normal carpellary character, and
reverts to the structure of the leaf. In this plant the pis-
tillum is a little contracted leaf the sides of which are pressed
face to face, the midrib elongated, and its apex discoloured,
or a little distended. If we compare this with the pistillum
of a single cherry, the mai'gins of the leaf with the ventral
suture, the elongated midrib with the style, the discoloured
distended apex with the stigma, they will be found to cor-
respond exactly.

In this case there is an indisputable identity of origin and
nature between the ovarium and the lamina of a leaf, —
between the little suture that occupies one angle of the car-
pellum of a cherry, and the line of union of the two edges of
the leaf, — and between the elongated midrib, with its dis-

14-4? ORGANOGRAPHY. BOOK I.

tended apex, and the style and stigma. There can be no
doubt that the plan of all carpella is the same ; so that the
ovarium is the lamina of a leaf, the style an elongated midrib,
and the stigma the denuded, secreting, humid apex of the
latter.

Such being the origin of the carpellum, its two edges will
correspond, one to the midrib, the other to the united mar-
gins of the leaf. These edges often appear in the carpellum
like two sutures, of which that which corresponds to the
midrib is called the dorsal, that which corresponds to the
united margins is named the ventral suture.

It is at some point of the ventral suture that is formed the
placenta, which is a copious developement of cellular sub-
stance, out of which the ovules or young seeds arise. It, the
placenta, originates from both margins of the carpellary leaf, —
but as they are generally in a state of cohesion, there appears
to be but one placenta, — nevertheless if, as sometimes happens,
the margins of the carpellary leaf do not unite, there will be
two obvious placenta? to each carpellum. Now, as the stigma
is the termination of the dorsal suture, it occupies the same
position as that suture with regard to the two placentae ; con-
sequently the normal position of the two placentas of a single
carpellum will, if they are separate, be right and left of the
stigma. This is a fact very important to bear in mind.

Pistilla consisting of but one carpellum are simple ; of
several, are compound. If the carpella of a compound pis-
till um are distinct entirely or in part, they are apocarpous, as in
Caltha ; if they are completely united into an undivided body,
as in Pyrus, they are syncarpous. That syncarpous pistilla
are really made up of a number of united carpella is easily
shown, as Goethe has well remarked, in the efenus Nijrella, in
which N. orientalis has the carpella partially united, while
N. damascena has them completely so. In the latter case,
however, the styles are distinct ; they and the stigmata are all
consolidated in a single body, when the pistillum acquires its
most complete state of complication, as in the Tulip ; which
is, however, if carefully examined, nothing but an obvious
modification of such a pistillum as that of Nigella damas-
cena.

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 145

There is this important conclusion that is deducible from
the foregoing considerations : viz., that, as the carpella are
modified leaves, they are necessarily subject to the same laws
of arrangement, and to no others, as leaves developed round a
common axis upon one or several planes. For no axiom appears
more incontestible in botany, than that all modifications of a
given organ are controlled essentially in the same way, and by
the same influences, as the organ itself in an unmodified state :
and hence every theory of the structure of fruit which is not
reducible to that which would be applicable to the structure
of whorls of leaves is vicious of necessity. I shall proceed to
demonstrate the perfect accordance of the carpellary theory
of structure in every point with these principles.

The placenta arises from the two margins, either distinct
or more usually combined, of a leaf folded inwards. When
a leaf is folded inwards, its margins will point towards the
stem or axis around which it is developed ; and in a whorl
of leaves such inflected margins would all be collected
round a common centre; or, if the axis were imaginary,
in consequence of the whorl being terminal, would be
placed next each other, in a circle of which the back of the
leaves would represent the circumference. Therefore the
placentae will always be turned towards the axis, or will
actually meet there, forming a common centre ; and, which
is a very important consequence of this law, if one carpellum
only, with its single placenta, be formed in a flower, the true
centre of that flower will be indicated by the side of the car-
pellum occupied by the placenta. Proofs of this may be
found in every blossom : but particularly in such as habitually
having but one carpellum occasionally form two, as the Wis-
teria sinensis, Alchemilla arvensis, Cerasus acida, &c. ; in
these the second carpellum, when added, does not arise by
the side of the first, but opposite to it, the face of its placenta
being in front of that of the habitual carpellum. A fourth
proof of this uniform direction of the placentas towards the
axis, is afforded by those pistilla in which a great number of
carpella is developed in several rows, as in the Strawberry
and the Ranunculus : in all these the placentas will be, with-
out exception, found directed towards the axis, and conse-

L

0.

146 ORGANOGRAPHY. BOOK I.

122 quently towards the back of every
row, except the inner. For ex-
ample, in the following diagram

\ let O be the axis, bb placenta?,
Cjf \^-A \cc the backs of carpella ; the pla-
r — i^y ^ f centae, /; b, of the inner row will

"~ be next the centre O ; the pla-
centa?, bb, of the second row will be
next the backs, c c, of the first row ;
and so on.

If the order of developement of leaves were exactly followed
in that of the stamens and carpella, it would happen [that the
latter would be invariably alternate with the inner row of sta-

123 mens ; for if a a (Jig. 123.) is the sta-
tion of five stamens, bb would be the
situations of the carpella: this relative
position is therefore considered'the
normal one, and is in fact that which
usually exists in perfectly regular
flowers ; but as all the parts of a
flower are subject to deviations,
either real or apparent, from what
is considered their normal state, in

consequence of the non-developement of some parts, or the
excessive developement of others, it frequently happens that
the carpella either bear no apparent relation to the stamens
or are opposite them. In Papilionaceous plants, for example,
whei'e only one carpellum is present, it is difficult to say that
it bears any exact relation to the stamens, although it is pro-
bable that its position is really normal with regard to them ;
and so also in Rosaceous plants, with numerous carpella, no
exact relation can be proved to exist between the latter and
the stamens, unless it may be said to be indicated by those
genera, such as Spiraea, in which the carpella are reduced to
five ; and, finally, in such plants as Delphinium, in which the
carpella are three, while the floral envelopes and male system
are divided upon a quinary plan, it is manifest that no alter-
nation can exist between the stamens and carpella.

As the vessels and petals most commonly consist each of a

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 147

single whorl of parts, so the pistillum is more frequently com-
posed of one whorl of carpella than of more. There are,
however, certain families in which several whorls are pro-
duced one within the other, as in Fragaria, Ranunculus,
Magnolia, Annona, and the like. In these cases it mostly
happens that the carpella are either entirely separate or
nearly so ; but it sometimes happens that syncarpous pistilla
are habitually produced with more than one whorl of car-
pella, and consequently of cells, as Nicotiana multivalvis, and
some varieties of the genus Citrus. In such instances the
placentae of the outer series will necessarily be applied to the
backs of the inner series, as has been just demonstrated.

This mutual relation of the different rows of carpella is
sometimes observed when the receptacle from which they
arise is either convex or concave : in the former state the
outer series will obviously be lowermost, and in the latter
uppermost; a circumstance that leads to no intricacy of struc-
ture when the carpella are distinct, but which may cause an
exceedingly anomalous structure in syncarpous pistilla, espe-
cially when accompanied by other unusual modifications of
structure. There can be no doubt that the true nature of
the composition of the pomegranate is to be explained upon
this principle. In order to make these considerations more
clear, let figs. 124, 125, and 126. represent — -Jig. 124. a convex
receptacle, with distinct carpella ; fig. 125. a concave one, with
the same; and^. 126. a concave one, with the carpella con-

124 125 126

solidated. In these, a a are the outer row of carpella, bb the
next, and dd the central row. The relative position of
these, as the receptacle is convex or concave, will now be
apparent.

L 2

148 ORGANOGRAPHY. BOOK I.

I have stated that the placenta, however simple it may ap-
pear to be, is really the result of the union of two united mar-
gins of a carpellary leaf: it is, therefore, essentially double;
and, accordingly, we find that in polyspermous ovaria the
ovula are almost always arranged in two rows, as in the Pea
and Bean, the Quince, the Paeony, &c. ; nevertheless there
are instances in which the placentae occupy a considerable
portion of the wall of the ovarium, and bear the ovula in a
great many rows, but in no certain order, as in Nymphaea ;
and, on the other hand, some plants have the placentae so
little developed, that not more than one ovulum is generated
between the two placentae, as in Boragineae, Labiatae, Umbel! i-
ferae, Stellatae, Compositae, and many others. There can be
no doubt, however, that all the latter cases are mere instances
of suppressed structure, in consequence of the general incom-
pleteness of developement.

When two leaves are developed upon a stem, they are
always opposite, and never side by side. As carpella are
modified leaves they necessarily obey this law ; and, conse-
quently, when a pair of carpella form a bilocular ovarium, the
separation of the two cells is directly across the axis of the
flower.

The partitions that are formed in ovaria, by the united
sides of cohering carpella, and which separate the inside into
cells, are called dissepiments or septa. It is extremely im-
portant to bear in mind, not only that such is really their
origin, but that they cannot possibly have any other origin,
in order to form an exact idea of the structure of pistilla.
Now, as each dissepiment is thus formed of two united sides,
it necessarily consists of two plates, which are, in the ovarium
state, often so completely united, that their double origin is
undiscoverable, but which frequently separate in the ripe
Pericarpium. This happens in Rhododendron, Euphorbia,
Pentstemon, and a multitude of other plants. The consider-
ation of this circumstance leads to certain laws which cannot
be subject to exception, but which are of great importance ;
the principal of which are these : —

1 . All dissepiments are vertical and never horizontal. — For

15

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 149

L-J

f

12? if a, b mfg. 127. represents the

' side of one carpellum and c, d
that of another, the dissepiment
a, c, b, d formed by this union
will have precisely the same di-
rection as that of the carpella, and
can never acquire any other ; and
the same would be true of the
sides f,./and g, k, if they formed themselves into dissepiments
by uniting with other carpella: consequently a partition in any
cell in the direction of *, k could not be a dissepiment, but
would be of a different nature.

2. They are uniformly equal in number
to the carpella out of which the pistillum is

formed. — Suppose the triangle A, B, C
represented a transverse section of an
ovarium formed by the union of three
carpella o, o, o ; then d, e, f would be
the dissepiments, and could not be either
more or less.

3. They proceed directly from the pla-
centa. — As the placenta is the margin

of the carpellary leaf, and as the dissepiment is the side of
the carpellary leaf, it is evident that a dissepiment cannot
exist apart from the placenta. Hence, when any partition
exists in an ovarium which is not connected with the pla-
centa, it follows that such a partition is not a dissepiment,
however much it may otherwise resemble one.

4. They are alternate with placenta, formed by the cohesion
of the margins of the same carpellum, and
opposite to placentae, formed by the co-
hesion of the contiguous margins of differ-
ent carpella. — Let the triangle A, B, C
represent a transverse section of a three-
celled ovarium of which d, e, f are the
dissepiments: the dissepiments d and e
will alternate with the placentae m, g,
both belonging to the carpellum A; but
l 3

150 OUGANOGRAPHY. BOOK I.

the dissepiment d will be opposite the placentae m, I, formed by
the cohesion of the contiguous margins of the carpella A and B.

5. A single carpellum can have no dissepiment whatever.

6. The dissepiment will always alternate with the stigma ; —
for the stigma is the extremity of the mid-rib of the carpellary
leaf, or of the dorsal suture of the carpellum; and the sides
of either of these (which form dissepiments) will be right and
left of the stigma, or in the same position with regard to the
latter organ as the sides of the lamina of a leaf to its apex.
Let the triangle a, b, c represent a 13°
transverse section of a three-celled ^
ovarium, of which d, e,f are the dis-
sepiments. The stigmata would oc-
cupy a position equal to that of the
spaces s, s, s, and would consequently
be alternate with d, e,f, the dissepi-
ments : they could not possibly be
placed opposite d, e,f, upon any prin-
ciple of structure with which we are
acquainted. This law proves, that neither the membrane
which separates the two cells of a Cruciferous siliqua, nor the
vertical plate that divides the ovarium of Astragalus into two
equal portions, are dissepiments ; both are expansions of the
placenta, or some other part, in different degrees.

Such is the structure of an ovarium in its most common
state ; certain deviations from it remain to be explained.
We have seen that when carpella become syncarpous, they
form a pistillum, the ovarium of which has as many cells and
dissepiments as there are carpella employed in its construc-
tion. But sometimes the united sides of the carpella do not
project so far into the cavity of the ovarium as to meet in the
axis, as in the Poppy; and then an ovarium is the result, which,
although composed of many carpella, is nevertheless one-
celled [fig. 133.) In such case the dissepiments project a short
distance only beyond the inner lining, or paries, of the ova-
rium, and, bearing on their edges the placenta?, the latter are
said to be parietal. In other plants, such as Corydalis, Viola,
and Orchis, the carpella are not folded together at all, but are
spread open and united by their edges (Jig. 132.) : in that case

©

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 151

the placentae do not project at all into the cavity of the ova-
rium, but are still more strictly parietal than the last.

131 132 133

Another class of anomalies of a still more remarkable cha-
racter, is that in which the dissepiments are obliterated, while
the placentae remain a distinct mass in the centre of the
ovarium, as in Lychnis ; forming what is called a. free central
placenta (Jig. 131.). But, if we examine these plants at a very
early period of their formation, long before the flowers expand,
the explanation of the anomaly will be obvious. Such plants
are, at that time, constructed upon the ordinary plan, with
their dissepiments meeting in the centre and forming there a
fungous placenta ; but subsequently the shell of the ovarium
grows more rapidly than the dissepiments, and breaks away
from them; while the excessive growth of the placenta after-
wards destroys almost all trace of them : their previous pre-
sence is only to be detected by lines upon the shell of the
ovarium, or by a separation of the mass of ovula into distinct
parcels upon the placenta.

All partitions whose position is at variance with the fore-
going laws are spurious. Such spurious dissepiments are
caused by many circumstances, the chief of which are the
following:, — the}' are caused by expansions of the placenta,
as in Cruciferae, when they form a partition stretching from
one side to the other of the fruit ; or they are mere dilatations
of the lining of the pericarpium, as in Cathartocarpus Fistula, in
which they are horizontal ; or they are internal expansions of
the dorsal or ventral suture, as in Amelanchier, Astragalus,
and Thespesia, in which they are distinguishable from their
dissepiments by not bearing the placentae, and by being op-
posite the stigma, or by projecting beyond the placentae ; or,
finally, they are caused by the sides of the ovarium projecting

l 4-

152 ORGANOGRAPHY. BOOK I.

into the cavity, uniting and forming many supernumerary
cells, as in Diplophractum.

11. Of the Receptacle.

The part upon which the carpella are seated is the apex of
the peduncle, or the summit of the floral branch, of which the
carpella are the termination. Usually this part, which is called
the receptacle, is flat, or merely a vanishing point; but in
other cases it is very much dilated, and then assumes a variety
of curious appearances. This receptacle is called torus, or
thalamus as w-ell as receptaculum, and, in Greek compounds,
has the name of Clinium.

In Annonaceae and Magnoliacese it elevates itself from the
base of the calyx, and bears the numerous stamens peculiar
to these orders : here it is called Gonophore (Gonophorum) by
De Candolle. In Caryophylleae the receptacle is elongated,
and bears on its summit the petals and stamens : M. De Can-
dolle calls this form Anthophore (Anthophorum). When the
receptacle bears only the ovarium, and is not a support to
either corolla or stamens (Plate V. fig. 1. a.) it is called Car-
pophore, or Gipwphore (Carpophorum, Gynophorum) : this
may either be a simple rounded stalk to the fruit, and of the
same texture with it, as in Capparis, Phaca, and others, — when
Richard calls it Basigynium or Podogynium, and Ehrhart llie-
caphore, — or it may be succulent and much dilated, so as to
resemble the receptacle of a Composita, bearing at the same
time many ovaria, as in the Strawberry and Raspberry, when
R-ichard calls it Polyphorum : most commonly such a recep-
tacle is sufficiently described by the adjective fleshy. In
Geranium it is remarkable for being lengthened into a taper-
ing cone, to which the styles adhere, in the form of a beak ;
and in Nelumbium it is excavated into a number of cavitities,
in which the ovaria are half hidden.

12. Of the Ovulum.

The ovulum (Plate V. fig. 16. to 26.) is a small, semipellu-
cid, pulpy body, borne by the placenta, and gradually chang-

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 15S

ing into a seed. Its internal structure is exceedingly difficult
to determine, either in consequence of its minuteness, or of
the extreme delicacy of its parts, which are easily torn and
crushed by the dissecting knife. It is doubtless to this cir-
cumstance chiefly, that the anatomy of the ovulum was almost
unknown to botanists of the last century, and that it has only
begun to be understood within ten or twelve years, durino-
which it has received ample illustration from several skilful
observers. Mr. Brown, indeed, claims to have pointed out
its real nature so long ago as 1814; but the brief and incom-
plete terms then used by that gentleman, in the midst of a
long description of a single species, in the Appendix to Captain
Flinders' Voyage, unaccompanied as they were by any explan-
atory remarks, prove indeed that he knew something of the
subject, but by no means entitle him to the credit of having,
at that time, made the world acquainted with it. The late
Mr. Thomas Smith seems to deserve the credit of hav-
ing first made any general remarks upon the subject : of
what extent they exactly were is not known, as his discoveries,
in 1818, were communicated, as it would seem, in convers-
ation only ; but it is to be collected from Mr. Brown's state-
ment that they were of a highly important nature. Since that
period the structure of the ovulum has received much atten-
tion from Messrs. Brown, in England ; Turpin and Adolphe
Brongniart, in France; and Treviranus, in Germany ; by all of
whom the subject has been greatly illustrated. It is, how-
ever, to the learned M. Mirbel, — who, by collecting the dis-
coveries of others, examining their accuracy, snd combining
them with numerous admirable observations of his own, has
given a full account of the gradual developement and the
different modifications of the ovulum — that we are indebted
for by far the best description of that important organ. His
two papers read before the Academy of Sciences at Paris, in
1828 and 1829, are a perfect model of candour and patient
investigation, and form the basis of what is here about to be
recorded on the subject. I regret, however that the space
which can now be devoted to the explanation of the structure
of the ovulum is by no means such as its intricacy and interest
demand.

154 ORGANOGRAPHY. BOOK I.

As the ovula are the production of the placentae, they
necessarily originate in the margins of the carpellary leaf; and
hence they have not only been compared to the buds found
upon the margins of some true leaves, in a theoretical point
of view, but it also has been attempted to be shown that they
are analogous to them in structure. Of the truth of the former
there can be little doubt; for, to say nothing of such plants as
Bryophyllum, which habitually form buds on the margins of
the leaves, the case of Malaxis paludosa, first recorded by
Professor Henslow, in which the edge of the leaf is frosted by
little micrpscopical points, which are neither exactly ovula nor
exactly buds, seems a sufficient proof: but that in structure
they are analogous to buds is by no means well made out.
M. Turpin indeed has attempted, with his usual ingenuity, to
demonstrate an analogy between the bracteae of Marcgraavia
and the outer integument or primine of the ovulum ; but his
statement cannot be regarded, as a sufficient evidence, of the
fact. It is, therefore, only safe, at present, to regard the
ovulum as analogous to the marginal buds of leaves in nature
and position, but not in structure.

In almost all cases the ovulum is enclosed within an ova-
rium, as would necessarily happen in consequence of the con-
volute nature of the carpellary leaves ; but if the convolution
is imperfect, as in Reseda, the ovula are partially naked ; and
if it does not exist at all, as in Cycadeae and Coniferae, the
ovula are then entirely naked ; and, instead of being fertilised
by molecules conveyed through the stigma and the style, as
in other plants, are exposed to the direct influence of the
pollen. This was first noticed by Mr. Brown; and, although
since contradicted, is no doubt perfectly true.

When the ovula are attached to the placenta by a kind of
cord, that cord is called the funiculus (Plate 5. fig. 26, a.),
and is a mere prolongation of the placenta.

In the beginning, the ovulum is a pulpy excrescence
(Plate 5. fig. 16.), appearing to be perfectly homogeneous,
with no trace of perforation or of envelopes. But, as it
advances in growth, it is gradually (Plate 5. fig. 17 to 21.)
enclosed in two sacs or integuments, which are open only at
their apex; where, in both these sacs, a passage exists, called

CIIAr. II. COMPOUND ORGANS IN FLOWERING TLANTS. 155

the foramen (Plate 5. fig. 21, a.) ; or, in the language of M.
Mirbel, Exostome (fig. 25, a.), in the outer integument, and
Endostome (fig. 25, &.), in the inner integument. The central
part is a fleshy, pointed, pulpy mass, called the nucleus, or
micelle (Plate V. fig. 19, 20. a, 22. b, 23. c, 24. d, 25. e, 27. e).

The outermost of the sacs (Plate V. fig. 22. c, 23. a, 25. c)
is called the primine. It is either merely a cellular coating,
or it is traversed by numerous veins or bundles of tubes ;
these are sometimes very apparent, as in the Orange tribes ;
and M. Mirbel seems disposed to think that they often exist
in a rudimentary state when they are not visible. Usually it
is nearly as long as the secondine, but sometimes is remark-
ably shorter, as in the Euphorbia Lathyris when very young
(Plate V. fig. 22.).

The outermost but one of the sacs (Plate V. fig. 23. b,
20. b, 25. d.) is called the second 'ine ; it immediately reposes
upon the primine, and often contracts an adhesion with it, so
that the two integuments become confounded. In order to
ascertain its existence, it is, therefore, often necessary to
examine the ovulum at a very early period of its growth.
It is probable that it always exists ; but Myrica, Alnus,
Corylus, Quercus, and Juglans have been named by M.
Mirbel as plants in which the secondine is not perceptible
(Plate V. fig. 24.). Its point is usually exerted beyond the
foramen of the primine.

The nucleus (Plate V. fig. 22. b, 18, 19, 20. a, 24. d, 25. e) is
a pulpy conical mass, enclosed by the primine and secondine,
and often covered up by them ; but frequently protruded
beyond the latter, and afterwards, at a subsequent period of
its growth, again covered by them. Sometimes its cuticle
separates in the form of a third coating of the ovulum, called
the tercine.

These three parts, the primine, the secondine, and the
nucleus, have all an organic connection at some one point of
their surface. That point is, in ovula whose parts do not
undergo any alteration of direction in the course of their
growth, at the base next the placenta ; so that the nucleus is,
like a cone, growing from the base of a cup, the base of
which is connected with the hiluni through another cup like

1 56 ORGANOGRAPHY. BOOK I.

itself (Plate V. fig. 23.). The axis of such an ovulum, which
M. Mirbel calls Orthotropous, is rectilinear, as in Myrica,
Cistus, Urtica, &c. ; and the foramen is at the end of the
ovulum most remote from the hilum.

But sometimes, while the base of the nucleus and that of
the outer sacs continue contiguous to the hilum, the axis of
the ovulum instead of remaining rectilinear is curved down
upon itself (Plate V. fig. 26, 27-); so that the foramen, in-
stead of being at the extremity of the ovulum most remote
from the hilum, is brought almost into contact with it. Ex-
amples of this are found in Papilionaceous plants, Caryophyl-
leous plants, Mignonette, &c. M. Mirbel, who first distin-
guished these, calls them Campulitropous. In both these
modifications the base of the ovulum and the base of the
nucleus are the same.

In a third class the axis of the ovulum remains rectilinear ;
but one of the sides grows rapidly, while the opposite side
does not grow at all, so that the point of the ovulum is gra-
dually pushed round to the base; while the base of the nucleus
is removed from the hilum to the opposite extremity (Plate V.
fig. 16 — 21.); and when this process is completed the whole
of the inside of the ovulum is reversed; so that the apex
of the nucleus, and consequently the foramen, corresponds
with the base of the ovulum. Such ovula as these M. Mirbel
terms Anatropous ,• they are very common : examples may be
found in the Almond, the Apple, the Ranunculus, the Cu-
cumber, &c. When the base of the nucleus is thus removed
from the base of the ovulum, a communication between the
two is always maintained by means of a vascular cord, called
the raphe (Plate V. fig. 24.*?, 25./). This raphe, which ori-
ginates in the placenta, runs up one side of the ovulum, until
it reaches the base of the nucleus ; and there it expands into
a sort of vascular disk, which is called the chalaza (Plate V.
fig. 24./ 25. g.). As the chalaza is uniformly at the base of
the nucleus, it will follow that, in Orthotropous and Campu-
litropous ovula it is confounded with the hilum ; while it
is only distinguished in Anatropous ones, in which alone it is
distinctly to be recognised.

It has been remarked that the raphe, or vascular extension

chap.it. compound organs in flowering plants. 157

of the placenta, always occupies the side next the ventral
suture of the ovarium ; and that when, as in Euonymus, it is
turned towards the dorsal suture, that circumstance arises
from an alteration in the position of the ovulum subsequent to
its being fertilised.

It has already been stated that the passage through the
primine and secondine is called the foramen ; or the exos-
tome, when speaking of that of the primine ; and the endos-
tome, in speaking of the secondine. Upon these M. Mirbel
remarks, — " These two orifices are at first very minute ; but
they gradually enlarge ; and when they have arrived at the
maximum of dilatation they can attain, they contract and
close up. This maximum of dilatation is so considerable in a
great number of species, in proportion to the size of the
ovulum, that, to give an exact idea of it, I would compare it
not to a hole, as those express themselves who have hitherto
spoken of the exostome and endostome, but to the mouth of
a goblet or of a cup. It may therefore be easily understood
that to perceive either the secondine or the nucleus, it is not
necessary to have recourse to anatomy. I have often seen,
most distinctly, the primine and secondine forming two large
cups, one of which encompassed the other without entirely
covering it, and the nucleus extending itself in the form of
an elongated cone beyond the secondine, to the bottom of
which its base was fixed."

In practical botany the detection of the foramen is often a
matter of great importance ; for it enables an observer to
judge from the ovulum of the direction of the radicle of the
future embryo : it having been ascertained by many observ-
ations that the radicle of the embryo is almost always pointed
to the foramen. A partial exception to this law exists, how-
ever, in Euphorbiaceae, in many of which M. Mirbel has
noticed that, after fertilisation, the axis of the nucleus and the
endostome is inclined five or six degrees, without the exos-
tome changing its position ; by this circumstance the foramen
of the secondine and that of the primine cease to correspond,
and the radicle, instead of pointing when formed to the exos-
tome, is directed to a point a short distance on one side of it.

Besides the two external integuments, M. Mirbel has re-

158 ORGANOGRAPHY. BOOK I.

marked the occasional presence of three others peculiar to
the nucleus, which he calls the tercine, quartine, and quintine.

The former is the external coat of the nucleus, and is very
generally, if not universally, present. As I am almost unac-
quainted either with it or the two latter, I can add nothing to
the following remarks of M. Mirbel upon the subject : — " The
quartine and quintine are productions slower to show them-
selves than the preceding. The quartine is not very rare,
although no one has previously indicated it ; as to the quin-
tine, which is the vesicula amnios of Malpighi, the additional
membrane of Mr. Brown, and the sac of the embryo of M.
Adolphe Brongniart, I am far from thinking that it only
exists in a small number of species, as Mr. Brown seems to
suppose. If no one has noticed the quartine, it is, no doubt,
because it has been confounded with the tercine ; nevertheless
these two envelopes differ essentially in their origin and
mode of growth. I have only discovered the quartine in
ovula of which the tercine is incorporated at an early period
with the secondine ; and I think that it is only in such cases
that it exists. At its first appearance it forms a cellular plate,
which lines all the internal surface of the wall of the cavity of
the ovulum ; at a later period it separates from the wall, and
only adheres to the summit of the cavity : at this period it is
a sac, or rather a perfectly close vesicle. Sometimes it rests
finally in this state, as in Statice ; in other cases it fills with
cellular tissue, and becomes a pulpy mass ; under this aspect
it is seen in Tulipa gesneriana. All this is the reverse of
what takes place in the tercine ; for this third envelope always
begins by being a mass of cellular tissue, (and at that time it
has the name, as we have seen, of nucleus,) and generally
finishes by becoming a vesicle.

" I have remarked the fifth envelope, or quintine, in many
species ; its general characters are such as to prevent its being
mistaken. Its complete developement takes place only in a
nucleus which remains full of cellular tissue, or in a quartine
that has filled with the same. At the centre of the tissue is
organised, as in a womb, the first rudiment of the quintine ;
it is a sort of delicate intestine, which holds by one end to the
summit of the nucleus, and by the other end to the chalaza.

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 159

The quintine swells from top to bottom ; it forces back on all
sides the tissue that surrounds it, and it often even invades the
place occupied by the quartine or the nucleus. A very
delicate thread, the suspensor, descends from the summit of
the ovulum into the quintine, and bears at its extremity a
globule which is the nascent embryo."

It is apparently this quintine that Mr. Brown describes, in
the ovulum of the Orchis tribe, as a thread consisting of a
simple series of short cells, the lowermost joint or cell of
which is probably the original state of what afterwards, from
enlargement and deposit of granular matter, becomes the
opaque speck, or rudiment, of the future embryo. (Observ.
on the Organs, fyc. of Orch. and Asclepiad. pp. 18, 19.)

" The existence," continues M. Mirbel, " of a cavity in
the quartine, or, indeed, the destruction of the internal tissue
of the nucleus, at the period when the quintine developes,
becomes the cause of some modifications in the manner of
existence of this latter integument. The quintine is never
seen, in certain Cucurbitacese, adhering to the chalaza : it is
nevertheless evident that the adhesion has existed. The
quintine, distended at its upper part, and suspended like a
lustre from the top of the cavity, still presents at its lower end
a portion of a rudimentary intestine become distinct ; the
separation occurred very early, in consequence of the tearino-
of the tissue of the nucleus.

The quintine of Statice is reduced to a sort of cellular
placenta, to the lower surface of which the embryo is attached.
This abortion of the quintine arises from the quartine havino-
a large internal cavity, which prevents the young quintine
from placing itself in communication with the chalaza, and
taking that developement which it acquires in a multitude of
other species."

The fluid matter contained within the nucleus is called the
liquor amnios, and is supposed to be what nourishes the
embryo during its growth.

When an ovulum grows erect from the base of the ovarium,
it is called erect ; when from a little above the base, ascending .
when it hangs from the summit of the cavity, it is jpendidous ;
and when from a little below the summit, it is suspended.

160

ORGANOGRAPHY.

BOOK I.

134

13. Of the Fruit.

135

136

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 1G1
163 o 164 165 a

163 b

166

165 b

The fruit is the ovarium or pistilhim arrived at maturity;
but, although this is the sense in which the term is strictly
applied, yet in practice it is extended to whatever is combined
with the ovarium when ripe. Thus the pine-apple fruit con-
sists of a mass of bracteae, calyces, corollae, and ovaria ; that of
the nut, the acorn, and many others, of the superior dry calyx
and ovarium ; that of the apple of succulent superior calyx,
and corolla, and ovarium ; and that of the strawberry-blite of
a succulent inferior calyx and dry ovarium.

The fruit being the matured ovarium, it should exhibit
upon some part of its surface the traces of a style or stigma ;
and this mark will, in many cases, enable the student to dis-
tinguish minute fruits from seeds. Many fruits were formerly
called naked seeds, such as those of Umbelliferae, Labiatae,
and Boragineae, and the grain of corn ; but now, that atten-
tion has been paid to the gradual developement of organs,
such errors have been corrected. In cases where a trace of
the style cannot be discovered, anatomy will generally show
whether a minute body is a seed or fruit, by the presence, in
the latter case, of two separable and obviously organically
distinct coatings to the nucleus of the seed ; but in other
cases, when the pericarpium and the integuments of the seeds
are combined in a single covering, and when no trace of
style remains, as sometimes happens, nothing can be deter-
mined as to the exact nature of a given body without follow-
ing it back in its growth to its young state. This, however,

M

162 ORGANOGRAPHY. BOOK I.

may be stated, that naked seeds, properly so called, are not
known to exist in more than three or four orders in the
whole vegetable kingdom ; viz. in Coniferae and Cycadeae,
where the ovula also are naked, and in Peliosanthes Teta
and Leontice, in which the ovula, originally enclosed in an
ovarium, rupture it at an early period after fertilisation, and
subsequently continue naked until they become seeds.

Such being the case, it follows that all the laws of structure
which exist in the ovarium are equally to be expected in the
fruit ; and this fact renders a repetition in this place of the
general laws of formation unnecessary. Nevertheless, as, in
the course of the advance of the ovarium to maturity, many
changes often occur which contribute to conceal the real
structure of the fruit, it is in all cases advisable, and in many
absolutely necessary, to examine the ovarium, in order to be
certain of the exact construction of the fruit itself. These
changes are caused by the abortion, non-developement, obli-
teration, addition, or union of parts. Thus the three-celled
six-ovuled ovarium of the oak and the hazel becomes, by the
non-developement of two cells and five ovules, a fruit with one
seed ; the three-celled ovarium of the cocoa-nut is converted
into a one-celled fruit by the obliteration of two cells and their
ovula ; and the two-celled ovarium of some Pedalineae becomes
many-celled by a division and elongation of the placentae.

In a very early state the ovarium of the Lychnis and of the
primrose consists of five cells, each with a placenta having a
number of ovula ; by degrees the dissepiments are ruptured
and obliterated by the rapid growth of the shell of the
ovarium ; and it finally becomes a fruit with only one cell, and
a large fungous placenta in the middle. In Cathartocarpus
fistula a one-celled ovarium changes into a fruit, having each
of its many seeds lodged in a separate cell, in consequence of
the formation of numerous horizontal membranes which in-
tercept the seeds. A still more extraordinary confusion of
parts takes place in the fruit of the pomegranate after the
ovarium is fertilised ; and many other cases might be men-
tioned.

Every fruit consists of two principal parts, the pericardium
and the seed, the latter being contained within the former.

CHAT. II. COMPOUND OIIGANS IN FLOWERING PLANTS. 163

When the ovarium is inferior, or coheres with the calyx, the
latter and the pericarpium are usually so completely united
as to be inseparable and undistinguishable : in such cases it
is usual to speak of the pericarpium without reference to the
calyx, as if no such union had taken place. Botanists call a
fruit, the pericarpium of which adheres to the calyx, an infe-
rior fruit (fructus injerus) ; and that which does not adhere to
the calyx, a superior fruit (fructus superus). But M. Des-
vaux has coined other words to express these ideas : a supe-
rior fruit he calls autocarpien ,■ an inferior fruit, heterocarpien ;
terms wholly unnecessary and unworthy of adoption.

Every thing which in a ripe fruit is on the outside of the
real integuments of the seed belongs to the pericarpium. It
consists of three different parts, the epicarpium, the sarcocar-
pium, and the endocarpium ; terms contrived by Richard, and
very useful in practice.

The epicarpium is the external integument or skin ; the
endocarpium, called put amen by Gaertner, the inner coat or
shell ; and the sarcocarpium, the intermediate flesh. Thus, in
the peach, the separable skin is the epicarpium, the pulpy
flesh the sarcocarpium, and the stone the endocarpium or
putamen. In the apple and pear the epicarp is formed by
the cuticle of the calyx, and the sarcocarpium is confluent
with the remainder of the calyx in one fleshy body.

The pericarpium is extremely variable in size and texture,
varying from the dimension of a single line in length to the
magnitude of two feet in diameter : and from the texture of a
delicate membrane to the coarse fabric of wood itself, through
various cartilaginous, coriaceous, bony, spongy, succulent, or
fibrous gradations.

The base of the pericarpium is the part where it unites
with the peduncle ; its apex is where the style was : hence
the organic and apparent apices of the fruit are often very
different, especially in such as have the style growing from
their sides, as in Rosaceae and Chrysobalaneae, Labiatae and
Boragineae.

When a fruit has arrived at maturity its pericarpium either
continues perfectly closed, when it is indehiscent, as in the
hazel-nut, or separates regularly round its axis, either wholly

m 2

164

ORGANOGRAPHY.

BOOK I.

A

d

or partially, into several pieces : the separation is called dehis-
cence, and such pieces valves ; and the axis from which the
valves separate in those cases where there is a distinct axis, is
called the columella.

When the dehiscence takes place through the dissepiments
it is said to be septicidal ; when through the back of the cells
it is called loeidicidal ; if along the inner edge of a simple
fruit it is called sutural ,• if the dissepiments are separated
from the valves the dehiscence is named septif vagal.

In septicidal dehiscence the dissepiments 167

divide into two plates and form the sides of v/\d
each valve, as in Rhododendron, Menziesia, / \
&c. Formerly botanists said that in this sort t— s— a
of dehiscence the valves were alternate with
the dissepiments, or that the valves had
their margins turned inwards. This may
be understood from Jig. 167., which represents the relative
position of parts in a transverse section of a fruit with septi-
cidal dehiscence ; v being the valves, d the dissepiments, and
a the axis.

In loculicidal dehiscence the dissepiments
form the middle of each valve, as in the lilac,
or in the diagram 168., where the letters
have the same value as above. In this it
was formerly said that the dissepiments were
opposite the valves.

In septifragal dehiscence the dissepiments
adhere to the axis and separate from the
valves, as in Convolvulus ; or in the dia-
gram 169., lettered as before.

In sutuval dehiscence there are no disse-
piments, the fruit being composed of only A
one carpellum, as the pea.

Besides these regular forms of valvular dehiscence, there is
a mode which obtains in a very few plants, called civcumscissile.
This occurs by a transverse circular separation, as in Ana-
gallis ; in Jeffersonia it only takes place half round the fruit.

Valvular dehiscence, which is by far the most common
mode by which pericarpia open, must not be confounded with

168

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 165

either rujrturing or solubility, — irregular and unusual con-
trivances of nature for facilitating the dispersion of seeds.
In valvular dehiscence the openings have a certain reference
to the cells, as has been already shown ; but neither rup-
turing nor solubility bear any distinct relation to the cells.
Rupturing consists in a spontaneous contraction of a portion
of the pericarpium, by which its texture is broken through
and holes formed, as in Antirrhinum and Campanula. Solubi-
lity arises from the presence of certain transverse contractions
of a one-celled pericarpium, through which it finally separates
into several closed portions, as in Ornithopus.

For the nature of the placenta and funiculus umbilicalis,
see the observations under ovarium. These parts, which
are mere modifications of each other, essentially appertain to
the pericarpium, in which the former often acquires a spongy
dilated substance, occasionally dividing the cells by spurious
dissepiments, and often giving to the fruit an appearance
much at variance with its true nature. In some seeds, as
Euonymus europseus, it becomes exceedingly dilated around
each seed, forming an additional envelope, called arillus.
The true character of this organ was unknown till it was
settled by Richard : before his time the term was applied, not
only in its true sense to an enlargement of the placenta, but
also to the endocarpium of certain Rubiaceae and Rutaceae, to
the testa of Jasminum, Orchideas, and others, and even to
the perianthium of Carex. A very remarkable instance of
the arillus is to be found in the nutmeg, in which it forms
the part called the mace, surrounding the seed. It is never
developed until after the impregnation of the ovulum.

Having thus explained the structure of the pericarpium, it
is in the next place necessary to enquire into the nature of its
modifications, which in systematic botany are of considerable
importance. It is on the one hand very much to be regretted
that the terms employed in this department of the science,
which is that of Carpology, have been often used so vaguely as
to have no exact meaning; while, on the other hand, they have
been so exceedingly multiplied by various writers, that the
phraseology of Carpology is a mere chaos. In practice but
a small number of terms is actually employed ; but it can-

m 3

166 ORGANOGRAPHY. BOOK I.

not be doubted that, if it were not for the inconvenience
of overburdening the science with terms, it would conduce
very much to clearness of description if botanists would
agree to make use of some very precise and uniform nomen-
clature.

What, for instance, can be more embarrassing than to find
the term nut applied to the superior plurilocular pericarpium
of Verbena, the gland of Corylus, and the achenia of Rosa
and Borago ; and that of berry to the fleshy envelope of
Taxus, the polyspermous inferior fruit of Ribes, the succulent
calyx of Blitum, and several other things ?

So much discordance, indeed, exists in the application of
terms expressive of the modifications of fruit, that it is quite
indispensable to give the definitions of some of the most
eminent writers upon the subject in their own words, in order
that the meaning attached by those authors to carpological
terms, when employed by themselves, may be clearly under-
stood.

In the phraseology of writers antecedent to Linnaus, the
following are the only terms of this description employed ;
viz. —

1. JBacca, a berry, any fleshy fruit.

2. Acinus, a bunch of fleshy fruit, especially a bunch of
grapes.

3. Caclirys, a cone, as of the pine tree.

4. Pilula, a cone like the Galbulus of modern botanists.

5. Folliculus (Fuchs), any kind of capsule.

6. Grossus, the fruit of the fig unripe.

7. Siliqua, the coating of any fruit.

In his " Philosophia Botanica" Linnaeus gives the follow-
ing definitions of the terms he employs : —

1. Capsula, hollow, and dehiscing in a determinate manner.

2. Siliqua, two-valved, with the seeds attached to both
sutures.

3. Legumen, two-valved, with the seeds attached to one
suture only.

4. Conceptaculum, one-valved, opening longitudinally on
one side, and distinct from the seeds.

5. Drupa, fleshy without valves, containing a nut.

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 167

6. Pomum, fleshy without valves, containing a capsule.

7. Bacca, fleshy without valves, containing naked seeds.

8. Strobilus, an amentum converted into a pericarpium.

Gartner has the following, with definitions annexed to
them : —

1. Capsula, a dry, membranous, coriaceous, or woody peri-
carpium, sometimes valveless, but more commonly dehiscing
with valves. Its varieties are, —

a. Utriculus, an unilocular one-seeded capsule, very thin
and transparent, and constantly valvular ; as in Chenopodium,
Atriplex, Adonis.

b. Samara, an indehiscent, winged, one or two-celled cap-
sule ; as Ulmus, Acer, Liriodendron.

c. Folliculus, a double one-celled, one-valved, membran-
ous, coriaceous capsule, dehiscing on the inside, and either
bearing the seed on each margin of its suture, or on a recep-
tacle common to both margins ; as Asclepias, Cinchona, and
Vinca.

2. Nux, a hard pericarpium, either indehiscent or never
dividing into more than two valves ; as in Nelumbium, Bora-
ginese, and Anacardium.

3. Coccum is a pericarpium of dry elastic pieces or coccula,
as in Diosma, Dictamnus, Euphorbia.

4. Drupa is an indehiscent pericarpium with a variable
rind, very different in substance from the putamen, which is
bony ; as in Lantana, Cocos, Sparganium, Gaura, &c.

5. Bacca, any soft pericarpium, whether succulent or other-
wise; provided it does not dehisce into regular valves, nor
contain a single stone adhering to it. Of this the following
are kinds : —

a. Acinus, a soft, succulent, semi-transparent unilocular
berry, with one or two hard seeds, as the grape, Rivina,
Rhipsalis, Rubus, Grossularia, &c.

b. Pomum, a succulent or fleshy, two or many celled
berry, the dissepiments of which are fleshy or bony, and
coherent at the axis ; as Pyrus, Crataegus, Cydonia, Sapota,
and others.

c. Pepo, a fleshy berry with the seeds attached at a dis-

m 4

168 ORGANOGRAPHY. BOOK I.

tance from the axis upon the parietes of the pericarp ; as
Cucumis, Stratiotes, Passiflora, Vareca, and others.

To the term bacca all other succulent fruits are referred
which belong to neither Acinus, Pomum, nor Pepo ; as Gar-
cinia, Caryophyllus, Cucubalus, Hedera.

6. Lcgumen, the fruit of Leguminosae.

7. Siliqua and Silicula, the fruit of Cruciferae.

Willdenaw defines those employed by him in the following
manner : —

1. Utriculus, a thin skin enclosing a single seed. Adonis,
Galium, Amaranthus.

2. Samara, a pericarpium containing one, or at most two
seeds, and surrounded by a thin membrane, either along its
whole circumference or at the point, or even at the side.
Ulmus, Acer, Betula.

3. Follicuhis, an oblong pericarpium bursting longitudi-
nally on one side, and filled with seeds. Vinca.

4. Capsida, a pericarpium consisting of a thin coat contain-
ing many seeds, often divided into cells, and assuming various
forms. Silene, Primula, Scrophularia, Euphorbia, Magnolia.

5. Nux, a seed covered with a hard shell which does not
burst. Corylus, Quercus, Cannabis.

6. Drupa, a nut covered with a thick succulent or carti-
laginous coat. Primus, Cocos, Tetragonia, Juglans, Myris-
tica, Sparganium.

7. Bacca, a succulent fruit containing several seeds, and
not dehiscing. It encloses the seeds without any determinate
order, or it is divided by a thin membrane into cells. Ribes,
Garcinia, Hedera, Tilia. Rubus has a compound bacca.

8. Pomum, a fleshy fruit that internally contains a capsule
for the seed. It differs from the celled berry in having a per-
fect capsule in the heart. Pyrus.

9. Pepo, a succulent fruit which has its seeds attached to
the inner surface of the rind. Cucumis, Passiflora, Stratiotes.

10. Siliqua, a dry elongated pericarp, consisting of two
halves held together by a common permanent suture. Cru-
ciferae. Silicula is a small form of the same.

11. Legumen, a dry elongated pericarpium, consisting of

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 169

two halves or valves externally forming two sutures. Legu-
minosae.

12. Lomentanii a legumen divided internally by spurious
dissepiments, not dehiscing longitudinally, but either remain-
ing always closed, as Cassia Fistula, or separating into pieces
at transverse contractions along its length, as Ornithopus.

The following are enumerated as spurious fruits.

13. Strobi/us, an Amentum the scales of which have be-
come woody. Pinus.

14. Spurious capsule. Fagus, Rumex, Carex.

15. Spurious nut. Traps, Coix, Mirabilis.

16. Spurious drupe. Taxus, Anacardium, Semecarpus.

17. Spurious bacca. Juniperus, Fragaria, Basella.

By this author the names of fruits are, perhaps, more loosely
and inaccurately applied than by any other.

Professor Link objects to applying particular names to
variations in anatomical structure ; observing, " that botanists
have strayed far from the right road in distinguishing these
terms by characters which are precise and difficult to seize.
Terms are only applied to distinct parts, as the leaf, peduncle,
calyx, and stamens, and not to modifications of them. Who
has ever thought of giving a distinct name to a labiate or
papilionaceous corolla, or who to a pinnated leaf?" But this
sort of reasoning is of little value if it is considered that the
fruit is subject to infinitely greater diversity of structure than
any other organ, and that names for these modifications have
become necessary, for the sake of avoiding a minute explan-
ation of the complex differences upon which they depend.
Besides, to admit, as Professor Link actually does, such
names as capsula, &c. is abandoning the argument; and
when the following definitions, which this learned botanist
has proposed, are considered, I think that little doubt need
exist as to whether terms should be employed in the manner
recommended by himself, or with the minute accuracy of the
French. According to Professor Link, the following are the
limits of Carpological nomenclature : —

1. Capsula^ any dry membranous or coriaceous pericarp.

2. Capsella, the same, if small and one-seeded.

170 ORGANOGRAPHY. BOOK I.

3. Nux, externally hard.

4. Nucula, externally hard, small, and one-seeded.

5. Drupa, externally soft, internally hard.

6. Pomum, fleshy or succulent, and large.

7. Bacca, fleshy or succulent, and small.

8. Bacca sicca, fleshy when unripe, dry when ripe, and
then distinguishable from the capsule by not being brown.

9. Legwnen, "I , . c . ,

, ~ r.-,- r the pericarps or certain natural orders.

10. Sihqua, J ' t

11. Amphispermium, a pericarpium which is of the same
figure as the seed it contains.

In more recent times there have been three principal
attempts at classing and naming the different modifications of
fruit ; namely, those of Richard, Mirbel, and Desvaux. These
writers have all distinguished a considerable number of varia-
tions, of which it is important to be aware for some purposes,
although their nomenclature is not much employed in practice.
But, in proportion as the utility of a classification of fruit con-
sists in its theoretical explanation of structure rather than in
a strict applicability to practice, it becomes important that it
should be founded upon characters which are connected with
internal and physiological distinctions rather than with external
and arbitrary forms. Viewing the subject thus, it is not to be
concealed that, notwithstanding the undoubted experience and
talent of the writers just mentioned, their carpological systems
are essentially defective. Besides this, each of the three writers
has felt himself justified in contriving a nomenclature at
variance with that of his predecessors, for reasons which it is
difficult to comprehend.

I have attempted to adjust the synonyms of carpological
writers, and have also ventured to propose a new arrange-
ment, in which those names which seem to be most legitimate
are retained in every case, their definitions only being altered ;
previously to which I shall briefly explain the methods of
Messrs. Richard, Mirbel, and Desvaux.

The Arrangement of Richard.

Class 1. Simple fruits.
§ 1. Dry.

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 171

* Indehiscent.

* * Dehiscent.
§ 2. Fleshy.

Class 2. Multiplied fruits.

Class 3. Aggregate or compound fruits.

The Arrangement of Mirbel.

Class 1. Gymnocarpiens. Fruit not disguised by the ad-
herence of any other organ than the calyx.

Ord. 1. Carcerulaires. Pericarpium indehiscent, but
sometimes with apparent sutures, generally dry,
superior or inferior, mostly unilocular and monosper-
mous, sometimes plurilocular and polyspermous.

Ord. 2. Capsalaires. Pericarpium dry, superior or
inferior, opening by valves, but never separating
into distinct pieces or cocci.

Ord. 3. Dieresiliens. Pericarpium superior or inferior,
dry, regular, and monocephalous (that is, having one
common style), composed of several distinct pieces
arranged systematically round a central real or
imaginary axis, and separating at maturity.

Ord. 4. Etairionaires. Pericarps several, irregular,
superior, one or many-seeded, with a suture at
the back.

Ord. 5. Cenobionaires. A regular fruit divided to the
base into several acephalous pericarpia ; that is to
say, not marked on the summit by the stigmatic scar,
the style having been inserted at their base.

Ord. 6. Dnipacees. Pericarpium indehiscent, fleshy
externally, bony internally.

Ord. 7. Bacciens. Succulent, many-seeded.
Class 2. Angiocarpiens. Fruit seated in envelopes not form-
ing part of the calyx.

The Arrangement of Desvaux.

Class 1. Pericarpium dry.

Ord. 1. Simple fruits.

172 ORGANOGRAPHY. BOOK I.

§ Indehiscent.
§ § Dehiscent.
Ord. 2. Dry compound fruits.
Class 2. Pericarpium fleshy.
Ord. 1. Simple fruits.
- Ord. 2. Compound fruits.

In explanation of the principles upon which the classifica-
tion of fruit which I now venture to propose is founded, it
will of course be expected that I should offer some observ-
ations. In the first place, I have made it depend primarily
upon the structure of the ovarium, by which the fruit is of
necessity influenced in a greater degree than by any thing
else, the fruit itself being only the ovarium at maturity. In
using the terms simple and compound, I have employed them
precisely in the sense that has been attributed to them in my
remarks upon the ovarium ; being of opinion that, in an
arrangement like the following and those which have pre-
ceded it, in which theoretical rather than practical purposes
are to be served, the principles on which it depends should
be conformable to the strictest theoretical rules of structure.
A consideration of the fruit without reference to the ovarium
necessarily induces a degree of uncertainty as to the real
nature of the fruit ; the abortion and obliteration, to which
almost every part of it is more or less subject, often disguising
it to such a degree that the most acute carpologist would be
unable to determine its true structure from an examination of
it in a ripe state only. In simple fruits are stationed those
forms in which the ovaria are multiplied so as to resemble a
compound fruit in every respect except their cohesion, they
remaining simple. But, as the passage which is thus formed
from simple to compound fruits is deviated from materially
when the ovaria are placed in more than a single series,
I have found it advisable to constitute a particular class of
such under the name of aggregate fruit. Care must be taken
not to confound these with the fourth class containing col-
lective fruits, as has been done by more carpologists than one.
While the true aggregate fruit is produced by the ovaria of
a single flower, a collective fruit, if aggregate, is produced by
the ovaria of many flowers ; a most important difference. As

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 173

the pericarpium is necessarily much affected by the calyx when
they adhere so as to form a single body, it is indispensable,
if a clear idea is to be attached to the genera of carpology, that
inferior or superior fruits should not be confounded under the
same name ; for this reason I have in all cases founded a dis-
tinction upon that character.

In order to facilitate the knowledge of the limits of the
genera of carpology, the following analytical table will be
found convenient for reference. It is succeeded by the cha-
racters of the genera in as much detail as is necessary for the
perfect understanding of their application.

Class I. Fruit simple. APOCARPI.
One or two-seeded.

Membranous, - -

Dry and bony,

Fleshy externally, bony internally,
Many-seeded.
Dehiscent.

One-valved, -

Two-valved,
Indehiscent, -

Class II. Fruit aggregate. AGGREGATI.

Ovaria elevated above the calyx.
Pericarpia distinct, -

Pericarpia cohering into a solid mass,

Ovaria enclosed within the fleshy tube of the calyx,

Class III. Fruit compound. SYNCARPI.
Sect. I. Superior.

A. Pericarpium dry externally.
Indehiscent.

Utricui.us.
achenium.
Drupa.

Foixiculus.

Legumen.

lomenium.

Et,erio.

SyNCARPIUM.

Cynarrhodum.

One-celled, -

-

Caryopsis.

Many-celled.

Dry internally.

Apterous

-

Carcerulus.

Winged,

-

Samara.

Pulpy internally,

-

Amphisarca.

Dehiscent.

By a transverse suture,

-

Pyxidium.

By elastic cocci,

-

Regma.

By a longitudinal suture,

-

CONCEPTACULUM.

By valves.

Placenta; opposite the lobes of

the

stigma.

Linear,

-

SlLIQUA.

Roundish,

-

SlLICULA.

174

ORGANOGRAPHY.

BOOK f.

Placentae alternate with the lobes of
the stigma.

Valves separating from the replum, Ceratium.

Sect. 2.
A.

Replum none,
Pericarpium fleshy.
Indehiscent.

Sarcocarpium separable,
Sarcocarpium inseparable,
Dehiscent, -
Inferior.

Pericarpium dry.
Indehiscent.

Capsula.

Hesperidium.
Nuculanium.
Trtma.

Cells two or more,

-

Cremocarpium.

Cell one.

Surrounded by a cupulate involucrum,

Glans.

Destitute of a cupula,

-

Cypsela.

Dehiscent or rupturing,

-

DlPLOTEGIA.

B. Pericarpium fleshy.

Epicarpium hard.

Seeds parietal,

-

Pepo.

Seeds not parietal,

-

Balausta.

Epicarpium soft.

Cells obliterated ; or unilocular,

-

Bacca.

Cells distinct, -

-

POMUM.

Class IV. Collective fruits. ANTHOCARPI.

Single.

Perianthium indurated, dry,

-

Dicr,Esiuji.

Perianthium fleshy, -

-

Sphalerocar-

Aggregate.

PIUM.

Hollow, -

-

Syconus.

Convex.

An indurated amentum,

-

Strobilus.

A succulent spike,

-

Sorosis.

Class I. Fruit simple. APOCARPI.

Ovaria strictly simple ; a single series only produced by a single flower.

I. Utriculus, Gcertner (Cystidium, Link.)

One-celled, one or few-seeded, superior, membranous, frequently dehiscent
by a transverse incision. This differs from the pyxis in texture, being strictly
simple, i. e. not proceeding from an ovarium with obliterated dissepiments.

Example. — Amaranthus, Chenopodium.

II. Achenium ; (Akenium, of many ; Spermidium ; Xylodium, Desv.; The-

cidium, Mirb. ; Nux, Linn.)

One-seeded, one-celled, superior, indehiscent, hard, dry, with the integu-
ments of the seed distinct from it.

Linnaeus includes this among his seeds, defining it " semen tectum epider-
mide ossea." I have somewhere seen it named Spermidium ; a good term if
it were wanted. M. Desvaux calls the nut of Anacardium a Xylodium.

Examples. — Lithospermum, Borago.

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 17.5

III. Drupa Drupe. —Jig, 163.

One-celled, one or two-seeded, superior, indehiscent, the outer coat (nau-
cum) soft and fleshy, and separable from the inner or endocarpium (the stone),
which is hard and bony ; proceeding from an ovarium which is perfectly
simple. This is the strict definition of the term drupa, which cannot strictly
be applied to any compound fruit, as that of Cocos, certain Verbenaceae, and
others, as it often is. Fruits of the last description are generally carcerules
with a drupaceous coat. The stone of this fruit is the Kux of Richard, but
not of others.

Examples. — Peach, Plum, Apricot.

IV. Foluculus. — Follicle (Hemigyrus, Desvaux; Plopocarpium, Desv.),

fig- I*).

One-celled, one or many-seeded, one-valved, superior, dehiscent by a
suture along its face, and bearing its seeds at the base, or on each margin of
the suture. This differs from the legumen in nothing but its having one
valve instead of two. The Hemigyrus of Desvaux is the fruit of Proteaceae,
and differs from the follicle in nothing of importance. When several follicles
are in a single flower, as in Nigella and Delphinium, they constitute a form of
fruit called Plopocarpium by Desvaux, and admitted into his Etaerio by
Mirbel.

Examples. — Preonia, Banksia, Nigella.

V. Legumen. — Pod (Legumen, Linn.; Gousse, Fr.), fig. 136, 137.

One-celled, one or many-seeded, two-valved, superior, dehiscent by a suture
along both its face and its back, and bearing its seeds on each margin of the
ventral suture. This differs from the follicle in nothing except its dehiscing by
two valves. In Astragalus two spurious cells are formed by the projection
inwards of either the dorsal or ventral suture, which forms a sort of dissepiment;
and in Cassia a great number of transverse diaphragms (phragmata) are formed
by projections of the placenta. Sometimes the legumen is indehiscent, as in
Cathartocarpus, Cassia fistula, and others ; but the line of dehiscence is in
such species indicated by the presence of sutures. When the two sutures of
the legumen separate from the valves, they form a kind of frame called replum,
as in Carmichaelia.

Examples. — Bean, Pea, Clover.

VI. Lomentum. — (Legumen lomentaceum, Rich.)

Differs from the legumen in being contracted in the spaces between each
seed, and there separating into distinct pieces, or indehiscent, but divided by
internal spurious dissepiments, whence it appears at maturity to consist of
many articulations and divisions.

Example. — Ornithopus.

Class II. Fruit aggregate. A G G RE G A TI.

Ovaria strictly simple ; more than a single series produced by eachjlower.

VII. Etaerio, Mirb. — (" Polychorion, Mirb. ; " Polysecus, Desvaux; Amalthea,

Desv. ; Erythrostomum, Desvaux), Jig. 161.
Ovaries distinct; pericarpia indehiscent, either dry upon a dry receptacle, as
Ranunculus, dry upon a fleshy receptacle, as strawberry, or fleshy upon a

176 ORGANOGRAPHY. BOOK I.

dry receptacle, as Rubus. The last is very near the syncarpium, from which
it differs in the ovaria not coalescing into a single mass. It is Desvaux's
Erythrostomum. This term is applied less strictly by M. Mirbel, who admits
into it dehiscent pericarpia, not placed upon an elevated receptacle, as Delphi-
nium and Paeonia ; but the fruit of these plants is better understood to be a
union of several follicules within a single flower. If there is no elevated
receptacle, we have Desvaux's Amalthea. The parts of an Etaerio are
Achenia.

Examples. Ranunculus, Fragaria, Rubus.

VIII. Syncarpium. — (Syncarpium, Rich. ; Asimina, Desv.)
Ovaries cohering into a solid mass, with a slender receptacle.
Examples. Annona, Magnolia.

IX. Cyxarrhodum. — (Cynarrhodum, Officin. Desvaux.)

Ovaries distinct ; pericarpia hard, indehiscent, enclosed within the fleshy
tube of a calyx.

Examples. Rosa, Calycanthus.

Class III. Fruit compound. SYNCARPI.
Ovaria compound.

Sect. 1. Fruit superior.
A. Pericarpium dry.

X. Caryopsis. — (Cariopsis, Rich. ; Cerio, Mirb.)

One-celled, one-seeded, superior, indehiscent, dry, with the integuments of
the seed cohering inseparably with the endocarpium, so that the two are undis-
tinguishable ; in the ovarium state evincing its compound nature by the pre-
sence of two or more stigmata ; but nevertheless unilocular, and having but
one ovulum.

Examples. Wheat, Barley, Maize.

XI. Reqma, Mirb. ; — (Elaterium, Rich. ; Capsula tricocca, L.)

Three or more celled, few-seeded, superior, dry, the cells bursting from the
axis with elasticity into two valves. The outer coat is frequently softer than
the endocarpium or inner coat, and separates from it when ripe; such regmata
are drupaceous. The cells of this kind of fruit are called cocci.

Example. Euphorbia.

XII. Carcerulus, Mirb. ; — (Dieresilis, Mirb. ,- Ca?nobio, Mirb. ; Synochorion,

Mirb.; Sterigmum, Desvaux ; Microbasis, Desvaux ,- Polexostylus,
Mirb.; Sarcobasis, Dec, Desv. ; Baccaularius, Desv. )
Many-celled, superior ; cells dry, indehiscent, few-seeded, cohering by a
common style round a common axis. From this the Dieresilis of Mirbel does
not differ in any essential degree. The same writer calls the fruit of Labiatai
(Jig. 162.), which Linnaeus and his followers mistake for naked seeds, Caano-
bio : it differs from the Carcerulus in nothing but the low insertion of the
style into the ovaria, and the distinctness of the latter.
Examples. Tilia, Tropaeolum, Malva.

XIII. Samara, Geertn. ; — Key. (Pteridium, Mirb. ; Pterodium, De$v.),Jig. 143.

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 177

Two or more celled, superior; cells few-seeded, indeliiscent, dry; elongated
into wing-like expansions. This is nothing but a modification of the Carcerule.
Examples. Fraxinus, Acer, Ulmus.

XIV. Pvxidium (Pyxidium, Ehr., Rich., Mirb.; Capsula circumscissa, L.),

Jig- 152.

One-celled, many-seeded ; superior, or nearly so ; dry, often of a thin tex-
ture ; dehiscent by a transverse incision, so that when ripe the seed and their
placenta appear as if seated in a cup, covered with a lid. This fruit is one-
celled by the obliteration of the dissepiments of several carpella, as is apparent
from the bundles of vessels which pass from the style through the pericarpium
down into the receptacle.

Example. Anagallis.

XV. Conceptaculum (Conceptaculum, Linn.; Double Follicule, Mirb.),

Jig. 138, 139.

Two-celled, many-seeded, superior, separating into two portions, the seeds
of which do not adhere to marginal placentae, as in the folliculus, to which this
closely approaches, but separate from their placentae, and lie loose in the cavity
of each cell.

Examples. Asclepias, Echites.

XVI. Siliqca, Linn. Jig. 155, 156, 157.

One or two-celled, many-seeded, superior, linear, dehiscent by two valves
separating from the replum ; seeds attached to two placentas adhering to the
replum, and opposite to the lobes of the stigma. The dissepiment of this fruit
is considered a spurious one formed by the projecting placentas, which some-
times do not meet in the middle ; in which case the dissepiment or phragma
has a slit in its centre, and is said to he fenestrate.

XVII. — Silicula. Linn.

This differs from the latter in nothing but its figure, and in containing fewer
seeds. It is never more than four times as long as broad, and often much shorter.
Examples. Thlaspi, Lepidium, Lunaria.

XVIII. Ceratium. — (Capsula siliquiformis, Dec. ; Conceptaculum, Desv.)
One-celled, many-seeded, superior, linear, dehiscent by two valves separat-
ing from the replum ; seeds attached to two spongy placenta? adhering to the
replum, and alternate with the lobes of the stigma. Differs from the siliqua in
the lobes of the stigma being alternate with the placentae, not opposite. This,
therefore, is regular, while that is irregular in structure.

Examples. Glaucium, Corydalis, Hypecoum.

XIX. Capsula, Capsule, Jig. 145, 146. 150, 151. 134, 135.

One or many-celled, many-seeded, superior, dry, dehiscent by valves, always
proceeding from a compound ovarium. The valves are variable in their
nature : usually they are at the top of the fruit, and equal in number to the
cells; sometimes they are twice the number; occasionally they resemble little
pores or holes below the summit, as in the Antirrhinum.

Examples. Digitalis, Primula, Rhododendron.

XX. Amphisarca. — (Amphisarca, Desv.)

Many-celled, many-seeded, superior, indehiscent ; indurated or woody exter-
nally, pulpy internally.

N

178 ORGANOGRAPHY. BOOK I.

Examples. Omphalocarpus, Adansonia, Crescentia.
B. Pericarpium fleshy.

XXI. Tryma (Tryma, Watson.)

Superior, by abortion one-celled, one-seeded, with a two-valved indehiscent
endocarpium, and a coriaceous or fleshy, valveless sarcocarpium.
Example. Juglans.

XXII. Nucula^ium. — (Nuculanium, Rich. ; Bacca, Desvaux.)

Two or more celled, few or many-seeded, superior, indehiscent, fleshy, of
the same texture throughout, containing several seeds, improperly called
nucules by the younger Richard. This differs scarcely at all from the berry,
except in being superior.

Examples. Grape, Achras.

XXIII. Hesperidium. — (Hesperidium, Desv. Rich.)

Many-celled, few-seeded, superior, indehiscent, covered by a spongy separ-
able rind ; the cells easily separable from each other, and containing a mass of
pulp, in which the seeds are imbedded. The pulp is formed by the cellular
tissue, which forms the lining of the cavity of the cells : this cellular tissue is
excessively enlarged and succulent, is filled with fluid, and easily coheres into
a single mass. The external rind is by M. De Candolle supposed to be an
elevated discus of a peculiar kind, analogous to that within which the fruit of
Nelumbium is seated ; and perhaps its separate texture and slight connexion
with the cells of the fruit seem to favour this supposition. But it is difficult
to reconcile with such an hypothesis the continuity of the rind with the style
and stigma, which is a sure indication of the identity of their origin ; and it is
certain that the shell of the ovarium and the pericarpium are the same. The
most correct explanation of this structure is to consider the rind a union of the
epicarp and sarcocarp, analogous to that of the drupa.

Example. Orange.

Sect. 2. Fruit inferior.

A. Pericarpium dry.

XXIV. Glans (Glans, Linn. Desv. ; Calybio, Mirb. ,• Nucula, Desvaux),

Jig. 164.

One-celled, one or few-seeded, inferior, indehiscent, hard, dry; proceeding
from an ovarium containing several cells and several seeds, all of which are
abortive but one or two ; seated in that kind of persistent involucre called
a cupule. The pericarpium is always crowned with the remains of the teeth
of the calyx ; but they are exceedingly minute, and are easily overlooked.
Sometimes the gland is solitary, and quite naked above, as in the common oak ;
sometimes there is more than one completely enclosed in the cupule, as the
beech and sweet chestnut.

Examples. Quercus, Corylus, Castanea.

XXV. Cypsela (Akena, Necker ; Akenium, Rich.; Cypsela, Mirb.; Ste-

phanoum, Desv.), fig. 147, 148.
One-seeded, one-celled, indehiscent, with the integuments of the seed not
cohering with the endocarpium ; in the ovarium state evincing its compound
nature by the presence of two or more stigmata ; but nevertheless unilocular,
and having but one ovulum. Such is the true structure of the Achenium ;
but, as that term is often applied to the simple superior fruits, called Nux by

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 179

Linnrcus, I have thought it hetter, in order to avoid confusion, to adopt the
name Cypsela.

Examples. All Composite.

XXVI. Cremocarpium (Cremocarpium, Mirb. ; Polakenium, or Pentake-
nium, Ttich. ; Carpadelium, Desv.), fig. 153, 154. 158, 159.
Two to five-celled, inferior ; cells one-seeded, indehiscent, dry, perfectly
close at all times ; when ripe separating from a common axis. M. Mirbel
confines the application of Cremocarpium to Umbellifera; ; but it is better to
let it apply to all fruits which will come within the above definition. It will
then be the same as Richard's Polakenium, excluding those forms in which the
fruit is superior. The latter botanist qualifies his term Polakenium according
to the number of cells of the fruit: thus when there are two ceWs'itis diakenium,
three triakenium, and so on. M. De Candolle calls the half of the fruit of
Umbellifera; ?nericarpc
Examples. Umbellifera?, Aralia, Galium.

XXVII. Diplotegia (Diplotegia, Desv.), fig. 144.

One or many-celled, many-seeded, inferior, dry, usually bursting either by
pores or valves. This differs from the Capsule only in being adherent to the
calyx.

Examples. Campanula, Leptospermum.

B. Peri carpi urn fleshy.

XXVIII. Pomum, Apple or Pome (Melonidium, Rich. ,- Pyridium, Mirb. ;

Pyrenarium, Desvaux ; Antrum, Mcench.) fig. 165.

Two or more celled, few-seeded, inferior, indehiscent, fleshy; the seeds dis-
tinctly enclosed in dry cells, with a bony or cartilaginous lining, formed by the
cohesion of several ovaria with the sides of the fleshy tube of a calyx, and some-
times with each other. These ovaria are called parietal by M. Richard. Some
forms of Nuculanium and this differ only in the former being distinct from the
calyx.

Examples. Apple, Cotoneaster, Crataegus.

XXIX. Pefo. — (Peponida, Rich.)

One-celled, many-seeded, inferior, indehiscent, fleshy ; the seeds attached to
parietal pulpy placenta;. This fruit has its cavity frequently filled at maturity
with pulp, in which the seeds are imbedded ; their point of attachment is, how-
ever, never lost. The cavity is also occasionally divided by projections of the
placenta into spurious cells, which has given rise to the belief that in Pepo Ma-
crocarpus there is a central cell, which is not only untrue but impossible.

Examples. Cucumber, Melon, Gourd.

XXX. Bacca, Berry (Bacca, L. ; Acrosarcum, Desvaux), fig. 160.
Many-celled, many-seeded, inferior, indehiscent, pulpy ; the attachment of

the seeds lost at maturity, when they become scattered in the substance of the
pulp. This is the true meaning of the term berry ; which is, however, often
otherwise applied, either from mistaking nucules for seeds, or from a mis-
apprehension of the strict limits of the term.
Example. Ribes.

XXXI. Balausta. — (Balausta, Officin. Rich.)

Many-celled, many-seeded, inferior, indehiscent ; the seeds with a pulpy

N 2 ^-

180 ORGANOGRAPHY. BOOK I.

coat, and attached distinctly to their placentae. The rind was called Malicorium
by Ruellius.

Example. Pomegranate.

Class IV. Collective Fruits. Anthocarpi.

Fruit of which the principal characters are derived from the incrassated floral
envelopes.

XXXII. Diclesium. — (Dyclesium, Desvaux ; Sclerantlium, Mcench ; Catacle-

sium, Desvaux ; Sacellus, Mirb.)
Pericarpium indehiscent, one-seeded, enclosed withi n an indurated perian-
thium.

Examples. Mirabilis, Spinacia, Salsola.

XXXIII. Sphalerocarpum. — (Sphalerocarpum, Desv. ; Nux baccata of

authors. )
Pericarpium indehiscent, one-seeded, enclosed within a fleshy perianthium.
Examples. Hippophae, Taxus, Blitum, Basella.

XXXIV. Stconus. — (Syconus, Mirb.)

A fleshy rachis, having the form of a flattened disk, or of a hollow receptacle,
with distinct flowers and dry pericarpia.
Examples. Ficus, Dorstenia, Ambora.

XXXV. Strobilus, Cone (Conus, or Strobilus, Rich., Mirb. ; Galbulus,

Gtertn. ; Arcesthide, Desvaux; Cachrys, Fuchs ; Pilula, Pliny),
fig. 166.
An amentum, the carpella of which are scale-like, spread open, and bear
naked seeds ; sometimes the scales are thin, with little cohesion ; but they often
are woody, and cohere into a single tuberculated mass.

The Galbulus differs from the Strobilus only in being round, and having
the heads of the carpella much enlarged. The fruit of the Juniper is a Gal-
bulus, with fleshy coalescent carpella. Desvaux calls it Arcesthide.
Example. Pinus.

XXXVI. Sorosis. — (Sorosis, Mirb.)

A spike or raceme converted into a fleshy fruit by the cohesion in a single
mass of the ovaria and floral envelopes.

Examples. Ananassa, Moms, Artocarpus.

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 181

14. Of the Seed.

17 6

181 184 185

As the fruit is the ovarium arrived at maturity, and is
therefore subject to the same laws of structure as the latter;
so is the seed the ovulum in its most perfect and finally
organised state, and constructed upon exactly the same plan
as the ovulum. But as the fruit, nevertheless, often differs
from the ovarium in the suppression, or addition, or modi-
fication of certain portions, so is the seed occasionally altered
from the precise structure of the ovulum, in consequence of
changes of like nature.

The seed is a body enclosed in a pericarpium, is clothed
with its own integuments, and contains the rudiment of a
future plant. It is the point of developement at which vege-
tation stops, and beyond which no increase, in the same
direction with itself, can take place. In a young state it has
already been spoken of under the name of ovulum ; to which
I also refer for all that relates to the insertion of seeds.

That side of a seed which is most nearly parallel with the
axis of a compound fruit, or the ventral suture or sutural line
of a simple fruit, is called the face, and the opposite side the
back. In a compound fruit with parietal placentas, the pla-
centa is to be considered as the axis with respect to the seed ;
and that part of the seed which is most nearly parallel with
the placenta, as the face. Where the raphe is visible, the
face is indicated by that.

When a seed is flattened lengthwise it is said to be com-

N 3

182 ORGANOGRAPHY. BOOK I.

pressed, when vertically it is depressed; a difference which
it is of importance to bear in mind, although it is not always
easy to ascertain it : for this purpose it is indispensable that
the true base and apex of the seed should be clearly under-
stood. The base of a seed is always that point by which it is
attached to the placenta, and which receives the name of
hilum ; the base being found, it would seem easy to deter-
mine the apex, as a line raised perpendicularly upon the
hilum, cutting the axis of the seed, ought to indicate the apex
at the point where the line passes through the testa : but the
apex so indicated would be the geometrical, not the natural
apex ; for discovering which with precision in all seeds, the
natural and geometrical apex of which do not correspond,
another plan must be followed. If the testa of a seed be
carefully examined, it will usually be found that it is com-
posed in great part of lines representing rows of cellular tissue,
radiating from some one point towards the base, or, in other
words, of lines running upwards from the hilum and meet-
ing in some common point. This point of union or radiation
is the true apex, which is not only often far removed from the
geometrical apex, but is sometimes even in juxtaposition with
the hilum, as in mignonette : in proportion, therefore, to the
obliquity of the apex of the seed will be the curve of its axis,
which is represented by a line passing through the whole
mass of the seed from the base to the apex, accurately follow-
ing its curve. If the lines above referred to are not easily
distinguished, another indication of the apex resides in a little
brown spot or areola, hereafter to be mentioned under the
name of chalaza. Where there is no indication either exter-
nally or internally of the apex, it may then be determined
geometrically.

The integuments of a seed are called the testa ; the rudi-
ment of a future plant, the embryo (Plate VI. fig. 1. b, &c.) ;
and a substance interposed between the embryo and the testa,
the albumen (fig. 1. a, 5. «, &c).

The testa, called also lorica by Mirbel, perisperme and
episperme by Richard, and spermodermis by De Candolle,
according to some consists, like the pericarpium, of three
portions; viz. 1. the external integument, tunica externa of

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 183

WilldenoWj testa of De Candolle ; 2. the internal integu-
ment, tunica interna of Willdenow, endopleura of De Can-
dolle, hilofere and tegmen of Mirbel ; and, 3. of an inter-
vening substance answering to the sarcocarpium, and called
sarcodcrmis by De Candolle : this last is chiefly present in
seeds with a succulent testa, and by many is considered a
portion of the outer integument, which is the most accurate
mode of understanding it.

The outer integument is either membranous, coriaceous,
crustaceous, bony, spongy, fleshy, or woody ; its surface is
either smooth, polished, rough, or winged, and sometimes is
furnished with hairs, as in the cotton and other plants, which,
when long and collected about either extremity, form what is
called the coma (sometimes also, but improperly, the pappus).
It consists of cellular tissue disposed in rows, with or without
bundles of vessels intermixed : in colour it is usually of a
brown or similar hue : it is readily separated from the inner
integument.

In Maurandya Barclayana it is formed of reticulated cel-
lular tissue ; in Collomia linearis and others it is caused
by elastic spirally twisted fibres enveloped in mucus, and
springing outwards when the mucus is dissolved ; in Casu-
arina it (or the inner integument) contains a great quantity of
spirally fibrous cellules. In the genus Crinum it is of a very
fleshy, succulent character, and has been mistaken for albumen,
from which it is readily known by its vascularity. According
to Mr. Brown, a peculiarly anomalous kind of partition,
which is found lying loose within the fruit of Banksia and
Dryandra, without any adhesion either to the pericarpium or
the seed, is a state of the outer integument. It is said that in
those genera the inner membrane (secondine) of the ovulum
before fertilisation is entirely exposed, the primine being
dimidiate and open its whole length ; and that the outer
membranes (primines) of the two collateral ovula, although
originally distinct, finally contract an adhesion by their
corresponding surfaces, and together constitute the anomalous
dissepiment. But it may be reasonably doubted whether the
integument here called secondine is not primine, and the sup-
posed primine arillus.

n 4

184 ORGANOGRAPHY. BOOK I.

The inner membrane (secondine) of the ovulum, however,
in general appears to be of greater importance as connected
with fecundation, than as affording protection to the nucleus
at a more advanced period. For in many cases, before im-
pregnation, its perforated apex projects beyond the aperture
of the testa, and in some plants puts on the appearance of an
obtuse, or even dilated stigma ; while in the ripe seed it is
often either entirely obliterated, or exists only as a thin film,
which might readily be mistaken for the epidermis of a third
membrane, then frequently observable.

" This third coat (tercine) is formed by the proper membrane
or cuticle of the nucleus, from whose substance in the unim-
pregnated ovulum it is never, I believe, separable, and at that
period is very rarely visible. In the ripe seed it is distin-
guishable from the inner membrane only by its apex, which
is never perforated, is generally acute and more deeply co-
loured, or even sphacelated."

M. Mirbel has, however, justly remarked that the pri-
mine and the secondine are, in the seed, very frequently con-
founded ; and that therefore the word testa is better employed,
as one which expresses the outer integument of the seed
without reference to its exact origin, which is practically
of little importance. The tercine is also, no doubt, often
absent. He observes, that these mixed integuments often give
rise to new kinds of tissue ; that in Phaseolus vulgaris the
testa consists, indeed, of three distinct layers, but of those the
innermost was the primine ; and that the others, which repre-
sent nothing that pre-existed in the ovulum, have a horny
consistence, and are formed of cylindrical cellules, which
elongate in the direction from the centre to the circumference.
And this is probably the structure of the testa of many Legu-
minosse.

It sometimes happens that the endopleura (or tercine ?)
thickens so much as to have the appearance of albumen, as in
Cathartocarpus fistula. In such a case as this it is only to
be distinguished from albumen by gradual observation from
the ovulum to the ripe seed.

With regard to the quartine and quintine, one of them is
occasionally present in the form of a fleshy sac that is inter-
posed between the albumen and the ovulum, and envelopes

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 185

the latter. It is what was called the vitellus by Gaertner, and
which M. Richard, by a singular prejudice, considered a dila-
tation of the radicle of the embryo, to his macropodal form of
which he referred the embryo of such plants. Instances of
this are found in Nymphaea and its allies, and also in Scita-
mineae, peppers, and Saururus. Mr. Brown, who first ascer-
tained the fact, considers this sac to be always of the same
nature and origin, and as the vesicula colliquamenti or amnios
of Malpighi.

The end by which the seed is attached to the placenta is
called the hilum or umbilicus (Plate VI. fig. 5. c, 17. e, 11. c,
&c.) ; it is frequently of a different colour from the rest of the
seed, not uncommonly being black. In plants with small
seeds it is exceedingly minute, and recognised with difficulty;
but in some it is so large as to occupy fully a third part of
the whole surface of the seed, as in the horse-chestnut, Sa-
poteae, and others. Seeds of this kind have been called
nauca by Gaertner. In grasses the hilum is indicated by a
brownish spot situated on the face of the seed, and is called
by M. Richard spilus. The centre of the hilum, through
which the nourishing vessels pass, is called by Turpin the
omphalodium. Sometimes the testa is enlarged in the form of
irregular lumps or protuberances about the umbilicus ; these
are called strophiolce or carunculee ; and the umbilicus, about
which they are situated, is said to be strophiolate or carun-
culate. M. Mirbel has ascertained that in Euphorbia Lathy-
ris the strophiola is the fungous foramen of the primine ; and
it is probable that such is often the origin of this tubercle :
but at present we know little or nothing upon the subject.

The foramen in the ripe seed constitutes what is called the
micropyle : it is always opposite the radicle of the embryo ;
the position of which is therefore to be determined without
dissection of the seed, by an inspection of the micropyle,
— often a practical convenience.

In some seeds, as the asparagus, Commelina, and others
{Jig. 185.), there is a small callosity at a short distance from the
hilum : this callosity gives way like a little lid at the time of
germination, emitting the radicle, and has been named by
Gaertner the embryolega.

At the apex of the seed in the orange and many other

186

ORGANOGRAPHY.

BOOK I.

plants may be perceived upon the testa a small brown spot,
formed by the union of certain vessels proceeding from the
hilum : this spot is the chalaza (Plate VI. fig. 11. b). In the
orange it is beautifully composed of dense bundles of spiral
vessels and spiral ducts, without woody fibre. The vessels
which connect the chalaza with the hilum constitute a parti-
cular line of communication, called the raphe : in most plants
it consists of a single line passing up the face of the seed ; but
in many Aurantiaceae and Guttiferae it ramifies elegantly in
every direction upon the surface of the testa.

The raphe is always a true indication of the face of the seed;
and it is very remarkable that the apparent exceptions to this
rule only serve to confirm it. Thus, in some species of Euony-
mus in which the raphe appears to pass along the back, an ex-
amination of other species shows, that the ovula of such species
are in fact resupinate ; so that with them the line of vascularity
representing the raphe is turned away from its true direction
by peculiar circumstances. In reality, the chalaza is the place
where the secondine and the primine are connected ; so that
in orthotropous seeds, or such as have the apex of the nucleus
at the apex of the seed, and in which, consequently, the
union of the primine and secondine takes place at the hilum,
there can be no apparent chalaza, and consequently no raphe :
the two latter can only exist as distinct parts in anatropous
seeds, when the base of the nucleus corresponds to the geo-
metrical apex of the seed. Hence, also, there can never be a
chalaza without a raphe, nor a raphe without a chalaza.

Something has already been said
about the arillus {Jig. 186. and 187.)
when speaking of the ovulum ; but
it more properly comes under con-
sideration along with the ripe seed.
As a general rule it may be stated,
that every thing proceeding from
the placenta and not forming part
of the seed is referable to the
arillus. Even in plants like Hib-
bertia volubilis and Euonymus
europaeus, in which it is of un-
usual dimensions, it is scarcely

186

187

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 187

visible in the unimpregnatecl ovarium ; and it is stated by
Mr. Brown, that he is not acquainted with any case in which
it covers the foramen of the testa before impregnation.

The mass enclosed within the true testa or outer integu-
ment is called the nucleus ; and consists either of albumen and
embryo, or of the latter only.

The albumen {jperispermium, Juss. ; endospermium, Rich. ;
medulla seminis, Jungius ; secimdince internee, Malpighi)
(Plate VI. fig. 5. a, l.a, 9. a, &c), when present, is a body
enclosing the embryo, and interposed between it and the in-
tegument of the seed : it is of various degrees of hardness,
varying from fleshy to bony, or even stony, as in some palms.
It is in all cases destitute of vascularity, and has been usually
considered as the amnios in an indurated state ; but Mr.
Brown is of opinion that it is formed by a deposition or
secretion of granular matter in the cellules of the amnios, or
in those of the nucleus itself. The albumen is often absent,
frequently much smaller than the embryo, but also occasion-
ally of much greater size. This is particularly the case in
monocotyledones, in some of which the embryo scarcely
weighs a few grains, while the albumen weighs many ounces,
as in the cocoa-nut. It is almost always solid, but in An-
nonaceae and the nutmeg tribe it is perforated in every
direction by dry cellular tissue, which appears to originate
from the remains of the nucleus in which the albumen has
been deposited : in this state it is said to be ruminated.

The embryo (or corculum) (Plate VI. fig. 1. b, &c.) is a
fleshy body, occupying the interior of the seed, and consti-
tuting the rudiment of a future plant. It is usually solitary,
but there are instances of the presence of several in one seed.
It was originally developed within the innermost membrane
of the ovulum. In most plants one embryo only is found in
each seed. It nevertheless occurs, not unfrequently, that more
than one is developed within a single testa, as occasionally in
the orange and the hazel nut, and very commonly in Coni-
ferae, Cycas, the onion, and the misseltoe. Now and then a
union takes place of these embryos.

It is divided into three parts; viz. the radicle (Plate VI.
fig. 2. b, &c.) {rhizoma or rostellum); cotyledons (fig. 2. a, &c),

188 ORGANOGIIAPHY. BOOK I.

and plumula (or gemmuld) (fig. 2. c) ; from which is also by
some distinguished the cauliculus or neck {collet, scapus, sca-
pellus, or tigelle). Mirbel admits but two principal parts ;
viz. the cotyledons, and what he calls the blasteme, which
comprises radicle, plumula, and cauliculus.

Upon certain remarkable differences in the structure of the
embryo, modern botanists have divided the whole vegetable
kingdom into three great portions, which form the basis of
what is called the natural system. These are, 1. Dicoty-
ledons ; 2. Monocotyledons ; and, 3. Acotyledons. In order
to understand exactly the true nature of the embryo in each
of these, it will be requisite first to describe it fully as it exists
in dicotyledons, and then to explain its organisation in the
two others.

If a common Dicotyledonous embryo (Plate VI. fig. 2.),
that of the apple for example, be examined, it will be found
to be an obovate, white, fleshy body, tapering and solid
at the lower end, and compressed and deeply divided into
two equal opposite portions at the upper end ; the lower
tapering end is the radicle, and the upper divided end consists
of two cotyledons. Within the base of the cotyledons is just
visible a minute point, which is the plumula. The imaginary
line of division between the radicle and the cotyledons is the
caulicidus. If the embryo be now placed in circumstances
favourable for germination, the following phenomena occur :
the radicle will become elongated downwards, forming a
little root ; the cauliculus will extend upwards ; the cotyledons
will elevate themselves above the earth and unfold ; and the
plumula will lengthen upwards, and give bhth to a stem and
leaves. Such is the normal or proper appearance of a dicoty-
ledonous embryo.

The exceptions to it chiefly consist, 1. in the cohesion of the
cotyledons in a single mass, instead of their unfolding ; 2. in
an increase of their number ; 3. in their occasional absence ;
and, 4. in their inequality. A cohesion of the cotyledons takes
place in those embryos, which Gaertner called pseudomonocoty-
ledonous, and Richard macrocephalous. In Hippocastanum, the
horse-chestnut, the embryo consists of a homogeneous undi-
vided mass, with a curved horn-like prolongation of one side

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 189

directed towards the hilum. If a section be made in the
direction of the axis of the horn-like prolongation through the
whole mass of the embryo, a slit will be observable above the
middle of the horn, at the base of which lies a little conical
body. In this embryo the slit indicates the division between
the two bases of a pair of opposite confluent cotyledons; the
conical body is the plumula, and the horn-like prolongation
is the radicle. In Castanea nearly the same structure exists,
except that the radicle, instead of being curved and exserted,
is straight, and enclosed within the projecting base of the two
cotyledons ; and in Tropaeolum, which is very similar to Cas-
tanea in structure, the bases of the cotyledons are slit into
four little teeth enclosing the radicle. The germination of
these seeds indicates more clearly that the cotyledonary body
consists of two and not of one cotyledon ; at that time the
bases of the cotyledons, which had been previously scarcely
visible, separate and elongate, so as to extricate the radicle
and plumula from the testa, within which they had been con-
fined. In number the cotyledons vary from two to a much
more considerable number. Ceratophyllum has constantly
four, of which two are smaller than the others ; in Coniferse
they vary from two to more than twelve.

Instances of the absence of cotyledons occur, 1 . In Cus-
cuta (Plate VI. fig. 19.), to which they may be supposed to be
denied in consequence of the absence of leaves in that genus ;
2. in Lentibularise ; 3. in Cyclamen, in which the radicle
enlarges exceedingly : to these a fourth instance has by some
been added in Lecythis, of which M. Richard gives the fol-
lowing account. The kernel is a fleshy almond-like body, so
solid and homogeneous that it is extremely difficult to dis-
cover its two extremities until germination takes place : at that
period one of the ends forms a little protuberance, which sub-
sequently bursts through the integuments of the seed, and
extends itself as a root; the other end produces a scaly plu-
mula, which in time forms the stem. The great mass of the
kernel is supposed by M. Richard to be an enlarged radicle.
I, however, see no reason for calling the two-lobed part of the
embryo (Plate VI. fig. 17. c) a plumula; it is merely coty-
ledons. An inequality of cotyledons is the most unusual

190 ORGANOGRAPHY. BOOK I.

circumstance with dicotyledons, and forms a distinct approach
to the structure of monocotyledons : it occurs in Trapa and
Sorocea, in which they are extremely disproportionate. In
Cycas they are also rather unequal ; but the structure of that
plant is essentially dicotyledonous.

The embryo of Monocotyledons (Plate VI. fig. 1. B. &c.)
is usually a solid, cylindrical, undivided, homogeneous body,
slightly conical at each extremity, with no obvious distinction
of radicle, plumula, or cotyledons. In germination the upper
end swells and remains within the testa (fig. 10. C. b, &c.) ;
the lower lengthens, opens, and emits from within one or
more radicles ; and a thread-like green body is protruded
from the upper part of the portion, which is lengthened beyond
the testa. Here the portion remaining within the testa is a
single cotyledon ; that which lengthens, producing radicles
from within its point, is the cauliculus and radicle ; and the
thread-like protruded green body is the plumula. If this is
compared with the germination of dicotyledons, an obvious
difference will be at once perceived in the manner in which
the radicles are produced : in monocotyledons they are
emitted from within the substance of the radicular extremity,
and are actually sheathed at the base by the lips of the pas-
sage through which they protrude ; while in dicotyledons they
appear at once from the very surface of the radicular extre-
mity, and consequently have no sheath at their base. Upon
this difference in economy, Richard proposed to substitute
the term Endorhizae for monocotyledons, and Exorhizae for
dicotyledons. Some consider the former less perfect than
the latter ; endorhizae being involute, or imperfectly developed,
exorhizae evolute, or fully developed. Dumortier adds to
these names endophyllous and exophyllous; because the young
leaves of monocotyledons are evolved from within a sheath
{coleopliyllum or coleoptilum), while those of dicotyledons
are always naked. The sheath at the base of the radicle of
monocotyledons is called the coleorhiza by Mirbel. Another
form of monocotyledonous embryo is that of Aroideae and
their allies, in which the plumula is not so intimately com-
bined with the embryo as to be undistinguishable, but is indi-
cated externally by a little slit above the base (Plate VI.

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 191

fig. 6. B. e), within which it lies until called into developement
by germination.

The exceptions to what has been now described ought, like
those of dicotyledons, rather to be called remarkable modi-
fications. Much stress has been laid upon them by several
writers, who have thought it requisite to give particular names
to their parts. To me, however, it appears far more advisable
to explain their analogies without the unnecessary creation of
new and bad names. In Graminece (Plate VI. fig. 4.) the
embryo consists of a lenticular body lying on the outside of
the base of the albumen on one side, and covered on its inner
face by that body, and on its outer face by the testa : if viewed
on the face next the testa, a slit will be observed of the same
nature as that in the side of the embryo of Aroideee ; opening
this cleft a small conical projection is discovered, pointing
towards the apex of the seed. If the embryo be then divided
vertically through the conical projection, it will be seen that
the latter (c) is a sheath including other little scales resem-
bling the rudiments of leaves ; that that part of the embryo
which lies next the albumen (d), and above the conical body, is
solid ; and that the lower extremity of the embryo (e) contains
within it the indication of an internal radicle, as in other
monocotyledons. In this embryo it is to be understood that
the conical projection is the plumul 'a ,• that part of the embryo
lying between it and the albumen, a single scutelliform coty-
ledon ; and the lower point of the embryo, the radicle. In
wheat there is a second small cotyledon on the outside of
the embryo, inserted a little lower down than the scutelliform
cotyledon. This last is called scutellwn by Gaertner, who
considered it of the nature of vitellus. The late M. Richard
considered the scutelliform cotyledon a particular modification
of the radicle, which he called hypoblastus ; the plumula a form
of cotyledon, called blastns ; the anterior occasional cotyledon
a peculiar appendage, named epiblastus ; and the radicle a pro-
tuberance of the cauliculus, called radiadoda. He further, in
reference to this peculiar opinion, termed embryos of this
description macropodous. In these ideas, however, Richard
was manifestly wrong, as is now well known.

From what has been stated, it is apparent that dicoty-

192 ORGANOGRAPHY. BOOK I.

ledons are not absolutely characterised by having two coty-
ledons, nor monocotyledons by having only one. The real
distinction between them consists in their endorhizal or
exorhizal germination, and in the cotyledons of dicotyledons
being opposite or verticillate, while they are in monocoty-
ledons solitary or alternate. Some botanists have, therefore,
recommended the substitution of other terms in lieu of those
in common use. M. Cassini suggests isodynamous or iso-
brious for dicotyledons, because their force of developement
is equal on both sides ; and anisodynamous or anisobrious for
monocotyledons, because their force of developement is
greater on one side than on the other. Another writer,
M. Lestiboudois, would call dicotyledons exoj)tiles, because
their plumula is naked ; and monocotyledons endoptiles,
because their plumula is enclosed within the cotyledons ; but
there seems little use in these proposed changes, which are
moreover as open to objections as the terms in common use.

The Acotyledonous embryo is not exactly, as its name
seems to indicate, an embryo without cotyledons ; for, in that
case, Cuscuta would be acotyledonous. On the contrary, it
is an embryo, which does not germinate from two fixed in-
variable points, namely, the plumula and the radicle, but
indifferently from any point of the surface; as in some of the
Arum tribe, and in all flowerless plants.

For further illustrations of the embryo, consult Plate VI.
and the explanation of its figures.

The direction of the embryo is either absolute or relative.
Its absolute direction is that which it has independently of
the parts that surround it. In this respect it varies much in
different genera ; it is either straight (Plate VI. fig. 5.), ar-
cuate (fig. 9.), or falcate, uncinate, or coiled up (fig. 8.) (cy-
clical), folded up, spiral (fig. 19.), or bent at right angles
(Plate V. fig. 28.) (gromonical, Link), serpentine, or in figure
like the letter S (sigmoid).

Its relative position is determined by the relation it bears
to the chalaza and micropyle of the seed ; or, in other words,
upon the relation that the integuments, the raphe, chalaza,
hilum, micropyle, and radicle bear to each other. If the sacs
of the ovulum are in no degree inverted, but have their com-

CHAP. II. COMPOUND ORGANS IN FLOWERING PLANTS. 193

mon point of origin at the hilum, there being (necessarily)
neither raphe nor chalaza visible, the radicle will in that case
be at the extremity of the seed most remote from the hilum,
and the embryo inverted with respect to the seed, as in Cistus,
Urtica, and others, where it is said to be antilropal. But if
the ovulum undergoes that remarkable extension of one side
already described in speaking of that organ, in which the sacs
are so inverted that their orifice is next the hilum, and their
base at the apex of the ovulum, then there will be a raphe
and chalaza distinctly present; and the radicle will, in the seed,
be at the end next the hilum, and the embryo will be erect
with respect to the seed, or orthotropal, as in the apple,
plum, &c. On the other hand, supposing that the sacs of
the embryo suffer only a partial degree of inversion, so that
their foramen is neither at the one extremity nor the other,
there will be a chalaza and a short raphe ; and the radicle will
point neither to the apex nor to the base of the seed, but the
embryo will lie, as it were, across it, or be heterotropal, as is
the case in the primrose. When an embryo is so curved as
to have both apex and radicle presented to the hilum, as in
Reseda, it is amphitropal.

In the words of Gsertner, an embrvo is ascending when its
apex is pointed to the apex of the fruit ; descending, if to the
base of the fruit ; centripetal, if turned towards the axis of
the fruit ; and centrifugal, if towards the sides of the fruit :
those embryos are called wandering, or vagi, which have no
evident direction.

The cotyledons are generally straight, and placed face to
face ; but there are numberless exceptions to this. Some are
separated by the intervention of albumen (Plate VI. fig. 11.);
others are naturally distant from each other without any
intervening substance. Some are straight, some waved,
others arcuate or spiral. When they are folded with their
back upon the radicle, they are called incumbent ,- if their
edges are presented to the same part, they are accumbent :
terms chiefly used in speaking of Cruciferae.

194 ORGANOGRAPHY. BOOK I.

15. Of Naked Seeds.

By naked seeds has been understood, by the school of Lin-
naeus, small seed-like fruit, like that of Labiatae, Boraginea?,
grasses, and Cyperaceae. But as these are distinctly covered
by pericarpia, as has been shown above, the expression in the
sense of Linnaeus is obviously incorrect, and is now abandoned.
Hence it has been inferred that there is no such thing in
existence as a naked seed ; that is to say, a seed which bears
on its own integuments the organ of impregnation. To this
proposition botanists had assented till the year 1825, when
Mr. Brown demonstrated the existence of seeds strictly
naked ; that is to say, from their youngest state destitute of
pericarpium, and receiving impregnation through their inte-
guments without the intervention of style or stigma, or any
stigmatic apparatus. That learned botanist has demonstrated
that seeds of this description are uniform in Coniferae and Cy-
cadeae, in which no pericarpial covering exists. But we have no
knowledge at present of such an economy obtaining in other
plants, as a constant character. It does however happen,
as the same observer has pointed out, that in particular
species the ovarium is ruptured at an early period by the
ovula, which thus, when ripe, become truly naked seeds ; re-
markable instances of which occur in Ophiopogon spicatus,
Leontice thalictroides, and Peliosanthes Teta*

195

CHAPTER III.

OF THE COMPOUND ORGANS IN FLOWERLESS PLANTS.

"We have now passed in review all the different organs which
exist in the most perfectly formed plants ; that is to say, in
those whose reproduction is provided for by the complicated
apparatus of sexes and of fertilising organs. Let us next
proceed to consider those lower tribes, some of which are
scarcely distinguishable from animals, where there is no evi-
dent trace of sexes, in which nothing constructed like seeds
is to be detected, and which seem to have no other provision
made for the perpetuation of their races than a dissolution
of their cellular system. In what I may have to say about
them, I shall not, however, do any thing more than give
a mere enumeration and description of their organs. All
speculative considerations are in this case left out of view :
those who wish to be informed upon such points may consult
the " Introduction to the Natural System of Botany."

1. Ferns.

Filices, or ferns, are plants consisting of a number of
leaves or fronds, as they are called, attached to a stem which
is either subterraneous or elongated above the ground, some-
times rising like a trunk to a considerable height. They are
the largest of known vegetables in which no organs of fructi-
fixation analogous to those of phaenogamous plants have been
discovered. Their petioles, or stipes (rac/iis, W. ; peridroma,
Necker), consist of sinuous strata of indurated, very compact,
woody fibre, connected by cellular tissue ; and the wood of
those which have arborescent trunks is formed by the cohe-
sion of the bases of such petioles round a hollow or solid
cellular axis. The organs of reproduction are produced from
the back or under side of the fronds. In Poli/podiacece, or

o 2

196 ORGANOGRAPHY. BOOK I.

what are more commonly called dorsiferous ferns, they ori-
ginate, either upon the cuticle or from beneath it, in the form
of spots at the anastomoses, margins, or extremities of the
veins. As they increase in growth they assume the appear-
ance of small heaps of granules, called sorts if examined
beneath the microscope these granules, commonly called cap-
sules, thecce, or conceptacles, are found to be little brittle com-
pressed bags formed of cellular membrane, partially sur-
rounded by a thickened longitudinal ring {gyrus, annidus,
gyroma), which at the vertex loses itself in the cellularity of
the membrane, and at the base tapers into a little pedicel ;
the thecae burst with elasticity by aid of their ring, and emit
minute particles named sporules, from which new plants are
produced; as from seeds, in vegetables of a higher order.
Interspersed with these thecae are often intermixed articulated
hairs ; and, in those genera in which the thecae originate
beneath the cuticle, the sori, when mature, continue covered
with the superincumbent portion of the cuticle, which is then
called the indusium or involucnim {membramda, Necker; glan-
dules squamosa:, Guettard). In Trichomanes and Hymeno-
phyllum the thecae are seated within the dilated cup-like
extremities of the lobes of the frond, and are attached to the
vein which passes through their axis, which is then called
their receptacle. In another tribe, called Gleichenece, the
thecae have a transverse complete, instead of a vertical incom-
plete ring, and they are nearly destitute of pedicels ; in a third
tribe the sori occupy the whole of the under surface of the
frond, which becomes contracted, and wholly alters its appear-
ance : the thecae have no ring, and the cellular tissue of their
membrane is not reticulated, but radiates regularly from the

apex.

In these it has been in vain endeavoured to discover traces
of organs of fecundation. Nevertheless, as it was difficult for
sexualists to believe that plants of so large a size were desti-
tute of such organs, it has been considered indispensable
that they should be found ; and, accordingly, while all seem
to agree in considering the thecae as female organs, a variety
of other parts have been dignified by the title of male organs :
thus, Micheli and Hedwig found them in certain stipitate

CHAP. III. COMPOUND ORGANS IN FLOWERLESS PLANTS. 197

glands of the frond ; Stashelin, Hill, and Schmidel, in the
elastic ring ; Koelreuter, in the indusium ; Gleichen, in the
stomata ; and Von Martius, in certain membranes enclosing
the spiral vessels. None of these opinions are now adopted.

In Ophioglosseae, a remarkable tribe of ferns, the fertile
frond is rolled up in two lines parallel with its axis or midrib,
and at maturity opens regularly by transverse valves along
its whole length, emitting a fine powder, which, when magni-
fied, is found to consist of particles of the same nature as the
sporules found in the thecae of other ferns : here there are no
thecae, the metamorphosed frond probably performing their
functions. Such is my view of the structure of Ophioglosseae ;
but by other botanists it is described as a dense spike of tWo-
valved capsules, dehiscing transversely.

2. EquisetacecB.

In these the organs of reproduction are arranged in an
amentum, consisting of scales bearing on their lower surface
an assemblage of cases, called t/iecce, follicidi, or i?ivolucrai
which dehisce longitudinally inwards. In these thecae are
contained two sorts of granules ; the one very minute and
lying irregularly among a larger kind, each of which is
wrapped in two filaments, fixed by their middle, rolled spir-
ally, having either extremity incrassated, and uncoiling with
elasticity. By Hedvvig the apex of the larger granules was
supposed to be a stigma, and the thickened ends of the fila-
ments anthers, the small granules being the pollen. At any
rate it is certain that the larger granules, round which the
elastic filaments are coiled, are the reproductive particles.

3. Lycopodiaceoe .

These are leafy plants with the habit of gigantic mosses.
Their leaves and stem have the same structure as those plants,
except that the former are sometimes provided with stomata,
and the latter with vessels. Their organs of reproduction
are of two kinds : the one kidney-shaped two-valved cases,
called thecce, conceptacles, or capsules, destitute of internal
divisions, and filled with minute pow<ler-like grannies, which,
in consequence of lateral compression, from being spherical,

o 3

198 ORGANOGRAPHY. BOOK I.

acquire the figure of irregular polygons ; the other three
or four-valved thecae, of a similar appearance, containing
three or four roundish fleshy bodies, each of which is at
least fifty times larger than the granules contained in the
first kind of theca, and is said by Brotero to burst with
elasticity, — an observation which requires verification. The
first kind of theca is found in all species of Lycopodiaceae ;
the second is only found simultaneously in a few. The con-
tents of both are believed to be sporules ; but no satisfactory
explanation has yet been offered of the cause of their differ-
ence in size, and probably also in structure. I would suggest
that the powder-like grains are true sporules, and that the
large ones are buds or viviparous organs, as has already been
stated by Haller and Willdenow. A writer in the " Transac-
tions of the Linnean Society " has figured and described the
growth of the larger grains of Lycopodium denticulatum,
and he considers that they exhibit the germination of a dico-
tyledonous plant ; but, independently of any mistrust which
may attach to the account, it is obvious enough that his own
drawings and description represent a mode of germination
analogous, not to that of dicotyledons, but rather to that of
monocotyledons, but also reducible to the laws which govern
the incipient vegetation of a bud.

The powder-like sporules are inflammable, and have been
supposed by Haller, Linnaeus, and others to be pollen, while
the larger have been considered seeds ; and to a part of the
surface of the theca the office of stigma has been attributed.
The thecae themselves have been fancied to be male apparatus
by Kcelreuter and Gaertner.

4. Marsileacece.

This very curious little order consists of plants differing
from each other so much, that, although consisting of only
four genera, it is necessary to subdivide it into two distinct
tribes. As I have never had an opportunity of examining
these plants in a fresh state, I beg to cite the observations of
M. Adolphe Brongniart, who appears to have given them an
especial attention.

In Marsileaceae, properly so called, says this botanist,

CHAP. HI. COMPOUND ORGANS IN FLOWERLESS PLANTS. 199

which consist of the two genera, Marsilea and Pilularia, we
remark at the base of the leaves certain involucra of a cori-
aceous, thick substance, and either indehiscent or opening
into several valves, divided internally into cells by mem-
branous dissepiments. Each of these cells contains two
other cells, inserted on a part of its inner coating : of these
one sort is ovaria, or rather grains, composed of an external
transparent membrane which swells with humidity, and be-
comes a thick layer of gelatinous substance ; the other is an
internal, hard, and coriaceous membrane, of a yellow colour,
and indicating on its surface a particular point, through which
the embryo is protruded upon being developed. The other
organs are more numerous, and consist of membranous bags,
slightly swelling from humidity, opening at the summit, and
enclosing in the middle of a gelatinous mucus many spherical
globules, which are much smaller than the grains. Their
leaves develope in a gyrate manner, like ferns.

In the second section of this order, to which the name
Salvinieae may be given, and which consists of the genera
Salvinia and Azolla, we find at the base of the leaves mem-
branaceous involucra of two sorts, and containing different
organs. One kind includes a bunch of grains of an ovate
figure, containing only one embryo in Salvinia, and from six
to nine in Azolla. The integument of these grains is thin,
reticulated, brownish, and does not swell in water like that of
true Marsileaceas : the pedicel which supports them appears,
in Salvinia, to communicate laterally with the grain. The
other involucra, which are supposed to be male organs, have
a very complex structure, and have been well observed by
Mr. Brown. In Salvinia they contain a great number of
spherical granules, attached by long pedicels to a central
column : these granules are much smaller than the grains ;
their surface is reticulated in like manner, and they do not
burst by the action of water. All the species are floaters, and
their leaves are not gyrate when developing, but are more
like those of Lycopodiaceae.

Thus far M. Brongniart. With respect to the nature of
these two kinds of grains or granules, it has been thought, as
is obvious from the foregoing remarks, that the smaller are

o 4

200 ORGANOGRAPHY. BOOK I.

males and the larger females ; which has been supposed to be
proved by the experiments of M. Savi of Pisa. This observer
introduced into different vessels, 1. the granules; 2. the
grains ; and, 3. the two intermixed. In the two first nothing
germinated ; in the third the grains floated to the surface and
developed themselves perfectly. These observations have,
however, been repeated by M. Duvernoy without the same
result. And it must be remarked that, if the functions of
these grains and granules be what has been attributed to
them, the male power of action and the female powers of
reception cannot exist till both are discharged from the mem-
branes or involucra, in which they are contained and placed
in contact in water. Is it impossible that the granules or sup-
posed male organs should be only grains in an imperfectly
developed condition ?

5. Mosses.

In the structure of these plants neither vessels nor woody
fibre are employed ; and from henceforward those organs
disappear from the organisation of all the tribes to be
noticed. Their stem consists of elongated cellular tissue,
from which arise leaves composed, in like manner, entirely of
cellular tissue without woody fibre ; the nerves, as they are
called, or, more properly speaking, costae, which are found in
many species, being formed by the approximation of cellules
more elongated than those that constitute the principal part
of the leaf. The leaves are usually a simple lamina ; but in
Polytrichum and a few others they are furnished with little
plates, called lamellae, running parallel with the leaf, and ori-
ginating from the upper surface. At the summit of some of
the branches of many species are seated certain organs, which
are called male flowers, but the true nature of which is not
understood. They are possibly organs of reproduction of a
particular kind, as both Mees and Haller are recorded to
have seen them produce young plants.

Agardh says they have only the form of male organs ; and
that they really appear to be gemmulae. By Hedwig they
were called spermatoajstidia.

But, whatever may be the nature of these organs, there is

CHAP. III. COMPOUND ORGANS IN FLOWERLESS PLANTS. 201

no doubt of the reproductive functions of the contents of what
is named the theca or capsule, which is a hollow urn-like body,
containing sporulcs : it is usually elevated on a stalk, named
the seta, with a bulbous base, surrounded by leaves of a dif-
ferent form from the rest, and distinguished by the name of
pcrichcctial leaves. If this theca be examined in its youngest
state, it will be seen to form one of several small sessile ovate
bodies (pistillidia, Agardh ; prosphj/ses, Ehrhart; adductores,
Hedwig), enveloped in a membrane tapering upwards into a
point ; when abortive they are called paraphyses. In process
of time the most central of these bodies swells, and bursts its
membranous covering, of which the greatest part is carried
upwards on its point, while the seta on which the theca is sup-
ported lengthens. This part, so carried upwards, is named
the calyptra : if it is torn away equally from its base, so as to
hang regularly over the theca, it is said to be mitriform ; but
if it is ruptured on one side by the expansion of the theca,
which is more frequently the case, it is denominated dimidiate.
When the calyptra has fallen off or is removed, the theca is
seen to be closed by a lid terminating in a beak or rostrum:
this lid is the operadum, and is either deciduous or persistent.
If the interior of the theca be now investigated, it will be
found that the centre is occupied by an axis, called the co-
lumella; and that the space between the columella and the
sides of the theca is filled with sporules. The brim of the
theca is furnished with an elastic external ring, Or annidus,
and an interior apparatus, called the peristomium: this is
formed of two distinct membranes, one of which originates
in the outer coating of the theca, the other in the inner coat;
hence they are named the outer and inner peristomia. The
nature of the peristomium is practically determined at the
period of the maturity of the theca. At this time both mem-
branes are occasionally obliterated ; but this is an unfrequent
occurrence : sometimes one membrane only remains, either
divided into divisions, called teeth, which are always some
multiple of four, varying from that number as high as eighty,
or stretching across the orifice of the theca, which is closed up
by it ; this is sometimes named the tympanum. Most fre-
quently both membranes are present, divided into teeth, from

202 ORGANOGRAPHY. BOOK I.

differences in the number or cohesion of which the generic
characters of mosses are in a great measure formed. For
further information upon the peristomium I must refer to
Mr. Brown's remarks upon Lyellia, in the 12th volume of the
Linnean Transactions.

The interior of the theca is commonly unilocular; but in
some species, especially of Polytrichum, it is separated into
several cells by dissepiments originating with the columella.

If at the base of the theca there is a dilatation or swelling
on one side, this is called a struma ; if it is regularly lengthened
downwards, as in most of the Splachnums, such an elongation
is called an apophysis.

The only material exception to this description of Musci
exists in Andraea, in which the theca is not an urn-like case,
but splits into four valves, cohering by the operculum and
base. From the foregoing description, it will be apparent
that the organs of reproduction of mosses cannot be said to
be analogous to the parts of fertilisation of perfect plants.
I must not, however, omit the opinion of other botanists upon
this subject. The office of males has been supposed by
Micheli to be performed by the paraphyses ; by Linnaeus and
Dillenius, by the theca? ; by Palisot de Beauvois, by the spo-
rules ; by Hill, by the peristomium ; by Kcelreuter, by the
calyptra; by Gaertner, by the operculum; and, finally,
Hedwig has supposed the males to be the staminidia. The
female organs were thought by Dillenius and Linnaeus to be
assemblages of staminidia; by Micheli and Hedwig, the young
thecae ; and, by Palisot de Beauvois, the columella.

For some suggestions as to the analogy that is borne
between the organs of mosses and of other plants, see Mor-
phology hereafter.

6. Hepaticce.

These differ remarkably from each other in the modi-
fications of their organs of reproduction, while they have a
striking resemblance in their vegetation. This latter, which
bears the name of frond or thallus, is either a leafy branched
tuft, as in mosses, with the cellular tissue particularly large,
and the leaves frequently furnished with lobes, and appendages

•CHAP. III. COMPOUND ORGANS IN FLOWERLESS PLANTS. 203

at the base, called stipida? or amphigastria ; or a sinuous flat
mass of green vegetable matter lying upon the ground.

In Jungermannia, that part which is most obviously con-
nected with the reproduction of the plant, and which bears an
indisputable analogy to the theca of mosses, is a valvular
brown case, called the capsule or conceptacle, elevated upon
a white cellular tender seta, and originating from a hollow
sheath or pericheetium arising among the leaves. This con-
ceptacle contains a number of spiral loose fibres (elateres),
enclosed in membranous cases, among which sporules lie
intermixed : when fully ripe, the membranous case usually
disappears, the spiral fibres, which are powerfully hygro-
metric, uncurl, and the sporules are dispersed. When young,
the conceptacle is enclosed in a membranous bag, which it
ruptures when it elongates, but which it does not carry
upwards upon its point, as mosses carry their calyptra. This
part, nevertheless, bears the latter name.

Besides the conceptacles of Jungermannia, there are two
other parts which are thought to be also intended for the
purpose of reproduction : of these one consists of spherical
bodies, scattered over the surface of some parts of the frond,
and containing a granular substance; the other is a hollow
pouch, formed out of the two coats of a flat frond, and produc-
ing from its inside, which is the centre of the frond, numerous
granulated round bodies, which are discharged through the
funnel-shaped apex of the pouch.

There are also other bodies situated in the axillae of the
perichaetial leaves, called anthers, (or spermatocystidia, by
Hedwig, and staminidia, by Agardh,) which " are externally
composed of an extremely thin, pellucid, diaphanous mem-
brane," — " within they are filled with a fluid, and mixed
with a very minute granulated substance, generally of an
olivaceous or greyish colour : this, when the anther has
arrived at a state of maturity, escapes through an irregularly
shaped opening, which bursts at the extremity."

In Monoclea and Targionia organs very analogous to those
of Jungermannia are formed for reproduction.

In March ant i a the frond is a lobed flat green substance,
not dividing into leaves and stems, but lying horizontally upon

204 ORGANOGRAPHY. BOOK I.

the ground, and emitting roots from its under surface. The
organs of reproduction consist, Jirstly, of a stalked fungilliform
receptacle, carrying on its apex a calyptra, and bearing thecal
on its under side ; secondly, of a stalked receptacle, plane on
the upper surface, with oblong bodies imbedded vertically in
the disk, and called anthers ; thirdly, " of little open cups
(cystula), sessile on the upper surface of the fronds, and con-
taining minute green bodies [gemmce), which have the power
of producing new plants." The first kind is usually con-
sidered a female flower, its sporules intermixed with elateres :
the second male, and the third viviparous apparatus. In
the opinion of many modern botanists, the granules of both
the two first are sporules : about the function of the last there
is no difference of opinion.

In Anthoceros, while the vegetation is the same as in Mar-
chantia, the organs of reproduction are very different. They
consist of a subulate column, issuing from a perichaetium
perpendicular to the frond, and opening halfway into two
valves, which discover, upon opening, a subulate columella,
to which sporules are attached without any elateres. There
are also cystulae upon the frond, in which are enclosed pedi-
cellate, reticulated bodies, called anthers.

Spharocarpus consists of a delicate roundish frond, on the
surface of which are clustered several cystulae, each of which
contains a transparent spherule filled with sporules.

In Riccia the spherules are not surrounded by cystulae, but
immersed in the substance of the frond.

7. Lichenes.

These have a lobed frond or thallus, the inner substance
of which consists wholly of reproductive matter, which breaks
through the upper surface in certain forms, which have
been called fructification. These forms are twofold ; firstly,
shields, or scutella, which are little coloured cups or lines with
a hard disk, surrounded by a rim, and containing asci, or
tubes filled with sporules : and, secondly, soredia, which are
heaps of pulverulent bodies scattered over the surface of the
thallus. The nomenclature of the parts of lichens has been
excessively extended beyond all necessity : it is, however,

CHAP. III. COMPOUND ORGANS IN FLOWERLESS PLANTS. 205

absolutely indispensable that it should be fully understood by
those who wish to read the systematic writers upon the
subject : —

1. Apothecia, are shields of any kind.

2. Scutellum, is a shield with an elevated rim, formed by the

thallus. Orbilla is the scutellum of Usnea.

3. Pelta, is a flat shield without any elevated rim, as in the

genus Peltidea.

4. Tubcrculum, or cephalodium, is a convex shield without an

elevated rim.

5. Trica, or Gyroma, is a shield, the surface of which is

covered with sinuous concentric furrows.

6. Lirella, is a linear shield, such as is found in Opegrapha,

with a channel along its middle.

7. Patellula, an orbicular sessile shield, surrounded by a rim

which is part of itself, and not a production of the thallus,
as in Lecidea. D. C.

8. Globulus, a round deciduous shield, formed of the thallus,

and leaving a hollow when it falls off, as in Isidium. D. C.

9. Pilidium, an orbicular hemispherical shield, the outside of

which changes to powder, as in Calycium. D. C.

10. Podetia, the stalk-like elongations of the thallus, which

support the fructification in Cenomyce.

11. Scypha [pplariuwy Neck.)> is a cup-like dilatation of the

Podetium, bearing shields on its margin.

12. Soredia (globtdi, glomeruli), are heaps of powdery bodies

lying upon any part of the surface of the thallus ; the
bodies of which the soredia are composed are called
conidia by Link, and propagula by others.

13. Cystula, or Cistella, a round closed apothecium, filled with

sporules, adhering to filaments which are arranged like
rays around a common centre, as in Sphaerophoron.

14. Pidvinuli, are spongy, excrescence-like bodies, sometimes

rising from the thallus, and often resembling minute
trees, as in Parmelia glomulifera. Greville.

15. Cyp/iellce, are pale tubercle-like spots on the under surface

of the thallus, as in Sticta. Grev.

16. Lacunce, are small hollows or pits on the upper surface of

the thallus. Grev.

206 ORGANOGRAPHY. BOOK I.

17. Nucleus pr oli gems, is a distinct cartilaginous body, coming

out entire from the Apothecia, and containing the spo-
rules. Grev.

18. Lamina proligcra, is a distinct body containing the

sporules, separating from the apothecia, often very convex
and variable in form, and mostly dissolving into a gela-
tinous mass. Grev.

19. Fibrillar, are the roots.

20. Excipuhis, is that part of the thai! us which forms a rim

and base to the shields.

21. Nucleus, is the disk of the shield which contains the

sporules and their cases.

22. Asci, are tubes, in which the sporules are contained while

in the nucleus.

23. Thallodes, is an adjective used to express an origin from

the thallus: thus, margo thallodes signifies a rim formed
by the thallus, excipulus thallodes a cup formed by the
thallus.

24. Lorulum, is used by Acharius to express a filamentous,

branched thallus.

25. Crusta is a brittle crustaceous thallus.

26. Gongyli, are the granules contained in the shields, and

have been thought to be the sporules by which lichens
are propagated : but this is doubted by Agardh.

8. Algce and Characece.

These, with fungi, constitute the lowest order of vegetable
developement : they vary in size from mere microscopic ob-
jects to a large size, and are composed of cellular tissue in
various degrees of combination ; some are even apparently ani-
mated, and thus form a link between the two great kingdoms
of organised matter. Their sporules are either scattered
through the general mass of each plant, or collected in cer-
tain places which are more swollen than the rest of the stem,
and sometimes resemble the pericarpia of perfect plants.
The terms used in speaking of the parts of Algae are the
following : —

CHAP. III. COMPOUND ORGANS IN FLOWERLESS PLANTS. 207

1. Gongylits ; a round hard body, which falls off the mother

plant, and produces a new individual : this is found in
Fuci. w.

2. Thallns ; the plant itself.

3. Apothecia ; the cases in which the organs of reproduction

are contained.
4s Peridiola, Fr. ; the membrane by which the sporules are
immediately covered.

5. Gramda ; large sporules, contained in the centre of many

Algae ; as in Gloionema of Greville. Crypt. Jf.. 6. 30.

6. Pseudoperithecium j "i terms used by Fries to express such

7. Pseudokymeniwn i J- coverings of Sporidia as resemble

8. Pseudoperidhim ; J in figure the parts named peri-

thecium, hymenium, and peridium in other plants: see
those terms.

9. Sporidia; granules which resemble sporules, but which

are of a doubtful nature. It is in this sense that Fries

declares that he uses the word : vide Plant, homonom.
p. 294.

10. Phycomater, Fries; the gelatine in which the sporules of

Byssaceae first vegetate.

11. VesiculcE; inflations of the thallus, filled with air, by means

of which the plants are enabled to float.

12. Hupha, Willd. ; the filamentous, fleshy, watery thallus of

Byssacese.

13. Nucula ; one of the apothecia of Characeas; described by

Greville to be a sessile, oval, solitary, spirally striated
body, with a membranous covering, and the summit
indistinctly cleft into five segments, containing sporules.

14. Globules; the second organ of Characea? ; the excellent

observer last quoted describes it as a minute round body
of a reddish colour, composed externally of a number of
triangular (always ?) scales, which separate, and produce
its dehiscence. The interior is filled with a mass of
elastic, transversely undulated filaments. The scales are
composed of radiating hollow tubes, partly filled with
minute coloured granules, which freely escape when the
tubes are injured : their nature is wholly unknown, and,
I believe, hitherto unnoticed.

208 ORGANOGRAPHY.

BOOK I»

15. Coniocystct; tubercle-like closed apothecia, containing a
mass of sporules.

9. Fungi.

The structure of these plants is yet more simple than that
of Algae, consisting of little besides cellular tissue, among
which sporules lie scattered. Some, of the lowest degree of
developement, are composed only of a few cellules, of which
one is larger than the rest, and contains the sporules; others
are more highly compounded, consisting of myriads of cellules,
with the sporules lying in cases, or asci. Notwithstanding the
extreme simplicity of these plants, writers upon fungi have
contrived to multiply the terms relating to them in a remark-
able manner. The following are all with which I am ac-
quainted : —

1. The pileus, or cap, is the uppermost part of the plant of

an Agaricus, and resembles an umbrella in form.

2. The stipes, is the stalk that supports the pileus.

3. The volva, or wrapper, is the involucrum-like base of the

stipes of Agaricus. It originally was a bag enveloping
the whole plant, and was left at the foot of the stipes
when the plant elongated and burst through it.

4. The velum, or veil, is a horizontal membrane, connecting

the margin of the pileus with the stipes : when it is
adnate with the surface of the pileus, it is a velum
universale : when it extends only from the margin of the
pileus to the stipes, it is a velum partiale.

5. The annulus, is that part of the veil which remains next

the stipes, which it surrounds like a loose collar.

6. Cortina, is a name given to a portion of the velum which

adheres to the margin of the pileus in fragments.

7. The hymenium, is the part in which the sporules imme-

diately lie ; in Agaricus, it consists of parallel plates,
called lamellce, or gills; these are adnate with the stipes,
when the end next it cohere with it: when they are
adnate, and at the same time do not terminate abruptly
at the stipes, but are carried down it more or less, they
are decurrent ; if they do not adhere to the stipes, they
are said to he free.

CHAP. III. COMPOUND ORGANS IN FLOWEIILESS PLANTS. 209

8. Stroma, is a fleshy body to which flocci are attached ; as

in Isaria and Cephalotrichum.

9. Flood, are woolly filaments found mixed with sporules in

the inside of many Gastromyci. The same name is
also applied to the external filaments of Byssaceae.

10. Orbicidus, is a round flat hymenium contained within the

peridium of some fungi ; as Nidularia. W.

11. Nucleus, is the central part of a perithecium.

12. Sporangium, is the external case of Lycoperdon and its

allies.

13. Sporangiola, are cases containing sporidia.

14. Perithecium, is a term used to express the part which

contains the reproductive organs of Sphaeria and its
co-ordinates.

15. Peridium, is also a kind of covering of sporidia; peridio-

Iujh is its diminutive.

16. Ostiolum, is the orifice of the perithecium of Sphaeria.

17. Sphcerula, is a globose peridium, with a central opening,

through which sporidia are emitted, mixed with a gela-
tinous pulp.

18. Capillitium, is a kind of purse or net, in which the sporules

of some fungi are retained ; as in Trichia. W.

19. Trichidium, or pecten, is a tender, simple, or sometimes

branched hair, which supports the sporules of some fungi;
as Geastrum. W.

20. Asci, are the tubes in which the sporidia are placed;

ascelli or thecce are the same thing.

21. Sporidia, are the immediate covering of sporules; spo-

ridiola are sporules.

22. Thallus, or thalamus, is the bed of fibres from which many

fungi arise.

23. Mycelia, are the rudiments of fungi, or the matter from

which fungi are produced.

210

BOOK II.

PHYSIOLOGY J OR, PLANTS CONSIDERED IN A STATE
OF ACTION.

GENERAL CONSIDERATIONS.

We have thus far considered plants as inert bodies, having
certain modifications of structure, and formed upon a plan,
the simplicity and uniformity of which is among the most
beautiful proofs of the boundless power and skill of the Deity.

Our next business is to enquire into the nature of their
vital actions, and to consider those phenomena in which the
analogy that undoubtedly exists between plants and animals
is most striking; in a word, to make ourselves acquainted
with the exact nature of the laws of vegetable life.

In explaining these things, it is not my purpose to notice all
the different speculations that ingenious men have from time
to time brought forward : for this would be incompatible with
the plan of my work, and would be far more curious than
useful. On the contrary, I propose, in the first place, to give
a summary exposition of the principal phenomena of vegeta-
tion, and then to support the statement by a detailed account
of the more important proofs of all doubtful points.

I am the more anxious that this should be understood,
because I know how prone the world is to misconstruction :
I therefore beg it to be remembered, that when particular
opinions are here passed over in silence, it is because I do
not think them sufficiently proved to be recorded consistently
with the plan I have prescribed to myself.

If we place a seed, — that of an apple, for instance, — in
earth at the temperature of 32° Fahr., it will remain inactive
till it finally decays. But if it is placed in moist earth above

BOOK II. GENERAL CONSIDERATIONS. 211

the temperature of 32°, and screened from the action of light,
its integument gradually imbibes moisture and swells, oxygen
is absorbed, carbonic acid expelled, and the vital action
of the embryo commences. It elongates downwards by the
radicle, and upwards by the cotyledons; the former pene-
trating the soil, the latter elevating themselves above it,
acquiring a green colour by the deposition of carbon absorbed
from the atmosphere in the light, and unfolding in the form of
two opposite roundish leaves. This is the first stage of vege-
tation : the young plant consists of little more than cellular
tissue ; only an imperfect developement of vascular and fibrous
tissue being discoverable, in the form of a sort of cylinder of
bundles, lying just in the centre. The part within the cylin-
der, at its upper end, is now the medulla, without it the
bark ; while the cylinder itself is the preparation for the
medullary sheath, and consists of vertical fibres passing
through cellular tissue, which separates them horizontally in
every direction.

The young root is now absorbing from the earth its nutri-
ment, which passes up to the summit of the plant by the
cellular substance of the medulla, and is thence impelled into
the cotyledons, where it is aerated and evaporated : such of
it as is not fixed in the cotyledons passes down through the
bark into the root.

Forced onwards by the current of sap, which is continually
impelled upwards from the root, the plumula next ascends in
the form of a little twig, at the same time sending roots in the
form of fibres downwards in the centre of the radicle, which
become the earliest portion of wood that is deposited : these
fibres, by their action, now compel the root to emit little rami-
fications. Previously to the elongation of the plumula its apex
has acquired the rudimentary state of a leaf: this continues
to develope as the plumula elongates, until, when the first inter-
nodium of the latter ceases to lengthen, the leaf has actually
arrived at its complete formation. When fully grown it repeats
in a much more perfect manner the functions previously per-
formed by the cotyledons : it aerates the sap that it receives,
and returns the superfluous portion of it downwards through

p 2

212 PHYSIOLOGY. BOOK II.

the bark to the root ; it also sends fibres down between the
medullary sheath and the bark, thus forming the first stratum
of wood in the new stem. During these operations, while
the plumula is ascending, its leaf forming and acting, and
the woody matter created by it descending, the cellular tissue
of the stem is forming, and expanding horizontally to make
room for the new matter forced into it ; so that developement
is going on simultaneously both in a horizontal and perpen-
dicular direction. This process may not inaptly be compared
to that of weaving, the warp being the perpendicular, and
the weft the horizontal, formation. In order to enable
the leaf to perform its functions of aeration completely it
is traversed by veins originating in the medulla, and has
delicate evaporating pores (stomata), which communicate with
a highly complex pneumatic system that extends to almost
every part of the plant.

After the production of its first leaf by the plumula, others
are successively produced around the axis at its elongating
point, all constructed alike, connected with the stem or axis
in the same manner, and performing precisely the same func-
tions as have been just described. At last the axis ceases to
elongate; the old leaves gradually fall off; the new leaves,
instead of expanding after their formation, retain their rudi-
mentary condition, harden, and fold over one another, so as
to be a protection to the delicate point of elongation ; or, in
other words, become the scales of a bud. We have now a
shoot with a woody axis, and a distinct pith and bark ; and
of a more or less conical figure. At the axilla of every leaf
a bud had been generated during the growth of the axis ; so
that the shoot, when deprived of its leaves, is covered from end
to end with little, symmetrically arranged, projecting points,
which are the buds. The cause of the figure of the perfect
shoot being conical is, that, as the wood originates from the
base of the leaves, the lower end of the shoot, which has the
greatest number of strata, because it has the greatest number
of leaves above it, will be the thickest; and the upper end,
which has had the fewest leaves to distend it by their deposit,
will have the least diameter. Thus that part of the stem
which has two leaves above it will have wood formed by two

BOOK II. GENERAL CONSIDERATIONS. 213

successive deposits ; that which has nine leaves above it will
have wood formed by nine successive deposits ; and so on :
while the extreme vital point, as it can have no deposit of
matter from above, will have no wood, the extremity being
merely covered by the rudiments of leaves hereafter to be
developed.

If at this time a cross section be examined, it will be found
that the interior is no longer imperfectly divided into two
portions, namely, medulla and skin, as it was when first ex-
amined in the same way, but that it has distinctly two, internal,
perfect, concentric lines, the outer indicating a separation of
the bark from wood ; and the inner, a separation of the wood
from the medulla : the latter too, which in the first observ-
ation was fleshy, and saturated with humidity, is become dis-
tinctly cellular, and altogether or nearly dry.

With the spring of the second year and the return of
warm weather vegetation recommences.

The uppermost, and perhaps some other, buds which were
formed the previous year gradually unfold, and pump up sap
from the stock remaining in store about them ; the place of the
sap so removed is instantly supplied by that which is next it ;
an impulse is thus given to the fluids from the summit to the
roots ; new sap is absorbed from the earth, and sent upwards
through the wood of last year ; and the phenomenon called the
flow of the sap is fully completed, to continue with greater or
less velocity till the return of winter. The axis of the buds
elongates upwards, forming leaves and buds in the same way as
the parent shoot : in like manner also each bud sends down its
roots, in the form of fibres within the bark and above the
wood of the shoot from which it sprang ; thus forming on the
one hand a new layer of wood, and on the other a fresh
deposit of bark. In order to facilitate this last operation, the
old bark and wood are separated in the spring by the exudation
from both of them of the glutinous, slimy substance called
cambium ; which appears to be expressly intended, in the
first instance, to facilitate the descent of the subcortical fibres
of the growing buds ; and, in the second place, to generate the
cellular tissue by which the horizontal dilatation of the axis is
caused, and which maintains a communication between the

p 3

214 PHYSIOLOGY. BOOK II.

bark and the centre of the axis. These lines of communica-
tion have, by the second year, become sufficiently developed to
be readily discovered, and are in fact the medullary rays spoken
of in the last book. It will be remembered that there was a
time when that which is now bark constituted a homogeneous
body with the medulla; and that it was after the leaves began
to come into action that the separation which now exists
between the bark and medulla took place. At the time when
they were indissolubly united they both consisted of cellular
tissue, with a few spiral vessels upon the line indicative of
future separation. When a deposit of wood was formed from
above between them they were not wholly divided the one
from the other, but the deposit was effected in such a way as
to leave a communication by means of cellular tissue between
the bark and the medulla ; and, as this formation is at all
times coaetaneous with that of the wood, the communication
so effected between the medulla and bark is quite as perfect
at the end of the third year as it is at the beginning of the
first; and so it will continue to be to the end of the growth of
the plant. The sap which has been sucked into circulation
by the unfolding leaves is exposed, as in the previous year, to
the effect of air and light ; is then returned through the petiole
to the stem, and sent downwards through the bark, to be
from it either conveyed to the root, or distributed horizon-
tally by the medullary rays to the centre of the stem. At the
end of the year the same phenomena occur as took place the
first season : wood is gradually deposited by slower degrees,
whence the last portion is denser than the first, and gives rise
to the appearance called the annual zones : the new shoot or
shoots are prepared for winter, and are again elongated cones,
as was the first ; and this latter has acquired an increase in
diameter proportioned to the quantity of new shoots which it
produced, new shoots being to it now what young leaves were
to it before.

The third year all that took place the year before is
repeated : sap is absorbed by the unfolding leaves ; and its
loss is made good by new fluids introduced by the roots and
transmitted through the alburnum or wood of the year
before ; new wood and liber are deposited by matter sent

BOOK II. GENERAL CONSIDERATIONS. 215

downwards by the buds ; cambium is exuded ; the horizontal
developement of cellular tissue is repeated, but more exten-
sively ; wood towards the end of the year is formed more
slowly, and has a more compact character ; and another ring
appears indicative of this year's increase.

In precisely the same manner as in the second and third
years of its existence will the plant continue to vegetate, till
the period of its decay, each successive year being a repetition
of the phenomena of that which preceded it.

After a certain number of years the tree arrives at the
age of puberty : the period at which this occurs is very uncer-
tain, depending in some measure upon adventitious circum-
stances, but more upon the idiosyncrasy, or peculiar constitu-
tion of the individual. About the time when this alteration of
habit is induced, by the influence of which the sap or blood of
the plant is to be partially directed from its former courses
into channels in which its force is to be applied to the pro-
duction of new individuals rather than to the extension of
itself; — about this time it will be remarked that certain of
the young branches do not elongate, as had been heretofore
the wont of others, but assume a short stunted appearance,
probably not growing two inches in the time which had been
previously sufficient to produce twenty inches of increase. Of
these little stunted branches, called spurs, the terminal bud
acquires a swollen appearance, and at length, instead of giving
birth to new leaves, produces from its bosom a cluster of
flower-buds, or alabastra, which had been enwrapped and
protected from injury during the previous winter by several
layers of imperfect leaves, now brought forth as bracteae. Sap
is impelled into the calyx through the pedicel by gentle de-
grees, is taken up by it, and exposed by the surface of its
tube and segments to air and light ; but having very imperfect
means of returning, all that cannot be consumed by the calyx
is forced onwards into the circulation of the petals, stamens,
and pistillum. The petals unfold themselves of a dazzling
white tinged with pink, and expose the stamens ; at the same
time the disk changes into a saccharine substance, which
nourishes the stamens and pistillum, and gives them energy to
perform their functions.

p 4

216 PHYSIOLOGY. BOOK II.

At a fitting time, the stigmatic surface of the pistillum being
ready to receive the pollen, this is injected upon it from the
anthers, which have remained in approximation to it for that
particular purpose. When the pollen touches the stigma,
the grains adhere firmly to it by means of its viscid surface,
then emit a delicate membranous tube, which pierces into the
stigmatic tissue, lengthens there, and conveys the vivifying
matter contained in the pollen towards the ovula, which it finally
enters by means of their foramen. This has no sooner oc-
curred than the petals and stamens fade and fall away, their
ephemeral but important functions being accomplished. All
the sap which is afterwards impelled through the peduncle
can only be disposed of to the calyx and ovarium, where it
lodges : both these swell and form a young fruit, which con-
tinues to grow as long as any new matter of growth is supplied
from the parent plant. After a certain period the juices of
the fruit cease to be increased by the addition of new matter,
its surface performs the functions of leaves in exposing the
juice to light and air ; finally the surface loses its green colour,
assumes the rich, ruddy glow of maturity; the juices cease to
be influenced by light ; the peduncle is no longer a passage for
fluids, but dries up and becomes unequal to supporting the
fruit, which at last falls to the earth. Here, if not destroyed
by animals, it lies and decays : in the succeeding spring its
seeds are stimulated into life, strike root in the mass of decayed
matter that surrounds them, and spring forth as new plants to
undergo all the vicissitudes of their parent.

Such are the progressive phenomena in the vegetation, not
only of the apple, but of all trees that are natives of northern
climates, and of a large part of the herbage of the same coun-
tries,— modified, of course, by peculiarities of constitution, as in
annual and herbaceous plants, and in those the leaves of which
are opposite and not alternate ; but all the more essential cir-
cumstances of their growth are the same as those of the apple
tree.

If we reflect upon these phenomena, our minds can scarcely
fail to be deeply impressed with admiration at the perfect sim-
plicity and, at the same time, faultless skill with which all the

BOOK II. GENERAL CONSIDERATIONS. 21?

machinery is contrived upon which vegetable life depends. A
few forms of tissue, interwoven horizontally and perpendicularly,
constitute a stem ; the developement, by the first shoot that the
seed produces, of buds which grow upon the same plan as the
first shoot itself, and a constant succession of the same phe-
nomenon, causes an increase in the length and breadth of the
plant ; an expansion of the bark into a leaf, within which
ramify veins proceeding from the seat of nutritive matter
in the new shoot, the provision of air-passages in its sub-
stance, and of evaporating pores on its surface, enables the
crude fluid sent from the roots to be elaborated and digested
until it becomes the peculiar secretion of the species; the
contraction of a branch and its leaves forms a flower ; the
disintegration of the internal tissue of a petal forms an anther;
the folding inwards of a leaf is sufficient to constitute a pistil-
lum ; and, finally, the gorging of the pistillum with fluid which
it cannot part with causes the production of a fruit.

In hot latitudes there exists another race of trees, of which
palms are the representatives, and in the north there are
many herbs, in which growth, by addition to the outside, is
wholly departed from, the reverse taking place; that is to
say, their diameter increasing by addition to the inside. As
the seeds of such plants are formed with only one cotyledon,
they are called monocotyledonous ; and their growth being
from the inside, they are also named endogenous. In these
plants the functions of the leaves, flowers, and fruit are in no-
wise different from those of dicotyledons ; their peculiarity
consisting only in the mode of forming their stems. When
a monocotyledonous seed has vegetated it usually does not
disentangle its cotyledon from the testa, but simply protrudes
the radicle; the cotyledon swelling, and remaining firmly
encased in the seminal integuments. The radicle shoots
downwards to become root ; and afterwards a leaf is emitted
from the side of the collum, which elongated at the same time
as the radicle. This first leaf is succeeded by another facing
it, and arising from its axilla ; the second produces a third
facing it, and arising also from its axilla; and, in this manner,
the production of leaves continues, until the plant, if caules-

218 PHYSIOLOGY. BOOK II.

cent, is ready to produce its stem. Up to this period no stem
having been formed, it has necessarily happened that the bases
of the leaves hitherto produced have been all upon the same
plane ; and as each has been produced from the bosom of the
other without any such intervening space, as occurs in dicoty-
ledonous plants, it would have been impossible for the matter
of wood, if any had been formed, to be sent downwards around
the circumference of the plant : it would, on the contrary, have
been necessarily deposited in the centre. In point of fact, how-
ever, no deposit of wood like that of dicotyledons takes place,
either now or hereafter. The union of the bases of the leaves
has formed a fleshy stock, cormus, or plate, which, if ex-
amined, will be found to consist of a mass of cellular tissue,
traversed by perpendicular bundles of vascular tissue and
woody fibre, taking their origin in the veins of the leaves, of
which they are manifest prolongations downwards ; and there
is no trace of bark, medullary rays, or central pith : the whole
body being a mass of pith, woody fibre, and vascular
tissue mixed together. To understand this formation yet
more clearly, consider for a moment the internal structure of
the petiole of a dicotyledon : it is composed of a bundle or
bundles of vascular tissue encased in woody fibre, surrounded
on all sides with pith, or, which is the same thing, parenchyma.
Now suppose a number of these petioles to be separated from
their laminae, and to be tied in a bunch parallel with each
other, and, by lateral pressure, to be squeezed so closely toge-
ther that their surfaces touch each other accurately, except at
the circumference of the bunch. If a transverse section of
these be made, it will exhibit the same mixture of bundles of
woody fibre and parenchyma, and the same absence of dis-
tinction between medulla, wood, and bark, which has been
noticed in the cormus, or plate, of monocotyledons.

As soon as the plate has arrived at the necessary diameter
it begins to elongate upwards, leaving at its base those leaves
that were before at its circumference, and carrying upwards
with it such as occupied its centre ; at the same time, new
leaves continue to be generated at the centre, or, as it must
now be called, at the apex of the shoot.

As fresh leaves are developed, they thrust aside to the cir-

BOOK II. GENERAL CONSIDERATIONS. 219

cumference those which preceded them, and a stem is by
degrees produced. Since it has not been formed by additions
made to its circumference by each successive leaf, it is not
conical, as in dicotyledons; but, on the contrary, as its in-
crease has been at the centre, which has no power to extend
its limits, being strictly confined by the circumference which,
when once formed, does not afterwards materially alter in
dimensions, it is, of necessity, cylindrical : and this is one
of the marks by which a monocotyledon is often to be
known in the absence of other evidence. The centre being
but little acted upon by lateral pressure, it remains loose in
texture, and, until it becomes very old, does not vary much
from the density acquired by it shortly after its formation ;
but the tissue of the circumference being continually jammed
together by the pressure outwards of the new matter formed
in the centre, in course of time becomes a solid mass of
woody matter, the cellular tissue once intermingled with it
being almost obliterated, and appearing among the bundles
it formerly surrounded, like the interstices around the minute
pebbles of a mosaic gem.

Such is the mode of growth of palms, and of a great pro-
portion of arborescent monocotyledons. But there are others
in which this is in some measure departed from. In the
common asparagus the shoots produce a number of lateral
buds, which all develope and influence its form, as the buds of
dicotyledons ; so that the cylindrical figure of monocotyle-
dons is exchanged for the conical ; its internal structure is
strictly endogenous. In grasses a similar conical figure pre-
vails, and for the same reason ; but they have this additional
peculiarity, that their stem, in consequence of the great rapi-
pidity of its growth, is fistular, with transverse phragmata at
its nodi. It is not certain whether the subsequent internal
growth of the stem is ever sufficient to fill up the central
cavity ; but, from a specimen of a bamboo in my possession, I
incline to think that the lower part of grass stems does some-
times become filled up with solid matter.

Upon one or other of the two plans now explained are all
flowering plants developed ; but in flowerless plants it is dif-
ferent. In arborescent ferns the stem consists of a cylinder of

220 PHYSIOLOGY. BOOK II.

hard sinuous plates connected by parenchyma, and surround-
ing a hollow axis, which sometimes becomes filled up with
solid matter. It would seem, in these plants, as if the stem
consisted of a mere adhesion of the petioles of the leaves in a
single row ; but we are, at present, too little acquainted with
them in a living state to form any fixed opinion upon the
subject.

In mosses and some Hepaticae the stem seems to consist of
nothing but an axis formed of the united bases of the leaves ;
and their growth may be considered analogous to that of an
annual shoot of a dicotyledon without its wood. The re-
mainder of flowerless plants are principally mere horizontal
expansions of cellular tissue, analogous to nothing that is
known in the other parts of the vegetable kingdom.

221

CHAPTER I.

ELEMENTARY ORGANS.

That of these the cellular tissue is the most important
is apparent by its being the only one of the elementary organs
that is uniformly present in plants ; and by its being the chief
constituent of all those compound organs that are most essen-
tial to the preservation of species.

It transmits fluids in all directions. In most cellular plants
no other tissue exists, and yet there a circulation of sap takes
place ; it constitutes the whole of the medullary rays, convey-
ing the elaborated juices from the bark towards the centre of
the stem ; all the parenchyma in which the sap is diffused
upon entering the leaf, and by which it is exposed to evapor-
ation, light, and atmospheric action, consists of cellular tissue ;
nearly all the bark in which the descending current of the
sap takes place is also composed of it; and in endogenous
plants, where no bark exists, there appears to be no other
route that the descending sap can take than through the cel-
lular substance in which the vascular system is imbedded.
It is, therefore, readily permeable to fluid, although it has no
visible pores.

In all cases of wounds, or even of the developement of new
parts, cellular tissue lis Jirst generated : for example, the
granulations that form at the extremity of a cutting when
imbedded in earth, or on the lips of incisions in the wood or
bark ; the extremities of young roots ; scales, which are gene-
rally the commencement of leaves ; pith, which is the first part
created when the stem shoots up ; nascent stamens and pistilla ;
ovula ; and, finally, many rudimentary parts ; — all these are at
first, or constantly, formed of cellular tissue alone.

It may be considered the Jlesh of vegetable bodies: the
matter which surrounds and keeps in their place all the ramifi-

222 PHYSIOLOGY. BOOK II.

cations or divisions of the vascular system is cellular tissue.
In this the plates of wood of exogenous plants, the fibres of
endogenous plants, the veins of leaves, and, indeed, the whole
of the central system of all of them, are either imbedded or
enclosed.

The action of impregnation appears to take place exclusively
through its agency. Pollen is only cellular tissue in a parti-
cular state; when it bursts, the vivifying particles it contains
are a still more minute state of the same tissue : the coats
of the anther are composed entirely of it ; and the tissue
of the stigma, through which impregnation is conveyed to
the ovula, is merely a modification of the cellular. The ovula
themselves, with their sacs, at the time they- receive the vivi-
fying influence, are a semitransparent congeries of cellules.

It is, finally, the tissue in "which alone amylaceous or sac-
charine secretions are deposited. These occur chiefly in tubers,
as in the potato and arrow-root; in rhizomata, as in the
ginger; in soft stems, such as those of the sago-palm and
sugar-cane ; in albumen, as that of corn ; in pith, as in the
Cassava; in the disk of the flower, as in Amygdalus; and,
finally, in the bark, as in all exogenous plants ; and cellular
tissue is the principal, or exclusive, constituent of these.

Woody fibre is apparently destined merely for the con-
veyance of fluid upwards or downwards, from one end of a
body to another, and for giving firmness and elasticity to every
part.

That it is intended for the conveyance of fluid in particular
channels seems to be proved, 1. from its constituting the
principal part of all wood, particularly of that which is formed
in stems the last in each year, and in which fluid first ascends
in the ensuing season ; 2. from its presence in the veins of
leaves where a rapid circulation is known to take place, form-
ing in those plants both the adducent and reducent channels
of the sap ; and, 3. from its passing downwards from the
leaves into the bark, thus forming a passage through which
the peculiar secretions may, when elaborated, arrive at the
stations where they are finally to be deposited. Mr. Knight
is clearly of opinion that they convey fluid either upwards or
downwards ; in which I fully concur with him : the power of

CHAP. I. ELEMENTARY ORGANS. 223

cuttings to grow when inverted seems, indeed, a conclusive
proof of this. Dr. Dutrochet, however, endeavours to prove
that they merely serve for a downward conveyance.

With regard to its giving Jirnmess and elasticity to every
pa?i, we need only consider its surprising tenacity, as evinced
in hemp, flax, and the like; and its constantly surrounding
and protecting the ramifications of the vascular system, which
has no firmness or tenacity itself. To this evidence might be
added, the admirable manner in which it is combined to
answer such an end. It consists, as has been seen, of ex-
tremely slender tubes, each of which is indeed possessed of
but a slight degree of strength ; but being of different lengths,
tapering to each extremity, and overlapping each other
in various degrees, these are consolidated into a mass that
considerable force is insufficient to break. Any one, who will
examine a single thread of the finest flax with a microscope
that magnifies 180 times, will find, that that which to the eye
appears a single thread, is in reality composed of many
distinct fibres.

The real nature of the functions of the vascular system has
been the subject of great difference of opinion; and may, indeed,
be said to be so still. Spiral vessels have been most commonly
supposed to be destined for the conveyance of air ; and it seems
difficult to conceive how any one accustomed to anatomical
observations, and who has remarked their dark appearance
when lying in water, can doubt that fact. Nevertheless, many
others, and among them Dr. Dutrochet, assert that they serve
for the transmission of fluids upwards from the roots. This
observer states, that if the end of a branch be immersed in
coloured fluid, it will ascend in both the spiral vessels and
ducts ; but that in the former it will only rise up to the level
of the fluid in which the branch is immersed, while, throuo-h
the latter, it will travel into the extremities of the branches.
It has, however, been asked with much justice, how the
opinion that spiral vessels are the sap-vessels is to be recon-
ciled with the fact of their non-existence in multitudes of
plants in which the sap circulates freely. To which might
have been, or perhaps has been, added the questions, why
they do not exist in the wood, where a movement of sap chiefly

224 PHYSIOLOGY. BOOK II.

takes place in exogenous trees ? and also, how it happens
that their existence is almost constantly connected with the
presence of sexes, if they are only sap-vessels ? And further,
it has always been remarked, that if a transverse section of a
vine, for instance, or any other plant, be put under water,
bubbles of air rise through the water from the mouths of the
spiral vessels. But then, it has been urged, that coloured
fluids manifestly rise in the spiral vessels ; a statement that
has been admitted, when the spiral vessels are wounded at
the part plunged in the colouring fluid, but denied in other
circumstances. Indeed, to any observer acquainted with the
difficulty of microscopic investigations, the obscurity that
practically surrounds a question of this sort must be apparent
enough.

The subject has, however, been investigated with much care
by Dr. L. W. Theodore Bischoff, who instituted some very
delicate and ingenious experiments, for the purpose of deter-
mining the real contents and office of the spiral vessels. It is
impossible to find room here for a detailed account of his
experiments, for which the reader is referred to his thesis, De
vera Vasorum Plantarum Spiralium Structura et Functiotie Com-
mentatio: Bonnae, 1829. It must be sufficient to state, that,
by accurate chemical tests, by the most careful purification of
the water employed from all presence of air, and by separating
bundles of the spiral vessels of the gourd {Cucurbita Pepo),
and of some other plants, from the accompanying cellular
substance, he came to the following conclusions, which, if
not exactly, are probably substantially, correct : " That plants,
like all other living bodies, require, for the support of their
vital functions, a free communication with air ; and that it is
more especially oxygen, which, when absorbed by the roots
from the soil, renders the crude fluid fit for the nourishment
and support of a plant, just as blood is rendered fit for that
of animals. But, for this purpose, it is not sufficient that the
external surface should be surrounded by the atmosphere ;
other aeriferous organs are provided, in the form of spiral
vessels, which are placed internally, and convey air contain-
ing an unusual proportion of oxygen, which is obtained through
the root, by their own vital force, from the earth and water.

CHAP. I. ELEMENTARY ORGANS. 225

In a hundred parts of this air twenty-seven to thirty parts are
of oxygen, which is in part lost during the day by the surface
of plants under the direct influence of the solar rays."

With such evidence of the aeriferous functions of the spiral
vessels it is difficult to contend ; and, indeed, it seems pro-
bable that this question is settled as far as spiral vessels, pro-
perly so called, are concerned. But there are many vessels
abounding in the wood, to which they give a porous appear-
ance when cut across, and which I have called ducts, that,
although perhaps mere modifications of the spiral vessel, are,
nevertheless, so far distinct as to convey air at one period of
their existence, and fluid at another. In the vine, for instance,
the true spiral vessels of the medullary sheath and of the herb-
aceous parts, always filled with air, must be carefully distin-
guished from the ducts of the wood ; which are, undoubtedly,
filled during the principal flow of the sap with that fluid,
although they finally become dry and empty. And it may
be further remarked, that the dotted ducts of such plants as
Phytocrene gigantea, or water-vine, so well represented by
Mr. Griffith in Dr. Wallich's Plantce Asiaticce Rario?rs, are
apparently the principal conduits in that curious plant, as
they are in Gramineae, and other monocotyledons, of the fluid
absorbed from the earth.

So that, while true spiral vessels may be admitted as un-
doubted vehicles of air, ducts of all kinds, and especially dotted
ducts, cannot be doubted to be the passages through which
fluid is conveyed when great rapidity is required. I have
already stated that, although all these vessels are, in the pre-
sent state of our anatomical knowledge, considered as equally
belonging to the vascular system, yet that the dotted will
rather be referred eventually to the cellular, and then their
lymphatic office will be unquestioned.

In regard to the functions of air-cells and lacunae, it may
be sufficient to remark, that in all cases in which they form a
part of the vital system, as in water plants, they are cavities
regularly built up of cellular tissue, and uniform in figure in
the same species ; while, on the other hand, where they are
not essential to vitality, as in the pith of the walnut, the rice-

226 PHYSIOLOGY. BOOK II.

paper plant, the stems of Umbelliferae, and the like, they are
ragged, irregular distensions of the tissue.

In the former case they are intended to enable plants to
float in water ; in the latter, they are caused by the growth of
one part more rapidly than another.

227

CHAPTER II.

OF THE ROOT.

It is the business of the root to absorb nutriment from the
soil, and to transmit it upwards into the stem and leaves; and
also to fix the plant firmly in the earth. Although moisture is,
no doubt, absorbed by the leaves of all and the stems of many
plants, yet it is certain that the greater part of the food of
plants is taken up by the roots; which, hence, are not in-
correctly considered vegetable mouths.

But it is not by the whole surface of the root that the
absorption of nutriment takes place ; it is the spongioles
almost exclusively to which that office is confided : and hence
their immense importance in vegetable economy, the absolute
necessity of preserving them in transplantation, and the certain
death that often follows their destruction. This has been
proved, in the following manner, by the celebrated Senebier:
— he took a radish, and placed it in such a position that the
extremity only of the root was plunged in water : it remained
fresh several days. He then bent back the root, so that its
extremity was curved up to the leaves : he plunged the bent
part in water, and the plant withered soon ; but it recovered
its former freshness upon relaxing the curvation, and again
plunging the extremity of the root into the water.

This explains why forest trees, with very dense umbrageous
heads, do not perish of drought in hot summers or dry situa-
tions, when the earth often becomes mere dust for a consider-
able distance from their trunk, in consequence of their foliage
turning off the rain: the fact is obviously that the roots near
the stem are inactive, and have little or nothing to do as pre-
servatives of life except by acting as conduits, while the func-
tions of absorption go on through the spongioles, which, being
at the extremities of the roots, are placed beyond the influence
of the shadow, and extend wherever moisture is to be found.
This property prevents a plant from exhausting the earth in

fi 2

228 PHYSIOLOGY. BOOK II.

which it grows ; for, as the roots are always spreading further
and further from the main stem, they are continually entering
new soil, the nutritious properties of which are unexhausted.

It is generally believed that roots increase only by their
extremities, and that, once formed, they never undergo any
subsequent elongation. This was first noticed by Du Hamel,
who passed fine silver threads through young roots at differ-
ent distances, marking on a glass vessel corresponding points
with some varnish : all the threads, except those that were
within two or three lines of the extremity, always continued
to answer to the dots of varnish on the glass vessel, although
the root itself increased considerably in length. Variations in
this experiment, which has also been repeated in another
way by Mr. Knight, produced the same result. It is possible
that this peculiarity may be universal in exogenous plants;
but it certainly is not constant in endogenous plants ; and I
doubt very much whether it is not confined to roots with a
woody structure. From the following experiments it will be
seen that in Orchideae the root elongates independently of its
extremity. On the 5th of August I tied threads tightly round
the root of a Vanilla, so that it was divided into three spaces,
of which one was 7 inches long, another 4 inches, and the
third, which wras the free growing extremity, 1 inch and f.
On the 19th of September the first space measured *J\ inches,
the second 4f inches, and the third or growing extremity
2-J inches. A root of Aerides cornutum was, on the 5th of
August, divided by ligatures into spaces, of which the first
measured 1 foot 3 inches, the second 1\ inches, the third
3^ inches, and the fourth, or growing end, 1 inch and -J.
On the 19th September the first space measured 1 foot
3^ inches, the second 2 J inches, the third §\ inches, and the
fourth 4f inches.

Occasionally roots appear destined to act as reservoirs of
nutriment, on which those of the succeeding year may feed
when first developed, as is the case in the Orchis, the Dahlia,
and others. But it must be remarked, that the popular no-
tion extends this circumstance far beyond its real limits, by
including among roots bulbs, tubers, and other forms of stem
in a state of anamorphosis.

CHAP. II. ROOT. 229

By some botanists, and among them by M. De Candolle, it
has been thought that roots are developed from special organs,
which are to them what leaf-buds are to branches; and this
function has been assigned to those little glandular swellings
so common on the willow, called lenticular glands by Guettard,
and lenticelles by De Candolle.

Accordingto Mr. Knight, the energies of a variety artificially
produced exist longer in the system of the root than in that
of the stem; so that it is more advisable to propagate old
varieties of fruit trees from cuttings of the root than from those
of the stem.

The roots not only absorb fluid from the soil, but they
return a portion of their peculiar secretions back again into
it; as has been found by Brugmans, who ascertained that
some plants exude an acid fluid from their spongioles ; and
also by Mr. Macare, who has proved that to excrete super-
abundant matter from the roots is a general property of the
vegetable kingdom. This, taken together with the fact that
plants cannot digest their own secretions, explains why soil
is so deteriorated by one species having long grown in it, that
it will not support other individuals of the same species, until
the fecal matter deposited in it shall have been decomposed.
This is the solution of the necessity of the rotation of crops.

8 3

230 PHYSIOLOGY. BOOK. II.

CHAPTER III.

OF THE SAP.

For the sustenance of plants a fluid is necessary which
is absorbed by the roots from the earth, then sent upwards
into the stem, afterwards impelled into the leaves, whence it
descends through the liber, transferring itself to the inmost
parts of the wood. This fluid, which constitutes the blood of
plants, is called the sap. When first introduced into the sys-
tem, and even when altered in some degree, by having dis-
solved the various substances it encounters in its passage, it is
true sap ; afterwards, when its nature has been more changed
by elaboration in the leaves, it becomes what is called the
proper juice.

If the sap be examined in its most simple state, it will be
found to consist of water, mucilage, and sugar. As the two
last can scarcely have been absorbed directly from the earth,
it is inferred that as soon as the fluids, taken up by the roots,
enter the system they suffer some chemical decomposition, the
result of which is the production of mucilage and sugar. In
addition to the supply of sap which is obtained by the roots,
a certain quantity is, no doubt, also absorbed from the
atmosphere by the leaves ; as is evident from succulent plants,
which will continue to grow and acquire weight long after
their roots are severed from the earth. This absorption
on the part of the leaves chiefly takes place at night, or in
cloudy weather ; while perspiration, on the other hand, goes
on in the daytime in bright weather.

With regard to the chemical nature and changes of the
sap, I cannot do better than give the statement of Link, with
some necessary alterations. The food of plants must be composed
of oxygen, hydrogen, carbon, and azote. Water, consisting of
oxygen and hydrogen alone, is not sufficient. Many ex-
periments, indeed, have been instituted to prove that pure
water is a sufficient food, especially by Van Helmont, Eller,

chap. in. sap. 231

Bonnet, Du Hamel, and others ; but it is probable, as Wal-
lerius has inferred, that the water out of which plants are
formed already contains the necessary chemical principles.
To this it is objected, that plants grown in water alone never
arrive at perfection or mature their seeds. But this is not
strictly true : they do perfect their seeds ; but it is not sur-
prising that crude water should be insufficient for purposes
which are fully answered by water properly mixed and
tempered.

That the extractive matter contained in earth was the real
food of plants, was long ago stated by Woodward and Kylbel;
and most physiologists have adopted this opinion. But it has
been estimated by Theodore de Saussure that a plant when
dried does not derive more than a twentieth part of its weight
from extractive matter and carbonic acid dissolved in water :
now, supposing this calculation not to be very accurate, yet it
is probable that it is not far from the truth ; and it at least
serves to show that extractive matter and carbonic acid are
not alone sufficient for the nutriment of plants.

Nevertheless, if neither extractive matter nor carbonic acid
can be considered to constitute exclusively the food of plants,
it is at least quite certain that they not only cannot exist with-
out the latter, but that it forms by far the greater part of their
food. It is well known that roots cannot perform their func-
tions unless within the reach of the atmosphere. This arises
from the necessity for their feeding upon carbonic acid, which,
after having been formed by the oxygen of the atmosphere
combining with the carbon in the soil, is then received into
the system of the plant, to be impelled upwards, dissolved in
the sap till it reaches the leaves, where it is decomposed by
light, the oxygen liberated, and the carbon fixed. It has also
been ascertained that, feed plants as you will, they will neither
grow nor live whether you offer them oxygen, hydrogen,
azote, or any other gaseous or fluid principle, unless carbonic
acid is present.

Those principles are called foreign to plants which cannot
be referred to either hydrogen, oxygen, carbon, or azote:
such, for example, are carbonate of soda, sulphate of soda,
nitrate of soda, the carbonates of potash, lime, and magnesia,

232 PHYSIOLOGY. BOOK II.

phosphate of lime, chlorides of soda and potash, and the
oxides of aluminum, silicium, iron, and manganese ; and
even, occasionally, phosphorus. De Saussure has demon-
strated that the chemical principles which are present in soil
are also to be found in the ashes of a plant that has grown in
it; but he admits they undergo certain chemical changes, in
consequence of the organic powers of vegetation. Dr. John,
also, has ascertained that several salts, when taken up by the
roots, undergo peculiar changes; as, for instance, potash into
soda. To these, many well known observations may be
added ; plants growing in saline places contain so much salt,
that it is perceptible to the taste. Potash also is yielded by
the ashes of plants growing in salt soil ; so that there is no
doubt that this substance is produced by the detraction by
organic power of the chlorine of chloride of potash.

There are, however, some experiments which, if they could
be depended on, would materially weaken these hypotheses.
Schrader grew barley and rye in well washed flower of sul-
phur, moistened with distilled water : they were afterwards
analysed, and found to contain silex, lime, and magnesia, as well
as oxides of iron and manganese. The same plants produced
in earth did not yield a greater weight of ashes than those
grown in sulphur; and these experiments are confirmed by
those of Braconnot, as recorded in the Annales de Chimie,
vol. lxi. p. 187. White mustard was grown in well washed
litharge and flower of sulphur, moistened with distilled
water ; and its ashes yielded oxide of silicium and alumi-
num, carbonate of lime, and oxide of iron. Both these ob-
servers conclude that these foreign principles were produced
by the organic power of vegetation; but Gehlen suggests
that, as many principles are dissolved in oxygen and dis-
persed through the atmosphere, they may be communicated
to plants by that medium. As it seems, however, certain
that chemical principles do undergo changes from organic
powers, it is not improbable that all the foreign principles of
plants were originally suspended in water ; but that plants
have no capability of doing more than decompose such com-
pound principles as they may absorb.

To reconcile the experiments of Saussure and John with

CHAP. III. SAP. 233

those of Schrader and Braconnot, it is suggested by Professor
Link that the power and necessity of taking up matter from
the soil varies in different plants : that some depend wholly
upon it for their formation, others less, and some not at all.
Thus, Salsolas grow but in saline soilj and in soil destitute of
salt become languid and weak; other plants will only vegetate
in calcareous earth : Trifolium pratense prefers gypsum, and
succulent plants scarcely require soil at all.

That some plants have the power of secreting one kind of
accessory principle, and others another kind from the same
food, is clear from the fact, that, if wheat and peas be grown
in the same water, earth, or medium, the former will uniformly
deposit silex in their cuticle, and the latter never.

The course which is taken by the sap after entering a plant is
the next subject of consideration. The opinion of the old
botanists was, that it ascended from the roots between the
bark and the wood : but this has been long disproved by
modern investigators, and especially by the experiments of
Mr. Knight. If a trunk is cut through in the spring, at the
time the sap is rising, this fluid will be found to exude more
or less from all parts of the surface of the section, except the
hardest heart-wood, but most copiously from the alburnum.
If a branch is cut half through at the same season, it will be
found that, while the lower face of the wound bleeds copiously,
scarcely any fluid exudes from the upper face; from which,
and other facts, it has been fully ascertained that the sap rises
through the wood, and chiefly through the alburnum. Ob-
servations of the same nature have also proved that it descends
through the liber. But the sap is also diffused laterally
through the cellular tissue, and this with great rapidity; as
will be apparent upon placing a branch in a coloured in-
fusion, which will ascend and descend in the manner just
stated, and will also disperse itself laterally in all directions
round the principal channels of its upward and downward
route.

Corti, in 1774, Fontana, L. C. Treviranus, and especially
Professor Amici, have made some most curious observations
upon the movement of the sap in Chara. If a portion of
Chara flexilis, or of any of the transparent species, or of any

234; PHYSIOLOGY. BOOK II.

crustaceous kind, the opaque cuticle of which is first scraped
away, be examined, a current of sap will be distinctly seen in
each cellule setting from joint to joint, flowing down one side
and returning up the other, without any membrane intervening
to separate the opposing curi'ents. Each cellule has a move-
ment of its own, independent of that of the cellules above and
below it. Sometimes the movement stops, and then goes on
again after a brief interval If a cellule is divided into two by
a ligature passed round it, a separate movement is seen in
each of the divisions. This motion is rendered distinctly
obvious by the numerous minute green granules which float
in the transparent fluid, and which follow the course of the
currents.

Another sort of motion, which it is probable is common to
all descriptions of plants, has been seen by Link and others,
particularly by Schultz, in the Chelidonium, Ficus Carica,
and other plants. It is described as an exceedingly rapid
motion of the fluid, which rushes out of one set of vessels,
apparently tubes of woody fibre, into another, in a constant,
uninterrupted stream. This has been denied, it is true, by
Dutrochet; but he does not appear to have succeeded in
seeing that which is nevertheless visible enough, if proper
precautions are taken. Mirbel and Cassini both confirm the
statements of Schultz ; and to their testimony I may be per-
mitted to add my own. In Alisma plantago and the trans-
parent stipules of Ficus elastica I have distinctly seen powerful
currents, such as are described, rushing along the tubes, like
a stream of water down an inclined channel.

That there must be an exceedingly rapid flow of sap in
many plants, is evident from the great loss they often expe-
rience by perspiration, — all which must be made good by fluid
absorbed by the roots. A young vine-leaf, in a hot day, per-
spires so copiously, that, if a glass be placed next its under
surface, it is presently covered with dew, which, in half an
hour, runs down in streams. Hales computed the perspir-
ation of plants to be seventeen times more than that of
the human body. He found a sun-flower lose one pound
four ounces, and a cabbage one pound three ounces a day
by perspiration. Guettard asserts that the young shoots of

CHAP. II. SAP. 235

Cornus mascula lose twice their own weight a day. This
perspiration is regulated by the number of the stomata : hence
evergreens, in which they are small, and less numerous than
in deciduous or herbaceous plants, perspire much less.

With this function are connected all the phenomena that
attend transplantation. If a growing plant is removed from
one situation to another in the summer, it will die ; because its
spongioles will be so much destroyed as to be incapable of
absorbing fluid from the soil as fast as it is given off by the
leaves ; and hence the system will be emptied of fluid. But if
a plant is growing in a pot, it may be transplanted at any
season of the year; because its spongioles, being uninjured,
will be able to counterbalance the loss caused by perspiration,
as well after transplantation as before, if not better.

With regard to the vessels through which this universal dif-
fusion of the sap takes place, it has already been stated that
its upward course is always through the woody fibre, and
probably also through the ducts; and that it passes down-
wards through the woody fibre. But there can be no reason-
able doubt that it is also dispersed through the whole system
by means of some permeable quality of the membranes of the
cellular tissue, which is invisible to our eyes, even aided by
the most powerful glasses. It has also been suggested that
the sap finds its way upwards, downwards, and laterally
through the intercellular passages which exist at the points of
union of every individual elementary organ. That such a
channel of communicating the sap is employed by Nature to
a certain extent I do not doubt, especially in those plants in
which the intercellular passages are very large ; but whether
this is an universal law, or has only a partial operation, is
quite unknown, and is not perhaps susceptible of absolute
proof. Link seems disposed to deny any conveyance of
fluids through the intercellular passages.

The accumulation of sap in plants appears to be attended
with very beneficial consequences, and to be deserving of the
especial attention of gardeners. It is well known how weak
and imperfect is the inflorescence of the turnip tribe, forced to
flower before their fleshy root is formed ; and how vigorous it
is after that reservoir of accumulated sap is completed. Mr.

236 PHYSIOLOGY. BOOK II.

Knight, in a valuable paper upon this subject, remarks that
the fruit of melons, which sets upon the plant when very
young, uniformly falls off; while, on the contrary, if not
allowed to set until the stem is well formed, and much sap
accumulated for its support, it swells rapidly, and ripens
without experiencing any deficiency of food in the course of
its growth. In like manner, if a fruit tree is by any circum-
stance prevented bearing its crop one year, the sap that would
have been expended accumulates, and powerfully contributes
to the abundance and perfection of the fruit of the succeeding
year. And again, the plan recommended by Mr. Knight, of
always planting large tubers of the potatoe, is another proof of
the importance of plenty of accumulated sap to the vigorous
growth of all plants.

The cause of the motion of the sap is a subject which has
long excited great curiosity, and has given rise to numberless
conjectures. It was for a long time believed that there was a
sort of circulation of the sap of plants, to and from a common
point, analogous to that of the blood of animals : but this was
disproved by Hales, and is not now believed. This excellent
observer, whose " Statics " are an eternal monument of his
industry and skill, thought that the motion of the sap, the
rapidity of which he had found to be greatly influenced by
weather, depended upon the contraction and expansion of the
air, which exists in great quantities in the interior of plants.
Others have ascribed the motion to capillary attraction.
Mr. Knight was once of opinion that it depended upon a
hygrometrical property of the plates of silver grain (me-
dullary rays), which traverse the stem in all directions. A
number of other theorists have called to their aid a supposed
irritability of the vessels ; but no contraction of the vessels has
ever yet been noticed, and certainly does not take place in
Chara, where the motion has been most distinctly observed.
Du Petit Thouars suggests that it arises thus : — in the spring,
as soon as vegetation commences, the extremities of the
branches and the buds begin to swell : the instant this hap-
pens a certain quantity of sap is attracted out of the circum-
jacent tissue for the supply of those buds ; the tissue, which is
thus emptied of its sap, is rilled instantly by that beneath or

CHAP. III. SAP. 237

about it: this is in its turn replenished by the next; and thus
the whole mass of fluid is set in motion, from the extremities
of the branches down to the roots. Du Petit Thouars is
therefore of opinion that the expansion of leaves is not the
effect of the motion of the sap, but, on the contrary, is the
cause of it ; and that the sap begins to move at the extremities
of the branches before it stirs at the roots. That this is really
the fact, is well known to foresters and all persons accus-
tomed to the felling or examination of timber in the spring.
Some good observations upon this were communicated to Mr.
Loudon's Gardener's Magazine, by Mr. Thomson, gardener
at Welbeck; who, however, drew a wrong inference from
them.

Amici is of opinion that the motion in Chara depends upon
galvanic action ; and Dutrochet has since formed a theory of
all the motions of fluids in plants depending upon the same
agency. He found that small bladders of animal and vegetable
membrane, being filled with a fluid of greater density than
water, securely fastened, and then thrown into water, acquired
weight ; he also remarked, that if the experiment was reversed,
by filling with water and immersing them in a denser fluid,
the contrary took place, and that the bladders lost weight : he
took a small bladder, and filled it with milk, or gum arabic
dissolved in water ; to the mouth of this bladder he adapted a
tube, and then plunged the bladder in water: in a short time
the milk rose in the tube, whence he inferred that water had
been attracted through the sides of the bladder. This experi-
ment was also reversed, by filling the bladder with water, and
plunging it in milk : the fluid then fell in the tube, whence he
inferred that water had been attracted through the coat of the
bladder into the milk. From these, and other experiments,
M. Dutrochet arrived at the inference that, if two fluids of
unequal density are separated by an animal or vegetable
membrane, the denser will attract the less dense through the
membrane that divides them : and this property he calls
endosmose, when the attraction is from the outside to the
inside; and exosmose, when it operates from the inside to the
outside. In pursuing this investigation he remarked, that if
an empty bladder is immersed in water, and the negative pole

238 PHYSIOLOGY. BOOK II.

of a galvanic battery introduced into it, while the positive
pole is applied to the water on the outside, a passage of fluid
takes place through the membrane, as had previously hap-
pened when the bladder contained a fluid denser than water ;
by reversing the experiment, the reverse was found to take
place: from all which Dutrochet deduces the following theory,
that when two fluids of unequal density are separated by an
intervening membrane, the more dense is negatively electri-
fied, and the less dense positively electrified ; in consequence
of which two electric currents of unequal power set through
the membrane, carrying fluid with them ; that which sets from
the positive pole, or less dense fluid, to the negative pole, or
more dense fluid, being much the most powerful : and that
the fluids of plants being more dense than those which sur-
round them, a similar action takes place between them and
the water in the soil, by means of which the latter is con-
tinually impelled into their system. Philosophers do not
seem disposed to admit the legitimacy of M. Dutrochet's con-
clusion, that this transmission takes place by means of galvanic
agency ; but that the phenomenon is correctly described by
the ingenious author, and that it is constantly operating in
plants, is beyond all dispute. It is by endosmose that vapour
is absorbed from the atmosphere, and water from the earth ;
that sap is attracted into fruits by virtue of their greater density ;
and probably that buds are enabled to empty the tissue that
surrounds them when they begin to grow : it will, perhaps, be
found the most ready explanation of most of the phenomena
connected with the movement of fluids.

239

CHAPTER IV.

OF THE PITH, WOOD, AND BARK.

Various are the notions that from time to time have been
entertained about the pith. The functions of brain, lunors,
stomach, nerves, spinal marrow, have by turns been ascribed
to it. Some have thought it the seat of fecundity, and have
believed that fruit trees deprived of pith became sterile; others
supposed that it was the origin of all growth ; and another
class of writers, we cannot say observers, have declared that
it was the channel of the ascent of sap. It is, however, no
part of the plan of this work to refute this and similar ex-
ploded speculations.

It is probable that its real and only use is to serve in the
infancy of a plant for the reception of the sap, upon which
the young and tender vessels that surround it are to feed
when they are first formed ; a time when they have no other
means of support. M. Dutrochet considers it to act not
only as a reservoir of nutriment for the young leaves, but also
to be the place in which the globules, which he calls nervous
corpuscles, are formed out of the elaborated sap. {JO Agent
Imme'diat, &c, p. 44, &c.)

The medullary sheath seems to perform a far more im-
portant part in the economy of plants ; it diverges from the
medulla whenever a leaf is produced, and, passing through the
petiole, ramifies among the cellular tissue of the lamina, where
it appears as veins : hence veins are always composed of
bundles of woody fibre and spiral vessels. So situated, the
veins are in the most favourable position that can be imagined
for absorbing the fluid that, in the first instance, is conducted
to the young pith, and that is subsequently impelled upwards
through the woody fibre. So essential is the medullary
sheath to vegetation in the early age of a branch, that, as is
well known, although the pith and the bark, and even the
young wood, may be destroyed, without the life of a young

240 PHYSIOLOGY. BOOK II.

shoot being much affected ; yet, if the medullary sheath be cut
through, the pith, bark, or wood being left, the part above the
wound will perish.

The bark acts as a protection to the young and tender
wood, guarding it from cold and external accidents. It is
also the medium in which the proper juices of the plant in their
descent from the leaves are finally elaborated, and brought to
the state which is peculiar to the species. It is from the
bark that they are horizontally communicated to the medullary
rays, by them to be deposited in the tissue of the wood.
Hence, the character of timber is almost wholly dependent
upon the influence of the bark, as is apparent from a vertical
section of a grafted tree, through the line of union of the
stock and scion. This line will be found so exactly drawn,
that the limits of the two are determined in the oldest spe-
cimens as accurately as if they were fixed by rule and line :
the woody tissue will be found uninterruptedly continuous
through the one into the other, and the bark of the two
indissolubly united ; but the medullary rays emanating from
the bark of each will be seen to remain as different as they
were, while the stock and scion were distinct individuals.

As the bark, when young, is green like the leaves, and as
the latter are manifestly a mere dilatation of the former, it is
highly probable, as Mr. Knight believes, that the bark exer-
cises an influence upon the fluids deposited in it wholly
analogous to that exercised by the leaves, which will be here-
after explained. Hence it has been named, with much truth,
the universal leaf of a vegetable.

The business of the medullary rays is, no doubt, exclu-
sively to maintain a communication between the bark, in which
the secretions receive their final elaboration, and the centre of
the trunk, in which they are at last deposited. This is apparent
from tangental sections of dicotyledonous wood manifesting
an evident exudation of liquid matter from the wounded me-
dullary rays, although no such exudation is elsewhere visible.
In endogenous plants, in which there appears no necessity for
maintaining a communication between the centre and circum-
ference, there are no medullary rays. These rays also serve
to bind firmly together the whole of the internal and external

CHAP. IV. PITH, WOOD, AND BARK. 2il

parts of a stem, and they give the peculiar character by which
the wood of neighbouring species may be distinguished. If
plants had no medullary rays, their wood would probably be,
in nearly allied species, undistinguishable ; for we are scarcely
aware of any appreciable difference in the appearance of
fibrous or vascular tissue. But the medullary rays differing
in abundance, in size, and in other respects, impress charac-
ters upon the wood which are extremely marked. Thus, in
the cultivated cherry, the plates of the medullary rays are
very thin, the adhesions of them to the bark are very slight,
and hence a section of the wood of that plant has a pale,
smooth, homogeneous appearance ; but in the wild cherry
the medullary plates are much thicker, they adhere to the
bark by deep broad spaces, and are arranged with great irre-
gularity, so that a section of the wood of that variety has a
deeper colour, and a twisted, knotty, very uneven appearance.
As the medullary rays develope only horizontally, when two
trees in which they are different are grafted or budded to-
gether, the wood of the stock will continue to preserve its
own peculiarity of grain, notwithstanding its being formed by
the woody matter sent down by the scion ; for it is the hori-
zontal developement that gives its character to the grain, and
not the perpendicular fibres which are incased in it.

The wood is at once the support of all the deciduous organs
of respiration, digestion, and impregnation, the deposit of the
secretions peculiar to individual species, and also the reservoir
from which newly forming parts derive their sustenance until
they can establish a communication with the soil. Regarding
the precise manner in which it is created, there has been
great diversity of opinion. Linnaeus thought it was produced
by the pith ; Grew, that the liber and wood were deposited
at the same time in a single mass which afterwards divided
in two, the one half adhering to the centre, the other to the
circumference ; Malpighi conceived that the wood of one year
was produced by an alteration of the liber of the previous
season. Duhamel believed that it was deposited by the se-
cretion already spoken of as existing between the bark and
wood, and called cambium : he was of opinion that this cam-
bium was formed in the bark, and became converted into both

242 PHYSIOLOGY. BOOK II.

cellular tissue and woody fibre; and he demonstrated the^
fallacy of those theories according to which new wood is
produced by the wood of a preceding year. He removed a
portion of bark from a plum tree ; he replaced this with a
similar portion of a peach tree, having a bud upon it. In a
short time a union took place between the two. After wait-
ing a sufficient time to allow for the formation of new wood, he
examined the point of junction, and found that a thin layer of
wood had been formed by the peach bud, but none by the
wood of the plum, to which it had been tightly applied.
Hence he concluded that alburnum derives its origin from the
bark, and not from the wood. A variety of similar experi-
ments was instituted with the same object in view, and they
were followed by similar results. Among others, a plate of
silver was inserted between the bark and the wood of a tree
at the beginning of the growing season. It was said, that if
new wood was formed by old wood it would be subsequently
found pushed outwards, and continuing to occupy the same
situation ; but that if new wood was deposited by the bark,
the silver plate would in time be found buried beneath new
layers of wood. In course of time the plate was examined,
and was found enclosed in wood.

Hence the question as to the origin of the wood seemed
settled ; and there is no doubt that the experiments of Du-
hamel are perfectly accurate and satisfactory as far as they
go. It soon, however, appeared that, although they certainly
proved that new wood is not produced by old wood, it was
not equally clear that it originated from the bark. Accord-
ingly a new set of experiments was instituted by Mr. Knight,
for the purpose of throwing a still clearer light upon the pro-
duction of the wood. Having removed a ring of bark from
above and below a portion of the bark furnished with a leaf,
Mr. Knight remarked that no increase took place in the wood
above the leaf, while a sensible augmentation was observable
in the wood below the leaf. It was also found that if the
upper part of a branch is deprived of leaves, the branch will
die down to the point where leaves have been left, and below
that will flourish. Hence an inference is drawn that the
wood is not formed out of the bark as a mere deposit from it,

CHAP. IV. PITH, WOOD, AND BARK. 24-3

but that it is produced from matter elaborated in the leaves
and sent downwards, — either through the vessels of the inner
bark, along with the matter for forming the liber by which it
is subsequently parted with ; or that it and the liber are
transmitted distinct from one another, the one adhering to the
alburnum, the other to the bark. I know of no proof of the
former supposition : of the latter there is every reason to
believe the truth. Mr. Knight is of opinion that two distinct
sets of vessels are sent down, one belonging to the liber, the
other to the alburnum ; and if a branch of any young tree,
the wood of which is formed quickly, be examined wdien it is
first bursting into leaf, these two sets may be distinctly seen
and traced. Take, for instance, a branch of lilac in the be-
ginning of April and strip off its bark : the new wood will be
distinctly seen to have passed downwards from the base of
each leaf, diverging from its perpendicular course, so as to
avoid the bundle of vessels passing into the leaf beneath it;
and if the junction of a new branch with that of the previous
year be examined, it will be found that all the fibres of wood
already seen proceeding from the base of the leaves, having
arrived at this point, have not stopped there, but have passed
rapidly downwards, adding to the branch an even layer of
fibrous matter or young wood ; and turning off at every pro-
jection which impedes them, just as the water of a steady but
rapid current would be diverted from its course by obstacles
in its stream. Now, if the new wood were a mere deposit of
the bark, the. latter, as it is applied to every part of the old
wood, would deposit the new wood equally over the whole
surface of the latter, and the deviation of the fibres from ob-
stacles in their downward course could not occur. This,
therefore, in my mind, places the question as to the origin of
the wood beyond all further doubt. Mirbel, who formerly
advocated the doctrine of wood being deposited by bark,
has, with the candour of a man of real science, fairly ad-
mitted the opinion to be no longer tenable ; and he has sug-
gested in its room that wood and bark are independent
formations, — which is no doubt true, — but, he adds, created
out of cambium, in which it is impossible to concur : for
this reason. All the writers hitherto mentioned or adverted

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244 PHYSIOLOGY. BOOK II.

to have considered the formation of wood only with reference
to exogenous trees, and to such only of them as are the com-
mon forest plants of Europe. Had they taken into account
exotic trees or any endogenous plants, they would have seen
that none of their theories could possibly apply to the form-
ation of wood in that tribe. In many exogenous plants of
tropical countries wood is not deposited in regular circles
all round the axis, but only on one side of the stem, or along
certain lines upon it : were it a deposit from the bark, or a
metamorphosis of cambium, it would necessarily be deposited
with some kind of uniformity. In endogenous trees there is
no cambium, and yet wood is formed in abundance; and the
new wood is created in the centre, and not in the circum-
ference : so that bark can have, in such cases, nothing what-
ever to do with the creation of wood.

No doubt aware of most of the difficulties in the way of
the common theories of the formation of wood, M. Du Petit
Thouars, an ingenious French physiologist, who had possessed
opportunities of examining the growth of vegetation in tro-
pical countries, constructed a theory, which, although in
many points similar to the one proposed, but not proved, by
his countryman, De la Hire, is nevertheless, from the facts
and illustrations skilfully brought by the French philosopher
to his aid, to be considered legitimately as his own. The
attention of Du Petit Thouars appears to have been first
especially called to the real origin of wood by having re-
marked, in the Isle of France, that the branches which are
emitted by the truncheons of Dracaena (with which hedges
are formed in that colony) root between the rind and old
wood, forming rays of which the axis of the new shoot is the
centre. These rays surround the old stem ; the lower ones
at once elongate greatly towards the earth, and the upper
ones gradually acquire the same direction ; so that at last, as
they become disentangled from each other, the whole of them
pass downwards to the soil. Reflecting upon this curious
fact, and upon a multitude of others which I have no space
to detail, he arrived at the conclusion, that it is not merely
in the property of increasing the species that buds agree with
seeds, but that they emit roots in like manner; and that the

CHAP. IV. PITH, WOOD, AND BARK. 245

wood and liber are both formed by the downward descent of
bud- roots, at first nourished by the moisture of the cambium,
and finally imbedded in the cellular tissue which is the result
of the organisation of that secretion. That first tendency
of the embryo, when it has disengaged itself from the seed,
to send roots downwards and a stem and leaves upwards, and
to form buds in the axilla? of the latter, is in like manner
possessed by the buds themselves ; so that plants increase in
size by an endless repetition of the same phenomenon.

Hence a plant is formed of multitudes of buds or fixed
embryos, each of which has an independent life and action:
by its elongation upwards forming new branches and con-
tinuing itself, and by its elongation downwards forming wood
and bark ; which is therefore, in Du Petit Thouars's opinion,
a mass of roots.

A great deal of opposition has been offered to this view,
especially among this writer's own countrymen ; but it is re-
markable that many of his antagonists have been from a class
of naturalists of whom it may be said, that they are better
known in consequence of the celebrity of the object of their
attack than for any reputation of their own. To this, how-
ever, there are some exceptions, as, for instance, MM. Mirbel
and Desfontaines, two of the most learned botanists of France.
This theory, nevertheless, seems the only one that is adapted
at once to the explanation of the real cause of the many anomal-
ous forms of exogenous stems which must be familiar to the re-
collection of all botanists, and that, at the same time is equally
applicable to the exogenous and endogenous modes of growth ;
a condition which, it will be readily admitted, is indispensable
to any theory of the formation of wood that may be proposed.
It also offers the simplest explanation of the phenomena that
are constantly occurring in the operations of gardening.

It has recently been a subject of discussion in the Academy
of Sciences at Paris; when M. Poiteau supported the theory,
and MM. Mirbel, Cassini, and Desfontaines opposed it. The
arguments used by the latter were two, both of which are un-
doubted fallacies. The first was, that if a large ring of bark
be taken from the stem of a sycamore, and be replaced by a
similar ring entirely destitute of buds from a red maple, the

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246 PHYSIOLOGY. BOOK II.

new bark will graft itself with the sycamore, and in time red
maple wood will be formed beneath it. They said this lig-
neous production could not be derived from the buds of the
red maple, because the ring of bark was devoid of any ; nor
could it proceed from the buds of the sycamore, because they
would produce sycamore wood. But it is obvious that, in this
experiment, the character of the red maple wood was derived
from its medullary rays, which first formed an adhesion with
those of the sycamore, and afterwards an independent hori-
zontal formation, through which the fibres of the sycamore
descended without altering its character. The other case
was, that if a large ring of bark be taken from the trunk of a
vigorous elm or other tree without being replaced with any
thing, new beds of wood will be found in the lower as well as
upper part of the trunk ; while no ligneous production wilt
appear on the ring of wood left exposed by the removal of the
bark. Now this is so directly at variance with the observ-
ations of others, that it is impossible to receive it as an ob-
jection until its truth shall have been demonstrated. It is
well known that if the least continuous portion of liber be
left upon the surface of a wound of this kind, that portion is
alone sufficient to establish the communication between the
upper and lower lips of the wound ; but, without some such
slight channel of union, it is directly contrary to experience
that the part of a trunk below an annular incision should in-
crease by the addition of new layers of wood until the lips
of the wound are united, unless buds exist upon the trunk
below the ring.

The secretion called cambium, in the opinion of those who
believe wood and bark to be independent simultaneous form-
ations from the surface of the old wood and bark, is the
matter which finally becomes organised as such : in Du Petit
Thouars's theory it is a matter of organisation only as far as
regards the origin of the cellular tissue of the medullary rays,
and of the bark ; while the superfluity of its moisture is a pro-
vision made by nature for the nutriment of the young fibres
that descend through it.

247

CHAPTER V.

OF THE LEAVES.

Leaves are at once organs of respiration, digestion, and
nutrition. They elaborate the crude sap impelled into them
from the stem, parting with its water, adding to it carbon, and
exposing the whole to the action of air ; and while they supply
the necessary food to the young fibres that pass downwards from
them, and from the buds in the form of alburnum and liber,
they also furnish nutriment to all the parts immediately above
and beneath them. There are many experiments to show that
such is the purpose of the leaves. If a number of rings of
bark are separated by spaces without bark, those which have
leaves upon them will live much longer than those which are
destitute of leaves. If leaves are stripped off a plant before
the fruit has commenced ripening, the fruit will fall off and
not ripen. If a branch is deprived of leaves for a whole sum-
mer, it will either die or not increase in size perceptibly. The
presence of cotyledons, or seminal leaves, at a time when no
other leaves have been formed for nourishing the young plant,
is considered a further proof of the nutritive purposes of
leaves : if the cotyledons are cut off, the seed will either not
vegetate at all, or slowly and with great difficulty ; and if they
are injured by old age, or any other circumstance, they pro-
duce a languor of habit which only ceases with the life of the
plant, if it be an annual. This is the reason why gardeners
prefer old melon and cucumber seeds to new ones : in the
former the nutritive power of the cotyledons is impaired, the
young plant grows slowly, a languid circulation is induced
from the beginning ; by which excessive luxuriance is checked,
and fruit formed rather than leaves or branches.

Various are the secretions of plants that take place through
the leaves : in those of monocotyledonous tropical plants in
our hot-houses, nothing is more common than to see drops of
water forming upon them from the effect of perspiration ; in

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248 PHYSIOLOGY. BOOK II.

Limnocharis Plumieri there is a large pore terminating the
veins of the apex of the leaf, from which water is constantly
distilled. The pitchers of Nepenthes, which are only a par-
ticular kind of leaves, secrete water enough to fill half their
cavity. But, besides this more subtle fluid, secretions of a
grosser quality take place in plants. The honey dew, which
is so often attributed to insects, is one instance of the perspir-
ation of a viscid, saccharine substance ; the manna of the ash
is another; and the gum ladanum that exudes from the
Cistus ladaniferus is a third instance of this kind of per-
spiration.

It is believed that absorption takes place indifferently by
either the upper or under surface of the leaf, but that some
plants absorb more powerfully by one surface than by the
other. Bonnet found that while the leaves of Arum, the
kidney-bean, the lilac, the cabbage, and others, retained their
verdure equally long whichever side was deprived of the
power of absorption, the Plantago, some Verbascums, the mar-
vel of Peru, and others, lost their life soonest where the upper
surface was prevented from absorbing ; and that in a number
of trees and shrubs the leaves were killed very quickly by
preventing absorption by the lower surface. From this there
is only one safe conclusion to be drawn ; that the absorbing
surface of leaves varies in different species, and depends upon
their peculiar organisation.

Leaves usually are so placed upon the stem that their upper
urface is turned towards the heavens, their lower towards the
earth ; but this position varies occasionally. In some plants
they are imbricated, so as to be almost parallel with the stem ;
in others they are deflexed till the lower surface becomes
almost parallel with the stem, and the upper surface is far re-
moved from opposition to the heavens. A few plants, more-
over, invert the usual position of the leaves by twisting the
petiole half round, so that either the two margins become
opposed to earth and sky, or the lower surface becomes up-
permost : this is especially the case with plants bearing phyl-
lodia, or spurious leaves.

At night a phenomenon occurs in plants which is called
their sleep : it consists in the leaves folding up and drooping,

CHAP. V. LEAVES. 249

as those of the sensitive plant when touched. This scarcely
happens perceptibly except in compound leaves, in which the
leaflets are articulated with the petiole, and the petiole with
the stem : it is supposed to be caused by the absence of light,
and will be farther spoken of under the head of irritability.

After the leaves have performed their functions, they fall
off: this happens at extremely unequal periods in different
species. In some they all wither and fall off by the end of a
single season ; in others, as the beech and hornbeam, they
wither in the autumn, but do not fall off till the succeeding
spring ; and, in a third class, they neither wither nor fall off
the first season, but retain their verdure during the winter,
and till long after the commencement of another year's
growth : these are our evergreens. Mirbel distinguishes
leaves into three kinds, as characterised by their periods of
falling: —

1. Fugacious or caducous, which fall shortly after their
appearance ; as in Cactus opuntia.

2. Deciduous or annual, which fall off in the autumn; as
Pyrus malus.

3. Persistent, evergreen, or perennial, which remain perfect
upon the plant beyond a single season ; as Ilex aquifolium,
Primus pseudo-cerasus, &c.

With regard to the cause of the fall of the leaf a number
of explanations have been given, which may be found in
JVilldenoio's Principles of Botany, p. 336. Sir James Smith
was of opinion with Vrolik, that it is evidently a sloughing or
casting off diseased or worn out parts, and in this I agree
with them ; but neither of these authors afford any ex-
planation of the cause of this sloughing ; nor do I think that
it has been satisfactorily accounted for by any one, except
Du Petit Thouars. If you will watch the progress of a
ti-ee, — of the elder for example, — says this writer, you will
perceive that the lowest leaves upon the branches fall long
before those at the extremities. The cause of this may be,
perhaps, explained upon the following principle. In the
first instance, the base of every leaf reposes upon the medulla
of the branch to the sheath of which it is attached. But, as
the branch increases in diameter by the acquisition of new

250 PHYSIOLOGY. BOOK II.

wood, the space between the base of the leaf and the medulla
becomes sensibly augmented. It has, therefore, been ne-
cessary that the fibres by which the leaf is connected with the
medulla should lengthen, in order to admit the deposition of
wood between the bark and the medulla. Now how does this
elongation take place ? As the bundles of fibres which run
from the medulla into the leaf-stalk are at first composed
only of spiral vessels, it is easy to conceive that they may be
susceptible of elongation by unrolling. And in this seems to
lie the mystery of the fall of the leaf; for the moment will
come when the spiral vessels are entirely unrolled, and in-
capable of any further elongation : they will, therefore, by
the force of vegetation, be stretched until they snap, when
the necessary communication between the branch and the leaf
is destroyed, and the latter falls off.

It is highly probable that this interruption of the necessary
communication between the leaves and their support is the
principal cause of the fall of the leaf in all cases ; and it
seems to be strongly supported by the following phenomena :
1. the early fall of the lower leaves of plants during the
period of vegetation ; 2. the fall of the leaves of evergreen
trees, and of those whose foliage withers and persists during
winter, at the period when new wood is formed by the
operation of new shoots in the spring ; 3. the ultimate fall of
those leaves which are subject to no fixed periods of de-
foliation ; 4. the persistence of the leaves of stunted trees,
which have not formed wood enough during a single season
to cause a rupture of the conducting vessels of the petioles,
as the beech and hornbeam. The weil known indication by
which gardeners judge of their probable success in trans-
planting a tree or other plant in leaf, may also be considered
a further proof of the justness of Du Petit Thouars's theory.
On such occasions, if the leaves wither and hang upon the
branches, the omen is unfavourable ; but if they are cast off,
it is a certain indication of success. Here the action of the
spiral vessels may be understood to be impaired by the in-
terruption of the regular transmission of oxygenated air
through them, caused by the act of transplantation : as soon
as the energies of the plant are renewed, a sudden increase of

CHAP. V. LEAVES. 251

diameter supervenes, the communication is cut off between the
leaves and the stem by the too rapid extension of the spiral
vessels, and the leaves fall off.

Respiration takes place by the power the leaves possess of
inspiring and expiring oxygen and decomposing carbonic
acid. They have been found to vitiate the atmosphere at nio-ht
by inhaling oxygen abundantly, and exhaling a small quantity
of carbonic acid ; and to restore the air to its purity in the
sun's rays, by decomposing their carbonic acid and partino-
with their oxygen.

It was long since remarked by Priestley, that if leaves are
immersed in water and placed in the sun, they part with
oxygen. This fact has been subsequently demonstrated by a
great number of curious experiments, to be found in the works
of Ingenhouz, Saussure, Senebier, and others. Saussure
found that plants in cloudy weather, or at night, inhaled the
oxygen of the surrounding atmosphere, but exhaled carbonic
acid if they continued to remain in obscurity. But, as soon as
they were exposed to the rays of the sun, they respired the
oxygen they had previously inhaled, in about the same
quantity as they received it, and with great rapidity. Dr.
Gilly found that grass leaves exposed to the sun in a jar for
four hours produced the following effect : —

At the beginning of the Experiment
there were in the Jar : —

Of nitrogen - - 10.507

Of carbonic acid - - -5.7
Of oxygen ... 2:793

19.000

At the close of the Experiment there
were : —

Of nitrogen - 10.507

Of carbonic acid - - .37

Of oxygen - - 7.79

18.667

Heyne tells us that the leaves of Bryophyllum calycinum
in India, are acid in the morning, tasteless at noon, and bitter
in the evening; Link himself found that they readily stained
litmus paper red in the morning, but scarcely produced any
such effect at noon. The same phenomenon is said also to
occur in other plants, as Cacalia ficoides, Sempervivum
arboreum, &c. This stain in the litmus paper could not have
arisen from the presence of carbonic acid, as that gas will not
alter blue paper, but it must have been caused by the oxygen
inhaled at night. It has also been found that this last power

252 PHYSIOLOGY. BOOK II.

is retained even at noon, if the plant is not exposed to the
sun. A similar explanation may be given of a phenomenon
remarked by Pajot de Charmes, who found that the flowers of
Cichorium intybus were daily changed from blue to white,
according to the action of light. It is also well known that
fruit is more acid in the morning than in the evening.

As the decomposition of carbonic acid gas is thus evidently
an important part of the act of respiration, it might be supposed
that to supply a plant with a greater abundance of carbonic
acid than the atmosphere will usually yield would be attended
with beneficial consequences. To ascertain this point several
experiments have been instituted ; the most important of
which are those of Saussure, who found that, in the sun, an
atmosphere of pure carbonic acid gas, or even air, containing
as much as sixty per cent., was destructive of vegetable life ;
that fifty per cent, was highly prejudicial ; and that the doses
became gradually less prejudicial as they were diminished.
From eight to nine per cent, of carbonic acid gas was found
more favourable to growth than common air. This, however,
was only in the sun : any addition, however small, to the
quantity of carbonic acid naturally found in the air was pre-
judicial to plants placed in the shade.

Nitrogen, per se, is incapable of affording any support to
the developement of plants, as was proved by Saussure, who
found that, five days after immersion in pure nitrogen, the
buds of poplars and willows were in a state of decay. This
is remarkable, considering how large a proportion of the air
we breathe consists of nitrogen.

While oxygen and carbon are thus essential to vegetation
when not administered in excess, almost all other gases are
more or less deleterious. Drs. Turner and Christison found
that so small a quantity as to,<joo °^ sulphurous acid gas, —
a proportion so minute as to be imperceptible to the smell, — •
was sufficient to destroy the life of leaves in forty-eight hours.
The same observers state, in an excellent paper in Brewster's
Journal for January, 1828, the effects of other gases upon
plants. I much regret that want of space prevents my giving
their experiments in detail : the results, which are as follows,
are very important. — Hydrochloric or muriatic acid gas was

CHAP. V. LEAVES. 253

found to produce effects not inferior, — nay, even superior, —
to those of the sulphurous acid. It was found that so small a
quantity as a fifth of an inch, although diluted with 10,000
parts of air, destroyed the whole vegetation of a plant of
considerable size in less than two days. " Nay, we afterwards
found that a tenth part of a cubic inch in 20,000 volumes of
air had nearly the same effects. In twenty-four hours the
leaves of a laburnum were all curled in on the edges, dry and
discoloured ; and, though it was then removed into the air,
they gradually shrivelled and died. Like the sulphurous
acid, the hydrochloric acid gas acts thus injuriously in a pro-
portion which is not perceptible to the smell. Even a thou-
sandth part of hydrochloric acid gas is not distinctly per-
ceptible; a ten thousandth made no impression on the nostrils
whatever, although great care was taken to dry thoroughly
the vessels used in making the mixtures."

" Chlorine may be expected to have the effects of hydro-
chloric acid gas ; and so indeed it has, but they appear to be
developed more slowly. Two cubic inches in two hundred
parts of air did not begin to affect a mignonette plant for
three hours ; half a cubic inch in a thousand parts of air did
not injure another in twenty-four hours : but when the plants
did become affected, the same drooping, bleaching, and de-
siccation were observed."

" Nitrous acid gas is probably as deleterious as the sul-
phurous and hydrochloric acid gases. In the proportion of
a hundred and eightieth, it attacked the leaves of a mignonette
plant in ten minutes ; and half a cubic inch in 700 volumes of
air caused a yellowish green discolouration in an hour, and
drooping and withering in the course of twenty-four hours.
The leaves were not acid on the surface."

" The effects of sulphureted hydrogen are quite different
from those of the acid gases. The latter attack the leaves at
the tips first, and gradually extend their operation towards
the leaf-stalks ; when, in considerable proportion, their effects
began in a few minutes, and if the quantity was not great, the
parts not attacked generally survived, if the plants were
removed into the air. The sulphureted hydrogen acts dif-
ferently: two cubic inches in 230 times their volume of air

254 PHYSIOLOGY. BOOK II.

had no effect in twenty-four hours. Four inches and a half in
eighty volumes of air caused no injury in twelve hours; but,
in twenty- four hours, several of the leaves, without being
injured in colour, were hanging down perpendicularly from
the leaf-stalks, and quite flaccid; and though the plant was
then removed into the open air, the stem itself soon began
also to droop and bend, and the whole plant speedily fell over
and died. When the effects of a large quantity, such as six
inches in sixty times their volume, were carefully watched,
it was remarked that the drooping began in ten hours, at once
from the leaf-stalks ; and the leaves themselves, except that
they were flaccid, did not look unhealthy. Not one plant
recovered, any of whose leaves had drooped before it was
removed into the air."

" The effects of ammonia were precisely similar to those of
sulphureted hydrogen just related, except that after the leaves
drooped they became also somewhat shrivelled. The pro-
gressive flaccidity of the leaves ; the bending of them at their
point of junction with the footstalk, and the subsequent bend-
ing of the stem ; the creeping, as it were, of the languor and
exhaustion from leaf to leaf, and then down the stem, were
very striking. Two inches of gas in 230 volumes of air
began to operate in ten hours. A larger quantity and pro-
portion seemed to operate more slowly."

" Cyanogen appears allied to the two last gases in property,
but is more energetic. Two cubic inches diluted with 230
times their volume of air affected a mignonette plant in five
hours; half a cubic inch in 700 volumes of air affected another
in twelve hours; and a third of a cubic inch in 1700 volumes
of air affected another in twenty-four hours. The leaves
drooped from the stem without losing colour ; and removal
into the air, after the drooping began, did not save the plants.

" Carbonic oxide is also probably of the same class, but its
power is much inferior. Four cubic inches and a half, diluted
with 100 times their volume of air, had no effect in twenty-
four hours on a mignonette plant. Twenty-three cubic inches,
with five times their volume of air, appeared to have as little
effect in the same time; but the plant began to droop when it
was removed from the jar, and could not be revived.

CHAP. V. LEAVES. 255

" Olefiant gas, in the quantity of four cubic inches and a half,
and in the proportion of a hundredth part of the air, had no
effect whatever in twenty-four hours.

" The protoxide of nitrogen, or intoxicating gas, the last we
shall mention, is the least injurious of all those we have tried;
indeed, it appears hardly to injure vegetation at all. Seventy-
two cubic inches were placed with a mignonette plant in a
jar of the capacity of 509 cubic inches for forty-eight hours ;
but no perceptible change had taken place at the end of that
time."

Hydrogen seems to act unequally upon vegetation. Saussure
found that a plant of Lythrum salicaria, after five weeks, had
caused no alteration in a known volume of hydrogen by
which it was surrounded, and had not itself experienced any
apparent effect. Sir Humphrey Davy, however, states that
some plants will grow in an atmosphere of hydrogen, while
others quickly perish under such treatment.

In order to enable plants to perform the functions of re-
spiration, and to expose their juices to the action of the
atmosphere, leaves are furnished with special organs which
are admirably adapted to the end in view. To prevent too
rapid an evaporation beneath the solar rays, the leaf is over-
spread with a cuticle, which, as has been stated, is a hollow
plate of membrane enclosing air; and at the same time to
furnish them with the means of parting with superfluous
moisture, at periods when the cuticle offers too much resist-
ance, the stomata act like valves, and open to permit its pas-
sage : or when, in dry weather, the stem does not supply
fluid in sufficient quantity from the soil for the nourishment
of the leaves, these same stomata open themselves at night,
and allow the entrance of atmospheric moisture, closing when
the cavities of the leaf are full. In submersed leaves, in which
no variation can take place in the condition of the medium in
which they float, both cuticle and stomata would be useless,
and accordingly neither exists. For the purpose of exposing
the fluids contained in the leaves to the influence of the air,
the cuticle would frequently offer an insufficient degree of
surface. In order, therefore, to increase the quantity of sur-
face that is exposed, the tissue of the leaf is cavernous, each

'256 PHYSIOLOGY. BOOK II.

stoma opening into a cavity beneath it, which is connected
with multitudes of intercellular passages. Nor are the stomata
and the cavernous parenchyma of the leaf the only means pro-
vided for the regulation of its functions. Hairs, no doubt,
perform no mean office in their economy. In some cases
these processes seem destined only for protection against
cold, as in those plants in which they only clothe the buds
and youngest leaves, falling away as soon as the tender parts
have become hardened ; but it can hardly be doubted that in
many others they are absorbent organs, intended to collect
humidity from the atmosphere. In succulent plants, or in such
as grow naturally in shady places, where moisture already
exists in abundance, they are usually wanting ; but in hot,
dry, exposed places, where it is necessary that the leaf should
avail itself of every means of collecting its food, there they
abound, lifting up their points and separating at the approach
of the evening dews, but again falling down, and forming a
layer of minute cavities above the cuticle, as soon as the heat
of the sun begins to be perceived.

257

CHAPTER VI.

OF THE BRACTE.E, CALYX, COROLLA, AND DISK.

The bracteae, when but slightly removed from the colour
and form of leaves, no doubt perform functions similar to
those of the latter organs ; and when coloured and petaloid,
it may be pi'esumed that they perform the same office as the
corolla. Nothing, therefore, need be said of them separately.

With regard to the calyx, corolla, and disk, I shall
chiefly follow M. Dunal's statements in his ingenious pam-
phlet, Sur les Fonctions cles Organes Jloraux colores et glan-
duleux. 4to. Paris, 1829. The calyx seems, when green,
to perform the functions of leaves, and to serve as a pro-
tection to the petals and sexual organs ; when coloured its
office is undoubtedly the same as that of the corolla.

The common notion of the use of the corolla is, that, inde-
pendently of its ornamental appearance, it is a protection to
the organs of fecundation : but, if it is considered that the
stamens and pistils have often acquired consistence enough to
be able to dispense with protection before the petals are enough
developed to defend them, it will become more probable that
the protecting property of the petals, if any, is of secondary
importance only.

Among the many speculations to which those interesting
ornaments have given birth is one, that the petals and nectaria
are the agents of a secretion which is destined to the nutrition
of the anthers and young ovula. These parts are formed in
the flower-bud long before they are finally called into action:
in the almond, for example, they are visible some time before
the spring, beneath whose influence they are destined to ex-
pand. In that plant, just before the opening of the flower,
the petals are folded up ; the glandular disk that lines the
tube of the calyx is dry and scentless ; and its colour is at
that time dull, like the petals at the same period. But as
soon as the atmospheric air comes in direct contact with

s

258 PHYSIOLOGY. BOOK II.

these parts, the petals expand and turn out of the calyx, the
disk enlarges, and the aspect of both organs is altered. Their
compact tissue gradually acquires their full colour and velvety
surface ; the surface of the disk, which before was dry, becomes
lubricated by a thick liquid, exhaling that smell of honey which
is so well known. At this time the stamens perform their
office. No sooner is that effected than they wither, the petals
dry up and fall away, the secretion from the disk gradually
dries up, and, in the end, the disk perishes along with the
other organs to which it appertained. If the disk of an
almond flower be broken before expansion, it will be seen that
the fractured surface has the same appearance as that of those
parts which in certain plants contain a large quantity of faecula,
as the tubers of the potato, Cyperus esculentus, &c. This
led M. Dunal to suspect that the young disks also contained
faecula. This he afterwards ascertained, by experiment, to
be the fact in the spadix of Arum italicum before the de-
hiscence of the anthers; but, subsequently to their bursting, no
trace of faecula could be discovered. Hence he inferred that
the action of the air upon the humid faecula of the disk had
the effect of converting it into a saccharine matter fit for the
nutrition of the pollen and young ovula; just as the faecula of
the albumen is converted in germination into nutritive matter
for the support of the embryo.

In support of this hypothesis M. Dunal remarks, that the
conditions requisite for germination are analogous to those
which cause the expansion of a flower. The latter open onlv,
in a temperature above 32° Fahr., that of 10° to 30° centig.
(50° to 86° Fahr.) being the most favourable; they require a
considerable supply of ascending sap, without the watery parts
of which they cannot open ; and, thirdly, flowers, even in aquatic,
plants, will not develope in media deprived of oxygen.

Thus the conditions required for germination and for
flowering are the same : the phenomena are in both cases
also very similar.

When a germinating seed has acquired the necessary
degree of heat and moisture, it abstracts from the air a por-
tion of its oxygen, and gives out an equal quantity of carbonic
acid gas ; but, as one volume of the latter gas equals one.

CHAP. VI. FLOWERS. 259

volume of oxygen, it is evident that the seed is, in tins way,
deprived of a part of its carbon. Some changes take place
in the albumen and cotyledons ; and, finally, the fsecula that
they contained is replaced by saccharine matter. In like
manner a flower, while expanding, robs the air of oxygen, and
gives out an equal volume of carbonic acid; and a sugary
matter is also formed, apparently at the expense of the faecula
of the disk or petals.

The quantity of oxygen converted into carbonic acid gas in
germination is, cccteris paribus, in proportion to the weight of
the seed ; but some seeds absorb more than others. Theodore
de Saussure has shown that exactly the same phenomenon
occurs in flowers.

Heat is a consequence of germination; the temperature is
also augmented during flowering, as has been proved by
Theodore de Saussure in the Arum, the gourd, the Bignonia
radicans, Polyanthes tuberosa, and others.

The greater part of the saccharine matter produced during
germination is absorbed by the radicle, and transmitted to the
first bud of the young plant. M. Dunal is of opinion that
the sugar of the nectary and petals is in like manner conveyed
to the anthers and young ovula, and that the free liquid
honey which exists in such abundance in many flowers, is a
secretion of superabundant fluid, since it can be taken away,
as is well known, without injury to the flower.

This opinion will probably be considered the better founded,
if it can be shown that the disengagement of caloric and de-
struction of oxygen are in direct relation to the developement
of the glandular disk, and also are most considerable at the
time when the functions of the anthers are most actively
performed.

In no plants, perhaps, is the glandular disk more developed
than in Arums ; and it is here that the most remarkable degree
of developement of caloric has been observed. Senebier found
that the bulb of a thermometer, applied to the surface of the
spadix of Arum maculatum, indicated a temperature 7° higher
than that of the external air. M. Hubert remarked this in
a still more striking degree upon Arum cordifolium at the
Isle of France. A thermometer placed in the centre of five

s 2

260

PHYSIOLOGY.

BOOK II.

spadixes stood at 111°, and in'the centre of twelve, at 121°,
although the temperature of the external air was only 66°.
The greatest degree of heat in these experiments was at sun-
rise. The same observer found that the male parts of six
spadixes, deprived of their glandular part, raised the tem-
perature only to 1 05°; and that the same number of female
spadixes only to 86°; and, finally, that the heat was wholly
destroyed by preventing the spadix from coming in contact
with the air.

From experiments of Saussure it seems certain that the dis-
engagement of heat, and, consequently, destruction of oxygen,
is chiefly caused by the action of the anthers, or at least of
the organs of fecundation, as appears from the following
table : —

Names.

Duration

of the

Experiment.

Oxygen destroyed.

By the bud.

By the
flower dur-
ing its ex-
pansion.

By the
flower in
withering.

Passiflora serratifolia
Hibiscus speciosus
Cucurbita maxima,

male flower -
Arum italicum, spadix

cold -
— — — — spadix hot
24 hours after

12 hours.

24

24

24

6 times its vol.
6

7,4

5 to 6

12

8,7

12
30

7
7

10

5

It was also found that flowers in which the stamens, disk,
pistil, and receptacle only were left, consumed more oxygen
than those that had floral envelopes, as is shown by the fol-
lowing table : —

Species.

Duration

of the

Experiment.

Oyxgen destroyed.

By the flowers entire.

By the usual organs
only.

Cheiranthus incanus
Tropaeolum majus -
Cucurbita maxima,

male
Hypericum calycinum
| Hibiscus speciosus
1 Cobaea scandens

24 hours.

24

10
24
12
24

1 1 '5 times their vol.
8-5

7-6
7-5
54
6-5

18 times their vol.
163

16-0

8-5
6-3

7-5

CHAP. VI. FLOWERS. 261

And it is here to be noticed, that those whose sexual ap-
paratus destroyed the most oxygen have the greatest quantity
of disk, and vice versa ; with the exception of Cobaea scandens,
in which the disk is very firm and persistent, and, probably,
therefore acts very slowly.

When the cup-shaped disk of the male flowers of the
gourd was separated from the anthers, the latter only con-
sumed 1 1*7 times their volume of oxygen in the same space of
time which was sufficient for the destruction of sixteen times
their volume when the disk remained. The spatha of Arum
maculatum consumed, in twenty-four hours, five times its
volume of oxygen; the termination of the spadix thirty times;
the sexual apparatus 132 times, in the same space of time.

An entire Arum dracunculus, in twenty-four hours, de-
stroyed thirteen times its volume of oxygen ; without its spatha
fifty-seven times ; cut into four pieces, its spatha destroyed
half its volume of oxygen ; the terminal appendix twenty-six
times; the male organs 135 times; the female organs ten
times.

The same ingenious observer also ascertained that double
flowers, that is to say those whose petals replace sexual
organs, vitiate the air much less than single flowers, in which
the sexual organs are perfect.

Is it not then, concludes M. Dunal, probable that the con-
sequence of all these phenomena is the elaboration of a matter
destined to the nutriment of the sexual organs? since the
production of heat and the destruction of oxygen are in direct
relation to the abundance of glandular surface, and since these
phenomena arrive at their maximum of intensity at the exact
period when the anthers are most developed, and the sexual
organs in the greatest state of activity.

M. De Candolle has remarked, that the colouring matter of
the corolla is probably very different from that of the leaves,
since it will not etiolate by the exclusion of light. It may,
however, be doubted whether this is strictly correct ; for it is
well known that forced flowers have little colour without full
exposure to light, and that the intensity of colour in blossoms
produced in stoves in winter is far less than that of the same
species flowering in the open air in summer.

S 3

262 PHYSIOLOGY. BOOK II.

CHAPTER VII.

OF THE STAMENS AND PISTILLUM.

Having already, in the last chapter, explained the chemical
action of the stamens and pistilla, I shall now confine myself
to the consideration of their physical effect upon each other.

The duty of the stamens is to produce the matter called
pollen, which has the power of fertilising the pistillum through
its stigma. The stamens are therefore the representatives in
plants of the male sex, the pistillum of the female sex.

The old philosophers, in tracing analogies between plants
and animals, were led to attribute to the former distinction of
sexes, chiefly in consequence of the practice among their
countrymen of artificially fertilising the female flowers of the
date with those which they considered male, and also from
the existence of a similar custom with regard to figs. This
opinion, however, was not accompanied by any distinct idea
of the respective functions of particular organs ; nor was it
generally applied, although Pliny, when he said that " all
trees and herbs are furnished with both sexes," may seem to
contradict this statement; the fact is, that his was rather an
empirical notion than an opinion depending upon philoso-
phical deduction. Nor does it appear that any more distinct
evidence existed of the universal sexuality of vegetables till
about the year 1676, when it was for the first time distinctly
pointed out by Grew. Claims are, indeed, laid to a priority of
discovery over this great observer by Caesalpinus, Malpighi,
and others ; but there is nothing so precise in their works as
we find in the declaration of Grew, " that the attire (meaning
stamens) do serve as the male for the generation of the seed."
It would not be useful, if I had the space, to enter into any
detailed account of the gradual advances which these opinions
made in the world, nor to trace the progress of discovery of
the precise nature of the several parts of the stamens and
pistillum. Suffice it to say that, in the hands of Linnaeus, the

CHAP. VII. STAMENS AND PISTILLUM. 263

doctrine of the sexuality of plants was finally established,
never again to be seriously controverted ; for the denial of this
fact, which has been since occasionally made by a few men,
such as Alston, Smellie, and Schelver, has merely exposed
the weakness of such hypercritics. We know that the powder
which is contained in the case of the anthers, and which is
called pollen, must generally come in contact with the viscid
surface of the stigma, or no fecundation can take place. It
is possible, indeed, without this happening, that the fruit may
increase in size, and that the seminal integuments may even
be greatly developed ; the elements of all these parts existing
before the action of the pollen can take effect: but, under
such circumstances, whatever may be the developement of
either the pericarpium or the seeds, no embryo can be formed.
I have said that it is generally indispensable that the pollen
and the stigma should come in contact. To this, however,
there is a notable exception in Orchideous plants, in which
nature seems to have specially guarded against the pollen
coming in contact with the stigma by locking it up in cells
from which it is not readily disengaged ; and to have provided,
in the form of glands and other apparatus of the stigma,
peculiar means of conveying the impregnating matter to the
stigma without actual contact between the latter and the
pollen. Mr. Brown has, indeed, attempted to show that even
in these plants actual contact between the two parts is neces-
sary, as, indeed, Monsieur Adolphe Brongniart had done
before him ; but the evidence to the contrary is so strong
that we pause for proof before we admit the conjectures and
statements that have been brought forward upon this subject.
Another order, that of Asclepiadeae, has also been included in
the number of those in which fertilisation takes place through
peculiar glands, without actual contact between stigma and
pollen ; but Mr. Brown states, that in this tribe the grains of
pollen are enclosed in a kind of sac, the most prominent
part of the convex edge of which is applied to the stigma
when fecundation is about to occur ; and then a number of ex-
tremely slender threads, each of which is the pollen tube of a
single grain, are emitted from this edge into the tissue of the
stigma : almost every grain in the sac is said to produce its

s 4

264f PHYSIOLOGY. BOOK II.

tube, and the tubes to be directed from all parts of it towards
the point of dehiscence.

This universality of sexes in vegetables must not, however,
be supposed to extend further than what are usually called,
chiefly from that circumstance, perfect plants. In cryptogamic
plants, beginning with ferns, and proceeding downwards
to fungi, there are either no sexual organs whatever, or the
males are so imperfectly developed as to be invisible or of
no effect.

The exact mode in which the pollen took effect was for a
long time an inscrutable mystery, and is even now not fully
explained. It was generally supposed, that, by some subtle
process, a material vivifying substance was conducted into the
ovula through the style ; but nothing certain was known upon
the subject until the observations of Amici and of Adolphe
Brongniart had been published. It is now known, that a
short time after the application of the pollen to the stigma
each grain of the former emits a tube of extreme tenuity, not
exceeding the 1500dth or 2000dth of an inch in diameter, which
pierces the conducting tissue of the stigma, and finds its way
down to the region of the placenta, including within it the
active molecules found in the grain ; no one has actually seen
the tubes pass further than the placenta; but there appears
to be good reason for supposing that the vivifying matter
communicated by the pollen tubes to the placenta is by some
unknown means transmitted by the latter to the foramen of the
ovulum, through which it finally passes into the nucleus, there
to become the new embryo. In order to facilitate the contact
between the placenta and the foramen of the ovulum, some
very curious contrivances have been remarked. In Euphorbia
Lathyris the apex of the nucleus is protruded far beyond the
foramen, so as to lie within a kind of hood-like expansion of
the placenta : in all campulitropous ovula the foramen is
bent downwards, by the unequal growth of the two sides, so
as to come in contact with the conducting tissue ; and in
Statice Armeria, Daphne Laureola, and some other plants,
the surface of the conducting tissue actually elongates and
stops up the mouth of the ovulum, while impregnation is
taking effect. Again, in Helianthemum and Cistus, which,

CHAP. VII. STAMENS AND PISTILLUM. 265

like the rest of their tribe, have the foramen of the ovulum
very remote from the placenta, Mons. Adolphe Brongniart
has observed, that, at the period of impregnation, the ovula
are bent down in such a way as to present their foramina to
the conducting tissue ; and that when, owing to the shortness
of the umbilical cords this is impossible, other not less in-
genious means of establishing the contact have been provided
by nature.

The function of the stigma has been already shown to be
to catch the grains of pollen. This is a mere mechanical
operation, and is effected by a viscid secretion, which is gene-
rally exuding from the surface of the stigma; which is also
generally covered with minute papillae, or sometimes with
fringes, all of which, undoubtedly, aid the action of the
organ. In some plants, as in Compositae, Campanulaceae,
Lobeliaceae, &c. the style is furnished with a sort of brush,
with which it sweeps out the cells of the anthers, and collects
the pollen either upon its own stigma, or scatters it upon that
which is next it.

/V/o /n <r

, ^ J M z^~l ft* ^

266 PHYSIOLOGY. BOOK II.

CHAPTER VIII.

OF THE FRUIT.

The fruit, which is mechanically destined as a mere protec-
tion to the seed, by which its race is to be maintained, is also,
next to the wood, the most important part in the productions
of vegetation. It constitutes the principal part of the food,
especially in winter, of birds and small animals ; it is often
more ornamental than the flowers themselves, and it con-
tributes most materially to the necessities and luxuries of
mankind. When ripe, it falls from the plant, and, borne down
by its weight, lies on the ground at the foot of the individual
that produced it: here its seeds vegetate, when it decays, and a
crop of new individuals arises from the base of the old one ; but,
as plants produced in such a manner would soon choke and
destroy each other, nature has provided a multitude of ways
for their greater dispersion. Many are carried to distant spots
by the animals which eat them ; others, provided with a sort
of wings, such as the Samara, and the pappus of Compositae,
fly away upon the wind to seek a distant station ; others scat-
ter their seeds abroad by an explosion of the pericarpium,
caused by a sudden contraction of the tissue ; others falling
upon the surface of streams, are carried along by the current ;
while others are dispersed by a variety of methods which it
would be tedious to enumerate. The fruit, during its growth,
is supported at the expense of the sap generally ; but most
especially of that which had been previously accumulated for
its maintenance. This is less apparent in perennial or ligne-
ous plants than in annual ones, but is capable of demonstra-
tion in both. Mr. Knight has well observed, that in annual
fruit-bearing plants, such as the melon, if a fruit is allowed to
form at a very early period of the life of the plant, as, for instance,
in the axilla of the third leaf, it rarely sets or arrives at ma-
turity, but falls off soon after beginning to swell, from want
of an accumulation of food for its support ; while, if the same

CHAP. VIII. FRUIT. 267

plant is not allowed to bear fruit until it has provided a con-
siderable supply of food, as will be the case after the leaves
are fully formed, and have been some little time in action,
the fruit which may then set swells rapidly, and speedily
arrives at the highest degree of perfection of which it may be
susceptible. And in woody trees, also, a similar phenomenon
occurs : it is well known to gardeners, that, if a season occurs
in which trees in a state of maturity are prevented bearing
their usual crops, the succeeding year their fruit is unusually
fine and abundant ; owing to their having a whole year's extra
stock of accumulated sap to feed upon.

The cause of the fruit attracting food from surrounding
parts is probably to be sought in the phenomenon called endos-
mose. All the sap that may be at first impelled into the fruit by
the action of vegetation, not being able to find an exit, collects
within the fruit, and, in consequence of evaporation, becomes
gradually more dense than that in the surrounding tissue : it
will then begin to attract to itself all the more aqueous fluid
that is in communication with it; and the impulse once given
in this way to the concentration of the sap in particular points
will continue until the growth of the fruit is completed, and
its tissue so much gorged as to be incapable of receiving any
more food, when it usually falls off.

M. Berard, of Montpelier, has made some curious ob-
servations upon the chemical actions of fruit, the substance of
which is as follows (See Annates de Chimie, vol. xvi. pp. 152.
225.: —

Fruit does not act like leaves on the air. The result of its
action, as well in light as in darkness, is, at every instant of
its formation, a loss of carbon by the fruit, which combines
with the oxygen of the air, and forms carbonic acid. This
loss of carbon is essential to the ripening of the fruit; for,
when the fruit is placed in an atmosphere deprived of oxygen,
this function becomes suspended, the ripening is stopped, and,
if the fruit remains attached to the tree, it dries up and dies.

A fruit which happens naturally to be enclosed in a shell
may, nevertheless, ripen, because the membrane which forms
the husk is permeable to the air. The communication be-
tween the external and internal air is so free, that the two

268 PHYSIOLOGY. BOOK II.

portions are always of uniform composition ; so that when
the air thus contained is analysed, it is always found to be of
the same composition as atmospheric air.

When fruits, separated from the tree, but capable of com-
pleting their own ripening, are placed in media free from
oxygen, they do not ripen : the power, however, is only sus-
pended, and may be re-established by placing the fruit in an
atmosphere capable of taking carbon from it. But, if the
fruit remain too' long in the first situation, although it pre-
serves the same external appearance nearly, it has entirely lost
the power of ripening.

Hence it results, that most fruits, and especially those that
do not require to remain on the tree, may be preserved for
some time, and the pleasure they afford us thus prolonged.
The most simple process consists in placing at the bottom of
a bottle, a paste formed of lime, sulphate of iron, and
water, and afterwards to introduce the fruit, it having been
pulled a few days before it would have been ripe. Such
fruits are to be kept from the bottom of the bottle, and,
as much as possible, from each other ; and the bottle to be
closed by a cork and cement. The fruits are thus placed in
an atmosphere free from oxygen, and may be preserved for a
longer or shorter time, according to their nature ; peaches,
prunes, and apricots, from twenty days to a month : pears
and apples for three months. If they are withdrawn after
this time, and exposed to the air, they ripen extremely well ;
but, if the times mentioned are much exceeded, they undergo
a particular alteration, and will not ripen at all.

Ripe fruit exposed to the air rots and decays : in this case,
it first changes the oxygen of the surrounding air into car-
bonic acid, and then liberates from itself a large quantity of
the same acid gas. It appears that the presence of oxygen
gas is necessary to the rotting or decay of fruits : when it is
absent, a different change takes place.

When the fruit cannot ripen, except on the tree, its ripen-
ing is not produced by a chemical change of the substances
it contained whilst still green, but by the change of new sub-
stances furnished to it by the tree; and when it appears to
lose the acid taste it had in its unripe state, it is because that

CHAP. VIII. FRUIT. 269

taste is hidden by the large quantity of sugar it receives in
ripening.

In the fruits which ripen off the tree the quantity of sugar
is also found considerably to increase; and, in this case, it
must be formed at the expense of the substances previously
in the fruit. Gum and lignin are the only principles the
proportion of which diminish at the same time ; it is, therefore,
natural to conclude, that it is the portions of these substances
which have disappeared that have been converted into sugar ;
and, as the lignin contains most carbon, it is natural to sup-
pose it is from it the oxygen takes the carbon to form car-
bonic acid, that change so indispensable to ripening.

Finally, the alteration the lignin suffers in the ripening
continues during the decay of the fruit. It becomes brown,
and its decomposition occasions the formation of much car-
bonic acid : sugar is also decomposed at this time, and it is
to its disappearance that the peculiar taste of decayed fruits
is to be attributed. The sugar, in its decomposition, also
gives rise, no doubt, to the formation of carbonic acid.

270 PHYSIOLOGY. BOOK II.

CHAPTER IX.

OF THE SEED.

The action of the seed is confined to that phenomenon which
occurs when the embryo that it contains is first called into
life, and which is named germination.

Excepting at this time the seed is an inert mass, often con-
taining nutritious matter, or some of the secretions of the
species, and covered with a skin, which is in many cases so
efficient a protection to the young embryo, that the seeds are
enabled to resist, not only, as is well known, the powerful
action of the gastric juice, after having been taken into the
stomach of animals, but even that of exceedingly high tem-
peratures. Spallanzani has stated, that he caused seeds to
germinate after immersion in boiling water; and a case is
mentioned by Duhamel, in which seeds retained their vitality
after an exposure to 235° of Fahrenheit. These are, however,
rare cases.

The earliest indication of germination consists in the parts
of the seeds swelling, in consequence of the absorption of
water by their cuticle, and a chemical change taking place
in the nature of its juices. This is said to depend upon a
loss of carbon, and an addition of oxygen, without which
latter in abundance, it is believed that seeds cannot germinate
at all. It is this which causes the starch of barley to be con-
verted into sugar in malt. For this reason it has been recom-
mended, that muriatic acid, chlorine, and various metallic
oxides, should be used in inducing the rapid germination of
seeds. Humboldt, Willdenow, and others, have declared their
use to be advantageous. Link says the same ; others deny the
utility ; and I believe that their action is very doubtful.

It is well known, that seeds will not germinate in the light.
This is caused by light decomposing the carbonic acid gas,
expelling the oxygen, and fixing the carbon, whence all the

CHAP. IX. SEED. 271

parts become hardened; a condition under which vegetation
cannot proceed.

If seeds are sown as soon as they are gathered, they gene-
rally vegetate at the latest in the ensuing spring; but if they
are dried first, it often happens that they will lie a whole year
or more in the ground without altering. This character
varies extremely in different species : the power of preserving
their vitality is also extremely variable; some will retain their
germinating powers many years, in any latitude, and under
almost any circumstances. Clover will come up from soil
newly brought to the surface of the earth, in places in which
no clover had been previously known to grow in the memory
of man. Many of the rarest plants in our gardens have been
raised from old seeds, taken off specimens in herbaria : others
perish so soon, that a few days' exposure is sufficient to
destroy them. This is particularly the case with such as
contain much oil.

As those conditions which are necessary to the germination
of seeds are, heat, moisture, and darkness, it follows, that, in
order to prevent this occurring, these three conditions are, if
possible, to be obviated. Thus, in packing seeds for tra-
velling to a long distance, it is found, by experience, that no
mode is so suitable for their conveyance as being packed
loosely in coarse canvass bags, hung to the ceiling of the cabin
of a ship; where they are exposed to light and air, and where
they are protected from damp : this is much better than
enveloping them in wax, or mixing them with sugar, as has
been sometimes done ; both pernicious practices. It has been
thought, that if seeds were mixed with charcoal, as their
carbon would, under such circumstances, always be in excess
to their oxygen, their vegetation might be safely suspended.
But it has not been found, from experience, that any practical
advantage arises from this method ; seeds perishing in char-
coal as quickly as in most other media. The best material
is the English coarse brown paper, made from old tarred
rope, in which a large quantity of tar is incorporated. No
material will preserve seeds so long a time as this ; while
cartridge paper offers them no protection whatever.

272 PHYSIOLOGY. BOOK II.

The germination of seeds may be retarded by excluding
them from light, and surrounding them with moist earth,
rammed very hard : mango-seed, packed in hard clay, will thus
travel safely from the West Indies ; it was thus that the
Araucaria Dombeyi was first brought to England from Chili ;
and many other seeds, which cannot otherwise be transported
will live a long time under such circumstances.

As soon as the chemical changes now spoken of have taken
effect, the embryo swells and bursts its envelopes, protruding
its radicle, which pierces the earth, deriving its support at first
from the cotyledons or albumen, but subsequently absorbing
nutriment from the earth, and communicating it upwards to
the young plant. The manner in which the embryo clears
itself from its integuments differs in various species ; some-
times it dilates equally in all directions, and bursts through its
coat, which thus becomes ruptured in every direction ; more
frequently the radicle passes out at the hilum, or near it, or
at a point apparently provided by nature for that purpose, as
in Canna, Commelina, &c. If the radicle has a coleorhiza
or rootsheath, this is soon perforated by the i-adicle con-
tained within it, which passes through the extremity ; as in
grasses, and most monocotyledonous plants. The cotyledons
either remain under ground, sending up their plumula from
their centre, as the oak ; or from the side of their elongated
cauliculus, as monocotyledons ; or they rise above the ground,
acquire a green colour, and perform the ordinary functions of
leaves, as in the radish and most plants. In the mangrove
germination takes place in the pericarpium before the seed
falls from the tree ; a long thread-like radicle is emitted,
which elongates till it reaches the soft mud in which such trees
usually grow, where it speedily strikes root, and separates
from its parent. Trapa natans has two very unequal cotyle-
dons ; of these, the larger sends out a very long petiole, to the
extremity of which are attached the radicle, the plumula, and
the smaller cotyledon (Mirbel). Cyclamen germinates like a
monocotyledon : its single cotyledon does not quit the seed
till the end of germination ; and its radicle thickens into a
fleshy knob, which roots from its base (Mirbel). The Cuscuta,

CHAP. IX. SEED. 273

which has no cotyledons, strikes root downwards, and lengthens
upwards, clinging to any thing near it, and performing all the
functions of a plant without either leaves or green colour.

In monocotyledons the cotyledon always remains within
the seminal integuments ; while its base lengthens and emits a
plumula. In Cycas, which has two cotyledons, the seminal
integuments open, and the radicle escapes. The cotyledons
remain within the integuments, in the oak ; but their petioles
lengthen and liberate the plumula.

274 PHYSIOLOGY.

BOOK II.

CHAPTER X.

OF COLOUR, SMELL, AND TASTE.

Upon this obscure subject Link has some good observ-
ations, the substance of which is as follows : —

The ordinary membranes and juices of plants are destitute
of colour : they acquire colour by losing oxygen and ac-
quiring carbon. Mucilage, sugar, starch, gluten, and other
principles of that kind, are entirely devoid of colour or white.
So also are vegetable membranes freed from foreign matter.
The addition of oxygen makes no difference ; for all the pure
acids of plants are white : but azote seems to possess a great
power of discolouration.

Young roots are white ; but their epidermis becomes
burned, as it were, by the surrounding atmosphere parting
with its hydrogen in forming water, and thus acquires a brown
or blackish cast. Some remarks upon this mode of staining
bodies are to be found in the Annales de Chimie, vol. v. p. 80.,
by Fourcroy; and in volume vi. p. 238. of the same work, by
Berthollet. In- woody roots the colouring principle generally
becomes red.

Young stems are green like the leaves : as they grow older
they are scorched like the roots. Within the stem a colour-
ing principle is formed, which seems to own its colour to
extractive matter in itself colourless; leaves are green from
loss of oxygen. If light is absent, and oxygen accumulates
in the green parts, those lose their colour ; but become green
again upon exposure to light. Humboldt has some excellent
remarks upon this in the Journal de Physique, vol.xl. p. 151.
He has there demonstrated, that not only light, but every
other agent which attracts oxygen from plants, will equally
produce green colour.

When leaves become sickly, they admit an unusual quantity
of oxygen, in consequence of which the green principle

CHAP. X. COLOUR, SMELL, AND TASTE. 275

changes to yellow or red, as we see in sickly or dying
leaves.

Where plants have lost their colour, from being placed in
darkness, they contain a smaller quantity of principles soluble
in alcohol than when in a green state, as has been shown by
Senebier in his Physiologie Vege/ale, vol. iv. p. 278. Hence,
principles deprived of oxygen which are soluble in alcohol
are produced only under exposure to light.

The colour of flowers depends upon their degree of dis-
oxydation, and may be arranged thus: 1. red changing into
blue ; 2. blue ; 3. yellow ; and, 4. scarlet, which is a modi-
fication of yellow : green is very uncommon.

Fruit is at first green : it is afterwards either scorched by
dryness, or, by the retention of oxygen, becomes sweet or
acid.

Mineral colours are known to depend upon particular
proportions of water : as, for instance, sulphate of copper.
Can they depend in plants upon a similar cause ; that is to
say, upon particular proportions of oxygen and hydrogen?

The odours of plants depend upon a certain volatile oil,
which varies extremely in different species. It is more or less
volatile, more or less soluble in alcohol, and more or less
miscible in water ; on which accounts there is a great differ-
ence in the readiness with which it yields to distillation.
This is especially apparent in the oil of roses, which, in hot
countries, or in hot weather, passes over very readily ; but,
in cold seasons, inseparably combines with the water used in
distillation.

There is no doubt that particles of the odoriferous oil are
continually flying off; and it has even been asserted, that
those of Dictamnus albus will inflame upon the application of
fire.

In proportion to the more or less volatile nature of their
oil are the odours of plants more or less diffused. Hence in
the same plant several scents may be distinguished, some at a
distance, some on a near approach, as in the flowers of Vicia
Faba. Some odours are not perceptible until the parts of a
plant are. rubbed, or they are more copiously given out when
this is done. Some are most apparent in the recent state,

T 2

276 PHYSIOLOGY. BOOK II.

others in the dried, as is the case with the melilots: in these
the odoriferous juices are combined with too much water,
which it is necessary to separate by drying before the fra-
grance is apparent.

Some flowers scatter their fragrance only at night : this is
particularly the case with Cruciferae, having dingy yellowish
brown petals. In these the volatile oil is either so rapidly
dispersed in the day-time as to be imperceptible ; while it is
more slowly and densely evolved in the night: or it may be
decomposed in the day-time by the extrication of oxygen.

Plants in hot countries are more fragrant than those of
cold countries, as is apparent in the rose ; but their fragrance
is sometimes so much dispersed by heat as to be imperceptible.
Nocca found the Calendula lose its smell in a hot-house ; and
the common horehound is destitute of smell in Portugal.

The tastes of plants are sweet, acid, bitter, astringent, or
austere and acrid. Vegetable membrane and resins commu-
nicate no taste to the palate, as they do not dissolve in the
mouth. Mucilage has no flavour ; sweetness is derived from
the presence of sugar, and acidity of acids ; bitterness usually
denotes the presence of extractive matter. The extractive
principle may be compared with neutral salts, which are
usually bitter, as sulphate of potash, lime, and magnesia com-
bined with acids and others ; for, as a neutral salt consists of
a metal, inflammable matter, and oxygen, so extractive matter
consists of carbon, hydrogen, and oxygen. The astringency
of minei-als is only perceptible in those neutral salts that con-
tain acid in excess, as alumine, sulphate of iron, sulphate
of copper, and others. With these we may compare the
astringent principle of vegetables, which also contains acid in
excess ; for it not only combines with the earths, but also
stains litmus paper red : the carbon and hydrogen it con-
tains may be compared with a metal and combustible matter.
That kind of taste which is called herbaceous is caused by a
mixture of mucilage with a little astringency. An acrid taste
is almost peculiar to volatile oils.

277

CHAPTER XI.

OF THE DIRECTIONS TAKEN BY THE ORGANS OF PLANTS.

The substance of all that is known upon this subject has
been combined with some excellent observations of his own
by Dr. Dutrochet in a memoir, of which I shall avail myself
in the following remarks : —

"The general phenomena of nature," says thiswriter, "which
are daily before our eyes, are often those which mankind con-
siders the least attentively. Those who are unaccustomed to
reflect upon such subjects can scarcely believe that there is
any very extraordinary mystery in the ascent of the stems of
vegetables, or in the descent of their roots ; and yet this is
one of the most curious circumstances connected with vesreta-
ble life. The downward direction of the roots may appear
easy of explanation : it may be said that, like all other bodies,
they have a tendency towards the centre of the earth, in
consequence of the known laws of gravity ; but on what prin-
ciple, then, is to be explained the upward tendency of the stem,
which is in direct opposition to those laws? and here lies the
difficulty. Dodart is the first who appears to have paid atten-
tion to this circumstance : he pretends to explain the turning
backwards of seeds sown in an inverted position by the fol-
lowing hypothesis : he assumed that the root is composed of
parts that contract by humidity; and that the stem, on the
contrary, contracts by dryness. For this reason, according
to him, it ought to happen that, when a seed is sown in an
inverted position, the radicle will turn back towards the earth,
which is the seat of humidity ; and that the plumula) on the
contrary, turns to the sky, or rather atmosphere, — a drier me-
dium than the earth. The experiments of Du Hamel are well
known, in which he attempted to force a radicle upwards and
a plumula downwards, by enclosing them in tubes, which
prevented the turning back of these parts. It was found that,
as the radicle and plumula could not take their natural direc-

t 3

278 PHYSIOLOGY. BOOK II.

tion, they became twisted spirally. These experiments, while
they prove that the opposite tendencies of the radicle and
plumula cannot be altered, still leave us in ignorance of the
cause of such tendencies. We are equally ignorant of the
oause of the directions of the leaves. Bonnet believed that he
could explain that phenomenon upon the hypothesis of Do-
dart just referred to, with respect to the radicle and plumula.
According to him the lower surface of the leaves is, like the
radicle, composed of fibres which contract by humidity; and the
upper, like the plumula, of fibres that contract by dryness.
As a proof of these assertions, Bonnet manufactured some
artificial leaves ; the upper surface of which was parchment,
which contracts by dryness, and the lower of linen, which
relaxes by moisture. These leaves were submitted to the
action of dryness and humidity ; and Bonnet found they were
affected much in the same way as true leaves, — so easy is it to
find proofs to support a favourite hypothesis."

In consequence of the unsatisfactory nature of these and
other theories, more modern physiologists have been satisfied
with inscribing the particular directions taken by plants
among the vital phenomena of vegetation. And this is, per-
haps, as much as we are likely to ascertain relating to it, and
all similar manifestations of the overruling power of nature.
Dutrochet, however, being of opinion that some more direct
explanation of this phenomenon is to be found, instituted a
variety of experiments of a novel kind. " Seeing," he remarks,
" that the stem is always directed towards heaven, and the
roots towards the earth, we cannot but believe that there is
some relation between the cause of gravitation and that of
the life of vegetables : the constant direction of the stem
towards the light leads us also to suppose that this agent per-
forms some important part in determining the directions of
the parts of plants. The stem must be placed in the midst
of the atmosphere in order to develope itself; the roots,
on the contrary, require to lie within the earth. Hence, it
may be inferred, that several causes concur to produce the
phenomena in question."

Dutrochet filled with earth a box, the bottom of which was
perforated with many holes : he placed seed of the kidney-

CHAP. XI. DIRECTIONS. 279

bean in these holes, and suspended the box in the air, at
about eighteen feet from the earth. Here the seeds, bein<*
placed in holes pierced through the bottom of the box,
received the influence of the atmosphere and light from below;
while the humid earth was placed above them. If the cause
of the different directions of the radicle and plumula con-
sisted in an affinity of the former for humidity, and of the
latter for the atmosphere, the radicle ought to shoot upwards,
and the plumula downwards ; but this did not take place.
The radicles, on the contrary, found their way downwards
out of the box into the atmosphere, where they quickly dried
up and perished ; and the plumulas forced their way back-
wards into the earth. This experiment was afterwards
modified, by increasing the quantity of earth above the seeds,
and by some other contrivances ; but the result was always
the same: it was uniformly found, that there was no affinity
between the radicle and the seat of moisture sufficient to
counteract the natural downward tendency of the roots. It
was also inferred, that there existed no more positive affinity
between the stems and the atmosphere than between the roots
and water.

There are certain parasitic plants which strike their roots
into the stems of other plants, and which always grow at
right angles with the stem to which they are fixed. The
seed of the miseltoe will germinate in any direction, either
upwards, downwards, or laterally. The first movement made
by this plant consists in an extension of its cauliculus, which
derives its support from the cotyledons, and which terminates
at the radicular end, in a small green tubercle of a paler
colour than the radicle itself. When the seed is fixed upon
a branch by its natural glue, this incipient movement is
effected at right angles with the branch ; the young shoot is
then curved backwards, and the radicular extremity descends
to the surface of the branch, to which it adheres by expanding
into a kind of disk. From this expansion the roots are
emitted, and penetrate the interior of the branch whereon
the seed of the miseltoe is fixed: its stem takes the directions
above mentioned with reference to the centre of the branch on
which it is fixed, and not with reference to the earth ; so that,

t 4

280 PHYSIOLOGY. BOOK II,

with regard to the latter, it is sometimes ascending, some-
times descending, sometimes horizontal. The same phe-
nomena occur if the germination takes place upon dead wood
or inorganic substances : a number of seeds were glued to the
surface of a cannon ball ; all the radicles were directed
towards the centre of the ball. Hence it is obvious that the
tendency of the miseltoe is not towards the surface of its
nutrition, but it obeys the attraction of the body upon which
it grows. The miseltoe, which does not grow on the earth,
obeys the attraction of any other body ; while those plants
which naturally grow in the earth obey no other attraction
than that of the earth. Parasitical fungi, those which con-
stitute mouldiness ; aquatics, which originate on stones, all
grow perpendicular to the body that produces them, and will
therefore be placed in all kinds of positions with respect to
the earth.

The tendency downwards of the roots, and upwards of the
stem, is chiefly observable in the ascending and descending
caudex ; that is to say, in the axes of the vegetable considered
as a whole. The lateral emissions of this axis always deviate
from its direction in a greater or less degree : we know that
the roots produced by the tap root, and the branches which
proceed from the side of the principal stem, scarcely ever
take a direction absolutely vertical. This is probably due to
several causes, one of which is undoubtedly the general ten-
dency of all the parts of plants to take a direction perpen-
dicular to the plane of the body on which they grow. The
branches of trees are to those which produce them what the
miseltoe is to the branch on which it vegetates : but, as there
is a double attraction operating upon all branches, — that is to
say, an attraction towards the stem and an attraction upwards,
in consequence of the general law to which they all submit, —
it results that a middle direction is taken, and, instead of one
branch continuing to grow at right angles with another, it
soon abandons that direction, and points its extremity towards
the sky.

It has been hitherto seen, that the roots of vegetables are
positively attracted by the body on which they grow: it ap-
pears, however, from the following experiment, that this

CHAP. XI. DIRECTIONS. 281

attraction is influenced. essentially by the mass of the body.
Thus, if a seed of miseltoe is made to vegetate on a thread,
the radicle turns itself in all sorts of ways, and exhibits no
signs of attraction to the thread. Dutrochet made a seed of
miseltoe germinate on a thread : he then glued it upon one of
the points of a fine needle, fixed like that of a compass,
balancing it by a bit of wax at the other end of the needle :
he next placed a piece of wood at about half a line distance
from the radicle, and then covered the whole apparatus with
a glass, placed under such conditions that it was impossible
that any cause could move the needle : in five days the
embryo began to bend, and direct its radicle towards the bit.
of wood without the needle's changing its position, although
it was extremely moveable upon its centre : in two days more
the radicle was directed perpendicularly to the bit of wood
with which it had come in contact, and still the needle had
not stirred. This proves, says Dr. Dutrochet, that the
direction of the radicle of the miseltoe towards a neighbouring-
body is not the immediate result of any attraction on the
part of such a body ; but that it is the result of a spontaneous
movement of the embryo, in consequence of the attracting
influence exerted upon its radicle, which is thus the mediate
or occasional cause of the phenomenon. It is obvious, indeed,
that the inflexion of the stem of the embryo of the miseltoe
could not be due to the immediate attraction on the part of
the bit of wood ; for an exterior power sufficient to produce
this inflexion would much more readily have produced a
change in the direction of the needle, to one of whose points
the seed was fixed : there can, therefore, be no doubt that
the movement was spontaneous ; that is to say, that it was
caused by an internal vital cause, put in action by the influence
of an exterior agent. This spontaneous direction of the
radicle of the miseltoe under the influence of attraction proves
incontestably that attraction only influenced its nervous powers,
and not its ponderable matter : and the same is undoubtedly
the case with terrestrial plants. The unknown power of at-
traction is only the accidental cause of the ascent of the stem,
and of the descent of the roots, and not the immediate cause s
in this case, attraction only operates as an agent for exciting

282 PHYSIOLOGY. BOOK II.

nervous action. Other evidence exists to confirm most in-
contestably this important conclusion, that the visible move-
ments of vegetation are all spontaneous ; being brought into
action by the influence of an external agent, but not move-
ments originating with that agent.

Light is another cause of no less power than that just de-
scribed : it is well known that a plant, placed in a room from
which the light is excluded, except at a single aperture,
directs its stem and leaves towards that aperture, and no
longer takes a perpendicular position. The same tendency
of the stems towards the light takes place in the open air.
As light is diffused nearly equally around all bodies exposed
to it, they will naturally assume a direction towards the
heavens ; so that light thus becomes an aid to gravitation. It
might even be believed that light alone was a sufficient cause
of the perpendicular position of the stems of vegetables, if
experience did not prove the contrary. Dutrochet laid
horizontally on the ground, in a dry and dark place, the
stems of Allium Cepa and Allium Porrum, taken up with their
bulbs. These plants, although taken out of the ground, con-
tinue to live for a long time ; their stems became curved, and
their upper end took a direction towards the heavens. This
happened in about ten days ; but, being repeated in the open
air, three days were sufficient to produce the direction. In
the first experiment, light being wholly excluded, gravitation
only could have operated in giving the stem a perpendicular
direction, — that power being the only one which is known to
act in a direction perpendicular to the horizon. Modifications
of this experiment were instituted, to be certain that humidity
had no effect, and the same result was obtained. In the pro-
secution of these investigations, it also appeared that it was
not merely the summit of the stem which had a tendency to
a perpendicular direction, but that all the moveable parts of
the plant possessed a similar disposition, provided they were
coloured.

Stems are sometimes directed towards the earth, in which
they attempt to bury themselves like roots; a phenomenon
worthy of the greatest attention, not only on its own account,
but for the sake of the circumstances connected with it. Many

CHAP. XI. DIRECTIONS. 283

vegetables, besides their above-ground stems, have also subter-
ranean stems : these creep horizontally in the interior of the
earth, without manifesting any tendency towards the sky :
they are white, like roots, of which they assume the course
and the station. Sometimes, however, they are pink, as in
Sparganium erectum ; in such cases it is the cuticle that is
coloured, and not the subjacent parenchyma : but, when-
ever the point of their stems approaches the surface of the soil,
it becomes green, and, from that moment, they acquire an up-
ward tendency. Is it hence to be inferred that there is some
recent connection between the colours of the parts of vege-
tables and the directions they assume?

" Generally," M. Dutrochet proceeds to remark, " stems are
directed towards the light, which is in accordance with their
colour, which is usually green ; while the roots have usually
a tendency to avoid the light, which coincides with their want
of colour. The colour of the roots is, in fact, nothing but that
of the vegetable tissue ; and can by no means be compared
to that of the petals of some plants, which arises from the
presence of a white colouring matter. Light, which is the
principal, but not sole, cause of the colour of stems and their
organs, has no power of infusing colour into the roots, as may
be easily seen by roots growing in glasses of water; in spite of the
influence of the light they constantly remain colourless; and
this does not depend upon immersion in water, because leaves
developed in that medium are nevertheless green. Although
roots have, in general, no tendency towards the light, yet such
a disposition does become manifest, provided the terminal
shoot of a root becomes slightly green, as occasionally hap-
pens. Having induced some seeds of Mirabilis Jalapa to
germinate in damp moss, I remarked that the young roots,
when about as long as the finger, were terminated by a shoot
of a slightly green colour. Wishing to know whether these
roots would turn towards the light, I placed them in a glass ves-
sel filled with water, having a wooden cover pierced with holes
to receive the roots and fix the seeds. I enveloped the vessel
in black cloth, leaving only a narrow vertical slit, through
which light could enter the interior. This slit was exposed
to the rays of the sun ; and, a few hours after, I found that

284 PHYSIOLOGY. BOOK II.

all my roots had hooked back their points towards the slit
through which light was introduced. The same experiment was
tried with colourless roots ; but no alteration in their direction
was produced. From this it appears evident that colour is one
of the conditions that determine the directions of vegetables
and their parts towards the light, and consequently towards the
sky. This is so true, that colourless stems are known to assume
the directions of roots. In the Sagittaria sagittifolia this is par-
ticularly obvious. Shoots are produced from the axillse of
all the radical leaves which grow at the bottom of the water.
These shoots have their points directed towards the sky, like
those of all vegetables. The young stems, which are produced
by these shoots, are entirely colourless, like roots ; and, instead
of taking a direction towards the sky, as coloured stems would
do, they lead downwards, pointing towards the centre of the
earth. In order to take this position, the young shoot forces
its way through the substance of the petiole which covers it ;
thus overcoming a mechanical obstacle in its tendency towards
the earth. This subterranean stem next takes a horizontal
course, and does not assume any tendency towards the sky
until the points become green. M. Dutrochet has also re-
marked a similar phenomenon in roots. It is well known that
exposed stems of many plants produce roots: when green, they
turn upwards, as in Pothos and Cactus phyllanthus ; when
colourless, they point downwards. Hence it is to be inferred
that stems do not descend merely because they are stems, but
because their parenchyma is coloured ; and that roots descend
not in their quality of roots, but because their parenchyma is
colourless. It seems, however, that although this law is uniform
in its operation in all terrestrial plants, yet that a deviation, or
apparent deviation, from it exists in the parasitic miseltoe.
The radicle of this plant, which is of a paler green than the
other parts, instead of turning towards the light, avoids it
with so much pertinacity, that it is impossible to induce it to
take such a direction ; so that it seems to be repelled by light.
Dutrochet does not seem to be able to satisfy himself of the
reason of this exception : but it appears to be by no means
difficult to account for. We have seen that, in the direction
of its radicle, nature has enabled it to fulfil its functions as a

CHAP. XI. DIRECTIONS. 285

parasitic plant by the attraction of the body on which it is
placed, rather than by the much more powerful attraction of
the earth. In order to ensure this particular tendency, without
possessing which the existence of the miseltoe would be put in
hazard, its root has received from the same all-powerful hand
a disposition so much greater than other plants to avoid light,
and to bury itself in the obscurity of the interior of a tree, as
to be sufficient to overcome the influence of its green colour-
ing matter.

The next direction of the parts of plants, which may be
called special, is that of the upper surface of the leaves
towards the sky, and of the lower towards the earth. This
disposition is so powerful, that, if the usual direction of a leaf
is inverted, the petiole will twist so as to enable it to recover
itself. This phenomenon has been noticed by Bonnet, whose
explanation has been already given (p. 278.), but which is ob-
viously inadmissible. There is always a natural difference
between the two faces of the leaf: the upper is always the
most deeply coloured ; a difference which will be found con-
stant in all cases. The face with the deepest colour turns
towards the sky or light, and, with the weakest colour, towards
the earth or obscurity ; and this is so constant a law, that it
will be found that, if that surface of the leaf which is naturally
inferior is more deeply coloured than the superior, the petiole
will be twisted round by the greater affinity of the lower sur-
face for the light, which will thus become uppermost, the leaf
presenting the appearance of an inverted leaf. This may be
seen in many grasses, but not in Zea Mays, Triticum repens,
and Agrostis rubra. Hence it is to be concluded, that the
upper surface of the leaf is not turned towards the heavens
merely in consequence of its quality of being the upper sur-
face, but because it is generally the most deeply coloured.

The same law influences the directions of the petals, in
which the upper surface, — that which is turned towards the
heavens, — is always the most highly coloured : this, indeed, is
sometimes not very apparent, but is nevertheless constant.
Even in white petals, — such, for example, as those of Lilium
album, — the upper face will be found of a dense but brilliant
white, while the lower is of a much paler hue. The white

286 PHYSIOLOGY. BOOK II.

colour of the petals, Dutrochet proceeds to remark, like all
the other colours of plants, is due to a particular kind of
colouring matter deposited in the parenchyma lying below the
cuticle. Thus the whiteness of the flowers of plants is not
dependent upon the absence of colour, like the roots and
etiolated stems : in the former a white colouring matter exists ;
in the latter the whiteness is caused by absence of colour.
Some apparent exceptions to this law, — such as the outside of
many monopetalous flowers being paler than the inside, as in
Digitalis purpurea, Fritillaria latifolia, and others, — Dutrochet
thinks may be explained thus : — They, no doubt, are due to
the tendency of the less coloured part to avoid the light,
which is manifested by bearing down the flower so as to
approach the seat of obscurity as nearly as possible : all such
flowers being always nodding. This tendency is aided by the
weakness of the peduncle, which seems to have been specially
provided for enabling such flowers to retire from the light.
In papilionaceous plants, the inside of the vexillum, which is
most deeply coloured, always turns itself towards the light ;
and the alae twist themselves half round, to effect the same
object. The ovaria often take a different direction after the fall
of the corolla than they had before. Thus, during flowering,
the ovarium of Digitalis purpurea was nodding like the flower,
the direction of which it was compelled to follow. Imme-
diately after the fall of the corolla, it turns upwards towards
the light, to which it is attracted by its green colour. A con-
trary phenomenon is presented by the ovarium of Convolvulus
arvensis. The flower is turned towards the sky : as soon as it
has fallen, the ovarium takes a direction towards the earth,
bending down the peduncle. This cannot be due to the
weight of the ovarium, which is much lighter than its pe-
duncle, but must depend upon its disposition to avoid the
light, on account of its pallid hue, which is nearly the same
as that of the root. In Convolvulus sepium, on the contrary,
in which the ovarium is equally pale, its erect position is
maintained, and the influence of decoloration counteracted by
the greater affinity to the light of two lai'ge green bracteae in
which it is enveloped.

From the following and some other experiments, Du-

CHAP. XI. DIRECTIONS. 287

trochet infers that the direction of leaves to the light is not
mechanically caused by the operation of an external agent,
but is due to a spontaneous motion, put in action by the
influence of external agency. He took a leaf and cut off its
petiole, the place of which was supplied by a hair, hooked by
one end upon the leaf, and having a piece of lead attached to
its opposite extremity. They were plunged in a vessel of
water: the weight of the lead carried the leaf to the bottom of
the water, where it stood erect in consequence of its lightness
inducing it to attempt to ascend. Being exposed in a window,
so that the under surface was turned to the light, no alteration
took place in its position. Now, as from Bonnet's experi-
ments, it is certain that leaves immersed in water act exactly
as if surrounded with air, it is to be inferred that the external
influence of the light is of no effect, unless aided by a spon-
taneous power within the vegetable which was destroyed by
the removal of the petiole. Leaves immersed in water under
similar circumstances, with their petioles and stem uninjured,
turned towards the light as they would have done in the open
air. The power thus supposed to exist in all probability
depends upon the same nervous matter which has elsewhere
been shown to exist, in a greater or less degree, in all plants,
and especially in those called sensitives.

Those who desire more information upon this very curious
subject should consult Dutrochet's work, Sur la Motility des
Vdgetaux.

288 PHYSIOLOGY. BOOK II.

CHAPTER XII.

OF IRRITABILITY.

The vitality of plants seems to depend upon the existence
of an irritability, which, although far inferior to that of ani-
mals, is, nevertheless, of an analogous character.

This has been proved by a series of interesting experiments
by M. Marcet, of Geneva, upon the exact nature of the action
of mineral and vegetable poisons. The subject of his observ-
ations was the common kidney-bean ; and in each experiment
a contrast was formed between the plant operated upon and
another watered with spring water. A vessel containing two
or three bean plants, each with five or six leaves, was watered
with two ounces of water, containing twelve grains of oxide
of arsenic in solution. At the end of from twenty-four to
thirty-six hours the plants had faded, the leaves drooped, and
had even begun to turn yellow. Attempts were afterwards
made to recover the plants, but without success. A branch
of a rose tree was placed in a solution of arsenic ; and in
twenty-four hours ten grains of water and 0.12 of a grain of
arsenic had been absorbed. The branch exhibited all the
symptoms of unnatural decay. In six weeks a lilac tree was
killed, in consequence of fifteen or twenty grains of moistened
oxide of arsenic having been introduced into a slit in one of the
branches. Mercury, under the form of corrosive sublimate,
was found to produce effects similar to those of arsenic ; but
no effect was produced upon a cherry tree, by boring a hole
in its stem, and introducing a few globules of liquid mercury.
Tin, copper, lead, muriate of barytes, a solution of sulphuric
acid, and a solution of potash, were found to be all equally
destructive of vegetable life ; but it was ascertained, by means
of sulphate of magnesia, that those mineral substances which
are innocuous to animals are harmless to vegetables also. In
the experiments with vegetable poisons, the bean plants were
carefully taken from the earth, and their roots immersed in

CHAP. XII. IRRITABILITY. 289

the solutions used. It had been previously ascertained that
plants so transplanted and placed in water under ordinary
circumstances would remain in excellent health for six or
eight days, and continue to vegetate as if in the earth. A
plant was put into a solution of mix vomica at nine in the
morning: at ten o'clock the plant seemed unhealthy; at one
the petioles were all bent in the middle; and in the evening
the plant was dead. Ten grains of an extract of Cocculus
suberosus, dissolved in two ounces of water, destroyed a
bean plant in twenty-four hours ; Prussic acid produced
death in twelve hours, laurel water in six or seven hours, a
solution of belladonna in four days, alcohol in twelve hours.

From the whole of his experiments, M. Marcet concludes,
— 1st, That metallic poisons act upon vegetables nearly as
they do upon animals : they appear to be absorbed and car-
ried into different parts of a plant, altering and destroying
the vessels by corrosive powers. 2dly, That vegetable poi-
sons, especially those which have been proved to destroy
animals by their action upon the nervous system, also cause
the death of plants : whence he infers that there exists in
the latter a system of organs which is affected by poisons,
nearly as the nervous system of animals.

These facts have been confirmed by other experiments of
M. Macaire, which will be mentioned presently under the head
of Poisons.

Irritability, in the common acceptation of the term in bo-
tany, means those extreme cases of excitability in which an
organ exhibits movements altogether different from those we
commonly meet with in plants. Of this kind of irritability
there are three distinct classes ; namely, those which depend
upon atmospheric phenomena, spontaneous motions, and such
as are caused by the touch of other bodies.

Among the cases of irritability excited by particular states
of the atmosphere, the singular phenomenon called, by Lin-
naeus, the sleep of plants is the most remarkable. Jn plants
with compound leaves, the leaflets fold together while the
petiole is recurved at the approach of night ; and the leaflets
again expand and raise themselves at the return of day.

In others the leaves converge over the flowers, as if to

V

290 PHYSIOLOGY. BOOK II.

shelter those more delicate organs from the chill air of night.
The flowers of the crocus and similar plants expand beneath
the bright beams of the sun, but close as soon as they are
withdrawn. The GEnotheras unfold their blossoms to the dews
of evening, and wither away at the approach of day. Some
Silenes roll up their petals in the day, and expand them at
night. The florets of numerous Compositae, and the petals of
the genus Mesembryanthemum, are erect in the absence of
sun, but become reflexed when acted upon by the sun's beams ;
and many other such phenomena are familiar to every observer
of nature. It is probable, indeed, that a different effect is
produced upon all plants by day and night, although it is less
visible in some than in others : thus plants of corn, in which
there is little indication of sleep when grown singly, exhibit
that phenomenon very distinctly when observed in masses;
their leaves become flaccid, and their ears droop at night.
These effects have been generally attributed to the action of
light ; and it is probable that that agent contributes very
powerfully to produce them ; for a flower removed from the
shade will often expand beneath a lamp, just as it will beneath
the sun itself. De Candolle found that he could induce plants
to acknowledge an artificial day and night, by alternate expo-
sure to the light of candles. There must, however, be some
cause beyond light, of the nature of which no opinion has yet
been formed : many flowers will close in the afternoon while
the light of the sun is still playing upon them, and the petals
of others will fold up under a bright illumination.

Spontaneous movements are far more uncommon than those
which have just been described. In Megaclinium falcatum,
the labellum, which is connected very slightly with the
columna, is almost continually in motion; in a species of
Pterostylis, shown me by Mr. Brown, I observed a kind of
convulsive action of the labellum ; the filaments of Oscilla-
torias are continually writhing like worms in pain ; several
other Confervas exhibit spontaneous movements : but the
most singular case of the kind is that of Hedysarum gyrans.
11 This plant has ternate leaves : the terminal leaflet, which is
larger than those at the side, does not move, except to sleep ;
but the lateral ones, especially in warm weather, are in con-
tinual motion, both day and night, even when the terminal

CHAP. XII. IRRITABILITY. 291

leaflet is asleep. External stimuli produce no effect; the
motions are very irregular ; the leaflets rise or fall more or
less quickly, and retain their position for uncertain periods.
Cold water poured upon it stops the motion, but it is imme-
diately renewed by warm vapour."

To this class of irritability ought, perhaps, to be referred
the curious phenomenon well known to exist in the fruit of
Momordica elaterium, the spirting cucumber. In this plant
the peduncle, at a certain period, when the fruit has attained
its perfect maturity, is expelled, along with the seeds and the
mucus that surrounds them, with very considerable violence.
Here, however, endosmosis appears to offer a satisfactory ex-
planation. According to Dutrochet, the fluid of the placen-
tary matter in this fruit gradually acquires a greater density
than that which surrounds it, and begins to empty the tissue
of the pericarpium : as the fruit increases in size the same
operation continues to take place ; the pulpy matter in the
centre is constantly augmenting in volume at the expense of
the pericarpium ; but, so long as growth goes on, theadditio n
of new tissue, or the distention of old, corresponds with the in-
crease of volume of the centre. At last growth ceases, but
endosmosis proceeds ; and then the tissue that lines the walls
of the central cell is pressed upon forcibly by the pulp that it
encloses, until this pressure becomes so violent that rupture
must take place somewhere. The peduncle, being articulated
with the fruit, at length gives way, and is expelled with vio-
lence ; at the same time the cellules of tissue lining the cavity
all simultaneously recover their form, the pressure upon them
being removed, and instantly contract the space occupied by
the mucous pulp ; the consequence of which is that it also is
forced outwards at the same time as the peduncle. It has
been found by measurement, that the diameter of the central
cavity is less after the bursting of the fruit than before.

Movements produced by touch, or by external violence,
are very frequent. The sensitive plant (Mimosa pudica),
which will rapidly fold up its leaves as if in a state of sleep,
is, perhaps, the most familiar instance : but many others also
exist. If the centre of the leaf of the Dionaea muscipula is
irritated, the sides collapse, so as to cross the ciliae of their

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292 PHYSIOLOGY. BOOKH.

margin, like the teeth of a steel-trap for catching animals.
Roth is recorded to have seen something of the same kind in
Drosera rotundifolia. If the bottom of the stamens of the
common berberry is touched on the inside with the point of
a needle, they spring up against the pistillum. The valves of
Impatiens noli-tangere, when the fruit is ripe, separate and
spring back with great elasticity when touched. In this case
the phenomenon is apparently capable of explanation upon
a similar principle to the Momordica elaterium. In the
fruit of Impatiens the tissue of the valves consists of cellules,
that gradually diminish in size from the outside to the inside ;
and the fluids of the external cellules are the densest. The
latter gradually empty the inner cellules and distend them-
selves, so that the external tissue is disposed to expand, and
the internal to contract, whenever any thing occurs to destroy
the force that keeps them straight. This at last happens by
the disarticulation of the valves, the peduncle, and the axis ;
and then each valve rapidly rolls inwards with a sudden
spontaneous movement. M. Dutrochet proved that it was
possible to invert this phenomenon by producing exosmose :
for that purpose he threw fresh valves of Impatiens into sugar
and water, which gradually emptied the external tissue, and,
after rendering the valves straight, at length curved them
backwards.

The column of the genus Stylidium, which in its quiescent
position is bent over one side of the corolla, if slightly
irritated, instantly springs with a jerk over to the opposite side
of the flower. In Kalmia the anthers are retained in little
niches of the corolla ; and, as soon as they are by any cause
extricated, the filaments, which had been curved back, recover
themselves with a spring. In certain orchideous plants, of
the tribe called Vandeae, the caudicula to which the pollen
masses are attached will often, upon the removal of the anther,
disengage themselves with a sudden jerk.

An elaborate exposition of the phenomena accompanying
the movements of the sensitive plant has been given by
Dutrochet, in his Recherches, fyc. sur la Structure intime des
Animaux et des Vegetaux, et sur lew Motilite, which should be
consulted by all readers desirous of studying the irritability
of that very remarkable plant.

293

CHAPTER XIII. *

OF THE EFFECT OF POISONS UPON VEGETATION.

When treating of irritability, some experiments of M. Marcet
were quoted which had a reference to this subject. It is
one, however, of sufficient importance to demand a chapter
by itself.

At present we know scarcely any thing of the causes of the
diseases of the vegetable kingdom; but it can scarcely be
doubted, that to ascertain what are the specific effects of
deleterious matters upon the vital powers of plants, is to lay
tfre foundation of an acquaintance with their pathology.

M. Marcet's experiments proved that narcotic and irritat-
ing poisons produced an effect upon vegetables altogether
analogous to that which they produce upon animals. The
very valuable experiments with gases by Drs. Turner and
Christison, mentioned formerly (p. 252.), lead to the same
conclusion. These gentlemen remark, that " the phenomena,
when compared with what was observed in the instances of
sulphurous and hydrochloric acid, would appear to establish,
in relation to vegetable life, a distinction among the poisonous
gases nearly equivalent to the difference existing between the
effects of the irritant and the narcotic poisons on animals.
The gases which rank as irritants in relation to animals
seem to act locally on vegetables, destroying first the parts
least plentifully supplied with moisture. The narcotic gases,
— including under that term those that act on the nervous
system of animals, — destroy vegetable life by attacking it
throughout the whole plant at once. The former, probabljr,
act by abstracting the moisture of the leaves; the latter, by
some unknown influence on their vitality. The former seem
to have upon vegetables none of that sympathetic influence
upon general life, which in animals follows so remarkably
injuries inflicted by local irritants.

u 3

294 PHYSIOLOGY. BOOK II.

A similar result was arrived at by M. Macaire, whose very
curious and instructive experiments are recorded in the Bi-
bliotheque Universelle, xxxi. 24-4., and which I think of sufficient
importance to be detailed at length.

The first plant used was the Berberis vulgaris. The six
stamina of the flowers of this plant have the property of
rapidly approaching the pistil when touched by the point of
an instrument. The motion occurs at the base of the stamens.
When cold, the motion is sometimes retarded. When put
into water or solution of gum, the flowers may be preserved
many days, possessing their irritability. The petals and
stamens close at night to open again in the morning. Putting
the stem of this plant into dilute prussic acid for four hours,
occasioned the loss of the contractile property by irritation ;
the articulation became flexible, and might be inclined in any
direction by the instrument. The leaves had scarcely begun
to fade. On placing the expanded flowers on the prussic
acid, the same effect took place, but much more rapidly.

The experiment being repeated, with an aqueous solution
of opium, a similar effect was produced in nine hours.

Dilute solutions of oxide of arsenic and arseniate of potash
were used : the stamens lost the power of approaching the
pistil ; but they were stiff, hard, withdrawn backwards, and
could not have their direction altered without fracture. It
seemed like an irritation, or a vegetable inflammation.

Solution of corrosive sublimate more slowly produced the
same effects.

Sensitive plant (Mimosa pudica). — Experiments were now
made with this vegetable. When a leaf of this plant is
cut, and allowed to fall on pure water, the leaflets generally
contract rapidly ; but after a few moments expand, and are
then susceptible of contraction by the touch of any other
body. They may thus be preserved in a sensible state two
or three davs. If the section be made with a very sharp
instrument, and without concussion, the leaves may be sepa-
rated without any contraction. The branches of this plant
may be preserved for several days in fresh water. Gum-
water also effects the same purpose.

When a cut leaf of this plant falls upon a solution of cor-

CHAP. XIII. EFFECT OF POISONS UPON VEGETATION. 295

rosive sublimate, the leaf rapidly contracts, and the leaflets
curl up in an unusual manner, and do not again expand.
When put into pure water, the sensibility does not return,
but the whole remains stiff and immovable. A little solution
of corrosive sublimate being put into a portion of pure water,
containing an expanded branch of the plant, gradually caused
curling up of the leaves, which then closed and fell. If the
solution be very weak, the leaves open on the morrow, and are
still sensible, but ultimately contract, twist, and remain stiff
till they die. Solutions of arsenic and arseniate of potash
produce the same effects.

A leaf of the sensitive plant was in a cold diluted solution
of opium : in a few moments it opened out as in water, and,
after half an hour, gave the usual signs of contractibility. In
six hours it was expanded, and had a natural appearance, but
could not be excited to move. The leaflets were flexible at
the articulations, and offered a singular contrast to the state
of irritation produced by corrosive sublimate. Pure water did
not recover the plant. A large branch, similarly situated,
expanded its leaves; but in half an hour had lost much of its
sensibility : the leaflets, though alive, seemed asleep, and
required much stimulating to cause contraction. In one hour
the contractions ceased : in two hours the branch was dead.

A leaf placed in prussic acid (Scheele's strength) con-
tracted, then slightly dilated, but was quite insensible, and
the articulations were flexible : water did not recover it. If
the acid be very weak, the leaflets dilate and appear to live,
but are insensible. A drop of the acid placed on two leaflets
of a healthy plant gradually causes contraction of the other
leaflets, pair by pair. Solutions of opium and corrosive
poisons have no effect when applied this way. After some
time they dilate, but are insensible to external irritation : the
sensibility returns in about half an hour; but the leaflets
appear as if benumbed.

The plant exposed to the vapour of prussic acid is affected
in the same way : ammonia appears to favour the recovery
of the plant.

A cup containing dilute prussic acid was so placed that
one or two leaves, or sometimes a branch, of a healthy plant

u 4

296 PHYSIOLOGY. BOOK II.

could be plunged into the liquid, or left to repose on its sur-
face. The leaflets remained fresh and extended, but were
almost immediately insensible. Being left in this state for
two hours, they were expanded ; and no irritation could cause
their contraction, though otherwise there was no appearance
of an unnatural state. At five o'clock in the evening the
leaves were left to themselves. At nine o'clock they were
open and insensible. At midnight they were still open,
whilst all the rest of the plant, and the neighbouring plants,
were depressed, contracted, and in the state of sleep. On
the morrow they resumed a little sensibility, but seemed
benumbed.

In the same manner M. Macaire has interfered with other
plants as to the state of sleep, and observes that prussic acid
thoroughly deranges the botanical indications of time of
Linnaeus.

297

CHAPTER XIV.

OF THE DISEASES TO WHICH PLANTS ARE SUBJECT.

The diseases to which plants are subject are many and
important: a few arise from mechanical causes, such as
bruises or wounds, but the origin of the greater part is
almost wholly unknown. It is probable, however, that
some of them arise from a derangement of the circulation
of the fluids, and an undue absorption of water, by which
a brown colour and decay are produced.

Tabes, or gangre?ie, consists in a general languor of the
system : the leaves and stem become flaccid, and the plant
withers away ; or, if it be succulent, becomes rotten. It is
said by Link to arise from exposure to excessive cold, and a
too rapid subsequent change to heat.

Anasarca, or dropsy, is a similar disease, peculiar to succu-
lent plants, arising from an excessive introduction of water
into the system. It produces rapid rottenness, and can only
be stopped by destroying all the parts affected by it, and ex-
posing the individual to a very dry atmosphere.

Scorching, or insolation, is a local disease attributable to
exposure to too high a temperature. It is vulgarly supposed
to be caused by drops of water collected on the surface of
leaves, and destroying them by acting as burning lenses ; but,
as there is no focus formed when the water-drops lie on the
leaves, it is obvious that no burning can be produced by them.
It is often, 1 believe, caused by excessively rapid evaporation.
Marcor, or weltifig, is a variety of this.

Chlorosis, or etiolation, is a kind of constitutional debility.
The individual affected is pale, and destitute of a healthy green :
the stems are weak, long, and slender; no flowers are pro-
duced ; and the plant is readily killed. It is supposed to de-
pend upon the accumulation of oxygen, and to be caused by
various circumstances. The attacks of insects upon the roots,

298 PHYSIOLOGY. BOOK II.

by which the motion of the sap is deranged, are often the real
cause. A form of this, in which healthy, well-formed leaves,
which apparently perform their natural functions, become per-
fectly white, is common in Camellia reticulata : neither the
cause nor the cure of this has been ascertained. Cold is
probably sometimes the cause of similar appearances.

Canker, or caries, exhibits itself continually in a brown dis-
colouration of the medulla and parts adjacent, and externally
in small brown dead spots, which gradually extend on all
sides, until they surround the branch and kill it. These spots
are always dry and hard, never containing any fluid. It is
this which is so fatal to many of the apple and pear trees of
this country. Its cause and mode of cure are equally un-
known. Apparently healthy shoots will, if grafted on another
stock, carry the disease with them, and, like the gout and
scrofula in human constitutions, will sooner or later be sure
to break out. The cure of the disease is, therefore, as far as
we know, impracticable.

Carcinoma is a disease in which an unusual deposit of cam-
bium takes place between the wood and bark : no wood is
formed ; but, instead, the cambium becomes putrid, and oozes
out through the bark, which thus separates from the alburnum.
The cause of this is probably to be sought in the soil. It is
a very dangerous disease, and the elm is particularly liable
to its attacks. Some fine trees of this kind perished, a few
years since, in the avenue at Camberwell called " The Grove."
As soon as the bark is separated from the wood, the interven-
ing space is peopled by swarms of Scolytus destructor, and
similar insects.

Extravasation, or gamming, consists in a discharge of thick
sap from particular parts of the tree through the bark : the cir-
cumjacent surface withers but does not rot, as in Carcinoma.

Albumitas is when a layer of soft wood is interposed between
others of a harder texture : it is supposed to arise from a wet
season.

Galls, or tumid excrescences, are local affections caused by
the puncture of insects. They are produced by an excessive
deposition of cellular tissue ; and are of no consequence to
the general health of the individual subject to them.

CHAP. XIV. DISEASES TO WHICH PLANTS AHE SUBJECT. 299

Albigo, ferrugo, and uredo, commonly called mildew, smut,
rust, brand, and other names, are diseases caused by the pre-
sence of myriads of minute fungi of the genera Erycibe,
Caeoma, Aspergillus, Puccinia, Uredo, and others. They
are to plants what intestinal worms are to animals. Whether
their presence is due to a languid state of the plant, which is
thus rendered unusually susceptible of their attacks ; whether
the minute particles from which they are generated rise up
from the earth through the vessels of the stem along with the
sap, or whether they are originally contained in the seed
and carried onwards with its growth, manifesting themselves
whenever the plant arrives at a suitable state ; finally, whether
they are produced spontaneously, in consequence of the par-
ticular state of the atmosphere and tissue of the plant, are all
points hereafter to be determined : nothing certain is known
upon the subject at present. A very good account of the
smut of barley is given by Mons. Adolphe Brongniart in the
Annates des Sciences, vol. xx. p. 171.

Ergot, or clavus, is an excrescence from the seeds of grasses,
of a brown or blackish colour ; its nature or origin is unde-
termined. It does not depend upon the presence of parasi-
tical fungi, and it possesses properties wholly foreign to the
plant that bears it. That of the rye is frequently used suc-
cessfully in medicine for the purpose of accelerating partu-
rition.

Spotting, or tiecrosis, is chiefly found upon the leaves and
soft parenchymatous parts of vegetables. It consists of small
black spots, below which the substance of the plant decays :
in many cases it no doubt arises from wet and cold, as in the
cucumber and melon, which are wholly free from it in the
warm weather of summer, but which are attacked imme-
diately upon the arrival of the cold dewy nights of August
and September.

Melligo and salsugo, by some reckoned diseases, are rather
natural exudations of the juices of certain plants. Melligo
produces the manna of the ash, the gum ladanum of the
Cistus, &c. ; salsugo, saline secretions of the same kind.

To these may be added, —

Suffocatio, or choking up, when every part diminishes in size.

300 PHYSIOLOGY. BOOK II,

Jeterus, or jaundice, a general yellowness.

Pernio, or chilblains, wounds caused by frost.

Rachitis, or premature falling of grain.

Verminatio, or being preyed upon by the larvae of insects.

Phthiriasis, or lousiness, when the leaves and stems are
infested by Aphides, or the like.

Squamatio, or scaliness, when scales are formed instead of
leaves.

Exostosis, or clubbing of the roots.

Crispatura, or curling, in consequence of the leaves being
punctured by insects.

Decoloration, or loss of colour.

Coloration, or staining.

Anthozusia, or change of the leaves into petals.

301

CHAPTER XV.

OF HYBRID PLANTS.

It is well known that, in the animal kingdom, if the male
and female of two distinct species of the same genus breed
together, the result is an offspring intermediate in character
between its parents, but uniformly incapable of procreation
unless with one of its parents ; while the progeny of varieties
of the same species, however dissimilar in habit, feature, or
general characters, is in all cases as fertile as the parents
themselves. A law verv similar to this exists in the vegetable
kingdom.

Two distinct species of the same genus will often together
produce an offspring intermediate in character between them-
selves, and capable of performing all its vital functions as
perfectly as either parent, with the exception of its being
unequal to perpetuating itself by seed ; or should it not be
absolutely sterile, it will become so in the second, third, or,
very rarely, fourth generation. It may, however, be rendered
fertile by the application of the pollen of either of its parents ;
in which case its offspring assumes the character of the parent
by which the pollen was supplied. This power of hybridising
appears to be far more common in plants than in animals ; for
while only a few animal mules are known, there is scarcely
a genus of domesticated plants in which this effect cannot be
produced by the assistance of man, in placing the pollen of
one species upon the stigma of another. It is, however, in
general only between nearly allied species that this intercourse
can take place ; those which are widely different in structure
and constitution not being capable of any artificial union.
Thus the different species of strawberry, of certain tribes of
Pelargonium, and of Cucurbitaceae, intermix with the greatest
facility, there being a great accordance between them in
general structure and constitution ; but no one has ever sue-

302 PHYSIOLOGY. BOOK II.

ceeded in compelling the pear to fertilise the apple, nor the
gooseberry the currant. And as species that are very dis-
similar appear to have some natural impediment which pre-
vents their reciprocal fertilisation, so does this obstacle, of
whatever nature it may be, present an insuperable bar to the
intercourse of different genera. All the stories that are cur-
rent as to the intermixture of oranges and pomegranates, of
roses and black currants, and the like, may therefore be set
down to pure invention.

By far the best series of observations that has been instituted
with a view to determine the laws of hybridism was that of
Kblreuter, who, about the year 1775, commenced a set of
experiments, which he continued to prosecute for twenty
years, upon species of the genera Digitalis, Verbascum, Sola-
num, Malva, Linum, Dianthus, and Mirabilis. It is upon
those experiments, combined with the subsequent experience
of others and my own observations, that the foregoing state-
ment has been made.

It has, nevertheless, been asserted by divers experienced
cultivators of the present day, that the conclusions drawn
from the experiments of Kblreuter have been too hasty ; and
that if they apply to the genera that were the special subject
of the attention of that observer, they are by no means appli-
cable to plants in general. It has been urged, in proof of this
statement, that many different species of African Gladioli, of
Pelargonium, of South American Amaryllis, of Crinum, of
Triticum, &c, breed freely together, and that their seedlings
are as fertile as themselves.

I must confess that these instances are by no means such
as to shake my confidence in the accuracy of the laws deduced
from Kblreuter's experiments. In the first place, there is a
degree of vagueness and looseness in all the cases that are
specified, which is particularly striking if compared with the
precision with which Kblreuter's experiments were conducted ;
secondly, in all the cases above mentioned, which I believe
are the most remarkable, there is much room for doubt
whether the supposed species upon which the argument is
founded are any thing more than wild varieties of each other.
The African Gladioli are known to intermix freely; but

CHAP. XV. OF HYBRID PLANTS. 303

Mr. Herbert, in his account of them, in the Horticultural
Transactions^ vol. iv. p. 16., admits that he cannot speak to
the power of their mules to perpetuate themselves by seed.
No botanist can fix positive characters to a large part of the
reputed species of Pelargonium, or to the South American
Amaryllises, which Mr. Herbert calls Hippeastra; many of the
supposed species of Crinum seem to have no better claim to
be so considered than the varieties that might be picked from
a bed of tulips; and, lastly, the Tritica caerulescens, poloni-
cum, and tomentosum, upon which Bellardi's experiments
were founded, are plants with the history of which no man is
acquainted, and which, in all probability, derive their origin
from the Triticum aestivum, or common wheat.

All I think that can be conceded upon this subject is, that
more hybrid plants are fertile to the third or fourth generation
than Kolreuter supposed : that they will all, in time, revert to
one or other of their parents, or become absolutely barren,
there can be no doubt whatever.

The cause of the sterility of mule plants is at present
entirely unknown. Sometimes, indeed, a deficiency of pollen
may be assigned ; but in many cases there is no perceptible
difference in the healthiness of structure of the fertilising
organs of a male plant and of its parents. I know of no
person who has attempted to prove this by comparative
anatomical observations, except Professor Henslow, of Cam-
bridge ; who, in an excellent paper upon a hybrid Digitalis,
investigated anatomically the condition of the stamens and
pistillum, both of his hybrid and its two parents, with great
care and skill. The result of his enquiry was, that no appre-
ciable difference could be detected.

Although this power of creating mule plants that are fertile
for two or three generations incontestably exists, yet in wild
nature hybrid varieties are far from common ; or, at least, there
are few well attested instances of the fact. Among the most
remarkable cases are the Cistus Ledon, constantly produced
between C. monspessulanus and laurifolius, and Cistus longi-
folius, between C. monspessulanus and populifolius, in the
wood of Fontfroide, near Narbonne, mentioned by Mr. Ben-
tham. Again, the same acute botanist ascertained that Saxi-

304 PHYSIOLOGY. BOOK II.

fraga luteopurpurea of Lapeyronse, and S. ambigua of De
Candolle, are only wild accidental hybrids between S. are-
tioides and calyciflora : they are only found when the two
parents grow together; but there they form a suite of inter-
mediate states between the two. Gentians having a similar
origin have also been remarked upon the mountains of
Europe. It is difficult not to believe that a great number of
the reputed species of Salix, Rosa, Rubus, and other intricate
genera, have also had a hybrid origin ; but I am not aware
that there is at present any positive proof of this.

In a practical point of view, I am inclined to believe that
the power of obtaining mule varieties by art is one of the most
important means that man possesses of modifying the works of
nature, and of rendering them better adapted to his purposes.
In our gardens some of the most beautiful flowers have such

o

an origin ; as, for instance, the roses obtained between
R. indica and moschata, the different mule Potentillae and
Cacti, the splendid Azaleas raised between A. pontica and
A. nudiflora coccinea, and the magnificent American-Indian
Rhododendrons. By crossing varieties of the same species, the
races of fruits and of culinary vegetables have been brought
to a state as nearly approaching perfection as we can sup-
pose possible. And if similar improvements have not taken
place in a more important department, — namely, the trees that
afford us timber, — our experience fully warrants our enter-
taining the belief that, if proper means were adopted, improved
varieties of as much consequence might be introduced into
our forests, as have already been created for our gardens.

In conducting experiments of this kind, it is well to know
that, in general, the characters of the female parent predomi-
nate in the flowers and parts of fructification; while the foliage
and general constitution are chiefly those of the male parent.
Thus, in the celebrated mule Rhododendron, gained by Lord
Carnarvon by fertilising R. arboreum with R. Catawbiense,
the mule variety had the flowers and colour of R. arboreum,
but more the leaves and hardiness of constitution of R. Ca-
tawbiense.

305

CHAPTER XVI.

OF FLOWERLESS PLANTS.

Very little can be said to be positively known of the manner
in which the organs of flowerless plants perform what are
supposed to be their functions. We are entirely ignorant of
the manner in which the stems of those that are arborescent
are developed, and of the course taken by their ascending and
descending fluids, — if, indeed, in them there really exist
currents similar to those of flowering plants ; which may be
doubted. We know not in what way the fertilising principle is
communicated to the sporules, or i-eproductive grains ; the use
of the different kinds of reproductive matter found in most
tribes is entirely concealed. from us; it is even suspected that
some of the simplest forms (of Algae and Fungi, at least) are
the creatures of spontaneous growth ; and, in fine, we seem to
have discovered little that is positive about the vital actions of
these plants, except that they are reproduced by their sporules,
which differ from seeds in germinating from any part of their
surface, instead of from two invariable points. Under these
circumstances, it would be useless to dwell upon the subject:
those who wish to make themselves acquainted with the
speculations of botanists, are referred to the valuable writings
of Hedwig on Mosses, of Sprengel upon Cryptogamic plants,
of Dr. Hooker on Jungermanniae, of Fries on Fungi, of
Agardh, Greville, and Bory de St. Vincent upon Algae, of
Meyer upon Lichens, of BischofF upon Equisetum, &c. ; and,
finally, to the Introduction to the Natural System of Botany
by the author of the present work.

306

BOOK III.

TAXONOMY ; OR, OF THE PRINCIPLES OF
CLASSIFICATION.

CHAPTER I.

OF THE GENERAL OBJECTS OF CLASSIFICATION.

The objects of classification are twofold : firstly, to place
natural bodies in such an arrangement, that the station of a
given object can be certainly discovered upon the application
of some particular mode of investigation ; and, secondly, to
arrange them so, that the relation they mutually bear to
each other in the scale of the creation may be distinctly mani-
fested. These objects may be attained either singly, or in
conjunction with each other; hence two distinct kinds of
arrangement have arisen : one called artificial^ in which the
sole purpose is to discover the names of individuals ; and the
other called natural, in which the natural affinity of beings
is preserved, and, at the same time, a power is maintained
of discovering any given individual by the application of a
particular mode of analysis.

In order to attain either or both of these ends, it is necessary
to possess a power, firstly, of analysing the facts we possess,
and of reducing them from their most complex to their most
simple state ; and, secondly, of recombining them in various
degrees, according to the peculiarities which our previous
analysis has shown us that they exhibit. To effect this in

CHAP. I. GENERAL OBJECTS OF CLASSIFICATION. 307

the vegetable kingdom, it has been found expedient to divide
plants into groups of different degrees of importance, called
Classes,

Subclasses,
Orders,

Tribes,

Genera,

Subgenera,
Species.
Of these, the first are characterised by peculiarities common
to all those that succeed them ; the second, by peculiarities
of a less universal application ; the third, by others of minor
importance ; and so on until we arrive at species, which form
the ultimate point of analysis to which our investigations can
extend. Species are created by Nature herself, and remain
always the same, in whatever manner they may be combined :
they form the basis of all classification, and are the only part
of it which can be considered absolute. For although, in a
natural system, all other combinations, whether genera, tribes,
orders, or by whatever name they may be known, comprehend
species agreeing much more with each other than with any
thing else, and having a positive general resemblance in the
majority of their features, yet no fixed limits can be assigned
to any of them : on the contrary, they pass, by means of
various intermediate species, into the other genera, tribes, or-
ders, &c. to which they are most nearly allied. For this
reason, viz. that no fixed limits can be assigned to orders,
genera, &c, we find the ideas about them fluctuating with the
degree of our knowledge ; which is the true cause of those
changes in the limits of genera, &c. which persons unacquainted
with the subject are apt to consider arbitrary ; but which, in
skilful hands, are dependent upon a progressive advance in
our knowledge of science.

Classifications are founded upon the modifications of various
organs of plants, the constancy or mutability of form of which
determine what is called the value of characters ; upon these
the different groups depend. It was formerly supposed that
the organs of fructification were more constant in their cha-

x 2

308 TAXONOMY. BOOK III.

racters, and less subject to variation, than any other part ; and
hence they were exclusively adopted as the basis of classifi-
cation. But modern investigations have shown that charac-
ters drawn from the mode in which plants grow, and from
certain anatomical peculiarities, are of much higher value : so
that the organs of fructification are now chiefly employed for
the distinction of genera, or of orders and tribes. And, even
in these minor groups, the organs of vegetation are frequently
of high importance.

What better characters, for example, can be found in the
fructification of Cinchonaceae than in the arrangement of
their leaves, which are universally opposite, entire, and con-
nected by intervening stipulae ; or how can the fructification
of Myrtaceae characterise that order more accurately than
their simple, opposite, entire, exstipulate, dotted leaves, with
an intramarginal vein ? No better characters are afforded by
the fructification than by the foliage of Stellatse, Gramineae,
and many others.

309

CHAPTER II.

OF ARTIFICIAL ARRANGEMENTS.

If a classification is to be entirely artificial, it is sufficient to
take some two or three parts of the fructification, and form a
scheme of arrangement out of their modifications. It is of no
consequence what these parts are, or how the object is effected,
provided the end is attained, of ascertaining readily and
certainly the name of a given object. That method will be
the best which depends upon the most obvious and perma-
nent characters. It must not, however, be expected that
such a kind of classification will be ever, under the most
favourable circumstances, in any degree perfect. This is im-
possible from the very nature of things : there is no part of
either the fructification or vegetation of plants sufficiently
constant in single characters to render such perfection prac-
ticable ; to the most ingeniously devised characters exceptions
will continually occur. The sexual system of Linnaeus, is,
in botany, the one to which the world has consented to ascribe
the greatest utility.

This celebrated system depends upon a consideration of
certain modifications in the arrangement, or difference in the
number, of the stamens and styles. To acquire the power of
referring plants to their places in this system, nothing more is
requisite than just so much knowledge of structure as will
enable the student to distinguish the one set of organs from
the other, to count their number, and to determine to which
of the modifications of arrangement admitted by Linnaeus
they are to be referred. Plence the great popularity acquired
by the Linnaean system, which is at first sight so simple and
pi'ecise as to leave nothing to be wished for. And it is in
reality extremely useful in many respects, and very generally

x 3

310 TAXONOMY. BOOK III.

applicable ; but, unfortunately, practical difficulties surround
the student as be proceeds, which often lead to confusion and
uncertainty. Nothing is more common than for plants to
have their stamens cohering at the base into a kind of
cup : such ought, if the Linnaean arrangement is rigidly
observed, to be referred to Monadelphia ; yet they are
constantly placed by Linnaeus himself in other classes. A
plant will bear flowers differing in the number of their
stamens upon the same individual, or upon different indi-
viduals ; and species of the same genus also differ from each
other in that respect: out of this arise, of necessity, the most
perplexing difficulties, which no ingenuity or exercise of the
reasoning faculties can overcome; because the system of
Linnaeus being in every respect artificial, depending wholly
and absolutely upon the technical characters he employs, no
check exists by which errors can be discovered, if they arise
out of variations or uncertainty in their characters.

Besides this, there is another difficulty of equal importance.
Unless the plant which is to be examined is in flower, it
cannot be referred to its station ; or if there is any imper-
fection in the developement of its stamens or styles, which is
a very common case, the same difficulty opposes itself. The
facilities, therefore, which have been attributed to the system
of Linnaeus by those who have adopted it, although un-
doubtedly great in one point of view, are by no means such
as have been represented and believed.

The following are the characters of the classes and orders
of the Linnaean System : —

Characters of the Classes,

Class I. Stamen 1 Monandria.

II. 2 Diandria.

HI. 3 Triandria.

IV. 4 Tetrandria.

y. $ Pentandria.

VI. 6 Hexandria.

VII. 7 Heptandria.

VIII. 8 - -" - Octandria.

CHAP. II.

OF

ARTIFICIAL ARRANGEMENTS. 31

Class IX.

Stamens

9 Enneandria.

X.

10 - - Decandria.

XL

12 — 19 - - Dodecandria.

XII.

f 20 or more, inserted ~) T , .
1 . , , 5- Icosandna.
1 into the calyx - J

XIII.

f 20 or more, inserted lp, , .
L into the receptacle J

XIV.

2 long and 2 short Didynamia.

XV.

4 long and 2 short Tetradynamia

XVI.
XVII.

XVIII.

XIX.
XX.

xxi.

XXII.

XXIII.

na.

Moncecia.

J" united by their fila- 1

I ments into a tube jMonadelPhia'

{united by their fila- ~i
ments into two I Diadelphia.
parcels - - J

{united by their fila- -%
ments into several L Polyadelpl
parcels - - J

{united by their an- "I
thers into a tube j S^Sn esia'
f united with the pis- 1 ^ , .

I tillum - _jGy™ndria.
"and pistils in sepa-"
rate flowers, but
both growing on
the same plant -
/-and pistils not only
in separate flow-
ers, but those
flowers situated
upon two different
plants
"and pistils separate'
in some flowers,
united in others,
<! either on the same
plant, or two or
three different
ones
x 4

Dicecia.

► Polygamia.

312

TAXONOMY.

BOOK III.

Class XXIV. Stamens <{

^ Cryptogamia.

-and pistils either not-
ascertained, or
not to be disco-
vered with any
certainty, inso-
much that the
plants cannot be
referred to any
of the foregoing
classes

Characters of the Orders.

These depend upon the number of the styles, or of the
stigmas, if there be no style, in the first thirteen classes; such
are accordingly named, —

Monogynia - - Style 1

Digynia - - 2

Trigynia

Tetragynia

Pentagynia

Hexagynia

Heptagynia

Octogynia

Enneagynia

Decagynia

Dodecagynia

Polygyria

3

5

6

7

8

9
10
12
more than 12.

In the 14th class, Didynamia, the orders depend upon the
nature of the ovarium. — In Gymnospermia, the first order, the
ovarium is divided into four lobes, from the base of which
proceeds a single style, and within each of which is contained
a single seed. In Angiospermia, the 2d order, the ovarium is
not lobed, and is usually two- celled, and many seeded.

In the 15th class, Tetr adynamia, the orders are character-
ised by the form of the fruit. Siliquoscc have a long pod.
Siliculosa? have a short one.

The orders of the 16th, 17th, and 18th classes, Mona-

CHAP. II. OF ARTIFICIAL ARRANGEMENTS. 313

delphia, Diadelphia, and Polyadelphia, depend upon the
number of the stamens, and have the same nomenclature as
the thirteen first classes.

The orders of Syngenesia are determined by the arrange-
ment of their flowers, and by the sex of their florets : thus —

Polygamia, has florets crowded together in heads.

1. Polygamia ccqualis, has each floret hermaphrodite, or
furnished with perfect stamens and pistillum.

2. Polygamia superjlua, has the florets of the disk herma-
phrodite ; those of the ray female only.

3. Polygamia frustranea, has the florets of the disk herma-
phrodite; those of the ray sterile.

4. Polygamia necessaria, has the florets of the disk male,
of the ray female.

5. Polygamia segregata, " has several florets, either simple
or compound, but with a proper calyx, included within one
common calyx."

Monogamia, has the flowers separate, not crowded in heads.
This order is generally abolished by Linnagan botanists, but
for no good reason.

The orders of the 20th, 21st, and 22d classes are distin-
guished by the number, &c. of the stamens;

The two orders of the 23d class depend upon whether the
genera are monoecious or dioecious.

The last class, Cryptogamia, is divided into orders accord-
ing to the principles of the natural system, and are, 1. Filices ;
2. Musci ; 3. Hepaticas ; 4. Algae; 5. Fungi.

Various modifications and alterations of this method have,
from time to time, been proposed by various writers; some re-
ducing the whole of Moncecia, Dioecia, and Polygamia to
other classes, others combining some of the smaller classes
with the larger ones. Of these and similar alterations it is
not necessary to say more in this place ; but I must not pass
by, with equal silence, the changes proposed by the late Pro-
fessor Richard. These have not, indeed, been adopted by
other writers : but this is, I conceive, to be attributed rather to
the neglect into which artificial systems have now fallen, than
to any other circumstance. As the changes are proposed upon

314 TAXONOMY. BOOK III.

philosophical principles, I shall notice them in the words of
M. Achille Richard, for the information of those botanists
who still interest themselves in the fate of the sexual system.

The 10 first classes are preserved without alteration.

The 11th, Polyandria, is characterised thus: stamens more
than 10, inserted under the pistil, which is either simple or
multiple; insertion hypogynous. This class, which replaces
Dodecandria, answers in all respects to the Polyandria of
Linnaeus.

The 12th class is Calycaudria, with the following charac-
ter: — stamens more than 10, inserted on the calyx, the
ovarium being superior or parietal ; insertion perigynous.
This answers in part to Dodecandria, and in part to Ico-
sandria. It contains all the true Rosaceae.

The 13th class is Hysterandria. Its character is, stamens
more than 10, inserted upon an ovarium which is perfectly
inferior ; insertion consequently epigynous. It answers to a
part of Icosandria, and contains Myrtus, Punica, &c.

These three classes are much more precise, and also main-
tain in a more perfect manner the natural relations of plants,
than those of Linnaeus ; whose characters, depending upon the
number of stamens, frequently lead the student into error.

In the 14th class, Didynamia, the orders designed by Lin-
naeus give a false idea of structure ; there being no such thing
as naked seeds, as expressed by his name Gymnospermia. For
this latter the name Tomogynia is proposed ; and for Angio-
sjpermia, Atomogynia.

The 19th class, Synantheria, replaces Syngenesia. The
stamens are united by the anthers only, so as to form a small
tube; and the ovary is monospermous. It comprehends the
plants called Compositae only ; and is divided into the follow-
ing orders, in the room of those of Linnaeus : —

1 . CardiiacecE ; head composed indifferently of male,
female, or hermaphrodite florets ; receptacle covered with
numerous hairs; style slightly swollen beneath the stigma;
connectivum sometimes lengthened beyond the anthers, so
as to form a five-toothed tube. To this belong Carduus,
Centaurea, &c.

CHAP. II. OF ARTIFICIAL ARRANGEMENTS. 315

2. Corymbifcrce ; head flosculous or radiate ; receptacle
naked or covered with palese, one to each floret. In the
preceding order there were several to each floret. Here
belong Tussilago, Gnaphalium, Erigeron, &c.

3. Chicoraccce ; head composed of ligulate florets wholly,
as in Lactuca, Cichorium, &c.

The 20th class, Symphysandria, is the Syngcnesla Mono-
gamia of Linnaeus, distinguished from the last by its poly-
spermous ovarium : it contains Lobelia, Viola, &c.

Gynandria, Moncecia, and Dicecia are preserved without
change.

24th class, Anomaloccia, is the same as Polygamia of
Linnaeus.

25th class, Agamia, is the Linnaean Cryptogamia.

From this explanation of Richard's proposed reformation
of the sexual system, it is apparent that its fault is its unne-
cessary alteration of the established nomenclature of Linnaeus ;
and that its merit consists in a better adjustment of the Do-
decandrous, Icosandrous, Polyandrous, and Syngenesious
classes ; which are, undoubtedly, improvements of great im-
portance.

By some writers the mode of analysing characters con-
trived by Lamarck, and continued by M. De Candolle in the
Flore Francaise, has been referred to artificial systems ; but
scarcely with propriety. We can hardly call that a system
which is merely a particular mode of analysis, without any
arrangement consequent upon it : nevertheless, as it is useful
to understand this mode of investigation, no better place can,
perhaps, be found for explaining it than the present.

The mental operation by which one thing is distinguished
from another consists in a continual contrasting of characters.
For instance, in a mass of individuals we distinguish one set
which is coloured, and another which is colourless; of those
that are coloured we distinguish red, black, blue, and green ;
of the red, some are square, others are round ; of the round,
some are sculptured on their surface, others are even : — and
so we "proceed, analysing the subject by a constant series of
contrasts, until we have arrived at the point beyond which no
analysis can go.

316

TAXONOMY.

BOOK III»

Such is the character of Lamarck's method : take, for in-
stance, the following instance from the Flore Fran^aise, 3d
edit. vol. i. p. 257.

ANCHUSA.

f Flowers in spikes, heads, or dense panicles
|_ Flowers widely scattered, or in loose racemes

{Leaves all alternate -

Each bunch of flowers with two opposite leaves
J" Flowers in racemes or panicles, leaves flat
(_ Flowers in heads, leaves undulated

{Stem straight, from nine to twelve inches high
Stems spreading, from six to nine inches high
f Calyx divided as far as the middle
\ Calyx divided almost to the base
f Flowers violet ; scales of the orifice bearded
1 Flowers azure blue ; scales slightly hairy

laxiflora.

3

sempervirens.

4

undulata.

5

tinctoria.

anguslifolia.

6

italica.

- Barrelieri.

Thus it is obvious that one character is contrasted with an-
other, until nothing more remains to contrast. The plan has
been successfully adopted by Messrs. Hooker and Taylor, in
their Muscologia Britannica; and I think it, or some similar
plan, should be introduced into every work on systematic na-
tural history, on account of the labour it saves the reader
when casual investigation only is his object.

But I do not entirely approve of the method as it stands in
the works of De Candolle. The mode of printing is particu-
larly objectionable; the constant reference from number to
number is fatiguing, and confuses ; and the contrast of cha-
racters is not brought sufficiently before the eye. I have
therefore used, in my own works, a slight modification, which
at least is free from the objections now mentioned. Of this
the following example is taken from the 43d page of my Sy-
nopsis of the British Flora.

ANALYSIS OF THE BRITISH GENERA OF CARYOPHYLLEjE.

Sepals united in a cylindrical tube (Sileneis).

Stigmata 2.

Calyx with bractese at the base

Calyx naked at the base
Stigmata 3 -

Stigmata 5.

Calyx-teeth simple

Calyx -teeth foliaceous

1. Dianthus.

2. Saponaria.

3. SlLENE.

4. Lychnis.

5. Agrostemma.

CHAP. II.

OF ARTIFICIAL ARRANGEMENTS.

317

Sepals distinct, or cohering only at the base (Akineee).
Capsule dehiscing with distinct valves.
Valves 2 -

Valves 3 - - -

Valves 6 - -

Valves 4 or 5.

Capsule with four cells
Capsule with one cell
Capsule dehiscing at the apex with teeth.
Petals entire.

Sepals and petals 4 - -

Sepals and petals 5 -

Petals toothed - - -

6. Buffonia.

7. Cherleria.

8. Spergula.

9. Elatine.
10. Sagina.

11. mcenchia.

12. Arenaria.

13. holosteubi.

I must not dismiss this subject without remarking, that,
however excellent this analytical method is, if well managed,
it is of all the very worst if used injudiciously. One false
step, either on the part of the author who frames it, or on
that of the reader, instantly leads astray, and induces errors
of the most serious kind. Every thing depends upon a judicious
selection of contrasting characters on the one hand, and a
scrupulous attention to them on the other. This method
ought never to be used by itself, but merely as a kind of key
to long generic or specific characters and descriptions.

318 TAXONOMY. BOOK III.

CHAPTER III.

OF THE NATURAL SYSTEM.

A natural method of arrangement differs essentially from
an artificial one in this, — that it does not depend upon modi-
fications of any one part more than of another. Its divisions
are framed from a careful consideration of every, even the
minutest, character that is appreciable ; and consist of species,
not arbitrarily collected by a few common signs, but agreeing
with each other as far as possible in every material point of
structure. Groups formed upon this principle will neces-
sarily consist of species having a greater resemblance to eacli
other than to any thing else; and, if skilfully constructed, will
have so great a general resemblance, that a knowledge of the
structure, habits, qualities, or other important peculiarities of
a single species, gives an accurate general idea of all the
others that the group contains. While an artificial mode of
classification leads to nothing further than the. determination
of the name of a given species, and consists of assemblages of
objects so incongruous and unlike, that, in the words of a
modern philosopher, " our ingenuity is exercised to determine
what can be the cause of their resemblance; " a natural system
is essentially composed of collections of species so like, that
our difficulty is rather in ascertaining their differences.

The classes, orders, &c. of a natural system depending thus
upon characters impressed upon vegetation by the hand of
Nature, and arising out of combinations of peculiarities that
are uniformly the same, and of resemblances about which
there can be no difference of opinion, it follows that there can
be but one system properly called natural. If our knowledge
of the subject were perfect, the mutual affinities, and the com-
binations of plants into1 classes and orders, would be as fixed
and unchangeable as the planetary system itself. But, in the
actual state of botanical science, the only parts that can be

CHAP. IIT. OF THE NATURAL SYSTEM. 319

considered approaching perfection are a few of the primary
divisions, and the lowest groups or natural orders, as they are
called. All that relates to the distribution of those orders, with
relation to each other, is in the highest degree imperfect and
fluctuating; a great defect in the subject viewed as a system,
but of little practical importance. In practice, indeed, it may
be doubted whether the real affinities of the minor natural
assemblages of plants can ever be distinctly preserved in any
arrangement for systematic purposes. In the words of Mr.
Herschel, " the classifications by which science is advanced"
(as distinguished from artificial systems of nomenclature)
" cross and intersect one another, as it were, in every pos-
sible way, and have for their very aim to interweave all the
objects of nature in a close and compact web of mutual rela-
tions and dependence." {Discourse, p. 140.) A natural class,
or tribe, or order, or genus, or species, will have a great
number of points of resemblance with others ; some of which
points will be of more importance, or more immediate, than
others ; and all of them affecting its position in a greater or
less degree: but upon paper we are constrained to follow a
lineal arrangement, in which only one point of agreement
instead of many can be indicated. We are, therefore, able to
point out by our classification, in a partial manner onlv the
relations borne by bodies to each other : and in proportion as
we fail in maintaining these affinities perfectly, do we recede
from the course of nature and become artificial. For this
there is clearly no help, if we wish that our classifications
should be adapted to practical purposes. If the subject is to
be treated as a mere operation of the mind, recourse can then
be had to systems founded on the principles of Oken, Fries,
and others, of which something will be said hereafter.

The earliest attempts at arrangement were natural, as far as
the knowledge of their authors enabled them to make them
so ; and artificial systems only arose after a long series of
years, out of the imperfect state of botanical science, which was
not sufficient to render a really natural system practicable.

At last a French naturalist, M. Antoine Laurent de Jussieu,
who with a profound knowledge of the subject combined great

320 TAXONOMY. BOOK III.

logical acuteness, conceived the idea of what is now universally
recognised as the natural system of botany.

Properly speaking, this system is subject to no kind of arti-
ficial arrangement : it consists of certain groups called natural
orders, all of which are, or should be, independent of each
other ; and the characters of which are derived indifferently
from every part of the plant. But as it would be extremely
embarrassing to the student to acquire a just notion of these
groups, unless some mode were devised of analysing their
characters, several plans have been invented by which the
groups have been reduced to a sort of artificial arrangement,
with greater or less violence to their mutual affinities. As all
these plans must, as has been shown, necessarily be linear,
the real affinities of plants must be very imperfectly indicated
by them : they are, therefore, of no value whatever, except for
the purpose of facilitating investigation. They must be under-
stood to form no part of what must strictly be called the
natural system ; they may be varied at pleasure, according to
the ingenuity of the botanist; and that will be the best which
is most facile, and which, at the same time, offers the fewest
interruptions to the series of mutual relations. At present I
think there are few botanists who will deny that they are all
extremely defective ; and that one of the greatest services that
could be rendered to systematic botany would be to devise
some scheme by which the orders could be better and more
naturally arranged under their primary classes. Whoever
does this will have to divest himself of all the prejudices, and
they are not a few, which have grown up with the system
of Jussieu, and that have taken deep root in the minds of his
followers : he must judge for himself upon every single point
that may come before him, and he must forget that any such
artificial arrangements have existed as those of Jussieu him-
self, De Candolle, and others. It is even to be expected
that the organs of vegetation will be, for this purpose, employed
even more than those of the fructification ; and that ana-
tomical characters analogous to those which characterise the
really natural primary divisions of Vasculares and Cellulares,
and of Exogense and Endogense, will be applied to the group-
ing, in subordinate masses, of the orders themselves.

CHAP. III.

OF THE NATURAL SYSTEM.

321

At present scarcely any attempts of this nature have been
made, except by Agardh and Bartling ; but the endeavours of
those botanists, however meritorious, are far from coming up
to what may be expected.

The first outline of the natural orders that are now adopted
was given to the public by Jussieu in 1789, in the following
form : —

INDEX OF THE CLASSES.

Acotyledones -

{Stamens hypogynous
Stamens perigynous
Stamens epigynous

{Stamens epigynous
Stamens perigynous
Stamens hypogynous
'Corolla hypogynous
Corolla perigynous
Dicotyle- Monopetalous J Corolla epigynous :
dones. •< With connate anthers

With distinct anthers -

/Stamens epigynous
, . Stamens hypogynous
|_ Stamens perigynous
L Diclinous, irregular

List of the Orders.

Class I.
Fungi.
Algae.
Hepaticae.
Musci.
Filices.
Naiades.

14.
15.
16.
17.
18.

Lilia.
Bromeliae.
Asphodel i.
Narcissi.
Irides.

Class I.
Class II.
Class III.
Class IV.
Class V.
Class VI.
Class VII.
Class VIII.
Class IX.

Class X.
Class XI.
Class XII.
Class XIII.
Class XIV.
Class XV.

Class II.

7. Aroideae.

8. Typhae.

9. Cyperoideae.

10. Gramineae.

Class III.

11. Palma?.

12. Asparagi.

13. Junci.

Class IV.

19. Musae.

20. Cannae.

21. Orchides.

22. Hydrocharides.

Class V.

23. Aristolochiae.

Class VI.

24. Elaea<rni.

25. Thymelaese.

26. Proteae.

322

TAXONOMY.

BOOK III.

27. Lauri.

28. Polygonese.

29. Atriplices.

Class VII.

30. Amaranthi.

31. Plantagines.

32. Nyctagines.

33. Plumbagines.

Class VIII.

34. Lysimachiae.

35. Pediculares.

36. Acanthi.

37. Jasmineae.

38. Vitices.

39. Labiatae.

40. Scrophulariae.

41. Solaneae.

42. Boragineae.

43. Convolvuli.

44. Polemonia.

45. Bignoniae.

46. Gentianae.

47. Apocyneae.

48. Sapotae.

Class IX.

49. Guaiacanae.

50. Rhododendra.

51. Ericae.

52. Campanulaceae.

Class X.

53. Cichoracae.

54. Cynarocephalae.

55. Corymbiferae.

Class XL

56. Dipsaceae.

57. Rubiaceae.

58. Caprifolia.

Class XII.

59. Araliae.

60. Umbelliferae.

Class XIII.

61. Ranunculaceae.

62. Papaveraceae.

63. Cruciferae.

64. Capparides.

65. Sapindi.

66. Acera.

67. Malpighiae.

68. Hyperica.

69. Guttiferae.

70. Aurantia.

71. Meliae.

72. Vites.

73. Gerania.

74. Malvaceae.

75. Magnolias.

76. Anonae.

77. Menisperma.

78. Berberides.

79. Tiliaceae.

80. Cisti.

81. Rutaceae.

82. Caryophylleae.

Class XIV.

83. Sempervivae.

84. Saxifragae.

85. Cacti.

86. Portulaceae.

87. Ficoideae.

88. Onagrae.

89. Myrti.

90. Melastomae.

91. Salicariae.

92. Rosaceae.

93. Leguminosae.

CHAP. III. OF THE NATURAL SYSTEM. 323

94<. Terebintaceae. 97. Cucurbitaceae.

95. Rhamni. 98. Urticas.

Class XV. 99. Amentaceae.

96. Euphorbiae. 100. Coniferae.

Appended to these is a list of genera, the characters of which
were not at that time sufficiently well known to enable Jussieu
to refer them to any of the preceding orders. They are
arranged according to the following artificial plan : —

1. Monopetalous with a superior ovarium.

2. Monopetalous with an inferior ovarium.

3. Polypetalous with a superior ovarium.

4. Polypetalous with an inferior ovarium.

5. Apetalous, hermaphrodite, with a superior ovarium.

6. Apetalous, hermaphrodite, with an inferior ovarium.

7. Apetalous, diclinous, with a superior ovarium.

8. Apetalous, diclinous, with an inferior ovarium.

In this attempt, which may be truly pronounced the most
important event which has occurred in botany, next to the
universal reformation of natural history by Linnaeus, advan-
tage was taken of an arrangement used in the Trianon Gar-
den in 1759, by Bernard de Jussieu, in which the natural
affinities of plants had been seized in a manner that is per-
fectly surprising, if we consider how little was known at that
time of those anatomical peculiarities upon which the natural
affinities of the vegetable kingdom are now determined.

Since the date of 1789, alterations, additions, and improve-
ments in the system of Jussieu have been constantly making.
For these the world is chiefly indebted to Jussieu himself, our
celebrated countryman Mr. Brown, De Candolle, the late
Louis Claude Richard, Kunth, Auguste St. Hilaire, Von Mar-
tius, and a few others. These have given a new feature to the
system, and have brought it to a far more advanced state of
completeness than, perhaps, could have been expected in the
short space of thirty or forty years. To show what that state
is, and the existing notions relating to the limits of natural
orders, would occupy much more space than could be spared
in the present work. The student will find ample inform-
ation upon the subject in my Introduction to the Natural System
of Botany, published in 1830.

Y 2

824 TAXONOMY. BOOK III.

CHAPTER IV.

OF SPECULATIVE MODES OF ARRANGEMENT.

Besides the two principles of classification now explained,
there is a third, which has arisen in the minds of certain
German metaphysical naturalists, and which they conceive to
be the true natural system ; but which may more properly be
termed a speculative attempt at forming a system by the mere
force of reason, without attending to the facts upon which
any system must depend. While other naturalists take
facts as the basis of all arrangement, and accommodate their
system to the data they possess, the authors of the specu-
lative modes of classification first form a system from the
idea that all matter is subject to the influence of certain
universal causes, which prevail equally in every kingdom of
nature; and then attempt to adjust facts to the arrangement
thus formed by the mere force of imagination. Strange as
this doctrine seems, and foreign as it may appear to every
principle of sound philosophy, yet, as it is possible that some
useful ideas may be elicited even from the wildest of such specu-
lations, I shall avail myself of an excellent exposition of the
subject by M. Choisy, of Geneva, to give some account of the
doctrines in question.

The first principle, they say, to be inculcated is, that there
is a fundamental difference between philosophical and empi-
rical science : there is, says Nees Von Esenbeck, a specu-
lative, and also an experimental, knowledge of things ; the
first is dependent upon a pure conception of nature, the last
relies upon material observation. In consequence of thus
distinguishing two methods, these philosophers consider them-
selves enabled to establish what they call unity, which is their
leading dogma ; and by which they mean the existence of
some single power that overrules all other powers, and deter-
mines the structure and existence of every thing. By the aid
of such facts as are applicable to their particular notions, each

CHAP. IV. SPECULATIVE MODES OF ARRANGEMENT. 325

philosopher then constructs his edifice, well cemented together
in all its parts, as he believes ; but, in reality, possessing no
solidity whatever. Their unity, — a vague and mysterious
notion, which is only intelligible with respect to the Deity, —
they think can be comprehended by man by other means than
by a comparison of the admirable works of the Creator ;
assertions destitute of proof, and even contradicted by expe-
rience, are said, nevertheless, to be demonstrated by the ten-
dency which they have to indicate a principle of union in
the different parts of the material world. The paths which
have been pursued to attain the unity which is sought for,
and the systems that have been invented for that purpose,
are many : the following are the principal. — First, They
declare that certain general laws exist which control the
universe. Secondly, All things are formed of the same
elements, in different states of combination. Thirdly, The
same principles and the same phenomena occur in the whole
of each individual, and in all its parts, as occurs in the earth
itself; and these are repeated down to the most minute phe-
nomenon throughout the whole globe.

Among general laws, the most important is that of polarity;
every unity arises in nature from a primitive, opposite,
and double action, and this double action is found in every
subject which is examined. The word p>ole is used to
express the two elements out of which this double action
arises ; and polarity indicates their respective actions. Thus,
we every where find the positive and negative, the real and
the imaginary, the light and the dark, the cause and the effect;
and, according to Oken, this polarity produces every simple
power in nature, by the juxtaposition of the plus and minus
of which it is composed : without this nothing would exist, and
there would be no world. Polarity is manifested by motion,
which depends entirely upon the primitive opposition of an
internal cause, and an exterior point of impulse : in itself it
exhibits an instance of unity ; but it is the result of a double
action, that of polarity. According to Nees, the system of the
world would not go on if the law of polarity did not exist ;
we must have an axis and an equator, which unite in the
motion of rotation ; we must even distinguish two sorts of

Y 3~

326 TAXONOMY. BOOK III.

polarity, one of which belongs to the shorter and the other to
the longer axis ; each of these has its major or objective pole,
and its minor or subjective pole : the point of meeting of the
axis, and all which pertains thereto, represents death ; and all
which exists towards the poles is endued with life. The
type of life, which is placed within the influence of fixed poles,
is called a year ; the type of life, which is within the influence
of varying poles, is called day and night : the four poles, thus
comprehending four elements of life, give rise to four king-
doms in animated nature ; that is to say, to fungi, plants,
animals, and man. Wilbrand is another author who has
written a work specially to examine the law of polarity. He
defines it to be " an opposition between two things which mu-
tually support each other, and of which one is nothing without
the other : the union of these two things is a third, which is the
result, and which would not exist without their opposition."
He has no difficulty in finding traces every where of this
double polar action ; he is neither embarrassed by magnetism
nor by electricity ; in them the positive and negative poles are
evidences, which cannot be overlooked: he also concludes
that all bodies ought to be susceptible of magnetism. Gal-
vanism is also to be readily explained by the doctrine of
polarity : but, in order to apply it equally to all parts of
chemistry, Wilbrand supposes that in every chemical analysis
there is a complex sort of synthesis ; that, whenever repulsion
occurs, it is accompanied by a contrary action of affinity.
Thus, in oxidation there is synthesis, but, at the same time, a
disengagement of heat, or analysis ; in the formation of salts
there is a polarity between the acid and its base : finally, if any
other chemical action takes place, there is a tendency to neu-
tralisation, and consequently a proof of the previous existence
of opposite elements susceptible of combining with each
other. Organic and inorganic matter are in opposition, as life
and death are. There is a true polarity between animals and
plants ; they form two opposite ranks, marching parallel with
each other, but with no communication, except at one ex-
tremity, where they seem to mix together. Vegetation offers
contrasts not less remarkable, in the relation of the root to
the bud, and of the stem to the leaf: the functions of the

CHAP. IV. SPECULATIVE MODES OF ARRANGEMENT. 327

sexual organs, and the geographical distribution of plants, are
still further proofs of the truth of this law of nature. The
animal kingdom, in which we can distinguish males and
females, respiration and circulation, arteries and veins, the
irritable system and the sensible system, and, finally, the two
symmetrical halves of the body, is rich in proofs of the oppo-
sitions required by polarity. Lastly, if we admit, with our
author, such further proofs as are afforded by the contrast
between the different colours of the solar spectrum ; between
light, an imponderable fluid, and the ponderable terrestrial
influences which control it ; between the different positions
produced by diurnal, barometrical, and magnetic oscillations ;
— if we admit all these, they must be sufficient, it would seem,
to convince the most incredulous, that the most general and
universal law of all nature is that of polarity. Such are the
reasonings on which the doctrines of polarity depend. Let
us now view the theories of elemental influence.

These opinions, of which Schelling is the author, consist in
taking some one of the imponderable fluids, such as light,
heat, or magnetism, as the type of unity, and as the primitive
source of the action of other elements, in thus explaining the
formation of these latter; and, lastly, in referring the nature
and action of all material bodies to the influence of polarity
upon ponderable matter.

According to Schelling, unity consists in magnetism ; which
is, with him, the first principle of matter, the germ of vitality,
and the common bond by which apparent differences are
reconciled. Electi-icity and magnetism are not different, the
former being a sort of diffuse magnetism; and all bodies
which seem destitute of magnetism really possess it in the
form of electricity. Light and heat are also modifications of
the same matter, and may be presumed to be different only in
the degree of their elasticity. Light is a combination of an
ethereal substance and an oxygenic principle : the first, which
may be considered the positive pole, produces the power of
expansion ; the second, which is the negative pole, determines
its material existence. Heat proceeds from certain efforts at
cohesion which take place between bodies, and from the tend-
ency to fix the equilibrium of their attractive powers, by which

y 4

328 TAXONOMY. BOOK III.

tendency the calorific fluid is disengaged. The existence of
this fluid cannot be understood without cohesion, which is
itself a combination of a positive general principle, and
identical with a special negative variable principle, which is
absolutely distinguished by its longitudinal action, and re-
latively distinguished by its transverse action : thus, the act of
cohesion between an azotic and a carbonic element is an abso-
lute act of cohesion between a positive and a negative; while
that which determines the union of a hydrogenic element and
an oxygenic element is an act of relative cohesion.

Steffens's theory is almost the same as that of Schelling.
In the view of this philosopher, magnetism and electricity are
of the highest rank : he also admits four ponderable elements ;
only he thinks that azote and carbon are more particularly
poles of magnetism, and hydrogen and oxygen those of elec-
tricity. He applies to geology and metallurgy what Schelling
did not attempt to extend beyond physics and chemistry :
finally, he views heat as a general indifference, a perfect satu-
ration, an absolute cohesion.

An opposite theory is held by Oken, a disciple of Schelling,
less submissive, and more bold in his opinions, than the last.
A substance which he names ether exists every wrhere; a
substance which forms and fills the universe; absolute as
God ; identical with God ; — but considered, with God, as
the origin of the physical world. This ether is influenced by
a tendency to centralisation, which constitutes gravity ; every
finite sphere possessing gravity is matter ; but matter is eternal,
— boundless, — filling all space, — is space itself, time, form,
and motion : it is therefore a being endued with properties and
relations almost wholly metaphysical, as far as has yet been
shown. We must give it life and real physical action : this
duty devolves upon light; and, according to the disciples of
Oken, Schelling is egregiously mistaken in ascribing it to
magnetism. Light is an active expansion of ether; it diffuses
itself through all space from the centre to which its material
properties give it a tendency ; its action is, therefore, periphe-
rical and negative on the one hand, and central and positive
on the other. The sun of our system is the consequence of
the central action, while the planets result from that of the

CHAP. IV. SPECULATIVE MODES OF ARRANGEMENT. 329

circumference ; and between these heavenly bodies there is a
reciprocal action of polarity, moving in straight lines, and
assuming a luminous appearance. Light, adds Oken, is not
matter, for the sun and planets lose nothing; it is merely an
expansion — a double action from the circumference to the
centre, and from the centre to the circumference. Light
cannot put the ether in motion without producing another
result, that of heat : heat is, therefore, ether acted upon by
light. Cold is ether unmoved and unexpanding: death,
darkness, cold, are therefore synonymous terms. Every mo-
tion is an indication of fire: all things have been formed by
fire, and all things will return to it; the only change, there-
fore, that bodies undergo in nature is that of their calorific
state. Fire, which is the joint production of heat and light,
is the first active element to be considered in material natural
bodies. Air is the second element, and may be considered as
ether surrounding the corporeal world : it derives also much
power of motion from its properties of polarity; and it is
gaseous. Water, the third element, is more fixed : it is liquid,
and composed of hydrogen, an azotic principle destitute of
vitality, and of oxygen, a zootic or vivifying principle. Finally,
earth, the fourth element, is the type of solidity, ether central-
ised and reduced into a mass. To this element the carbonic
principle is essential. The union of these four elements, and
of the principles which belong to them, determine all appear-
ances in the physical world. As to electricity, it only per-
forms a very secondary part; it is the expansion of air and of
other elements — the centropherical action of the sun and
planets; which are therefore electrical with respect to each
other. The sun has electricity in excess, the planets in de-
ficiency. Magnetism is a struggle between ponderable matter
and light; but it only appertains to the metals, and especially
to iron : all metals possess it, virtually at least, although their
magnetic properties may not be manifested unless they are
approached by iron. The existence of a magnetic fluid is,
therefore, not to be admitted, any more than the fluids called
by the French caloric or lumic : all these pretended fluids
are mere expansions or actions, and not bodies. The four
ponderable elements, considered by themselves, each constitute

330 TAXONOMY. BOOK III.

a kingdom of nature, which may be called that of single ele-
ments ; the combination of two, three, or four of them gives
birth to the mineral, vegetable, and animal kingdoms. Such
are the opinions of Oken ; which one of his disciples, Blasche,
pronounces unattackable.

There are also other means of attaining this unity, in which
so much virtue is expected to be found. It may be attained
by reducing every thing to a small number of principal agents;
by the repetition of the same phenomena in a multitude of
different ways, and especially by numerical analogies. It is
declared essential to the perfect understanding of natural ob-
jects, that they should always be reducible to a determinate
number of genera and families, beyond which number no di-
vision can take place. There is, however, considerable diffi-
culty in determining what this number is. It is either wholly
arbitrary, or it depends upon the number of elements, the
existence of which is admitted; and upon the number of
modifications of which they are susceptible. Thus, with
Oken, 4 is the sacred number in the mineral kingdom ;
classes, orders, and genera are all affected by this number :
only the families intermediate betweeen orders and genera
are classed in tens. From this mode of subdivision it follows,
that nature has produced minerals after certain constant and
unchangeable laws; that their number is as fixed as their
station ; and, finally, that neither genera nor families are to be
fabricated at will. The numbers 3, 4, and 10 appears to pre-
vail in the vegetable kingdom, and 3 and its multiples among
animals. In the zoological classification of Goldfuss, the
number 4 prevails almost universally for both orders and
families.

These doctrines of numbers have been carried even farther
by Wagner and Goldbeck, who have attempted to restore
the old Pythagorean doctrine, that numbers are the principles
of things. They declare that, till their time, every observer
or philosopher had been in error ; that what the Europeans
fancy to be science is no science at all ; that even the notions
of their German brethren were notoriously mere plays upon
words : and that numbers, and numbers alone, can be the
basis of systems. Man thinks, compares, acts only as a

CHAP. IV. SPECULATIVE MODES OF ARRANGEMENT. 331

mathematician; every thing about him is numerical. It is
chiefly from the mystical contemplation of 0 that the most
important results are obtained. Dr. Goldbeck calls his book,
" The Meaning qfO, or thejirst Dcrum of Light in the Horizon
of Truth." It must however be confessed, that this sort of phi-
losophy has found but little favour in the eyes of the world.

The influence of the planets is another notion which has
gained some partisans, who see, in the action of beings, and
especially of such as are organic, nothing but a repetition of the
elliptical course of the planets, and who find in every thing
its axis, its poles, and its focus. The ellipsis traced by the
earth ought, according to Runge, to be repeated by every thing
that it bears ; all of which consequently move in an ellipsis.
In the eyes of Kieser there is only one organic principle,
which varies in various directions, and always terminates its
elliptical cycle under the form of man, animal, or plant. The
details of this assimilation of the phenomena of the planets
with those which control living beings are highly curious.

The forces that determine the actions of all bodies, and in
particular of the heavenly bodies, are not such as are usually
admitted. Thus Oken objects altogether to the theories of
Newton : with this philosopher, force of projection and mutual
attraction are words devoid of meaning, as expressing no dis-
tinct ideas. But substitute for them polarity, original and
reciprocal polar action, and nothing can be more clear and
satisfactory than the ideas which are derived from those ex-
pressions. It is this polarity which determines and fixes the
number, size, and distance of the different stars that compose
our mundane system. Those which are not subject to these
laws, such as comets, are not so because their degree of po-
larity is not fixed : so long as they retain any degree what-
ever they will circulate around the sun ; they may be created
from time to time by the polarisation of the luminous matter
of the ether; and, consequently, when they reach any point in
space in which this polarity entirely ceases, their course is
stayed, and they are again resolved into ether: such is the
end of comets which do not re-appear. Polarity can only take
place from the sun to planets, satellites, or comets ; it cannot
take place between one sun and another, or from a smaller to

332 TAXONOMY. BOOK III.

a more considerable sun, of which the former is itself a planet.
Nothing, therefore, can be more absurd than to suppose that
the universe has a common centre, about which revolve other
centres, themselves having bodies revolving round them. The
universe is composed of a series of systems independent of
each other.

The theory of the elements is the basis of both the physical
and chemical opinions of these philosophers ; who have there-
fore been particularly occupied in investigating those sciences
which have the most direct relation with those elements. Thus
the nature of light, and the theories of opaqueness and trans-
parency, have given rise to much controversy between the two
chief antagonists, Schelling and Oken. The first admits that
there is much uncertainty as to the nature of the luminous
fluid. To him the arguments of Newton and of Euler appear
equal : he, nevertheless, has a leaning for those of the latter.
He says that the luminous matter diffused between the sun
and the earth is influenced by the former in such a way, that
the oscillations caused by that influence are communicated to
our atmosphere. He thinks that transparency is the result
of an indifference, of a positive and negative saturation of the
elements ; and as combustion is nothing but the struggle of
these elements, transparency ought to result from combustion :
he considers water and glass as examples of the truth of this
theory. Opaqueness results from bodies being removed from
the influence of the sun by a different action of their elements.
Oken considers that transparency is due to the free expansion
of the luminous fluid, which can only take place under two
conditions : first, the disorganisation of bodies which are trans-
parent; and secondly, their being composed of two substances:
for bodies absolutely identical, as metals, are necessarily
opaque ; the phenomena of reflection and refraction are ex-
plained by combining the power of the luminous fluid to ex-
pand with its tendency to centralise. A colour is a partial
luminous expansion, a mixture of light and darkness. The
object of the prism and the lens is not to create colours, but
to render visible those clear-obscure rays which we say are
coloured, and which escaped before on account of their mi-
nuteness.

CHAP. IV. SPECULATIVE MODES OF ARRANGEMENT. 333

With regard to the three kingdoms of nature, they are in
immediate dependence upon the elements. Oken sets out
from these, X.Jire (a mixture of heat, light, and weight) ; 2.
air or condensed fire (a mixture of azote, oxygen, and car-
bon); 3. water, or condensed air (a mixture of hydrogen,
oxygen, and carbon) ; 4. earth, or condensed water, with car-
bon in excess. Such are the elements which constitute the
four bases of all natural beings. Earth is the only one of
these four which is susceptible of change; fire, air, and water
being always the same. The changes that occur in the earth
are induced by the three other elements ; so that the number of
these changes can never exceed three. When the earth com-
bines with one of the other elements, a binary alliance occurs,
forming minerals, or terrestrial bielementary bodies; if air, earth,
and water ally themselves, and are only influenced by fire, light,
or heat, plants, or trielementary bodies, are generated ; and
where all four elements concur in the formation of a product,
that product is an animal, or a quadrielementary body. Hence
there are in nature four kingdoms, four great masses — the
elements, minerals, vegetables, and animals.

This elemental theory of Oken, joined to the necessity of
finding in every being subdivisions corresponding with the
influence of the four elements, brings it to pass that the num-
ber 4 exercises a paramount influence over all his classifica-
tions. The number is, however, by no means admitted by
his brother philosophers ; Grohmann sees three non-intellec-
tual masses or spheres, from which he distinguishes the intel-
lectual or physical element. Each of these masses subdivides
into three others, each increasing in dignity and originating
from its predecessors. The inorganic mass is divided into
tellurism, atmosphere, and light; the plant into root, stem,
and flower ; the animal, into abdomen, chest, and head. The
forces of nature are expansion, contraction, and crystallis-
ation. Organic forms are dependent upon sensibility, irrita-
bility, and the force of organisation.

Groh maintains the existence of a triple subdivision in
the solar system ; namely, magnetism, electrity, and halism,
corresponding with the elements of fire, air, and water : this
author, however, admits 7 as the divisor of vegetation, and
9 as that of animals.

334; TAXONOMY. BOOK III.

The relations of the two kingdoms of organic matter have,
of course, occupied the attention of the philosophers whose
doctrines are under consideration. According to Oken,
organisation is a planet upon our planet : the principle of life
is galvanism ; its base is the mass of organic matter. Beyond
this, all organisation proceeds from a mucus, which is nothing
but terrestrial matter modified by air and water. The original
mucus, out of which everything has proceeded, is the sea, living,
in its very essence, in a perpetual organising motion. Love
sprang from the foam of the sea ; it is in it that the power of
organisation resides, especially in hot countries. From those
countries vegetables, animals, and man himself, derive their
origin. All organic beings must necessarily die, because they
only represent one of the poles of the organic world, and this
world is eternal only as a whole. Spontaneous motion is the
only means of distinguishing organic from inorganic matter ;
it is the evidence of the superiority of one over the other.
Wherever, in the original universal mucus, the sea, earth,
water, and air are united, there is an organic point. The first
of these organic points, solid on the outside, and fluid within,
are little vesicles, or infusoria. Plants and animals are nothing
but metamorphoses of these infusoria : whence it follows
that the theory of generation is synthetical, and not analy-
tical. Besides, this organisation is twofold, the planetary
and the solar, the obscure and the luminous, the plant and
the animal. The plant, not excited to motion by the presence
of nutritive juices, dies ; animals move about to find the means
of subsistence. Such, and such alone, is the difference of the
two kingdoms.

Nees Von Esenbeck, being guided by the considerations of
polarity which have already been alluded to, admits four
kingdoms in organic matter; viz. fungi, or the northern and
terrestrial system ; plants, or the southern and solar system ;
animals, or the circumferential and nocturnal system ; and man,
or the central and diurnal system. Like Oken, this naturalist
believes that the first organic elements are simple and ele-
mentary vesicles : but he goes still further, and determines
that fungi are, in fact, the type and origin of the texture and
structure of the vegetable kingdom. The notions of Kieser
are also something of this kind.

CHAP. IV. SPECULATIVE MODES OF ARRANGEMENT. 335

In applying these opinions to the systematic arrangement of
the vegetable kingdom, Nees Von Esenbeck separates it into
two grand divisions, — fungi, and plants properly so called.
They consist of organic vesicles of the most simple and
primitive nature, which may be considered the basis of vege-
table tissue, and which are capable of being extended in any
and every direction, according to the predominance of the
poles. Plants are organic beings, formed by the enlargement
of those vesicles which had acquired the figure of a tube.
Three is the original number of their parts and subdivisions;
but, by the influence of metamorphosis of a more or less
active nature, the numbers 2 and 5 are also produced :
thus the divisor of the parts of acotyledones is 2 (a state-
ment which some recent observations of Turpin made, as
it would seem, without his being aware of the opinion of
Nees, appear to confirm), of monocotyledones 3, of dico-
tyledones 5.

According to Oken a plant consists of four principal parts,
— the parenchyma or pith, the stock, the flower, and the fruit :
the first is divided into cells, veins or vessels, and tracheae ;
the second into root, stem, and leaves ; the third into seed,
capsule, and corolla ; the fourth is incapable of division.
These ten fundamental organs give rise to the ten principal
classes; viz.

A. Parenchymatosc.

1. Cellular. Fungi consisting merely of cellules or pulveru-
lent grains, or simple filaments.

2. Venous. Fungi with their cellules or filaments con-
tained in a common vesicle.

3. Tracheal. Fungi with a triple envelope.

B. Cauline.

4. Radical. Plants with roots, but without a true stem ;
mosses, lichens, &c.

5. Cauline. Plants with roots and a perfect stem. Mono-
cotyledones.

6. Foliar. Plants with roots, stems, and perfect leaves.
Apetalous dicotyledones.

336 TAXONOMY. BOOK III.

C. Floral.

7. Seminal. Plants with a naked seed and no capsule.
Epigynous dicotyledons.

8. Capsular. Seed covered with a pericarpium ; corolla
monopetalous and hypogynous ; monopetalous dicotyledones.

9. Corolline. Plants with a perigynous corolla ; poly-
petalous perigynous dicotyledones.

D. Fructual.

10. Fructual. Dicotyledones with a polypetalous hypo-
gynous corolla.

Each of these classes is subdivided into four orders, accord-
ing to the same fundamental organs ; and into ten tribes, ac-
cording to the ten secondary organs ; and each tribe into ten
genera, according to the same principles : so that the number
of genera in botany must of necessity be 750. But I need
not pursue these fantasies any further.

Having thus shown what the general principles are upon
which these philosophers would form their systems, I shall
next proceed to detail the more particular principles in use
among them ; in doing which I cannot do better than repro-
duce a translation I some years since made, for the Philo-
sophical Magazine, of the canons of Fries upon this subject.
They are the following : —

§ 1. Nature is an universal complication of phenomena,
existing and acting in all places and at all times; an infinite
power made manifest by the successive evolutions of a finite
power; the sum of the whole creation in a continuous state —
all existent matter proceeding from perfection and pregnant
with futurity.

In nature there is a perpetual struggle, an uninterrupted rota-
tion. The powers of formation and destruction operate alter-
nately, whence nature is always dead and regenerate. The
human mind, viewing this last phenomenon in its most extensive
and, at the same time, most satisfactory sense, calls eternity in a
state of ceaseless variation by the name of Nature.
§ 2. Nature must be considered as either perfect or ap-
proaching perfection (vel ut naturans vel ut naturata).

CHAP. IV. SPECULATED MODES OF ARRANGEMENT. 337

§ 3. The powers and the productions of nature are co-
existent.

All power is as it were a law under which a given production
holds its existence, but in such a manner that all power is the
finite revelation of an infinite law. To act and to exist is the
same thing.

Power therefore is nature without production ; Production is
matter without power. Neither exists in nature by itself.
$ 4. All the powers of nature are more or less perfect mani-
festations of one primitive power, which acts by its different
productions, according to the same eternal, immutable, abso-
lute laws. But the powers of nature act only by mutual re-
action ; so that each power of nature becomes in its products
impeded, interrupted, or quiescent.

The most perfect primitive power appears nowhere in nature
absolute; but more or less impeded. Hence the powers of na-
ture are various, some one among them being more perfect or
active than the rest (less impeded).

The existence of nature depends upon this kind of control,
and successive evolution ; every power which is absolute and
independent of restraint becomes infinite, and ceases to be per-
ceptible as a finite power — (Nature).

Powers of low degree act upon those of higher degree ; but
the lowest powers, when not struggling with higher, contain
opposing principles in themselves ; for example, attraction (re-
pulsion), electricity, magnetism, &c.

This opposition, which pervades all nature, is called Polarity.

The more agreement there is between powers, the greater
also the agreement between their productions.

The more perfect a power, the more complex its actions ; the
more perfect its productions.

The more complex are actions, with the more difficulty are
their laws explained : thus, for example, the laws of affinity and
of motion are almost ascertained; by no means those of vitality
or of sensation.

§ 5. All things which exist in nature are a whole, and at
the same time a part of a larger whole. They are capable of
beind themselves resolved into other wholes until the human
mind sinks under ideas of sublimity and subtilty which are
imperceptible to it, — of the universe and of atoms.

An atom is a whole (an individual), a plant is a whole, the

z

338 TAXONOMY. BOOK III.

earth is a whole, the universe is a whole : hence all things which
exist are parts of one highest whole.

The vital principle of every individual is one ; the same vitality
animates the universe ; so that there is one and the same primi-
tive power which is revealed, by divers phenomena, in divers
degrees of perfection. § 4.

Let us imagine all nature to be an immense sphere ; all the
rays converging in the centre, where they finally become con-
fluent in a point, which may be called the point of identity.
This point comprehends the perfection of all the rays ; for that
the most perfect and most completely formed creations, as the
sun, are always situated in the centre, is testified by all authority,
by all experience.

The powers of nature diverging from each centre in polar op-
position, are continually passing into opposite series. A new
sphere is formed by each opposition, whence the highest (most
perfect) sphere is again and again resolved into new spheres,
which form wholes of themselves, and each of which, according
as its power is a more or less perfect evolution, in itself reflects
the whole in a more or less distinct degree.

The centres of these spheres may be exceedingly distant from
each other, but their rays always impinge upon the rays of some
other sphere : hence they are not the most perfect forms (summa)
of each section which run into each other, but those which are
least perfect (infima).

The different spheres, therefore, being dependent upon the
same eternal laws, and only varying according to the idea pe-
culiar to each sphere, answer the one to the other. Hence
among all natural productions, a more near or more remote re-
semblance is perceptible : the one of them being such resem-
blance as exists between subjects contained in the same sphere :
— Salts, for example, which are formed of the same basis com-
bined with different acids ; the other being such resemblance as
exists between subjects contained in different spheres of the
same degree of evolution, as Isomorphous Salts, the bases of
which are different, but the form the same, on account of the
identical relation of their elements. The former is called Affinity,
the latter Analogy.

§ 6. It is impossible for the human mind, itself a finite
creation, to regard nature, whether her powers or her pro-
ductions are considei'ed, in the light of the whole manifestation
of an infinite power, but only as parts or fragments of such

CHAP. IV. SPECULATED MODES OF ARRANGEMENT. 339

manifestation. But to comprehend these as one whole, that
is, as an eternal and immutable, yet ever varying body, or,
as innumerable forms of one highest whole, is the end of all
disquisition, the sum of which we call a System.

It is necessary not to confound with systems, properly so
called, those indexes of nature which are incorrectly called
Artificial Systems. Indexes have references only to names,
systems to ideas. " Turn primum homines res ipsas neglexerint,
quum nimio studio nomina quaerere inciperent." — Galen.

§ 7. A system contains within itself the seeds of some more
complete evolution, but it does not admit of arbitrary altera-
tions.

Not that any absolute system can ever be contrived ; for I am

by no means of the opinion of those who expect that a system

is to be as unchangeable as if it were petrified.

§ 8. If nature be closely pursued, a system is called Na-
tural ; if this Ariadnean thread be not followed, it is called
Artificial or factitious.

There is, however, no absolutely natural system ; such is only
ideal : neither is there any merely artificial system ; because its
principles must necessarily be borrowed from nature herself.

Besides, nature wholly disavows our sections, she being a
whole ; all systems, therefore, as far as their arrangement is
concerned, are necessarily artificial.

It is by the comparison of various systems with each other
that our notions of such as are natural and such as are artificial
are acquired, those having the former designation which press
most closely upon the footsteps of nature. Hence it is that a
system which is to-day called natural, becomes to-morrow, by the
accession of new ideas, artificial ; as that of Tournefort, &c.

Is it not, then, a vain labour to search after a natural system,
since such will never be found ; and are not all attempts at it
rash, until every thing which is capable of observation shall have
been observed? If this were admitted, it would be useless to
seek for perfection in any thing ; for we can never hope that our
experience will be perfect ; and there will be no want of subjects
for examination to a person who shall live a thousand ages
hence. Such sublime truths as the present age shall strike out,
are, therefore, not to be contemned because they will become
more full and perfect hereafter.

§ 9. A system of nature proceeding from subjects of the most

z 2

340 TAXONOMY. BOOK III.

simple organisation to such as are more perfect, or from the
circumference to the centre, is called a Mathematical System.

For mathematicians assume that nature herself proceeded
from forms of the most simple kind to those which are more
perfect ; and that, therefore, is the most natural road, which
nature herself has followed in forming her creations.

All natural bodies, indeed, originate in successive develope-
ment, yet in a continuous series within a determinate sphere.
Every new sphere originates in a digression from a series which
is otherwise continuous. Whenever a more perfect sphere is
separated from .one which preceded it, and has acquired a higher
station than its parent, it may be itself pressed down by such
new ones as emerge from itself; but the depressed sphere is also
capable of continuation in its descent ; and under this mode of
developement the same principles and the same types are re-
generated under more perfect forms in the higher spheres.

Those, therefore, are mistaken who assume that nature pro-
ceeded iu a simple series to her most perfect productions.
Thus, for example, all parasites, both animals and plants, must
necessarily have been created later than their matrix (and should
therefore be the most perfect parts of the creation). But Fungi,
which are the latest in the series of vegetable developement, are
the most simple of all in their structure.

In Minerals, of which the most simple are at the same time
the most perfect, the Mathematical system may be employed,
because it corresponds with the Philosophical. But in higher
spheres, in which vitality must be considered, the laws of ma-
thematics are of no avail.

§ 10. A system of nature which takes for the basis of its
arrangement the order of developement of individuals is called
Physiological.

But take care not to imagine that the first series of evolution
is a simple one. As the evolution of the animal and vegetable
kingdom may be said to have proceeded with nearly equal
paces, so the different sections of vegetables cannot be said to
have arisen out of a simple series, but out of parallel or radiant
series. Many Algae must have been created more recently than
the most perfect plants, Entozoa than the most perfect animals.
Whence it is to be inferred, 1st, That nature, properly speak-
ing, can only be said to have proceeded from the most simple
forms to those which are more compound, in theory {de ideis) ;

CHAP. IV. SPECULATED MODES OF ARRANGEMENT. 341

but, 2dly, to have often operated in an inverse order in her
forms.

§ 11. Philosophical systems do not depend upon individual
productions which are subject to continual variation, but upon
eternal and unchangeable ideas. These always proceed from
the centre to the circumference, or from the most perfect pro-
ductions to those of a lower order.

This is the method of my Mycological system, and it agrees
with the Mathematical system if the order be inverted.

A Philosophical system depends upon the laws of logic : for
the laws of logic are by no means notions contrived by man, but
eternal and immutable, and established by Nature herself. As
the rotation of the heavenly bodies, discovered after the laws of
mathematics, must necessarily follow those laws ; so also no
observation in nature can invalidate the laws of logic. For the
laws of logic are the laws of nature.

It must be observed, however, that a system, although logi-
cally true, may be naturally false, because it may have been
deduced from false principles; but every true system cannot
deviate from the rules of logic.
§ 1 2. A Philosophical system is superior to all others.

It may at first appear, perhaps, of little moment, what way we
follow in enumerating the productions of nature ; but if one
way is more certain and more facile than another, that is surely
to be preferred.

To me it appears most advisable to commence with that
which is most perfect, most completely developed, and there-
fore most easily understood ; and thence to descend to forms of
a more imperfect kind, and therefore of a more doubtful nature.
The half-developed portions of the lower forms would never be
understood, if they were not more completely developed in the
higher forms. This is the path which is pointed out both by
experience and common sense ; the idea of a seed is not derived
from an Uredo, nor that of a vegetable from an Erineum ; but
the reverse.

This is especially true of those lower spheres which bring up
the rear : the last point of simplicity will never be attained, and
will never be determined ; although our microscopes are daily
extending our views, the poles of vitality will never be reached.
It is better, therefore, to set out from a certain point (the centre)
than from an uncertain point (the circumference), which may be
^extended to infinity.

z S

342 TAXONOMY. BOOK III.

So it is more wise, in studying Man, to take our notions of
humanity from those in whom it exists in the highest degree of
perfection, rather than to search over-curiously for a man whose
intellect is approximating to that of animals.

§ 13. In a systematic arrangement the higher forms are
always to be taken before the lower.

The highest arrangement is always to be taken from the
highest and most essential characters, — from each highest
character originates a particular section, — and all the sections
which are subordinate to this character are to be comprehended
under its common title. The higher the distinction, the greater
its dignity and importance.

Nature is always passing into series in polar opposition : hence
a dichotomous mode of distribution is not only the most natural,
but almost the only true one. Logic and nature, which are ever
in accordance, prove this continually. Thus, for instance, na-
tural bodies are more properly divided, into organic and inor-
ganic, than, overlooking this distinctioii, into minerals, plants,
and animals ; so also is the distribution of vegetables into
cotyledonous and acotyledonous preferable to that of mono-
cotyledonous and dicotyledonous.

But as the most sacred things are the most open to abuse, so
also is the dichotomous disposition, which is of the highest value
when nature is strictly followed, the most artificial of all when
arbitrary distinctions take the place of those which are essential ;
as the analytical index of Lamarck. Many, for this reason, alto-
gether object to such a form of arrangement ; but the abuse of
a thing does not destroy its use.

When the members of a bipartite section are again dichoto-
mously divided upon analogous principles, four sections are cre-
ated, of which the first and second, and the third and fourth,
are in affinity ; but the first and third, and the second and fourth,
are in analogy.

But when this method of division becomes circuitous, a more
direct path is undoubtedly to be discovered : hence other num-
bers are admitted, especially the quaternary (or double dicho-
tomy), and also others in which dichotomy is understood.

There are other and most acute observers (Oken, MacLeay)
who contend for other fixed fundamental numbers. Care must
be taken, however, that no cabalistical or occult virtues are at-
tributed to any particular number ; in the higher spheres a
higher number is, on account of the multiplicity of organs, ad-

CHAP. IV. SPECULATED MODES OF ARRANGEMENT. 343

missible than can be used in the lower spheres ; the only object
of such a contrivance being to explain in what direction rays
pass off from their centre, and at what points the rays of differ-
ent spheres impinge upon each other. To do this a determin-
ate number is required.

We must, moreover, avoid extending too precipitately any
system whatever to specialities. We can proceed in no direc-
tion further than the power of arrangement acquired by what
we positively know of nature admits. I certainly am not of the
number of those who assume that infinity is to be circumscribed
within strict limits ; although I may be of opinion that infinity
and universal harmony are better explained by them than ac-
cording to any arbitrary rules of arrangement.

In the formation of sections and genera it is most especially
necessary to beware that they do not depend upon characters
alone ; so that if the character should hereafter prove defective,
the section or the genus may still remain unchanged. In this
lies the difference between an artificial and natural arrangement;
the former depending upon characters, the latter upon affinity.
Hence Linnaeus did not characterise his families of plants, nor
Ehrenberg those of fungi, rightly perceiving that affinity is of
the first importance, characters of secondary.

It is occasionally necessary to admit into a particular section
a genus or species in which the most important character of
such section does not exist, but then its truly essential character
cannot have been detected. Thus, when we say that Rosacea;
are dicotyledoneous, perigynous, polypetalous, &c, and refer to
them Alchemilla, it will be easily seen that the really essential
character of Rosacea? remains to be discovered.
§ 14. Every sphere (section) expresses a particular idea;
hence its character is best expressed by a simple notion.

But to effect this, it is necessary that the character which is
really most essential shall have been detected. For if a section,
of which the primary character is unknown, be circumscribed
by a simple notion, the most arbitrary and artificial arrangement
possible would be the result.

When the essential character is once detected, all others will
be wholly dependent upon it (for when this character is changed
the others are changed also), and those which do not depend
upon it are accidental.

It must not, however, from this be understood that a system
is to be applied to one part only of its subject : on the contrary,

z 4

344 TAXONOMY. BOOK III.

it embraces all parts, arranging them upon the same principles,
— but when they diverge in opposite directions, one is to be
chosen in preference to another.

§ 15. Physical or Physiological marks are capable of distin-
guishing spheres (sections) of the highest order only ; but in
those of the lowest they are always to be consulted.

Physiological characters, as being those which are most essen-
tial, are little subject to variation, and therefore will not suffice
for distinguishing the lower spheres (orders, genera, species);
they are, nevertheless, to be continually consulted as to origin,
station, geographical distribution, &c. which illustrate the series
of affinities in various ways.

§ 16. Essential characters are generally the most hidden,
and demand acute investigation ; the most superficial being
those which are accidental.

Hence it is that accidental characters, or those of a lower
order, are first seized, as being those which are most immediately
under our eyes : thus the low distinctions of species and varieties
are easily acquired by mere tyros, while the higher are within
the comprehension of* masters of the science alone.

The whole progress which has been made in natural history
has been a succession of triumphs of the more essential charac-
ters over those accidental ones which had been previously re-
ceived. Thus, in the following comparison, how much more
important are those distinctions which are
Essential than those which are Superficial.

1 . Mammalia, Amphibia, Pisces,

of Linnaeus.

2. Monocotyledones, Dicotyle-

dones, &c.

3. Hymenomycetes, Gastero-

mycetes, &c.

4. Lichens from their fruit.

1. Quadrupeds, Serpents, Fishes,

of old authors.

2. Trees, shrubs, herbs, &c.

3. Fungi stipitati, sessiles, clavi-

formes.

4. Lichens from their thallus.

The foregoing proposition must not, however, be inverted, by
supposing that the more hidden characters are, the more essential;
Natural History would then become not only micrological, but
very difficult and erroneous. Where an object is easily distin-
guished by marks immediately under our eyes, microscopical
differences are not to be sought after. Besides, characters in-
dicated by highly magnifying microscopes are, in fact, as super-
ficial as those seen by the naked eye.

CHAP. IV. SPECULATED MODES OF ARRANGEMENT. 345

§ 17. The primary powers of nature are arranged accord-
ing to the following laws. They are these : —

A. Terrestrial (Tellustres), acting together or in contac 1.

a. Acting together and continuous in their productions.

1. Sensibility, or the power of motion, sensation, and con-

sciousness. The object of Psychology.

2. Vitality, or the power of absorbing heterogeneous mat-

ter, of assimilating it to an internal circulation, and of
bringing forth progeny of the same nature as the parent.
The object of Physiology.

b. Acting in contact, and absolute in their productions*

3. Affinity. The object of Chemistry.

4. Electricity. The object of Physics.

B. Sidereal (Siderales), acting from a great distance.

a. Reproduction. 1. Light.

b. Production. 2. Attraction.

§ 18. The productions of nature, which are co-existent with
these, are also considered as, —

A. Terrestrial; various in form, placed in juxtaposition

or cohesion with each other, arranged both by terres-
trial and sidereal influence, and composed of parts
which, taken together, form a whole. Natural bodies
properly so called ; the objects of Natural History.

a. Organic ,■ reproductive, composed of various definite organs,

and formed by internal developement.

1. Animals, possessing sensation. The objects of Zoology.

2. Vegetables, possessing vitality (not sensation). The
objects of Botany.

b. Inorganic ; productive, homogeneous, formed of particles

in juxtaposition (and not possessing the qualities of or-
ganic bodies).

3. Minerals; ponderable. The objects of Mineralogy.

4. Elements ; imponderable. The objects of Physics.

B. Sidereal; a system of Earths, which are spheroidal,

very distant from each other, subject to the influence of
sidereal power alone, and composed of the heterogeneous,
but individually entire, productions of nature. Stars,
the objects of Astronomy.

346 TAXONOMY. BOOK III.

a. Possesing light and attraction, reproductive, central.

1. Swis.

b. Possessing attractive power, but no light of their own,
productive, circumferential. 2. Planets.

VEGETABLES

are Living, insensible organic bodies.

§ 19. The end of life (and therefore of vegetation) is two-
fold: the preservation of the individual and of the kind; the
former is called Nutrition, the latter Generation. Hence there
is a twofold system of organs ; namely, of nutrition and of
multiplication. But the organs of nutrition are either pre-
pared by the mother {Germination), or developed by the plant
itself (Vegetation); so also the organs of multiplication are
either confined to the plant (Floivcring) , or continued in a new
individual (Fructification).

There are, therefore, four primary functions of vegetables :

germination, vegetation, flowering, and fructification. This is

the basis of my system.

§ 20. According to these two systems of organs, and four
primary functions of life, the following arrangement is pro-
duced of —

Vegetables.
A. Organs of Nutrition.
a. in Germination.

1. Cotyledoneous, producing

cotyledons.
2. Nemeous, producing a
tit lead.

, in Vegetation.

1. Vascular, having cellular
tissue and spiral vessels.

2. Cellular, having cellular
tissue, and no spiral vessels.

B. Organs of Multiplication.

c. in Flowering.

1. Phaenogamous, having sexes
or manifest Jlowers.

2. Cryptogamous, having no
sexes, and destitute of

Jlowers.

d. in Fructification.

1. Spermideous, bearing
seeds.

2. Sporideous, bearing
spo rules.

§ 21. Upon the same principles Cotyledoneous Vegeta-
bles (Vascular, Phanerogamous, and Spermideous) are divided
according; to —

CHAP. IV. SPECULATED MODES OF ARRANGEMENT.

847

A. Their Organs of Nutrition.

a. in Germination.

1. Dicotyledoneous, with a
double expanded cotyledon.

2. Monocotyledoneous, with
a single enclosed cotyledon.

b. in Vegetation.

1. Exogeneous, the trunk
youngest at the circumfer-
ence.

2. Endogeneous, the trunk
youngest, and softest in the
centre.

B. Organs of Multiplication.
c. in Flowering.

1. (Androdynamous ?

2. (Gynodynamous?)

d. in Fructification.

1. Seminiferous. Agardh.

2. Graniferous. Agardh.

§ 22. Nemeous Vegetables (Cellular, Cryptogamous, Spo-
rideous, are also disposed according to —

A. Organs of Nutrition.

a. in Germination.

1. Heteronemeous, threads in
germination copulating into
a heterogeneous body.

2. Homonemeous, threads in
germination either separate
or confluent into a homo-
geneous body.

b. in Vegetation.

1. Diplogeneous, formed of
regular connected cellules.

2. Haplogeneous, formed of
anomalous somewhat jila-
mentose cellules.

§ 23. The organs of Vegetation offer modes of subdivision
in proportion to the lateness of their evolution.

Germination offers very few, Vegetation a greater number,
Flowers many, Fruit very numerous modes.

Their dignity is the converse of this ; the most essential modes
depending upon germination and vegetation, the less essential
upon flowering, and almost accidental modes upon the fruit (at
least the pericarpium).

In this manner the vegetable kingdom, or rather world, is di-
vided into two hemispheres by Germination, and into four quar-

B. Organs of multiplication.

c. in Flowering.

1. Cryptandrous, something
analogous to sexual di-
stinction.

2. Anandrous (Link), nothing
analogous to sexual differ-
ence.

d. in Fructification.

1. ? Sporiferous. Agardh.

2. ? Sporidiiferous. Agardh.

348 TAXONOMY. BOOK III.

ters by Vegetation, into Classes by Flowers, and into Orders
and Families by Fructification.

§ 24. Systems truly constructed upon these principles also
comprehend all other essential differences, and at the same
time explain them.

349

CHAPTER V.

OF THE VALUE OF CHARACTERS.

The basis of the natural system of botany consists in a just
view of the mutual affinities of plants; and this is only to be
obtained by determining the precise value of the various cha-
racters by which these affinities are indicated. Plants agree
with or are distinguished from each other by various peculi-
arities of form or structure : all these peculiarities, of what
kind soever they may be, are called characters. For example,
a lichen is distinguished from a nettle by having a cellular
instead of a vascular organisation ; its cellularity is, therefore,
one of the distinguishing characters of the lichen : it is also
distinguished from mosses by its organs of reproduction being
contained in scutella instead of thecae; its scutella are also,
therefore, a discriminative character. The sweetbriar-rose is
distinguished from the dog-rose by its leaves being covered
with sweet-scented glands; these, therefore, are a distinctive
character of the sweetbriar-rose. The rose and the vetch are
both constructed with pinnated leaves and stipulas; pinnated
leaves and stipulae are, therefore, characters of agreement
between the rose and vetch. The apple and pear have both
an inferior fleshy fruit or pome ; they agree, therefore, in the
character of the fruit, and so on : in short, every permanent
circumstance whatsoever, in which plants differ or agree, is a
character. The value of these characters is, however, ex-
tremely different, as will presently be seen.

Those characters are of the highest value which are the
most constant ; and those are of the lowest value which are
the most inconstant.

The value of a character is, in the first place, to be deter-
mined by the purpose to which it is to be applied. A dis-
tinction may be extremely important in characterising a large
quantity of species ; which will be useless when the object is

350 TAXONOMY. BOOK III.

to distinguish one species from another ; because the universal
existence of it in the whole mass of species which renders it,
in a collective sense, important, destroys its value when the
discrimination of species or subordinate groups is the object
in view. Thus the peculiar state of the fibrous tissue of gym-
nospermous dicotyledons, by which they are anatomically
distinguished from all other plants, is of no importance in
discriminating one genus of that group from another, because
it is common to them all. On this account, the more uni-
versal a character is, the better is it adapted for the most
extensive collections of species; and the more circumscribed
and unfrequent it is, the better it is adapted to the distinction
of genera or species.

The permanence of a character, or, in other words, the
absence of a tendency to variation in the modification of any
organ, is another consideration, of the first importance in
determining its value; those which are the most permanent
being of the highest value, and those which are the most
variable being of the lowest. For instance, the capsule and
seed of a plant will be produced from generation to genera-
tion without sensible variation ; this, therefore, is a constant
and valuable character : but the colour of its flowers may be
white or blue, and the surface of its leaves smooth or hairy ;
the colour, therefore, of the flower, and the surface of the
leaves are, in such a case, inconstant and worthless characters.
It is not easy to lay down any general rules upon this subject,
the number of exceptions being so great as to invalidate
almost any rule which can be proposed. It is, however, very
important to know what the experience of botanists has taught
them; and this I will now endeavour to explain.

Anatomical differences have been found of the highest value
in characterising the primary divisions of the vegetable king-
dom : the presence of spiral vessels is universal in flowering
plants ; while their absence is equally characteristic of flower-
less plants. The presence of glandular swellings upon the
walls of the fibrous tissue of gymnosperomous dicotyledons is
a mark by which they may be always known. How far ana-
tomical differences are important in fixing the limits of sub-

CHAP. V. THE VALUE OF CHARACTERS. 351

ordinate groups is not yet known ; but much is to be expected
from future enquiries.

The modes in which plants grow, which may be called
their physiological differences, are of very great importance.
Not only are exogenous and endogenous plants thus positively
limited, but in the latter grasses are instantly known by
their hollow stems and phragmata; and palms by their simple
cylindrical stems, with a terminal bud only. This subject is
like the last, still in its youngest infancy.

The root, whether true or spurious, is not often employed
as a character, chiefly on account of the difficulty of observing
it, and its being seldom preserved in herbaria. It will fre-
quently distinguish varieties from each, as in the radish, and
other garden productions : it sometimes affords good charac-
ters for species, as in the genus crocus, some grasses, and
many herbaceous plants ; in which latter it is especially im-
portant to observe whether it is creeping or fibrous. In the
genus orchis sections are formed from differences in the roots,
some consisting of an undivided lobe, others having their roots
palmate, and others fasciculate ; occasionally, but, I believe,
only in monocotyledones, it is a good aid for discriminating
certain natural orders ; thus, Asphodeleae are mostly charac-
terised by their scaly bulbs, and Irideaeby their solid rhizomata,
or cormi ; but generally the root or root-like bodies are to be
excluded from all characters higher than those of species.

The stem is of the greatest importance in many of the first
characters of vegetation : its greater or less degree of vigour
distinguishes the varieties of Phased us vulgaris, and those of
numerous other plants; its direction is a common charac-
teristic of species, as to whether it is erect or decumbent, or
twining or trailing, and so on ; its form, whether round or
semiterete, or angular or triquetrous, &c. is always of value
in distinguishing species : in Labiatas and Stellatae, it is an im-
portant character of the order, being universally square ; its
substance, whether fistular or solid, is occasionally, but not
often, taken into account in distinguishing species ,- and, finally,
its internal anatomy is of the greatest consequence in dis-
tinguishing the highest divisions of the vegetable kingdom.
The more remarkable of these have been noticed in speaking

352 TAXONOMY. BOOK III.

of physiological characters ; but, independently of those great
modifications of growth, it is probable that many orders are
capable of being distinguished by the manner in which the
vascular and cellular systems are respectively arranged. We
know that Calycanthese have the peculiarity of possessing four
additional woody axes lying in the bark ; and there seems good
reason for believing that other orders possess other distinctive
characters.

The mode in which the stem ramifies will sometimes dis-
tinguish a species ; but the presence or absence of the abortive
branches called spines, is rarely indicative of more than wild
and cultivated varieties of the same species.

The hairs, prickles, and other appendages of the external
surface of plants, are chiefly used to mark species or varieties.
Species are often excellently characterised by the presence or
absence of hairs or prickles upon particular parts, and also
by their direction and form : but these are sometimes falla-
cious characters, depending upon the situation in which
plants grow, and other accidents. The form of hairs is of
more consequence ; thus, in Elaeagneae they are lepidote; in
Euphorbiacege and Malvaceae they are stellate or furcate ; in
Borafrineae they have a bulbous base ; and the genus Indi-
gofera is distinctly characterised by the hairs being attached
by their middle.

Leaf-buds are scarcely ever noticed by botanists ; and yet it
is not improbable that the arrangement of their leaves before
expansion may offer characters of moment, as in Salix ; and it is
certain that in some genera, Fraxinus, for instance, the colour
and form of the buds afford the surest distinction of species.

Leaves afford a multitude of characters, some of which are
used merely to distinguish species and varieties ; others are of
a higher class. To the former belong all those differences in
margin and figure to which leaves are particularly subject;
generally every decided difference in the mode of division or
form of the leaf is accounted a distinction of a species ; but
this must not be understood as a uniformly constant cha-
racter ; for in many garden plants species vary with entire
and cut, or even pinnatifid leaves, and with linear, lanceolate,
or even broader leaves ; differences which in such cases serve

CHAP. V. THE VALUE OF CHARACTERS. 353

only to characterise varieties ; this is the case with Tilia
Europaea, Alnus glutinosa, Fagus sylvatica, Cytisus Labur-
num, and many others : on which account differences in the
degree of division, or in the outline of leaves, must not be
trusted to as characters indicative of species, unless they are
accompanied by other differences in other parts of the organs
of either vegetation or fructification. The nature of the
margin of a leaf is sometimes of very great importance in
characterising natural orders; thus, in Cinchonaceae and
Myrtaceae it is always perfectly entire ; but in many orders it
is of no value, as in Rosacea?, in which leaves vary from being
entire to serrate, and to almost every degree of division. The
degree of composition sometimes affords characters of a high
rank, applicable to the distinction of genera, or even of
natural orders ; thus, Berberis is known by the composition of
its leaves, which is most apparent in the section called Ma-
honia, and indicated in those with simple leaves by an articu-
lation at the apex of the petiole : in true Aurantiaceae, the
leaves are always compound, as is indicated by the leaflets
being constantly articulated with the petiole ; but in other
orders the composition of the leaves is of scarcely any value,
even for distinguishing genera ; thus, in Rosaceae, pinnated,
pinnatifid, and simple leaves are found in the same genus, as
Pyrus for instance. Insertion is a point of the highest con-
sequence, and less liable to exceptions than most characters.
It is a general rule, that there cannot be opposite and alter-
nate leaves in the same natural order ; and although to this
there are exceptions, yet upon the whole it may be taken as a
good character. Most monocotyledonous plants have alter-
nate leaves, but in some they are approximated so much as to
appear as if opposite. The arrangement of the veins often
affords excellent characters : in most monocotyledonous plants,
the veins are simple and parallel ; in most dicotyledonous
plants they are reticulated ; in all true Myrtaceae, the venae
externae form a continuous line parallel with the margin, by
which, I believe, they are to be positively distinguished ; in
most Amentaceae, the venae primaries run directly to the teeth
of the margin, in which they terminate, without bend or
interruption ; and numberless other cases may be instanced,

A A

354 TAXONOMY. BOOK III.

in which characters of similar importance may be obtained
from venation. Dotting, that is to say, the presence of recep-
ticles of oil within the substance of a leaf, giving it a clotted
appearance if viewed against the light, is generally a character
of natural orders : thus Myrtaceae are distinctly separated from
Melastomaceae, by their leaves being dotted ; and Auran-
tiaceae, and some others, are to be known by their dots, while
Samydeae have a mixture of dots and short transparent
bars.

According to Mr. Brown, the Stomata are sometimes of im-
portance in determining the limits and affinities of genera, or
of their natural sections, according as they vary in figure,
position, and size, with respect to the meshes of the cuticle.
He remarks, that they occupy both surfaces of the leaf in all
the Proteaceae of Southern Africa, except Brabejum.

The presence or absence of Stipulcc is a character of the
same kind of importance as the insertion of leaves : generally,
stipulae cannot be present and absent in the same natural
order ; and to this the exceptions are so few as not to invali-
date the rule. All Rosaceae, for instance, have stipulae, except
Lovvea berberifolia and Spiraeas, in which they are absent.

The Bractece are usually subordinate to other characters,
and are generally employed as a means of distinguishing
species, the distinctions of which are often conveniently ex-
pressed by the relative length of the bracteae and pedicel, the
form of the bracteae, and similar chai*acters ; but in some
plants they possess peculiarities of so marked a kind that
they are used for distinguishing genera : in Gramineae, for
instance, bracteae constitute the whole of the floral envelopes,
and are exclusively used for generic characters. In Compositae,
the bracteae, out of which the involucrum and appendages of
the receptacle are formed, afford good distinctions of genera ;
and in Umbelliferae, they afforded Linnaeus generic characters
which he thought good, although they are undervalued at
present.

The Liflorescence is chiefly used to distinguish species ; it
seldom affords generic characters, but occasionally those of
ordei's. In the latter case, however, it is only the great forms
of inflorescence which can be taken into account; thus, a

CHAP. V. THE VALUE OF CHARACTERS. 355

spike, raceme, or panicle, may all be expected to exist in the
same natural order; but a cyme will scarcely be found with
them; and the umbel and capital um are usually confined
exclusively to certain orders. Thus, the inflorescence of Betu-
lineae and Salicineae is a catkin, of Compositae a capitulum,
and of Umbelliferse an umbel; but in Asphodeleae we have the
spike, raceme, and panicle, along with the umbel.

With the Calyx the organs of fructification are said to begin.
Slight modifications of its form and surface are used for cha-
racterising sj)ccies i more decided peculiarities denote genera ;
thus, the species of Myosotis differ in having calyxes, open or
closed, acute or obtuse, naked or covered with hairs ; and the
genera Polemonium and Phlox are distinguished by the former
having an urceolate calyx, the latter a prismatic one. Cha-
racters in the calyx, of a still higher kind, distinguish some
natural orders; especially that of its being adherent or not
adherent to the ovarium : this is generally considered a
point of the greatest importance; but there are very nume-
rous exceptions to it, of which more will be said when we
come to the ovarium. The position of the lobes of the
calyx or sepals, with respect to the axis of inflorescence,
is important in distinguishing some natural orders : Leo-u-
minosae, for instance, in which the fifth lobe of the calyx
is anterior with respect to the axis of inflorescence, are by
that character alone separable from Rosaceae, in which it is
posterior with respect to the axis. The aestivation of the
calyx should always be carefully noted ; it is often different
from that of the corolla, and is frequently the character of an
order; thus, Thymelaeae are distinguished from Proteaceae by
the aestivation of the calyx of the latter being valvate, of the
former imbricate. All Malvaceae, and the orders more im-
mediately allied to them, have a valvate aestivation.

The Corolla offers many valuable characters : by the dif-
ference in its colour or odour, varieties are distinguished;
species are known by variations in its form, surface, or pro-
portions ; genera and orders, by distinctions in its form, com-
position, insertion, and aestivation. For example, a mono-
petalous and polypetalous plant rarely co-exist in the same
genus, or even order: hypogynous, perigynous, or epigynous

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356 TAXONOMY. BOOK III.

corollas are in like manner incompatible with each other in
the same order; but whether a corolla is rotate, infundibuli-
form, or hypocrateriform, is never of more than generic im-
portance: its aestivation distinguishes orders, and, perhaps,
occasionally genera; but is scarcely of so much consequence
as the aestivation of the calyx. In Asclepiadeae, the aestiva-
tion is imbricate ; but Mr. Brown admits into the same order
a valvate aestivation. The appendages of the corolla, such as
are found in Caryophylleae, Asclepiadeae, Brodiaea, Narcissus,
and others, seldom characterise any higher group than a
genus; they are, however, admitted into the characters of
some natural orders, as, for example, Olacineae.

In considering the peculiarities of the Stamens, it will be
found that their length, with respect to the other parts of
fructification, and their surface, are scarcely ever of more than
specific importance; nevertheless, in Boragineae, their length
with respect to the corolla has been taken as a generic cha-
racter; and the nakedness or hairiness of the anthers distin-
guishes Chelone from Pentstemon. Their insertion, whether
perigynous, hypogynous, or epigynous, usually distinguishes
natural orders; but to this there are many exceptions; thus,
in Papaveraceae, which are characterised by having hypo-
gynous stamens, Eschscholtzia has them perigynous ; in Ano-
naceae, which has hypogynous stamens, Eupomatia has them
perigynous : in short, there is no doubt that the insertion of
the stamens, although in many cases an important character,
has been much overvalued. But the most valid circum-
stance to consider, with respect to the stamens, is their inser-
tion with regard to the petals : commonly they are alternate
with them; but in Primulaceae, and some others, they are
opposite to them; Rhamneae and Celastrineae are distinctly
separated by that character, which will be seen to be of
peculiar importance, when it is recollected that if stamens are
opposite to the petals, they necessarily indicate not only the
character, which is apparent, but also the suppressio?i of the
first series of stamens. The proportion that stamens bear to
one another is also a character of value in dividing orders ; as
in Labiatae, for example, and true Scrophnlarineae and Oro-
bancheae, in which they are didynamous, with the fifth stamen

CHAP. V. THE VALUE OF CHARACTERS. 357

abortive ; the tetradynamous stamens of Cruciferae are a prin-
cipal feature of that order. They should always agree with
the outer parts of fructification in number or proportion ;
that is to say, if the divisions of the calyx and corolla are five,
the stamens should either be five or some multiple of it. If
this is departed from, the flower becomes unsymmetrical,
and an irregularity of structure is then indicated, which may
characterise either a genus or an order: didynamous and
tetradynamous stamens are of this kind. Their union into
one or more bundles, as in Leguminosae, Malvaceae, Hyperi-
cineae, &c. is a character, the importance of which is very
variable.

The manner in which the Anthers are attached to their
filament is sometimes a good generic character, as in the
order of Amaryllideae, for example ; but the mode of their
dehiscence and the number of their cells are characters ap-
pertaining to orders ; Melanthaceae and Irideae, for instance,
are readily known by their anthers bursting on the side next
the corolla, instead of that next the pistillum ; and one of the
distinguishing characters of Malvaceae is, to have unilocular
anthers. The aestivation of anthers may occasionally furnish
valuable characters; but this is a subject hitherto not much
attended to. Their cohesion into a tube is the great character
of Compositae, Lobelia, and others.

The Pollen will sometimes furnish excellent characters ; of
course varying in importance in proportion to the degree in
which the pollen recedes from its ordinary nature. Thus,
Campanulaceae have round pollen, Lobeliaceae oval ; here it
is a character of an order. Some Onaerariae have it cohering
by filamentous processes, in others it is not coherent ; in that
order it is only of generic value. In Asclepiadeas it coheres
in fleshy masses, while in Apocineae it is granular ; here it has
the power of distinguishing those two orders. In Orchideaa
it coheres in various degrees, whence it has been found useful
for characterising the subordinate groups of that natural
order. It is probable that much remains to be done in ap-
plying the characters of pollen to purposes of discrimination.

The presence or absence of a Disk is usually a character
of generic value only. It is scarcely sufficiently universal

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358 TAXONOMY. BOOK III.

at any time to limit an order : its exact value is not suf-
ficiently known.

In examining the Pistillum, the first thing to observe
is whether it is superior or inferior. This is a point of
primary importance, notwithstanding the numerous excep-
tions which exist with respect to it. Thus, in Anonaceae
with superior ovara, we have Eupomatia with an inferior
one; in Gesnereag it is variable, and in Saxifrageae the
genera differ in this character; but still it must always be
looked upon as among the very best distinctions that can
be used for limiting natural orders. Who, for example,
has ever seen Cinchonaceae, Umbelliferae, Compositae, or
Orchideae, with a superior ovarium ? or where is the instance
of Ranunculaceae, Papaveraceae, or Caryophyllese, having an
inferior ovarium ? The next thing to remark is its internal
structure, whether simple or compound, unilocular or pluri-
locular, with placentae proceeding from the sides, the axis, or
the centre. The value of these characters is uncertain: for
the most part it is this. A simple and compound pistillum
will not co-exist in the same genus, but may in the same
order; as in Rosaceae, in which all degrees of combination of
pistilla are to be found. This law is, however, influenced by
the prevalence of one state of pistillum over others in the
same order. For example, in Leguminosae, the pistillum is
universally simple ; for this reason, Moringa, in which it is
compound, has been properly excluded : it would be difficult
to reconcile a pistillum of more than two cells with Cruci-
ferae, or a simple pistillum with Scrophularineae and Labiatae.
Yet in the genus Nicotiana, the type of which is a bilocular
ovarium, we have a species (N. multivalvis) in which it is pluri-
locular ; and the same happens with one species of Nolana.
A unilocular and plurilocular pistillum may be found in the
same order, but scarcely in the same genus : placentas from
the axis and the sides of an ovarium are so much at variance
with each other, that when the latter is in excess, as in Papa-
veraceae and Butomeae, they cannot co-exist in the same
natural order ; but when the parietal placenta is only caused
by a partial contraction of the dissepiments, as in Cyrtan-
draceae, Pedalineae, and Gesnerieoe, it differs so little from the

CHAP. V. THE VALUE OF CHARACTERS. 359

placenta in the axis, that the two may be expected to be found
in the same order, or perhaps in even the same genus. Se-
paration of the styles, or their union in a single style, is
occasionally used as a character for orders and genera ; but
it is not always a good one, and should at least be accom-
panied by others of more importance. The structure of the
stigma is usually a character of genera, but not often of
orders, unless in Goodenovieae and the neighbouring tribes,
in which the presence of a peculiar appendage, called the
indusium, is so remarkable as to be used for a character of
those orders.

The insertion of the Ovula, when they are definite in num-
ber, especially in simple pistilla, often affords excellent cha-
racters for orders. Thus, in Myristicese, the ovula are erect ;
in Laurineae, pendulous ; in Santalaceae they are pendulous;
in Elaeagneae, erect ; Juncagineae, with erect ovula, are so dis-
tinguished from Fluviales with pendulous ovula, and abund-
ance of similar cases may be cited. The position of the fora-
men is of great importance, inasmuch as it indicates the
direction of the radicle, but of this more will be said when
I speak of the seed.

The character of the Fruit is of much the same importance
as that of the pistillum. The points in which it chiefly differs
is its texture and mode of dehiscence. Its form and surface
are often used to distinguish species; its texture and dehiscence
for characters of genera, and even of orders. With respect
to its texture, that is to say, whether it is fleshy or dry, cap-
sular or baccate, membranous or woody, it is seldom that
these characters can be used for distinctions of orders ; for
instance, in Onagrariae, Myrtaceae, Melastomaceae, and many
others, there are genera, the fruit of some of which is baccate,
of others capsular; and there can scarcely be a group of plants
in which the fruit, if usually dry, may not be expected to be
fleshy ; or if fleshy, in which we ought not to look for it in a
dry state. It is somewhat different with regard to dehiscence
or indehiscence. In Cruciferae, Ranunculaceae, Rosaceae,
Leguminosae, and many others, the fruit varies from perfect
indehiscence with solitary seeds to dehiscence with many-
seeds ; but there is no instance of dehiscence in Boragineae,

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360 TAXONOMY. BOOK III.

Compositae, or Labiatae. The mode of dehiscence is never
of higher value than for distinguishing genera; it never ought
to be taken as the distinctive character of orders. Jussieu, it
is true, divided Rhodoraceae from Ericeae, and Pediculares
from Scrophularineae, upon differences in dehiscence ; but
these principles are now abandoned.

The nature of the testa of the Seed is not often taken into
account, except for genera, which sometimes derive their
characters from the seed being winged or not winged ; but
Mr. Brown has employed it for characterising a few orders of
monocotyledones.

Albumen is held by many botanists of great account; and
there is no doubt that if it exists in excess, it becomes one of
the most important of all characters by which natural orders
can be distinguished : but as it pre-exists in all seeds, remains
of it may also be expected to be found in all seeds : thus, in
Rosacea?, in which it is said to be absent, it unquestionably
exists ; when, therefore, albumen is taken as a character
for a natural order, it must be present in great abundance ;
under such a restriction, no character can be more valuable.
Its absence in Bisjnoniaceae divides that order from Scro-
phularineae, in which it is abundant. Its disproportion to the
embryo is a good character for Orobancheae, as distinguished
from Scrophularineae. The texture of the albumen is also
taken into account in characterising orders ; in some it is
fleshy, in others oily, in others horny or bony, and in Ano-
naceae and Myristiceae it is remarkable for being ruminate.

The Embryo, as the miniature representation of the future
plant, would naturally be expected to possess some distinctive
characters of a higher nature than any others ; and such is
found to be the fact. The want of one cotyledon, and peculiar
mode of germination in monocotyledones, distinguish that great
class from dicotyledones : its structure divides Aroideae from
other monocotyledonous orders ; its position separates Gra-
mineae from Cyperaceae ; its form characterises Amaranthaceae
and Chenopodeae ; the direction of its radicle with regard to
the hilum is a great peculiarity of Cistineae and many other
orders.

Finally, the Proportion that one part bears to another is

CHAP. V. THE VALUE OF CHARACTERS. 361

sometimes of generic, and always of specific value ; in the
latter case it is of peculiar importance. Species are apt to
vary in the size, colour, surface, or even form of many of the
organs, but it is much more seldom that the proportion that
one part bears to another changes.

Such is a general view of the relative value of the principal
characters employed by botanists for distinguishing plants:
many others are occasionally called into use ; but the know-
ledge of them will be better acquired by experience than by
precept. That the value assignable to each particular cha-
racter is, in many cases, far from definite, is apparent. This
arises out of the very nature of the subjects upon which the
science of botany depends. The rules under which nature
arranges the modifications of vegetable structure are, to our
feeble apprehension, so uncertain, that it is beyond our power
to reduce them within any fixed laws.

I cannot quit this part of my subject without saying a word
or two upon the nature of affinity and analogy, to which much
importance is attached by some naturalists. It is assumed
that the first systematic division of which beings are sus-
ceptible, is into two series, agreeing with each other in general
circumstances, and being in analogy ; the component parts of
each series according in particulai's, and being in affinity with
each other. The relations of analogy, we are told, are ideally
represented by two lines running parallel with each other;
and those of affinity, otherwise called transition, by circles
connected with each other in inextricable entanglement. That
this is in many cases a distinction that it is important to
draw, is undoubted ; but I confess it does not appear to
me to possess the degree of value that is attached to it.
Every student of the natural relations of plants must neces-
sarily keep it constantly in view ; for I presume that analogy
is equivalent to remote affinity, and affinity to immediate ana-
logy ; differences perfectly well understood. But that no
more absolute idea can attach to the two terms is surely
evident from this, — that cases must be continually occurring
in which they are convertible, and that their application
depends altogether upon contingent circumstances. Thus,

362 TAXONOMY. BOOK III.

for example, the genera Berberis and Bocagea are in analogy
if considered with reference to Berberideae and Anonaceae ;
but in affinity if viewed as a part of Thalamiflorse : so, again,
Aroideae and Aristolochiae are in analogy with respect to
Monocotyledones and Dicotyledones, but in affinity as to
Vasculares.

Having thus explained the usual value of characters, let
us next proceed to enquire what difference there is in their
nature. Characters are either positive or negative ; that is to
say, either explanatory of something that is present, or of
something that is absent. Thus, when we say that two plants
are distinguished by the one having ovate leaves and the
other cordate leaves, such a character would be positive,
being founded upon differences present to our senses. Again,
when one class of plants is said to have two cotyledons and
another but one, that chai'acter is positive. But if we say
that A. has ovate leaves, and B. leaves not ovate, the latter
would be a negative character : it does not explain what sort
of leaves B. possesses, but merely tells us that they are not
like those of A. Hence it is obvious, that while positive cha-
racters offer distinct points of comparison between one thing
and another, negative characters afford no room for com-
parison. When we know what the characters are that two
objects possess, we have the means of comparing them with
each other ; but if we are only acquainted with the character
of one, we, of course, have no means afforded us of com-
parison. For this reason, while positive characters can be
used for combining objects, negative characters can be only
used for separating them. When we say that a plant is
monopetalous, or polypetalous, or apetalous, monandrous,
polyandrous, or icosandrous, vascular or cellular, resem-
blances or differences are pointed out which have a real
existence, and from which positive characters may be ob-
tained ; but when we speak of plants not being monopetalous,
or polypetalous, not being monandrous or polyandrous, and
so on, no information whatever is afforded beyond that simple
fact, and no conclusion can be drawn from such statements.
Negative characters should never, therefore, be employed,

CHAP. V. THE VALUE OF CHARACTERS. 363

except in case of necessity; and they should, if used, be
understood merely as standing in the place of better cha-
racters, to be subsequently supplied as the science advances
towards perfection. Care, however, must be taken not to
confound with negative characters, positive characters de-
pending upon a negation, as has been done by a French
botanist of no mean fame ; such, for instance, as having no
corolla, no calyx, no leaves ; these are not negative characters
at all, but positive, indicating, indeed, the absence of some-
thing; but that very absence is a positive character: thus, if
we say A. is a plant furnished with a corolla, and B. is a
plant destitute of a corolla, such a character would indicate
distinctly both the quality and difference of both A. and B.,
and consequently would be positive ; but if we were to say A.
has a rotate corolla and B. has not a rotate corolla, such a
character would be negative, because, while we learn the
quality of the corolla of A., we know nothing about that of B.
further than that it is not like A.'s ; it may be hypocrateri-
form or infundibuliform, monopetalous or polypetalous, or
may be even wholly wanting, for aught is shown by the cha-
racter : this is what is really negative, and what ought to be
avoided.

Characters may be also prominent or obscure, that is to say,
readily seen or discoverable with difficulty; and botanists are
divided in opinion both as to the respective value of such,
and the propriety of introducing the latter into the distinctions
of plants. But if we reflect a moment, and consider what the
test of a character should be, there cannot be an instant's
difficulty in determining which of these kinds of characters to
adopt. The goodness of a character depends, first, upon its
applicability, and, secondly, upon its permanency ; those which
are most applicable and most constant are in all cases to have
the preference; therefore, in deciding between an obvious and
an obscure character, we have nothing to do but to ascertain
which is most applicable and most constant. If we find a
character, however minute and difficult to seize, answering
better to these qualities than others which are more obvious
and easily seen, the former is undoubtedly to be preferred ;

364/ TAXONOMY. BOOK III.

for it must be always borne in mind that the great object is not
to make science easy, but perfect. Undoubtedly, if an obvious
character and an obscure one are equally permanent and
applicable, the former is to be preferred ; because, if we can
combine facility with certainty, it is very desirable that we
should do so.

365

CHAPTER VI.

OF SPECIES, VARIETIES, GENERA, ORDERS, AND CLASSES.

The next point of consideration is the meaning that is at-
tached to the words species, genus, order, and class, and the
characters upon which those groups severally depend.

A species is a union of individuals agreeing with each other
in all essential characters of vegetation and fructification, ca-
pable of reproduction by seed without change, breeding freely
together, and producing perfect seed from which a fertile
progeny can be reared. Such are the true limits of a species;
and if it were possible to try all plants by such a test, there
would be no difficulty in fixing them, and determining what
is species and what is variety. But, unfortunately, such is
not the case. The manner in which individuals agree in their
external characters is the only guide which can be followed
in the greater part of plants. We do not often possess the
means of ascertaining what the effect of sowing their seed or
mixing the pollen of individuals would be; and, consequently,
this test, which is the only sure one, is, in practice, seldom
capable of being applied. The determination of what
is a species, and what a variety, becomes therefore wholly
dependent upon external characters, the power of duly ap-
preciating which, as indicative of specific difference, is only to
be obtained by experience, and is, in all cases, to a certain
degree, arbitrary. It is probable that, in the beginning,
species only were formed ; and that they have, since the cre-
ation, sported into varieties, by which the limits of the species
themselves have now become greatly confounded. For ex-
ample, it may be supposed that a Rose, or a few species of
Rose, were originally created. In the course of time these
have produced endless varieties, some of which, depending for
a long series of ages upon permanent peculiarities of soil or

366 TAXONOMY. BOOK III.

climate, have been in a manner fixed, acquiring a constitution
and physiognomy of their own. Such supposed varieties have
again intermixed with each other, producing other forms, and
so the operation has proceeded. But as it is impossible, at
the present day, to determine which was the original or
originals, from which all the Roses of our own time have
proceeded, or even whether they were produced in the man-
ner I have assumed; and as the forms into which they divide
are so peculiar as to render a classification of them indispens-
able to accuracy of language ; it has become necessary to give
names to certain of those forms, which are called species.
Thus it seems that there are two sorts of species: the one,
called natural species, determined by the definition given
above; and the other, called botanical species, depending only
upon the external characters of the plant. The former have
been ascertained to a very limited extent : of the latter nearly
the whole of sytematic botany consists. In this sense a
species may be defined to be " an assemblage of individuals
agreeing in all the essential characters of vegetation and fruc-
tification." Here the whole question lies with the word
essential. What is an essential character of a species ? This
will generally depend upon a proneness to vary, or to be con-
stant in particular characters, so that one class of characters
may be essential in one genus, another class in another genus ;
and these points can be only determined by experience.
Thus, in the genus Dahlia, the form of the leaves is found to
be subject to great variation; the same species producing from
seed, individuals, the form of whose leaves vary in a very
striking manner : the form of the leaves is, therefore, in
Dahlia, not a specific character. In like manner, in Rosa,
the number of prickles, the surface of the fruit, or the surface
of their leaves, and their serratures, are found to be gene-
rally fluctuating characters, and cannot often be taken as
essential to species. The determination of species is, there-
fore, in all respects, arbitrary, and must depend upon the dis-
cretion or experience of the botanist. It may, nevertheless,
be remarked, that decided differences in the forms of leaves,
in the figure of the stem, in the surface of the different parts,
in the inflorescence, in the proportion of parts, or in the form

CHAP. VI. SPECIES, VARIETIES, GENERA, ETC. 367

of the sepals and petals, usually constitute good specific
differences.

A genus is an assemblage of species, agreeing with each
other in the essential characters of fructification. It is an
artificial means of condensing our ideas of the forms of plants,
by sinking characters of minor importance in such as are of
greater. While species depend upon the endless modifi-
cations of the organs of vegetation, genera depend upon the
less numerous varieties of the organs of fructification, to
which those of vegetation are subordinate. But as the value
of the characters derived from the organs of fructification is
uncertain, and dependent upon no fixed rules, so the limits of
genera are arbitrary, and depend upon the caprice of botanists.
Hence we find that some are disposed to excessive combin-
ation, and others to excessive division, in their genera. The
only rule that can be given is this, that as genera are des-
tined to analyse and simplify our ideas by reducing variable
characters to those which are less variable, and characters
which are common to many plants to those which are com-
mon to a few, care must be taken that this end is effected by
a perfect analysis of the characters of fructification. And
this being the case, an excessive multiplication of genera,
which ought to be only the result of a very careful analysis,
is infinitely better than an excessive reduction of them. The
former leads to precision of ideas, the latter to confusion of
them. In general, a genus should not be formed upon a
solitary species, unless that species is so distinctly charac-
terised that it cannot be referred to any other known genus;
but wherever two or more species can be found agreeing in
particular modifications of the structure of their fructification,
by which they also differ from others, such two or more
species are to be taken as the representatives of a genus.

Strong peculiarities in the vegetation of plants may be
sometimes used as generic characters, but those of the
fructification should always be preferred if they can be
found.

An order is an assemblage of genera, agreeing with each
other in the higher characters of vegetation and fructification.
Orders, like genera, are a contrivance for analysing and sim-

368 TAXONOMY. BOOK III.

plifying our ideas, by reducing their number ; and, like genera,
they are also to a certain degree arbitrary. But as orders de-
pend upon modifications of structure of a less variable kind
than either genera or species, so are their limits better under-
stood. Orders are characterised by all the parts both of
vegetation and fructification, but their essential distinctions
depend upon a few only, such as the presence or absence of
stipulse; the insertion of the leaves, whether opposite or
alternate; the degree of division of the calyx and corolla,
station of the stamens, structure of the fruit, figure of the
embryo, presence or absence of albumen, &c. &c.

Classes are merely orders of a higher kind, combined by a
few characters common to and distinctive of many.

369

BOOK IV.

GLOSSOLOGY J OR, OF THE TERMS USED IN BOTANY.

In order to comprehend the language of botanists, it is ne-
cessary that the unusual terms or words which are employed
in writing upon the subject, and which are either different
from words in vulgar use, or which are in botany employed in
a particular sense, should be fully explained.

It is a very common plan to mix up Glossology with
Organography, or to confound the definition and explanation of
those characteristic terms of the science which are universally
applicable, with the description of particular organs : but this
plan is attended with many inconveniences, and is far less
simple than to treat of the two separately. It was an error
into which Linnaeus fell, in composing his admirable Philo-
sophia Botanica; and is the more remarkable, if the logical pre-
cision with which that work is otherwise composed be con-
sidered. Instead of distinguishing those terms which have a
general application to all plants or parts of plants, according
to circumstances, from such as have a particular application,
and relate only to special modifications, he placed under
his definition of each organ those terms which he knew to
be applicable to it; but, as it was not his practice to repeat
terms after they had been once explained, it frequently
happened that beginners in the science, finding a given term
explained once only, and with reference to a particular
organ, fell into the mistake of supposing that that term
was applicable only to the organ under which it was ex-
plained. To avoid this difficulty, other botanists have col-

B B

S70 GLOSSOLOGY. BOOK IV.

lected under each organ all the terms which could by
possibility be applied to it, and have repeated them over and
over again without regard to previous definitions; as if they
supposed it impossible to convey by words an idea of the
meaning of any term whatever, without noticing at length
every possible application of it. Thus, in Willdenow's Prin-
ciples of Botany, the most common and simple terms are
repeated five, six, and even seven times ; and in a more modern
work, of very high character (Les Elemens de Physiologic
Vegetate et de Botanique, by Mirbel), the same practice has
been carried so far, that the application of the word simple is
explained in twenty-three different instances.

The true principles of arranging the glossology of science
have, however, been long before the public. In the year
1797 Professor Link, of Berlin, in his Prodromus Philosophize
Botanicce, distinguished the characteristic or common terms
used in botany from those which applied only to particular
organs ; and his example was afterwards followed by Illiger, a
learned German naturalist, who, in the year 1810, proposed
a total reformation of the method of describing the terms
employed in Natural History (see his Versuch einer Syste-
matischen vollstdndigen Terminologie fur das Thierreich nnd
PJlanzenreich). Little attention, however, was paid to the
principles of these writers till the year 1813; when the
learned Professor De Candolle adopted them in his Theorie
Elementaire de la Botanique, with his accustomed skill and
sagacity.

The characteristic terms of botany are those which have a
general application to any or all the parts of plants, and must
not be confounded with such as have a particular application
only, which will be found under the organs to which they re-
spectively belong : the former are either individualov collective;
of which the first apply to plants, or parts of plants, con-
sidered abstractedly; the second to plants, or their parts,
considered in masses. To these are to be added those
syllables and marks which, either prefixed or affixed to a
known term, occasion an alteration in its signification. These
I call terms of qualification. In the following arrangement,
those terms which are seldom used are marked with a f ; and

CLASS I. INDIVIDUAL TERMS. 371

those are entirely omitted which are used in Botany in their
common acceptation.

CHARACTERISTIC TERMS are either Individual or Collective.
Characteristic Individual Terms are either Absolute or Relative.

Characteristic Individual Absolute Terms relate to, —

1. Figure.

A. with respect to general form.

B. outline.

C. the apex or point.

2. Division.

A. With respect to the margin.
6. incision.

C. composition or ramification.

3. Surface.

A. With respect to marking or evenness.

B.

appendages,

C.

polish.

4.

Texture.

5.

Size.

6.

Duration-

7.

Colour.

8.

Variegation.

9.

Vetoing.

Characteristic Individual Relative Terms comprehend, —
1. Estivation.
1. Direction.
3. Insertion.

A. with respect to the mode of attachment or of adhesion.

B. situation.

Characteristic Collective Terms relate to, —

1 . Arrangement.

2. JVumber.

Class I. Of Individual Terms.

The terms which are included in this class are applied to the
parts of a plant considered by themselves, and not in masses :
they are either absolute, being used with reference to their
own individual quality ; or relative, being employed to ex-
press the relation which is borne by plants, or their parts, to
some other body. Thus, for example, when we say that a
plant has a lateral, ovate spike of flowers, the term lateral is
relative, being used to express the relation which the spike
bears to the stem ; and the term ovate is absolute, being ex-

b b 2

372

GLOSSOLOGY.

BOOK IT.

pressive of the actual form of the spike : and, again, in
speaking of a rugose, terminal capsule, rugose is absolute, ter-
minal is relative.

I. Of Individual Absolute Terms.

These relate to figure, division, surface, texture, size,
duration, colour, variegation, and veining.

1. Of Figure.

A. With respect to general form.

1. Conical (conicus, f pyramidalis) ; having the figure of a
true cone ; as the prickles of some roses, the root of
carrot, &c.

2. Conoidal (conoideus) ; resembling a conical figure, but not
truly one ; as the calyx of Silene conoidea.

3. Prism-shaped (prism aticus); having several longitudinal an-
gles and intermediate flat faces ; as the calyx of Frankenia
pulverulenta.

4. Globose {globosus, sphcericus, f globulosus) ; forming nearly
a true sphere ; as the fruit of Ligustrum vulgare, many
seeds, &c.

5. Cylindrical (cylindricns) ; having nearly a true cylindrical
figure; as the stems of grasses, and of most monocotyledonous
plants.

6. Tubular (tubulosus, f tubulatus) ; approaching a cylindrical
figure, and hollow ; as the calyx of many Silenes, &c.

7. Fistulous (Jistulosus) : this is said of a cylindrical or terete

CLASS I.

INDIVIDUAL ABSOLUTE TERMS.

SY3

body, which is hollow, but closed at each end, as the leaves
and stems of the onion.

8. Cubical (f cubicus) ; having or approaching the form of a
cube : a very rare form, chiefly occurring in some seeds, as
that of Vicia latbyroides.

9. Club-shaped (clavatus, f claviformis) ; gradually thickening
upwards from a very taper base ; as the appendages of
the flower of Schwenkia, or the style of Campanula and
Michauxia.

10. Turbinate, or top-shaped (ttirbinatus); inversely conical,
with acontraction towards the point, as the fruit of some roses.

11. Pear-shaped {pyi-iformis) ; differing from turbinate in being
more elongated, as in many kinds of pears.

12. f Tear-shaped (ilac/inpnccformis) ; the same as pear-shaped,
except that the sides of the inverted cone are not contracted ;
as the seed of the apple.

13. fStrombus-shaped (\strombuliformis) ; twisted in a long
spire, so as to resemble the convolutions of the shell called a
Strombus ; as the pod of Acacia strombulifera, or Medicago
polymorpha.

14. Spiral {spiralis); twisted like a corkscrew.

15. Cochleate (cochleatus) ; twisted in a short spire, so as to
resemble the convolutions of a snail -shell; as the pod of
Medicago cochleata, the seed of Salicornia.

16. Turnip-shaped (napiformis) ; having the figure of a de-
pressed sphere ; as the root of the turnip, radish, &c.

17. f Placenta-shaped (f plo cent ifor mis) ; thick, round, and con-
cave, both on the upper and lower surface ; as the root of
Cyclamen.

B B 3

374 GLOSSOLOGY. BOOK IV.

18. Lens-shaped (lenticularis, lentiformis) ; resembling a double
convex lens, as the seeds of Amaranthus.

19. Buckler-shaped (scutatus, scutiformis), having the figure of
a small round buckler, as the scales upon the leaves
of Elseagnus ; lens-shaped, with an elevated rim.

20. Bossed (umbonatus) ; round, with a projecting point in the
centre, like the boss of an ancient shield, as the pileus of

many species of Agaricus.

21. Gibbous {gibbus, gibbosus) ; very convex or tumid, as the
leaves of many succulent plants : properly speaking, this
term should be restricted to solid convexities.

22. fMelon-shaped, (\meloniformis) ; irregularly spherical,
with projecting ribs; as the stem of Cactus melocactus: a
bad term.

23. Spheroidal (spheroideus) ; a solid with a spherical figure,
a little depressed at each end. De Cand.

24. Ellipsoidal (ellipsoideus) ; a solid with an elliptical figure.
De Cand.

25. Ovoidal (ovoideus) ; a solid with an ovate figure, or re-
sembling an egg. De Cand.

26. Shield-shaped (clypeatus) ; in the form of an ancient buck-
ler ; the same as scutate, No. 19.

27- Spindle-shaped (fusiformis, "ffnsinns) ; thick, tapering to
each end ; as the root of the long radish. Sometimes co-
nical roots are called fusiform, but improperly.

28. Terete, or taper (teres) ; the opposite of angular; usually
employed in contradistinction to that term, when speaking of
long bodies. Many stems are terete.

29. Half terete (semiteres) ; flat on one side, terete on the
other.

30. Compressed (compressus) ; flattened lengthwise, as the pod
of a pea.

91. Depressed (depressus) ; flattened vertically, as the root of a
turnip.

32. Plane (planus) ; a perfectly level or flat surface, as that of
many leaves.

33. Cushioned (pulvinatus) ; convex, and rather flattened : sel-
dom used.

34. Discoidal (discoideus) ; orbicular, with some perceptible
thickness, parallel faces, and a rounded border ; as the fruit
of Strychnos Nux-vomica.

35. Curved (arcuatus, curvatus) ; bent, but so as to represent the

CLASS I.

INDIVIDUAL ABSOLUTE TERMS.

375

arc of a circle; as the fruit of Astragalus hamosus, Medicago
falcata, &c.

36. Scimitar-shaped (acinaciformis) ; curved, fleshy, plane on
the two sides, the concave border thick, the convex border
thin ; as the leaves of Mesembryanthemum acinaciforme.

37. Axe-shaped (dolabriformis) ; fleshy, nearly straight, some-
what terete at the base, compressed towards the upper end ;
one border thick and straight, the other enlarged, convex,
and thin ; as the leaves of Mesembryanthemum dolabri-
forme.

38. Falcate (Jalcatus) ; plane and curved, with parallel edges,
like the blade of a reaper's sickle ; as the pod of Medicago
falcata : any degree of curvature, with parallel edges, re-
ceives this name.

39. Tongue-shaped (linguiformis) ; long, fleshy, plain, convex,
obtuse ; as the leaves of Sempervivum tectorum, and some
aloes.

40. Angular (angulosiis) ; having projecting longitudinal angles.
We say obtuse-angled when the angles are rounded, as in the
stem of Salvia pratensis ; and acute-angled when they are
sharp, as in many Carices. Some call these angles the
acies.

41. Three-cornered (trigonus) ; having three longitudinal angles
and three plain faces, as the stem of Carex acuta.

51 53 54 56

42. Three-edged (triangularis, triqueter) ; having three acute
angles with concave faces, as the stems of many plants ;
generally used as a synonyme of trigonus.

43. Two-edged (anceps) ; compressed, with two sharp edges, a&
the stem of an Iris.

B B 4

376 GLOSSOLOGY. BOOK IV.

44. Keeled (carinatus) ; formed in the manner of the keel of
a boat; that is to say, with a sharp projecting ridge, aris-
ing from a flat or concave central rib, as the glumes of
grasses.

45. Channelled (canaliculatiis) ; long and concave, so as to re-
semble a gutter or channel ; as the leaves of Lygeum Spar-
tum, Tradescantia virginica, &c.

46. Boat-shaped (cymbiformis, navicularis) ; having the figure of
a boat in miniature ; that is to say, concave, tapering to each
end, with a keel externally, as the glumes of Phalaris cana-
densis : scarcely different from 44.

47* Whip-shaped (Jlagelliformis) ; long, taper, and supple, like
the thong of a whip ; as the stem of Vinca, and of many
plants. This term is confined to stems and roots.

48. Rope-shaped (Jimalis, ffuniliformis) ; formed of coarse
fibres resembling cords, as the roots of Pandanus, and other
arborescent monocotyledons. Mirbel.

49. Thread-shaped (Jilijbrmis) ; slender like a thread, as the
filaments of most plants, and the styles of many.

50. Hair-shaped (capillaris) ; the same as filiform, but more de-
licate, so as to resemble a hair; it is also applied to the
fine ramifications of the inflorescence of some plants, as
grasses.

51. Necklace-shaped (moniliformis, -fnodosus, Mirb.) ; cylin-
drical or terete, and contracted at regular intervals ; as the
pods of Sophora japonica, Ornithopus perpusillus, &c, the
hairs of Dicksonia arborescens, &c.

52. Worm-shaped {yermicularis) ; thick, and almost cylindrical,
but bent in different places ; as the roots of Polygonum Bis-
torta. Willd.

53. Knotted (torulosus) ; a cylindrical body, uneven in surface,
as the pod of Chelidonium : this is very nearly the same as
moniliform.

54. Trumpet-shaped (tubceformis, tubatus) ; hollow, and dilated
at one extremity, like the end of a trumpet, De Cand. ; as the
corolla of Caprifolium sempervirens.

55. Horned (comutus, cornicidatus) ; terminating in a process
resembling a horn, as the fruit of Trapa bicornis. If there
are two horns, the word bicornis is used ; if three, tricornis ;
and so on.

56. Beaked (proboscideus) ; having a hard terminal horn, as the
fruit of Martynia.

CLASS I.

INDIVIDUAL ABSOLUTE TERMS.
61 62 66

377

57. Crested (cristatus) ; having an elevated, irregular, or notched
ridge, resembling the crest of a helmet. This term is chiefly
applied to seeds, and to the appendages of the anthers of
some Ericae ; such as E. triflora and comosa.

58. Petal-like (petaloideus) ; having the colour and texture of a
petal ; as one lobe of the calyx of Mussaenda, the bracteae of
many plants, the stamen of Canna, the stigmata of Iris.

59. Leaf-like [foliaceus, f foliiformis, \phylloideus) ; having the
texture or form of a leaf; as the lobes of the calvx of Rosa,
the apex of the fruit of Fraxinus, the persistent petals of
Melanorhaea.

60. Winged (alatus) ; having a thin broad margin ; as the fruit of
Paliurus australis, the seed of Malcomia, Bignonia, &c. In
composition pterus is used ; as dipterus for two-winged, trip-
terns for three-winged, tetrapterns for four-winged, &c. ; pe-
r/pterus when the wing surrounds any thing ; epipterus when
it terminates.

61. tMill-sail-shaped (^molendinaceus); having many wings
projecting from a convex surface ; as the fruit of some um-
belliferous plants, and of Moringa.

62. fKnob-like (fgongi/lodes) ; having an irregular, roundish
figure.

63. Halved (dimidiatus) ; only half, or partially formed. A leaf
is ca-lled dimidiate when one side only is perfect ; an anther
when one lobe only is perfect; and so on.

64-. Fan-shaped {.flabellijbrmis) ; plaited like the rays of a fan ;
as the leaf of Borassus flabelliformis.

65. Grumous (grumosus) ; in form of little clustered grains, as
the root of Neottia Nidus-avis, Mirb. ; rather as the faecula
in the stem of the Sago palm.

66. f Testicular (f testiculatus); having the figure of two oblong
bodies, as the roots of Orchis mascula.

378

GLOSSOLOGY.

BOOK IV.

67. Ringent, or personate (ringens, personatus) ; a term applied
to a monopetalous corolla, the limb of which is unequally
divided ; the upper division, or lip, being arched ; the lower
prominent, and pressed against it, so that when compressed,
the whole resembles the mouth of a gaping animal ; as the
corolla of Antirrhinum.

68. Labiate (labiatus) ; a term applied to a monopetalous calyx
or corolla, which is separated into two unequal divisions; the
one anterior, and the other posterior with respect to the axis :
hence bilabiate is more commonly used than labiate. Salvia,
and many other plants, afford examples. It is often employed
instead of ringent.

69. Wheel-shaped (rotatits); a calyx or corolla, or other organ,
of which the tube is very short, and the segments spreading ;
as the corolla of Veronica and Galium.

70. Salver-shaped {hypocrateriformis) ; a calyx or corolla, or
other organ, of which the tube is long and slender, and the
limb flat ; as in Phlox.

71. Funnel-shaped (hifundibidaris, infundibidiformis) ; a calyx
or corolla, or other organ, in which the tube is ob conical,
gradually enlarging upwards into the limb, so that the whole
resembles a funnel ; as the corolla of Nicotiana.

72. Bell-shaped (campamdatus, \campanaceus, ■\-campanifo?-mis) ;
a calyx, corolla, or other organ, in which the tube is inflated
and gradually enlarged into a limb, the base not being
conical ; as the corolla of Campanula.

73. Pitcher-shaped (urceolatus) ; the same as campanulate, but
more contracted at the orifice, with an erect limb ; as the
corolla of Vaccinium myrtillus.

74-. Cup-shaped (cyathiformis) ; the same as pitcher-shaped, but

CLASS I.

INDIVIDUAL ABSOLUTE TERMS.

379

not contracted at the margin; the whole resembling a drink-
ing cup ; as the limb of the corolla of Symphytum.

15. f Cupola-shaped (\cupuliformis) ; slightly concave, with a
nearly entire margin ; as the calyx of Citrus, or the cup of
an acorn.

76. Kneepan-shaped (patelliform is) ; broad, round, thick ; con-
vex on the lower surface, concave on the other : the same as
meniscoideus, but thicker. The embryo of Flagellaria indica
is patelliform.

77- f Pulley-shaped (\trochlearis) ; circular, compressed, con-
tracted in the middle of its circumference, so as to resemble
a pulley; as the embryo of Commelina communis.

78. Scutelliform (scutelliformis) ; the same as patelliform, but
oval : not round, as the embryo of grapes.

79. Brush-shaped (\muscariformis) ; formed like a brush or
broom ; that is to say, furnished with long hairs towards one
end of a slender body, as the style and stigma of many Com-
positae.

80. -J-Acetabuliform (\acetabuliformis, j-acetabtdeus); concave,
depressed, round, with the border a little turned inwards; as
the fruit of some lichens.

81. f Goblet-shaped (\crateriformis) ; concave, hemispherical, a
little contracted at the base ; as some Pezizas.

82. fCotyliform (fcoti/liformis) ; resembling rotate, but with an
erect limb.

83. f Poculiform (f poculiformis) ; cup-shaped, with a hemi-
spherical base and an upright limb ; nearly the same as
campanulate.

84-. f Pouch-shaped (f scrotiformis) ; hollow, and resembling a
little double bag ; as the spur of many Orchises.

380

GLOSSOLOGY.

BOOK IV.

85. f Foxglove-shaped (\dighaliformis) ; like campanulate, but
longer, and irregular ; as the corolla of Digitalis.

86. f Vase-shaped (f vascularis) ; formed like a flower-pot; that
is to say, resembling an inverted truncate cone.

87. f Tapeworm-shaped (\tcenianus) ; long, cylindrical, con-
tracted in various places, in the manner of the tapeworm.

88. f Sausage-shaped (fbotidiformis) ; long, cylindrical, hollow,
curved inwards at each end ; as the corolla of some Ericas.

89. f Umbrella-shaped (-f- umbraculiformis) ; resembling an ex-
panded umbrella ; that is to say, hemispherical and convex,
with rays, or plaits, proceeding from a common centre ; as
the stigma of poppy.

90. fMeniscoid {\meniscoidetis) ; thin, concavo-convex, and he-
mispherical, resembling a watch-glass.

91. Mushroom-headed {fungiformis, fwngilliformis) ; cylindri-
cal, having a rounded, convex, overhanging extremity ; as
the embryo of some monocotyledonous plants, as Musa.

92. f Nave-shaped (\modioliformis) ; hollow, round, depressed,
with a very narrow orifice ; as the ripe fruit of Gaultheria.

93. Hooded {cucidlatus) ; a plane body, the apex or sides of
which are curved inwards, so as to resemble the point of a
slipper, or a hood ; as the leaves of Pelargonium cucullatum,
the spatha of Arum, the labellum of Pharus.

94. -f- Saddle-shaped (f sellceformis) ; oblong, with the sides hang-
ing down, like the laps of a saddle ; as the labellum of
Cateleya Loddigesii.

95- Turgid (turgidus) ; slightly swelling.

96. Bladdery (ittflatits) ; thin, membranous, slightly transparent,

CLASS I.

INDIVIDUAL ABSOLUTE TERMS.

381

swelling equally, as if inflated with air ; as the calyx of Ca-

cubalus.
97. Bellying (ventricosus) ; swelling unequally on one side, as the

corolla of many labiate and personate plants.
9S. Regular (regularis) ; in which all the parts are symmetrical :

a rotate corolla is regular; the flower of a cherry is regular.

99. Irregular {irregularis) ; in which symmetry is destroyed by
some inequality of parts : a labiate corolla, the flower of the
horse-chesnut, and the violet, are irregular.

100. Abnormal (abnormis) ; in which some departure takes place
from the ordinary structure of the family or genus to which
a given plant belongs. Thus, Nicotiana multivalvis, in which
the ovarium has many cells instead of two, is unusual or
abnormal.

101. Normal (normalis) ; in which the ordinary structure pecu-
liar to the family or genus of a given plant is in nowise
departed from.

B. With respect to outline.

A 6 7

f)

1. Outline (ambitus, circumscripta) ; the figure represented by
the margin of a body.

2. Linear (linearis) ; narrow, short, with the two opposite mar-
gins parallel ; as the leaf of the Taxus.

3. f Band-shaped (\fasciarius) ; narrow, very long, with the two
opposite margins parallel ; as the leaves of Zostera marina.

4. Strap-shaped (ligulatus, loratus), narrow, moderately long,
with the two opposite margins parallel ; as the leaves of
Amaryllis equestris.

5. Lanceolate (lanceolatus) ; narrowly elliptical, tapering to each

382

GLOSSOLOGY.

BOOK IV.

end ; as the leaf of Plantago lanceolata, Daphne meze-
reum, &c.

6. Oblong (pblongus) ; elliptical, obtuse at each end ; as the
leaf of the hazel.

7. Oval (pvalis, ellipticus) ; elliptical, acute at each end ; as the
leaf of Cornus sanguinea.

8. Ovate, or fegg-shaped (ovatus) ; oblong or elliptical, broadest
at the lower end, so as to resemble the longitudinal section
of an egg ; as the leaf of Stellaria media.

9. Orbicular (orbicularis) ; perfectly circular, as the leaf of Co-
tyledon orbiculare.

10. Roundish (rotundus, subrotundus, rotundatus) ; orbicular, a
little inclining to be oblong ; as the leaf of Lysimachia num-
mularia, Mentha rotundifolia.

11. Spatulate (spatidatus) ; oblong, with the lower end very
much attenuated, so that the whole resembles a chemist's
spatula ; as the leaf of Bellis perennis.

12. Wedge-shaped (cuneatus, cuneiformis, \cunearius) ; inversely
triangular, with rounded angles ; as the leaf of Saxifraga
tridentata.

13. Awl-shaped (sabidatus) ; linear, very narrow, tapering into a
very fine point from a broadish base ; as the leaves of Arena-
ria tenuifolia, Ulex europaeus.

14. Needle-shaped (acerosus) ; linear, rigid, tapering into a fine
point from a narrow base ; as the leaves of Juniperus com-
munis.

15. Sword-shaped (ensiformis, gladiatus) ; lorate, quite straight,
with the point acute ; as the leaf of an Iris.

16. f Parabolical (fparabolicus) ; between ovate and ellip-

CLASS I.

INDIVIDUAL ABSOLUTE TERMS.

383

tical, the apex being obtuse; as the leaf of Amaranthus
Blitum.

17. Rhomboid (rhombeus, rhomboideus) ; oval, a little angular in
the middle ; as the leaf of Hibiscus rhombifolius.

18. Deltoid (deltoides) ; a solid, the transverse section of which
has a triangular outline, like the Greek A ; as the leaf of
Mesembryanthemum deltoideum.

19. Triangular {triangularis) ; having the figure of a triangle of
any kind ; as the leaf of Betula alba.

20. Trapeziform (trapeziformis, trapezoideus) ; having four edges,
those which are opposite not being parallel ; as the leaf of
Adiantum trapeziforme, Populus nigra.

21. Heart-shaped (cordatus, cordiformis) ; having two round
lobes at the base, the whole resembling the heart in a pack
of cards; as the leaf of Alnus cordifolia.

22. Eared (auriculatu.fi) ; having two small rounded lobes at the
base ; as the leaf of Salvia officinalis.

23. Crescent-shaped (Junatus, lunidatus, f semilunatus) ; resem-
bling the figure of the crescent ; as the glandular apex of the
involucral leaves of many Euphorbias.

2-t. Kidney-shaped [reniformis, -\renarius) ; resembling the figure

of a kidney ; that is to say, crescent-shaped, with the ends

rounded ; as the leaf of Asarum europaeum.
25. Arrow-headed (sagittatus) ; gradually enlarged at the base

into two acute straight lobes, like the head of an arrow ; as

the leaf of Rumex acetosella.

26. Halbert-headed (hastatus) ; abruptly enlarged at the base
into two acute diverging lobes, like the head of an halbert ;
as the leaf of Arum maculatum.

384.

GLOSSOLOGY.

BOOK IV.

27. Fiddle-shaped (panduratus, panduriformis) ; obovate, with a
deep recess or sinus on each side ; as the leaves of Rumex
pulcher.

28. Lyre-shaped (lyratus) ; the same as panduriform, but with
several sinuses on each side, which gradually diminish in size
to the base ; as the leaf" of Geum urbanum, Raphanus rapha-
nistrum.

29. Runcinate, or hook-backed (runcinatus) ; curved in a direc-
tion from the apex to the base ; as the leaf of Leontodon
taraxacum.

30. Tapering (attenuatus) ; gradually diminishing in breadth.

31. Wavy (undulatus) ; having an uneven, alternately convex
and concave margin, as the holly leaf.

32. Equal (czqualis) ; when both sides of a figure are symmetri-
cal ; as the leaf of an apple.

33. Unequal (incequalis) ; when the two sides of a figure are not
symmetrical ; as the leaf of Begonia.

34. Equal-sided (izquilateriis) ; the same as equal.

35. Unequal-sided (incequilaterus) ; the same as unequal.

36. Oblique (obliquus) ; when the degree of inequality in the
two sides is slight.

37. Halved {dimidiatus) ; when the degree of inequality is so
great that one half of the figure is either wholly or nearly
wanting; as the leaf of many Bryonias.

C. Jlith respect to the apex, or point.

CLASS I. INDIVIDUAL ABSOLUTE TERMS. 38 5

1. Awned {aristatus) ; abruptly terminated in a hard, straight
subulate point of various lengths; as the pales of grasses'
The arista is ahvays a continuation of the costa, and some-
times separates from the lamina below the apex.

2. Mucronate (mucronatus); abruptly terminated by a hard, short
point ; as the leaf of Statice mucronata.

3. Cuspidate (cuspidatus)-, tapering gradually into a rigid point
It is also used sometimes to express abruptly acuminate; as
the leaf of many Rubi.

4. Cirrhous (cirrhotics, apice circhiatus) ; terminated by a spiral
or flexuose, filiform appendage ; as the leaf of Gloriosa
superba. This is due to an elongation of a costa.

5. Pungent (pungent); terminating gradually in a hard, sharp
point ; as the leaves of Ruscus aculeatus.

6. Bristle-pointed (setosus, fsetiger) ; terminating gradually in a
very fine, sharp point; as the leaves of many mosses.

7. Hair-pointed (piliferus) ; terminating in a very fine, weak
point; as the leaves of many mosses.

8. Pointletted (apiculatus) ; terminating abruptlv in a little
point; differing from mucronate in the point being part of
the limb, and not arising wholly from a costa.

9. Hooked (uncinatus, funcatus) ; curved suddenly back at the
point; as the leaves of Mesembryanthemum uncinatum.

10. Beaked (rostratus, rostellatus) ; terminating gradually in a
hard, long, straight point; as the pod of rad'ish.

11. Acute, or sharp-pointed (acutus) ; terminating at once in a
point, not abruptly, but without tapering in any decree • as
any lanceolate leaf. "

12. Taper-pointed (acuminates); terminating very gradually in
a point ; as the leaf of Salix alba.

13. +Acuminose (\acuminosus); terminating gradually in a flat
narrow end. '

14. Tail-pointed (caudatus); excessively acuminated, so that the
point is long and weak, like the tail of some animal • as
the calyx of Aristolochia trilobata, the petals of Bra'ssia
caudata.

15. Blunt (obtusus) ; terminating gradually in a rounded end •
as the leaf of Berberis vulgaris.

16. Blunt with a point (obtusus cum acumine) ; terminating
abruptly ,n a round end, the middle of which is suddenly
lengthened into a point ; as the leaf of many Rubi.

17. Retuse (retusus); terminating in a round end, the centre of
which is depressed; as the leaf of Vaccinium Vitis Idaea.

c c

386 GLOSSOLOGY. BOOK IV.

18. Emarginate (emarginatus) ; having a notch at the end, as if
a piece had been taken out ; as the leaf of Buxus sempervirens.

19. \ Accisus ; when the end has an acute sinus between two
rounded angles. Link.

20. Truncate (truncatus) ; terminating very abruptly, as if a
piece had been cut off; as the leaf of Liriodendron tulipifera.

21. Bitten (prcemorsus, fsuccisus) ; the same as truncate, except
that the termination is ragged and irregular, as if bitten off:
the term is generally applied to roots ; the leaf of Caryota
urens is another instance.

22. fDedaleous (j- dcedaleus) ; when the point has a large circuit,
but is truncated and rugged. W.

23. Trident-pointed (trident atus) ; when the point is truncated,
and has three indentations ( W. ) ; as Saxifraga tridentata,
Potentilla tridentata.

24. Headed (capitatus) ; suddenly much thicker at the point
than in any other part : a term confined to cylindrical or
terete bodies ; as Mucor, glandular hairs, &c.

25. Lamellar (lamellatus, lamellosus) ; having two little plates at
the point, as the style of many plants.

26. f Blunt (fhebetatus, De Cand.) ; having a soft, obtuse termi-
nation.

27. Pointless (muticm). This term is employed only in con-
tradistinction to some other that indicates being pointed :
thus, if, in contrasting two things, one was said to be mu-
cronate, the other, if it had not a mucro, would be called
pointless ; and the same term would be equally employed in
contrast with cuspidate or aristate, or any such. It is also
used absolutely.

2*. Of Division.
A. With respect to the margin.

3 4 5

3 4 5

1. Entire (integer); properly speaking, this means having no
kind of marginal division ; but sometimes it has been used
to indicate not pinnatifid, and also nearly destitute of mar-
ginal division.

2. Quite entire {integerrimus) ; perfectly free from division of
the margin.

3. Crenated (crenatus) ; having convex teeth. When these teeth
are themselves crenated, we say bicrenate.

CLASS I.

INDIVIDUAL ABSOLUTE TERMS.

387

4. Sawed (serratus) ; having sharp, straight-edged teeth pointing
to the apex. When these teeth are themselves serrate, we
say bisermte, or daplicato-serrate.

5. Toothed (dentatus) ; having sharp teeth with concave edges.
When these teeth are themselves toothed, we say duplicato-
dentate, or doubly toothed, but not bidentate, which means
two-toothed.

6. Gnawed (erosus) j having the margin irregularly toothed, as
if bitten by some animal.

7. Curled (crispus) ; having the margin excessively irregularly
divided and twisted ; as in many varieties of the garden
endive, Mentha crispa, Ulmus cucullata.

8 9 10

8. Repand (repa?idus, fsimwlatus) ; having an uneven, slightly
sinuous margin ; as the leaf of Solanum nigrum.

9. Angular (angulatus, angulosus) ; having several salient angles
on the margin ; as the leaf of Datura Stramonium.

10. Sinuate (sinuatus) ; having the margin uneven, alternately
with deep concavities and convexities ; as the leaf of Quercus
robur.

B. With respect to incision.

1 2 3

c c 2

388

GLOSSOLOGY.

BOOK IV.

1. Torn (lacerus) ; irregularly divided by deep incisions

2. Cut (incisus) ; regularly divided by deep incisions.

3. Slashed (laciniatus) ; divided by deep, taper-pointed, cut
incisions.

4. Squarrose-slashed (squarroso-laciniatus) ; slashed with minor
divisions at right angles with the others.

5. Lobed (lobatus) ; partly divided into a determinate number of
segments. We say bilobus, two-lobed, as in the leaf of Bau-
hinia porrecta ; trilobus, three-lobed, as in the leaf of Ane-
mone hepatica ; and so on.

6. Split (fissus); divided nearly to the base into a determinate
number of segments. We say bifidus, split in two; trifidus,
in three ; as in the leaf of Teucrium chamaepitys ; and so on.
When the segments are very numerous, multifidus is used.

7. Parted (partitus) ; divided into a determinate number of
segments, which extend nearly to the base of the part to
which they belong. We say bipartilus, parted in two ; tri-
partitus, in three ; and so on.

8. Palmate {palmatus) ; having five lobes, the midribs of which
meet in a common point, so that the whole bears some re-
semblance to a human hand ; as the leaf of Passiflora
caerulea.

9. Pedate (pedatus); the same as palmate, except that the two
lateral lobes are themselves divided into smaller segments,
the midribs of which do not directly run into the same point
as the rest; as the leaf of Arum dracunculus, Helleborus
niger, &c.

10. Fingered (digitatus) ; the same as palmate, but the segments
less spreading, and narrower.

11. Pinnatifid (pmnatifidus, pennatipartitus, pinnaticisus) ; di-
vided almost to the axis into lateral segments, something in
the way of the side divisions of a feather; as Polypodium
vulgare. M. De Candolle distinguishes several modifications
of pinnatifidus : — 1. Pinnatifidus, when the lobes are divided

CLASS I.

INDIVIDUAL ABSOLUTE TERMS.

389

down to half the breadth of the leaf; 2. pinnatipartitus,
when the lobes pass beyond the middle, and the parenchyma
is not interrupted ; 3. pinnatisectus, when the lobes are di-
vided down to the midrib, and the parenchyma is interrupted ;
4. pinnatilobatus, when the lobes are divided to an uncertain
depth : lyrate and the like belong to this modification. He
has similar variations of palmatus and pedatus ; viz. palmatu
fidus, jmlmatipartitus, palmatisectus, palmatilobatus ; and peda-
tifidus, pedatipartitus, pedatisectus, and pedatilobatus.
]2. Comb-shaped (pectinatus) ; the same as pinnatifid; but the
segments very numerous, close, and narrow, like the teeth
of a comb ; as the leaf of Lavandula dentata, all Mer-
tensias.

C. With respect to composition or ramification.

1. Simple (simplex) ; scarcely divided or branched at all.

2. Quite simple (simplicissimus) ; not divided or branched
at all.

3. Compound (compositus) ; having various divisions or ramifi-
cations. As compared with the two following, it applies to
cases of leaves in which the petiole is not divided ; as in the
orange.

4. Decompound (decompositus) ; having various compound divi-
sions or ramifications. In leaves it is applied to those the
petiole of which bears secondary petioles ; as in the leaf of
Mimosa purpurea.

12 9 16

! ttta.-ai.

CC "6

390 GLOSSOLOGY. BOOK IV.

5. Supradecompound {supradecompositus) ; having various de-
compound divisions or ramifications. In leaves it is applied
to such as have the primary petiole divided into secondary
ones, and the secondary into a third set ; as in the leaf of
Daucus Carota.

6. fBi folio! ate {-fbifoliolatus, binatus); when in leaves the com-
mon petiole is terminated by two leaflets growing from the

s i m e point; as in Zygophyllum Fabago. This term has the
same application as unijugus and conjugatus. We say trifo-
liolate, or ternate, when the petiole bears three leaflets from
the same point, as in Menyanthes trifoliata ; f quadrifoliolate,
if there are four from the same point, as in Marsilea quadri-
folia ; and quinquefoliolate, or quinate, if there are five from
the same point, as in Potentilla reptans ; and so on.

7. f Vertebrate (f vertebratus) ; when the leaf is contracted at
intervals, there being an articulation at each contraction ; as
in Cussonia spicata. Mirb.

8. Pinnate '(pinnatus) ; when simple leaflets are arranged on
each side a common petiole ; as in Polypodium vulgare.

9. Pinnate with an odd one [impari-pinnatus) ; when the petiole
is terminated by a single leaflet or tendril ; as in Pyrus aucu-
paria. If there is a tendril, as in the pea, it is called
cirrhose.

10. Equally pinnate {paripinnatus, abrupte pinnatus) ; when the
petiole is terminated by neither leaflet nor tendril, as Orobus
tuberosus.

11. f Alternately pinnate (f aliernatim pinnatus); when the leaf-
lets are alternate upon a common petiole ; as in Potentilla
rupestris. Mirb.

12. Interruptedly pinnate {interrupts pinnatus) ; when the leaf-
lets are alternately small and large, as in the potatoe.

13. f Decreasingly pinnate {\decrescente pinnatus) ; when the
leaflets diminish insensibly in size from the base of the leaf
to its apex ; as in Vicia sepium. Mirb.

14. -j-Decursively pinnate [\ decursive pinnatus) ; when the petiole
is winged by the elongation of the base of the leaflets ; as in
Melianthus. Mirb. This is hardly different from pinnatifid.

15. Digitato-pinnate {digit at o-pinnatus) ; when the secondary
petioles, on the sides of which the leaflets are attached, part
from the summit of a common petiole. Mirb.

16. Twin digitato-pinnate (bidigitato-pinnatus, biconjugato-pin-
natus); the secondary petioles, on the sides of which the

CLASS I. INDIVIDUAL ABSOLUTE TERMS. 391

leaflets are arranged, proceed in twos from the summit of a
common petiole; as in Mimosa purpurea. Mirb.

17. Bigeminate (bigeminatus, biconjugatus) ; when each of
two secondary petioles bears a pair of leaflets ; as in Mimosa
unguis Cati. Mirb.

18. Tergeminate (tergeminus, -\tergeminatus) ; when each of
two secondary petioles bears towards its summit one pair of
leaflets, and the common petiole bears a third pair at the
origin of the two secondary petioles ; as in Mimosa tergemina.
Mirb.

19. Thrice digitato-pinnate (ftridigitato-pinnatus, ternato-pin-
natus) ; when the secondary petioles, on the sides of which
the leaflets are attached, proceed in threes from the summit
of a common petiole ; as in Hoffmannseggia. Mirb.

20. f Quadridigitato-pinnatus, as in Mimosa pudica, and \Mul-
tidigitato-jrinnatus, are rarely used, but are obvious modi-
fications of the last.

21. Bipinnate (bipinnatus, -fduplicato-pinnatus); when the leaflets
of a pinnate leaf become themselves pinnate ; as in Mimosa
Julibrissin, Fumaria officinalis, &c.

22. Biternate (biternatus, ■\duplicato-ternatus); when three
secondary petioles proceed from the common petiole, and
each bears three leaflets ; as in Fumaria bulbosa, Imperatoria
Ostruthium, &c. Mirb.

23. Triternate (triternatus) ; when the common petiole divides
into three secondary petioles, which are each subdivided into
three tertiary petioles, each of which bears three leaflets ; as
the leaf of Epimedium alpinum.

24. Tripinnate (tripinnatus) ; when the leaflets of a bipinnate
leaf become themselves pinnate ; as in Thalictrum minus, or
CEnanthe Phellandrium.

25. Faired (conjugatus, unijugus, -funijugatus); when the petiole
of a pinnated leaf bears one pair of leaflets ; as Zygophyllum
Fabago. Bijugus is when it bears two pairs ; as in Mimosa
fagifolia : trijugus, quadrijugus, quinquejugus, &c. are also
employed when required. Multijugus is used when the num-
ber of pairs becomes very considerable ; as in Orobus sylva-
ticus, Astragalus glycyphyllus.

26. Branched (ramosus) ; divided into many branches : if the
divisions are small, we say ramulosus.

27. Somewhat branched (subramosus) ; having a slight tendency
to branch.

cc t

392

GLOSSOLOGY.

BOOK JV.

28. Excurrent (excurrens) ; in which the axis remains always in
the centre, all the other parts being regularly disposed round
it; as the stem of Pinus Abies.

29. Much-branched (ramosissimiis) ; branched in a great de-
gree.

30. f Disappearing {\deliquescens) ; branched, but so divided
that the principal axis is lost trace of in the ramifications; as
the head of an oak tree.

31. Dichotomous (dichotomus) ; having the divisions always in
pairs ; as the branches and inflorescence of Stellaria holostea:
if they are in threes, we say trichotomus ; as the stem of
Mirabilis Jalapa.

32. Twin (didymus) ; growing in pairs, or divided into two equal
parts ; as the fruit of Galium.

33. Forked (jiircatus) ; having "long terminal lobes, like the
prongs of a fork; as Ophioglossum pendulum.

34. Stellate {stellatus) ; divided into segments, radiating from a
common centre; as the hairs of most malvaceous plants.

35. Jointed {articulatus) ; falling in pieces at the joints, or
separating readily at the joints; as the pods of Ornithopus,
the leaflets of Guilandina Bonduc : it is also applied to
bodies having the appearance of being jointed ; as the stem
and leaves of Juncus articulatus

36. Granular {granulatus) ; divided into little knobs or knots ;
as the roots of Saxifraga granulata.

37. fByssaceous {\byssaceus) ; divided into very fine pieces,
like wool ; as the roots of some Agarics.

38. f Tree-like {\dendroides) ; divided at the top into a number
of fine ramifications, so as to resemble the head of a tree ; as
Lycopodium dendroideum.

39. f Brush-shaped (f aspergilliformis) ; divided into several fin
ramifications, so as to resemble the brush (aspergillus) used
for sprinkling holy water in the ceremonies of the Catholic
Church ; as the stigmas of grasses.

CLASS I.

INDIVIDUAL ABSOLUTE TERMS.

393

40. Partitioned {loculosus, \septatus, \phragmiger) ; divided by
internal partitions into cells ; as the pith of the plant that
produces the Chinese rice-paper. This is never applied to
fruits.

41. Anastomosing (anastomozans); the ramifications of any thing
which are united at the points where they come in contact
are said to anastomose. This term is confined to veins.

42. Ruminate (ruminatus) ; when a hard body is pierced in
various directions by narrow cavities filled with dry cellular
matter ; as the albumen of the nutmeg, and the Anona.

43. fCancellate {\cancellatus) ; when the parenchyma is wholly
absent, and the veins alone remain, anastomosing and form-
ing a kind of net-work ; as the leaves of Hydrogeton fenes-
tralis.

44. Perforated (pertusus) ; when irregular spaces are left open in
the surface of any thing, so that it is pierced with holes ■ as
the leaves of Dracontium pertusum.

3*. Of Surface.
A. With respect to marking, or evenness.

1. Rugose (rugosus) ; covered with reticulated lines, the spaces
between which are convex- as the leaves of sage.

2. Netted (reticulates) ; covered with reticulated lines which
project a little ; as the under surface of the leaves of most
Melastomas, the seeds of Geranium rotundifolium.

3. f Half-netted {fsemireticulatus) ; when, of several layers of
any thing, the outer one only is reticulated; as in the roots
of Gladiolus communis.

4. Pitted (scrobiculatus) ; having numerous small shallow de-
pressions, or excavations ; as the seed of Datisca cannabina,
Passiflora, &c.

5. Lacunose (lacunosus) ; having numerous large, deep depres-
sions, or excavations.

6. Honey-combed (Javosus, alveolatus) ; excavated in the man-
ner of a section of honeycomb; as the receptacle of many
Compositae, the seeds of Papaver.

394

GLOSSOLOGY.

BOOK IV.

7. fAreolate (fareolatus); divided into a number of irregular
squares or angular spaces.

8. Scarred (cicatrisatus) ; marked by the scars left by bodies
that have fallen off: a stem, for instance, is scarred by the
leaves that have fallen.

9. Ringed (annulatus) ; surrounded by elevated or depressed
bands; as the roots of some plants, the cupula? of several
oaks, &c.

10. Striated (striatus) ; marked by longitudinal lines; as the
petals of Geranium striatum.

11. Lined {lineatus) ; the same as striatus.

12. Furrowed (sidcatus) ; marked by longitudinal channels ; as
the stem of Conium, of the parsnep, of Spiraea Ulmaria, &c.

13. f Aciculated (f aciculatus) ; marked with very fine irregular
streaks, as if produced by the point of a needle.

14. Dotted (punctatus) ; covered by minute impressions, as if
made by the point of a pin ; as the seed of Anagallis arvensis,
Geranium pratense.

15. Even (cequatus) ; the reverse of any thing expressive of
inequality of surface.

B. With respect to appendages or superficial processes.

20 '^l t~ *~~ 27 ~~~**J' pumu^ //ptp

14 12 32 33

1. Unarmed (inermis) ; destitute of any kind of spines or
prickles.

2. Spiny (spinosus) ; furnished with spines, as the branches of
Crataegus Oxyacantha.

3. Prickly (aculeatus) ; furnished with prickles, as the stem of a
rose.

4. Bristly (echinatus) ; furnished with numerous rigid hairs, or
straight prickles ; as the fruit of Castanea vesca.

CLASS I. INDIVIDUAL ABSOLUTE TERMS. 395

5. Muricated (muricatus) ; furnished with numerous short, hard
excrescences ; as the fruit of the Arbutus Unedo.

6. Spiculate (-\spiculatus) ; covered with fine fleshy, erect
points.

7- Rough [scaber, asper, exasperatus) ; covered with hard, short,
rigid points ; as the leaves of Borago officinalis.

8. Roughish {scabridus) ; slightly covered with short, hardish
points ; as the leaf of Thymus Acinos.

9. Tubercled (tuberculatus, veri-ucosus) ; covered with little ex-
crescences or warts ; as the stem of Cotyledon tuberculata,
the leaf of Aloe margaritifera.

10. Pimpled (papillosus, fjxipulosus) ; covered with minute tu-
bercles or excrescences, of uneven size, and rather soft; as
the leaves of Mesembryanthemum crystallinum.

11. Hairy (pilosus); covered with short, weak, thin hairs; as
the leaf of Prunella vulgaris, Daucus Carota.

12. Downy (pubens, pubescens) ; covered with very short, weak,
dense hairs. Pubescens is most commonly employed in
Latin, but pubens is more classical ; as the leaves of Cyno-
glossum officinale, Lonicera Xylosteum, &c.

13. Hoary [incanns] ; covered with very short, dense hairs, placed
so closely as to give an appearance of whiteness to the sur-
face from which they grow; as the leaf of Mathiola incana.

14. Shaggy (hirtus, villosus) ; covered with long, weak hairs ; as
Epilobium hirsutum.

15. Tomentose (tomentosus) ; covered with dense, rather rigid,
short hairs, so as to be sensibly perceptible to the touch ;
as Onopordum Acanthium, Lavatera arborea, &c.

16. Velvety (yelutinus) ; the same as the last, but more dense,
so that the surface resembles that of velvet ; as Cotyledon
coccineus.

17- Woolly (lanatus) ; covered with long, dense, curled, and
matted hairs, resembling wool ; as Verbascum Thapsus,
Stachys germanica.

18. Hispid (hispidus) ; covered with long, rigid hairs ; as the
stem of Echium vulgare.

19. Floccose (Jloccosus) ; covered with dense hairs, which fall
away in little tufts ; as Verbascum floccosum, and pulveru-
lentum.

20. Glandular (glandulosus) ; covered with hairs bearing glands
upon their tips ; as the fruit of roses, the pods of Adeno-
carpus.

396 GLOSSOLOGY. BOOK IV.

21. Bearded (barbatus, crinitus) ; having tufts of long, weak hairs
growing from different parts of the surface ; as the leaves of
Mesembryanthemum barbatum. It is also applied to bodies
bearing very long, weak hairs in solitary tufts, or parcels ;
as the filaments of Anthericum, the pods of Adesmia.

22. Strigose (strigosus) ; covered with sharp, appressed, rigid
hairs. W. Linnaeus considers this word synonymous with
hispid.

23. Silky (sericeus) ; covered with very fine, close-pressed hairs,
silky to the touch ; as the leaves of Protea argentea, Alche-
milla alpina, &c.

24>. -j-Peronate (fperonatus) ; laid thickly over with a woolly
substance, ending in a sort of meal. W. This term is only
applied to the stipes of Fungi.

25. Cobwebbed {arachnoides) ; covered with loose, white, en-
tangled, thin hairs, resembling the web of a spider ; as Cal-
ceolaria arachnoidea.

26. Ciliated (ciliatus) ; having fine hairs, resembling the eye-
lash, at the margin; as the leaves of Luzula pilosa, Erica
tetralix, &c.

27. Fringed {Jimbriatus) ; having the margin bordered by long
filiform processes thicker than hairs ; as the petals of Cu-
cubalus fimbriatus.

28. Feathery (plumosus); consisting of long hairs, which are
themselves hairy ; as the pappus of Leontodon taraxacum,
the beard of Stipa pinnata.

29. Stinging (iirens) ; covered with rigid, sharp-pointed, bristly
hairs, which emit an irritating fluid when touched ; as the
leaves of the Urtica urens.

30. Mealy (Jarinosus) ; covered with a sort of white scurfy
substance ; as the leaves of Primula farinosa, and of some
poplars.

31. Leprous (lepidotus, leprosus) ; covered with minute peltate
scales ; as the foliage of Elaeagnus.

32. Ramentaceous (ramentaceus) ; covered with weak, shri-
velled, brown, scale-like processes ; as the stems of many
ferns.

33. Scaly (squamosus) ; covered with minute scales, fixed by
one end ; as the young shoots of the pine tribe.

34. Chaffy (paleaceus) ; covered with small, weak, erect, mem-
branous scales, resembling the paleae of grasses ; as the
receptacle of many compound plants.

CLASS I. INDIVIDUAL ABSOLUTE TERMS. 397

C. With respect to polish or texture.

1. Shining (nitidas) ; having a smooth, even, polished surface ;
as many leaves.

2. Smooth (glaber, or Icevis) ; being free from asperities or
hairs, or any sort of unevenness.

3. Polished (Icevigatus, \politus) ; having the appearance of a
polished substance ; as the testa of Abrus precatorius, and
many seeds.

4. ^Glittering (\splendens) ; the same as polished, but when the
lustre is a little broken, from slight irregularity of surface.

5. Naked (nudus, denudatus) ; the reverse of hairy, downy, or
any similar term : it is not materially different from glaber.

6. Opaque (opacus) ; the reverse of shining, dull.

7. Viscid (viscidus, glutinosus) ; covered with a glutinous exu-
dation.

8. Mucous, or slimy (mucosus) ; covered with a slimy secretion ;
or with a coat that is readily soluble in water, and becomes
slimy ; as the fruit of Salvia Verbenaca.

9. fGreasy (functuosus) ; having a surface which, though not
actually greasy, feels so.

10. Dewy (roridus) ; covered with little transparent elevations of
the parenchyma, which have the appearance of fine drops

• of dew.

11. f Dusty (flentiginosus) ; covered with minute dots, as if
dusted ; the calyx and corolla of Ardisia lentiginosa.

12. Frosted (pruinosus) ; nearly the same as roridus, but applied
to surfaces in which the dewy appearance is more opaque, as
if the drops were congealed ; as the surface of the leaves of
Rosa pruinosa and glutinosa.

13. Powdery (pulverulentus) ; covered with a fine bloom or
powdery matter ; as the leaves of Primula farinosa.

14-. Glaucous (glaucus) ; covered with a fine bloom of the colour
of a cabbage-leaf.

15. Caesious (ccesius) ; like glaucous, but greener.

16. Whitened (dealbatus) ; covered with a very opaque white
powder ; as the leaves of many Cotyledons.

4. Of Texture, or Substance.

1. Membranaceous {membra naceus) ; thin and semitransparent,
like a fine membrane ; as the leaves of mosses.

2. Papery (papyraceus, chartaceus) ; having the consistence of
writing paper, and quite opaque ; as most leaves.

398 GLOSSOLOGY. BOOK IV.

3- Leathery (coriaceus, f alntaceus) ; having the consistence of
leather; as the leaves of Pothos acaulis, Prunus lauro-cerasus,
and others.

4. Crustaceous (crustaceus) ; hard, thin, and brittle ; as the testa
of asparagus, or of Passiflora.

5. Cartilaginous (cartilaginous) ; hard and tough ; as the testa of
an apple-seed.

6. Loose (laxus) ; of a soft cellular texture, as the pith of most
plants. The name is derived from the parts of the substance
appearing as if not in a state of cohesion.

7. Scarious (scariosus) ; having a thin, dry, shrivelled appear-
ance; as the involucral leaves of many species of Centaurea.

8. Corky (suberosus) ; having the texture of the substance called
cork; as the bark of Ulmus suberosa.

9. Coated (corticatus) ; harder externally than internally.

10. Spongy (spongiosus) ; having the texture of a sponge ; that
is to say, very cellular, with the cellules filled with air ; as the
coats of many seeds.

11. Horny (cornetcs) ; hard, and very close in texture, but ca-
pable of being cut without difficulty, the parts cut off not
being brittle ; as the albumen of many plants.

12. Oleaginous (oleaginosus) ; fleshy in substance, but filled
with oil.

13. Bony (osseus) ; hard, and very close in texture, not cut with-
out difficulty, the parts cut off being brittle ; as the stone of
a peach.

14. Fleshy (carnosus) ; firm, juicy, easily cut.

15. Waxy (ceraceus, cereus) ; having the texture and colour of
new wax ; as the pollen masses of particular kinds of
Orchis.

16. Woody (lignosus, ligneus) ; having the texture of wood.

17. Thick (crassus) ; something more thick than usual. Leaves,
for instance, are generally papery in texture ; the leaves of
cotyledons, which are much more fleshy, are called thick.

18. Succulent (succulentus) ; very cellular and juicy; as the
stems of Stapelias.

19. Gelatinous {gelatinosus) ; having the texture and appearance
of jelly ; as Ulvas, and similar things.

20. Fibrous {Jibrosus) ; containing a great proportion of loose
woody fibre ; as the rind of a cocoa-nut.

21. \ Medullary or pithy (f medullosus) ; filled with spongy
pith.

CLASS I. INDIVIDUAL ABSOLUTE TERMS. 399

22. Mealy (jarhiaceus) ; having the texture of flour in a mass;
as the albumen of wheat.

23. Tartareous [tartareus) ; having a rough, crumbling surface ;
like the thallus of some Lichens.

24. Berried (baccatus) ; having a juicy, succulent texture; as
the calyx of Blitum.

25. Herbaceous (herhaceus) ; thin, green, and cellular; as the
tissue of membranous leaves.

5. Of Size.

Most of the terms which relate to this quality are the same
as those in common use ; and being employed in precisely the
same sense, do not need explanation. But there are a few
which have a particular meaning attached to them, and are
not much known in common language. These are, —

1. Dwarf (nanus, pumilus, pygmceus) ; small, short, dense, as
compared with other species of the same genus, or family.
Thus, Myosotis nana is not more than half an inch high ;
while the other species are much taller.

2. Very small (pusilltcs, perpusillus) ; the same as the last,
except that a general reduction of size is understood, as well
as dwarfishness.

3. Low (humilis) ; when the stature of a plant is not particularly
small, but much smaller than of other kindred species. Thus,
a tree twenty feet high may be lotv, if the other species of
its genus are forty or fifty feet high.

4. Depressed (depressus) ; broad and dwarf, as if, instead of
growing perpendicularly, the growth had taken place hori-
zontally ; as some species of Cochlearia, Coronopus Ruellii,
and many others.

5. Little (exiguus) ; this is generally used in opposition to
large, and means small in all parts, but well proportioned.

6. Tall (elatus, procerus) ; this is said of plants which are
taller than their parts would have led one to expect.

7. Lofty (exaltatics) ; the same as the last, but in a greater
degree.

8. Gigantic (giganteus) ; tall, but stout and well proportioned.

To this class must also be referred words or syllables
expressing the proportion which one part beat's to another.

1. Isos, or equal, placed before the name of an organ, indicates

400 GLOSSOLOGY. BOOK IV.

that it is equal in number to that of some other understood :
thus, isostemonous is said of plants the stamens of which are
equal in number to the petals. De Cancl.

2. Anisos, or unequal, is the reverse of the latter: thus, anisos-
temonous would be said of a plant the stamens of which are
not equal in number to the petals.

3. \Meios, or less, prefixed to the name of an organ, indicates
that it is something less than some other organ understood :
thus, \meiostemonous would be said of a plant the stamens of
which are fewer in number than the petals.

4. Duplo, triplo, &c. or double, triple, &c. signify that the
organs to the name of which they are prefixed are twice or
thrice as numerous or large as those of some other.

The terms which express measures of length are the
following : —

1. A hair's breadth (capillus, its adjective capillaris) ; the twelfth
part of a line.

2. A line (linea, adj. linealis) ; the twelfth part of an inch.

3. A nail {unguis); half an inch, or the length of the nail of the
little finger.

4. An inch (pottex, uncia ; adj. pollicaris, uncialis); the length of
the first joint of the thumb.

5. A small span (spithama, adj. spithamceus); seven inches, or
the space between the thumb and the fore-finger separated
as widely as possible.

6. A palm (palmus, adj. palmaris) ; three inches, or the breadth
of the four fingers of the hand.

7. A span (dodrans, adj. dodrantalis) ; nine inches, or the space
between the thumb and the little finger separated as widely
as possible.

8. A foot (pes, adj. pedalis) ; twelve inches, or the length of a
tall man's foot.

9. A cubit (cubitus, adj. cubitalis); seventeen inches, or the dis-
tance between the elbow and the tip of the fingers.

10. An ell (ulna, brachium ; adj. ulnaris, brachialis) ; twenty-four
inches, or the length of the arm.

11. A toise (orgya, adj. orgyalis) ; six feet or the ordinary
height of man.

12. Sesqui. This term, prefixed to the Latin name of a mea-
sure, shows that such measure exceeds its due length by one
half: thus, sesquipedalis means a foot and a half.

CLASS I. INDIVIDUAL ABSOLUTE TERMS. 101

13. fA millimetre = ^oVo °^a nne-

14. f A centimetre = 4? lines and -y*g\fo*

15. f A decimetre = 3 inches, eight lines, -fVaV

16. fA metre = 3 feet, 11 lines, -S^fo.

Obs. The four last terms are French measures, which are
rarely used, and for which no equivalent Latin terms are
employed.

6. Of Duration.

The terms in ordinary use to express the .absolute period
of duration of a plant are sufficiently precise for common
purposes, but are too inaccurate to be longer admitted within
the pale of science. I have, therefore, adopted the phrase-
ology of M. De Candolle, as far as relates to words expressive
of the actual term of vegetable existence.

1. Monocarpous ; bearing fruit but once, and dying after
fructification ; as wheat. Some live but one year, and are
called annuals : the term of the existence of others is pro-
longed to two years ; these are biennials : others live for many
years before they flower, but die immediately afterwards ;
as the Agave americana. The latter have no English name.
Annuals are indicated by the signs G or © ; biennials by $
or ® ; and the others by x .

2. Polycarpous (better sychnocarpous) ; having the power of
bearing fruit many times without perishing. Of this there
are two forms : —

A. Caulocarpous, or those whose stem endures many years,
constantly bearing flowers and fruits ; as trees and shrubs.
The sign of these is I? .

B. Rhizocarpous, or those whose root endures many years,
but whose stems perish annually ; as herbaceous plants.
The sign of these is If.

3. Hysteranthous ; when leaves appear after flowers; as the
Almond, Tussilago fragrans, &c.

4. f Synanthous ; when flowers and leaves appear at the same
time.

5. f Proteranthous ; when the leaves appear before the flowers.

6. Double-bearing [biferus) ; when any thing is produced twice
in one season.

7. f Often-bearing {\multiferus); when any thing is proouced
several times in one season

D D

402 GLOSSOLOGY. BOOK IV.

Besides the foregoing, those that follow require expla-
nation : —

1. Of an hour (horarius) ; which endures for an hour or two
onty; as the flowers of Talinum, Cistus, &c.

2. Of a day (ephemerus, fdiurnus); which endures but a day, as
the flower of Tigridia. Biduus is said of things that endure
two days ; and triduus, three days.

3. Of a night [nocturnus) ; which appears during the night, and
perishes before morning ; as the flowers of the night-bloom-
ing Cereus.

4s Of a month [menstrualis, \menstruus) ; which lasts for a
month. Bimestris is said of things that exist for two months ;
Irimestris, for three months.

5. Yearly (annotinus) ; that which has the growth of a year.
Thus, rami annotini are branches a year old.

6. Of the same year (hornus) ; is said of any thing the produce
of the year. Thus, rami horni would be branches not a
year old.

7. Deciduous (deciduns) ; finally falling off, as the calyx and
corolla of Cruciferae.

8. Caducous (caducus) ; falling off very early, as the calyx of
the poppy.

9. Persistent (persistens, + restarts, Linn.) ; not falling off, but
remaining green until the part which bears it is wholly ma-
tured ; as the leaves of evergreen plants, the calyx of Labiatae,
and others.

10. Withering, or fading (marcescens) ; not falling off until the
part which bears it is perfected, but withering long before
that time ; as the flowers of Orobanche.

11. Fugacious (fugax); falling off, or perishing very rapidly ; as
many minute Fungi, the petals of Cistus, &c.

12. Permanent (perennans) ; not different from persistent : it is
generally applied to leaves.

13. Perennial (perennis) ; lasting for several years.

7. Of Colour.

The most useful books to consult for the distinctions of
colours are Symes's Book of Colours, and the chromatic scale
in the Duke of Bedford's publication upon Ericas.

The best practical arrangement of colours, as applied to

CLASS I. INDIVIDUAL ABSOLUTE TERMS. 403

plants, is that of Dr. Bischoff, in bis excellent Terminology ,-
what follows is chiefly taken from that work.

There are eight principal colours, under which all the
others may be arranged ; viz. white, grey, black, brown,
yellow, green, blue, and red.

I. White {albus ; in words compounded of Greek, leuco-).

1. Snow-white (niveus) ; as the purest white; Camellia ja-
ponica.

2. Pure white (candidus ; in Greek composition, argo-); very
pure, but not so clear as the last ; Lilium candidum,

3. Ivory-white (cream colour ; eburneus, eborinus) ; white
verging to yellow, with a little lustre ; Convallaria majalis.

4. Milk-white (Jacteus ; in words compounded of Greek, ga-
lacto-) ; dull white verging to blue.

5. Chalk-white (cretaceus, calcareus, gypseus) ; very dull white
with a little touch of grey.

6. Silvery (argenteus) ; a little changing to bluish grey, with
something of a metallic lustre.

7. Whitish (albidus) ; any kind of white a little soiled.

8. Turning white (albescens) ; changing to a whitish cast from
some other colour.

9. Whitened (dealbatm), slightly covered with white upon a
darker ground.

II. Grey.

10. Ash-grey (cinereus ; in words compounded of Greek, te-
phro- and spodo-) ; a mixture of pure white and pure black,
so as to form an intermediate tint.

11. Ash-greyish (cineraceus) ; the same, but whiter.

12. Pearl-grey (griseus) ; pure grey a little verging to blue.

13. Slate-grey (schistaceus) ; grey bordering on blue.

14-. Lead-coloured (plumbeus); the same with a little metallic
lustre.

15. Smoky (Jiimeus,Jiimosus) ; grey changing to brown.

16. Mouse-coloured (murinus); grey with a touch of red.

17. Hoary (canus, or incanus) ; a greyish whiteness, caused by
hairs overlying a green surface.

18. Rather hoary (canescens) ; a variety of the last.

III. Black.

19. Pure black (ater ; in Greek composition, mela- or mc-
lano-); is black, without the mixture of any other colour.

D D 2

404- GLOSSOLOGY. BOOK IV.

Atratus and nigritus ; when a portion only of something is
black ; as the point of the glumes of Carex.

20. Black (niger) ; a little tinged with grey. A variety is
nigrescens.

21. Coal-black (anthracinus) ; a little verging upon blue.

22. Raven-black {cor acinus, pullus) ; black with a strong lustre.

23. Pitch-black (piceus); black changing to brown. From this
can scarcely be distinguished brown-black (menmonius).

IV. Brown.

24. Chesnut-brown (badius) ; dull brown, a little tinged with
red.

25. Brown (Jiiscus ; in Greek composition, phceo-) ; brown
tinged with greyish or blackish.

26. Deep-brown (brunneus) ; a pure dull brown. Umber-brown
(umbrinus) is nearly the same.

27- Bright brown (spadiccus); pure and very clear brown.

28. Rusty (Jerrugineus) ; light brown with a little mixture
of red.

29. Cinnamon (cinnamometis) ; bright brown mixed with yellow
and red.

30. Red-brown (porphyreus) ; brown mixed with red.

31. Rufous (riifus, nifescens) ; rather redder than the last.

32. f Glandaceus ; like the last, but yellower.

33. Liver-coloured [hepaticus); dull brown with a little yellow.

34. Fuligineus, or Juliginosus ; dirty brown, verging upon
black.

35. Lurid (luridus) ; dirty brown a little clouded.

V. Yellow.

36. Lemon-coloured (citreus or citrinus) ; the purest yellow
without any brightness.

37. Golden yellow [aureus, auratus ; in Greek composition,
chryso-) ; pure yellow, but duller than the last, and bright.

38. Yellow (luteus ; in Greek composition, xantho-) ; such yellow
as gamboge.

39. Pale yellow (Jlavus, luteolus, lutescens, JIavidus,Jlavescens) ;
a pure, but paler yellow than the preceding.

40. Sulphur-coloured (sulphureus) ; a pale, lively yellow, with a
mixture of white.

41. Straw-coloured (stramineus) ; dull yellow mixed with
white.

CLASS I. INDIVIDUAL ABSOLUTE TERMS. 405

42. Leather yellow (alittaceus) ; whitish yellow.

43. Ochre-colour (ochraceus)\ yellow, imperceptibly changing
to brown.

44. Ochroleacus ; the same, but whiter.

45. Waxy yellow (cerinus) ; dull yellow, with a soft mixture of
reddish brown.

46. Yolk of egg (vitellimis) ; dull yellow, just turning to red.

47. Apricot-colour (armeniacus) ; yellow, with a perceptible
mixture of red.

48. Orange-colour (aurantiacus, aurantius) ; the same, but
redder.

49. Saffron-coloured (croceus) ; the same, but deeper, and with
a dash of brown.

50. Helvolus ; greyish yellow with a little brown.

51. Isabella-yellow (gilvus); dull yellow with a mixture of
grey and red.

52. Testaceous (testaceus) ; brownish yellow, like that of un-
glazed earthenware.

53. Tawny (Julvus) ; dull yellow with a mixture of grey and
brown.

54. Cervinus ; the same, darker.

55. Livid {lividus) ; clouded with greyish, brownish, and
blueish.

VI. Green.

56- Grass-green (smaragdinus, prasiniis) ; clear, lively green,
without any mixture.

57. Green (viridis ; in Greek composition, chloro-) ; clear green,
but less bright than the last. Virens, virescens, virididus,
viridescens, are shades of this.

58. Verdigris-green (ceruginosus); deep green with a mixture of
blue.

59. Sea-green (glancus, \thalassicus, glaucescens) ; dull green,
passing into greyish blue.

60. Deep green (atrovirens); green, a little verging upon
black.

61. Yellowish green [Jlavovirens) ; much stained with yellow.

62. Olive-green (olivaceus ; in Greek composition, elaio-) ; a
mixture of green and brown.

VII. Blue.

63. Prussian blue (cyaneus ; in Greek composition, cyano-) ; a
clear, bright blue.

n D 3

406 GLOSSOLOGY. BOOK IV.

64. Indigo (\indigoticus) ; the deepest blue.

65. Blue (ccerideus) ; something lighter and duller than the
last.

66- Sky-blue (azureus) ; a light, pure, lively blue.

67. Lavender-colour (ccesius) ; pale blue with a slight mixture
of grey.

68. Violet (violaceus, ianthinus) ; pure blue stained with red,
so as to be intermediate between the two colours.

69. Lilac (lilacinus) ; pale, dull violet, mixed a little with white.

VIII. Red.

70. Carmine (kermesinus, puniceus) ; the purest red without any
admixture.

71. Red (ruber; in Greek composition, erythro-); the com-
mon term for any pure red. Rubescens, rubeus, rubellus,
rubicundus, belong to this.

72. Rosy (roseus ; in Greek composition, rhodo-) ; pale, pure
red.

Flesh-coloured (carneus, incarnatus) ; paler than the last,
with a slight mixture of red.

74. Purple (purpureus) ; dull red with a slight dash of blue.

75. Sanguine (sanguineus) ; dull red passing into brownish
black.

76. Phaeniceous ( phceniceus, puniceus) ; pure, lively red, with a
mixture of carmine and scarlet.

77. Scarlet (coccineus); pure carmine slightly tinged with
yellow.

78. Flame-coloured (jtammeus, igneus) ; very lively scarlet ;
fiery red.

79. Bright red (rutilans, rutilus) ; reddish with a metallic lustre.

80. Cinnabar (citmabarinus) ; scarlet with a slight mixture of
orange.

81. Vermilion (miniatus, fvermiculatus) ; scarlet with a de-
cided mixture of yellow.

82. Brick-colour (lateritius) ; the same, but dull and mixed
with grey.

83. Brown-red (rubiginosus, hcematiticus) ; dull red with a slight
mixture of brown.

84. Xerampelinus ; dull red with a strong mixture of brown.

85. Coppery (cupreus) ; brownish red with a metallic lustre.

86. Githagineus ; greenish red.

CLASS I.

INDIVIDUAL ABSOLUTE TERMS.

407

8. Of Variegation, or Marking.

2 3 4 5 6 7

17 11

1. Variegated (variegatus) ; the colour disposed in various irre-
gular, sinuous spaces.

2. Blotched (maculatus) ; the colour disposed in broad, irregular
blotches.

3. Spotted (guttatus) ; the colour disposed in small spots.

4. Dotted (pwictatus) ; the colour disposed in very small round
spots.

5. Clouded (nebulosus) ; when colours are unequally blended
together.

6. Marbled (marmoratus) ; when a surface is traversed by irre-
gular veins of colour ; as a block of marble often is.

7. Tessellated (tessellatus) ; when the colour is arranged in small
squares, so as to have some resemblance to a tessellated
pavement.

8. Bordered (limbatus) ; when one colour is surrounded by an
edging of another.

9. Edged (marginatus) ; when one colour is surrounded by a
very narrow rim of another.

10. Discoidal (discoidalis) ; when there is a single large spot of
colour in the centre of some other.

11. Banded (fasciatus) ; when there are transverse stripes of
one colour crossing another.

12. Striped (yittatus) ; when there are longitudinal stripes of one
colour crossing another.

13. Ocellated (ocellatas); when a broad spot of some colour has
another spot of a different colour within it.

14. Painted (pictus) ; when colours are disposed in streaks of
unequal intensity.

D D 4

408 GLOSSOLOGY. BOOK IV

15. Zoned (zonatus) ; the same as ocellated, but the concentric
bands more numerous.

16. Blurred {lituratiis). This, according to De Candolle, is
occasionally, but rarely, used to indicate spots or rays which
seem formed by the abrasion of the surface ; but I know of
no instance of such a character.

17- Lettered {grammicus) ; when the spots upon a surface
assume the form and appearance of letters; as some Ope-
graphas.

9. Of Veining.

In terms expressive of this quality the word nerves is ge-
nerally used, but very incorrectly.

1. Ribbed (nervosus, -fnervatus) ; having several ribs ; as Plan-
tago lanceolata, &c.

2. One-ribbed (uninervis, \uninervatus, costatus) ; when there is
only one rib ; as in most leaves.

3. Three-ribbed (trinervis) ; when there are three ribs all pro-
ceeding from the base ; as in Chironia Centaurium. Quinque-
nervis, when there are five ; as in Gentiana lutea. Septemnervis,
when there are seven ; as in Alisma Plantago ; and so on.

4-. Triple-ribbed (triplinervis) ; when of three ribs the two lateral
ones emerge from the middle one a little above its base ; as
in Melastoma multiflora. Quint uplinervis, &c. are used to
express the obvious modifications of this.

5. -flndirecte venosus ; when the lateral veins are combined with-
in the margin, and emit other little veins. Link.

6. f Evanescenti-venosus ; when the lateral veins disappear within
the margin. lb.

7. f Combinate venosus ; when the lateral veins unite before they
reach the margin, lb.

8. Straight-ribbed (f rectinervis, fparallelenervis, directe venosus,
Link); when the lateral ribs are straight; as in Alnus glu-
tinosa, Castanea vesca, &c. Mirb. When the ribs are straight
and almost parallel, but united at the summit; as in grasses.
De Cand.

9. f Curve-ribbed (f curvinervis, f converginervis) ; when the ribs
describe a curve, and meet at the point ; as in Plantago
lanceolata.

10. \Ruptinervis, when a straight-ribbed leaf has its ribs inter-
rupted at intervals. De Cand.

CLASS I. INDIVIDUAL RELATIVE TERMS. 409

1 1. \ Penniformis ; when the ribs are disposed as in a pinnated
leaf, but confluent at the point ; as in the Date. De Cand.

12. f Pahniformis ; when the ribs are arranged as in palmate
leaves ; as in the Chamaerops. lb.

13. f Penninervis ; when the ribs are pinnated (De Cand.); as
in Castanea vesca.

14-. f Pedatinervis ; when the ribs are pedate. De Cand.

15. \ Pahninervis ; when they are palmated. lb.

16. f Peltinervis ; when they are peltate. lb.

17. \Vaginervis ; when the veins are arranged without any
order ; as in Ficoideae. lb.

18. \Retinervis; when the veins are reticulated, or like
lace. lb.

19. \ Nullinervis, or enervis ; when there are no ribs or veins
whatever. lb.

20. f Falsinervis ; when the veins have no vascular tissue, but
are formed of simple, elongated, cellular tissue ; as in mosses,
Fuci, &c.

21. f Hinoideus ; when all the veins proceed from the midrib,
and are parallel and undivided ; as in Scitamineae. Link.
When they are connected by little cross veins, the term is
fvenuloso-hinoideus. lb.

22. f Venosus ; when the lateral veins are variously divided. lb.

II. Of Individual Relative Terms.

These are arranged under the heads of Estivation, or the
relation which organs bear to each other in the bud state;
Direction, or the relation which organs bear to the surface of
the earth, or to the stem of the plant which forms the axis,
either real or imaginary, round which they are disposed ; and
Insertion, or the manner in which one part is inserted into, or
adheres to, another.

1. Of Estivation.

The term estivation, or projloration, is applied to the parts
of the flower when unexpanded ; and vernation is expressive
of the foliage in the same state. The ideas of their modifi-
cations are, however, essentially the same.

1. Involute (involutiva, involuta) ; when the edges are rolled
inwards spirally on each side (Link) ; as the leaf of the apple.

410

16 17 -v^s^- 2u 21 22

2. Revolute (revolutiva, revoluta) ; when the edges are rolled
backwards spirally on each side [Link) ; as in the leaf of the
rosemary.

3. Obvolute {obvolutiva, obvoluta (Link); semi-amplexa, De
Cand. ) ; when the margins of one alternately overlap those of
that which is opposite to it.

4. Convolute (convolativa, convoluta) ; when one is wholly rolled
up in another, as in the petals of the wall-flower.

5. Supervolute (supervolutiva) ; when one edge is rolled in-
wards, and is enveloped by the opposite edge rolled in an
opposite direction ; as the leaves of the apricot.

6. Induplicate (indnplicativa) ; having the margins bent abruptly
inwards, and the external face of these edges applied to
each other without any twisting ; as in the flowers of some
species of Clematis.

7. Conduplicate (conduplicativa, conduplicata) ; when the sides
are applied parallelly to the faces of each other.

8. Plaited (plicativa, plicata); folded lengthwise, like the plaits
of a closed fan ; as the vine and many palms.

9. Replicate (replicativa) ; when the upper part is curved back
and applied to the lower ; as in the Aconite.

10. Curvative (curvatlva) ; when the margins are slightly curved,
either backwards or forwards, without any sensible twisting.
De Cand.

1 ] . Wrinkled (corrugata, corrugativa) ; when the parts are folded
up irregularly in every direction ; as the petals of the
poppy.

12. Imbricated (imbricativa, imbricata) ; when they overlap each
other parallelly at the margins without any involution. This
is the true meaning of the term. M. De Candolle applies it
in a different sense. (Theorie, ed. I. p. 399.)

CLASS I. INDIVIDUAL RELATIVE TERMS. 411

13. Equitant {equitativa, equitans, Link ; amplexa, De Cand.) .
when they overlap each other parallelly and entirely, without
any involution ; as the leaves of Iris.

14. Reclinate {reclinata) ; when they are bent down upon their
stalk.

15. Circinate (circinatus) ; when they are rolled spirally down-
wards.

16. Valvate (valvata, valvaris); applied to each other by the
margins only; as the petals of Umbelliferae, the valves of a
capsule, &c.

17. Quincunx (quincuncialis) ; when the pieces are five in num-
ber, of which two are exterior, two interior, and the fifth
covers the interior with one margin, and has its other margin
covered by the exterior ; as in Rosa.

18. Twisted (torsiva, spiraliter contorta) ; the same as contorted,
except that there is no obliquity in the form or insertion of
the pieces ; as in the petals of Oxalis.

19. Contorted {contorta) ; each piece being oblique in figure,
and overlapping its neighbour by one margin, its other mar-
gin being, in like manner, overlapped by that which stands
next it ; as Apocyneae.

20. Alternative (alternativa) ; when, the pieces being in two
rows, the inner is covered by the outer in such a way that
each of the exterior rows overlaps half of two of the inte-
rior ; as in Liliaceae.

21. Vexillary (vexillaris) ; when one piece is much larger than
the others, and is folded over them, they being arranged face
to face ; as in papilionaceous flowers.

22. Cochlear (cochlearis) ; when one piece, being larger than the
others, and hollowed like a helmet or bowl, covers all the
others ; as in Aconitum, some species of personate plants, &c.

2. Of Direction.

1. Erect {erectus, arrectus) ; pointing towards the zenith.

2. Straight {rectus) ; not wavy or curved, or deviating from a
straight direction in any way.

3. Very straight (slrictus) ; the same as the last, but in
excess.

4. Swimming {natans) ; floating under water ; as Confervae.

5. Floating (jliiitans); floating upon the surface of water ; as
the leaves of Nuphar.

412

GLOSSOLOGY.

BOOK IV.

6. Submersed {submenus, demersus) ; buried beneath water.

7. Descending (descendens) ; having a direction gradually down-
wards.

8. Hanging down (dependens) ; having a downward direction,
caused by its own weight.

9. Ascending (ascendens, assurgens) ; having a direction up-
wards, with an oblique base ; as many seeds.

10. Perpendicular (verticalis, perpendicularis) ; being at right
angles with some other body.

11. Oblique (obliquus); when the margin points to the heavens,
the apex to the horizon ; as the leaves of Protea and Fri-
tillaria.

12. Horizontal ( horizontalis) ; when the plane points to the
heavens, the apex to the horizon ; as most leaves.

13. Inverted (inversus) ; having the apex of one thing in an op-
posite direction to that of another ; as many seeds.

14. Revolute (revolulus) ; rolled backwards from the direction
ordinarily assumed by similar other bodies ; as certain ten-
drils, and the ends of some leaves.

15. Involute (i?ivolutus) ; rolled inwards.

16. Convolute (convolutus) ; rolled up.

17. Reclining (reclinatus) ; falling gradually back from the per-
pendicular ; as the branches of the banyan tree.

18. Resupinate (resupinatus) ; inverted in position by a twisting
of the stalk ; as the flowers of Orchis.

19. f Inclining (-finclinatus, declinatus) ; the same as reclining,
but in a greater degree.

20. Pendulous {pendulus); hanging downwards, in consequence
of the weakness of its support.

CLASS I.

INDIVIDUAL RELATIVE TERMS.

413

21. Drooping (cermcus) ; inclining a little from the perpendi-
cular, so that the apex is directed towards the horizon.

22. Nodding (nutans) ; inclining very much from the perpen-
dicular, so that the apex is directed downwards.

30

23. One-sided (secundus); having all the parts by twists in their
stalks turned one way ; as the flowers of Antholyza.

24. Inflexed (iriflexus, incurvus, intrqflexus, introcurvus, infrac-
tus) ; suddenly bent inwards.

25. Reflexed (reflexus, recurvus, retrqflexus, retrocurvus, re-
Jractus) ; suddenly bent backwards.

26. Deflexed (deflexus, declinaius) ; bent downwards.

27- Flexuose (Jlexuosus) ; having a gently bending direction,
alternately inwards and outwards.

28. Tortuous (tortuosus) ; having an irregular, bending, and
turning direction.

29. Knee-jointed (geniculatus) ; bent abruptly like a knee ; as
the stems of many grasses.

30. Spiral (spiralis, anjractuosus) ; resembling in direction the
spires of a corkscrew, or other twisted thing.

31. Circinate (circinatus, gyratus, circinalis) ; bent like the head
of a crosier ; as the young shoots of ferns.

32. Twining (volubilis) ; having the property of twisting round
some other body.

a. To the right hand, or dextrorsum ; when the twisting is
from left to right, or in the direction of the sun's course ;
as the hop.

b. To the left hand (sinistrorsum) ; when the twisting is from
right to left, or opposite to the sun's course ; as Con-
volvulus sepium.

414

GLOSSOLOGY.

BOOK IV.

33. Turned backwards (retrorsus) ; turned in a direction oppo-
site to that of the apex of the body to which the part turned
appertains.

34. Turned inwards (introrsus, anticus) ; turned towards the
axis to which it appertains.

35. Turned outwards (extrorsus, posticus) ; turned away from
the axis to which it appertains.

36. Procumbent (procumbens, humifusus) ; spread over the sur-
face of the ground.

37- Prostrate (prostratus, pronus) ; lying flat upon the earth, or
any other thing.

38. Decumbent (decumbens) ; reclining upon the earth, and
rising again from it at the apex.

39. Diffuse (diffusus) ; spreading widely.

40. Straggling (divaricatus) ; turning off from any thing irregu-
larly, but at almost a right angle ; as the branches of many
things.

41. Brachiate (brachiatus) ; when ramifications proceed from a
common axis nearly at regular right angles, alternately in
opposite directions.

42. Spreading (patens) ; having a gradually outward direction ;
as petals from the ovarium.

42 43

43. Converging (connivens) ; having a gradually inward direc-
tion; as many petals.

44. Opposite (adversus, -foppositus) ; pointing directly to a par-
ticular place ; as the radicle to the hilum.

45. Uncertain (vagus) ; having no particular direction.

46. Peritropal (peritropus) ; directed from the axis to the ho-
rizon. This and the four following are only applied to the
embryo of the seed.

CLASS I.

INDIVIDUAL RELATIVE TERMS.

415

47. Orthotropal {orthotropus ;) straight, and having the same
direction as the body to which it belongs.

48. Antitropal (antitropus) ; straight, and having a direction
contrary to that of the body to which it belongs.

49. Amphitropal (amphitropus) ; curved round the body to
which it belongs.

50. Homotropal (Jwmotropu's) ; having the same direction as the
body to which it belongs, but not being straight.

3. Of Insertion.
A. With respect to the mode of attachment, or of adhesion.

1 2

19 12

1. Peltate (peltatus, umbilicatus) ; fixed to the stalk by the
centre, or by some point distinctly within the margin ; as
the leaf of Tropaeolum.

2. Sessile (sessilis) ; sitting close upon the body that supports
it without any sensible stalk.

3. Decurrent (decnrrens, decursivus) ; prolonged below the point
of insertion, as if running downwards.

4. Embracing (amplectans) ; clasping with the base.

5. Stem-clasping (amplexicaulis) ; the same as the last, but ap-
plied only to stems.

6. Half-stem-clasping [semi- amplexicaulis) ; the same as the last,
but in a smaller degree.

7. Perfoliate (perfoliatus) ; when the two basal lobes of an am-
plexicaul leaf are united together, so that the stem appears
to pass through the substance of the leaf.

8. Connate (connatus) ; when the bases of two opposite leaves
are united together.

416 GLOSSOLOGY. BOOK IV.

9. Sheathing (vaginans) ; surrounding a stem or other body by
the convolute base : this chiefly occurs in the petioles of
grasses.

10. Adnate (adnatus, annexus) ; adhering to the face of a
thing.

11. Innate (innatus) ; adhering to the apex of a thing.

12. Versatile (versatilis, f oscillatorius) ; adhering slightly by the
middle, so that the two halves are nearly equally balanced,
and swing backwards and forwards.

13. Stipitate (stipitatus) ; elevated on a stalk which is neither a
petiole nor a peduncle.

14. f Palaceous (fpalaceus) ; when the foot-stalk adheres to the
margin. Willd.

15. Separate (fsolutus, liber, \distinctus) ; when there is no
cohesion between parts.

16. Accrete (accretus) ; fastened to another body, and growing
with it. De Cand.

17. Adhering {adherens) ; united laterally by the whole sur-
face with another organ. De Cand.

18. Cohering (coherens, fcoadnatus, coadunatus,-\ coalitus, -\con-
natus,conJluens) : this term is used to express, in general, the
fastening together of homogeneous parts. De Cand. Such
are M. De Candolle's definitions of these three terms ; but
in practice there is no difference between them.

19. Articulated (articulatus) ; when one body is united with
another by a manifest articulation.

B. With respect to situation.

1. Dorsal (dorsalis) ; fixed upon the back of any thing.

2. Lateral (lateralis) ; fixed near the side of any thing.

3. Marginal (marginalis) ; fixed upon the edge of any thing.

4. Basal (basilaris) ; fixed at the base of any thing.

5. Radical (radicalis) ; arising from the root.

6. Cauline (caulinus) ; arising from the stem.

7- Rameous (rameus,ramealis) ; of or belonging to the branches.

8. Axillary (axillaris, \alaris) ; arising out of the axilla.

9. Floral (Jloralis) ; of or belonging to the flower.

10. Epiphyllous (foliar is, epiphyllus) ; inserted upon the leaf.

11. Terminal (terminalis) ; proceeding from the end.

12. Of the leaf-stalk (petiolaris) ; inserted upon the petiole.

13. Crowning (coronans) ; situated on the top of any thing.
Thus, the limbs of the calyx may crown the ovarium ; a
gland at the apex of the filament may crown the stamen ;
and so on.

CLASS n.

COLLECTIVE TERMS.

417

14. Epigeous (epigcBiis) ; growing close upon the earth.

15. Subterranean (hypogceus, f subterraneus) ; growing under the
earth.

16. Amphigenous (amphigenus).

17. Epigynous (epigyniis) ; growing upon the summit of the
ovarium.

18. Hypogynous (hypogytius) ; growing from below the base
of the ovarium.

19. Perigynous (perigy?ius) ; growing upon some body that sur-
rounds the ovarium.

Class II. Of Collective Terms.

It has already been explained, that collective terms are
those which apply to plants, or their parts, considered in
masses ; by which is meant that they cannot be applied to any
one single part or thing, without a reference to a larger num-
ber being either expressed or understood. Thus, when leaves
are said to be opposite, that term is used with respect to
several, and not to one ; and when a panicle is said to be lax
or loose, it means that the flowers of a panicle are loosely
arranged ; and so on.

Of Arrangement.

E E

418 GLOSSOLOGY. BOOK IV.

1. Opposite (oppositus) ; placed on opposite sides of some other
body or thing on the same plane. Thus, when leaves are
opposite, they are on opposite sides of the stem ; when petals
are opposite, they are on opposite sides of the ovarium ; and
so on.

2. Alternate (alternus) ; placed alternately one above the other
on some common body, as leaves upon the stem.

3. Stellate (stellatus, stelliformis, stellulatus) ; the same as ver-
ticillate, No. 4., except that the parts are narrow and
acute.

4. Whorled (verticillatus) ; when several things are in opposi-
tion round a common axis, as some leaves round their stem ;
sepals, petals, and stamens round the ovarium, &c

5. Ternate (ternus) ; when three things are in opposition
round a common axis.

6. Loose \laxus) ; when the parts are distant from each other,
with an open, light kind of arrangement ; as the panicle
among the other kinds of inflorescence.

7. Scattered (sparsus) ; used in opposition to whorled, or oppo-
site, or ternate, or other such terms.

8. Compound (compositus) ; when formed of several parts
united in one common whole ; as pinnated leaves, all kinds
of inflorescence beyond that of the solitary flower.

9. Crowded (confertus) ; when the parts are pressed closely
round about each other.

10. Imbricated [imbricatus) ; when parts lie over each other in
regular order, like tiles upon the roof of a house; as the
scales upon the cup of some acorns.

11. Rosulate {rosulatus, rosularis) ; when parts which are not
opposite, nevertheless become apparently so by the con-
traction of the joints of the stem, and lie packed closely
over each other, like the petals in a double rose; as in the
offsets of houseleek.

12. Caespitose (ccespitosus) ; forming dense patches, or turfs; as
the young stems of many plants.

13. Fascicled (Jasciculattts) ; when several similar things pro-
ceed from a common point; as the leaves of the larch, for
example.

14. Distichous (distichus, bifarius) ; when things are arranged
in two rows, the one opposite to the other ; as the florets
of many grasses.

CLASS ] I.

COLLECTIVE TERMS.

4,19

15. In rows (serialis) ; arranged in rows which are not neces-
sarily opposite each other : biserialis, in two rows ; triserialis,
in three rows : but these are seldom used. In their stead,
we generally add Jariam to the end of a Latin numeral :
thus, bifariam means in two rows ; trifariam, in three rows ;
and so on.

16. One-sided (unilateralis, secundus) ; arranged on, or turned
towards, one side only ; as the flowers of Antholyza.

17. Clustered {aggregatus, coacervatus, conglomeratus) ; col-
lected in parcels, each of which has a roundish figure ; as
the flowers of Cuscuta, Adoxa, Trientalis, &c.

18. Spiral (spiralis); arranged in a spiral manner round some
common axis ; as the flowers of Spiranthes.

19. Decussate (decussatus) ; arranged in pairs that alternately
cross each other ; as the leaves of many plants.

20. Fastigiate (fastigiatus) ; when all the parts are nearly
parallel, with each pointing upwards to the sky ; as the
branches of Populus fastigiata, and many other trees.

21. Squarrose (squarrosus) ; when the parts spread out at right
angles, or thereabouts, from a common axis ; as the leaves of
some mosses, the involucra of some Compositae, &c.

22. Fasciated ( Jasciatus) ; when several contiguous parts grow
unnaturally together into one ; as the stems of some plants,
the fruits of others, &c.

23. Scaly (squamosus) ; covered with small scales, like leaves.

24. Starved (depauperatus) ; when some part is less perfectly
developed than is usual with plants of the same family. Tims,

E E 2

420 GLOSSOLOGY. BOOK IV.

when the lower scales of a head of aCyperaceous plant pro-
duce no flowers, then scales are said to be starved.

25. Distant {distans, remotus, rarus) ; in contradiction to imbri-
cated, or dense, or approximated, or any such words.

26. Interrupted (interruptus) ; when any symmetrical arrange-
ment is destroyed by local causes ; as, for example, a spike
is said to be interrupted when here and there the axis is un-
usually elongated, and not covered with flowers ; a leaf
is interruptedly pinnated when some of the pinnae are much
smaller than the others, or wholly wanting ; and so on.

27. Continuous, or uninterrupted [conti7iicus) ; the reverse of
the last.

28. Entangled [intricatus) ; when things are intermixed in such
an irregular manner that they cannot be readily disentangled;
as the hairs, roots, and branches of many plants.

29. Double, or twin (\duplicatus, geminatus) ; growing in
pairs.

30. Rosaceous (rosaceus) ; having the same arrangement as the
petals of a single rose.

31. Radiant (radiatus) ; diverging from a common centre, like
rays ; as the ligulate florets of any compound flower.

2#. Of Number.

1. None (nullus) ; absolutely wanting.

2. Numerous (numerosus) ; so many that they cannot be counted
with accuracy ; or several, but not of any definite number.

3. Solitary (solitarius, unicus) ; growing singly.

4. Many (in Greek compounds, poly) ; has the same meaning as
numerous.

5. Few (in Greek compounds, oligos) ; means that the number
is small, not indefinite. It is generally used in contrast with
many {poly) when no specific number is employed ; as in the
definition of things, the number of which is definite, but
variable.

CLASS II.

COLLECTIVE TERMS.

421

Besides the above, M. De Candolle has the following Table
of Numbers (Thdorie, 502.) : —

Derived from the

Derived from the

Latin.

Greek.

uni

mono

1.

bi

di

2.

tri

tri

3.

quadri

tetra

4.

quinque

penta

5.

sex

hexa

6.

septem

hepta

7.

octo

octo

8.

novem

ennea

9.

decern

deca

10.

undecim

endeca

11.

duodecim

dodeca

12, or from 11 to 19.

viginti

icos

20.

pauci

oligos

a small number.

pluri

-

a middling number.

multi

poly

a great number.

bini, gemini

2 together.

terni, ternati

-

3 together.

quaterni,quaternati

-

4 together.

quini, quinati

-

5 together.

seni

-

6 together.

septeni

-

7 together.

octoni

-

8 together.

noni, noveni

.

9 together.

deni, -J- denarii

-

10 together.

duodeni

-

12 together.

viceni

-

20 together.

simplici

-

solitary, or simple.

duplici

-

double.

triplici

.

triple.

quadruplici

-

quadruple.

quintuplici

-

quintuple.

sextuplici

-

sextuple.

multiplici

-

multiple.

tripli

-

f triple, only applied to
the ribs of leaves.

E E 3

422 GLOSSOLOGY. BOOK IV.

Class III. Of Terms of Qualification.

Terms of qualification are generally syllables prefixed to
words of known signification, the value of which is altered
by such addition. These syllables are often Latin prepo-
sitions.

1. Ob, prefixed to a word, indicates inversion: thus, o&ovate
means inversely ovate; oicordate, inversely cordate; oiconi-
cal, inversely conical ; and so on. Hence it is evident that this
prefix cannot be properly applied to any terms except such
as indicate that one end of a body is wider than the other ;
for if both ends are alike, there can be no apparent inversion :
therefore when the word o&lanceolate is used, as by some
French writers, it literally means nothing but lanceolate ; for
that figure, being strictly regular, cannot be altered in figure
by inversion.

2. Sub, prefixed to words, implies a slight modification, and
may be Englished by somewhat : as, subovate means some-
what ovate ; .swiviridis, somewhat green ; si<6rotundus, some-
what round ; swipurpureus, somewhat purple ; and so on.
The same effect is also given to a term by changing the ter-
mination into ascens, or escens : thus, \mdescens signifies
greenish ; rubescens, reddish ; and so on.

Signs.

In botany a variety of marks, or signs, are employed to
express particular qualities or properties of plants. The
principal writers who have invented these signs are Linnaeus,
Willdenow, De Candolle, Trattinnick, and Loudon : —

* Linn., JVilld., De Cand., Tratt., indicates that a good

description will be found at the reference to which it is

affixed.
f Linn., Willd., De Cand., Tratt., indicates that some

doubt or obscurity relates to the subject to which it is

affixed.
.' De Cand., shows that an authentic specimen has been

examined from the author to whose name or work it is

annexed.
? The note of interrogation varies in its effect according to

the place in which it is inserted. When found after a

specific name, as Papaver cambricum ? it signifies that

CLASS III. SIGNS. 423

it is uncertain whether the plant so marked is that spe-
cies, or some other of the genus ; if after the generic
name, as Papaver? cambricum, it shows an uncertainty
whether the plant so marked belongs to the genus Pa-
paver ; when found affixed to the name of an author, as
Papaver cambricum Linn., Smith, Lam. ? it signifies that,
while there is no doubt of the plant being the same as
one described under that name by Linnaeus and Smith,
it is doubtful whether it is not different from that of
Lamarck. It may be remarked, that when the interroga-
tion has a general, and not a particular application, it
should be placed at the commencement of the para-
graph ; as ?Papaver cambricum Smith, &c, not Papaver
cambricum Smith ? &c. as is the usual practice.

b Linn. Willd. A tree or shrub.

± Loudon. A deciduous tree.

1 Loudon. An evergreen tree.

b Tratt. A true tree ; as the oak.

b De Cand. An under-shrub ; as Laurustinus.

■** Loudon. A deciduous under-shrub.

a- Loudon. An evergreen under-shrub.

b De Cand.

$ Tratt.

5 DeCand.} A shrub.

5 Tratt. J

a Loudon. A deciduous shrub.

« Loudon. An evergreen shrub.

5 De Cand. A small tree.

5 De Cand. A tree more than twenty-five feet high.

T Tratt. 1 A simple-stemmed arborescent monocotyledon-

1 Loudon. J ous tree ; such as a palm.

% Linn, Willd., De Cand., Tratt. 1 A perennial.

A Loudon. J

O De Cand. Monocarpous in general.

© De Cand. I A monocarpous perennial.

O Trait. J

O Linn., Willd., Tratt.^k

© De Cand. J- Annual.

O Loudon. J

<$ Linn., Willd.

© De Cand.

J- Caulocarpous.

OO Tratt.
O Loudon.

Biennial.

E E 4-

424 GLOSSOLOGY. BOOK IV.

£! Tratt. A plant that is propagated by new tubers, which

perish as soon as they have borne a plant ; as

the potatoe.
? Tratt. A plant that is propagated by suckers ; as Poa

pratensis.
III. Tratt. A plant that is propagated by runners ; as the

strawberry.
£ Tratt. A viviparous plant; or one that increases by buds

which fall from it ; as Lilium tigrinum.
# Tratt. A stemless plant ; as Carduus acaulis.
$ Tratt. A plant whose flowers are borne upon a scape ; as

Hieracium Pilosella.
~& Tratt. A plant which bears its flowers and leaves upon

two separate stems ; as Curcuma Zedoaria. This

sort of plant is called by Trattinnick hetero-

phytous.

Hj? Tratt. 1 A Calamarious, or grassy, plant; as Bromus

juif Loudon. J mollis.

'""- De Cand. 1 A . • • , .
„, 5- A twining plant,

p Tratt. J B v

( De Cand. Which twines to the right.

) De Cand. Which twines to the left.

_£ Loudon. A deciduous twining plant.

iL Loudon. An evergreen twining plant.

1 Loudon. A deciduous climbing plant.

A_ Loudon. An evergreen climbing plant.

-* Loudon. A deciduous trailing plant.

s~ Loudon. An evergreen trailing plant.

„* Loudon. A deciduous creeping plant.

%r Loudon. An evergreen creeping plant.

^ Loudon. A deciduous herbaceous plant.

£ Loudon. An evergreen herbaceous plant,

tf Loudon. A bulbous plant.

* Loudon. A fusiform-rooted plant.
xTLoudon. A tuberous-rooted plant.

* Loudon. An aquatic plant.
£ Loudon. A parasitical plant.

A De Cand., Tratt. An evergreen plant.
00 De Cand. 1 An indefinite number.
OO Tratt. J

<? Willd., &c. The male sex.

$ Willd., &c. The female sex.

$ Willd., &c. The hermaphrodite sex.

CLASS III. ABBREVIATIONS. 425

J? Willd. The neuter sex.
c? — ? Willd. "1 Monoecious ; or the male and female on one

S2 Tratt. J plant.
C?.* ? Willd. ) Dioecious ; or the male and female in different

S Tratt. i plants.
ft | $ Willd. Hermaphrodite and female in one compound

flower.
^ | fj Willd. Hermaphrodite and neuter in one compound
flower.
$ — <$ Willd. Hermaphrodite and male on one stem.
8. — $ Willd. Hermaphrodite and female on one stem.

Abbreviations.

These are only known in the botanical works which are
written in Latin : they are of little importance, and, as will
be seen by the mark f prefixed, are scarcely ever used. The
following list is chiefly taken from Trattinnick. (Synodus,
i. 16.): —

f iEst. JEstate.

Alb. Albumen.

f Alp. Alpes, Alpinus.

Anth. Anthera, Anthodium, Antheris.

Apr. Aprilis, Apricus.

■f Arv. Arva, Arvensis.

■f At. Arena, Arenosus.

\ Art. Artificialis

\ Aug. Augustus.

-f- Augm. Augtnentum.

Aut. Aututnnus, Autumnalis.

B. Beatus or Defunctus ; used in speaking of a person
who is recently deceased, and is equivalent to our
English word " late."

Br. Bractea

Cal. Calyx.

Cald. Caldarium.

■f Camp. Campus, Campestris.

■f Carpell. Carpellum.

f Carpid. Carpidium.

f Carpol. Carpologia.

Cel. Celeberrimus.

Char. Character, Characterisiicus.

426

GLOSSOLOGY.

BOOK IV.

CI.

Clarissimus, Classis.

f Coll.

Collis, Collinus, Collectanea.

Cor.

Corolla, Corollarium.

f Cot.

Cotyledon.

Cult.

Cultus, Cultura.

Dec.

December, Decas, Decandria.

Descr.

Descriptio.

f Des.

Desideratur.

Diff.

Differentia.

f Diss.

Dissepimentum, Dissertatio.

•j- Dum.

Dumetum.

Ed.

Editio, Editor, Edidis.

f Excl.

Exclnsio.

Embr.

Embryo.

Ess.

Essentialis.

Fam.

Familia.

Feb.

Februarius.

Fil.

Filamentum.

Fl.

Flos, Flumen, Floret, Floralis.

Fol.

Folium.

Fr.

Fructus.

Fructif.

Fructificatio.

f Fun.

Funiculus umbilicalis.

Gen.

Genus, Genericus.

Germ.

Germen.

f Glar.

Glareosus.

H.

Herbarium, Habitat.

Hab.

Habitat, Habeo.

Herb.

Herbarium, Herba.

f Hexap.

Hexapodium.

Hort.

Hort us.

f Hortul.

Ho?iula?ius, Hortulanarium, Hortulus.

f Hosp.

Hospes, Hospitatur.

•f- Hum.

Humidus, Humus.

Ic.

Icon, b. bona, m. mala. p. picta. /. lignea, n.

nigra.

111.

Jllust ratio, lllustris.

Infl.

Inflorescentia.

f Ind.

Ineditus, Inedidis.

Ind.

Indicus, India, a. australis, or. orientalis, occ.
alis, Index.

Occident

Inf.

Inferus.

f Inund.

Inundatus.

CLASS III.

ABBREVIATIONS. 427

Jan.

Januarius.

Jul.

Julius.

Jun.

Junius, Junior.

f Juv.

Juvenis, Juventus.

Lat.

Latus, Latitudo, Lateralis.

f Lin.

Line a. Linearis.

Lit.

Liter a.

f Litt.

Littus, Litteralis.

Long.

Longus, Longitudo.

L. c.

Loco citato.

■f Loc.

Loculamention, Locusta.

t Maj.

Majus.

f Mar.

Mare, Marinus.

f Mat.

Matutinus, Maturus.

Mart.

Martins.

Mont.

Monies, Montanus.

Mss.

Manuscriptum.

f Mus.

Museum.

fN.

Numerus.

Nat.

Naturalis.

•f- Nem.

Nemus, Nemorosus.

No.

Numero.

Norn.

Nomen, gen. genericum, triv. triviale, s. specificum,

barb, barbarum, leg. legale, syn. synonymum.

Oct.

Octobris.

Obs.

Observatio, Observandum.

t Or.

Origo, Originarium, Oriens, Orientale.

Ord.

Ordo, Ordinarium.

Ov.

Ovarium.

P.

Pagina, Pars.

f Pal.

Paludes, Paludosus.

Ped.

Peduncidus.

Peric.

Pericardium.

Perig.

Perigonium.

Pet.

Petalum, Petiolus.

t Phyll.

Phyllum, Phyllodium.

Pist.

Pistillum.

f Pom.

Pomeridianum, Pomum.

Plac.

Placenta.

Poll.

Pollen, Pollicaris.

f Pr. v.

Primo vere.

Rad.

Radix, Radius, Radiatus.

Ram.

Ramus, Rameus, Ramosus.

428

GLOSSOLOGY.

BOOK IV,

f Rec.

Receptacidum, Recapitulatio.

S.

Seu, Sive.

Sep.

Sepalum, Sepes.

f Salt.

Sattus, Saltuarium.

Sect.

Sectio v. Divisio.

f Segm.

Segmentum.

Sept.

September, Septum.

f Ser.

Series.

Sem.

Semen, Semis.

Sice.

Siccum.

Stam.

Stamen, Stamineum

Stigm.

Stigma.

Stip.

Stipes, Stipula, Stipularis.

Sp.

Species, Specificus.

Spont.

Spontaneus.

f Spor.

Sporula.

-f- Sporang

. Sporangium.

Styl.

Stylus.

Subd.

Subdivisio.

Subv.

Subvarietas.

Sup.

Superus.

t Sylv.

Sylvestris, Sylva.

Syn.

Synonymum, Synopsis, Synodus.

T.

Tabula, Tomus.

fTep.

Tepidarium.

•f- Temp.

Tempestas, Temperatura.

Trib.

Tribus, Divisio.

-j- Triv.

Trivialis.

f Turf.

Turfosus.

V.

Volumen, Vide, Vel, Vulgo.

Var.

Varietas.

-j- Vern.

Vernalis, Vernaculum.

f Vert.

Vertex, Verticalis.

V. s. c.

Vidi siccam cultam.

V. s. s.

Vidi siccam spontaneam.

V. v. c.

Vidi vivam cultam.

V. v. s.

Vidi vivam spontaneam.

Veg.

Vegetabile, Vegetatio.

f Vir.

Viridarium, Vires, Viridis.

f Vesc.

Vesca, Vescarium.

f Vise.

Viscosus, Viscositas.

f Volv.

Volva, Volvaceus.

CLASS III. ABBREVIATIONS. 429

The following excellent Table of Abbreviations was con-
trived by the late Mr. Ferdinand Bauer, to express all the sub-
jects for which illustrations are required in botanical drawings.
It is much to be regretted that these abbreviations, which are
in every way unexceptionable, are not universally adopted for
references to plates : they would not only form a common
means of comparison between the figures of different authors,
but would also keep continually within the view of artists the
nature of the subjects they are employed to analyse. It may
be added that the Table, if considered without reference to the
abbreviations, is in itself an excellent sketch of the principal
modes, degrees, and analogies of the regular morphosis, or
developement, of fructification. When the letters used are
capitals, they indicate that the object is magnified ; when
small, that it is of the natural size ; when with a score ( — )
drawn beneath them, that it is less than the natural size : —

a. A flower before expansion.
a 1. A flower expanded.

b. The operculum of a flower ; generally formed by the con-

fluence of the calyx and corolla.

c. The perianthium ; the floral integument of monocotyle-

donous plants, and the generally simple one of dicoty-
ledones. (Corolla of Linnaeus ; calyx of Jussieu.)

c 1. External leaflets of the perianthium ; having generally
the nature of a calyx. (Calyx of Linnaeus.)

c 2. Internal leaflets of the perianthium, except c 3. and c 4.;
having usually the texture of petals. (Corolla of Lin-
naeus.)

c 3. The labellum, or its appendages. In Orchideae.

c 4. The hypogynous scales of grasses. (Nectarium of Lin-
naeus.)

c 4. Appendages of the perianthium.

d. The calyx.

e. A monopetalous corolla.
e 1. Petals.

e 2. Appendages of the corolla. (Nectarium of Linnaeus ; pa-
rapetala of Ehrhart.)

f. The discus, whether hypogynous or epigynous.

f 1. Scales or glands, whether hypogynous or epigynous.

430 GLOSSOLOGY. BOOK IV.

g. Sexual organs combined in a column ; in Orchideae and

Stylideae.

g 1. Sexual organs separate; the floral envelopes being re-
moved.

h. The stamens.

h 1. An anther.

h 2. Pollen.

h 3. Pollen masses ; in Orchideae and Asclepiadeae.

h 4. Sterile stamens.

h 5. The corona of a tube of stamens ; in Asclepiadeae. (Nec-
tarium of Linnaeus.)

i. The pistil.

i 1. The ovarium.

i 2. The stigma.

i 3. The indusium of the stigma ; in Goodenoviae and Bruno-
niaceae.

i 4. An ovulum.

1. A compound fruit ; common to several flowers.

1 1. Several distinct pericarpia ; belonging to a single flower.

m. Induviae ; the remains of the flower, which either in-
crease the fruit in size, or surmount it, or are adherent
to it.

m 1. Pappus.

m 2. The calyptra of mosses.

n. The pericarpium ; comprehending all its species, from the

simple caryopsis of grasses.

n 1. Pericarpium open.

n 2. A dissepiment.

n 3. Valves.

n 4. An operculum.

n 5. The peristomum of mosses.

n 6. The placenta. (Receptacle of the seeds of Gaertner.)

n 7. Funiculus umbilicalis.

n 8. The strophiola, or Caruncula umbilicalis.

n 9. Arillus.

o. The seed.

o 1. Wing of the seed.

o 2. Coma of the seed; in Asclepiadeae and Epilobium.

o 3. Integument of the seed.

o 4. Albumen. (Perisperm of Jussieu ; Endosperm of
Richard.)

o 5. Vitellus ; in Scitamineae and Nymphaea.

CLASS III. ABBREVIATIONS. 4-31

p. The embryo.

p 1. Cotyledon.

p 2. Plumula.

p 3. Radicle.

q. A leaf.

q 1. The petiole.

q 2. A stipula.

r. Portion of the stem or scape.

s. Inflorescence; comprehending all the species except the

two following, s 1. and 2.

si. A compound flower.

s 2. The locusta of a grass (either one-flowered or many-
flowered).

t. The involucrum of an umbel, or a head.

t 1. The involucrum of a compound flower. (Calyx communis
of Linnaeus.)

t 2. Glume of grasses. (Calyx of Linnaeus.)

t 3. Outer calyx of Malvaceae, Dipsaceae, Brunoniae.

t 4. Involucrum of ferns. (Indusium of Swartz.)

t 5. Bracteoe.

t 6. Scales of a catkin.

t 7. Paleae.

t 8. The paraphyses of mosses.

t 9. The calyptra, when formed of connate bracteae.

u. Receptacle of a single flower.

u 1. Common receptacle either of a compound flower, a catkin,
or a head.
Placed under one of the above (thus, V), shows that a
part is expanded, or opened, by force.

f Indicates a vertical section (used thus, 't4).

Indicates a transverse section (used thus, '...*).

432

BOOK V.

PHYTOGRAPHY ; OR, OF THE RULES TO BE OBSERVED
IN DESCRIBING AND NAMING PLANTS.

We now proceed to investigate the principles upon which
plants are described and named. It would be impossible for
any person to recognise a plant discovered by another, unless
such a description of it were put upon record as should express
all its essential features ; and unless it were, at the same time,
furnished with a distinctive name, it could never be subse-
quently spoken of intelligibly. For these reasons, the mode
of describing and naming plants is one of the most important
practical subjects in the science.

It may appear, at first sight, extremely easy to describe a
plant, and we constantly find travellers and others attempting
to do so in vulgar language ; but their accounts are always
so vague, that no distinct idea can be formed of the subject
of their descriptions, which remains an enigma until some
botanist, following their steps, shall happen to be able to put
its characters into scientific language.

The great object of descriptions in Natural History is to
enable any person to recognise a known species after its sta-
tion has been discovered in a classification ; and also to put
those who have not had the opportunity of examining a plant
themselves into possession of all the facts necessary to acquire
a just notion of its structure and affinities.

There are two means of effecting this object ; the one by
means of detailed descriptions, the other by the aid of briefer
abstracts of the most essential characters only.

433

CHAPTER I.

OF DIAGNOSES ; OR, OF GENERIC AND SPECIFIC CHARACTERS.

We have seen that plants are distinguished from each other
by their characters : of the application of these characters we
must now speak. Were each species to be characterised
independently of other species, and to be described with all
the minute circumstances of structure that belong to it, the
progress of investigation would be too slow, and the length
of time requisite to acquire information much too great : — for
this reason, the process of enquiry has been simplified, by
collecting in groups all those species which have certain great
characters in common, and abstracting those characters, which
then become the distinctions of classes : the species of a class
are again collected into other groups, agreeing in some other
common peculiarities which are, in like manner, abstracted,
and form the characters of orders. Thus reduced in extent,
the species of each order are submitted to the same process
of combination ; the characters by which they are combined
become distinctive of genera; and the species are, finally, left
shorn of the greatest part of their characters, which are thus
reduced within a very narrow compass. Each plant has,
therefore, four characters ; or, if sub-classes, sub-orders, or
other modes of division are adopted, as many separate cha-
racters as there may be divisions.

These characters are of two sorts ; the one called essential,
the other differential. The former are the most commonly
employed for orders and genera ; the latter are chiefly used
in discriminating species : the former are the most valuable,
and will probably, in time, supersede the others, which convey
little information, and are only useful in aiding us in our ana-
lysis of large bodies of species ; the latter are often called
definitions ; but, as no definite limits can be traced between

F F

434 PHYTOGRAPHY. BOOK V.

living things, a strict definition in natural history becomes
impracticable, for which reason the term differential must be
admitted instead.

Differential characters express, in the least possible space,
the distinctions between plants : they should contain nothing
superfluous, nor any thing which can be considered implied
by the contrasted characters of those with which they are to
be compared. By this means the distinctions of species are
brought into the least possible compass, and the analysis of
heir characters becomes so effectual, that a botanist is ex-
tpected to be able, without difficulty, to determine the exact
station and name of any one of the 100,000 species supposed
to exist. Nothing can sound better than this ; but, unfortu-
nately, the advantages of differential characters are not quite
so great as would appear. In sacrificing every thing to
brevity, it is found in practice that doubts and ambiguities
are continually created ; and for this especial reason, among
others, that differential characters must necessarily be framed
upon a consideration of what we know, and not with reference
to what we do not know : on this account, a differential cha-
racter, constructed in the most unexceptionable manner by
one botanist, may be unintelligible to another, who possesses
more knowledge, or a greater number of species. For ex-
ample, when Linnaeus framed the differential character of
Rosa indica, " germinibus ovatis pedunculisque glabris,
caule subinermi, petiolis aculeatis," it probably distinguished
that species from all others that he knew : but our acquaint-
ance with roses is so much more extensive than that of Lin-
naeus, that we have many roses to which his character is
equally applicable. A differential character, moreover, conveys
no information beyond that of the differences between one
thing and another, and can be viewed in no other light than
as a convenient method of analysis. For this reason, the
essential character is more generally adopted at the present
day, either to the exclusion of the differential character, or in
union with it.

The essential character of a plant expresses, as its name
implies, those peculiarities which are known by experience to
be most essential to it ; but admits nothing unimportant or

CHAP. I. GENERIC AND SPECIFIC CHARACTERS. l.'3.r

superfluous, or that is common to all the species of the same
genus, or to all the genera of the same order, or to all the
orders of the same class. It may be said to comprehend the
chief differences and resemblances of bodies. In drawing up
essential characters much discretion requires to be exercised :
they may be over short, or over long ; characters of import-
ance may be omitted, and others of no importance intro-
duced. Hence no better evidence need be desired of the
merit of a botanist than his essential characters, — from which
a practised eye will readily detect both how much the author
knows, and what he does not know. As models of the man-
ner in which these should be drawn up, no book can be
consulted with more advantage than the Genera Plantarum
of Jussieu, in which classical elegance of language, and as
much rigid botanical precision as was supposed necessary at
the time the work was written, are combined in a manner that
has seldom been surpassed. The defects of that work were
inseparable from the state of botany at the time it appeared ;
the characters of the genera and orders not embracing all
those points of structure which are now known to be essential.

The following character, assigned by Mr. Brown to the
order Proteace.e (Prodr. Fl. N. Holl. p. 363.), maybe taken
as a specimen of the manner in which an essential character
of the briefest kind ought to be constructed : —

" Perianthium tetraphyllum v. quadrifidum, sestivatione
valvata. Stamina quatuor (altero nunc sterili), foliolis peri-
anthii opposita. Ovarium unicum, liberum. Stylus simplex.
Stigma subindivisum. Semen (pericarpii varii) exalbumino-
sum. Embryo dicotyledoneus (quandoque polycotyledoneus),
rectus. JRadicula infera."

In this character enough is expressed to distinguish the
order from all others ; and, at the same time, by a careful
suppression of all superfluous terms, it is reduced within
exceedingly narrow limits. Such a character as this leaves
nothing to be desired, when the essence only of a mass of
characters is the object in view.

The following, from the same author, is a specimen of an
essential character of Acanthace;e, of a more extended
kind : —

F F 2

436 PHYTOGRAPHY. BOOK V.

" Calyx 5—4 — divisus, partitus v. tubulosus, aequalis v. in-
sequalis ; raro multifidus v. integer et obsoletus : persistens.
Corolla monopetala, hypogyna, staminifera, plerumque irre-
gularis ; limbo ringente v. bilabiato, raro unilabiato ; nunc
subaequalis ; decidua. Stamina saepius duo, antherifera,
modo 4 didynama, brevioribus quandoque effcetis. Antherce
v. biloculares, loculis insertione inaequalibus aequalibusve ;
v. uniloculares; longitudinaliter dehiscentes. Ovarium disco
glanduloso basi cinctum, biloculare loculis 2 polyspermis.
Stylus I. Stigma bilobum, raro indivisum. Capsula bilocularis,
loculis 2 polyspermis, abortione quandoque monospermis,
elastice bivalvis. Dissepimenttim contrarium, per axin (medio
quandoque apertam) bipartibile, segmentis valvulis adnatis
modo ab iisdem elastice dissilientibus, integris v. raro sponte
bipartibilibus ; margine interiore seminiferis. Semina proces-
subus subulatis adscendentibus dissepimenti plerumque sub-
tensa, subrotunda : Testa laxa. Albumen nullum. Embryo
curvatus v. rectus ; Cotyledones magnae, suborbiculata? :
Radicula teres, descendens, et simul centripeta, curvata v.

recta; Plumula inconspicua . Herbce v. Frutices, intra

tropicos praecipue provenientes ; pube, dum adsit, simplici,
nunc capitata, rarissime stellata. Folia opposita, raro
quaterna, exstipulata, simplicia, indivisa, integra v. serrata ;
raro sinuata v. sublobata. Injlorescentia terminalis v. axillaris,
spicata, racemosa, fasciculata, paniculata v. solitaria. Flores
in spicis saepius oppositi, nunc alterni, tribracteati, bracteis
lateralibus raro deficientibus, quandoque magnis foliaceis
calycem nanum, interdum obsoletum, includentibus."

In this instance a much greater number of particulars is
introduced than in the former ; but still it comprehends
nothing like all the characters that would be included in a
general description.

The following is also a specimen of a generic and specific
character, from the same author. It shows the plan upon
which the essential characters of genera should be con-
structed : —

" Veronica L.} Juss.
" Hebe Juss.

" Calyx 4-partitus, raro 5-partitus. Corolla subrotata ;

CHAP. I. GENERIC AND SPECIFIC CHARACTERS. 437

Tubus calyce brevior; Limbiis 4-partitus, inaequalis, lobis
indivisis. Stamina 2, antherifera, sterilia nulla. Capsida

valvis medio septiferis v. bipartibilis . Herboe v. Frutices.

Folia opposita, quandoque verticillata, v. alterna, scepe dentata
v. incisa. Inflorescentia varia* Calyces ebracteati.

" § 1. Capsida bipartibilis.

" 1. V.formosa, fruticosa, foliis perennantibus decussatis
lanceolatis integerrimis glaberrimis basi acutis, ramis bifariam
pilosiusculis, corymbis axillaribus paucifloris." (Prodi: 434.)

In these characters it is difficult to say which is most to be
admired, — the skill with which every thing superfluous is re-
trenched, or the ingenuity with which every thing essential is
introduced. Nothing that is general to the order is intro-
duced into the generic character ; and nothing that the generic
character comprehends is discoverable in the specific. By
making the peculiarity of Capsula bipartibilis the distinction
of a section, the necessity of introducing that circumstance
into the specific characters of any of the species compre-
hended in the section is avoided.

Compare with this the following generic and specific cha-
racters taken from Labillardiere's Sertum Austro-Caledoni-
cum : —

" Microsemma ; a genus of Ternstroniiaceae (?). Calyx
5-phyllus, rare 6-phyllus, persistens, foliolis tribus interiori-
bus. Coronula petaloidea, petalis 10 — 12 distinctis. Stamina
numerosa (30 circiter), hypogina, filamentis inter se basi
subconnatis, aniheris bilocularibus reniformibus. Germen
globulosum, superum, stylo simplici, stigmate 5-6-fido. Cap-
sida ovata, 10 — 12 — locularis, valvis medio septiferis, 10 — 12 —
valvis. Semina solitaria, in summo valvularum intiis affixa,
perispermo carnoso, radicula supera." (p. 58.)

Upon this character it may be observed, that the calyx is
described awkwardly, and at a greater expense of words than
is necessary : if he had said, calyx 5-6-phyllus imbricatus,
the same idea would have been expressed : rare should be raro.
In the next place, "coronula petaloidea" is a bad term, con-
veying no precise notion of the organ it is intended to de-
signate. What is a coronula ? If it is a row of petals, why

f f 3

438 PHYTOGKArilY. BOOK V.

call it otherwise ? And it appears to be so, because it is imme-
diately afterwards described as consisting of 10 — 12 distinct
petals. In the next sentence, hypogina is misspelt ; and the
anthers are said to be bilocular and reniform, a character by
no means essential; while their being covered with glandular
dots, and the mode of their attachment to the filament, both
of which should have been introduced, are omitted. Again, the
germen, meaning the ovarium, is said to be globulose : what is
globulose ? Is it bullet-shaped, or round and small ? If the
former, the term is inapplicable ; if the latter, the meaning
is not expressed : it probably was intended for " subglobose."
The capsule is said to be ovate, a quality of no consequence if
it existed ; but not true, inasmuch as it appears from the figure
to be round. The construction of what follows is what we
call in English putting the cart before the horse : instead of
" valvis medio septiferis 10 — 12 valvis," it should have been,
10 — 12 valvis, valvis medio septiferis;" and all that is said
about the attachment of the seeds might have been better
expressed by two words, " semina pendula." It is said that
they are attached to the top of the valves, in the inside : did
any one ever hear of seeds being attached to the outside ?
Let the character be properly cut down, and see what remains
of it.

MlCROSEMMA.

"Sepala 5 — 6, imbricata,persistentia. PetalalQ — 12. Stamina
numerosa, hypogyna, submonadelpha : antheris bilocularibus.
Ovarium superum ; stylus simplex ; stigmata 5 — 6. Capsula
10-3 2-locularis, valvis totidem loculicidis; semina solitaria
pendula ; albumen carnosum ; radicula supera."

But it is not in inaccuracy of language alone, or in the
misplacing the members of a sentence, that an essential
character may be defective : it may be expressed with a good
selection of terms, and a due attention to arrangement ; but the
terms may be wrongly applied, or important characters may
be omitted, or the author may not understand the structure
of what he is describing. Take, as an instance, the following
character of Carex, by the late Sir James Smith.

CHAP. J. GENERIC AND SPECIFIC CHARACTERS. 439

" Barren Jlowcrs numerous, aggregate, in one, or more,
oblong, dense catkins ; their scales imbricated every way. Calyx
a single, lanceolate, undivided, permanent scale to each floret.
Corolla none. Filaments 3, rarely fewer, capillary, erect, or
drooping, longer than the scales. Anthers vertical, long,
linear, of 2 cells.

" Fertile Jioxvers numerous, in the same, or more usually in
a different catkin, very rarely on a separate plant. Calyx as
in the barren flower. Corolla a single, hollow, compressed,
ribbed, often angular, permanent glume to each floret ; con-
tracted, mostly cloven, and often elongated at the extremity.
Germen superior, roundish ; with three, rarely but two, angles,
very smooth. Style one, terminal, cylindrical, short. Stigmas
three, more rarely two only, awl-shaped, long, tapering, downy,
deciduous. Seed the shape of the germen, with unequal
angles, loosely coated with the enlarged, either hardened or
membranous, permanent corolla, both together constituting
the fruit."

This character is carefully written, but full of inaccurate
and confused applications of terms. The term catkin should
be spike ; for a catkin is deciduous, a spike persistent: and
the inflorescence in Carex is of the latter kind. In the next
place, what is called the calyx is a bractea. What is called the
corolla of the fertile flowers is two confluent bracteae ; and,
therefore, not a single glume, but a double one. Finally,
what is called the seed is the pericarpium : in the young state
it is called the germen, which is equivalent to ovarium ; but,
by the time the ovarium is ripe, it is metamorphosed into a
seed.

Inaccuracies of this kind not only disfigure botanical writ-
ings, but very often lead the inexperienced botanist into errors
and misconceptions.

In constructing essential and differential characters, it is
customary to use the nominative case for genera and orders,
and the ablative for species ; but in English the nominative
only is employed in both cases.

f f 4

440

CHAPTER II.

OF DESCRIPTIONS.

We have now seen that the principal characters of a plant
can be comprehended in the essential and differential charac-
ters. But as these contain only such peculiarities as are
supposed to be most essential, a great number of circumstances
are omitted from them which, in the view of the botanist
drawing them up, may appear unessential, but which to
another may seem of the first importance. On this account,
a plant cannot be considered completely known until a full
description of every part shall have been obtained. In this
description every circumstance connected with the external or
internal organisation should be included, and a full state-
ment made of all the peculiarities of every part, however
obscure or difficult to observe. It is upon descriptions
of this kind that systematic botany is based : essential and
differential characters are only relative to the degree of know-
ledge of the person who prepares them : a description is in-
dependent of all relative knowledge ; it exhibits a plant as it
actually is, without reference to its resemblances or differences.
The former are adapted to the state of knowledge of a parti-
cular era ; the latter, if complete, to that of all eras.

Notwithstanding their importance, descriptions of this kind
are very rare : they occupy too much space in books to be
inserted conveniently ; they are difficult to draw up ; and it
seldom happens that an observer has the means of describing
every part of a plant : the root, or the fruit, or the flower, or
some other part, is probably not to be procured, and this
renders a description, even in the best hands, necessarily
imperfect.

In drawing up a description, care must be taken that every
term is used in its strict sense ; that all is perspicuous and free
from ambiguity ; and that the different parts are described in

CHAP. II. OF DESCRIPTIONS. 4-41

their just order, beginning with the root, and ending with the
fruit. The following is the form in which a perfect descrip-
tion would be prepared : it shows the order in which the dif-
ferent parts are spoken of, and the points of structure to
which it is desirable to advert. The student will do well to
consult it carefully : he should take common plants, the de-
scriptions of which he can find in books, and, for the sake of
exercise, describe them himself according to this form ; com-
paring them afterwards with the printed descriptions of
botanists. A number of the points which I think it necessary
to describe are usually overlooked by others, as unimportant,
or as too difficult to ascertain : these I have marked with
an asterisk ; so that those points which are commonly ad-
verted to may be distinguished from those that are usually
omitted : —

Root. Its figure, quality, substance, duration, and *ana-
tomical internal analysis.

Stem. Its figure, direction, duration, articulation, ramifica-
tion, size, surface, and * internal analysis.

Leaves. Their * vernation, * internal structure, figure,
articulation, insertion, margin, surface, venation, direction,
colour, texture, and size.

Petiole. Its form, surface, and the proportion it bears to
the leaf.

Stipulcc. Their position, texture, surface, insertion, dura-
tion, figure, and proportion to the petiole.

Inflorescence. Its nature, order of developement, ramifica-
tion, position, and proportion to the leaves.

Bractece. Their numbers, figure, station, proportion to the
adjacent parts, surface, texture, *venation.

Flowers. Their order, and time of expansion.
Calyx. Its structure, figure, station with respect to the
ovarium and the axis of inflorescence, surface, aestivation,
odour, size, proportion to the corolla, colour, and venation.

Corolla. Its structure, figure, station with respect to the
ovarium and axis of inflorescence and adjacent parts, sur-
face, aestivation, size, colour, proportion to the calyx and
stamens, and venation.

Stamens. Their number, direction, aestivation, station with

442 PHYTOGRAPHY. BOOK V.

respect to the petals, insertion, proportion to the ovarium and
corolla ; whether separate, or combined in several parcels ;
whether in one series or several, of equal or unequal length.
Filaments, their form, length, and surface. Anthers, their mode
of insertion on the filament, dehiscence with respect to the
axis, whether inwards or outwards, and, with respect to
themselves, whether transversely or longitudinally, by pores,
or otherwise ; their form ; *structure of the endothecium ;
surface, colour, size ; the proportion they bear to the size of
the filaments, the number of their valves, the nature of the
connectivum.

Pollen. Its colour, form, size, surface ; whether distinct or
cohering ; and *mode of bursting.

Disk. If present, its size, figure, texture, and station.

Ovarium. Its apparent, as well as theoretical, structure;
the position of its carpella with respect to the organs around
it; its surface; mode of division; number of ribs, if any;
veins ; cells. Ovula, their number ; insertion upon the
placenta ; position with respect to the axis of the ovarium ;
*the situation of their foramen. Styles, their number, length,
figure, surface, direction, and proportion. Stigmata, their
number, form, and surface.

Fruit. Its texture, form ; whether naked, or covered by the
remains of the floral envelopes ; whether sessile or stipitate ;
mode of dehiscence, if any; number of its valves and cells; situ-
ation of the placentae; nature of its axis; number of its seeds.

Seed. Its position with respect to the axis of the fruit,
mode of insertion, form, surface ; the texture and nature of
the testa, arillus, and other appendages, if any ; *position of
the raphe and chalaza. Albumen, its texture, if any. Embryo,
its direction, position with respect to the axis of the fruit, to
the hilum of the seed, and to the albumen ; the proportion it
bears to the mass of the latter; the form of its cotyledons and
radicle ; *its mode of germination.

The medical and economical qualities.

Its distribution on the surface of the earth.
. The points in which it agrees or disagrees with other species.

Descriptions, it must be observed, are of two kinds, collec-
tive and specific ; the former explaining minutely the characters

€HAP. II. OF DESCRIPTIONS. 4 + 3

common to several species, as in an order or a genus ; the
latter, the character of one species only. The difference be-
tween these two, and the manner of applying each of them,
will be best understood by the following examples.

The following mode of fully describing an order is taken
from M. Adolphe Brongniart's excellent memoir on Rham-
neje: —

" Calyx monophyllus 4-5-fidus, externe saepius villosus.
Tubus expansus subplanus, hemisphaericus, urceolatus, cam-
panulatus vel subcylindricus, liber, vel inferius ovario adnatus,
vel cum eo omnino cohaerens ; interius nudus, vel in pluribus,
disco carnoso aut fauci limitato, aut in laciniis effuso, tectus.
Laciniae ovatae, triangulares, rarius subulatae, acutae, interius
subcarnosae, in pluribus in medio linea carnosa prominente
notatae, et apice callosae ; in praefloratione valvatim applicatae.

"Petala cum calycis laciniis alternantia,ejusque fauci inserta,
saepius sub margine disci affixa, unguiculata, ungue plus mi-
niisve longo. Laminae rarius patentes, planae, superius integrae
vel emarginatae, in plerisque concavae, convolutae vel cucul-
latae, stamina vel eorum filamenta involventes, in pluribus
nullae. Praefloratio complicata.

" Stamina petalis opposita. Filamenta calycis fauci vel
margini disci inserta, et cum unguibus petalorum basi saepius
cohaerentia, laciniis calycis breviora. Anthcra in petalis
cucullatis reconditae, vel e petalis convolutis exsertae, parte
media vel inferiori dorsi ad apicem filamenti affixae, versatiles,
introrsae (rarissime extrorsae); vel ovatae, biloculares, loculis
parallelis, aut basi divergentibus, rima longitudinali dehiscen-
tibus; vel reniformes, uniloculares (loculis superius confluen-
tibus), rima simplici arcuata. bivalvim hiantes. Pollen siccum
ellipticum, sulco secundum longitudinem notatum ; madefac-
tum sphaericum, laeve, vel trimamillosum.

Discus forma maxime varians, in Colletid parvus, fundumque
tubi calycis occupans ; in plerisque tubum calycis strato plus
minusve crasso tegens ejusque formam accipiens (in Zizypho,
Paliuro, Ventilagine, Hove?iid, Colubrind, subplanus, penta-
gons, angulis ad insertionem staminum emarginatis ; in
Rhamno, Sageretia, Scutid, urceolatus vel cupulaaformis), et
fauci margine distincto limitatus; in aliis {Rctanilld, Cryp-

444 PHYTOGUAPHY. BOOK V.

tandrd, Phylica, a plerisque auctoribus ut disco destitutis
descriptis) super lacinias calycis etiam efFusus, ej usque super-
ficiem interibrem a fundo usque ad apicem laciniarum sub-
stantia carnosa incrustans ; an in quibusdam nullus ? (in
Pomaderri et Cryptandrce speciebus ;) margine petalis stamini-
busque insertionem praebens.

Ovarium liberum, disco plus minusve immersum, vel caly-
cis tubo semi-adhaerens, seu omnino adhasrens ; ovatum vel
subglobosum, bi-triloculare, rarissime quadriloculare (in qui-
busdam Rhamnis) ; loculis monospermis.

Ovulum in quolibet loculo solitarium erectura, e fundo
loculi natum, sessile vel podospermio brevi sufFultum. Podo-
spermium, dum adest, ante evolutionem floris angustum, nee
foramen testae tegens, ad anthesin superiiis dilatatum, et ut
cupula parva basin ovuli foramenque amplectens, celluloso-
spongiosum, vasibus raphes percursum. Testa laevis vel dorso
(in Rhamnis) sulco profundo notata, inferius prope hilum
perforata. Foramen in ovulis sessilibus mammillae albidae en-
docarpii respondens, in pedicellatis cupula spongiosa podo-
spermi tectum, nee ei adhaerens. Membrana testae e stratis
tribus formata, exterius cuticulatum tenuissimum, medium
transverse fibrosum, testam seminis producturum, interius
spongiosum, primum maximam partem ovuli occupans, dehinc
incremento nuclei evanescens, raphes vasa continens. M.cm~
brana interior albida, tenuis, primum libera, deinde testae
plus minusve adhaerens (in Pomaderri semi-adnata, in Phylicis,
Rhamnis aliisque pluribus omnino adnata), circum chalazam
superiiis affixa, inferius tubulosa, perforata, tubulo in fora-
mine testae incluso. Chalaza superiiis notata, e duplici strato
(ut in omnibus seminibus) formata; exterius vasculosum, va-
sorum raphes expansione productum, testae insertum; interius
spongiosum, in ovulo semi-evoluto fuscescens, nuclei membrana
continuum. Nucleus subcylindricus, liber, superiiis chalaza?
affixus, pendulus, inferius in mammilla brevi, foramineinclusa,
productus; interius laxe cellulosus, in medio sacculum amnii
continens, e mammilla usque ad chalazam extensum, in cujus
cavitate granula parva natant ; prope mammillam Embryo
sub forma globuli sphaerici primum visus est.

" Fructus subsphaericus, liber vel calyce adnato plus minusve
tectus; pericarpium exterius carnosum, drupaceum, spon-

CHAP. II. OF DESCRIPTIONS. 445

giosum vel siccum tenuissimum ; interius (endocarpium)
fibrosum, durum, plus minusve crassum ; aut lignosum inde-
hiscens, nucem 2— 3-locularem (seu abortu unilocularem), seu
nuculas 2 — 3 distinctas efformans; aut crustaceum dehiscens,
capsulam tricoccam producens, coccis interius et inferius rima
longitudinali dehiscentibus.

"Semen in quolibet loculo solitarium, erectum, sessile vel
podospermio brevi cupulseformi suffultum. Testa laevissima,
fusca, fibrosa, Crustacea vel membranacea (in fructibus lignosis,
ex. gr. Zizyp/iis), raphe laterali interius notata, vel raphe dor-
sali, sulco profundo exteriori inclusa superiusque testam per-
forante, praedita (in Rkamnis). C/ialaza, ut in ovulo. Nucleum
membrana propria, libera, vel testae subadhaerente, inclusum.
Endospermium carnosum, flavescens, cellulosum, lateribus
embiyonis applicatum. Embryo magnus, semini subcon-
formis, sed magis compressus, flavescens vel virescens, cotyle-
donibus planis applicatis, carnosis ; radicula brevi infera.

" Arbores, frutices vel suffrutices, ramulis inpluribus spine-
scentibus. Folia simplicia, altema, subopposita, vel rarius exacte
opposita [in Colletiis), penninervia vel triplmervia, sparsa vel
subdistic/ia, basi scepiiis bistipulala, stipulis parvis, caducis vel
spine -scent ibus et persistentibns [in Zizyphis, Paliuro). Flores
axillareS) solitarii, fascicidati, timbellati, vel cymosi> rarius
sjricati, in spicis simplicibns vel interruptis (ramulis nudis),
glomerathn dispositi {in Sageretia, Gouania, Ventilagine), in
quibusdam paniculas terminates effbrmantes (in Ceanotho, Ber-
chemia, Pomaderri), vel glomerati seu capitati (in Cryptandra,
Phylica, &c.)"

As an instance of a somewhat different mode of describing
an order, the following natural character of Amarantace^e, by
the learned Dr. Von Martius, may be studied with advantage:
it exhibits the manner in which characters are valued by the
philosophers of Germany : —

"Flores hermaphroditi, raro diclines: dioici aut abortu
polygamo-monoici, aut singuli aut nonnulli glomerati bracteati.
Perianthium hypogynum, liberum, persistens, duplex, utrumque
compagne simile, exterius (calyx) diphyllum, nunc deficiens
(evanescens) ; interius (corolla) pentaphyllum, petalis distinctis
aut raro connatis ; rarissime triphyllum. Stamina hypogyna,

446 PHYTOGRAPHY. BOOK V;

quina, aut quinario numero dupla aut multipla, raro pauciora,
ultra quinque vix fertilia, uniserialia, nunc distincta, nunc
monadelpha, in cupidam aut in tubum connata ; Jilamentis
fertilibus petalis oppositis ; anthcris medio dorso affixis, nunc
didymis bilocularibus, nunc unilocularibus, longitudinaliter
medio antice dehiscentibus, polline globoso, minuto, creber-
rimo. Pistillum unicum. Ovarium simplex, mono aut oligo-
spermum, ovulis funiculo central i libero appensis. Stylus
unicus vel nullus, ex ovario transiens s. continuus, et in utri-
culo (plerumque) persistens. Stigma simplex vel multiplex.
Pericaypium : Utriculus membranaceus, evalvis et irregulariter
dehiscens, aut circumscissus mono aut oligospermus. Semina
lentiformia, subglobosa v. elliptica, ad hilum emarginata, ver-
ticaliter appensa; testa Crustacea, membrana interna tenui.
Albumen centrale, farinaceum. Embryo periphericus, arcuatus;
cotyledonibus plano-convexis incumbentibus ; plumula incon-
spicua ; radicula umbilicum spectante.

" Herbce aut sujfrutices ramosas vel ramosissimse, caide tere-
tiusculo, rarius angulato, humiles aut difFuso-incumbentes
aliis vegetabilibus.

fi Folia opposita vel alterna, simplicia, saepe breviter petio-
lata, integra, subintegerrima uninervia, venis subparallelis com-
binatis, venulis creberrime reticulatis, exstipulata.

"Flores pedicellis brevissimis subsessiles, sicciusculi, scariosi
et quasi glumacei, glomerati, capitati vel spicati, colore vario.
Pubes frequens, septata, articulata aut ganglionea, plerumque
simplex, raro stellata.

" Evolutio.

" Cotyledones epigaeae, integerrimas, glaberrimas, subsuc-
cosae, in alternifoliis nonnunquam oblique oppositae, in op-
positifoliis basi conjugatae. Radicula subsimplex, fibrillosa
et Cauliculus crassiusculi, internodio primario saepe elongate
Folia plumules vernatione sursum complicata. Gemmatio :
Gemmis nudis. JEstivatio calycina equitans. JEstivatio
corollina interdum apice aperta (dum corolla calyce inclusa),
quincuncialis : duobus tribusve petalis exterioribus, sibi later-
aliter imbricatis et interiores subvalvulares, vel hinc imbricatas
plus minusve tegentibus.

CHAP. II. OF DESCRIPTIONS. 447

"JEstivatio staminca erecta, pistiilo ante anthesin saepe sta-
mina superante, posteaincluso. Prolepsis florum composita et
indeterminate (Link). Anthesis sursum peracta.

" Propagation

" Anther arum dehiscentia simnltanea, completa, antheris
efFoetis explanatis vel tortis et versatilibus. Stigma pollen
papillis pilisque affigens, dum divisum sensim sensimque ex-
pansum. Disscminatio aut floribus integris super pericarpium
semenqne clansis decidentibus, saepe ope lanae involventis volU
tantibus, seminibusve aut ex utriculo circumscisso libere aut
una cum utriculo delabentibus.

" Metamorphosis.

" Folia sursum magnitudine decrescentia, floralia nunc
reliquis minora, nunc omnino deficientia aut in squamas ad
divisiones florescentiae mutata, bractearum sub specie con-
tracta, sicca, scariosa atque calycis foliolis similia. Foliolorum
calycinorum fabrica et species quasi repetita in petalis vix
in orbem regularem dispositis, orbe non nisi in staminum
monadelphorum perigynia absoluto.

"Metamorphosis retrocedens s. negativa in florum glomerulis,
nonnullos flores in gemmulas spinosas coercens.

"Luxuries caules rachesque florum fasciatos vel florum
diclinorum hermaphroditismum incompletum sistens, aut
semina in corpuscula vacua caudata extenuans.

" Qualitas.

"Herbae, praesertim junioris, folia textura laxiuscula molli,
elementis mucilaginosis, saccharinis et fibrosis pollentia ideo-
que oleracea. Semina farinacea, amylo et muco pollentia.
Virtus nutriens, emolliens, demulcens, in systema lymphati-
cum praevalens. Unicae hucusque speciei cognitae, Gom-
phrence officinalis Mart., radix antidotalis, tonica, stimulans.

" Statio et Habitatio.

"Plantae et gregariac et solitariae; plures diffusae villosiores
in siccis lapidosis arenosisve apricis regionibus, alias erectse

448 PHYTOGRAPHY. BOOK V.

vel super alia vegetabilia decumbentes, pube rariore adspersae,
in sylvarum marginibus lucisque primaevis vivunt ; nonnullae
subsalsa maritimaque diligunt loca ; in depressis, haud multum
super oceanum elevatis, frequentiores ac in montanis. Ob-
viam venit haec plantarutn familia in utroque hemisphaerio ;
sub ipsa iEquatore rarius, inde si versus Polos procedas,
utrinqne frequentior, ita ut ejus vis versus Tropicas augeri
videatur. Cujusvis generis Plaga ampla, aliis Americae,
Asise, Novae Hollandiae peculiaribus, aliis paucissimis com-
munibus, paucis hucusque Europaeis et Africanis."

As an example of a full description of a species, the follow-
ing account of Cephaelis Ipecacuanha is taken from Dr. Von
Martius's Materia Medica Brasiliensium : —

" Radix perennis, simplex vel in ramos paucos divergentes
divisa, oblique terrain intrans, flexuosa, torta, 4 — 6 pollices
longa, raro longior, pennam anserinam circiter crassa, versus
basin et apicem plerumque paulo attenuata, annulata, annulis
ut plurimum ultra dimidiam radicis crassitiem latis inaequa-
libus ; passim fibras agens tenues, flexuosas, simplices vel
parum divisas in fibrillas patentes epidermide laevigata, glabra,
in planta viva dilute fusca, in sicca umbrina et tandem urn-
brino-nigricante vel griseo-fusca obductas ; cortice seu paren-
chymate, quod annulos exhibet, aequabili, primum molliusculo,
subamylaceo, albo, tandem siccescente pallide rubente vel
testaceo-roseo, resinoso-splendente, facilius a filo centrali
lignoso tereti dilute flavido secedente, idque passim in con-
spectum dante.

" Caidis suflfruticosus, 2 — 3 pedes longus, adscendens, inter-
dum declinatus inque terra latitans, passim nodosus et e nodis
radices agens reliquis similes, ut plurimum simplices, teres,
crassitie pennae anserinae vel cygneae, vel simplicissimus, vel
adultior ramos paucos sarmentoso-emittens ; epidermide cras-
siuscula laevigata vel longitudinaliter rimis aperta, in parte
subterranea fusca, in parte extraterranea inferiore foliis desti-
tuta cinereoalba glabra, in superiore viridi pubescente.

" Folia in apice caulis ramorumque 4 — 6, raro plura, oppo-
sita, subhorizontaliter patentia, petiolata, oblongo-obovata,
acuta, versus basin attenuata, margine integerrima vel obiter
subrepanda, 3 — 4 pollices longa, 1 — 2 lata, uti pars suprema

CHAP. II. OF DESCRIPTIONS. 449

caulis et ramorum pilis brevibus adpressis scabriuscula, ob-
scure viridia, subtus pallida, nervo medio venisque lateralibus
ibidem prominentibus percursa.

" Petioli semiunguiculares, semiteretes, supra paulo canali-
culati, pubescentes.

" Stipules petiolos connectentes, erectae adpressae, basi
membranaceas superne utrinque in lacinias setosas 4 — 6 fissae,
marcescentes et cum foliis deciduae.

" Pedunculi solitarii, axillares, teretes, pubescentes, floriferi
erectiusculi, fructiferi refracti, unciam et ultra longi.

"Fibres in capitulum involucratum semiglobosum collect]",
8 — 12, raro plures, in quovis involucro, singuli bracteati.

" Involucrum commune monophyllum, patens, profunde 4 — ,
rarius 5 — 6 — partitum in lacinias obovatas brevi acumine ter-
minatas ciliatas.

" Bractece (s. involiicrum partiale) pro singulo flore singulae,
ovato-oblongae, acuta?, pubescentes.

" Calyx ovario adnatus, minutus, obovatus, albidus, extus
pubescens, superne sectus in dentes 5 breves obtusiusculos
erectos.

" Corolla alba, infundibuliformis, tubo cylindrico vix sur-
sum dilatato extus et in fauce tenuissime pubescens, limbo
quam tubus duplo breviore, in lacinias 5 ovatas acutiusculas
patenti — reflexas diviso.

" Stamina 5. Filamenta filiformia, alba, glabra, in tubi parte
superiore adnata. Anther ce lineares, quam filamenta paulo
longiores, nonnihil exsertae.

" Ovarium calyce inclusum, obovatum, in vertice disco car-
noso medio umbilicato albido notatum. Stylus flliformis,
longitudine tubi corollini, albus. Stigmata 2, linearia, obtusa,
patentia.

"Bacca ovata, obtusa, magnitudine vix semen Phaseoli multi-
jlori aequans, primum purpurea, dein violaceo-atra, carnosa,
mollis, calyce parvo non ampliato coronata, bilocularis, dis-
sepimento longitudinal i carnoso, disperma.

" Nucuhe 2, hinc convexae inde planae ibidemque sulco tenui
exaratae, pallidae, testaceae, glabrae. Nucleus albus, albumine
corneo. cmbryone erecto subclavato."

A briefer and comparative mode of describing species is,

G G

450 PHYTOGRAPHY. BOOK V.

however, more frequently employed ; of which the following
of Hypericum perforatum, from Sir James Smith's English
Flora, is a good instance : —

" Root woody, somewhat creeping. Stem taller than the
last (H. quadrangulum), and much more bushy, in conse-
quence of the much greater length of its axillary leafy branches ;
its form round, with only two opposite ribs or angles, not so
acute as those of H. quadrangulum. The whole herb is more-
over of a darker green, with a more powerful scent when rub-
bed ; staining the fingers with dark purple, from the greater
quantity of coloured essential oil lodged in the herbage and even
in the petals. Leaves very numerous, smaller than the last ;
elliptical, or ovate, obtuse, various in width. Flowers bright
yellow, dotted and streaked with black or dark purple;
numerous, in dense, forked, terminal panicles. Calyx narrow.
Styles short, erect. Capside large, ovate." (English Flora,
hi. 325.)

In order to show the materials from which a plant is de-
scribed, it has become customary to add, immediately after
the indication of its native country, within a parenthesis, cer-
tain explanatory abbreviations ; such as v. s. sp. (vidi siccam
spontaneam), meaning that a wild specimen has been examin-
ed in a dried state ; or v. s. c. (vidi siccam cultam), meaning
that a cultivated specimen has been examined in a dried state ;
v. v. sp. (vidi vivam spontaneam), meaning that it has been
seen wild in a living state ; or v. v. c. (vidi vivam cultam),
meaning that it has been seen cultivated in a living state ; and
the like. These are useful things to know, because it enables
a reader to judge of the goodness of the materials from which
an author has been describing. But they are capable of
much improvement. It now appears, indeed, whether a
plant has been seen alive or dried, wild or cultivated, but we
have nothing to show what the nature of the examination has
been to which it has been subjected in either case. A plant
may have been seen alive, and not examined or analysed until
it was dried : another may have been inspected in a dried
state, without having been analysed ; or if analysed, the
analysis may have been very imperfect : no examination may
have been made of the interior of the ovarium, of the fruit, or

CHAP. II. OF DESCRIPTIONS. 451

of the seed ; all points upon which it is useful to possess in-
formation. It is, therefore, desirable that some alteration, or
rather extension, of these abbreviations, should be contrived,
something after the following manner : — v. v. et ex. Jl. ov.
Jr. 5., seen alive; examined, flower, ovarium, fruit, and seed:
if all these are named, they will all have been examined;
if part only, then the other parts will be understood not to
have been examined. The great necessity of making some
such addition as this, will, I am sure, be felt by every one
accustomed to consult botanical works. At all events, it is
indispensable that it should be stated whether a plant has
been examined sufficiently, as well as seen ; because merely to
inspect a plant in a herbarium will often enable the observer
to form but a very imperfect idea of its organisation. For
this reason I have introduced the abbreviation exam, (exam-
inavi) into some of my own works, thus : —

" Habitat in Mexico ,- Pavon. [exam. s. sp. in Herb.
Lambert.)"

Connected with this subject, is the mode of stating the
native countries of plants, and of citing the authorities upon
which the statement is made. For this purpose the two rules
of M. De Candolle are unexceptionable.

1. If you have yourself seen a specimen collected in its
native country, then the name of the collector, which is
placed immediately after that of the country, is printed in
italics : but, 2. If you have no other authority for the habit-
ation than some printed book, or manuscripts, then the name
of the author from whom you derive your information is
printed in Roman characters ; thus : —

Hab. in Mexico, Graham ; Caribaeis, Jacquin ; Florida,
Frazer ; Louisiana, Rafinesque.

Here it is seen that you have examined Mexican specimens
collected by Mr. Graham, and Florida ones from Frazer ;
but that you trust to the writings of Jacquin and Rafinesque
for its being also found in the West Indies and in Louisiana.

a a 2

452 PHYTOGRAPHY.

BOOK V.

CHAPTER III.

OF PUNCTUATION.

As the principle of composing and punctuating generic and
specific characters, and descriptions, when written in Latin,
differs from that employed in ordinary composition, a few rules
upon the subject may with propriety be introduced here.

In the characters of classes, orders, or genera, the nominative
case is employed, the ablative being only occasionally intro-
duced : each adjective is separated by a comma ; and the
different members of a sentence by a semicolon, or a period ;
as, " Perianthium deciduum. Ovarium liberum, sessile, mono-
spermum, ovulo erecto. Stylus brevissimus. Stigma sublo-
batum. Semen nucamentaceum, arillo multipartite Albumen
ruminatum, sebaceo-carnosum."

Or,-

" Perianthium deciduum. Ovarium liberum, sessile, mo-
nospermum, ovulo erecto ; stylus brevissimus ; stigma subloba-
tum. Semen nucamentaceum, arillo multipartito ; albumen
ruminatum, sebaceo-carnosum."

The latter is the better of the two, because the semicolons
show that the parts connected by them all form a portion of
the same organ; while, if the period is exclusively used, it
would appear as if the parts divided by it were all so many
distinct organs.

In specific characters, it is customary to employ the ablative
case ; not to separate the adjectives that belong to the same
noun by any point ; to use commas to divide the members of
the sentence; to employ the colon to indicate when a new
sentence forms a part of that which precedes ; and to exclude
the semicolon altogether, or to employ it to separate adjec-
tives in the nominative case, when such are introduced, as is
sometimes the case, from the ablative part of the character.
Thus we write, —

CHAP. III. OF PUNCTUATION. 453

" Stemodia balsa?nea, cauli procumbenti, ramis subhirsutis,
foliis ovatis obtusis basi in petiolum brevem angustatis glabris :
floralibus conformibus, floribus axillaribus sessilibus solitariis
vel utrinque 2 — 3 glomeratis, calycibus 5-partitis : laciniis lan-
ceolato-s ubulatis."

And not, —

" Stemodia balsamea, cauli procumbenti, ramis subhirsutis,
foliis ovatis, obtusis, basi in petiolum brevem angustatis, gla-
bris, floralibus conformibus, floribus axillaribus, sessilibus,
solitariis, vel utrinque 2 — 3 glomeratis, calycibus 5-partitis,
lanciniis lanceolato-subulatis."

If this character were punctuated in the latter manner, it
would not be certain whether or not laciniis referred to calyx,
or to any thing else ; in the former case it is distinctly in-
dicated.

If a semicolon is introduced into a specific charactei', it is
when an adjective in the nominative case immediately follows
the specific name, preceding all that part that is in the abla-
tive : thus, —

" Gesneria misera, procumbens ; foliis obovatis villosis," &c.

In detailed descriptions ', the mode of composing and punc-
tuating is much the same as in the characters of genera ;
the nominative case being chiefly used, and commas being
placed between each adjective. The members of a sentence
are divided by semicolons ; and if colons are employed, it is
in the same sense as in specific characters.

Although such are the most approved rules of punc-
tuation, yet it must be confessed they are little attended to
by many botanists ; although it cannot be doubted that they
tend very much to perspicuity and precision of language.

G G 3

454 PHYTOGRAPHY. BOOK V.

CHAPTER IV.

OF NOMENCLATURE AND TERMINOLOGY.

The following are the canons instituted by Linnaeus, with
reference to this subject. They are what guide the botanist
in his doubts ; and, although exceptionable in some points, as
will hereafter appear, are, upon the whole, well deserving of
attention and respect.

1. The names of plants are of two kinds ; those of the class
and order, which are understood ; and of the genus and species,
which are expressed. The name of the class and order never
enter into the denominations of a plant.

2. All plants agreeing in genus, are to have the same
generic name.

3. All plants differing in genus, are to have a distinct ge-
neric name.

4. Each generic name must be single.

5. Two different genera cannot be designated by the same
name.

6. It is the business of those who distinguish new genera
to name them.

7. Generic names derived from barbarous languages
ought on no account to be admitted.

8. Generic names compounded of two entire words are
improper, and ought to be excluded. Thus, Vitis Idaea must
give way to Vaccinium, and Crista Galli to Rhinanthus.

9. Generic names formed of two Latin words, are scarcely
tolerable : some of them have been admitted, such as Cornu-
copice, Rosmarinus, Sempervivum, &c, but this example is not
to be imitated.

10. Generic names, formed half of Latin and half of Greek,
are hybrid, and on no account to be admitted : such are
Cardamindum, ChrysanthemzWww, &c.

CHAP. IV. OF NOMENCLATURE AND TERMINOLOGY. 455

J 1 . Generic names compounded of the entire generic name
of one plant, and a portion of that of another, are un-
worthy of botany ; such as Cannacorus, lAYio?iarcissusi Lauro-
cerasus.

12. A generic name, to which is prefixed one or more
syllables, so as to alter its signification, and render it appli-
cable to other plants, is not admissible. 2fo/6ocastanum,
Ci/nocrambe, Chaincener'mm, &c, are of this kind.

13. Generic names ending in oides are to be rejected; as,
Agrimono/cfes, Asteroides, Sec.

14. Generic names formed of other generic names, with
the addition of some final syllable, are disagreeable, as Aceto-
sella, Balsam //a, Rapistriim, &c.

15. Generic names sounding alike, lead to confusion.

16. No generic names can be admitted, except such as are
derived from either the Greek or Latin languages.

17. Generic names appertaining previously to Zoology, or
other sciences, are to be cancelled, if subsequently applied in
botany.

18. Generic names at variance with the characters of any
of the species ai-e bad.

19. Generic names the same as those of the class or order
cannot be tolerated.

20. Adjective generic names are not so good as substantive
ones, but may be admitted.

21. Generic names ought not to be misapplied, to gaining
the goodwill or favour of saints, or persons celebrated in other
sciences ; they are the only reward that the botanist can ex-
pect, and are intended for him alone.

22. Nevertheless, ancient poetical names of deities, or of
great promoters of the science, are worthy of being retained.

23. Generic names that express the essential chai-acter or
habit of a plant are the best of all.

24. The ancient names of the classics are to be respected.

25. We have no right to alter an ancient generic name to
one more modern, even although it may be for the better :
this would, in the first place, be an endless labour ; and, in
the next place, would tend to inextricable confusion.

26. If new generic names are wanted, it must be first

g o 4

4>56 PHYTOGRAPHY. BOOK V.

ascertained whether no one among the existing synonyms is
applicable.

27. If an old genus is divided into several new ones, the
old name will remain with the species that is best known.

28. The termination and euphony of generic names are to
be consulted, as far as practicable.

29. Long, awkward, disagreeable names are to be avoided,
such as Calophyllodendron of Vaillant, Coriotragemato-
dendros of Plukenet, and the like.

30. The names of classes and orders are subject to the same
rules as those of genera. They ought always to express some
essential and characteristic marks.

31. The names of both classes and orders must always
consist of a single word, and not of sentences.

I have thought it right to give these Linnaean canons,
firstly, because they are undoubtedly excellent in many re-
spects ; secondly, because we must attribute much of the
greater perfection of natural history, since the time of Lin-
naeus, to the adoption of them ; and, thirdly, because they are
constantly appealed to, by the school of Linnaeus, as a standard
of language, from which no departure whatever is allowable.

It is, however, necessary to remark, that, notwithstanding
the undoubted excellence of many of these rules, yet there
are others, adherence to which is often out of the question,
and which have, indeed, fallen wholly into disuse. It seems
to be an admitted principle, that it is of little real importance
what name an object bears, provided it serves to distinguish
that object from every thing else. This is the material point,
to which all other considerations are secondary : thus, if A. or
B. are universally known by the names of Thomas or John,
it is quite as well as if they were called William or James.
This being so, it will follow that Nos. 7, 9, 11, 12, 14, and
16, of the Linnaean canons, are either frivolous or unimportant ;
or, at least, that no person is bound, either in reason or by
custom, to observe them. This is particularly apparent in
considering the practice now universally adopted, although
condemned by Linnaeus, of converting the names by which
plants are known in countries called barbarous, into scientific

CHAP. IV. OF NOMENCLATURE AND TERMINOLOGY. 457

generic names, by adding a Latin termination to them. The
advantage of this practice to travellers is known to be very
great, as it puts them in possession of a certain part of the
language of the country in which the plants are found. Such
names are often not less euphonous than those admitted by
the Linnsean school as unexceptionable : witness, Licaria and
Eperua, rejected Caribean generic names ; and Glossarrhena,
Guldenstadtia, Schlechtendahlia ; and similar admitted Lin-
naean names. Indeed, so impossible is it to construct generic
names that will express the peculiarities of the species they
represent, that I quite agree with those who think a good,
well-sounding, unmeaning name by far the best that can be
contrived. The great rule to follow is this : —

In constructing a generic name, take care that it is har-
monious, and as unlike all other generic names as it can be.
In adopting generic names, always take the most ancient,
whether better or worse than those that have succeeded it.
Attend as much as you will to the canons of Linnaeus in
forming a name of your own; but never allow them to induce
you to commit the incivility of rejecting the names of other
persons, because they do not think fit to acknowledge arbi-
trary rules which you are disposed to obey ; and let the con-
duct of Schreber, a German botanist, who has been held up
to universal scorn for haying presumed, without authority or
any sort of pretension to a knowledge of the plants of Aublet,
to alter the whole nomenclature of that author, to the great
confusion of science, be a warning to you, never to be induced
to sanction any similar deviation from the rules of courtesy
in science.

When species are named after individuals, the rule of con-
struction is this: if the individual is the discoverer of the
plant, or the describer of it, the specific name is then to be in
the genitive singular ; as Caprifolium Douglasii, Carex Men-
ziesii; Messrs. Douglas and Menzies having been the dis
coverers of these species; and Planera Richardi, the species
so called having been described by Richard : but if the name
is merely given in compliment, without reference to either of
these circumstances, the name should be rendered in an
adjective form, with the termination anus, a, um ; as Pinus

458 PHYTOGRAPHY. BOOK V.

Lambertiana, in compliment to Mr. Lambert : and, for this
reason, such names as Rosa Banksiae and R. Brunonii are
wrong; they should have been R. Banksiana and R. Bru-
noniana.

It is customary to name an order from the genus that most
accurately represents its characters, adding the termination
aceee to such names as end in a or as, or even us. Rosaceae
from Rosa, Spondiaceae from Spondias, Connaraceae from
Connarus; or by converting the terminations us or urn into ecB ;
as Rhamneae from Rhamnus, Menispermeae from Menisper-
mum. But this is not very strictly adhered to ; many well-
known old names, not constructed upon this principle, being
still retained ; such as Salicariae, Leguminosae, Caryophylleae,
Gramineae, Palmae, &c.

There is no rule for the construction of the names of the
higher divisions in Botany.

In terminology, every name should have a distinct, positive
meaning, which cannot be misunderstood ; all terms that have
two meanings being bad. For instance, the term nectarium,
which is sometimes applied to glands secreting honey ; some-
times to modifications of the petals or stamens ; and even to
the disk itself, is, in such an extended signification, un-
intelligible. Again, the term corolla, unless limited to the
inner series of the floral envelopes, may be often applied to
the calyx, and then ceases to have any precise signification.
Capsule has been applied by various authors to a polyspermous
dehiscent compound fruit, or to an indehiscent polyspermous
fruit, or to an indehiscent monospermous fruit : so applied it
has no distinct meaning. For this reason modern botanists
have contrived a large number of new terms, which have con-
tributed much to the perspicuity of botanical writings. But
if this has been, in many cases, done advantageously, it has
unfortunately happened that in others additional terms have
been created uselessly, to the great confusion of the science.
Thus, the old word albumen is perfectly well understood as
the matter lying between the embryo and the seed coats when
the seed is mature ; nevertheless, we have the terms perisperm
and endosperm contrived for the same part : testa is synony-
mous with episperm ; putamen with endocarpium : for funiculus

CHAP. IV. OF NOMENCLATURE AND TERMINOLOGY. 459

umbilicalis we have trophosperm and podosperm ; and, un-
fortunately, numerous other instances might be adduced.
The rule to be observed in terminology is evidently this ; that
as no word ought to have two applications or meanings, so no
idea should be expressed by more than one term ; and if a
term, expressive of a distinct point of structure, already exists,
no new term should, on any account, be created, from the
fancy that it may be better, or more expressive, than the old
one. To do so, is not only unwise, but absolutely mis-
chievous.

460 PHYTOGRAPHY. BOOK V.

CHAPTER V.

OF SYNONYMS.

The synonyms of plants are the names applied to particular
species by different authors. Names are often unlike each
other ; in which case synonyms become indispensable to a
right knowledge of a plant; but when one name only has
been given by common consent, synonyms, in that case, are
of less importance. The objects that they serve are these :
they indicate —

1. The names of the authors who have described the spe-
cies, and the place in their writings in which the descrip-
tion is to be found.

2. The chronology of the species, pointing out the period
at which it was first made known to the world.

3. The works in which figures are to be found.

4. The various names under which it has, from time to
time, been known.

Synonyms, therefore, if complete, present a brief but very
instructive history of a plant. In monographs, or complete
accounts of particular groups of plants, no synonyms of any
importance whatever ought to be omitted: in more concise
works, one or two of the principal are sufficient. The im-
portance of a synonym depends upon its being that of some
author who has written, in an original manner, upon a given
plant. In proportion as originality decreases, the value of
synonyms decreases also.

In arranging synonyms, a strict chronological order should
be maintained, beginning with the most ancient name, and
ending with the most recent. But, although the citation of
the names must be strictly chronological, it does not therefore
follow that the quotation of the works in which the names
occur should be chronological also : this would lead to great

CHAP. V. OF SYNONYMS. 461

confusion and inconvenience. It has been found practically
better to arrange the names chronologically ; and to arrange
under each name, in chronological order, those authors who
have spoken of the plant by each name.

This will be more apparent from the following example,
from the Systema Nahtrale of De Candolle, in which the dates
of the authors' works are introduced to demonstrate the chro-
nological order of their quotations. In practice the dates are
usually omitted : it would be, perhaps, an improvement if
they were always added.

TROLLIUS ASIATICUS.

Helleborus aconiti folio flore globoso croceo. Amm. ruth.

p. 76. n. 101. (1739.)
Trollius asiaticus. Lin.! sp. pi. 782 (exclas. Buxb. et Tourn.

syn.) (1763.) — Mill. diet. n. 2. (1768.) — Gmel. Jl. sib. 4.

p. 190. n. 23. (1769.) — Pall. itin. 2. p. 528. (1793.) — *Curt.

Bot. Mag. t. 235. (1793). — Willd. sp. 2. p. 1334. (1799.) —

Poir.l diet. 8. p. 122. (1808.)
T. europaeus Sobol.Jl. petr. p. 134. n. 376? (1799.)
T. sertiflorus Salisb. in Lin. soc. 8. p. 303. (1807.)

In order to show distinctly the different value of these
synonyms, M. De Candolle marks with an asterisk (*) those in
which good original descriptions are to be found ; and to
explain which have been ascertained by the actual inspection
of authentic specimens, he marks such names with a note of
admiration immediately succeeding the name of an author:
thus, Lin. ! sp. pi. 427. would mean that the original speci-
men from which the plant was described by Linnaeus in the
Species Plantarwn, page 427., had been actually examined by
himself; whereas, if the note of admiration had been omitted,
it would have appeared that the only evidence, with respect
to the plant described by Linnaeus, was obtained from the
book itself. This distinction is of great importance, as it
shows upon which synonyms implicit reliance can be placed,
and to which we can turn with less confidence.

In proportion to the importance of synonyms ought to be the
care with which they are quoted. No synonyms ought to be
■adopted by a writer upon the credit of others ; he should always

462 PHYTOGRAPHY. BOOK V.

judge for himself; or, if that should not be in his power, he
should take care to show which have been ascertained by him-
self, and for which he trusts to others. It is especially import-
ant never to suppose that plants are the same whose names are
the same. Upon this point it particularly behoves the botanist
to be vigilant ; for nothing is more common than for writers
to mistake the plants intended by each other. Thus, R. pim-
pinellifolia of Linnaeus, is R. spinosissima ; R. pimpinellifolia
of Pallas is a distinct variety, if not species, called altaica by
Willdenow ; R. pimpinellifolia of Villars is Rosa alpina ;
R. pimpinellifolia of Bieberstein is probably R. grandiflora.
Care must also be taken not to suppose that the plants with
different names are different species. It frequently happens
that a known species, already described by one botanist, is
described as new by another : this arises from a variety of
causes ; the original description is imperfect, or inaccurate, so
that the species to which it refers cannot be recognised ; or a
species may have been described by one botanist, in a work
unknown to another, who has therefore described it anew.
This is an evil, for which there is no other remedy than vigil-
ance on the part of those who take the lead in science;
and who, from time to time, apply themselves to purify it
from the errors that are daily accumulating. So difficult,
however, is it to detect repetitions, that even in the publica-
tions of the most distinguished and skilful writers they occur
in numberless instances : for instance, the Unonas uncinata,
hamata, and esculenta of Dunal and De Candolle are iden-
tically the same.

463

CHAPTER VI.

OF HERBARIA.

To a botanist who studies the science with much attention,
and with a view to becoming perfectly acquainted with it,
neither books nor the most elaborate descriptions prove suf-
ficient. He finds it indispensable to have continually within
his reach some portion of as many species as he can procure.
If he has access to a botanical garden, a great many species
may thus be readily accessible ; although, even in such a case,
it is only at particular periods that he can study the flowers
and fruit of any of them : a garden, too, seldom contains more
than a fifteenth or a tenth of the number of known species ;
and far more frequently not a twentieth.

For these reasons, botanists have contrived a method of
preserving, by drying and pressure, specimens of plants which
represent all that it is most essential to recognise. A collection
of such specimens was formerly known by the expressive name
of Hortus Siccus ; but is now universally called an Herbarium.
If well prepared and arranged, such a collection is invaluable
to any working botanist, because it enables him instantly, at
all times, to compare plants themselves with each other, and
with the accounts of other botanists ; or to examine them with
reference to points of structure not previously considered. It
will, therefore, be useful to explain, shortly, the best modes of
preparing, arranging, and preserving herbaria.

What is called the specimen of a plant, is a small shoot
bearing flowers and fruit, either together or separately, pressed
flat and dried, so that it may be conveniently fixed upon a
sheet of paper. As a plant is, in all cases, an aggregation of
individuals growing upon exactly the same plan, and pro-
ducing the same kind of reproductive organs, it follows that
a single shoot, comprehending leaves, flowers, and fruit, is a
representation of the largest tree of the forest, and will give as

464- PHYTOGRAPHY. BOOK V.

distinct an idea of the individual as if a huge limb were before
the botanist. It is this fact that enables us to form herbaria.
Besides the dried twigs thus described, an herbarium should
contain specimens of the wood of each species, and also a
collection of fruits and seeds, which, being often large, hard,
and incapable of compression, are not fit to be incorporated
with the dried specimens themselves.

In selecting specimens for drying, care must be taken that
they exhibit the usual character of the species ; no imperfect
or monstrous shoot should be made use of. If the leaves of
different parts of the species vary, as is often the case in
herbaceous plants, examples of both should be preserved.
The twig should not be more woody than is unavoidable,
because of its not lying compactly in the herbarium. If the
flowers grow from a very large, woody part of the trunk, as
is often the case, as in some Malpighias, Cynometra, &c,
then they should be preserved with a piece of the bark only
adhering to them. It is also very important that ripe fruit
should accompany the specimen. When the fruit is small, or
thin, or capable of compression without injury, a second dried
specimen may be added to that exhibiting the flowers; but
when it is large and woody, it must be preserved separately,
in a manner I shall presently describe.

Next to a judicious selection of specimens, it is important
to dry them in the best manner. For this purpose various
methods have been proposed : some of the simplest and most
practicable may be mentioned. If you are in a country where
there is a great deal of sun-heat, it is an excellent plan to
place your specimen between the leaves of a sheet of paper,
and simply to pour as much sand or dried earth over it as
will press every part flat, and then to leave it in the full sun-
shine. A few hours are often sufficient to dry a specimen
thoroughly in this manner. But in travelling, when con-
veniences of this kind cannot be had, and in wild uninhabited
regions, it is better to have two or more pasteboards of the
size of the paper in which your specimens are dried, and some
stout cord or leathern straps. Having gathered specimens
until you are apprehensive of their shrivelling, fill each sheet
of paper with as many as it will contain ; and having thus

CHAP. Vr. OF HERBARIA. 465

formed a good stout bundle, place it between the pasteboards,
and compress it with your cord or straps. In the evening, or
at the first convenient opportunity, unstrap the package, take
a fresh sheet of paper, and make it very dry and hot before a
fire; into the sheet, so heated, transfer the specimens in the
first sheet of paper in your package ; then dry that sheet, and
shift into it the specimens lying in the second sheet; and so
go on, till all your specimens are shifted; then strap up the
package anew, and repeat the operation at every convenient
opportunity, till the plants are dry. They should then be
transferred to fresh paper, tied up rather loosely, and laid by.
Should the botanist be stationary, or in any civilised country,
he may dry his paper in the sun ; or, if the number of speci-
mens he has to prepare is inconsiderable, he may simply put
them between cushions in a press resembling a napkin-press,
laying it in the sun, or before a hot fire. It is extremely im-
portant that specimens should be dried quickly, otherwise
they are apt to become mouldy and rotten, or black, and to
fall in pieces. Notwithstanding all the precautions that can
be taken, some plants, such as Orchideaa, will fall in pieces in
drying: when this is the case, the fragments are to be care-
fully preserved, in order that they may be put together when
the specimen is finally glued down. In many cases, particu-
larly those of Coniferee, Ericae, &c, the leaves may be pre-
vented falling off by plunging the specimen, when newly
gathered, for a minute into boiling water. The great object
in drying a specimen is to preserve its colour, if possible,
which is not often the case, and not to press it so flat as to
crush any of the parts, because that renders it impossible
subsequently to analyse them.

Specimens of wood should be truncheons, five or six inches
long, and three or four inches in diameter, if the plant grows
so much. They should be planed smooth at each extremity,
but neither varnished nor polished.

Specimens of fruits simply require to be dried in the sun.

When specimens shall have been thoroughly dried, they
should be fastened, by strong glue, not gum, nor paste, to
half sheets of good stout white paper : the place where they
were found, or person from whom they were obtained, should

II H

466 PHYTOGRAPHY. BOOK V.

be written at the foot of each specimen, and the name at the
lowest right-hand corner. If any of the flowers, or fruits, or
seeds, are loose, they should be put into small paper cases,
which may be glued, in some convenient place, to the paper.
These cases are extremely useful; and fragments so pre-
served, being well adapted for subsequent analysis, will often
prevent the specimen itself from being pulled in pieces.

The best size for the paper appears, by experience, to be
lOf inches by 161. Linnaeus used a size resembling our
foolscap ; but it is much too small : and a few employ
paper 11| inches by 18^; but that is larger than is neces-
sary, and much too expensive.

In analysing dried specimens, the flowers or fruits should
always be softened in boiling water : this renders all the parts
pliable, and often restores them to their original position.

In arranging specimens when thus prepared, every species
of the same genus should be put into a wrapper formed of a
whole sheet of paper, and marked at the lower left corner
with the name of the genus. The genera should then be put
together according to their natural orders.

In lai'ge collections it is often found difficult to preserve
that exact order which is indispensable to the utility of an
herbarium; and, accordingly, we constantly find botanists
embarrassed by multitudes of unarranged specimens. As this
is a great evil, I trust that a few hints upon the subject may
not be without their use ; especially as, by attending to them
myself, I have probably not 500 unarranged specimens in a
collection of between 20,000 and 30,000species. — Never suffer
collections, however small, to accumulate ; but the very day,
if possible, that a parcel of dried plants arrives, put each in
its place. For this purpose they should not be glued down ;
but each species, with a ticket explaining its origin, name,
&c, should be laid loose upon a half sheet of waste paper,
and then put into the cover of the genus to which it be-
longs : if the genus is not recognised, and there is no time for
determining it, then take a cover, marked with the name of
the order at its lower left-hand corner, and put them in it;
or, if the order is not known, then put the specimens into
covers marked with the names of countries instead of orders,

CHAP. VI. OF HERBARIA. 467

after which you can examine them, from time to time, as oppor-
tunities may occur : in the herbarium above named there is
about 300 species thus laid by for consideration. Afterwards,
when leisure permits, those generic covers in which there
appears to be the greatest accumulation of loose specimens
should be examined, the species compared and sorted, new
species glued upon fresh half sheets of paper, and duplicates
taken out. The advantage of this plan is, that, under any cir-
cumstances, if it is wished to consult a particular order, all
the materials you possess will be found, in some state or other,
collected into one place. I am persuaded, that if this simple
method were attended to, the confusion now so common in
herbaria, and which renders so many of them almost useless,
would never exist.

Fruits, if large, will be placed loose on shelves, in cases
with glass fronts; or, if smaller, in little bottles, in which
also seeds should be preserved; each fruit or bottle being
labelled, and the whole arranged according to natural order.
Specimens of wood may be conveniently combined with a car-
pological collection, and arranged on the same plan. When
the sections of wood are very large, as is sometimes the case,
it may be convenient to have an extra compartment at the
base of the case, in which they can be placed.

The cases in which the specimens are arranged may be
made of any well seasoned timber; mahogany is best; but
pine wood will answer the purpose. They should consist of
little closets, of a size convenient for moving from place to
place ; of which, two, placed one on the other, will form a
tier. Each closet should have folding doors, and its shelves
should be in two rows : the distance from shelf to shelf
should be six inches. The sides and ends of the closets
should be made of f in. board; but for the shelves -| in. is
sufficient.

To preserve plants against the depredations of insects, by
which, especially the little Anobium castaneum, they are apt
to be much infested, it has been recommended to wash each
specimen with a solution of corrosive sublimate in campho-
rated spirits of wine ; but, independently of this being a doubt-
ful mode of preservation, it is expensive, and, in large collec-

H H 2

468 PHYTOGRAPHY. BOOK V.

tions, excessively troublesome. I have found that suspending
little open paper bags, filled with camphor, in tfie inside of the
doors of my cabinets, a far more simple and a most effectual
protection. It is true that camphor will not drive away the
larvae that may be carried into the herbarium in fresh speci-
mens; but the moment they become perfect insects they quit
the cases, without leaving any eggs behind them.

In all large collections of specimens there must necessarily
be a constant accumulation of duplicates ; as they are of no
utility to the possessor, he will, if he is a liberal man, and
wish well to science, distribute them among his friends, or
other men of science, in order that the means of observation
and examination, upon which the progress of science depends,
may be multiplied at the greatest possible number of points.
He will not hoard them up till insects, dust, and decay
destroy them ; he will not plead want of leisure (meaning
want of inclination) for looking them out, or, when applied to
for them, invent some frivolous excuse for avoiding compli-
ance with the request ; on the contrary, he will be anxious to
disembarrass himself of that which is superfluous, and it will
be his greatest pleasure to find himself able to supply others
with the same means of study as himself. Conduct with
regard to the disposal of duplicate specimens is a sure
sign of the real nature of a man's mind. We may be per-
fectly certain, for all experience proves it, that to be liberal
in the distribution of duplicates, is a sign of a liberal, gener-
ous disposition, and of a man who studies science for its own
sake; while, on the other hand, a contrary line of conduct is
an equally certain indication of a contracted spirit, and of a
man who studies science less for the sake of advancing it, than
in the hope of being able to gain some little additional repu-
tation by which his own fame may be extended. A private
individual has, no doubt, a right to do as he likes with that
which is his own, just as a miser has a right to hoard his
money, if such is his taste ; but, of the keepers of public
collections, it is the bounden duty to take care that every
thinf in their charge be rendered, in every possible manner,
available for the advancement of science. For acting to the
contrary they are publicly answerable.

469

CHAPTER VII.

OF BOTANICAL DRAWINGS.

Another important method of indicating and preserving the
characters of plants is by means of botanical drawings ; which,
if carefully executed, and accompanied by magnified analyses
of the parts that are not visible upon external inspection, are
the very best means of expressing the peculiarities of a spe-
cies. But to render drawings really useful, there are many
circumstances to be attended to.

In the first botanical works that were illustrated by figures,
the drawings were rude, and ill calculated to convey any clear
idea of the object they were intended to represent ; but as a
knowledge of the science advanced, great improvement took
place in their execution, minute accuracy was introduced into
the outline of the leaves, the form and position of the flowers
were carefully expressed ; and if the parts of fructification
were neglected, it was because their importance was not un-
derstood. By degrees, the analysis of those parts began to be
attended to ; attempts were made, with various success, to
represent the minute points in the organs of fructification.
At last, the subject of carpology was taken up by the cele-
brated Gsertner, who published two quarto volumes, in which
numerous plates represented, often in a magnified state, the
internal structure of fruits, and especially of their seeds. From
the appearance of this work, I think, it is that decided im-
provements in the drawings of the analysis of flowers may be
dated. Since that period botanical drawings have been gra-
dually improving, till, at last, many have been executed which
seem to leave nothing to be desired.

A botanical drawing should represent a branch of the plant
in flower, and also in fruit, of the natural size, in which all the
characters of the leaves and ramifications, the direction and
relative position of parts, the mode of expansion, the arrano-e-

h h 3

470 PHYTOGRAPHY. BOOK V.

ment of the flowers, and, in short, all that can be seen by the
naked eye should be accurately expressed. It should also
contain analyses of all the parts of fructification, magnified so
much that every character may be distinctly seen ; and this
analysis, to be complete, should express the state of the organs
of fructification, not only at the period of the expansion of
the flowers, but in the bud state, and when arrived at perfect
maturity. If to this the germination, and vernation, and
highly magnified anatomical representations of the tissue and
internal structure of the stem and leaves be added, the draw-
ing may be considered complete.

But as the expense of preparing and publishing such
drawings would be enormous, botanists usually content them-
selves with a representation of those parts only that are sup-
posed to be most essential ; such as the structure of the flower
when expanded, and of the fruit and seed when ripe ; and
this is found, for systematic purposes, sufficiently complete,
provided such details as are introduced are perfectly clear and
correct.

In order to enable the student, who is interested in this sub-
ject, to form a more distinct notion of the relative utility of
botanical drawings, a reference to some of the most perfect
that have yet been executed is subjoined.

As instances of the highest perfection of which botanical
drawings are at present susceptible, the volume of illustra-
tions of the structure of wheat, by Mr. Francis Bauer,
preserved in the British Museum; the analysis of RafHesia,
published in the 12th volume of the Linnaean Transactions,
and the microscopic drawings of the fructification of Orchi-
deous plants, now in course of publication, both also by the
same distinguished artist, may be justly said to be entitled to
the highest place. Next to these come the drawings of New
Holland plants in the Appendix to Captain Flinders's voyage
to that country ; and the three fascicles of figures of New
Holland plants, by Mr. Ferdinand Bauer. A very high sta-
tion is also claimed by Dr. Hooker's figures of British Jun-
germanniae, in which great skill as an artist is combined with
deep and accurate microscopic research. In all these works
the details of analysis are carried to a great extent.

CHAP. VII. OF BOTANICAL DRAWINGS. 471

Among works in which fewer details are introduced, espe-
cial mention must be made of the drawings of Palms, and
the fijmres that illustrate Dr. Von Martius's Nova Genera et
Species Plantarum ; Mr. Turpin's plates in Humboldt and
Kunth'sNova Genera Plantarum, and Delessert's Icones Plan-
tarum ; and some excellent analyses of the parts of fructifica-
tion of Rhamneae and Bruniaceae, in his memoirs upon those
orders, by M. Adolphe Brongniart.

Almost every scientific work of reputation of the present
day contains figures which are formed upon the models of those
now enumerated ; from which they differ in the quantity of
analysis that is introduced, a circumstance generally regulated
by theprice at which they are published.

Of anatomical plates, the best are those of Kieser, in his
Memoire sur l'Organisation des Plantes; of M. Mirbel, in
his Memoire sur l'Ovule ; of M. Francis Bauer, in his dissec-
tions of Orchideous plants ; and of Mr. Adolphe Brongniart,
in his various papers in the volumes of the Annales des
Sciences.

I have mentioned these as instances of good drawings,
because they are easily accessible, and incontestably are well
adapted to improving the taste and execution of a student;
but there are very many other modern works, in which the
figures maybe also studied with great advantage. Whatever
bears the name of Francis or Ferdinand Bauer, Hooker,
Greville, Mirbel, Poiteau fils, Redoute, Reichenbach, L. C.
Richard, Sovverby, Sturm, or Turpin, may almost always be
profitably studied.

H H 4

472

BOOK VI.

GEOGRAPHY.

Under this head is to be considered the manner in which
plants are affected by climate or station, and the conditions
under which particular forms of vegetation are confined to
certain zones of temperature ; as the palms to the tropics, the
true pines to extra-tropical regions.

This is one of the most curious and difficult subjects with
which we can occupy ourselves. It embraces a consideration
of the constitution of the atmosphere, and geological structure
of all parts of the globe ; and of the specific effects of par-
ticular conditions of climate and soil upon vegetation : all
points upon which we can scarcely be said to know any thing.
It involves the discussion of the plan upon which the world
was originally clothed with verdure; and as Humboldt most
truly observes, it is closely connected with " the physical con-
dition of the world in general. Upon the predominance of
certain families of plants in particular districts depend the
character of the country, and the whole face of Nature*
Abundance of grasses forming vast savannahs, or of palms or
coniferae, have produced most important effects upon the
social state of the people, the nature of their manners, and
the degree of developement of the arts of industry."

If we examine the surface of the globe, we shall find its
vegetation varying according to its inequalities and its differ-
ences of soil ; we shall see that the plants of the valleys are
not those of the mountains, nor those of the marsh like the
vegetables of the river or of dry grounds; it will also be seen
that the vegetation of all valleys, all mountains, marshes, or
rivers, has a similar character in the same latitudes. The

BOOK VI. GEOGRAPHY. A1S

flora of the granitic mountains of Spain and Portugal is very
different from that of the calcareous mountains of the same
kingdoms ; in Switzerland, Teucrium montanum always in-
dicates a calcareous soil ; and the same may be said of certain
Orchises, ustulata, and hircina, for instance, in our own coun-
try. Hence it is inferred, that the differences in the character
of vegetation, depend upon circumstances connected with
the soil or atmosphere in which they grow. A great deal of
ingenious discussion upon this matter will be found in M. De
Candolle's article on botanical geography, published in the
18th volume of the Dictionnaire des Sciences Naturelles.

But as I do not find much that can be called positive de-
ductions from such facts as have been ascertained, I shall,
without entering into speculations as to the causes why one
description of plants grows in one situation, and others in
another, confine myself to an exposition of the positive facts
which appear to have been hitherto distinctly ascertained.

It has been found convenient to divide the surface of the
earth into different stations, when treating of botanical geo~
graphy. In this part of the subject I shall adopt the arrange-
ment and distinctions of M. De Candolle ; agreeing with him
that they at least indicate the most remarkable differences of
station, if they are not susceptible of any rigorous definition.

He admits the following classes: —

1. Maritime, or saline plants; that is to say, those which,
without being plunged in salt water, and floating on its sur-
face, are nevertheless constrained to live in the vicinity of salt
water, for the sake of absorbing what may be required for
their nourishment. Among these, it is requisite to distin-
guish those which, like the Salicornia, grow in salt marshes,
where they absorb saline principles, both by their leaves
and roots, from those which, like Roccella fuciformis, exist
upon rocks exposed to the sea air, and appear to absorb by
their leaves alone ; and, finally, a third class, such as Eryn-
gium campestre, which do not require salt water, but which
live on the sea-coast, as well as elsewhere, because their
constitution is so robust, that they are not affected by the
action of salt.

474 GEOGRAPHY. BOOK VI.

2. Marine plants, also called Thalassiophytes by M. Lamou-
roux, which live either plunged in salt water or floating on
its surface. These plants are distributed over the bottom of
the sea, or of salt water, in proportion to the degree of salt-
ness of the water, the usual degree of its agitation, the con-
tinuity or intermittence of their immersion, the tenacity of the
soil, and perhaps also the intensity of the light.

3. Aquatic plants, living plunged in fresh water, either entirely
immerged, as Confervas ; or floating on its surface, as Stratiotes ;
or fixed in the soil by their roots, with the foliage in the
water, as several kinds of Potamogeton ; or rooted in the soil,
and either floating on the surface, as Nymphaea ; or rising
above it, as Alisma plantago. This last division is very near
the following class.

4. Plants of fresh water marshes, and of very wet places,
among which it is chiefly necessary to distinguish those of
bogs, of marshy meadows, and of the banks of running
streams ; and, finally, those of places inundated in winter, but
more or less dried up during the summer.

5. Plants of meadows and pastures, in the study of which
it is requisite to distinguish those that by their natural or
artificial association form the turf of the meadow, and those
others which grow mixed together with the greatest facility.

6. Plants of cultivated soil. This class has been entirely
produced by the agency of man : the plants which grow in
cultivated land are those which, in a wild state, preferred
light substantial soils : many have been transported from one
country to another with the seeds of other cultivated plants.
Those individuals of the same species, which are found in
fields, vineyards, and gardens, are often different in some
respects, according to the peculiar manner in which they have
been cultivated.

7. The plants of rocks ; these pass by insensible gradations
to those of walls, rocky and stony places, and even of gravel ;
and the latter soil, as its fragments diminish in size, conduct
us by degrees to the following class. Rock plants offer some
remarkable singularities depending upon the nature of the
rock.

BOOK VI. GEOGRAPHY. 475

8. The plants of sands, or of very barren soil ,• in the classi-
fication of which much difficulty is experienced : thus, plants
of the sand of the sea-shore are confounded with saline
plants; those of barren soil with the species of cultivated
land, and those of coarse sand are not different from those of
gravel.

9. Plants of sterile places that are very compact, as stiff
clayey soil, or such as have their surface hardened by drought
or heat, or those which are trodden hard by man or animals.
This is an heterogeneous class, and contains plants of very
uncertain characters.

10. Plants which follow man. These are few in number,
and more fixed in their station, either in consequence of
nitrous salts being necessary to their existence ; or because,
perhaps, azotized matter is required for their nutriment.

11. Forest plants, among which are to be distinguished,
firstly, the trees that form the forest, and the herbs which
grow beneath their shade. The latter are to be separated
into two kinds, those which can support a considerable degree
of shade during all the year, which are found in evergreen
woods ; or such as require light in the winter, like those which
are found among deciduous trees.

12. Bushes and hedge plants. The shrubs which compose
this division differ from the plants of the forest in their smaller
size, and by the thinness of their leaves ; the herbaceous kinds
that grow among them are ordinarily climbing plants.

13. Subterranean plants, which live either in dark caverns
as the byssus, or within the bosom of the earth, as the truffle*
These can dispense altogether with light, and several cannot
even endure it. Plants that grow in the hollows of old trees
have great analogy with those of caverns.

14.. Mountain plants, as subdivisions of which all the other
stations may be taken. We generally class among mountain
plants such as, in Europe, are not found lower than 500
yards; but this is quite an arbitrary limit. The most im-
portant division is between those which grow on mountains*
the summit of which is covered with eternal snow, and those of
mountains which lose their crest of snow in the summer. In

476 GEOGRAPHY. BOOK VI.

the former, the supply of water is not only continual, but
more abundant and colder as the heats of summer advance ;
in the latter, on the contrary, the supply of water ceases when
it becomes most requisite. The former are evidently much
more robust than the latter.

15. Parasitical plants ,■ that is to say, such as are either
destitute of the power of pumping up their nourishment from
the soil, or of elaborating it completely; or as cannot exist
without absorbing the juices of other vegetables. These are
found in all the preceding stations. They may be divided
into, first, those which grow on the surface of others, as the
Cuscuta and the Misletoe : and, secondly, intestinal parasites,
which are developed in the interior of living plants, and pierce
the epidermis to make their appearance outwardly, such as
the Uredo and iEcidium.

16. Epiphytes, or false parasites, which grow upon either
dead or living vegetables, without deriving any nourishment
from them. This class, which has often been confounded
with the preceding, has two distinctly characterised divisions.
The first which approaches true parasites, comprehends cryp-
togamous plants, the germs of which, probably carried to their
stations by the very act of vegetation, develope themselves at
the period when the plant, or that part where they lie, begins
to die, then feed upon the substance of the plant during its
mortal throes, and fatten upon it after its decease; such are
Nemasporas and many Sphaerias : these are spurious intestinal
parasites. The second comprehends those vegetables, whether
cryptogamic, such as lichens and Musci, or phanerogamous,
as Epidendrums, which live upon living plants, without de-
riving any nutriment from them, but absorbing moisture from
the surrounding atmosphere; these are superficial false para-
sites : many of them will grow upon rocks, dead trees, or earth.

Thus we see that M. De Candolle has found it necessary
to divide vegetation into sixteen stations. I do not attach
much importance to several of them, because they are vague
and uncertain of application, and frequently common to many
plants ; but it is, nevertheless, useful to bear in mind, that
such distinctions do exist, and to point them out whenever

BOOK VI. GEOGRAPHY. 477

they take any very decided peculiarity of character. This is,
indeed, indispensable, in order to enable us hereafter to form
any definite appreciation of the nature of the influence of the
combined agency of soil, temperature, and atmosphere.

The next, and by far the most important head under which
the geographical distribution of plants is to be considered, is
with reference to temperature and light. These depend,
firstly, upon latitude; and, secondly, upon elevation above
the sea.

As we proceed from the pole towards the equator, we find
the temperature gradually increasing: and, as we ascend from
the surface of the ocean up into the atmosphere, we find the
temperature gradually decreasing, until we reach a point at
which perpetual frost holds his throne, and where vegetation
ceases.

In like manner we find, as we recede from the equator to
the pole, we quit the country of palms and other arborescent
monocotyledonous plants, for the habitations of deciduous
dicotyledonous trees, Coniferae, and cryptogamic plants ; and
that as we rise into the atmosphere as considerable a change
takes place. Thus, in Teneriffe, the foot of the mountain is
occupied by Crithmum latifolium, succulent Euphorbias, Plo-
cama pendula, and Prenanthes spinosa: to these succeed vines,
corn, Canarina campanula, and Messerschmidia fruticosa : a
third class, consisting of laurels, Ilex, Ardisias, heaths, and
Viburnums, occupy the succeeding tract. These are sur-
mounted by pines, Cytisus, and Spartium microphyllum ; and,
finally, the scenery is closed by Spartium nubigenum, Juni-
per us oxycedrus, Scrophularia, Viola, and Festuca. (See
Humboldt's Travels.)

Therefore, in considering the matter of the vegetation of a
given climate, it is necessary to take into account the temper-
ature peculiar to the latitude itself, and the reduction caused
by elevation.

The decrement of caloric, as we ascend into the air, will be
understood by the following table, calculated by Mr. Daniell,
from observations made by Mr. Green the aeronaut, in an
aerial voyage performed in 1821. These are particularly

>T/-\0

478 GEOGRAPHY. BOOK VI.

instructive ; because they were all made within the space of
half an hour, under circumstances which varied as little as
possible.

The temperature at the surface of the earth was - 74

at an elevation of 2,952 feet, was - 70

7,288 - - 72°

9,993 - - 69°

11,059 - - 45°

11,293 - - 38°

The difference between the temperature of the highest elevation
and the earth's surface amounting to 36° in the space of twenty-
seven minutes.

The amount of the decrement of heat, as compared with
that of latitude, has been calculated to be, in France, equal
to one degree of retrogressive latitude for every 540 feet of
vertical elevation ; that is to say, the temperature of a district
of 3240 feet of elevation, in 45° N. lat., would be equal to
the temperature of 51° N. lat. on a level with the sea. But,
from Humboldt's computations, it appears that, nearer the
equator, this proportion varies. He found, from careful and
repeated observations, between 0 and 3000 feet of elevation,
that in the middle of the temperate zone, the mean temper-
ature of the year decreased in a degree equivalent to 2° of
N. lat. for every 600 feet of elevation ; the mean summer heat
1° 30'; the mean autumnal heat 1° 24'; or, on an average,
the decrement of temperature was about 1° of latitude for
every 396 feet of elevation. Temperature decreasing in this
rapid ratio, it is evident that, if vegetation is affected by tem-
perature, it will offer great differences in the ascent of a
mountain. And accordingly it is found, as will be seen by
the following tables, that the nature of the vegetation towards
the upper limits at which plants grow, gradually changes from
that of the base of the mountain, until plants entirely disap-
pear at the limits of perpetual snow.

BOOK VI.

GEOGRAPHY.

479

CHIMBORAZO (ANDES).
Lat. 2° 50'. S. — Height, 21,450 Feet.

Elevation
in Feet.

Mean Temperature.

Vegetation.

0

3,250

5,200

9,750

11,375

15,525

14,500

15,600

Of the year - 80°
Ditto - 71°
Ditto - 66°
Ditto - 60°
Ditto - 46°

Of the year - 29°

Palms.

Palms cease to grow.

Tree ferns cease.

Cinchonas cease.

Alstonias and Befarias cease.

Grasses cease.

Culcitium rufescens ceases.

Limits of perpetual snow.

POPOCAYAN (MEXICO).
Lat. 19° 20'. N. — Height, 17,550 Feet.

Elevation
in Feet.

Mean Temperature.

Vegetation.

10,400
11,375
15,000

15,275

Of the year - 53°
Of the year - 44°

Oaks cease to grow.
Alnus mexicana ceases.
Pinus occidentalis ceases.
Limits of perpetual snow.

ETNA (SICILY).

Lat. 3S° 6'. N. — Height, 11,560 Feet.

Elevation
in Feet.

Mean Temperature.

Vegetation.

0 to 100 J

1,100
2,175
4,550

6,500

8,125

9,750

10,000

Of the year - 64° "1
Of July and Aug. 76° J

Palma;, Musaceae, Saccharum.

Oranges, olive, and rice cease to grow.
Vine, wheat, and maize cease.
Oaks and chestnuts cease.
Rye and Pinus sylvestris cease.
Fagus sylvestris and Betula become

shrubs.
Juniperus and Berberis cease.
Phajnogamous plants disappear.
Lichens cease.

480

GEOGRAPHY.

EOOK VI.

MONT BLANC (ALPS).
Lat. 44°. N. — Height, 15,600 Feet.

Elevation
in Feet.

Mean Temperature.

Vegetation.

0
0
1,950
2,925
3,900
4, 6 SO
5,850
6,695
7,800
8,190
8,780

Of August - 69°
Of the year - 53°

Of the year - 32°

The vine ceases.
Castanea vesca ceases.
Oaks cease.
Betula alba ceases.
Pinus Abies ceases.

V Rhododendrons cease.

Sulix herbacea ceases.
Limits of perpetual snow.

MONT PERDU (PYRENEES).
Lat. 44°. N Height, 11,375 Feet.

Elevation
in Feet.

Mean Temperature.

Vegetation.

3,250
5,280
6,175
7,800

8,780 |

Of the year - 42°

Of August - 42°
Of the year - 25°

Oaks cease to grow,

Pinus picea ceases.

Pinus rubra and uncinata cease.

V Limits of perpetual snow.

SULITELMA (LAPLAND).

Lat. 68° N. —Height, 6,175.

Elevation
in Feet.

Mean Temperature.

Vegetation.

975
1,950 |
2,925
3,640 |

Of the year - 34°
Of August - 60°
Of the year - 31°
Ditto - 27°
Of August - 54°

Of the year - 21°
Of August - 49°

Pinus sylvestris ceases.
V Betula alba ceases.
Salix herbacea and lanceolata cease.
J- Limits of perpetual snow.

ROOK VI. GEOGRAPHY. IS 1

The effect of elevation is not, in Europe, the same with all
plants; there are many that grow indifferently upon the plains
and upon mountains as high as perpetual snow. M.De Can-
dolle speaks of 700 instances, with which he is acquainted, of
the prevalence of this law. But, on the other hand, there are
many plants, the limits of which are strictly circumscribed by
elevation or equivalent temperature ; as, for example, the
chestnut does not rise higher in the Swiss Alps, in the parallel
of 45°, than 2,400 feet ; on Etna, in latitude 38°, it reaches
no higher than 4000 feet. Many of the plants found on
plains in the north of Europe occupy the mountains of the
south. The olive, in 44° of latitude, its most northern
range, will not grow at a greater elevation than 1200 feet,
In general it is found that, as we approach the equator,
vegetation becomes more and more affected by elevation ; and
that as we recede from it, the effects of elevation gradually
cease.

The cause of the influence of elevation upon plants is
ascribed, in the first place, to reduced temperature ; secondly,
to a greater intensity of solar light; and, thirdly, to a decrease
in humidity. The rate at which temperature decreases as we
ascend from the surface of the earth varies according to
latitude: Humboldt has shown that, in the temperate and
torrid zones, the decrement of heat is essentially different. In
the equatorial zone, the temperature of the region lying at
the height of between 3000 and 6000 feet, — on which the
clouds repose that are visible to the natives of the plains, —
decreases much more slowly than either above or below that
elevation; but, in the temperate zone, the decrease is more
gradual. In proof of this the following table has been formed
by Humboldt • —

i i

482

GEOGRAPHY.

BOOK VI.

Elevation

above the Sea

in Feet.

Equatorial Zone,
Lat. 0°— 21°.

Temperate Zone,
Lat. 45°— 47°.

Mean Temperature
of the Year.

Difference.

Mean Temperature
of the Year.

Difference.

0

80°

12°

4°

9°

11°

10°

53°

12°
9°
9°

3,000

68°

41°

6,000

64°

32° '

9,000

55°

23°

12,000

44°

15,000

34°

The diminution of the density of the air as we ascend,
produces a corresponding increase in the intensity of the light ;
a circumstance in which high elevation again corresponds with
high latitudes.

It is said that the humidity of the atmosphere decreases as
we ascend, and that to this may be ascribed much of the
effect produced upon vegetation by great heights. That the
humidity of the atmosphere does much affect vegetation is not
to be doubted; and if it were certain that the air became
gradually drier as we ascend, a second cause, as powerful as
that of temperature, would be found for the effects of elevation
upon vegetation. But it is certain that the humidity of the
air does not change gradually, as we ascend, with the cha-
racter of vegetation ; on the contrary, it has been found that
atmospheric humidity is either uniform or increased to heights
far beyond uniformity of vegetation, and then suddenly di-
minishes to a large amount, vegetation not suddenly altering
with it ; so that it would seem as if the atmosphere were com-
posed of deep beds of air, suddenly differing from each other
in the elasticity of their aqueous vapour.

From observations made by Capt. Sabine, with a Daniell's
hygrometer, at Ascension, it appears that, on that island, at
seventeen feet above the sea, the amount of dryness was 5° ;
and, at 2237 feet higher, was 3° 5'; so that, in this case, the
air became more humid as he ascended. At Trinidad the
amount of dryness on a level with the sea was 5°; at 1060

BOOK VI. GEOGRAPHY. 483

feet higher the air was saturated with moisture ; in this in-
stance, also, humidity increased with elevation. At Jamaica
it was found that, on a level with the sea, the degree of dry-
ness was 7° ; at 4080 feet higher the air was saturated with
moisture; but at 4580 feet the dryness was 16°. Hence it
is to be inferred that, in these observations, the lower bed of
the atmosphere was not passed through, either at Ascension
or in Trinidad ; but that, in Jamaica, it had been left below
at the time the third observation was taken ; and that, in that
island the lower stratum of air is something more than 4000
feet deep. In Mr. Green's voyage the degree of dryness of
the air, at an elevation of 9893 feet, was 5°, nearly the same
as it was observed to be on the surface of the earth below at
the same time; but, at 11,059 feet, it was 13°; and at 11,293
feet, the highest point at which an observation was made, it
was still 13°; so that it would seem that the humidity of the
atmosphere, at that time, did not vary through a bed of air
rising pei'haps 2000 feet beyond the highest limits of vegeta-
tion in Europe.

It must be confessed that these observations are by no
means sufficiently numerous to become the foundation of any
thing connected with the effect of elevation upon the cha-
racters of plants ; but they, at least, answer the purpose of
showing that, in the present state of our information, the
effects of humidity are not appreciable in investigating the
subject.

Whether the increased rarity of the air, as we ascend, has
any effect upon vegetation, is not determined. It is not easy
to say in what way it can act, according to any yet known
physiological laws, unless, as M. De Candolle remarks, in
supplying an insufficient quantity of oxygen for absorption.
But, as we find plants of the plains grow indifferently on the
highest mountains, it does not seem that there is any such
diminution of oxygen as interposes with the operations of
vegetation. The diminution of atmospheric pressure, which
of course takes place at high elevations, may facilitate eva-
poration ; but we have yet to learn in what precise way that
phenomenon influences vegetation.

From what has now been said, all that is apparent is, that,

i i 2

48 1 GEOGRAPHY. BOOK VT.

as we ascend in the atmosphere, temperature diminishes and
light increases in a proportion corresponding, to a certain
degree, with the climate of higher latitudes ; but even to this
there are exceptions, depending upon particular circum-
stances, and especially upon the amount of summer heat, of
which more will be said presently. Thus, at Enontekissi, in
Lapland, in 68° 30' N. lat., at an elevation of 1356 feet above
the sea, a climate which, from its situation, should be scarcely
clothed with herbage, Von Buch found corn, orchards, and a
rich vegetation.

Having now seen what great differences are produced in
the characters of vegetation by elevation above the sea, let us
next take a view of the influence caused by latitude. In the
countries lying near the equator, the vegetation consists of
dense forests of leafy evergreen trees, palms, and arborescent
ferns, among which are intermingled epiphytal herbs and
rigid grasses : there are no rich verdant meadows, such as
form the chief beauty of our northern climate ; and the lower
orders of vegetation, such as mosses, fungi, and confervas, are
very rare : Myrtaceae, Melastomaceae, Musaceae, Piperaceae,
Scitamineae, and frutescent Compositae abound. As we re-
cede from the equator these gradually give way to trees with
deciduous leaves, to Coniferae, Rosaceae, and Amentaceae;
rich meadows appear, abounding with tender herbs; the
epiphytal Orchideae disappear, and are replaced by terres-
trial fleshy- rooted species ; mosses clothe the trunks of aged
trees ; decayed vegetables are covered with parasitical fungi ;
and the waters abound with Confervae. Approaching the poles
trees wholly disappear; dicotyledonous plants of all kinds
become comparatively rare; and grasses and cryptogamic
plants constitute the chief features of vegetation. To what
cause, except that of temperature, and perhaps light, these
effects are to be ascribed, is unknown. They are found to
exist equally towards either pole ; and it is evident, from the
uniform manner in which the influence of the controlling
cause, whatever it may be, is exercised, that the laws under
which the geographical distribution of plants is determined,
are as certain and immutable as any of those with the nature
of which we are acquainted. It is probable that temperature

BOOK VI. GLOUllAl'HY. 485

is the principal cause, from the well-known fact that the
vegetable productions of hot climates can be successfully cul-
tivated in cold ones by the aid of heat ; and that the plants of
cold climates may be cultivated in hotter climates by an arti-
ficial reduction of temperature. But that other causes also
operate, is apparent from the impossibility of cultivating the
plants of any high latitudes in those considerably to the south.
Thus, when living plants were brought to England from Mel-
ville Island, no means whatever could be discovered of keeping
them alive, although the temperature at which they were main-
tained did not materially vary from that to which they must
have been often exposed, in the summer season, in their own
climate. Assuming, however, for the present, that temper-
ature is the most efficient cause of variety in the distribution
of plants, the first point to consider is, how far temperature
and latitude are uniformly the same in either hemisphere.
This has been discussed, with his habitual skill, by Baron
Humboldt, of whose observations I must avail myself in
nearly all that I can say upon the subject. According to this
observer, the geographical parallels of latitude do not indicate
corresponding temperature, either in the old and new world,
or in the northern and southern hemisphei'es. In the new
world the temperature decreases more rapidly as we recede
from the equator than in the old world ; and in the southern
hemisphere, beyond the parallel of 34°, the summers are
colder than in corresponding latitudes of the northern hemi-
sphere; but the winters milder. On this account Baron
Humboldt concludes that " the lines of equal mean annual
heat, which may be called isothermal, are not parallel with
the equator, but intersect the geographical parallels at a va-
riable angle."

The following table shows the difference in the mean annual
heat of the same latitudes in the old and new worlds : —

i i 3

4-86

GEOGRAPHY.

BOOK VI.

Latitude.

Mean Heat of the Year in the

Difference.

Old "World.

New World.

0°
20
30
40
50
60

80°

77

70

63

50

40

80°

77

67

54

38

24

0°
0
3
9
12

16

Hence it appears that the old world is much warmer than
the new, and that the temperature of America does not de-
crease, from Florida to the Gulf of St. Lawrence, in the
same ratio as in Europe, from Egypt to Scandinavia. But
although, in the temperate parts of North America, the mean
annual heat of a given place is the same as that of Europe
some degrees more to the northward, yet the temperature of
particular seasons do not accord in the same degree; but the
colder the winters the hotter the summers are found: thus, —

The summer of Philadelphia, lat. 39° 56'N.is the

same as that of Rome - lat. 41° 53' N.

The winter of Philadelphia, lat. 39° 56' N. is the

same as that of Vienna - - - lat. 48° 13' N.

The summer of Quebec, lat. 4-6° 47' N. is hotter

than that of Paris .... lat. 48° 50' N.

The winter of Quebec, lat 46° 47' N. is colder

than that of St. Petersburgh - - - lat. 59° 5G' N.

In general, the summers of the temperate parts of North
America, as far as 40° N. lat., are about 4° warmer than in
Europe under the same isothermal parallel ; whence it can be
understood why magnolias and other equinoctial-looking trees
extend so far to the north, since, in the parallel of 36°, the
summer heat to which these trees are exposed scarcely differs
from the mean annual heat of the equator. It is, therefore,
extremely important in the study of botanical geography, to
take into account, not only the mean temperature of the year,
but also the mean summer heat.

According to Barton, the climate to the west of the Alle-
ghany mountains is much warmer than that on the east, or
Atlantic side, where the same plants exist 3° or 4° higher up

BOOK VI. GEOGRAPHY. 487

on the west than on the east side of the range. It is probable,
however, that this difference does not extend higher up than
Lake Erie, in 42° N. lat. ; for, both beyond Lake Superior and
Hudson's Bay, the earth is said to be constantly frozen at
three feet from the surface ; a phenomenon which also occurs
in Siberia, about the river Lena, in about 62° N. lat., near
the town of Jakutsk ; while, in Lapland, in 70° near Vadsoe,
the temperature of the earth is found to be as much as 3° or
4° above the freezing point; whence it appears that the
climate of the north of Europe is warmer than that of the
same latitudes in Asia and America. We therefore shall not be
far away, if we conclude that the isothermal lines bend towards
the tropics in Europe, and towards the poles in Tartary and
America.

As we approach the equator there appears to be little differ-
ence in the mean temperature of the year, either in the new
or old world.

Of the Old World.

The mean temperature of Senegal is 79.7° in lat. 24° 30' N.
of Madras is 80.4° in lat. 13° 5' N.
of Batavia is 77.4° in lat. 6° 10' S.
of Manilla is 78.0° in lat. 15° N.

Of the New World.

The mean temperature of Cumana is 81.6° in lat. 10° 27' N.
of the Antilles is 81.6° in lat. 15° N.
of Vera Cruz is 78.0° in lat. 19° 12' N.
of Havannah is 78.0° in lat. 23° 12' N.

It is probable, however, that the summers of Asia are more
fervid than those of America; for, according to Roxburgh,
the mean temperature of Madras, in latitude 13° 5" N., in
the month of July, is 89.4° ; while that of Cumana, in latitude
10° 27', does not exceed 84.4°.

To the south of the equator, the temperature of the east
seems to be higher than that of corresponding latitudes in
the west : thus, the mean temperature of the Mauritius, in
20° 9' S. lat., has been ascertained to be 80.4° ; while that of

i i 4

488 GEOGRAPHY. BOOK VI.

Rio Janeiro, in latitude 20° 59' S., is as low as 74.3° ; and at
the Havannah, in nearly the same parallel in the northern
hemisphere, it ranges between 77° and 77. 9°. The whole of
the western coast of South America, as far as the sands of
Peru, in latitude 10° and 14° S., are affected so much by the
continual prevalence of clouds and the low temperature (59.9°)
of the currents setting round Cape Horn, that the mean tem-
perature of the year in those parts does not exceed 68° or 69°.
Hence the plants of Lower Peru live in a temperature not ex-
ceeding, by day, 68° or 72°, and by night 59° or 62°. Near
the coast Humboldt observed the thermometer as low as even
55.4° in 12° 2' S. lat. With this exception there is little dif-
ference in the temperature of the southern hemisphere as low
as 34° S. lat., either in New Holland, Africa, or America.
The mean temperature of Port Jackson, in 33° 51' S. lat., has
been ascertained to be 66.6° ; of the Cape of Good Hope, in
33° 55' S. lat., to be 66.8° ; and of Buenos Ayres, in 34° 36'
S. lat., to be 67.6°. In the northern hemisphere the mean
temperature, in latitude 34 , is 67.8°. It is extremely pro-
bable that, as far as the parallel of 57° S. lat., the differences
in the temperature of the two hemispheres are greater in the
summer than the winter. The cold of the Falkland Istands,
in latitude 5l£° S., is less than that of London in the same
latitude to the north. The arborescent ferns and epiphytal
Orchideae are often injured by the cold in Van Diemen's
Island, latitude 42° S. ; and in the southern part of New
Zealand, latitude 46° S. Cook observed, in latitude 43°-
44° S., in July in the middle of winter, that the thermometer
at noon was usually between 46° and 51°. At Rome, latitude
41° 53' N., the thermometer at noon in January rarely reaches
51°-53° : in Paris the mean noon-day temperature of January
is, according to Arago, 38.7°. For this reason it is supposed
that the climate of the southern hemisphere does not differ
from that of the north so much in the greater coldness of the
winters as of the summers. According to Humboldt, the
greatest heat in the parallels of 48° and 58° of S. lat., does
not exceed 43.7°-46.8°; while at St. Petersburgh and Umea,
in 59° 66' and 63° 50' N. lat., it is 65.2° and 62.6°. In the
Straits of Magellan, between 53° and 54° S. lat., snow falls

BOOK. VI. GEOGRAPHY. 489

almost daily in the middle of summer ; and, in the same place,
in the middle of December, the sun not setting for eighteen
hours together, Krusenstern observed that the thermometer
never rose higher than 52°; while, on the contrary, Von
Buch remarked it as high as 79.4-° in Lapland under the
parallel of 70°. In 60° S. lat., which nearly answers to the
position of St. Petersburgh in the northern hemisphere, Cook
and Forster found the temperature at midsummer not higher
than 36° ; and icicles were continually forming on their ship.
Even in the extreme points of Lapland, in 70° N. lat., the
pines attain the height of sixty feet ; while at the Straits of
Magellan and in Station Island, near New Year's Harbour,
in latitude 55° S., nothing like a tree is found, except scrubby
birches and Winterese.

Viewing the distribution of plants with respect to longitude,
we find that, while the great forms of vegetation are wholly
controlled by circumstances attendant upon the parallels of
latitude, there are wide differences, of a secondary nature,
which correspond in some with the parallels of longitude;
and that particular genera and species do not extend beyond
the limits of particular districts, to which they give peculiar
features. Thus, in North America, on the east of the Rocky
Mountains, azaleas, rhododendrons, magnolias, vacciniums,
actaeas, and oaks, form the principal features of the landscape ;
while, on the western side of the dividing ridge, these genera
almost entirely disappear, and no longer constitute a striking
characteristic of the vegetation. The genera of Proteaceae
and the Ericeae, at the Cape of Good Hope, are replaced in
New Holland by different genera of Proteaceae, and by Epa-
crideae ; while neither the one nor the other exist on the con-
tinent of South America, with the exception of some Rhopalas.
The natural order of Bromeliaceae is exclusively confined to
America: Calathea, a genus of Marantaceae, is only found on
the same continent: cinnamon, cloves, and nutmegs are con-
fined to the Indian Archipelago ; and hundreds of other in-
stances are to be named of similar exclusive stations. Whether
these differences depend upon geological causes, or arise from
some other circumstances, is entirely unknown.

Such are the most striking facts connected with the dis-

490 GEOGRAPHY. BOOK VI.

tribution of temperature with respect to vegetation. It will
have been seen that little is known of the proportion of
humidity in the atmosphere of different climates, and that the
amount of light in various latitudes has scarcely been noticed.
That the effect of both these agents upon vegetation is most
important, cannot be doubted ; especially of the latter, upon
which the most material vital functions of vegetation mainly
depend : but, unfortunately, there are no data from which the
precise amount or action of light in different latitudes can be
appreciated.

I shall now proceed to state what is known or conjectured
of the distribution of the different orders or divisions of vege-
tables over the surface of the globe. In doing this, I shall
merely translate a portion of the very valuable essay of Baron
Humboldt upon the subject, as published in the Dictionnaire
des Sciences Naturelles, vol. xviii. p. 422, in which is compre-
hended the sum of all that is known of the laws that are
observed in the distribution of the various forms of vege-
tation. — " The numerical relations of the forms of vegetation
are capable of being investigated in two very different modes.
Supposing that the natural families of plants are studied
without reference to their geographical distribution, the ques-
tion will arise as to which type of organisation it is after
which the greatest number of species have been created. Are
there most Glumaceae (Cyperaceae, Gramineae, and Junceae
are so called by M. De Humboldt,) or Compositae in the
world ? Do these two tribes together constitute a fourth part
of phaenogamous vegetation ? What proportion is borne by
Monocotyledones to Dicotyledones ? Questions of this kind
refer rather to the science of vegetable organisation and of
mutual affinities. But if, instead of studying natural groups
of species in this abstract manner, we view them with refer-
ence to the relations they bear to climate or to the distribution
over the surface of the globe, other questions of a much more
varied nature will arise. Which families, for instance, are
more predominant in the torrid zone than in the polar circle?
Are Compositae more numerous in the same parallel of latitude
or in the same isothermal line in the old world or the new ?
Do those forms which are found to diminish in retreating from

BOOK VI. GEOGRAPHY. 491

the equator to the pole follow a similar law of decrement in
rising from the plains into the mountains of the equator ? Do
the proportions borne by one family to another vary on the
same isothermal line ; and are such proportions the same on
either side of the equator? These are, properly speaking,
questions of geographical botany : they are connected with
the most important problems of meteorology, and of the
physics of the globe in general.

" In studying the geographical distribution of particular
forms, we can pause either at a consideration of particular spe-
cies, genera, or natural families. It often happens that a particu-
lar species, especially of those kinds which I have called social,
covers a vast extent of country : such, for instance are, in the
north, the heaths and forests of pines ; such are, in equinoctial
America, the assemblages of multitudes of Cactus, Croton,
Bambusa, and Brathys, of the same species. It is curious to
examine such instances of multiplication and organic develope-
ment. We may enquire what species, in a given zone, pro-
duces the greatest number of individuals ? and we may mark
the families to which the predominant species belong in dif-
ferent climates.

" In a northern climate, where compositae and ferns are to
phaenogamous plants in the relation of one to thirteen, and of
one to twenty-five (that is to say, when these proportions are
found by dividing the total number of phaenogamous plants
by the number of Compositae and ferns), one single species of
fern may occupy ten times as much land as all the Compositae
put together. In such a case, ferns would exceed Compositae
by their mass, by the number of individuals belonging to par-
ticular species of Pteris or Polypodium ; but they would not
exceed them if a comparison were instituted between the dif-
ferent forms exhibited by the two groups of Compositae and
ferns, and the sum total of phaenogamous species. As the
multiplication of all species does not follow a single law, and
as they do not all produce an equal number of individuals,
the quotients obtained by dividing the total number of phaeno-
gamous plants, by the number of species of different families,
do not by themselves determine the aspect, or, it might almost
be said, the nature, of the monotony of vegetation in different

i-9'2 GEOGRAPHY. BOOK. \ J.

quarters of the world. A traveller is often surprised at the
continual repetition of individuals of one species, and of the
masses of such individuals which are continually occurring;
but he has equal reason to wonder at the rarity of other spe-
cies which are useful to mankind. Thus, in countries where
whole forests are formed by Rubiaceae (Cinchonaceae), Legu-
minosae, and Terebinthaceae, the Cinchonas, logwood, and
balsam trees are comparatively very rare.

" In the consideration of species, the subject may also be
viewed in an absolute manner with reference to the number of
species which prevail in particular zones. This interesting kind
of comparison has been made in M. De Candolle's grand work,
and Mr. Kunth has carried it into effect with more than 3500
Compositae now known. It does not, indeed, indicate what
families predominate, in a given degree, over other phaenoga-
mous plants, either with regard to the number of species, or
the mass of individuals ; but it determines the numerical
relations of species of the same family in different latitudes.
The most varied forms of ferns, for instance, are found in the
tropics ; it is in the mountainous, temperate, humid, and
shady regions of those parts of the world that the family of
ferns produces the greatest number of species. In the tem-
perate zone there are fewer than in the tropics, and the total
number continues to decrease as we approach the pole ; but
as a cold country, Lapland, for instance, produces species
that have a greater power of resisting low temperature than
the great mass of phaenogamous plants, it happens that, in
Lapland, the relative proportion borne by ferns to the rest of
the flora is greater than in France or Germany. The nume-
rical relations which appear in the tables that are now about
to be produced, are entirely unlike the relations indicated by
an absolute comparison of the species that vegetate under dif-
ferent parallels of latitude. The variation which is observ-
able in proceeding from the equator to the poles is conse-
quently different in those two methods. In that of fractions,
which is adopted by Mr. Brown and myself, there are two
causes of variation ; that is to say, the total numbers of phae-
nogamous plants do not vary in passing from one parallel of
latitude, or rather from one isothermal zone to another, in

BOOK VI. GEOGRAPHY. 493

the same proportions as the number of species of a given
family.

" If from species or individuals of the same form, which re-
produce themselves in conformity to certain fixed laws, we
pass to those divisions of the natural system which are ab-
stractions of different degrees of importance, we may either
confine ourselves to genera, or orders, or sections of a still
higher degree. There are certain genera and families which
belong exclusively to certain zones, and a particular com-
bination of the conditions of climate; but there is also a great
number of genera and families, of which we find represent-
atives under all zones and at all elevations. The earliest
researches upon the geographical distribution of forms were
those of M. Treviranus, published in his ingenious work on
Biology (vol. ii. pp. 47. 63. 83. 129.), and the object of these
was the stations of genera upon the globe. But it is more
difficult to obtain general results from such a method than
from that which compares the number of species of each
family, or the great groups of a particular family to the whole
mass of phaenogamous plants. In the frozen zone, the variety
of genuine forms does not diminish in any thing like the
degree of decrement of species ; a greater number of genera, in
a given number of species, is always to be found in such
countries : and so it also is with the summits of high moun-
tains, which are colonised by a great number of genera sup-
plied by the more abundant vegetation of the plains.

" It is very instructive to study the vegetation of the
tropics and of the temperate zone between the parallels of
40° and 50°, in two different ways : firstly, in determining the
numerical properties of the flora of a large extent of country,
including both mountains and plains ; and, secondly, in ascer-
taining those proportions for the plains only of the temperate
and torrid zones. As in our herbaria we have indicated, by
barometrical measurement, the elevation of each plant in more
than 4000 cases above the level of the sea in equinoctial Ame-
rica, it will be easy, when the account of the species is
completed (it is now completed), to separate those which
grow at or above an elevation of 6000 feet from such as are
inhabitants of a lower region. This operation will affect

494> GEOGRAPHY. BOOK VI.

most sensibly those families that abound in alpine species : as,
for instance, Gramineae and Compositse. At 6000 feet of
elevation, the mean temperature of the air, on the back of the
equatorial Andes, is 62° 6', which is equal to that of July at
Paris. Although, upon the table-land of the Cordilleras, we
find the same annual temperature as in high latitudes, yet it
is not right to generalise too much such analogies between
the temperate climates of equatorial mountains and low sta-
tions in the circumpolar zone. These analogies are not so
great as is supposed; they are much influenced by the partial
distribution of heat in different seasons of the year. The
quotient does not regularly change, in rising from the plains
into the mountains, in the same manner as it does in ap-
proaching the pole; as happens with Monocotyledones in
general, ferns, and Compositse.

" We may, moreover, remark, that the developement of the
vegetation of different families depends neither upon geogra-
phical nor isothermal latitude alone; but that, on the con-
trary, the quotients are not in accordance on the same
isothermal line of the temperate zone in the plains of America
and of the old world. Under the tropics, there is a remark-
able difference between America, India, and the western side
of Africa. The distribution of organised beings over the
surface of the globe depends not only upon very complicated
conditions of climate, but also upon geological causes, the
nature of which is wholly unknown, but which are connected
with the original state of our planet. In the equinoctial zone
of Africa palms are not very numerous, if compared with the
much greater number in South America. Differences such
as these, far from turning us from a search after the laws
of nature, should, on the contrary, excite us to contemplate
those laws in their most complicated forms. Lines of equal
heat do not follow the parallel of the equator ; they have con-
vex and concave summits, which are distributed very regularly
over the globe, and form different systems along the eastern
and western sides of the two worlds, in the centre of conti-
nents, and in the vicinity of oceans. It is probable that,
when the globe shall have been more correctly examined, it
will be found that the lines of maxima of grouping (that is,

BOOK VI. GEOGRAPHY. 495

lines drawn through those points where the fractions are
reduced to their smallest denominator) will be isothermal
lines. If we divide the globe into lines of longitude, and
compare the numerical proportions of those lines under
similar isothermal latitudes, the existence of different systems
of grouping will at once be evident. From such systems can
be distinguished, even in the present imperfect state of our
knowledge, those of the new world, of western Africa, of
India, and of New Holland. As we find that, notwithstanding
the regular increase of heat from the equator to the poles, the
maximum of heat is not always identical in different countries
in different degrees of longitude ; so there exist places where
certain families attain a greater degree of developement than
elsewhere; as is the case with Compositae in the temperate
region of North America, and especially at the southern ex-
tremity of Africa."

Now follow tables of the different numerical proportions of
certain extensive families and divisions of plants, as far as
they have been ascertained. I give them in Baron Hum-
boldt's words, with a few interpolations, which are distin-
guished by being included within crotchets [ ].

" ACOTYLEDONES.

" Cryptogamic plants (fungi, lichens, mosses, and ferns);
cellular and vascular Agamae of M. De Candolle. Taking
the plants of the plains along with those of the mountains,
we have found, under the tropics, ^ ; but their number ought
to be much greater. Mr. Brown has shown that it is probable
that, in the torrid zone, the proportion is -^ for the plains,
and I for the mountains. In the temperate zone cryptoga-
mous plants are generally to phaenogamous as 1 to 2 ; in the
frozen zone they maintain as large a proportion, and often
much surpass it. [In Melville Island the numbers are
58 crypt, to 67 phaenog., or nearly equal: in Sweden, ac-
cording to the computation of Wahlenberg, they are some-
thing less than 4 to 1 ; and it is probable that this is a near
approximation to the true proportions of Sweden, the crypto-
gamic flora of that country having been more accurately
investigated than that of any other part of the world.]

496 .GEOGRAPHY. BOOK VI.

" In separating cryptogamous plants into three groups, we
observe that ferns are more numerous, the denominator of
the fraction being smaller in the frozen than in the temperate
zone. Lichens and mosses also increase towards the frozen
zone. The geographical disti'ibution of ferns depends upon
the combination of local circumstances of shade, humidity,
and moderate warmth. Their maximum (that is to say, the
place where the denominator of the fraction of the group
becomes the smallest possible,) is found to be in the moun-
tainous parts of the tropics, especially in small islands, in
which the proportion rises to £-, and even higher. Not dis-
tinguishing the plains from the mountains, Mr. Brown finds
the proportion of ferns in the torrid zone to be ^ : in Arabia,
India, New Holland, and Western Africa (within the tropics)
it is gV : our American herbaria only indicate ^V : but ferns
are rare in the wide valleys and arid table land of the Andes,
where we were constrained to reside a long time. In the
temperate zone ferns are tV> in France TV, in Germany, ac-
cording to recent observations, ^\. The group of ferns is
extremely rare on Atlas, and is almost entirely absent from
Egypt. [In Sicily, Presl finds them ^; in Sweden, according
to Wahlenberg, they are about ttoO In the frozen zone
ferns appear to increase to oV- [There are none in Melville
Island.]

" MONOCOTYLEDONES.

" The denominator becomes progressively smaller in going
from the equator to 62° N. lat. ; it again increases in still
more northern regions, on the coast of Greenland, where
Gramineae are very rare. [ Mr. Brown remarks that, in the
list of Greenland plants, Dicotyledones are to Monocoty-
ledones as 4 to 1, or in nearly the equinoctial ratio; and in
Spitzbergen, as well as can be judged, the proportion of Di-
cotyledones appears to be still further increased. This inver-
sion was found to depend as much on the reduction of the
proportion of Gramineae as on the increase of certain dicoty-
ledonous families, especially Saxifrageae and Cruciferae. The
flora of Melville Island is, however, very different, Dicoty-

BOOK VI. GEOGRAPHY. 497

ledones being to Monocotyledones as 5 to 2, or in as low a
ratio as has any where been observed ; while the proportion
of grasses is nearly double that of any part of the world.
Parry's Appendix."] The proportion varies from \ to \ in
different parts of the tropics. Among 3880 phanerogamous
plants found in equinoctial America by M. Bonpland and
myself, there are 654 Monocotyledones and 3226 Dicoty-
ledones ; here, therefore, the great division of Monocoty-
ledones forms I of phaenogamous plants. According to
Mr. Brown, this proportion is in the old world (India, equi-
noctial Africa, and New Holland) ^. Under the temperate
zone it is found to be %; France 1 : 4f ; Germany 1 : 4J;
North America, according to Pursh, 1 : 4i ; kingdom of Na-
ples 1 : 44; Switzerland 1:4^; Great Britain 1 : 3f ; [Sweden
1 : 3/V; but in Sicily, according to Presl, it is 1 : 5jV> which
is much too high]. In the frozen zone i,

" Glumace^e (that is to say, the three families of Juncese,
Cyperaceae, and Gramineae united). — Trap* ttJ Temp. ^;
Frozen \. This increase towards the north is due to the
greater prevalence of Junceae and Cyperaceae, which are much
more rare, as compared with other phaenogamous plants, in
the temperate and torrid zones. Comparing the species of
these three families, we find that Gramineae, Cyperaceae, and.
Junceae are in the tropics as 25, 7, 1 ; in the temperate parts
of the old world as 7, 5, 1 ; within the polar circle as 2f, 2§,
and 1. In Lapland there are as many Gramineae as Cype-
raceae; thence, towards the equator, Cyperaceae and Junceae
diminish much more than Gramineae. The form of Junceae
almost disappears in the tropics.

" Junce;e alone. — Trop. lio'. Temp. -gV> (Germany-^,
France -fa), [Sicily ?&$"]> Frozen ?V, [Melville Island -J^-].

" Cyperaceje alone. — Trop. America scarcely -g-j, Western
Africa ^ India ^, New Holland T\; Temp, perhaps 2*o»
(Germany Vp, France, according to De Candolle, ^, Den-
mark ^,) [Sweden rather more than 1V5 Sicily -jV]; Frozen i,,
in Lapland and Kamtchatka ; [Melville Island -iT].

" Gramineae alone. — Trop. I have always supposed iV 5 but
Mr. Brown finds for western Africa t1^ 5 for India TV; and
Mr. Horneman makes the proportion of Guinea jfo; Temp.

K K

498 GEOGRAPHY. BOOK VI.

Germany^, France-^, [Sweden not quite ^, Sicily A];
Frozen -fo [ Melville Island nearly £J.

u Composite. Not distinguishing plants of the plains from
those of the mountains, we found them in equinoctial America
■} and \; but of 534 compositae of our herbaria, only 94 were
found between the plains and 3000 feet of elevation ; a height
at which the mean temperature is 71° 3', equalling that of
Cairo, Algiers, and Madeira. From the plains to 6000 feet,
where the mean temperature is that of Naples, we found 265
compositae. Therefore the proportion of compositae in the
regions of equinoctial America, below 6000 feet, is from ^ to
-Jq. This result is very remarkable, inasmuch as it proves
that, within the tropics in the low and hot region of the new
continent, there are fewer compositae; and in the subalpine
and temperate regions, more than under the same conditions
in the old world. Mr. Brown finds for the Congo River and
Sierra Leone J^, for India and New Holland ^. In the
temperate zone compositae are, in America, }; and this is
probably the proportion borne by compositae on the very
high stations of equinoctial America, to the whole mass of
phaenogamous plants in the same places; at the Cape of
Good Hope |, in France •*» or more properly -f7, in Ger-
many ^, [in Sweden between tl and -^j, in Sicily rather less
than i]. In the frozen zone compositae are, in Lapland -—,
in Kamtchatka fa [ in Melville Island TV]'

" Leguminos^e. — Trop. America -j^, Indian, New Hol-
land -£, western Africa ^ ; Temp. France fa Germany fa
North America fa Siberia fa [Sweden fa Sicily £J;
Frozen fa [ Melville Island fa}.

"Labiate. — Trop.-fo; Temp. North America fa Ger-
many fa France fa [Sicily fa, Sweden A]; Frozen fa
[Melville Island 0]. The scarcity of Labiatae and Cruci-
ferae, in the temperate zone of the new continent, is a very
remarkable phenomenon.

" Malvaceae. — Trop. America 4V* India and Western Africa
^j, the coast of Guinea alone 4^ ; Temp, jfo; Frozen 0.

"Crucifer.^. — Trop. Scarcely any, except in mountainous
regions beyond from 7,000 to 10,000 ft. of elevation ; France
fa Germany ia, [Sweden fa Sicily fa Balearic Islands

BOOK VI. GEOGRAPHY. 499

according to Cambessedes ^-, Melville Island i] North Ame-

rica

T2*

RuBiACEiE. — Without dividing the family into several sec-
tions we find for the Tropics, in America ¥'g> in Western
Africa -^ ; for the Temperate zone, in Germany T\j, in France
•vV; for the frozen zone in Lapland ^. Mr. Brown separates
the great family of Rubiaceae into two groups, distinguished
by peculiar relations to climate. That of Stellatae without
stipulae principally belongs to the temperate zone ; it is almost
wholly absent under the tropics, except on the summit of
mountains. The group, with opposite stipulate leaves, (Cin-
chonacecc, Lindl.) belongs exclusively to equatorial regions.

" Euphorbiacejs. — Trop. America ^, India and New
Holland ^j, Western Africa ^ ; Temp. France -fa, Germany
th>* [Sicily 5^, Sweden T^, Balearic Islands &}; Frozen*
Lapland 7^.

"Ericem. — Trqp. America ^.j Temp. France T^T, Ger-
many Jy, North America ^\ ; Frozen, Lapland ^.

"Amentacejs.— Trop, America ^; Temp. France ^
Germany -^ N. America ¥V ; Frozen, Lapland ^V

(: Umbellifer^e. — Scarcely any in the tropics below 7000 ft.,
but taking together, in equinoctial America, both the plains and
the high mountains, too; in the Temp, zone much more in
the old than in the new world, France -fa, North America -^ ;
Frozen, Lapland ^l.

"In comparing the two worlds, we find in general in the new
continent, under the equator, fewer Cyperaceae and Cinchona-
ceae,and more Compositae ; in the temperate zone fewer Labiatae
and Cruciferae, and more Compositas, Ericeae, and Amentaceae,
than in the corresponding zones of the old world. The families
that increase from the equator towards the poles (according
to the method effractions) are Glumaceae, Ericeae, and Amen-
taceae ; those which diminish from the equator to the pole are
Leguminosae, Rubiaceae, Euphorbiaceae, and Malvaceae; the
families that appear to attain their maximum in the temperate
zone, are Compositae, Labiatae, Umbelliferae, and Cruciferae."

To these most instructive and interesting remarks Baron
Humboldt has added the following table, with which this sub-
ject must terminate.

k k 2

500

GEOGRAPHY.

BOOK VI.

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BOOK VI. GEOGRAPHY. 501

From what has now been said, it would seem that the forms
assumed by vegetation in different latitudes are dependent
upon particular conditions of climate and soil, and that it is to
variations of these conditions that we are to ascribe the differ-
ence between the Flora of the equator and of the polar regions.
And this is no doubt true : but there are, nevertheless, some
plants which have a remarkable power of adapting themselves
to all climates and circumstances ; and there are others which
readily naturalize themselves in climates similar to their own.
Of the latter, examples present themselves at every step ; all
the hardy plants of our gardens may in some sort be con-
sidered of this nature ; for although they do not grow spon-
taneously in the fields, they flourish almost without care in
our gardens. The pine apple has gradually extended itself
eastward from America, through Africa, into the Indian
Archipelago ; where it is now as common as if it were a plant
indigenous to the soil ; and in like manner the spices of the
Indies have become naturalized on the coast of Africa and in
the West Indian Islands. Of the former description the in-
stances are not numerous, but they are very remarkable. In
the woods of Georgia, in North America, grows the Rosa laevi-
gata, which, while all the other species of rose of that country
are entirely different from those of other regions, is identical
with the R. sinica of China ; to the Flora of which country,
that of North America has no resemblance. Samolus Valer-
andi is found all over the world, from the frozen north to the
burning south ; associated here with Amentaceae and similar
northern forms, and there mixed with palms and the genuine
denizens of the tropics. Above 350 species are said to be
common to Europe and North America, and even among the
peculiar features of the Flora of New Holland, Mr. Brown re-
cognised 166 European species. The presence of many of such
strangers may undoubtedly be referred to the agency of man,
by whom they have been transported from climate to climate,
along with corn and by other means; as, for example, at
Pont Juvenal, near Montpellier, the vicinity of which abounds
with Barbary plants ; the seeds of which are known to have
been brought across the Mediterranean along with the Bar-
bary wool, which is disembarked at that station. In like

k k 3

502 GEOGRAPHY. BOOK VI.

manner the various kinds of corn have been carried about from
country to country for the service of mankind, until their real
home has become doubtful. Medicago sativa abounds in
Chili, whither it has been transported by the Spaniards ; and
instances in abundance of similar cases could be produced.
But it must not thence be inferred, that all cases of species
growing in places far away from their kindred forms, are to
be referred to migration : for this, the agency of man, of
animals, of seas, of wind, and of torrents, will doubtless have
done a great deal ; but none of the causes, nor any other with
which I am acquainted, will explain the identity of the Calypso
borealis, Orchis viridis, and Betula nana of North America
and of Europe ; of the Potamogetons common to Europe and
New Holland ; of the Rosa, already adverted to, as common
to North America and China ; of the wide diffusion of Samo-
lus valerandi, and, most especially, of the identity of the
cryptogamic plants of various countries, plants incapable of
cultivation, unconnected with the purposes of man, and of all
others, the most difficult of transport under any form. To
us it appears that such plants must have been originally
created in the places where they now exist ; the contingent
circumstances under which they are found having been favour-
able to the particular mode of vegetable developement which
was necessary for their formation. And this may, I think, be
admitted, as a circumstance connected with the original
creation of the world, without having recourse to the theory
of some philosophers, that Nature exercises at this time the
power of producing plants without parents ; a subject upon
which Professor Link remarks, that " we find buried in the
earth the remains of plants which formerly existed, but which
are now unknown. New forms have, therefore, been produced
by nature different from the first. Wherever a salt spring
breaks out at a distance from the sea, its vicinity immediately
abounds with salt plants, although none grew there before.
When lakes are drained a new kind of vegetation springs up :
thus, when the Danish island of Zeland was drained, Vilny
observed Carex cyperoides springing up, although that species
is naturally not a native of Denmark, but native of the North
of Germany. Hence it is easy to infer, that some plants have
been produced at one time and others at another, some earlier

BOOK VI. GEOGRAPHY. 503

and some later : and to this cause may be attributed the smal-
ler number of species found upon islands than upon con-
tinents, the former having been produced the latest. Per-
haps plants change from one to the other, as certain organic
bodies when young belong to a less perfect class than when
they are older. On the naked rocks we find Lichens, on the
mud Confervas, in ancient strata the remains of Monocotyle-
donous plants, in more recent strata those of Dicotyledons."

In concluding this important and very interesting subject,
I must refer the reader who is desirous of further information
to the writings of Mr. Brown in the appendix to Captain
Flinders's Voyagers, and Captain Tuckey's Expedition to the
Congo : to M. De Candolle's Essay upon the Geography of
Plants, published in the 18th volume of the Dictionnaire des
Sciences Naturelles ; to the numerous writings of Baron Hum-
boldt; and to the observations upon the subject by Pro-
fessor Schouw, as translated in Brewster's Edinburgh Journal.

k k 4

504

BOOK VII.

MORPHOLOGY J OR, OF THE METAMORPHOSIS OF
ORGANS.

That part of botany which treats of the gradual transmut-
ation of leaves into the various organs of a plant, which shows
that bracteae are leaves affected by the vicinity of the fructifi-
cation, that the calyx and corolla are formed by the adhesion
and verticillation of leaves, that the filament is a form of
petiole, and the anther of lamina; and, finally, that the ova-
rium itself is a convolute leaf, with its costa elongated into a
style, and the extremity of its vascular system denuded under
the form of stigma, is called morphology.

This doctrine has already been treated of in this work, in
connection with the different organs of which mention has been
made ; but it is so curious and important as to deserve especial
mention. It seems to have originated with Linnaeus, was
deeply entered upon by the celebrated poet Gothe, has been
universally adopted in Germany, and been partially received
in France and England ; in the former country by Du Petit
Thouars, De Candolle, and others ; and in this kingdom by
most of the botanists of the present day.

The first idea of the subject appeared in the second volume
of the tenth edition of the Sy sterna Natar<v, published in
1759, in which Linnaeus thus expresses himself: — " Leaves
are the creation of the present year, bracteae of the second,
calyx of the third, petals of the fourth, stamens of the Jifth,
and the. stamens are succeeded by the pistillum. This is ap-
parent from ornithogalums, luxuriant plants, proliferous plants,
double flowers, and cardui."

Book vii. morphology. 505

In December, 1 760, these novel propositions were sustained
by Linnaeus in a thesis prepared in the name of his pupil Ull-
mark, called the Prolepsis Plantarum. The substance of this
paper I shall endeavour to condense, in order that it may ap-
pear how far the discoveries or hypotheses of some modern
writers are entitled to novelty ; leaving out, however, all that
relates to the physiological explanation given by Linnaeus of
his doctrine, which, being formed upon notions that, although
entertained at that time, are now known to be inconsistent
with facts, need not here be repeated.

Linnaeus commences by remarking, that " as soon as leaves
have expanded themselves in spring, a bud is observable in
the axilla of each. This bud swells as the year advances,
and in time becomes manifestly composed of little scales ; in
the autumn the leaves fall off, but the bud remains ; and in
the succeeding spring swells, disengages itself from its enve-
lopes, and becomes lengthened : when its outer scales have
dried up and fallen off, the inner ones are expanded into
leaves (like the wings of a butterfly emerging from its pupa),
which separate from each other by means of a gradual exten-
sion of the young branch, and presently each new leaf is found
to contain in its bosom a little scaly bud, which, in the follow-
ing season, will also be developed as a branch, with other
leaves and other buds. Now when I see a tree adorned with
leaves, and in the bosom of these leaves provided with its
little buds, it is natural to enquire of what do these buds con-
sist. Do they consist of the rudiments of leaves with their
gemmules, the latter of other leaves and buds, and so on to
infinity, or, at least, as far as the extension of the plant is
likely to proceed ? Nature organises living beings out of such
minute particles, and even from fluids themselves, that the
best eye may in vain seek to penetrate far into her mysteries.
I shall, however, endeavour to show that the composition of
buds does not extend further at one time than provision for
six years; just as, among animals, we find the little volvox
globator containing within the mother its children, grand-
children, great-grandchildren, and great-great-grandchildren
down to the sixth generation." The substance of the subse-
quent observations is this.

506 MORPHOLOGY. BOOK VII.

" If a plant, which has flowered and fruited for many suc-
cessive years in a pot, is transferred to a rich soil and warmer
station, it breaks forth into branches instead of flowers.
Hence it appears that branches and leaves can be produced
from the provision made for flowers, provided circumstances
are favourable to their development."

As to bractece, " the bulbs of hyacinths and ornithogalums
afford good evidence of their nature. Both bulbs and buds
are winter coverings of plants, with this difference, that bulbs
are the bases of leaves of the previous year, while buds are
the rudiments of leaves of a coming year. Wherever bulbs
grow, there are formed the persistent bases of leaves, within
which young leaves are to be developed : within these latter
leaves repose the buds or rudiments of future plants, exactly
the same as the buds of ti'ees. These buds consist of the ru-
diments of leaves of the succeeding year ; small indeed, but
containing in their axillae other rudiments of like nature.
Now, if it happens that such a plant flowers, the bud, which
would otherwise have produced leaves the year after, is con-
verted into a scape a year earlier ; whence it comes to pass
that the rudimentary leaves lying in the bud lose a part of
their nutriment, in consequence of the sap being drawn off to
the fructification : in consequence of which those leaves con-
tinue small, assume a different structure, easily wither, and
are called by botanists bracteae. Thus bracteae are nothing
but leaves which would have been developed another year if
the plant had not flowered."

As to the calyx. " That the calyx is only the approxi-
mated leaves of a plant, is apparent from several instances.
The calyxes of Pyrus and Mespilus are often expanded into
perfect leaves ; the rose offers a similar instance of the change.
The leaves of Mesembryanthemum barbatum are supplied
with a most curious apparatus of hairs ; and the calyx con-
sists of five pieces, in all respects similar to the leaves of the
stem. The calycine leaves, indeed, are often very small,
juiceless, and different from those of the stem, as if scales of
buds previous to their development ; but that they still are
nothing but leaves of the same nature as those of the stem,
must be concluded from this, that when plants, roses and

BOOK VII. MORPHOLOGY. 507

Genm rivale for example, become, in consequence of exces-
sive nutriment, proliferous, the calycine leaves, which before
were small and dry, expand into leaves in size, colour, figure,
texture, and substance, exactly like those of the stem. Hence
it is not to be doubted, that the calyx and the leaves of the
stem were in the beginning alike."

As to the petals, " It is often very difficult to distinguish
them from the calyx. The white corolla of Helleborus niger,
after flowering, assumes the green appearance of the calyx.
In luxuriant flowers of Rosa and Geum, the corolla some-
times becomes wholly green, and assumes the foliaceous na-
ture of the calyx. As the calyx is nothing but leaves, and as
each leaf contains in its axilla the rudiment of a plant con-
sisting of the rudiments of leaves of a future year, it follows
that the petals are of necessity the rudiment immediately
within the calycine leaves ; the petals, therefore, would have
been leaves another year, if flowers had not been produced."

As to the stamens. " From double flowers it is apparent that
stamens do change into petals and petals into calyx. This is
so well known that it need not be insisted on. Now, as from
the axilla of every leaf arises the rudiment of a plant, and
from the axilla of the calyx are produced the petals, which
are nothing but mere tender leaves, and as these petals must
have, like other leaves, the rudiments of leaves in their axilla,
it follows that stamens are so, for they can be transmuted into
petals, as the petals can into the leaves of the calyx."

As to the pistiUum. The evidence of this being also re-
ducible to leaves, is taken from a change observed in the
flowers of Carduus heterophyllus and tataricus, in which the
style was changed into two green leaves like bracteae, and
from the common conversion of the pistillum into leaves in
proliferous individuals of the rose, the anemone, and others.
I do not, however, find any clear evidence of Linnaeus having
entertained a distinct idea of the true origin and structure of
the pistillum.

Such were the sentiments of this great naturalist. I adduce
them, not only in justice to the memory of that highly gifted
man, but also because I know that his opinion carries with it,
especially in this country, just that degree of authority which

508 MORPHOLOGY. BOOK VII.

is requisite to fix attention upon a theory apparently too mys-
terious or paradoxical to make its way without some such
powerful assistance.

In the following remarks I shall endeavour to condense
what has been said by writers on morphology under two
heads : in the first, treating of regular metamorphosis, that is
to say, of that which is connected with the structure of all
vegetables ; and in the second, of irregular metamorphosis, or
of that which influences particular plants or parts of plants,
and which occurs only in occasional instances.

509

CHAPTER I.

REGULAR METAMORPHOSIS.

If the structure of a perfect plant is attentively considered, it
will be found to consist of a congeries of branches succes-
sively produced out of each other from one common stock,
and each furnished with exactly the same organs or append-
ages as its predecessor. This continues until the fructifi-
cation is produced, when an alteration takes place in the
extremity of the fructifying branch, which is incapable, gene-
rally speaking, of further prolongation ; but, as the branches,
before they bore fruit, were repetitions the one of the other,
so are the branches bearing fruit also repetitions of each
other. If a thousand sterile or a thousand fertile branches
from the same tree are compared together, they will be found
to be formed upon the same uniform plan, and to accord in
every essential particular. Each branch is also, under favour-
able circumstances, capable of itself becoming a separate in-
dividual, as is found by cuttings, budding, grafting, and other
horticultural processes. This being the case, it follows, that
what is proved of one branch is true of all other branches.

It is also known that the elementary organs used by nature
in the construction of vegetables, are essentially the same;
that the plan upon which these organs are combined, however
various their modifications, is also uniform ; that the fluids all
move, the secretions all take place, the functions are all regu-
lated, upon one simple plan ; in short, that all the variations
we see in the vegetable world are governed by a few simple
laws, which, however obscurely they may be understood by
us, evidently take effect with the most perfect uniformity.

Hence it is not only true, that what can be demonstrated
of one branch is true of all other branches of a particular
individual, but also, that whatever can be shown to be the

510 MORPHOLOGY. BOOK VII.

principles that govern the structure of one individual, will also
be true of all other individuals.

It is particularly requisite that this should be clearly under-
stood, in order that a just estimate may be formed of the
nature of the proofs to be now adduced in regard to the
doctrines of morphology. Whatever can be demonstrated to
be true, with regard to one single individual, is true of all
other individuals : whatever is proved with reference to one
organ, is proved by implication, as to the same oi'gan, in all
other individuals whatsoever.

Moreover, the fact of one organ being readily transformed
into another organ, is in itself a strong presumption of the
identity of their origin and nature; for it does not happen
that one part assumes the appearance and functions of another
if they are essentially different. Thus, while the functions of
the hand may be performed by the feet, as we know they oc-
casionally are in animals, nothing whatsoever leads the heart
to perform the functions or assume the appearance of the
liver, or the liver of any other organ. This is one of the
arguments of Linnaeus.

The first organ which requires consideration is the stipula.
It is not present in all plants; but, when it does exist, is
found at the base of the footstalk of the leaves. It generally
is a membranous process, with a bundle of vessels passing up
its centre ; or it is entirely destitute of a vascular system. In
the rose the former is the case ; but nothing is more common
than to find a leaflet accompanying the stipula; and in a
specimen of Rosa bracteata which I once had in my posses-
sion there were no stipulas, but, in their stead, two pinnated
exstipulate leaves. Hence stipulas are to be considered as
rudimentary leaves.

The bractese are the organs intermediate between the
leaves and the calyx. Their nature is extremely various,
sometimes having a greater resemblance to the leaves, and
sometimes to the calyx. In some roses, as R. canina, they
are obviously dilated petioles, to which a leaflet now and then
is attached : in other species, as R. spinosissima, they differ
in no respect from the other leaves. In the tulip a bractea is
occasionally present upon the scape, a little below the flower;

CHAP. I. REGULAR METAMORPHOSIS. 511

this is always of a nature partaking both of the leaf and the
flower. In Pinus abies the purple scale-like bracteae often
become gradually narrower, and acquire a green colour like
leaves. It has been stated by some botanists, that bracteae
are distinguishable from leaves by not producing buds in
their axillae ; but the inaccuracy of such a distinction is ap-
parent from a variety of cases. In Polygonum viviparum,
and all viviparous plants, the flowers themselves are converted
into buds within the bracteae. There is a bud in the axillae of
every bractea of the rose. The common daisy often bears
buds in the axillae of the bracteae of its involucrum ; in which
state it is commonly known in gardens by the name of hen
and chickens. In the permanent monster called Muscari
monstrosum, a small cluster of branches covered with minute
imbricated coloured bracteae is produced in lieu of each
flower. Here all parts of the fructification, instead of re-
maining at rest to perform their functions, are attempting, but
in vain, to become organs of vegetation; or, in other words,
to assume that state from which, for the purposes of per-
petuating the species, they had been metamorphosed by
nature. Hence it is clear that bracteae cannot be essentially
distinguished from leaves.

Such being the case with the bracteae, let us see if any
positive line of demarcation exists between them and the
calyx. With the calyx begins the flower properly so named ;
it forms what some morphologists call the outer whorl of the
fructification, and with it commences a new order of leaves,
— namely, those of the fructification, — said to be distinguished
from the leaves of vegetation by their constantly verticillate
arrangement, and by the want of buds in their axillae.
With the leaves of the fructification all power of further
increase ceases; the energies of the plant being diverted,
when they commence, from increasing the individual to mul-
tiplying the species. The general resemblance of the calyx
to the ordinary leaves of vegetation is well known : its green
colour, and tendency to develope itself into as many leaves as
it consists of divisions, especially in double roses, is so no-
torious that it need not be insisted on. In the case of Me-
sembiyanthemum barbatum, noticed by Linnaeus, there is no

512 MORPHOLOGY. BOOK VII.

difference whatsoever between the leaves of the calyx and
those of the stem. In a specimen of a cowslip now before
me, the calyx is formed of five perfect leaves, in no respect
different from the others, except in being a little smaller.
The resemblance, however, between the calyx and the stem
leaves is often not apparent ; but the identity of the calyx and
bracteae is usually more obvious. In Calycanthus, the transition
from the one to the other is so gradual, that no one can say
where the distinction lies ; and in numberless Ericas the
resemblance of the bracteae and calyx is perfect. The di-
visions of the calyx are also occasionally gemmiferous. A
case is mentioned by Roper, in which one of the sepals of
Caltha palustris was separated from the rest, and furnished with
a bud. And Du Petit Thouars speaks of a specimen of Bras-
sica napus, in which branches were produced within the calyx.

I have myself a monster of Herreria
parviflora {Jig. A), of the same na-
ture. From this it is apparent that
the divisions of the calyx are not
only not distinguishable from brac-
teae, but that there is often a strong
tendency in the former to assume
the ordinary appearance of leaves.
There is, however, another point to
which it is necessary to advert, in order to complete the proof
of the identity of calyx and leaves ; this is the verticillate ar-
rangement of the former.

Leaves are either opposite, alternate, or whorled ; and it has
been shown, in speaking of them, that these differences depend
wholly upon their greater or less degree of approximation. If
the leaves of a plant are rightly considered, they will be found
to be inserted spirally round a common axis ; that is to say, a
line drawn from the base of the lower leaf to that of the one
above it, thence continued to the next, and so on, would have a
spiral direction. When leaves become approximated by pairs,
the spire is interrupted, and the leaves are opposite : let the
interruption be a little greater, and the leaves become ter-
nate; and if the interruption be very considerable, what is
called a whorl is produced, in which several leaves are placed

CHAP. I. REGULAR METAMORPHOSIS. 513

opposite to each other round a common axis, as in Galium.
Now a whorl of this nature is exactly of the nature of a
calyx, only it surrounds the axis of the plant, instead of ter-
minating it. As we know that such approximations often
take place in the stem in the direct line of growth, when
the propulsion of the matter of vegetation exists in its greatest
activity, there is no difficulty in comprehending the possibility
of such an approximation constantly existing at the end of
the system of growth, where the propulsion of the matter
of vegetation ceases. But the calyx and more inner whorls of
the fructification do not always retain their verticillate posi-
tion ; on the contrary, they occasionally separate from each
other, and assume the same position with regard to the axis
of vegetation as is naturally proper to the leaves. This is
particularly striking in a very common, permanent monster of
Ulium album, known in the gardens by the name of the
double white lily. In this plant the whole verticillation of
die parts of fructification is destroyed ; the axis is not stopped
by a pistillum, but is elongated into a stem, around which the
white leaves of the calyx are alternately imbricated; and in
double tulips the outer whorl, representing the calyx, fre-
quently loses its verticillate arrangement, and becomes imbri-
cated like leaves of a stem. The same structure also occurs
in the double white Fritillaria meleagris. Hence it cannot
be doubted, that the calyx consists of leaves in a particular
state.

The corolla forms the second line or whorl of the fructi-
fication. It consists of several divisions, usually not green,
and always alternate with those of the calyx. It is a series
of leaves arising within those of the calyx, from which it is
sometimes, indeed, very easy to distinguish it; but from which
it is so often impossible to discriminate it, that the difference
between the calyx and corolla has been one of the most de-
batable subjects in botany. No limits can be found in Caly-
canthus ; the same is true of Illicium, and several similar
plants. In all Liliaceas, Asphodeleae, Orchideee, and Scita-
mineae, the only distinction that can be drawn between the
calyx and corolla is, that the one is inserted within the other ;
they are alike in figure, colour, texture, odour, and function,

L L

514> MORPHOLOGY. BOOK VII.

Whatever, therefore, lias been proved to be true of the calyx
is also true of the corolla. There are also cases in which the
petals have actually reverted to the state of leaves. In a
Campanula Rapunculus, seen by Roper, the corolla had
become five green leaves like those of the calyx ; the same
was found in an individual of Verbascum pyramidatum, de-
scribed by Du Petit Thouars ; proliferous flowers of Geum
and Rosa, in which the petals were converted into leaves, are
adduced by Linnaeus.

The third whorl, or series of the fructification, is occupied
by the stamens. These often consist of a single row, equal in
number to the divisions of the corolla, with which they are,
in that case, alternate. The exceptions to this in flowers with
a definite number of stamens are not numerous; and such as
do occur are to be considered as wanting the outer row of
stamens, and developing the second row instead. Thus in
Primulaceae, in which the stamens are opposite to the petals,
and therefore belonging to a second whorl, the first makes its
appearance in Schwenkia, which undoubtedly forms part of
the order, in the form of clavate or subulate processes arising
from the sinuses of the limb. These and similar processes,
which are far from uncommon in plants, and which are known
by a number of different names, such as scales of the orifice
of the corolla, glands, nectary, cup, &c. are in most cases me-
tamorphosed stamens. In Narcissus the cup is formed of three
stamens of the first row, become petaloid and united at their
margins; while the six, which form the second and third rows,
are in their usual state, and within the tube. This is shown,
firstly, by the frequent divisions of this cup into three lobes,
which then alternate with the inner row of perianthium, or
the petals ; secondly, by a distinct tendency in double Nar-
cissi, particularly N. poeticus, to produce abortive anthers on
the margin of the lobes of the cup; and, thirdly, by the
genus Brodiasa and its allies. In that genus the crown of the
original species consists of three petaloid pieces, not united
into a cup as in Narcissus, but wholly separate from each
other : in Leucocoryne ixioides these pieces are not petaloid,
but clavate ; and in Leucocoryne odorala the pieces have the
same figure as in L. ixioides, but almost constantly bear more

CHAP. I. REGULAR METAMORPHOSIS. 513

or less perfect anthers. That the anthers are mere alter-
ations of the margins of petals, there is no difficulty in de-
monstrating. In Nymphaea the passage from the one to the
other may be distinctly traced. In double roses the precise
nature of this metamorphosis is shown in a very instructive
way : if any double rose is examined, it will be seen that
those petals which are next the stamens contract their claw
into the form of a filament; a distortion of the upper part,
or lamina, also takes place ; the two sides become membra-
neous, and put on the colour and texture of the anther ; and
sometimes the perfect lobe of an anther will be found on one
side of a petal, and the half-formed, mis-shapen rudiment of
another on the opposite side. In Aquilegia vulgaris this
transformation is still more curious, but equally distinct : the
petals of that plant consist of a long sessile purple horn or
bag, with a spreading margin ; while the stamens consist of a
slender filament, bearing a small, oblong, two-celled yellow
anther ; in single and regularly formed flowers, nothing can
be more unlike than the petals and stamens ; but in double
flowers the transition is complete: the petals, which first
begin to change, provide themselves with slender ungues ; the
next contract their margin, and acquire a still longer unguis;
in the next the purple margin disappears entirely; two yellow
lobes like the cells of the anther take its place, and the horn,
diminished in size, no longer proceeds from the base as in the
genuine petal, but from the apex of the now filiform unguis :
in the last transition the lobes of the anther are more fully
formed, and the horn is almost contracted within the dimen-
sions of the connectivum, retaining, however, its purple
colour: the next stage is the perfect stamen. No further
evidence can, I think, be required of the formation of stamens
out of petals ; if more is wished for, the first double flower
that may present itself to the observer may be appealed to.
The conversion of stamens into green leaves is far more
uncommon ; this, indeed, very rarely occurs. It was seen
by Roper in the Campanula Rapunculus already referred to;
and Du Petit Thouars found the stamens of Brassica napus
converted into branches, bearing verticillate leaves. Thus it

ll2

516 MORPHOLOGY. BOOK VII.

appears that the stamens, like the petals, calyx, and bractea?,
are merely modified leaves.

We now come to the consideration of a fourth series of the
fructification, the discus : this is so frequently absent, and is
of so obscure a nature, that few morphologists take it into
their consideration. It is, however, necessary to understand
it, if possible, especially as, when present, it occasionally pre-
sents itself under very singular and various forms. In many
plants it consists of a mere annular fleshy ring, encompassing
the base of the ovarium ; in others it forms a sort of cup, in
which the ovaria are inclosed as in certain Pseonies ; and it
very frequently makes its appearance as hypogynous glands or
scales : it is almost always between the stamens and pistillum.
That it is not an organ of a distinct nature may, I think,
be safely inferred from its having no existence in a large num-
ber of flowers : but if it is not an organ of itself, it must be
a modification of something else ; and in that view, from its
situation, it would be referable either to the stamens or pis-
tillum. It has so little connection with the latter, from which
it always separates at maturity, that it can scarcely be referred
to it. With the stamens it has, perhaps, a stronger relation :
it consists of the same cellular substance as the connectivum
of the anthers ; is very often of the same colour; whenever it
separates into what are called hypogynous glands or scales,
these always alternate with the innermost series of stamens.
In the Paeony the discus may, in some measure, be compared
to the inner row of scales which exists between the stamens
and pistillum of the nearly related genus Aquilegia. M.
Dunal has noticed half the disk of a Cistus bearing stamens ;
and a variety of instances may be adduced of an insensible
gradation from the stamens to the most rudimentary state of
this organ.

The fifth and last series of fructification is the pistillum.
Let us first consider this organ in its simple state, and
then advert to it in a state of composition. The simple pis-
tillum, that of the pea for instance, consists of an ovarium,
bearing its ovula on one side in two parallel contiguous rows,
and at its upper extremity tapering into a style which termi-
nates in a stigma. If this organ be further examined, it will

CHAP. I. REGULAR METAMORPHOSIS. 517

be found that there is a suture running down each edge from
the style to the base ; it will be also seen that the ovula are
attached to one of these sutures, and that the style is an
elongation of the other ; further it will be perceived, that the
two sides of the ovarium are traversed by veins emanating
from the suture that terminates in the style, and that these
veins take a slightly ascending direction towards the suture
that bears the ovula. Now, if when the pod of the pea is
half grown, it be laid open through the suture that bears the
ovula, all these circumstances will, at that time, be distinctly
visible ; and if it then be compared with one of the leaflets of
the plant, it will be apparent that the suture bearing ovula
answers to the two edges of the leaf, the suture without ovula
to the costa, and the style to the mucro. Hence it might,
almost without further evidence, be suspected that the ovarium
was an alteration of the leaf; but if the enquiry be carried
further in other plants, this suspicion becomes converted into
certainty. In the first place, the suture without ovula, which
has been said to be the costa, is always external with respect
to the axis of fructification, as would be the case with the
costa of a leaf folded up and terminating the fructification.
In the next place, nothing is more common than to find the
pistillum converted either into petals or into leaves : its
change into petals is to be found in numerous double flowers ;
as, for example, double Narcissi, Hibiscus Rosa sinensis,
wall-flowers, ranunculuses, saxifrages, and others. These,
however, only show its tendency to revert to petals as the
representatives of leaves. The cases of its reverting to other
organs are much more instructive. In the double Ulex Eu-
ropaeus the ovarium is extremely like one of the segments of
the calyx; its ovuliferous suture is not closed: in the room of
ovula it sometimes bears little yellow processes, like minia-
ture petals, and its back corresponds to what would be the
back of the calyx ; no style or stigma are visible ; sometimes
two of these metamorphosed ovaria are present : in that case
the sutures which should bear ovula are opposite to each
other, just as the inflexed margins of two opposite leaves
would be. In Kerria Japonica, which is only known in our
gardens in a double state, the ovaria are uniformly little

l l 3

618 MORPHOLOGY. BOOK VII.

miniature leaves, with serrated margins corresponding to the
ovuliferous suture of the ovarium, and an elongated point
representing the style; their interior is occupied by other
smaller leaves. Nothing is more common among roses than
to find the ovaria converted into perfect leaves ; in such cases
the margins uniformly occupy the place of the ovuliferous
suture, and the costa that of the sterile suture. But the most
instructive and satisfactory proof of the pistillum being merely
a modified leaf, is to be found in the common double cherry
of the gardens. In this plant the place of the ovarium is
usually occupied by a leaf extremely similar to those of the
branches, but much smaller ; it is folded together ; its margins
are serrated, and, in consequence of the folding, placed so as
to touch each other; and they occupy the place of the ovuli-
ferous suture of a real pistillum. The costa of this leaf cor-
responds to the station of the sterile suture of the ovarium,
and is not only lengthened into a process representing a style,
but is actually terminated by a stigma. I think, therefore,
that all doubt as to the foliaceons nature of the pistillum must
cease. There is thus a greater identity of function between
the pistillum and the other series of the fructification than
would at first appear probable. We seldom, indeed, find it
converted into stamens, but it often takes upon itself the form
of petals, as has been shown above; and although cases are
very rare of pistilla bearing pollen, yet several instances are
known of ovula being borne by the stamens. This occurs
continually in Sempervivum tectorum; I have shown it to
happen in an Amaryllis, known in gardens as the double JBar-
badoes lily (see the Horticultural Transactions, vol. vi.) ; and
it is constantly the case in a particular variety of the com-
mon wall-flower, cultivated in the Apothecaries' garden at
Chelsea.

Thus we see that there is not only a continuous uninter-
rupted passage from the leaves to the bracteae, from bractese
to calyx, from calyx to corolla, from corolla to stamens, and
from stamens to pistillum, from which circumstance alone the
origin of all these organs might have been referred to the
leaves; but that there is also a continual tendency on the part
of every one of them to revert to the form of leaf. Some

HAP. I. REGULAR METAMORPHOSIS. 519

botanists say, that all this depends upon an alternation of
expansion and contraction, which may be compared to the
mechanical oscillation of the pendulum, and to the physical
alternation observed in animated beings and the periods of
life. The leaves, they say, are an expansion of vegetation,
and the flower a contraction of it ; and in the flower itself,
while the calyx is contracted, the corolla is dilated, the
stamens again are contracted, and the pistillum expanded;
and with the ultimate contraction of the ovulum ceases the
vegetable system.

All that has hitherto been said of the pistillum relates to it
only in its simple state. In a state of composition it differs
so much in appearance from its simple form, that all the old
race of botanists was entirely ignorant of the true theory of
its construction. No trace is to be found in the writings of
Linnaeus of any thing which can be construed into an acquaint-
ance with this subject : nor can I find an indication of it in
any writer before the appearance of Gothe's Versuch die
Metamorphose der Pftanzen zn Erkldren, in 1790. At section
78. of that work are the following remarkable words : —
" Keeping in view the observations that have now been made,
there will be no difficulty in discovering the leaf in the seed-
vessel, notwithstanding the variable structure of that part, and
its peculiar combinations. Thus, the pod is a leaf which is
folded up, and grown together at its edges, and the capsule
consists of several leaves grown together ; and the compound
fruit is composed of several leaves united round a common
centre, their sides being opened so as to form a communi-
cation between them, and their edges adhering together. This
is obvious from capsules, which, when ripe, split asunder ; at
which time each portion is a separate pod. It is also shown
by different species of one genus, in which modifications exist
of the principle on which their fruit is formed : for instance,
the capsules of Nigella orientalis consist of pods assembled
round a centre, and partially united ; in Nigella Damascena
their union is complete."

Having already spoken at length upon this subject, when
considering the structure of the fruit, it is not necessary
to repeat the arguments here. There is no doubt of the truth

l l 4

520 MORPHOLOGY. BOOK VII.

of the theory, which is now universally adopted by all philo-
sophical botanists.

As it may thus be proved that all the parts of a flower are
merely modified leaves, there can be no difficulty in admitting
the following propositions as the basis of morphology : —

" Every flower, with its peduncle and bracteolae, being the
developement of a flower-bud, and flower-buds being alto-
gether analogous to leaf-buds, it follows, as a corollary, that
every flower, with its peduncle and bracteolae, is a metamor-
phosed branch.

" And further, the flowers being abortive branches, what-
ever the laws are of the arrangement of branches with respect
to each other, the same will be the laws of the arrangement
of flowers with respect to each other.

" In consequence of a flower and its peduncle being a
branch in a particular state, the rudimentary or metamor-
phosed leaves which constitute bracteae, floral envelopes, and
sexes, are subject to exactly the same laws of arrangement as
regularly formed leaves." ( Outline of the First Principles of
Botany, edit. 2.)

Therefore all theories of structure inconsistent with these
propositions must of necessity be vicious. For this reason
there is no difficulty in rejecting the hypothesis of M. Dunal,
that in a flower every organ consists of two parts, one standing
in front of the other, and forming what he calls a chorisie ;
than which no doctrine more utterly unsupported by facts, or
more entirely irreconcilable with whatever is known of structure,
can easily be imagined. To admit it would be to overturn
all the admitted rules of philosophy, by exalting a few seeming
exceptions to great general laws above those laws themselves.

521

CHAPTER II.

IRREGULAR METAMORPHOSIS.

It is probable, that all plants have a particular range, in
some cases more extended than in others, to which they are
best suited in consequence of their constitutional peculiarities,
which become visible in consequence of the effect produced
by a change of situation, although not appreciable otherwise.
The two great agents by which they are affected, that is to
say, soil and atmosphere, will, in their natural situations, be
nearly uniform. And so long as this uniformity of the con-
ditions under which they exist continues, their structure will
remain unchanged ; but let an alteration take place, their
atmosphere, for instance, change from that of the valley to
that of the mountain; the soil from alluvial deposit to chalk
or slate, and the mean temperature under which they are
formed fall several degrees : or remove a plant from its native
spot, and cultivate it in the l'ich soil of a garden for several
generations ; thus submitting it to what may be called the
effect of domestication. Under such circumstances, an alter-
ation will be produced in the structure of the plant, which
will become manifest by external characters. This is what
is called irregular metamorphosis ; and may be considered
the cause of the endless varieties of form into which garden
plants are continually sporting. In a wild state these varieties
are comparatively rare ; while, on the contrary, new forms
miscalled species, are always starting up in every botanic
garden. In the garden of Berlin, Link states, that Ziziphora
dasyantha, after many years, changed to another form, which
might be called Z. intermedia.

But although there is no reasonable doubt that irregular
metamorphosis does take place in consequence of some change
in the conditions under which plants are formed, the cosmica
momenta of some writers, yet it is certain that we are entirely

522 MORPHOLOGY. BOOK VII.

ignorant of the specific causes by which metamorphoses are
effected. We know that the cellular tissue, and the secreted
matter or proper juices, are what chiefly manifest their sensi-
bility of change ; but beyond this we know absolutely nothing
whatsoever. In this want of information the simplest manner
of treating this subject is to take the parts of vegetation in
succession, and to state what is known of the irregular meta-
morphosis of each.

The roots and tubers undergo a vast variety of changes j
some of which are the effects of domestication, and others
produced in wild individuals. Some grasses, when growing
in situations more dry than those to which they have been
accustomed, acquire bulbs ; as if laying by reservoirs of
nourishment to meet the casual want of a sufficient supply of
food. Other roots sport, when domesticated, into various
forms and colours ; as is familiarly exemplified in all those
which supply our tables. In the turnip the form varies from
spherical to depressed, oblong, and fusiform ; the epidermis
from white to yellow, purple and green : the same may be
said of the radish. The celery, the root of which is fibrous
when wild, produces under domestication a fleshy round root
like that of a turnip, known in gardens by the name of
celeriac. The common potato, the colour of which is usually
yellow, produces a variety deeply stained, not on the epidermis
only, but through its whole substance with purple. The
parsnip varies from fusiform to spherical; and there are hun-
dreds of similar cases of which every body must be aware.

Metamorphosis of the stem is much less frequent than
those of the root. The stems of the common cabbage are
naturally hard and stringy ; but in a variety, called by the
French Chou moellier, the stem is succulent and fusiform ; and
in the Kohl Rabi it forms a succulent tumour above the
ground, in form and size resembling a turnip. In alpine situa-
tions the stem becomes shortened in proportion to the eleva-
tion at which it is produced, but it lengthens in low humid
situations. Domestication has also rendered tall stems mere
dwarf, and dwarf stems taller: the common Dahlia, the mean
height of which may be estimated at six feet, lias been reduced
by cultivation to a stature not exceeding three. Cabbages

CHAP. II. IRREGULAR METAMORPHOSIS. 523

and many culinary plants have undergone a similar change;
while the common hemp has sported into a gigantic variety
twice the usual size. The stem occasionally becomes fasciatcd ;
that is to say, assumes the appearance of a number of separate
stems, glued together side by side, as in the common cocks-
comb Celosia. This was formerly believed to arise from the
union of several stems ; a manifest error, as an inspection of a
dissected stem will prove : it is an extremely irregular form-
ation, something analogous to that which constantly obtains in
Bauhinia.

The leaves undergo a thousand metamorphoses, of which I
shall only select a few remarkable cases. They become suc-
culent and roll inwards, forming what gardeners call a heart ;
as in the cabbage and the lettuce. Their parenchyma extends
more rapidly than the veins and margins; this produces
puckering, as in curled leaves. If the parenchyma and margin
are together produced in excess, we then have what gar-
deners call a curl, as in the plants known by the respective
names of curled cress, curled savory, curled endive, &c. If
this tendency to parenchymatous developement proceed much
further, the surface is not merely puckered, but processes arise
from it in every direction, and occasionally assume grotesque
figures, or even the resemblance of other leaves : the Scotch
kail of gardeners is an instance of this. The parenchyma is
formed more slowly than the veins and margins ; this pro-
duces what are called cut or pinnatifid leaves, as in many
garden plants, such as the cut-leaved Fagus sylvatica, Ainu's
glutinosa, and others. Occasionally in compound leaves an
unusual number of leaflets is produced, as seven in some tre-
foils in room of three ; a doubly pinnate leaf in some roses in
lieu of a simply pinnate one. In other plants the reverse
occurs : there is a Dahlia, which constantly produces simple
leaves in room of compound ones.

In flowers irregular metamorphoses are extremelv common ;
they consist of a multiplication of the petals, of a transform-
ation of petals into stamens, and of a change in colour or in
smell. In roses the multiplication of petals is the nearly uni-
versal cause of the double state of their flowers ; in the Rose
CEillet, and many Anemones, impletion depends upon a con-

524> MORPHOLOGY. BOOK VII.

version of petals into stamens. I have, in a paper read before
the Horticultural Society, and published in the sixth volume
of their Transactions, endeavoured to show that these changes
always take place in the order of developement, or from cir-
cumference to centre ; that is to say, that the calyx is trans-
formed into petals, the petals into stamens, and the stamens
into ovarium ; but that the reverse does not occur. It is
there observed, that alterations of another kind may happen,
such as changes in the appearance of the stamens occasioned
by abortion ; but such metamorphoses are to be considered
imperfect attempts on the part of particular organs to revert
to their primitive forms. It is further remarked, that if me-
tamorphosis took place from centre to circumference, or in a
direction the inverse of developement, it would not be easy to
show the cause of the greater beauty of double than of single
flowers; because the inevitable consequence of a reversed
order of transformation would be, that the rich or delicate
colour of the petals, upon which all flowers depend for their
beauty, would be converted into the uniform green of the
calyx. Such a change, therefore, instead of producing a
flower more beautiful than its original, would tend to destroy
its beauty. But if the true order of alteration be from the
circumference to the centre, and if the different organs of
fructification are only susceptible of being converted into
those which are next them, and the axis of inflorescence, and
if no retrograde action takes place, the reason of the superior
beauty of double flowers will be manifest. In the latter case
the calyx may, indeed, throw off its dull green colour and
assume the vivid hues of the petals, as in the Pasony and
primrose, and the petals may dilate themselves, and in at-
tempting to perform the functions of stamens may multiply
and transform themselves into a hundred grotesque and cu-
rious appearances ; but no diminution of beauty or loss of
brilliant colours will take place. Such were the opinions I
ventured to entertain in 1825; they concern a subject pecu-
liarly exposed to doubt and difference of opinion : but I
think that the weight of evidence is in favour of those opi-
nions rather than the contrary.

With regard to colour, its infinite changes and metamor-

CHAP. II. IRREGULAR METAMORPHOSIS. 525

phoses in almost every cultivated flower can be compared to
nothing but the alterations caused in the plumage of birds, or
the hairs of animals by domestication. No cause has ever
been assigned to these phenomena, neither has any attempt
been made to determine the cause in plants. We are, how-
ever, in possession of the knowledge of some of the laws
under which change of colour is effected. A blue flower will
change to white or red, but not to bright yellow ; a bright
yellow flower will become white or red, but never blue. Thus
the hyacinth, of which the primitive colour is blue, produces
abundance of white and red varieties, but nothing that can be
compared to bright yellow ; the yellow hyacinths, as they are
called, being a sort of pale yellow ochre colour verging to
green. Again, the ranunculus, which is originally of an
intense yellow, sports into scarlet, red, purple, and almost any
colour but blue. White flowers, which have a tendency to
produce red, will never sport to blue, although they will to
yellow ; the rose, for example, and Chrysanthemums. It is
also probable that white flowers, with a tendency to produce
blue, will not vary to yellow ; but of this I have no instance
at hand.

Smell varies in degree rather than in nature ; some plants,
which are but slightly perfumed, as the common China rose,
acquire a powerful fragrance when converted to the variety
called " the sweet-scented ;" but I am not acquainted with any
case among flowers in which a positive difference of smell
exists in two varieties of the same species.

Metamorphoses of the fruit are very common, and administer
largely to the wants of mankind. They consist of alteration
in colour, size, flavour, smell, and structure. The wild blue
sloe of our hedges has, in the course of ages, by successive
domestication, been converted into the purple, white, and yel-
low plums of our desserts. The wild crab is the original from
which have sprung the many coloured, Proteus-like variety of
the apple; some of which are destitute of smell, others scented
like the pine apple, and a few partaking of the perfume of the
rose. In peas the parchment-like lining of the pod occa-
sionally disappears, and the whole substance of the seed vessel
consists of lax cellular tissue. In the orange a second fruit

526 MORPHOLOGY. BOOK VII.

is sometimes produced in the inside, agreeing in all respects
with the outer fruit, even in peel ; this is doubtless due to an
attempt at producing a second series of pistilla. In a variety
of citrons called the fingered shaddock, well known in China,
this tendency to form a second row of pistilla is not only in
excess, but the cells of the fruit, in attempting to separate
themselves into the simple individuals of which the fruit of
the shaddock is ordinarily composed, divide it into distinct
lobes irregularly arranged round a common axis.

Having thus passed in review the irregular metamorphoses
of plants through all the different parts, there still remains a
subject on which it is requisite to say a kw words. This is
the permanency of such metamorphoses, or their capability
of being perpetuated by seeds. It is a general law of nature,
that seeds will pei-petuate a species but not a variety; and
this is no doubt true, if rightly considered : and yet it may
be urged, if this be so, how have the varieties, well known to
gardeners and agriculturists, for many years been unceasingly
carried on from generation to generation without change ? The
long, red, and round white radishes of the markets, for in-
stance, have been known from time immemorial in the
same state in which they now exist. The answer is this.
A species will perpetuate itself from seed for ever under any
circumstances, and left to the simple aid of nature : but acci-
dental varieties cannot be so perpetuated ; if suffered to be-
come wild, they very soon revert to the form from which they
originally sprung. It is necessary that they should be cul-
tivated with the utmost care ; that seed should be saved from
those individuals only in which the marks of the variety are
most distinctly traced ; and all plants that indicate any dis-
position to cast off their peculiar characteristics should be
rejected. If this is carefully done, the existence of any variety
of annual or perennial plant may undoubtedly be prolonged
through many generations ; but in woody plants this scarcely
happens, it being a rare occurrence to find any variety of tree
or shrub producing its like when increased by seed.

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EXPLANATION OF THE PLATES.

N. B. All the figures in the plates, of which the following is an explanation,
are more or less magnified : the drawings from which they have been pre-
pared are in all cases original, except where it is stated to the contrary.

PLATE I.

Fig. 1 . A small portion of a section of the cellular tissue of the pith of Caly-
canthus floridus, showing the pore-like spots upon the membrane.

Fig. 2. A section of the leaf of Lilium candidum, after A. Brongniart • a cu-
ticle of the upper surface; b, ditto of the lower surface; c, stomata cut through
in different directions; these last are seen to open into cavities in the paren-
chyma ; d, upper layer of parenchyma ; e, intermediate ditto ; /, lower ditto.

Fig. 3. Cubical cellular tissue, passing gradually into prismatical, from the stem
of the gourd, cut vertically ; after Kieser.

Fig. 4. Fibres forming arches in the endothecium of Linaria cymbaiaria ; after
Purkinje.

Fig. 5. Fusiform cellules in the wood of a young branch of Viscum album •
after Kieser; a, common hexagonal cells of the pith, with grains of amydon
sticking to their sides ; 6, fusiform cellules, considered by Kieser to be pierced
with holes ; c, other cells of the same figure, with lines of dots spirally arranged
on the membrane; d, others, in which the dots are run into lines; e,f, others,
in which the cellules have all the appearance of short spiral vessels. Kieser
considers these not as spiral vessels but as cellules of a peculiar kind, replacing
spiral vessels in the viscum.

Fig. 6. A portion of the cuticle of Billbergia amaena, with the membrane torn
on one side, showing that it does not tear with an even edge, but breaks into
little teeth.

Fig. "(• Muriform cellular tissue, forming the medullary processes of Platanus
occidentalis. Each cellule contains particles of brownish matter of very
irregular size and form.

Fig. 8. a, Glandular hairs of the peduncle of Primula sinensis; 1, the glandular
apex more highly magnified, with a particle of the viscid secretion of the species
on its point; 2, the apex of another hair, showing that the end is open, a coni-
cal piece of the viscid secretion lying in the orifice: b, a hair of Dorstenia,
showing the cellular base from which it arises, and that it consists of a single
hollow conical curved cell.

Fig. 9. A branched hair from the cilia of the leaf of a species of Verbascum.

Fig. A. A simple coloured hair in Dichorizandra rufa.

Pig, B. A hair with tumid articulations from the leaf of Gesnerla tuberosa.

528 EXPLANATION OF THE PLATES.

Fig. 10. a, Stellate hairs from the leaf of a species of Hibiscus; b, a scale of

the calyx of Eloeagnus argentea ; c, a hair of Chrysophyllum Cainito.
Fig. 1 1 . Reticulated cellular tissue from the testa of Maurandya Barclayana.
Fig. 12. Spiral oblong cellules lying among the parenchyma of the leaf of

Oncidium altissimum.
Fig. 13. Deep columnar cellules, with parallel fibres from the endothecium of

Calla sethiopica; the top of each cell being flat; after Purkinje.
Fi". 14. Arched fibres connected by a membrane in the endothecium of Nym-

phaeaalba; after Purkinje.
Fig. 1 5. Flat oval cellules, witli marginal incisions in the endothecium of Phlomis

fruticosa; after Purkinje.
Fig. 16. One of the elastic fibres upon the testa of Collomia linearis, unrolled

spirally, and lying within its mucous sheath ; magnified 500 times.
Fig. 17. A part of one of the elaters of a Jungermannia, showing a broad spiral

fibre loosely twisted inside a transparent tubular membrane, with a dilated

thickened mouth.
Fig. 18. Convex membranes, with lateral radiating fibres, forming together im-
perfect cells ; in the endothecium of Veronica perfoliata ; after Purkinje,
Fig. 19. Radiating fibres, in the place of cellules in the endothecium of Polygala

chamaebuxus; after Purkinje.
Fig* 20. Prismatical depressed cells, with straight fibres on the walls ; from the

endothecium of Polygala speciosa ; after Purkinje.

PLATE II.

Fig. 1. Common woody fibre; a, slightly magnified; b, very highly magnified,
and shown as seen by transmitted light ; the extremities only are seen : c, cel-
lular tissue.

Fig. 2. Woody fibre from the leaf of Oncidium altissimum, from a preparation
by Mr. Griffith. In this there are small tubercles growing from the surface of
some of the fibres, irregularly, or arranged in a spiral direction ; a is magnified
1 80 times ; at b, which is magnified 350 times, the form of the tubercles is more
distinctly shown ; and it is seen that small granules are contained within
the fibre.

Fig. 3. The dotted ducts of Zamia horrida. The little oval spaces that have
been supposed to be holes, are shown to be opaque ; most of them are oblique ;
but some of them are exactly transverse, rounder, and have a distinct line
passing through their longer axis.

Fig. 4. Woody fibre from the stem of Calycanthus floridus : in this the sides
of the tubes are marked with small oval dots, exactly as in Zamia.

Fig. 5. A minute portion of a section of the wood of a species of Gnetum from
Tavoy ; a, woody fibre, filled with loose and rather angular particles of greenish
matter; b, glandular woody fibre, showing its large size in proportion to the
other, and the appearance of its glands.

Fig. 6. A vertical radiant section of the wood of yew, magnified 250 times;
after Kieser; showing what he calls the spiral porous cells. The spires vary
from one to four in each cell ; and the glands, when present, are always situated
between the spires, as at a, b, e, and g. Some of the cellules have no glands,
as c, d,f, h, i. The yew has true spiral vessels besides these.

Fig. 7. A small portion of a vessel in the wood of an Ephedra from Chili,

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EXPLANATION OF THE PLATES. 529

taken from the vicinity of the medullary sheath : its membrane is distinctly
perforated at the upper part with oval holes : at the lower part the place of
these holes is occupied by glands like those of Gnetum, in fig. 5. ; or of Abies,
in fig. 8. It would therefore seem, that the oval holes in the membrane of
Ephedra are places from which the glands have fallen. Magnified 350 times.

Fig. 8. A vertical radiant section of the wood of Pinus Abies, showing the
glands upon the walls of woody fibre, magnified 520 times ; after Kieser ; but
corrected by showing that the glands are convex, and the supposed pores in
their centre often opaque.

Fig. 9. The termination of a spiral vessel, extracted from the root of a hyacinth
by Mr. Valentine : this shows distinctly the enveloping membrane.

Fig. 10. A fragment of a spiral vessel, bent abruptly to show that it is cylindrical
and not flat ; magnified 500 times.

Fig. 1 1. A spiral vessel, with each twist composed of four fibres, from the stem of
Nepenthes distillatoria. This is the largest spiral vessel yet known.

Fig. 12. A minute portion of a transverse section of an Indian tree, showing a
medullary ray, a ; the mouths of several bundles of ducts, bbb ; and the ends
of the woody fibre, c c,dd, in which the latter are imbedded. The wood of
this plant is exceedingly compact ; evidently owing to the denseness and
stoutness of the woody fibre.

Fig. 1 3. Two vessels from the stem of Impatiens balsamina ; magnified 1 30 times ;
after Kieser : a is a duct, with the spires broken in some places, and inoscu-
lating in others, so as to form the reticulated vessel of this author ; b, a spiral
vessel, with the spires broken at the top into rings.

Fig. 14. A horizontal section of the stem of Tropaeolum majus, magnified
130 times; after Kieser. This is to show the intercellular passages, which are
unusually large ; at a they are empty ; at b filled.

Fig. 15. A tangental section of Sassafras wood, magnified 130 times; after
Kieser ; a a, two banded dotted vessels ; or, as Kieser calls them, punctuated
spiral vessels ; b b, the mouths of the medullary rays, showing how they are
connected with the bark.

Fig. 16. Dr. BischofF's representation of the manner in which spiral vessels pass
successively into annular and dotted ducts. This figure is imaginary ; but
Dr. BischofF asserts that he has actually seen such a vessel in the garden
spinage. (Spinacia oleracea.)

Fig. 17. Two sorts of dotted vessels from the wood of Phaseolus vulgaris, mag-
nified 1 30 times ; after Kieser : a, has the bands much more nearly approx-
imated than b, in which the spaces between the bands is almost fusiform.

Fig. 18. A bundle of ducts from the stem of a Lycopodium ; from a prepar-
ation by Mr. Griffith : this shows the manner in which such vessels are packed
together when in situ, and their terminations.

Fig. 19. A dotted duct and short woody fibre from the stem of Phytocrene
gigantea; from a drawing by Mr. Griffith, in Dr. Wallich's Planta Asiaticce,
t. 216.

Fig. 20. The same, from the same authority, showing that this sort of vessel is
really composed of short cylindrical cellules, placed end to end, and opening
into each other.

Fig. 21. A section of the cyst, or receptacle of oil in the rind of a lemon, showing
that it is a mere cavity built up of cellular tissue.

M M

530 EXPLANATION OF THE PLATES.

PLATE III.

Fig. 1. A cluster of six-sided air-cells from the stem of Limnocharis Plumieri :
they are formed entirely of prismatical cells ; a a, partitions dividing the air
cells in two.

.Fig. 2. A partition or diaphragm of the last-mentioned plant, showing the open
passages that exist at the angles of the cells. When dry the rims of the
passages are dark, as at a : when immersed in water, the dark rim disappears,
and the whole partition has the uniform appearance of b.

Fig. 3. A portion of the cuticle, and a stoma, of the leaf of Oncidium altissimum ;
a, the stoma, formed of two parallel glands or cells, which open by curving
outwards. In this plant the stomata are very minute and few : on the mem-
brane of each mesh of the cuticle are found sticking from four to six spherical
semi-transparent green globules.

Fig. 4. Stomata of Strobilanthes Sabiniana. They are very large, and crowded
together in an irregular manner.

Fig. 5. Ditto of Croton variegatum : this is an instance of a cuticle with sinuous
lines. The orifice of each stoma is closed up with brownish matter.

Fig. 6. A stoma of Canna iridiflora.

Fig. 7. A cavity beneath the cuticle, in the parenchyma of Begonia sanguinea ;
seen from the inside, so that the cuticle is farthest from the eye. It is divided
by sub-cylindrical cellules into five spaces, in each of which there lies a
stoma.

Fig. 8. One of the stomata of the same, more magnified, and showing that the
medial line does not touch either end, and that the cavity of the stoma is filled
with granular matter.

Fig- 9. Stomata of the under side of the leaf of Caladium esculentum, with a
portion of cuticle. These appear to be somewhat angular cellules, occupying
the centre of every area of the cuticle. The stoma consists of an oval space,
in the centre of which is a narrow cleft, with a border distinctly coloured
orange or brownish, and having no communication with the circumference :
the space between the cleft and the latter filled with a pale green granular
substance. The cleft is sometimes seen closed, as at a, and then there is
scarcely any appearance of a border.

Fig. 10. Cuticle and stomata of Yucca gloriosa: the latter lie in square areolae,
and consist of two parallelograms lying parallel with each other. Small sphe-
roidal bodies, having a luminous appearance under the microscope, stick here
and there to the inside of the cuticle.

Fig. Hi Stomata of Limnocharis Plumieri. These also lie in square areolae,
but they have the ordinary structure : they are found in different degrees of
openness, or even quite closed, upon a small piece of the same specimen.

Fig. 12. Stamen of Lemna trisulca: anthers bursting vertically.

Fig. 13. Stamen of Polygonum Convolvulus; a, seen in front ; b, from behind;

c, the connectivum of the anther.
Fig. 14. Stamen of Correa alba ; a, seen in front ; b, from behind.
Fig. 15. Stamen of Stachys sylvatica; a, filament; b, connectivum; c, anther,

its lobes separated at the base by the connectivum.
Fig. 16. Anther of Alchemilla arvensis ; one-celled, and bursting transversely.
Fig. 17. Stamen of Scrophularia chrysanthemifolia ; a, part of the filament, and

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EXPLANATION OF THE PLATES. 531

the anther, which is one-celled, after bursting ; b, the same, before the de-
hiscence of the anther.

Fig. 18. Anther of Lamium album ; its lobes, as in fig. 16., separated at their
base by the large connectivum.

Fig. 1 9. Stamen of a species of Zygophyllum ; a, the anther ; b, the filament ;
c, the scale to which the filament adheres.

Fig. 20. The one-celled anther and filament of Callitriche.

Fig. 21. The stamen of Sparganium ramosum.

Fig. 22. The stamen of Vaccinium amaenum ; a, the pores by which the anther
bursts.

Fig. 23. The anther of Begonia Evansiana ; a, the oblique immersed cells ;

b, the connectivum.

Fig. 24. Anther of Cucumis sativa ; a, seen from the front ; b, from behind ;

c, the connectivum ; d, the sinuous lobes of the anther.

Fig. 25. Stamen of Hermannia flammea; a, filament; b, scale to which the
latter has grown.

Fig. 26. Halved stamen of Synaphea dilatata, after Ferdinand Bauer; a, fila-
ment ; b, connectivum ; c, single lobe of the anther after bursting.

Fig. 27. Stamen of Eupomatia laurina, after the same.

Fig. 28. Stamen of Cephalotus follicularis, after the same ; a, a granular con-
nectivum.

Fig. 29. Stamen of Pterospora Andromedea ; a, an appendage of the anther.

Fig. 30. Stamen of Securinega nitida ; the cells opening transversely.

Fig. 31. Stamen of Chloranthus monostachys; a, connectivum.

Fig. 32. Stamen of Eriodendron Samaiima, after Von Martius ; anther sinuous
and one-celled.

PLATE IV.

Figs. I, 2, 3. Different views of the stamens and stigma of Stylidium violaceum,
after Ferdinand Bauer ; a a, anthers ; b, a column formed by the union of their
filaments ; c, a cup-like disk, consisting of the flattened and united apices of
the filaments ; d, the stigma, the style of which is united with the column of
filaments through its whole length. Fig. 1. The anthers when burst, seen in
front ; fig. 3. the same, from behind ; fig. 2. the anthers pushed aside so as to
show the stigma.

Fig. 4. Stamen of Rhynchanthera cordata, after Von Martius ; a, a minute mem-
brane that separates the filament d from the elongated connectivum c ; b, the
attenuated beak-like apex of the anther, opening by a single pore at the point.

Fig. 5. Stamen of Lasiandra Maximiliana, after Von Martius ; a, dilated bases of
the two cells of the anther; 6, pore at the apex, through which the pollen is
discharged.

Fig. 6. Stamen of Glossarrhen floribundus, after Von Martius; a, a dilated
petaloid connectivum, to the face of which the lobes of the anther adhere;
b, the filament.

Fig. 7. Stamen of Lacistema pubescens, after Von Martius; a, filament;
b, forked connectivum ; c c, separated lobes of the anther.

Fig. 8. Stamen of Gomphrena leucocephala, after Von Martius ; a, broad dilated
two-toothed filament, bearing a linear one-celled anther.
M M 2

532 EXPLANATION OF THE PLATES.

Fig. 9. Stamen of Humirium floribundum, after Von Martius ; a, a large tu-

berculated petaloid connectivum.
Fig. 10. Stamen of a species of Cryptocarya, from Chili, in which the anther

opens, as in other Laurineae, by valves that roll back when they separate ;

a, one lobe of the anther, with the valve not separated ; b, the other lobe, with

the valve in the act of rolling back ; c c, abortive stamens under the form of

Fig. 11. Stamen of Berberis vulgaris, exhibiting the same phenomenon ; a, valve
closed ; b, valve separated and recurved.

#*# All the following figures of pollen are taken, with scarcely any alteration,
from Purkinje, and are drawn to the same scale, so that their relative sizes
are known.
Fig. 12. Pollen of Stratiotes aloides.

13. Calla aethiopica.

14. Elytnus sabulosus.

15. Avena latifolia.

16. Scirpus romanus.

17. Pancratium declinatum.

18. Populus alba.

19. Mirabilis Jalapa.

20. Urtica dioica.

21. Armeria fasciculata.

22. Plumbago rosea.

23. Cineraria maritima.

24. Salvia interrupta.

25. Stachytarpheta mutabilis.

26. Polygala spinosa.

27. Heracleum sibiricum.

28. Acacia lophantha.

29. Iresine diffusa.

30. Fuchsia coccinea.

31. Scorzonera radiata.

Fig. 32. Grains of pollen of Gesneria bulbosa emitting their tubes ; magnified
180 times. The tube is of extreme tenuity, and may be withdrawn from
the stigmatic tissue with great facility. Masses of granular matter may be
seen descending the tubes at irregular intervals.

Fig. S3- A grain of pollen of the same plant, with its tube magnified 500 times ;
this shows that the tube is an extension of the outer membrane of the grain of
pollen, if the latter was coated by more than one. The granular matter is
seen passing down the tubes, and quitting the grain of pollen, which finally
becomes a transparent empty vesicle.

Fi". 34. Grain of pollen of Datura stramonium, emitting its tube ; after Brong-
niart ; a, pollen-tube.

Fig. 35. Grain of pollen of Ipomasa hederacea, emitting its tube ; after Brong-
niart ; a, pollen-tube.

/'/„/, I

EXPLANATION OF THE PLATES. 533

Fig. 36. Mode in which the pollen acts upon the stigma in OEnothera biennis :
a a, pollen-tubes ; b b, tissue of the stigma into which these tubes penetrate ;
after Brongniart.

Fig. 37. Mode in which the pollen acts upon the stigma in Antirrhinum majus;
after Brongniart : the pollen sticks to the surface of the stigma, and the tubes
plunge down between the utricles of cellular tissue, of which the stigma
consists.

Fig. 38. A grain of pollen of the same plant with its tube, more highly mag-
nified : a, the pollen-tube.

PLATE V.

Fig. 1 . Vertical section of the ovarium of Dictamnus albus ; a, gynophorus, or
elongated base of the ovarium ; b, base of the style ; c, cavity where the car-
pella have not united ; d, cell ; e, placenta, with ovula attached to it.

Fig. 2. Transverse section of the same in a more advanced state, where the car-
pella are beginning to separate : a a, carpella ; b, an ovulum cut through ;
c, placenta.

Fig. 3. Pistillum of Coriaria myrtifolia ; consisting of five carpella, each bearing
a single linear stigma, and collected round a common elevated axis, the base of
which is seen at a.

Fig. 4. Ovarium of Lamium album ; a, base of the style ; b, carpella pressed
together into a square concave body; c, fleshy lobed disk.

Fig. 5. Pistillum of Pinguicula vulgaris; a, ovarium; b, style; c, stigma con-
sisting of two very unequal lobes.

Fig. 6. A vertical section of the same ; a, the central free placenta ; b, ovula ;
c, point where the placenta is connected, before fertilisation, with the stig-
matic tissue.

Fig. 7. A perpendicular section of the pistillum of Vaccinium amaenum ; a,
inferior ovarium combined with the tube of the calyx ; b, limb of the calyx ;
c, epigynous disk ; d, placenta ; e, ovula ; f, style ; g, stigma.

Fig. 8. A transverse section of the ovarium of Hydrophyllum canadense, showing
its remarkable placentation ; a, wall of the ovarium ; b, left placenta ; c, right
placenta ; e, one of their points of union, the other is seen on the opposite
side ; d, a fleshy secreting annular disk. In this case, two placenta? grow up
face to face from the base of the ovarium, and gradually unite at their edges, e,
enclosing the ovula within the cavity they thus form ; this is proved by Ne-
mophila, in which the placentation is the same, except that the placenta? are
always distinct from each other ; one of these placentae, the ovuliferous face
turned towards the eye, is represented at fig. 8.

Fig. 9. A perpendicular section of the inferior ovarium of Thamnea uniflora,
after A. Brongniart; a, tube of the calyx ; b, wall of the ovarium ; c, epigynous
disk ; d, ovula collected round a columnar placenta.

Fig. 10. Transverse section of the ovarium of Viola tricolor, showing its parietal
placentation ; a, one of the three placentas.

Fig. 11. Stigma of the same plant, which is inflated and hollow, with an orifice
obliquely situated at its apex.

Fig. 12. Bifid stigma of Chloanthes staechadis, after Ferdinand Bauer.

Fig. 13. Hairy apex of the style and stigma, with its indusium, of Brunonia
australis, after Ferdinand Bauer; a, stigma; b, indusium.
M M 3

534 EXPLANATION OF THE PLATES.

Fig. 14. The same, divided perpendicularly ; a, stigma; b, indusium.

Fig. 15. Stigma of Banksia coceinea, with a part of the style, after Ferdinand
Bauer.

Fig. 16. The earliest state of the ovula of Cucumis anguria; this, and the
succeeding figures, to 25 inclusive, are after Mirbel.

Fig. 17. Three of these ovules in a more advanced state.

Fig. 18. An ovulum at the period when the apex of the nucleus a is just ap-
pearing through the primine. The foramen has already become oblique with
respect to the apex of the ovulum.

Fig. 1 9. An ovulum of the same, at the period when the secundine is appearing
through the foramen ; a, nucleus ; b, border of secundine ; the nucleus is now
more oblique than before.

Fig- 20. An ovulum of the same, at a subsequent period, but still long before
the expansion of the flower ; the several parts are more developed ; the
nucleus, which at first was terminal, has now become lateral, and is evidently
turning towards the base of the ovulum : a, nucleus ; b, border of secundine.

Fig. 21. An ovulum of the same after fertilisation ; in the interval between this
state and the last, the primine has grown over the secundine and nucleus ; the
apex of the latter has turned completely to the base of the ovulum ; and the
foramen is contracted into the little perforation at a.

Fig. 22. Ovulum of Euphorbia lathyris, in a very young state, long before the
expansion of the flower ; a, kind of cap projecting from the wall of the ovarium,
and into which the apex of the nucleus b is inserted ; this hood finally closes
over the foramen, into which it protrudes as the nucleus retreats ; c, the
primine ; the secundine is a similar cap included within the primine.

Fig. 23. Very young ovulum of Hutu graveolens ; a, the primine ; b, the se-
cundine ; c, the nucleus : in the end the primine extends, contracts at its
foramen, and closes over the secundine and nucleus.

Fig. 24. Vertical section of an ovulum of Alnus glutinosa ; a, the umbilical
cord ; b, foramen ; c, primine (and secundine perhaps united with it) ; d, nu-
cleus ; e, vessels of the raphe ; f, place of the chalaza.

Fig. 25. An oblique vertical section of the fertilised ovulum of Tulipa ges-
neriana ; a, foramen of the primine (or Exostome) ; b, foramen of the
secundine (or Endostome) ; c, primine ; d, secundine ; e, nucleus, its apex
concealed within that of the secundine ; f, vessels of the raphe ; g, place of
the chalaza.

Fig. 26. Ovulum of Lepidium ruderale ; after A. Brongniart : a, umbilical
cord ; b, foramen ; c, point of the nucleus seen through the primine and
secundine.

Fig. 27. Half ripe seed of the same, cut through perpendicularly ; after Brong-
niart : a, the umbilical cord ; b, foramen ; c, primine ; d, secundine ; e, nu-
cleus;^ embryo partially formed, its radicle pointing to the foramen ; g, the
point where the nourishing vessels of the placenta expand (the chalaza).

Fig. 28. A perpendicular section of the ripe seed of the same, after A. Brong-
niart; the primine and secundine are consolidated; and the nucleus is
entirely absorbed by the embryo ; a, umbilical cord ; b, foramen, now become
the micropyle ; g, chalaza ; h, cotyledons of the embryo ; i, radicle ;
k, plumula.

Fig. 29. Mode of fertilisation in Cucurbita Pepo, after Adolphe Brongniart;
o, portion of the placenta; b, ovulum ; c, its foramen ; d, the bundle of stig-

rial, TJ

I& 18

S/nv . May 28

EXPLANATION OF THE PLATES. 535

matic tissue through which the fertilising matter is conveyed, and to which the
foramen is closely applied ; e, the bundle of vessels that communicates with the
umbilicus ; f, the commencement of the raphe.

PLATE VI.

Fig. 1. A, Vertical section of the seed of Canna lutea; a, albumen; b, embryo.

— B, Embryo extracted and divided vertically ; a, cotyledon ; b, plumula
concealed within the embryo ; c, radicle, with internal rudiments of roots.

Fig. 2. A, Vertical section of the seed of Myrica cerifera ; a, cotyledons ;
b, radicle ; c, plumula ; d, remains of foramen ; e, hilum. — B, Embryo ex-
tracted entire ; a, cotyledons; b, radicle.

Fig. 3. Vertical section of the seed of Luzula campestris; a, albumen;

b, embryo.

Fig. 4. Vertical section of the grain of Bromus mollis ; a, albumen ; b, embryo ;

c, its plumula ; d, its cotyledon ; e, its radicle, with internal rudiment of
a root.

Fig. 5. Vertical section of the seed of Rheum rhaponticum ; a, albumen ;

b, embryo ; c, hilum ; d, remains of foramen.

Fig. 6. A, Seed of Triglochin palustre; a, fungous chalaza; b, raphe; c, hilum.

— B, Embryo of the same; a, cotyledon; b, radicle ; c, fissure, within which
the plumula lies. — C, The same halved vertically; a, cotyledon; b, radicle;

c, fissure ; d, plumula.

Fig. 7. A, Seed of a species of Begonia ; o, hilum B, The dicotyledonous

embryo.

Fig. 8. Coiled up embryo of Basella rubra ; a, radicle ; b, cotyledons.

Fig. 9. Vertical section of the seed of Mesembryanthemum crystallinum ; a, al-
bumen ; b, radicle of the embryo.

Fig. 10. Anatomy of the grain, and germination of Scirpus supinus, after
Richard. — A, A vertical section; a, albumen; b, embryo. — B, The embryo
extracted, enlarged, and halved vertically; a, cotyledon ; b, radicle.— C, The
seed germinating and halved ; a, albumen ; 6, cotyledon ; c, plumula ; d, young
root ; e, sheath of the latter.

Fig. 11. A, Seed of Ribes rubrum ; a, chalaza ; b, raphe ; c, hilum.— B, The
same, halved vertically, showing the minute embryo, with two spreading coty-
ledons lying at the base of the albumen ; b, section of the raphe ; c, hilum ;
d, albumen.

Fig 12. Embryo of a species of Mammillaria; the cotyledons very small.

Fig. 13. Embryo of Geranium Robertianum ; a, radicle; b, line of union of the
two cotyledons ; c, one of the plaits in the latter.

Fig. 14. Section of the seed of Alisma Damasonium, after Mirbel ; a, cotyledon;
b, radicle ; c, plumula.

Fig. 15. Part of the seed of Olyra latifolia, after Richard ; a, albumen ; b, back
cotyledon ; c, front ditto ; d, radicle ; e, plumula.

Fig. 16. Embryo of Ruppia maritima, after Richard; a, plumula; 6, coty-
ledon. ,

Fig. 11. Vertical section of the seed of Pekea tuberculosa, after Richard;
a, radicle ; b, collet ; c, cotyledons.

Fig. 18. Embryo and ruminated albumen of Eupomatia laurina, after Ferdinand
Bauer (a vertical section).

M M 4

536 EXPLANATION OF THE PLATES.

Fig. 19. Spiral twisted embryo of Cuscuta europsea.

Fig. 20. Half the embryo of a bean (Vicia Faba) after Mirbel; a, one of the
cotyledons ; b, plumula ; c, radicle ; d, scar from which the other cotyledon
has been cut.

Fig. 21. Germination of Lachenalia serotina ; a, albumen ; b, cotyledon ; c, plu-
mula; d, radicle.

Fig. 22. Germination of Calla aethiopica, after Mirbel ; a, exterior elongation of
the cotyledon; b, seed ; c, front leaf of the plumula; d, radicle.

Fig. 23. Germination of Allium Cepa ; a, albumen ; b, embryo elongated
, beyond the testa.

Fig. 24. The same further advanced ; a, seed ; b, base of the cotyledon ; c, radicle
or young root ; d, plumula.

Fig. 25. Germination of Baptisia australis, after De Candolle ; a a, cotyledons.

Fig. 26. Germination of Cercis siliquastrum, after De Candolle; a a, cotyledons.

Fig. 27. Thecae, or Sporangiola of Erysiphe adunca, after Greville.

Fig. 28. Sporules of Phascum crassinervium, after Greville.

Fig. 29. Asci, or Theca2 of Sphaeria tubaeformis, after Greville.

Fig. 30. Thecae of various Lichens, after Von Martius.

INDEX.

I. SUBSTANTIVES.

Abbreviations, 424.
Achenium, 170.
Acicula, 107.
Acid, 134.
Acinus, 166, 167.
Acrosarcum, 179.
Active molecules, 134.
Aculei, 44.

Additional membrane, 158.
Adductores, 201.
Adelphia, 124.
Adnascens, 52.
Adnascentia, 57.
Adnatum, 52. 57.
iEstivation, 106.
Affinity, 361.
Age of trees, 66.
Aiguillons, 42.
Ailes, 1 1 9.
Air-cells, 27.
Akena, 178.
Ala, 49.
Alse, 119. 121.
Alabastrus, 106.
Albigo 299.

Albumen, 134. 187. 360.
Alburnitas, 298.
Alburnum, 65.
Amalthea, 175.
Ambitus, 381.
Amentum, 109.
Ammonia, 254.
Amphanthium, 108.
Amphigastria, 203.
Amphisarca, 177.
Amphispermium, 170.
Anabices, 55.
Analogy, 361.
Analytical method, 316.
Anasarca, 297.
Anatomical differences, 350.
Androcaeum, 136.
Androphorum, 124.
Annulus, 196. 201. 208.
Anther, 126. 357.

Anthesis, 106.
Anthodium, 111.
Anthophorum, 152.
Anthozusia, 300.
Antrum, 179.
Apex, 87. 126. 163.
Apices, 122.
Apophysis, 202.
Apothecia, 205. 207.
Appendages of the axis, 78.
Appendages, 116.
Appendices, 57.
Appendix, 121.
Arbor, 48.
Arbrisseau, 48.
Arbusculus, 48.
Arbustum, 48.
Arcesthide, 180.
Arillus, 165. 186.
Arista, 103.
Arsenic, 288.

Artificial arrangements, 309.
Ascelli, 209.
Ascending axis, 44.
Asci, 204. 206.
Ascidium, 96.
Asimina, 176.
Asparagi, 47.
Aulasum, 117.
Awn, 103.
Axilla, 49. 79.
Axis, 107.

ascending, 44.

Azote, 1. 252.

Bacca, 166, 167, 168. 170. 178. 179.

Bacca sicca, 170.

Baccaularius, 176.

Bacilli, 53.

Back, 181.

Balausta, 179.

Bale, 104.

Barbs, 39.

Bark, 61. 240.

Base, 87. 163.

538

INDEX.

Basigynium, 152.

Basis of vegetation, chemical, 1.

— — , organic, 1.

Bastrb'hren, 12.

Beard, 103.

Blast^me, 188.

Blastus, 191.

Blatt, 79.

Bouquet, 110.
Bourgeon, 49.
Bourrelet, 95.
Bouton, 106.
Boyau, 133.
Brachium, 400.
Bracteae, 101. 257. 354.
Bracteola?, 101.
Branches, 47.
Branchlets, 47,
Brindilles, 47.
Bristles, 38.
Buisson, 48.
Bulb, 49. 51.
Bulbilli, 53.
Bulbo-tuber, 55.
Bulbus solidus, 52.
squamosus, 53.

Cachrys, 166. 180.
C-enobio, 176.
Caetonium, 103.
Calamus, 56.
Calathidium, 111.
Calcar, 120.
Calybio, 178.
C Jyculus, 102.
Calyptra, 201.
Calyx, 112. 257. 355.

communis, 102.

Cambium, 63. 246.
Canaux entrecellulaires, 26.
Canker, 298.

Cap, 208.

Capillamentum, 125.
Capillitium, 209.
Capillus, 400.
Capitulum, 110, 111. 126.
Capreolus, 96.
Capsella, 169.

Capsula, 104. 126. 166, 167, 168,
169. 177.

■ circumscissa, 177.

— siliquiformis, 177,

tricocca, 176.

Carbon, 1.

Carbonic acid, 251.

— oxide, 254.

Carcerulus, 176.
Carcinoma, 298.
Car^ne, 119.
Caries, 298.

Carina, 119.
Carpadelium, 179.
Carpella, 143.
Carpophorum, 152.
Carunculae, 185.
Caryopsis, 176.
Catulus, 109.
Caudex, 76.

ascendens, 45.

intermedius, 45.

repens, 58.

Caudicula, 131.
Cauliculi, 47.
Cauliculus, 188.
Caulis, 56.

Cayeu, 52.

Cells, 138.

Cellular integument, 61.

■ tissue, 3. 221.

— membranous, 8

— — fibrous, 10.

— reticulated, 10.

Cellule d'air, 28.

Centimetre, 401.

Cephalanthium, 111.

Cephalodium, 205.

Ceratium, 177.

Cerio, 176.

Cervix, 58.

Cicatricula, 80.

Ciliae, 38.

Circumscription, 87. 381.

Cirrhus, 96.

Chaff of the receptacle, 102.

Chalaza, 156. 186.

Chalumeau, 56.

Characters, 433.

■ , value of, 349.

Chaton, 109.
Chaume, 56.
Chilblains, 300.
Chlorine, 252.
Chlorosis, 297.
Choking-up, 299.
Classes, 368.
Classification, 306.
Clavicula, 96.
Clavus, 299.
Claw, 118.
Clinanthium, 108.
Clinium, 152.
Clostres, 9.
Cloves, 52.
Clubbing, 300.
Coarcture, 45.
Coccum, 167.
Coleophyllum, 190.
Coleoptilum, 190.
Coleorhiza, 190
Collare, 95.

INDEX.

539

Collectors, 140.

Collet, 188.

Collum, 45.

Coloration, 300.

Colour, 274.

, cause of, in tissue, 5.

Colum, 139.

Columella, 164.

Columna, 125.

Coma, 47. 102.

Concentric zones, 64.

Conceptacles, 196. el seq.

Conceptaculum, 166. 177.

Conidia, 205.

Coniocysta, 208.

Coniothecae, 126.

Connectivum, 126. 128.

Contextus cellulosus, 3.

Conus, 180.

Copper, 288.

Corculum, 187.

Corolla, 117. 257. 355.

Corollula, 1 1 9.

Cormus, 54.

Cornua, 121.

Corona, 121.

staminea, 122.

Corpuscula vermiformia, 25.

Corrosive sublimate, 288.
Cortex, 83.
Cortina, 208.
Corymbus, 110.
Costa, 89.

Cotyledons, 80. 187. 193.
Coulant, 57.
Coussinet, 95.
Creeping stem, 55.
Cremocarpium, 179.
Crini, 38.
Crispatura, 300.
Crusta, 206.
Crypta, 27.
Cubit, 400.
Culmus, 45. 56.
Cupula, 102.
Curling, 300.
Cuticle, 31.
Cyanogen, 254.
Cyma, 47. 112.
Cynarrhodum, 176.
Cyphellae, 205.
Cypsela, 178.
Cystella, 205.
Cystidium, 170.
Cystulae, 204, 205.

Debris, 80.
Decimetre, 401.
Decoloration, 300.
Dehiscence, 164.

Descriptions, 440.
Diachyma, 83.
Diagnoses, 433.
Dielesium, 180.
Dieresilis, 176.
Diploe, 83.
Diplotegia, 179.
Directions, 277.
Diseases, 297.
Disk, 137, 257. 357.
Dissepiments, 148.

, spurious, 151.

Dodrans, 400.

Dotting, 354.

Down, 38.

Double follicule, 177.

Dragon, 57.

Drawings, 469.

Dropsy, 297.

Drupa, 166, 167, 168. 170. 175.

Ducts, 23.

, annular, 23.

, dotted, 24.

, reticulated, 23.

, moniliform, 25.

, necklace-shaped, 25.

, strangulated, 25.

Ductus intercellulares, 26.
Dumus, 48.
Duramen, 65.

Elateres, 203.

Elaterium, 176.

Elementary organs, 221.

— ■ , spurious, 26.

Ell, 400.

Elytriculi, 106.

Embryo, 187. 360.

, fixed, 49.

Embryotega, 185.
Endocarpium, 163.
Endogenous stems, 72.
Endopleura, 183.
Endoptiles, 192.
Endorhizae, 190.
Endosmose, 237.
Endospermium, 187.
Endostome, 155.
Endothecium, 128.
Entrenoeud, 46.
Epi, 108.
Epicarpium, 163.
Epiblastus, 191.
Epidermis, 61.
Epillet, 109.
Episperme, 182.
Ergot, 299.
Erythrostomum, 175.
Estivation, 409.
Etaerio, 175.

540

INDEX.

Etendard, 119.
Etiolation, 297.
Excipulus, 206.
Exogenous stem, 59.
Exoptiles, 192.
Exorhiza;, 190.
Exosmose, 237.
Exostome, 155.
Exostosis, 300.
Exothecium, 126.
Extravasation, 298.

Face, 181.

Fasciculus, 110.

Fasergefasse, 12.

Fausses trachees, 23.

Faux, 118.

Ferrugo, 299.

Fibre, 1, 2.

Fibrillar, 76, 77. 206.

Fibrous cellular tissue, 10.

Filament, 125.

Fistulas spirales, 17.

Fixed embryo, 49.

Flagella, 47.

Flagellum, 57.

Fleuron, 106.

Flocci, 209.

Florets, 106.

Florets of the ray, 111.

disk, 111.

Flosculi, 106.

Flowerless plants, 305.

Foliation, 53.

Folliculus, 166, 167, 168. 175. 197.

Foliolum, 94.

Foot, 400.

Foramen, 155.

Fornix, 122.

Fovilla, 134.

Fries's dogmata, 336.

Frond, 195.

Fructus inferus, 163.

1 superus, 163.

Fruit, 1 60. 266. 359.

Frutex, 48.

Fruticulus, 48.

Fulcra, 96.

Fundus plantae, 45.

Funiculus, 154.

'- umbilicalis, 139.

Galbulus, 180.
Galea, 118.
Galls, 298.
Gangrene, 297.
Gemma, 49.
Gemma;, 204.
Gemmula, 188.
Generic characters, 433.

Geniculum, 46.
Genus, 367.
Geography, 472.
Germen, 138.
Germination, 270.
Gills, 208.
Glands, 42.
Glandes a godet, 43.

cellulaires, 43.

vasculaires, 43.

corticales, 33.

n miliaires, 33.

epidermoidales, 33.

vesiculaires, 27.

Glandulas cutanea?, 33.

hypogynae, 137.

impressae, 27.

— lenticulares, 44.

squamosa^, 196.

urceolares, 43.

utriculares, 43.

Glandular hairs, 39.

Glans, 178.

Globules, 207.

Globuli, 205.

Globuline, 6.

Globulus, 205.

Glochis, 39.

Glomeruli, 205.

Glomerulus, 111.

Glomus, 111.

Gluma, 103.

Glumella, 104.

Glumellula, 104.

Gluten, 134.

Goldbach's speculations, 330.

Gonophorum, 152.

Gongyli, 206, 207.

Gousse, 175.

Grands pores, 33.

Granula, 207.

Grappe, 108.

Groh's speculations, 333.

Grossification, 139.

Grossus, 166.

Growth, rapidity of, 7.

Gum, 134.

Gumming, 298.

Gynaeceum, 138.

Gynobasis, 137.

Gynophore, 139.

Gynostemium, 126.

Gyroma, 196. 205.

Gyrus, 196.

Hairiness, 38.
Hairs, 38. 352.

, lymphatic, 40.

, secreting, 40.

Hairsbreadth, 400.

INDEX.

541

Harm, 39.
Hampe, 107.
Heat in vegetables, 260.
Heart- wood, 65.
Helmet, 118.
Hemigyrus, 175.
Herbaria, 463.
Hesperidium, 178.
Hilofere, 183.
Hilum, 185.
Hirsuties, 38.
Hooks, 39.
Horns, 121.
Hybernaculum, 49.
Hybridism, 301.
Hydrogen, 1. 255.
Hymenium, 208.
Hypanthodium, 108.
Hypha, 207.
Hypoblastus, 191.
Hypophyllium, 95.

Inch, 400.
Indusium, 140. 196.
Induviae, 80.
Inflammability, 275.
Inflorescence, 106. 354.
Inflorescences, 354.
Inner bark, 61.
Innovations, 47.
Insertion, 353.
Insolation, 297.
Intercellular passages, 26.
Internodium, 46.
Intervenium, 91.
Jnvolucellum, 102.
Involucrum, 102. 196, 197.
Irritability, 288.
lulus, 109.

Jaundice, 300.
Jet, 57.
Jeterus, 300.
Juba, 112.

Keel, 119.

Labellum, 118.
Lacinula, 120.
Lacuna, 28. 205.
Lamarck's system, 316.
Lame, 118.
Lamella, 121. 208.
Lamina, 79. 86. 118.

proligera, 206.

Languette, 95.
Latex, 86.
Laub, 79.
Laying, 57.
Lead, 288.

Leaf, 79. 247. 352.

Leaf-buds, 49. 352.

Leaflet, 94.

Lecus, 54.

Legumen, 166. 168. 170. 175.

• lomentaceum, 175.

Lenticelles, 44.
Lenticular glands, 44.
Lepals, 136.
Lepicena, 103.
Lepis, 41.
Lepisma, 137.
Liber, 61.
Ligneae fistulae, 12.
Ligula, 95. 100. 121.
Limbus, 86. 118.
Lime, 134.
Limes communis, 45.
Line, 400.
Linea, 400.
Linnean system, 310.
Lip, 118.
Lirella, 205.
Loculi, 126.
Locusta, 103. 109.
Lodicula, 104.
Lomentum, 169. 175.
Lorica, 182.
Lorulum, 206.
Loss of colour, 300.
Lousiness, 300.
Luftbehalter, 28.
Lymphaeducts, 23.

Mace, 165.

Malate of potash, 134.

Malic acid, 134.

Malleolus, 57.

Marcor, 297.

Margin, 87.

Maturation, 267.

Meatus intercellulares, 26.

Medulla seminis, 187.

Medullary rays, 63. 240.

sheath, 64. 239.

Melligo, 299.
Melonidium, 179.
Membrane, 1, 2.
Membranous cellular tissue, 8.
Membranula, 196.
Mercury, 288.
Merithallus, 46.
Mesophyllum, 83.
Metre, 401.
Microbasis, 176.
Micropyle, 185.
Milk-vessels, 27.
Millimetre, 401.
Moria, 106.
Morphology, 504.

542

INDEX.

Muriate of barytes, 288.
Muscarium, 110.
Mycelia, 209.

Nacelle, 119.
Nail, 400.
Naked seeds, 161.
Natural system, 308.
Nauca, 185.
Neck, 45. 188.
Necrosis, 299.
Nectar, 121.
Nectarilyma, 122.
Nectarium, 104. 121, 122.
Nectarostigma, 122.
Nectarotheca, 120.
Nees's speculations, 324.
Nitrogen, 1. 252.
Nitrous acid, 252.
Nodus, 46.
Nceud, 46.

vital, 45.

Nomenclature, 454.

Nucamentum, 109.

Nucelle, 155.

Nucleus, 52. 155. 187. 200. 206.

proligerus, 206.

Nucula, 170. 178. 207.
Nuculanium, 178.
Number, 420.
Nux, 167, 168. 170. 174.
■ baccata, 180.

Ochrea, 99, 100.
OefFnungen, 33.
Offsett,58.

Oken's speculations, 328.
Olefiant gas, 255.
Omphalodium, 185.
Onglet, 118.
Operculum, 96. 201.
Oplarium, 205.
Orbilla, 205.
Orbiculus, 121. 209.
Order, 368.
Organs, elementary, 1.
i of vegetation, 100.

of fructification, 100.

Orgya, 400.
Ostiolum, 209.
Outline, 381.
Outre, 96.
Ovarium, 138.
Ovula, 138. 152. 359.
Oxalate of lime, 29.
Oxygen, 1. 251.

Pagina, 87.
Paillette, 102.
Palate, 118.

Paleae, 102.
Paleolae, 104.
Palm, 400.
Panicle, 111.
Papillae, 43.
Pappus, 114.
Papulae, 44.
Paquet, 109.
Paracorolla, 122.
Parapetalum, 122.
Paraphyllia, 99.
Paraphyses, 201. 122.
Parastades, 122.
Parastemon, 122.
Parenchyma, 3. 9.
Paries, 150.
Parties £l£mentaires, 1 .
^— ^— similaires, 1.
Patellula, 205.
Pecten, 209.
Pedicel, 106.
Pediculus, 125.
Pedunculus, 106.
Pelta, 205.
Pentakenium, 179.
Pepo, 167, 168. 179.
Peponida, 179.
Perapetalum, 122.
Peraphyllum, 115.
Perianthium, 113.
Pericarpium, 162.
Pericladium, 95.
Periclinium, 102.
Peridiola, 207.
Peridiolum, 209.
Peridium, 209.
Peridroma, 195.
Perigonium, 114.
Perigynandra communis, 102.

interior, 117.

Perigynium, 104. 137.
Periphoranthium, 102.
Perisperm, 182. 187.
Perisporum, 105.
Peristachyum, 103.
Peristomium, 201.
Perithecium, 209.
Pernio, 300.
Pes, 400.
Petals, 117.
Petiole, 79. 86. 94.
Petiolule, 94.
Petits tubes, 12.
Phorantium, 108.
Phosphate of lime, 134.

of magnesia 4.

Phthiriasis, 300.
Phycomater, 207.
Phycostemones, 137.
Phyllodia, 95.

INDEX.

54S

Phyllum, 114.

Physiological differences, 351.
Pileus, 208.
Pili, 38.

capitati, 39.

Malpighiacei, 40.

pseudo-Malpighiacei, 40.

^— biacuminati, 40.

subulati, 38.

scutati, 41.

Pilidium, 205.
Pilula, 166. 180.
Pistillidia, 201.
Pistillum, 138. 262. 358.
Pith, 60. 239.
Pithy part, 3.
Placenta, 139. 144.

, free central, 151.
Plateau, 54. 139.
Plopocarpium, 175.
Plumula, 188.
Podetia, 205.
Podogynium, 152.
Podospermium, 139.
Poils en ecusson, 41.

en goupillon, 40.

navette, 40.

fausse navette, 40.

Poincon, 110.
Poisons, 288. 293.
Polakenium, 179.
Polarity, 325.
Polexostylus, 176.
Pollen, 129. 357.

tubes, 133.

Pollex, 400.

Polychorion, 175.

Polyphorum, 152.

Polysecus, 175.

Pomum, )67, 168. 170. 179.

Pores of the epidermis, 33.

corticaux, 33.

allonges, 33.

e\raporatoires, 33.

in tissue, nonexistent, 2. 4.

Potash, 288.
Prefloration, 409.
Prickles, 44. 352.
Primine, 155.
Propaculum, 58.
Propagines, 53.
Propago, 57.
Propagula, 205.
Proper juice, 230.
Proportion, 360.
Prosenchyma, 9.
Prosphyses, 201.
Protoxide of nitrogen, 255.
Prussic acid, 295.

Pseudobulb, 58.
Pseudohymenium, 207.
Pseudoperidium, 207.
Pseudoperithecium, 207.
Pseudo-tuber, 77.
Pteridium, 176.
Pterodium, 176.
Pubescence, 38.
Pulpa, 3.
Pulvinuli, 205.
Pulvinus, 95.
Punctuation, 452.
Putamen, 163.
Pyrenarium, 179.
Pyridium, 179.
Pyxidium, 177.

Quartine, 158.
Quintine, 158.

Raceme, 108.
Rachis, 107. 195.
Rachitis, 300.
Radicle, 187.
Radiculae, 76.
Radiculoda, 191.
Radii, 11C.
Ramastra, 94.
Rameau, 47.
Ramenta, 41.
Rami, 47.
Ramilles, 47.
Ramuli, 47.
Raphe, 126. 156. 186.
Raphides, 29.
Receptacle 152. 196.

of the seeds, 139.

of the flower, 107.

Receptacles of secretion, 27.

of oil, 27.

Receptacula succi, 27.
Regma, 176.
Reliquiae, 80.
Respiration, 251.
Reservoir d'air, 28.
Reservoirs accidentels, 27.

en ccecum, 27.

vesiculates, 27.

■^— — du sue propre, 27.

Reticulum, 99.

Rhizina, 76.

Rhizoma, 58. 187.

Rhizula, 76.

Rictus, 118.

Rootstock, 58.

Root, 76. 227. 351.

Rostella, 39.

Rostellum, 187.

Rostrum, 121.

544

INDEX.

Runner, 57.
Rupturing, 165.
Russia mats, 62.

Sac of the embryo, 158.
Saccus, 121.
Saftrbhren, 23.
Salsugo, 299.
Samara, 167, 168. 176.
Sap, 230.
Sap-vessels, 23.
Sapwood, 65.
Sarcobasis, 176.
Sarcocarpium, 163.
Sarcodermis, 183.
Sarcoma, 137.
Sarmentum, 57.
Sautilles, 53.
Scabrities, 43.
Scale, 102.
Scales, 41.
Scaliness, 300.
Scape, 107. 188.
Scapellus, 188.
Scaphium, 119.
Scar of leaves, 80.
Schilling's speculations, 32"
Schraubengefasse, 17.

Scion, 47.
Scobina, 107.
Scorching, 297.

Scutella, 204.

Scutellum, 191.

Scutum, 122.

Scyphus, 121. 205.

Secondine, 155.

Secundinse interna:, 187.

Seed, 162. 181. 270. 360.

Seeds, naked, 161. 194.

Sepals, 114.

Septa, 148.

in woody fibre, 14.

Septum, 126.

Sertulum, 1 10.

Seta, 201.

, of grasses, 104.

Setae, 38. 42.

, hypogynous, 105.

Sexual system, 310.

Sheath, 95.

Shields, 204.

Shrub, 48.

Signs, 422.

Silica, 134.

Silicula, 177.

Siliqua, 166. 168. 170. 177.

Silver grain, 63.

Similary parts, 1.

Small span, 400.

Smell, 274.

Soboles, 55. 57.

Solubility, 165.

Soredia, 204, 205.

Sori, 196.

Sorosis, 180.

Souche, 54.

Sous-arbrisseau, 48.

Spadix, 110.

Span, 400.

Spatha, 103.

Spathella, 104.

Species, 365.

Specific characters, 433.

Speculative opinions, 324.

Spermaphorum, 139.

Spermatocystidium, 126. 200. 203.

Spermidium, 174.

Spermodermis, 182.

Sphaerula, 209.

Sphalerocarpu m, 180.

Spicula, 103. 109.

Spike, 108.

Spilus, 185.

Spines, 48.

of the leaves, 98.

Spiral vessels, 17. 223.
Spiralgefasse, 17.
Spithama, 400.
Spongiola? seminales, 43.
Spongiole, 77.
Sporangiola, 209.
Sporangium, 209.
Sporidia, 207. 209.
Sporidiola, 209.
Sporule, 196, el seq.
Spotting, 299.
Spurious bacca, 169.

drupe, 169.

capsule, 169.

■ nut, 169.

Squama, 102.
Squamatio, 300.
Squamelles, 102.
Squamulae, 104.
Staining, 300.
Stamens, 122. 262. 356.
Staminidia, 203.
Standard, 119.

Starch, 134.

Steffens's speculations, 328.

Stem, 44. 56. 361.

Stephanbum, 178.

Sterigmum, 176.

Stigma, 141.

Stimuli, 38.

Stings, 38.

Stipellae, 99.

Stipes, 45. 195. 208.

Stipulae, 99. 203. 354.

Stole, 57.

INDEX.

545

Stolo, 57.

Stomata, 33. 84. 35-1.

Stomatia, 33.

Stragulum, 103.

Straw, 56.

Striga, 42.

Strobilus, 167. 169. 180.

Stroma, 209.

Strophiola?, 185.

Struma, 95. 202.

Style, 139.

Stylopodium, 137.

Stylotegium, 121.

Sucker, 57.

SufFocatio, 299.

Suffrutex, 48.

Sugar, 134.

Sulphate of magnesia, 288.

of potash, 1 34.

Sulphuretted hydrogen, 252.
Sulphuric acid, 288.
Sulphurous acid gas, 252.
Surculus, 57.
Surface, 87.
Surgeon, 57.
Suture, 144.
Syconus, 180.
Syncarpium, 176.
Synochorion, 176.
Synonyms, 460.
System, Lamarck's, 316.

, analytical, 316.

, natural, 318.

, Jussieu's, 321.

■ -, Linnean, 310.

, artificial, 339.

, natural, 339.

, factitious, 339.

, mathematical, 340.

, physiological, 340.

, philosophical, 340.

, speculative, 325.

Tabes, 297.

Talarae, 119.

Taste, 274.

Tegmen, 103. 183.

Tegmenta, 51.

Tela cellulosa, 3.

Tendril, 96.

Tercine, 155.

Terminology, 454.

Testa, 182.

Testiculus, 126.

Testis, 126.

Thalamus, 108. 152. 209.

Thallus, 202. 209. 267.

Theca, 126.

Thecae, 126. 196, et seq.

Thecaphore, 139. 15*.

Thecidium, 174.
Throat, 118.
Thyrsula, 112.
Thyrsus, 112.
Tigelle, 188.
Tin, 288.
Tissue, cellular, 3.

, vascular, 17.

Tissu cellulaire allonge, 1 2.
■ ■ ■ ligneux, 12.
— — organique, 1.
Toise, 400.
Tomentum, 38.
Torus, 152.
Tracheae, 17.

Transportation of seed, 272.
Tree, 48.
Trica, 205.
Trichidium, 209.
Tronc, 47.
Trophopollen, 126.
Trophospermium, 139.
Truncus, 45.

, ascendens, 45.

Tryma, 1 78.
Tube, 118. 139.
Tuber, 55.

Tuberculum, 55. 205.
Tubes corpusculiferes, 23.
Tumid excrescences, 298.
Tunic, 53.
Tunica externa, 1 82.

interna, 183.

Turio, 47.

Turpentine vessels, 27.
Tympanum, 201.

Ulna, 400.
Umbel, 110.
Umbilical cord, 1 39.
Umbilicus, 185.
Unci, 39.
Uncia, 400.
Undershrub, 48.
Unguis, 118. 400.
Urceolus, 104.
Uredo, 299.
Utriculus, 167, 168. 170.

Vaisseaux en ( hapelet, 25.

etrangles, 25.

lymphatiques, 23.

pneumatiques, 23.

fendu, 24.

propres, 27.

■ propres fasciculaires, 1 2.

Vagina, 95.
Vaginellae, 41.
Value of characters, 349.
Valves, 104. 126.

N N

546

INDEX.

Valvals, 104.
Vasa fibrosa, 12.

moniliformis, 25.

propria, 27.

spiralis, 17.

Vascular system, 223.

tissue, 17.

Vasculum, 96.
Vegetable tissue, 1.
Veil, 208.
Veins, 88.
Velvet, 38.
Velum, 208.
Velumen, 38.
Vena?, 90.
Venule, 90.
Verminatio, 300.
Vernation, 53. 409.
Verruca?, 43.
Verticillaster, 112.
Verticillus, 80.
Vesicula, 95. 207.

' amnios, 158. 185.
■ colliquamenti, 185.

Vessels of the latex, 86.
Vexillum, 119.
Villus, 38.

Vimen, 47.
Vine, 58.
Virgultum, 47.
Vital vessels, 13.
Vitellus, 185.
Viticula, 58.
Vitta?, 27.
Volva, 208.
Vrille, 96.

Wagner's speculations, 330.

Warts, 43.

Welting, 297.

Whorl, 80.

Wilbrand's speculations, 326.

Wings, 119.

Wood, 241.

Woody fibre, 12. 222.

■ , glandular, 15.

■ , granular, 15.

Xylodium, 174.

Yellow resin, 134.

Zellengewebe, 3.

II. ADJECTIVES.

Abdominal, 381.
Abnormal, 381.
Abrupte" pinnatus, 390.
Acaulis, 58.
Accisus, 386.
Accretus, 416.
Acerosus, 382.
Acetabuleus, 379.
Aciculated, 394.
Acinaciformis, 375.
Acormous, 58.
Accumbent, 193.
Aculeatus, 394.
Acuminatus, 385.
Acuminose, 885.
Acute, 885.
Adhering, 416.
Adnate, 128. 208. 416.
Adventitious, 50.
Adversus, 414.
iEqualis, 384.
iEqualivenium, 91.
^quilaterus, 384.
.SLruginosus, 405.
Aggregatus, 419.
Alaris, 416.
Alatus, 377.
Albescens, 403.
Albidus, 403.

Albus, 403.
Alsinaceous, 119.
Alternately pinnate, 390.
Alternative, 411.
Alternus, 418.
Alutaceus, 398. 405.
Alveolatus, 393.
Amphigenus, 417.
Amphitropal, 193. 415.
Amplexus, 411.
Amplexicaulis, 415.
Amplectans, 415.
Anastomozing, 393.
Anatropous, 156.
Anceps, 375.
Androus, 124.
Anfractuosus, 413.
Angiocarpien, 171.
Angular, 375. 387.
Anisodynamous, 192.
Anisobrious, 192.
Anisos, 400.
Anisostemonous, 400.
Annexus, 416.
Annotinus, 402.
Annual, 249.
Annular, 23.
Annulatus, 394.
Anthracinus, 404.

INDEX.

54-7

Anticus, 128. 414.
Antitropal, 193. 415.
Appendiculate, 116.
Apetalous, 119.
Apice circinatus, 385.
Apiculatus, 385.
Apocarpus, 144.
Arachnoid, 39. 396.
Arcuatus, 374.
Areolate, 394.
Argenteus, 403.
Argo, 403.
Aristatus, 385.
Armeniacus, 405.
Arrectus, 411.
Arrow-headed, 383.
Articulatus, 392. 416.
Artiphyllous, 46.
Asoending, 159. 412.
Ascens, 422.
Asper, 39. 395.
Aspergilliformis, 392.
Assurgens, 412.
Ater, 403.
Atratus, 404.
Atrovirens, 405.
Attenuatus, 384.
Aurantiacus, 405.
Aurantius, 405.
Auratus, 404.
Aureus, 404.
Auriculatus, 383.
Autocarpien, 163.
Avenium, 91.
Awl-shaped, 382.
Awned, 385.
Axe-shaped, 375.
Axillary, 79. 416.
Azureus, 406.

Baccatus, 385.
Baccien, 171.
Badius, 404.
Banded, 407.
Band-shaped, 381.
Barbatus, 39. 396.
Basal, 416.
Basilaris, 416.
Basinervia, 93.
Beaked, 376. 385.
Bearded, 39. 125. 596.
Bell-shaped, 378.
Bellying, 381.
Berried, 399.
Biconjugatus, 391.
Biconjugato-pinnatus, 390.
Bicornis, 376.
Bidentate, 387.
Bidigitato-pinnatus, 390.
Biduus, 402.

Bifarius, 418.
Biferus, 401.
Bifidus, 388.
Bifoliolate, 390.
Bifurcate, 125.
Bigeminate, 391.
Bijugus, 391.
Bilobus, 388.
Bimestris, 402.
Bimorious, 106.
Binate, 390.
Bipartitus, 388.
Bipinnate, 391.
Biserrate, 387.
Bitten, 386.
Bitten off, 77.
Bladdery, 380.
Blotched, 407.
Blunt, 385, 386.
Blunt with a point, 385.
Blurred, 408.
Boat-shaped, 376.
Bony, 398.
Bordered, 407.
Botuliformis, 380.
Brachialis, 400.
Brachiate, 47. 414.
Branched, 39. 391.
Bristle-pointed, 385.
Bristly, 394.
Brunneus, 404.
Brush-shaped, 379. 392.
Buckler-shaped, 374.
Butterfly-shaped, 119.
Byssaceous, 392.

Caducous, 249. 402.
Casspitose, 418.
Calcareus, 403.
Calyptrate, 114.
Campaniformis, 378.
Campanaceus, 878.
Campanulatus, 118. 378.
Campulitropous, 156.
Canaliculatus, 376.
Cancellate, 393.
Candidus, 403.
Canescens, 403.
Canus, 403.
Capillaris, 376. 400.
Capitatus, 386.
Capsulaire, 171.
Carcerulaire, 171.
Carinatus, 376.
Carneus, 406.
Carnosus, 398.
Cartilaginous, 398.
Caryophyllaceous, 119.
Cassideous, 119.
Catapetalous, 118.
N N 2

54-8

INDEX.

Caudatus, 385.
Caulinus, 416.
Caulocarpous, 401.
Cenobionnaire, 171.
Centrifugal (inflorescence), 110.

(embryo), 193.

Centripetal (embryo), 193.

(inflorescence), 1 1 0.

Ceraceus, 398.
Cereus, 398.
Cerinus, 405.
Cernuous, 413.
Cervinus, 405.
Chaffy, 396.
Chalk-white, 403.
Channelled, 376.
Chartaceus, 397.
Chloro, 405.
Chryso, 404.
Cicatrisatus, 394.
Ciliated, 396.
Cineraceus, 403.
Cinereus, 403.
Cinnabarinus, 406.
Cinnamomeus, 404.
Circinate, 53. 411. 413.
Circumscissile, 164.
Cirrhous, 385.
Citreus, 404.
Citrinus, 404.
Clavate, 125. 373.
Claviformis, 373.
Closed, 47.
Clouded, 407.
Club-shaped, 573.
Clustered, 419.
Clypeatus, 374.
Coacervatus, 419.
Coadnatus, 416.
Coalitus, 416.
Coated, 398.
Cobwebbed, 396.
Cochlearis, 411.
Cochleate, 373.
Coccineus, 406.
Cceruleus, 406.
Coesious, 397. 406.
Cohering, 416.
Comb-shaped, 389.
Combinat& venosus, 92. 408.
Compositus, 389. 418.
Compound, 21. 46. 389.
Compound (leaf), 87.
Compressed, 9. 182. 374.
Conduplicate, 53. 410.
Confertus, 418.
Confluens, 416.
Conglomeratus, 419.
Conical, 372.
Conjugatus, 391.

Connate, 82. 415.
Connivens, 414.
Conoidal, 372.
Continuus, 420.
Con tortus, 41 1.
Convergenti-iiervosus, 91,
Converginervis, 408.
Converging, 414.
Convolute, 53. 410. 412.
Coracinus, 404.
Cordatus, 383.
Cordiformis, 383.
Coriaceus, 398.
Corky, 398.
Corneus, 393.
Corniculatus, 376.
Cornutus, 376.
Corollaris, 96.
Coronans, 416.
Corrugatus, 410.
Corticatus, 398.
Corymbose, 1 lO.
Costatus, 92. 408.
Cotyliform, 379.
Crassus, 398.
Crateriformis, 379.
Cream, colour, 403.
Creeping (stem), 55.
Crenated, 386.
Crescent-shaped, 383.
Crested, 377.
Cretaceus, 403.
Crinitus, 396.
Crispus, 387.
Cristatus, 377.
Croceus, 405.
Crowded, 418.
Cruciate, 119.
Crustaceous, 398.
Cubical, 373.
Cubitalis, 400.
Cucullatus, 380.
Cunearius, 382.
Cuneatus, 382.
Cuneiformis, 382.
Cupola-shaped, 379.
Cupreus, 406.
Cup-shaped, 378.
Cupuliformis, 379.
Curbed, 387.
Curvative, 410.
Curve-ribbed, 408.
Curved, 374.
Curve-veined, 92.
Curvinervis, 408.
Curvinervium, 92.
Curvivenium, 92.
Cushioned, 374.
Cuspidate, 385.
Cut, 388.

INDEX.

549

Cyaneus, 406.
Cyano, 406.
Cyathiformis, 378.
Cyclical, 192.
Cylindrical, 9. 372.
Cymbiformis, 376.

Daedaleous, 386.
Dealbatus, 397. 403.
Decandrous, 125.
Deciduous, 249. 402.
Declinate, 124. 412, 413.
Decompound, 389.
Decreasingly pinnate, 390.
Decumbens, 414.
Decurrent, 81. 208. 415.
Decursively pinnate, 390.
Decursivus, 415.
Decussatus, 419.
Deflexus, 413.
Dehiscent, 163.
Deliquescens, 392.

— (caulis), 48.

Deliquescent (panicle), 111.
Deltoid, 383.
Demersus, 412.
Dendroides, 392.
Dentatus, 387.
Denudatus, 397.
Depauperatus, 419.
Dependens, 412.
Depressed, 182. 374. 399.
Descending, 412.
Determinatus (caulis), 48.
Dewy, 397.
Diadelphous, 124.
Diandrous, 124.
Dichotomous, 392.
Didynamous, 124.
Didymus, 392.
Dieresilien, 171.
Diffuse, 414.
Digitato-pinnate, 390.
Digitaliformis, 380.
Digitatus, 388.
Digitinervius, 93.
Dimidiate, 201. 377. 384.
Dipterus, 377.
Directe venosus, 93. 408.
Disappearing, 392.
Discoidal, 374. 407-
Distans, 420.
Distichous, 418.
Distinctus, 416.
Distractile, 126.
Diurnus, 402.
Divaricating, 40. 94. 411.
Diverging, 94.
Divided, 46.
Dodecandrous, 125.

Dodrantalis, 400.
Dolabriibrmis, 375.
Dorsal, 144. 416.
Dotted, 24. 394. 407.
Double-bearing, 401.
Downy, S95.
Drooping, 413.
Dumosus, 48.
Duplicato-dentate, 387.

pinnate, 391.

—serrate, 387.

Duplicatus, 420.
Duplo, 400.
Dusty, 397.
Dwarf, 399.

Eared, 383.
Eborinus, 403.
Eburneus, 403.
Echinatus, 394.
Edged, 407.
Egg-shaped, 382.
Elatus, 399.
Ellipsoidal, 374.
Ellipticus, 382.
Emarginate, 386.
Embracing, 415.
Empty, 101.
Endophyllous, 190.
Endogenous, 59.
Enervis, 409.
Enneandrous, 125.
Ensiformis, 382.
Entangled, 420.
Entire, 46. 386.
Ephemerus, 402.
Epigasus, 417.
Epigynous, 123. 417.
Epiphyllus, 416.
Epipterus, 377.
Equal, 120. 384.
Equal-veined, 91.
Equatus, 394.
Equitant, 411.
Equally pinnate, 390.
Equal-sided, 384.
Erect, 159. 411.
Erosus, 387.
Erythro, 406.
Escens, 422.
Etairionnaire, 171.
Evanescente venosus, 92. 408.
Even, 394.
Evergreen, 249.
Exaltatus, 399.
Exaspiratus, 395.
Excurrens (caulis), 17.
Excurrent, 392.
Exiguus, 399.
Exogenous, 59.
K N 3

550

INDEX.

Exophyllous, 190.
Exserted, 124.
Extrorsus, 128. 414.

Fading, 402.
Falcate, 375.
Falsely-ribbed, 93.
Falsinervis, 409.
Falsinervius, 91.
Fan-shaped, 377.
Farinaceus, 398.
Farinosus, 396.
Fasciarius, 381.
Fasciatus, 407. 419.
Fasciculated, 78. 418.
Fastigiate, 419.
Favosus, 393.
Feather-veined, 93.
Feathery, 396.
Ferrugineous, 404.
Fibrous, 77. 398.
Fiddle-shaped, 384.
Filiformis, 376.
Fimbriatus, 396.
Fingered, 388.
Fissus, 388.
Fistulous, 372.
Five-ribbed, 93.
Flabelliformis, 377.
Flagelliformis, 376.
Flammeus, 406.
Flavidus, 404.
Flavescens, 404.
Flavovirens, 405.
Flavus, 404.
Fleshy, 398.
Flexuosus, 413.
Floating, 411.
Floralis, 416.
Floccose, 395.
Fluitans, 411.
Foliaceus, 53. 377.
Foliaris, 96. 416.
Foliiformis, 377.
Forked, 392.
Foxglove-shaped, 380.
Free, 208.
Fringed, 396.
Frosted, 397.
Fugacious, 249. 402.
Fulcraceus, 53.
Fuligineus, 404.
Fuliginosus, 404.
Fulvus, 405.
Fumeus, 403.
Fumosus, 403.
Funalis, 376.
Fungilliformis, 380.
Fungiformis, 380.
Funiliformis, 376.

Funnel-shaped, 378.
Furcatus, 392.
Furrowed, 394.
Fuscus, 404.
Fusiform, 9. 77. 374.
Fusinus, 374.

Galacto, 403.
Gamopetalous, 118.
Gamosepalous, 116.
Ganglioneous, 40.
Gelatinous, 398.
Gerninatus, 420.
Geniculate, 125. 413.
Gibbous, 374.
Giganteus, 399.
Gigantic, 399.
Gilvus, 405.
Githagineus, 406.
Glaber, 397.
Gladiatus, 382.
Glandaceus, 404.
Glandular, 395.
Glaucous, 397. 405.
Glaucus, 405.
Glaucescens, 405.
Glittering, 397.
Globose, 372.
Globulosus, 372.
Glochidatus, 39.
Glutinosus, 397.
Gnawed, 387.
Goblet-shaped, 379.
Gongylodes, 377.
Grammicus, 408.
Granular, 392.
Granulatus, 392.
Greasy, 397.
Griseus, 403.
Gromonical, 192.
Grumous, 377.
Guttatus, 407.
Gymnocarpien, 171.
Gypseus, 403.
Gyratus, 413.

Haematiticus, 406.
Hair-pointed, 385.
Hair-shaped, 376.
Hairy, 395.
Halberd-headed, 383.
Half-netted, 393.
Half-terete, 374.
Halved, 377. 384.
Hastatus, 383.
Headed, 386.
Heart-shaped, 383.
Hebetatus, 386.
Helvolus, 405.
Hepaticus, 404.

INDEX.

.551

Heptandrous, 125.
Herbaceous, 399.
Helerocarpien, 163.
Heterotropal, 193.
Hexandrous, 125.
Hidden-veined, 93.
Hinoideus, 92. 409.
Hirtus, 395.
Hispid, 395.
Hoary, 395.
Homotropal, 415.
Honeycombed, 393.
Hooded, 380.
Hooked, 305.
Hooked-back, 384.
Horarius, 402.
Horizontal, 412.
Horned, 376.
Horny, 398.
Hornus, 402.
Humifusus, 414.
Humilis, 399.
Hypocrateriform, 118. 378.
Hypogasous, 417.
Hypogynous, 123. 417.
Hysteranthus, 401.

Ianthinus, 406.
Icosandrous, 125.
Igneus, 406.
Imbricated, 410. 418.
Imparipinnatus, 390.
Inaequalis, 384.
Inaequilaterus, 384.
Incanus, 395. 403.
Incarnatus, 406.
Incisus, 388.
Inclinate, 412.
Included, 124.
Incumbent, 193.
lncurvus, 413.
Indefinite, 125.
Indehiscent, 163.
Indeterminatus (caulis), 48.
Indirecte venosus, 92. 408.
Indigoticus, 406.
Induplicate, 410.
Induviatus, 80.
Inermis, 394.
Inferior (calyx), 1 15.
Inflatus, 380.
Inflexed, 413.
Infra-axillary, 79.
Infractus, 413.
Infundibuliform, 118. 378.
Innate, 128. 416.
Integer, 386.
Integerrimus, 386.
Interruptedly pinnate, 390.
Interruptus, 420.

Intricatus, 420.
Introcurvus, 413.
Introflexus, 413.
Introrsus, 128. 414.
Introvenium, 93.
Inverted, 412.
Involute, 409. 412.
Irregular, 9. 120. 381,
Isobrious, 192.
Isodynamous, 192.
Isos, 399.
Isostemonous, 400.
Ivory-white, 403.

Jointed, 392.

Keeled, 376.
Kermesinus, 406.
Kidney-shaped, 383.
Knee-jointed, 413.
Kneepan-shaped, 379.
Knoblike, 377.
Knotted, 376.

Labiate, 118. 378.
Labiose, 119.
Lachrymaeformis, 373.
Lacerus, 388.
Laciniatus, 388.
Lacteus, 403.
Lacunose, 393.
Laevigatus, 397.
Laevis, 397.
Lamellar, 386.
Lamellatus, 386.
Lanatus, 395.
Lanceolate, 38.
Latent, 50.
Lateral, 416.
Laterinervius, 92.
Lateritius, 406.
Laxus, 398. 418.
Leaf-like, 377.
Leathery, 398.
Lens-shaped, 374.
Lenticular, 374.
Lentiformis, 374.
Lentiginosus, 397.
Lepidotus, 41. 396-
Leprous, 396.
Leprosus, 396.
Lettered, 408.
Leuco, 403.
Liber, 416.
Ligneus, 398.
Lignosus, 398.
Ligulatus, 381.
Lilacinus, 406.
Liliaceous, 119.
Limbatus, 407.
N N *

552

INDEX.

Linealis, 400.
Linear, 381.
Lineatus, 394.
Lined, 394.
Linguiformis, 375.
Little, 399.
Lituratus, 408.
Lividus, 405.
Lobatus, 388.
Lobed, 9. 388.
Loculicidal, 164.
Loculosus, 393.
Lofty, 399.
Loose, 398. 418.
Loratus, 381.
Low, 399.
Lunatus, 383.
Lunulatus, 383.
Luridus, 404.
Luteolus, 404.
Lutescens, 404.
Luteus, 404.
Lymphatic, 40.

Macrocephalous, 183.
Macropodous, 191.
Maculatus, 407.
Manicate, 39.
Many-headed, 77.
Marbled, 407.
Marcescens, 402.
Marginal, 416.
Marginatum, 407.
Marmoratus, 407.
Masked, 118.
Mealy, 396. 398.
Medullary, 398.
Meios, 400.
Meiostemonous, 400.
Mela, 403.
Melano, 403.
Melon-shaped, 374.
Membranous, 86.
Membranaceous, 397-
Memnonius, 404.
Meniscoideus, 380»
Menstrualis, 402.
Menstruus, 402.
Milk-white, 403.
Millsail-shaped, 377.
Miniatus, 406.
Mitriform, 201.
Mixtinervius, 92.
Modioliformis, 380.
Molendinaceus, 377.
Monadelphous, 124.
Monandrous, 124.
Monocarpous, 401.
Moniliform, 25. 376.
Monopetalous, 118.

Monophyllus, 1 16.
Morious, 106.
Much-branched, 392.
Mucous, 397.
Mucronate, 385.
Multiceps, 77.
Multiferus, 401.
Multifidus, 388.
Multijugus, 391.
Multidigitato-pinnatus, 39 1 .
Muricated, 395.
Muriform, 9.
Murinus, 403.
Muscariformis, 379.
Mushroom-headed, 380.
Muticus, 386.

Naked, 52. 397.
Naked (seeds), 161. 194.
Nanus, 399.
Napiformis, 373.
Natans, 411.
Nave-shaped, 380.
Navicularis, 376.
Nebulosus, 407.
Necklace-shaped, 25. 376.
Needle-shaped, 382.
Nervatus, 93. 408.
Nerved, 88.
Nervosus, 408.
Netted, 92. 393.
Niger, 404.
Nigritus, 404.
Nitidus, 397.
Niveus, 403.
Nocturnus, 402.
Nodding, 413.
Nodosus, 376.
Nodulose, 77. 400.
Normal, 381.
Nudus, 397.
Nullinervis, 409.
Nullinervius, 91.
Nutans, 413.

Ob, 422.

Oblique, 94. 384. 412.
Oblong, 8. 382.
Obtusus, 385.

cum acumine, 385.

Obvolute, 410.
Ocellated, 407.
Ochraceus, 405.
Ochroleucus, 405.
Octandrous, 125.
Often-bearing, 401.
Oleaginous, 398.
Oligos, 420.
Olivaceus, 405.
One- ribbed, 408.

INDEX.

55S

One-sided, 40. 413. 419.
Opaque, 397.
Operculate, 114.
Opposite, 414. 418.
Orbicular, 332.
Orgyalis, 400.

Orthotropous, 156. 193. 415.
Oscillatorius, 416.
Osseous, 398.
Oval, 382.
Ovate, 382.
Ovoidal, 374.

Painted, 407.
Paired, 391.
Palaceus, 416.
Paleaceous, 114. 396.
Palmaris, 400.
Palmate, 388.
Palmatifidus, 389.
Palmatilobatus, 389.
Palmatipartitus, 389.
Palmatisectus, 389.
Palmiformis, 409.
Palminervis, 93. 409.
Panduratus, 384.
Panduriformis, 384.
Papery, 397.
Papilionaceous, 119.
Papillosus, 395.
Papulosus, 395.
Papyraceus, 397.
Parabolical, 382.
Parallelinervis, 408.
Paralleli-nervosus, 91.
Parietal (pistilla), 139.
Paripinnatus, 390.
Parted, 388.
Partial (umbel), 110.
Partiale, 208.
Partitioned, 393.
Partitus, 388.
Patelliformis, 379.
Patens, 414.
Pear-shaped, 373.
Pectinatus, 389.
Pedalinervius, 93.
Pedalis, 400.
Pedate, 388.
Pedatifidus, 389.
Pedatilobatus, 389.
Pedatinervis, 409.
Pedatipartitus, 389.
Pedatisectus, 389.
Peduncularis, 96.

(cirrhus), 112.

Peltate, 415.
Peltinervis, 409.
Peltinervius, 93.
Pendulous, 159. 412

Pennatipartitus, 388.
Penniformis, 409.
Penninervis, 92. 409.
Pennivenius, 93.
Pentandrous, 125.
Perennans, 402.
Perennial, 249. 402.
Perfoliate, 82. 415.
Perforated, 393.
Perichanial, 201.
Perigynous, 123. 417.
Peripterus, 377.
Peritropal, 414.
Permanent, 402.
Peronate, 396.
Persistent, 249. 402.
Personate, 118. 378.
Perpendicular, 412.
Perpusillus, 399.
Pertusus, 393.
Pervious, 47.
Petal-like, 377.
Petaloideous, 377.
Petiolaceus, 53.
Petiolaris, 96. 416.
Phragmiger, 393.
Phceniceus, 406.
Phylloideus, 377.
Piceus, 404.
Pictus, 407.
Piliferus, 385.
Pilose, 114. 395.
Pimpled, 395.

Pinnate with an odd one, 390.
Pinnated, 39. 390.
Pinnaticisus, 388.
Pinnatifid, 388.
Pinnatilobatus, 389.
Pinnatisectus, 389.
Pitcher-shaped, 378.
Pithy, 398.
Pitted, 393.
Pivotante, 77.
Placenta-shaped, 373.
Plaited, 410.
Plane, 374.
Pleiophyllous, 46.
Plicativus, 410.
Plumbeus, 403.
Plumosus, 39. 114. 396.
Poculiform, 379.
Pointless, 386.
Pointletted, 385.
Polished, 397.
Politus, 397.
Pollicaris, 400.
Poly, 420.
Polyadelphous, 124.
Polyandrous, 125.
Polycarpous, 401

55*

INDEX.

Polyraorious, 106.
Polypetalous, 117.
Porphyreus, 404.
Posticus, 128. 414.
Pouch-shaped, 379.
Powdery, 397.
Praemorse, 77. 386.
Prasinus, 405.
Prickly, 394.
Prism-shaped, 372.
Prismatical, 9.
Proboscideus, 376.
Procerus, 399.
Procumbens, 414.
Pronus, 414.
Prostratus, 414.
Proteranthous, 401.
Pruinosus, 397.
Pseudo-costatus, 93.
Pterus, 377.
Pubens, 39.5.
Pubescens, 395.
Pullus, 404.
Pulley-shaped, 379.
Pulverulentus, 397.
Pulvinatus, 374.
Pumilus, 399.
Punctatus, 394. 407.
Puniceus, 406.
Pungent, 385.
Pure white, 403.
Purpureus, 406.
Pusillus, 399.
Pygmasus, 399.
Pyramidalis, 372.
Pyriformis, 373.

Quadridigitato-pinnatus, 391.
Quinate, 390.
Quincunx, 411.
Quintuplinervius, 93.

Radiating, 93.
Radiatus, 420.
Radicalis, 107. 416.
Ramealis, 416.
Rameous, 416.
Ramentaceous, 86. 396.
Ramosus, 391.
Ramosissimus, 392.
Rarus, 420.
Reclinate, 411, 412.
Rectinervis, 408.
Rectivenius, 91.
Rectus, 411.
Reflexed, 94.
Regular, 50. 120. 381.
Remotus, 420.
Renarius, 383.
Reniformis, 383.

Repand, 387.
Replicate, 410.
Restans, 402.
Resupinate, 412.
Reticulated, 23. 88. 92. 393.
Retinervis, 92. 409.
Retrorsus, 414.
Retuse, 385.
Revolute, 410. 412.
Rhizocarpous, 401.
Rhodo, 406.
Rhomboid, 383.
Ribbed, 92. 408.
Right-angled, 94.
Ringed, 394.
Ringent, 118. 378.
Rope-shaped, 376.
Roridus, 397.
Rosaceous, 1 1 9. 420.
Roseus, 406.
Rostellatus, 385.
Rostratus, 385.
Rosulate, 418.
Rotate, 378.
Rotundatus, 382.
Rotundus, 382.
Rough, 39. 395.
Roughish, 395.
Roundish, 382.
Rubellus, 406.
Rubens, 406.
Ruber, 406.
Rubescens, 406.
Rubicundus, 406.
Rubiginosus, 406.
Rufescens, 404.
Rufus, 404.
Rugose, 393.
Ruminated, 187. 393.
Runcinate, 384.
Ruptinervius, 92. 408.
Rutilans, 406.
Rutilus, 406.

Saddle-shaped, 380.
Sagittatus, 383.
Salver-shaped, 378.
Sanguineus, 406.
Sausage-shaped, 380.
Sawed, 387.
Scaber, 395.
Scabridus, 395.
Scabrous, 43.
Scaly, 396. 419.
Scarious, 398.
Scarred, 394.
Schistaceus, 403.
Scimitar-shaped, 375.
Scrobiculatus, 393.
Scrotiformis, 379.

INDEX.

555

Scutatus, 374.
Scutelliform, 379.
Scutiformis, 374.
Secreting, 40.
Secundatus, 40.
Secundus, 413. 419.
Sellaeformis, 380.
Semi-amplexa, 410.
Semi-amplexicaulis, 415.
Semilunatus, 383.
Semireticulatus, 393.
Semiteres, 374.
Sepalous, 116.
Septatus, 393.
Septicidal, 164.
Septifragal, 164.
Serialis, 419.
Sericeus, 39. 396.
Serratus, 387.
Sesqui, 400.
Sesquipedalis, 400.
Sessile, 94. 415.
Setiger, 385.
Setosus, 38. 114. 385.
Shaggy, 395.
Sharp-pointed, 385.
Sheathing, 95. 416.
Shield-shaped, 374.
Shining, 397.
Sigmoid, 192.
Silky, 39. 396.
Silvery, 403.
Simple, 21. 46. 111. 389.

(leaf), 87.

Simplicissimus, 389.
Sinuate, 387.
Sinuolatus, 387.
Sinuous, 9.
Slashed, 388.
Slimy, 397.
Smaragdinus, 405.
Smooth, 397.
Snow-white, 403.
Solutus, 416.
Spadiceus, 404.
Sphaericus, 372.
Spheroidal, 374.
Spatulate, 382.
Sparsus, 418.
Spiculate, 395.
Spindle-shaped, 374.
Spiny, 394.

Spiral, 125. 373. 412. 419.
Spiraliter contortus, 411.
Spithamaeus, ■400.
Splendens, 397.
Split, 388.
Spodo, 403.
Spongy, 398.
Spotted, 407.

Spreading, 94. 414.
Squamosus, 41. 396. 419.
Square, 9.
Squarrose, 419.
Squarrose-slashed, 388.
Squarroso-laciniatus, 388.
Stalked, 42.
Starved, 419.
Stellate, 40. 392. 418.
Stelliformis, 418.
Stellulatus, 418.
Stem less, 58.
Stemclasping, 415.
Sterile (stamens), 136.
Stinging, 396.
Stipitatus, 416.
Stipulaceus, 53.
Straggling, 414.
Straight, 41 1.
Straight-ribbed, 408.

veined, 91, 92.

Stramineus, 404.
Strangulated, 25.
Strapshaped, 381.
Striated, 394.
Strictus, 411.
Strigose, 42. 396.
Striped, 407.
Strombuliformis, 373.
Strombus-shaped, 373.
Stupose, 125.
Sub, 422.
Submersed, 412.
Sub-parallel, 94.
Subramosus, 391.
Suberosus, 398.
Subrotundus, 382.
Subulatus, 382.
Succisus, 386.
Succulent, 86. 398.
Sulcatus, 394.
Sulphureus, 404.
Superior (calyx), 115.
Supervolute, 410.
Supra-axillary, 79.
Supradecompound, 390.
Suspended, 159.
Sutural, 164.
Swimming, 411.
Sword-shaped, 382.
Sychnocarpous, 401.
Synanthous, 401.
Syncarpous, 144.

Taenianus, 380.
Tail-pointed, 385.
Tall, 399.
Taper, 374.
Taper-pointed, 385.
Tapering, 384.

556

INDEX.

Tap-rooted, 77.
Tapeworm -shaped, 380.
Tartareous, 399.
Tear-shaped, 373.
Tephro, 403.
Terete, 374.
Tergeminate, 39 J.
Terminal, 416.
Ternate, 390. 418.
Ternato-pinnatus, 391.
Testaceus, 405.
Tessellated, 407.
Testiculatus, 377.
Tetradynamous, 124.
Tetrandrous, 125.
Thalassicus, 405.
Thallodes, 206.
Thick, 398.
Threadshaped, 375.
Three-cornered, 375.
Three-edged, 376.
Three-ribbed, 93.
Thrice digitato-pinnate, 391.
Tomentose, 395.
Tongue-shaped, 375.
Toothed, 39. 387.
Tooth-letted, 39.
Top-shaped, 373.
Torn, 388.
Torsivus, 411.
Tortuous, 413.
Torulose, 40. 376.
Trapeziform, 383.
Treelike, 392.
Triadelphous, 124.
Triandrous, 124.
Triangular, 375. 383.
Tricornis, 376.
Tricostatus, 93.
Tridentatus, 386.
Tridigitato-pinnatus, 39 1 .
Triduus, 402.
Trifariam, 419.
Trifidus, 388.
Trifoliolate, 390.
Trigonus, 375.
Trijugus, 391.
Trilobus, 388.
Trimestris, 402.
Trinervis, 93.
Tripartitus, 388.
Tripinnate, 391.
Triple-ribbed, 93. 408.
Triplinervius, 93. 408.
Triplicostatus, 93.
Triplo, 400.
Triqueter 375.
Triternate, 391.
Trochlearis, 379.
Trumpet-shaped, 37G.

Truncate, 386.
Tubaeformis, 376.
Tubatus, 376.
Tubercled, 395.
Tubular, 372.
Tunicated, 52.
Turbinate, 373.
Turgid, 380.
Turnip-shaped, 77. 373.
Twin, 392.

digitato-pinnate, 390.

Twining, 418.
Twisted, 411.
Two-edged, 375.

Ulnaris, 400.
Umbilicate, 415.
Umbonatus, 374.
Umbraculiformis, 380.
Umbrella-shaped, 380.
Umbrinus, 404.
Unarmed, 394.
Uncatus, 385.
Uncertain, 414.
Uncialis, 400.
Uncinatus, 385.
Unctuosus, 397.
Undulatus, 385.
Unequal, 120. 384.
Unequal-sided, 384.
Unguiculate, 119.
Unicus, 420.
Unijugatus, 391.
Unijugus, 391.
Unilateral! s, 419.
Uninervis, 408.
Universal (number), 110.
Universale, 208.
Urceolatus, 378.
Urens, 396.

Vacuus, 101.
Vaginans, 416.
Vaginervis, 93. 409.
Vagus, 193. 414.
Valvaris, 411.
Valvate, 411.
Variegatus, 407.
Vascularis, 380.
Vase-shaped, 380.
Veinless, 91.
Velutinus, 38. 395.
Velvety, 395.
Venous, 88.
Venosus, 92. 409.
Ventral, 144.
Ventricosus, 381.
Venuloso-hinoideus, 92.
Venuloso-nervosus, 91.
Vermicularis, 376

INDEX.

557

Vermiculatus, 406.
Verrucosus, 395.
Versatile, 128. 416.
Vertebrate, 390.
Verticalis, 412.
Verticillatus, 418.
Vexillary, 411.
Virens, 405.
Virescens, 405.
Virgate, 47.
Viridis, 405.
Villosus, 395.
Vimineous, 47.
Violaceus, 406.
Viscid, 397.
Viridescens, 405.
Viridulus, 405.
Vitellinus, 405.
Vittatus, 407.
Volubilis, 413.

Wandering, 193.

Wavy, 384.
Waxy, 398.
Wedge-shaped, 382.
Wheel-shaped, 378.
Whip-shaped, 376.
White, 403.
Whitened, 397.
Whitish, 403.
Whorled, 418.
Winged, 377.
Withering, 402.
Woody, 398.
Woolly, 395.
Worm-shaped, 376.
Wrinkled, 410.

Xantho, 404.
Xerampelinus, 406.

Yearly, 402.

Zoned, 408.

THE END.

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