Applied biology; an elementary textbook and laboratory guide online

BIOLOGY

LIBRARY

G



APPLIED BIOLOGY

AN ELEMENTARY TEXTBOOK AND
LABORATORY GUIDE



BY

MAURICE A. BIGELOW, PH.D.

PROFESSOR OF BIOLOGY IN TEACHERS COLLEGE, COLUMBIA

UNIVERSITY; CO-AUTHOR OF THE "TEACHING OF

BIOLOGY IN THE SECONDARY SCHOOL"

AND

ANNA N. BIGELOW, M.S.

TEACHER OF HIGH-SCHOOL BIOLOGY



THE MACMILLAN COMPANY
1911

-All rights reserved,



ECOLOGY

LIBRARY

G



COPYRIGHT, 1911,
BY THE MACMILLAN COMPANY.



Set up and electrotyped. Published October, 1911.



Nortoooti

J. 8. Gushing Co. Berwick & Smith Co.
Norwood, Mass., U.S.A.



PKEFACE

THIS book is intended for use as a combined textbook and
practical guide for a year's course of five hours per week.
It attempts to select from the fields of botany, zoology, and
human biology the essential facts and especially the great
ideas of the science of life which are of interest to the average
intelligent person who has no time and reason for more exten-
sive study of biology.

The word " applied " in the title of this volume should not
be understood in the limited sense of economics, nor solely
with reference to human physiology and hygiene. It is true
that in these two lines biology has vastly important applica-
tions to human life, but it must not be overlooked that in
certain phases the science has value in the intellectual and
aesthetic life of cultured citizens. Hence, in the most liberal
interpretation, " applied biology " must present those facts
and ideas of the science which apply to human life in its
combined intellectual, esthetic, economic, and hygienic out-
look. It has been the aim of the authors to select for this
book the facts and ideas in these lines which seem best
adapted to that stage of education which for the vast majority
of students is the climax of formal education. In other words,
it has been attempted to present the science of biology applied
to the daily life of the average intelligent citizen.

This book presents an order of study and selection of mate-
rials which have long appealed to the authors as a very
helpful answer to the widespread criticisms of the common
elementary courses of botany and zoology from the pure-
no r f\ f\



VI PREFACE

science point of view. It is far from being merely a theo-
retical attack upon the problems of an introductory course
in biology, for a large part of the radically new arrangement
of subject matter has been worked out in practice by the
authors and by several other teachers who have worked under
suggestions from the authors.

The authors trust that the critical readers whose attention
may be attracted to parts of this book which seem to depart
radically from the traditional introduction to biology, espe-
cially by means of separate courses in botany and zoology,
may be so kind as to frame their criticisms in the light of the
explanations and defense which have been written for an
accompanying " Teachers' Manual of Biology." See foot-note
on the first page of Chapter I.

A noticeable feature of the book is omission or at least lack
of emphasis upon several hundred technical terms commonly
used in elementary books of botany and zoology. Italics have
been used for emphasizing the most important scientific terms
when introduced and defined, while technical words in the
plain type should be understood by students as important
for special study, for temporary use in the text, or for com-
parison with other books. The authors realize that in select-
ing the biological terms for emphasis they may have omitted
some really useful terms, and it may be that certain italicized
words which have a narrow range of application do not deserve
the emphasis given them. A further discussion of this ques-
tion of technical words will be included in the "Teachers'
Manual."

This book also departs widely from the traditional teaching
of biological sciences, in that it presents much laboratory work
in the form of demonstrations by the teacher instead of
entirely as individual work for the students. This introduces
an important problem which can be adequately presented only
in the " Teacher s' Manual"; but the experience of many



PREFACE Vll

science teachers in secondary schools and colleges is leading
towards some golden mean between the old-time lecture and
demonstration method and the more recent laboratory work
for individual students. The authors have suggested for
demonstrations all practical work which experience shows is
ill-adapted for individual study by students with limited time
and training. See foot-note on page 10.

. One of the authors has discussed the meaning of the move-
ment towards a course in introductory biology, instead of
separate courses in botany and zoology, in Chapter V of Part II
in Lloyd and Bigelow's " Teaching of Biology in the Secondary
School," and also in School Science and Mathematics for Octo-
ber, 1908; and the principles there stated have been held
fundamental while making this book of "Applied Biology."
See also the " Teachers' Manual."

While it would be easily possible to select from this book
material for a very elementary course of biology in the first
year of some high schools, the authors have planned to issue
a smaller book especially arranged with reference to the
present peculiar conditions obtaining in high schools where
a course of biology comes in the first year.

The authors acknowledge the useful suggestions and con-
structive criticisms which they have received from many
teachers of biology ; and especially are they grateful for the
help on numerous problems which have been discussed with
Professor H. M. Blchards and Professor C. C. Curtis, of
Columbia University, and with Miss Jean Broadhurst and
Miss Caroline Stackpole, of the Department of Biology in
Teachers College, Columbia University. Also, acknowledg-
ments are due publishers and authors who have granted per-
mission for the use of numerous illustrations from standard"
books. As far as sources were known to the authors, credit
for figures has been given in the legends.

The authors cordially invite correspondence from teachers



V1U PREFACE

who have suggestions arid criticisms, or who need help in
conducting courses along the lines laid down in this " Applied
Biology' 7 and the accompanying "Teachers' Manual of
Biology."

M. A. B.

NEW YORK CITY,
September, 1911.



CONTENTS
PAET I

INTRODUCTORY STUDY: PRINCIPLES OF BIOLOGY

CHAPTER PA6K

I. BIOLOGY: THE SCIENCE OF LIFE ...... 1

II. CHANGES AND COMPOSITION OF LIFELESS AND LIVING MATTER 5

III. THE CHARACTERISTICS OF LIVING THINGS . . .10

I. Chemical Composition of Living compared with Life-
less Things. II. Life-Activities : (a) Animals, (&) Plants

IV. THE STRUCTURE AND LIFE OF AN ANIMAL : INTRODUCTION

TO ANIMAL BIOLOGY 23

The Structure (Anatomy) of the Frog .... 25

The Tissues of the Frog : Introduction to Microscopic Study 37
The Work of Organs of the Frog : Introduction to Animal

Physiology 44

Development of the Frog : Introduction to Embryology . 57

Classification of the Frog 64

V. THE STRUCTURE AND LIFE OF A PLANT : INTRODUCTION TO

PLANT BIOLOGY ........ 66

The Structure of a Bean Plant 67

The Reproduction of the Bean Plant 76

The Work of the Organs of a Plant : Introduction to Plant

Physiology ......... 85

Classification of the Bean Plant 121

VI. COMPARISON OF ANIMAL AND PLANT BIOLOGY . . . 122

VII. CLASSIFICATION OF ANIMALS AND PLANTS .... 133

ix



CONTENTS



PART II

PRINCIPLES OF BIOLOGY ILLUSTRATED BY TYPES
OF PLANTS

CHAPTER PAGE

VIII. STUDIES OF SEED-PLANTS ....... 146

Seeds and Seedlings 146

Roots of Seed-Plants 156

Stems of Seed-Plants 163

Leaves of Seed- Plants 188

Flowers of Seed-Plants 196

Seed-Plants without True Flowers : Gymnosperms . . 213

Fruits of Seed-Plants .216

Seed-Plants Reproducing without Flowers . . . 225

General Notes on Seed-Plants 228

IX. STUDIES OF SPORE-PLANTS 232

I. Higher Spore-Plants Ferns, Mosses . . . 233

II. Lower Spore- Plants Algae, Fungi .... 245

III. Bacteria 276



PAET III

PRINCIPLES OF BIOLOGY ILLUSTRATED BY TYPES
OF ANIMALS

X. THE SIMPLEST ANIMALS : PROTOZOA ..... 300
XI. THE SIMPLEST MANY-CELLED ANIMALS : PORIFERA AND

CCELENTERATA ........ 320

XII. THE WORM-LIKE ANIMALS 340

XIII. THE ECHINODERMS 355

XIV. THE ARTHROPODS 35C

Crustaceans ......... 358

Arachnids . . .376

Myriapods 379

Insects 380

XV. THE SHELL-ANIMALS : MOLLUSCA ... . 405



CONTENTS XI

CHAPTER PAGE

XVI. THE VERTEBRATES . .417

Fishes 419

Amphibians . . . 424

Reptiles 426

Birds 429

Mammals .......... 436

Life-Histories of Vertebrates 442



PART IV

PRINCIPLES OF BIOLOGY APPLIED TO HUMAN
STRUCTURE AND LIFE

INTRODUCTION. HUMAN BIOLOGY AND CLASSIFICATION OF MAN . 466
XVII. HUMAN STRUCTURE AND LIFE-ACTIVITIES . . . 467

XVIII. BIOLOGY APPLIED TO HEALTHFUL LIVING . . . 525
Personal Hygiene ........ 625

Effects of Stimulants and Narcotics . . . .539

Bacteriology applied to Human Health .... 554

PART V
XIX. EVOLUTION AND HEREDITY OF ANIMALS AND PLANTS 661



PART I

INTRODUCTION TO BIOLOGICAL STUDY



CHAPTER I
BIOLOGY: THE SCIENCE OF LIFE

1.* Living and Lifeless Things. Since the science of
biology deals with living things, it is of importance that at
the beginning of our study we should stop to consider that
all things which we know through our senses are either living
or lifeless. This will be evident if we attempt to write the
names of some common things, grouping them according to
whether they appear to have life or not. It is not difficult
to decide that air, soil, minerals, and water belong in the
list of lifeless things and that the most common animals and
plants are examples of the living; but we are puzzled by such
objects as dry seeds, undeveloped eggs of animals, some
plants in the winter condition, and many microscopic ani-
mals which show no signs of life when dry. Are such things
living or lifeless ? Usually it is not possible to answer until
time and proper conditions have given an opportunity for
changes which suggest life-activities. However, such uncer-
tain cases must be left undecided until after a careful study
of the differences between living and lifeless things.



* In the "Teachers' Manual of Biology" designed to accompany this
book there will be found, in paragraphs numbered to correspond with those
in this textbook, notes on books, materials, and methods of interest to
teachers, or to advanced students in normal-school classes,

B 1



-APPLIED* BIOLOGY



2. Organisms, Organic and Inorganic Matter. Except
in science study, we rarely stop to think of the facts brought
out in the problem above; but for the purposes of our later
work in science it is important that we stop and make such
a survey as above suggested, and recognize clearly that in
this world of ours there are two kinds of things, the living *
(collectively called animals and plants) and the lifeless
(e.g., air, soil, water, minerals, etc.). Living things are in
science commonly called organisms, and the substance of
which their bodies are composed, or which they form, is
organic matter. Lifeless substance which has not been
formed by organisms is called inorganic or mineral matter.
All substances, then, in living and lifeless things are composed
of matter which, as we learn through our five senses, exists in
many different forms.

3. The Sciences. Knowledge regarding the living and
lifeless things of nature is systematically arranged in the
natural sciences. A common division of these sciences is that
into (1) the physical sciences (chemistry, physics, geology,
mineralogy), and (2) the biological sciences, which are con-
cerned with living things. We shall see later that there is
much chemistry and physics used in the study of living
things, and hence it will be made clear that these two sciences
deal not only with lifeless things, but also with all substances
and changes which are found in both living and lifeless
things.

4. Biology, Botany, and Zoology. The study which
this book will direct deals primarily with living things, both
plants and animals. Biology is the science which treats of



* Throughout this book italics are used for words and phrases which are
very important in biology, and especially for scientific words where they
are first introduced and defined. Such emphasized words and their mean-
ings should be given special attention by students. Technical biological
words which have a very limited use, perhaps applicable to only a few
animals or plants, are printed in plain type ; and also they are in parentheses
if not important except for reference to other biological books.



BIOLOGY: THE SCIENCE OF LIFE 3

life and all living things plants, animals, and man. There
are two subdivisions of biology; namely, zoology, treating
of animals, and botany, treating of plants. Zoology is often
called animal biology, and botany, plant biology. The division
of biology into botany and zoology does not mean that plants
and animals are entirely unlike; but, on the contrary, we
shall find later that these two kinds of living things have
many points of remarkable similarity in both structure and
activities. This similarity is especially striking in many
microscopic living things which so combine both plant and
animal characteristics that biologists have not decided
whether they are animals or plants. But although there is
often a great similarity between animals and plants, it is
sometimes convenient to study the two kinds of living things
separately, and so biological science is subdivided into
botany and zoology. These two subdivisions of biology
are most important for advanced students; but the best
and most interesting beginning study is that which directs
attention to the great facts common to all living things.
Hence this book for beginners is called " Biology," to indicate
that it uses both animals and plants to illustrate facts and
ideas which are true of all living things.

5. Applied Biology. More important than the similarity
of animals and plants is the fact that many animals are in
structure and activities very much like the human body;
and hence the study of animals and plants helps us to under-
stand better the human body and its life-activities. More-
over, thousands of animals and plants profoundly affect
human life. For example, they provide all the food-supply
for mankind ; many harmfully influence human health ;
and some, such as pet animals and ornamental plants,
contribute much to the pleasures of life. Clearly, some
knowledge of the science of living things ought to be of
great interest to educated citizens, because it applies in so
many ways directly or indirectly to human life. Recogniz-



4 APPLIED BIOLOGY

ing this fact, it is the aim of this book (1) to call attention to
the most important facts and principles to be learned by the
study of selected animals and plants, and then (2) to show
how biological science applies to everyday human life.
This book is therefore entitled " Applied Biology " ; that
is to say, biology, the science of all life, is applied to, or looked
at from the standpoint of, human life as represented in the
experiences and interests of intelligent people in general.



CHAPTER II

CHANGES AND COMPOSITION OF LIFELESS AND LIVING

MATTER*

IN our later studies of living things (animals, plants, and
man) we shall often need to have in mind some important
facts and principles relating to the composition of both
living and lifeless things and to the changes which occur
in them ; and these are outlined in this chapter.

6. Three States of Matter. Soil, water, and air are
forms of lifeless matter which are examples of the three
states, solid, liquid, and gaseous, in which matter exists.

Matter in one of these states may be transformed into
either of the other states. Thus water, which is ordinarily
liquid, may be cooled and frozen into ice (the solid state),
or it may be heated and changed into vapor or steam (the
gaseous state). Iron and other common metals, which are
ordinarily solid, may be melted into the liquid state and at an
extremely high temperature may even change to a gaseous
state. Liquid air is made by reducing the temperature to
312 F. by subjecting air to great pressure in powerful
machines.

7. Physical Change. In all such changes of matter from
one state to another (from solid to liquid, or to the gaseous,
etc.) the same substance continues to exist. Ice is only
solid water, steam is a gaseous state of water, molten iron
cools into solid iron, and sugar and salt will dissolve in water.
In .these cases there has been a change in the state of matter,



* Students who have previously taken courses in chemistry and physics
should read this chapter as a review of familiar facts, but from a new view-
point.

5



6 APPLIED BIOLOGY

but not a change in composition. Such changes of state
which do not affect the composition of substances are called
physical changes.

That branch of science which treats of the form and physi-
cal changes of matter produced by heat, light, sound, elec-
tricity, gravitation, etc., was formerly called natural phi-
losophy, but is now usually known as physics.

8. Chemical Change. All matter is subject to another
kind of change in which the composition is affected and new
substances are formed. Ordinary burning of wood or gas,
and dissolving baking soda in vinegar or other acid, are com-
mon examples. The substances burned, or dissolved in acids,
are changed to other substances. Such transformations
which affect the composition of matter are chemical changes.

9. Elements. The nature of chemical change will be
clear after some further consideration of the composition
of matter. In chemistry, the science which treats of the
composition and chemical changes of substances, we learn
that all forms of matter all living and lifeless substances
in land, air, and water are composed of about 80 elements,
of which about 20 are very common. Some of these ele-
ments exist naturally in the solid state ; for example, iron,
copper, lead, sulphur, gold, nickel, silver, platinum, carbon,
magnesium, aluminum, tin, and zinc. Some others, like
mercury (quicksilver), are liquid; and still others are gases,
of which the two known as oxygen and nitrogen constitute
the greater part of the air.

Chemical Symbols. For convenience in writing the names
of the elements, chemists have adopted certain symbols or
abbreviations. The ones which will be most needed for ref-
erence in this book are : H for hydrogen ; N, nitrogen ;
O, oxygen; C, carbon; S, sulphur; P, phosphorus; Na,
sodium (or natrium) ; K, potassium (or kalium) ; Fe, iron
(or ferrum) ; Ca, calcium (lime). A table giving the full list
may be found in any elementary textbook of chemistry.



CHANGES OF LIFELESS AND LIVING MATTER 7

10. Compounds of Elements. Now, the elements have
the power of combining with each other so as to form various
compounds. To illustrate : the burning of magnesium is
a chemical combination between magnesium and oxygen of
the air two elements are here united to form a new sub-
stance, which is a compound of magnesium and oxygen
and is known as oxide of magnesium. Such a union of any
substance with oxygen is called oxidation. The burning
of coal is in part a combination between the elements oxygen
and carbon, but coal contains elements besides carbon.
All ordinary burning or combustion is an oxidation; that is,
the forming of a combination between oxygen of the air and
some other elements. In all cases of chemical change there
is a combining of elements into new or different substances.
Such substances composed of two or more elements are
called compounds. Most of the materials in the solid matter
of the earth are compounds; water, which is the most
abundant substance, is a compound of the elements hydrogen
and oxygen; and most of the materials in the bodies of
animals and plants are compounds. Air, however, is not a
chemical compound; the nitrogen and oxygen are not
united into a new substance, but are simply mixed together,
just as dry sand and sugar can be mixed without change of
composition in either. Other minor constituents of the
air will be mentioned later.

Using the chemical symbols for the elements, chemists
write MgO for magnesium oxide formed by burning magne-
sium (Mg) in the oxygen of the air, and ZnO for zinc oxide
formed by burning zinc in the same way. The formula MgO
expresses the composition of a molecule of magnesium oxide
and means that it is made up of one atom of magnesium
united with one of oxygen. This is the simplest possible
compound. In most compounds of two or more elements
there is a greater proportion of, certain elements, and this
is expressed by numbers after the elements of which there is



8 APPLIED BIOLOGY

more than one atom in the compound. Examples are : water,
written H 2 O, meaning that two atoms of hydrogen (H) are
combined with one .of oxygen (O) ; and sulphuric acid,
written H 2 S04, meaning that two atoms of hydrogen, one
of sulphur, and four of oxygen are combined to form the
acid.

In the above example of burning magnesium there are two
elements; but more than two elements are often involved
in a chemical change. One compound of several elements
may cause a chemical change in another compound, as dis-
solving baking soda (HNaCOs) in sulphuric acid (H 2 S0 4 )
illustrates. This dissolving of baking soda in acid illustrates
the most common kind of chemical change, for most sub-
stances on the earth are compounds. It has been noted
that the burning of magnesium involves only two elements,
but the ordinary burning of coal and other common fuels is
a union of compounds with oxygen, resulting in several
new compounds in the smoke and ashes.

Disintegration of Compounds. Not only may elements
unite to form compounds, but these may be separated into
simpler ones or even into their constituent elements. For
example, water may be formed by burning hydrogen gas
so that oxygen of the air unites with the hydrogen as shown
by the formula H 2 O, but water may also be decomposed by an
electric current passed through it in a suitable apparatus
and the two constituent elements (hydrogen and oxygen)
in gaseous form be collected separately. Such disintegra-
tion of compounds into the constituent elements is not so
common in nature as is change of compounds into simpler
ones.

11. Composition and Changes of Living Matter. The
principles stated in this chapter have been illustrated by
lifeless matter, but we shall see in later lessons that they
are also applicable to living matter. Living things are
composed of a number of common elements united in very



CHANGES OF LIFELESS AND LIVING MATTER 9

complex substances, and in their bodies there are constant
physical and chemical changes connected with all life-activi-
ties. Especially do foods eaten and oxygen from the breathed
air become involved in numerous changes in the living
matter of animal and plant bodies. Many times in later
lessons we shall need to refer to the principles of chemistry
and physics which this chapter reviews.

Summary : (1) Both living and lifeless matter may un-
dergo physical and chemical changes; and (2) all matter is
composed of elements, usually combined in compounds, and
capable under certain conditions of new recombinations into
other compounds.



CHAPTER III
THE CHARACTERISTICS OF LIVING THINGS

I. CHEMICAL COMPOSITION OF LIVING COMPARED
WITH LIFELESS THINGS

IN order to understand the relations of living and life-
less things, we need to know whether the organic matter of
living things is composed of peculiar substances which are
not found in inorganic matter. A few simple experiments
will show some remarkable similarity of composition.

12. Water in Living Things. Water, which is itself life-
less, forms a large part of the bodies of animals and plants, as
the following experiments show.

(D)* With a delicate balance, weigh carefully a piece of plant
stem or a leaf, record the weight, place in a warm, dry place (e.g.,
over a radiator, lamp, or stove, or in sunlight), and when dry weigh
again. The loss in weight represents approximately the amount of



* Directions for practical work are printed in the smaller type throughout
this book. Problems for individual work in the laboratory are marked (L).
Most of the laboratory work requires the supervision of a teacher, but it will
be found that most exercises require little or no apparatus and may be con-
ducted in the ordinary class-room if, as in many schools, there is no special
laboratory.

The letter Z>, at the beginning of a paragraph in small type, indicates that