H.W. CONN
PROFESSOR OF BIOLOGY IN WESLEYAN UNIVERSITY
AUTHOR OF THE STORY OF GERM LIFE, EVOLUTION OF TO-DAY, THE LIVING WORLD, ETC.
WITH FIFTY ILLUSTRATIONS
NEW YORK D. APPLETON AND COMPANY 1903
Copyright, 1899,
By D. APPLETON AND COMPANY.
PREFACE.
That the living body is a machine is a statement that is frequently made without any very accurate idea as to what it means. On the one hand it is made with a belief that a strict comparison can be made between the body and an ordinary, artificial machine, and that living beings are thus reduced to simple mechanisms; on the other hand it is made loosely, without any special thought as to its significance, and certainly with no conception that it reduces life to a mechanism. The conclusion that the living body is a machine, involving as it does a mechanical conception of life, is one of most extreme philosophical importance, and no one interested in the philosophical conception of nature can fail to have an interest in this problem of the strict accuracy of the statement that the body is a machine. Doubtless the complete story of the living machine can not yet be told; but the studies of the last fifty years have brought us so far along the road toward its completion that a review of the progress made and a glance at the yet unexplored realms and unanswered questions will be profitable. For this purpose this work is designed, with the hope that it may give a clear idea of the trend of recent biological science and of the advances made toward the solution of the problem of life.
Middletown, Conn., U.S.A.
October 1, 1898.
CONTENTS.
introduction—Biology a new science—Historical
biology—Conservation of energy—Evolution—Cytology—New
aspects of biology—The mechanical
nature of living organisms—Significance of the new
biological problems—Outline of the subject [1]
PART I.
THE RUNNING OF THE LIVING MACHINE.
CHAPTER I.
IS THE BODY A MACHINE?
What is a machine?—A general comparison of a body and
a machine—Details of the action of the machine—Physical
explanation of the chief vital functions—The
living body is a machine—The living machine
constructive as well as destructive—The vital factor [19]
CHAPTER II.
THE CELL AND PROTOPLASM.
Vital properties—The discovery of cells—The cell doctrine—The
cell—The cellular structure of organisms—The
cell wall—Protoplasm—The reign of protoplasm—The
decline of the reign of protoplasm—The
structure of protoplasm—The nucleus—Centrosome—Function
of the nucleus—Cell division or karyokinesis—Fertilization
of the egg—The significance of
fertilization—What is protoplasm?—Reaction against
the cell doctrine—Fundamental vital activities as
located in cells—Summary [54]
PART II.
THE BUILDING OF THE LIVING MACHINE.
CHAPTER III.
THE FACTORS CONCERNED IN THE BUILDING OF THE LIVING
MACHINE.
History of the living machine—Evidence for this
history—Historical—Embryological—Anatomical—Significance
of these sources of history—Forces at work in
the building of the living machine—Reproduction—Heredity—Variation—
Inheritance of variations—Method of machine building—Migration and
isolation—Direct influence of environment—Consciousness—Summary
of Nature's power of building machines—The origin of the cell
machine—General summary [131]