The living organism; an introduction to the problems of biology

Preface

Among the many branches of that organised pursuit of knowledge which has attained in this age its most marked development, there is none which has so profoundly influenced current thought as Biology. The conceptions derived from biological research have proved not only an intellectual gain of remarkable value in their proper sphere ; but they have had, so dominant are they in character, far-reaching results in other directions. The great tide of new ideas has been too strong to be contained within its own channel. The neighbouring fields of philosophy have been affected. The human outlook on Nature has been changed.

But just as new ideas colour those which have been previously acquired, so does the loss of a single conception involve the disturbance of many. And, therefore, if Biology is to be a sub-

VI ject of education as well as of research, there are urgent reasons why all who aid in its progress should help to make its foundations stronger, more self-contained, and steadier. Without dwelling on this point, it may at least he observed that inaccurate conclusions and unsound speculation have more serious issues in the case of Biology than in any other of the Natural Sciences.

Security against these results must come about through care in the instruction of rudiments. As far as the intellectual difficulties of the rudiments will permit, a change in the prevalent attitude of the student towards them seems desirable. Too much is taken for granted. The problems and generalisations of the science of living objects are regarded too complacently by the beginner. He is too easily contented with description and narrative ; and it may be mentioned that practical work in the laboratory is often little more than an aid in remembering description. That which is a mere statement or a collection of terms in a text-hook does not become a course of reasoning because it is followed concretely in the laboratory. The dissection of typical organisms is not necessarily an intellectual exercise.

PREFACE vii

Moreover, since Biology as the science of living things deals with phenomena of which we all have some kind of knowledge, its ideas lend themselves very readily to popular discussion. It has provided new terms and phrases for a public interested . in novelty but impatient of study. Yet the common occurrence of such terms as Heredity and Natural Selection does not imply a widespread extension of scientific research. The respect shown for any generalisation of a chemical or physical nature affords a striking contrast to the confidence with which biological subjects are discussed. It would appear that the problems of inanimate Nature, the qualities and changes of matter, are to be left in the hands of experts who approach them after a rigorous training, while untrained judgment may exercise itself over the mystery of life.

Nevertheless it is with great diffidence that I have ventured on this essay to deal with some of the difficulties of the subject, and to sketch in outline a course of thought which may serve as an introduction to more special study. Detail has been sacrificed in it to breadth of view. Practical illustration is to be found in many excellent text-books, and by the side of those

Vlll more solid achievements this effort must play a supplementary and subordinate part. The object of the book will be attained if it succeeds, although it may be chiefly by negative criticism, in directing attention to the important truth, that though chemical and physical changes enter largely into the composition of vital activity, there is much in the living organism that is outside the range of these operations.

Chapter III An Outline Of The Scheme Of Biology

Explanatory remarks — Elementary ideas of Biology belong to two classes — Common forms and changes of life to be described in general terms — Details not to obscure gener-

X alities — Generalisations simplify description — Changes of matter common to all forms — Description of the scheme of Biology ....... Pages 19-29

Chapter IV The Structures Accessory To Alimentation In Man

General description — The organ concerned in exchange of gaseous material — The organ occupied in distribution and excretion — Mechanical analogies are misleading — The general results of circulation .... 30-42

Chapter V A Description Of Other Forms With Regard To

ALIMENTATION

Vertebrates — Molluscs — Arthropods — Ecliinoderms — Simpler animals — Plants — Summary and amplification . 43-55

Chapter VI The Object Of Classification

Need of an order for living objects — Simple description inadequate— The process of classification — Difficulty in applying the process to living objects — Dual aspect of the organism as possessing form and as presenting change — Classification simplified by regarding both form and function — Idea of development in classification— Conception of types— Influence of authority — Communication of knowledge increases its exactness — Opinions of others to be recognised — Summary . . . . . . • .56-79

CONTENTS xi

Chapter VII Certain General Statements Concerning Organisms

AS INDIVIDUALS

Explanatory — Life continuous, Forms intermittent — Form disturbed in reproduction, but life persists — Death the sequel to reproduction — Further discussion of growth — Assimilation the reality underlying growth — Reproduction connected with the process of growth — Permanence of the form — Summary ...... Pages 80-96

Chapter VIII A General Description Of The Organism As Related To Its Surroundings

Relation of Subject and Object — Our difference from other organisms in relation to surroundings — One part of life engaged in observing other parts — Natural Science chiefly describes phenomena — Organism both Subject and Object — Organism and surroundings inseparable in some respects — Thought based on sensation, but implying something more — The same world of Objects giving impressions to innumerable individuals — Meaning of “Self” — Perceptions and ideas — Province of Biology — No disparity between organism and environment — A contrast necessary — Link between organism and environment . ..... 97-117

Chapter IX The Material Basis Of Life

Introductory — Living changes few in number and forming a constant group — Matter concerned in the changes to be

Xll considered — Difficulty in perceiving the substance as common — Degrees in resemblance of material — Similarity of substance and similarity of behaviour — Process of generalising — Observation needs control and definition — Limitation of chemical methods — Application of chemical nomenclature — Complementary relation of plants and animals — Chemical names given to certain constant phenomena Pages 118-136

Chapter X The Organism As A Chemical Aggregate

Description of chemical changes — The organism as an aggregate of certain kinds of matter — Chemical description not distinctive— Description of matter in general terms — Reality of sensations — Perception of sameness in material objects is exact — All knowledge of Nature based upon the perception of similarity in quantity or quality — Test of sameness applied to living matter — Primary restriction of observation— Protoplasm more than a chemical compound — Constant features of living matter do not preclude variety of form — Difficulty in localising attributes . . 137-158

Chapter XI The Organism As A Centre For The Transformation

OF ENERGY

Physical methods and results applicable on certain conditions — Classes of change to which applicable — Conception of energy — Energy of animals derived from plants — The organism not an ordinary conservative system — Resemblance of organic activity to that of other systems — Distinctive features of organic activity ..... 159-174

CONTENTS xm

Chapter XII Certain Aspects Of Form And Development

Need of guidance — Meaning of degree in these matters — Externals of life dealt with in form — Structure and material to be considered — Value of analysis — Structure demonstrates composite nature of activity — Organism together with environment form a system — External changes affecting the organism — Reaction of the organism — Danger of pseudo-explanations — Cell-division incidental to growth and reproduction — Idea of cell to be used with reservation — Products of cell-division not necessarily alike — Prejudice in matters of form and change — Environment assists comprehension of development — Extension of idea of development and environment — Two main paths of development — Hypotheses useful in co-ordinating facts — Ideas of cell-arrangement more useful than ideas of cell — Cell-arrangement less significant than combination of function — Nerve- development connected with highest function — Equilibrium checked by the Organism — Summary

Chapter XIII The Meaning Of Sensation

Introduction — Illustration of ordinary mutual action — Additional results when one object alive — Effects of external things belong to two classes — Character of sensation — Implication of mechanism in consciousness — The sentient subject ........ 229-249

Chapter XIV Some Of The Problems Presented By The Organism

Recapitulatory — Species — Variation and Adaptation — The Cell as Agent — The unity of the Organism . . 250-266

Chapter I

The introduction to a fresh study in some cases is a definite event in personal history. It is possibly an occurrence marked by some circumstance of time or place. Certain ideas may be suggested for the first time or, it may be, facts first come within our ken under conditions which render the occurrence memorable. But this is rare.

The acquisition of any portion of knowledge is, in reality, seldom a sudden operation. It is more usually an insensible drifting through a multitude of mental states, and one idea may be the result of many preliminary efforts.

It is difficult to claim for any portion of knowledge that it is absolutely new, and difficult to assign to it an origin or moment of inception. A little reflection makes it clear that most of our thoughts grow gradually out of those which previously existed. The more recent mental

CHAP.

conditions, so far as they are progressive, are built up of simpler and earlier states. A gradual progress in thought may often be traced through many stages from an origin which is distant and obscure, though great care and skill are necessary for success in this performance.

This statement, if it can be realised for a single idea, or even for any given class of thoughts, holds still more true of such a vast body of knowledge as is denoted in speaking of Natural Science. There is no absolute and marked beginning of such a subject, as there can be no end, in minds which have ever been active in its acquisition.

We shall learn hereafter that minds must be so occupied as long as they exist. Activity of this kind is a condition of their existence. We are always learning , though not always are ive learning with method or with advantage.

We perceive Objects and Changes

It is unnecessary to speak of the variety or the number of objects which come within our perception, and the instances of change are innumerable. A complex world of endless objects and changes appears before us, and our attempts to understand it have created Natural Science,

I

The Act of Perception is the Beginning of

Knowledge

The objects and the changes in those objects, which together constitute our world, give rise to successive acts of perception. It may he said that perception is exercised on objects (or things), and on changes (or events); and each individual perceives within certain limits, and not beyond. Our science or knowledge is based upon, and begins with, the perception of our surroundings.

The Amount of Knowledge depends partly upon the Extent of Perception

This statement must be true, if knowledge be a result of perception. The wider the region surveyed, in other words, the greater the number of objects and changes perceived, and the more accurate the perception, the greater will be the amount of knowledge. The value of knowledge, however, is estimated by very different means. The worth is not likely to be confused with the amount.

The Range of Perception for the Individual is

limited

The individual can explore but a limited region of the world. A few alone of its innumer-

CHAP.

able objects and changes can come within the compass of his means of perception. The experience of other individuals may assist him to widen the circle of his own knowledge. Information gained from others may add to his personal store.

It is the aim of education to put the learner in touch with accumulated knowledge, as well as to render successive additions to knowledge possible. The capacity to perceive may be greatly extended by a careful training which has these ends in view.

The Exercise of Perception needs to be assisted

and directed

The mere accumulation of facts, as gained from repeated acts of perception on one’s own part, or from statements of perception on the part of others, is not the only end towards which the student of science is directed. Unassisted efforts would probably lead to this result in the main, and then little intellectual progress would be made. Guidance and direction are always needed by the learner, and in almost all stages of civilisation the younger generation has been found to rely upon the older.

The Extent of Knowledge is not so important as

its Nature

We do not necessarily know more, because we

I have come into touch with a larger number of facts or statements. Knowledge, or science, does not begin until facts are perceived to be connected in some way or other.

The facts to he known are without limit. On the other hand, the capacity of the individual to perceive when facts are connected is limited very narrowly. It is important, then, that the working of our perception should take the right direction. The meaning of right, however, remains to he defined.

To observe is to perceive intelligently

It has been stated that ordinary perception, even when the action frequently repeats itself, does not necessarily lead to knowledge. For comprehension of what is perceived, it is essential that the percipient individual should he able to refer the things or events which are before him to that permanent record of past experience which he speaks of as his mind.

Perception may be intelligent, or it may be without meaning and without use. When it is directed to a certain end, and when it is consciously performed for definite purposes, it is usual to describe it as an act of observation.

Exact Knowledge begins with accurate Observation

There is no doubt that accuracy in personal

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observation is essential to progress. Without some training in the special modes of observation which are needed in the branch of knowledge to be undertaken by the student, he cannot expect to be able to interpret rightly the records of previous observers. Their work will not be understood, nor will their descriptions convey the right meaning to him.

The methods of acquiring exact knowledge and of gaining a faculty for correctly interpreting recorded facts of observation, based as they are primarily upon accurate personal observation, cannot be given in a few propositions. The following pages describe a few conditions which have a special bearing on Biology.

An Experiment is a special Kind of Observation

When the events to be observed are very complex, it is usual to resort to an experiment , whereby acquaintance may be made with a single aspect or a single component of a given change at a time. All observation partakes more or less of the character of an experiment, in so far as it has ulterior aims.

The Number of different Substances in the World is limited, though the Number of different Forms is indefinite

There is no doubt that the number of different objects even within our own compass is inde-

I finitely large, and within the known world there is no imaginable limit to the variety of distinct things. Yet the many objects coming under our observation are not unlike in all respects. In some of their properties they are frequently alike. Their distinctness or separateness is none the less true because they possess some degree of sameness. The substance or material of two distinct objects may be alike, while the form , shape, size, situation, or state may differ.

Herein lies the main boundary between the province of Chemistry and that of Biology. Chemistry deals with the composition of bodies, and does not regard their form. It is concerned, too, with the nature of the changes which may occur when different objects are brought together, but it pays no attention to the form or to the identity of those objects.

We may say, then, that Chemistry is confined to substance, while Biology deals with the substance and also with the form and identity of certain objects.

The term Form may be used to denote Condition or State, as well as Shape and Size

Form is that which is occupied or filled, that which contains, as distinct from what is contained. And so we come to use the word form as the sign for the mode or state in which an

CHAP.

object appears to us. The form is opposed to

the substance of an object. The matter or substance may be similar in different objects, while great variety of substance may be presented under the same form.

Then, as we find expressed in the science of Chemistry, matter exhibits great variation, independently of difference of form. With what is denoted by the narrower meaning of the term form Chemistry does not often concern itself. The investigation of states of matter, on the other hand, does form part of chemical research, though it is, speaking strictly, the subject of Physics.

The Acquisition of systematic Knowledge is the End in view

The propositions which have now been laid down form a suitable introduction to our subject. They have no special reference to any particular branch of natural science, but they apply to all knowledge derived directly or indirectly from observation.

In connection with Biology, however, they are apt to be forgotten. In that science it is more than usually important to start in the right direction, and, indeed, to maintain throughout a correct attitude with regard to the foundations of our knowledge of Nature. For this reason, after recapitulating the gist of what

I has been already stated, we shall proceed in the following chapter to extend our list of preliminary statements.

We derive our knowledge of Nature from the exercise of observation, an act which has two component parts — the normal activity of the senses on the one hand, and the direct control of the intelligence on the other. The mere perception of the objects and changes among which we live is not enough for reasoning beings. It is not enough to receive impressions of nature as a series of separate and distinct phenomena, nor to receive them as a crowd of confused images.

The acquisition of systematic knowledge exacts much more than a passive submission to external influences. It is a process evidently controlled and directed to a large extent by the experience accumulated in the past and made accessible through records. One’s own observation does not bring to light the connections between phenomena and the orders among events, until it is aided by the experience of others and shaped by reflection.

Indeed any course of study is only to be distinguished from the daily round of ordinary watchfulness and reflection by the fact that these activities, which are evoked in some degree from every individual by his surroundings, are therein directed and controlled to a definite purpose.

Chap. I

And with such a purpose do we undertake the study of Biology.

Biology is the Science which treats of living

Things

Such a statement as this will scarcely satisfy the inquirer, for it does not tell him enough. As to what is meant by a living thing , there is indeed a general, though indefinite, consent, and it is sufficient for the ordinary pursuits and thoughts of most people. Animals or plants as examples of living things are easily recognised. Mistakes are made, it is true ; but, as a rule, the thoughts we have about animals and plants are precise enough for ordinary purposes. To be more precise or more definite, our ideas would need an amplification which must be the result of guidance and training.

Although it may be useful at this stage to make a more exact statement of the nature of our subject, it will not be till the end of our course, in default of some previous training, that the meaning of the statement can be comprehended more definitely. It suffices now to say, that the science of Biology is a certain body of connected knowledge , which is derived from the observation of living objects and from reflections based on that observation.