LEATACACACACACACAT ASA S010) C1 GAUL GLU) 88, PA PAMACAEL EARL TE 


Anh al el el te nally ttl. Pha Nee ne 


SAA ATTA PAS 


sett 
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OF SPECIES: — 


oR, 


3 Gourse of Six Lectures to GHorking Men, 


BUREAU OF 
AMERICAN ETHNOLOGY 
0026 
cp) sy 1896 


ex. LIBRARY 
THOMAS H. HUXLE igi, ight The 


PROFESSOR OF NATURAL HISTORY IN THE JERMYN STREET SCILOOL OF MINES, 


’ ” ‘i: 


NEW YORK: 
D. APPLETON AND COMPANY, 


1895, 


wy 


ars 


oarey 


_ PREFACE TO THE AMERICAN EDITION. 


_ Tue publication of Mr. Darwin’s work on the 
ae. « «Origin of Species,” whether we consider the import- 
e .. 3 “atice of the questions it raises, the ability with which 

he treats them, the boldness and originality of his 

E ‘ - speculations, or the profound and universal interest 
which the book awakened, must be looked upon as 
marking an era in the progress of science. But while_ 

> it called forth a due share of candid discussion and 
aes intelligent criticism, it has been vehemently and per- 
te sistently assailed by many who understood nothing of 
its real character; and the subject has hence been so 
overloaded with prejudice and perversion that unscien- 
tific people hardly know what to think or believe about 

it. In these circumstances, those who disencumber the 
subject of its difficulties, simplify its statements, relieve 

it of technicalities, and bring it so distinctly within the 
horizon of ordinary apprehension that persons of com- 
mon sense may judge for themselves, perform an in- 


valuable service. 


Such is the character o' 


volume. | a 
Prefixed to the English edition, is the 
note from Professor Huxley: “ Mr. J. Aldous - 
who is taking shorthand notes of my ‘Lect 


account, =s ae those notes for the use of my andi 
I willingly accede to this request, on the understan 
that a notice is prefixed to the effect that I have n 
Soe to revise the Lectures, or to make alteration in 


in a ane of fact.” 

The reader will not regret that the Lectures appear 
in this form. Taken from the lips of the distinguished — 
naturalist, as he addressed an audience of ‘ Working — 
Men,’ they have a clearness, a directness, and a sim-— 

plicity which belonged to the circumstances of pe 
delivery. In this respect, the following Lectures are. 
incomparable. Dealing with the most abstruse and 
fundamental questions of mind and organization, these 
subjects are nevertheless presented in so lucid and at- ‘g 
tractive a manner as to impress vividly the commonest 
imagination. 

The gift of translating the high questions of science 
into popular forms of expression, without sacrificing ac- 
curacy and introducing error, is a very rare one among 
scientific men, but Professor Huxley possesses it in an 


Piet es i ia [PE tem i “ 


eminent degree: his lectures are models of their class. 


~ 
Tie 


8 


-ered.—The Origination of Living Beings . . . 52 


. The Perpetuation of Living Beings, Hereditary Trans- 
mission and Variation. Te Fe neha ge Pe oe: ad 


| 4 . The Conditions of Existence as affecting the Perpetua- 
4 ia merc iaving Beings.“ . =. ea at MD 


BY ‘VL A Critical Examination of the Position of Mr. Darwin’s 
ge Work, “On the Origin of Species,” in relation to the 
¥ complete Theory of the Causes of the Phenomena of 
% OE ree rei ae eR 
= 
4G 2 
4 
H 
f, 


LEC TUBS. f; 
Aen PRESENT CONDITION OF ORGANIC NATURE. 


at Be Win it was my duty to consider what subject I 
f would select for the six lectures which I shall now 
have the pleasure of delivering to you, it occurred to 
= that I could not do better than endeavour to put 
_ before you in a true light, or in what I might perhaps 
* = with more modesty call, that which I conceive myself 
to be the true light, the position of a book which has 
been more praised and more abused, perhaps, than 
any book which has appeared for some years ;—I mean 
_ Mr. Darwin’s work on the “ Origin of Species.” That 
work, I doubt not, many of you have read; for I know 
the inquiring spirit which is rife among you. At any 
rate, all of you will have heard of it,—some by one kind 
of report and some by another kind of report; the 
attention of all and the curiosity of all have been prob- 
ably more or less excited on the subject of that work. 
All Ican do, and all I shall attempt to do, is to put 
before you that kind of judgment which has been - 
formed by a man, who, of course, is liable to judge 
__—s erroneously ; but at any rate, of one whose business 
: and profession it is to form judgments upon questions 
of this nature. 


oe or rather to a statement of those facts ae of 
those principles which the work itself dwells upon, an 
brings more or less directly before us. I have no righ 
to suppose that all or any of you are naturalists; an 
even if you were, the misconceptions and misunder- 
standings prevalent even among naturalists on these — 
matters would make it desirable that I should take the 
course I now propose to take,—that I should start from 
the beginning,—that I should endeavour to point out 
what is the existing state of the organic world—that 
I should point out its past condition—that I should 
state what is the precise nature of the undertaking 
which Mr..Darwin has taken in hand; that I should 
endeavour to show you what are the only methods by 
which that undertaking can be brought to an issue, — 
and to point out to you how far the author of the work 
in question has satisfied those conditions, how far he has 
not satisfied them, how far they are satisfiable by man, 
and how far they are not satisiiable by man. And for 
to-night, in taking up the first part of this question, 
I shall endeavour to put before you a sort of broad 
notion of our knowledge of the condition of the living 
world. There are many ways of doing this. I might 
deal with it pictorially and graphically. Following 
the example of Humboldt in his “ Aspects of Nature,” 
I might endeavour to point out the infinite variety of 
organic life in every mode of its existence, with refer: 
ence to the variations of climate and the like; and such 
an attempt would be fraught with interest to us all; 


e lie ore s ei me, 
i Sead, tee aon ae 
ering 1s: “ORGANIC verte: 


4 


Slice, ‘the subject before us, such a course 
Id not be that best calculated to assist us. In an 


to the foundations of living Nature, if I may so say, 
and discover the principles involved in some of her 

most secret operations. I propose, therefore, in the 

rst place, to take some ordinary animal with which 
ss are all familiar, and, by easily comprehensible and 
obvious examples wn: from it, to show what are the 
; B bin of problems which living beings in yeneral lay 
Pir. a before us; and-I shall then show you that the same 
_ problems are laid open to us by all kinds of living 
s beings. But, first, let me say in what sense I have 
R* aged, the woods “organic nature.” In speaking of the 
34 a causes which lead to our present knowledge of organic 
re. nature, I have used it almost as an equivalent of the 
-_-word “living,” and for this reason,—that in almost all 
living beings you can distinguish several distinct por- 
tions set apart to do particular things and work in a 
particular way. These are termed “organs,” and the 

_ whole together is called “organic.” And as it is 
Fi { - universally characteristic of them, this term “ organic ” 
_ has been very conveniently employed to denote the 
___whole of living nature,-—the whole of the plant world, 
and the whole of the animal world. 

Few animals can be more familiar to you than that 
whose skeleton is shown on this diagram. You need 
not bother yourselves with this “ Aywus caballus” 
written under it; that is only the Latin name of it, 
and does not make it any better. It simply means the 
common Horse. Suppose we wish to understand all 
about the Horse. Onur first object must be to study 

1* 


the Saletidee which by its power of contraction a : 
the animal to move. These muscles move the hard 


parts one upon the other, and so give that strength 


and power of motion which renders the Horse so useful — 
to us in the performance of those services in which we oa 


employ him. 


And then, on separating and removing the whole sh 
of this skin anil flesh, you have a great series of bones, — 
hard structures, bound together with ligaments, and Ae 


forming the skeleton which is represented here. 


In that skeleton there are a number of parts to be 


recognized. ‘This long series of bones, beginning from 
the skull and ending in the tail, is called the spine, and 
these in front are the ribs; and than there are two pairs 
limbs, one before and one behind; and these are what 
we all know as the fore-legs and the hind-legs. If we 
pursue our researches into the interior of this animal, 
we find within the framework of the skeleton a great 


cavity, or rather, I should say, two great cavities—one 


cavity beginning in the skull and running through the 
neck-bones, along the spine, and ending in the tail, 
containing the brain and the spinal marrow, which are 
extremely important organs. The second great cavity, 
commencing with the mouth, contains the gullet, the 
stomach, the long intestine, and all the rest of those 
internal apparatus which are essential for digestion ; 
and then in the same great cavity, there are lodged the 
heart and all the great vessels going from it; and, be- 
sides that, the organs of respiration—the lungs; and 


Bi ve: beg ¢ 


es. | OF ORGANIC NATURE. 11 


i a ; 
then the kidneys, and the organs of reproduction, and 


_.be the upper part of the 


go on. Let us now endeavor to reduce this notion of a 
horse that we now have, to some such kind of simple 
expression as can be at once, and without difficulty, re- 


tained in the mind, apart from all minor details. If I 
make a transverse section, that is, if I were to saw a dead 
horse across, I should find that, if I left out the details, 
and supposing I took my section through the anterior 
region, and through the fore-limbs, I should have here 
this kind of section of the body (Fig. 1). Here would 


animal—that great mass 
of bones that we spoke 
of as the spine (a, Fig. 
1).. Here I should have 
the alimentary canal (0, 
Fig. 1). Here I should 
have the heart (¢, Fig. 1); 
and then you see, there Yj 
would bea kindof double l/ Z 
tube, the whole being in- li 
closed within the hide ; 

the spinal marrow would be placed in the upper tube 
(a, Fig. 1), and in the lower tube (0, Fig. 1), there would 
be the alimentary canal and the heart; and here I 
shall have the legs proceeding from each side. For 
simplicity’s sake, I represent them merely as stumps 
(ee, Fig. 1). Now that is a horse—as mathematicians 
would say—reduced to its most simple expression. 
Carry that in your minds, if you please, as a simplified 
idea of the structure of the Horse. The considerations 
which I have now put before you belong to what we 
technically call the ‘ Anatomy’ of the Horse. Now, 


Fie. 1. 


THE PRESENT CONDIT Te 


ws 


suppose we go to work upon these several par 
and hair, and skin and bone, and lay open these » 
ous organs with our scalpels, and examine them 


queer-looking things that are called ganglionic cor- 
puscles. If we take a slice of the bone and examine ~ 
it, we shall find that it is very like this diagram of a 
section of the bone of an ostrich, though differing, of 
course, in some details; and if we take any part what- __ 
soever of the tissue, and examine it, we shall find it 
all has a minute structure, visible only under the Be 
microscope. All these parts constitute microscopic 
anatomy or ‘Histology.’ These parts are constantly 
being changed ; every part is constantly growing, de- 
caying, and being replaced during the life of the animal. 
The tissue is constantly replaced by new material; and = 
if you go back to the young state of the tissue inthe 
case of muscle, or in the case of skin, or any of the 

organs I have mentioned, you will find that they all 

come under the same condition. Every one of these 

microscopic filaments and fibres (I now speak merely — 
of the general character of the whole process)—every 

one of these parts—could be traced down to some 

modification of a tissue which can be readily divided 

into little particles of fleshy matter, of that substance 

which is composed of the chemical ele- 
ments, carbon, hydrogen, oxygen, and ni- 
trogen, having such a shape as this (Fig. 
2). These particles, into which all primi- 
tive tissues break up, are called cells. 


wae te) Serre 


i. Ce 


Ces ‘onoasic eter 


J Py 
r xt 
é 


be 
ey 
I were tink a tion of a piece of the skin of 
he and, I should find that it was made up of these 
pir I examine the fibres which form the various” 
ns of all living animals, I should find that all of 
n, at one time or other, had been formed out of a 
a ibstance consisting of similar elements; so that you 
see, just as we reduced the whole body i in the gross to 
that sort of simple expression given in Fig. 1, so we 
wu may reduce the whole of the microscopic structural 
Peictients to a form of even greater simplicity ; just as 
a plan of the whole body may be so represented in a 
: ae (Fig. 1), so the primary structure of every tissue 
may be represented by a mass of cells (Fig. 2). 
a Having thus, in this sort of general way, sketched 
Ee you what I may call, a ae the architecture of 
the body of the Horse (what we term technically its 
3 Morphology), I must now turn to another aspect. A 
ia horse is not a mere dead structure: it is an active, 
Pt living, working machine. Hitherto we have, as it 
were, been looking at a steam-engine with the fires out, 
and nothing in the boiler; but the body of the living 
. ; animal is a beautifully-formed active machine, and 
every part has its different work to do in the working 
of that machine, which is what we call its life. The 
Horse, if you see him after his day’s work is done, is 
- cropping the grass in the fields, as it may be, or munch- 
ing the oats in his stable. What is he doing? His 
jaws are working as a mill—and a very complex mill 
too—erinding the corn, or crushing the grass to a pulp. 
As soon as that operation has taken place, the food is 
passed down to the stomach, and there it is mixed with 
the chemical fluid called the gastric juice, a substance 
which has the peculiar property of making soluble and 


leaving behind those nate which are nant 1 
80 that abe have, first, the mill, then a sort of 


blood is contained in a vast system of pipes, sprea r 
through the whole body, connected with a force pu 
—the heart, —which, by its position and by = col 


culating in one direction, never allowing it to rest; 
and then, by means of ae circulation of the blood, : 


the flesh, the hair, and every other part of the body, 
draws from it that which it wants, and every one of 
these organs derives those materials which are meces-_ 
sary to enable it to do its work. : 
The action of each of these organs, the performance eS 
of each of these various duties, involve in their opera- 
tion a continual absorption of the matters necessary for 
their support, from the blood, and a constant formation _ 
of waste products, which are returned to the blood, and 
conveyed by it to the lungs and the kidneys, which are 
organs that have allotted to them the office of extract- 
ing, separating, and getting rid of these waste products ; 
and thus the general nourishment, labour, and repair 
of the whole machine is kept up with order and reg- 
wlarity. But not only is it a machine which feeds and - 
appropriates to its own support the nourishment neces- 
sary to its existence—it is an engine for locomotive 
purposes. The Horse desires to go from one place to 
another; and to enable it to do this, it has those strong 


Ne ig 


he 
oe 


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(ee 
ae. 


ty 


cilwap £2: Sumles i, re 


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de 


» al 


OF ORGANIC NATURE. ra. 15 


os 8, mals are put in motion by means of a sort 
Bier phic apparatus formed by the brain and the - 
uppinal cord running through the spine or back- 


ol fibres termed nerves, which proceed to all parts 
of the stricture. By means of these the eyes, nose, 
- tongue, and skin—all the organs of perception—trans- 
fs, beats impressions or sensations to the brain, which acts 
asa sort of great central telegraph-office, receiving 
impressions and sending messages to all parts of the 
> bod , and putting in motion the muscles necessary to 
accomplish any movement that may be desired. So 
a _ that here you have an extremely complex and beauti- 
_ fully-proportioned machine, with all its parts working 
a ~ harmoniously together towards one common object— 
. the preservation of the life of the animal. 
Now, note this: the Horse makes up its waste by 
= feeding, and its food is grass or oats, or perhaps other 
Sp vegetable products; therefore, in the long run, the 
source of all this complex machinery lies in the vege- 
table kingdom. But where does the grass, or the oat, 
or any other plant, obtain this nourishing food-pro- 
ducing material? At first it is a little seed, which 
soon begins to draw into itself from the earth and the 
surrounding air matters which in themselves contain 
no vital properties whatever; it absorbs into its own 
substance water, an inorganic body ; it draws into its 
substance carbonie acid, an inorganic matter ; and am- 
monia, another inorganic matter, found in the air; and 
then, by some wonderful chemical process, the details 
of which chemists do not yet understand, though they 
are near foreshadowing them, it combines them into 


ws 


Fal 
a) 


life. So that, you see, the waste products of the P 
mal economy, the effete materials which are 
ually being thrown off by all living beings, 
form of organic matters, are constantly replac 
supplies of the necessary repairing and rebu: 
materials drawn from the plants, which in their tu 
manufacture them, so to speak, by a mysterious co 
bination of those same inorganic materials. a 

Let us trace out the history of the Horse in anoth 
direction. After a certain time, as the result of si 
ness or disease, the effect of accident, or the cons 
quence of old age, sooner or later, the animal dies. 
The multitudinous operations of this beautiful me- 
chanism flag in their performance, the Horse loses its 
vigour, and after passing through the curious series of — 
changes comprised in its formation and preservation, 
it finally decays, and ends its life by going back into 
that inorganic world from which all but an inappre- 
ciable fraction of its substance was derived. Its bones 
become mere carbonate and phosphate of lime; the — 
matter of its flesh, and of its other parts, becomes, in 
the long run, converted into carbonic acid, into water, _ 
and into ammonia. You will now, perhaps, under- 
stand the curious relation of the animal with the plant, : 
of the organic with the imorganic world, which is 


shown in this diagram. i 
: ; ; : a 

The plant gathers these inorganic materials together 

Feigee es : i 

and makes them up into its own substance. The ani- 


mal eats the plant and appropriates the nutritious por- 


at pe £ om : 
vai wee ty" 
, (fie, 


* bh 
4. ‘ 
an 


_ INORGANIC WORLD. 


Se hye ‘ 
leks as Carbonic Acid. Water. Ammonia. Saline. 
Fiat bee * , \ = a 


oi? 
WN ') 


Se genep animes 


VEGETABLE WORLD. (Fie. 8.) ANIMAL WORLD. 


“ae a ps P . e . 
the materials of which our bodies are composed are 
J 


largely, in all probability, the substances which con- 
- stituted the matter of long extinct creations, but which 


ae in the interval constituted a part of the inorganic 


world. 


yet, 


ie 
af 


| Thus we come to the conclusion, strange at first 
sight, that the Marrer constituting the living world is 


er identical with that which forms the inorganic world. 
And not less true is it, that, remarkable as are the 
ee 


_ 


& 
ra S| 
wa 
% >» 
ey 


_ powers or, in other words, as are the Forces which are 
exerted by living beings, yet all these forces are either 
identical with those which exist in the inorganic world, 


_ or they are convertible into them; I mean in just the 


same sense as the researches of physical philosophers 
have shown that heat is convertible into electricity, 


- 


terms of the other,—even 5. I say, that — 
applicable to the living world. Consider why 
skeleton of this horse capable of supporting the 


cohesion which combines together the particles of ‘me 
ter composing this piece of chalk? What is there in 
the as contractile power of the animal but. the 


sense seepery into the force of gravity oi ite 
overcomes? Or, if you go to more hidden processes, | - 
in what does the process of digestion differ from those — 
processes which are carried on in the laboratory of the __ 
chemist? Even if we take the most recondite and 
most complex operations of animal life—those of the — 
nervous system, these of late years have been shown to _ 
be—I do not say identical in any sense with the elec- oy 
trical processes—but this has been shown, that they — 
are in some way or other associated with them; thatis 
to say, that every amount of nervous action is accom- Be 
panied by a certain amount of electrical disturbance in : 
the particles of the nerves in which that nervous action — at 
is carried on. In this way the nervous action is re-— 
lated to electricity in the same way that heat is re- 
lated to electricity ; and the same sort of argument 
which demonstrates the two latter to be related to one 
another shows that the nervous forces are correlated to 
electricity ; for the experiments of M. Dubois Rey- 
mond and others have shown that whenever a nerve 
is in a state of exciment, sending a message to the 


faa ng : _: a = a ol 
he bas oF owsante fap Ee 
ee of the electrical condition of that nerve 
does not exist at other times; and there are a_ 


we come to the See conclusion that not aes as 
to living matter itself, but as to the forces that matter 
exe orts, there is a close relatiouship between the organic 
; and the inorganic world—the difference between them 
ing from the diverse combination and disposition 
FA. ‘identical forces, and not from any primary diver- 
| pty: so far as we can see. 
¥. [said just now that the Horse eventually died and 
Be Aiecarac converted into the same inorganic substances 
from whence all but an inappreciable fraction of its 
substance demonstrably originated, so that the actual 
S _-wanderings of matter are as remarkable as the trans- 
__ migrations of the soul fabled by Indian tradition. But 
zs before death has occurred, in the one sex or the other, 
Sa and in fact in both, certain products or parts of the 
ae _ organism have been set free, certain parts of the organ- 
ie ism of the two sexes have come into contact with one 
another, and from that conjunction, from that union 
: i which then takes place, there results the formation of a 
new being. At stated times the mare, from a particu- 
__ lar part of the interior of her body, called the ovary, 
___ gets rid of a minute particle of matter comparable in 
all essential respects with that which we called a cell a 
_ little while since, which cell contains a kind of nucleus 
‘in its centre, surrounded by a clear space and by a vis- 
cid mass of protein substance (Fig. 2); and though it 
is different in appearance from the eggs which we are 
mostly acquainted with, it is really an egg. After a 
time this minute particle of matter, which may only be 


upon its surface there < ferigncl a little. 
which afterwards becomes divided and marked by 
groove. ‘The lateral boundaries of the groove ex 
upwards and downwards, and at length give rise 
double tube. In the upper smaller tube the sp 
marrow and brain are fashioned ; in the lower, t 
mentary canal and heart, and at length two pairs o 
buds shoot out at the sides of the body, which are the 
rudiments of the limbs. In fact a true drawing of a 
section of the embryo in this state would in all essen- 
tial respects resemble that diagram of a horse reduced 
to its simplest expression, which I first placed before 
you (Fig. 1). = 
Slowly and gradually these changes take place. . 
The whole of the body, at first, can be broken up into | 
“cells,” which become in one place metamorphosed — 
into muscle,—in another place into gristle and bone, — 
—in another place into fibrous tissue,—and in another _ 
into hair; every part becoming gradually and slowly — a 
fashioned, as if there were an artificer at work at each 
of these sariilne structures that we have mentioned. 
This embryo, as it is called, then passes into other con- = 
ditions. This diagram represents the embryo of a dog; 
and I should tell vou that there is a time when the 
embryos of neither dog, nor horse, nor porpoise, nor 
monkey, nor man, can be distinguished by any essen- 
tial feature one from the other; there is a time when 
they each and all of them resemble this one of the Dog. 
But as development advances, all the parts acquire 
their speciality, till at length you have the embryo — 
converted into the form of the parent from which it faq 
a 


ina its existence as a aikiiie pore of pies 
ter, which, being supplied with nutriment (derived, 

as I have err, from the inorganic world), grows up 
a. to the special type and construction of its 
ens works and undergoes a constant waste, and 
that waste is made good by nutriment derived from 
a _ the imorganic world; the waste given off in this way 
| being directly added to the inorganic world; and 
eventually the animal itself dies, and, by the proécbes 
fe af. decomposition, its whole body is retaruad to those 
om ‘ conditions of inorganic matter in which its substance 
originated. 

This, then, is that which is true of every living 
form, from the lowest plant to the highest animal—to 
man himself. You might define the life of every one 
in exactly the same terms as those which I have now 
used; the difference between the highest and the 
__ lowest being simply in the complexity of the develop- 

mental changes, the variety of the structural fornis, 
the diversity of the physiological functions which are 
_ exerted by each. 

If I were to take an oak tree as a specimen of the 
plant world, I should find that it originated in an acorn, 
which, too, commenced in a cell; the acorn is placed 
in the ground, and it very speedily begins to absorb 
the inorganic matters I have named, adds enormously 
to its bulk, and we can see it, year after year, extend- 
ing itself upward and downward, attracting and ap- 
propriating to itself inorganic materials, which it vivi- 
fies, and eventually, as it ripens, gives off its own 
proper acorns, which again run the same course. But 
I need not multiply examples—from the highest to the 


Ht fi 


22 ~ THE PRESENT CONDITION 


lowest the essential features of life are the 
have described in each of these cases. : 
So much, then, for these particular features 
organic world, which you can understand and ¢ 
hend, so long as you confine yourself to one sort 
living being, and study that only. 3 
But, as you know, horses are not the only 
creatures in the world; and again, horses, like 
other animals, have certain limits—are confined to a — 
- certain area on the surface of the earth on which we 
live—and, as that is the simpler matter, I may take — 
that first. In its wild state, and before the discovery 
of America, when the natural state of things was inter- 
fered with by the Spaniards, the Horse was only to be — 
found in parts of the earth which are known to geo- — 
graphers as the Old World; that is to say, you might 
meet with horses in Burdse, Asia, or Africa; but there — 
were none in Australia, and there were none whatso- 
ever in the whole continent of America, from Labrador 
down to Cape Horn. This is an empirical fact, and 
it is what is called, stated in the way I have given it 
you, the “ Geographical Distribution ” of the Horse. 

_ Why horses should be found in Europe, Asia, and 
Africa, and not in America, is not obvious; the expla- 
nation that the conditions of life in America are un- ; 
favorable to their existence, and that, therefore, they 
had not been created there, evidently does not apply ; for 
when the invading Spaniards, or our own yeomen farm- 
ers, conveyed horses to these countries for their own 
use, they were found to thrive well and multiply very 
rapidly ; and many are even now running wild in those 
countries, and in a perfectly natural condition. Now, 
suppose we were to do for every animal what we have 


x ‘inguish the particular district or region to which each | 


4 a: and supposing we tabulated all these results, 


‘. pas. as a Pfednlt the Geogr aii Distribution of plants. 


I pass on from that now, as 1 merely wished to 
_ explain to you what I meant by the use of the term 
“Geographical Distribution.” As I said, there is another 


aspect, and a much more important one, and that is, 


the relations of the various animals to one another. 
The Horse is a very well defined matter-of-fact sort of 
animal, and we are all pretty familiar with its structure. 
I dare say it may have struck you, that it resembles 
very much no other member of the animal kingdom, 
except perhaps the Zebra or the Ass. But let me ask 


you to look along these diagrains. Here is the skeleton 


of the Horse, and here the skeleton of the Dog. You 


will notice that we have in the Horse a skull, a back- 
bone and ribs, shoulder-blades and haunch-bones. In 


the fore-limb, one upper arm-bone, two fore arm-bones, 


wrist-bones (wrongly called knee), and middle hand- 


bones, ending in the three bones of a finger, the last 
of which is sheathed in the horny hoof of the fore-foot: 
in the hind-limb, one thigh-bone, two leg-bones, ankle- 
bones, and middle foot-bones, ending in the three bones 
of a toe, the last of which is encased in the hoof of the 
hind-foot. Now turn to the Dog’s skeleton. We find 
identically the same bones, but more of them, there 
being more toes in each foot, and hence more toe-bones. 

Well, that is a very curious thing! The fact is 
that the Dog and the Horse—when one gets a look at 
them without the outward impediments of the skin— 


are found to be made in very much the 
fashion. And if I were to make a transy 


a 


an see he has just the same bones; and if T Lwee 
to make a transverse section of it, it would be 
same again. In your mind’s eye turn him ‘aroun Se 
as to put his backbone in a position inclined oblique 7 
upwards and forwards, just as in the next three dia- 
grams, which represent the skeletons of an Orang, < 
Chimpanzee, a Gorilla, and you find you have 3 
trouble in identifying the bones throughout; and last 
turn to the end of the series, the diagram representi: 
a man’s skeleton, and still you find no great structura 
feature essentially altered. There are the same bone 
in the same relations. From the Horse we pass « 
and on, with gradual steps, until we arrive at last al 5 
the highest known forms. On the other hand, take 
the other line of diagrams, and pass from the Horse 
downwards in the scale to this fish; and still, though — a 
the modifications are vastly — the eacaneee framie- BG 


Pi of Sagar 


ai the caus running aoe it, which contains the 
spinal cord; here are the ribs, here the shoulder-blade; 
here is the little short upper-arm bone, here are the __ 
two forearm bones, the wrist-bone, and the finger-bones. 
Strange, is it not, that the Porpoise should havein 
this queer looking affair—its flapper (as it is called), __ 
the same fundamental elements as the fore-leg of the eh 
Horse or the Dog, or the Ape or Man; and here you 
will notice a very curious thing—the hinder limbs are — 


a 
* 


wf X.3 


: w, let. us eee another jump. Let us go be 
1e Codfish: here you see is the forearm, in this. 
pectoral fin—cearrying your mind’s eye onward 
1 the flapper of the Porpoise. And here you have 
inder limbs restored in the shape of these ventral 
5 ‘If I were to make a transverse section of this, I 
3 hould fiud just the same organs that we have before 
r noticed. So that, you see, aa comes out this strange 
0! ‘lusion as the result of our investigations, that the 
Horse, when examined and compared with other ani- 
% al Hs found by no means to stand alone in nature ; 
but that there are an enormous number of other crea- 
% Res which have backbones, ribs, and legs, and other 
| parts arranged in the same general manner, and in all 
Ss { i heir formation exhibiting the same broad peculiarities. 
I am sure that you cannot have followed me even 
ein this extremely elementary exposition of the struc- 
tural relations of animals, without seeing what I have 
_ been driving at all through, which is to show you that, 
step by step, naturalists have come to the idea of a 
a unity of plan, or conformity of construction, | among 
animals which appeared at first sight to be peireinel 
dissimilar. 

And here you have evidence of such a unity of plan 
among all the animals which have backbones, and 
which we technically call Vertebrata. But there are 
multitudes of other animals, such as crabs, lobsters, 
spiders, and so on, which we term Annulosa. In these 
I could not point ont to you the parts that correspond 
with those of the Horse—the backbone, for instance— 
as they are constructed upon a very different principle, 
which is also common to all of them; that is to say, 
the Lobster, the Spider, and the. Centipede, have a 

2 


26 THE PRESENT CONDITION 


common plan running through their whole arrange- = 


ment, in just the same way that the Horse, the Dog, 
and the Porpoise assimilate to each other. 

Yet other creatures—whelks, cuttlefishes, oysters, 
snails, and all their tribe (d/ol/usca)—resemble one 
another in the same way, but differ from both Verte- 
brata and Annulosa ; and the like is true of the ani- 
mals called Culenterata (Polypes) and Protozoa (ani- 
malcules and sponges). 

Now by pursuing this sort of comparison, naturalists 
have arrived at the conviction that there are—some 
think five, and some seven—but certainly not more 
it is simpler to 
assume five—distinct plans or constructions in the 
whole of the animal world; and that the hundreds of 
thousands of species of creatures on the surface of the 


earth, are all reducible to those five, or, at most, seven, 


plans of organization. 


But can we go no further than that? When one 


has got so far, one is tempted to go on a step and in- 
quire whether we cannot go back yet further and bring 
down the whole to modifications of one primordial 
unit. The anatomist cannot do this; but if he call to 
his aid the study of development, he can do it. For 
we shall find that, distinct as those plans are, whether 
it be a porpoise or man, or lobster, or any of those 
other kinds I have mentioned, every one begins its ex- 
istence with one and the same primitive form,—that of 
the egg, consisting, as we have seen, of a introgenons 
substance, having a small particle or nucleus in the 
centre of it. Furthermore, the earlier changes of each 
are substantially the same. And it is in this that lies 
that true “unity of organization ” of the animal king- 


3 


% 


oO be i ieted by the careful study of develop- 
1ent. But is it possible to go another step further 
|, and to show that in the same way the whole of 
the organic world is reducible to one primitive con- 
< dition of form? Is there among the plants the same 
rimitive form of organization, and is that identical 
a “ith that of the animal kingdom? The reply to that 
. question, too, is not uncertain or doubtful. It is now 
.. pore that every plant begins its existence under the 
same form; that is to say, in that of a cell—a particle 
of Pieosenous matter having substantially the same 

* onditions. So that if you trace back the oak to its 
Z % first germ, or a man, or a horse, or lobster, or oyster, 
4g or any other animal you choose to name, you shall find 
each and all of these commencing their existence in 
forms essentially similar to each other: and, further- 
aA more, that the first processes of growth, and many of 
“§ the subsequent modifications, are essentially the same 
~ in principle in almost all. 

In conelusion, let me, in a few words, recapitulate 
the positions which I have laid down. And you must 
understand that I have not been talking mere theory ; 
I have been speaking of matters which are as plainly 
demonstrable as the commonest propositions of Euclid 
—of facts that must form the basis of all speculations 
_and beliefs in Biological science. We have gradually 
traced down all organic forms, or, in other words, we 
have analyzed the present condition of animated na- 
ture, until we found that each species took its origin in 
a form similar to that under which all the others com- 


mence their existence. We have found the whole of 3 
BUREAU OF 
AMERICAN ETH NOLOGY 


Jas 
Bie 


1430565 


28 PRESENT CONDITION OF ORGANIC NATURE. 


the vast array of living forms, with which we are sur- 
rounded, constantly growing, increasing, decaying, and 
disappearing ; the animal constantly attracting, modify- 
ing, and applying to its sustenance the matter of the 
vegetable kingdom, which derived its support from the 
absorption and conversion of inorganic matter. And 
so constant and universal is this absorption, waste, and 
reproduction, that it may be said with perfect certainty 
that there is left in no one of our bodies at the present 
moment a millionth part of the matter of which they 
were originally formed! We have seen, again, that 
not only is the living matter derived from the imor- 
ganic world, but that the forces of that matter are all 
of them correlative with and convertible into those of 
inorganic nature. 

This, for our present purposes, is the best view of 
the present condition of organic nature which I can lay 
before you: it gives you the great outlines of a vast 
picture, which you must fill up by your own study. 

In the next lecture I shall endeavour in the same 
way to go back into the past, and to sketch in the same 
broad manner the history of life in epochs preceding 
our own. 


PECL MEE: LT, 
THE PAST CONDITION OF ORGANIC NATURE. 


Ty the lecture which I delivered iast Monday even- 
ing, | endeavoured to sketch in a very brief manner, 
but as well as the time at my disposal would permit, 
the present condition of organic nature, meaning by 
that large title simply an indication of the great, broad, 
and general principles which are to be discovered by 
those who look attentively at the phenomena of or- 
ganic nature as at present displayed. The general re- 
sult of our investigations might be summed up thus: 
we found that the multiplicity of the forms of animal 
life, great as that may be, may be reduced to a com- 
paratively few primitive plans or types of construction ; 
that a further study of the development of those dif- 
ferent forms revealed to us that they were again re- 
ducible, until we at last brought the infinite diversity 
of animal, and even vegetable life, down to the primor- 
dial form of a single cell. 

We found that our analysis of the organic world, 
whether animals or plants, showed, in the long run, 
that they might both be reduced into, and were, in 
fact, composed of the same constituents. And we saw 
that the plant obtained the materials constituting its 


30 THE PAST CONDITION 


substance by a peculiar combination of matters belong- 
ing entirely to the inorganic world; that, then, the 
animal was constantly appropriating the nitrogenous 
matters of the plant to its own nourishment, and re 
turning them back to the inorganic world, in what we 
spoke of as its waste; and that, finally, when the 
animal ceased to exist, the constituents of its body » 
were dissolved and transmitted to that inorganie world 
whence they had been at first abstracted. Thus we 
saw in both the blade of grass and the horse but the 
same elements differently combined and arranged. We 
discovered a continual circulation going on,—the plant 
drawing in the elements of inorganic nature and com- 
bining them into food for the animal creation ; the ani- 
mal borrowing from the plant the matter for its own 
support, giving off during its life products which re- 
turned immediately to the inorganic world ; and that, 
eventually, the constituent materials of the whole strue- 
ture of both animals and plants were thus returned to 
their original source: there was a constant passage 
from one state of existence to another, and a returning 
back again. 

Lastly, when we endeavoured to form some notion 
of the nature of the forces exercised by living beings, 
we discovered that they—if not capab.e of being sub- 
jected to the same minute analysis as the constituents 
of those beings themselves—that they were correlative 
with—that they were the equivalents of the forces of 
inorganic nature—that there were, in the sense in 
which the term is now used, convertible with them, 
That was our general result. 

And now, leaving the Present, I must endeavour 
in the same manner to put before you the facts that 


OF ORGANIC NATURE. 31 


are to be discovered in the Past history of the living 
world, in the past conditions of organic nature. We 
have, to-night, to deal with the facts of that history— 
a history involving periods of time before which our 
mere human records sink into utter insignilicance—a 
history the variety and physical magnitude of whose 
events cannot even be foreshadowed by the history of 
human life and human phenomena—a history of the 
most varied aud complex character. 

We must deal with the history, then, in the first 
place, as we should deal with all other histories. The 
historical student knows that his first business should 
be to inquire into the validity of his evidence, and the 
nature of the record in which the evidence is contain- 
ed, that he may be able to form a proper estimate of 
the correctness of the conclusions which have been 
drawn from that evidence. So, here, we must pass, in 
the first place, to the consideration of a matter which 
may seem foreign to the question under discussion. 
We must dwell upon the nature of the records, and 
the credibility of the evidence they contain; we must 
look to the completeness or incompleteness of those 
records themselves, before we turn to that which they 


contain and reveal. The question of the credibility of 


the history, happily for us, will not require much con- 
sideration, for, in this history, unlike those of human 
origin, there can be no ecavilling, no differences as to 
the reality and truth of the facts of which it is made 
up; the facts state themselves, and are laid out clearly 
before us. 

But, although one of the greatest difficulties of the 
historical student is cleared out of our path, there are 
other difficulties—difficulties in rightly interpreting the 


ar. as fae are secreted to us—whiel TB 
pared with the greatest ditticulties of “eG 
ot: ‘historical, study. 


<a that this is a vast hee We almost from tl 
sublime to the ridiculous—from the contemplation 
the history of the past ages of the world’s existence t 
the consideration of the history of the formation of 
mud! But, in nature, there is nothing mean and un 
worthy of attention ; there is nothing ridiculous or con. _ 
temptible in any of her works; and this inquiry, you” 
will soon, see, I hope, takes us to the very root and 
foundation’ of our subject. i 

How, then, is mud formed? Always, with some 
trifling exception, which I need not consider now— 
always, as the result of the action of water, wearing 
down and disintegrating the surface of the earth and — 
rocks with which it comes in contact—pounding and 
grinding it down, and carrying the particles away to — 
places where they cease to be disturbed by this me-— 
chanical action, and where they can subside and rest. 
For the ocean, urged by winds, washes, as we know, 
a long extent of coast, and every wave, loaded as it is 
with particles of sand and gravel as it breaks upon the 
shore, does something towards the disintegrating pro- 


ae 

cess. And thus, slowly but surely, the hardest rocks 
are gradually ground down to a powdery substance; 
and the mud thus formed, coarser or finer, as the case 
<o ie 


ae 
on 
mae ea 


OF ORGANIC NATURE. 


- 7 ibe. is carried by the rush of the tides, or currents, 
a | it reaches the comparatively deeper parts of the 
- ocean, in which it can sink to the bottom, that is, to 
parts where there is a depth of about fourteen or fifteen 
‘a thoms, a depth at which the water is, usually, nearly 
¥ ae and in which, of course, the finer particles 
of this detritus, or mud, as we call it, sinks to the 
geppitom. 
Or, again, if you take a river, rushing down trom 
its mountain sources, brawling over the stones and 
_ rocks that intersect its path, loosening, removing, and 
carrying with it in its downward course the pebbles 


ie 


~ 
° 


“ 
an 
‘* 


and lighter matters from its banks, it crushes and 
, pounds down the rocks and earths in precisely the 
same way as the wearing action of the sea waves. The 
: matters forming the deposit are torn from the mountain- 
side and whirled impetuously into the valley, more 
slowly over the plain, thence into the estuary, and from 
the estuary they are swept into the sea. The coarser 


and heavier fragments are obviously deposited first, 

that is, as soon as the current begins to lose its force 

by becoming amalgamated with the stiller depths of 

_ the ocean, but the finer and lighter particles are carried 
further on, and eventually deposited in a deeper and 
stiller portion of the ocean. 

It clearly follows from this that mud gives us a 
chronology ; for it is evident that supposing this, which 
I now sketch, to be the sea bottom, and supposing this 
to be a coast-line; from the washing action of the sea 
upon the rock, wearing and grinding it down into a 

sediment of mud, the mud will be carried down, and 

at length, deposited in the deeper parts of this sea bot- 

tom, where it will form a layer; and then, while that 
O* 


ually have layers of mud constantly forming and. 
ening one above the other, and conveying a reco1 
time. 


youngest and the lowest the oldest, and that tea 
ent beds shall be older at any par toules eae or § 


be sure that the bottom eee was deposited first, al 
that the upper layers were formed afterwards. Here, 

you see, is the first step in the history—these layers of 
mud give us an idea of time. oi 
The whole surface of the earth—I speak broad 2 
and leave out minor qu such. 04 
layers of mud, so hard, the majority of them, that we 
call them rock, whether limestone or sandstone, or 
other varieties of rock. And, seeing that every part 
of the crust of the earth is made up in this way, you 
might think that the determination of the chronology, 
the fixing of the time which it has taken to form this 4 
crust is a comparatively simple matter. To takea broad e 
cs 


average, ascertain how fast the mud is deposited upon 
the bottom of the sea, or in the estuary of rivers; take 
it to be an inch, or two, or three inches a year, or what- 
ever you may roughly estimate it at; then take the 


ere > % oa, ed 12 
alc . + me 


Be, "oF onvasto viet 


vision, divide the total thickness by that of the quan- 
deposited in one year, and the result will, of course, 
give you the number of years which the crust has taken 
te form. 

‘Truly, that looks a very simple process! It would 
be - so except for certain difficulties, the very first of 
aa eich i is that of finding how rapidly sediments are de- 
Sz ‘posited ; but the main difficulty—-a difficulty which 
4 F -yenders any certain calculations of such a matter out 
of the question—is this, the sea-bottom on which the 
b- deposit takes place is continually shifting. 

- pas i _ Instead of the surface of the earth being that stable, 
a. fixed thing that it is popularly believed to be, being, 
— in common parlance, the very emblem of fixity itself, 
it is incessantly moving, and is, in fact, as unstable as 
_ the surface of the sea, except that its undulations are 
‘infinitely slower and enormously higher and deeper. 


he 


% a FS 


P E Now, what is the effect of this oscillation? Take 
Res , the case to which I have previously referred. The finer 
or coarser sediments that are carried down by the 


current of the river, will only be carried out a certain 

distance, and eventually, as we have already seen, on 

reaching the stiller part of the ocean, will be deposited 
at the bottom. 
‘a Let C y (Fig. 4) be the sea-bottom, y D the shore, 
_ wy the sea-level, then the coarser deposit will subside 
over the region B, the finer over A, while beyond A 
there will be no deposit at all; and, consequently, no 
record will be kept, simply because no deposit is going 
on. Now, suppose that the whole land, C, D, which 


sequence wilt be that the layer of mud coe being , 
for the most Ae further than the force of curren’ 


layer, whenever [ may be exposed to our view, as Ps 
record of time in the manner in which we are now — 
regarding this subject, as it would give us only ame 
imperfect and partial record it would seem to repre- 
sent too short a period of time. | 
Suppose, on the other hand, that the land (C D) 
had gone on rising slowly and gradually—say an inch 
or two inches in the course of a century,—what would 
be the practical effect of that movement? Why, that — 
the sediment A and B which has been already depos- _ 
ited, would eventually be brought nearer to the shore- 
level, and again subjected to the wear and tear of the 


sea; and directly the sea begins to act upon it, it would 


of course soon cut up and carry. it away, to a greater 
or less extert, to be re- “deposited further out. | 


i ns down in this way a pal many times, c 
ve that the thickness of the deposits formed at 


iat you see it is idclatply necessary from thei 
- facts, seeing that our record entirely consists of accumu- 
gi " lations of mud, superimposed one on the other; seeing 
By ithe next pings that any particular spots on which 
‘ eee mnlations have occurred, have been constantly 
" | moving up and down, and sometimes out of the reach 
® m0: a deposit, and at other times its own deposit broken 
. up and carried away, it follows that our record must 
i pe in the highest degree imperfect, and we have hardly 
A a trace left of thick eon its, or any definite knowledge 
3 z the area that they occupied in a great many Cases. 
~ And mark this! That supposing even that the whole 
P _ surface of the earth had been accessible to the geolo- 
‘ gist,—that man had had ‘access to every part of the 
earth, and had made sections of the whole, and put 
them all together,—even then his record must of neces- 
sity be imperfect. 
But to how much has man really access? If you 
will look at this Map you will see that it represents 
_ the proportion of the sea to the earth: this coloured 
_ part indicates all the dry land, and this other portion 
is the water. You will notice at once that the water 
covers three-fifths of the whole surface of the globe, 
and has covered it in the same manner ever since man 
has kept any record of his own observations, to say 


ad 


aan 8 


paises of ae eae SS during wh 
tivated geological inquiry. So that three 
surface of the earth is shut out from us bec 
under the sea. Let us look at the other two-fif 
see what are the countries in which anything tl 
be termed searching geological inquiry has been 
out: a good deal of France, Germany, and Great | 
ain and Ireland, bits of Spain, of Italy, and of Ri 
have been examined, but of the whole great mass — ar 
Africa, except parts of the southern extremity, we know | 
next to nothing; little bits of India, but oF the great 
part of the Asiatic continent nothing; bits of the 
Northern American States and of Coun but of the 
greater part of the continent of North America, and 
in still larger proportion, of South America, nothing! 
Under these circumstances, it follows that even with | 
reference to that kind of imperfect information which 
we can possess, it is only about the ten thousandth part Ss 
of the accessible parts of the earth that has been exam- 
ined properly. Therefore, it is with justice that them 
most thoughtful of those who are concerned in these 
inquiries insist continually upon the imperfection of — 
the geological record; for, I repeat, it is absolutely — 
necessary, from the nature of things, that that record — 
should be of the most fragmentary and imperfect char- 
acter. Unfortunately this circumstance has been con- 
stantly forgotten. Men of science, like young colts 
in a fresh pasture, are apt to be exhilarated on being 
turned into a new field of inquiry, and to go off at a 
hand-gallop, in total disregard of hedges and ditches, 
losing sight of the real limitation of their inquiries, 
and to forget the extreme imperfection of what isreally 
known. Geologists have imagined that they could tell s, 


— — 
“id ee «Dogr 


5 


oo wa 
7 ‘. “ 


~ 


_— & > te 

" Meme: ay ; Pad 
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vied a. Me eh? 


or ‘ORGANIC NATURE. $9.06 


3 what was Ping on at all parts of the earth’s surface 
during a given epoch ; they have talked of this deposit 
being g contemporaneous with that deposit, until, from 
our Tittle local histories of the changes at limited spots 
of th earth’s surface, they have constructed a universal 
history of the globe as full of wonders and portents as 
any other story of antiquity. 
__ But what does this attempt to construct a universal 
history of the globe imply It implies that we shall 
a not only have a precise knowledge of the events which 
have occurred at any particular point, but that we shall 
_ be able to say what events, at any one spot, took place 
at the same time with those at other spots. 
7 a Let us see how far that is in the nature of things 
__ practicable. Suppose that here I make a section of 
the Lake of Killarney, and here the section of another 
_ lake—that of Loch Lomond in Scotland for instance. 
_ The rivers that flow into them are constantly carrying 
down deposits of mud, and beds, or strata, are being as 
_ constantly formed, one above the other, at the bottom 
of those lakes. Now, there is not a shadow of doubt 
» that in these two lakes the upper beds are all older than 
_ the lower—there is no doubt about that; but what does 
this tell us about the age of any given bed in Loch 
Lomond, as compared with that of any given bed in 
the Lake of Killarney? It is, indeed, obvious that if 
. any two sets of deposits are separated and discontinu- 
ous, there is absolutely no means whatever given you 
by the nature of the deposit of saying whether one is 
much younger or older than the other; but you may 
say, as many have said and think, that the case is very 
much altered if the beds which we are comparing are 


40 THE PAST CONDITION 


continuous. Suppose two beds of munud hardened into — 
rock,—A and B are seen in section. (Fig. 5.) 

~ Well, you say, it is admitted that the lowermost 
bed is always the older. Very well; B, therefore, is 
older than A. No doubt, as a whole, it is so; or if 


Fie. 5. 


any parts of the two beds which are in the same verti- 
cal line are compared, it isso. But suppose you take 
what seems a very natural step further, and say that 
the part a of the bed A is younger than the part 6 of 
the bed B. Is this sound reasoning? If you find any 
record of changes taking place at 6, did they eceur be- — 
fore any events which took place while a was being 
deposited? It looks all very plain sailing, indeed, to 
say that they did; and yet there is no proof of any- 
thing of the kind. As the former Director of this In- 
stitution, Sir H. De la Beche, long ago showed, this 
reasoning may involve an entire fallacy. It is extremely 
possible that @ may have been deposited ages before 0. 
It is very easy to understand how that can be. To 
return to Fig.4; when A and B were deposited, they 
were substantially contemporaneous; A being simply 
the finer deposit, and B the coarser of the same detritus 
or waste of land. Now suppose that the sea-bottom 
goes down (as shown in Fig. 4), so that the first deposit 


a se no farther ae b, forming the bed BY the 


tot. fine sediment (A.A') Lite Si another of 
se sediment (BB’). Now suppose the whole sea- 
ttom is raised up, and a section exposed about the 
int A’; no doubt, at this spot, the upper bed is 
ounger than the ie eeen: But we should obviously 
y err if we conciuded that the mass of the upper 
at A was younger than the lower bed at B; for 
V e have just seen that they are cofitemporanagus de- 
> ae Still more should we be in error if we supposed 
the upper bed at A to be younger than the continu- 
ation of the lower bed at B'; for A was deposited long 
before B’. In fine, if, eehioad of comparing imme- 
aa liately adjacent parts of two beds, one of which lies 
* ‘upon ¢ another, we compare distant parts, it is quite pos- 
sible that the upper may be any number of years older 
ie than the under, and the under any number of years 
a pootnesr than the upper. 
ag Now you must not suppose that I put this before 
you for the purpose of raising a paradoxical difficulty ; 
Z the fact is, that the great mass of deposits have taken 
place in sea-bottoms which are gradually sinking, and 
4 _ have been formed under the very conditions I am here 
---s- supposing. 
— Do not run away with the notion that this subverts 
the principle I laid down at first. The error lies in 
extending a principle which is perfectly applicable to 
deposits in the same vertical line to deposits which are 
not in that relation to one another. 
E It is in consequence of circumstances of this kind, 
. and of others that I might mention to you, that our 


ried ig se ee a, Vera tae tlie bed Ajand 


& ay and strictly a valid so —- wi 


selves to one vertical section. Ido not m 
you that there are no qualifying circums 
that, even in very considerable areas, we m 
speak of conformably superimposed beds bein; 
- or younger than others at many different po 
we can never ue quite sure In coming to” ) 


any oak in ‘he pee or any very aoe 3 
tance between the points to be compared. ice 

Well now, so much for the record itself,—so much 
for its imperfections,—so much for the conditions to 
observed in interpreting it, and its chronological inc 
cations, the moment we pass beyond the limits of a 
vertical linear section. ‘= 

Now let us pass from the record to that which it 
contains,-from the book itself to the writing and t 
figures on its pages. This writing and these figure: 
consist of remains of animals and plants which, in the 
great majority of cases, have lived and died in the very 
spot in which we now find them, or at least in the im- 
mediate vicinity. You must all of you be aware— 
and I referred to the fact in last Monday’s lecture— 
that there are yast numbers of creatures living at the 
bottom of the sea. These creatures, like all others, 
sooner or later die, and their shells and hard parts lie 
at the bottom; and then the fine mud which is being 
constantly brought down by rivers and the action of 
the wear and tear of the sea, covers them over and 


protects them from any further change or alteration; __ 
and, of course, as in process of time the mud becomes 
hardened and solidified, the shells of these animals are | 


SieY 


: a ‘ OF oR RC wis 


aI a nd firmly imbedded in the limestone or 
one which is being thus formed. You may see 
the Sage of ae in a upstairs specimens of 


a have been preserved and fossilized. 

‘4 Not only does this process of imbedding and fos- 
. “ail zation occur with marine and other aquatic animals 
Br and plants, but it affects those land animals and plants 
i which are drifted away to sea, or become buried in 
bogs or morasses; and the animals which have been 
tie down by their fellows and crushed in the mud 
at the river’s bank, as the herd have come to drink. 
In any of these cases, the organisms may be crushed 
or be mutilated, before or ao. putrefaction, in such a 
3 - manner that Cethans only a part will be left in the 
- form in which it reaches us. It is, indeed, a most re- 
markable fact, that it is quite an exceptional case to 
find a skeleton of any one of all the thousands of wild 
land animals that we know are constantly being kill- 
ed, or dying in the course of nature: they are preyed 
on and devoured by other animals, or die in places 
where their bodies are not afterwards protected by 
mud. ‘There are other animals existing in the sea, the 
shells of which form exceedingly large deposits. You 
are probably aware that before the attempt was made 
to lay the Atlantic telegraphic cable, the Government 
employed vessels in making a series of very careful ob- 
servations and soundings of the bottom of the Atlantic ; 
and although, as we must all regret, that up to the 


es present had ee project ee ‘fot! suc 


was found that over the whole of that immense are: 


_ 


the satisfaction of knowing that it yielde 
remarkable results to science. The Atlan 
had to be sounded right across, to depths of 
miles in some places, and the nature of its bott 
carefully ascertained. Well, now, a space of 
1,000 miles wide from east to west, and I do 


rate 600 or 700 miles, was Sirona oxanitniel and 


parts are deposited in this part of the ocean, and 
doubtless gradually acquiring solidity and becoming 
metamorphosed into a chalky limestone. Thus, you 
see, it is quite possible in this way to preserve unmis- 
takable records of animal and vegetable life. — When 
ever the 8ea-bottom, by some of those undulations of 
the earth’s crust that I have referred to, becomes up- — 
heaved, and sections or borings are made, or pits are ; 
dug, Fe we become able to examine the contents and — 
constituents of these ancient sea-bottoms, and find out i 
what manner of animals lived at that period. : 3 

Now it is a very important consideration in its bear- = 
ing on the completeness of the record, to inquire how = 
far the remains contained in these fossiliferous lime- 
stones are able to convey anything like an accurate 
or complete account of the animals which were in ex- 
istence at the time of its formation. Upon that point 
we can form a very clear judgment, and one in which eee 
there is no possible room for any mistake. There are 
of course a great number of animals—such as jelly- i 
fishes, and other animals—without any hard parts, — 


v hick we Sout: Faeihlg expect to find any 
uC es whatever : : there is nothing of them to preserve. 
‘hin a very short time, you will have noticed, after 
are removed from the water, they dry up to a 
nothing ; certainly they are not of a nature to 
leave any very visible traces of their existence on such 
e Dodies as chalk or mud. ‘Then again, look at land ani- 
om als; it is, as I have said, a very uncommon thing to 
1 a land animal entire after death. Insects and 
, er carnivorous animals very speedily pull them to 
- - pieces putrefaction takes place, and so, out of the hun- 
- dreds of thousands that are known to die every year, 
it is the rarest thing in the world to see one imbedded 


Shy 


: ae |. such a way that its remains would be preserved for 
a lengthened period. Not only is this the case, but 
~ even when animal remains have been safely imbedded, 
certain natural agents may wholly destroy and remove 
_ them. 
Almost all the hard parts of animals—the bones 
and so on—are composed chiefly of phosphate of lime 
and carbonate of lime. Some years ago, I had to make 
an inquiry into the nature of some very curious fossils 
sent tome from the North of Seotland. Fossils are 
usually hard bony structures that have become imbed- 
_ ded in the way I have described, and have gradually 
acquired the nature and solidity of the body with 
__which they are associated; but in this case I had a 
series of holes in some pieces of rock, and nothing else. 
Those holes, however, had a certain definite shape 
about them, and when I got a skilful workman to make 
castings of the interior of these holes, I found that they 
were the impressions of the joints of a back-bone and 
of the armour of a great reptile, twelve or more feet 


ae as “4 


“et - a 


long. This great beast had died oe got bm 
sand, the sand had gradually hardened over 11 
but couered porous. Water had trickled ‘th 
and that water being probably charged with a su 
fluity of carbonic acid, had dissolved all the pho 

and carbonate of ine: and the bones themselves 
thus decayed and entirely disappeared; b 
sandstone happened to have consolidated by that | 
the precise shape of the bones was retained. If th 
sandstone had remained soft a little longer, we shou 
have known nothing whatsoever of the existence = the 
reptile whose bones it had encased. oa 


which have existed at one period on this earth nae 
entirely perished, and left no trace whatever of their 
forms, may be proved to you by other considerations. 
There arelarge tracts of sandstone in various parts of 
the world, in which no body has yet found anything | . 
but ae Not a bone of any description, but an 
enormous number of traces of footsteps. There is no 
question about them. There is a whole valley in Con- 
necticut covered with these footsteps, and not a single 
fragment of the animals which made them have yet — 
been found. Let me mention another case while upon 
that matter, which is even more surprising than those 
to which I have yet referred. There is a limestone 
formation near Oxford, at a place called Stonesfield, 
which has yielded the remains of certain very inter- 
esting mammalian animals, and up to this time, if 1 Bs. 


recollect rightly, there have been found seven speci- =~ 
mens of its lower jaws, and not a bit of anything else, 
neither limb-bones nor skull, or any part whatever; — sy 
not a fragment of the whole system! Of course, it ii 


” ae 
a 


if Fg aie nea 


— 
EA ees Ee <> a 
7 on = 


A me e OF ORGANIC NATURE, AT 
oa me Poy ay 


ould be preposterous to imagine that the beasts had 
1othing else but a lower jaw! The probability is, as_ 
Dr. Prickland showed, as the result of his observations 
4 on dead dogs in the river Thames, that the lower jaw, 
ot cing secured by very firm ligaments to the bones 
of the head, and being a weighty affair, would easily 
if g ‘be » knocked off, or might drop away from the body as 
it Boated in water in a state of decomposition. The 
_ jaw would thus be deposited immediately, while tlie 
I tof the body would float and drift away altogether, 
Bs ultimately reaching the sea, and perhaps becoming de- 
& _ stroyed. The jaw becomes covered up and pecservad 
| om in the river silt, and thus it comes that we have such 
ie 2 curious circumstance as thet of the lower jaws in 
3 ae Stonesfield slates. So that, you see, faulty as these 
_ layers of stone in the earth’s crust are, defective as they 
oat necessarily are as a record, the account of contempora- 
- neous vital phenomena presented by them is, by the 
. necessity of the case, infinitely more defective and frag- 
- mentary. 
It was necessary that I should put all this very 
strongly before you, because, otherwise, you might 
have been led to think differently of the completeness 
of our knowledge by the next facts I shall state to you. 
The Re cedechds of the last three-quarters of a cent 7 
have, in truth, revealed a wonderful richness of or ganic 
life in those rocks. * Certainly not fewer than thirty or 
forty thousand different species of fossils have been dis- 
covered. You have no more ground for doubting that 
these creatures really lived and died at or near the 
places in which we find them than you have for like 
scepticism about a shell on the sea-shore. The evidence 
is as good in the one ease as in the other. 


48 THE PAST CONDITION * 


Our next business is to look at the general charac 


ter of these fossil remains, and it is a subject which will 
be requisite to consider carefully; and the first point 
for us is to examine how much the extinct /vora and 
Fuuna as a whole—disregarding altogether the succes- 
sion-of their constituents, of which I shall speak after- 


wards—differ from the “Vora and Fauna of the present - 


day ;—how far they differ in what we do know about 
them, leaving altogether out of consideration specula- 
tions based on what we do not know. 

I strongly imagine that if it were not for the pecu- 
liar appearance that fossilized animals have, that any 
of you might readily walk through a museum which 
contains fossil remains mixed up with those of the pres- 
ent forms of life, and I doubt very much whether your 
uninstructed eyes would lead you to see any vast or 
wonderful difference between the two. If you looked 
closely, you would notice, in the first place, a great 
many things very like animals with which you are 
acquainted now: you would see differences of shape 
and proportion, but on the whole a close similarity. 

I explained what I meant by Orprrs the other day, 
when I described the animal kingdom as being divided 
into sub-kingdoms, classes, and orders. If you divide 
the animal kingdom into orders, you will find that 
there are above one hundred and twenty. The num- 
ber may vary on one side or the-other, but this is a 
fair estimate. That is the sum total of the orders of 
all the animals which we know now, and which have 
been known in past times, and left remains behind. 

Now, how many of those are absolutely: extinet ? 
That is to say, how many of these orders of animals 
have lived at a former period of the world’s history, 


‘ ies. 2, 
- . oe. : "> 

.- 5 f 4 a Vid et ou 
A ee Pe ee er HES Pe & 


x 


_ OF ORGANIC NATURE. 


it ha ve at present no representatives? That is the 
e in which I meant to use the word “extinct.” IT. 


ent moment. So that estimating the number of 
— extin #t animals is a sort of way of comparing the past 
creation as a whole with the present as a whole. To 
make that clear, I have written in red ink on these 

~ dias erams the names of all those extinct orders, and in 
i lack ink the names of the rest. Among the mammalia 
: and birds there are none extinct; but when we come 
to the reptiles there is a most rondewfal thing: out of 
- :: the eight orders, or thereabouts, which you can make 
es i among reptiles, one-half are extinct. These diagrams 
of the plesiosaurus, the ichthyosaurus, the pterodactyle, 
= give you a notion of some of these extinct reptiles. 
3 And here is the cast of the pterodactyle and bones of 
Pa the ichthyosaurus and the plesiosaurus, just as fresh as 
we _ if it had been recently dug up in a churchyard. Thus, 
in the reptile class, there are no less than half of the 
orders which are absolutely extinct. If we turn to the 
Amphibia, there was one extinct order, the Labyrintho- 
donts, typitied by the large salamander-like beast shown 

in this diagram. 

No order of fishes is known to be extinct. Every 
fish that we find in the strata—to which I have been 
referring—can be identified and placed in one of the 
orders which exist at the present day. There is not 
known to bea single ordinal form of insect extinct. 
There are only two orders extinct among the Crustacea. 
There is not known to be an extinct order of these crea- 
tures, the parasitic and other worms ; but there are two, 


not to say three, absolutely extinct orders of this class, 
3 


NE 


6 


So that, you see, out of ca ates Bey. ; 
of animals, taking them altogether, you will n 
outside estimate, find above ten or a dozen 
Summing up all the order of animals which 1 


present day; that is to say, that the difference d 
not amount to much more than ten per cent.; and t 
proportion of extinct orders: of plants is still sm : 
I think that that is a very oe a most asto ish- 


have eal during the eonetnen of the sae of = 
tke earth as it at present exists 5 it is, ies a most : os 


bes sheuld pa sO exceedingly small. er 
But now, there is another point of view in whi 
we must look at this past creation. Suppose that we 
were to sink a vertical pit through the floor beneath 
us, and that I could succeed in making a section right 
through in the direction of New Zealand, I should find | 
in each of the different beds through which I passed — 
the remains of animals which I should find in that_ 
stratum and not in the others. First, I should come — a 
upon beds of gravel or drift containing the bones of 
large animals, such as the elephant, rhinoceros, and 
cave tiger. Rather curious things to fall across in 
Piccadilly! If I should dig lower still, I should come 
upon a bed of what we call the London clay, and in 
this, as you will see in our galleries up-stairs, arefound __ 
remains of strange cattle, remains of turtles, palms, and 
large tropical fruits; with shell-fish such as you see the a 


of n OW BS only es ase regions. Tf I went below 
oe come upon the mae and there I ee 


Ido fot Few what Mr. Godwin Austin would say 
comes next, but probably rocks containing more am- 
nites, a more ichthyosauri and plesiosauri, with 
number of other things ; and under that I should 
with yet older rocks, containing numbers of strange 
lis and fishes ; ; and in thus passing from the surface 
a te » the lowest depths of the earth’s crust, the forms of 
= tn life and vegetable life which I should meet with 
1 the successive beds would, looking at them broadly, 
aa » the more different the futther that I went down. 
a Or, in other words, inasmuch as we started with the 
> clear principle, that in a series of naturally-disposed 
-mud beds the lowest are the oldest, we should come 
‘to this result, that the a we go back in time the 


Pile life of an epoch and hak which now exists. ‘That 
_ was the conclusion to which I wished to bring you at 
a. the end of this Lecture. 


LECTURE ML. 


THE METHOD BY WHICH THE CAUSES OF THE PRES. 
ENT AND PAST CONDITIONS OF ORGANIC NATURE 
ARE TO BE DISCOVERED.—THE ORIGINATION OF 
LIVING BEINGS. 


Ix the two preceding lectures I have endeavoured 
to indicate to you the extent of the subject-matter of 
the inquiry upon which we are engaged; and now, 
having thus acquired some conception of the Past and 
Present phenomena of Organic Nature, I must turn, to- 
night, to that which constitutes the great problem which 
we have set before ourselves;—I mean, the question 
of what knowledge we have of the causes of these 
phenomena of organic nature, and how such knowl- 
edge is obtainable. 

Here, on the threshold of inquiry, an objection 
meets us. There are in the world a number of ex- 
tremely worthy, well-meaning persons, whose judg- 
ments and opinions are entitled to the utmost respect 
‘on account of their sincerity, who are of opinion that 
Vital Phenomena, and especially all questions relating 
to the origin of vital phenomena, are questions quite 
apart from the ordinary run of inquiry, and are, by 
their very nature, placed out of our reach. They say 


1 some way totally different fri the faery course 
E of nature, and that therefore they conceive it to be 
By futile, not to say presumptuous, to attempt to inquire 


o such sincere and earnest persons, I would only 
say, fess a question of this kind is not to be shelved 
upon theoretical or speculative grounds. You may 
remember the story of the Sophist who demonstrated 
to Diogenes in the most complete and satisfactory man- 
a ner that he could not walk; that, in fact, all motion 
was an impossibility ; and that Diogenes refuted him 
; by simply getting up and walking round his tub. So, 
3 in the same way, the man of science replies to. objec- 
‘old tions of this kind, by simply getting up and w alking 
onward, and losin’ what science has done and is 
doing.—by pointing to that immense inass of facts 
___ which have been ascertained and systematized under the 
forms of the great doctrines of Morphology, of Develop- 
ment, of Distribution, and the like. He sees an enor- 
mous mass of facts and laws relating to organic beings, 
which stand on the same good sound foundation as 
every other natural law; and, therefore, with this mass 
of facts and laws before us, seeing that, as far as organic 
matters have hitherto been accessible and studied, they 
have shown themselves capable of yielding to scientific 
investigation, we may accept this as proof that order 
and law reign there as well as in the rest of nature ; 
and the man of science says nothing to objectors of 
this sort, but supposes that we can and shall walk to 
the origin of organic nature, in the same,way that we 
have walked to a knowledge of the laws and vrinciples 
of the inorganic world. 


54 METHOD OF DISCOVERY. 


But there are objectors who say the same from 
ignorance and ill-will. To such I would reply that the 
objection comes ill from them, and that the real pre- 
sumption, [ may almost say the real blasphemy, in this 
matter, is in the attempt to limit that inquiry into the 
causes of phenomena which is the source of all human 
blessings, and from which has sprung all human pros- 
perity and progress; for, after all, we can accomplish 
comparatively little; the limited range of our own 
faculties bounds us on every side,—the field of our 
powers of observation is stnall enough, and he who en- 
deavours to narrow the sphere of our inquiries is only 
pursuing a course that is likely to produce the greatest 
harm to his fellow-men. 

But now, assuming, as we all do, I hope, that these 
phenomena are properly accessible to inquiry, and set- 
ting out upon our search into the causes of the phe- 
nomena of organic nature, or, at any rate, setting out to 
discover how much we at present know upon these 
abstruse matters, the question arises as to what is to be 
our course of proceeding, and what method we must 
lay down for our guidance. I reply to that question, 
that our method must be exactly the same as that 
which is pursued in any other scientific inquiry, the 
method of scientific investigation being the same for 
all orders of facts and phenomena whatsoever. 

I must dwell a little on this point, for I wish you 
to leave this room with a very clear conviction that 
scientific investigation is not, as many people seem to 
suppose, some kind of modern black art. I say that 
you might easily gather this impressson from the man- 
ner in which many persons speak of scientific inquiry, 
or talk about inductive and deductive philosophy, or 


METHOD OF DISCOVERY. 5D 


the principles of the “ Baconian philosophy.” I do 
protest that, of the vast number of cants in this world, 
there are none, to my mind, so contemptible as the 
pseudo-scientific cant which is talked about the ‘“ Ba- 
conian philosophy.” 

To hear people talk about the great Chancellor,— ~ 
and a very great man he certainly was,—you would 
think that it was he who had invented science, and 
that there was no such thing as sound reasoning before 
the time of Queen Elizabeth! Of course, you say, 
that cannot possibly be true; you perceive, on a mo- 
ment’s reflection, that such an idea is absurdly wrong ; 
and yet, so firmly rooted is this sort of impression,—Il 
cannot call it an idea, or conception,—the thing is too 
absurd to be entertained,—but so completely does it 
exist at the bottom of most men’s minds, that this has 
been a matter of observation with me for many years 
past. There are many men who, though knowing ab- 

solutely nothing of the subject with which they may 
be dealing, wish, nevertheless, to damage the author 
of some view with which they think fit to disagree. 
What they do, then, is not to go and learn something 
about the subject, which one would naturally think the 
best way of fairly dealing with it; but they abuse the 
originator of the view they question, in a general man- 
ner, and wind up by saying that, “ After all, you know, 
the principles and method of this author are totally 
opposed to the canons of the Baconian philosophy.” 
Then everybody applauds, as a matter of course, and 
agrees that it must be so. But if you were to stop 
them all in the middle of their applause, you would 
probably find that neither the speaker nor his ap- 
plauders could tell you how or in what way it was so; 


neither the one nor the hee ens th 
of what ey mnean when they speak of the “ 
philosophy.” 

You will understand, I hope, that I hae 
slightest desire to join in the outery against el 
orale the intellect, or the great genius of Lord 
cellor Bacon. He was undoubtedly a very great 
let people say what they will of him; but not 
standing all that he did for philosophy, it would: 


oe originated yah the first man, wee ae was; ; 
and indeed existed long before him, for many of the 


higher order of brutes as completely and effectively as_ 
by ourselves. We see in many of the brute creation _ 
the exercise of one, at least, of the same powers of : “ig 
reasoning as that which we ourselves employ. <3 
The method of scientific investigation is nothing — 
but the expression of the necessary mode of working © — 
of the human mind. It is simply the mode at which __ 
all phenomena are reasoned about, rendered precise 
and exact. There is no more difference, but there is 
just the same kind of difference, between the mental  __ 
operations of a man of science and those of an ordinary 
person, as there is between the operations and methods 
of a baker or of a butcher weighing out his goodsin com- 
mon seales, and the operations of a chemist in perform- 
ing a difficult and complex analysis by means of his 
balance and finely-graduated weights. It is not that 
the action of the scales in the one case, and the balance t. 
in the other, differ in the principles of their construc- 
tion or manner of working; but the beam of one is set 


nas ~— axis than the other, and of course 
4 a the addition of a much smaller weight. 
: Mou will understand this better, perhaps, if I give 
you some familiar example. You have all heard it re- 
_ peated, I dare say, that men of science work by means 
ee. nduction and Deduction, and that by the help of 
3 ~ these operations, they, in a sort of sense, wring from 
Nature certain other things, which are called Natural 
Sea and Causes, and that out of these, by some cun- 
ing skill of their own, they build up Hypotheses and 
eories. And it is imagined by many, that the opera- 
tions of the common mind can be by no means com- 
pared with these processes, and that they have to be 
acquired by a sort of special apprenticeship to the craft. 
To hear all these large words, you would think that 
- ‘the mind of a man of science must be constituted dif- 
ferently from that of his fellow-men; but if you will 
AS not be frightened by terms, you will discover that you 
me are quite wrong, and that all these terrible apparatus 
t 
in 


fe 


“ii 


fo 
ee 
Bs 


are being used by yourselves every day and every hour 
- of your lives. 
E There is a well-known incident in one of Molicre’s 
plays, where the author makes the hero express un- 
bounded delight on being told that he had been talk- 
ing prose during the whole of his life. In the same 
way, I trust, that you will take comfort, and be de- 
lighted with yourselves, on the discovery that you 
have been acting on the principles of inductive and 
deductive philosophy during the same period. Prob- 
ably there is not one here to-night who has not in the 
course of the day had occasion to set in motion a com- 
plex train of reasoning, of the very same kind, though 
differing of course in degree, as that which a scientific 

3* 


man goes through in tracing the causes { 
nomena. | 
A very trivial ee ae will serve te 
this. Suppose you go into a fruiterer’s shop, ’ v: 


it is sour; you look at it, and see that - iS hard. 
green. Vou take up another one, and that too is’ 
green, and sour. The shopman ae you a 


have already iat 
Nothing can be more anak than that, you thi 
but if you will take the trouble to analyze and trace 
out into its logical elements what has been done by 
the mind, you will be greatly surprised. In the first — 
place, you have performed the operation of Induc- : 
tion. You found that, in two experiences, hardness 
and greenness in apples go together with sourness. It ee 
was so in the first case, and it was confirmed by the 
second. ‘True, it is a very small basis, but still it is 
enough to make an induction from; you generalize Re 
the facts, and you expect to find sourness in apples — 
where you get hardness and greenness. You found 
upon that a general law, that all hard and green apples 
are sour; and that, so far as it goes, is a perfect induc- 
tion. Well, having got your natural law in this way, 
when you are offered another apple which you find is 
hard and green, you say, “ All hard and green apples 
are sour; this apple is hard and green, therefore this 
apple is sour.” That train of reasoning is what logi- 
cians call a syllogism, and has all its various parts and 
ternis,—its major premiss, its minor premiss, and its 


eee a is ; a Ot wa} ? ‘ 


Ar 
4 > 
rn} 


nA 
x 


-" é : is _ ‘ 
- a Toa oe 4 


¢* 


nao 
yA bo 
fla 


Sart 


. hich, if drawn ey would have to be exhibited in 
_ two or three other syllogisms, you arrive at your final 
+ determination, ot, will not have that apple.” So that, 


by Induction, and upon that you have founded a De- 
duction, and Feganaiets out the special conclusion of the 
a particular case. Well now, suppose, having got your 
5a aw, that at some time iarensds: you are discussing 
he qualities of apples with a friend: you will say to 
him, “Tt is a very curious thing,—but I find that all 
hard and green apples are sour!” Your friend says 
_to you, “ But how do you know that?” You at once 
reply, “Oh, because I have tried it over and over 
again, and have always found them to be so.” Well, 
if we were talking science instead of common sense, we 
should call that an Experimental Verification. And, if 
still opposed, you go further, and say, “I have heard 
from the people in Somersetshire and Devonshire, 
where a large number of apples are grown, that they 
have observed the same thing. It is also found to be 
the case in Normandy, and in North America. In 
short, I find it to be the universal experience of man- 
kind wherever attention has been directed to the sub- 
ject.” Whereupon, your friend, unless he is a very 
unreasonable man, agrees with you, and is convinced 
that you are quite right in the conclusion you have 
drawn. He believes, although perhaps he does not 
know he believes it, that the more extensive Verifica- 
tions are,—that the more frequently experiments have 
been made, and results of the same kind arrived at,— 
that the.more varied the conditions under which the 
same results have been attained, the more certain is 


you, therefore, eh the law you nee laid | dove 
be a good one, and he must believe it. 

In science we do the same thing ;—the ph 
exercises precisely the same faculties, though i in 
more delicate manner. In scientific inquiry it becomes 
a matter of duty to expose a supposed law to every 
possible kind of verification, and to take care, more- 
over, that this is done intentionally, and not left toa 
mere accident, as in the case of the apples. And ieee a: 
science, as in common life, our confidence ina lawis 
in exact proportion to the absence of variation in the 
result of our experimental verifications. For instance, — 
if you let go your grasp of an article you may have in © 
your hand, it will immediately fall to the ground. That 
is a very common verification of one of the best estab- 
lished laws of nature—that of gravitation. The method — 
by which men of science establish the existence of that 
law is exactly the same as that by which we have estab- _ 
lished the trivial proposition about the sournessof hard — 
and green apples. But we believe it in such an exten- 
sive, thorough, and unhesitating manner because the 
universal experience of mankind verifies it, and we can 
verity it ourselves at any time; and that is the strongest 
possible foundation on which any natural law can rest. 

So much by way of proof that the method of estab- 
lishing laws in science is exactly the same as that pur- 
sued in common life. Let us now turn to another 
matter (though really it is but another phase of the 
same question), and that is, the method by which, from 


ie Meow i NE ee 3 eee 
— ‘OF DISCOVERY. : | a KF 


I want to put the case clearly before you, and I will 
‘efore show you what I mean by another familiar 
mple. I will suppose that one of you, on coming 
~ down in the morning to the parlour of your house, finds 
that a tea-pot and some spoons which had been left in 
- the room on the previous evening are gone,—the win- 
on dow w is open, and you observe the mark of a dirty hand 
i i the window-frame, and perhaps, in addition to that, 
g “you notice the impress of a hob-nailed shoe on the 
gravel outside. All these phenomena have struck your 
: a attention instantly, and before two minutes have passed 
¢ you say, “Oh, somebody has broken open the window, 
rig entered the room, and run off with the spoons and the 


- 
oa 
? 


ss 
zm? Pct ” That speech is out of your mouth in a mo- 
ment. And you will probably add, “I know there 
has; I am quite sure of it!” You mean to say exactly 


what you know; but in reality what you have said has 

, been the expression of what is, in all essential particu- 
lars, a Hypothesis. You do not know it at all; it is 
nothing but a hypothesis rapidly framed in your own 
mind! And it is a hypothesis founded on a long train 
of inductions and deductions. 

What are those inductions and deductions, and how 
have you got at this hypothesis? You have observed, 
in the first place, that the window is open; but by a 
train of reasoning involving many Inductions and De- 
ductions, you have probably arrived long before at the 
General Law—and a very good one it ththat windows 
do not open of Giomineles and you therefore conclude 
that something has opened the window. <A second 
general law that you have arrived at in the same way 


ia = 
p's 


In the third place, you look at the marks on ti 
dow-sill, and the shoe-marks outside, and: you say t 
in all previous experience the former kind of m 
has never been produced by anything else b 
hand of a human being; and the same experience shor 
that no other animal but man at present wears shoes” 
with hob-nails on them such as would produce th 
marks in the gravel. I do not know, even if we coul 
discover any of those “missing links” that are talk 
about, that they would help us to any other conclusion! 
At any rate the law which states our present experience 
is strong enough for my present purpose. You next 
reach the conclusion, that as these kinds of marks have — 
not been left by any other animals than men, or are 
liable to be formed in any other way than by a man’s. 
hand and shoe, the marks in question have been formed 
by a man in that way. You have, further, a general ~ 
law, founded on observation and experience, and that, 
too, is, I am sorry to say, a very universal and unim- 
peachable one,—that some men are thieves; and you 
assume at once from all these premisses—and that is 
what constitutes. your hypothesis—that the man who 
made the marks outside and on the window-sill, opened 
the window, got into the room, and stole your tea-pot 
and spoons. You have now arrived at a Vera Causa ; 
—you have assumed a Cause which it is plain iscom- 
petent to produce all the phenomena you have observed. 
You can explain all these phenomena only by the hy- 
pothesis of a thief. But that isa hypothetical conclu. 
sion, of the justice of which you have no absolute proof 


Pr suppose your first action, assuming you are a man 
Ps > ordinary common sense, and that you have estab- 
. ed this hypothesis to your own satisfaction, will 
_yery likely be to go off for the police, and set them on 
e- the track of the burglar, with the view to the recovery 
Ss of your property. But just as you are starting with 
= oth is object, some person comes in, and on learning what 
eon. are about, says, “ My good Grice: you are going 
on a great deal too fast. How do you know that the 
-man who really made the marks took the spoons? It 
in Baas have been a monkey that took them, and the 
man may have merely looked in afterwards.” You 
would probably reply, “ Well, that is all very well, 
a _ but you see it is contrary to all experience of the way 
____ tea-pots and spoons are abstracted ; so that, at any rate, 
your hypothesis is less probable than mine.” While 
you are talking the thing over in this way, another 
* friend arrives, one of that good kind of people that I 
was talking of a little while ago. And he might say, 
“Oh, my dear sir, you are certainly going on a great 
deal too fast. You are most presumptuous. Yon ad- 
mit that all these occurrences took place when you 
were fast asleep, at a time when you could not possibly 
have known anything about what was taking place. 
How do you know that the laws of Nature are not sus- 
pended during the night? It may be that there has 
been some kind of supernatural interference in this 
ease.” In point of fact, he declares that your hypoth- 
esis is one of which you cannot at all demonstrate the 
truth, and that you are by no means sure that the 


laws of Nitune sire “he same ean yo 
when you are awake. 

-Well, now, you cannot at the OR ans r 
kind of reasoning. You feel that your worthy frie 
has you somewhat at a disadvantage. You w 
perfectly convinced in your own mind, howe 
you are quite right, and you say to him, “ Mi 
‘friend, I can only be guided by the natural probab 
ties of the case, and if you will be kind enough to stand 
aside and permit me to pass, I will go and fetch the 
police.” Well, we will suppose that your journey is 
successful, aa that by good Inck you meet with : 
policeman; that eventually the burglar is found with 
your property on his person, and the marks correspond~ 
to his hand and to his boots. Probably any jury would — 
consider those facts a very good experimental verifica- _ 
tion of your hypothesis, touching the cause of the ab- 
normal phenomena observed in your parlour, and would 
act accordingly. . 

Now, in this supposititious case I have taken phe- a4 
nomena of a very common kind, in order that you = 
might see what are the different steps in an ordinary 
process of reasoning, if you will only take the trouble 
to analyze it carefully. All the operations | have de 
scribed, you will see, are involved in the mind of any 
man of sense in leading him to a conclusion as to the 
course he should take in order to make good a robbery 
and punish the offender. I say that you are led, in 
that case, to your conclusion by exactly the same train 
of reasoning as that which a man of science pursues ‘ 
when he is endeavouring to discover the origin and 
laws of the most occult phenomena. The process is, 
and always must be, the same; and precisely the same 


= Pes ca ta tam vl é ra JS 
Bont : aie 


>Re. 
PI 


: 
Rae 


le Rot yeagoning was employed by Newton ind 
lace i in their endeavours to discover and define the 
ses of the movements of the heavenly bodies, as you, 
| ‘your own common sense, would employ to detect 
slar. The only difference is, that the nature of 
. inquiry being more abstruse, every step has to be 
_ most carefully watched, so that there may not be a 
ngle crack or flaw in your hypothesis. A flaw or 
ack in many of the hypotheses of daily life may be 
. ittle or no moment as affecting the general correct- 
ness of the conclusions at which we may arrive; but 
e in a scientific i inquiry a fallacy, great or small, is sivay s 
B of importance, and is sure to be constantly productive 
of mischievous, if not fatal, results in the long run. 
Do not allow Soniealors to be misled by the com- 
mon notion that a hypothesis is untrustworthy simply 
because it is a hypothesis. It is often urged, in respect 
> to some scientific conclusion, that, after all, it is only 
a hypothesis. But what more have we to guide us in 
nine-tenths of the most important affairs of daily life 
_ than hypotheses, and often very ill-based ones? So 
_ that in science, where the evidence of a hypothesis is 
_ subjected to the most rigid examination, we may rightly 
pursue tle same course. You may have hypotheses 
. and hypotheses. A man may say, if he likes, that the 
moon is made of green cheese: that is a hypothesis. 
But another man, who has devoted a great deal of time 
_ and attention to the subject, and availed himself of the 
most powerful telescopes and the results of the observa- 
tions of others, declares that in his opinion it is prob- 
ably composed of materials very similar to those of 
which our own earth is made up: and that is also only a 
hypothesis. But I need not tell you that there is an 


- 


es wee OF aes ea . 65 


oh 


is sure to have a corresponding value; and th 
is a mere hasty random guess is likely to have | 
value. Every great step in our progress in disco 
causes has been made in exactly the same way a 
which I have detailed to you. A person observ 
occurrence of certain facts and phenomena asks, né tu- 
rally enough, what process, what kind of operation | 
known to occur in nature applied to the particulai 
case, will unravel and explain the mystery? He 
you have the scientific hypothesis; and its value will 
be proportionate to the care and completeness wi 
which its basis had been tested and verified. It is in 
these matters as in the commonest. affairs of practical 
life: the guess of the fool will be folly, while the guess 
of the wise man will contain wisdom. In all cases, 
you see that the value of the result depends on the 
patience and faithfulness with which the investigator 
applies to his hypothesis every possible kind of verifi- 
cation. | 
I dare say I may have to return to this point by- 
-and-by; but having dealt thus far with our logical 
methods, I must now turn to something which, perhaps, 
you may consider more interesting, or, at any rate, 
more tangible. But in reality there are but few things __ 
that can be more important for you to understand than : 
the mental processes and the means by which we obtain 
scientific conclusions and theories.* Having granted 
that the inquiry is a proper one, and having determined 


* Those who wish to study fully the doctrines of which I have en- 
deavoured to give some rough and ready illustrations, must read Mr. John 
Stuart Mill’s ‘System of Logic.” 


: the Been of the methods we are to pursue and 
h only can lead to success, I must now turn to the 


a let me say at once, lest some of you misun- 
derstand me, that I have extremely little to report. 
> question of how the present condition of organic 
re came about, resolves itself into two questions. 
‘he first is: How has organic or living matter com- 
~ menced its existence? And the second is: How has it 
a 2 been perpetuated? On the second question I shall 
a: _have more to say hereafter. But on tlre first one, what 
.4 now have to say will be for the most part of a nega- 
tive character. 

If you consider what kind of evidence we can have 
upon this matter, it will resolve itself into two kinds. 
We may have kinorieal evidence and we may have ex- 

3 perimental evidence. It is, for example, conceivable, 
that inasmuch as the hardened mud which forms a 
considerable portion of the thickness of the earth’s 

crust contains faithful records of the past forms of life, 

and inasmuch as these differ more and more as we go 
further down,—it is possible and conceivable that we 
might come to some particular bed or stratum which 
should contain the remains of those creatures with 
which organic life began upon the earth. And if we 

did so, and if such forms of organic life were pre- 

servable, we should have what I would call historical 

evidence of the mode in which organic life began upon 
this planet. Many persons will tell you, and indeed 
you will find it stated in many works on geology, that 

this has been done, and that we really possess such a 


record; there are some who imagine tha 
- forms of life of which we have as yet dis 
_ records, are in truth the forms in which anir 
gan upon the globe. The grounds on which 
that supposition are these :—That if you go | 
the enormous thickness of the earth’s crust : 
down to the older rocks, the higher vertebrat 


posed to be the oldest rocks, the animal remains whi 
are found are almost always confined to four forms,- 
Oldhamia, whose precise nature is not known, whether 
plant or animal; Lingula, a kind of molluse ; Trilo- 
bites, a ee animal, having the same ‘omens 
plan of construction, though differing in many details - 
from a lobster or crab; and Hymenocaris, which is 
also a crustacean. So that you have all the Hauna re- 
duced, at this period, to four forms: one a kind of ani- 
mal or plant that we know nothing about, and three 
undoubted animals—two crustaceans and one mollusc, __ 
I think, considering the organization of these mol- 
lusca and crustacea, and looking at their very complex 
nature, that it does indeed require a very strong ima- : 
gination to conceive that these were the first created of p. 
all living things. And you must take into considera- 4 
tion the fact that we have not the slightest proof that 
these which we call the oldest beds are really so: I re- rs 
peat, we have not the slightest proof of it. When you 
find in some places that in an enormous thickness of : 
rocks there are but very scanty traces of life, or abso- 


- = os + re . “ 
, eer SS. ae 


“ts 
> 


a 


1e records of living forms ; I think it is iratosathlod to 
ies any reliance on the supposition, or to feel oneself 
fied in supposing that these are the forms in which 
lite first commenced. I have not time here to enter 
upon the technical grounds upon which I am led to 
this conclusion,—that could hardly be done properly 
in in half a dozen lectures on that part alone ;—I must 
— eontent myself with saying that I do not at all believe 
i that these are the oldest forms of life. 

Ee Ee ' I turn to the experimental side to see what evidence 
_ _wehave there. To enable us to say that we know any- 
thing about the experimental origination of organiza- 
re. tion and life, the investigator ought to be able to take 
‘Inorganic matters, such as ehirbinis acid, ammonia, wa- 
___ ter, and salines, in any sort of inorganic combination, 


3 ie 
= f 


os and be able to build them up into Protein matter, and 
a3 that that Protein matter ought to begin to live in an 


organic form. That, nobody has done as yet, and I 

suspect it will be a long while before anybody does 

doit. But the thing is by no means so impossible as 

it looks ; for the researches of modern chemistry have 

shown us—I won’t say the road towards it, but, if I 

may so say, they have shown the finger-post pointing 
to the road that may lead to it. 

It is not many years ago—and you must recollect 

that Organic Chemistry is a young science, not above 

a couple of generations old,—you must not expect too 

much of it; it is not many years ago since it was said 

to be perfectly impossible to fabricate any organic 

compound ; that is to say, any non-mineral compound 

which is to be found in an organized being. It re- 


mained s0 < os a very long period j but i 18 | 
siderable number of years: since a dscns sh 


very complex character, ae forms one om th 
products of animal structures. And of late 1¢ 


and others, have been added to the list. I nee 
tell you that chemistry is an enormous distance f 
the goal I indicate; all I wish to point out to you : 
that it is by no means safe to say that that goal — 
not be reached one day. It may be that it is impos-_ 
sible for us to produce the conditions requisite to the 
origination of life; but we must speak modestly abo 
the matter, and Neoleet that Science has put her foot 
upon the bottom round of the ladder. Truly he would ~ 
be a bold man who would venture to predict where she Ae 
will be fifty years hence. ies 
There is another inquiry which bears indirectly se 
upon this question, and upon which I must say afew 
words. You are all of you aware of the phenomena 
of what is called spontaneous generation. Our fore- 
fathers, down to the seventeenth century, or there- 
abouts, all imagined, in perfectly good faith, that cer- 
tain vegetable and animal forms gave birth, in the 
process of their decomposition, to insect life. Thus, if 
you put a piece of meat in the sun, and allowed it to 
putrefy, they conceived that the grubs which soon be- 
gan to appear were the result of the action of a power 
of spontaneous generation which the meat contained. 
And they could give you receipts for making various 
animal and vegetable preparations which would pro- 
duce particular kinds of animals. A very distinguish- 
ed Italian naturalist, named Redi, took up the ques- 


4, 


4 
f 
Peet Mutt fake ee ee 


i o = i> Fe te A) 


aw 
a! 


we As 


pi fi 
tree 


Leer ig 


ee ee 
ya oper ees 3 


ni ee 


idee Pak ee 
Pers, Ot LS oe SS ee a 


; os A oe ee 
fae. “7. a a he’s 


ee Feats SEP 4 Zarey 1. ees 
amine oF LIVING BEINGS. ae fe Nae 
>: 


: our own great Harvey, the pial ae the 
an of the blood. You will constantly find his 


ant me believed it as profuundly as any man 
oe his time; but he happened to enunciate a very cu- 
Ti ons proposition—that every living thing came from 
an egg ; he did not mean to use the word in the sense 
in which we now employ it, he only meant to say that 
. a every living thing geibinated in a little rounded par- 
ticle of organized sabateiae and it is from this cir- 
a ~ cumstance, probably, that the notion of Har vey having 
ad opposed the doctrine originated. Then came Beat 
__ and he proceeded to upset the doctrine in a very simple 
manner. He merely covered the piece of meat with 
some very fine gauze, and then he exposed it to the 
same conditions. The result of this was that no grubs 
or insects were produced; he proved that the grubs 
originated from the insects who came and deposited 
_, their eggs in the meat, aud that they were hatched 
_ by the heat of the sun. By this kind of inquiry he 
thoroughly upset the doctrine of spontaneous genera- 
tion, for his time at least. 

- Then came the discovery and application of the 
microscope to scientific inquiries, which showed to 
naturalists that besides the organisms which they 
already knew as living beings and plants, there were 
an immense number of minute things which could be 
obtained apparently almost at will from decaying vege- 
table and animal forms. Thus, if you took some or- 
dinary black pepper or some hay, and steeped it in 


water, you would find in the course of a fe 
the water had become impregnated with 
number of animaleules swimming about ; 
tions. From facts of this kind naturalists ) 
revive the theory of spontaneous generatio 
were headed here by an English naturalist,—N 
They said that these things were absolutely bego 
in. the water of the decaying substances out of whic 
the infusion was made. It did not matter whethér you _ 
took animal or vegetable matter, you had only to steey 
it in water and expose it, and you would soon 
plenty of animalcules. They made a hypothesis a ) 
this which was a very fair one. They said, this matt 
of the animal world, or of the higher plants, appears to 
be dead, but in reality it has a sort of dim life about 
which, if it is placed under fair conditions, will caus 
to break t up into the forms of these little animaleules, __ 
and they will go through their lives in the same way as 
the animal or plant of which they once formed a part. 
The question now became very hotly debated. S 
Spallanzani, an Italian naturalist, took up opposite 
‘views to those of Needham and Button and by means : 
of certain experiments he showed that it was quite pos- 
sible to stop the process by boiling the water, and clos- _ 
ing the vessel in which it was contained. “Oh!” said_ 
his opponents; “ but what do you know you may be 
doing when you heat the air over the water in this way # 
You may be destroying some property of the air requi- 
site for the spontaneous generation of the animaleules.” 
However, Spallanzani’s views were supposed to be 
upon the right side, and those of the others fell into 
discredit ; although the fact was that Spallanzani had 


on 


Pint made good his views. Well, then, the subject con- 


a tinued to be revived from time to time, and experiments _ 


were made by several persons; but these experiments 
__-were not altogether satisfactory. It was found that if 
a you put an infusion in which animaleules would appear 
if it were exposed to the air into a vessel and boiled 
e: it, and then sealed up the mouth of the vessel, so that 
no air, save such as had been heated to 212°, could 
reach its contents, that then no animalcules would be 
a found; but if you took the same vessel aud exposed 
the infusion to the air, then you would get animalcules. 
Furthermore, it was found that if you connected the 
mouth of the vessel with a red-hot tube in such a way 
- that the air would have to pass through the tube be- 
fore reaching the infusion, that then you would get 
no animaleules. Yet another thing was noticed: if 
you took two flasks containing the same kind of infu- 
sion, and left one entirely exposed to the air, and in 
the mouth of the other placed a ball of cotton wool, 
so that the air would have to filter itself through it 
before reaching the infusion, that then, although you 
might have plenty of animalcules in the first flask, you 
would certainly obtain none from the second. 

These experiments, you see, all tended towards one 
eonc!usion—that the infusoria were developed from little 
minute spores or eggs which were constantly floating 

. in the atmosphere, which lose their power of germi- 
nation if subjected to heat. But one observer now made 
auother experiment, which seemed to go entirely the 
other way, and puzzled him altogether. He took some 
of this boiled infusion that I have been speaking of, 
and by the use of a mercurial bath—a kind of trough 
used in laboratories—he deftly inverted a vessel con- 

+ 


of the alunos shut off from any paudhieds comm 

tion with the outer air by being inverted upon o 
mercury. 
He then decors some pe oxygen and. x 


a outside of the vessel, up through the mercury into 
the infusion; so that he thus had it exposed to a per 
fectly pure atmosphere of the same constituents as th 
external air. Of course, he expected he would get n 
infusorial animalcules at all in that infusion; but, t 
his great dismay and discomfiture, he found he almos 
ee did get them. ae 
Rustharmigie it has been found that experiments ee 
made in the manner described above answer well with 
most infusions; but that if you fill the vessel with — 
boiled milk, and then stop the neck with cotton-wool, 
you will have infusoria. So that you see there were 
two experiments that brought you to one kind of con- 
clusion, and three to another; which was a most un- 
satisfactory state of things to arrive at in a scientific 
inquiry. i a 
Some few years after this, the question began to be _ 
very hotly discussed in France. There was M. Pouchet, 
a professor at Rouen, a very learned man, but certainly 
not a very rigid experimentalist. He published a num- — 
ber of experiments of his own, some of which were very — 
ingenious, to show that if you went to work in a proper 
way, there was a truth in the doctrine of spontaneous 
generation. Well, it was one of the most fortunate 
things in the world that M. Pouchet took up this ques 


~ tior n, because it induced a distinguished French chemist, 
-M. Pasteur, to take up the question on the other side; 
and he has certainly worked it out in the most perfect 
- manner. Iam glad to say, too, that he has published 
z his researches in time to enable me to give you an ac- 
count of them. He verified all the experiments which 
ze have just mentioned to you—and then finding those 
__ extraordinary anomalies, as in the case of the mercury 
bath and the milk, he set himself to work to discover 
_ their nature. In the case of milk he found it to be a 
question of temperature. Milk in a fresh state is 
slightly alkaline; and it is a very curious circumstance, 
but this very slight degree of alkalinity seems to have 
the effect of preserving the organisms which fall into 
it from the air from being destroyed at a temperature 
of 212°, which is the boiling point. But if you raise 
the temperature 10° when you boil it, the milk behaves 
like everything else; and if the air with which it comes 
in contact, after being boiled at this temperature, is 
passed through a red-hot tube, you will not get a trace 
of organisms. 

He then turned his attention to the mercury bath, 
and found on examination that the surface of the mer- 
cury was almost always covered with a very fine dust. 
He found that even the mercury itself was positively 
full of organic matters; that from being constantly 
exposed to the air, it had collected an immense num- 
ber of these infusorial organisms from the air. Well, 
under these circumstances he felt that the case was 
quite clear, and that the mereury was not what it had 
appeared to M. Schwann to be—a bar to the admission 
of these organisms; but that, in reality, it acted asa 
reservoir from which the infusion was immediately 


ORIGINATION OF 


supplied with the large quantity that ha 
him. | 


ought not only to be able to show the cocked 13, bute 
Pe to be able to Saale and sow them, and produce 
he resulting organisms.” He, accordingly, constra 
a very ingenious apparatus to ana him to accoinp. 
this trapping of this “germ dust” in the air. He fixed 
in the window of his room a glass tube, in the centre 
of which he had placed a ball of gun-cotton, which, 
as you all know, is ordinary cotton-wool, which, from 
having been steeped in strong acid, is conan into — 
a sabeeale: of great leeds power. It is also solu-— 
ble in alcohol and ether. One end of the glass tube — 
was, of course, open to the external air; and at the 
other end of it he placed an aspirator, a contrivance 
for causing a current of the external air to pass through 
the tube. He kept his apparatus going for four-and- 
twenty hours, and then removed the dusted gun-cot- 
ton, and dissolved it in alcohol and ether. He then al- 
lowed this to stand for a few hours, and the result was, 
that a very fine dust was gradually deposited at the 
bottom of it. That dust, on being transferred to the 
stage of a microscope, was found to contain an enor- 
mous number of starch grains. You know that the 
materials of our food and the greater portion of plants 
are composed .of starch, and we are constantly making 
use of it in a variety of ways, so that there is always 


OE Sh ne a as ea a di ee ed 


ORIGINATION OF LIVING BEINGS. aL 


a ‘quantity of it suspended in the air. It is these starch 
_ grains which form many of those bright specks that 
__we see dancing in a ray of light sometimes. But be- 
sides these, M. Pasteur found also an immense number 
_ of other organic substances such as spores of fungi, 
which had been floating about in the air and had got 
caged in this way. 
| He went farther, and said to himself, “If these. 
really are the things that give rise to the appearance 
< of spontaneous generation, I ought to be able to take 
a ball of this dusted gun-cotton and put it into one of 
my vessels, containing that boiled infusion which has 
been kept away from the air, and in which no in- 
_ fusoria are at present developed, and then, if I am right, 
the introduction of this gun-cotton will give rise to 
organisms.” 

Accordingly, he took one of these vessels of infu- 
sion, which had been kept eighteen months, without 
the least appearance of life, and by a most ingenious 
contrivance, he managed to break it open and intro- 
duce such a ball of gun-cotton, without allowing the 
infusion or the cotton ball to come into contact with 
any air but that which had been subjected to a red 
heat, and in twenty-four hours he had the satisfaction 
of finding all the indications of what had been hitherto 
ealled spontaneous generation. He had succeeded in 
eatching the germs and developing organisms in the 
way he had anticipated. 

It now struck him that the truth of his conclusions 
might be demonstrated without all the apparatus he 
had employed. To do this, he took some decaying 
animal or vegetable substance, such as urine, which is 
an extremely decomposable substance, or the juice of 


a 


‘then boiled the diguld and bent that long medio a Hs 
S shape or zig-zag, leaving it open at the end. The — 


infusion then gave no trace of any appearance of spon- _ 


taneous generation, however long it might be left, as 


all the germs in the air were deposited in the beginning 


of the bent neck. He then cut the tube close to the — 

vessel, and allowed the ordinary air to have free and 
direct access; and the result of that was the appearance 
of organisms in it, as soon as the infusion had been 
allowed to stand long enough to allow of the growth 
of those it received from the air, which was about forty- 
eight hours. The result of M. Pasteur’s experiments 
proved, therefore, in the most conclusive manner, that all 
the appearances of spontaneous generation arose from 
nothing . more than the depacii of the germs of or- 
ganisms which were constantly floating in the air. 

To this conclusion, however, the objection was 
made, that if that were the cause, then the air would 
contain such an enormous number of these germs, that 
it would be a continual fog. But M. Pasteur replied 
that they are not there in anything like the number we 
might suppose, and that an exaggerated view has been — 
held ow that subject; he showed that the chances of 
animal or vegetable life appearing in infusions, depend 
entirely on the conditions under which they are ex- 
posed. If they are exposed to the ordinary atmosphere 
around us, why, of course, you may have organisms 
appearing early. But, on the other hand, if they are 
exposed to air from a great height, or from some very 
quiet cellar, you will often not find a single trace of 
life. 


h ht ities appearances are like dae 
1s in the piece of meat, which was = 


} matters by the direct method to which I have 
‘ Temote as that possibility may be. 


LECTURE 1¥. 


THE PERPETUATION OF LIVING BEINGS, HEREDITA 
TRANSMISSION AND VARIATION. 


THE inquiry which we ‘undertook, at our ee 
ing, into the state of our now ieiee of the causes « 
the phenomena of organic nature,—of the past and of 
the present,—resolved itself into two subsidiary in- 
quiries: the first was, whether we know anything 
either historically or experimentally, of the mode « 
origin of living beings; the second subsidiary inquiry 
was, whether, granting the origin, we know anything — 
about the perpetuation and moditications of the forms — 
of organic beings. The reply which I had to give to — 
the first question was altogether negative, and the chief 
result of my last lecture was, that, neither historically 
nor experimentally, do we at present know anything 
whatsoever about the origin of living forms. We saw 
that, historically, we are not likely to know anything 
about it, although we may perhaps learn something ex- 
perimentally; but that at present we are an enormous 
distance from the goal I indicated. 

I now, then, take up the next question, What do 
we know of the reproduction, the perpetuation, and the 
modifications of the forms of living beings, supposing 


hat we have put the question as to their origination on 
one side, and have assumed that at present the causes 


es of their origination are beyond us, and that we know 
nothing about them? Upon this question the state of 
our knowledge is extremely different ; it is exceedingly | 


large, and, ti not complete, our experience is certainly 


most extensive. It would be impossible to lay it all 
before you, and the most I can do, or need do to-night, 


is to take up the principal points and put them before 
you with such prominence as may subserve the pur- 


poses of our present argument. 

The method of the perpetuation of organic beings 
is of two kinds,—the asexual and the sexual. In the 
first the perpetuation takes place from and by a par- 


ticular act of an individual organism, which sometimes 


may not be classed as belonging to any sex at all. In 


the second case, it is in consequence of the mutual ac- 


tion and interaction of certain portions of the organisms 
of usually two distinct individuals,—the male and the 
female. The cases of asexual perpetuation are by no 
means so common as the cases of sexual perpetuation ; 
and they are by no means so common in the animal as 
in the vegetable world. You are all probably familiar 
with the fact, as a matter of experience, that you can 
propagate plants by means of what are called “ cut- 
tings ;” for example, that by taking a cutting from a 
geranium plant, and rearing it properly, by supply- 
ing it with light and warmth and nourishment from 
the earth, it grows up and takes the form of its parent, 
having all the properties and peculiarities of the ori- 
ginal plant. 
Sometimes this process, which the gardener per- 
forms artificially, takes place naturally; that is to say, 
A" 


~~ =) he oo See en. Wes Le ee ee ee oe Oi *. ante 
ME PR Ek cea Sater Sikh cht anit ty 
. ; . Lo > sete ~ ee ns, i. ye La » thes 


82 THE PERPETUATION OF LIVING BEINGS, 


drops off, and becomes capable of growing as a separate 
thing. That is the case with many bulbous plants, 
which throw off in this way secondary bulbs, which 
are lodged in the ground and become developed into 
plants. This is an asexual process, and from it results — 
the repetition or reproduction of the form of the ¢ ori- 


ginal being from which the bulb proceeds. 


Ainone animals the same thing takes place. Among | 


the lower forms of animal life, the infusorial animal- 
culge we have already spoken of throw off certain por- 
tions, or break themselves up in various directions, 
sometimes transversely or sometimes longitudinally ; 
or they may give off buds, which detach themselves 
and develop into their proper forms. There is the 
common fresh-water Polype, for instance, which multi- 
plies itself in this way. Just in the same way as the 
gardener is able to multiply and reproduce the pecu- 
liarities and characters of particular plants by means 
of cuttings, so can the physiological experimentalist, 
—as was shown by the Abbé Trembley many years 
ago,—so can he do the same thing with many of the 
lower forms of animal life. M. de Trembley showed 
that you could take a polype and cut it into two, or 
four, or many pieces, mutilating it in all directions, 
and the pieces would still grow up and reproduce com- 
pletely the original form of the animal. These are all 
cases of asexual multiplication, and there are other in- 
stances, and still more extraordinary ones, in which 
this process takes place naturally, in a more hidden, a 
more recondite kind of way. You are all of you fa- 
miliar with those little green insects, the Ap/cs or 
blight, as it is called. These little animals, during 


Toes, Neen ae Pe eee eo 


5 ss HEREDITARY TRANSMISSION AND VARIATION. 83 


SS Oeae , 


a very considerable part of their existence, multiply 
_ themselves by means of a kind of internal budding, the 
buds being developed into essentially asexual animals, 
which are neither male nor female; they become con- 
verted into young Ap/ides, which repeat the process, 
and their offspring after them, and so on again; you 
may go on for nine or ten, or even twenty or more suc- 
cessions ; and there is no very good reason to say how 
soon it might terminate, or how long it might not go 
on if the proper conditions of warmth and nourishment 
were kept up. 

Sexual reproduction is. quite a distinct matter. 
Here, in all these cases, what is required is the detach- 
ment of two portions of the parental organisms, which 
portions we know as the egg or the spermatozoon. In 
plants it is the ovule and the pollen-grain, as in the 
flowering plants, or the ovule and the antherozooid, as 
in the flowerless. Among all forms of animal life, the 
spermatozoa proceed tebe the male sex, and the egg is 
the product of the female. Now, w Kat is omikable 
about this mode of reproduction is this, that the egg 
by itself, or the spermatozoa by themselves, are unable 
to assume the parental form; but if they be brougnt 
into contact with one another, the effect of the mixture 
of organic substances proceeding from two sources ap- 
pears to confer an altogether new vigour to the mix- 
ed product. This process is brought about, as we all 
know, by the sexual intercourse of the two sexes, and 
is called the act of impregnation. The result of this 
act on the part of the male and female is, that the 
formation of a new being is set up in the ovule or egg; 
this ovule or egg soon begins to be divided and sub- 
divided, and to be fashioned into various complex or- 


- is 


ganisms, and eventually to pee into th 
one of its parents, as I explained in the fing 


organic beings is secured. Why there chon bet 
two modes—why this ree eon should be — 


au but it is most assuredly the fact, and it is wa 
mais, that, however long the process of asexue 
multiplication could be continued,—I say there is good 
reason to believe that it would come to an end if anew _ 
commencement were not obtained by a conjunction of 
the two sexual elements. ere 
That character which is common to these two dis- 
tinct processes is this, that, whether we consider the 


reproduction, or perpetuation, or modification of or- 

ganic beings as they take place asexually, or as they _ r 
may take place sexually,—in either case, I say, the off- 
spring has a constant tendency to assume, speaking __ 
generally, the character of the parent. As I said just ; 
now, if you take a slip of a plant, and tend it with care, : 


it a eventually grow up and develop into a plant 
like that from which it had sprung; and this tendency 
is so strong that, as gardeners know, this mode of mul- 
tiplying by means of cuttings is the only secure mode 
of propagating very many varieties of plants ; the pecu- 
liarity of the primitive stock seems to be better pre- 
served if you propagate it by means of a slip than if 
you resort to the sexual mode. 

Again, in experiments upon the lower animals, such 
as the polype, to which I have referred, it-is most ex- | 
traordinary that, although cut up into various pieces, a” 
each particular piece will grow up into the form of the | 
primitive stock ; the head, if separated, will reproduce 


ee 


| HEREDITARY TRANSMISSION AND VARIATION. 85 


. and the tail; and if you cut off the tail, you 


will find that that pill reproduce the body and all the 
rest of the members, without in any way deviating 
from the plan of the organism from which these por- 
;, . Hons have been detached. And so far does this go, 
- that some experimentalists have carefully examined 
the lower orders of animals,—among them the Abbé 
_ Spallanzani, who made a number of experiments upon 
om ‘snails and salamanders,—and have found that they 
ee. might mutilate them to an incredible extent; that you 
ag - might eut off the jaw or the greater part of ‘the head, 
or the leg or the tail, and repeat the experiment sey- 
eral times, perhaps, cutting off the same member again 
and again; and yet each of those types would be 
reproduced according to the primitive type: nature 
making no mistake, never putting on a fresh kind of 
leg, or head, or tail, but always tending to repeat and 
to return to she primitive type. 
: It is the same in sexual reproduction: it is a mat- 
ter of perfectly common experience, that the tendency 
on the part of the offspring always is, speaking broadly, 
to reproduce the form of the parents. The proverb 
has it that the thistle does not bring forth grapes ; so, 
among ourselves, there is always a likeness, more or 
less marked and distinct, between children and their 
parents. That is a matter of familiar and ordinary ob- 
servation. We notice the same thing occurring in the 
cases of the domestic animals—dogs, for instance, and 
their offspring. In all these cases of propagation and 
perpetuation, there seems to be a tendency in the off- 
spring to take the characters of the parental organisms. 
To that tendency a special name is given—and as I 
may very often use it, I will write it up here on this 


~~ q a) 
+ oT — et ern 
: ‘ eT 
5 e r * 


black-board that you may remember it—it. 
Atavism ; it expresses this tendency to revert 
ancestral type, and comes from the Latin i 
ancestor. 

Well, this Atavism which I shall cok of, is, as oe 
said hers. one of the most marked and striking ten- 
dencies of organic beings; but, side by side with thi: 
hereditary tendency, there is an equally distinct and 
remarkable tendency to variation. The tendency to 
reproduce the original stock has, as it were, its limits, 
and side by side with it there is a tendency to vary in 
certain directions, as if there were two opposing pow- 
ers working upon the organic being, one tending to 
take it in a straight line, and the other tending to make 
it diverge from that straight line, first to one side and 
then to the other. 

So that you see these two tendencies need not pre- 
cisely contradict one another, as the ultimate result 
may not always be very remote from what would have 
been the case if the line had been quite straight. 

This tendency to variation is less marked in that 
mode of propagation which takes place asexually ; it is 
in that mode that the minor characters of animal and 
vegetable structures are most completely preserved. 
Still, it will happen sometimes, that the gardener, 
when he has planted a cutting of some favourite plant, 
will find, contrary to his expectation, that the slip 
grows up a little different from the primitive stock— 
that it produces flowers of a different colour or make, 
or some deviation in one way or another. This is what 
is called the “ sporting” of plants. 

In animals the phenomena of asexual propagation 
are so obscure, that at present we cannot be said to 


ie 


=f vd 2 AW OP 
ie oF 4 ape if ae 


De sere el Ss 


_-—s—s HEREDITARY TRANSMISSION AND VARIATION. 87 


+ 
know much about them; but if we turn to that mode 


of perpetuation which results from the sexual process, 


then we find variation a perfectly constant occurrence, 
to a certain extent ; and, indeed, I think that a certain 


amount of variation from the primitive stock is the 
se 


necessary result of the method of sexual propagation 
itself; for, inasmuch as the thing propagated proceeds 
from two organisms of different sexes and different 


makes and temperaments, and as the offspring is to be 


either of one sex or the other, it is quite clear that it 
cannot be an exact diagonal of the two, or it would be 
of no sex at all; it cannot be an exact intermediate 
form between that of each of its parents—it must de- 
viate to one side or the other. You do not find that 
the male follows the precise type of the male parent, 
nor does the female always inherit the precise charac- 
teristics of the mother,—there is always a proportion 
of the female character in the male offspring, and of 
the male character in the female offspring. That must 
be quite plain to all of you who have looked at all at- 
tentively on your own children or those of your neigh- 
bours; you will have noticed how very often it may 
happen that the son shall exhibit the maternal type of 
character, or the daughter possess the characteristics 
of the father’s family. There are all sorts of intermix- 
tures and intermediate conditions between the two, 
where complexion, or beauty, or fifty other different 
peculiarities belonging to either side of the house, are 
reproduced in other members of the same family. In- 
deed, it is sometimes to be remarked in this kind of 
variation, that the variety belongs, strictly speaking, 
to neither of the immediate parents; yeu will see a 


‘ehild in a family who is not like either its father or its 


mother; but some old person who knew its grand- 
father or grandmother, or, it may be, an unele, or, per- 
haps, even a more distant relative, will see a grea 
similarity between the child and one of these. In this — 
way it constantly happens that the characteristic of 
some previous member of the family comes out and 
is reproduced and recognized in the most unexpected __ 
manner. eee 
But apart from that matter of general experience, 
there are some cases which put that curious mixture in 
avery clear light. You are aware that the offspring of 
the Ass and the Horse, or rather of the he-Ass and the 
Mare, is what is called a Mule; and, on the other hand, 
the offspring of the Stallion and the she-Ass is what is 
called a Hinny. It is a very rare thing in this country 
to see a Hinny. I never saw one myself; but they 
have been very carefully studied. Now, the curious 
thing is this, that although you have the same elements 
in the experiment in each ease, the offspring is entirely 
different in character, according as the male influence 
comes from the Ass or the Horse. Where the Ass is 
the male, as in the case of the Mule, you find that the 
head is like that of the Ass, that the ears are long, the 
tail is tufted at the end, the feet are small, and the 
voice is an unmistakable bray; these are all points 
of similarity to the Ass; but, on the other hand, the 
barrel of the body and the cut of the neck are much 
more like those of the Mare. Then, if you look at the 
Hinny,—the result of the union of the Stallion and 
the she-Ass, then you find it is the Horse that has the 
predominance; that the head is more like that of the 
Horse, the ears are shorter, the legs coarser, and the 
type is altogether altered; while the voice, instead 


te “-MEREDIYARY “TRANSMISSION AND VARIATION. 


eng 


Here, you see, is a most curious oe you take ex- 
ian actly the same elements, Ass and Horse, but you com- 
bine the sexes in a different manner, and the result is 
a _ mnodified accordingly. You have in this case, however, 
a result which is not general and universal—there is 
> Paetaly an important preponderance, but not always 
3 on the same side. 

____ Here, then, is one intelligible, and, perhaps, neces- 
ms: sary cause of variation: the fact, that there are two 
sexes sharing im the production of the offspring, and 


4 that the share taken by each is different and variable, 
not only for each combination, but also for different 
members of the same family. 

. : Secondly, there is a variation, to a certain extent,— 
- 


though in all probability the influence of this cause has 
been very much exaggerated—but there is no doubt 
that variation. is EY to a certain extent, by what 
| are commonly known as external conditions,—such as 
temperature, food, warmth, and moisture. In the long 
run, every variation depends, in some sense, upon ex- 
ternal conditions, seeing that everything has a cause 
of its own. I use the term “ external conditions ” now 
in the sense in which it is ordinarily employed: cer- 
tain it is, that external conditions have a definite effect. 
You may take a plant which has single flowers, and 
by dealing with the soil, and nourishment, and so on, 
you may by-and-by convert single flowers into double 
flowers, and make thorns shoot out into branches. 
You may thicken or make various modifications in the 
shape of the fruit. In animals, too, you may produce 
analogous changes in this way, as in the case of that 
deep bronze colour which persons rarely lose after 


of external soudanour converts aps are original : 


only instructions, teachings, into habits, or, in other. 


words, into organizations, to a great extent; but this 
second cause of variation cannot be considered to be 


by any means a large one. The third cause that I 
have to mention, however, is_a very extensive one. It | 


is one that, for want of a better name, has been called 
‘spontaneous variation ;” which means that when we 
do not know anything about the cause of phenomena, 
we call it spontaneous. In the orderly chain of causes 


and effects in this world, there are very few things of — 
which it can be said with truth that they are spon-— 


taneous. Certainly not in these physical matters,—in 
these there is nothing of the kind,—everything depends 
on previous conditions. But when we cannot trace the 
cause of phenomena, we call them spontaneous. 

Of these variations, multitudinous as they are, but 
little is known with perfect accuracy. I will mention 
to you some two or three cases, because they are very 
remarkable in themselves, and also because I shall 
want to use them afterwards. Réaumur, a famous 
French naturalist, a great many years ago, in the essay 
which he wrote upon the art of hatching chickens,— 
which was indeed a very curious essay,—had occasion 
to speak of variations and monstrosities. One very re- 
markable case had come under his notice of a variation 


in the form of a human member, in the person of a 
> Maltese, of the naine of Gratio Kelleia, who was born 


with six fingers upon each hand, and the like number 
of toes to each of his feet. That was a case of spon- 
taneous variation. Nobody knows why he was born 


with that number of fingers and toes, and as we don’t 


know, we call it a case of “spontaneous” variation. 
There is another remarkable case also. I select these, 


because they happen to have been observed and noted 


very carefully at the time. It frequently happens that 
a variation occurs, but tle persons who notice it do not 
take any care in noting down the particulars, until at 
length, when inquiries come to be made, the exact cir- 
cumstances are forgotten ; and hence, multitudinous as 
may be such “spontaneous” variations, it is exceed- 


ingly difficult to get at the origin of them. 


The second vase is one of which you may find the 
whole details in the “ Philosophical Transactions” for 
the year 1813, in a paper communicated by Colonel 
Humphrey to the President of the Royal Society,— 
“On a new Variety in the Breed of Sheep,” giving an 
account of a very remarkable breed of sheep, which 
at one time was well known in the northern states of 
America, and which went by the name of the Ancon 
or the Otter breed of sheep. In the year 1791, there 
was a farmer of the name of Seth Wright in Massa- 
chusetts, who had a flock of sheep, consisting of a ram 
and, I think, of some twelve or thirteen ewes. Of this 
flock of ewes, one at the breeding-time bore a lamb 
which was very singularly formed; it had a very long 
body, very short legs, and those legs were bowed! I 
will tell you by-and-by how this singular variation in 
the breed of sheep came to be noted, and to have the 


tion, or to any person who compares animale 
others of the same kind. It is strictly true that 
are never any two specimens which are exactly 
however similar, they will always differ in some « 
tain particular. 

Now let us go back to Atavisin,—to the heredi tary 
tendency I spoke of. What will come of a variation 
when you breed from it, when Atavism comes, if I 
may say so, to intersect variation? The two cases of 
which I have mentioned the history, give a most excel- _ 
lent illustration of what occurs. Gratio Kelleia, the 
Maltese, married when he was twenty-two years of age, 
and, as I suppose there were no six-fingered ladies in 
Malta, he married an ordinary five-fingered person. — 
The result of that marriage was four children; the 
first, who was christened Salvator, had six fingers 
and six toes, like his father; the second was George, 
who had five fingers and toes, but one of them was 
deformed, showing a tendency to variation; the third 
was André; he had five fingers and five toes, quite 
perfect; the fourth was a girl, Marie; she had five 
fingers and five toes, but her thumbs were deformed, 
showing a tendency towards the sixth. 

These children grew up, and when they came to 
adult years, they all married, and of course it hap- 
pened that they all married five-fingered and five-toed 
persons. Now let us see what were the results. Sal- 
vator had four children; they were two boys, a girl, 
and another boy: the first two boys and the girl were 


3 fourth boy had ae five Sieh and five toes. George 


had only four children: there were two girls with six 
fingers and six toes; there was one girl with six fingers 


2 i and five toes on the right side, and five fingers and five 
toes on the left ahile” so that she was half and half. 


| Se ee: 


The last, a boy, had five fingers and five toes. The 
third, Andre, you will recollect; was perfectly well- 
formed, and he had many children whose hands and 
feet were all regularly developed. Marie, the last, 


3 Py ho, of course, married a man who had only five fin- 


gers, had four children: the first, a boy, was born with 
six toes, but the other three were normal. 

Now observe what very extraordinary phenomena 
are presented here. You have an accidental variation 
arising from what you may call a monstrosity; you 
have that monstrosity tendency or variation diluted in 
the first instance by an admixture with a female of 
normal construction, and you would naturally expect 
that, in the results of such an union, the monstrosity, 
if repeated, would be in equal proportion with the 
normal type; that is to say, that the children would 


‘be half and half, some taking the peculiarity of the 


father, and the others being of the purely normal type 
of the mother; but you sce we have a great prepon- 
derance of the abnormal type. Well, this comes to be 
mixed once more with the pure, the normal type, and 


the abnormal is again produced in large proportion, 


notwithstanding the second dilution. Now what would 
have happened if these abnormal types had intermar- 
ried with each other; that is to say, suppose the two 
boys of Salvator had taken it into their heads to marry 
their first cousins, the two first giris of George, their 


uncle? 
abnormal type of their sa 
probably have been, that their Stspenee wo 
been in every case a further development of that 
normal type. You see it is only in the fourth, in the 
person of Marie, that the tendency, when it appea 
but slightly in as second generation, is washed o 
in the third, while the progeny of Andre, who escaped 
in the first instance, escape altogether. oF 

We have in this case a ae example of nate Be 
tendency to the perpetuation of a variation. Here it 
is certainly a variation which carried with it no use © 
or benefit; and yet you see the tendency to perpetu- 
ation may be so strong, that, notwithstanding a great 
admixture of pure blood, the variety continues itself 
up to the third generation, which is largely marked _ 
with it. In this case, as I have said, there was no 
means ofthe second generation intermarrying with any 
but five-fingered persons, and the question naturally 
suggests itself, What would have been the result of 
such marriage? NRéaumur narrates this case only as 
far as the third generation. Certainly it would have 
been an exceedingly curious thing if we could have 
traced this matter any further; had the cousins inter- 
married, a six-fingered variety of the human race might 
have been set up. 

To show you that this supposition is by no means 
an unreasonable one, let me now point out what took 
place in the case of Seth Wright’s sheep, where it hap- 
pened to be a matter of moment to him to obtain a 
breed or raise a flock of sheep like that accidental va- 
riety that I have described—and I will tell you why. 
In that part of Massachusetts where Seth Wright was 


ay > = 
Se eee ce eS i 


“je 


95 


oe 


E ri ng, the fields were separated by fences, and the 


4 sheep, which were very active and robust, would roam 


A. 


eo 
‘is 
i 


abroad, and without much difficulty jump over these 


¥ 
a. 
an 
ie 
Pd 
ae 
ss 
= 
ao 


fences into other people’s farms. As a matter of course, 
this exuberant activity on the part of the sheep con- 
stantly gave rise to all sorts of quarrels, bickerings and 


contentions among the farmers of the neighbourhood ; 


so it occurred to Seth Wright, who was, like his suc- 
cessors, more or less ’cute, that if he could get a stock 


of sheep like those with the bandy legs, they would not 


be able to jump over the fences so readily, and he acted 
upon that idea. He killed his old ram, and as soon as 
the young one arrived at maturity, he bred altogether 
from it. The result was even more striking than in the 
human experiment which I mentioned just now. Col- 
onel Humphreys testifies that it always happened that 
the offspring were either pure Ancons or pure ordinary 
sheep ; that in-no case was there any mixing of the 
Ancons with the others. In consequence of this, in 
the course of a very few years, the farmer was able to 
get a very considerable flock of this variety, and a large 
number of them were spread throughout Massachusetts. 
Most unfortunately, however—I suppose it was because 
they were so common—nobody took enough notice of 
them to preserve their skeletons ; and although Colonel 
Humphreys states that he sent a skeleton to the presi- 
dent of the Royal Society at the same time that he 
forwarded his paper, and I am afraid that the variety 
has entirely disappeared ; for a short time after these 
sheep had become prevalent in that district, the Merino 
sheep were introduced; and as their wool was much 
more valuable, and as they were a quiet race of sheep, 
and showed no tendency to trespass or jump over fences, 


rior to that of the Merino, was gradually al 
out. ae 
You see that these facts illustrate perfe 
what may be done if you take care to breed from 
that are similar to each other. After having go 
variation, if, 4 crossing a variation with ome ol 


the variation is exceedingly strong. | 
This is what is called “ como and it is = oma 
the same process as that by which Seth Wright bred his — 
Ancon sheep, that our breeds of cattle, dogs, and fowls, — 
are obtained. There are some possibilities of excep- 
tion, but still, speaking broadly, I may say that this is 
the way in-which all our varied races of domestic ani- — 
mals have arisen; and you must understand that it is 
not one peculiarity or one characteristic alone in which 
animals may vary. ‘There is not a single peculiarity 
or characteristic of any kind, bodily or mental, in which 
offspring may not vary to a certain extent from the 
parent and other animals. , e. 
Among ourselves this is well known. The simplest —_ 
physical peculiarity is mostly reproduced. I knowa  — 
case of a man whose wife has the lobe of one her ears “ 
a little flattened. An ordinary observer might scarcely 
notice it, and yet every one of her children has an 
approximation to the same peculiarity to some ex- 
tent. Same 
If you look at the other extreme, too, the orawen 
diseases, such as gout, scrofula, and consumption, may 


aS", See ae ee Ps 


s + 
ie -D “ee 


HEREDITARY TRANSMISSION AND VARIATION, 


97 


Teg of the Ancon ae 
However, these facts are best illustrated in initials 
Se aid the extent of the variation, as is well known, is 
: very remarkable in dogs. For example, there are 
_ some dogs very much it a than others ; indeed, the 
variation is so enormous that probably the smallest dog 
-__ would be about the size of the head of the largest ; 
there are very great variations in the structural forms 
not only of the skeleton but also in the shape of the 
skull, and in the proportions of the face and the dis- 
position of the teeth. 
a8" The Pointer, the Retriever, Bulldog, and the Ter- 
__ rier, differ very greatly, and yet there is every reason 
to believe that every one of these races has arisen from 
the same source,—that all the most important races 
have arisen by this selective breeding from accidental 
variation. 

A still more striking case of what may be done by 
selective breeding, and it is a better case, because there 
is no chance of that partial infusion of error to which 
I allude, has been studied very carefully by Mr. Dar- 
win,—the case of the domestic pigeons. I dare say 
there may be some among you who may be pigeon 
Janciers, and I wish you to understand that in ap- 
proaching the subject, I would speak with all humility 
and hesitation, as I regret to say that I am not a pigeon 
fancier. I know it is a great art and mystery, and a 
thing upon which a man must not speak lightly ; but 
i. hall endeavour, as far as my understanding goes, to 
give you a summary of the published and pecubiiahen 


information which I have gained from Mr. Darwin. 
5 


somewhere about a hundred and fifty kinds 
—there are four kinds which may be selected 
senting the extremest divergences of one kind from a 
other. Their names are the Carrier, the — ti 
Fantail, and the Tumbler. 
that I have here they are 
relative sizes to each other. 
rier; you will notice this large excrescence on “its 
beak; it has a comparatively small head; there is a 
bare space round the eyes; it has a long — a very _ 
long beak, very strong legs, large feet, long wings, and — 
soon. The second one is the Pouter, a very large bird, — 
with very long legs and beak. It is called the Pouter 
because it is in the habit of causing its gullet to swell — 
up by inflating it with air. I should tell you that all | 
pigeons have a tendency to do this at times, but in the — 
Pouter it is carried to an enormous extent. The birds 
appear to be quite proud of their power of swelling 
and puffing themselves ont in this way; and I think it 
is about as droll a sight as you can well see to look at 
a cage full of these pigeons puffing and blowing them- 
mules out in this ridiculous manner. 

This diagram is a representation of the third kind 
I mentioned—the Fantail. It is, you see, a small bird, 
with exceedingly small legs and a very small beak. 
It is most curiously distinguished by the size and ex- 
tent of its tail, which, instead of containing fourteen 
feathers, may have many more,—say thirty, or even 
more—I believe there are some with as many as forty- 
two. This bird has a curious habit of spreading out 
the feathers of its tail in such a way that they reach 
forward, and touch its head ; and if this can be accom- 


a = 


99 


- But here is the last great variety,—the Tumbler 5. 


‘ a ott of that great variety, one of the principal kinds, 


; and one most prized, is the specimen represented here 


a ‘ —the short-faced Tumbler. Its beak, you see, is re- 


duced to a mere nothing. Just compare the beak of 
this one and that of the first one, the Carrier—I believe 


_ the orthodox comparison of the head and beak of a 
thoroughly well-bred Tumbler is to stick an oat into a 


cherry, and that will give you the proper relative pro- 
portions of the head and beak. The feet and legs are 


_ exceedingly small, and the bird appears to be quite a 
dwarf when placed side by side with this great Carrier. 


These are differences enough in regard to their ex- 
ternal appearance; but these differences are by no 
means the whole or even the wost important of the dif- 
ferences which obtain between these birds. There is 
hardly a single point of their structure which has not 
become more or less altered; and to give you an idea 
of how extensive these alterations are, I have here some 
very good skeletons, for which I am indebted to my 
friend Mr. Tegetmeier, a great authority in these mat- 
ters; by means of which, if you examine them by-and- 
by, you will be able to see the enormous difference in 
their bony structures. 

I had the privilege, some time ago, of access to 
some important MSS. of Mr. Darwin, who, I may tell 


_ you, has taken very great pains and spent much valu- 


able time and attention on the investigation of these 
variations, and getting together all the facts that bear 
upon them. I obtained from these MSS. the follow- 
ing summary of the differences between the domestic 


the first place, ae biel of the skull may d 
deal, and the development of the bones of the 
vary a great deal; the back varies a good deal ; - 
shape of the lower jaw varies; the tongue varies 
greatly, not only in correlation to the length an 
of the beak, but it seems also to have a kind of i 
pendent variation of its own. Then the amount « 
naked skin round the eyes, and at the base of the bea 
may vary enormously; so may the length of the e 
lids, the shape of the nostrils, and the length of 
neck. I have already noticed the habit of blowing ou 
the gullet, so remarkable in the Pouter, and compara. 
tively so in the others. There are great differences, 
too, in the size of the female and lie male, the shape — 
of the body, the number and width of the processes of 
the ribs, the development of the ribs, aud the size, 
shape, and development of the breastbone. We may 
notice, too,—and I mention the fact because it has 
been disputed by what is assumed to be high author- 
ity,—the variation in number of the sacral vertebree. 
The number of these varies from eleven to fourteen, 
and that without any diminution in the number of the 
vertebree of the back or of the tail. Then the number 
and position of the tail-feathers may vary enormously, 
and so may the number of the primary and secondary 
feathers of the wings. Again, the length of the feet 
and of the beak,—although they have no relation to. 
each other, yet appear to go together,—that is, you ¥ 
have a long beak wherever you have long feet. There 
are differences also in the periods of the acquirement of 
the perfect plumage,—the size and shape of the eggs,— 


- natur So fight; a aad the powers of flight,—so-call- 
peed is one eet enormous flying pee a 


heels in the air, instead of pursuing a distinct 
e. And, lastly, the dispositions and voices of the 
: ~ dirds may vary. Thus the case of the pigeons shows 
ae u that there is hardly a single particular,—whether 
stinct, or habit, or bony structure, or of plumage, 
either the internal economy or the external shape, 
in which some variation or change may not take place, 
~ which, by selective breeding, may become perpetuated, 


and form the foundation of, and give rise to, a new 


2 vit ou carry in your mind’s eye these four varieties 
of pigeons, you will bear with you as good a notion as 
_ you can have, perhaps, of the enormous extent to which 
_ a deviation frem a primitive type may be carried by 
_ means of this process of selective breeding. 


Bi __* The “ Carrier,” I learn from Mr. Tegetmeier, does not carry ; 
6 _ ahigh-bred bird of this breed being but a poor flier. The birds 
_ which fly long distances, and come home,—‘“ homing” birds,— 
_ and are consequently used as carriers, are not “carriers” in the 
_ fancy sense, 


LECTURE V. 


THE CONDITIONS OF EXISTENCE AS AFFECTING THE 
PERPETUATION OF LIVING BEINGS. 


In the last Lecture I endeavoured to prove to you 
that, while, as a general rule, organic beings tend to 
reproduce their kind, there is in them, also, a constantly 
recurring tendency to vary—to vary to a greater or to 
a less extent. Such a variety, I pointed out to you, 
might arise from causes which we do not understand ; 
we therefore called it spontaneous; and it might come 
into existence as a definite and marked thing, without 
any gradations between itself and the form which pre- 
ceded it. I further pointed out, that such a variety 
having once arisen, might be perpetuated to some ex- 
tent, and indeed to a very marked extent, without any 
direct interference, or without any exercise of that pro- 
cess which we called selection. And then I stated 
further, that by such selection, when exercised artifi- 
cially—if you took care to breed only from those forms 
which presented the same peculiarities of any variety 
which had arisen in this manner—the variation might 
be perpetuated, as far as we can see, indefinitely. 

The next question, and it is an important one for 
us, is this: Is there any limit to the amount of varia- 


: PERPETUATION OF LIVING BEINGS. 103 


hier from the primitive stock which can be produced 
by this process of selective breeding? In considering 
this question, it will be useful to élaas the character-_ 
istics, in respect of which organic beings vary, under 
two heads: we may consider structural characteristics, 
P . and we may consider physiological characteristics. 
e In the first place, as regards structural characteris- 
re tics, I endeavoured to show you, by the skeletons which 
a I had upon the table, and by reference to a great many 
_-well-ascertained facts, that the different breeds of 
‘ Pigeons, the Carriers, Pouters, and Tumblers, might 
i vary in any of their internal and important structural 
characters to a very great degree; not only might there 
be changes in the proportions of the skull, and the char- 
acters of the feet and beaks, and so on; but that there 
might be an absolute difference in the number of the 
vertebree of the back, as in the sacral vertebre of the 
Pouter; and so great is the extent of the variation in 
these and similar characters that I pointed out to you, 
by reference to the skeletons and the diagrams, that 
these extreme varieties may absolutely differ more from 
one another in their structural characters than do what 
naturalists call distinct Srectes of pigeons; that is to 
say, that they differ so much in structure that there is 
a greater difference between the Pouter and the Tum- 
bler than there is between such wild and distinct forms 
as the Rock Pigeon or the Ring Pigeon, or the Ring 
Pigeon and the Stock Dove; and indeed the differences 
are of greater value than this, for the structural differ- 
ences between these domesticated pigeons are such as 
would be admitted by a naturalist, supposing he knew 
nothing at all about their origin, to entitle them to 
constitute even distinct genera. 


As I have used a term Sencaes and s 
bly use it a good deal, I had better perha 
word or two to axles what I mean by 

Animals and plants are divided into grow 
tree gradually smaller, beginning me a 


Province to a Crass, from a Crass to an Orper, 
Orpers to Famirirs, and from these to Gmnrra, unt 
we come at length to the smallest groups of animals — 
which can be detined one from the other by constant 
characters, which are not sexual; and these are what 
naturalists call Species in practice, whatever they may 
do in theory. } 

If in a state of nature you find any two groups of. 
living beings, which are separated one from the other — 
by some constantly-recurring characteristic, 1 don’t 
care how slight and trivial, so long as it is defined and 
constant, and does not depend on sexual peculiarities, © 
then all naturalists agree in calling them two species ; 
that is what is meant by the use of the word species— 
that is to say, it is, for the practical naturalist, a mere 
question of structural differences.* 

We have seen now—to repeat this point once more, 
and it is very essential that we should rightly under- 
stand it—we have seen that breeds, known to have 
been derived from a common stock by selection, may 
be as different in their structure from the original stock 
as species may be distinct from each other. oa 

But is the like true of the physiological charac- 


* TI lay stress here on the practical signification of ‘‘ Species.” Wheth- 
er a physiological test between species exist or not, it is hardly ever ap- 
plicable by the practical naturalist. 


PERPETUATION OF LIVING BEINGS. 105 


2 poristics of animals? Do the physiological differences 
ian of varieties amount in degree to those observed between 
_ forms which naturalists call distinct species? This is 
a most important point for us to consider. 

As regards the great majority of physiological char- 
acteristics, there is no doubt that they are capable of 
being developed, increased, and modified by selection. 

There is no doubt that breeds may be made as dif- 
ig ferent as species in many physiological characters. I 
a have already pointed out to you very briefly the differ- 
ent habits of the breeds of Pigeons, all of which depend 
__- upon their physiological peculiarities,—as the peculiar 
habit of tumbling, in the Tumbler,—the peculiari- 

ties of flight, in the “homing” birds,—the strange 
habit of spreading out the tail, and walking in a pecu- 
liar fashion, in the Fantail,—and, lastly, the habit of 
blowing out the gullet, so characteristic of the Pouter. 
These are all due to physiological modification, and in 
all these respects these birds differ as much from each 
other as any two ordinary species do. 
So with Dogs in their habits and instincts. It is 
a physiological peculiarity which leads the Greyhound 
to chase its prey by sight,—that enables the Beagle to 
track it by the scent,—that impels the Terrier to its 
rat-hunting propensity, ads the Retriever 
to its habit of retrieving. These habits and instincts 
are all the results of physiological differences and pecu- 
liarities, which have been developed from a common 
stock, at least there is every reason to believe so. But 
it is a most singular circumstance, that while you may 
run through almost the whole series of physiological 
processes, without finding a check to your argument, 
you come at last to a point where you do find a check, 
, az 


and that is in the Lone processes 
is a most singular circumstance in respect” t 
- species—at least about some of them—and i 
sufficient for the purposes of this argument, | 
true of only one of them, but there is, in fact, a grea 
number of such cases—and that is, that similar as th 
may appear to be to mere races or breeds, they preser 
a marked peculiarity in the reproductive process. — 
you breed from the male and female of the same ra 

you of course have offspring of the like kind, and if © 
you make the offspring brecd together, you obtain the — 
same result, and if you breed from these again, you — 
will still have the same kind of offspring; there isno _ 
check. But if you take members of two distinct spe- 
cies, however similar they may be to each other, and — 
make them breed together, you will find a check, with 
some modifications ‘and Scot however, which I — 
shall speak of presently. If you cross two such species 
with each other, then,—although you may get offspring 
in the case of the first cross, yet, if you attempt to breed 
from the products of that crossing, which are what are 
ealled Hysrips—that is, if you couple a male and a 
female hybrid—then the result is that in ninety-nine 
cases out of a hundred you will get no offspring at Lae 
there will be no result whatsoever. 

The reason of this is quite obvious in some cases ; 
the male hybrids, although possessing all the external 
appearances and characteristics of perfect animals, are 
physiologically imperfect and deficient in the structural 
parts of the reproductive elements necessary to gener- 
ation. It is said to be invariably the case with the — a 
male mule, the cross between the Ass and the Mare; | 
and hence it is, that, although crossing the Horse with 


the Pokies is easy enough, and is constantly done, as far 


as I am aware, if you take two mules, a male and a 


2 
rs 
A; 
4 


—— 


yim ie: 


- female, and endeavour to breed from them, you get 


o). Be offspring whatever; no generation will take place. 


Pia is what is called the sterility of the hybrids be- 
- tween two distinct species. 

You see that this is a very extraordinary circam- 
stance ; one does not see why it should be. The com- 
mon peeilveion! explanation is, that it is to prevent the 


impurity of the blood resulting from the crossing of 


one species with another, but you see it does not in 
reality do anything of the kind. There is nothing in 
this fact that hybrids cannot breed with each other, to 
establish such a theory; there is nothing to prevent 
the Horse breeding with the Ass, or the Ass with the 
Horse. So that this explanation breaks down, as a 
great many explanations of this kind do, that are only 
founded on mere assumptions. 

Thus you see that there is a great difference be- 
tween “mongrels,” which are crosses between distinct 
races, and “ hybrids,” which are crosses between dis- 
tinct species. The mongrels are, so far as we know, 
fertile with one another. But between species, in many 
eases, you cannot succeed in obtaining even the first 
cross: at any rate it is quite certain that the hybrids 
are often absolutely infertile one with another. 

Here is a feature, then, great or small as it may be, 
which distinguishes natural species of animals. Can 
we find any approximation to this in the different races 
known to be produced by selective breeding from a 
common stock? Up to the present time the answer 
to that question is absolutely a negative one. As far 
as we know at present, there is nothing approximating 


to this check. In crossing the breeds betwee I 
tail and the Pouter, the Carrier and the Tu mb] or 


gether the mongrels. Take the Carrier and the Fan 
for instance, and let them represent the Horse and 


grel,—we will say the male and female mongrel,—and, 
as far as we know, these two when crossed would not __ 
be less fertile than the original cross, or than Carrier 
with Carrier. Here, you see, is a physiological con- 
trast between the races produced by selective modifica- 
tion and natural species. I shall inquire into the value  __ 
of this fact, and of some modifying circumstances, by _ 
and by; for the present I merely put it broadly before © 
VOU ae 
But while considering this question of the limita- 
tions of species, a word must be said about what is 
called Recurrence—the tendency of races which have 
been developed by selective breeding from varieties to 
return to their primitive type. This is supposed by 
many to put an absolute limit to the extent of selective 
and all other variations. People say, “It is all very 

well to talk about producing these different races, but 

you know very well that if you turned all these birds 

wild, these Pouters, and Carriers, and so on, they would 

all return to their primitive stock.” This is very com- 
monly assumed to be a fact, and it is an argument that 

is commonly brought forward as conclusive; but if 

you will take the trouble to inquire into it rather closely, 

I think you will find that it is not worth very much. 

The first question of course is, Do they thus return te 


the ccitivees stock? And commonly as the thing is 
assumed and accepted, it is extremely difficult to get 
og ny thing like good evidence of it. It is constantly said, 
F. for example, that if domesticated Horses are turned 
ee: wild, as they have been in some parts of Asia Minor 
_ South America, that they return at once to the 
primitive stock from which they were bred. But the 
_ first answer that you make to this assumption is, to 
_ ask who knows what the primitive stock was; and the 
ineoond answer is, that in that case the wild Horses of 
Asia Minor ought to be exactly like the wild Horses 
of South America. If they are both like the same 
thing, they ought manifestly to be like each other! 
The best authorities, however, tell you that it is quite 
different. The wild Horse of Asia is said to be of a 
‘dun colour, with a largish head, and a great many 
other peculiarities ; while the best authorities on the 
wild Horses of South America tell you that there is 
nothing of this sort in the wild Horses there; the cut 
of their heads is very different, and they are commonly 
chestnut or bay-coloured. It is quite clear, therefore, 
that as by these facts there ought to have been two 
‘primitive stocks, they go for nothing in support of the 
assumption that races recur to one primitive stock, and 
so far as this evidence is concerned, it falls to the 
ground. 

Suppose for a moment that it were so, and that 
domesticated races, when turned wild, did return to 
some common condition, I cannot see that this would 
prove much more than that similar conditions are likely 
to produce similar results; and that when you take 
back domesticated animals into what we call natural 
conditions, you do exactly the same thing as if you 


Me 
+4 - 
‘ 
< 
mw, 
— 
- 
> 


There is an important fact, however, forcibly brou 
forward by Mr. Darwin, which has been noticed — 


connection with the breeding of domesticated pigeons; 


and it is, that however different these breeds of pigeons 


may be froin each other, and we have already noticed 


the great differences in these breeds, that if, among 
any of those variations, you chance to have a blue 


pigeon turn up, it will be sure to have the black bars 


across the wings, which are characteristic of the one ae 


nal wild stock, the Rock Pigeon. 

Nowy; this is certainly a very remarkable cireum- 
stance; but I do not see myself how it tells very 
strongly either one way or the other. I think, in fact, 
that this argument in favour of recurrence to the primi- 
tive type might prove a great deal too much for those 
who so constantly bring it forward. For example, Mr. 
Darwin has very forcibly urged, that nothing is com- 
moner than if you examine a dun horse—and I had an 
opportunity of verifying this illustration lately, while 
in the islands of the West Highlands, where there are 
a great many dun horses—to find that horse exhibit 
along black stripe down his back, very often stripes 
on his shoulder, and very often stripes on his legs. I, 
myself, saw a pony of this description a short time ago, 
in a baker’s cart, near Rothesay, in Bute: it had the 
long stripe down the back, and stripes on the sheulders 


si wh hot Le Thon bad ij 
Ree ae ep eRe eee ees 


ee ee 


111 


and legs, just like those of the Ass, the Quagga, and 
the Zebra. Now, if we interpret the theory of recur- 
rence as applied to this case, might it not be said that 
here was a case of a variation exhibiting the characters 
Be and conditions of an animal occupying something like 
an intermediate position between the Horse, the Ass, 
the Quagga, and the Zebra, and from which these had 
been developed? In the same way with regard even 
to Man. Every anatomist will tell you that there is 
hy nothing commoner, in dissecting the human body, than 

to meet with what are called muscular variations—that 
is, if you dissect two bodies very carefully, you will 
probably find that the modes of attachment and inser- 
tion of the muscles are not exactly the same in both, 
there being great peculiarities in the mode in which 
the muscles are arranged; and it is very singular, that 
in some dissections of the human body you will come 
upon arrangements of the muscles very similar indeed 
to the same parts in the Apes. Is the conclusion in 
that case to be, that this is like the black bars in the 
ease of the Pigeon, and that it indicates a recurrence 
to the primitive type from which the animals have been 
probably developed? ‘Truly, I think that the oppo- 
nents of modification and variation had better leave 
the argument of recurrence alone, or it may prove alto- 
gether too strong for them. 

To sum up,—the evidence as far as we have gone 
is against the argument as to any limit to divergences, 
so far as structure is concerned; and in favour of a 
physiological limitation. By selective breeding we 
can produce structural divergences as great as those 
of species, but we cannot produce equal physiological 
divergences. For the present I leave the question 
there. 


is an ya ae important one—is ee : “Do 
tive breeding occur in nature? Because, if 


nothing in accounting for the origin of species. — 
natural causes competent to play the part of sele 
in perpetuating varieties? Here we labour under 
great difficulties. In the last lecture I had occas 


evidence even of the first origin of those varieties which 
we know to have occurred in domesticated animals. — 
I told you, that almost always the origin of these varie 
ties is overlooked, so that I could only produce two — 
or three cases, as that of Gratio Kelleia and of re 
Ancon sheep. People forget, or do not take notice ee 
them until they come to have a prominence; and if 
that is true of artificial cases, under our own eyes, and — : 
in animals in our own care, how much more difficult _ 5 
it must be to have at first hand good evidence of the ss 
origin of varieties in nature! Indeed, 1 .donot know 
that it is possible by direct evidence to prove the origin s 
of a variety in nature, or to prove selective breeding ; : 
but I will tell you ae we can prove—and this comes 
to the same thing—that varieties exist in nature within 

the limits of species, and, what is more, that when a 
variety has come into existence in nature, there are B 
natural causes and conditions, which are amply com- : 
petent to play the part of a selective breeder; and al- 
though that is not quite the evidence that one would 
like to have—though it is not direct testimony—yet it 
is exceeding good and exceedingly powerful evidence "7 
in its way. 

As to the first point, of varieties existing among 


2 of every scitdealist, and of any person who has 
r turned any attention at all to the characteristics. 
plants and animals in a state of nature; but I may 
well take a few definite cases, and I at begin with 
an himself. 
-I am one of those who believe that, at present, there 
is no evidence whatever for saying, that mankind sprang 
originally from any more than a single pair; I must say, 
tha at I cannot see any good ground whatever, or even 
ned 
jig any tenable sort of evidence, for believing that there 
S is more than one species of Man. Nevertheless, as you 
oe. just as there are numbers of varieties in animals, 
so there are remarkable varieties of men. I speak not 
Fe ipety of those broad and distinct variations’ which 
-- you see at a glance. Everybody, of course, knows the 
3 difference between a Negro and a white man, and can tell 
a Chinaman from-an Englishman. They each have pecu- 
liar characteristics of colour and physiognomy ; but you 
must recollect that the characters of these races go very 
far deeper—they extend to the bony structure, and to 
the characters of that most important of all organs to 
us—the brain ; so that, among men belonging to differ- 
ent races, or even within the same race, one man shall 
have a brain a third, or half, or even seventy per cent. 
bigger than another; and if you take the whole range 
of human brains, you will find a variation in some cases 
of a hundred per cent. Apart from these variations 
in the size of the brain, the characters of the skull vary. 
Thus if I draw the figures of a Mongul and a Negro 
head on the blackboard, in the case of the last the 
breadth would be about seven-tenths, and in the other 
it would be nine-tenths of the total length. So 


pet 


a 
a WY 
my 


that you see there is abundant Fires 
eros eet in their natural condition. 


mostly large foxes in tive North, and ee one 
the South. In Germany alone, the foresters reck re 
some eight different sorts. 

Of the tiger, no one supposes that there is more than 
one species; they extend from the hottest parts of 
Bengal, into the dry, cold, bitter steppes of Siberia, 
into a latitude of 50°,—so that they may even prey 
upon the reindeer. These tigers have exceedingly dif 
ferent characteristics, but still they all keep their gen- _ 
eral features, so that there is no doubt as to their being 
tigers. The Siberian tiger has a thick fur, a small — 
mane, and a longitudinal stripe down the back, while © 
the tigers of Java and Sumatra differ in many impor- 
tant respects from the tigers of Northern Asia. So 
lions vary; so birds vary; and so, if you go further 
back and lower down in creation, you find fishes vary. 
In different streams, in the same country even, you 
will find the trout to be quite different to each other 
and easily recognizable by those who fish in the par- 
ticular streams. There is the same differences in 
leeches; leech collectors can easily point out to you 
the differences and the peculiarities which you your- 
self would probably pass by ; so with fresh-water mus- 
sels; so, in fact, with every animal you can mention. 

In plants there is the same kind of variation. Take 
such a case even as the common bramble. The bota- 
nists are all at war about it; some of them wanting to 


a ee | 
Fae, oe, eee = 


q. 


_ a tT SE - +20" ", ia eke yt es AA f 
Ee OPES: gry ot EES, a Meee ey eee eae 


§ 


Nie 


se and they cannot settle to this day which is a 
species and which is a variety! 


So that there can be no doubt whatsoever that any 
_ plant and any animal may vary in nature; that varie- 


ties may arise in the way I have described,—as sponta- 


neous varieties,—and that those varieties may be per- 
_ petuated in the same way that I have shown you 


fe spontaneous varieties are perpetuated ; I say, therefore, 


that there can be no doubt as to the origin and per- 
petuation of varieties in nature. 

But the question now is :—Does selection take place 
in nature? is there anything like the operation of man 
in exercising selective breeding, taking place in nature ¢ 
You will observe that, at present, I say nothing about 
species; I wish to confine myself to the consideration 
of the production of those natural races which every- 
body admits to exist. The question is, whether in na- 
ture there are causes competent to produce races, just 
in the same way as man is able to produce, by selec- 
tion, such races of animals as we have already noticed. 

When a variety has arisen, the Conprrions or Exist- 
ENCE are such as to exercise an influence which is 
exactly comparable to that of artificial selection. By 
Conditions of Existence I mean two things,—there are 
conditions which are furnished by the physical, the in- 
organic world, and there are conditions of existence 
which are frenichod by the organic world. There is, 
in the first place, Crmate; under that head I in- 
clude only temperature and the varied amount of 
moisture of particular places. In the next place 
there is what is technically called Srarion, which 


is in the sea, and a marine ee may ae a st 
higher or deeper. So again with land animals: t 


calcareous, and others to an arenaceous soil. Tl 
third condition of existence is Foop, by which I me: 


case of a plant the Inorganic matters, such as ; carbonic : 
acid, water, ammonia, and the earthy salts or salines ;_ | 
in. the ease of the ed the inorganic and organic 

matters, which we have seen they require; then these 
are all, at least the two first, what we may call the 
inorgani¢. or physical conditions of existence. Food — 

takes a mid-place, and then come the organic condi- 
tions; by which I mean the conditions which depend 
upon the state of the rest of the organic creation, upon 
the number and kind of living beings, with which an 
animal is surrounded. You may class these under two 
heads: there are organic beings, which operate as 
opponents, and there are organic beings which operate 
as helpers to any given organic creature. The oppo- 
nents may be of two kinds: there are the indurect op- 
ponents, which are what we may call rivals ; and there 
are the direct opponents, those which strive to destroy 
the creature ; and these we call enemies. By rivals I 
mean, of course, in the case of plants, those which 
require for their support the same kind of soil and 
station, and, among animals, those which require the 


- > 
g: 
4 : 


PERPETUATION OF LIVING BEINGS. 417 


me kind of station, or food, or climate ; those are the 
‘indirect opponents ; the direct opponents are, of course, 
those which prey upon an animal or vegetable. The 
___ helpers may also be regarded as direct and indirect: in 
____the case of a carnivorous animal, for example, a particu- 
Jar herbaceous plant may in multiplying be an indirect 
helper, by enabling the herbivora on which the carni- 
__—-yore preys to get more food, and thus to nourish the 
__ earnivore more abundantly ; the direct helper may be 
a best illustrated by reference to some parasitic creature, 

such as the tape-worm. The tape-worm exists in the 
human intestines, so that the fewer there are of men 
_ the fewer there will be of tape-worms, other things 
being alike. It is a humiliating reflection, perhaps, 
that we may be classed as direct helpers to the tape- 
worm, but the fact is so: we can all see that if there 
were no men there would be no tape-worms. 

It is extremely difficult to estimate, in a proper way, 
the importance and the working of the Conditions of 
Existence. I do not think there were any of us who 
had the remotest notion of properly estimating them 
until the publication of Mr. Darwin’s work, which has 
placed them before us with remarkable clearness ; and 
I must endeavour, as far as I ean in my own fashion, to 
give you some notion of how they work. We shall find 
it easiest to take a simple case, and one as free as possi- 
ble from every kind of complication. 

I will suppose, therefore, that all the habitable part of 
this globe—the dry land, amounting to about 51,000,000 
square miles,—I will suppose that the whole of that dry 
land has the same climate, and that it is composed of 
the same kind of rock or soil, so that there will be the 


single plant, with no opponents, no tape aa n¢ 


rivals ; it is to be a “ fair field and no favour.” Now, 


I will ask you to imagine further that it shall be a ee 
which shall produce every year fifty seeds, which is a 

very moderate number for a plant to produce; aa 
that, by the action of the winds and currents, these 
pecs shall be equally and gradually distributed over the — 
whole surface of the land. I want you now to trace 
out what will occur, and you will observe that I am not 
talking fallaciously any more than a mathematician 
does when he expounds his problem. If you show that 
the conditions of your problem are such as may actually 
occur in nature, and do not transgress any of the known 
laws of nature in working out your proposition, then 
you are as safe in the conclusion you arrive at, as is the 
mathematician in arriving at the solution of his problem. 
In science, the only way of getting rid of the complica- 


tions with which a subject of this kind is environed, is 


to work in this deductive method. What will be the 
result then? I will suppose that every plant requires 
one square foot of ground to live upon ; and the result 
will be that, in the course of nine years, the plant will 
have occupied every single available spot in the whole 
globe! Ihave chalked upon the blackboard the figures 
by which I arrive at the result :— 


4 i 


Ret ee Se ee 


ond ee , res. Ss 

cA 7. a+. whe ae - 4 
bP tome fairs ae he ald Ney Se Say Son “i el eo 
bt ee Diet hae ; 5 ¢ nite ye 


PERPETUATION OF LIVING 


Plants. Plants. 

1 x 50 in 1st year = 50 

a eepo : Sed oe 2,500 

Sees CO" Sta 8 = 125,000 

125,000 x 50 “ 4th “ = 6,250,000 
6,250,000 x 50 “ Sth “ = 312,500,000 
312,500,000 x 50 “ 6th “ = 15,625,000,000 
15,625,000,000 x 50 “ Tth “ = 781,250,000,000 
781,250,000,000 x 50 “ 8th “ =  — 39,062,500,000,000 


89,062,500,000,000 x 50 “ 9th « 1,953,125,000,000,000 


im 51,000,000 sq. miles—the dry sur- 


i: face of the earth x 27,878,400— =sq. ft. 1,421,798,400,000,000 
- the number of sq. ft. in 1 sq. mile re 
being 531,326,600,000,009 
square feet less than would be required at the end of the ninth year. 

You will see from this that, at the end of the first 
_ year the single plant will have produced fifty more of its 
kind ; by the end of the second year these will have 
increased to 2,500; and so on, in succeeding years, you 
get heyond even trillions ; and I am not at all sure that 
I could tell you what the proper arithmetical denomina- 
tion of the total number really is; but, at any rate, you 
will understand the meaning of all those noughts. 
Then you see that, at the bottom, I have taken the 
51,000,000 of square miles, constituting the surface of 
the dry land; and as the number of square feet are 
placed under and abstracted from the number of seeds 
that would be produced in the ninth year, you can see 
at once that there would be an immense number more 
of plants than there would be square feet of ground for 
their accommodation. This is certainly quite enough 
to prove my point ; that between the eighth and ninth 
year after being planted, the single plant would have 
stocked the whole available surface of the earth. 

This is a thing which is hardly conceivable —it seems 


—and although he was much ‘bneed for his ie 
at the time, they have never yet been disprove 
never will be—he showed that in consequence ¢ 
increase in the number of organic beings in a geomet 
cal ratio, while the means of existence cannot be 
to increase in the same ratio, that there must com 
time when the number of organic beings will be in © 
excess of the power of production of nutriment, = at 


those organic beings. At the end of the a year 1 we % 
have seen that het plant would not be able to get its 
full square foot of ground, and at the end of another — 
year it would have to share that space with fifty others 
the produce of the seeds which it would give off. © 

What, then, takes place? Every plant grows up, 
flourishes, occupies its square foot of ground, and gives 
off its fifty seeds ; but notice this, that out of this num- & 
ber only one can come to anything; there is thus, asit 
were, forty-nine chances to one against its growing up; 
it depends upon the most fortuitous circumstances 
whether any one of these fifty seeds shall grow up and 
flourish, or whether it shall die and perish. Thisis 
what Mr. Darwin has drawn attention to, and calledthe 
“SrruGGLE FoR Existence;” and I have taken this 
simple case of a plant because some people imagine that _ 
the phrase seems to imply a sort of fight. 

I have taken this plant and shown you that this is 
the result of the ratio of the increase, the necessary re- 
sult of the arrival of a time coming for every species 


a» __ PERPETUATION OF LIVING BEINGS. 121 
4 Gua 


when Rekselly as many members must be destroyed as 
are: born ; that is the inevitable ultimate result of the 
Trace of ptodection Now, what is the result of all this? © 
a have said that there are forty-nine struggling against 
ev ery one; and it amounts to this, that the ciate 
a possible Bact given to any one seed may give it an 
Derehtare which will enable it to get ahead of all the 
oe others ; anything that will enable any one of these seeds 
# to, germinate six hours before any of the others will, 
| othe things being alike, enable it to choke them out 
altogether. I have ae you that there is no particu- 
lar in which plants will not vary from each other ; it is 
quite possible that one of our imaginary plants may 
_ vary in such a character as the thickness of the integu- 
ment of its seeds. It might happen that one of the 
plants might produce seeds having a thinner integu- 
: - ment, and that would enable the seed of that plant | to 
germinate a little quicker than those of any of the 
i others, and those seeds would most inevitably extin- 
- guish the forty-nine times as many that were strug- 
gling with them. 

Ihave put it in this way, but you see the practical 
result of the process is the same as if some person had 
nurtured the one and destroyed the other seeds. It does 
hot matter how the variation is produced, so long as it 
is once allowed to oceur. The variation in the: plant 
once fairly started, tends to become hereditary and 
reproduce itself’; as seeds would spread themselves in 
the same way sud take part in the struggle with the 
forty-nine hundred, or forty-nine thousand, with which 
they might be ee teeed: Thus, by degrees, this variety, 
with some slight organic change or pianlifineic: he 
spread itself over the whole surface of the Rebiishig 

6 


122 CONDITIONS AFFECTING THE 


globe, and extirpate or replace the other kinds. That 


is what is meant by Naruran Sexzcrion; that isthe 


kind of argument by which it is perfectly demonstrable 
that the conditions of existence may play exactly the 
same part for natural varieties as man does for domesti- 
cated varieties. No one doubts at all that particular 
circumstances may be more favorable.for one plant and 
less so for another, and the moment you admit that, you 
admit the selective power of nature. Now, although I 
have been putting a hypothetical case, you must not 
suppose that I have been reasoning hypothetically. 
There are plenty of direct experiments which bear out 
what we may call the theory of natural selection ; there 
is extremely good authority for the statement that if you 
take the seed of mixed varieties of wheat and sow it, 
collecting the seed next year and sowing it again, at 
length you will find that out of all your varieties, only 
two or\three have lived, or perhaps even only one. 
There were one or two varieties which were best fitted 
to get on, and they have killed out the other kinds in 
just the same way and with just the same certainty as 
if you had taken the tronble to remove them. As I 
have already said, the operation of nature is exactly the 
same as the artificial operation of man. 

But if this be true of that simple case, which I put 
before you, where there is nothing but the rivalry of one 
member of a species with others, what must be the 
operation of selective conditions, when you recollect as 
a matter of fact, that for every species of animal or 
plant there are fifty or a hundred species which might 
all, more or less, be comprehended in the same climate, 
food, and station ;—that every plant has multitudinous 
animals which prey upon it, and which are its direct 


a ponents ; and that these hate other animals preying 

tip. on them, ,—that every plant has its indirect helpers in 
; - the birds that scatter abroad its seed, and the animals - 
4 that manure it with their dung ;—I say, when these 
things are considered, it seems impossible that any 
_ variation which may arise in a species in nature should 
: 4 not tend in some way or other, either to be a little 
_ better or worse than the previous stock: if it is a little 
___ better it will have an advantage over and tend to extir- 
§ pate the latter in this crush and struggle; and if it is « 
little worse it will itself be extirpated. 

____I know nothing that more appropriately expresses 
ioe this, than the phrase, “ the struggle for existence ; ” be- 
ES cause it brings before your minds, in-a vivid sort of 
‘way, some of the simplest possible circumstances con- 
nected with it. When a struggle is intense, there must 
___ be some who are sure to be trodden down, crushed, and 
overpowered by others; and there will be some who 
just manage to get through only by the help of the 
slightest accident. I recollect reading an account of the 
famous retreat of the French troops, under Napoleon, 
from Moscow. Worn out, tired, and dejected, they at 
length came to a great river over which there was but 
one bridge for the passage of the vast army. Disorgan- 
iged and demoralized as it was, the struggle must cer- 
tainly have been a terrible one—everyone heeding only 
himself, and crushing through and treading down his 
fellows. The writer of the narrative, who was himself 
one of those who were fortunate enough to succeed in 
getting over, and not among the thousands who were 
left behind or forced into the river, ascribed his escape 
to the fact that he saw striding onward through the 
mass a great strong fellow,—one of the French Cuiras- 


ew 


124 CONDITIONS AFFECTING THE 


siers, who had on a large blue cloak—and he had 
enough presence of mind to catch and retain a hold of 
this strong man’s cloak. He says, “I caught hold of 
his cloak, and although he swore at me and cut at and 
struck me by turns, and at last, when he found he could 
not shake me off, fell to entreating me to leave go or I 
should prevent him from escaping, besides not assisting 
myself, I still kept tight hold of him, and would not 
quit my grasp until he had at last dragged me through.” 
Here you see was a case of selective saving—if we may 
so term it—depending for its success on the strength of 
the cloth of the Cuirassier’s cloak. It is the same in 
nature ; every species has its Beresina; it has to fight 
its way through and struggle with other species; and 
when well nigh overpowered, it may be that the 
smallest chance, something in its colour, perhaps—the 
minutest circumstance—will turn the scale one way or 
the other. 

Suppose that by a variation of the black race it had 
produced the white man at any time—you know that 
the Negroes are said to believe this to have been the 
case, and to imagine that Cain was the first white man, 
and that we are his descendants—suppose that this had 
ever happened, and that the first residence of this 
human being was on the West Coast of Africa. There 
is no great structural difference between the white man 
and the Negro, and yet there is something so singularly 
different in the constitution of the two, that the malarias 
of that country, which do not hurt the black at all, eut 
off and destroy the white, thus you see there would 
have been a selective operation performed. If the white 
man had risen in that way, he would have been selected 
out and removed by means of the malaria. Now there 


ys Lee a ot oo leas “asf J , 
oe Me nt fe ae aie iin, 


io 


i. & : 
Aa —~ heal | 


wa ; ooo ' abe Se ey EN, Pi hs y; :? _ >? 7 ~ re = ay. 
-— as 7 rae ~ : . ws 
_ PERPETUATION OF LIVING BEINGS. 125 


mong pigs, and it is a case of selection of colour, too. 

In the woods of Florida there are a great many pigs,” 

and it is a very curious thing that they are all black, 

ci every one of them. Professor Wyman was there some 
years ago, and on noticing no pigs but these black ones, 
he asked some of the people how it was that they 

a had no white pigs, and the reply was that in the woods 

of Fiorida there was a root which they called the 

Paint Root, and that it the white pigs were to eat any 

of it, it had the effect of making their hoofs crack, and 

_ they died, but if the black pigs eat any of it, it did not 

hurt them at all. Here was a very simple case of 

natural selection. A skilful breeder could not more 
carefully develop the black breed of pigs, and weed out 

S all the white pigs, than the Paint Root does. 

PN To show you how remarkably indirect may be such 
natural selective agencies as I have referred to, I will 
conclude by noticing a case mentioned by Mr. Darwin, 

and which is certainly one of the most curious of its 
kind. It is that of the Humble Bee. It has been 
noticed that there are a great many more humble bees 
in the neighbourhood of towns, than out in the open 
country ; and the explanation of the matter is this: the 
humble bees build nests, in which they store their honey 
and deposit the larvee and eggs. The field mice are 
amazingly fond of the honey and larve; therefore, 
wherever there are plenty of field mice, as in the coun- 
try, the humble bees are kept down; but in the neigh- 
bourhood of towns, the number of cats which prowl 
about the fields eat up the field mice, and of course the 
more mice they eat up the less there are to prey upon 
the larvee of the bees—the cats are therefore the npr 


126 CONDITIONS, ETO. 


RECT HELPERS Of the bees.* Coming back a step farther 
we may say that the old maids are also indirect friends 
of the humble bees, and indirect .enemies of the field 
mice, as they keep the cats which eat up the latter! 
This is an illustration somewhat beneath the dignity of 
the subject, perhaps, but it occurs to me in passing, and 
with it I will conclude this lecture. 


* The humble bees, on the other hand, are direct helpers of 
some plants, such as the heartsease and red clover, which are 
fertilized by the visits of the bees; and they are indirect helpers 
of the numerous insects which are more or less completely sup- 
ported by the heartsease and red clover. 


LECTURE VI. 


\ ORITICAL EXAMINATION OF THE POSITION OF 
MR. DARWIN’S WORK, “ON THE ORIGIN OF 
SPECIES,” IN RELATION TO THE COMPLETE 
THEORY OF THE CAUSES OF THE PHENOME- 

_ NA OF ORGANIC NATURE. 


In the preceding five lectures I have endeavoured to 
give you an account of those facts, and of those reason- 


ings from facts, which form the data upon which all 


theories regarding the causes of the phenomena of or- 
ganic nature must be based. And, although I have had 
frequent occasion to quote Mr. Darwin—as all persons 
hereafter, in speaking upon these subjects, will have 
occasion to quote his famous book on the “ Origin of 
Species,’—you must yet remember that, wherever I 
have quoted him, it has not been upon theoretical 
points, or for statements in any way connected with his 
particular speculations, but on matters of fact, brought 
forward by himself, or collected by himself, and which 
appear incidentally in his book. If a man will make 
a book, professing to discuss a single question, an en- 
eyclopzedia, I cannot help it. 

Now, having had an opportunity of considering in 
this sort of way the different statements bearing upon 
all theories whatsoever, I have to-night to lay before 


LT have already stated to you that the inquiry 1 
ing the causes of the phenomena of organic nat 
solves itself into two problems—the first be 
ee of the a of ee or organic 


ter—supposing its creation to have already taken place 
my object is to show in consequence of what laws anc 
what demonstrable properties of organic matter, and of | 
its environments, such states of organic nature as those 
with which we are acquainted must have come about. 
This, you will observe, is a perfectly legitimate propo- 
sition ; every person has a right to define the limits of 
the i eerie which he sets before himself; and yet itis 
a most singular thing that in all the rmuilthfereae and 
not een: ignorant attacks which have been nae 
upon the “ Origin of Species,” there is nothing which has _ 
been more speciously criticised than this particular limi- 
tation. If people have nothing else to urge against the 
book, they say—“ Well, after all, you see Mr. Darwin’s 
explanation of the ‘ Origin of Species’ is not good for 
much, because, in the long run, he admits that he does 
not know how organic matter began to exist. But if 
you admit any special creation for the first particle of 
organic matter you may just as well admit it for all the 
rest; five hundred or five thousand distinct creations 


an t s “ ae ee aye 
ry iS aa ‘ Se eS eet rt 
5 oe ee Jae N ", ye oa 
me im ¥ #5 bra ) Ng al es 
> mS” 4 a? eo Ee. — : > e 


ta 


el 


5g Ole 
oe 


bg ye. ~~ ~ 4 
ey = af 
, P ‘ a 


Me os . | 
mag THE: PHENOMENA OF ORGANIC NATURE. 129 
are | nist as rues, and just as little difficult to 
understand, as one.” ‘The answer to these cavils is 
it wo-fold. Ta the first place, all human inquiry must- 
~ stop somewhere ; all our knowledge and all our inves- 
i _ tigation cannot ‘aks us beyond the limits set by the 
inite and restricted character of our faculties, or de- 
~ atroy the endless unknown, which accompanies, like 
its shadow, the endless procession of phenomena. So 
ay as I can venture to offer an opinion on such a 
_ matter, the purpose of our being in existence, the 
ee - highest object that human beings can set before then 
selves, is not the pursuit of any such chimera as the 

annihilation of the unknown; but it is simply the un- 

wearied endeavour to ware its boundaries a little 


te 
oon 
ig 
ae 


a 
a 
a 


further from our little sphere of action. 
_-—sCT wonder if any historian would for a moment admit 
om the objection, that it is preposterous to trouble ourselves 
about the history-of the Roman Empire, because we do 


not know anything positive about the origin and first 
building of the city of Rome! Would it be a fair ob- 
jection to urge respecting the sublime discoveries of a 
Newton, or a Kepler, those great philosophers, whose 
discoveries have been of the profoundest benefit and 
service to all men,—to say to them—“ After all that 
you have told us as to how the planets revolve, and how 
they are maintained in their orbits, you cannot tell us 
what is the cause of the origin of the sun, moon, and 
stars. So what is the use of what you have done?” 
Yet these objections would not be one whit more pre- 
posterous than the objections which have been made to 
the “Origin of Species.” Mr. Darwin, then, had a 
perfect right to limit his inquiry as he pleased, and the 
only question for us—the inquiry being so limited—is 
6* 


- Get 5 Hs = 
Ones 2 Ls — 
- é é, ¥ a —— 
: 4 fhe, 
‘ <i 
> ‘< - .. , 
. 
‘ 


must nee and govern all investigation, ¢ or 
has broken them ; and it was because our i 


employed) in endeavouring to illustrate the. Bere 
nature of scientific inquiry in general. We shall no 
have to put in practice the principles that I then 1 
down. oa 
I stated to you in substance, ee not in nee t 
wherever there are complex masses of phenomena to be 
inquired into, whether they be phenomena of the affair 
of daily life, or whether they belong to the more abstruse 
and difficult problems laid before the philosopher, our 
course of proceeding in unravelling that complex chain 
of phenomena with a view to get at its cause, is always 
the same; in all cases we must invent a hypothesis; we 
must place before ourselves some more or less likely 
supposition respecting that cause; and then, having 
assumed a hypothesis, having ee: 2 cause for the 
phenomena in question, we must endeavour, onthe one _ 
hand, to demonstrate our hypothesis, or, on the other, to. 
upset and reject it altogether, by testing it in three 
ways. We must, in the first place, be prepared to 
prove that the supposed causes of the phenomena 
exist in nature; that they are what the logicians 
call vera cause—true causes ;—in the next place, we __ 
should be prepared to show that the assumed causes of 
the phenomena are competent to produce such pheno- 
mena as those which we wish to_explain by them; and 
in the last place, we ought to be able to show that no- 


a ae ss 


‘THE PHENOMENA OF ORGANIC NATURE. 131 


other beter causes are competent to produce these 
_ phenomena. If we can succeed in satisfying these 
i _ three conditions, we shall have demonstrated our hypo- 
thesis ; or ifiee T ought to say, we shall have proved 
ie it as far as certainty is possible for us; for, after all, 
there is no one of our surest convictions whish may not 
; be upset, or at any rate modified by a further accession 
of knowledge. It was because it satisfied these con- 
ditions that we accepted the hypothesis as to the dis- 
| oe _ appearance of the tea-pot and spoons in the case I sup- 
‘a posed in a previous lecture; we found that our hypo- 
thesis on that subject was iehable and valid, because 
* the supposed cause existed in nature, fecanse it was 
- - competent to account for the phenomena, and because 
no other known cause was competent to account for 
R them ; and it is upon similar grounds that any hypo- 
thesis you choose to name is accepted in science as 
tenable and valid. 

What is Mr. Darwin’s hypothesis? A I apprehend 
it—for I have put it into a shape more convenient for 
common purposes than I could find verbatim in his book 
—as | apprehend it, I say, it is, that all the phenome- 
na of organic nature, past and present, result from, 

_or are caused by, the inter-action of those properties of 
organic matter, which we have called Aravism and 
Variasitity, with the Conprrions or Existence ; or, 
in other words,—given the existence of organic matter, 
its tendency to transmit its properties, and its tendency 
occasionally to vary ; and, lastly, given the conditions 
of existence by which organic matter is surrounded— 
that these put together are the causes of the Present 
and of the Past conditions of Organic Nature. 

Such is the hypothesis as I understand it. Now 


en us see ay ee it will stand the y various es 
down just now. In the first | place, do ae 


to prove that they do ine and I take it ihe ‘em 
abundant evidence that they do exist ; so far, therefor 
the hypothesis does not break down. | | 

But in the next place comes a much more diffi 
inquiry :—Are the causes indicated competent to giv 
rise to the phenomena of organic nature? I suspec 
that this is indubitable to a certain extent. It is de- 
monstrable, I think, as I have endeavoured to show 
you, that they are portent competent to give rise to all 
the phenomena which are exhibited by Races in nature. — 
Furthermore, I believe that they are quite competent 
to account for all that we may call purely structural 
phenomena which are exhibited by Spxcixs in nature. 
On that point also I have already enlarged somewhat. 
Again, I think that the causes assumed are competent 
to account for most of the physiological characteristics 
of species, and I not only think that they are competent 
to account for them, but I think that they account for 
many things which otherwise remain wholly unaccount- 
able and inexplicable, and I may say incomprehensible. 
For a full exposition of the grounds on which this con- 
viction is based, I must refer you to Mr. Darwin’s 
work ; all that I can do now is to illustrate what I have 
said by two or three cases taken almost at random. 


Mira> 4 ae 
wi oat 
SO, a gs 


Ps 


Be Th eee 
a er San ee 


ile 


ay 


¥ vt Pras i 


é'” 


oe, 


Se re mmesoxesa OF ORGANIC NATURE. 133 


— 


dr ow ‘your attention, on a previous evening, to the 
: which are embodied in our systems of Classifi- 


parison of the different members of the animal 
| agdom one det another. fi! mentioned that the 


Bedieca: ; that ack of these sub-kingdoms is again 
: dixisible into provinces; that each province may be 
livided into classes, and the classes into the successively 
smaller groups, orders, families, genera, and species. 
ea? Now, i in each of these groups, the resemblance in 
Pecatiure among the members of the group is closer in 
_ proportion as ig group is smaller. Thus, a man and 
a worm are members of the animal itidcay 3 in virtue 
of certain apparently slight though ripllt fundamental 
resemblances which shay present. But a man and a 
fish are members of the same Sub-kingdom Vertebrata, 
because they are much more like one another than 
either of them is to a worm, or a snail, or any member 
of the other sub-kingdoms. For similar reasons men 
and _horses are arranged as members of the same Class, 
na Mammalia ; men and apes as members of the same 
“= » Order, Pan aias ; and if there were any animals more 
like men than they were like any of the apes, and yet 
different from men in important and constant particu- 
lars of their organization, we should rank them as 
‘members of the same Family, or of the same Genus, 
but as of distinct Species. 

That it is possible to arrange all the varied forms of 
animals into groups, having this sort of singular subor- 
dination one to the other, is a very remarkable circum- 
stance; but, as Mr. Darwin remarks, this is a result 
which is quite to be expected, if the principles which he 


which are the results of the examination ard_ 


» 


134 MR. DARWIN’S WORK AND 


lays down be correct. Take the case of the races which — 


are known to be produced by the operation of atavism 
and variability, and the conditions of existence which 
check and modify these tendencies. Take the case of 
the pigeons that I brought before you: there it was 
shown that they might be all classed as belonging to 
some one of five principal divisions, and that within 
these divisions other subordinate groups might be 
formed. The members of these groups are related to 
one another in just the same way as the genera of a 
family, and the groups themselves as the families of an 
order, or the orders of a class; while all have the same 
sort of structural relations with the wild Rock-pigeon, 
as the members of any great natural group have with a 
real or imaginary typical form. Now, we know that 
all varieties of pigeons of every kind have arisen by a 
process of selective breeding from a common stock, the 


Rock-pigeon ; hence, you see, that if all species of ani- — 


mals have proceeded from some common stock, the gen- 
eral character of their structural relations, and of our 
systems of classification, which express those relations, 
would be just what we find them to be. In other 
words, the hypothetical cause is, so far, competent to 
produce effects similar to those of the real cause. 

Take, again, another set of very remarkable facts,— 
the existence of what are called rudimentary organs, 
organs for which we find no obvious use, in the par- 
ticular animal economy in which they are found, and 
yet which are there.. 

Such are the splint-like bones in the leg of the 
horse, which I here show you, and which correspond 
with bones which belong to certain toes and fingers 
in the human hand and foot. In the horse you see 


£ P AW ie =* 
* +i ea) in 7 Sree 
. ate bie ane. ak) a , 
Pee eee FF eee 


. r. eh ate es on val 
bets - _ a ate os , Nha 


ex 


wee A so 
~ ay ee » e 
5 A ; es te 


igh THE B PHENOMENA « OF ORGANIC NATURE. 135 


, 2 quite rudimentary, and bear neither toes nor 
ers; so that the horse has only one “finger” in 
s fore-foot and one “toe” in his hind-foot. But it 
pt is a very curious thing that the animals closely allied - 
to the horse show more toes than he ; as the rhinoceros, 
for ‘instance: he has these extra tbe well formed, and © 
~ anatomical facts show very clearly that he is very closely 
_ related to the horse indeed. So we may say that ani- 
| nal in an anatomical sense nearly related to the 
: horse, have those parts which are rudimentary in him, 
| ©. filly developed. 
a ey _ Again, the sheep and the cow have no cutting-teeth, 
i. but only a hard pad in the upper jaw. That. is the 
~ common characteristic of ruminants in gencral. But 
= Sia calf has in its upper jaw some rudiments of teeth 
~ which never are developed, and never play the part 
of teeth at all. Well, if you go back in time, you find 
some of the older, now extinct, allies of the ruminants 
have well-developed teeth in their upper jaws; and at 
the present day the pig (which is in structure closely 
k connected with ruminants) has well-developed teeth in 
3 its upper jaws; so that here is another instance of 
a _ organs well developed and very useful, in one animal, 
__- represented by rudimentary organs, for which we can 
discover no purpose whatsoever, in another closely 
: allied animal. The whalebone whale, again, has horny 
“whalebone” plates in its mouth, and no teeth; but 
the young fcetal whale, before it is born, has teeth in 
its jaws ; they, however, are never used, and they never 
come to-anything. But other members of the group to 
which the whale belongs have well-developed teeth in 
both jaws. 
Upon any hypothesis of special creation, facts of this 


mouth both sprang from a whale that had t : 

that the teeth of the foetal whale are merely r 
—recollections, if we may so say—of the extine 
So in the case of the horse and the rhinoceros: sw 

that both have descended by modification from some 

earlier form which had the normal number of toes, and — 
the persistence of the rudimentary bones which no 
longer support toes in the horse becomes com 
hensible. : 

In the language that we speak in England, anil in 
the language of the Greeks, there are identical verbal 
roots, or elements entering into the composition of 
words. The fact remains unintelligible so long as we — 
suppose English and Greek to be independently created — 
tongues; but when it is shown that both languages aren” ag 
descended from one original, the Sanscrit, we give an 
explanation of that resemblance. In the same way the 
existence of identical structural roots, if I may so term — . 
them, entering into the composition of widely different 
ee is striking evidence in favour of the descent 
of those animals from a common original. 

To turn to another kind of illustration :—If you 
regard the whole series of stratified rocks—that enor- 
mous thickness of sixty or seventy thousand feet that 
I have mentioned before, constituting the only record 
we have of a most prodigious lapse of time, that time 
being, in all probability, but a fraction of that of which 
we have no record ;—if you observe in these successive _ 
strata of rocks successive groups of animals arising and 


m2 eee 
er oe ia 


HE P. NOMENA OF ORGANIC NATURE. 137 era 


ae OS feng ey 
- . wes 
pce ae, 

ee = _ 


A a constant succession, giving you the same ~ 


Ps 


nd of impression, as you travel from one group of 
‘to another, as you would have in travelling from ~ 


Sie 


eo to another ;—when you find this constant 


= and ask eat it means, it is only a paltering 
words if you are offered the reply,—‘‘ They were 


ie But if, on the other hand, you look on all forms of 
ganized beings as the results of the —— modifi- 


= 6 you see that these alder conditions are the necessary 
ae predecessors of the present. Viewed in this light the 

facts of paleontology receive a meaning —upon any 
= - other hypothesis, I am unable to see, in the slightest 
— degree, what knowledge or signification we are to ; draw 

: ta out of them. Again, note as bearing upon the same 
point, the singular likeness which ébtains between the 
successive Faun and I'lore, whose remains are pre- 
served on the rocks: you never find any great and 
enormous difference between the immediately successive 

_ Faunee and Florz, unless you have reason to believe 
there has also been a great lapse of time or a great 
change of conditions. The animals, for instance, of the 
newest tertiary rocks, in any part of the world, are 
always, and without exception, found to be closely allied 
with those which now live in that part of the world. 
For example, in Europe, Asia, and Africa, the large 
mammals are at present rhinoceroses, hippopotamuses, 
elephants, lions, tigers, oxen, horses, &c.; and if you 
examine the newest tertiary deposits, which contain the 
animals and plants which immediately preceded those 


138 MR. DARWIN’S WORK AND 


which now exist in the same country, you do not find 


gigantic specimens of ant-eaters and kangaroos, but you ~ 


find rhinoceroses, elephants, lions, tigers, &c.,—of differ- 
ent species to those now living,—but still their close 
allies. If you turn to South America, where, at the 


present day, we have great sloths and armadilloes and 


creatures of that kind, what do you find in the newest 
tertiaries? You find the great sloth-like creature, the 
Megatherium, and the great armadillo, the Glyptodon, 
and soon. And if you go to Australia you find the 
same law holds good, namely, that that condition of or- 


ganic nature which has preceded the one which now — 


exists, presents differences perhaps of species, and. of 
genera, but that the great types of organic structure 
are the same as those which now flourish. 

What meaning has this fact upon any other hypo- 
thesis or supposition than one of successive modifica- 
tion? But if the population of the world, in any age, 
is the result of the gradual modification of the forms 
which peopled it in the preceding age,—if that has been 
the case, it is intelligible enough ; because we may ex- 
pect that the creature that results from the modification 
of an elephantine mammal shall be something like an 
elephant, and the creature which is produced by the 
modification of an armadillo-like mammal shall be like 
an armadillo. Upon that supposition, I say, the facts 
are intelligible; upon any other, that I am aware of, 
they are not. 

So far, the facts of paleontology are consistent with 
almost any form of the doctrine of progressive modifi- 
cation ; they would not be absolutely inconsistent with 
the wild speculations of De Maillet, or with the less 
objectionable hypothesis of Lamarck. But Mr. Dar- 


THE PHENOMENA OF ORGANIC NATURE. 39 


win’s views have one peculiar merit ; and that is, that 
they are perfectly consistent with an array of facts which 
are utterly inconsistent with and fatal to, any other 
hypothesis of progressive modification which has yet 
been advanced. It is one remarkable peculiarity of 
Mr. Darwin’s hypothesis that it involves no necessary 
progression or incessant modification, and that it is 
perfectly consistent with the persistence for any length 
of time of a given primitive stock, contemporaneously 
with its modifications. To return to the case of the 
domestic breeds of pigeons, for example ; you have the 
Dove-cot pigeon, which closely resembles the Rock 
pigeon, from which they all started, existing at the 
same time with the others. And if species are devel- 
oped in the same way in nature, a primitive stock and 
its modifications may, occasionally, all find the con- 
ditions fitted for their existence; and though they 
come into competition, to a certain extent, with one 
another, the derivative species may not necessarily ex- 
tirpate the primitive one, or vice versa. 

Now palzontology shows us many facts which are 
pertectly harmonious with these observed efiects of the 
process by which Mr. Darwin supposes species to have 
originated, but which appear to me to be totally in- 
consistent with any other hypothesis which has been 
proposed. There are some groups of animals and 
plants, in the fossil world, which have been said to 
belong to “persistent types,’ because they have per- 
sisted, with very little change indeed, through a very 
great range of time, while everything about them has 
changed largely. There are families of fishes whose 
type of construction has persisted all the way from the 
carboniferous rock right up to the cretaceous; and 


140 MR. DARWIN’S WORK AND 


others which have lasted through almost the whole 
range of the secondary rocks, and from the lias to the 
older tertiaries. It is something stupendous this—to 
consider a genus lasting without essential modifications 
through all this enormous lapse of time while almost — 
everything else was changed and modified. 

Thus I have no doubt that Mr. Darwin’s hypothesis 
will be found competent to explain the majority of 
the phenomena exhibited by species in nature; but in 
an earlier lecture I spoke cautiously with repect to its 
power of explaining all the physiological peculiarities 
of species. 

There is, in fact, one set of these peculiarities which 
the theory of selective modification, as it stands at 
present, is not wholly competent to explain, and that is 
the group of phenomena which I mentioned to you 
under the name of Hybridism, and which I explained 
to consist in the sterility of the offspring of certain spe- 
cies when crossed one with another. It matters not one 
whit whether this sterility is universal, or whether it 
exists only in a single case. Every hypothesis is bound 
to explain, or, at any rate, not be inconsistent with, the 
whole of the facts which it professes to account for ; and 
if there is a single one of these facts which can be shown 
to be inconsistent with (I do not merely mean inexpli- 
cable by, but contrary to,) the hypothesis, the hypothesis 
falls to the ground,—it is worth nothing. One fact with 
which it is positively inconsistent is worth as much, and 
as powerful in negativing the hypothesis, as five hun- 
dred. If I am right in thus defining the obligations of 
a hypothesis, Mr. Darwin, in order to place his views 
beyond the reach of all possible assault, ought to be 
able to demonstrate the possibility of developing from 


pes ae as 4 
Pa 


oF “ogaxte xare, 


eal om you see, rt vo have not done that you have not 
tric! tly fulfilled all the conditions of the problem; you 
e not shown that you can produce, by the cause 
ssumed, all the phenomena which you have in nature. 
are the phenomena of Hybridism staring you in 
face, and you cannot say, “I can, by selective 
- mo Epdifiesition, produce these same results. ” Now, it is 
a 1itted on all hands that, at present, so far as experi- 
1 nents have gone, it has not been found possible to pro- 
du ce this complete physiological divergence by selective 
bre eding. I stated this very clearly before, and I now 
a refer to the point, because, if it could be proved, not 
3 only that this has not been done, but that it cannot be 
4 done ; if it could be demonstrated that it is impossible 
Ss to breed selectively, from any stock, a form which shall 
al breed with another, produced from the same stock ; 
and if we were shown that this must be the necessary 
and inevitable result of all experiments, I hold that 
z Mr. Darwin’s hypothesis would be utterly shattered. 


s, But has this been done? or what is really the state 
= of the case? It is simply that, so far as we have gone 


yet with our breeding, we have not produced from a 
common stock two breeds which are not more or less 
fertile with one another. 
I do not know that there is a single fact which 
_ would justify any one in saying that any degree of ster- 
ility has been observed between breeds absolutely 
known to have been produced by selective breeding 
from a common stock. On the other hand, I do not 


142 MR. DARWIN’S WORK AND 


know that there is a single fact which can justify any — 


one in asserting that such sterility cannot be produced 
by proper experimentation. ‘or my own part, I see 
every reason to believe that it may, and will be so pro- 
duced. For, as Mr. Darwin has very properly urged, 
when we consider the phenomena of sterility, we find 
they are most capricious; we do not know what it is 
that the sterility depends on. There are some animals 
which will not breed in captivity ; whether it arises 
from the simple fact of their being shut up and deprived 
of their liberty, or not, we do not know, but they 
certainly will not breed. What an astounding thing 
this is, to find one of the most important of all functions 
annihilated by mere imprisonment ! 

So, again, there are cases known of animals which 
have been thought by naturalists to be undoubted spe- 
cies, which have yielded fertile hybrids; while there 
are other species which present what everybody believes 
to be varieties* which are more or less infertile with 
one another. There are other cases which are truly 
extraordinary; there is one, for example, which has 
been carefully examined,—of two kinds of sea-weed, 
of which the male element of the one, which we may 
call A, fertilizes the female element of the other, B; 
while the male element of B will not fertilize the female 
element of A; so that, while the former experiment 
seems to show us that they are varieties, the latter 
leads to the conviction that they are species. 


* And as I conceive with very good reason; but if any objec- 
tor urges that we cannot prove that they have been produced by 
artificial or natural selection, the objection must be admitted— 
ultra-sceptical.as it is. But in science, scepticism is a duty. 


a a, eerie! Se 
is — ya Ray - he ox r Feil A s ~ 
a ; 

5 ‘tw PHENOMENA OF ORGANIC NATURE. 143 


a 


pe»: 


hen we see how capricious and uncertain this 


- thos ose conditions will not be better understood by and 
ce vy, and we have no ground for supposing that we may 
_ no be able to experiment so as to obtain that crucial 

result which I mentioned just now. So that though 
| Mr. Darwiu’s hypothesis does not completely extricate 
ay 2 from this difficulty at present, we have not the least 

_ right to say it will not do so. 
ae There is a wide gulf between the thing you cannot 
@ Pecan and the thing that upsets you altogether. 
_ There is hardly any hypothesis in this world "wheel 
= has not some fact in connection with it which has not 
4 - been explained, but that is a very different affair to a 
7 fact that entirely opposes your hypothesis ; in this case 
- all you can say is, that your hypothesis is in the same 
position as a good many others. 

_ Now, as to the third test, that there are no other 
causes competent to explain the phenomena, I explained 
_ to you that one should be able to say of a hypothesis, 
_ that no other known causes than those supposed by it 
are competent to give rise to the phenomena. Here, 
I think, Mr. Darwin’s view is pretty strong. I really 

believe that the alternative is either Darwinism or 

nothing, for I do not know of any rational conception 
or theory of the organic universe which has any scien- 
tific position at all beside Mr. Darwin’s. I do not 
know of any proposition that has been put before us 
with the intention of explaining the phenomena of 
organic nature, which has in its favor a thousandth 
part of the evidence which may be adduced in favour 
of Mr. Darwin’s views. Whatever may be the objec- 


ay, 


ie AT Sr eis > (e 


ity is, how unknown the conditions on which it. 
ends, I say that we have no right to affirm that. 


Lh: _ MR. DARWIN’S WORK AND 


tions to his views, certainly all others are absolutely out : . 


of court. 


Take the Lamarckian hypothesis, for example. La-- 


marck was a great naturalist, and to a certain extent 


went the right way to work ; he argued from what was — 4 


undoubtedly a true cause of some of the phenomena of 
organic nature. He said it is a matter of experience 
that an animal may be modified more or less in conse- 
quence of its desires and consequent actions. Thus, if 
a man exercise himself as a blacksmith, his arms will 


become strong and muscular; such organie modifica- 


tion is a result of this particular action and exercise. 
Lamarck thought that by a very simple supposition 
based on this truth he could explain the oirgin of the 
various animal species: he said, for example, that the 


short-legged birds which live on fish, had been converted — 


into the long-legged waders by desiring to get the fish 
without wetting their feet, and so stretching their legs 
more and more through successive generations. If 
Lamarck could have shown experimentally, that even 
races of animals could be produced in this way, there 
might have been some ground fer his speculations. 
But he could show nothing of the kind, and his hy- 
pothesis has pretty well dropped into oblivion, as it de- 
served to do. I said in an earlier lecture that there are 
hypotheses and hypotheses, and when people tell you 
that Mr. Darwin’s strongly-based hypothesis is nothing 
but a mere modification of Lamarck’s, you will know 
what to think of their capacity for forming a judgment 
on this subject. 

But you must recollect that when I say I think it 
is either Mr. Darwin’s hypothesis or nothing; that 
either we must take his view, or look upon the whole 


. erate we fi the ak 
‘ eee ee Ae Tae a oa 
1 dak gz q “ s a F i ali ins iy = : 
Ee inal wae eee eee ets Coe ~<a ms oe et” . $ 
ee eee ee ee Oe ae ee Pet Oe reine 


me = 
of organic nature as an enigma, the meaning of which 


an is wholly hidden from us; you must understand that I 
3 Pas that I accept it AroasbisisallyA in exactly the same 
way as I accept any other hypothesis. Men of science 
do not pledge themselves to creeds ; they are bound by 
articles of no sort; there is not a single belief that it 
- isnot a bounden duty with them to hold with a light 
hand and to part with it, cheerfully, the moment it is 
_ really proved to be contrary to any fact, great or small. 
_ And if in course of time I see good reasons for such a 
__ proceeding, I shall have no hesitation in coming before 
__—-you, and pointing out any change in my opinion without 
; _ finding the slightest occasion to blush for so doing. So 
I say that we accept this view as we accept any other, 
so long as it will help us, and we feel bound to retain it 
only so long as it will serve our great purpose—the 
___ improvement of Man’s estate and the widening of his 
: knowledge. The moment this, or any other conception, 
ceases to be useful for these purposes, away with it to 

the four winds ; we care not what becomes of it! 
But to say truth, although it has been my business 
_ to attend closely to the controversies roused by the 
publication of Mr. Darwin’s book, I think that not one 
of the enormous mass of objections and obstacles which 
have been raised is of any great value, except that 
sterility case which I brought before you just now. 
All the rest are misunderstandings of some sort, arising 
either from prejudice, or want of knowledge, or still 
more from want of patience and care in reading the 

work. 

For you must recollect that it is not a book to be 
read with as much ease as its pleasant style may lead 
you to imagine. You spin through it as if it were a 


= 


‘ 


“novel the first time you read it, and think y 
about it; the second time you read it you 


amazed to find how little you i. soul ap 
its vast scope and objects. I can positively say 
~never take it up without tee in it some o mes 


found book; and I eee this feature of it Ke Or 0 
of Species” explains why so many persons have v 
tured to pass judgment and criticisms upon it whic 
are by no means worth the paper they are written on. 

Before concluding these lectures there is one p 
to which I must advert,—though, as Mr. Darwin has 


sundry occasions that if Mr. Darwin’s views are sound, — 
they apply as much to man as to the lower mammals, 
seeing that it is perfectly demonstrable that the struc- 
tural differences which separate man from the apes are — 
not greater than those which separate some apes from __ 
others. There cannot be the slightest doubt in the 
world that the argument which applies to the improve- __ 
ment of the horse from an earlier stock, or of ape from __ 
ape, applies to the improvement of man from some ~ 
simpler and lower stock than man. There is nota  — 
single faculty—functional or structural, moral, intel- 
lectual, or instinctive,—there is no faculty whatever 
that is not capable of improvement; there is no faculty a 
whatsoever which does not depend upon structure, and 
as structure tends to vary, it is capable of being im- 3 
proved. | 
Well, I have taken a good deal of pains at various 


es. “THE PHENOMENA OF ORGANIO NATURE. 147 
imes to prove this, and I have endeavoured to meet 
Z objections of those who maintain, that the structural 
/ differences between man and the lo wer animals are of 
so vast a character and enormous extent, that even if 
_ Mr. Darwin’s views are correct, you cannot imagine this 
particular modification to take place. It is, in fact, 
easy matter to prove that, so far as structure is con- 
cerned, man differs to no greater extent from the ani- 
= ehish: are immediately below him than these do 
-* om other members of the same order. Upon the 
~ other hand, there is no one who estimates more highly 
than I do the dignity of human nature, and the width 
e. Sy ~ of the gulf in intellectual and moral matters, which lies 
_ between man and the whole of the lower creation. 
But I find this very argument brought forward 
_ vehemently by some. “ You say that man has pro- 
ceeded from a modification of some lower animal, and 
Al you take painsto prove that the structural differences 
4 _ which are said to exist in his brain do not exist at all, 
and you teach that all functions, intellectual, moral, 
and others, are the expression or the result, in the long 
run, of structures, and of the molecular forces which 
they exert.’ It is quite true that I do so. 

“ Well, but,” I am told at once, somewhat triumph- 
antly, “‘ you say in the same breath that there is a great 
moral and intellectual chasm between man and the 

___ lower animals. How is this possible when you declare 
that moral and intellectual characteristics depend on 
structure, and yet tell us that there is no such gulf be- 
tween the structure of man and that of the lower ani- 
mals ?”’ 

I think that objection is based upon a misconception 
of the real relations which exist between structure and 


< p: 


function, between mechanism and work. — 
the expression of molecular forces and arr me 
aoa but, does it follow from see ici 


former i Is wes exactly proportioned to the latter | 4 
which follows on a variation in structure may rE] 
mously greater than the variation of the Siren he 
you see, the objection falls to the ground. ot ae 
Take a couple of watches—made by the same mak 
and as completely alike as possible ; set them upon 
table, and the function of each—which is its rate 


shall be able to distinguish no difference between them ; 
but let me take a pair of pincers, and if my hand is 
steady enough to do it, let me just lightly crush to- 
gether the bearings of the balance-wheel, or force to a — 
slightly different angle the teeth of the escapement of — 
one of them, and of course you know the immediate — 
result will be that the watch, so treated, from that mo- 
ment will cease to go. But what proportion is there _ 
between the structural alteration and the functional — 
result? Is it not perfectly obvious that the alteration 
is of the minutest kind, yet that slight as it is, it has 
prodnced an infinite difference in the performance of 
the functions of these two instruments ? 

Well, now, apply that to the present question. 
What is it that constitutes and makes man what he is? — 
What is it but his power of language—that language 
giving him the means of recording his experience— 
making every generation somewhat wiser than its 
predecessor,—more in accordance with the established 
order of the universe ? 


THE PHENOMENA OF ORGANIC NATURE. 149 


et." ib ; 
What is it but this power of speech, of recording 


to 


. experience, which enables men to be men-—looking 
before and after and, in some dim sense, understanding 
the working of this wondrous universe—and which dis- 


 tinguishes man from the whole of the brute world? I 
say that this functional difference is vast, unfathomable, 
and truly infinite in its consequences ; and I say at the 
_ same time, that it may depend upon structural differ- 
ences which shall be absolutely inappreciable to us with 


our present means of investigation. What is this very 


speech that we are talking about? I am speaking to 
you at this moment, but if you were to alter, in the 
minutest degree, the proportion of the nervous forces 
now active in the two nerves which supply the muscles 
of my glottis, I should become suddenly dumb. The 
voice is produced only so long as the vocal chords are 
parallel ; and_these are parallel only so long as certain 
muscles contract with exact equality; and that again 
depends on the equality of action of those two nerves I 
spoke of. So that a change of the minutest kind in the 
structure of one of these nerves, or in the structure of 
the part in which it originates, or of the supply of blood 
to that part, or of one of the muscles to which it is dis- 
tributed, might render all of us dumb. But a race of 
dumb men, deprived of all communication with those 
who could speak, would be little indeed removed from 
the brutes. And the moral and intellectual difference 
between them and ourselves would be practically in- 
finite, though the naturalist should not be able to find 
a single shadow of even specific structural difference. 
But let me dismiss this question now, and, in con- 
clusion, let me say that you may go away with it as my 
mature conviction, that Mr. Darwin’s work is the 


150 MR. DARWIN'S WORK, ETC. 


greatest contribution which has been made to biological 
science since the publication of the “ Régne Animal ” 
of Cuvier, and since that of the “ History of Develop- 
ment,” of Von Baer. I believe that if you strip it of 
its theoretical part it still remains one of the greatest 
encyclopzedias of biological doctrine that any one man 
ever brought forth ; and I believe that, if you take it as 
the embodiment of a hypothesis, it is destined to be the 
guide of biological and psychological speculation for the 
next three or four generations. 


1 Fee < 
Pe. _D. APPLETON & CO.’S PUBLICATIONS. ee. 
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{OLLECTED ESSAYS: By Tuomas H. Huxtey. 
~ New complete edition, with revisions, the Essays being grouped 
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IX.-EVOLUTION AND ETHICS, AND OTHER ESSAYS. 


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CRITICAL HISTORY OF FREE THOUGHT 
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"pd PA HISTORY OF PHILOSOPHY IN EPITOME. 

5 By ALBERT SCHWEGLER. ‘Translated from the first edition 
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LOGRAPHICAL HISTORY OF PHILOSO- 

PHY, from its Orisin in Greece down to the Present Day. 
- -By GEorGE Henry Lewes. Two volumes in one. 8vo. 
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his existence and his happiness. Having done this, its part is played. Our interest 
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interest in philosophy has become purely historical.”—F rom the Introduction. 


New York: D. APFLETON & CO., 72 Fifth Avenue. 


Joun BAcH McMaster. Tobe com 


top, $2.50 each, 


dents, of Congresses, of embassies, of treaties, 
of the ambition of political leaders, and of the 
rise of great parties in the nation. Yet the his- 
tory of the people is the chief theme. At every 
stage of the splendid progress which separates the 
America of Washington and Adams from the 
JOHN BACH MCMASTER. America in which we live, it has been the au- 
thor’s purpose to describe the dress, the occupa- 
tions, the amusements, the literary canons of the times; to note the changes 
of manners and morals; to trace the growth of that humane spirit which 
abolished punishment for debt, and reformed the discipline of prisons and 
of jails; to recount the manifold improvements which, in a thousand ways, 
have multiplied the conveniences of life and ministered to the happiness of 
our race; to describe the rise and progress of that long series of mechanical 
inventions and discoveries which is now the admiration of the world, and our 
just pride‘and boast ; to tell how, under the benign influence of liberty and 
peace, there sprang up, in the course of a single century, a prosperity unpar- 
alleled in the annals of human affairs. 


«The pledge given by Mr. McMaster, that ‘the history of the people,shall be the - 


chief theme,’ is punctiliously and satisfactorily fulfilled. He carries out his promise in 
a complete, vivid, and delightful way. We should add that the literary execution of 
the work is worthy of the indefatigable industry and unceasing vigilance with which 
the stores of historical material have been accumulated, weighed, and sifted. The 
cardinal qualities of style, lucidity, animation, and energy, are everywhere present. 

eldom indeed has a book in which matter of substantial value has been so happily 
united to attractiveness of form been offered by an American author to his fellow- 
citizens.” —NVew York Sun. 


‘‘To recount the marvelous progress of the American people, to describe their life, 
their literature, their occupations, their amusements, is Mr. McMaster’s object. His 
theme is an important one, and we congratulate him on his success. It has rarely been 
our province to notice a book with so many excellences and so few defects.” —New York 
Herald. 


“Mr. McMaster at once shows his grasp of the various themes and his special 
capacity as a historian of the people. His aim is high, but he hits the mark,”— 
New York Fournal of Commerce. 


“«, . . The author’s pages abound, too, with illustrations of the best kind of histori- 
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after the ‘modern style of historical writing, in a mere report, but with the true artistic 


method, in a well-digested narrative. . If Mr. McMaster finishes his work in the 
spirit and with the thoroughness and skill with which it has begun, it will take its place 
among the classics of American literature.” —Christian Union. 


New York: D. APPLETON & CO., 72 Fifth Avenue. 


pleted in six volumes. Vols. I, iG III, 
and IV now ready. 8vo, cloth, gilt 


In the course of this narrative much is written _ 
of wars, conspiracies, and rebellions; of Presi- 


> 


inna