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THE present volume consists of essays which I have 
contributed to various periodicals, or read before scien- 
tific societies during the last fifteen years, with others 
now printed for the first time. The two first of the- 
series are printed without alteration, because, having 
gained me the reputation of being an independent 
originator of the theory of " natural selection," they 
may be considered to have some historical value. I 
have added to them one or two very short explanatory 
notes, and have given headings to subjects, to make 
them uniform with the rest of the book. The other 
essays have been carefully corrected, often consider- 
ably enlarged, and in some cases almost rewritten, se- 
as to express more fully and more clearly the views 
which I hold at the present time ; and as most of 
them originally appeared in publications which have- 
a very limited circulation, I believe that the larger 
portion of this volume will be new to many of my 
friends and to most of my readers. 

I now wish to say a few words on the reasons which 
have led me to publish this work. The second essay, 
especially when taken in connection with the first, 
contains an outline sketch of the theory of the origin 
of species (by means of what was afterwards termed 
by Mr. Darwin "natural selection,") as conceived 


by me before I had the least notion of the scope and 
nature of Mr. Darwin's labours. They were published 
in a way not likely to attract the attention of any but 
working naturalists, and I feel sure that many who 
have heard of them, have never had the opportunity 
of ascertaining how much or how little they really con- 
tain. It therefore happens, that, while some writers 
give me more credit than I deserve, others may very 
naturally class me with Dr. Wells and Mr. Patrick 
Matthew, who, as Mr. Darwin has shown in the his- 
torical sketch given in the 4th and 5th Editions of 
the " Origin of Species," certainly propounded the 
fundamental principle of " natural selection " before 
himself, but who made no further use of that principle, 
and failed to see its wide and immensely important 

The present work will, I venture to think, prove, 
that I both saw at the time the value and scope of 
the law which I had discovered, and have since been 
able to apply it to some purpose in a few original 
lines of investigation. But here my claims cease. 
I have felt all my life, and I still feel, the most 
sincere satisfaction that Mr. Darwin had been at 
work lon before me, and that it was not left for me 

tD 7 

to attempt to write " The Origin of Species." I have 
long since measured my own strength, and know well 
that it would be quite unequal to that task. Far 
abler men than myself may confess, that they have 
not that untiring patience in accumulating, and that 
wonderful skill in using, large masses of facts of the 


most varied kind, that wide and accurate physio- 
logical knowledge, that acuteness in devising and 
skill in carrying out experiments, and that admirable 
style of composition, at once clear, persuasive and 
judicial, qualities, which in their harmonious combi- 
nation mark out Mr. Darwin as the man, perhaps of 
all men now living, best fitted for the great work he 
has undertaken and accomplished. 

My own more limited powers have, it is true, enabled 
me now and then to seize on some conspicuous group 
of unappropriated facts, and to search out some gene- 
ralization which might bring them under the reign 
of known law ; but they are not suited to that more 
scientific and more laborious process of elaborate in- 
duction, which in Mr. Darwin's hands has led to such 
brilliant results. 

Another reason which has led me to publish this 
volume at the present time is, that there are some im- 
portant points on which I differ from Mr. Darwin, and 
I wish to put my opinions on record in an easily 
accessible form, before the publication of his new 
work, (already announced,) in which I believe most 
of these disputed questions will be fully discussed. 

I will now give the date and mode of publication of 
each of the essays in this volume, as well as the amount 
of alteration they have undergone. 


First published in the " Annals and Magazine of 


Natural History," September, 1855. Reprinted with- 
out alteration of the text. 



First published in the " Journal of the Proceedings 
of the Linnsean Society," August, 1858. Reprinted 
without alteration of the text, except one or two 
grammatical emendations. 


First published in the a Westminster Review," July, 
1867. Reprinted with a few corrections and some 
important additions, among which I may especially 
mention Mr. Jenner Weir's observations and experi- 
ments on the colours of the caterpillars eaten or 
rejected by birds. 


First published in the " Transactions of the Lin- 
nsean Society," Vol. XXV. (read March, 1864), under 
the title, " On the Phenomena of Variation and Geo- 
graphical Distribution, as illustrated by the Papilionidas 
of the Malayan Region." 

The introductory part of this essay is now reprinted, 
omitting tables, references to plates, &c., with some ad- 
ditions, and several corrections. Owing to the publi- 

Fit EF ACE. Vll 

cation of Dr. Felder's " Voyage of tlie Novara" (Lepi- 
doptera) in the interval between the reading of my 
paper and its publication, several of my new species 
must have their names changed for those given to 
them by Dr. Felder, and this will explain the want of 
agreement in some cases between the names used 
in this volume and those of the original paper. 

Not previously published. 


First published in the " Intellectual Observer," July, 
1867. Keprinted with considerable emendations and 



First published in the " Journal of Travel and Na- 
tural History" (No. 2), 1868. Now reprinted with 
considerable emendations and additions, by which I 
have endeavoured more clearly to express, and more 
fully to illustrate, my meaning in those parts which 
have been misunderstood by my critics. 


First published in the " Quarterly Journal of 
Science," October, 1867. Now reprinted with a few 
alterations and additions. 



First ' published in the "Anthropological Review," 
May, 1864. Now reprinted with a few important alter- 
ations and additions. I had intended to have consider- 
ably extended this essay, but on attempting it I found 
that I should probably weaken the effect without add- 
ing much to the argument. I have therefore preferred 
to leave it as it was first written, with the exception 
of a few ill-considered passages which never fully ex- 
pressed my meaning. As it now stands, I believe it 
contains the enunciation of an important truth. 


This is the further development of a few sentences 
at the end of an article on " Geological Time and the 
Origin of Species," which appeared in the " Quarterly 
Review," for April, 1869. I have here ventured to 
touch on a class of problems which are usually consi- 
dered to be beyond the boundaries of science^ but 
which, I believe, will one day be brought within her 

For the convenience of those who are acquainted 
with any of my essays in their original form, I sub- 
join references to the more important additions and 
alterations now made to them. 



Essays I. and II. are unaltered, but short notes are 
added at pp. 19, 24, 29, and 40. 

III. Mimicry, and other Protective Resemblances 
among Animals. 


53 Additional illustration of protective colouring in 

the case of the wood-dove and the robin. 
63 On moths resembling bird's dung and mortar. 
86 Correction of some names of African Papilios and 

a reference to Mr. Trimen's observations. 
89 Mr. Jenner Weir's observation on birds which 

refused to eat Spilosoma menthrasti. 
102 An additional case of snake mimicry in Oxyrhopus 


107 Mr. Salvin's case of mimicry among hawks. 
113 Name, Diadema anomala, added. 
117 to 122. Use of gay colours in caterpillars, with an 
account of Mr. Jenner Weir's and Mr. Butler's 

IV. The Malayan Papilionidce or Swallow-tailed 
Butterflies y as illustrative of the Theory of Natural 

135 to 140. Additions to the discussion on the rank of 
the Papilionidse, and on the principles which 
determine the comparative rank of groups in the 
animal kingdom. 



164: Illustration of variability from Mr. Baker's re- 
vision of the British Roses. 

173 Additional facts, on local variations of colour. 

15^6 Additional genus of birds (Ceycopsis) peculiar 
to Celebes. 

199, 200. Concluding remarks. 

Nl.The Philosophy of Birds' Nests. 

218 On nesting of Terns and Gulls, rewritten. 
220 to 222. Daines Barrington, and others, on the song 
of birds. 

223 On young birds learning to build, by memory and 


224 Levaillant, on mode of nest-building. 
229 On imperfect adaptation in birds' nests. 

V1L A Theory of Birds' Nests. 

231, 232. Introductory passages modified, with some 

233 How modifications of organization would affect the 
form of the nest. 

235 Illustration from the habits of children and savages. 

235, 236. Objection t term " hereditary habit " 

237 Passage rewritten, on more or less variable char- 
acters in relation to nidification. 

248 On males choosing or rejecting females, and on 
the various modes in which colour may be 
acquired by female birds. 


249 On probable ancestral colours of female birds. 
255 Protective colouring of the Waxwing. 

VIII. Creation ly Law. 

293 Amount of variation in dogs. 

296, 297. The " Times " on Natural Selection. 

298 to 300. On intermediate or generalized forms of 
extinct animals as an indication of transmuta- 
tion or development. 

302 Tabular demonstration of the Origin of Species by 
Natural Selection. 

IX. The development of Human Races, under 
the law of Natural Selection. 

316 On colour as perhaps correlated with immunity 

from disease in man. 

326, 327. On the probable future development of man. 
330 Concluding paragraph rewritten. 

London, March, 1870. 


I. Oil the Law which has regulated the introduction of Neiv 

Geographical distribution dependent on Geologic Changes A Law 
deduced from well-known Geographical and Geological facts The 
form of a true system of Classification determined by this Law Geo- 
graphical Distribution of Organisms Geological Distribution of the 
forms of Life High Organization of very ancient Animals consistent 
with this Law Objections to Forbes' Theory of Polarity Eudi- 
mentary Organs Conclusion Pp. 1 25 

II. On the Tendency of Varieties to depart indefinitely from the 
Original Type. 

Instability of Varieties supposed to prove the permanent distinctness of 
Species The Struggle for Existence The Law of Population of 
Species The Abundance or Earity of a Species dependent upon its 
more or less perfect Adaptation to the Conditions of Existence 
Useful Variations will tend to Increase, useless or hurtful Variations 
to Diminish Superior Varieties will ultimately extirpate the Ori- 
ginal Species The Partial Eeversion of Domesticated Varieties 
explained Lamarck's Hypothesis very different from that now 
advanced Conclusion Pp. 26 44 

III. Mimicry, and other Protective Resemblances among 

Test of true and false Theories Importance of the Principle of Utility 
Popular Theories of Colour in Animals Importance of Conceal- 
ment as influencing Colour Special modifications of Colour Theory 
of Protective Colouring Objection that Colour as being dangerous 
should not exist in Nature Mimicry Mimicry amongJL/epidoptera 
Lepicloptera mimicking other Insects Mimicry among Beetles 
Beetles mimicking other Insacts Insects mimicking Species of other 
Orders Cases of Mimicry among the Vertebrata Mimicry among 
Snakes Mimicry among Birds Mimicry among Mammals Objec- 


tions to Mr. Bates' Theory of Mimicry Mimicry by Female Insects 
only Cause of the dull Colours of Female Birds Use of the gaudy 
Colours of many Caterpillars Summary General deductions as to 
Colour in Nature Conclusion Pp. 45 129 

IY. TJie Malayan Papilionidce, or Swallow-tailed Butterflies, 
as illustrative of the Theory of Natural Selection. 

Special value of the Diurnal Lepidoptera for inquiries of this Nature 
Question of the rank of the Papilionidae Distribution of the Papi- 
lionidie Definition of the word Species Laws and Modes of Varia- 
tion Simple Yariability Polymorphism or Dimorphism Local 
form or variety Co-existing Variety Race or Subspecies Species 
Variation as specially influenced by Locality Local Variation of 
Size Local Variation of Form Local Variations of Colour Re- 
marks on the facts of Local Variation Mimicry Concluding 
Remarks on Variation in Lepidoptera Arrangement Geographical 
Distribution Remarkable peculiarities of the island of Celebes 
Concluding Remarks Pp. 130200 

Y. On Instinct in Man and Animals. 

How Instinct may be best Studied Definition of Instinct Does Man 
possess Instincts ? How Indians travel through unknown and track- 
less Forests Pp. 201 210 

YL The Philosophy of Birds' Nests. 

Instinct or Reason in the Construction of Birds' Nests Do Men build 
by Reason or by Imitation ? Why does each Bird build a peculiar 
kind of Nest ? How do young Birds learn to build their first Nest ? 
Do Birds sing by Instinct or by Imitation ? Man's Works mainly 
Imitative Birds do Alter and Improve their Nests when altered con- 
ditions require it Conclusion Pp. 211 230 

VII. A Theory of Birds' Nests ; showing the relation of certain 
differences of colour in female birds to their mode of nidifi- 

Changed Conditions and persistent Habits as influencing Nidification 
Classification of Nests Sexual differences of Colour in Birds The 
Law which connects the Colours of Female Birds with the mode of 
Nidification What the Facts Teach us Colour more variable than 


Structure or Habits, and therefore the Character which has generally 
been modified Exceptional cases confirmatory of the above Explana- 
tion Eeal or apparent exceptions to the Law stated at p. 240 
Various modes of Protection of Animals Females of some groups 
require and obtain more Protection than the Males Conclusion 

Pp. 231- 263 

YIII. Creation by Law. 

laws from which the Origin of Species may be deduced Mr. Darwin's 
Metaphors liable to Misconception A case of Orchis-structure ex- 
plained by Natural Selection Adaptation brought about by General 
Laws Beauty in Nature How new Forms are produced by Varia- 
tion and Selection The Objection that there are Limits to Variation 
Objection to the argument from Classification The Times on 
Natural Selection Intermediate or generalized forms of Extinct 
Animals an indication of Transmutation or Development Conclu- 
sion A Demonstration of the Origin of Species . Pp. 264 301 

IX. The Development of Human Races under the Law of 
Natural Selection. 

Wide difference of Opinion as to Man's Origin Outline of the Theory 
of Natural Selection Different effects of Natural Selection on 
Animals and on Man Influence of External Nature in the develop- 
ment of the Human Mind Extinction of Lower Eaces The Origin 
of the Eaces of Man The Bearing of these views on the Antiquity 
of Man Their Bearing on the Dignity and Supremacy of Man 
Their Bearing on the future Development of Man Summary Con- 
clusion Pp. 302331 

X. The Limits of Natural Selection as applied to Man. 

What Natural 'Selection can Not do The Brain of the Savage shown 
to be Larger than he Needs it to be Size of Brain an important 
Element of Mental Power Comparison of the Brains of Man and of 
Anthropoid Apes Eange of intellectual power in Man Intellect of 
Savages and of Animals compared The use of the Hairy Covering 
of Mammalia The Constant absence of Hair from certain p irts of 
Man's body a remarkable Phenomenon Savage Man feels the want 
of this Hairy Covering Man's Naked Skin could not have been pro- 
duced by Natural Selection Feet and Hands of Man considered as 


Difficulties on the Theory of Natural Selection The Origin of Some 
of Man's Mental Faculties, by the preservation of Useful Variations, 
not possible Difficulty as to the Origin of the Moral Sense Sum- 
v mary of the Argument as to the Insufficiency of Natural Selection to 
account for the Development of Man The Origin of Consciousness 
The Nature of Matter Matter is Force All Force ia probably 
Will-force Conclusion .... . Pp. 332 371 



Geographical Distribution dependent on Geologic 

EVERY naturalist who has directed his attention to 
the subject of the geographical distribution of animals 
and plants, must have been interested in the singular 
facts which it presents. Many of these facts are quite 
different from what would have been anticipated, 
and have hitherto been considered as highly curious, 
but quite inexplicable. None of the explanations 
attempted from the time of Linnseus are now 
considered at all satisfactory ; none of them have 
given a cause sufficient to account for the facts 
known at the time, or comprehensive enough to 
include all the new facts which have since been, and 
are daily being added. Of late years, however, a 
great light has been thrown upon the subject by 
geological investigations, which have shown that the 
present state of the earth and of the organisms now 

* Written at Sarawak in February, 1855, and published in 
the " Annals and Magazine of Natural History," September, 



inhabiting it, is but the last stage of a long and 
uninterrupted series of changes which it has under- 
gone, and consequently, that to endeavour to explain 
and account for its present condition without any 
reference to those changes (as has frequently been 
done) must lead to very imperfect and erroneous 

The facts proved by geology are briefly these : 
That during an immense, but unknown period, the 
surface of the earth has undergone successive 
changes; land has sunk beneath the ocean, while 
fresh land has risen up from it; mountain chains 
have been elevated ; islands have been formed into 
continents, and continents submerged till they have 
become islands ; and these changes have taken place, 
not once merely, but perhaps hundreds, perhaps 
thousands of times : That all these operations have 
been more or less continuous, but unequal in their 
progress, and during the whole series the organic 
life of the earth has undergone a corresponding 
alteration. This alteration also has been gradual, 
but complete ; after a certain interval not a single- 
species existing which had lived at the commence- 
ment of the period. This complete renewal of the 
forms of life also appears to have occurred several 
times : That from the last of the geological epochs 
to the present or historical epoch, the change of 
organic life has been gradual : the first appearance 
of animals now existing can in many cases be traced, 
their numbers gradually increasing in the more re- 


cent formations, while other species continually die 
out and disappear, so that the present condition of 
the organic world is clearly derived by a natural 
process of gradual extinction and creation of species 
from that of the latest geological periods. We may 
therefore safely infer a like gradation and natural 
sequence from one geological epoch to another. 

Now, taking this as a fair statement of the results 
of geological inquiry, we see that the present geo- 
graphical distribution of life upon the earth must 
be the result of all the previous changes, both of the 
surface of the earth itself and of its inhabitants. 
Many causes, no doubt, have operated of which we 
must ever remain in ignorance, and we may, there- 
fore, expect to find many details very difficult of 
explanation, and in attempting to give one, must 
allow ourselves to call into our service geological 
changes which it is highly probable may have 
occurred, though we have no direct evidence of their 
individual operation. 

The great increase of our knowledge within the 
last twenty years, both of the present and past history 
of the organic world, has accumulated a body of 
facts which should afford a sufficient foundation for 
a comprehensive law embracing and explaining them 
all, and giving a direction to new researches. It is 
about ten years since the idea of such a law sug- 
gested itself to the writer of this essay, and he has 
since taken every opportunity of testing it by all 
the newly-ascertained facts with which lie has become 

B 2 


acquainted, or has been able to observe himself. 
These have all served to convince him of the correct- 
ness of his hypothesis. Fully to enter into such a 
subject would occupy much space, and it is only in 
consequence of some views having been lately pro- 
mulgated, he believes, in a wrong direction, that he 
now ventures to present his ideas to the public, with 
only such obvious illustrations of the arguments and 
results as occur to him in a place far removed from 
all means of reference and exact information. 

A Law deduced from well-known Geographical and 
Geological Facts. 

The following propositions in Organic Geography 
and Geology give the main facts on which the 
hypothesis is founded. 


1. Large groups, such as classes and orders, are 
generally spread over the whole earth, while smaller 
ones, such as families and genera, are frequently 
confined to one portion, often to a very limited dis- 

2. In widely distributed families the genera are 
often limited in range ; in widely distributed genera, 
well marked groups of species are peculiar to each 
geographical district. 

3. When a group is confined to one district, and 
is rich in species, it is almost invariably the case 
that the most closely allied species are found in the 
same locality or in closely adjoining localities, and 


that therefore the natural sequence of the species by 
affinity is also geographical. 

4. In countries of a similar climate, but separated 
by a wide sea or lofty mountains, the families, genera 
and species of the one are often represented by 
closely allied families, genera and species peculiar to- 
the other. 


5. The distribution of the organic world in time is 
very similar to its present distribution in space. 

6. Most of the larger and some small groups ex- 
tend through several geological periods. 

7. In each period, however, there are peculiar 
groups, found nowhere else, and extending through 
one or several formations. 

8. Species of one genus, or genera of one family 
occurring in the same geological time are more closely 
allied than those separated in time. 

9. As generally in geography no species or genus 
occurs in two very distant localities without being 
also found in intermediate places, so in geology the 
life of a species or genus has not been interrupted. 
In other words, no group or species has come into 
existence twice. 

10. The following law may be deduced from these 
facts : Evert/ species has come into existence coincident 
both in space and time icith a pre-existing closely allied 

This law agrees with, explains and illustrates all 
the facts connected with the following; branches of 


the subject : 1st. The system of natural affinities. 
2nd. The distribution of animals and plants in 
space. 3rd. The same in time, including all the 
phenomena of representative groups, and those 
which Professor Forbes supposed to manifest polar- 
ity. 4th. The phenomena of rudimentary organs. 
We will briefly endeavour to show its bearing upon 
each of these. 

The Form of a true system of Classification determined 
by this Law. 

If the law above enunciated be true, it follows that 
the natural series of affinities will also represent the 
order in which the several species came into exist- 
ence, each one having had for its immediate anti- 
type a closely allied species existing at the time of 
its origin. It is evidently possible that two or three 
distinct species may have had a common antitype, 
and that each of these may again have become the 
antitypes from which other closely allied species were 
created. The effect of this would be, that so long as 
each species has had but one new species formed on 
its model, the line of affinities will be simple, and 
may be represented by placing the several species in 
direct succession in a straight line. But if two or 
more species have been independently formed on the 
plan of a common antitype, then the series of affini- 
ties will be compound, and can only be represented 
by a forked or many branched line. Now, all at- 
tempts at a Natural classification and arrangement 


of organic beings show, that both these plans have 
obtained in creation. Sometimes the series of affini- 
ties can be well represented for a space by a direct 
progression from species to species or from group to 
group, but it is generally found impossible so to con- 
tinue. There constantly occur two or more modifica- 
tions of an organ or modifications of two distinct 
organs, leading us on to two distinct series of species, 
which at length differ so much from each other as 
to form distinct genera or families. These are the 
parallel series or representative groups of naturalists, 
and they often occur in different countries, or are 
found fossil in different formations. They are said 
to have an analogy to each other when they are so 
far removed from their common antitype as to differ 
in many important points of structure, while they 
still preserve a family resemblance. We thus see how 
difficult it is to determine in every case whether a 
given relation is an analogy or an affinity, for it is 
evident that as we go back along the parallel or -diver- 
gent series, towards the common antitype, the analogy 
which existed between the two groups becomes an 
affinity. We are also made aware of the difficulty 
of arriving at a true classification, even in a small 
and perfect group ; in the actual state of nature it 
is almost impossible, the species being so numerous 
and the modifications of form and structure so varied, 
arising probably from the immense number of species 
which have served as antitypes for the existing spe- 
cies, and thus produced a complicated branching of 


the lines of affinity, as intricate as the twigs of a 
gnarled oak or the vascular system of the human 
body. 'Again, if we consider that we have only frag- 
ments of this vast system, the stem and main branches 
being represented by extinct species of which we have 
no knowledge, while a vast mass of limbs and boughs 
and minute twigs and scattered leaves is what we 
have to place in order, and determine the true posi- 
tion each originally occupied with regard to the others, 
the whole difficulty of the true Natural System of 
classification becomes apparent to us. 

We shall thus find ourselves obliged to r.eject 
all those systems of classification which arrange 
species or groups in circles, as well as those 
which fix a definite number for the divisions of 
each group. The latter class have been very gener- 
ally rejected by naturalists, as contrary to nature, 
notwithstanding the ability with which they have 
been advocated ; but the circular system of affini- 
ties seems to have obtained a deeper hold, many 
eminent naturalists having to some extent adopted 
it. We have, however, never been able to find a 
case in which the circle has been closed by a 
direct and close affinity. In most cases a palpable 
analogy has been substituted, in others the affinity 
is very obscure or altogether doubtful. The com- 
plicated branching of the lines of affinities in 
extensive groups must also afford great facilities 
for giving a show of probability to any such 
purely artificial arrangements. Their death - blow 


was given by the admirable paper of the lamented 
Mr. Strickland, published in the "Annals of Na- 
tural History," in which he so clearly showed the 
true synthetical method of discovering the Natural 

Geographical Distribution of Organisms. 

If we now consider the geographical distribu- 
tion of animals and plants upon the earth, we 
shall find all the facts beautifully in accordance 
with, and readily explained by, the present hypo- 
thesis. A country having species, genera, and 
whole families peculiar to it, will be the neces- 
sary result of its having been isolated for a long 
period, sufficient for many series of species to 
have been created on the type of pre-existing 
ones, which, as well as many of the earlier- 
formed species, have become extinct, and thus 
made the groups appear isolated. If in any case 
the antitype had an extensive range, two or more 
groups of species might have been formed, each 
varying from it in a different manner, and thus 
producing several representative or analogous groups. 
The Sylviadas of Europe and the Sylvicolidse of 
North America, the Heliconidae of South America 
and the Euploeas of the East, the group of Tro- 
gons inhabiting Asia, and that peculiar to South 
America, are examples that may be accounted for 
in this manner. 

Such phenomena as are exhibited by the Gala- 


pagos Islands, which contain littte groups of plants 
and animals peculiar to themselves, but most nearly 
allied to those of South America, have not hither- 
to received any, even a conjectural explanation. 
The Galapagos are a volcanic group of high anti- 
quity, and have probably never been more closely 
connected with the continent than they are at 
present. They must have been first peopled, like 
other newly-formed islands, by the action of winds 
and currents, and at a period sufficiently remote 
to have had the original species die out, and the 
modified prototypes only remain. In the same way 
we can account for the separate islands having each 
their peculiar species, either on the supposition that 
the same original emigration peopled the whole of 
the islands with the same species from which differ- 
ently modified prototypes were created, or that the 
islands were successively peopled from each other, 
but that new species have been created in each on 
the plan of the pre-existing ones. St. Helena is a 
similar case of a very ancient island having obtained 
an entirely peculiar, though limited, flora. On the 
other hand, no example is known of an island which 
can be proved geologically to be of very recent 
origin (late in the Tertiary, for instance), and yet 
possesses generic or family groups, or even many 
species peculiar to itself. 

When a range of mountains has attained a great 
elevation, and has so remained during a long geolo- 
gical period, the species of the two sides at and 


near their bases will be often very different, repre- 
sentative species of some genera occurring, and even 
whole genera being peculiar to one side only, as is 
remarkably seen in the case of the Andes and Rocky 
Mountains. A similar phenomenon occurs when an 
island has been separated from a continent at a very 
early period. The shallow sea between the Peninsula 
of Malacca, Java, Sumatra and Borneo was probably 
a continent or large island at an early epoch, and 
may have become submerged as the volcanic ranges 
of Java and Sumatra were elevated. The organic 
results we see in the very considerable number of 
species of animals common to some or all of these 
countries, while at the same time a number of closely 
allied representative species exist peculiar to each, 
showing that a considerable period has elapsed since 
their separation. The facts of geographical distribu- 
tion and of geology may thus mutually explain each 
other, in doubtful cases, should the principles here 
advocated be clearly established. 

In all those cases in which an island has been 
separated from a continent, or raised by volcanic or 
coralline action from the sea, or in which a moun- 
tain-chain has been elevated in a recent geological 
epoch, the phsenomena of peculiar groups or even 
of single representative species will not exist. Our 
own island is an example of this, its separation from 
the continent being geologically very recent, and we 
have consequently scarcely a species which is pecu- 
liar to it; while the Alpine range, one of the most 


recent mountain elevations, separates faunas and floras 
which scarcely differ more than may be due to climate 
and latitude alone. 

The series of facts alluded to in Proposition (3), 
of closely allied species in rich groups being found 
geographically near each other, is most striking and 
important. Mr. Lovell Reeve has well exemplified it 
in his able and interesting paper on the Distribution 
of the Bulimi. It is also seen in the Humming- 
birds and Toucans, little groups of two or three 
closely allied species being often found in the same 
or closely adjoining districts, as we have had the 
good fortune of personally verifying. Fishes give 
evidence of a similar kind : each great river has 
its peculiar genera, and in more extensive genera 
its groups of closely allied species. But it is the 
same throughout Nature ; every class and order of 
animals will contribute similar facts. Hitherto no 
attempt has been made to explain these singular 
phenomena, or to show how they have arisen. Why 
are the genera of Palms and of Orchids in almost 
every case confined to one hemisphere ? Why are 
the closely allied species of brown-backed Trogons all 
found in the East, and the green-backed in. the 
West? Why are the Macaws and the Cockatoos 
similarly restricted ? Insects furnish a countless 
number of analogous examples ; the Goliathi of 
Africa, the OrnithopteraB of the Indian Islands, the 
Heliconidse of South America, the DanaidaB of the 
East, and in all, the most closely allied species found 


in geographical proximity. The question forces itself 
upon every thinking mind, why are these things 
so ? They could not be as they are had no law 
regulated their creation and dispersion. The law 
here enunciated not merely explains, but necessitates 
the facts we see to exist, while the vast and long- 
continued geological changes of the earth readily 
account for the exceptions and apparent discrepan- 
cies that here and there occur. The writer's object 
in putting forward his views in the present imper- 
fect manner is to submit them to the test of other 
minds, and to be made aware of all the facts 
supposed to be inconsistent with them. As his 
hypothesis is one which claims acceptance solely 
as explaining and connecting facts which exist in 
nature, he expects facts alone to be brought to dis- 
prove it, not a priori arguments against its pro- 

Geological Distribution of the Forms of Life. 

The phenomena of geological distribution are ex- 
actly analogous to those of geography. Closely allied 
species are found associated in the same beds, and 
the change from species to species appears to have 
been as gradual in time as in space. Geology, how- 
ever, furnishes us with positive proof of the extinc- 
tion and production of species, though it does not 
inform us how either has taken place. The extinction 
of species, however, offers but little difficulty, and 
the modus operandi has been well illustrated bv Sir 


C. Lyell in his admirable " Principles." Geological 
changes, however gradual, must occasionally have 
modified external conditions to such an extent as 
to have rendered the existence of certain species 
impossible. The extinction would in most cases be 
effected by a gradual dying-out, but in some in- 
stances there might have been a sudden destruction 
of a species of limited range. To discover how the 
extinct species have from time to time been replaced 
by new ones down to the very latest geological period, 
is the most difficult, and at the same time the most 
interesting problem in the natural history of the 
earth. The present inquiry, which seeks to elimi- 
nate from known facts a law which has determined, 
to a certain degree, what species could and did ap- 
pear at a given epoch, may, it is hoped, be consi- 
dered as one step in the right direction towards a 
complete solution of it. 

High Organization of very ancient Animals consistent 
ivith this Law. 

Much discussion has of late years taken place on 
the question, whether the succession of life upon the 
globe has been from a lower to a higher degree of 
organization. The admitted facts seem to show that 
there has been a general, but not a detailed pro- 
gression. Mollusca and Eadiata existed before Ver- 
tebrata, and the progression from Fishes to Reptiles 
and Mammalia, and also from the lower mammals 
to the higher, is indisputable. On the other hand. 


it is said that the Mollusca and Radiata of the very 
earliest periods were more highly organized than 
the great mass of those now existing, and that the 
very first fishes that have been discovered are by no 
means the lowest organised of the class. Now it is 
believed the present hypothesis will harmonize with 
all these facts, and in a great measure serve to 
explain them ; for though it may appear to some 
readers essentially a theory of progression, it is in 
reality only one of gradual change. It is, however, 
by no means difficult to show that a real progression 
in the scale of organization is perfectly consistent 
with all the appearances, and even with apparent 
retrogression, should such occur. 

Returning to the analogy of a branching tree, as 
the best mode of representing the natural arrange- 
ment of species and their successive creation, let us 
suppose that at an early geological epoch any group 
(say a class of the Mollusca) has attained to a great 
richness of species and a high organization. Now 
let this great branch of allied species, by geologi- 
cal mutations, be completely or partially destroyed. 
Subsequently a new branch springs from the same 
trunk, that is to say, new species are successively 
created, having for their antitypes the same lower 
organized species which had served as the antitypes 
for the former group, but which have survived the 
modified conditions which destroyed it. This new 
group being subject to these altered conditions, has 
modifications of structure and organization given 


to it, and becomes the representative group of the 
former one in another geological formation. It may, 
however, happen, that though later in time, the new 
series of species may never attain to so high a 
degree of organization as those preceding it, but 
in its turn become extinct, and give place to yet 
another modification from the same root, which may 
be of higher or lower organization, more or less 
numerous in species, and more or less varied in form 
and structure than either of those which preceded it. 
Again, each of these groups may not have become 
totally extinct, but may have left a few species, the 
modified prototypes of which have existed in each 
succeeding period, a faint memorial of their former 
grandeur and luxuriance. Thus every case of ap- 
parent retrogression may be in reality a progress, 
though an interrupted one : when some monarch of 
the forest loses a limb, it may be replaced by a 
feeble and sickly substitute. The foregoing remarks 
appear to apply to the case of the Mollusca, which, 
at a very early period, had reached a high organi- 
zation and a great development of forms and species 
in the testaceous Cephalopoda. In each succeeding 
age modified species and genera replaced the former 
ones which had become extinct, and as we approach 
the present sera, but few and small representatives of 
the group remain, while the Gasteropods and Bi- 
valves have acquired an immense preponderance. In 
the long series of changes the earth has undergone, 
the process of peopling it with organic beings has 


been continually going on, and whenever any of the 
higher groups have become nearly or quite extinct, 
the lower forms which have better resisted the modi- 
fied physical conditions have served as the antitypes 
on which to found the new races. In this manner 
alone, it is believed, can the representative groups 
at successive periods, and the risings and fallings in 
the scale of organization, be in every case explained. 

Objections to Forbes* Theory of Polarity. 

The hypothesis of polarity, recently put forward by 
Professor Edward Forbes to account for the abun- 
dance of generic forms at a very early period and at 
present, while in the intermediate epochs there is 
a gradual diminution and impoverishment, till the 
minimum occurred at the confines of the Palaeozoic 
and Secondary epochs, appears to us quite unne- 
cessary, as the facts may be readily accounted for 
on the principles already laid down. Between the 
Palaeozoic and Neozoic periods of Professor Forbes, 
there is scarcely a species in common, and the 
greater part of the genera and families also dis- 
appear to be replaced by new ones. It is almost 
universally admitted that such a change in the 
organic world must have occupied a vast period of 
time. Of this interval we have no record ; pro- 
bably because the whole area of the early formations 
now exposed to our researches was elevated at the 
end of the Palaeozoic period, and remained so through 
the interval required for the organic changes which 



resulted in the fauna and flora of the Secondary- 
period. The records of this interval are buried 
beneath the ocean which covers three-fourths of the 
globe. Now it appears highly probable that a long 
period of quiescence or stability in the physical con- 
ditions of a district would be most favourable to the 
existence of organic life in the greatest abundance, 
both as regards individuals and also as to variety of 
species and generic group, just as we now find that 
the places best adapted to the rapid growth and in- 
crease of individuals also contain the greatest pro- 
fusion of species and the greatest variety of forms, 
the tropics in comparison with the temperate and 
arctic regions. On the other hand, it seems no 
less probable that a change in the physical conditions 
of a district, even small in amount if rapid, or 
even gradual if to a great amount, would be highly 
unfavourable to the existence of individuals, might 
cause the extinction of many species, and would pro- 
bably be equally unfavourable to the creation of new 
ones. In this too we may find an analogy with the 
present state of our earth, for it has been shown to 
be the violent extremes and rapid changes of phy- 
sical conditions, rather than the actual mean state 
in the temperate and frigid zones, which renders 
them less prolific than the tropical regions, as exem- 
plified by the great distance beyond the tropics 
to which tropical forms penetrate when the climate 
is equable, and also by the richness in species and 
forms of tropical mountain regions which principally 


differ from the temperate zone in the uniformity of 
their climate. However this may be, it seems a 
fair assumption that during a period of geological 
repose the new species which we know to have been 
created would have appeared, that the creations 
would then exceed in number the extinctions, and 
therefore the number of species would increase. 
In a period of geological activity, on the other hand, 
it seems probable that the extinctions might exceed 
the creations, and the number of species consequently 
diminish. That such effects did take place in con- 
nexion with the causes to which we have imputed 
them, is shown in the case of the Coal formation, 
the faults and contortions of which show a period of 
great activity and violent convulsions, and it is in 
the formation immediately succeeding this that the 
poverty of forms of life is most apparent. We 
have then only to suppose a long period of somewhat 
similar action during the vast unknown interval at 
the termination of the Palaeozoic period, and then 
a decreasing violence or rapidity through the Second- 
ary period, to allow for the gradual repopulation of 
the earth with varied forms, and the whole of the 
facts are explained.* We thus have a clue to the 
increase of the forms of life during certain periods, 
and their decrease during others, without recourse 

* Professor Ramsay has since shown that a glacial epoch 
probably occurred at the time of the Permian formation, 
which will more satisfactorily account for the comparative 
poverty of species. 

G 2 


to any causes but those we know to have existed, 
and to effects fairly deducible from them. The pre- 
cise manner in which the geological changes of the 
early formations were effected is so extremely 
obscure, that when we can explain important facts 
by a retardation at one time and an acceleration at 
another of a process which we know from its nature 
and from observation to have been unequal, a cause 
so simple may surely be preferred to one so obscure 
and hypothetical as polarity. 

I would also venture to suggest some reasons 
against the very nature of the theory of Professor 
Forbes. Our knowledge of the organic world 
during any geological epoch is necessarily very im- 
perfect. Looking at the vast numbers of species 
and groups that have been discovered by geologists, 
this may be doubted ; but we should compare their 
numbers not merely with those that now exist upon 
the earth, but with a far larger amount. We have 
no reason for believing that the number of species 
on the earth at any former period was much less 
than at present ; at all events the aquatic portion, 
with which geologists have most acquaintance, was 
probably often as great or greater. Now we know 
that there have been many complete changes of 
species ; new sets of organisms have many times been 
introduced in place of old ones which have become 
extinct, so that the total amount which have existed 
on the earth from the earliest geological period must 
have borne about the same proportion to those now 


living, as the whole human race who have lived and 
died upon the earth, to the population at the present 
time. Again, at each epoch, the whole earth was 
no doubt, as now, more or less the theatre of life, 
and as the successive generations of each species 
died, their exuviae and preservable parts would be 
deposited over every portion of the then existing 
seas and oceans, which we have reason for supposing 
to have been more, rather than less, extensive than 
at present. In order then to understand our possible 
knowledge of the early world and its inhabitants, 
we must compare, not the area of the whole field of 
our geological researches with the earth's surface, 
but the area of the examined portion of each forma- 
tion separately with the whole earth. For example, 
during the Silurian period all the earth was Silurian, 
and animals were living and dying, and depositing 
their remains more or less over the whole area of the 
globe, and they were probably (the species at least) 
nearly as varied in different latitudes and longitudes 
as at present. What proportion do the Silurian dis- 
tricts bear to the whole surface of the globe, land and 
sea (for far more extensive Silurian districts probably 
exist beneath the ocean than above it), and what 
portion of the known Silurian districts has been 
actually examined for fossils ? Would the area of 
rock actually laid open to the eye be the thousandth 
or the ten-thousandth part of the earth's surface? 
Ask the same question with regard to the Oolite or 
the Chalk, or even to particular beds of these when 


they differ considerably in their fossils, and you may 
then get some notion of how small a portion of the 
whole we know. 

But yet more important is the probability, nay 
almost the certainty, that whole formations contain- 
ing the records of vast geological periods are entirely 
buried beneath the ocean, and for ever beyond our 
reach. Most of the gaps in the geological series 
may thus be filled up, and vast numbers of un- 
known and unimaginable animals, which might help 
to elucidate the affinities of the numerous isolated 
groups which are a perpetual puzzle to the zoologist, 
may there be buried, till future revolutions may 
raise them in their turn above the waters, to afford 
materials for the study of whatever race of intelli- 
gent beings may then have succeeded us. These con- 
siderations must lead us to the conclusion, that our 
knowledge of the whole series of the former inhabi- 
tants of the earth is necessarily most imperfect and 
fragmentary, as much so as our knowledge of the 
present organic world would be, were we forced to 
make our collections and observations only in spots 
equally limited in area and in number with those 
actually laid open for the collection of fossils. Now, 
the hypothesis of Professor Forbes is essentially one 
that assumes to a great extent the completeness of 
our knowledge of the whole series of organic beings 
which have existed on the earth. This appears to 
be a fatal objection to it, independently of all other 
considerations. It may be said that the same ob- 


jections exist against every theory on such a subject, 
but this is not necessarily the case. The hypothesis 
put forward in this paper depends in no degree 
upon the completeness of our knowledge of the 
former condition of the organic world, but takes 
what facts we have as fragments of a vast whole, 
and deduces from them something of the nature and 
proportions of that whole which we can never know 
in detail. It is founded upon isolated groups of 
facts, recognizes their isolation, and endeavours to 
deduce from them the nature of the intervening 

Rudimentary Organs 

Another important series of facts, quite in accord- 
ance with, and even necessary deductions from, the 
law now developed, are those of rudimentary organs. 
That these really do exist, and in most cases 
have no special function in the animal oeconomy, 
is admitted by the first authorities in comparative 
anatomy. The minute limbs hidden beneath the skin 
in many of the snake-like lizards, the anal hooks 
of the boa constrictor, the complete series of jointed 
finger -bones in the paddle of the Manatus and 
whale, are a few of the most familiar instances. In 
botany a similar class of facts has been long re- 
cognised. Abortive stamens, rudimentary floral en- 
velopes and undeveloped carpels, are of the most 
frequent occurrence. To every thoughtful naturalist 
the question must arise, What are these for ? What 
have they to do with the great laws of creation? 


Do they not teach us something of the system of 
Nature ? If each species has been created inde- 
pendently, and without any necessary relations with 
pre-existing species, what do these rudiments, these 
apparent imperfections mean ? There must be a 
cause for them ; they must be the necessary results 
of some great natural law. Now, if, as it has been 
endeavoured to be shown, the great law which has 
regulated the peopling of the earth with animal and 
vegetable life is, that every change shall be gradual; 
that no new creature shall be formed widely differing 
from anything before existing; that in this, as in 
everything else in Nature, there shall be gradation 
and harmony, then these rudimentary organs are 
necessary, and are an essential part of the system of 
Nature. Ere the higher Vertebrata were formed, for 
instance, many steps were required, and many organs 
had to undergo modifications from the rudimental 
condition in which only they had as yet existed. 
We still see remaining an antitypal sketch of a wing 
adapted for flight in the scaly flapper of the penguin, 
and limbs first concealed beneath the skin, and then 
weakly protruding from it, were the necessary gra- 
dations before others should be formed fully adapted 
for locomotion.* Many more of these modifica- 
tions should we behold, and more complete series 

* The theory of Natural Selection lias now taught us that 
these are not the steps by which limbs have been formed ; and 
that most rudimentary organs have been produced by abortion* 
owing to disease, as explained by Mr. Darwin. 


of them, had we a view of all the forms which have 
ceased to live. The great gaps that exist between 
fishes, reptiles, birds, and mammals would then, no 
doubt, be softened down by intermediate groups, and 
the whole organic world would be seen to be an 
unbroken and harmonious system 


It has now been shown, though most briefly and 
imperfectly, how the law that " Every species has come 
into existence coincident both in time and space with a 
pre-existing closely allied species" connects together 
and renders intelligible a vast number of independent 
and hitherto unexplained facts. \ The natural system 
of arrangement of organic beings, their geographical 
distribution, their geological sequence, the phenomena 
of representative and substituted groups in all their 
modifications, and the most singular peculiarities of 
anatomical structure, are all explained and illus- 
trated by it, in perfect accordance with the vast 
mass of facts which the researches of modern na- 
turalists have brought together, and, it is believed, 
not materially opposed to any of them. It also 
claims a superiority over previous hypotheses, on 
the ground that it not merely explains, but necessi- 
tates what exists. Granted the law, and many of 
the most important facts in Nature could not have 
been otherwise, but are almost as necessary deduc- 
tions from it, as are the elliptic orbits of the planets 
from the law of gravitation. 



Instability of Varieties supposed to prove the permanent 
distinctness of Species. 

ONE of the strongest arguments which have been ad- 
duced to prove the original and permanent distinct- 
ness of species is, that varieties produced in a state of 
domesticity are more or less unstable, and often have 
a tendency, if left to themselves, to return to the 
normal form of the parent species; and this insta- 
bility is considered to be a distinctive peculiarity of 
all varieties, even of those occurring among wild 
animals in a state of nature, and to constitute a pro- 
vision for preserving unchanged the originally created 
distinct species. 

In the absence or scarcity of facts and observa- 
tions as to varieties occurring among wild animals, 
this argument has had great weight with natural- 
ists, and has led to a very general and somewhat 

* Written at Ternate, February, 1858; and published in 
the Journal of the Proceedings of the Linnsean Society for 
August, 1858. 


prejudiced belief in the stability of species. Equally 
general, however, is the belief in what are called 
" permanent or true varieties," races of animals 
which continually propagate their like, but which 
differ so slightly (although constantly) from some 
other race, that the one is considered to be a variety 
of the other. Which is the variety and which the 
original species, there is generally no means of de- 
termining, except in those rare cases in which the 
one race has been known to produce an offspring 
unlike itself and resembling the other. This, how- 
ever, would seem quite incompatible with the " per- 
manent invariability of species," but the difficulty is 
overcome by assuming that such varieties have strict 
limits, and can never again vary further from the 
original type, although they may return to it, which, 
from the analogy of the domesticated animals, is 
considered to be highly probable, if not certainly 

It will be observed that this argument rests en- 
tirely on the assumption, that varieties occurring in 
a state of nature are in all respects analogous to or 
even identical with those of domestic animals, and 
are governed by the same laws as regards their per- 
manence or further variation. But it is the object 
of the present paper to show that this assumption is 
altogether false, that there is a general principle in 
nature which will cause many varieties to survive 
the parent species, and to give rise to successive 
variations departing further and further from the 


original type, and which also produces, in domesti- 
cated animals, the tendency of varieties to return to 
the parent form. 

The Struggle for Existence. 

The life of wild animals is a struggle for exist- 
ence. The full exertion of all their faculties and 
all their energies is required to preserve their own 
existence and provide for that of their infant off- 
spring. The possibility of procuring food during the 
least favourable seasons, and of escaping the attacks 
of their most dangerous enemies, are the primary 
conditions which determine the existence both of 
individuals and of entire species. These conditions 
will also determine the population of a species; and by 
a careful consideration of all the circumstances we 
may be enabled to comprehend, and in some degree 
to explain, what at first sight appears so inex- 
plicable the excessive abundance of some species, 
while others closely allied to them are very rare. 

Tlie Law of Population of Species. 

The general proportion that must obtain between 
certain groups of animals is readily seen. Large 
animals cannot be so abundant as small ones ; the 
carnivora must be less numerous than the herbivora ; 
eagles and lions can never be so plentiful as pigeons 
and antelopes; and the wild asses of the Tartarian 
deserts cannot equal in numbers the horses of the 
more luxuriant prairies and pampas of America. The 


greater or less fecundity of an animal is often con- 
sidered to be one of the chief causes of its abun- 
dance or scarcity; but a consideration of the facts 
will show us that it really has little or nothing to 
do with the matter. Even the least prolific of 
animals would increase rapidly if unchecked, whereas 
it is evident that the animal population of the globe 
must be stationary, or perhaps, through the influence 
of man, decreasing. Fluctuations there may be; but 
permanent increase, except in restricted localities, is 
almost impossible. For example, our own observa- 
tion must convince us that birds do not go on 
increasing every year in a geometrical ratio, as they 
would do, were there not some powerful check to 
their natural increase. Very few birds produce less 
than two young ones each year, while many have 
six, eight, or ten; four will certainly be below the 
average ; and if we suppose that each pair produce 
young only four times in their life, that will also be 
below the average, supposing them not to die either 
by violence or want of food. Yet at this rate how 
tremendous would be the increase in a few years 
from a single pair! A simple calculation will show 
that in fifteen years each pair of birds would have 
increased to nearly ten millions ! * whereas we have 
no reason to believe that the number of the birds of 
any country increases at all in fifteen or in one 
hundred and fifty years. With such powers of in- 

* This is under estimated. The number would really 
amount to more than two thousand millions! 


crease the population must have reached its limits, 
and have become stationary, in a very few years 
after the origin of each species. It is evident, there- 
fore, that each year an immense number of birds 
must perish as many in fact as are born ; and as 
on the lowest calculation the progeny are each year 
twice as numerous as their 'parents, it follows that, 
whatever be the average number of individuals exist- 
ing in any given country, twice that number must 
perish annually, a striking result, but one which 
seems at least highly probable, and is perhaps under 
rather than over the truth. It would therefore ap- 
pear that, as far as the continuance of the species 
and the keeping up the average number of indi- 
viduals are concerned, large broods are superfluous. 
On the average all above one become food for hawks 
and kites, wild cats or weasels, or perish of cold 
and hunger as winter comes on. This is strikingly 
proved by the case of particular species ; for we 
find that their abundance in individuals bears no 
relation whatever to their fertility in producing off- 

Perhaps the most remarkable instance of an im- 
mense bird population is that of the passenger 
pigeon of the United States, which lays only one, 
or at most two eggs, and is said to rear gener- 
ally but one young one. Why is this bird so 
extraordinarily abundant, while others producing two 
or three times as many young are much less plen- 
tiful ? The explanation is not difficult. The food 


most congenial to this species, and on which it 
thrives best, is abundantly distributed over a very 
extensive region, offering such differences of soil 
and climate, that in one part or another of the 
area the supply never fails. The bird is capable of 
a very rapid and long-continued flight, so that it 
can pass without fatigue over the whole of the dis- 
trict it inhabits, and as soon as the supply of food 
begins to fail in one place is able to discover 
a fresh feeding-ground. This example strikingly 
shows us that the procuring a constant supply of 
wholesome food is almost the sole condition re- 
quisite for ensuring the rapid increase of a given 
species, since neither the limited fecundity, nor the 
unrestrained attacks of birds of prey and of man 
are here sufficient to check it. In no other birds 
are these peculiar circumstances so strikingly com- 
bined. Either their food is more liable to failure, 
or they have not sufficient power of wing to search 
for it over an extensive area, or during some 
season of the year it becomes very scarce, and less 
wholesome substitutes have to be found ; and thus, 
though more fertile in offspring, they can never in- 
crease beyond the supply of food in the least 
favourable seasons. 

Many birds can only exist by migrating, when 
their food becomes scarce, to regions possessing a 
milder, or at least a different climate, though, as 
these migrating birds are seldom excessively abun- 
dant, it is evident that the countries they visit are 


still deficient in a constant and abundant supply of 
wholesome food. Those whose organization does not 
permit them to migrate when their food becomes 
periodically scarce, can never attain a large popu- 
lation. This is probably the reasons why wood- 
peckers are scarce with us, while in the tropics they 
are among the most abundant of solitary birds. 
Thus the house sparrrow is more abundant than the 
redbreast, because its food is more constant and 
plentiful, seeds of grasses being preserved during 
the winter, and our farm-yards and stubble-fields 
furnishing an almost inexhaustible supply. Why, as 
a general rule, are aquatic, and especially sea birds, 
very numerous in individuals ? Not because they 
are more prolific than others, generally the con- 
trary ; but because their food never fails, the sea- 
shores and river-banks daily swarming with a fresh 
supply of small mollusca and Crustacea. Exactly 
the same laws will apply to mammals. Wild cats 
are prolific and have few enemies ; why then are 
they never as abundant as rabbits ? The only in- 
telligible answer is, that their supply of food is 
more precarious. It appears evident, therefore, that 
so long as a country remains physically unchanged, 
the numbers of its animal population cannot ma- 
terially increase. If one species does so, some others 
requiring the same kind of food must diminish in 
proportion. The numbers that die annually must be 
immense ; and as the individual existence of each 
animal depends upon itself, those that die must be 


the weakest the very young, the aged, and the 
diseased while those that prolong their existence 
can only be the most perfect in health and vigour 
those who are best able to obtain food regularly, and 
avoid their numerous enemies. It is, as we com- 
menced by remarking, " a struggle for existence," in 
which the weakest and least perfectly organized 
must always succumb. 

The Abundance or Rarity of a Species dependent upon 
its more or less perfect Adaptation to the Con- 
ditions of Existence. 

It seems evident that what takes place among the 
individuals of a species must also occur among the 
several allied species of a group, viz., that those 
which are best adapted to obtain a regular supply 
of food, and to defend themselves against the attacks 
of their enemies and the vicissitudes of the seasons, 
must necessarily obtain and preserve a superiority 
in population ; while those species which from some 
defect of power or organization are the least capa- 
ble of counteracting the vicissitudes of food-supply, 
&c., must diminish in numbers, and, in extreme 
cases, become altogether extinct. Between these ex- 
tremes the species will present various degrees of 
capacity for ensuring the means of preserving life ; 
and it is thus we account for the abundance or rarity 
of species. Our ignorance will generally prevent us 
from accurately tracing the effects to their causes; 
but could we become perfectly acquainted with the 



organization and habits of the various species of ani- 
mals, and could we measure the capacity of each for 
performing the different acts necessary to its safety 
and existence under all the varying circumstances by 
which it is surrounded, we might be able even to 
calculate the proportionate abundance of individuals 
which is the necessary result. 

If now we have succeeded in establishing these 
two points 1st, that the animal population of a 
country is generally stationary, being kept down by a 
periodical deficiency of food, and other checks; and, 
2nd, that the comparative abundance or scarcity of the 
individuals of the several species is entirely due to their 
organization and resulting habits, which, rendering it 
more difficult to procure a regular supply of food and 
to provide for their personal safety in some cases than 
in others, can only be balanced by a difference in the 
population which have to exist in a given area we 
shall be in a condition to proceed to the consider- 
ation of varieties, to which the preceding remarks 
have a direct and very important application. 

Useful Variations will tend to Increase ; useless or hurt- 
fid Variations to Diminish. 

Most or perhaps all the variations from the 
typical form of a species must have some definite 
effect, however slight, on the habits or capacities of 
the individuals. Even a change of colour might, by 
rendering them more or less distinguishable, affect 
their safety; a greater or less development of hair 


might modify their habits. More important changes, 
such as an increase in the power or dimensions of 
the limbs or any of the external organs, would 
more or less affect their mode of procuring food 
or the range of country which they could inhabit. 
It is also evident that most changes would affect, 
either favourably or adversely, the powers of pro- 
longing existence. An antelope with shorter or 
weaker legs must necessarily suffer more from the 
attacks of the feline carnivora ; the passenger pigeon 
with less powerful wings would sooner or later be 
affected in its powers of procuring a regular supply 
of food ; and in both cases the result must neces- 
sarily be a diminution of the population of the 
modified species. If, on the other hand, any species 
should produce a variety having slightly increased 
powers of preserving existence, that variety must 
inevitably in time acquire a superiority in numbers. 
These results must follow as surely as old age, in- 
temperance, or scarcity of food produce an increased 
mortality. In both cases there may be many 
individual exceptions; but on the average the rule 
will invariably be found to hold good. All varieties 
will therefore fall into two classes those which 
under the same conditions would never reach the 
population of the parent species, and those which 
would in time obtain and keep a numerical su- 
periority. Now, let some alteration of physical 
conditions occur in the district a long period of 
drought, a destruction of vegetation by locusts, the 

D 2 


irruption of some new carnivorous animal seeking 
" pastures new " any change in fact tending to 
render existence more difficult to the species in 
question, and tasking its utmost powers to avoid 
complete extermination ; it is evident that, of all 
the individuals composing the species, those forming 
the least numerous and most feebly organized 
variety would suffer first, and, were the pressure 
severe, must soon become extinct. The same .causes 
continuing in action, the parent species would next 
suffer, would gradually diminish in numbers, and 
with a recurrence of similar unfavourable conditions 
might also become extinct. The superior variety 
would then alone remain, and on a return to 
favourable circumstances would rapidly increase in 
numbers and occupy the place of the extinct species 
and variety. 

Superior Varieties will ultimately Extirpate the original 

The variety would now have replaced the species, 
of which it would be a more perfectly developed 
and more highly organized form. It would be in 
all respects better adapted to secure its safety, and 
to prolong its individual existence and that of the 
race. Such a variety could not return to the ori- 
ginal form ; for that form is an inferior one, and 
could never compete with it for existence. Granted, 
therefore, a u tendency " to reproduce the original 
type of the species, still the variety must ever re- 


main preponderant in numbers, and under adverse 
physical conditions again alone survive. But this 
new, improved, and populous race might itself, in 
course of time, give rise to new varieties, exhibiting 
several diverging modifications of form, any of which, 
tending to increase the facilities for preserving ex- 
istence, must, by the same general law, in their 
turn become predominant. Here, then, we have 
progression and continued divergence deduced from the 
general laws which regulate the existence of animals 
in a state of nature, and from the undisputed fact 
that varieties do frequently occur. It is not, how- 
ever, contended that this result would be invariable; 
a change of physical conditions in the district might 
at times materially modify it, rendering the race 
which had been the most capable of supporting ex- 
istence under the former conditions now the least so, 
and even causing the extinction of the newer and, 
for a time, superior race, while the old or parent 
species and its first inferior varieties continued to 
flourish. Variations in unimportant parts might 
also occur, having no perceptible effect on the life- 
preserving powers ; and the varieties so furnished 
might run a course parallel with the parent species, 
either giving rise to further variations or returning 
to the former type. All we argue for is, that cer- 
tain varieties have a tendency to maintain their 
existence longer than the original species, and this 
tendency must make itself felt ; for though the doc- 
trine of chances or averages can never be trusted to 


on a limited scale, yet, if applied to high numbers, 
the results come nearer to what theory demands, 
and, as we approach to an infinity of examples, 
become strictly accurate. Now the scale on which 
nature works is so vast the numbers of individuals 
and the periods of time with which she deals ap- 
proach so near to infinity, than any cause, how- 
ever slight, and however liable to be veiled and 
counteracted by accidental circumstances, must in 
the end produce its full legitimate results. 

The Partial Reversion of Domesticated Varieties 

Let us now turn to domesticated animals, and in- 
quire how varieties produced among them are affected 
by the principles here enunciated. The essential 
difference in the condition of wild and domestic 
animals is this, that among the former, their well- 
being and very existence depend upon the full exer- 
cise and healthy condition of all their senses and 
physical powers, whereas, among the latter, these are 
only partially exercised, and in some cases are abso- 
lutely unused. A wild animal has to search, and 
often to labour, for every mouthful of food to ex- 
ercise sight, hearing, and smell in seeking it, and 
in avoiding dangers, in procuring shelter from the 
inclemency of the seasons, and in providing for the 
subsistence and safety of its offspring. There is no 
muscle of its body that is not called into daily and 
hourly activity; there is no sense or faculty that is 


not strengthened by continual exercise. The domes- 
tic animal, on the other hand, has food provided 
for it, is sheltered, and often confined, to guard it 
against the vicissitudes of thq seasons, is carefully 
secured from the attacks of its natural enemies, and 
seldom even rears its young without human assist- 
ance. Half of its senses and faculties become quite 
useless, and the other half are but occasionally 
called into feeble exercise, while even its muscular 
system is only irregularly brought into action. 

Now when a variety of such an animal occurs, 
having increased power or capacity in any organ or 
sense, such increase is totally useless, is never called 
into action, and may even exist without the animal 
ever becoming aware of it. In the wild animal, on 
the contrary, all its faculties and powers being 
brought into full action for the necessities of ex- 
istence, any increase becomes immediately available, 
is strengthened by exercise, and must even slightly 
modify the food, the habits, and the whole economy 
of the race. It creates as it were a new animal, 
one of superior powers, and which will necessarily 
increase in numbers and outlive those which are in- 
ferior to it. 

Again, in the domesticated animal all variations 
have an equal chance of continuance ; and those 
which would decidedly render a wild animal unable 
to compete with its fellows and continue its existence 
are no disadvantage whatever in a state of domesti- 
city. Our quickly fattening pigs, short-legged sheep 


pouter pigeons, and poodle dogs could never have 
come into existence in a state of nature, because 
the very first step towards such inferior forms would 
have led to the rapid extinction of the race; still 
less could they now exist in competition with their 
wild allies. The great speed but slight endurance 
of the race horse, the unwieldly strength of the 
ploughman's team, would both be useless in a state 
of nature. If turned wild on the pampas, such ani- 
mals would probably soon become extinct, or under 
favourable circumstances might each gradually lose 
those extreme qualities which would never be called 
into action, and in a few generations revert to a 
common type, which must be that in which the 
various powers and faculties are so proportioned to 
each other as to be best adapted to procure food and 
secure safety, that in which by the full exercise of 
every part of its organisation the animal can alone 
continue to live. Domestic varieties, when turned 
wild, must return to something near the type of 
the original wild stock, or become altogether extinct.* 
We see, then, that no inferences as to the per- 
manence of varieties in a state of nature can be 
deduced from the observations of those occurring 
among domestic animals. The two are so much op- 
posed to each other in every circumstance of their 

* That is, they will vary, and the variations which tend to 
adapt them to the wild state, and therefore approximate them 
to wild animals, will be preserved. Those individuals which do 
not vary sufficiently will perish. 


existence, that what applies to the one is almost sure 
not to apply to the other. Domestic animals are ab- 
normal, irregular, artificial ; they are subject to varia- 
tions which never occur and never can occur in a state 
of nature : their very existence depends altogether on 
human care ; so far are many of them removed from 
that just proportion of faculties, that true balance of 
organisation, by means of which alone an animal left 
to its own resources can preserve its existence and 
continue its race. 

Lamarck's Hypothesis very different from that now 

The hypothesis of Lamarck that progressive changes 
in species have been produced by the attempts of ani- 
mals to increase the development of their own or- 
gans, and thus modify their structure and habits has 
been repeatedly and easily refuted by all writers on 
the subject of varieties and species, and it seems to 
have been considered that when this was done the 
whole question has been finally settled ; but the view 
here developed renders such hypothesis quite un- 
necessary, by showing that similar results must be 
produced by the action of principles constantly at 
work in nature. The powerful retractile talons of 
the falcon- and the cat-tribes have not been produced 
or increased by the volition of those animals; but 
among the different varieties which occurred in the 
earlier and less highly organized forms of these 
groups, those always survived longest which had the 


greatest facilities for seizing their prey. Neither did 
the giraffe acquire its long neck by desiring to reach 
the foliage of the more lofty shrubs, and constantly 
stretching it neck for the purpose, but because any 
varieties which occurred among its antitypes with a 
longer neck than usual at once secured a fresh range 
of pasture over the same ground as their shorter-necked 
companions, and on the first scarcity of food were 
thereby enabled to outlive them. Even the peculiar 
colours of many animals, more especially of insects, so 
closely resembling the soil or leaves or bark on which 
they habitually reside, are explained on the same 
principle ; for though in the course of ages varieties 
of many tints may have occurred, yet those races 
having colours best adapted to concealment from their 
enemies would inevitably survive the longest. We have 
also here an acting cause to account for that balance 
so often observed in nature, a deficiency in one set 
of organs always being compensated by an increased 
development of some others powerful wings accom- 
panying weak feet, or great velocity making up for 
the absence of defensive weapons ; for it has been 
shown that all varieties in which an unbalanced 
deficiency occurred could not long continue their 
existence. The action of this principle is exactly 
like that of the centrifugal governor of the steam 
engine, which checks and corrects any irregularities 
almost before they become evident; and in like 
manner no unbalanced deficiency in the animal king- 
dom can ever reach any conspicuous magnitude, 


because it would make itself felt at the very first 
step, by rendering existence difficult and extinction 
almost sure soon to follow. An origin such as is 
here advocated will also agree with the peculiar 
character of the modifications of form and structure 
which obtain in organized beings the many lines 
of divergence from a central type, the increasing 
efficiency and power of a particular organ through 
a succession of allied species, and the remarkable 
persistence of unimportant parts, such as colour, tex- 
ture of plumage and hair, form of horns or crests, 
through a series of species differing considerably 
in more essential characters. It also furnishes us 
with a reason for that "more specialized structure" 
which Professor Owen states to be a characteristic 
of recent compared with extinct forms, and which 
would evidently be the result of the progressive 
modification of any organ applied to a special pur- 
pose in the animal economy. 


We believe we have now shown that there is a 
tendency in nature to the continued progression of 
certain classes of varieties further and further from 
the original type a progression to which there ap- 
pears no reason to assign any definite limits and 
that the same principle which produces this result 
in a state of nature will also explain why domestic 
varieties have a tendency, when they become wild, 
to revert to the original type. This progression, 


by minute steps, in various directions, but always 
checked and balanced by the necessary conditions, 
subject to which alone existence can be preserved, 
may, it is believed, be followed out so as to agree 
with all the phenomena presented by organized be- 
ings, their extinction and succession in past ages, 
and all the extraordinary modifications of form, in- 
stinct and habits which they exhibit. 




THERE is no more convincing proof of the truth of 
a comprehensive theory, than its power of absorbing 
and finding a place for new facts, and its capability 
of interpreting phenomena which had been previously 
looked upon as unaccountable anomalies. It is thus 
that the law of universal gravitation and the undu- 
latory theory of light have become established and 
universally accepted by men of science. Fact after 
tact has been brought forward as being apparently 
inconsistent with them, and one after another these 
very facts have been shown to be the consequences 
of the laws they were at first supposed to disprove. 
A false theory will never stand this test. Advancing 
knowledge brings to light whole groups of facts 
which it cannot deal with, and its advocates steadily 
decrease in numbers, notwithstanding the ability 
and scientific skill with which it may have been 
supported. The great name of Edward Forbes did 
not prevent his theory of " Polarity in the distribu- 
tion of Organic beings in Time " from dying a 
natural death ; but the most striking illustration of 
the behaviour of a false theory is to be found in the 
" Circular and Quinarian System " of classification 


propounded by MacLeay, and developed by Swainson, 
with an amount of knowledge and ingenuity that 
have rarely been surpassed. This theory was emi- 
nently attractive, both from its symmetry and com- 
pleteness, and from the interesting nature of the 
varied analogies and affinities which it brought to 
light and made use of. The series of Natural His- 
tory volumes in " Lardner's Cabinet Cyclopaedia," 
in which Mr. Swainson developed it in most de- 
partments of the animal kingdom, made it widely 
known ; and in fact for a long time these were 
the best and almost the only popular text-books for 
the rising generation of naturalists. It was favour- 
ably received too by the older school, which was 
perhaps rather an indication of its unsoundness. A 
considerable number of well-known naturalists either 
spoke approvingly of it, or advocated similar princi- 
ples, and for a good many years it was decidedly 
in the ascendent. With such a favourable introduc- 
tion, and with such talented exponents, it must have 
become established if it had had any germ of truth 
in it; yet it quite died out in a few short years, 
its very existence is now a matter of history ; and so 
rapid was its fall that its talented creator, Swainson, 
perhaps lived to be the last man who believed in it. 

Such is the course of a false theory. That of a 
true one is very different, as may be well seen by 
the progress of opinion on the subject of Natural 
Selection. In less than eight years "The Origin of 
Species " has produced conviction in the minds of 


a majority of the most eminent living men of science. 
New facts, new problems, new difficulties as they 
arise are accepted, solved or removed by this theory; 
and its principles are illustrated by the progress and 
conclusions of every well established branch of human 
knowledge. It is the object of the present essay to 
show how it has recently been applied to connect to- 
gether and explain a variety of curious facts which 
had long been considered as inexplicable anomalies. 

Importance of the Principle of Utility. 

Perphaps no principle has ever been announced 
so fertile in results as that which Mr. Darwin so 
earnestly impresses upon us, and which is indeed a 
necessary deduction from the theory of Natural Se- 
lection, namely that none of the definite facts of 
organic nature, no special organ, no characteristic 
form or marking, no peculiarities of instinct or of 
habit, no relations between species or between groups 
of species can exist, but which must now be or 
once have been useful to the individuals or the races 
which possess them. This great principle gives us a 
clue which we can follow out in the study of many 
recondite phenomena, and leads us to seek a mean- 
ing and a purpose of some definite character in 
minutisB which we should be otherwise almost sure 
to pass over as insignificant or unimportant. 

Popular Theories of Colour in Animals. 
The adaptation of the external colouring of animals 


to their conditions of life has long been recognised, 
and has been imputed either to an originally created 
specific peculiarity, or to the direct action of climate, 
soil, or food. Where the former explanation has been 
accepted, it has completely checked inquiry, since we 
could never get any further than the fact of the 
adaptation. There was nothing more to be known 
about the matter. The second explanation was soon 
found to be quite inadequate to deal with all the varied 
phases of the phenomena, and to be contradicted by 
many well-known facts. For example, wild rabbits are 
always of grey or brown tints well suited for conceal- 
ment among grass and fern. But when these rabbits 
are domesticated, without any change of climate or 
food, they vary into white or black, and these varie- 
ties may be multiplied to any extent, forming white 
or black races. Exactly the same thing has occurred 
with pigeons ; and in the case of rats and mice, 
the white variety has not been shown to be at all 
dependent on alteration of climate, food, or other 
external conditions. In many cases the wings of an 
insect not only assume the exact tint of the bark 
or leaf it is accustomed to rest on, but the form 
and veining of the leaf or the exact rugosity of 
the bark is imitated ; and these detailed modifications 
cannot be reasonably imputed to climate or to food, 
since in many cases the species does not feed on 
the substance it resembles, and when it does, no 
reasonable connexion can be shown to exist between 
the supposed cause and the effect produced. It was 


reserved for the theory of Natural Selection to solve 
all these problems, and many others which were not 
at first supposed to be directly connected with them. 
To make these latter intelligible, it will be necessary 
to give a sketch of the whole series of phenomena 
which may be classed under the head of useful or 
protective resemblances. 

Importance of Concealment as Influencing Colour. 

Concealment, more or less complete, is useful to 
many animals, and absolutely essential to some. Those 
which have numerous enemies from which they can- 
not escape by rapidity of motion, find safety in con- 
cealment. Those which prey upon others must also 
be so constituted as not to alarm them by their pre- 
sence or their approach, or they would soon die of 
hunger. Now it is remarkable in how many cases 
nature gives this boon to the animal, by colouring it 
with such tints as may best serve to enable it to es- 
cape from its enemies or to entrap its prey. Desert 
animals as a rule are desert-coloured. The lion is 
a typical example of this, and must be almost in- 
visible when crouched upon the sand or among 
desert rocks and stones. Antelopes are all more or 
less sandy-coloured. The camel is pre-eminently so. 
The Egyptian cat and the Pampas cat are sandy 
or earth-coloured. The Australian kangaroos are of 
the same tints, and the original colour of the wild 
horse is supposed to have been a sandy or clay- 


The desert birds are still more remarkably pro- 
tected by their assimilative hues. The stonechats, the 
larks, the quails, the goatsuckers and the grouse, 
which abound in the North African and Asiatic 
deserts, are all tinted and mottled so as to resemble 
with wonderful accuracy the average colour and as- 
pect of the soil in the district they inhabit. The 
Rev. H. Tristram, in his account of the ornithology 
of North Africa in the 1st volume of the " Ibis,'* 
says : "In the desert, where neither trees, brush- 
wood, nor even undulation of the surface afford the 
slightest protection to its foes, a modification of colour 
which shall be assimilated to that of the surround- 
ing country, is absolutely necessary. Hence without 
exception the upper plumage of every bird, whether 
lark, chat, sylvain, or sand-grouse, and also the fur 
of all the s,,ialler mammals, and the skin of all tJie 
snakes and lizards, is of one uniform isabelline or 
sand colour." After the testimony of so able an 
observer it is unnecessary to adduce further exam- 
ples of the protective colours of desert animals. 

Almost equally striking are the cases of arctic 
animals possessing the white colour that best con- 
ceals them upon snowfields and icebergs. The polar 
bear is the only bear that is white, and it lives 
constantly among snow and ice. The arctic fox, the 
ermine and . the alpine hare change to white in 
winter only, because in summer white would be 
more conspicuous than any other colour, and there- 
fore a danger rather than a protection; but the 


American polar hare, inhabiting regions of almost 
perpetual snow, is white all the year round. Other 
animals inhabiting the same Northern regions do 
not, however, change colour. The sable is a good 
example, for throughout the severity of a Siberian 
winter it retains its rich brown fur. But its habits 
are such that it does not need the protection of 
colour, for it is said to be able to subsist on fruits 
and berries in winter, and to be so active upon the 
trees as to catch small birds among the branches. 
So also the woodchuck of Canada has a dark-brown 
fur ; but then it lives in burrows and frequents river 
banks, catching fish and small animals that live in 
or near the water. 

Among birds, the ptarmigan is a fine example of 
protective colouring. Its summer plumage so exactly 
harmonizes with the lichen-coloured stones among 
which it delights to sit, that a person may walk 
through a flock of them without seeing a single 
bird; while in winter its white plumage is an 
almost equal protection. The snow-bunting, the jer- 
falcon, and the snowy owl are also white-coloured 
birds inhabiting the arctic regions, and there can 
be little doubt but that their colouring is to some 
extent protective. 

Nocturnal animals supply us with equally good illus- 
trations. Mice, rats, bats, and moles possess the least 
conspicuous of hues, and must be quite invisible at 
times when any light colour would be instantly seen. 
Owls and goatsuckers are of those dark mottled tints 

E 2 


that will assimilate with bark and lichen, and thus 
protect them during the day, and at the same time 
be inconspicuous in the dusk. 

It is only in the tropics, among forests which never 
lose their foliage, that we find whole groups of birds 
whose chief colour is green. The parrots are the most 
striking example, but we have also a group of green 
pigeons in the East ; and the barbets, leaf-thrushes, 
bee-eaters, white-eyes, turacos, and several smaller 
groups, have so much green in their plumage as to 
tend greatly to conceal them among the foliage. 

Special Modifications of Colour. 

The conformity of tint which has been so far shown 
to exist between animals and their habitations is of 
a somewhat general character; we will now consider 
the cases of more special adaptation. If the lion is 
enabled by his sandy colour readily to conceal him- 
self by merely crouching down upon the desert, how, 
it may be asked, do the elegant markings of the 
tiger, the jaguar, and the other large cats agree 
with this theory ? We reply that these are generally 
cases of more or less special adaptation. The tiger 
is a jungle animal, and hides himself among tufts 
of grass or of bamboos, and in these positions the 
vertical stripes with which his body is adorned must 
so assimilate with the vertical stems of the bamboo, 
as to assist greatly in concealing him from his ap- 
proaching prey. How remarkable it is that besides 
the lion and tiger, almost all the other large cats 


are arboreal in their habits, and almost all have 
ocellated or spotted skins, which must certainly tend 
to blend them with the background of foliage ; while 
the one exception, the puma, has an ashy brown 
uniform fur, and has the habit of clinging so closely 
to a limb of a tree while waiting for his prey to 
pass beneath as to be hardly distinguishable from the 

Among birds, the ptarmigan, already mentioned, 
must be considered a remarkable case of special 
adaptation. Another is a South-American goatsucker 
(Caprimulgus rupestris) which rests in the bright 
sunshine on little bare rocky islets in the Upper Eio 
Negro, where its unusually light colours so closely 
resemble those of the rock and sand, that it can 
scarcely be detected till trodden upon. 

The Duke of Argyll, in his " Reign of Law," has 
pointed out the admirable adaptation of the colours 
of the woodcock to its protection. The various 
browns and yellows and pale ash-colour that occur 
in fallen leaves are all reproduced in its plumage, so 
that when according to its habit it rests upon the 
ground under trees, it is almost impossible to detect 
it. In snipes the colours are modified so as to be 
equally in harmony with the prevalent forms and 
colours of marshy vegetation. Mr. J. M. Lester, 
in a paper read before the Rugby School Natural 
History Society, observes : " The wood-dove, when 
perched amongst the branches of its favourite fir, is 
scarcely discernible ; whereas, were it among some 


lighter foliage, the blue and purple tints in its plumage 
would far sooner betray it. The robin redbreast too, 
although it might be thought that the red on its breasfc 
made it much easier to be seen, is in reality not at 
all endangered by it, since it generally contrives to 
get among some russet or yellow fading leaves, where 
the red matches very well with the autumn tints, 
and the brown of the rest of the body with the bare 

Reptiles offer us many similar examples. The most 
arboreal lizards, the iguanas, are as green as the leaves 
they feed upon, and the slender whip-snakes are ren- 
dered almost invisible as they glide among the foliage 
by a similar colouration. How difficult it is some- 
times to catch sight of the little green tree-frogs 
sitting on the leaves of a small plant enclosed in a 
glass case in the Zoological Gardens ; yet how much 
better concealed must they be among the fresh green 
damp foliage of a marshy forest. There is a North- 
American frpor^' found on lichen-covered rocks and 

-~ A 

walls, which is so coloured as exactly to resemble 
them, and as long as it remains quiet would certainly 
escape detection. Some of the geckos which cling 
motionless on the trunks of trees in the tropics, are 
of such curiously marbled colours as to match exactly 
with the bark they rest upon. 

In every part of the tiopics there are tree-snakes 
that twist among boughs and shrubs, or lie coiled up 
on the dense masses of foliage. These are of many 
distinct groups, and comprise both venomous and 


harmless genera; but almost all of them are of a 
beautiful green colour, sometimes more or less adorned 
with white or dusky bands and spots. There can 
be little doubt that this colour is doubly useful to 
them, since it will tend to conceal them from their 
enemies, and will lead their prey to approach them 
unconscious of danger. Dr. Gunther informs me 
that there is only one genus of true arboreal snakes 
(Dipsas) whose colours are rarely green, but are of 
various shades of black, brown, and olive, and these 
are all nocturnal reptiles, and there can be little doubt 
conceal themselves during the day in holes, so that the 
green protective tint would be useless to them, and 
they accordingly retain the more usual reptilian hues. 
Fishes present similar instances. Many flat fish, as 
for example the flounder and the skate, are exactly 
the colour of the gravel or sand on which they 
habitually rest. Among the marine flower gardens 
of an Eastern coral reef the fishes present every 
variety of gorgeous colour, while the river fish even 
of the tropics rarely if ever have gay or conspicuous 
markings. A very curious case of this kind of ad- 
aptation occurs in the sea-horses (Hippocampus) of 
Australia, some of which bear long foliaceous ap- 
pendages resembling seaweed, and are of a brilliant 
red colour ; and they are known to live among sea- 
weed of the same hue, so that when at rest they 
must be quite invisible. There are now in the aqua- 
rium of the Zoological Society some slender green 
pipe-fish which fasten themselves to any object at 


the bottom by their prehensile tails, and float about 
with the current, looking exactly like some simple 
cylindrical algae. 

It is, however, in the insect world that this 
principle of the adaptation of animals to their en- 
vironment is most fully and strikingly developed. 
In order to understand how general this is, it is 
necessary to enter somewhat into details, as we shall 
thereby be better able to appreciate the significance 
of the still more remarkable phenomena we shall 
presently have to discuss. It seems to be in pro- 
portion to their sluggish motions or the absence of 
other means of defence, that insects possess the pro- 
tective colouring. In the tropics there are thousands 
of species of insects which rest during the day cling- 
ing to the bark of dead or fallen trees ; and the 
greater portion of these are delicately mottled with 
gray and brown tints, which though symmetrically 
disposed and infinitely varied, yet blend so completely 
with the usual colours of the bark, that at two or 
three feet distance they are quite undistinguishable. 
In some cases a species is known to frequent only 
one species of tree. This is the case with the com- 
mon South American long -horned beetle (Onychocerus 
scorpio) which, Mr. Bates informed me, is found 
only on a rough-barked tree, called Tapiriba, on the 
Amazon. It is very abundant, but so exactly does 
it resemble the bark in colour and rugosity, and so 
closely does it cling to the branches, that until it 
moves it is absolutely invisible ! An allied species (0. 


concentricus) is found only at Para, on a distinct 
species of tree, the bark of which it resembles with 
equal accuracy. Both these insects are abundant, and 
we may fairly conclude that the protection they derive 
from this strange concealment is at least one of the 
causes that enable the race to flourish. 

Many of the species of Cicindela, or tiger beetle, 
will illustrate this mode of protection. Our common 
Cicindela campestris frequents grassy banks, and is 
of a beautiful green colour, while C. maritima, which 
is found only on sandy sea- shores, is of a pale bronzy 
yellow, so as to be almost invisible. A great number 
of the species found by myself in the Malay islands 
are similarly protected. The beautiful Cicindela glo- 
riosa, of a very deep velvety green colour, was only 
taken upon wet mossy stones in the bed of a moun- 
tain stream, where it was with the greatest difficulty 
detected. A large brown species (C. heros) was found 
chiefly on dead leaves in forest paths ; and one which 
was never seen except on the wet mud of salt marshes 
was of a glossy olive so exactly the colour of the mud 
as only to be distinguished when the sun shone, by its 
shadow! Where the sandy beach was coralline and 
nearly white, I found a very pale Cicindela ; wherever 
it was volcanic and black, a dark species of the same 
genus was sure to be met with. 

There are in the East small beetles of the family 
Buprestido3 which generally r3st on the midrib of a 
leaf, and the naturalist often hesitates before picking 
them off, so closely do they resemble pieces of bird's 


dung. Kirby and Spence mention the small beetle 
Onthophilus sulcatus as being like the seed of an um- 
belliferous plant ; and another small weevil, which is 
much persecuted by predatory beetles of the genus 
Harpalus, is of the exact colour of loamy soil, and 
was found to be particularly abundant in loam pits. 
Mr. Bates mentions a small beetle (Chlamys pilula) 
which was ^indistinguishable by the eye from the 
dung of caterpillars, while some of the Cassidse, from 
their hemispherical forms and pearly gold colour, re- 
semble glittering dew-drops upon the leaves. 

A number of our small brown and speckled weevils 
at the approach of any object roll off the leaf they 
are sitting on, at the same time drawing in their legs 
and antennae, which fit so perfectly into cavities for 
their reception that the insect becomes a mere oval 
brownish lump, which it is hopeless to look for among 
the similarly coloured little stones and earth pellets 
among which it lies motionless. 

The distribution of colour in butterflies and moths 
respectively is very instructive from this point of 
view'. The former have all their brilliant colouring on 
the upper surface of all four wings, while the under 
surface is almost always soberly coloured, and often 
very dark and obscure. The moths on the contrary 
have generally their chief colour on the hind wings 
only, the upper wings being of dull, sombre, and often 
imitative tints, and these generally conceal the hind 
wings when the insects are in repose. This arrange- 
ment of the colours is therefore eminently protective, 


because the butterfly always rests with his wings raised 
so as to conceal the dangerous brilliancy of his upper 
surface. It is probable that if we watched their habits 
sufficiently we should find the under surface of the 
wings of butterflies very frequently imitative and pro- 
tective. Mr. T. W. Wood has pointed out that the 
little orange-tip butterfly often rests in the evening on 
the green and white flower heads of an umbelliferous 
plant, and that when observed in this position the beau- 
tiful green and white mottling of the under surface 
completely assimilates with the flower heads and ren- 
ders the creature very difficult to be seen. It is pro- 
bable that the rich dark colouring of the under side of 
our peacock, tortoiseshell, and red-admiral butterflies 
answers a similar purpose. 

Two curious South American butterflies that always 
settle on the trunks of trees (Gynecia clirce and Calli- 
zona acesta) have the under surface curiously striped 
and mottled, and when viewed obliquely must closely 
assimilate with the appearance of the furrowed bark 
of many kinds of trees. But the most wonderful 
and undoubted case of protective resemblance in a 
butterfly which I have ever seen, is that of the 
common Indian Kallima inachis, and its Malayan 
ally, Kallima paralekta. The upper surface of these 
insects is very striking and showy, as they are of 
a large size, and are adorned with a broad band of 
rich orange on a deep bluish ground. The under 
side is very variable in colour, so that out of fifty 
specimens no two can be found exactly alike, but 


every one of them will be of some shade of ash or 
brown or ochre, such as are found among dead, dry, 
or decaying leaves. The apex of the upper wings 
is produced into an acute point, a very common form 
in the leaves of tropical shrubs and trees, and the 
lower wings are also produced into a short narrow 
tail. Between these two points runs a dark curved 
line exactly representing the midrib of a leaf, and 
from this radiate on each side a few oblique lines, 
which serve to indicate the lateral veins of a leaf. 
These marks are more clearly seen on the outer por- 
tion of the base of the wings, and on the inner side 
towards the middle and apex, and it is very curious 
to observe how the usual marginal and transverse 
stria? of the group are here modified and strengthened 
so as to become adapted for an imitation of the 
venation of a leaf. We come now to a still more 
extraordinary part of the imitation, for we find re- 
presentations of leaves in every stage of decay, 
variously blotched and mildewed and pierced with 
holes, and in many cases irregularly covered with 
powdery black dots gathered into patches and spots, 
so closely resembling the various kinds of minute 
fungi that grow on dead leaves that it is impossible 
to avoid thinking at first sight that the butterflies 
themselves have been attacked by real fungi. 

But this resemblance, close as it is, would be of little 
use if the habits of the insect did not accord with it. 
If the butterfly sat upon leaves or upon flowers, or 
opened its wings so as to expose the upper surface, or 


exposed and moved its head and antenna? as many 
other butterflies do, its disguise would be of little 
avail. We might be sure, however, from the analogy 
of many other cases, that the habits of the insect are 
such as still further to aid its deceptive garb ; but 
we are not obliged to make any such supposition, since 
I myself had the good fortune to observe scores of 
Kallima paralekta, in Sumatra, and to capture many 
of them, and can vouch for the accuracy of the fol- 
lowing details. These butterflies frequent dry forests 
and fly very swiftly. They were never seen to settle 
on a flower or a green leaf, but were many times lost 
sight of in a bush or tree of dead leaves. On such oc- 
casions they were generally searched for in vain, for 
while gazing intently at the very spot where one had 
disappeared, it would often suddenly dart out, and 
again vanish twenty or fifty yards further on. On 
one or two occasions the insect was detected reposing, 
and it could then be seen how completely it assimilates 
itself to the surrounding leaves. It sits on a nearly 
upright twig, the wings fitting closely back to back, 
concealing the antennaB and head, which are drawn up 
between their bases. The little tails of the hind wing 
touch the branch, and form a perfect stalk to the leaf, 
which is supported in its place by the claws of the 
middle pair of feet, which are slender and inconspicu- 
ous. The irregular outline of the wings gives exactly 
the perspective effect of a shrivelled leaf. We thus 
have size, colour, form, markings, and habits, all com- 
bining together to produce a disguise which may be 


said to be absolutely perfect ; and the protection which 
it affords is sufficiently indicated by the abundance of 
the individuals that possess it. 

The Rev. Joseph Greene has called attention to the 
striking harmony between the colours of those British 
moths which are on the wing in autumn and winter, 
and the prevailing tints of nature at those seasons. In 
autumn various shades of yellow and brown prevail, 
and he shows that out of fifty-two species that fly 
at this season, no less than forty-two are of corres- 
ponding colours. Orgyia antiqua, 0. gonostigma, the 
genera Xanthia, Glsea, and Ennomos are examples. In 
winter, gray and silvery tints prevail, and the genus 
Chematobia and several species of Hybernia which 
fly during this season are of corresponding hues. No 
doubt if the habits of moths in a state of nature were 
more closely observed, we should find many cases of 
special protective resemblance. A few such have al- 
ready been noticed. Agriopis aprilina, Acronycta psi, 
and many other moths which rest during the day on the 
north side of the trunks of trees can with difficulty bo 
distinguished from the grey and green lichens that 
cover them. The lappet moth (Gastropacha querci) 
closely resembles both in shape and colour a brown 
dry leaf; and the well-known buff- tip moth, when at 
rest is like the broken end of a lichen-covered branch. 
There are some of the small moths which exactly re- 
semble the dung of birds dropped on leaves, and on this 
point Mr. A. Sidgwick, in a paper read before the 
Rugby School Natural History Society, gives the 


following original observation : " I myself have more 
than once mistaken Cilix compressa, a little white and 
grey moth, for a piece of bird's dung dropped upon a 
leaf, and vice versa the dung for the moth. Bryophila 
Glandifera and Perla are the very image of the mortar 
walls on which they rest ; and only this summer, in 
Switzerland, I amused myself for some time in watch- 
ing a moth, probably Larentia tripunctaria, fluttering 
about quite close to me, and then alighting on a wall of 
the stone of the district which it so exactly matched as 
to be quite invisible a couple of yards off." There are 
probably hosts of these resemblances which have not 
been observed, owing to the difficulty of finding many 
of the species in their stations of natural repose. Ca- 
terpillars are also similarly protected. Many exactly 
resemble in tint the leaves they feed upon ; others are 
like little brown twigs, and many are so strangely 
marked or humped, that when motionless they can 
hardly be taken to be living creatures at all. Mr. 
Andrew Murray has remarked how closely the larva of 
the peacock moth (Saturnia pavonia-minor) harmonizes 
in its ground colour with that of the young buds of 
heather on which it feeds, and that the pink spots with 
which it is decorated correspond with the flowers and 
flower-buds of the same plant. 

The whole order of Orthoptera, grasshoppers, locusts, 
crickets, &c., are protected by their colours harmoniz- 
ing with that of the vegetation or the soil on which 
they live, and in no other group have we such strik- 
ing examples of special resemblance. Most of the 


tropical Mantidae and Locustidsc are of the exact tint of 
the leaves on which they habitually repose, and many 
of them in addition have the veinings of their wings 
modified so as exactly to imitate that of a leaf. This 
is carried to the furthest possible extent in the wonder- 
ful genus, Phyllium, the ec walking leaf," in which not 
only are the wings perfect imitations of leaves in every 
detail, but the thorax and legs. are flat, dilated, and 
leaf-like ; so that when the living insect is resting 
among the foliage on which it feeds, the closest ob- 
servation is often unable to distinguish between the 
animal and the vegetable. 


The whole family of the Phasmidce, or spectres, to 
which this insect belongs, is more or less imitative, and 
a great number of the species are called " walking-stick 
insects," from their singular resemblance to twigs and 
branches. Some of these are a foot long and as thick 
as one's finger, and their whole colouring, form, rugos- 
ity, and the arrangement of the head, legs, and anten- 
na?, are such as to render them absolutely identical in 
appearance with dead sticks. They hang loosely about 
shrubs in the forest, and have the extraordinary habit 
of stretching out their legs unsymmetrically, so as to 
render the deception more complete. One of these 
creatures obtained by myself in Borneo (Ceroxylus 
laceratus) was covered over with foliaceous excrescences 
of a clear olive green colour, so as exactly to resemble a 
stick grown over by a creeping moss or jungermannia. 
The Dyak who brought it me assured me it was grown 
over with moss although alive, and it was only after a 


most minute examination that I could convince myself 
it was not so. 

We need not adduce any more examples to show 
how important are the details of form and of colouring 
in animals, and that their very existence may often 
depend upon their being by these means concealed from 
their enemies. This kind of protection is found appar- 
ently in every class and order, for it has been noticed 
wherever we can obtain sufficient knowledge of the 
details of an animal's life-history. It varies in degree, 
from the mere absence of conspicuous colour or a 
general harmony with the prevailing tints of nature, 
up to such a minute and detailed resemblance to inor- 
ganic or vegetable structures as to realize the talisman 
of the fairy tale, and to give its possessor the power of 
rendering itself invisible. 

Theory of Protective Colouring. 

We will now endeavour to show how these wonderful 
resemblances have most probably been brought about. 
Returning to the higher animals, let us consider the 
remarkable fact of the rarity of white colouring in the 
mammalia or birds of the temperate or tropical zones 
in a state of nature. There is not a single white land- 
bird or quadruped in Europe, except the few arctic or 
alpine species, to which white is a protective colour. 
Yet in many of these creatures there seems to be no 
inherent tendency to avoid white, for directly they are 
domesticated white varieties arise, and appear to thrive 
as well as others. We have white mice and rats, white 



cats, horses, dogs, and cattle, white poultry, pigeons, 
turkeys, and ducks, and white rabbits. Some of these 
animals have been domesticated for a long period, 
others only for a few centuries ; but in almost every 
case in which an animal has been thoroughly domesti- 
cated, parti-coloured and white varieties are produced 
and become permanent. 

It is also well known that animals in a state of nature 
produce white varieties occasionally. Blackbirds, star- 
lings, and crows are occasionally seen white, as well as 
elephants, deer, tigers, hares, moles, and many other 
animals ; but in no case is a permanent white race 
produced. Now there are no statistics to show that 
the normal- coloured parents produce white offspring 
oftener under domestication than in a state of nature, 
and we have no right to make such an assumption if 
the facts can be accounted for without it. But if the 
colours of animals do really, in the various instances 
already adduced, serve for their concealment and pre- 
servation, then white or any other conspicuous colour 
must be hurtful, and must in most cases shorten an 
animal's life. A white rabbit would be more surely the 
prey of hawk or buzzard, and the white mole, or field 
mouse, could not long escape from the vigilant owl. 
So, also, any deviation from those tints best adapted 
to conceal a carnivorous animal would render the pur- 
suit of its prey much more difficult, would place it at 
a disadvantage among its fellows, and in a time of 
scarcity would probably cause it to starve to death. 
On the other hand, if an animal spreads from a 


temperate into an arctic district, the conditions are 
changed. During a large portion of the year, and 
just when the struggle for existence is most severe, 
white is the prevailing tint of nature, and dark colours 
will be the most conspicuous. The white varieties will 
now have an advantage ; they will escape from their 
enemies or will secure food, while their brown com- 
panions will be devoured or will starve ; and as " like 
produces like" is the established rule in nature, the 
white race will become permanently established, and 
dark varieties, when they occasionally appear, will soon 
die out from their want of adaptation to their environ- 
ment. In each case the fittest will survive, and a race 
will be eventually produced adapted to the conditions 
in which it lives. 

We have here an illustration of the simple and effec- 
tual means by which animals are brought into harmony 
with the rest of nature. That slight amount of varia- 
bility in every species, which we often look upon as 
something accidental or abnormal, or so insignificant as 
to be hardly worthy of notice, is yet the foundation of 
all those wonderful and harmonious resemblances which 
play such an important part in the economy of nature. 
Variation is generally very small in amount, but it 
is all that is required, because the change in the 
external conditions to which an animal is subject is 
generally very slow and intermittent. When these 
changes have taken place too rapidly, the result has 
often been the extinction of species ; but the general 
rule is, that climatal and geological changes go on 

F 2 


slowly, and the slight but continual variations in the 
colour, form, and structure of all animals, has fur- 
nished individuals adapted to these changes, and who 
have become the progenitors of modified races. Eapid 
multiplication, incessant slight variation, and survival 
of the fittest these are the laws which ever keep the 
organic world in harmony with the inorganic, and 
with itself. These are the laws which we believe have 
produced all the cases of protective resemblance already 
adduced, as well as those still more curious examples 
we have yet to bring before our readers. 

It must always be borne in mind that the more won- 
derful examples, in which there is not only a general 
but a special resemblance as in the walking leaf, the 
mossy phasma, and the leaf-winged butterfly repre- 
sent those few instances in which the process of modi- 
fication has been going on during an immense series 
of generations. They all occur in the tropics, where 
the conditions of existence are the most favourable, 
and where climatic changes have for long periods 
been hardly perceptible. In most of them favourable 
variations both of colour, form, structure, and instinct 
or habit, must have occurred to produce the perfect 
adaptation we now behold. All these are known to 
vary, and favourable variations when not accompanied 
by others that were unfavourable, would certainly 
survive. At one time a little step might be made in 
this direction, at another time in that a change of 
conditions might sometimes render useless that which 


it had taken ages to produce great and sudden physi- 


cal modifications might often produce the extinction 
of a race just as it was approaching perfection, and a 
hundred checks of which we can know nothing may 
have retarded the progress towards perfect adaptation ; 
so that we can hardly wonder at there being so few 
cases in which a completely successful result has been 
attained as shown by the abundance and wide diffusion 
of the creatures so protected. 

Objection that Colour, as being dangerous, should not exist 
in Nature. 

It is as well here to reply to an objection that will 
no doubt occur to many readers that if protection is 
so useful to all animals, and so easily brought about 
by variation and survival of the fittest, there ought 
to be no conspicuously-coloured creatures ; and they 
will perhaps ask how we account for the brilliant 
birds, and painted snakes, and gorgeous insects, that 
occur abundantly all over the world. It will be advis- 
able to answer this question rather fully, in order that 
we may be prepared to understand the phenomena of 
" mimicry," which it is the special object of this paper 
to illustrate and explain. 

The slightest observation of the life of animals will 
show us, that they escape from their enemies and 
obtain their food in an infinite number of ways ; and 
that their varied habits and instincts are in every case 
adapted to the conditions of their existence. The 
porcupine and the hedgehog have a defensive armour 
that saves them from the attacks of most animals. 


The tortoise is not injured by the conspicuous colours 
of his shell, because that shell is in most cases an effec- 
tual protection to him. The skunks of North America 
find safety in their power of emitting an unbearably 
offensive odour; the beaver in its aquatic habits and 
solidly constructed abode. In some cases the chief 
danger to an animal occurs at one particular period of 
its existence, and if that is guarded against its numbers 
can easily be maintained. This is the case with many 
birds, the eggs and young of which are especially ob- 
noxious to clanger, and we find accordingly a variety 
of curious contrivances to protect them. "We have 
nests carefully concealed, hung from the slender extre- 
mities of grass or boughs over water, or placed in the 
hollow of a tree with a very small opening. When 
these precautions are successful, so many more indivi- 
duals will be reared than can possibly find food during 
the least favourable seasons, that there will always be a 
number of weakly and inexperienced young birds who 
will fall a prey to the enemies of the race, and thus 
render necessary for the stronger and healthier indi- 
viduals no other safeguard than their strength and 
activity. The instincts most favourable to the produc- 
tion and rearing of offspring will in these cases be 
most important, and the survival of the fittest will act 
so as to keep up and advance those instincts, while 
other causes which tend to modify colour and marking 
may continue their action almost unchecked. 

It is perhaps in insects that we may best study the 
varied means by which animals are defended or con- 


cealed. One of the uses of the phosphorescence with 
which many insects are furnished, is probably to 
frighten away their enemies ; for Kirby and Spence 
state that a ground beetle (Carabus) has been observed 
running round and round a luminous centipede as if 
afraid to attack it. An immense number of insects 
have stings, and some stingless ants of the genus Poly- 
rachis are armed with strong and sharp spines on the 
back, which must render them unpalatable to many of 
the smaller insectivorous birds. Many beetles of the 
family Curculionidse have the wing cases and other ex- 
ternal parts so excessively hard, that they cannot be 
pinned without first drilling a hole to receive the pin, 
and it is probable that all such find a protection in 
this excessive hardness. Great numbers of insects hide 
themselves among the petals of flowers, or in the cracks 
of bark and timber ; and finally, extensive groups and 
even whole orders have a more or less powerful and 
disgusting smell and taste, which they either possess 
permanently, or can emit at pleasure. The attitudes of 
some insects may also protect them, as the habit of 
turning up the tail by the harmless rove-beetles (Sta- 
phylindidaa) no doubt leads other animals besides chil- 
dren to the belief that they can sting. The curious 
attitude assumed by sphinx caterpillars is probably a 
safeguard, as well as the blood-red tentacles which 
can suddenly be thrown out from the neck, by the 
caterpillars of all the true swallow-tailed butterflies. 

It is among the groups that possess some of these 
varied kinds of protection in a high degree, that we 


find the greatest amount of conspicuous colour, or at 
least the most complete absence of protective imitation. 
The stinging Hymenoptera, wasps, bees, and hornets, 
are, as a rule, very showy and brilliant insects, and 
there is not a single instance recorded in which any one 
of them is coloured so as to resemble a vegetable or in- 
animate substance. The Chrysididse, or golden wasps, 
which do not sting, possess as a substitute the power of 
rolling themselves up into a ball, which is almost as 
hard and polished as if really made of metal, and they 
are all adorned with the most gorgeous colours. The 
whole order Hemiptera (comprising the bugs) emit a 
powerful odour, and they present a very large propor- 
tion of gay -coloured and conspicuous insects. The 
lady-birds (Coccinellidas) and their allies the Eu- 
morphida?, are often brightly spotted, as if to attract 
attention ; but they can both emit fluids of a very 
disagreeable nature, they are certainly rejected by 
some birds, and are probably never eaten by any. 

The great family of ground beetles (Carabidse) 
almost all possess a disagreeable and some a very 
pungent smell, and a few, called bombardier beetles, 
have the peculiar faculty of emitting a jet of very 
volatile liquid, which appears like a puff of smoke, 
and is accompanied by a distinct crepitating explosion. 
It is probably because these insects are mostly nocturnal 
and predacious that they do not present more vivid hues. 
They are chiefly remarkable for brilliant metallic tints 
or dull red patches when they are not wholly black, 
and are therefore very conspicuous by day, when insect- 


eaters are kept off by their bad odour and taste, but 
are sufficiently invisible at night when it is of impor- 
tance that their prey should not become aware of their 

It seems probable that in some cases that which 
would appear at first to be a source of danger to its 
possessor may really be a means of protection. Many 
showy and weak -fly ing butterflies have a very broad 
expanse of wing, as in the brilliant blue Morphos of 
Brazilian forests, and the large Eastern Papilios ; yet 
these groups are tolerably plentiful. Now, specimens 
of these butterflies are often captured with pierced and 
broken wings, as if they had been seized by birds from 
whom they had escaped ; but if the wings had been 
much smaller in proportion to the body, it seems pro- 
bable that the insect would be more frequently struck 
or pierced in a vital part, and thus the increased ex- 
panse of the wings may have been indirectly beneficial. 

In other cases the capacity of increase in a species is 
so great that however many of the perfect insect may 
be destroyed, there is always ample means for the con- 
tinuance of the race. Many of the flesh flies, gnats, 
ants, palm-tree weevils and locusts are in this cate- 
gory. The whole family of Cetoniadas or rose chafers, 
so full of gaily-coloured species, are probably saved 
from attack by a combination of characters. They fly 
very rapidly with a zigzag or waving course ; they hide 
themselves the moment they alight, either in the corolla 
of flowers, or in rotten wood, or in cracks and hollows 
of trees, and they are generally encased in a very hard 


and polished coat of mail which may render them 
unsatisfactory food to such birds as would be able to 
capture them. The causes which lead to the develop- 
ment of colour have been here able to act unchecked, 
and we see the result in a large variety of the most 
gorgeously-coloured insects. 

Here, then, with our very imperfect knowledge of 
the life-history of animals, we are able to see that 
there are widely varied modes by which they may 
obtain protection from their enemies or concealment 
from their prey. Some of these seem to be so com- 
plete and effectual as to answer all the wants of the 
race, and lead to the maintenance of the largest pos- 
sible population. When this is the case, we can well 
understand that no further protection derived from a 
modification of colour can be of the slightest use, and 
the most brilliant hues may be developed without any 
prejudicial effect upon the species. On some of the 
laws that determine the development of colour some- 
thing may be said presently. It is now merely neces- 
sary to show that concealment by obscure or imitative 
tints is only one out of very many ways by which 
animals maintain their existence ; and having done 
this we are prepared to consider the phenomena of 
what has been termed " mimicry." It is to be par- 
ticularly observed, however, that the word is not here 
used in the sense of voluntary imitation, but to imply 
a particular kind of resemblance a resemblance not in 
internal structure but in external appearance a resem- 
blance in those parts only that catch the eye a re- 


semblance that deceives. As this kind of resemblance 
has the same effect as voluntary imitation or mimicry, 
and as we have no word that expresses the required 
meaning, " mimicry " was adopted by Mr. Bates (who 
was the first to explain the facts), and has led to 
some misunderstanding ; but there need be none, if 
it is remembered that both a mimicry " and a imita- 
tion" are used in a metaphorical sense, as implying 
that close external likeness which causes things un- 
like in structure to be mistaken for each other. 


It has been long known to entomologists that certain 
insects bear a strange external resemblance to others 
belonging to distinct genera, families, or even orders, 
and with which they have no real affinity whatever. 
The fact, however, appears to have been generally con- 
sidered as dependent upon some unknown law of " ana- 
logy " some " system of nature," or "general plan," 
which had guided the Creator in designing the myriads 
of insect forms, and which we could never hope to 
understand. In only one case does it appear that the 
resemblance was thought to be useful, and to have been 
designed as a means to a definite and intelligible 
purpose. The flies of the genus Volucella enter the 
nests of bees to deposit their eggs, so that their larvae 
may feed upon the larvse of the bees, and these flies 
are each wonderfully like the bee on which it is 
parasitic. Kirby and Spence believed that this resem- 
blance or " mimicry " was for the express purpose of 


protecting the flies from the attacks of the bees, and 
the connection is so evident that it was hardly possible 
to avoid this conclusion. The resemblance, however, 
of moths to butterflies or to bees, of beetles to wasps, 
and of locusts to beetles, has been many times noticed 
by eminent writers ; but scarcely ever till within the 
last few years does it appear to have been considered 
that these resemblances had any special purpose, or 
were of any direct benefit to the insects themselves. 
In this respect they were looked upon as accidental, 
as instances of the " curious analogies " in nature 
which must be wondered at but which could not be ex- 
plained. Recently, however, these instances have been 
greatly multiplied; the nature of the resemblances 
has been more carefully studied, and it has been found 
that they are often carried out into such details as 
almost to imply a purpose of deceiving the observer. 
The phenomena, moreover, have been shown to follow 
certain definite laws, which again all indicate their 
dependence on the more general law of the " survival 
of the fittest," or " the preservation of favoured races 
in the struggle for life." It will, perhaps, be as well 
here to state what these laws or general conclusions 
are, and then to give some account of the facts which 
support them. 

The first law is, that in an overwhelming majority of 
cases of mimicry, the animals (or the groups) which 
resemble each other inhabit the same country, the same 
district, and in most cases are to be found together 
on the very same spot. 


The second law is, that these resemblances are not 
indiscriminate, but are limited to certain groups, which 
in every case are abundant in species and individuals, 
and can often be ascertained to have some special 

The third law is, that the species which resemble 
or " mimic " these dominant groups, are comparatively 
less abundant in individuals, and are often very rare. 

These laws will be found to hold good, in all the 
cases of true mimicry among various classes of animals 
to which we have now to call the attention of our 

Mimicry among Lepidoptera. 

As it is among butterflies that instances of mimicry 
are most numerous and most striking, an account of 
some of the more prominent examples in this group will 
first be given. There is in South America an extensive 
family of these insects, the Heliconids3, which are in 
many respects very remarkable. They are so abundant 
and characteristic in all the woody portions of the 
American tropics, that in almost every locality they 
will be seen more frequently than any other butterflies. 
They are distinguished by very elongate wings, body, 
and antennce, and are exceedingly beautiful and varied 
in their colours ; spots and patches of yellow, red, or 
pure white upon a black, blue, or brown ground, being 
most general. They frequent the forests chiefly, and all 
fly slowly and weakly; yet although they are so conspi- 
cuous, and could certainly be caught by insectivorous 


birds more easily than almost any other insects, their 
great abundance all over the wide region they inhabit 
shows that they are not so persecuted. It is to be es- 
pecially remarked also, that they possess no adaptive 
colouring to protect them during repose, for the under 
side of their wings presents the same, or at least an 
equally conspicuous colouring as the upper side ; and 
they may be observed after sunset suspended at the end 
of twigs and leaves where they have taken up their 
station for the night, fully exposed to the attacks of 
enemies if they have any. These beautiful insects 
possess, however, a strong pungent semi-aromatic or 
medicinal odour, which seems to pervade all the juices 
of their system. When the entomologist squeezes the 
breast of one of them between his fingers to kill it, a 
yellow liquid exudes which stains the skin, and the 
smell of which can only be got rid of by time and re- 
peated washings. Here we have probably the cause of 
their immunity from attack, since there is a great deal 
of evidence to show that certain insects are so disgust- 
ing to birds that they will under no circumstances 
touch them. Mr. Stainton has observed that a brood 
of young turkeys greedily devoured all the worthless 
moths he had amassed in a night's "sugaring," yet 
one after another seized and rejected a single white 
moth which happened to be among them. Young phea- 
sants and partridges which eat many kinds of cater- 
pillars seem to have an absolute dread of that of the 
common currant moth, which they will never touch, and 
tomtits as well as other small birds appear never to eat 


the same species. In the case of the Heliconidse, how- 
ever, we have some direct evidence to the same effect. 
In the Brazilian forests there are great numbers of in- 
sectivorous birds as jacamars, trogons, and puffbirds 
which catch insects on the wing, and that they de- 
stroy many butterflies is indicated by the fact that the 
wings of these insects are often found on the ground 
where their bodies have been devoured. But among 
these there are no wings of Heliconidse, while those 
of the large showy Nymphalidse, which have a much 
swifter flight, are often met with. Again, a gentleman 
who had recently returned from Brazil stated at a meet- 
ing of the Entomological Society that he once observed 
a pair of puffbirds catching butterflies, which they 
brought to their nest to feed their young ; yet during 
half an hour they never brought one of the Heliconidse, 
which were flying lazily about in great numbers, and 
which they could have captured more easily than any 
others. It was this circumstance that led Mr. Belt to 
observe them so long, as he could not understand why 
the most common insects should be altogether passed 
by. Mr. Bates also tells us that he never saw them 
molested by lizards or predacious flies, which often 
pounce on other butterflies. 

If, therefore, we accept it as highly probable (if not 
proved) that the Heliconidse are very greatly protected 
from attack by their peculiar odour and taste, we find it 
much more easy to understand their chief characteristics 
their great abundance, their slow flight, their gaudy 
colours, and the entire absence of protective tints on 


their under surfaces. This property places them some- 
what in the position of those curious wingless birds of 
oceanic islands, the dodo, the apteryx, and the moas, 
which are with great reason supposed to have lost the 
power of flight on account of the absence of carnivorous 
quadrupeds. Our butterflies have been protected in a 
different way, but quite as effectually ; and the result 
has been that as there has been nothing to escape from, 
there has been no weeding out of slow flyers, and as 
there has been nothing to hide from, there has been no 
extermination of the bright-coloured varieties, and no 
preservation of such as tended to assimilate with sur- 
rounding objects. 

Now let us consider how this kind of protection must 
act. Tropical insectivorous birds very frequently sit on 
dead branches of a lofty tree, or on those which overhang 
forest paths, gazing intently around, and darting off at 
intervals to seize an insect at a considerable distance, 
which they generally return to their station to devour. 
If a bird began by capturing the slow-flying, conspicuous 
Heliconidse, and found them always so disagreeable that 
it could not eat them, it would after a very few trials 
leave off catching them at all ; and their whole appear- 
ance, form, colouring, and mode of flight is so peculiar, 
that there can be little doubt birds would soon learn to 
distinguish them at a long distance, and never waste 
any time in pursuit of them. Under these circumstances, 
it is evident that any other butterfly of a group which 
birds were accustomed to devour, would be almost 
equally well protected by closely resembling a Heliconia 


externally, as if it acquired also the disagreeable odour ; 
always supposing that there were only a few of them 
among a great number of the Heliconias. If the birds 
could not distinguish the two kinds externally, and 
there were on the average only one eatable among 
fifty uneatable, they would soon give up seeking for 
the eatable ones, even if they knew them to exist. If, 
on the other hand, any particular butterfly of an eatable 
group acquired the disagreeable taste of the Heliconias 
while it retained the characteristic form and colouring 
of its own group, this would be really of no use to it 
whatever ; for the birds would go on catching it among 
its eatable allies (compared with which it would rarely 
occur), it would be wounded and disabled, even if re- 
jected, and its increase would thus be as effectually 
checked as if it were devoured. It is important, there- 
fore, to understand that if any one genus of an extensive 
family of eatable butterflies were in danger of extermi- 
nation from insect-eating birds, and if two kinds of 
variation were going on among them, some individuals 
possessing a slightly disagreeable taste, others a slight 
resemblance to the Heliconida?, this latter quality would 
be much more valuable than the former. The change 
in flavour would not at all prevent the variety from 
being captured as before, and it would almost certainly 
be thoroughly disabled before being rejected. The ap- 
proach in colour and form to the HeliconidaB, however, 
would be at the very first a positive, though perhaps a 
slight advantage ; for although at short distances this 
variety would be easily distinguished and devoured, yet 



at a longer distance it might be mistaken for one of the 
uneatable group, and so be passed by and gain another 
day's life, which might in many cases be sufficient 
for it to lay a quantity of eggs and leave a numerous 
progeny, many of which would inherit the peculiarity 
which had been the safeguard of their parent. 

Now, this hypothetical case is exactly realized in 
South America. Among the white butterflies forming 
the family Pieridse (many of which do not greatly 
differ in appearance from our own cabbage butterflies) 
is a genus of rather small size (Leptalis), some species 
of which are white like their allies, while the larger 
number exactly resemble the Heliconidse in the form 
and colouring of the wings. It must always be re- 
membered that these two families are as absolutely dis- 
tinguished from each other by structural characters as 
are the carnivora and the ruminants among quadrupeds, 
and that an entomologist can always distinguish the one 
from the other by the structure of the feet, just as 
certainly as a zoologist can tell a bear from a buffalo 
by the skull or by a tooth. Yet the resemblance of a 
species of the one family to another species in the other 
family was often so great, that both Mr. Bates and my- 
self were many times deceived at the time of capture, 
and did not discover the distinctness of the two insects 
till a closer examination detected their essential differ- 
ences. During his residence of eleven years in the 
Amazon valley, Mr. Bates found a number of species 
or varieties of Leptalis, each of which was a more or 
less exact copy of one of the Heliconidoe of the district 


it inhabited ; and the results of his observations arc 
embodied in a paper published in the Linnean Trans- 
actions, in which he first explained the phenomena of 
" mimicry " as the result of natural selection, and 
showed its identity in cause and purpose with protec- 
tive resemblance to vegetable or inorganic forms. 

The imitation of the HeliconidaB by the Leptalides 
is carried out to a wonderful degree in form as well as 
in colouring. The wings have become elongated to the 
same extent, and the antenna? and abdomen have both 
become lengthened, to correspond with the unusual 
condition in which they exist in the former family. 
In colouration there are several types in the different 
genera of Heliconid^e. The genus Mechanitis is gene- 
rally of a rich semi-transparent brown, banded with 
black and yellow ; Methona is of large size, the wings 
transparent like horn, and with black transverse bands ; 
while the delicate Ithomias are all more or less trans- 
parent, with black veins and borders, and often with 
marginal and transverse bands of orange red. These 
different forms are all copied by the various species 
of Leptalis, every band and spot and tint of colour, 
and the various degrees of transparency, being exactly 
reproduced. As if to derive all the benefit possible 
from this protective mimicry, the habits have become 
so modified that the Leptalides generally frequent the 
very same spots as their models, and have the same 
mode of flight; and as they are always very scarce 
(Mr. Bates estimating their numbers at about one to a 
thousand of the group they resemble), there is hardly a 

G 2 


possibility of their being found out by their enemies. 
It is also very remarkable that in almost every case the 
particular Ithomias and other species of Heliconida3 
which they resemble, are noted as being very common 
species, swarming in individuals, and found over a 
wide range of country. This indicates antiquity and 
permanence in the species, and is exactly the condition 
most essential both to aid in the development of the 
resemblance, and to increase its utility. 

But the Leptalides are not the only insects who have 
prolonged their existence by imitating the great pro- 
tected group of Heliconidse ; a genus of quite another 
family of most lovely small American butterflies, the 
Erycinidse, and three genera of diurnal moths, also 
present species which often mimic the same dominant 
forms, so that some, as Ithomia ilerdina of St. Paulo, 
for instance, have flying with them a few individuals 
of three widely different insects, which are yet dis- 
guised with exactly the same form, colour, and mark- 
ings, so as to be quite undistinguishable when upon the 
wing. Again, the Heliconidse are not the only group 
that are imitated, although they are the most frequent 
models. The black and red group of South American 
Papilios, and the handsome Erycinian genus Stalachtis, 
have also a few who copy them ; but this fact offers no 
difficulty, since these two groups are almost as domi- 
nant as the Heliconidse. They both fly very slowly, 
they are both conspicuously coloured, and they both 
abound in individuals ; so that there is every reason to 
believe that they possess a protection of a similar kind 


to the Heliconida3, and that it is therefore equally an 
advantage to other insects to be mistaken for them. 


There is also another extraordinary fact that we are 
not yet in a position clearly to comprehend : some 
groups of the Heliconida3 themselves mimic other 
groups. Species of Heliconia mimic Mechanitis, and 
every species of Napeogenes mimics some other Heli- 
conideous butterfly. This would seem to indicate that 
the distasteful secretion is not produced alike by all 
members of the family, and that where it is deficient 
protective imitation comes into play. It is this, per- 
haps, that has caused such a general resemblance 
among the HeliconidaB, such a uniformity of type with 
great diversity of colouring, since any aberration 
causing an insect to cease to look like one of the family 
would inevitably lead to its being attacked, wounded, 
and exterminated, even although it was not eatable. 
In other parts of the world an exactly parallel series 
of facts have been observed. The Danaidas and the 
Acrseidse of the Old World tropics form in fact one 
great group with the HeliconidaB. They have the same 
general form, structure, -and habits: they possess the 
same protective odour, and are equally abundant in 
individuals, although not so varied in colour, blue and 
white spots on a black ground being the most general 
pattern. The insects which mimic these are chiefly 
Papilios, and Diadema, a genus allied to our peacock 
and tortoiseshell butterflies. In tropical Africa there is 
a peculiar group of the genus Danais, characterized 
by dark-brown and bluish-white colours, arranged in 


bands or stripes. One of these, Danais niavius, is 
exactly imitated both by Papilio hippocoon and by 
Diadema anthedon ; another, Danais echeria, by Pa- 
pilio cenea ; and in Natal a variety of the Danais is 
found having a white spot at the tip of wings, accom- 
panied by a variety of the Papilio bearing a corre- 
sponding white spot. Acrsea gea is copied in its very 
peculiar style of colouration by the female of Papilio 
cynorta, by Panopaaa hirce, and by the female of Elym- 
nias phegea. Acrsea euryta of Calabar has a female 
variety of Panopea hirce from the same place which 
exactly copies it ; and Mr. Trimen, in his paper on 
Mimetic Analogies among African Butterflies, published 
in the Transactions of the Linnsean Society for 1868, 
gives a list of no less than sixteen species and varieties 
of Diadema and its allies, and ten of Papilio, which in 
their colour and markings are perfect mimics of species 
or varieties of Danais or Acrsea which inhabit the same 

Passing on to India, we have Danais tytia, a butter- 
fly with semi-transparent bluish wings and a border of 
rich reddish brown. This remarkable style of colour- 
ing is exactly reproduced in Papilio agestor and in 
Diadema nama, and all three insects not unfrequently 
come together in collections made at Darjeeling. In 
the Philippine Islands the large and curious Idea 
leuconoe with its semi-transparent white wings, veined 
and spotted with black, is copied by the rare Papilio 
idasoides from the same islands. 

In the Malay archipelago the very common and 


beautiful Euplaea miclamus is so exactly mimicked by 
two rare Papilios (P. paradoxa and P. senigma) that I 
generally caught them under the impression that they 
were the more common species ; and the equally com- 
mon and even more beautiful Euplaea rhadamanthus, 
with its pure white bands and spots on a ground of 
glossy blue and black, is reproduced in the Papilio 
caunus. Here also there are species of Diadema imi- 
tating the same group in two or three instances ; but 
we shall have to adduce these further on in connexion 
with another branch of the subject. 

It has been already mentioned that in South America 
there is a group of Papilios which have all the char- 
acteristics of a protected race, and whose peculiar 
colours and markings are imitated by other butterflies 
not so protected. There is just such a group also in 
the East, having very similar colours and the same 
habits, and these also are mimicked by other species 
in the same genus not closely allied to them, and also 
by a few of other families. Papilio hector, a common 
Indian butterfly of a rich black colour spotted with 
crimson, is so closely copied by Papilio romulus, that 
the latter insect has been thought to be its female. A 
close examination shows, however, that it is essentially 
different, and belongs to another section of the genus. 
Papilio antiphus and P. diphilus, black swallow-tailed 
butterflies with cream-coloured spots, are so well imi- 
tated by varieties of P. theseus, that several writers 
have classed them as the same species. Papilio liris, 
found only in the island of Timor, is accompanied 


there by P. senomaus, the female of which so exactly 
resembles it that they can hardly be separated in the 
cabinet, and on the wing are quite undistinguishable. 
But one of the most curious cases is the fine yellow- 
spotted Papilio coon, which is unmistakeably imitated 
by the female tailed form of Papilio memnon. These 
are both from Sumatra ; but in North India P. coon 
is replaced by another species, which has been named 
P. doubledayi, having red spots instead of yellow ; 
and in the same district the corresponding female 
tailed form of Papilio androgeus, sometimes considered 
a variety of P. memnon, is similarly red-spotted. Mr. 
Westwood has described some curious day-flying moths 
(Epicopeia) from North India, which have the form 
and colour of Papilios of this section, and two of these 
are very good imitations of Papilio polydorus and 
Papilio varuna, also from North India. 

Almost all these cases of mimicry are from the 
tropics, where the forms of life are more abundant, 
and where insect development especially is of unchecked 
luxuriance ; but there are also one or two instances in 
temperate regions. In North America, the large and 
handsome red and black butterfly Danais erippus is 
very common ; and the same country is inhabited by 
Limenitis archippus, which closely resembles the 
Danais, while it differs entirely from every species of 
its own genus. 

The only case of probable mimicry in our own coun- 
try is the following : A very common white moth 
CSpilosoma menthastri) was found by Mr. Staintoa 


to be rejected by young turkeys among hundreds of 
other moths on which they greedily fed. Each bird in 
succession took hold of this moth and threw it down 
again, as if too nasty to eat. Mr. Jenner Weir also 
found that this moth was refused by the Bullfinch, 
Chaffinch, Yellow Hammer, and Red Bunting, but 
eaten after much hesitation by the Robin. We may 
therefore fairly conclude that this species would be dis- 
agreeable to many other birds, and would thus have an 
immunity from attack, which may be the cause of its 
great abundance and of its conspicuous white colour. 
Now it is a curious thing that there is another moth, 
Diaphora mendica, which appears about the same time, 
and whose female only is white. It is about the same 
size as Spilosoma menthastri, and sufficiently resembles 
it in the dusk, and this moth is much less common. It 
seems very probable, therefore, that these species stand 
in the same relation to each other as the mimicking 
butterflies of various families do to the Heliconida3 and 
Danaidse. It would be very interesting to experiment 
on all white moths, to ascertain if those which are 
most common are generally rejected by birds. It may 
be anticipated that they would be so, because white 
is the most conspicuous of all colours for nocturnal in- 
sects, and had they not some other protection would 
certainly be very injurious to them. 

Lepidoptera mimicking oilier Insects. 
In the preceding cases we have found Lepidoptera 
imitating other species of the same order, and such 


species only as we have good reason to believe were free 
from the attacks of many insectivorous creatures ; but 
there are other instances in which they altogether lose 
the external appearance of the order to which they be- 
long, and take on the dress of bees or wasps insects 
which have an undeniable protection in their stings. 
The Sesiidse and jiEgeriidas, two families of day-flying 
moths, are particularly remarkable in this respect, and 
a mere inspection of the names given to the various 
species shows how the resemblance has struck every- 
one. We have apiformis, vespiforme, ichneumoni- 
forme, scoliasforme, sphegiforme (bee-like, wasp-like, 
ichneumon-like, &c.) and many others, all indicating a 
resemblance to stinging Hymenoptera. In Britain we 
may particularly notice Sesia bombiliformis, which very 
closely resembles the male of the large and common 
humble bee, Bombus hortorum ; Sphecia craboni- 
forme, which is coloured like a hornet, and is (on 
the authority of Mr. Jenner Weir) much more like it 
when alive than when in the cabinet, from the way in 
which it carries its wings ; and the currant clear-wing, 
Trochilium tipuliforme, which resembles a small black 
wasp (Odynerus sinuatus) very abundant in gardens at 
the same season. It has been so much the practice to 
look upon these resemblances as mere curious analogies 
playing no part in the economy of nature, that we have 
scarcely any observations of the habits and appearance 
when alive of the hundreds of species of these groups 
in various parts of the world, or how far they are ac- 
companied by Hymenoptera, which they specifically 


resemble. There are many species in India (like those 
figured by Professor Westwood in his " Oriental Ento- 
mology ") which have the hind legs very broad and 
densely hairy, so as exactly to imitate the brush-legged 
bees (Scopulipedes) which abound in the same country. 
In this case we have more than mere resemblance of 
colour, for that which is an important functional struc- 
ture in the one group is imitated in another whose 
habits render it perfectly useless. 

Mimicry among Beetles. 

It may fairly be expected that if these imitations of 
one creature by another really serve as a protection 
to weak and decaying species, instances of the same 
kind will be found among other groups than the Le- 
pidoptera ; and such is the case, although they are 
seldom so prominent and so easily recognised as those 
already pointed out as occurring in that order. A few 
very interesting examples may, however, be pointed out 
in most of the other orders of insects. The Coleop- 
tera or beetles that imitate other Coleoptera of distinct 
groups are very numerous in tropical countries, and 
they generally follow the laws already laid down as 
regulating these phenomena. The insects which others 
imitate always have a special protection, which leads 
them to be avoided as dangerous or uneatable by small 
insectivorous animals ; some have a disgusting taste 
(analogous to that of the Heliconidae) ; others have 
such a hard and stony covering that they cannot be 
crushed or digested ; while a third set are very active, 


and armed with powerful jaws, as well as having some 
disagreeable secretion. Some species of Eumorphidae 
and Hispidae, small flat or hemispherical beetles which 
are exceedingly abundant, and have a disagreeable se- 
cretion, are imitated by others of the very distinct 
group of Longicornes (of which our common musk- 
beetle may be taken as an example). The extraordi- 
nary little Cyclopeplus batesii, belongs to the same 
sub-family of this group as the Onychocerus scorpio 
and 0. concentricus, which have already been adduced 
as imitating with such wonderful accuracy the bark 
of the trees they habitually frequent ; but it differs 
totally in outward appearance from every one of its 
allies, having taken upon itself the exact shape and 
colouring of a globular Corynomalus, a little stinking 
beetle with clubbed antennae. It is curious to see how 
these clubbed antennae are imitated by an insect be- 
longing to a group with long slender antennae. The 
sub-family Anisocerinae, to which Cyclopeplus belongs, 
is characterised by all its members possessing a little 
knob or dilatation about the middle of the antenna?. 
This knob is considerably enlarged in C. batesii, and 
the terminal portion of the antennas beyond it is so 
small and slender as to be scarcely visible, and thus an 
excellent substitute is obtained for the short clubbed 
antennas of the Corynomalus. Erythroplatis corallifer 
is another curious broad flat beetle, that no one would 
take for a Longicorn, since it almost exactly resembles 
Cephalodonta spinipes, one of the commonest of the 
South American Hispidae ; and what is still more 


remarkable, another Longicorn of a distinct group, 
Streptolabis hispoicles, was found by Mr. Bates, which 
resembles the same insect with equal minuteness, a 
case exactly parallel to that among butterflies, where 
species of two or three distinct groups mimicked the 
same Heliconia. Many of the soft -winged beetles 
( Malacoderms ) are excessively abundant in indivi- 
duals, and it is probable that they have some similar 
protection, more especially as other species often strik- 
ingly resemble them. A Longicorn beetle, Psecilo- 
derma terminale, found in Jamaica, is coloured exactly 
in the same way as a Lycus (one of the Malacoderms) 
from the same island. Eroschema poweri, a Longicorn 
from Australia, might certainly be taken for one of 
the same group, and several species from the Malay 
Islands are equally deceptive. In the Island of Celebes 
I found one of this group, having the whole body and 
elytra of a rich deep blue colour, with the head only 
orange ; and in company with it an insect of a totally 
different family (Eucnemidae) with identically the same 
colouration, and of so nearly the same size and form 
as to completely puzzle the collector on every fresh 
occasion of capturing them. I have been recently in- 
formed by Mr. Jenner Weir, who keeps a variety of 
small birds, that none of them will touch our com- 
mon fC soldiers and sailors " (species of Malacoderms), 
thus confirming my belief that they were a protected 
group, founded on the fact of their being at once very 
abundant, of conspicuous colours, and the objects of 


There are a number of the larger tropical weevils 
which have the elytra and the whole covering of the 
body so hard as to be a great annoyance to the entomo- 
logist, because in attempting to transfix them the points 
of his pins are constantly turned. I have found it ne- 
cessary in these cases to drill a hole very carefully with 
the point of a sharp penknife before attempting to insert 
a pin. Many of the fine long-antennsed AnthribidaB (an 
allied group) have to be treated in the same way. We 
can easily understand that after small birds have in vain 
attempted to eat these insects, they should get to know 
them by sight, and ever after leave them alone, and it 
will then be an advantage for other insects which are 
comparatively soft and eatable, to be mistaken for them. 
We need not be surprised, therefore, to find that there 
are many Longicorns which strikingly resemble the 
"hard beetles " of their own district. In South Brazil, 
Acanthotritus dorsalis is strikingly like a Curculio of the 
hard genus Heiliplus, and Mr. Bates assures me that he 
found Grymnocerus cratosomoides (a Longicorn) on the 
same tree with a hard Cratosomus (a weevil), which it 
exactly mimics. Again, the pretty Longicorn, Phacel- 
locera batesii, mimics one of the hard Anthribidse of the 
genus Ptychoderes, having long slender antenna. In 
the Moluccas we find Cacia anthriboides, a small Longi- 
corn which might be easily mistaken for a very common 
species of Anthribidse found in the same districts ; and 
the very rare Capnolymma stygium closely imitates the 
common Mecocerus gazella, which abounded where it 
was taken. Doliops curculionoides and other allied' 


Longicorns from the Philippine Islands most curiously 
resemble, both in form and colouring, the brilliant 
Pachyrhynchi, Curculionidas, which are almost pecu- 
liar to that group of islands. The remaining family of 
Coleoptera most frequently imitated is the Cicindelida?. 
The rare and curious Longicorn, Colly rodes lacordairei, 
has exactly the form and colouring of the genus Collyris, 
while an undescribed species of Heteromera is exactly 
like a Therates, and was taken running on the trunks 
of trees, as is the habit of that group. There is one 
curious example of a Longicorn mimicking a Longicorn, 
like the Papilios and Heliconidse which mimic their 
own allies. Agnia fasciata, belonging to the sub-family 
Hypselominae, and Nemophas grayi, belonging to the 
Lamiinse, were taken in Amboyna on the same fallen 
tree at the same time, and were supposed to be the same 
species till they were more carefully examined, and 
found to be structurally quite different. The colouring 
of these insects is very remarkable, being rich steel-blue 
black, crossed by broad hairy bands of orange buff, and 
out of the many thousands of known species of Longi- 
corns they are probably the only two which are so 
coloured. The Nemophas grayi is the larger, stronger, 
and better armed insect, and belongs to a more widely 
spread and dominant group, very rich in species and 
individuals, and is therefore most probably the subject 
of mimicry by the other species. 

Beetles mimicking other Insects. 
We will now adduce a few cases in which beetles 


imitate other insects, and insects of other orders imi- 
tate beetles. 

Charis melipona, a South American Longicorn of 
the family Necydalidse, has been so named from its 
resemblance to a small bee of the genus Melipona. 
It is one of the most remarkable cases o^ mimicry, 
since the beetle has the thorax and body densely hairy 
like the bee, and the legs are tufted in a manner most 
unusual in the order Coleoptera. Another Longicorn, 
Odontocera ody nereides, has the abdomen banded with 
yellow, and constricted at the base, and is altogether 
so exactly like a small common wasp of the genus Ody- 
nerus, that Mr. Bates informs us he was afraid to take it 
out of his net with his fingers for fear of being stung. 
Had Mr. Bates's taste for insects been less omnivorous 
than it was, the beetle's disguise might have saved it 
from his pin, as it had no doubt often done from the 
beak of hungry birds. A larger insect, Sphecomorpha 
chalybea, is exactly like one of the large metallic blue 
wasps, and like them has the abdomen connected with 
the thorax by a pedicel, rendering the deception most 
complete and striking. Many Eastern species of Lon- 
gicorns of the genus Oberea, when on the wing ex- 
actly resemble Tenthredinidae, and many of the small 
species of Hesthesis run about on timber, and cannot 
be distinguished from ants. There is one genus of 
South American Longicorns that appears to mimic 
the shielded bugs of the genus Scutellera. The Gym- 
nocerous capucinus is one of these, and is very 
like Pachyotris fabricii, one of the Scutelleridae. The 


beautiful Gymnocerous dulcissimus is also very like 
the same group of insects, though there is no known 
species that exactly corresponds to it ; but this is not 
to be wondered at, as the tropical Hemiptera have 
been comparatively so little cared for by collectors. 

Insects mimicking Species of other Orders. 

The most remarkable case of an insect of another 
order mimicking a beetle is that of the Condylodera 
tricondyloides, one of the cricket family from the Phi- 
lippine Islands, which is so exactly like a Tricondyla 
(one of the tiger beetles), that such an experienced 
entomologist as Professor Westwood placed it among 
them in his cabinet, and retained it there a long time 
before he discovered his mistake ! Both insects run 
along the trunks of trees, and whereas Tricondylas are 
very plentiful, the insect that mimics it is, as in all 
other cases, very rare. Mr. Bates also informs us that 
he found at Santarem on the Amazon, a species of 
locust which mimicked one of the tiger beetles of the 
genus Odontocheila, and was found on the same trees 
which they frequented. 

There are a considerable number of Diptera, or two- 
winged flies, that closely resemble wasps and bees, 
and no doubt derive much benefit from the whole- 
some dread which those insects excite. The Midas 
dives, and other species of large Brazilian flies, have 
dark wings and metallic blue elongate bodies, resem- 
bling the large stinging Sphegidae of the same coun- 
try; and a very large fly of the genus Asilus has 



black-banded wings and the abdomen tipped with rich 
orange, so as exactly to resemble the fine bee Euglossa 
dimidiata, and both are found in the same parts of 
South America. We have also in our own country spe- 
cies of Bombylius which are almost exactly like bees. 
In these cases the end gained by 'the mimicry is no 
doubt freedom from attack, but it has sometimes an 
altogether different purpose. There are a number of 
parasitic flies whose larva? feed upon the larvas of bees, 
such as the British genus Volucella and many of 
the tropical Bombylii, and most of these are exactly 
like the particular species of bee they prey upon, so 
that they can enter their nests unsuspected to deposit 
their eggs. There are also bees that mimic bees. The 
cuckoo bees of the genus Nomada are parasitic on the 
Andrenidse, and they resemble either wasps or species 
of Andrena ; and the parasitic humble-bees of the genus 
Apathus almost exactly resemble the species of humble- 
bees in whose nests they are reared. Mr. Bates informs 
us that he found numbers of these " cuckoo" bees and 
flies on the Amazon, which all wore the livery of 
working bees peculiar to the same country. 

There is a genus of small spiders in the tropics which 
feed on ants, and they are exactly like ants themselves, 
which no doubt gives them more opportunity of seizing 
their prey; and Mr. Bates found on the Amazon a 
species of Mantis which exactly resembled the white 
ants which it fed upon, as well as several species of 
crickets (Scaphura), which resembled in a wonderful 
manner different sand-wasps of large size, which are 


constantly on the search for crickets with which to 
provision their nests. 

Perhaps the most wonderful case of all is the large 
caterpillar mentioned by Mr. Bates, which startled him 
by its close resemblance to a small snake. The first 
three segments behind the head were dilatable at the 
will of the insect, and had on each side a large black 
pupillated spot, which resembled the eye of the reptile. 
Moreover, it resembled a poisonous viper, not a harm- 
less species of snake, as was proved by the imitation of 
keeled scales on the crown produced by the recumbent 
feet, as the caterpillar threw itself backward ! 

The attitudes of many of the tropical spiders are 
most extraordinary and deceptive, but little attention 
has been paid to them. They often mimic other in- 
sects, and some, Mr. Bates assures us, are exactly like 
flower buds, and take their station in the axils of leaves, 
where they remain motionless waiting for their prey. 

Cases of Mimicry among the Vertebrata. 

Having thus shown how varied and extraordinary 
are the modes in which mimicry occurs among insects, 
we have now to enquire if anything of the same kind 
is to be observed among vertebrated animals. When 
we consider all the conditions necessary to produce a 
good deceptive imitation, we shall see at once that such 
can very rarely occur in the higher animals, since they 
possess none of those facilities for the almost infinite 
modifications of external form which exist in the very 
nature of insect organization. The outer covering of 

H 2 


insects being more or less solid and horny, they are 
capable of almost any amount of change of form 
and appearance without any essential modification 
internally. In many groups the \vings give much of 
the character, and these organs may be much modified 
both in form and colour without interfering with their 
special functions. Again, the number of species of 
insects is so great, and there is such diversity of form 
and proportion in every group, that the chances of an 
accidental approximation in size, form, and colour, of 
one insect to another of a different group, are very 
considerable ; and it is these chance approximations 
that furnish the basis of mimicry, to be continually 
advanced and perfected by the survival of those 
varieties only which tend in the right direction. 

In the Vertebrata, on the contrary, the skeleton 
being internal the external form depends almost en- 
tirely on the proportions and arrangement of that 
skeleton, which again is strictly adapted to the func- 
tions necessary for the well-being of the animal. The 
form cannot therefore be rapidly modified by variation, 
and the thin and flexible integument will not admit 
of the development of such strange protuberances as 
occur continually in insects. The number of species of 
each group in the same country is also comparatively 
small, and thus the chances of that first accidental 
resemblance which is necessary for natural selection 
to work upon are much diminished. We can hardly 
see the possibility of a mimicry by which the elk could 
escape from the wolf, or the buffalo from the tiger. 


There is, however, in one group of Vertebrata such a 
general similarity of form, that a very slight modi- 
fication, if accompanied by identity of colour, would 
produce the necessary amount of resemblance ; and 
at the same time there exist a number of species which 
it would be advantageous for others to resemble, since 
they are armed with the most fatal weapons of offence. 
We accordingly find that reptiles furnish us with a 
very remarkable and instructive case of true mimicry. 

Mimicry among Snakes. 

There are in tropical America a number of venomous 
snakes of the genus Elaps, which are ornamented with 
brilliant colours disposed in a peculiar manner. The 
ground colour is generally bright red, on which are 
black bands of various widths and sometimes divided 
into two or three by yellow rings. Now, in the same 
country are found several genera of harmless snakes, 
having no affinity whatever with the above, but 
coloured exactly the same. For example, the poisonous 
Elaps fulvius often occurs in Guatemala with simple 
black bands on a coral-red ground ; and in the same 
country is found the harmless snake Pliocerus equalis, 
coloured and banded in identically the same manner. 
A variety of Elaps corallinus has the black bands 
narrowly bordered with yellow on the same red ground 
colour, and a harmless snake, Homalocranium semi- 
cinctum, has exactly the same markings, and both are 
found in Mexico. The deadly Elaps lemniscatus has 
the black bands very broad, and each of them divided 


into three by narrow yellow rings ; and this again is 
exactly copied by a harmless snake, Pliocerus elapoides, 
which is found along with its model in Mexico. 


But, more remarkable still, there is in South Ame- 
rica a third group of snakes, the genus Oxyrhopus, 
doubtfully venomous, and having no immediate affinity 
with either of the preceding, which has also the same 
curious distribution of colours, namely, variously dis- 
posed rings of red, yellow, and black; and there are 
some cases in which species of all three of these 
groups similarly marked inhabit the same district. 
For example, Elaps mipartitus has single black rings 
very close together. It inhabits the west side of the 
Andes, and in the same districts occur Pliocerus eury- 
zonus and Oxyrhopus petolarius, which exactly copy 
its pattern. In Brazil Elaps lemniscatus is copied by 
Oxyrhopus trigeminus, both having black rings dis- 
posed in threes. In Elaps hemiprichii the ground 
colour appears to be black, with alternations of two 
narrow yellow bands and a broader red one; and of 
this pattern again we have an exact double in Oxy- 
rhopus formosus, both being found in many localities 
of tropical South America. 

What adds much to the extraordinary character of 
these resemblances is the fact, that nowhere in the 
world but in America are there any snakes at all 
which have this style of colouring.' Dr. Gunther, of 
the British Museum, who has kindly furnished some 
of the details here referred to, assures me that this is 
the case ; and that red, black, and yellow rings occur 


together on no other snakes in the world but on Elaps 
and the species which so closely resemble it. In all 
these cases, the size and form as well as the coloura- 
tion, are so much alike, that none but a naturalist 
would distinguish the harmless from the poisonous 

Many of the small tree-frogs are no doubt also 
mimickers. When seen in their natural attitudes, I 
have been often unable to distinguish them from beetles 
or other insects sitting upon leaves, but regret to say 
I neglected to observe what species or groups they 
most resembled, and the subject does not yet seem to 
have attracted the attention of naturalists abroad. 

Mimicry among Birds. 

In the class of birds there are a number of cases 
that make some approach to mimicry, such as the 
resemblance of the cuckoos, a weak and defenceless 
group of birds, to hawks and Gallinaccse. There is, 
however, one example which goes much further than 
this, and seems to be of exactly the same nature as 
the many cases of insect mimicry which have been 
already given. In Australia and the Moluccas there is 
a genus of honeysuckers called Tropidorhynchus, good 
sized birds, very strong and active, having powerful 
grasping claws and long, curved, sharp beaks. They 
assemble together in groups and small flocks, and they 
have a very loud bawling note, which can be heard 
at a great distance, and serves to collect a number 
together in time of danger. They are very plentiful 


and very pugnacious, frequently driving away crows, 
and even hawks, which perch on a tree where a few of 
them are assembled. They are all of rather dull and 
obscure colours. Now in the same countries there is 
a group of orioles, forming the genus Mimeta, much 
weaker birds, which have lost the gay colouring of 
their allies the golden orioles, being usually olive-green 
or brown ; and in several cases these most curiously 
resemble the Tropidorhynchus of the same island. For 
example, in the island of Bouru is found the Tropido- 
rhynchus bouruensis, of a dull earthy colour, and the 
Mimeta bouruensis, which resembles it in the follow- 
ing particulars : The upper and under surfaces of the 
two birds are exactly of the same tints of dark and 
light brown ; the Tropidorhynchus has a large bare 
black patch round the eyes; this is copied in the 
Mimeta by a patch of black feathers. The top of the 
head of the Tropidorhynchus has a scaly appearance 
from the narrow scale-formed feathers, which are imi- 
tated by the broader feathers of the Mimeta having a 
dusky line down each. The Tropidorhynchus has a 
pale ruff formed of curious recurved feathers on the 
nape (which has given the whole genus the name of 
Friar birds) ; this is represented in the Mimeta by a 
pale band in the same position. Lastly, the bill of the 
Tropidorhynchus is raised into a protuberant keel at the 
base, and the Mimeta has the same character, although 
it is not a common one in the genus. The result is, 
that on a superficial examination the birds are identical, 
although they have important structural differences, 


and cannot be placed near each other in any natural 
arrangement. As a proof that the resemblance is really 
deceptive, it may be mentioned that the Mimeta is 
figured and described as a honeysucker in the costly 
" Voyage de 1' Astrolabe," under the name of Philedon 
bouruensis ! 

Passing to the island of Ceram, we find allied species 
of both genera. The Tropidorhynchus subcornuttis is 
of an earthy brown colour washed with yellow ochre, 
with bare orbits, dusky cheeks, and the usual pale re- 
curved nape-ruff. The Mimeta forsteni is absolutely 
identical in the tints of every part of the body, the 
details of which are imitated in the same manner as 
in the Bouru birds already described. In two other 
islands there is an approximation towards mimicry, 
although it is not so perfect as in the two preced- 
ing cases. In Timor the Tropidorhynchus timoriensis 
is of the usual earthy brown above, with the nape-ruff 
very prominent, the cheeks black, the throat nearly 
white, and the whole under surface pale whitish brown. 
These various tints are all well reproduced in Mimeta 
virescens, the chief want of exact imitation being that 
the throat and breast of the Tropidorhynchus has a 
very scaly appearance, being covered with rigid pointed 
feathers which are not imitated in the Mimeta, although 
there are signs of faint dusky spots which may easily 
furnish the groundwork of a more exact imitation by 
the continued survival of favourable variations in the 
same direction. There is also a large knob at the base 
of the bill of the Tropidorhynchus which is not at all 


imitated by the Mimeta. In the island of Morty 
(north of Gilolo) there exists the Tropidorhynchus 
fuscicapillus, of a dark sooty brown colour, especially 
on the head, while the under parts are rather lighter, 
and the characteristic ruff of the nape is wanting. 
Now it is curious that in the adjacent island of Gilolo 
should be found the Mimeta phacochromus, the upper 
surface of which is of exactly the same dark sooty 
tint as the Tropidorhynchus, and is the only known 
species that is of such a dark colour. The under side 
is not quite light enough, but it is a good approxi- 
mation. This Mimeta is a rare bird, and may very 
probably exist in Morty, though not yet found there ; 
or, on the other hand, recent changes in physical geo- 
graphy may have led to the restriction of the Tropido- 
rhynchus to that island, where it is very common. 

Here, then, we have two cases of perfect mimicry 
and two others of good approximation, occurring 
between species of the same two genera of birds ; and 
in three of these cases the pairs that resemble each 
other are found together in the same island, and 
to which they are peculiar. In all these cases the 
Tropidorhynchus is rather larger than the Mimeta, 
but the difference is not beyond the limits of varia- 
tion in species, and the two genera are somewhat 
alike in form and proportion. There are, no doubt, 
some special enemies by which many small birds are 
attacked, but which are afraid of the Tropidorhynchus 
(probably some of the hawks), and thus it becomes 
advantageous for the weak Mimeta to resemble the 


strong, pugnacious, noisy, and very abundant Tropi- 

My friend, Mr. Osbert Salvin, has given me another 
interesting case of bird mimicry. In the neighbour- 
hood of Rio Janeiro is found an insect-eating hawk 
(Harpagus diodon), and in the same district a bird- 
eating hawk (Accipiter pileatus) which closely re- 
sembles it. Both are of the same ashy tint beneath, 
with the thighs and under wing-coverts reddish brown, 
so that when on the wing and seen from below they 
are undistinguishable. The curious point, however, is 
that the Accipiter has a much wider range than the 
Harpagus, and in the regions where the insect-eating 
species is not found it no longer resembles it, the under 
wing-coverts varjdng to white ; thus indicating that 
the red-brown colour is kept true by its being useful 
to the Accipiter to be mistaken for the insect-eating 
species, which birds have learnt not to be afraid of. 

Mimicry among Mammals. 

Among the Mammalia the only case which may be 
true mimicry is that of the insectivorous genus Cla- 
dobates, found in the Malay countries, several species 
of which very closely resemble squirrels. The size is 
about the same, the long bushy tail is carried in the 
same way, and the colours are very similar. In this 
case the use of the resemblance must be to enable the 
Cladobates to approach the insects or small birds on 
which it feeds, under the disguise of the harmless fruit- 
eating squirrel. 


Objections to Mr. Bates' Theory of Mimicry. 

Having now completed our survey of the most pro- 
minent and remarkable cases of mimicry that have yet 
been noticed, we must say something of the objections 
that have been made to the theory of their production 
given by Mr. Bates, and which we have endeavoured to 
illustrate and enforce in the preceding pages. Three 
counter explanations have been proposed. Professor 
Westwood admits the fact of the mimicry and its pro- 
bable use to the insect, but maintains that each species 
was created a mimic for the purpose of the protection 
thus afforded it. Mr. Andrew Murray, in his paper on 
the " Disguises of Nature," inclines to the opinion that 
similar conditions of food and of surrounding circum- 
stances have acted in some unknown way to produce the 
resemblances ; and when the subject was discussed before 
the Entomological Society of London, a third objection 
was added that heredity or the reversion to ancestral 
types of form and colouration, might have produced 
many of the cases of mimicry. 

Against the special creation of mimicking species 
there are all the objections and difficulties in the way 
of special creation in other cases, with the addition of 
a few that are peculiar to it. The most obvious is, 
that we have gradations of mimicry and of protective 
resemblance a fact which is strongly suggestive of a 
natural process having been at work. Another very 
serious objection is, that as mimicry has been shown 
to be useful only to those species and groups which 


are rare and probably dying out, and would cease to 
have any effect should the proportionate abundance of 
the two species be reversed, it follows that on the 
special-creation theory the one species must have been 
created plentiful, the other rare ; and, notwithstanding 
the many causes that continually tend to alter the pro- 
portions of species, these two species must have always 
been specially maintained at their respective propor- 
tions, or the very purpose for which they each received 
their peculiar characteristics would have completely 
failed. A third difficulty is, that although it is very 
easy to understand how mimicry may be brought 
about by variation and the survival of the fittest, it 
seems a very strange thing for a Creator to protect 
an animal by making it imitate another, when the 
very assumption of a Creator implies his power to 
create it so as to require no such circuitous protection. 
These appear to be fatal objections to the application 
of the special-creation theory to this particular case. 
The .other two supposed explanations, which may 
be shortly expressed as the theories of " similar con- 
ditions" and of " heredity," agree in making mimicry, 
where it exists, an adventitious circumstance not ne- 
cessarily connected with the well-being of the mimick- 
ing species. But several of the most striking and 
most constant facts which have been adduced, directly 
contradict both these hypotheses. The law that mi- 
micry is confined to a few groups only is one of these, 
for " similar conditions " must act more or less on all 
groups in a limited region, and " heredity " must 


influence all groups related to each other in an equal 
degree. Again, the general fact that those species 
which mimic others are rare, while those which are 
imitated are abundant, is in no way explained by either 
of these theories, any more than is the frequent occur- 
rence of some palpable mode of protection in the 
imitated species. " Reversion to an ancestral type " 
no way explains why the imitator and the imitated 
always inhabit the very same district, whereas allied 
forms of every degree of nearness and remoteness 
generally inhabit different countries, and often dif- 
ferent quarters of the globe; and neither it, nor 
" similar conditions," will account for the likeness be- 
tween species of distinct groups being superficial only 
a disguise, not a true resemblance ; for the imitation 
of bark, of leaves, of sticks, of dung ; for the resem- 
blance between species in different orders, and even 
different classes and sub-kingdoms ; and finally, for the 
graduated series of the phenomena, beginning with a 
general harmony and adaptation of tint in autumn and 
winter moths and in arctic and desert animals, and 
ending with those complete cases of detailed mimicry 
which not only deceive predacious animals, but puzzle 
the most experienced insect collectors and the most 
learned entomologists. 

Mimicry by Female Insects only. 

But there is yet another series of phenomena con- 
nected with this subject, which considerably strengthens 
the view here adopted, while it seems quite incompa- 


tible with either of the other hypotheses ; namely, the 
relation of protective colouring and mimicry to the 
sexual differences of animals. It will be clear to every 
one that if two animals, which as regards " external 
conditions " and " hereditary descent," are exactly 
alike, yet differ remarkably in colouration, one resem- 
bling a protected species and the other not, the resem- 
blance that exists in one only can hardly be imputed 
to the influence of external conditions or as the effect 
of heredity. And if, further, it can be proved that 
the one requires protection more than the other, and 
that in several cases it is that one which mimics the 
protected species, while the one that least requires 
protection never does so, it will afford very strong 
corroborative evidence that there is a real connexion 
between the necessity for protection and the pheno- 
menon of mimicry. Now the sexes of insects offer 
us a test of the nature here indicated, and appear to 
furnish one of the most conclusive arguments in favour 
of the theory that the phenomena termed " mimicry " 
are produced by natural selection. 

The comparative importance of the sexes varies 
much in different classes of animals. In the higher 
vertebrates, where the number of young produced at a 
birth is small and the same individuals breed many 
years in succession, the preservation of both sexes is 
almost equally important. In all the numerous cases 
in which the male protects the female and her offspring, 
or helps to supply them with food, his importance in 
the economy of nature is proportionately increased, 


though it is never perhaps quite equal to that of the 
female. In insects the case is very different ; they 
pair but once in their lives, and the prolonged existence 
of the male is in most cases quite unnecessary for the 
continuance of the race. The female, however, must 
continue to exist long enough to deposit her eggs in a 
place adapted for the development and growth of the 
progeny. Hence there is a wide difference in the need 
for protection in the two sexes ; and we should, there- 
fore, expect to find that in some cases the special pro- 
tection given to the female was in the male less in 
amount or altogether wanting. The facts entirely con- 
firm this expectation. In the spectre insects (Phas- 
midae) it is often the females alone that so strikingly 
resemble leaves, w r hile the males show only a rude 
approximation. The male Diadema misippus is a very 
handsome and conspicuous butterfly, without a sign of 
protective or imitative colouring, while the female is 
entirely unlike her partner, and is one of the most 
wonderful cases of mimicry on record, resembling 
most accurately the common Danais chrysippus, in 
whose company it is often found. So in several species 
of South American Pieris, the males are white and 
black, of a similar type of colouring to our own 
" cabbage " butterflies, while the females are rich 
yellow and buff, spotted and marked so as exactly to 
resemble species of HeliconidaB with which they asso- 
ciate in the forest. In the Malay archipelago is found 
a Diadema which had always been considered a male 
insect on account of its glossy metallic-blue tints, 


while its companion of sober brown was looked upon 
as the female. I discovered, however, that the reverse 
is the case, and that the rich and glossy colours of 
the female are imitative and protective, since they 
cause her exactly to resemble the common Euploea 
midamus of the same regions, a species which has 
been already mentioned in this essay as mimicked 
by another butterfly, Papilio paradoxa. I have since 
named this interesting species Diadema anomala (see 
the Transactions of the Entomological Society, 1869, 
p. 285). In this case, and in that of Diadema misippus, 
there is no difference in the habits of the two sexes, 
which fly in similar localities; so that the influence 
of " external conditions " cannot be invoked here as 
it has been in the case of the South American Pieris 
pyrrha and allies, where the white males frequent 
open sunny places, while the Heliconia-like females 
haunt the shades of the forest. 

We may impute to the same general cause (the 
greater need of protection for the female, owing to 
her weaker flight, greater exposure to attack, and 
supreme importance) the fact of the colours of female 
insects being so very generally duller and less conspi- 
cuous than those of the other sex. And that it is 
chiefly due to this cause rather than to what Mr. 
Darwin terms " sexual selection " appears to be 
shown by the otherwise inexplicable fact, that in the 
groups which have a protection of any kind inde- 
pendent of concealment, sexual differences of colour 
are either quite wanting or slightly developed. The 



Heliconidse and Danaidse, protected by a disagree- 
able flavour, have the females as bright and conspi- 
cuous as the males, and very rarely differing at all 
from them. The stinging Hymenoptera have the two 
sexes equally well coloured. The Carabidaa, the Coc- 
cinellidye, Chrysomelida3, and the Telephori have both 
sexes equally conspicuous, and seldom differing in 
colours. The brilliant Curculios, which are protected 
by their hardness, are brilliant in both sexes. Lastly, 
the glittering CetoniadaB and Buprestidas, which seem 
to be protected by their hard and polished coats, their 
rapid motions, and peculiar habits, present few sexual 
differences of colour, while sexual selection has often 
manifested itself by structural differences, such as- 
horns, spines, or other processes. 

Cause of the dull Colours of Female Birds. 

The same law manifests itself in Birds. The female 
while sitting on her eggs requires protection by con- 
cealment to a much greater extent than the male ; and 
we accordingly find that in a large majority of the 
cases in which the male birds are distinguished by 
unusual brilliancy of plumage, the females are much 
more obscure, and often remarkably plain-coloured. 
The exceptions are such as eminently to prove the 
rule, for in most cases we can see a very good reason 
for them. In particular, there are a few instances 
among wading and gallinaceous birds in which the 
female has decidedly more brilliant colours than the 
male; but it is a most curious and interesting fact 


that in most if not all these cases the males sit upon 
the eggs; so that this exception to the usual rule 
almost demonstrates that it is because the process of 
incubation is at once very important and very dan- 
gerous, that the protection of obscure colouring is 
developed. The most striking example is that of the 
gray phalarope (Phalaropus fulicarius). When in 
winter plumage, the sexes of this bird are alike in 
colouration, but in summer the female is much the 
most conspicuous, having a black head, dark wings, 
and reddish-brown back, while the male is nearly 
uniform brown, with dusky spots. Mr. Gould in his 
" Birds of Great Britain " figures the two sexes in 
both winter and summer plumage, and remarks on 
the strange peculiarity of the usual colours of the two 
sexes being reversed, and also on the still more curious 
fact that the " male alone sits on the eggs," which 
are deposited on the bare ground. In another British 
bird, the dotterell, the female is also larger and more 
brightly-coloured than the male ; and it seems to be 
proved that the males assist in incubation even if they 
do not perform it entirely, for Mr. Gould tells us, 
"that they have been shot with the breast bare of 
feathers, caused by sitting on the eggs." The small 
quail-like birds forming the genus Turnix have also 
generally large and bright-coloured females, and we 
are told by Mr. Jerdon in his " Birds of India " that 
"the natives report that during the breeding season 
the females desert their eggs and associate in flocks 
while the males are employed in hatching the eggs." 

I 2 


It is also an ascertained fact, that the females are 
more bold and pugnacious than the males. A further 
confimation of this view is to be found in the fact 
(not hitherto noticed) that in a large majority of the 
cases in which bright colours exist in both sexes incu- 
bation takes place in a dark hole or in a dome-shaped 
nest. Female kingfishers are often equally brilliant 
with the male, and they build in holes in banks. Bee- 
eaters, trogons, motmotSj and toucans, all build in 
holes, and in none is there any difference in the sexes, 
although they are, without exception, showy birds. 
Parrots build in holes in trees, and in the majority 
of cases they present no marked sexual difference 
tending to concealment of the female. Woodpeckers 
are in the same category, since though the sexes often 
differ in colour, the female is not generally less con- 
spicuous than the male. Wagtails and titmice build 
concealed nests, and the females are nearly as gay as 
their mates. The female of the pretty Australian bird 
Pardalotus punctatus, is very conspicuously spotted 
on the upper surface, and it builds in a hole in the 
ground. The gay-coloured hang-nests (Icterinse) and 
the equally brilliant tanagers may be well contrasted; 
for the former, concealed in their covered nests, pre- 
sent little or no sexual difference of colour while the 
open-nested tanagers have the females dull-coloured 
and sometimes with almost protective tints. No doubt 
there are many individual exceptions to the rule here 
indicated, because many and various causes have com- 
bined to determine both the colouration and the habits 


of birds. These have no doubt acted and re-acted 
on each other; and when conditions have changed 
one of these characters may often have become modi- 
fied, while the other, though useless, may continue 
by hereditary descent an apparent exception to what 
otherwise seems a very general rule. The facts pre- 
sented by the sexual differences of colour in birds and 
their mode of nesting, are on the whole in perfect 
harmony with that law of protective adaptation of 
colour and form, which appears to have checked to 
some extent the powerful action of sexual selection, 
and to have materially influenced the colouring of 
female birds, as it has undoubtedly done that of 
female insects. 

Use of the gaudy Colours of many Caterpillars. 

Since this essay was first published a very curious 
difficulty has been cleared up by the application of 
the general principle of protective colouring. Great 
numbers of caterpillars are so brilliantly marked and 
coloured as to be very conspicuous even at a consi- 
derable distance, and it has been noticed that such 
caterpillars seldom hide themselves. Other species, 
however, are green or brown, closely resembling the 
colours of the substances on which they feed, while 
others again imitate sticks, and stretch themselves out 
motionless from a twig so as to look like one of its 
branches. Now, as caterpillars form so large a part of 
the food of birds, it was not easy to understand why 
any of them should have such bright colours and mark 


ings as to make them specially visible. Mr. Darwin 
had put the case to me as a difficulty from another 
point of view, for he had arrived at the conclusion that 
brilliant colouration in the animal kingdom is mainly 
clue to sexual selection, and this could not have acted 
in the case of sexless larvse. Applying here the analogy 
of other insects, I reasoned, that since some caterpillars 
were evidently protected by their imitative colouring, 
and others by their spiny or hairy bodies, the bright 
colours of the rest must also be in some way useful to 
them. I further thought that as some butterflies and 
moths were greedily eaten by birds while others were 
distasteful to them, and these latter were mostly of con- 
spicuous colours, so probably these brilliantly coloured 
caterpillars were distasteful, and therefore never eaten 
by birds. Distastefulness alone would however be of 
little service to caterpillars, because their soft and juicy 
bodies are so delicate, that if seized and afterwards re- 
jected by a bird they would almost certainly be killed. 
Some constant and easily perceived signal was therefore 
necessary to serve as a warning to birds never to touch 
these uneatable kinds, and a very gaudy and conspi- 
cuous colouring with the habit of fully exposing them- 
selves to view becomes such a signal, being in strong 
contrast with the green or brown tints and retiring 
habits of the eatable kinds. The subject was brought 
by me before the Entomological Society (see Proceed- 
ings, March 4th, 1867), in order that those members 
having opportunities for making observations might do 
so in the following summer ; and I also wrote a letter to 


the Field newspaper, begging that some of its readers 
would co-operate in making observations on what in- 
sects were rejected by birds, at the same time fully 
explaining the great interest and scientific importance 
of the problem. It is a curious example of how few of 
the country readers of that paper are at all interested 
in questions of simple natural history, that I only 
obtained one answer from a gentleman in Cumber- 
land, who gave me some interesting observations on 
the general dislike and abhorrence of all birds to the 
"Gooseberry Caterpillar," probably that of the Magpie- 
moth (Abraxas grossulariata). Neither young phea- 
sants, partridges, nor wild-ducks could be induced to 
eat it, sparrows and finches never touched it, and all 
birds to whom he offered it rejected it with evident 
dread and abhorrence. It will be seen that these ob- 
servations are confirmed by those of two members of 
the Entomological Society to whom we are indebted 
for more detailed information. 

In March, 1869, Mr. J. Jenner Weir communicated a 
valuable series of observations made during many years, 
but more especially in the two preceding summers, in 
his aviary, containing the following birds of more or 
less insectivorous habits: Robin, Yellow - Hammer, 
Reed-bunting, Bullfinch, Chaffinch, Crossbill, Thrush, 
Tree-Pipit, Siskin, and Redpoll. He found that hairy 
caterpillars were uniformly rejected ; five distinct species 
were quite unnoticed by all his birds, and were allowed 
to crawl about the aviary for days with impunity. The 
spiny caterpillars of the Tortoiseshell and Peacock but- 


terflies were equally rejected ; but in both these cases 
Mr. Weir thinks it is the taste, not the hairs or spines, 
that are disagreeable, because some very young cater- 
pillars of a hairy species were rejected although no hairs 
were developed, and the smooth pupaa of the above- 
named butterflies were refused as persistently as the 
spined larvae. In these cases, then, both hairs and 
spines would seem to be mere signs of uneatableness. 

His next experiments were with those smooth gaily- 
coloured caterpillars which never conceal themselves, 
but on the contrary appear to court observation. Such 
are those of the Magpie moth (Abraxas grossulariata), 
whose caterpillar is conspicuously white and black 
spotted the Diloba coeruleocephala, whose larvae is 
pale yellow with a broad blue or green lateral band 
the Cucullia verbasci, whose larvse is greenish white 
with yellow bands and black spots, and Anthrocera 
filipendulse (the six spot Burnet moth), whose cater- 
pillar is yellow with black spots. These were given 
to the birds at various times, sometimes mixed with 
other kinds of larvse which were greedily eaten, but 
they were in every case rejected apparently unnoticed, 
and were left to crawl about till they died. 

The next set of observations were on the dull- 
coloured and protected larvse, and the results of nu- 
merous experiments are thus summarised by Mr. 
Weir. " All caterpillars whose habits are nocturnal, 
which are dull coloured, with fleshy bodies and 
smooth skins, are eaten with the greatest avidity. 
Every species of green caterpillar is also much re- 


lished. All Geometry, whose larvse resemble twigs 
as they stand out from the plant on their anal 
prolegs, are invariably eaten." 

At the same meeting Mr. A. G. Butler, of the 
British Museum, communicated the results of his 
observations with lizards, frogs, and spiders, which 
strikingly corroborate those of Mr. Weir. Three green 
lizards (Lacerta viridis) which he kept for several 
years, were very voracious, eating all kinds of food, 
from a lemon cheesecake to a spider, and devouring 
flies, caterpillars, and humble bees ; yet there were 
some caterpillars and moths which they would seize 
only to drop immediately. Among these the principal 
were the caterpillar of the Magpie moth (Abraxas 
grossulariata) and the perfect six spot Burnet moth 
(Anthrocera filipendulaB). These would be first seized 
but invariably dropped in disgust, and afterwards left 
unmolested. Subsequently frogs were kept and fed 
with caterpillars from the garden, but two of these 
that of the before-mentioned Magpie moth, and that 
of the V. moth (Halia wavaria), which is green with 
conspicuous white or yellow stripes and black spots 
were constantly rejected. When these species were 
first offered, the frogs sprang at them eagerly and 
licked them into their mouths; no sooner, however, 
had they done so than they seemed to be aware of 
the mistake that they had made, and sat with gaping 
mouths, rolling their tongues about until they had 
got quit of the nauseous morsels. 

With spiders the same thing occurred. These two 


caterpillars were repeatedly put into the webs both of 
the geometrical and hunting spiders (Epeira diadema 
and Lycosa sp.), but in the former case they were 
cut out and allowed to drop ; in the latter, after dis- 
appearing in the jaws of their captor down his dark 
silken funnel, they invariably reappeared, either from 
below or else taking long strides up the funnel again. 
Mr. Butler has observed lizards fight with and finally 
devour humble bees, and a frog sitting on a bed of 
stone-crop leap up and catch the bees which flew over 
his head, and swallow them, in utter disregard of 
their stings. It is evident, therefore, that the posses- 
sion of a disagreeable taste or odour is a more effec- 
tual protection to certain conspicuous caterpillars and 
moths, than would be even the possession of a sting. 
The observations of these two gentlemen supply 
a very remarkable confirmation of the hypothetical 
solution of the difficulty which I had given two years 
before. And as it is generally acknowledged that 
the best test of the truth and completeness of a 
theory is the power which it gives us of prevision, 
we may I think fairly claim this as a case in which 
the power of prevision has been successfully exerted, 
and therefore as furnishing a very powerful argu- 
ment in favour of the truth of the theory of Natural 

t Summary. 

I have now completed a brief, and necessarily very 
imperfect, survey of the various ways in which the 


external form and colouring of animals is adapted to 
be useful to them, either by concealing them from their 
enemies or from the creatures they prey upon. It has, 
I hope, been shown that the subject is one of much 
interest, both as regard a true comprehension of the 
place each animal fills in the economy of nature, and 
the means by which it is enabled to maintain that 
place; and also as teaching us how important a part 
is played by the minutest details in the structure 
of animals, and how complicated and delicate is the 
equilibrium of the organic world. 

My exposition of the subject having been necessarily 
somewhat lengthy and full of details, it will be as 
well to recapitulate its main points. 

There is a general harmony in nature between the 
colours of an animal and those of its habitation. 
Arctic animals are white, desert animals are sand- 
coloured ; dwellers among leaves and grass are green ; 
nocturnal animals are dusky. These colours are not 
universal, but are very general, and are seldom re- 
versed. Going on a little further, we find birds, 
reptiles, and insects, so tinted and mottled as exactly 
to match the rock, or bark, or leaf, or flower, they 
are accustomed to rest upon, and thereby effec- 
tually concealed. Another step in advance, and we 
have insects which are formed as well as coloured so 
as exactly to resemble particular leaves, or sticks, or 
mossy twigs, or flowers; and in these cases very 
peculiar habits and instincts come into play to aid 
in the deception and render the concealment more 


complete. We now enter upon a new phase of the 
phenomena, and come to creatures whose colours neither 
conceal them nor make them like vegetable or mineral 
substances; on the contrary, they are conspicuous 
enough, but they completely resemble some other 
creature of a quite different group, while they differ 
much in outward appearance from those with which 
all essential parts of their organization show them 
to be really closely allied. They appear like actors 
or masqueraders dressed up and painted for amuse- 
ment, or like swindlers endeavouring to pass them- 
selves off for well-known and respectable members 
of society. What is the meaning of this strange 
travestie ? Does Nature descend to imposture or mas- 
querade ? We answer, she does not. Her principles 
are too severe. There is a use in every detail of 
her handiwork. The resemblance of one animal to 
another is of exactly the same essential nature as the 
resemblance to a leaf, or to bark, or to desert sand, 
and answers exactly the same purpose. In the one 
case the enemy will not attack the leaf or the bark, 
and so the disguise is a safeguard ; in the other case 
it is found that for various reasons the creature re- 
sembled is passed over, and not attacked by the usual 
enemies of its order, and thus the creature that 
resembles it has an equally effectual safeguard. We 
are plainly shown that the disguise is of the same 
nature in the two cases, by the occurrence in the 
same group of one species resembling a vegetable 
substance, while another resembles a living animal of 


another group; and we know that the creatures re- 
sembled, possess an immunity from attack, by their 
being always very abundant, by their being conspi- 
cuous and not concealing themselves, and by their 
having generally no visible means of escape from 
their enemies ; while, at the same time, the particular 
quality that makes them disliked is often very clear, 
such as a nasty taste or an indigestible hardness. 
Further examination reveals the fact that, in several 
cases of both kinds of disguise, it is the female only 
that is thus disguised ; and as it can be shown that the 
female needs protection much more than the male, 
and that her preservation for a much longer period is 
absolutely necessary for the continuance of the race, 
we have an additional indication that the resemblance 
is in all cases subservient to a great purpose the 
preservation of the species. 

In endeavouring to explain these phenomena as 
having been brought about by variation and natural 
selection, we start with the fact that white varieties 
frequently occur, and when protected from enemies 
show no incapacity for continued existence and in- 
crease. We know, further, that varieties of many 
other tints occasionally occur; and as f 'the survival 
of the fittest " must inevitably weed out those whose 
colours are prejudicial and preserve those whose 
colours are a safeguard, we require no other mode of 
accounting for the protective tints of arctic and 
desert animals. But this being granted, there is 
such a perfectly continuous and graduated series of 


examples of every kind of protective imitation, up to 
the most wonderful cases of what is termed "mimicry," 
that we can find no place at which to draw the line, 
and say, so far variation and natural selection will 
account for the phenomena, but for all the rest we 
require a more potent cause. The counter theories 
that have been proposed, that of the " special creation " 
of each imitative form, that of the action of " similar 
conditions of existence " for some of the cases, and of 
the laws of Ce hereditary descent and the reversion to 
ancestral forms " for others, have all been shown 
to be beset with difficulties, and the two latter to be 
directly contradicted by some of the most constant and 
most remarkable of the facts to be accounted for. 

General deductions as to Colour in Mature. 

The important part that " protective resemblance " 
has played in determining the colours and markings 
of many groups of animals, will enable us to under- 
stand the meaning of one of the most striking facts 
in nature, the uniformity in the colours of the vege- 
table as compared with the wonderful diversity of the 
animal world. There appears no good reason why 
trees and shrubs should not have been adorned with 
as many varied hues and as strikingly designed pat- 
terns as birds and butterflies, since the gay colours 
of flowers show that there is no incapacity in vege- 
table tissues to exhibit them. But even flowers them- 
selves present us with none of those wonderful designs, 
those complicated arrangements of stripes and dots 


and patches of colour, that harmonious blending of 
hues in lines and bands and shaded spots, which are 
so general a feature in insects. It is the opinion of 
Mr. Darwin that we owe much of the beauty of 
flowers to the necessity of attracting insects to aid 
in their fertilisation, and that much of the develop- 
ment of colour in the animal world is due to " sexual 
selection,'* colour being universally attractive, and thus 
leading to its propagation and increase; but while 
fully admitting this, it will be evident from the facts 
and arguments here brought forward, that very much 
of the variety both of colour and markings among 
animals is due to the supreme importance of con- 
cealment, and thus the various tints "of minerals and 
vegetables have been directly reproduced in the ani- 
mal kingdom, and again and again modified as more 
special protection became necessary. We shall thus 
have two causes for the development of colour in the 
animal world, and shall be better enabled to under- 
stand how, by their combined and separate action, 
the immense variety we now behold has been pro- 
duced. Both causes, however, will come under the 
general law of " Utility," the advocacy of which, in its 
broadest sense, we owe almost entirely to Mr. Darwin. 
A more accurate knowledge of the varied phenomena 
connected with this subject may not improbably give 
us some information both as to the senses and the 
mental faculties of the lower animals. For it is 
evident that if colours which please us also attract 
them, and if the various disguises which have been 


here enumerated are equally deceptive to them as to 
ourselves, then both their powers of vision and their 
faculties of perception and emotion, must be essentially 
of the same nature as our own a fact of high philo- 
sophical importance in the study of our own nature 
and our true relations to the lower animals. 


Although such a variety of interesting facts have 
been already accumulated, the subject we have been 
discussing is one of which comparatively little is really 
known. The natural history of the tropics has never 
yet been studied on the spot with a full appreciation 
of " what to observe " in this matter. The varied 
ways in which the colouring and form of animals serve 
for their protection, their strange disguises as vege- 
table or mineral substances, their wonderful mimicry 
of other beings, offer an almost unworked and inex- 
haustible field of discovery for the zoologist, and will 
assuredly throw much light on the laws and conditions 
which have resulted in the wonderful variety of colour, 
shade, and marking which constitutes one of the most 
pleasing characteristics of the animal world, but the 
immediate causes of which it has hitherto been most 
difficult to explain. 

If I have succeeded in showing that in this wide 
and picturesque domain of nature, results which have 
hitherto been supposed to depend either upon those 
incalculable combinations of laws which we term 
chance or upon the direct volition of the Creator, are 


really due to the action of comparatively well-known 
and simple causes, I shall have attained my present 
purpose, which has been to extend the interest so 
generally felt in the more striking facts of natural 
history to a large class of curious but much neglected 
details ; and to further, in however slight a degree, 
our knowledge of the subjection of the phenomena of 
life to the "Reign of Law." 




Special Value of the Diurnal Lepidoptera for enquiries 
of this nature. 

WHEN the naturalist studies the habits, the structure, 
or the affinities of animals, it matters little to which 
group he especially devotes himself; all alike offer him 
endless materials for observation and research. But, 
for the purpose of investigating the phenomena of geo- 
graphical distribution and of local, sexual, or general 
variation, the several groups differ greatly in their 
value and importance. Some have too limited a range, 
others are not sufficiently varied in specific forms, 
while, what is of most importance, many groups 
have not received that amount of attention over the 
whole region they inhabit, which could furnish mate- 
rials sufficiently approaching to completeness to enable 
us to arrive at any accurate conclusions as to the 
phenomena they present as a whole. It is in those 
groups which are, and have long been, favourites with 
collectors, that the student of distribution and varia- 
tion will find his materials the most satisfactory, from 
their comparative completeness. 


Pre-eminent among such groups are the diurnal 
Lepidoptera or Butterflies, whose extreme beauty 
and endless diversity have led to their having been 
assiduously collected in all parts of the world, and 
to the numerous species and varieties having been 
figured in a series of magnificent works, from those 
of Cramer, the contemporary of Linnseus, down to 
the inimitable productions of our own Hewitson.* 
But, besides their abundance, their universal distri- 
bution, and the great attention that has been paid 
to them, these insects have other qualities that espe- 
cially adapt them to elucidate the branches of inquiry 
already alluded to. These are, the immense develop- 
ment and peculiar structure of the wings, which not 
only vary in form more than those of any other 
insects, but offer on both surfaces an endless variety 
of pattern, colouring, and texture. The scales, with 
which they are more or less completely covered, imi- 
tate the rich hues and delicate surfaces of satin or 
of velvet, glitter with metallic lustre, or glow with 
the changeable tints of the opal. This delicately 
painted surface acts as a register of the minutest 
differences of organization a shade of colour, an 
additional streak or spot, a slight modification of 
outline continually recurring with the greatest regu- 
larity and fixity, while the body and all its other 

* W. C. Hewitson, Esq., of Oatlands, Walton-on-Thames, 
author of " Exotic Butterflies " and several other works, illus- 
trated by exquisite coloured figures drawn by himself; and 
owner of the finest collection of Butterflies in the world. 

K 2 


members exhibit no appreciable change. The wings 
of Butterflies, as Mr. Bates has well put it, "serve 
as a tablet on which Nature writes the story of the 
modifications of species ; " they enable us to perceive 
changes that would otherwise be uncertain and diffi- 
cult of observation, and exhibit to us on an enlarged 
scale the effects of the climatal and other physical 
conditions which influence more or less profoundly 
the organization of every living thing. 

A proof that this greater sensibility to modifying 
causes is not imaginary may, I think, be drawn from 
the consideration, that while the Lepidoptera as a 
whole are of all insects the least essentially varied in 
form, structure, or habits, yet in the number of their 
specific forms they are not much inferior to those 
orders which range over a much wider field of nature, 
and exhibit more deeply seated structural modifica- 
tions. The Lepidoptera are all vegetable-feeders in 
their larva-state, and suckers of juices or other liquids 
in their perfect form. In their most widely separated 
groups they differ but little from a common type, 
and offer comparatively unimportant modifications of 
structure or of habits. The Coleoptera, the Diptera, 
or the Hymenoptera, on the other hand, present far 
greater and more essential variations. In either of 
these orders we have both vegetable and animal- 
feeders, aquatic, and terrestrial, and parasitic groups. 
Whole families are devoted to special departments in 
the economy of nature. Seeds, fruits, bones, car- 
cases, excrement, bark, have each their special and 


dependent insect tribes from among them; whereas 
the Lepidoptera are, with but few exceptions, confined 
to the one function of devouring the foliage of living 
vegetation. We might therefore anticipate that their 
species - population would be only equal to that of 
sections of the other orders having a similar uniform 
mode of existence ; and the fact that their numbers 
are at all comparable with those of entire orders, so 
much more varied in organization and habits, is, I 
think, a proof that they are in general highly sus- 
ceptible of specific modification. 

Question of the rank of the Papilionidce. 

The Papilionidas are a family of diurnal Lepidop- 
tera which have hitherto, by almost universal consent, 
held the first rank in the order ; and though this 
position has recently been denied them, I cannot 
altogether acquiesce in the reasoning by which it has 
been proposed to degrade them to a lower rank. In 
Mr. Bates's most excellent paper on the Heliconida3, 
(published in the Transactions of the Linnasan So- 
ciety, vol. xxiii., p. 495) he claims for that family 
the highest position, chiefly because of the imperfect 
structure of the fore legs, which is there carried to 
an extreme degree of abortion, and thus removes 
them further than any other family from the Hes- 
peridge and Heterocera, which all have perfect legs. 
Now it is a question whether any amount of differ- 
ence which is exhibited merely in the imperfection 
or abortion of certain organs, can establish in the 


group exhibiting it a claim to a higli grade of organ- 
ization ; still less can this be allowed when another 
group along with perfection of structure in the same 
organs, exhibits modifications peculiar to it, together 
with the possession of an organ which in the re- 
mainder of the order is altogether wanting. This is, 
however, the position of the Papilionidae. The per- 
fect insects possess two characters quite peculiar to 
them. Mr. Edward Doubleday, in his " Genera of 
Diurnal Lepidoptera," says, " The Papilionidae may 
be known by the apparently four-branched median 
nervule and the spur on the anterior tibiae, charac- 
ters found in no other family." The four -branched 
median nervule is a character so constant, so pecu- 
liar, and so well marked, as to enable a person to 
tell, at a glance at the wings only of a butterfly, 
whether it does or does not belong to this family ; 
and I am not aware that any other group of butter- 
flies, at all comparable to this in extent and modifi- 
cations of form, possesses a character in its neuration 
to which the same degree of certainty can be attached. 
The spur on the anterior tibiae is also found in some 
of the Hesperidae, and is therefore supposed to show a 
direct affinity between the two groups : but I do not 
imagine it can counterbalance the differences in neura- 
tion and in every other part of their organization. 
The most characteristic feature of the Papilionidae, 
however, and that on which I think insufficient 
stress has been laid, is undoubtedly the peculiar 
structure of the larvae. These all possess an extra- 


ordinary organ situated on the neck, the well-known 
Y-shaped tentacle, which is entirely concealed in a 
state of repose, but which is capable of being sud- 
denly thrown out by the insect when alarmed. When 
we consider this singular apparatus, which in some 
species is nearly half an inch long, the arrange- 
ment of muscles for its protrusion and retraction, 
its perfect concealment during repose, its blood-red 
colour, and the suddenness with which it can be 
thrown out, we must, I think, be led to the con- 
clusion that it serves as a protection to the larva, 
by startling and frightening away some enemy when 
about to seize it, and is thus one of the causes which 
has led to the wide extension and maintained the per- 
manence of this now dominant group. Those who 
believe that such peculiar structures can only have 
arisen by very minute successive variations, each one 
advantageous to its possessor, must see, in the pos- 
session of such an organ by one group, and its 
complete absence in every other, a proof of a very 
ancient origin and of very long-continued modifica- 
tion. And such a positive structural addition to 
the organization of the family, subserving an impor- 
tant function, seems to me alone sufficient to warrant 
us in considering the Papilionidse as the most highly 
developed portion of the whole order, and thus in 
retaining it in the position which the size, strength, 
beauty, and general structure of the perfect insects 
liave been generally thought to deserve. 

In Mr. Trimen's paper on "Mimetic Analogies 


among African Butterflies," in the Transactions of the 
Linnsean Society, for 1868, lie has argued strongly 
in favour of Mr. Bates' views as to the higher posi- 
tion of the Danaidse and the lower grade of the 
Papilionidse, and has adduced, among other facts, the 
undoubted resemblance of the pupa of Parnassius, a 
genus of Papilionidoa, to that of some HesperidsB and 
moths. I admit, therefore, that he has proved the 
Papilionidas to have retained several characters of 
the nocturnal Lepidoptera which the Danaidse have 
lost, but I deny that they are therefore to be con- 
sidered lower in the scale of organization. Other 
characters may be pointed out which indicate that 
they are farther removed from the moths even than 
the Danaidse. The club of the antennae is the most 
prominent and most constant feature by which but- 
terflies may be distinguished from moths, and of 
all butterflies the Papilionidaa have the most beauti- 
ful and most perfectly developed clubbed antennae. 
Again, butterflies and moths are broadly character- 
ised by their diurnal and nocturnal habits respectively, 
and the Papilionidse, with their close allies the Pier- 
idge, are the most pre-eminently diurnal of butterflies, 
most of them lovers of sunshine, and not presenting 
a single crepuscular species. The great group of the 
Nymphalidse, on the other hand (in which Mr. Bates 
includes the Danaidse and Heliconidae as sub-fami- 
lies), contains an entire sub-family (Brassolidse) and 
a number of genera, such as Thaumantis, Zeuxidia, 
Pavonia, &c., of crepuscular habits, while a large 


proportion of the Satyridae and many of the Dana- 
idse are shade -loving butterflies. This question, of 
what is to be considered the highest type of any 
group of organisms, is one of such general interest to 
naturalists that it will be well to consider it a little 
further, by a comparison of the Lepidoptera with some 
groups of the higher animals. 

Mr. Trimen's argument, that the lepidopterous type, 
like that of birds, being pre-eminently aerial, " there- 
fore a diminution of the ambulatory organs, instead 
of being a sign of inferiority, may very possibly in- 
dicate a higher, because a more thoroughly aerial 
form," is certainly unsound, for it would imply that 
the most aerial of birds (the swift and the frigate- 
birds, for example) are the highest in the scale of 
bird-organization, and the more so on account of their 
feet being very ill adapted for walking. But no or- 
nithologist has ever so classed them, and the claim to 
the highest rank among birds is only disputed be- 
tween three groups, all very far removed from these. 
They are 1st. The Falcons, on account of their 
general perfection, their rapid flight, their piercing 
vision, their perfect feet armed with retractile claws, 
the beauty of their forms, and the ease and rapidity of 
their motions ; 2nd. The Parrots, whose feet, though 
ill-fitted for walking, are perfect as prehensile organs, 
and which possess large brains with great intelligence, 
though but moderate powers of flight ; and, 3rd. The 
Thrushes or Crows, as typical of the perching birds, 
on account of the well-balanced development of their 


whole structure, in which no organ or function has 
attained an undue prominence. 

Turning now to the Mammalia, it might be argued 
that as they are pre-eminently the terrestrial type 
of vertebrates, to walk and run well is essential to the 
typical perfection of the group ; but this would give 
the superiority to the horse, the deer, or the hunting 
leopard, instead of to the Quadrumana. We seem here 
to have quite a case in point, for one group of Quad- 
rumana, the Lemurs, is undoubtedly nearer to the 
low Insectivora and Marsupials than the Carnivora or 
the Ungulata, as shown among other characters by 
the Opossums possessing a hand with perfect opposable 
thumb, closely resembling that of some of the Lemurs ; 
and by the curious Graleopithecus, which is sometimes 
classed as a Lemur, and sometimes with the Insecti- 
vora. Again, the implacental mammals, including 
the Ornithodelphia and the Marsupials, are admitted 
to be lower than the placental series. But one of the 
distinguishing characters of the Marsupials is that the 
young are born blind and exceedingly imperfect, and 
it might therefore be argued that those orders in 
which the young are born most perfect are the highest, 
because farthest from the low Marsupial type. This 
would make the Ruminants and Ungulata higher than 
the Quadrumana or the Carnivora. But the Mam- 
malia offer a still more remarkable illustration of the 
fallacy of this mode of reasoning, for if there is one 
character more than another which is essential and 
distinctive of the class, it is that from which it derives 


its name, the possession of mammary glands and the 
power of suckling the young. What more reasonable, 
apparently, than to argue that the group in which 
this important function is most developed, that in 
which the young are most dependent upon it, and 
for the longest period, must be the highest in the 
Mammalian scale of organization? Yet this group is 
the Marsupial, in which the young commence suckling 
in a foetal condition, and continue to do so till they 
are fully developed, and are therefore for a long time 
absolutely dependent on this mode of nourishment. 

These examples, I think, demonstrate that we can- 
not settle the rank of a group by a consideration of 
the degree in which certain characters resemble or 
differ from those in what is admitted to be a lower 
group ; and they also show that the highest group of 
a class may be more closely connected to one of the 
lowest, than some other groups which have developed 
laterally and diverged farther from the parent type, 
but which yet, owing to want of balance or too great 
specialization in their structure, have never reached 
a high grade of organization. The Quadrumana afford 
a very valuable illustration, because, owing to their 
undoubted affinity with man, we feel certain that they 
are really higher than any other order of Mammalia, 
while at the same time they are more distinctly allied 
to the lowest groups than many others. The case of 
the PapilionidaB seems to me so exactly parallel to 
this, that, while I admit all the proofs of affinity 
with the undoubtedly lower groups of Hesperidse and 


moths, I yet maintain that, owing to the complete 
and even development of every part of their organi- 
zation, these insects best represent the highest per- 
fection to which the butterfly type has attained, and 
deserve to be placed at its head in every system of 

Distribution of tlie Papilionidce. 

The Papilionidaa are pretty widely distributed over 
the earth, but are especially abundant in the tropics, 
where they attain their maximum of size and beauty, 
and fhe greatest variety of form and colouring. 
South America, North India, and the Malay Islands 
are the regions where these fine insects occur in the 
greatest profusion, and where they actually become 
a not unimportant feature in the scenery. In the 
Malay Islands in particular, the giant Ornithoptera? 
may be frequently seen about the borders of the cul- 
tivated and forest districts, their large size, stately 
flight, and gorgeous colouring rendering them even 
more conspicuous than the generality of birds. In 
the shady suburbs of the town of Malacca two large 
and handsome Papilios (Memnon and ISTephelus) are 
not uncommon, flapping with irregular flight along 
the roadways, or, in the early morning, expanding 
their wings to the invigorating rays of the sun. In 
Amboyna and other towns of the Moluccas, the mag- 
nificent Deiphobus and Severus, and occasionally even 
the azure-winged Ulysses, frequent similar situations, 
fluttering about the orange-trees and flower-beds, or 


sometimes even straying into the narrow bazaars or 
covered markets of the city. In Java the golden- 
dusted Arjuna may often be seen at damp places on 
the roadside in the mountain districts, in company 
with Sarpedon, Bathycles, and Agamemnon, and less 
frequently the beautiful swallow-tailed Antiphates. 
In the more luxuriant parts of these islands one can 
hardly take a morning's walk in the neighbourhood 
of a town or village without seeing three or four 
species of Papilio, and often twice that number. No 
less than 130 species of the family are now known 
to inhabit the Archipelago, and of these ninety-six 
were collected by myself. Thirty species are found 
in Borneo, being the largest number in any one island, 
twenty-three species having been obtained by myself 
in the vicinity of Sarawak; Java has twenty-eight 
species ; Celebes twenty-four, and the Peninsula of 
Malacca, twenty- six species. Further east the num- 
bers decrease ; Batchian producing seventeen, and New 
Guinea only fifteen, though this number is certainly 
too small, owing to our present imperfect knowledge 
of that great island. 

Definition of the word Species. 

In estimating these numbers I have had the usual 
difficulty to encounter, of determining what to con- 
sider species and what varieties. The Malayan region, 
consisting of a large number of islands of generally 
great antiquity, possesses, compared to its actual area, 
a great number of distinct forms, often indeed dis- 


tinguished by very slight characters, but in most 
cases so constant in large series of specimens, and 
so easily separable from each other, that I know not 
on what principle we can refuse to give them the 
name and rank of species. One of the best and most 
orthodox definitions is that of Pritchard, the great 
ethnologist, who says, that " separate origin and dis- 
tinctness of race, evinced by a constant transmission of 
some characteristic peculiarity of organization," consti- 
tutes a species. Now leaving out the question of 
" origin," which we cannot determine, and taking 
only the proof of separate origin, " the constant trans- 
mission of some characteristic peculiarity of organiza- 
tion" we have a definition which will compel us to 
neglect altogether the amount of difference between 
any two forms, and to consider only whether the dif- 
ferences that present themselves are permanent. The 
rule, therefore, I have endeavoured to adopt is, that 
when the difference between two forms inhabiting 
separate areas seems quite constant, when it can be 
defined in words, and when it is not confined to a 
single peculiarity only, I have considered such forms 
to be species. When, however, the individuals of 
each locality vary among themselves, so as to cause 
the distinctions between the two forms to become 
inconsiderable and indefinite, or where the differences, 
though constant, are confined to one particular only, 
such as size, tint, or a single point of difference in 
marking or in outline, I class one of the forms as a 
variety of the other. 


I find as a general rule that the constancy of species 
is in an inverse ratio to their range. Those which 
are confined to one or two islands are generally very 
constant. When they extend to many islands, con- 
siderable variability appears ; and when they have an 
extensive range over a large part of the Archipelago, 
the amount of unstable variation is very large. These 
facts are explicable on Mr. Darwin's principles. When 
a species exists over a wide area, it must have had, 
and probably still possesses, great powers of disper- 
sion. Under the different conditions of existence in 
various portions of its area, different variations from 
the type would be selected, and, were they completely 
isolated, would soon become distinctly modified forms ; 
but this process is checked by the dispersive powers 
of the whole species, which leads to the more or less 
frequent intermixture of the incipient varieties, which 
thus become irregular and unstable. Where, how- 
ever, a species has a limited range, it indicates less 
active powers of dispersion, and the process of modi- 
fication under changed conditions is less interfered 
with. The species will therefore exist under one or 
more permanent forms according as portions of it have 
been isolated at a more or less remote period. 

Laws and Modes of Variation. 

What is commonly called variation consists of several 
distinct phenomena which have been too often con- 
founded. I shall proceed to consider these under the 
heads of 1st, simple variability ; 2nd, polymorphism ; 


3rd, local forms ; 4th, co-existing varieties ; 5th, races 
or subspecies ; and 6th, true species. 

1. Simple variability. Under this head I include all 
those cases in which the specific form is to some extent 
unstable. Throughout the whole range of the species, 
and even in the progeny of individuals, there occur 
continual and uncertain differences of form, analogous 
to that variability which is so characteristic of domestic 
breeds. It is impossible usefully to define any of these 
forms, because there are indefinite gradations to each 
other form. Species which possess these characteristics 
have always a wide range, and are more frequently the 
inhabitants of continents than of islands, though such 
cases are always exceptional, it being far more common 
for specific forms to be fixed within very narrow limits 
of variation. The only good example of this kind of 
variability which occurs among the Malayan Papilio- 
nida3 is in Papilio Severus, a species inhabiting all the 
islands of the Moluccas and New Guinea, and exhibit- 
ing in each of them a greater amount of individual 
difference than often serves to distinguish well - 
marked species. Almost equally remarkable are the 
variations exhibited in most of the species of Ornithop- 
tera, which I have found in some cases to extend even 
to the form of the wing and the arrangement of the 
nervures. Closely allied, however, to these variable 
species are others which, though differing slightly from 
them, are constant and confined to limited areas. After 
satisfying oneself, by the examination of numerous 
specimens captured in their native countries, that the 


one set of individuals are variable and the others are 
not, it becomes evident that by classing all alike as 
varieties of one species we shall be obscuring an impor- 
tant fact in nature ; and that the only \> ay to exhibit 
that fact in its true light is to treat the invariable local 
form as a distinct species, even though it does not offer 
better distinguishing characters than do the extreme 
forms of the variable species. Cases of this kind are 
the Ornithoptera Priamus, which is confined to the 
islands of Ceram and Amboyna, and is very constant 
in both sexes, while the allied species inhabiting New 
Guinea and the Papuan Islands is exceedingly variable ; 
and in the island of Celebes is a species closely allied to 
the variable P. Severus, but which, being exceedingly 
constant, I have described as a distinct species under 
the name of Papilio Pertinax. 

2. Polymorphism or dimorphism. By this term I 
understand the co-existence in the same locality of two 
or more distinct forms, not connected by intermediate 
gradations, and all of which are occasionally produced 
from common parents. These distinct forms generally 
occur in the female sex only, and their offspring, in- 
stead of being hybrids, or like the two parents, appear 
to reproduce all the distinct forms in varying propor- 
tions. I believe it will be found that a considerable 
number of what have been classed as varieties are really 
cases of polymorphism. Albinoism and melanism are 
of this character, as well as most of those cases in 
which well-marked varieties occur in company with the 
parent species, but without any intermediate forms. If 



these distinct forms breed independently, and are never 
reproduced from a common parent, they must be con- 
sidered as separate species, contact without intermix- 
ture being a good test of specific difference. On the 
other hand, intercrossing without producing an inter- 
mediate race is a test of dimorphism. I consider, 
therefore, that under any circumstances the term 
" variety " is wrongly applied to such cases. 

The Malayan Papilionidas exhibit some very curious 
instances of polymorphism, some of which have been 
recorded as varieties, others as distinct species; and 
they all occur in the female sex. Papilio Memnon 
is one of the most striking, as it exhibits the mixture 
of simple variability, local and polymorphic forms, all 
hitherto classed under the common title of varieties. 
The polymorphism is strikingly exhibited by the fe- 
males, one set of which resemble the males in form, 
with a variable paler colouring ; the others have a 
large spatulate tail to the hinder wings and a distinct 
style of colouring, which causes them closely to resem- 
ble P. Coon, a species having the two sexes alike and 
inhabiting the same countries, but with which they have 
no direct affinity. The tailless females exhibit simple 
variability, scarcely two being found exactly alike even 
in the same locality. The males of the island of Borneo 
exhibit constant differences of the under surface, and 
may therefore be distinguished as a local form, while 
the continental specimens, as a whole, offer such large 
and constant differences from those of the islands, that 
I am inclined to separate them as a distinct species, to* 


which the name P. Androgeus (Cramer) may be ap- 
plied. We have here, therefore, distinct species, local 
forms, polymorphism, and simple variability, which 
seem to me to be distinct phenomena, but which have 
been hitherto all classed together as varieties. I may 
mention that the fact of these distinct forms being one 
species is doubly proved. The males, the tailed and 
tailless females, have all been bred from a single group 
of the larvae, by Messrs. Payen and Bocarme, in Java, 
and I myself captured, in Sumatra, a male P. Memnon, 
and a tailed female P. Achates, under circumstances 
which led me to class them as the same species. 

Papilio Pammon offers a somewhat similar case. 
The female was described by Linnaeus as P. Polytes, 
and was considered to be a distinct species till Wes- 
termann bred the two from the same larvae (see 
Boisduval, " Species General des Lepidopteres," p. 272). 
They were therefore classed as sexes of one species by 
Mr. Edward Doubleday, in his " Genera of Diurnal 
Lepidoptera," in 1846. Later, female specimens were 
received from India closely resembling the male in- 
sect, and this was held to overthrow the authority of 
M. Westermann's observation, and to re-establish P. 
Polytes as a distinct species ; and as such it accord- 
ingly appears in the British Museum List of Papilio- 
nidae in 1856, and in the Catalogue of the East India 
Museum in 1857. This discrepancy is explained by the 
fact of P. Pammon having two females, one closely re- 
sembling the male, while the other is totally different 
from it. A long familiarity with this insect (which 

L 2 


replaced by local forms or by closely allied species, occurs 
in every island of the Archipelago) has convinced me 
of the correctness of this statement ; for in every place 
where a male allied to P. Pammon is found, a female 
resembling P. Polytes also occurs, and sometimes, 
though less frequently than on the continent, another 
female closely resembling the male : while not only has 
no male specimen of P. Polytes yet been discovered, 
but the female (Polytes) has never yet been found in 
localities to which the male (Pammon) does not extend. 
In this case, as in the last, distinct species, local forms, 
and dimorphic specimens, have been .confounded under 
the common appellation of varieties. 

But, besides the true P. Polytes, there are several 
allied forms of females to be considered, namely, P. 
Theseus (Cramer), P. Melanides (De Haan), P. Elyros 
(G. R. Gray), and P. Romulus (Linnaeus). The dark 
female figured by Cramer as P. Theseus seems to be 
the common and perhaps the only form in Sumatra, 
whereas in Java, Borneo, and Timor, along with males 
quite identical with those of Sumatra, occur females 
of the Polytes form, although a single specimen of 
the true P. Theseus taken at Lombock would seem to 
show that the two forms do occur together. In the 
allied species found in the Philippine Islands (P. Al- 
phenor, Cramer = P. Ledebouria, Eschscholtz, the 
female of which is P. Elyros, G. R. Gray,) forms 
corresponding to these extremes occur, along with a 
number of intermediate varieties, as shown by a fine 
series in the British Museum. We have here an 


indication of how dimorphism may be produced ; for 
let the extreme Philippine forms be better suited to 
their conditions of existence than the intermediate 
connecting links, and the latter will gradually die 
out, leaving two distinct forms of the same insect, 
each adapted to some special conditions. As these 
conditions are sure to vary in different districts, it 
will often happen, as in Sumatra and Java, that the 
one form will predominate in the one island, the 
other in the adjacent one. In the island of Borneo 
there seems to be a third form; for P. Melanides 
(De Haan) evidently belongs to this group, and has 
all the chief characteristics of P. Theseus, with a 
modified colouration of the hind wings. I now come 
to an insect which, if I am correct, offers one of the 
most interesting cases of variation yet adduced. Pa- 
pilio Romulus, a butterfly found over a large part of 
India and Ceylon, and not uncommon in collections, 
has always been considered a true and independent 
species, and no suspicions have been expressed regard- 
ing it. But a male of this form does not, I believe, 
exist. I have examined the fine series in the British 
Museum, in the East India Company's Museum, in 
the Hope Museum at Oxford, in Mr. Hewitson's and 
several other private collections, and can find nothing 
but females ; and for this common butterfly no male 
partner can be found except the equally common P. 
Pammon, a species already provided with two wives, 
and yet to whom we shall be forced, I believe, to 
assign a third. On carefully examining P. Romulus, 


I find that in all essential characters the form and 
texture of the wings, the length of the antennas, the 
spotting of the head and thorax, and even the peculiar 
tints and shades with which it is ornamented it 
corresponds exactly with the other females of the 
Fammon group ; and though, from the peculiar mark- 
ing of the fore wings, it has at first sight a very dif- 
ferent aspect, yet a closer examination shows that 
every one of its markings could be produced by slight 
and almost imperceptible modifications of the various 
allied forms. I fully believe, therefore, that I shall 
be correct in placing P. Romulus as a third Indian 
form of the female P. Pammon, corresponding to P. 
Melanides, the third form of the Malayan P. Theseus. 
I may mention here that the females of this group 
have a superficial resemblance to the Polydorus group 
of Papilios, as shown by P. Theseus having been con- 
sidered to be the female of P. Antiphus, and by P. 
Romulus being arranged next to P. Hector. There is 
no close affinity between these two groups of Papilio, 
and I am disposed to believe that we have here a 
case of mimicry, brought about by the same causes 
which Mr. Bates has so well explained in his account 
of the Heliconidaa, and which has led to the singular 
exuberance of polymorphic forms in this and allied 
groups of the genus Papilio. I shall have to devote 
a section of my essay to the consideration of this 

The third example of polymorphism I have to bring 
forward is Papilio Ormenus, which is closely allied 


to the well-known P. Erechtheus, of Australia. The 
most common form of the female also resembles that 
of P. Erechtheus ; but a totally different-looking in- 
sect was found by myself in the Aru Islands, and 
figured by Mr. Hewitson under the name of P. Ones- 
imus, which subsequent observation has convinced me 
is a second form of the female of P. Ormenus. Com- 
parison of this with BoisduvaPs description of P. 
Amanga, a specimen of which from New Guinea is 
in the Paris Museum, shows the latter to be a closely 
similar form ; and two other specimens were obtained 
by myself, one in the island of Goram and the other in 
Waigiou, all evidently local modifications of the same 
form. In each of these localities males and ordinary 
females of P. Ormenus were also found. So far there 
is no evidence that these light- coloured insects are 
not females of a distinct species, the males of which 
have not been discovered. But two facts have con- 
vinced me this is not the case. At Dorey, in New 
Guinea, where males and ordinary females closely 
allied to P. Ormenus occur (but which seem to me 
worthy of being separated as a distinct species), I 
found one of these light-coloured females closely fol- 
lowed in her flight by three males, exactly in the same 
manner as occurs (and, I believe, occurs only) with 
the sexes of the same species. After watching them 
a considerable time, I captured the whole of them, and 
became satisfied that I had discovered the true rela- 
tions of this anomalous form. The next year I had 
corroborative proof of the correctness of this opinion 


by the discovery in the island of Batchian of a new 
species allied to P. Ormenus, all the females of which, 
either seen or captured by me, were of one form, and 
much more closely resembling the abnormal light- 
coloured females of P. Ormenus and P. Pandion than 
the ordinary specimens of that sex. Every naturalist 
will, I think, agree that this is strongly confirmative 
of the supposition that both forms of female are of 
one species ; and when we consider, further, that in 
four separate islands, in each of which I resided for 
several months, the two forms of female were obtained 
and only one form of male ever seen, and that about 
the same time, M. Montrouzier in Woodlark Island, 
at the other extremity of New Guinea (where he 
resided several years, and must have obtained all the 
large Lepidoptera of the island), obtained females 
closely resembling mine, which, in despair at finding 
no appropriate partners for them, he mates with a 
widely different species it becomes, I think, suffi- 
ciently evident this is another case of polymorphism 
of the same nature as those already pointed out in 
P. Pammon and P. Memnon. This species, however, 
is not only dimorphic, but trimorphic ; for, in the 
island of Waigiou, I obtained a third female quite 
distinct from either of the others, and in some degree 
intermediate between the ordinary female and the 
male. The specimen is particularly interesting to 
those who believe, with Mr. Darwin, that extreme 
difference of the sexes has been gradually produced 
by what he terms sexual selection, since it may be 


supposed to exhibit one of the intermediate steps in 
that process, which has been accidentally preserved in 
company with its more favoured rivals, though its 
extreme rarity (only one specimen having been seen 
to many hundreds of the other form) would indicate 
that it may soon become extinct. 

The only other case of polymorphism in the genus 
Papilio, at all equal in interest to those I have now 
brought forward, occurs in America; and we have, 
fortunately, accurate information about it. Papilio 
Turnus is common over almost the whole of tem- 
perate North America ; and the female resembles the 
male very closely. A totally different-looking insect 
both in form and colour, Papilio Glaueus, inhabits the 
same region ; and though, down to the time when 
Boisduval published his " Species General," no con- 
nexion was supposed to exist between the two species, 
it is now well ascertained that P. Glaucus is a second 
female form of P. Turnus. In the " Proceedings 
of the Entomological Society of Philadelphia," Jan., 
1863, Mr. Walsh gives a very interesting account of 
the distribution of this species. He tells us that in 
the New England States and in New York all the 
females are yellow, while in Illinois and further south 
all are black; in the intermediate region both black 
and yellow females occur in varying proportions. 
Lat. 37 is approximately the southern limit of the 
yellow form, and 42 the northern limit of the black 
form ; and, to render the proof complete, both black 
and yellow insects have been bred from a single batch 


of eggs. He further states that, out of thousands 
of specimens, he has never seen or heard of inter- 
mediate varieties between these forms. In this in- 
teresting example we see the effects of latitude in 
determining the proportions in which the individuals 
of each form should exist. The conditions are here 
favourable to the one form, tJiere to the other ; but 
we are by no means to suppose that these conditions 
consist in climate alone. It is highly probable that 
the existence of enemies, and of competing forms of 
life, may be the main determining influences; and 
it is much to be wished that such a competent ob- 
server as Mr. Walsh would endeavour to ascertain 
what are the adverse causes which are most efficient 
in keeping down the numbers of each of these con- 
trasted forms. 

Dimorphism of this kind in the animal kingdom 
does not seem to have any direct relations to the 
reproductive powers, as Mr. Darwin has shown to 
be the case in plants, nor does it appear to be very 
general. One other case only is known to me in 
another family of my eastern Lepidoptera, the Pier- 
idas ; and but few occur in the Lepidoptera of other 
countries. The spring and autumn broods of some 
European species differ very remarkably; and this 
must be considered as a phenomenon of an analo- 
gous though not of an identical nature, while the 
Araschnia prorsa, of Central Europe, is a striking 
example of this alternate or seasonal dimorphism. 
Among our nocturnal Lepidoptera, I am informed, 


many analogous cases occur ; and as the whole 
history of many of these has been investigated by 
breeding successive generations from the egg, it is 
to be hoped that some of our British Lepidopterists 
will give us a connected account of all the abnormal 
phenomena which they present. Among the Coleop- 
tera Mr. Pascoe has pointed out the existence of two 
forms of the male sex in seven species of the two 
genera Xenocerus and Mecocerus belonging to the 
family Anthribidae, (Proc. Ent. Soc. Lond., 1862); 
and no less than six European Water-beetles, of the 
genus Dytiscus, have females of two forms, the most 
common having the elytra deeply sulcate, the rarer 
smooth as in the males. The three, and sometimes 
four or more, forms under which many Hymenop- 
cerous insects (especially Ants) occur, must be con- 
sidered as a related phenomenon, though here each 
form is specialized to a distinct function in the 
economy of the species. Among the higher animals, 
albinoism and melanism may, as I have already stated, 
be considered as analogous facts ; and I met with 
one case of a bird, a species of Lory (Eos fuscata), 
clearly existing under two differently coloured forms, 
since I obtained both sexes of each from a single 
flock, while no intermediate specimens have yet been 

The fact of the two sexes of one species differing 
very considerably is so common, that it attracted but 
little attention till Mr. Darwin showed how it could 
in many cases be explained by the principle of 


sexual selection. For instance, in most polygamous 
animals the males fight for the possession of the 
females, and the victors, always becoming the pro- 
genitors of the succeeding generation, impress upon 
their male offspring their own superior size, strength, 
or unusually developed offensive weapons. It is thus 
that we can account for the spurs and the superior 
strength and size of the males in Gallinaceous birds, 
and also for the large canine tusks in the males of 
fruit-eating Apes. So the superior beauty of plumage 
and special adornments of the males of so many birds 
can be explained by supposing (what there are many 
facts to prove) that the females prefer the most beau- 
tiful and perfect-plumaged males, and that thus, slight 
accidental variations of form and colour have been 
accumulated, till they have produced the wonderful 
train of the Peacock and the gorgeous plumage of 
the Bird of Paradise. Both these causes have no 
doubt acted partially in insects, so many species 
possessing horns and powerful jaws in the male sex 
only, and still more frequently the males alone re- 
joicing in rich colours or sparkling lustre. But there 
is here another cause which has led to sexual differ- 
ences, viz., a special adaptation of the sexes to diverse 
habits or modes of life. This is well seen in female 
Butterflies (which are generally weaker and of slower 
flight), often having colours better adapted to con- 
cealment; and in certain South American species (Pa- 
pilio torquatus) the females, which inhabit the forests, 
resemble the JEneas group of Papilios which abound 


in similar localities, while the males, which frequent 
the sunny open river-banks, have a totally different 
colouration. In these cases, therefore, natural selec- 
tion seems to have acted independently of sexual 
selection ; and all such cases may be considered as 
examples of the simplest dimorphism, since the off- 
spring never offer intermediate varieties between the 
parent forms. 

The phenomena of dimorphism and polymorphism 
may be well illustrated by supposing that a blue-eyed, 
flaxen-haired Saxon man had two wives, one a black- 
haired, red-skinned Indian squaw, the other a woolly- 
headed, sooty-skinned negress and that instead of the 
children being mulattoes of brown or dusky tints, 
mingling the separate characteristics of their parents 
in varying degrees, all the boys should be pure Saxon 
boys like their father, while the girls should altogether 
resemble their mothers. This would be thought a 
sufficiently wonderful fact ; yet the phenomena here 
brought forward as existing in the insect-world are 
still more extraordinary ; for each mother is capable 
not only of producing male offspring like the father, 
and female like herself, but also of producing other 
females exactly like her fellow-wife, and altogether 
differing from herself. If an island could be stocked 
with a colony of human beings having similar phy- 
siological idiosyncrasies with Papilio Pammon or 
Papilio Ormenus, we should see white men living 
with yellow, red, and black women, and their off- 
spring always reproducing the same types ; so that 


at the end of many generations the men would remain 
pure white, and the women of the same well-marked 
races as at the commencement. 

The distinctive character therefore of dimorphism 
is this, that the union of these distinct forms does 
not produce intermediate varieties, but reproduces the 
distinct forms unchanged. In simple varieties, on the 
other hand, as well as when distinct local forms or 
distinct species are crossed, the offspring never re- 
sembles either parent exactly, but is more or less in- 
termediate between them. Dimorphism is thus seen to 
be a specialized result of variation, by which new phy- 
siological phenomena have been developed ; the two 
should therefore, whenever possible, be kept separate. 

3. Local form, or variety. This is the first step in 
the transition from variety to species. It occurs in 
species of wide range, when groups of individuals have 
become partially isolated in several points of its area 
of distribution, in each of which a characteristic form 
has become more or less completely segregated. Such 
forms are very common in all parts of the world, and 
have often been classed by one author as varieties, by 
another as species. I restrict the term to those cases 
where the difference of the forms is very slight, or 
where the segregation is more or less imperfect. The 
best example in the present group is Papilio Agamem- 
non, a species which ranges over the greater part of 
tropical Asia, the whole of the Malay archipelago, 
and a portion of the Australian and Pacific regions. 
The modifications are principally of size and form, 


and, though slight, are tolerably constant in each local- 
ity. The steps, however, are so numerous and gradual 
that it would be impossible to define many of them, 
though the extreme forms are sufficiently distinct. Pa- 
pilio Sarpedon presents somewhat similar but less nu- 
merous variations. 

4. Co-existing Variety. This is a somewhat doubtful 
case. It is when a slight but permanent and heredi- 
tary modification of form exists in company with the 
parent or typical form, without presenting those inter- 
mediate gradations which would constitute it a case 
of simple variability. It is evidently only by direct 
evidence of the two forms breeding separately that this 
can be distinguished from dimorphism. The difficulty 
occurs in Papilio Jason, and P. Evemon, whioh in- 
habit the same localities, and are almost exactly alike 
in form, size, and colouration, except that the latter 
always wants a very conspicuous red spot on the under 
surface, which is found not only in P. Jason, but in all 
the allied species. It is only by breeding the two in- 
sects that it can be determined whether this is a case of 
a co-existing variety or of dimorphism. In the former 
case, however, the difference being constant and so very 
conspicuous and easily defined, I see not how we could 
escape considering it as a distinct species. A true case 
of co-existing forms would, I consider, be produced, if 
a slight variety had become fixed as a local form, and 
afterwards been brought into contact with the parent 
species, with little or no intermixture of the two ; and 
such instances do very probably occur. 


5. Race or subspecies. These are local forms com- 
pletely fixed and isolated ; and there is no possible test 
but individual opinion to determine which of them shall 
be considered as species and which varieties. If sta- 
bility of form and " the constant transmission of some 
characteristic peculiarity of organization " is the test of 
a species (and I can find no other test that is more 
certain than individual opinion) then every one of 
these fixed races, confined as they almost always are 
to distinct and limited areas, must be regarded as a 
species ; and as such I have in most cases treated them. 
The various modifications of Papilio Ulysses, P. Peran- 
thus, P. Codrus, P. Eurypilus, P. Helenus, &c., are 
excellent examples; for while some present great and 
well-marked, others offer slight and inconspicuous dif- 
ferences, yet in all cases these differences seem equally 
fixed and permanent. If, therefore, we call some of 
these forms species, and others varieties, we introduce a 
purely arbitrary distinction, and shall never be able to 
decide where to draw the line. The races of Papilio 
Ulysses, for example, vary in amount of modification 
from the scarcely differing New Guinea form to those 
of Woodlark Island and New Caledonia, but all seem 
equally constant ; and as most of these had already 
been named and described as species, I have added the 
New Guinea form under the name of P. Autolycus. 
We thus get a little group of Ulyssine Papilios, the 
whole comprised within a very limited area, each one 
confined to a separate portion of that area, and, though 
differing in various amounts, each apparently constant. 


Few naturalists will doubt that all these may and pro- 
bably have been derived from a common stock, and 
therefore it seems desirable that there should be a unity 
in our method of treating them ; either call them all 
varieties or all species. Varieties, however, continually 
get overlooked ; in lists of species they are often alto- 
gether unrecorded ; and thus we are in danger of 
neglecting the interesting phenomena of variation and 
distribution which they present. I think it advisable, 
therefore, to name all such forms ; and those who will 
not accept them as species may consider them as sub- 
species or races. 

6. Species. Species are merely those strongly 
marked races or local forms which when in contact 
do not intermix, and when inhabiting distinct areas 
are generally believed to have had a separate origin, 
and to be incapable of producing a fertile hybrid 
offspring. But as the test of hybridity cannot be 
applied in one case in ten thousand, and even if it 
could be applied would prove nothing, since it is 
founded on an assumption of the very question to 'be 
decided and as the test of separate origin is in every 
case inapplicable and as, further, the test of non- 
intermixture is useless, except in those rare cases 
where the most closely allied species are found in- 
habiting the same area, it will be evident that we 
have no means whatever of distinguishing so-called 
"true species" from the several modes of variation 
here pointed out, and into which they so often pass 
by an insensible gradation. It is ouite true that, in 



the great majority of cases, what we term " species " 
are so well marked and definite that there is no dif- 
ference of opinion about them ; but as the test of a 
true theory is, that it accounts for, or at the very 
least is not inconsistent with, the whole of the phe- 
nomena and apparent anomalies of the problem to be 
solved, it is reasonable to ask that those who deny 
the origin of species by variation and selection should 
grapple with the facts in detail, and show how the 
doctrine of the distinct origin and permanence of 
species will explain and harmonize them. It has been 
recently asserted by Dr. J. E. Gray (in the Proceed- 
ings of the Zoological Society for 1863, page 134), 
that the difficulty of limiting species is in proportion 
to our ignorance, and that just as groups or countries 
are more accurately known and studied in greater 
letail the limits of species become settled. This state- 
ment has, like many other general assertions, its por- 
tion of both truth and error. There is no doubt that 
many uncertain species, founded on few or isolated 
specimens, have had their true nature determined by 
the study of a good series of examples : they have 
been thereby established as species or as varieties ; 
and the number of times this has occurred is doubtless 
very great. But there are other, and equally trust- 
worthy cases, in which, not single species, but whole 
groups have, by the study of a vast accumulation of 
materials, been proved to have no definite specific 
limits. A few of these must be adduced. In Dr. 
Carpenter's " Introduction to the Study of the Fora- 


minifera," he states that "there is not a single specimen 
of plant or animal of which the range of variation has 
been studied by the collocation and comparison of so 
large a number of specimens as have passed under the 
review of Messrs. Williamson) Parker, Rupert Jones, and 
myself, in our studies of the types of this group ; " and 
the result of this extended comparison of specimens 
is stated to be, " The range of variation is so great 
among the Foraminifera as to include not merely those 
differential characters ivhicli have been usually accounted 
SPECIFIC, but also those upon which the greater part 
of the GENERA of this group have been founded, and even 
in some instances those of its ORDERS " (Foraminifera, 
Preface, x). Yet this same group had been divided 
by D'Orbigny and other authors into a number of 
clearly defined families, genera, and species, which these 
careful and conscientious researches have shown to 
have been almost all founded on incomplete knowledge. 
Professor DeCandolle has recently given the results 
of an extensive review of the species of Cupuliferas. 
He finds that the best-known species of oaks are those 
which produce most varieties and subvarieties ; that 
they are often surrounded by provisional species ; 
and, with the fullest materials at his command, two- 
thirds of the species he considers more or less doubt- 
ful. His general conclusion is, that (i in botany the 
lowest series of groups, SUBVARIETIES, VARIETIES, and 
RACES are very badly limited; these can be grouped into 
SPECIES a little less vaguely limited, which again can 
be formed into sufficiently precise GENERA.." This 

M 2 


general conclusion is entirely objected to by the writer 
of the article in the " Natural History Review," who, 
however, does not deny its applicability to the par- 
ticular order under discussion, while this very differ- 
ence of opinion is another proof that difficulties in 
the determination of species do not, any more than 
in the higher groups, vanish with increasing mate- 
rials and more accurate research. 

Another striking example of the same kind is seen 
in the genera Rubus and Rosa, adduced by Mr. 
Darwin himself; for though the amplest materials 
exist for a knowledge of these groups, and the most 
careful research has been bestowed upon them, yet 
the various species have not thereby been accurately 
limited and defined so as to satisfy the majority of 
botanists. In Mr. Baker's revision of the British 
Roses, just published by the Linnsean Society, the 
author includes under the single species Rosa canina, 
no less than twenty-eight named varieties, distin- 
guished by more or less constant characters and often 
confined to special localities ; and to these are referred 
about seventy of the species of Continental and British 

Dr. Hooker seems to have found the same thing 
in his study of the Arctic flora. For though he has 
had much of the accumulated materials of his pre- 
decessors to work upon, he continually expresses him- 
self as unable to do more than group the numerous 
and apparently fluctuating forms into more or less im- 
perfectly defined species. In his paper on the "Dis- 


tribution of Arctic Plants," (Trans. Linn. Soc. xxiii., 
p. 310) Dr. Hooker says: "The 'most able and ex- 
perienced descriptive botanists vary in their estimate 
of the value of the f specific term ' to a much greater 
extent than is generally supposed." . . "I think 
I may safely affirm that the * specific term ' has three 
different standard values, all current in descriptive 
botany, but each more or less confined to one class 
of observers." . . u This is no question of what 
is right or wrong as to the real value of the spe- 
cific term ; I believe each is right according to the 
standard he assumes as the specific." 

Lastly, I will adduce Mr. Bates's researches on the 
Amazons. During eleven years he accumulated vast 
materials, and carefully studied the variation and dis- 
tribution of insects. Yet he has shown that many 
species of Lepidoptera, which before offered no special 
difficulties, are in reality most intricately combined 
in a tangled web of affinities, leading by such gradual 
steps from the slightest and least stable variations to 
fixed races and well-marked species, that it is very 
often impossible to draw those sharp dividing-lines 
which it is supposed that a careful study and full 
materials will always enable us to do. 

These few examples show, I think, that in every 
department of nature there occur instances of the in- 
stability of specific form, which the increase of mate 
rials aggravates rather than diminishes. And it must 
be remembered that the naturalist is rarely likely to 
err on the side of imputing greater indefiniteness to 


species than really exists. There is a completeness 
and satisfaction to the mind in denning and limiting 
and naming a species, which leads us all to do so 
whenever we conscientiously -can, and which we know 
has led many collectors to reject vague intermediate 
forms as destroying the symmetry of their cabi- 
nets. We must therefore consider these cases of ex- 
cessive variation and instability as being thoroughly 
well established ; and to the objection that, after all, 
these cases are but few compared with those in which 
species can be limited and defined, and are therefore 
merely exceptions to a general rule, I reply that a 
true law embraces all apparent exceptions, and that 
to the great laws of nature there are no real excep- 
tions that what appear to be such are equally results 
of law, and are often (perhaps indeed always) those 
very results which are most important as revealing 
the true nature and action of the law. It is for such 
reasons that naturalists now look upon the study of 
varieties as more important than that of well-fixed 
species. It is in the former that we see nature still 
at work, in the very act of producing those wonderful 
modifications of form, that endless variety of colour, 
and that complicated harmony of relations, which 
gratify every sense and give occupation to every 
faculty of the true lover of nature. 

Variation as specially influenced by Locality. 

The phenomena of variation as influenced by locality 
have not hitherto received much attention. Botanists, 


ifc is true, are acquainted with the influences of climate, 
altitude, and other physical conditions, in modifying 
the forms and external characteristics of plants ; but 
I am not aware that any peculiar influence has been 
traced to locality, independent of climate. Almost 
the only case I can find recorded is mentioned in 
that repertory of natural-history facts, " The Origin 
of Species," viz. that herbaceous groups have a ten- 
dency to become arboreal in islands. In the animal 
world, I cannot find that any facts have been pointed 
out as showing the special influence of locality in 
giving a peculiar fades to the several disconnected 
species that inhabit it. What I have to adduce on 
this matter will therefore, I hope, possess some in- 
terest and novelty. 

On examining the closely allied species, local forms, 
and varieties distributed over the Indian and Malayan 
regions, I find that larger or smaller districts, or even 
single islands, give a special character to the majority 
of their Papilionidse. For instance : 1. The species 
of the Indian region (Sumatra, Java, and Borneo) 
are almost invariably smaller than the allied species 
inhabiting Celebes and the Moluccas ; 2. The species 
of New Guinea and Australia are also, though in a 
less degree, smaller than the nearest species or va- 
rieties of the Moluccas ; 3. In the Moluccas them- 
selves the species of Amboyna are the largest; 4. 
The species of Celebes equal or even surpass in size 
those of Amboyna; 5. The species and varieties of 
Celebes possess a striking character in the form of 


the anterior wings, different from that of the allied 
species and varieties of all the surrounding islands ; 
6. Tailed species in India or the Indian region become 
tailless as they spread eastward through the archi- 
pelago ; 7. In Amboyna and Ceram the females of 
several species are dull -coloured, while in the adjacent 
islands they are more brilliant. 

Local variation of Size. Having preserved the finest 
and largest specimens of Butterflies in my own col- 
lection, and having always taken for comparison the 
largest specimens of the same sex, I believe that the 
tables I now give are sufficiently exact. The differences 
of expanse of wings are in most cases very great, and 
are much more conspicuous in the specimens themselves 
than on paper. It will be seen that no less than four- 
teen Papilionida3 inhabiting Celebes and the Moluccas 
are from one- third to one-half greater in extent of wing 
than the allied species representing them in Java, Su- 
matra, and Borneo. Six species inhabiting Amboyna 
are larger than the closely allied forms of the northern 
Moluccas and New Guinea by about one-sixth. These 
include almost every case in which closely allied 
species can be compared. 

Species of Papilionidae of the Closely allied species of Java and 

Moluccas and Celebes (large). the Indian region (small). 

Expanse. Expanse. 

Inches. Inches. 

Ornithoptera Helena f O. Pompeus 5'8 

Amboyna) 7 '6 { O. Amphrisius 6'0 

Papilio Adamantius 

(Celebes) 5'8 

P. Lorquinianus (Mo- 
luccas) 4'8 

P. Peranthus 3'8 



Species of Papilionidce of the 
Moluccas and Celebes (large). 


P. Blumei (Celebes) ... 5-4 
P. Alphenor( Celebes)... 4'8 
P. Gigon (Celebes) ... 5'4 
P. Deucalion ( Celebes)... 4-6 
P. Agamemnon, var. 

(Celebes) 4'4 

P. Eurypilus (Moluccas) 4'0 
P. Telephus (Celebes)... 4-3 
P. JEgisthus (Moluccas) 4'4 
P. Milon (Celebes) ... 4'4 
P. Androcles (Celebes)... 4'8 
P. Polyphontes (Celebes) 4'6 
Leptocircus Ennius 

(Celebes) 2'0 

Species inhabiting Ainboyna 

Papilio Ulysses 

P. Polydorus 

P. Deiphobus 

P. Gambrisius 

P. Codrus 

Ornithoptera Priamus, 






Closely allied species of Java and 
the Indian region (small). 


P. Brama , ... 4'0 

P. Theseus 3-6 

P. Demolion 4-0 

P. Macareus 37 

P. Agamemnon, var. ... 38 
P. Jason... .. 3-4 

P. Rama 

P. Sarpedon .. 
P. Antiphates 
P. Diphilus .. 


L. Meges 1-8 

Allied species of New Guinea and 
the North Moluccas (smaller). 

P. Autolycus 52 

P. Telegonus 

P. Leodamas 

P. Deiphontes 

P. Ormenus 

P. Tydeus 

P. Codrus, var. papu- 


Ornitnoptera Poseidon, 




Local variation of Form. The differences of form are 
equally clear. Papilio Pammon everywhere on the con- 
tinent is tailed in both sexes. In Java, Sumatra, and 
Borneo, the closely allied P. Theseus has a very short 
tail, or tooth only, in the male, while in the females the 
tail is retained. Further east, in Celebes and the South 
Moluccas, the hardly separable P. Alphenor has quite 


lost the tail in the male, while the female retains it, but 
in a narrower and less spatulate form. A little further, 
in Gilolo, P. Nicanor has completely lost the tail in 
both sexes. 

Papilio Agamemnon exhibits a somewhat similar 
series of changes. In India it is always tailed; in 
the greater part of the archipelago it has a very short 
tail ; while far east, in New Guinea and the adjacent 
islands, the tail has almost entirely disappeared. 

In the Polydorus-group two species, P. Antiphus 
^and P. Diphilus, inhabiting India and the Indian 
region, are tailed, while the two which take their 
place in the Moluccas, New Guinea, and Australia, 
P. Polydorus and P. Leodamas, are destitute of tail, 
the species furthest east having lost this ornament 
the most completely. 

Western species, Tailed. Allied Eastern species not Tailed. 

Papilio Pammon (India) ... P. Thesus (Islands) minute tail. 

P. Agamemnon, var. (India) P. Agamemnon, var. (Islands). 

P. Antiphus (India, Java) ... P. Polydorus (Moluccas). 

P. Diphilus (India, Java) ... P. Leodamas (New Guinea). 

The most conspicuous instance of local modification 
of form, however, is exhibited in the island of Celebes, 
which in this respect, as in some others, stands alone 
and isolated in the whole archipelago. Almost every 
species of Papilio inhabiting Celebes has the wings 
of a peculiar shape, which distinguishes them at a 
glance from the allied species of every other island. 
This peculiarity consists, first, in the upper wings 
being generally more elongate and falcate ; and se- 


condly, in the costa or anterior margin being much 
more curved, and in most instances exhibiting near 
the base an abrupt bend or elbow, which in some 
species is very conspicuous. This peculiarity is visible, 
not only when the Celebesian species are compared 
with their small- sized allies of Java and Borneo, but 
also, and in an almost equal degree, when the large 
forms of A.mboyna and the Moluccas are the objects 
of comparison, showing that this is quite a distinct 
phenomenon from the difference of size which has just 
been pointed out. 

In the following Table I have arranged the chief 
Papilios of Celebes in the order in which they exhibit 
this characteristic form most prominently. 

Papilios of Celebes, having the Closely allied Papilios of the sur- 
wings falcate or with abruptly rounding islands, with less falcate 

curved costa. wings and slightly curved costa. 

1. P. Gigon P. Demotion (Java). 

2. P. Pamphylus P. Jason (Sumatra). 

3. P. Milon P. Sarpedon (Moluccas, Java). 

4. P. Agamemnon, var. ... P. Agamemnon, var. (Borneo). 

5. P. Adamantius P. Peranthus (Java). 

6. P. Ascalaphus P. Deiphontes (Gilolo). 

7. P. Sataspes P. Helenus (Java). 

8. P. Blumei P. Brama (Sumatra). 

9. P. Androcles P. Anfciphates (Borneo). 

10. P. Rhesus P. Aristseus (Moluccas). 

11. P. Theseus, var. (male) ... P. Thesus (male) (Java). 

12. P. Codrus, var P. Codrus (Moluccas). 

13. P. Encelades P. Leucothoe (Malacca). 

It thus appears that every species of Papilio exhibits 
this peculiar form in a greater or less degree, except 
one, P. Polyphontes, allied to P. Diphilus of India 



and P. Polydorus of the Moluccas. This fact I shall 
recur to again, as I think it helps us to understand 
something of the causes that may have brought about 
the phenomenon we are considering. Neither do the 
genera Ornithoptera and Leptocircus exhibit any traces 
of this peculiar form. In several other families of 
Butterflies this characteristic form reappears in a few 
species. In the Pieridse the following species, all 
peculiar to Celebes, exhibit it distinctly : 
1. Pieris Eperia compared with P. Coronis (Java). 

2. Thyca Zebuda 

3. T. Rosenbergii 

4. Tachyris Hombronii ... 

5. T. Lycaste 

6. T. Zarinda 

7. T. Ithome 

8. Eronia tritsea 

9 Iphias Glaucippe, var. 

Thyca Descombesi 

T. Hyparete (Java). 

T. Lyncida. 

T. Lyncida. 

T. Nero (Malacca). 

T. Nephele. 

Ercnia Valeria 

Iphias Glaucippe 

The species of Terias, one or two Pieris, and the genus 
Callidryas do not exhibit any perceptible change of 

In the other families there are but few similar 
examples. The following are all that I can find in my 
collection : 

Cethosia ^Eole ... compared with Cethosia Biblis (Java). 
Eurhinia megalonice Eurhinia Polynice 

Limenitis Limire ... Limenitis Procris 

Cynthia Arsinoe, var. Cynthia Arsinoe (Java, 

Sumatra, Borneo) 


All these belong to the family of the Nymphalidse. 
Many other genera of this family, as Diadema, Adolias, 
Charaxes, and Cyrestis, as well as the entire families 
of the Danaidse, SatyridaB, Lycsenidse, and Hesperidse, 
present no examples of this peculiar form of the upper 
wing in the Celebesian species. 

Local variations of Colour. In Amboyna and Ceram 
the female of the large and handsome Ornithoptera 
Helena has the large patch on the hind wings con- 
stantly of a pale dull ochre or buff colour, while in 
the scarcely distinguishable varieties from the adjacent 
islands of Bouru and New Guinea, it is of a golden 
yellow, hardly inferior in brilliancy to its colour in 
the male sex. The female of Ornithoptera Priamus 
(inhabiting Amboyna and Ceram exclusively) is of a 
pale dusky brown tint, while in all the allied species the 
same sex is nearly black with contrasted white mark- 
ings. As a third example, the female of Papilio Ulysses 
has the blue colour obscured by dull and dusky tints, 
while in the closely allied species from the surrounding 
islands, the females are of almost as brilliant an azure 
blue as the males. A parallel case to this is the occur- 
rence, in the small islands of Goram, Matabello, Ke, 
and Aru, of several distinct species of Euplasa and 
Diadema, having broad bands or patches of white, 
which do not exist in any of the allied species from 
the larger islands. These facts seem to indicate some 
local influence in modifying colour, as unintelligible 
and almost as remarkable as that which has resulted 
in the modifications of form previously described. 


Remarks on the facts of Local variation. 

The facts now brought forward seem to me of the 
highest interest. We see that almost all the species 
in two important families of the Lepidoptera (Papi- 
lionidse and Pieridse) acquire, in a single island, a 
characteristic modification of form distinguishing them 
from the allied species and varieties of all the sur- 
rounding islands. In other equally extensive families 
no such change occurs, except in one or two isolated 
species. However we may account for these pheno- 
mena, or whether we may be quite unable to account 
for them, they furnish, in my opinion, a strong cor- 
roborative testimony in favour of the doctrine of the 
origin of species by successive small variations ; for 
we have here slight varieties, local races, and un- 
doubted species, all modified in exactly the same 
manner, indicating plainly a common cause producing 
identical results. On the generally received theory 
of the original distinctness and permanence of species, 
we are met by this difficulty : one portion of these 
curiously modified forms are admitted to have been 
produced by variation and some natural action of local 
conditions ; whilst the other portion, differing from 
the former only in degree, and connected with them 
by insensible gradations, are said to have possessed 
this peculiarity of form at their first creation, or to 
have derived it from unknown causes of a totally dis- 
tinct nature. Is not the a priori evidence in favour 
of an identity of the causes that have produced such 


similar results ? and have we not a right to call upon 
our opponents for some proofs of their own doctrine, 
and for an explanation of its difficulties, instead of 
their assuming that they are right, and laying upon 
us the burthen of disproof? 

Let us now see if the facts in question do not them- 
selves furnish some clue to their explanation. Mr. 
Bates has shown that certain groups of butterflies have 
a defence against insectivorous animals, independent 
of swiftness of motion. These are generally very 
abundant, slow, and weak fliers, and are more or less 
the objects of mimicry by other groups, which thus 
gain an advantage in a freedom from persecution 
similar to that enjoyed by those they resemble. Now 
the only Papilios which have not in Celebes acquired 
the peculiar form of wing, belong to a group which is 
imitated both by other species of Papilio and by 
Moths of the genus Epicopeia. This group is of weak 
and slow flight; and we may therefore fairly conclude 
that it possesses some means of defence (probably in 
a peculiar odour or taste) which saves it from attack. 
Now the arched costa and falcate form of wing is gener- 
ally supposed to give increased powers of flight, or, as 
seems to me more probable, greater facility in making 
sudden turnings, and thus baffling a pursuer. But the 
members of the Polydorus-group (to which belongs 
the only unchanged Celebesian Papilio), being already 
guarded against attack, have no need of this increased 
power of wing ; and " natural selection " would there- 
fore have no tendency to produce it. The whole family 


of DanaidaB are in the same position : they are slow 
and weak fliers ; yet they abound in species and indi- 
viduals, and are the objects of mimicry. The Satyrida) 
have also probably a means of protection perhaps their 
keeping always near the ground and their generally 
obscure colours ; while the Lyca3nida3 and Hesperidse 
may find security in their small size and rapid motions. 
In the extensive family of the Nymphalida3, however, 
we find that several of the larger species, of com- 
paratively feeble structure, have their wings modified 
(Cethosia, Limenitis, Junonia, Cynthia), while the large- 
bodied powerful species, which have all an excessively 
rapid flight, have exactly the same form of wing in 
Celebes as in the other islands. On the whole, there- 
fore, we may say that all the butterflies of rather large 
size, conspicuous colours, and not very swift flight have 
been affected in the manner described, while the smaller 
sized and obscure groups, as well as those which are 
the objects of mimicry, and also those of exceedingly 
swift flight have remained unaffected. 

It would thus appear as if there must be (or once 
have been) in the island of Celebes, some peculiar 
enemy to these larger-sized butterflies which does not 
exist, or is less abundant, in the surrounding islands. 
Increased powers of flight, or rapidity of turning, was 
advantageous in baffling this enemy ; and the peculiar 
form of wing necessary to give this would be readily 
acquired by the action of " natural selection" on the 
slight variations of form that are continually occurring. 

Such an enemy one would naturally suppose to be 


an insectivorous bird ; but it is a remarkable fact that 
most of the genera of Fly-catchers of Borneo and Java 
on the one side (Muscipeta, Philentoma,) and of the 
Moluccas on the other (Monarcha, Ehipidura), are 
almost entirely absent from Celebes. Their place seems 
to be supplied by the Caterpillar-catchers (Grauca- 
lus, Campephaga, &c.), of which six or seven species 
are known from Celebes and are very numerous in 
individuals. We have no positive evidence that these 
birds pursue butterflies on the wing, but it is highly 
probable that they do so when other food is scarce. 
Mr. Bates has suggested to me that the larger Dragon- 
flies (^Eshna, &c.) prey upon butterflies ; but I did not 
notice that they were more abundant in Celabes than 
elsewhere. However this may be, the fauna of Celebes 
is undoubtedly highly peculiar in every department of 
which we have any accurate knowledge ; and though we 
may not be able satisfactorily to trace how it has been 
effected, there can, I think, be little doubt that the 
singular modification in the wings of so many of the 
butterflies of that island is an effect of that complicated 
action and reaction of all living things upon each other 
in the struggle for existence, which continually tends 
to readjust disturbed relations, and to bring every 
species into harmony with the varying conditions of 
the surrounding universe. 

But even the conjectural explanation now given fails 
us in the other cases of local modification. Why the 
species of the Western islands should be smaller than 
those further east, why those of Amboyna should 



exceed in size those of Gilolo and New Guinea why 
the tailed species of India should begin to lose that 
appendage in the islands, and retain no trace of it on 
the borders of the Pacific, and why, in three separate 
cases, the females of Amboyna species should be less 
gaily attired than the corresponding females of the 
surrounding islands, are questions which we cannot 
at present attempt to answer. That they depend, how- 
ever, on some general principle is certain, because ana- 
logous facts have been observed in other parts of the 
world. Mr. Bates informs me that, in three distinct 
groups, Papilios which on the Upper Amazon and in 
most other parts of South America have spotless upper 
wings obtain pale or white spots at Para and on the 
Lower Amazon ; and also that the ^Eneas-group of Pa- 
pilios never have tails in the equatorial regions and the 
Amazons valley, but gradually acquire tails in many 
cases as they range towards the northern or southern 
tropic. Even in Europe we have somewhat similar 
facts ; for the species and varieties of butterflies peculiar 
to the island of Sardinia are generally smaller and more 
deeply coloured than those of the mainland, and the 
same has recently been shown to be the case with the 
common tortoiseshell butterfly in the Isle of Man ; 
while Papilio Hospiton, peculiar to the former island, 
has lost the tail, which is a prominent feature of the 
closely allied P. Machaon. 

Facts of a similar nature to those now brought for- 
ward would no doubt be found to occur in other 
groups of insects, were local faunas carefully studied in 


relation to those of the surrounding countries ; and 
they seem to indicate that climate and other physical 
causes have, in some cases, a very powerful effect in 
modifying specific form and colour, and thus directly 
aid in producing the endless variety of nature. 


Having fully discussed this subject in the preceding 
essay, I have only to adduce such illustrations of it, as 
are furnished by the Eastern Papilionidae, and to show 
their bearing upon the phenomena of variation already 
mentioned. As in America, so in the Old "World, 
species of Danaidse are the objects which the other 
families most often imitate. But besides these, some 
genera of Morphida3 and one section of the genus 
Papilio are also less frequently copied. Many species 
of Papilio mimic other species of these three groups so 
closely that they are undistinguishable when on the 
wing ; and in every case the pairs which resemble 
each other inhabit the same locality. 

The following list exhibits the most important and 
best marked cases of mimicry which occur among the 
Papilionidse of the Malayan region and India : 

Mimickers. Species mimicked. Common habitat. 

1. Papilio paradoxa Euplcea Midamusl 

(male & female) (male & female) J bumatra > 0. 

2. P. Catmus ... 

3. P. Thule ... 
4. P. Macareus 

... E. Rhadamanthus . 

... Danais sobrina ... 
... D. Aglaia 

Borneo and Su- 
New Guinea. 
Malacca, Java. 

N 2 


Mimickers. Species mimicked. Common habitat. 

5. Papilio Agestor. . . 

6. P. Idseoides ... 

7. P. Delessertii ... 

Danais Tytia. . . 
Hestia Leuconoe 
Idcopsis daos 

Northern India- 

8. P. Pandion (fe- 

male) Brasilia bioculata . New Guinea. 

PAPILIO (PoLYDORUs- and Coosr-groups). 

9. P. Pammon (Ro- 

mulus, female)... Papilio Hector .., India. 

10. P. Theseus, var. 

(female) P. Antiphus Sumatra,Bornco. 

11. P. Theseus, var. 

(female) P. Diphilus Sumatra, Java. 

12. P. Memnon, var. 

(Achates, female) P. Coon Sumatra. 

13. P. Androgeus,var. 

(Achates, female) P. Doubledayi ... Northern India. 

14. P. (Enomaus (fe- 

male) P. Liris Timor. 

We have, therefore, fourteen species or marked varie- 
ties of Papilio, which so closely resemble species of 
other groups in their respective localities, that it is not 
possible to impute the resemblance to accident. The 
first two in the list (Papilio paradoxa and P. Caunus) 
are so exactly like Euploea Midamus and E. Rhadaman- 
thus on the wing, that although they fly very slowly, I 
was quite unable to distinguish them. The first is a 
very interesting case, because the male and female differ 
considerably, and each mimics the corresponding sex 
of the Euploea. A new species of Papilio which I 
discovered in New Guinea resembles Danais sobrina, 


from the same country, just as Papilio Marcareus re- 
sembles Danais Aglaia in Malacca, and (according to 
Dr. Horsfield's figure) still more closely in Java. The 
Indian Papilio Agestor closely imitates Danais Tytia, 
which has quite a different style of colouring from the 
preceding; and the extraordinary Papilio Idaeoides 
from the Philippine Islands, must, when on the wing, 
perfectly resemble the Hestia Leuconoe of the same 
region, as also does the Papilio Delessertii imitate 
the Ideopsis daos from Penang. Now in every one of 
these cases the Papilios are very scarce, while the 
DanaidaB which they resemble are exceedingly abun- 
dant most of them swarming so as to be a positive 
nuisance to the collecting entomologist by continually 
hovering before him when he is in search of newer and 
more varied captures. Every garden, every roadside, 
the suburbs of every village are full of them, indicating 
very clearly that their life is an easy one, and that 
they are free from persecution by the foes which keep 
down the population of less favoured races. This 
superabundant population has been shown by Mr. 
Bates to be a general characteristic of all American 
groups and species which are objects of mimicry ; and 
it is interesting to find his observations confirmed by 
examples on the other side of the globe. 

The remarkable genus Drusilla, a group of pale- 
coloured butterflies, more or less adorned with ocellate 
spots, is also the object of mimicry by three distinct 
genera (Melanitis, Hyantis, and Papilio). These in- 
sects, like the Danaidse, are abundant in individuals, 


have a very weak and slow flight, and do not seek 
concealment, or appear to have any means of protec- 
tion from insectivorous creatures. It is natural to 
conclude, therefore, that they have some hidden pro- 
perty which saves them from attack ; and it is easy 
to see that when any other insects, by what we call 
accidental variation, come more or less remotely to 
resemble them, the latter will share to some extent in 
their immunity. An extraordinary dimorphic form of 
the female of Papilio Ormenus has come to resemble 
the Drusillas sufficiently to be taken for one of that 
group at a little distance ; and it is curious that I cap- 
tured one of these Papilios in the Aru Islands hovering 
along the ground, and settling on it occasionally, just 
as it is the habit of the Drusillas to do. The resem- 
blance in this case is only general ; but this form of 
Papilio varies much, and there is therefore material 
for natural selection to act upon, so as ultimately to 
produce a copy as exact as in the other cases. 

The eastern Papilios allied to Polydorus, Coon, 
and Philoxenus, form a natural section of the genus 
resembling, in many respects, the ^Eneas-group of 
South America, which they may be said to represent 
in the East. Like them, they are forest insects, 
have a low and weak flight, and in their favourite 
localities are rather abundant in individuals ; and like 
them, too, they are the objects of mimicry. We may 
conclude, therefore, that they possess some hidden 
means of protection, which makes it useful to other 
insects to be mistaken for them. 


The Papilios which resemble them belong to a very 
distinct section of the genus, in which the sexes differ 
greatly ; and it is those females only which differ most 
from the males, and which have already been alluded 
to as exhibiting instances of dimorphism, which resem- 
ble species of the other group. 

The resemblance of P. Romulus to P. Hector is, 
in some specimens, very considerable, and has led to 
the two species being placed following each other in 
the British Museum Catalogues and by Mr. E. Double- 
day. I have shown, however, that P. Romulus is 
probably a dimorphic form of the female P. Pammon, 
and belongs to a distinct section of the genus. 

The next pair, Papilio Theseus, and P. Antiphus, 
have been united as one species both by De Haan 
and in the British Museum Catalogues. The ordi- 
nary variety of P. Theseus found in Java almost as 
nearly resembles P. Diphilus, inhabiting the same 
country. The most interesting case, however, is the 
extreme female form of P. Memnon (figured by Cramer 
under the name of P. Achates), which has acquired 
the general form and markings of P. Coon, an insect 
which differs from the ordinary male P. Memnon, 
as much as any two species which can be chosen 
in this extensive and highly varied genus; and, as 
if to show that this resemblance is not accidental, 
but is the result of law, when in India we find a 
species closely allied to P. Coon, but with red instead 
of yellow spots (P. Doubledayi), the corresponding 
variety of P. Androgeus (P. Achates, Cramer, 182, 


A, B,) has acquired exactly the same peculiarity of 
having red spots instead of yellow. Lastly, in the 
island of Timor, the female of P. (Enomaus (a species 
allied to P. Memnon) resembles so closely P. Liris 
(one of the Polydorus-group), that the two, which 
were often seen flying together, could only be distin- 
guished by a minute comparison after being captured. 

The last six cases of mimicry are especially instruc- 
tive, because they seem to indicate one of the pro- 
cesses by which dimorphic forms have been produced. 
When, as in these cases, one sex differs much from 
the other, and varies greatly itself, it may happen 
that occasionally individual variations will occur having 
a distant resemblance to groups which are the objects 
of mimicry, and which it is therefore advantageous to 
resemble. Such a variety will have a better chance of 
preservation ; the individuals possessing it will be mul- 
tiplied ; and their accidental likeness to the favoured 
group will be rendered permanent by hereditary trans- 
mission, and, each successive variation which increases 
the resemblance being preserved, and all variations 
departing from the favoured type having less chance 
of preservation, there will in time result those singular 
cases of two or more isolated and fixed forms, bound 
together by that intimate relationship which consti- 
tutes them the sexes of a single species. The reason 
why the females are more subject to this kind of 
modification than the males is, probably, that their 
slower flight, when laden with eggs, and their exposure 
to attack while in the act of depositing their eggs 


upon leaves, render it especially advantageous for 
them to have some additional protection. This they 
at once obtain by acquiring a resemblance to other 
species which, from whatever cause, enjoy a compara- 
tive immunity from persecution. 

Concluding remarks on Variation in Lepidoptera. 

This summary of the more interesting phenomena 
of variation presented by the eastern Papilionidse is, 
I think, sufficient to substantiate my position, that 
the Lepidoptera are a group that offer especial faci- 
lities for such inquiries ; and it will also show that 
they have undergone an amount of special adaptive 
modification rarely equalled among the more highly 
organized animals. And, among the Lepidoptera, the 
great and pre-eminently tropical families of Papilionida3 
and Danaida3 seem to be those in which complicated 
adaptations to the surrounding organic and inorganic 
universe have been most completely developed, offer- 
ing in this respect a striking analogy to the equally 
extraordinary, though totally different, adaptations 
which present themselves in the Orchidea?, the only 
family of plants in which mimicry of other organisms 
appears to play any important part, and the only one 
in which cases of conspicuous polymorphism occur ; for 
as such we must class the male, female, and hermaph- 
rodite forms of Catasetum tridentatum, which differ so 
greatly in form and structure that they were long con- 
sidered to belong to three distinct genera. 


Arrangement and Geographical Distribution of the 
Malayan Papilionidce. 

Arrangement. Although the species of Papilionidaa 
inhabiting the Malayan region are very numerous, 
they all belong to three out of the nine genera into 
which the family is divided. One of the remaining 
genera (Eurycus) is restricted to Australia, and another 
(Teinopalpus) to the Himalayan Mountains, while no 
less than four (Parnassius, Doritis, Thais, and Seri- 
cinus) are confined to Southern Europe and to the 
mountain-ranges of the Palaearctic region. 

The genera Ornithoptera and Leptocircus are highly 
characteristic of Malayan entomology, but are uniform 
in character and of small extent. The genus Papilio, 
on the other hand, presents a great variety of forms, 
and is so richly represented in the Malay Islands, that 
more than one-fourth of all the known species are 
found there. It becomes necessary, therefore, to divide 
this genus into natural groups before we can success- 
fully study its geographical distribution. 

Owing principally to Dr. Horsfield's observations 
in Java, we are acquainted with a considerable number 
of the larvae of Papilios ; and these furnish good char- 
acters for the primary division of the genus into na- 
tural groups. The manner in which the hinder wings 
are plaited or folded back at the abdominal margin, the 
size of the anal valves, the structure of the antennae, 
and the form of the wings are also of much service, 
as well as the character of the flight and the style of 


colouration. Using these characters, I divide the 
Malayan Papilios into four sections, and seventeen 
groups, as follows : 


a. Priamus-group. 1 , 

c. Brookeanus-group. j Black and ^ een ' 

b. Pompeus-group. Black and yellow. 


A. Larvae short, thick, with numerous fleshy tubercJes ; 

of a purplish colour. 

a. Nox-group. Abdominal fold in male very large ; 

anal valves small, but swollen ; antennae mode- 
rate ; wings entire, or tailed ; includes the Indian 
Philoxenus - group . 

b. Coon-group. Abdominal fold in male small ; anal 

valves small, but swollen; antennas moderate; 
wings tailed. 

c. Polydorus-group. Abdominal fold in male small, 

or none; anal valves small or obsolete, hairy; 
wings tailed or entire. 

B. Larvae with third segment swollen, transversely or 

obliquely banded ; pupa much bent. Imago with 
abdominal margin in male plaited, but not re- 
flexed ; body weak ; antennae long ; wings much 
dilated, often tailed. 

d. Ulysses-group. 

Protenor - group (Indian) is 

e. Peranthus-group. 

f. Memnon-group. 

somewhat intermediate be- 
tween these, and is nearest 

to the Nox-group. 
g. Helenus-group. 
h. Erectheus-group. 
i. Pammon-group. 
k. Demolion-group. 

C. Larvae subcylindrical, variously coloured. Imago with 
abdominal margin in male plaited, but not re- 
flexed ; body weak ; antennas short, with a thick 
curved club; wings entire. 


1. Erithonius-group. Sexes alike, larva and pupa 
something like those of P. Demotion. 

m. Paradoxa-group. Sexes different. 

n. Dissimilis - group. Sexes alike ; larva bright - 
coloured; pupa straight, cylindric. 

D. Larvae elongate, attenuate behind, and often bifid, with 
lateral and oblique pale stripes, green. Imago 
with the abdominal margin in male reflexed, 
woolly or hairy within ; anal valves small, hairy ; 
antennas short, stout ; body stout. 

o. Macareus -group. Hind wings entire. 

p. Antiphates-group. Hind wings much tailed (swal- 

q. Eurypylus-group. Hind wings elongate or tailed. 


Making, in all, twenty distinct groups of Malayan 

The first section of the genus Papilio (A) comprises 
insects which, though differing considerably in struc- 
ture, having much general resemblance. They all have 
a weak, low flight, frequent the most luxuriant forest- 
districts, seem to love the shade, and are the objects 
of mimicry by other Papilios. 

Section B consists of weak-bodied, large-winged in- 
sects, with an irregular wavering flight, and which, 
when resting on foliage, often expand the wings, which 
the species of the other sections rarely or never do. 
They are the most conspicuous and striking of eastern 

Section C consists of much weaker and slower-flying 
insects, often resembling in their flight, as well as in 
their colours, species of Danaida3. 


Section D contains the strongest-bodied and most 
swift-flying of the genus. They love sunlight, and 
frequent the borders of streams and the edges of 
puddles, where they gather together in swarms con- 
sisting of several species, greedily sucking up the 
moisture, and, when disturbed, circling round in the 
air, or flying high and with great strength and 

Geographical Distribution. One hundred and thirty 
species of Malayan PapilionidjB are now known within 
the district extending from the Malay peninsula, on 
the north-west, to Woodlark Island, near New Guinea, 
on the south-east. 

The exceeding richness of the Malayan region in 
these fine insects is seen by comparing the number 
of species found in the different tropical regions of the 
earth. From all Africa only 33 species of Papilio are 
known ; but as several are still undescribed in collec- 
tions, we may raise their number to about 40. In all 
tropical Asia there are at present described only 65 
species, and I have seen in collections but two or three 
which have not yet been named. In South America, 
south of Panama, there are 150 species, or about one- 
seventh more than are yet known from the Malayan 
region ; but the area of the two countries is very dif- 
ferent ; for while South America (even excluding Pata- 
gonia) contains 5,000,000 square miles, a line encircling 
the whole of the Malayan islands would only include an 
area of 2,700,000 square miles, of which the land-area 
would be about 1,000,000 square miles. This superior 


richness is partly real and partly apparent. The break- 
ing up of a district into small isolated portions, as 
in an archipelago, seems highly favourable to the segre- 
gation and perpetuation of local peculiarities in certain 
groups ; so that a species which on a continent might 
have a wide range, and whose local forms, if any, 
would be so connected together that it would be im- 
possible to separate them, may become by isolation 
reduced to a number of such clearly defined and con- 
stant forms that we are obliged to count them as 
species. From this point of view, therefore, the 
greater proportionate number of Malayan species may 
be considered as apparent only. Its true superiority 
is shown, on the other hand, by the possession of 
three genera and twenty groups of Papilionidas against 
a single genus and eight groups in South America, 
and also by the much greater average size of the Ma- 
layan species. In most other families, however, the 
reverse is the case, the South American Nymphalida3, 
Satyridse, and ErycinidaB far surpassing those of the 
East in number, variety, and beauty. 

The following list, exhibiting the range and distri- 
bution of each group, will enable us to study more 
easily their internal and external relations. 

Range of the Groups of Malayan Papilionidce. 

1. Prianms - group. Moluccas to Woodlark 

Island 5 species. 

2. Pompeus group. Himalayas to New 

Guinea, (Celebes, maximum) ... ... 11 ,, 

3. Brookeana- group. Sumatra and Borneo... 1 



4. Nox-group. North India, Java, and Philip- 

pines ... ... ... ... ... ... 5 species. 

5. Coon-gronp. North India to Java 2 

6. Poly dorus- group. India to New Guinea 

and Pacific 7 ,, 

7. Ulysses-group. Celebes to New Caledonia 4 

8. Peranthus - group. India to Timor and 

Moluccas (India, maximum) 9 

9. Memnon-group. India to Timor and Mo- 

luccas (Java, maximum) ... ... ... 10 ,, 

10. Helenus- group. Africa and India to New 

Guinea 11 

11. Pammon-group. India to Pacific and Aus- 

tralia 9 ., 

12. Erectheus-group. Celebes to Australia ... 8 

13. Demolion-group. India to Celebes ... 2 

14. Erithonius-group. Africa, India, Australia 1 

15. Paradoxa-group. India to Java (Borneo, 

maximum) 5 ., 

16. Dissimilis-group. India to Timor (India, 

maximum) 2 

17. Macareus-group. India to New Guinea ... 10 

18. Antiphates-group. Widely distributed ... 8 

19. Eurypylus-group. India to Australia ... 15 


20 Leptocircus -group. India to Celebes ... 4 

This Table shows the great affinity of the Malayan 
with the Indian Papilionidge, only three out of the 
nineteen groups ranging beyond, into Africa, Europe, 
or America. The limitation of groups to the Indo- 
Malayan or Austro- Malay an divisions of the archi- 
pelago, which is so well marked in the higher animals, 
is much less conspicuous in insects, but is shown in 
some degree by the Papilionidas. The following groups 


are either almost or entirely restricted to one portion 
of the archipelago : 

IndO'Malayan Region. Austro-Malayan Region. 

Nox-group. Priamus- group. 

Coon-group. Ulysses -group. 

Macareus-group (nearly). Erechtheus-group. 

Par adoxa - group . 
Dissimilis-group (nearly). 
Broo keanus - group . 

The remaining groups, which range over the whole 
archipelago, are, in many cases, insects of very power- 
ful flight, or they frequent open places and the sea- 
beach, and are thus more likely to get blown from 
island to island. The fact that three such character- 
istic groups as those of Priamus, Ulysses, and Erech- 
theus are strictly limited to the Australian region of 
the archipelago, while five other groups are with equal 
strictness confined to the Indian region, is a strong 
corroboration of that division which has been founded 
almost entirely on the distribution of Mammalia and 

If the various Malayan islands have undergone 
recent changes of level, and if any of them have been 
more closely united within the period of existing 
species than they are now, we may expect to find 
indications of such changes in community of species 
between islands now widely separated ; while those 
islands which have long remained isolated would have 
had time to acquire peculiar forms by a slow and 
natural process of modification. 


An examination of the relations of the species of 
the adjacent islands, will thus enable us to correct 
opinions formed from a mere consideration of their 
relative positions. For example, looking at a map of 
the archipelago, it is almost impossible to avoid the 
idea that Java and Sumatra have been recently united; 
their present proximity is so great, and they have 
such an obvious resemblance in their volcanic struc- 
ture. Yet there can be little doubt that this opinion 
is erroneous, and that Sumatra has had a more recent 
and more intimate connexion with Borneo than it has 
had with Java. This is strikingly shown by the mam- 
mals of these islands very few of the species of Java 
and Sumatra being identical, while a considerable 
number are common to Sumatra and Borneo. The 
birds show a somewhat similar relationship ; and we 
shall find that the distribution of the Papilionidas tells 
exactly the same tale. Thus : 

Sumatra has... 21 species"! 

-g 30 20 sp. common to both islands; 

Sumatra ... 21 } 

j oo I S P* common to both islands ; 

Borneo ., ... 30 ] 

9 o 20 sp. common to both islands ; 

showing that both Sumatra and Java have a much 
closer relationship to Borneo than they have to each 
other a most singular and interesting result, when we 
consider the wide separation of Borneo from them both, 
and its very different structure. The evidence fur- 
nished by a single group of insects would have had 



but little weight on a point of such magnitude if 
standing alone ; but coming as it does to confirm 
deductions drawn from whole classes of the higher 
animals, it must be admitted to have considerable 

We may determine in a similar manner the relations 
of the different Papuan Islands to New Guinea. Of 
thirteen species of PapilionidaB obtained in the Aru 
Islands, six were also found in New Guinea, and 
seven not. Of nine species obtained at Waigiou, six 
were New Guinea, and three not. The five species 
found at Mysol were all New Guinea species. Mysol, 
therefore, has closer relations to New Guinea than 
the other islands ; and this is corroborated by the 
distribution of the birds, of which I will only now 
give one instance. The Paradise Bird found in Mysol 
is the common New Guinea species, while the Aru 
Islands and Waigiou have each a species peculiar to 

The large island of Borneo, which contains more 
species of Papilionidas than any other in the archi- 
pelago, has nevertheless only three peculiar to itself; 
and it is quite possible, and even probable, that one 
of these may be found in Sumatra or Java. The last- 
named island has also three species peculiar to it; 
Sumatra has not one, and the peninsula of Malacca 
only two. The identity of species is even greater 
than in birds or in most other groups of insects, and 
points very strongly to a recent connexion of the 
whole with each other and the continent. 


Remarkable Peculiarities of the Island of Celebes. 

If we now pass to the next island (Celebes), sepa- 
rated from those last mentioned by a strait not wider 
than that which divides them from each other, we 
have a striking contrast; for with a total number 
of species less than either Borneo or Java, no fewer 
than eighteen are absolutely restricted to it. Further 
east, the large islands of Ceram and New Guinea have 
only three species peculiar to each, and Timor has 
five. We shall have to look, not to single islands, 
but to whole groups, in order to obtain an amount 
of individuality comparable with that of Celebes. For 
example, the extensive group comprising the large 
islands of Java, Borneo, and Sumatra, with the penin- 
sula of Malacca, possessing altogether 48 species, has 
about 24, or just half, peculiar to it; the numerous- 
group of the Philippines possess 22 species, of which 
17 are peculiar; the seven chief islands of the Moluccas 
have 27, of which 12 are peculiar ; and the whole 
of the Papuan Islands, with an equal number of species, 
have 17 peculiar. Comparable with the most isolated 
of these groups is Celebes, with its 24 species, of 
which the large proportion of 18 are peculiar. We 
see, therefore, that the opinion I have elsewhere ex- 
pressed, of the high degree of isolation and the remark- 
able distinctive features of this interesting island, is 
fully borne out by the examination of this conspi- 
cuous family of insects. A single straggling island 
with a few small satellites, it is zoologically of equal 

o 2 


importance with extensive groups of islands many 
times as large as itself ; and standing in the very centre 
of the archipelago, surrounded on every side with islets 
connecting it with the larger groups, and which seem 
to afford the greatest facilities for the migration and 
intercommunication of their respective productions, it 
yet stands out conspicuous with a character of its own 
in every department of nature, and presents peculiari- 
ties which are, I believe, without a parallel in any 
similar locality on the globe. 

Briefly to summarize these peculiarities, Celebes 
possesses three genera of mammals (out of the very 
small number which inhabit it) which are of singular 
and isolated forms, viz., Cynopithecus, a tailless Ape 
allied to the Baboons ; Anoa, a straight-horned Ante- 
lope of obscure affinities, but quite unlike anything 
else in the whole archipelago or in India : and Babi- 
rusa, an altogether abnormal wild Pig. With a rather 
limited bird population, Celebes has an immense pre- 
ponderance of species confined to it, and has also six 
remarkable genera (Meropogon, Ceycopsis, Strepto- 
citta, Enodes, Scissirostrum, and Megacephalon) en- 
tirely restricted to its narrow limits, as well as two 
others (Prioniturus and Basilornis) which only range 
to a single island beyond it. 

Mr. Smith's elaborate tables of the distribution of 
Malayan Hymenoptera (see " Proc. Linn. Soc." Zool. 
vol. vii.) show that out of the large number of 301 
species collected in Celebes, 190 (or nearly two-thirds) 
are absolutely restricted to it, although Borneo on one 


side, and the various islands of the Moluccas on the 
other, were equally well explored by me ; and no less 
than twelve of the genera are not found in any other 
island of the archipelago. I have shown in the present 
essay that, in the Papilionidre, it has far more species of 
its own than any other island, and a greater proportion 
of peculiar species than many of the large groups of 
islands in the archipelago and that it gives to a large 
number of the species and varieties which inhabit it, 
1st, an increase of size, and, 2nd, a peculiar modifica- 
tion in the form of the wings, which stamp upon the 
most dissimilar insects a mark distinctive of their 
common birth-place. 

What, I would ask, are we to do with phenomena 
such as these? Are we to rest content with that very 
simple, but at the same time very unsatisfying expla- 
nation, that all these insects and other animals were 
created exactly as they are, and originally placed ex- 
actly where they are, by the inscrutable will of their 
Creator, and that we have nothing to do but to register 
the facts and wonder ? Was this single island selected 
for a fantastic display of creative power, merely to ex- 
cite a childlike and unreasoning admiration ? Is all 
this appearance of gradual modification by the action of 
natural causes a modification the successive steps of 
which we can almost trace all delusive ? Is this har- 
mony between the most diverse groups, all presenting 
analogous phenomena, and indicating a dependence 
upon physical changes of which we have independent 
evidence, all false testimony ? If I could think so, the 


study of nature would have lost for me its greatest 
charm. I should feel as would the geologist, if you 
could convince him that his interpretation of the earth's 
past history was all a delusion that strata were never 
formed in the primeval ocean, and that the fossils he so 
carefully collects and studies are no true record of a 
former living world, but were all created just as they 
now are, and in the rocks where he now finds them. 

I must here express my own belief that none of these 
phenomena, however apparently isolated or insignificant, 
can ever stand alone that not the wing of a butterfly 
can change in form or vary in colour, except in har- 
mony with, and as a part of the grand march of nature. 
I believe, therefore, that all the curious phenomena I 
have just recapitulated, are immediately dependent on 
the last series of changes, organic and inorganic, in 
these regions ; and as the phenomena presented by the 
island of Celebes differ from those of all the surround- 
ing islands, it can, I conceive, only be because the past 
history of Celebes has been, to some extent, unique and 
different from theirs. We must have much more evi- 
dence to determine exactly in what that difference has 
consisted. At present, I only see my way clear to one 
deduction, viz., that Celebes represents one of the oldest 
parts of the archipelago ; that it has been formerly more 
completely isolated both from India and from Australia 
than it is now, and that amid all the mutations it has 
undergone, a relic or substratum of the fauna and 
flora of some more ancient land has been here pre- 
served to us. 


It is only since my return home, and since I have 
been able to compare the productions of Celebes side 
by side with those of the surrounding islands, that I 
have been fully impressed with their peculiarity, and 
the great interest that attaches to them. The plants 
and the reptiles are still almost unknown ; and it is to 
be hoped that some enterprising naturalist may soon 
devote himself to their study. The geology of the 
country would also be well worth exploring, and its 
newer fossils would be of especial interest as eluci- 
dating the changes which have led to its present ano- 
malous condition. This island stands, as it were, upon 
the boundary-line between two worlds. On one side is 
that ancient Australian fauna, which preserves to the 
present day the facies of an early geological epoch ; on 
the other is the rich and varied fauna of Asia, which 
seems to contain, in every class and order, the most 
perfect and highly organised animals. Celebes has 
relations to both, yet strictly belongs to neither : it 
possesses characteristics which are altogether its own ; 
and I am convinced that no single island upon the 
globe would so well repay a careful and detailed re- 
search into its past and present history. 

Concluding Remarks. 

In writing this essay it has been my object to show 
how much may, under favourable circumstances, be 
learnt by the study of what may be termed the external 
physiology of a small group of animals, inhabiting a 
limited district. This branch of natural history had 


received little attention till Mr. Darwin showed how 
important an adjunct it may become towards a true 
interpretation of the history of organized beings, and 
attracted towards it some small share of that research 
which had before been almost exclusively devoted to 
internal structure and physiology. The nature of spe- 
cies, the laws of variation, the mysterious influence 
of locality on both form and colour, the phenomena of 
dimorphism and of mimicry, the modifying influence 
of sex, the general laws of geographical distribution, 
and the interpretation of past changes of the earth's 
surface, have all been more or less fully illustrated 
by the very limited group of the Malayan Papilio- 
nidso ; while, at the same time, the deductions drawn 
therefrom have been shown to be supported by analo- 
gous facts, occurring in other and often widely-sepa- 
rated groups of animals. 



THE most perfect and most striking examples of what 
is termed instinct, those in which reason or observa- 
tion appear to have the least influence, and which 
seem to imply the possession of faculties farthest re- 
moved from our own, are to be found among insects. 
The marvellous constructive powers of bees and wasps, 
the social economy of ants, the careful provision for 
the safety of a progeny they are never to see mani- 
fested by many beetles and flies, and the curious pre- 
parations for the pupa state by the larvae of butterflies 
and moths, are typical examples of this faculty, and 
are supposed to be conclusive as to the existence of 
some power or intelligence, very different from that 
which we derive from our senses or from our reason. 

How Instinct may be best Studied. 

Whatever we may define instinct to be, it is evi- 
dently some form of mental manifestation, and as we 
can only judge of mind by the analogy of our own 
mental functions and by observation of the results of 
mental action in other men and in animals, it is in- 
cumbent on us, first, to study and endeavour to com- 
prehend the minds of infants, of savage men, and of 


animals not very far removed from ourselves, before 
we pronounce positively as to the nature of the mental 
operations in creatures so radically different from us 
as insects. We have not yet even been able to ascer- 
tain what are the senses they possess, or what relation 
their powers of seeing, hearing, and feeling have to 
ours. Their sight may far exceed ours both in delicacy 
and in range, and may possibly give them knowledge 
of the internal constitution of bodies analogous to that 
which we obtain by the spectroscope ; and that their 
visual organs do possess some powers which ours do 
not, is indicated by the extraordinary crystalline rods 
radiating from the optic ganglion to the facets of the 
compound eye, which rods vary in form and thickness 
in different parts of their length, and possess distinc- 
tive characters in each group of insects. This complex 
apparatus, so different from anything in the eyes of 
vertebrates, may subserve some function quite incon- 
ceivable by us, as well as that which we know as 
vision. There is reason to believe that insects appre- 
ciate sounds of extreme delicacy, and it is supposed 
that certain minute organs, plentifully supplied with 
nerves, and situated in the subcostal vein of the wing 
in most insects, are the organs of hearing. But be- 
sides these, the Orthoptera (such as grasshoppers, 
&c.) have what are supposed to be ears on their fore 
legs, and Mr. Lowne believes that the little stalked 
balls, which are the sole remnants of the hind wings 
in flies, are also organs of hearing or of some ana- 
logous sense. In flies, too, the third joint of the 


antennae contains thousands of nerve-fibres, which 
terminate in small open cells, and this Mr. Lowne 
believes to be the organ of smell, or of some other, 
perhaps new, sense. It is quite evident, therefore, 
that insects may possess senses which give them a 
knowledge of that which we can never perceive, and 
enable them to perform acts which to us are incom- 
prehensible. In the midst of this complete ignorance 
of their faculties and inner nature, is it wise for us 
to judge so boldly of their powers by a comparison 
with our own ? How can we pretend to fathom the 
profound mystery of their mental nature, and decide 
what, and how much, they can perceive or remem- 
ber, reason or reflect! To leap at one bound from 
our own consciousness to that of an insect's, is as 
unreasonable and absurd as if, with a pretty good 
knowledge of the multiplication table, we were to 
go straight to the study of the calculus of functions, 
or as if our comparative anatomists should pass from 
the study of man's bony structure to that of the fish, 
and, without any knowledge of the numerous inter- 
mediate forms, were to attempt to determine the homo- 
logies between these distant types of vertebrata. In 
such a case would not error be inevitable, and would 
not continued study in the same direction only render 
the .erroneous conclusions more ingrained and more 

Definition of Instinct. 
Before going further into this subject, we must 


determine what we mean by the term instinct. It 
has been variously defined as u disposition operating 
without the aid of instruction or experience," " a 
mental power totally independent of organization," or 
"a power enabling an animal to do that which, in those 
things man can do, results from a chain of reasoning, 
and in things which man cannot do, is not to be ex- 
plained by any efforts of the intellectual faculties." 
We find, too, that the word instinct is very frequently 
applied to acts which are evidently the result either 
of organization or of habit. The colt or calf is said 
to walk instinctively, almost as soon as it is born ; 
but this is solely due to its organization, which ren- 
ders walking both possible and pleasurable to it. So 
we are said instinctively to hold out our hands to 
save ourselves from falling, but this is an acquired 
habit, which the infant does not possess. It appears 
to me that instinct should be defined as sc the per- 
formance by an animal of complex acts, absolutely 
without instruction or previously-acquired knowledge." 
Thus, acts are said to be performed by birds in build- 
ing their nests, by bees in constructing their cells, 
and by many insects in providing for the future wants 
of themselves or their progeny, without ever having 
seen such acts performed by others, and without any 
knowledge of why they perform them themselves. 
This is expressed by the very common term " blind 
instinct." But we have here a number of assertions 
of matters of fact, which, strange to say, have never 
been proved to be facts at all. They are thought to 


be so self-evident that they may be taken for granted. 
No one has ever yet obtained the eggs of some bird 
which builds an elaborate nest, hatched these eggs by 
steam or under a quite distinct parent, placed them 
afterwards in an extensive aviary or covered garden, 
where the situation and the materials of a nest simi- 
lar to that of the parent birds may be found, and then 
seen what kind of nest* these birds would build. If 
under these rigorous conditions they choose the same 
materials, the same situation, and construct the nest 
in the same way and as perfectly as their parents did, 
instinct would be proved in their case ; now it is only 
assumed, and assumed, as I shall show further on, 
without any sufficient reason. So, no one has ever 
carefully taken the pupse of a hive of bees out of the 
comb, removed them from the presence of other bees, 
and loosed them in a large conservatory with plenty 
of flowers and food, and observed what kind of cells 
they would construct. But till this is done, no one 
can say that bees build without instruction, no one 
can say that with every new swarm there are no bees 
older than those of the same year, who may be the 
teachers in forming the new comb. Now, in a scien- 
tific inquiry, a point which can be proved should not 
be assumed, and a totally unknown power should not 
be brought in to explain facts, when known powers 
may be sufficient. For both these reasons I decline to 
accept the theory of instinct in any case where all 
other possible modes of explanation have not been 


Does Man possess Instincts. 

Many of the upholders of the instinctive theory 
maintain, that man has instincts exactly of the same 
nature as those of animals, but more or less liable to 
be obscured by his reasoning powers; and as this is 
a case more open to our observation than any other, 
I will devote a few pages to its consideration. Infants 
are said to suck by instinct, and afterwards to walk 
by the same power, while in adult man the most pro- 
minent case of instinct is supposed to be, the powers 
possessed by savage races to find their way across a 
trackless and previously unknown wilderness. Let 
us take first the case of the infant's sucking. It is 
sometimes absurdly stated that the new-born infant 
" seeks the breast," and this is held to be a wonderful 
proof of instinct. No doubt it would be if true, but 
unfortunately for the theory it is totally false, as 
every nurse and medical man can testify. Still, the 
child undoubtedly sucks without teaching, but this is 
one of those simple acts dependent upon organization, 
which cannot properly be termed instinct, any more 
than breathing or muscular motion. Any object of 
suitable size in the mouth of an infant excites the 
nerves and muscles so as to produce the act of suction, 
and when at a little later period, the will comes into 
play, the pleasurable sensations consequent on the act 
lead to its continuance. So, walking is evidently de- 
pendent on the arrangement of the bones and joints, 
and the pleasurable exertion of the muscles, which 


lead to the vertical posture becoming gradually the 
most agreeable one ; and there can be little doubt 
that an infant would learn of itself to walk, even if 
suckled by a wild beast. 

How Indians travel through unknown and trackless 

Let us now consider the fact, of Indians finding their 
way through forests they have never traversed before. 
This is much misunderstood, for I believe it is only 
performed under such special conditions, as at once to 
show that instinct has nothing to do with it. A savage, 
it is true, can find his way through his native forests 
in a direction in which he has never traversed them 
before ; but this is because from infancy he has been 
used to wander in them, and to find his way by in- 
dications which he has observed himself or learnt from 
others. Savages make long journeys in many direc- 
tions, and, their whole faculties being directed to the 
subject, they gain a wide and accurate knowledge 
of the topography, not only of their own district, 
but of all the regions round about. Every one who 
has travelled in a new direction communicates his 
knowledge to those who have travelled less, and de- 
scriptions of routes and localities, and minute incidents 
of travel, form one of the main staples of conversation 
round the evening fire. Every wanderer or captive 
from another tribe adds to the store of information, 
and as the very existence of individuals and of whole 
families and tribes, depends upon the completeness of 


this knowledge, all the acute perceptive faculties of 
the adult savage are devoted to acquiring and perfect- 
ing it. The good hunter or warrior thus comes to 
know the bearing of every hill and mountain range, 
the directions and junctions of all the streams, the 
situation of each tract characterized by peculiar 
vegetation, not only within the area he has himself 
traversed, but for perhaps a hundred miles around 
it. His acute observation enables him to detect 
the slightest undulations of the surface, the various 
changes of subsoil and alterations in the character of 
the vegetation, that would be quite imperceptible to 
a stranger. His eye is always open to the direction 
in which he is going ; the mossy side of trees, the 
presence of certain plants under the shade of rocks, 
the morning and evening flight of birds, are to him 
indications of direction, almost as sure as the sun in 
the heavens. Now, if such a savage is required to 
find his way across this country in a direction in 
which he has never been before, he is quite equal 
to the task. By however circuitous a route he has 
come to the point he is to start from, he has observed 
all the bearings and distances so well, that he knows 
pretty nearly where he is, the direction of his own 
home and that of the place he is required to go to. 
He starts towards it, and knows that by a certain time 
he must cross an upland or a river, that the streams 
should flow in a certain direction, and that he should 
cross some of them at a certain distance from their 
sources. The nature of the soil throughout the whole 


region is known to him, as well as all the great fea- 
tures of the vegetation. As he approaches any tract oi 
country he has been in or near before, many minute 
indications guide him, but he observes them so cau- 
tiously that his white companions cannot perceive by 
what he has directed his course. Every now and 
then he slightly changes his direction, but he is never 
confused, never loses himself, for he always feels at 
home ; till at last he arrives at a well-known country, 
and directs his course so as to reach the exact spot 
desired. To the Europeans whom he guides, he seems 
to have come without trouble, without any special ob- 
servation, and in a nearly straight unchanging course. 
They are astonished, and ask if he has ever been the 
same route before, and when he answers "No," con- 
clude that some unerring instinct could alone have 
guided him. But take this same man into another 
country very similar to his own, but with other streams 
and hills, another kind of soil, with a somewhat dif- 
ferent vegetation and animal life ; and after bringing 
him by a circuitous route to a given point, ask him to 
return to his starting place, by a straight line of fifty 
miles through the forest, and he will certainly decline 
to attempt it, or, attempting it, will more or less com- 
pletely fail. His supposed instinct does not act out of 
his own country. 

A savage, even in a new country, has, however, 
undoubted advantages, from his familiarity with forest 
life, his entire fearlessness of being lost, his accurate 
perception of direction and of distance, and he is thus 



able very soon to acquire a knowledge of the district 
that seems marvellous to a civilized man ; but my own 
observation of savages in forest countries has convinced 
me, that they find their way by the use of no other 
faculties than those which we ourselves possess. It 
appears to me, therefore, that to call in the aid of a 
new and mysterious power to account for savages 
being able to do that which, under similar conditions, 
we could almost all of us perform, although perhaps 
less perfectly, is almost ludicrously unnecessary. 

In the next essay I shall attempt to show, that much 
of what has been attributed to instinct in birds, can be 
also very well explained by crediting them with those 
faculties of observation, memory, and imitation, and 
with that limited amount of reason, which they un- 
doubtedly exhibit. 




Instinct or Reason in the Construction of Birds' Nests. 

BIRDS, we are told, build their nests by instinct, while 
man constructs his dwelling by the exercise of reason. 
Birds never change, but continue to build for ever on 
the self-same plan ; man alters and improves his houses 
continually. Reason advances ; instinct is stationary. 

This doctrine is so very general that it may almost 
be said to be universally adopted. Men who agree 
on nothing else, accept this as a good explanation of 
the facts. Philosophers and poets, metaphysicians and 
divines, naturalists and the general public, not only 
agree in believing this to be probable, but even adopt 
it as a sort of axiom that is so self-evident as to need 
no proof, and use it as the very foundation of their 
speculations on instinct and reason. A belief so general, 
one would think, must rest on indisputable facts, and 
be a logical deduction from them. Yet I have come to 
the conclusion that not only is it very doubtful, but 
absolutely erroneous ; that it not only deviates widely 
from the truth, but is in almost every particular exactly 
opposed to it. I believe, in short, that birds do not 
build their nests by instinct; that man does not con- 

P 2 


struct his dwelling by reason ; that birds do change and 
improve when affected by the same causes that make 
men do so ; and that mankind neither alter nor improve 
when they exist under conditions similar to those which 
are almost universal among birds. 

Do Men build by Reason or by Imitation? 

Let us first consider the theory of reason, as alone 
determining the domestic architecture of the human 
race. Man, as a reasonable animal, it is said, con- 
tinually alters and improves his dwelling. This I en- 
tirely deny. As a rule, he neither alters nor improves, 
any more than the birds do. What have the houses of 
most savage tribes improved from, each as invariable as 
the nest of a species of bird ? The tents of the Arab 
are the same now as they were two or three thousand 
years ago, and the mud villages of Egypt can scarcely 
have improved since the time of the Pharoahs. The 
palm-leaf huts and hovels of the various tribes of South 
America and the Malay Archipelago, what have they 
improved from since those regions were first inhabited ? 
The Patagonian's rude shelter of leaves, the hollowed 

O * 

bank of the South African Earthmen, we cannot even 
conceive to have been ever inferior to what they now 
are. Even nearer home, the Irish turf cabin and the 
Highland stone shelty can hardly have advanced much 
during the last two thousand years. Now, no one 
imputes this stationary condition of domestic archi- 
tecture among these savage tribes to -instinct, but to 
simple imitation from one generation to another, and 


the absence of any sufficiently powerful stimulus to 
change or improvement. No one imagines that if an 
infant Arab could be transferred to Patagonia or to 
the Highlands, it would, when it grew up, astonish 
its foster-parents by constructing a tent of skins. On 
the other hand, it is quite clear that physical condi- 
tions, combined with the degree of civilization arrived 
at, almost necessitate certain types of structure. The 
turf, or stones, or snow the palm-leaves, bamboo, or 
branches, which are the materials of houses in various 
countries, are used because nothing else is so readily 
to be obtained. The Egyptian peasant has none of 
these, not even wood. What, then, can he use but 
mud ? In tropical forest-countries, the bamboo and the 
broad palm-leaves are the natural material for houses, 
and the form and mode of structure will be decided 
in part by the nature of the country, whether hot or 
cool, whether swampy or dry, whether rocky or plain, 
whether frequented by wild beasts, or whether subject 
to the attacks of enemies. When once a particular 
mode of building has been adopted, and has become 
confirmed by habit and by hereditary custom, it will 
be long retained, even when its utility has been lost 
through changed conditions, or through migration into 
a very different region. As a general rule, through- 
out the whole continent of America, native houses are 
built directly upon the ground strength and security 
being given by thickening the low walls and the roof. 
In almost the whole of the Malay Islands, on the 
contrary, the houses are raised on posts, often to a 


great height, with an open bamboo floor; and the 
whole structure is exceedingly slight and thin. Now, 
what can be the reason of this remarkable difference 
between countries, many parts of which are strikingly 
similar in physical conditions, natural productions, and 
the state of civilization of their inhabitants ? We ap- 
pear to have some clue to it in the supposed origin 
and migrations of their respective populations. The 
indigenes of tropical America are believed to have im- 
migrated from the north from a country where the 
winters are severe, and raised houses with open floors 
would be hardly habitable. They moved southwards 
by land along the mountain ranges and uplands, and 
in an altered climate continued the mode of construc- 
tion of their forefathers, modified only by the new 
materials they met with. By minute observations of 
the Indians of the Amazon Valley, Mr. Bates arrived 
at the conclusion that they were comparatively recent 
immigrants from a colder climate. He says : " No 
one could live long among the Indians of the Upper 
Amazon without being struck with their constitutional 
dislike to the heat. . . Their skin is hot to the touch, 
and they perspire little. . . They are restless and 
discontented in hot, dry weather, but cheerful on cool 
days, when the rain is pouring down their naked 
backs." And, after giving many other details, he 
concludes, " How different all this is with the Negro, 
the true child of tropical climes ! The impression gra- 
dually forced itself on my mind that the Red Indian 
lives as an immigrant or stranger in these hot regions, 


and that his constitution was not originally adapted, 
and has not since become perfectly adapted, to the 

The Malay races, on the other hand, are no doubt 
very ancient inhabitants of the hottest regions, and 
are particularly addicted to forming their first settle- 
ments at the mouths of rivers or creeks, or in land- 
locked bays and inlets. They are a pre-eminently 
maritime or semi-aquatic people, to whom a canoe is a 
necessary of life, and who will never travel by land if 
they can do so by water. In accordance with these 
tastes, they have built their houses on posts in the 
water, after the manner of the lake-dwellers of ancient 
Europe ; and this mode of construction has become so 
confirmed, that even those tribes who have spread far 
into the interior, on dry plains and rocky mountains, 
continue to build in exactly the same manner, and 
find safety in the height to which they elevate their 
dwellings above the ground. 

Why does each Bird build a peculiar kind of Nest ? 

These general characteristics of the abode of savage 
man will be found to be exactly paralleled by the nests 
of birds. Each species uses the materials it can most 
readily obtain, and builds in situations most congenial 
to its habits. The wren, for example, frequenting 
hedgerows and low thickets, builds its nest generally of 
moss, a material always found where it lives, and among 
which it probably obtains much of its insect food ; but 
it varies sometimes, using hay or feathers when these 


are at hand. Rooks dig in pastures and ploughed fields 
for grubs, and in doing so must continually encounter 
roots and fibres. These are used to line its nest. What 
more natural ! The crow feeding on carrion, dead rab- 
bits, and lambs, and frequenting sheep-walks and war- 
rens, chooses fur and icool to line its nest. The lark 
frequents cultivated fields, and makes its nest, on the 
ground, of grass lined with Jiorsehair materials the 
most easy to meet with, and the best adapted to its 
needs. The kingfisher makes its nest of the lones of 
the fish which it has eaten. Swallows use clay and 
mud from the margins of the ponds and rivers over 
which they find their insect food. The materials of 
birds' nests, like those used by savage man for his 
house, are, then, those which come first to hand ; and 
it certainly requires no more special instinct to select 
them in one case than in the other. 

But, it will be said, it is not so much the materials 
as the form and structure of nests, that vary so much, 
and are so wonderfully adapted to the wants and habits 
of each species; how are these to be accounted for 
except by instinct ? I reply, they may be in a great 
measure explained by the general habits of the species, 
the nature of the tools they have to work with, and the 
materials they can most easily obtain, with the very 
simplest adaptations of means to an end, quite within 
the mental capacities of birds. The delicacy and per- 
fection of the nest will bear a direct relation to the 
size of the bird, its structure and habits. That of the 
wren or the humming-bird is perhaps not finer or more 


beautiful in proportion than that of the blackbird, the 
magpie, or the crow. The wren, having a slender beak, 
long legs, and great activity, is able with great ease to 
form a well-woven nest of the finest materials, and 
places it in thickets and hedgerows which it frequents 
in its search for food. The titmouse, haunting fruit- 
trees and walls, and searching in cracks and crannies for 
insects, is naturally led to build in holes where it has 
shelter and security ; while its great activity, and the 
perfection of its tools (bill and feet), enable it readily 
to form a beautiful receptable for its eggs and young. 
Pigeons having heavy bodies and weak feet and bills (im- 
perfect tools for forming a delicate structure) build rude, 
flat nests of sticks, laid across strong branches which 
will bear their weight and that of their bulky young. 
They can do no better. The Caprimulgidae have the 
most imperfect tools of all, feet that will not support 
them except on a flat surface (for they cannot truly 
perch) and a bill excessively broad, short, and weak, and 
almost hidden by feathers and bristles. They cannot 
build a nest of twigs or fibres, hair or moss, like other 
birds, and they therefore generally dispense with one 
altogether, laying their eggs on the bare ground, or 
on the stump or flat limb of a tree. The clumsy hooked 
bills, short necks and feet, and heavy bodies of Parrots, 
render them quite incapable of building a nest like 
most other birds. They cannot climb up a branch 
without using both bill and feet ; they cannot even 
turn round on a perch without holding on with their 
bill. How, then, could they inlay, or weave, or twist 


the materials of a nest? Consequently, they all lay 
in holes of trees, the tops of rotten stumps, or in 
deserted ants' nests, the soft materials of which they 
can easily hollow out. 

Many terns and sandpipers lay their eggs on the 
bare sand of the sea-shore, and no doubt the Duke of 
Argyll is correct when he says, that the cause of 
this habit is not that they are unable to form a nest, 
but that, in such situations, any nest would be con- 
spicuous and lead to the discovery of the eggs. The 
choice of place is, however, evidently determined by 
the habits of the birds, who, in their daily search 
for food, are continually roaming over extensive tide- 
washed flats. Gulls vary considerably in their mode of 
nesting, but it is always in accordance with their struc- 
ture and habits. The situation is either on a bare rock 
or on ledges of sea-cliffs, in marshes or on weedy shores. 
The materials are sea-weed, tufts of grass or rushes, 
or the debris of the shore, heaped together with as 
little order and constructive art as might be expected 
from the webbed feet and clumsy bill of these birds, 
the latter better adapted for seizing fish than for 
forming a delicate nest. The long-legged, broad-billed 
flamingo, who is continually stalking over muddy flats 
in search of food, heaps up the mud into a conical 
stool, on the top of which it lays its eggs. The bird 
can thus sit upon them conveniently, and they are 
kept dry, out of reach of the tides. 

Now I believe that throughout the whole class of 
birds the same general principles will be found to hold 


good, sometimes distinctly, sometimes more obscurely 
apparent, according as the habits of the species are 
more marked, or their structure more peculiar. It 
is true that, among birds differing but little in struc- 
ture or habits, we see considerable diversity in the 
mode of nesting, but we are now so well assured that 
important changes of climate and of surface have oc- 
cured within the period of existing species, that it 
is by no means difficult to see how such differences 
have arisen. Simple habits are known to be here- 
ditary, and as the area now occupied by each species 
is different from that of every other, we may be sure 
that such changes would act differently upon each, and 
would often bring together species which had acquired 
their peculiar habits in distinct regions and under 
different conditions. 

How do Young Birds learn to Build their First Nest? 

But it is objected, birds do not learn to make their 
nest as man does to build, for all birds will make 
exactly the same nest as the rest of their species, even if 
they have never seen one, and it is instinct alone that 
can enable them to do this. JSTo doubt this would be 
instinct if it were true, and I simply ask for proof 
of the fact. This point, although so important to the 
question at issue, is always assumed without proof, and 
even against proof, for what facts there are, are op- 
posed to it. Birds brought up from the egg in cages 
do not make the characteristic nest of their species, 
even though the proper materials are supplied them, 


and often make no nest at all, but rudely heap together 
a quantity of materials ; and the experiment has never 
been fairly tried, of turning out a pair of birds so 
brought up, into an enclosure covered with netting, 
and watching the result of their untaught attempts at 
nest-making. With regard to the song of birds, how- 
ever, which is thought to be equally instinctive, the 
experiment has been tried, and it is found that young 
birds never have the song peculiar to their species if 
they have not heard it, whereas they acquire very 
easily the song of almost any other bird with which 
they are associated. 

Do Birds sing by Instinct or by Imitation ? 

The Hon. Daines Barrington has given an account of 
his experiments in the "Philosophical Transactions " for 
1773 (Vol. 63) ; he says : " I have educated nestling 
linnets under the three best singing larks the sky- 
lark, woodlark, and titlark, every one of which, instead 
of the linnet's song, adhered entirely to that of their 
respective instructors. When the note of the titlark 
linnet was thoroughly fixed, I hung the bird in a room 
with two common linnets for a quarter of a year, which 
were full in song ; the titlark linnet, however, did not 
borrow any passage from the linnet's song, but adhered 
stedfastly to that of the titlark." He then goes on to 
say that birds taken from the nest at two or three weeks 
old have already learnt the call-note of their species. 
To prevent this the birds must be taken from the nest 
when a day or two old, and he gives an account of a 


goldfinch which he saw at Knighton in Radnorshire, and 
which sang exactly like a wren, without any portion of 
the proper note of its species. This bird had been 
taken from the nest at two or three days old, and had 
been hung at a window opposite a small garden, where 
it had undoubtedly acquired the notes of the wren 
without having any opportunity of learning even the 
call of the goldfinch. 

He also saw a linnet, which had been taken from the 
nest when only two or three days old, and which, not 
having any other sounds to imitate, had learnt almost 
to articulate, and could repeat.the words "Pretty Boy," 
and some other short sentences. 

The Rev. W. H. Herbert made similar observations, 
and states that the young whinchat and wheatear, 
which have naturally little variety of song, are ready in 
confinement, to learn from other species, and become 
much better songsters. The bullfinch, whose natural 
notes are weak, harsh, and insignificant, has never- 
theless a wonderful musical faculty, since it can be 
taught to whistle complete tunes. The nightingale, on 
the other hand, whose natural song is so beautiful, is 
exceedingly apt in confinement to learn that of other 
birds instead. Bechstein gives an account of a redstart 
which had built under the eaves of his house, which 
imitated the song of a caged chaffinch, in a window 
underneath, while another in his neighbour's garden 
repeated some of the notes of a blackcap, which had a 
nest close by. 

These facts and many others which might be quoted, 


render it certain .that the peculiar notes of birds 
are acquired by imitation, as surely as a child learns 
English or French, not by instinct, but by hearing the 
language spoken by its parents. 

It is especially worthy of remark that, for young 
birds to acquire a new song correctly, they must be 
taken out of hearing of their parents very soon, for 
in the first three or four days they have already 
acquired some knowledge of the parent notes, which 
they will afterwards imitate. This shows that very 
young birds can both hear and remember, and it would 
be very extraordinary if, after they could see, they 
could neither observe nor recollect, and could live for 
days and weeks in a nest and know nothing of its 
materials and the manner of its construction. During 
the time they are learning to fly and return often to 
the nest, they must be able to examine it inside and 
out in every detail, and as we have seen that their 
daily search for food invariably leads them among the 
materials of which it is constructed, and among places 
similar to that in which it is placed, is it so very 
wonderful that when they want one themselves they 
should make one like it? How else, in fact, should 
they make it ? "Would it not be much more remark- 
able if they went out of their way to get materials 
quite different from those used in the parent nest, 
if they arranged them in a way they had seen no 
example of, and formed the whole structure differently 
from that in which they themselves were reared, and 
which we may fairly presume is that which their whole 


organization is best adapted to put together with cele- 
rity and ease. It has, however, been objected that 
observation, imitation, or memory, can have nothing 
to do with a bird's architectural powers, because the 
young birds, which in England are born in May or 
June, will proceed in the following April or May to 
build a nest as perfect and as beautiful as that in 
which it was hatched, although it could never have 
seen one built. But surely the young birds before they 
left the nest had ample opportunities of observing its 
form, its size, its position, the materials of which 
it was constructed, and the manner in which those 
materials were arranged. Memory would retain these 
observations till the following spring, when the ma- 
terials would come in their way during their daily 
search for food, and it seems highly probable that the 
older birds would begin building first, and that those 
born the preceding summer would follow their ex- 
ample, learning from them how the foundations of the 
nest are laid and the materials put together. Again, 
we have no right to assume that young birds gener- 
ally pair together. It seems more probable that in 
each pair there is frequently only one bird born the 
preceding summer, who would be guided, to some ex- 
tent, by its partner. At all events, till the crucial 
experiment is made, and a pair of birds raised from 
the egg, without ever seeing a nest, are shown to 
be capable of making one exactly of the parental type, 
I do not think we are justified in calling in the aid 
of an unknown and mysterious faculty to do that 


which is so strictly analogous to the house-building of 
savage man. In support of the view that birds learn 
and improve in nest-building, it may be mentioned, 
that the celebrated American observer, Wilson, strongly 
insists on the variety in the nests of birds of the same 
species, some being so much better finished than others ; 
and he believes that the less perfect nests are built by the 
younger , the more perfect by the older birds. 

Again, we always assume that because a nest ap- 
pears to us delicately and artfully built, that it there- 
fore requires much special knowledge and acquired 
skill (or their substitute, 'instinct) in the bird who 
builds it. We forget that it is formed twig by twig 
and fibre by fibre, rudely enough at first, but crevices 
and irregularities, which must seem huge gaps and 
chasms in the eyes of the little builders, are filled up 
by twigs and stalks pushed in by slender beak and 
active foot, and that the wool, feathers, or horsehair 
are laid thread by thread, so that the result seems a 
marvel of ingenuity to us, just as would the rudest 
Indian hut to a native of Brobdignag. 

Levaillant has given an account of the process of nest- 
building by a little African warbler, which cufficiently 
shows that a very beautiful structure may be produced 
with very little art. The foundation was laid of moss 
and flax interwoven with grass and tufts of cotton, and 
presented a rude mass, five or six inches in diameter, 
and four inches thick. This was pressed and trampled 
down repeatedly, so as at last to make it into a kind of 
felt. The birds pressed it with their bodies ; turning 


round upon them in every direction, so as to get it 
quite firm and smooth before raising the sides. These 
were added bit by bit, trimmed and beaten with the 
wings and feet, so as to felt the whole together, pro- 
jecting fibres being now and then worked in with the 
bill. By these simple and apparently inefficient means, 
the inner surface of the nest was rendered almost as 
smooth and compact as a piece of cloth. 

Man's Works mainly Imitative. 

But look at civilised man ! it is said ; look at Grecian, 
and Egyptian, and Roman, and Gothic, and modern Ar- 
chitecture ! What advance ! what improvement ! what 
refinements ! This is what reason leads to, whereas 
birds remain for ever stationary. If, however, such 
advances as these are required, to prove the effects of 
reason as contrasted with instinct, then all savage and 
many half-civilized tribes have no reason, but build in- 
stinctively quite as much as birds do. 

Man ranges over the whole earth, and exists under 
the most varied conditions, leading necessarily to 
equally varied habits. He migrates he makes wars 
and conquests one race mingles with another dif- 
ferent customs are brought into contact the habits of 
a migrating or conquering race are modified by the 
different circumstances of a new country. The civilized 
race which conquered Egypt must have developed its 
mode of building in a forest country where timber 
was abundant, for it is not probable that the idea of 
cylindrical columns originated in a country destitute 



of trees. The pyramids might have been built by an 
indigenous race, but not the temples of El Uksor and 
Karnak. In Grecian architecture, almost every char- 
acteristic feature can be traced to an origin in wooden 
buildings. The columns, the architrave, the frieze, the 
fillets, the cantelevers, the form of the roof, all point 
to an origin in some southern forest-clad country, and 
strikingly corroborate the view derived from philology, 
that Greece was colonised from north-western India. 
But to erect columns and span them with huge blocks 
of stone or marble, is not an act of reason, but one 
of pure unreasoning imitation. The arch is the only 
true and reasonable mode of covering over wide spaces 
with stone ; and therefore, Grecian architecture, how- 
ever exquisitely beautiful, is false in principle, and is 
by no means a good example of the application of 
reason to the art of building. And what do most of 
us do at the present day but imitate the buildings of 
those that have gone before us ? We have not even 
been able to discover or develop any definite style of 
building best suited for us. We have no characteristic 
national style of architecture, and to that extent are 
even below the birds, who have each their characteristic 
form of nest, exactly adapted to their wants and habits. 

Birds do Alter and Improve their Nests when altered 
Conditions require it. 

The great uniformity in the architecture of each 
species of bird which has been supposed to prove a 
nest-building instinct, we may, therefore, fairly impute 


to the uniformity of the conditions under which each 
species lives. Their range is often very limited, and 
they very seldom permanently change their country, 
so as to be placed in new conditions. When, how- 
ever, new conditions do occur, they take advantage 
of them just as freely and wisely as man could do. 
The chimney and house-swallows are a standing proof 
of a change of habit since chimneys and houses were 
built, and in America this change has taken place 
within about three hundred years. Thread and worsted 
are now used in many nests instead of wool and 
horsehair, and the jackdaw shows an affection for the 
church steeple which can hardly be explained by in- 
stinct. In the more thickly populated parts of the 
United States, the Baltimore oriole uses all sorts of 
pieces of string, skeins of silk, or the gardener's bass, 
to weave into its fine pensile nest, instead of the single 
hairs and vegetable fibres it has painfully to seek in 
wilder regions ; and Wilson, a most careful observer, 
believes that it improves in nest-building by practice 
the older birds making the best nests. The purple 
martin takes possession of empty gourds or small boxes, 
stuck up for its reception in almost every village and 
farm in America ; and several of the American wrens 
will also build in cigar boxes, with a small hole cut in 
them, if placed in a suitable situation. The orchard 
oriole of the United States offers us an excellent ex- 
ample of a bird which modifies its nest according to 
circumstances. When it is built among firm and stiff 


branches it is very shallow, but when, as is often the 



case, it is suspended from the slender twigs of the 
weeping willow, it is made much deeper, so that when 
swayed about violently by the wind the young may not 
tumble out. It has been observed also, that the nests 
built in the warm Southern States are much slighter 
and more porous in texture than those in the colder 
regions of the north. Our own house-sparrow equally 
well adapts himself to circumstances. When he builds 
in trees, as he, no doubt, always did originally, he 
constructs a well-made domed nest, perfectly fitted to 
protect his young ones ; but when he can find a con- 
renient 5 liole in a building or among thatch, or in any 
well-sheltered place, he takes much less trouble, and 
forms a very loosely-built nest. 

A curious example of a recent change of habits has 
occurred in Jamaica. Previous to 1 854, the palm swift 
(Tachornis phsenicobea) inhabited exclusively the palm 
trees in a few districts in the island. A colony then 
established themselves in two cocoa-nut palms in 
Spanish Town, and remained there till 1857, when 
one tree was blown down, and the other stripped of 
its foliage. Instead of now seeking out other palm 
trees, the swifts drove out the swallows who built in 
the Piazza of the House of Assembly, and took pos- 
session of it, building their nests on the tops of the 
end walls and at the angles formed by the beams and 
joists, a place which they continue to occupy in con- 
siderable numbers. It is remarked that here they form 
their nest with much less elaboration than when built 
in the palms, probably from being less exposed. 


Our little gold-crested warbler also varies its nest 
according to circumstances, building an open cup- 
shaped nest where there is a natural canopy of thick 
foliage, while in more exposed situations it forms a 
perfect domed nest with a side entrance. Again, there 
are decided imperfections in the nesting of many birds 
which are quite compatible with our present theory, but 
are hardly so with that of instinct, which is supposed 
to be infallible. The Passenger pigeon of America 
often crowds the branches with its nests till they break, 
and the ground is strewn with shattered nests, eggs, 
and young birds. Rooks' nests are often so imperfect 
that during high winds the eggs fall out; but the 
Window- Swallow is the most unfortunate in this re- 
spect, for White, of Selborne, informs us that he has 
seen them build, year after year, in places where their 
nests are liable to be washed away by a heavy rain and 
their young ones destroyed. 


A fair consideration of all these facts will, I think, 
fully support the statement with which I commenced, 
and show, that the mental faculties exhibited by birds in 
the construction of their nests, are the same in kind as 
those manifested by mankind in the formation of their 
dwellings. These are, essentially, imitation, and a slow 
and partial adaptation to new conditions. To compare 
the work of birds with the highest manifestations of 
human art and science, is totally beside the question. I 
do not maintain that birds are gifted with reasoning 


faculties at all approaching in variety and extent to 
those of man. I simply hold that the phenomena 
presented by their mode of building their nests, when 
fairly compared with those exhibited by the great mass 
of mankind in building their houses, indicate no essen- 
tial difference in the kind or nature of the mental facul- 
ties employed. If instinct means anything, it means 
the capacity to perform some complex act without 
teaching or experience. It implies innate ideas of a 
very definite kind, and, if established, would overthrow 
Mr. Mill's sensationalism and all the modern philosophy 
of experience. That the existence of true instinct may 
be established in other cases is not impossible, but in 
the particular instance of birds' nests, which is usually 
considered one of its strongholds, I cannot find a par- 
ticle of evidence to show the existence of anything 
beyond those lower reasoning and imitative powers, 
which animals are universally admitted to possess. 





THE habit of forming a more or less elaborate struc- 
ture for the reception of their eggs and young, must 
undoubtedly be looked upon as one of the most re- 
markable and interesting characteristics of the class of 
birds. In other classes of vertebrate animals, such 
structures are few and exceptional, and never attain 
to the same degree of completeness and beauty. Birds' 
nests have, accordingly, attracted much attention, and 
have furnished one of the stock arguments to prove 
the existence of a blind but unerring instinct in the 
lower animals. The very general belief that every 
bird is enabled to build its nest, not by the ordinary 
faculties of observation, memory, and imitation, but 
by means of some innate and mysterious impulse, has 
had the bad effect of withdrawing attention from the 
very evident relation that exists between the struc- 
ture, habits, and intelligence of birds, and the kind of 
nests they construct. 

In the preceding essay I have detailed several of 
these relations, and they teach us, that a consideration 
of the structure, the food, and other specialities of a 


bird's existence, will give a clue, and sometimes a very 
complete one, to the reason why it builds its nest of 
certain materials, in a definite situation, and in a more 
or less elaborate manner. 

I now propose to consider the question from a more 
general point of view, and to discuss its application 
to some important problems in the natural history of 

Changed Conditions and persistent Habits as influencing 

Besides the causes above alluded to, there are two 
other factors whose effect in any particular case we can 
only vaguely guess at, but which must have had an 
important influence in determining the existing details 
of nidification. These are changed conditions of ex- 


istence, whether internal or external, and the influence 
of hereditary or imitative habit ; the first inducing al- 
terations in accordance with changes of organic struc- 
ture, of climate, or of the surrounding fauna and 
flora ; the other preserving the peculiarities so pro- 
duced, even when changed conditions render them no 
longer necessary. Many facts have been already given 
which show that birds do adapt their nests to the situa- 
tions in which they place them, and the adoption of 
eaves, chimneys, and boxes, by swallows, wrens, and 
many other birds, shows that they are always ready 
to take advantage of changed conditions. It is pro- 
bable, therefore, that a permanent change of climate 
would cause many birds to modify the form or 


materials of their abodes, so as better to protect their 
young. The introduction of new enemies to eggs or 
young birds, might introduce many alterations tend- 
ing to their better concealment. A change in the 
vegetation of a country, would often necessitate the 
use of new materials. So, also, we may be sure, that 
as a species slowly became modified in any external or 
internal characters, it would necessarily change in some 
degree its mode of building. This effect would be 
produced by modifications of the most varied nature ; 
such as the power and rapidity of flight, which must 
often determine the distance to which a bird will go to 
obtain materials for its nest; the capacity of sustain- 
ing itself almost motionless in the air, which must 
sometimes determine the position in which a nest can 
be built ; the strength and grasping power of the foot 
in relation to the weight of the bird, a power abso- 
lutely essential to the constructor of a delicately- woven 
and well-finished nest ; the length and fineness of the 
beak, which has to be used like a needle in building 
the best textile nests ; the length and mobility of the 
neck, which is needful for the same purpose ; the pos- 
session of a salivary secretion like that used in the 
nests of many of the swifts and swallows, as well as 
that of the song-thrush peculiarities of habits, which 
ultimately depend on structure, and which often deter- 
mine the material most frequently met with or most 
easily to be obtained. Modifications in any of these 
characters would necessarily lead, either to a change in 
the materials of the nest, or in the mode of combin- 


ing them in the finished structure, or in the form or 
position of that structure. 

During all these changes, however, certain speciali- 
ties of nest-building would continue, for a shorter or 
a longer time after the causes which had necessitated 
them had passed away. Such records of a vanished 
past meet us everywhere, even in man's works, not- 
withstanding his boasted reason. Not only are the 
main features of Greek architecture, mere reproduc- 
tions in stone of what were originally parts of a 
wooden building, but our modern copyists of Gothic 
architecture often build solid buttresses capped with 
weighty pinnacles, to support a wooden roof which has 
no outward thrust to render them necessary ; and even 
think they ornament their buildings by adding sham 
spouts of carved stone, while modern waterpipes, stuck 
on without any attempt at harmony, do the real duty. 
So, when railways superseded coaches, it was thought 
necessary to build the first-class carriages to imitate 
a number of coach-bodies joined together ; and the 
arm-loops for each passenger to hold on by, which 
were useful when bad roads made every journey a suc- 
cession of jolts and lurches, were continued on our 
smooth macadamised mail-routes, and, still more ab- 
surdly, remain to this day in our railway carriages, 
the relic of a kind of locomotion we can now hardly 
realize. Another good example is to be seen in our 
boots. When elastic sides came into fashion we had 
been so long used to fasten them with buttons or laces, 
that a boot without either looked bare and unfinished, 


and accordingly the makers often put on a row of 
useless buttons or imitation laces, because habit ren- 
dered the appearance of them necessary to us. It is 
universally admitted that the habits of children and of 
savages give us the best clue to the habits and mode 
of thought of animals ; and every one must have 
observed how children at first imitate the actions of 
their elders, without any regard to the use or appli- 
cability of the particular acts. So, in savages, many 
customs peculiar to each tribe are handed down from 
father to son merely by the force of habit, and are 
continued long after the purpose which they origi- 
nally served has ceased to exist. With these and a 
hundred similar facts everywhere around us, we may 
fairly impute much of what we cannot understand in 
the details of Bird-Architecture to an analogous cause. 
If we do not do so, we must assume, either that birds 
are guided in every action by pure reason to a far 
greater extent than men are, or that an infallible in- 
stinct leads them to the same result by a different 
road. The first theory has never, that I am aware 
of, been maintained by any author, and I have already 
shown that the second, although constantly assumed, 
has never been proved, and that a large body of facts 
is entirely opposed to it. One of my critics has, in- 
deed, maintained that I admit " instinct " under the 
term a hereditary habit ;" but the whole course of my 
argument shows that I do not do so. Hereditary 
habit is, indeed, the same as instinct when the term 
is applied to some simple action dependent upon a 


peculiarity of structure which is hereditary; as when 
the descendants of tumbler pigeons tumble, and the 
descendants of pouter pigeons pout. In the present 
case, however, I compare it strictly to the hereditary, 
or more properly, persistent or imitative, habits of 
savages, in building their houses as their fathers did. 
Imitation is a lower faculty than invention. Children 
and savages imitate before they originate ; birds, as 
well as all other animals, do the same. 

The preceding observations are intended to show, 
that the exact mode of nidification of each species of 
bird is probably the result of a variety of causes, which 
have been continually inducing changes in accordance 
with changed organic or physical conditions. The 
most important of these causes seem to be, in the first 
place, the structure of the species, and, in the second, 
its environment or conditions of existence. Now we 
know, that every one of the characters or conditions 
included under these two heads is variable. We have 
seen that, on the large scale, the main features of the 
nest built by each group of birds, bears a relation to 
the organic structure of that group, and we have, 
therefore, a right to infer, that as structure varies, the 
nest will vary also in some particular corresponding 
to the changes of structure. We have seen also, that 
birds change the position, the form, and the con- 
struction of their nest, whenever the available ma- 
terials or the available situations, vary naturally or 
have been altered by man; and we have, therefore, 
a right to infer that similar changes have taken place, 


when, by a natural process, external conditions have 
become in any way permanently altered. AVe must 
remember, however, that all these factors are very 
stable during many generations, and only change at 
a rate commensurate with those of the great physical 
features of the earth as revealed to us by geology ; and 
we may, therefore, infer that the form and construction 
of nests, which we have shown to be dependent on 
them, are equally stable. If, therefore, we find less 
important and more easily modified characters than 
these, so correlated with peculiarities of nidification as 
to indicate that one is probably the cause of the 
other, we shall be justified in concluding that these 
variable characters are dependent on the mode of nidi- 
fication, and not that the form of the nest has been 
determined by these variable characters. Such a corre- 
lation I am now about to point out. 

Classification of Nests. 

For the purpose of this inquiry it is necessary to 
group nests into two great classes, without any re- 
gard to their most obvious differences or resemblances, 
but solely looking to the fact of whether the contents 
(eggs, young, or sitting bird) are hidden or exposed 
to view. In the first class we place all those in 
which the eggs and young are completely hidden, no 
matter whether this is effected by an elaborate covered 
structure, or by depositing the eggs in some hollow 
tree or burrow underground. In the second, we group 
all in which the eggs, young, and sitting bird are 


exposed to view, no matter whether there is the most 
beautifully formed nest, or none at all. Kingfishers, 
which build almost invariably in holes in banks ; 
Woodpeckers and Parrots, which build in hollow trees ; 
the Icteridaa of America, which all make beautiful 
covered and suspended nests ; and our own Wren, 
which builds a domed nest, are examples of the former ; 
while our Thrushes, Warblers, and Finches, as well 
as the Crowshrikes, Chatterers, and Tanagers of the 
tropics, together with all Raptorial birds and Pigeons, 
and a vast number of others in every part of the 
world, all adopt the latter mode of building. 

It will be seen that this division of birds according to 
their nidification, bears little relation to the character 
of the nest itself. It is a functional not a structural 
classification. The most rude and the most perfect 
specimens of bird-architecture are to be found in both 
sections. It has, however, a certain relation to natural 
affinities, for large groups of birds, undoubtedly allied, 
fall into one or the other division exclusively. The 
species of a genus or of a family are rarely divided 
between the two primary classes, although they are 
frequently divided between the two very distinct modes 
of nidification that exist in the first of them. 

All the Scansorial or climbing, and most of the 
Eissirostral or wide-gaped birds, for example, build 
concealed nests; and, in the latter group, the two 
families which build open nests, the Swifts and the 
Goat-suckers, are undoubtedly very widely separated 
from the other families with which they are asso- 


ciatecl in our classifications. The Tits vary much in 
their mode of nesting, some making open nests con- 
cealed in a hole, while others build domed or even pen- 
dulous covered nests, but they all come under the same 
class. Starlings vary in a similar way. The talking 
Mynahs, like our own starlings, build in holes, the 
glossy starlings of the East (of the genus Calornis) form 
a hanging covered nest, while the genus Sturnopastor 
builds in a hollow tree. One of the most striking cases 
in which one family of birds is divided between the 
two classes, is that of the Finches ; for while most of 
the European species build exposed nests, many of 
the Australian finches make them dome-shaped, 

Sexual differences of Colour in Birds. 

Turning now from the nests to the creatures who 
make them, let us consider birds themselves from a 
somewhat unusual point of view, and form them into 
separate groups, according as both sexes, or the males 
only, are adorned with conspicuous colours. 

The sexual differences of colour and plumage in 
birds are very remarkable, and have attracted much 
attention; and, in the case of polygamous birds, have 
been well explained by Mr. Darwin's principle of sexual 
selection. We can, to a great extent, understand 
how male Pheasants and Grouse have acquired their 
more brilliant plumage and greater size, by the con- 
tinual rivalry of the males both in strength and beauty ; 
but this theory does not throw any light on the causes 
which have made the female Toucan, Bee-eater, Parro- 


quet, Macaw and Tit, in almost every case as gay and 
brilliant as the male, while the gorgeous Chatterers, 
Manakins, Tanagers, and Birds of Paradise, as well as 
our own Blackbird, have mates so dull and incon- 
spicuous that they can hardly be recognised as be- 
longing to the same species. 

The Law which connects the Colours of Female Birds 
with the mode of Nidification. 

The above-stated anomaly can, however, now be ex- 
plained by the influence of the mode of nidification, 
since I find that, with but very few exceptions, it is 
the rule that when both sexes are of strikingly gay and 
conspicuous colours, the nest is of the first class, or 
such as to conceal the sitting bird ; while, whenever there 
is a striking contrast of colours, the male being gay and 
conspicuous, the female dull and obscure, the nest is open 
and the sitting bird exposed to view. I will now pro- 
ceed to indicate the chief facts that support this state- 
ment, and will afterwards explain the manner in which 
I conceive the relation has been brought about. 

We will first consider those groups of birds in which 
the female is gaily or at least conspicuously coloured, 
and is in most cases exactly like the male. 

1. Kingfishers (Alcedinidse). In some of the most 
brilliant species of this family the female exactly re- 
sembles the male ; in others there is a sexual difference, 
but it rarely tends to make the female less conspicuous. 
In some, the female has a band across the breast, which 
is wanting in the male, as in the beautiful Halcyon 


diops of Tern ate. In others the band is rufous in the 
female, as in several of the American species ; while 
in Dacelo gaudichaudii, and others of the same genus, 
the tail of the female is rufous, while that of the male 
is blue. In most kingfishers the nest is in a deep 
hole in the ground ; in Tanysiptera it is said to be 
in a hole in the nests of termites, or sometimes in 
crevices under overhanging rocks. 

2. Motmots (Momotidae). In these showy birds the 
sexes are exactly alike, and the nest in a hole under 

3. Puff-birds (Bucconidae). These birds are often 
gaily coloured ; some have coral-red bills ; the sexes 
are exactly alike, and the nest is in a hole in slop- 
ing ground. 

4. Trogons (Trogonidsa). In these magnificent birds 
the females are generally less brightly coloured than the 
males, but are yet often gay and conspicuous. The 
nest is in a hole of a tree. 

5. Hoopoes (Upupidse). The barred plumage and 
long crests of these birds render them conspicuous. The 
sexes are exactly alike, and the nest is in a hollow tree. 

6. Hornbills (BucerotidaB). These large birds have 
enormous coloured bills, which are generally quite as 
well coloured and conspicuous in the females. Their 
nests are always in hollow trees, where the female is 
entirely concealed. 

7. Barbets (Capitonidae). These birds are all very 
gaily-coloured, and, what is remarkable, the most bril- 
liant patches of colour are disposed about the head and 


neck, and are very conspicuous. The sexes are exactly 
alike, and the nest is in a hole of a tree. 

8. Toucans (Rhamphastidcc). These fine birds are 
coloured in the most conspicuous parts of their body, 
especially on the large bill, and on the upper and lower 
tail coverts, which are crimson, white, or yellow. The 
sexes are exactly alike, and they always build in a hol- 
low tree. 

9. Plaintain-eaters (Musophagidas). Here again the 
head and bill are most brilliantly coloured in both sexes, 
and the nest is in a hole of a tree. 

10. Ground cuckoos (Centropus). These birds are 
often of conspicuous colours, and are alike in both sexes. 
They build a domed nest. 

11. "Woodpeckers (Picidaa). In this family the fe- 
males often differ from the males, in having a yellow 
or white, instead of a crimson crest, but are almost as 
conspicuous. They all nest in holes in trees. 

12. Parrots (Psittaci). In this great tribe, adorned 
with the most brilliant and varied colours, the rule is, 
that the sexes are precisely alike, and this is the case 
in the most gorgeous families, the lories, the cockatoos, 
and the macaws ; but in some there is a sexual dif- 
ference of colour to a slight extent. All build in holes, 
mostly in trees, but sometimes in the ground, or in 
white ants' nests. In the single case in which the nest 
is exposed, that of the Australian ground parrot, Pezo- 
porus formosus, the bird has lost the gay colouring of 
its allies, and is clothed in sombre and completely pro- 
tective tints of dusky green and black. 


13. Gapers (EuryljemidaB). In these beautiful East- 
ern birds, somewhat allied to the American chatterers, 
the sexes are exactly alike, and are adorned with the 
most gay and conspicuous markings. The nest is a 
woven structure, covered over, and suspended from the 
extremities of branches over water. 

14. Pardalotus (Ampelida?). In these Australian 
birds the females differ from the males, but are 
often very conspicuous, having brightly-spotted heads. 
Their nests are sometimes dome-shaped, sometimes 
in holes of trees, or in burrows in the ground. 

15. Tits (Paridae). These little birds are always 
pretty, and many (especially among the Indian species) 
are very conspicuous. They always have the sexes 
alike, a circumstance very unusual among the smaller 
gaily-coloured birds of our own country. The nest is 
always covered over or concealed in a hole. 

16. Nuthatches (Sitta). Often very pretty birds, the 
sexes alike, and the nest in a hole. 

17. (Sittella). The female of these Australian 

nuthatches is often the most conspicuous, being white- 
and black-marked. The nest is, according to Gould, 
c c completely concealed among upright twigs connected 

18. Creepers (Climacteris). In these Australian 
creepers the sexes are alike, or the female most con- 
spicuous, and the nest is in a hole of a tree. 

19. Estrelda, Amadina. In these genera of Eastern 
and Australian finches the females, although more or less 
different from the males, are still very conspicuous 

R 2 


having a red rump, or being white spotted. They 
differ from most others of the family in building 
domed nests. 

20. Certhiola. In these pretty little American 
creepers the sexes are alike, and they build a domed 

21. Mynahs (Sturnidas). These showy Eastern star- 
lings have the sexes exactly alike. They build in holes 
of trees. 

22. Calornis (Sturnidce). These brilliant metallic 
starlings have no sexual differences. They build a 
pensile covered nest. 

23. Hangnests (Icteridse). The red or yellow and 
black plumage of most of these birds is very conspi- 
cuous, and is exactly alike in both sexes. They are 
celebrated for their fine purse-shaped pensile nests. 

It will be seen that this list comprehends six im- 
portant families of Fissirostres, four of Scansores, the 
Psittaci, and several genera, with three entire families 
of Passeres, comprising about twelve hundred species, 
or about one-seventh of all known birds. 

The cases in which, whenever the male is gaily 
coloured, the female is much less gay or quite incon- 
spicuous, are exceedingly numerous, comprising, in 
fact, almost all the bright-coloured Passeres, except 
those enumerated in the preceding class. The follow- 
ing are the most remarkable : 

1. Chatterers (Cotingida3). These comprise some of 
the most gorgeous birds in the world, vivid blues, 


rich purples, and bright reds, being the most charac- 
teristic colours. The females are always obscurely 
tinted, and are often of a greenish hue, not easily 
visible among the foliage. 

2. Manakins (Pipridce). These elegant birds, whose 
caps or crests are of the most brilliant colours, are 
usually of a sombre green in the female sex. 

3. Tanagers (Tanagrid^e). These rival the chatterers 
in the brilliancy of their colours, and are even more 
varied. The females are generally of plain and sombre 
hues, and always less conspicuous than the males. 

In the extensive families of the warblers (SylviadaB), 
thrushes (Turdidaa), flycatchers (Muscicapidas), and 
shrikes (Laniadaj), a considerable proportion of the 
species are beautifully marked with gay and conspi- 
cuous tints, as is also the case in the Pheasants and 
Grouse ; but in every case the females are less ga}^ 
and are most frequently of the very plainest and least 
conspicuous hues. Now, throughout the whole of these 
families the nest is open, and I am not aware of a 
single instance in which any one of these birds builds 
a domed nest, or places it in a hole of a tree, or under- 
ground, or in any place where it is effectually con- 
cealed. * 

In considering the question we are now investigating, 
it is not necessary to take into account the larger and 
more powerful birds, because these seldom depend 
much on concealment to secure their safety. In the 
raptorial birds bright colours are as a rule absent ; 
and their structure and habits are such as not to re- 


quire any special protection for the female. The larger 
waders are sometimes very brightly coloured in both 
sexes ; but they are probably little subject to the attacks 
of enemies, since the scarlet ibis, the most conspicuous 
of birds, exists in immense quantities in South America. 
In game birds and water-fowl, however, the females 
are often very plainly coloured, when the males are 
adorned with brilliant hues ; and the abnormal family 
of the Megapodida; offers us the interesting fact of an 
identity in the colours of the sexes (which in Mega- 
cephalon and Talegalla are somewhat conspicuous), in 
conjunction with the habit of not sitting on the eggs 
at all. 

What the Facts Teach us. 

Taking the whole body of evidence here brought 
forward, embracing as it does almost every group of 
bright-coloured birds, it will, I think, be admitted 
that the relation between the two series of facts in 
the colouring and nidification of birds has been suffi- 
ciently established. There are, it is true, a few 
apparent and some real exceptions, which I shall con- 
sider presently ; but they are too few and unimportant 
to weigh much against the mass of evidence on the 
other side, and may for the present be neglected. 
Let us then consider what we are to do with this 
unexpected set of correspondences between groups of 
phenomena which, at first sight, appear so discon- 
nected. Do they fall in with any other groups of 
natural phenomena ? Do they teach us anything of the 


way in which nature works, and give us any insight 
into the causes which have brought about the marvel- 
lous variety, and beauty, and harmony of living things? 
I believe we can answer these questions in the affirm- 
ative; and I may mention, as a sufficient proof that 
these are not isolated facts, that I was first led to 
see their relation to each other by the study of an 
analogous though distinct set of phenomena among in- 
sects, that of protective resemblance and " mimicry." 
On considering this remarkable series of correspond- 
ing facts, the first thing we are taught by them seems 
to be, that there is no incapacity in the female sex 
among birds, to receive the same bright hues and 
strongly contrasted tints with which their partners are 
so often decorated, since whenever they are protected 
and concealed during the period of incubation they 
are similarly adorned. The fair inference is, that it is 
chiefly due to the absence of protection or concealment 
during this important epoch, that gay and conspicuous 
tints are withheld or left undeveloped. The mode in 
which this has been effected is very intelligible, if we 
admit the action of natural and sexual selection. It 
would appear from the numerous cases in which both 
sexes are adorned with equally brilliant colours (while 
both saxes are rarely armed with equally developed 
offensive and defensive weapons when not required for 
individual safety), that the normal action of " sexual 
selection " is to develop colour and beauty in both 
sexes, by the preservation and multiplication of all 
varieties of colour in either sex which are pleasing 


to the other. Several very close observers of the 
habits of animals have assured me, that male birds and 
quadrupeds do often take very strong likes and dis- 
likes to individual females, and we can hardly believe 
that the one sex (the female) can have a general taste 
for colour while the other has no such taste. How- 
ever this may be, the fact remains, that in a vast 
number of cases the female acquires as brilliant and 
as varied colours as the male, and therefore most pro- 
bably acquires them in the same way as the male does ; 
that is, either because the colour is useful to it, or is 
correlated with some useful variation, or is pleasing to 
the other sex. The only remaining supposition is that 
it is transmitted from the other sex, without being ot 
any use. From the number of examples above adduced 
of bright colours in the female, this would imply that 
colour-characters acquired by one sex are generally 
(but not necessarily) transmitted to the other. If this 
be the case it will, I think, enable us to explain the 
phenomena, even if we do not admit that the male 
bird is ever influenced in the choice of a mate by her 
more gay or perfect plumage. 

The female bird, while sitting on her eggs in an 
uncovered nest, is much exposed to the attacks of 
enemies, and any modification of colour which ren- 
dered her more conspicuous would often lead to her 
destruction and that of her offspring. All variations 
of colour in this direction in the female, would there- 
fore sooner or later be eliminated, while such modifi- 
cations as rendered her inconspicuous, by assimilating 


her to surrounding objects, as the earth or the foliage, 
would, on the whole, survive the longest, and thus 
lead to the attainment of those brown or green and 
inconspicuous tints, which form the colouring (of the 
upper surface at least), of the vast majority of female 
birds which sit upon open nests. 

This does not imply, as some have thought, that all 
female birds were once as brilliant as the males. The 
change has been a very gradual one, generally dating 
from the origin of genera or of larger groups, but 
there can be no doubt that the remote ancestry of 
birds having great sexual differences of colour, were 
nearly or quite alike, sometimes (perhaps in most 
cases) more nearly resembling the female, but occa- 
sionally perhaps being nearer what the male is now. 
The young birds (which usually resemble the females) 
will probably give some idea of this ancestral type, 
and it is well known that the young of allied species 
and of different sexes are often undistinguishable. 

Colour more variable than Structure or Habits, and 
therefore the Character which has generally been 

At the commencement of this essay, I have endea- 
voured to prove, that the characteristic differences and 
the essential features of birds' nests, are dependent on 
the structure of the species and upon the present and 
past conditions of their existence. Both these factors 
are more important and less variable than colour; and 
we must therefore conclude that in most cases the mode 


of nidification (dependent on structure and environ- 
ment) lias been the cause, and not the effect, of the 
similarity or differences of the sexes as regards colour. 
When the confirmed habit of a group of birds, was to 
build their nests in holes of trees like the toucans, or in 
holes in the ground like the kingfishers, the protection 
the female thus obtained, during the important and 
dangerous time of incubation, placed the two sexes on 
an equality as regards exposure to attack, and allowed 
" sexual selection," or any other cause, to act unchecked 
in the development of gay colours and conspicuous 
markings in both sexes. 

When, on the other hand (as in the Tanagers and 
Flycatchers), the habit of the whole group was to build 
open cup-shaped nests in more or less exposed situa- 
tions, the production of colour and marking in the 
female, by whatever cause, was continually checked by 
its rendering her too conspicuous, while in the male it 
had free play, and developed in him the most gorgeous 
hues. This, however, was not perhaps universally the 
case ; for where there was more than usual intelligence 
and capacity for change of habits, the danger the fe- 
male was exposed to by a partial brightness of colour 
or marking might lead to the construction of a concealed 
or covered nest, as in the case of the Tits and Hang- 
nests. When this occurred, a special protection to the 
female would be no longer necessary ; so that the 
acquisition of colour and the modification of the nest, 
might in some cases act and react on each other and 
attain their full development together. 


Exceptional Cases confirmatory of the above 

There exist a few very curious and anomalous facts 
in the natural history of birds, which fortunately serve 
as crucial tests of the truth of this mode of explaining 
the inequalities of sexual colouration. It has been long 
known, that in some species the males either assisted in, 
or wholly performed, the act of incubation. It has also 
been often noticed, that in certain birds the usual sexual 
differences were reversed, the male being the more 
plainly coloured, the female more gay and often larger. 
I am not, however, aware that these two anomalies had 
ever been supposed to stand to each other in the rela- 
tion of cause and effect, till I adduced them in support 
of my views of the general theory of protective adapta- 
tion. Yet it is undoubtedly the fact, that in the best 
known cases in which the female bird is more conspi- 
cuously coloured than the male, it is either positively 
ascertained that the latter performs the duties of in- 
cubation, or there are good reasons for believing such 
to be the case. The most satisfactory example is that 
of the Gray Phalarope (Phalaropus fulicarius), the 
sexes of which are alike in winter, while in summer 
the female instead of the male takes on a gay and 
conspicuous nuptial plumage ; but the male performs 
the duties of incubation, sitting upon the eggs, which 
are laid upon the bare ground. 

In the Dotterell (Eudromias morinellus) the female 
is larger and more brightly coloured than the male ; and 


here, also, it is almost certain that the latter sits upon 
the eggs. The Turnices of India also, have the female 
larger and often more brightly coloured ; and Mr. 
Jerdon states, in his " Birds of India," that the natives 
report, that, during the breeding season, the females 
desert their eggs and associate in flocks, while the 
males are employed in hatching the eggs. In the few 
other cases in which the females are more brightly 
coloured, the habits are not accurately known. The 
case of the Ostriches and Emeus will occur to many as 
a difficulty, for here the male incubates, but is not less 
conspicuous than the female ; but there are two reasons 
why the case does not apply ; the birds are too large 
to derive any safety from concealment, from enemies 
which would devour the eggs they can defend them- 
selves by force, while to escape from their personal foes 
they trust to speed. 

We find, therefore, that a very large mass of facts 
relating to the sexual colouration and the mode of 
nidification of birds, including some of the most 
extraordinary anomalies to be found in their natural 
history, can be shown to have an interdependent re- 
lation to each other, on the simple principle of the need 
of greater protection to that parent which performs the 
duties of incubation. Considering the very imperfect 
knowledge we possess of the .habits of most extra- 
European birds, the exceptions to the prevalent rule 
are few, and generally occur in isolated species or in 
small groups ; while several apparent exceptions can 
be shown to be really confirmations of the law. 


Real or apparent Exceptions to the Law stated at 
page 240. 

The only marked exceptions I have been able to 
discover are the following : 

1. King crows (Dicrourus). These birds are of a 
glossy black colour with long forked tails. The sexes 
present no difference, and they build open nests. This 
apparent exception may probably be accounted for by 
the fact that these birds do not need the protection 
of a less conspicuous colour. They are very pugna- 
cious, and often attack and drive away crows, hawks, 
and kites ; and as they are semi-gregarious in their 
habits, the females are not likely to be attacked while 

2. Orioles (Qriolidae). The true orioles are very gay 
birds ; the sexes are, in many Eastern species, either 
nearly or quite alike, and the nests are open. This 
is one of the most serious exceptions, but it is one 
that to some extent proves the rule ; for in this case 
it has been noticed, that the parent birds display 
excessive care and solicitude in concealing the nest 
among thick foliage, and in protecting their offspring 
by incessant and anxious watching. This indicates 
that the want of protection consequent on the bright 
colour of the female makes itself felt, and is obviated 
by an increased development of the mental faculties. 

3. Ground thrushes (Pittidoo). These elegant and 
brilliantly-coloured birds are generally alike in both 
sexes, and build an open 'nest. It is curious, however, 


that this is only an apparent exception, for almost all 
the bright colours are on the under surface, the back 
being usually olive green or brown, and the head black, 
with brown or whitish stripes, all which colours would 
harmonize with the foliage, sticks, and roots which 
surround the nest, built on or near the ground, and 
thus serve as a protection to the female bird. 

4. Grallina Australis. This Australian bird is of 
strongly contrasted black and white colours. The sexes 
are exactly alike, and it builds an open clay nest in 
an exposed situation on a tree. This appears to be 
a most striking exception, but I am by no means 
sure that it is so. We require to know what tree it 
usually builds on, the colour of the bark or of the 
lichens that grow upon it, the tints of the ground, 
or of other surrounding objects, before we can say 
that the bird, when sitting on its nest, is really con- 
spicuous. It has been remarked that small patches 
of w r hite and black blend at a short distance to form 
grey, one of the commonest tints of natural objects. 

5. Sunbirds (Nectarineidse). In these beautiful 
little birds the males only are adorned with brilliant 
colours, the females being quite plain, yet they build 
covered nests in all the cases in which the nidification 
is known. This is a negative rather than a positive 
exception to the rule, since there may be other causes 
besides the need for protection, which prevent the 
female acquiring the gay colours of her mate, and 
there is one curious circumstance which tends to 
elucidate it The male of Leptocoma zeylanica is said 


to assist in incubation. It is possible, therefore, that 
the group may originally have used open nests, and 
some change of conditions, leading the male bird to 
sit, may have been followed by the adoption of a 
domed nest. This is, however, the most serious ex- 
ception I have yet found to the general rule. 

6. Superb warblers (MaluridaB). The males of these 
little birds are adorned with the most gorgeous colours, 
while the females are very plain, yet they make domed 
nests. It is to be observed, however, that the male 
plumage is nuptial merely, and is retained for a very 
short time ; the rest of the year both sexes are plain 
alike. It is probable, therefore, that the domed nest 
is for the protection of these delicate little birds against 
the rain, and that there is some unknown cause which 
has led to the development of colour in the males only. 

There is one otlier case which at first sight looks 
like an exception, but which is far from being one 
in reality, and deserves to be mentioned. In the 
beautiful Waxwing, (Bombycilla garrula,) the sexes 
are very nearly alike, and the elegant red wax tips to 
the wing-feathers are nearly, and sometimes quite, 
as conspicuous in the female as in the male. Yet it 
builds an open nest, and a person looking at the bird 
would say it ought according to my theory to cover 
its nest. But it is, in reality, as completely protscted 
by its colouration as the most plainly coloured bird 
that flies. It breeds only in very high latitudes, and 
the nest, placed in fir-trees, is formed chiefly of 
lichens. Now the delicate gray and ashy and purplish 


hues of the head and back, together with the yellow 
of the wings and tail, are tints that exactly harmonize 
with the colours of various species of lichens, while 
the brilliant red wax tips exactly represent the crimson 
fructification of tho common lichen, Cladonia cocci- 
fera. When sitting on its nest, therefore, the female 
bird will exhibit no colours that are not common 
to the materials of which it is constructed ; and the 
several tints are distributed in about the same pro- 
portions as they occur in nature. At a short distance 
the bird would be indistinguishable from the nest it is 
sitting on, or from a natural clump of lichens, and 
will thus be completely protected. 

I think I have now noticed all exceptions of any 
importance to the law of dependence of sexual colour 
on nidification. It will be seen that they are very 
few in number, compared with those which support 
the generalization ; and in several cases there are 
circumstances in the habits or structure of the species 
that sufficiently explain them. It is remarkable also 
that I have found scarcely any positive exceptions, 
that is, cases of very brilliant or conspicuous female 
birds in which the nest was not concealed. Much less 
can there be shown any group of birds, in which the 
females are all of decidedly conspicuous colours on 
the upper surface, and yet sit in open nests. The 
many cases in which birds of dull colours in both 
sexes make domed or concealed nests, do not, of course, 
affect this theory one way or the other ; since its 
purpose is only to account for the fact, that brilliant 


females of brilliant males are always fou'.id to have 
covered or hidden nests, while obscure females of 
brilliant males almost always have open and exposed 
nests. The fact that all classes of nests occur with 
dull coloured birds in both sexes merely shows, as I 
have strongly maintained, that in most cases the 
character of the nest determines the colouration of 
the female, and not vice versa. 

If the views here advocated are correct, as to the 
various influences that have determined the specialities 
of every bird's nest, and the general colouration of 
female birds, with their action and reaction on each 
other, we can hardly expect to find evidence more 
complete than that here set forth. Nature is such a 
tangled web of complex relations, that a series of 
correspondences running through hundreds of species, 
genera, and families, in every part of the system, can 
hardly fail to indicate a true casual connexion ; and 
when, of the two factors in the problem, one can be 
shown to be dependent on the most deeply seated and 
the most stable facts of structure and conditions of 
life, while the other is a character universally admitted 
to be superficial and easily modified, there can be 
little doubt as to which is cause and which effect. 

Various modes of Protection of Animals, 

But the explanation of the phenomenon here at- 
tempted does not rest alone on the facts I have been 
able now to adduce. In the essay on " Mimicry," 
it is shown how important a part the necessity for 


protection has played, in determining the external form 
and colouration, and sometimes even the internal 
structure of animals. 

As illustrating this latter point, I may refer to the 
remarkable hooked, branched, or star-like spiculaa in 
many sponges, which are believed to have the function 
chiefly, of rendering them unpalatable to other crea- 
tures. The Holothuridaa or sea-cucumbers possess a 
similar protection, many of them having anchor-shaped 
spicules embedded in their skin, as the Synapta ; while 
others (Cuviera squamata) are covered with a hard 
calcareous pavement. Many of these are of a bright 
red or purple colour, and are very conspicuous, while 
the allied Trepangj or Beche-de-mer (Holothuria 
edulis), which is not armed with any such defensive 
weapons, is of a dull sand- or mud-colour, so as hardly 
to be distinguished from the sea bed on which it 
reposes. Many of the smaller marine animals are 
protected by their almost invisible transparency, while 
those that are most brightly coloured will be often 
found to have a special protection, either in stinging 
tentacles like Physalia, or in a hard calcareous crust, 
as in the star fishes. 

Females of some Groups require and obtain more Pro- 
tection than the Males. 

In the struggle for existence incessantly going on, 
protection or concealment is one of the most general 
and most effectual means of maintaining life ; and it is 
by modifications of colour that this protection can be 


most readily obtained, since no other character is sub- 
ject to such numerous and rapid variations. The case I 
have now endeavoured to illustrate is exactly analogous 
to what occurs among butterflies. As a general rule, 
the female butterfly is of dull and inconspicuous colours, 
even when the male is most gorgeously arrayed ; but 
when the species is protected from attack by a disa- 
greeable odour, as in the Heliconidaa, DanaidaB and 
Acrceida?, both sexes display the same or equally bril- 
liant hues. Among the species which gain a protec- 
tion by imitating these, the very weak and slow-flying 
Leptalides resemble them in both sexes, because both 
sexes alike require protection, while in the more active 
and strong-winged genera Papilio, Pieris, and Dia- 
dema it is generally the females only that mimic the 
protected groups, and in doing so often become actually 
more gay and more conspicuous than the males, thus 
reversing the usual and in fact almost universal char- 
acters of the sexes. So, in the wonderful Eastern leaf- 
insects of the genus Phyllium, it is the female only 
that so marvellously imitates a green leaf; and in all 
these cases the difference can be traced to the greater 
need of protection for the female, on whose continued 
existence, while depositing her eggs, the safety of the 
race depends. In Mammalia and in reptiles, however 
brilliant the colours may be, there is rarely any differ- 
ence between that of the sexes, because the female is 
not necessarily more exposed to attack than the male. 
It may, I think, be looked upon as a confirmation of 
this view, that no single case is known either in the 

s 2 


above-named genera Papilio, Pieris, and Diadema or 
in any other butterfly, of a male alone, mimicking 
one of the Danaida3 or Heliconidae. Yet the necessary 
colour is far more abundant in the males, and varia- 
tions always seem ready for any useful purpose. This 
seems to depend on the general law, that each species 
and each sex can only be modified just as far as is 
absolutely necessary for it to maintain itself in the 
struggle for existence, not a step further. A male 
insect by its structure and habits is less exposed to 
clanger, and also requires less protection than the 
female. It cannot, therefore, alone acquire any further 
protection through the agency of natural selection. 
But the female requires some extra protection, to 
balance the greater danger to which she is exposed, 
and her greater imroriance to the existence of the 
species ; and this she always acquires, in one way or 
another, through the action of natural selection. 

In his " Origin of Species," fourth edition, p. 241, 
Mr. Darwin recognises the necessity for protection as 
sometimes being a cause of the obscure colours of fe- 
male birds ; but he does not seem to consider it so 
very important an agent in modifying colour as I am 
disposed to do. In the same paragraph (p. 240), he 
alludes to the fact of female birds and butterflies being 
sometimes very plain, sometimes as gay as the males; 
but, apparently, considers this mainly due to peculiar 
laws of inheritance, which sometimes continue acquired 
colour in the line of one sex only, sometimes in both. 
Without denying the action of such a law (which Mr. 


Darwin informs me he has facts to support), I impute 
the difference, in the great majority of cases, to the 
greater or less need of protection in the female sex in 
these groups of animals. 


To some persons it will perhaps appear, that the 
causes to which I impute so much of the external as- 
pect of nature are too simple, too insignificant, and too 
unimportant for such a mighty work. But I would 
ask them to consider, that the great object of all the 
peculiarities of animal structure is to preserve the life 
of the individual, and maintain the existence of the 
species. Colour has hitherto been too often looked 
upon as something adventitious and superficial, some- 
thing given to an animal not to be useful to itself, but 
solely to gratify man or even superior beings to add 
to the beauty and ideal harmony of nature. If this 
were the case, then, it is evident that the colours of 
organized beings would be an exception to most other 
natural phenomena. They would not be the product 
of general laws, or determined by ever-changing ex- 
ternal conditions ; and we must give up all inquiry 
into their origin and causes, since (by the hypothesis) 
they are dependent on a Will whose motives must ever 
be unknown to us. But, strange to say, no sooner do 
we begin to examine and classify the colours of natural 
objects, than we find that they are intimately related 
to a variety of other phenomena, and are like them 
strictly subordinated to general laws. I have here 


attempted to elucidate some of these laws in the case 
of birds, and have shown how the mode of nidification 
has affected the colouring of the female sex in this 
group. I have before shown to how great an extent, 
and in how many ways, the need of protection has 
determined the colours of insects, and of some groups 
of reptiles and mammalia, and I would now call parti- 
cular attention to the fact that the gay tints of flowers, 
so long supposed to be a convincing proof that colour 
has been bestowed for other purposes than the good of 
its possessor, have been shown by Mr. Darwin to follow 
the same great law of utility. Flowers do not often 
need protection, but very often require the aid of insects 
to fertilize them, and maintain their reproductive powers 
in the greatest vigour. Their gay colours attract in- 
sects, as do also their sweet odours and honeyed secre- 
tions ; and that this is the main function of colour in 
flowers is shown by the striking fact, that those flowers 
which can be perfectly fertilized by the wind, and do 
not need the aid of insects, rarely or never have gaily- 
coloured flowers. 

This wide extension of the general principle of utility 
to the colours of such varied groups, both in the animal 
and vegetable kingdoms, compels us to acknowledge 
that the " reign of law" has been fairly traced into this 
stronghold of the advocates of special creation. And 
to those who oppose the explanation I have given of 
the facts adduced in this essay, I would again respect- 
fully urge that they must grapple with the whole of the 
facts, not one or two of them only. It will be admitted 


that, on the theory of evolution and natural selection, a 
wide range of facts with regard to colour in nature have 
been co-ordinated and explained. Until at least an 
equally wide range of facts can be shown to be in har- 
mony with any other theory, we can hardly be expected 
to abandon that which has already done such good ser- 
vice, and which has led us to the discovery of so many 
interesting and unexpected harmonies among the most 
common (but hitherto most neglected and least un- 
derstood), of the phenomena presented by organized 



AMONG the various criticisms that have appeared on 
Mr. Darwin's celebrated " Origin of Species," there 
is, perhaps, none that will appeal to so large a number 
of well educated and intelligent persons, as that con- 
tained in the Duke .of Argyll's " Reign of Law." The 
noble author represents the feelings and expresses the 
ideas of that large class, who take a keen interest in 
the progress of Science in general, and especially that 
of Natural History, but have never themselves studied 
nature in detail, or acquired that personal knowledge 
of the structure of closely allied forms, the wonder- 
ful gradations from species to species and from group 
to group, and the infinite variety of the phenomena 
of " variation " in organic beings, which are abso- 
lutely necessary for a full appreciation of the facts and 
reasonings contained in Mr. Darwin's great work. 

Nearly half of the Duke's book is devoted to an 
exposition of his idea of " Creation by Law," and he 
expresses so clearly what are his difficulties and ob- 
jections as regards the theory of u Natural Selection," 
that I think it advisable that they should be fairly 
answered, and that his own views should be shown to 
lead to conclusions, as hard to accept as any which he 
imputes to Mr. Darwin. 


The point on which the Duke of Argyll lays most 
stress, is, that proofs of Mind everywhere meet us in 
Nature, and are more especially manifest wherever we 
find "contrivance" or "beauty." He maintains that 
this indicates the constant supervision and direct in- 
terference of the Creator, and cannot possibly be 
explained by the unassisted action of any combination 
of laws. Now, Mr. Darwin's work has for its main 
object, to show, that all the phenomena of living 
things, all their wonderful organs and complicated 
structures, their infinite variety of form, size, and 
colour, their intricate and involved relations to each 
other, may have been produced by the action of a 
few general laws of the simplest kind, laws which are 
in most cases mere statements of admitted facts. The 
chief of these laws or facts are the following : 

1. The Law of Multiplication in Geometrical Pro- 
gression. All organized beings have enormous powers 
of multiplication. Even man, who increases slower 
than all other animals, could under the most favour- 
able circumstances double his numbers every fifteen 
years, or a hundred-fold in a century. Many animals 
and plants could increase their numbers from ten to 
a thousand-fold every year. 

2. The Law of Limited Populations. The number 
of living individuals of each species in any country, 
or in the whole globe, is practically stationary ; whence 
it follows that the whole of this enormous increase 
must die off almost as fast as produced, except only 
those individuals for whom room is made by the death 


of parents. As a simple but striking example, take 
an oak forest. Every oak will drop annually thou- 
sands or millions of acorns, but till an old tree falls, 
not one of these millions can grow up into an oak. 
They must die at various stages of growth. 

3. The Law of Heredity, or Likeness of Offspring 
to their Parents. This is a universal, but not an 
absolute law. All creatures resemble their parents in 
a high degree, and in the majority of cases very ac- 
curately; so that even individual peculiarities, of what- 
ever kind, in the parents, are almost always transmitted 
to some of the offspring. 

4. The Law of Variation. This is fully expressed 
by the lines : 

" No being on this earthly ball, 
Is like another, all in all." 

Offspring resemble their parents very much, but not 
wholly each being possesses its individuality. This 
u variation " itself varies in amount, but it is always 
present, not only in the whole being, but in every 
part of every being. Every organ, every character, 
every feeling is individual ; that is to say, varies from 
the same organ, character, or feeling in every other 

5. The Law of unceasing Change of Physical Con- 
ditions upon the Surface of the Earth. Geology shows 
us that this change has always gone on in times past, 
and we also know that it is now everywhere going on. 

6. The Equilibrium or Harmony of Nature. When 
a species is well adapted to the conditions which 


environ it, it flourishes ; when imperfectly adapted it 
decays ; when ill-adapted it becomes extinct. If all 
the conditions which determine an organism's well- 
being are taken into consideration, this statement can 
hardly be disputed. 

This series of facts or laws, are mere statements of 
what is the condition of nature. They are facts or 
inferences which are generally known, generally ad- 
mitted but in discussing the subject of the " Origin 
of Species " as generally forgotten. It is from these 
universally admitted facts, that the origin of all the 
varied forms of nature may be deduced by a logical 
chain of reasoning, which, however, is at every step 
verified and shown to be in strict accord with facts ; 
and, at the same time, many curious phenomena which 
can by no other means be understood, are explained 
and accounted for. It is probable, that these primary 
facts or laws are but results of the very nature of life, 
and of the essential properties of organized and un- 
organized matter. Mr. Herbert Spencer, in his " First 
Principles" and his " Biology" has, I think, made us 
able to understand how this may be; but at present 
we may accept these simple laws without going further 
back, and the question then is whether the variety, the 
harmony, the contrivance, and the beauty we perceive 
in organic beings, can have been produced by the 
action of these laws alone, or whether we are required 
to believe in the incessant interference and direct action 
of the mind and will of the Creator. It is simply a 


question of how the Creator has worked. The Duke 
(and I quote him as having well expressed the views 
of the more intelligent of Mr. Darwin's opponents) 
maintains, that He has personally applied general laws 
to produce effects, which those laws are not in them- 
selves capable of producing; that the universe alone, 
with all its laws intact, would be a sort of chaos, with- 
out variety, without harmony, without design, without 
beauty ; that there is not (and therefore we may pre- 
sume that 'there could not be) any self-developing 
power in the universe. I believe, on the contrary, 
that the universe is so constituted as to be self-regu- 
lating; that as long as it contains Life, the forms under 
which that life is manifested have an inherent power 
of adjustment to each other and to surrounding na- 
ture; and that this adjustment necessarily leads to the 
greatest amount of variety and beauty and enjoyment, 
because it does depend on general laws, and not on 
a continual supervision and re-arrangement of details. 
As a matter of feeling and religion, I hold this to be 
a far higher conception . of the Creator and of the 
Universe that that which may be called the u continual 
interference " hypothesis ; but it is not a question to 
be decided by our feelings or convictions, it is a ques- 
tion of facts and of reason. Could the change, which 
Geology shows us has ever taken place in the forms 
of life, have been produced by general laws, or does 
it imperatively require the incessant supervision of a 
creative mind ? This is the question for us to consider, 
and our opponents have the difficult task of proving 


a negative, if we show that there are both facts and 
analogies in our favour. 

Mr. Darwin's Metaphors liable to Misconception. 

Mr. Darwin has laid himself open to much miscon- 
ception, and has given to his opponents a powerful 
weapon against himself, by his continual use of meta- 
phor in describing the wonderful co-adaptations of 
organic beings. 

" It is curious," says the Duke of Argyll, " to ob- 
serve the language which this most advanced disciple 
of pure naturalism instinctively uses, when he has to 
describe the complicated structure of this curious 
order of plants (the Orchids). f Caution in ascribing 
intentions to nature,' does not seem to occur to him as 
possible. Intention is the one thing which he does see, 
and which, when he does not see, he seeks for diligently 
until he finds it. He exhausts every form of words and 
of illustration, by which intention or mental purpose 
can be described. ' Contrivance ' c curious contriv- 
ance,' i beautiful contrivance,' these are expressions 
which occur over and over again. Here is one sen- 
tence describing the parts of a particular species : ' the 
Labellum is developed into a long nectary, in order to 
attract Lepidoptera, and we shall presently give reason 
for suspecting that the nectar is purposely so lodged, 
that it can be sucked only slowly in order to give time 
for the curious chemical quality of the viscid matter 
setting hard and dry.' ' Many other examples of 
similar expressions are quoted by the Duke, who 


maintains that no explanation of these " contrivances " 
has been or can be given, except on the supposition of 
a personal contriver, specially arranging the details of 
each case, although causing them to be produced by 
the ordinary processes of growth and reproduction. 

Now there is a difficulty in this view of the origin 
of the structure of Orchids which the Duke does not 
allude to. The majority of flowering plants are fer- 
tilized, either without the agency of insects or, when 
insects are required, without any very important modi- 
fication of the structure of the flower. It is evident, 
therefore, that flowers might have been formed as 
varied, fantastic, and beautiful as the Orchids, and yet 
have been fertilized without more complexity of struc- 
ture than is found in Violets, or Clover, or Primroses, 
or a thousand other flowers. The strange springs 
and traps and pitfalls found in the flowers of Orchids 
cannot be necessary per se, since exactly the same end 
is gained in ten thousand other flowerg which do not 
possess them. Is it not then an extraordinary idea, 
to imagine the Creator of the Universe contriving the 
various complicated parts of these flowers, as a me- 
chanic might contrive an ingenious toy or a difficult 
puzzle? Is it not a more worthy conception that they 
are some of the results of those general laws which 
were so co-ordinated at the first introduction of life 
upon the earth as to result necessarily in the utmost 
possible development of varied forms ? 

But let us take one of the simpler cases adduced 
and see if our general laws are unable to account for it. 


A Case of Orchis-structure explained by Natural 

There is a Madagascar Orchis the Angnccum ses- 
quipeclale with an immensely long and deep nectary. 
How did such an extraordinary organ come to be 
developed ? Mr. Darwin's explanation is this. The 
pollen of this flower can only be removed by the base 
of the proboscis of some very large moths, when trying 
to get at the nectar at the bottom of the vessel. The 
moths w r ith the longest probosces would do this most 
effectually ; they would be rewarded for their long 
tongues by getting the most nectar ; whilst on the other 
hand, the flowers with the deepest nectaries would be 
the best fertilized by the largest moths preferring 
them. Consequently, the deepest nectar ied Orchids 
and the longest tongued moths would each confer on the 
other an advantage in the battle of life. This would 
tend to their respective perpetuation, and to the con- 
stant lengthening of nectaries and probosces. Now 
let it be remembered, that what we have to account 
for, is only the unusual length of this organ. A nec- 
tary is found in many orders of plants and is especially 
common in the Orchids, but in this one case only is 
it more than a foot long. How did this arise ? We 
begin with the fact, proved experimentally by Mr. 
Darwin, that moths do visit Orchids, do thrust their 
spiral trunks into the nectaries, and do fertilize them 
by carrying the pollinia of one flower to the stigma of 
another. He has further explained the exact mechanism 


by which this is effected, and the Duke of Argyll ad- 
mits the accuracy of his observations. In our British 
species, such as Orchis pyramidalis, it is not necessary 
that there should be any exact adjustment between 
the length of the nectary and that of the proboscis of 
the insect ; and thus a number of insects of various 
sizes are found to carry away the pollinia and aid in 
the fertilization. In the Angracum sesquipedale, how- 
ever, it is necessary that the proboscis should be forced 
into a particular part of the flower, and this would 
only be done by a large moth burying its proboscis 
to the very base, and straining to drain the nectar 
from the bottom of the long tube, in which it occupies 
a depth of one or two inches only. Now let us start 
from the time when the nectary was only half its 
present length or about six inches, and was chiefly 
fertilized by a species of moth which appeared at the 
time of the plant's flowering, and whose proboscis was 
of the same length. Among the millions of flowers 
of the Angra3cum produced every year, some would 
always be shorter than the average, some longer. The 
former, owing to the structure of the flower, would 
not get fertilized, because the moths could get all the 
nectar without forcing their trunks down to the very 
base. The latter would be well fertilized, and the 
longest would on the average be the best fertilized of 
all. By this process alone the average length of the 
nectary would annually increase, because, the short-nec- 
taried flowers being sterile and the long ones having 
abundant offspring, exactly the same effect would be 


produced as if a gardener destroyed the short ones 
and sowed the seed of the long ones only ; and this 
we know by experience would produce a regular in- 
crease of length, since it is this very process which 
has increased the size and changed the form of our 
cultivated fruits and flowers. 

But this would lead in time to such an increased 
length of the nectary that many of the moths could 
only just reach the surface of the nectar, and only the 
few with exceptionally long trunks be able to suck up a 
considerable portion. 

This would cause many moths to neglect these flowers 
because they could not get a satisfying supply of nec- 
tar, and if these were the only moths in the country 
the flowers would undoubtedly suifer, and the further 
growth of the nectary be checked by exactly the same 
process which had led to its increase. But there are 
an immense variety of moths, of various lengths of 
proboscis, and as the nectary became longer, other and 
larger species would become the fertilizers, and would 
carry on the process till the largest moths became 
the sole agents. Now, if not before, the moth would 
also be affected, for those with the longest probosces 
would get most food, would be the strongest and most 
vigorous, would visit and fertilize the greatest number 
of flowers, and would leave the largest number of de- 
scendants. The flowers most completely fertilized by 
these moths being those which had the longest nec- 
taries, there would in each generation be on the average 
an increase in the length of the nectaries, and also 



an average increase in the length of the probosces of 
the moths ; and this would be a necessary result from 
the fact that nature ever fluctuates about a mean, or 
that in every generation there would be flowers with 
longer and shorter nectaries, and moths with longer 
and shorter probosces than the average. No doubt 
there are a hundred causes that might have checked 
this process before it had reached the point of develop- 
ment at which we find it. If, for instance, the 
variation in the quantity of nectar had been at any 
stage greater than the variation in the length of the 
nectary, then smaller moths could have reached it 
and have effected the fertilization. Or if the growth 


of the probosces of the moths had from other causes 
increased quicker than that of the nectary, or if the 
increased length of proboscis had been injurious to 
them in any way, or if the species of moth with the 
longest proboscis had become much diminished by 
some enemy or other unfavourable conditions, then, 
in any of these cases, the shorter nectaried flowers, 
which would have attracted and could have been ferti- 
lized by the smaller kinds of moths, would have had 
the advantage. And checks of a similar nature to 
these no doubt have acted in other parts of the world, 
and have prevented such an extraordinary develop- 
ment of nectary as has been produced by favourable 
conditions in Madagascar only, and in one single species 
of Orchid. I may here mention that some of the 
large Sphinx moths of the tropics have probosces 
nearly as long as the nectary of AngraBCum sesquipe- 


dale. I have carefully measured the proboscis of a 
specimen of Macrosila cluentius from South America, in 
the collection of the British Museum, and find it to 
be nine inches and a quarter long ! One from tropical 
Africa (Macrosila morganii) is seven inches and a 
half. A species having a proboscis two or three inches 
longer could reach the nectar in the largest flowers 
of Angraecum sesquipedale, whose nectaries vary in 
length from ten to fourteen inches. That such a moth 
exists in Madagascar may be safely predicted ; and 
naturalists who visit that island should search for it 
with as much confidence as Astronomers searched for 
the planet Neptune, and I venture to predict they 
will be equally successful ! 

Now, instead of this beautiful self-acting adjust- 
ment, the opposing theory is, that the Creator of the 
Universe, by a direct act of his "Will, so disposed 
the natural forces influencing the growth of this one 

C5 O 

species of plant as to cause its nectary to increase to 
this enormous length; and at the same time, by an 
equally special act, determined the flow of nourish- 
ment in the organization of the moth, so as to cause 
its proboscis to increase in exactly the same propor- 
tion, having previously so constructed the AngraBCum 
that it could only be maintained in existence by the 
agency of this moth. But what proof is given or 
suggested that this was the mode by which the ad- 
justment took place ? None whatever, except a feel- 
ing that there is an adjustment of a delicate kind, 
and an inability to see how known causes could have 

T 2 


produced such an adjustment. I believe I have 
shown, however, that such an adjustment is not only 
possible but inevitable, unless at some point or other 
we deny the action of those simple laws which we 
have already admitted to be but the expressions ot 
existing facts. 

Adaptation brought about ly General Laws. 

It is difficult to find anything like parallel cases in 
inorganic nature, but that of a river may perhaps 
illustrate the subject in some degree. Let us suppose 
a person totally ignorant of Modern Geology to study 
carefully a great Kiver System. He finds in its 
lower part, a deep broad channel filled to the brim, 
flowing slowly through a flat country and carrying 
out to the sea a quantity of fine sediment. Higher up 
it branches into a number of smaller channels, flow- 
ing alternately through flat valleys and between high 
banks ; sometimes he finds a deep rocky bed with 
perpendicular walls, carrying the water through a 
chain of hills; where the stream is narrow he finds 
it deep, where wide shallow. Further up still, he 
comes to a mountainous region, with hundreds of 
streams and rivulets, each with its tributary rills and 
gullies, collecting the water from every square mile of 
surface, and every channel adapted to the water that it 
has to carry. He finds that the bed of every branch, 
and stream, and rivulet, has a steeper and steeper slope 
as it approaches its sources, and is thus enabled to 
carry off the water from heavy rains, and to bear away 


the stones and pebbles and gravel, that would other- 
wise block up its course. In every part of this system 
he would see exact adaptation of means to an end. 
He would say, that this system of channels must have 
been designed, it answers its purpose so effectually. 
Nothing but a mind could have so exactly adapted 
the slopes of the channels, their capacity, and fre- 
quency, to the nature of the soil and the quantity of 
the rainfall. Again, he would see special adaptation 
to the wants of man, in broad quiet navigable rivers 
flowing through fertile plains that support a large 
population, while the rocky streams and mountain 
torrents, were confined to those sterile regions suit- 
able only for a small population of shepherds and 
herdsmen. He would listen with incredulity to the 
Geologist, who assured him, that the adaptation and 
adjustment he so admired was an inevitable result of 
the action of general laws. That the rains and rivers, 
aided by subterranean forces, had modelled the country, 
had formed the hills and valleys, had scooped out the 
river beds, and levelled the plains ; and it would only 
be after much patient observation and study, after 
having watched the minute changes produced year 
by year, and multiplying them by thousands and ten 
thousands, after visiting the various regions of the 
earth and seeing the changes everywhere going on, 
and the unmistakable signs of greater changes in past 
times, that he could be made to understand that 
the surface of the earth, however beautiful and har- 
monious it may appear, is strictly due in every detail 


to the action of forces which are demonstrably self- 

Moreover, when he had sufficiently extended his 
inquiries, he would find, that every evil effect which 
he would imagine must be the result of non-adjust- 
ment does somewhere or other occur, only it is not 
always evil. Looking on a fertile valley, he would 
perhaps say " If the channel of this river were not 
well adjusted, if for a few miles it sloped the wrong 
way, the water could not escape, and all this luxuri- 
ant valley, full of human beings, would become a 
waste of waters." Well, there are hundreds of such 
cases. Every lake is a valley " wasted by water," 
and in some cases (as the Dead Sea) it is a positive 
evil, a blot upon the harmony and adaptation of the 
surface of the earth. Again, he might say " If rain 
did not fall here, but the clouds passed over us to some 
other regions, this verdant and highly cultivated plain 
would become a desert." And there are such deserts 
over a large part of the earth, which abundant rains 
would convert into pleasant dwelling-places for man. 
Or he might observe some great navigable river, 
and reflect how easily rocks, or a steeper channel 
in places, might render it useless to man; and a 
little inquiry would show him hundreds of rivers in 
every part of the world, which are thus rendered 
useless for navigation. 

Exactly the same thing occurs in organic nature. 
We see some one wonderful case of adjustment, some 
unusual development of an organ, but we pass over the 


hundreds of cases in which that adjustment and develop- 
ment do not occur. No doubt when one adjustment is 
absent another takes its place, because no organism can 
continue to exist that is not adjusted to its environ- 
ment ; and unceasing variation with unlimited powers 
of multiplication, in most cases, furnish the means 
of self-adjustment. The world is so constituted, that 
by the action of general laws there is produced the 
greatest possible variety of surface and of climate ; 
and by the action of laws equally general, the greatest 
possible variety of organisms have been produced, 
adapted to the varied conditions of every part of the 
earth. The objector would probably himself admit, 
that the varied surface of the earth the plains and 
valleys, the hills and mountains, the deserts and vol- 
canoes, the winds and currents, the seas and lakes 
and rivers, and the various climates of the earth are 
all the results of general laws acting and re-acting 
during countless ages ; and that the Creator does not 
appear to guide and control the action of these laws 
here determining the height of a mountain, there 
altering the channel of a river here making the rains 
more abundant, there changing the direction of a 
current. He would probably admit that the forces of 
inorganic nature are self-adjusting, and that the result 
necessarily fluctuates about a given mean condition 
(which is itself slowly changing), while within certain 
limits the greatest possible amount of variety is pro- 
duced. If then a '''contriving mind" is not neces- 
sary at every step of the process of change eternally 


going on in the inorganic world, why are we re- 
quired to believe in the continual action of such 
a mind in the region of organic nature ? True, the 
laws at work are more complex, the adjustments more 
delicate, the appearance of special adaptation more re- 
markable; but why should we measure the creative 
mind by our own ? Why should we suppose the ma- 
chine too complicated, to have been designed by the 
Creator so complete that it would necessarily work out 
harmonious results ? The theory of a continual inter- 
ference" is a limitation of the Creator's power. It 
assumes that he could not work by pure law in the 
organic, as he has done in the inorganic world ; it 
assumes that he could not foresee the consequences 
of the laws of matter and mind combined that re- 
sults would continually arise which are contrary to 
what is best, and that he has to change what would 
otherwise be the course of nature, in order to produce 
that beauty, and variety, and harmony, which even we, 
with our limited intellects, can conceive to be the 
result of self-adjustment in a universe governed by 
unvarying law. If we could not conceive the world 
of nature to be self-adjusting and capable of endless 
development, it would even then be an unworthy idea 
of a Creator, to impute the incapacity of our minds 
to him; but when many human minds can conceive, 
and can even trace out in detail some of the adapta- 
tions in nature as the necessary results of unvarying 
law, it seems strange that, in the interests of religion, 
any one should seek to prove that the System of Na- 


ture, instead of being above, is far below our highest 
conceptions of it. I, for one, cannot believe that the 
world would come to chaos if left to Law alone. I 
cannot believe that there is in it no inherent power 
of developing beauty or variety, and that the direct 
action of the Deity is required to produce each spot 
or streak on every insect, each detail of structure in 
every one of the millions of organisms that live or 
have .lived upon the earth. For it is impossible to 
draw a line. If any modifications of structure could 
be the result of law, why not all ? If some self-adapta- 
tions could arise, why not others ? If any varieties of 
colour, why not all the varieties we see ? No attempt 
is made to explain this, except by reference to the fact 
that "purpose" and "contrivance" are everywhere 
visible, and by the illogical deduction that they could 
only have arisen from the direct action of some mind, 
because the direct action of our minds produces simi- 
lar " contrivances " ; but it is forgotten that adapta- 
tion, however produced, must have the appearance 
of design. The channel of a river looks as if made 
for the river, although it is made ly it ; the fine layers 
and beds in a deposit of sand, often look as if they had 
been sorted, and sifted, and levelled, designedly; the 
sides and angles of a crystal exactly resemble similar 
forms designed by man ; but we do not therefore con- 
clude that these effects have, in each individual case, 
required the directing action of a creative mind, or see 
any difficulty in their being produced by natural Law. 


Beauty in Nature. 

Let us, however, leave this general argument for 
a while, and turn to another special case, which has 
been appealed to as conclusive against Mr. Darwin's 
views. " Beauty " is, to some persons, as great a 
stumbling-block as " contrivance." They cannot con- 
ceive a system of the Universe, so perfect, as neces- 
sarily to develop every form of Beauty, but suppose 
that when anything specially beautiful occurs, it is a 
step beyond what that system could have produced, 
something which the Creator has added for his own 

Speaking of the Humming Birds, the Duke of Ar- 
gyll says : " In the first place, it is to be observed of 
the whole group, that there is no connection which 
can be traced or conceived, between the splendour of 
the humming birds and any function essential to their 
life. If there were any such connection, that splen- 
dour could not be confined, as it almost exclusively 
is, to only one sex. The female birds are, of course, 
not placed at any disadvantage in the struggle for 
existence by their more sombre colouring." And after 
describing the various ornaments of these birds, he 
says : " Mere ornament and variety of form, and these 
for their own sake, is the only principle or rule with 
reference to which Creative Power seems to have 
worked in these wonderful and beautiful birds. . . 
A crest of topaz is no better in the struggle for ex- 
istence than a crest of sapphire. A frill ending in 


spangles of the emerald is no better in the battle of 
life than a frill ending in spangles of the ruby. A tail 
is not affected for the purposes of flight, whether its 
marginal or its central feathers are decorated with 
white. . . Mere beauty and mere variety, for their 
own sake, are objects which we ourselves seek when 
we can make the Forces of Nature subordinate to the 
attainment of them. There seems to be no conceivable 
reason why we should doubt or question, that these 
are ends and aims also in the forms given to living 
organisms" ("Reign of Law," p. 248). 

Here the statement that "no connection can be con- 
ceived between the splendour of the humming birds 
and any function essential to their life," is met by 
the fact, that Mr. Darwin has not only conceived 
but has shown, both by observation and reasoning, 
how beauty of colour and form may have a direct 
influence on the most important of all the functions 
of life, that of reproduction. In the variations to 
which birds are subject, any more brilliant colour 
than usual would be attractive to the females, and 
would lead to the individuals so adorned leaving more 
than the average number of offspring. Experiment 
and observation have shown, that this kind of sexual 
selection does actually take place ; and the laws of 
inheritance would necessarily lead to the further de- 
velopment of any individual peculiarity that was at- 
tractive, and thus the splendour of the humming birds 
is directly connected with their very existence. It is 
true that " a crest of topaz may be no better than a 


crest of sapphire," but either of these may be much 
better than no crest at all ; and the different conditions 
under which the parent form must have existed in 
different parts of its range, will have determined dif- 
ferent variations of tint, either of which were ad- 
vantageous. The reason why female birds are not 
adorned with equally brilliant plumes is sufficiently 
clear ; they would be injurious, by rendering their pos- 
sessors too conspicuous during incubation. Survival 
of the fittest, has therefore favoured the development 
of those dark green tints on the upper surface of so 
many female humming birds, which are most conducive 
to their protection while the important functions of 
hatching and rearing the young are being carried on. 
Keeping in mind the laws of multiplication, variation, 
and survival of the fittest, which are for ever in action, 
these varied developments of beauty and harmonious 
adjustments to conditions, are not only conceivable 
but demonstrable results. 

The objection I am now combating is solely founded 
on the supposed analogy of the Creator's mind to 
ours, as regards the love of Beauty for its own sake ; 
but if this analogy is to be trusted, then there ought 
to be no natural objects which are disagreeable or 
ungraceful in our eyes. And yet it is undoubtedly 
the fact that there are many such. Just as surely 
as the Horse and Deer are beautiful and graceful, 
the Elephant, Rhinoceros, Hippopotamus, and Camel 
are the reverse. The majority of Monkeys and Apes 
are not beautiful ; the majority of Birds have no beauty 


of colour ; a vast number of Insects and Reptiles are 
positively ugly. Now, if the Creator's mind is like 
ours, whence this ugliness? It is useless to say "that 
is a mystery we cannot explain," because we have 
attempted to explain one-half of creation by a method 
that will not apply to the other half. We know that 
a man with the highest taste and with unlimited 
wealth, practically does abolish all ungraceful and dis- 
agreeable forms and colours from his own domains. 
If the beauty of creation is to be explained by the 
Creator's love of beauty, we are bound to ask why 
he has not banished deformity from the earth, as the 
wealthy and enlightened man does from his estate and 
from his dwelling ; and if we can get no satisfactory 
answer, we shall do well to reject the explanation 
offered. Ao-ain, in the case of flowers, which are 

O / ' 

always especially referred to, as the surest evidence of 
beauty being an end of itself in creation, the whole 
of the facts are never fairly met. At least half the 
plants in the world have not bright-coloured or beau- 
tiful flowers ; and Mr. Darwin has lately arrived at 
the wonderful generalization, that flowers have become 
beautiful solely to attract insects to assist in their 
fertilization. He adds, " I have come to this conclu- 
sion from finding it an invariable rule, that when a 
flower is fertilized by the wind it never has a gaily- 
coloured corolla." Here is a most wonderful case of 
beauty being useful^ when it might be least expected. 
But much more is proved ; for when beauty is of no 
use to the plant it is not given. It cannot be imag- 


ined to do any harm. It is simply not necessary, and 
is therefore withheld ! We ought surely to have been 
told how this fact is consistent with beauty being " an 
end in itself," and with the statement of its being 
given to natural objects " for its own sake." 

How new Forms are produced l>y Variation and 

Let us now consider another of the popular objec- 
tions which the Duke of Argyll thus sets forth : 

a Mr. Darwin does not pretend to have discovered 
any law or rule, according to which new Forms have 
been born from old Forms. He does not hold that 
outward conditions, however changed, are sufficient to 
account for them. . . His theory seems to be far 
better than a mere theory to be an established scien- 
tific truth in so far as it accounts, in part at least, 
for the success and establishment and spread of new 
Forms when tliey have arisen. But it does not even 
suggest the law under which, or by or according to 
which, such new Forms are introduced. Natural Se- 
lection can do nothing, except with the materials 
presented to its hands. It cannot select except among 
the things open to selection. . . Strictly speaking, 
therefore, Mr. Darwin's theory is not a theory on 
the Origin of Species at all, but only a theory on the 
causes which lead to the relative success or failure 
of such new forms as may be born into the world." 
(" Reign of Law," p. 230.) 

In this, and many other passages in his work, the 


Duke of Argyll sets forth his idea of Creation as a 
" Creation by birth," but maintains that each birth 
of a new form from parents differing from itself, has 
been produced by a special interference of the Creator, 
in order to direct the process of development into 
certain channels ; that each new species is in fact a 
"special creation," although brought into existence 
through the ordinary laws of reproduction. He main- 
tains therefore, that the laws of multiplication and 
variation cannot furnish the right kinds of materials 
at the right times for natural selection to work on. 
I believe, on the contrary, that it can be logically 
proved from the six axiomatic laws before laid down, 
that such materials would be furnished ; but I prefer 
to show there are abundance of facts which demon- 
strate that they are furnished. 

The experience of all cultivators of plants and 
breeders of animals shows, that when a sufficient 
number of individuals are examined, variations of 
any required kind can always be met with. On 
this depends the possibility of obtaining breeds, races, 
and fixed varieties of animals and plants; and it is 
found, that any one form of variation may be accu- 
mulated by selection, without materially affecting the 
other characters of the species ; each seems to vary 
in the one required direction only. For example, in 
turnips, radishes, potatoes, and carrots, the root or 
tuber varies in size, colour, form, and flavour, while 
the foliage and flowers seem to remain almost sta- 
tionary ; in the cabbage and lettuce, on the contrary, 


the foliage can bo modified into various forms and 
modes of growth, the root, flower, and fruit remain- 
ing little altered ; in the cauliflower and brocoli the 
flower heads vary ; in the garden pea the pod only 
changes. We get innumerable forms of fruit in the 
apple and pear, while the leaves and flowers remain 
undistinguishable ; the same occurs in the gooseberry 
and garden currant. Directly however, (in the very 
same genus) we want the flower to vary in the Ribes 
sanguineum, it does so, although mere cultivation 
for hundreds of years has not produced marked dif- 
ferences in the flowers of Ribes grossularia. When 
fashion demands any particular change in the form 
or size, or colour of a flower, sufficient variation 
always occurs in the right direction, as is shown by 
our roses, auriculas, and geraniums ; when, as re- 
cently, ornamental leaves come into fashion sufficient 
variation is found to meet the demand, and we have 
zoned pelargoniums, and variegated ivy, and it is 
discovered that a host of our commonest shrubs and 
herbaceous plants have taken to vary in this direction 
just when we want them to do so ! This rapid varia- 
tion is not confined to old and well-known plants 
subjected for a long series of generations to culti- 
vation, but the Sikim Rhododendrons, the Fuchsias, 
and Calceolarias from the Andes, and the Pelargoniums 
from the Cape are equally accommodating, and vary 
just when and where and how we require them. 

Turning to animals we find equally striking exam- 
ples. If we want any special quality in any animal 


we have only to breed it in sufficient quantities and 
watch carefully, and the required variety is always 
found, and can be increased to almost any desired ex- 
tent. In Sheep, we get flesh, fat, and wool ; in Cows, 
milk ; in Horses, colour, strength, size, and speed ; in 
Poultry, we have got almost any variety of colour, 
curious modifications of plumage, and the capacity of 
perpetual egg-laying. In Pigeons we have a still 
more remarkable proof of the universality of varia- 
tion, for it has been at one time or another the fancy 
of breeders to change the form of every part of 
these birds, and they have never found the required 
variations absent. The form, size, and shape of bill 
and feet, have been changed to such a degree as is 
found only in distinct genera of wild birds ; the num- 
ber of tail feathers has been increased, a character 
which is generally one of the most permanent nature, 
and is of high importance in the classification of 
birds ; and the size, the colour, and the habits, have 
been also changed to a marvellous extent. In Dogs, 
the degree of modification and the facility with which 
it is effected, is almost equally apparent. Look at 
the constant amount of variation in opposite direc- 
tions that must have been going on, to develop the 
poodle and the greyhound from the same original 
stock ! Instincts, habits, intelligence, size, speed, 
form, and colour, have always varied, so as to produce 
the very races which the wants or fancies or passions 
of men may have led them to desire. Whether they 
wanted a bull-dog to torture another animal, a grey- 



hound to catch a hare, or a bloodhound to hunt down 
their oppressed fellow-creatures, the required varia- 
tions have always appeared. 

Now this great mass of facts, of which a mere 
sketch has been here given, are fully accounted for 
by the " Law of Variation " as laid down at the 
commencement of this paper. Universal variability 
small in amount but in every direction, ever fluctuat- 
ing about a mean condition until made to advance in 
a given direction by " selection," natural or artificial, 
is the simple basis for the indefinite modification 
of the forms of life ; partial, unbalanced, and con- 
sequently unstable modifications being produced by 
man, while those developed under the unrestrained 
action of natural laws, are at every step self-adjusted 
to external conditions by the dying out of all unad- 
justed forms, and are therefore stable and compara- 
tively permanent. To be consistent in their views, our 
opponents must maintain that every one of the varia- 
tions that have rendered possible the changes produced 
by man, have been determined at the right time and 
place by the will of the Creator. Every race produced 
by the florist or the breeder, the dog or the pigeon 
fancier, the ratcatcher, the sporting man, or the slave- 
hunter, must have been provided for by varieties occur- 
ring when wanted ; and as these variations were never 
withheld, it would prove, that the sanction of an all- 
wise and all-powerful Being, has been given to that 
which the highest human minds consider to be trivial, 
mean, or debasing. 


This appears to be a complete answer to the theory, 
that variation sufficient in amount to be accumulated 
in a given direction must be the direct act of the 
Creative Mind, but it is also sufficiently condemned 
by being so entirely unnecessary. The facility with 
which man obtains new races, depends chiefly upon 
the number of individuals he can procure to select 
from. When hundreds of florists or breeders are all 
aiming at the same object, the work of change goes on 
rapidly. But a common species in nature contains a 
thousand- or a million-fold more individuals than any 
domestic race ; and survival of the fittest must unerr- 
ingly preserve all that vary in the right direction, 
not only in obvious characters but in minute details, 
not only in external but in internal organs ; so that 
if the materials are sufficient for the needs of man, 
there can be no want of them to fulfil the grand pur- 
pose of keeping up a supply of modified organisms, 
exactly adapted to the changed conditions that are 
always occurring in the inorganic world. 

The Objection that there are Limits to Variation. 

Having now, I believe, fairly answered the chief ob- 
jections of the Duke of Argyll, I proceed to notice one 
or two of those adduced in an able and argumentative 
essay on the " Origin of Species " in the North British 
Review for July, 1867. The writer first attempts to 
prove that there are strict limits to variation. When 
we begin to select variations in any one direction, the 
process is comparatively rapid, but after a considerable 

u 2 


amount of change has been effected it becomes slower 
and slower, till at length its limits are reached and no 
care in breeding and selection can produce any further 
advance. The race-horse is chosen as an example. 
It is admitted that, with any ordinary lot of horses 
to begin with, careful selection would in a few years 
make a great improvement, and in a comparatively 
short time the standard of our best racers might be 
reached. But that standard has not for many years 
been materially raised, although unlimited wealth and 
energy are expended in the attempt. This is held to 
prove that there are definite limits to variation in any 
special direction, and that we have no reason to sup- 
pose that mere time, and the selective process being 
carried on by natural law, could make any material 
difference. But the writer does not perceive that this 
argument fails to meet the real question, which is, not 
whether indefinite and unlimited change in any or all 
directions is possible, but whether such differences as 
do occur in nature could have been produced by the 
accumulation of variations by selection. In the matter 
of speed, a limit of a definite kind as regards land 
animals does exist in nature. All the swiftest animals 
deer, antelopes, hares, foxes, lions, leopards, horses, 
zebras, and many others, have reached very nearly the 
same degree of speed. Although the swiftest of each 
must have been for ages preserved, and the slowest 
must have perished, we have no reason to believe 
there is any advance of speed. The possible limit 
under existing conditions, and perhaps under possible 


terrestrial conditions, has been long ago reached. 
In cases, however, where this limit had not been so 
nearly reached as in the horse, we have been enabled 
to make a more marked advance and to produce a 
greater difference of form. The wild dog is an animal 
that hunts much in company, and trusts more to en- 
durance than to speed. Man has produced the grey- 
hound, which differs much more from the wolf or the 
dingo than the racer does from the wild Arabian. 
Domestic dogs, again, have varied more in size and 
in form than the whole family of Canidae in a state 
of nature. No wild dog, fox, or wolf, is either so 
small as some of the smallest terriers and spaniels, 
or so large as the largest varieties of hound or New- 
foundland dog. And, certainly, no two wild animals 
of the family differ so widely in form and proportions 
as the Chinese pug and the Italian greyhound, or the 
bulldog and the common greyhound. The known range 
of variation is, therefore, more than enough for the 
derivation of all the forms of Dogs, Wolves, and Foxes 
from a common ancestor. 

Again, it is objected that the Pouter or the Fan- 
tail pigeon cannot be further developed in the same 
direction. Variation seems to have reached its limits 
in these birds. But so it has in nature. The Fan- 
tail has not only more tail feathers than any of the 
three hundred and forty existing species of pigeons, 
but more than any of the eight thousand known 
species of birds. There is, of course, some limit to 
the number of feathers of which a tail useful for flight 


can consist, and in the Fan-tail we have probably 
reached that limit. Many birds have the oesophagus 
or the skin of the neck more or less dilatable, but in 
no known bird is it so dilatable as in the Pouter 
pigeon. Here again the possible limit, compatible 
with a healthy existence, has probably been reached. 
In like manner the differences in the size and form 
of the beak in the various breeds of the domestic 
Pigeon, is greater than that between the extreme 
forms of beak in the various genera and sub-families 
of the whole Pigeon tribe. From these facts, and 
many others of the same nature, we may fairly infer, 
that if rigid selection were applied to any organ, we 
could in a, comparatively short time produce a much 
greater amount of change than that which occurs be- 
tween species and species in a state of nature, since 
the differences which we do produce are often com- 
parable with those which exist between distinct genera 
or distinct families. The facts adduced by the writer 
of the article referred to, of the definite limits to va- 
riability in certain directions in domesticated animals, 
are, therefore, no objection whatever to the view, that 
all the modifications which exist in nature have been 
produced by the accumulation, by natural selection, of 
small and useful variations, since those very modifi- 
cations have equally definite and very similar limits. 

Objection to the Argument from Classification. 

To another of this writer's . objections that by Pro- 
fessor Thomson's calculations the sun can only have 


existed in a solid state 500,000,000 of years, and 
that therefore time would not suffice for the slow pro- 
cess of development of all living organisms it is 
hardly necessary to reply, as it cannot be seriously 
contended, even if this calculation has claims to ap- 
proximate accuracy, that the process of change and 
development may not have been sufficiently rapid to 
have occurred within that period. His objection to 
the Classification argument is, however, more plau- 
sible. The uncertainty of opinion among Naturalists 
as to which are species and which varieties, is one of 
Mr. Darwin's very strong arguments that these two 
names cannot belong to things quite distinct in nature 
and origin. The Reviewer says that this argument is of 
no weight, because the works of man present exactly 
the same phenomena; and he instances patent inven- 
tions, and the excessive difficulty of determining whether 
they are new or old. I accept the analogy though it 
is a very imperfect one, and maintain that such as it 
is, it is all in favour of Mr. Darwin's views. For 
are not all inventions of the same kind directly affili- 
ated to a common ancestor? Are not improved Steam 
Engines or Clocks the lineal descendants of some ex- 
isting Steam Engine or Clock ? Is there ever a new 
Creation in Art or Science any more than in Nature ? 
Did ever patentee absolutely originate any complete 
and entire invention, no portion of which was derived 
from anything that had been made or described be- 
fore ? It is therefore clear that the difficulty of dis- 
tinguishing the various classes of inventions which 


claim to be new, is of the same nature as the difficulty 
of distinguishing varieties and species, because neither 
are absolute new creations, but both are alike de- 
scendants of pre-existing forms, from which and from 
each other they differ by varying and often imper- 
ceptible degrees. It appears, then, that however plau- 
sible this writer's objections may seem, whenever he 
descends from generalities to any specific statement, 
his supposed difficulties turn out to be in reality 
strongly confirmatory of Mr. Darwin's view. 

TIte " Times," on Natural Selection. 

The extraordinary misconception of the whole sub- 
ject by popular writers and reviewers, is well shown 
by an article which appeared in the Times news- 
paper on (t The Reign of Law." Alluding to the 
supposed economy of nature, in the adaptation of 
each species to its own place and its special use, the 
reviewer remarks : "To this universal law of the 
greatest economy, the law of natural selection stands 
in direct antagonism as the law of ' greatest possible 
waste ' of time and of creative power. To conceive 
a duck with webbed feet and a spoon-shaped bill, 
living by suction, to pass naturally into a gull with 
webbed feet and a knife-like bill, living on flesh, in 
the longest possible time and in the most laborious 
possible way, we may conceive it to pass from the 
one to the other state by natural selection. The battle 
of life the ducks will have to fight will increase in 
peril continually as they cease (with the change of 


their bill) to be ducks, and attain a maximum of 
danger in the condition in which they begin to be 
gulls ; and ages must elapse and whole generations 
must perish, and countless generations of the one 
species be created and sacrificed, to arrive at one 
single pair of the other." 

In this passage the theory of natural selection is 
so absurdly misrepresented that it would be amusing, 
did we not consider the misleading effect likely to 
be produced by this kind of teaching in so popular 
a journal. It is assumed that the duck and the gull 
are essential parts of nature, each well fitted for its 
place, and that if one had been produced from the 
other by a gradual metamorphosis, the intermediate 
forms would have been useless, unmeaning, and un- 
fitted for any place, in the system of the universe. 
Now, this idea can only exist in a mind ignorant 
of the very foundation and essence of the theory of 
natural selection, which is, the preservation of useful 
variations only, or, as has been well expressed, in 
other words, the " survival of the fittest." Every 
intermediate form which could possibly have arisen 
during the transition from the duck to the gull, so 
far from having an unusually severe battle to fight 
for existence, or incurring any a maximum of danger," 
would necessarily have been as accurately adjusted 
to the rest of nature, and as well fitted to maintain 
and to enjoy its existence, as the duck or the gull 
actually are. If it were not so, it never could have 
been produced under the law of natural selection. 


Intermediate or generalized Forms of extinct Animals, 
an indication of Transmutation or Development. 

The misconception of this writer illustrates another 
point very frequently overlooked. It is an essential 
part of Mr. Darwin's theory, that one existing animal 
has not been derived from any other existing animal, 
but that both are the descendants of a common an- 
cestor, which was at once different from either, but, 
in essential characters, intermediate between them both. 
The illustration of the duck and the gull is therefore 
misleading ; one of these birds has not been derived 
from the other, but both from a common ancestor. 
This is not a mere supposition invented to support the 
theory of natural selection, but is founded on a variety 
of indisputable facts. As we go back into past time, 
and meet with the fossil remains of more and more 
ancient races of extinct animals, we find that many 
of them actually are intermediate between distinct 
groups of existing animals. Professor Owen con- 
tinually dwells on this fact : he says in his " Paleon- 
tology," p. 284 : "A more generalized vertebrate 
structure is illustrated, in the extinct reptiles, by 
the affinities to ganoid fishes, shown by Ganocephala, 
Labyrinthodontia, and Icthyopterygia ; by the affinities 
of the Pterosauria to Birds, and by the approximation 
of the Dinosauria to Mammals. (These have been re- 
cently shown by Professor Huxley to have more affinity 
to Birds.) It is manifested by the combination of 
modern crocodilian, chelcnian, and lacertian characters 


in the Cryptodontia and the Dicnyodontia, and by the 
combined lacertian and crocodilian characters in the 
Thecodontia and Sauropterygia." In the same work 
he tells us that, " the Anoplotherium, in several im- 
portant characters resembled the embryo Ruminant, 
but retained throughout life those marks of adhesion 
to a generalized mammalian type ;" and assures us 
that he has " never omitted a proper opportunity for 
impressing the results of observations showing the 
more generalized structures of extinct as compared 
with the more specialized forms of recent animals." 
Modern paleontologists have discovered hundreds of 
examples of these more generalized or ancestral types. 
In the time of Cuvier, the Ruminants and the Pachy- 
derms were looked upon as two of the most distinct 
orders of animals ; but it is now demonstrated that 
there once existed a variety of genera and species, 
connecting by almost imperceptible grades such widely 
different animals as the pig and the camel. Among 
living quadrupeds we can scarcely find a more isolated 
group than the genus Equus, comprising the horses, 
asses, and Zebras ; but through many species of Palo- 
plotherium, Hippotherium, and Hipparion, and numbers 
of extinct forms of Equus found in Europe, India, and 
America, an almost complete transition is established 
with the Eocene Anoplotherium and Paleotherium, 
which are also generalized or ancestral types of the 
Tapir and Rhinoceros. The recent researches of M. 
Gaudry in Greece have furnished much new evidence 
of the same character. In the Miocene beds of Pikermi 


he has discovered the group of the Simocyonidse inter- 
mediate between bears and wolves ; the genus Hyasnictis 
which connects the hyaenas with the civets ; the Ancylo- 
therium, which is allied both to the extinct mastodon 
and to the living pangolin or scaly ant-eater ; and 
the Helladotherium, which connects the now isolated 
giraffe with the deer and antelopes. 

Between reptiles and fishes an intermediate type has 
been found in the Archegosaurus of the Coal forma- 
tion; while the Labyrinthodon of the Trias combined 
characters of the Batrachia with those of crocodiles, 
lizards, and ganoid fishes. Even birds, the most appa- 
rently isolated of all living forms, and the most rarely 
preserved in a fossil state, have been shown to possess 
undoubted affinities with reptiles ; and in the Oolitic 
Archseopteryx, with its lengthened tail, feathered on 
each side, we have one of the connecting links from 
the side of birds ; while Professor Huxley has recently 
shown that the entire order of Dinosaurians have re- 
markable affinities to birds, and that one of them, the 
Compsognathus, makes a nearer approach to bird orga- 
nisation than does Archseopteryx to that of reptiles. 

Analogous facts to these occur in other classes of 
animals, as an example of which we have the authority 
of a distinguished paleontologist, M. Barande, quoted 
by Mr. Darwin, for the statement, that although the 
Paleozoic Invertebrata can certainly be classed under 
existing groups, yet at this ancient period the groups 
were not so distinctly separated from each other as 
they are now ; while Mr. Scudder tells us, that some of 


the fossil insects discovered in the Coal formation of 
America offer characters intermediate between those of 
existing orders. Agassiz, again, insists strongly that the 
more ancient animals resemble the embryonic forms of 
existing species ; but as the embryos of distinct groups 
are known to resemble each other more than the adult 
animals (and in fact to be undistinguishable at a very 
early age), this is the same as saying that the ancient 
animals are exactly what, on Darwin's theory, the 
ancestors of existing animals ought to be ; and this, 
it must be remembered, is the evidence of one of the 
strongest opponents of the theory of natural selection. 


I have thus endeavoured to meet fairly, and to an- 
swer plainly, a few of the most common objections to 
the theory of natural selection, and I have done so in 
every case by referring to admitted facts and to logical 
deductions from those facts. 

As an indication and general summary of the line 
of argument I have adopted, I here give a brief de- 
monstration in a tabular form of the Origin of Species 
by means of Natural Selection, referring for the facts 
to Mr. Darwin's works, and to the pages in this volume, 
where they are more or less fully treated. 



A Demonstration of the Origin of Species by Natural 


ISMS, pp. 29, 265 ; (" Origin 
of Species," p. 75, 5th Ed.) 



or general likeness with 
individual differences of pa- 
rents and offspring, pp. 
266,287-291,308; ("Origin 
of Species," chap. I., II., V.) 


DITIONS, universal and un- 
ceasing. See " Ly ell's 
Principles of Geology." 

(afterwards taken as Proved Facts). 

the deaths equalling the 
births on the average, p. 30 ; 
(" Origin of Species," chap. 

or Natural Selection; mean- 
ing simply, that on the 
whole those die who are 
least fitted to maintain their 
existence ; (" Origin of Spe- 
cies," chap. IV.) 

to keep them in harmony 
with the Changed Condi- 
tions ; and as the changes 
of conditions are perma- 
nent changes, in the sense 
of not reverting back to 
identical previous condi- 
tions, the changes of or- 
ganic forms must be in the 
same sense permanent, and 
thus originate SPECIES. 




AMONG the most advanced students of man, there exists 
a wide difference of opinion on some of the most vital 
questions respecting his nature and origin. Anthro- 
pologists are now, indeed, pretty well agreed that man 
is not a recent introduction into the earth. All who 
have studied the question, now admit that his anti- 
quity is very great ; and that, though we have to some 
extent ascertained the minimum of time during which 
he must have existed, we have made no approximation 
towards determining that far greater period during 
which he may have, and probably has existed. We 
can with tolerable certainty affirm that man must have 
inhabited the earth a thousand centuries ago, but we 
cannot assert that he positively did not exist, or that 
there is any good evidence against his having existed, 
for a period of ten thousand centuries. We know 
positively, that he was contemporaneous with many 
now extinct animals, and has survived changes of the 
earth's surface fifty or a hundred times greater than 
any that have occurred during the historical period ; 
but we cannot place any definite limit to the number 


of species he may have outlived, or to the amount of 
terrestrial change he may have witnessed. 

Wide differences of opinion as to Mail's Origin. 

But while on this question of man's antiquity there 
is a very general agreement, and all are waiting 
eagerly for fresh evidence to clear up those points 
which all admit to be full of doubt, on other, and 
not less obscure and difficult questions, a considerable 
amount of dogmatism is exhibited ; doctrines are put 
forward as established truths, no doubt or hesitation 
is admitted, and it seems to be supposed that no 
further evidence is required, or that any new facts 
can modify our convictions. This is especially the case 
when we inquire, Are the various forms under which 
man now exists primitive, or derived from pre-exist- 
ing forms ; in other words, is man of one or many 
species ? To this question we immediately obtain dis- 
tinct answers diametrically opposed to each other : the 
one party positively maintaining, that man is a species 
and is essentially one that all differences are but local 
and temporary variations, produced by the different 
physical and moral conditions by which he is sur- 
rounded ; the other party maintaining with equal con- 
fidence, that man is a genus of many species, each of 
which is practically unchangeable, and has ever been 
as distinct, or even more distinct, than we now be- 
hold them. This difference of opinion is somewhat 
remarkable, when we consider that both parties are 
well acquainted with the subject ; both use the same 


vast accumulation of facts ; both reject those early 
traditions of mankind which profess to give an ac- 
count of his origin ; and both declare that they aro 
seeking fearlessly after truth alone ; yet each will 
persist in looking only at the portion of truth on 
his own side of the question, and at the error which 
is mingled with his opponent's doctrine. It is my 
wish to show how the two opposing views can be 
combined, so as to eliminate the error and retain the 
truth in each, and it is by means of Mr. Darwin's 
celebrated theory of " Natural Selection " that I hope 
to do this, and thus to harmonise the conflicting 

' O 

theories of modern anthropologists. 

Let us first see what each party has to say for 
itself. In favour of the unity of mankind it is argued, 
that there are no races without transitions to others ; 
that every race exhibits within itself variations of 
colour, of hair, of feature, and of form, to such a de- 
gree as to bridge over, to a large extent, the gap that 
separates it from other races. It is asserted that no 
race is homogeneous ; that there is a tendency to vary ; 
that climate, food, and habits produce, and render 
permanent, physical peculiarities, which, though slight 
in the limited periods allowed to our observation, would, 
in the long ages during which the human race has ex- 
isted, have sufficed to produce all the differences that 
now appear. It is further asserted that the advocates 
of the opposite theory do not agree among themselves ; 
that some would make three, some five, some fifty or 
a hundred and fifty species of man ; some would have 



had each species created in pairs, while others require 
nations to have at once sprung into existence, and 
that there is no stability or consistency in any doctrine 
but that of one primitive stock. 

The advocates of the original diversity of man, on 
the other hand, have much to say for themselves. 
They argue that proofs of change in man have never 
been brought forward except to the most trifling 
amount, while evidence of his permanence meets us 
everywhere. The Portuguese and Spaniards, settled 
for two or three centuries in South America, retain 
their chief physical, mental, and moral characteristics ; 
the Dutch boers at the Cape, and the descendants of 
the early Dutch settlers in the Moluccas, have not lost 
the features or the colour of the Germanic races ; the 
Jews, scattered over the world in the most diverse 
climates, retain the same characteristic lineaments 
everywhere ; the Egyptian sculptures and paintings 
show us that, for at least 4000 or 5000 years, the 
strongly contrasted features of the Negro and the 
Semitic races have remained altogether unchanged ; 
while more recent discoveries prove, that the mound- 
builders of the Mississippi valley, and the dwellers 
on Brazilian mountains, had, even in the very in- 
fancy of the human race, some traces of the same 
peculiar and characteristic type of cranial formation 
that now distinguishes them. 

If we endeavour to decide impartially on the merits 
of this difficult controversy, judging solely by the evi- 
dence that each party has brought forward, it certainly 


seems that the best of the argument is on the side of 
those who maintain the primitive diversity of man. 
Their opponents have not been able to refute the per- 
manence of existing races as far back as we can trace 
them, and have failed to show, in a single case, that 
at any former epoch the well marked varieties of man- 
kind approximated more closely than they do at the 
present day. At the same time this is but negative 
evidence. A condition of immobility for four or five 
thousand years, does not preclude an advance at an 
earlier epoch, and if we can show that there are 
causes in nature which would check any further phy- 
sical change when certain conditions were fulfilled 
does not even render such an advance improbable, if 
there are any general arguments to be adduced in its 
favour. Such a cause, I believe, does exist ; and I 
shall now endeavour to point out its nature and its 
mode of operation. 

Outline of the Theory of Natural Selection. 

In order to make my argument intelligible, it is 
necessary for me to explain very briefly the theory of 
" Natural Selection " promulgated by Mr. Darwin, 
and the power which it possesses of modifying the 
forms of animals and plants. The grand feature in 
the multiplication of organic life is, that close general 
resemblance is combined with more or less individual 
variation. The child resembles its parents or ancestors 
more or less closely in all its peculiarities, deformities, 
or beauties ; it resembles them in general more than it 

x 2 


does any other individuals ; yet children of the same 
parents are not all alike, and it often happens that 
they differ very considerably from their parents and 
from each ether. This is equally true, of man, of all 
animals, and of all plants. Moreover, it is found that 
individuals do not differ from their parents in certain 
particulars only, while in all others they are exact 
duplicates of them. They differ from them and from 
each other, in every particular: in form, in size, in 
colour ; in the structure of internal as well as of external 
organs ; in those subtle peculiarities which produce 
differences of constitution, as well as in those still more 
subtle ones which lead to modifications of mind and 
character. In other words, in every possible way, in 
every organ and in every function, individuals of the 
same stock vary. 

Now, health, strength, and long life, are the results 
of a harmony between the individual and the universe 
that surrounds it. Let us suppose that at any given 
moment this harmony is perfect. A certain animal is 
exactly fitted to secure its prey, to escape from its 
enemies, to resist the inclemencies of the seasons, and 
to rear a numerous and healthy offspring. But a 
change now takes place. A series of cold winters, for 
instance, come on, making food scarce, and bringing 
an immigration of some other animals to compete with 
the former inhabitants of the district. The new immi- 
grant is swift of foot, and surpasses its rivals in the 
pursuit of game; the winter nights are colder, and 
require a thicker fur as a protection, and more 


nourishing food to keep up the heat of the system. 
Our supposed perfect animal is no longer in harmony 
with its universe ; it is in danger of dying of cold or 
of starvation. But the animal varies in its offspring. 
Some of these are swifter than others they still 
manage to catch food enough; some are hardier and 
more thickly furred they manage in the cold nights to 
keep warm enough ; the slow, the weak, and the thinly 
clad soon die off. Again and again, in each succeed- 
ing generation, the same thing takes place. By this 
natural process, which is so inevitable that it cannot 
be conceived not to act, those best adapted to live, live ; 
those least adapted, die. It is sometimes said that we 
have no direct evidence of the action of this selecting 
power in nature. But it seems to me we have better 
evidence than even direct observation would be, because 
it is more universal, viz., the evidence of necessity. 
It must be so ; for, as all wild animals increase in a 
geometrical ratio, while their actual numbers remain 
on the average stationary, it follows, that as many die 
annually as are born. If, therefore, we deny natural 
selection, it can only be by asserting that, in such a 
case as I have supposed, the strong, the healthy, the 
swift, the well clad, the well organised animals in 
every respect, have no advantage over, do not on the 
average live longer than, the weak, the unhealthy, the 
slow, the ill-clad, and the imperfectly organised indi- 
viduals ; and this no sane man has yet been found 
hardy enough to assert. But this is not all ; for the 
offspring on the average resemble their parents, and 


the selected portion of each succeeding generation will 
therefore be stronger, swifter, and more thickly furred 
than the last ; and if this process goes on for thousands 
of generations, our animal will have again become 
thoroughly in harmony with the new conditions in 
which it is placed. But it will now be a different 
creature. It will be not only swifter and stronger, 
and more furry, it will also probably have changed in 
colour, in form, perhaps have acquired a longer tail, 
or differently shaped ears ; for it is an ascertained 
fact, that when one part of an animal is modified, 
some other parts almost always change, as it were in 
sympathy with it. Mr. Darwin calls this " correlation 
of growth," and gives as instances, that hairless dogs 
have imperfect teeth ; white cats, w r hen blue-eyed, are 
deaf; small feet accompany short beaks in pigeons ; 
and other equally interesting cases. 

Grant, therefore, the premises : 1st. That peculiari- 
ties of every kind are more or less hereditary. 2nd. 
That the offspring of every animal vary more or less 
in all parts of their organization. 3rd. That the 
universe in which these animals live, is not absolutely 
invariable ; none of which propositions can be denied ; 
and then consider, that the animals in any country 
(those at least which are not dying out) must at each 
successive period be brought into harmony with the 
surrounding conditions ; and we have all the elements 
for a change of form and structure in the animals, 
keeping exact pace with changes of whatever nature 
in the surrounding universe. Such changes must be 


slow, for the changes in the universe are very slow ; 
but just as these slow changes become important, when 
we look at results after long periods of action, as we 
do when we perceive the alterations of the earth's sur- 
face during geological epochs; so the parallel changes 
in animal form become more and more striking, in. 
proportion as the time they have been going on is 
great ; as we see when we compare our living animals 
with those which we disentomb from each successively 
older geological formation. 

This is, briefly, the theory of " natural selection," 
which explains the changes in the organic world as 
being parallel with, and in part dependent on, those in 
the inorganic. What we now have to inquire is, 
Can this theory be applied in any way to the question 
of the origin of the races of man ? or is there anything 
in human nature that takes him out of the category 
of those organic existences, over whose successive 
mutations it has had such powerful sway ? 

Different effects of Natural Selection on Animals and 
on Man. 

In order to answer these questions, we must consider 
why it is that a natural selection " acts so powerfully 
upon animals ; and we shall, I believe, find, that its 
effect depends mainly upon their self-dependence and 
individual isolation. A slight injury, a temporary 
illness, will often end in death, because it leaves the 
individual powerless against its enemies. If an herbi- 
vorous animal is a little sick and has not fed well for a 


day or two, and the herd is then pursued by a beast of 
prey, our poor invalid inevitably falls a victim. So, in 
a carnivorous animal, the least deficiency of vigour pre- 
vents its capturing food, and it soon dies of starvation. 
There is, as a general rule, no mutual assistance 
between adults, which enables them to tide over a 
period of sickness. Neither is there any division of 
labour; each must fulfil all the conditions of its 
existence, and, therefore, " natural selection " keeps 
all up to a pretty uniform standard. 

But in man, as we now behold him, this is different. 
He is social and sympathetic. In the rudest tribes 
the sick are assisted, at least with food ; less robust 
health and vigour than the average does not entail 
death. Neither does the want of perfect limbs, or 
other organs, produce the same effects as among ani- 
mals. Some division of labour takes place ; the swiftest 
hunt, the less active fish, or gather fruits ; food is, to 
some extent, exchanged or divided. The action of 
natural selection is therefore checked ; the weaker, the 
dwarfish, those of less active limbs, or less piercing 
eyesight, do not suffer the extreme penalty which falls 
upon animals so defective. 

In proportion as these physical characteristics be- 
come of less importance, mental and moral qualities 
will have increasing influence on the well-being of 
the race. Capacity for acting in concert for pro- 
tection, and for the acquisition of food and shelter ; 
sympathy, which leads all in turn to assist each other ; 
the sense of right, which checks depredations upon our 


fellows ; the smaller development of the combative and 
destructive propensities ; self-restraint in present appe- 
tites ; and that intelligent foresight which prepares for 
the future, are all qualities, that from their earliest 
appearance must have been for the benefit of each 
community, and would, therefore, have become the 
subjects of " natural selection." For it is evident 
that such qualities would be for the well-being of 
man ; would guard him against external enemies, 
against internal dissensions, and against the effects of 
inclement seasons and impending famine, more surely 
than could any merely physical modification. Tribes 
in which such mental and moral qualities were pre- 
dominant, would therefore have an advantage in the 
struggle for existence over other tribes in which they 
were less developed, would live and maintain their 
numbers, while the others would decrease and finally 

Again, when any slow changes of physical geogra- 
phy, or of climate, make it necessary for an animal 
to alter its food, its clothing, or its weapons, it can 
only do so by the occurrence of a corresponding 
change in its own bodily structure and internal or- 
ganization. If a larger or more powerful beast is to 
be captured and devoured, as when a carnivorous ani- 
mal which has hitherto preyed on antelopes is obliged 
from their decreasing numbers to attack buffaloes, it 
is only the strongest who can hold, those with most 
powerful claws, and formidable canine teeth, that can 
struggle with and overcome such an animal. Natural 


selection immediately comes into play, and by its 
action these organs gradually become adapted to their 
new requirements. But man, under similar circum- 
stances, does not require longer nails or teeth, greater 
bodily strength or swiftness. He makes sharper spears, 
or a better bow, or he constructs a cunning pitfall, 
or combines in a hunting party to circumvent his 
new prey. The capacities which enable him to do this 
are what he requires to be strengthened, and these 
will, therefore, be gradually modified by " natural se- 
lection," while the form and structure of his body will 
remain unchanged. So, when a glacial epoch comes 
on, some animals must acquire warmer fur, or a cover- 
ing of fat, or else die of cold. Those best clothed by 
nature are, therefore, preserved by natural selection. 
Man, under the same circumstances, will make him- 
self warmer clothing, and build better houses ; and 
the necessity of doing this will react upon his mental 
organization and social condition will advance them 
while his natural body remains naked as before. 

When the accustomed food of some animal becomes 
scarce or totally fails, it can only exist by becoming 
adapted to a new kind of food, a food perhaps less 
nourishing and less digestible. " Natural selection " 
will now act upon the stomach and intestines, and all 
their individual variations will be taken advantage of, 
to modify the race into harmony with its new food. 
In many cases, however, it is probable that this can- 
not be done. The internal organs may not vary quick 
enough, and then the animal will decrease in numbers, 


and finally become extinct. But man guards himself 
from such accidents by superintending and guiding 
the operations of nature. He plants the seed of his 
most agreeable food, and thus procures a supply, in- 
dependent of the accidents of varying seasons or na- 
tural extinction. He domesticates animals, which serve 
him either to capture food or for food itself, and thus, 
changes of any great extent in his teeth or digestive 
organs are rendered unnecessary. Man, too, has every- 
where the use of fire, and by its means can render 
palatable a variety of animal and vegetable substances, 
which he could hardly otherwise make use of; and thus 
obtains for himself a supply of food far more varied and 
abundant than that which any animal can command. 

Thus man, by the mere capacity of clothing him- 
self, and making weapons and tools, has taken away 
from nature that power of slowly but permanently 
changing the external form and structure, in accord- 
ance with changes in the external world, which she 
exercises over all other animals. As the competing 
races by which they are surrounded, the climate, the 
vegetation, or the animals which serve them for food, 
are slowly changing, they must undergo a corre- 
sponding change in their structure, habits, and con- 
stitution, to keep them in harmony with the new 
conditions to enable them to live and maintain their 
numbers. But man does this by means of his intellect 
alone, the variations of which enable him, with an 
unchanged body, still to keep in harmony with the 
changing universe. 


There is one point, however, in which nature will 
still act upon him as it does on animals, and, to some 
extent, modify his external characters. Mr. Darwin 
has shown, that the colour of the skin is correlated 
with constitutional peculiarities both in vegetables and 
animals, so that liability to certain diseases or freedom 
from them is often accompanied by marked external 
characters. Now, there is every reason to believe 
that this has acted, and, to some extent, may still 
continue to act, on man. In localities where certain 
diseases are prevalent, those individuals of savage races 
which were subject to them would rapidly die off; 
while those who were constitutionally free from the 
disease would survive, and form the progenitors of a 
new race. These favoured individuals would probably 
be distinguished by peculiarities of colour, with which 
again peculiarities in the texture or the abundance 
of hair seem to be correlated, and thus may have 
been brought about those racial differences of colour, 
which seem to have no relation to mere temperature 
or other obvious peculiarities of climate. 

From the time, therefore, when the social and sym- 
pathetic feelings came into active operation, and the 
intellectual and moral faculties became fairly deve- 
loped, man would cease to be influenced by " natural 
selection " in his physical form and structure. As an 
animal he would remain almost stationary, the changes 
of the surrounding universe ceasing to produce in him 
that powerful modifying effect which they exercise 
over other parts of the organic world. But from the 


moment that the form of his body became stationary, 
his mind would become subject to those very influ- 
ences from which his body had escaped ; every slight 
variation in his mental and moral nature which should 
enable him better to guard against adverse circum- 
stances, and combine for mutual comfort and protection, 
would be preserved and accumulated ; the better and 
higher specimens of our race would therefore increase 
and spread, the lower and more brutal would give way 
and successively die out, and that rapid advancement 
of mental organization would occur, which has raised 
the very lowest races of man so far above the brutes 
(although differing so little from some of them in 
physical structure), and, in conjunction with scarcely 
perceptible modifications of form, has developed the 
wonderful intellect of the European races. 

Influence of external Nature in the development of the 
Human Mind. 

But from the time when this mental and moral 
advance commenced, and man's physical character 
became fixed and almost immutable, a new series of 
causes would come into action, and take part in his 
mental growth. The diverse aspects of nature would 
now make themselves felt, and profoundly influence the 
character of the primitive man. 

When the power that had hitherto modified the body 
had its action transferred to the mind, then races would 
advance and become improved, merely by the harsh dis- 
cipline of a sterile soil a'nd inclement seasons. Under 


their influence, a hardier, a more provident, and a 
more social race would be developed, than in those 
regions where the earth produces a perennial supply 
of vegetable food, and where neither foresight nor 
ingenuity are* required to prepare for the rigours of 
winter. And is it not the fact that in all ages, and 
in every quarter of the globe, the inhabitants of tem- 
perate have been superior to those of hotter countries ? 
All the great invasions and displacements of races have 
been from North to South, rather than the reverse ; 
and we have no record of there ever having existed, 
any more than there exists to-day, a solitary instance 
of an indigenous inter - tropical civilization. The 
Mexican civilization and government came from the 
North, and, as well as the Peruvian, was established, 
not in the rich tropical plains, but on the lofty and 
sterile plateaux of the Andes. The religion and civi- 
lization of Ceylon were introduced from North India ; 
the successive conquerors of the Indian peninsula came 
from the North-west ; the northern Mongols conquered 
the more Southern Chinese ; and it was the bold and 
adventurous tribes of the North that overran and in- 
fused new life into Southern Europe. 

Extinction of Loiuer Races. 

It is the same great law of " the preservation of 
favoured races in the struggle for life," which leads 
to the inevitable extinction of all those low and 
mentally undeveloped populations with which Euro- 
peans come in contact. The red Indian in North 


America, and in Brazil; the Tasmanian, Australian, 
and New Zealander in the southern hemisphere, die 
out, not from any one special cause, but from the 
inevitable effects of an unequal mental and physical 
struggle. The intellectual and moral, as well as the 
physical, qualities of the European are superior; the 
same powers and capacities which have made him 
rise in a few centuries from the condition of the 
wandering savage with a scanty and stationary popu- 
lation, to his present state of culture and advancement, 
with a greater average longevity, a greater average 
strength, and a capacity of more rapid increase, 
enable him when in contact with the savage man, to 
conquer in the struggle for existence, and to increase at 
his expense, just as the better adapted, increase at the 
expense of the less adapted varieties in the animal and 
vegetable kingdoms, just as the weeds of Europe 
overrun North America and Australia, extinguishing 
native productions by the inherent vigour of their 
organization, and by their greater capacity for existence 
and multiplication. 

The Origin of the Races of Man. 

If these views are correct ; if in proportion as 
man's social, moral, and intellectual faculties became 
developed, his physical structure would cease to be 
affected by the operation of " natural selection," we 
have a most important clue to the origin of races. 
For it will follow, that those great modifications of 
structure and of external form, which resulted in the 


development of man out of some lower type of animal, 
must have occurred before his intellect had raised him 
above the condition of the brutes, at a period when he 
was gregarious, but scarcely social, with a mind per- 
ceptive but not reflective, ere any sense of right or 
feelings of sympathy had been developed in him. He 
would be still subject, like the rest of the organic 
world, to the action of 6t natural selection," which 
would retain his physical form and constitution in har- 
mony with the surrounding universe. He was pro- 
bably at a very early period a dominant race, spreading 
widely over the warmer regions of the earth as it then 
existed, and in agreement with what we see in the 
case of other dominant species, gradually becoming 
modified in accordance with local conditions. As he 
ranged farther from his original home, and became 
exposed to greater extremes of climate, to greater 
changes of food, and had to contend with new enemies, 
organic and inorganic, slight useful variations in his 
constitution would be selected and rendered permanent, 
and would, on the principle of a correlation of growth," 
be accompanied by corresponding external physical 
changes. Thus might have arisen those striking char- 
acteristics and special modifications which still distin- 
guish the chief races of mankind. The red, black, 
yellow, or blushing white skin ; the straight, the curly, 
the woolly hair ; the scanty or abundant beard ; the 
straight or oblique eyes; the various forms of the 
pelvis, the cranium, and other parts of the skeleton. 
But while these changes had been going on, his 


mental development had, from some unknown cause, 
greatly advanced, and had now reached that condition 
in which it began powerfully to influence his whole 
existence, and would therefore become subject to the 
irresistible action of " natural selection." This action 
would quickly give the ascendency to mind : speech 
would probably now be first developed, leading to a 
still further advance of the mental faculties ; and from 
that moment man, as regards the form and structure of 
most parts of his body, would remain almost station- 
ary. The art of making weapons, division of labour, 
anticipation of the future, restraint of the appetites, 
moral, social, and sympathetic feelings, would now 
have a preponderating influence on his well being, 
and would therefore be that part of his nature on 
which " natural selection " would most powerfully act; 
and we should thus have explained that wonderful per- 
sistence of mere physical characteristics, which is the 
stumbling-block of those who advocate the unity of 

We are now, therefore, enabled to harmonise the 
conflicting views of anthropologists on this subject. 
Man may have been, indeed I believe must have been, 
once a homogeneous race ; but it was at a period of 
which we have as yet discovered 110 remains, at a period 
so remote in his history, that he had not yet acquired 
that wonderfully developed brain, the organ of the 
mind, which now, even in his lowest examples, raises 
him far above the highest brutes ; at a period when 
he had the form but hardly the nature of man, when 



he neither possessed human speech, nor those sympa- 
thetic and moral feelings which in a greater or less 
degree everywhere now distinguish the race. Just in 
proportion as these truly human faculties became deve- 
loped in him, would his physical features become fixed 
and permanent, because the latter would be of less im- 
portance to his well being ; he would be kept in har- 
mony with the slowly changing universe around him, 
by an advance in mind, rather than by a change in 
body. If, therefore, we are of opinion that he was not 
really man till these higher faculties were fully deve- 
loped, we may fairly assert that there were many ori- 
ginally distinct races of men ; while, if we think that 
a being closely resembling us in form and structure, 
but with mental faculties scarcely raised above the 
brute, must still be considered to have been human, 
we are fully entitled to maintain the common origin of 
all mankind. 

The Bearing of these Views on the Antiquity of 

These considerations, it will be seen, enable us to 
place the origin of man at a much more remote geo- 
logical epoch than has yet been thought possible. He 
may even have lived in the Miocene or Eocene period, 
when not a single mammal was identical in form with 
any existing species. For, in the long series of ages 
during which these primeval animals were being slowly 
changed into the species which now inhabit the earth, 
the power which acted to modify them would only 


affect the mental organization of man. His brain 
alone would have increased in size and complexity, and 
his cranium have undergone corresponding changes of 
form, while the whole structure of lower animals was 
being changed. This will enable us to understand how 
the fossil crania of Denise and Engis agree so closely 
with existing forms, although they undoubtedly existed 
in company with large mammalia now extinct. The 
Neanderthal skull may be a specimen of one of the 
lowest races then existing, just as the Australians are 
the lowest of our modern epoch. We have no reason 
to suppose that mind and brain and skull modification, 
could go on quicker than that of the other parts of the 
organization ; and we must therefore look back very far 
in the past, to find man in that early condition in which 
his mind was not sufficiently developed, to remove his 
body from the modifying influence of external condi- 
tions and the cumulative action of " natural selection." 
I believe, therefore, that there is no a priori reason 
against our finding the remains of man or his works 
in the tertiary deposits. The absence of all such 
remains in the European beds of this age has little 
weight, because, as we go further back in time, it is 
natural to suppose that man's distribution over the 
surface of the earth was less universal than at present. 
Besides, Europe was in a great measure submerged 
during the tertiary epoch ; and though its scattered 
islands may have been uninhabited by man, it by no 
means follows that he did not at the same time exist in 
warm or tropical continents. If geologists can point 

Y 2 


out to us the most extensive land in the warmer regions 
of the earth, which has not been submerged since 
Eocene or Miocene times, it is there that we may ex- 
pect to find some traces of the very early progenitors of 
man. It is there that we may trace back the gradually 
decreasing brain of former races, till we come to a time 
when the body also begins materially to differ. Then 
we shall have reached the starting point of the human 
family. Before that period, he had not mind enough 
to preserve his body from change, and would, there- 
fore, have been subject to the same comparatively rapid 
modifications of form as the other mammalia. 

Their Bearing on the Dignity and Supremacy of Man. 

If the views I have here endeavoured to sustain 
have any foundation, they give us a new argument for 
placing man apart, as not only the head and culmi- 
nating point of the grand series of organic nature, but 
as in some degree a new and distinct order of being. 
From those infinitely remote ages, when the first rudi- 
ments of organic life appeared upon the earth, every 
plant, and every animal has been subject to one great 
law of physical change. As the earth has gone through 
its grand cycles of geological, climatal, and organic 
progress, every form of life has been subject to its 
irresistible action, and has been continually, but imper- 
ceptibly moulded into such new shapes as would pre- 
serve their harmony with the ever-changing universe. 
No living thing could escape this law of its being ; 
none (except, perhaps, the simplest and most rudi- 


mentary organisms), could remain unchanged and live, 
amid the universal change around it. 

At length, however, there came into existence a 
being in whom that subtle force we term mind, be- 
came of greater importance than his mere bodily struc- 
ture. Though with a naked and unprotected body, 
this gave him clothing against the varying inclemen- 
cies of the seasons. Though unable to compete with 
the deer in swiftness, or with the wild bull in strength, 
this gave him weapons with which to capture or over- 
come both. Though less capable than most other ani- 
mals of living on the herbs and the fruits that unaided 
nature supplies, this wonderful faculty taught him to 
govern and direct nature to his own benefit, and make 
her produce food for him, when and where he pleased. 
From the moment when the first skin was used as 
a covering, when the first rude spear was formed to 
assist in the chase, when fire was first used to cook his 
food, when the first seed was sown or shoot planted, 
a grand revolution was effected in nature, a revolu- 
tion which in all the previous ages of the earth's his- 
tory had had no parallel, for a being had arisen who 
was no longer necessarily subject to change with the 
changing universe a being who was in some degree 
superior to nature, inasmuch as he knew how to con- 
trol and regulate her action, and could keep himself 
in harmony with her, not by a change in body, but 
by an advance of mind. 

Here, then, we see the true grandeur and dignity 
of man. On this view of his special attributes, we 


may admit, that even those who claim for him a 
position as an order, a class, or a sub-kingdom by 
himself, have some show of reason on their side. He 
is, indeed, a being apart, since he is not influenced 
by the great laws which irresistibly modify all other 
organic beings, $"ay more ; this victory which he has 
gained for himself, gives him a directing influence 
over other existences. Man has not only escaped 
" natural selection " himself, but he is actually able 
to take away some of that power from nature which 
before his appearance she universally exercised. We 
can anticipate the time when the earth will produce 
only cultivated plants and domestic animals ; when 
man's selection shall have supplanted "natural selec- 
tion ;" and when the ocean will be the only domain 
in which that power can be exerted, which for count- 
less cycles of ages ruled supreme over all the earth. 

Their Bearing on the future Development of Man. 

We now find ourselves enabled to answer those who 
maintain, that if Mr. Darwin's theory of the Origin of 
Species is true, man too must change in form, and be- 
come developed into some other animal as different from 
his present self as he is from the Gorilla or the Chim- 
panzee ; and who speculate on what this form is likely 
to be. But it is evident that such will not be the case ; 
for no change of conditions is conceivable, which will 
render any important alteration of his form and organi- 
zation so universally useful and necessary to him, as 
to give those possessing it always the best chance of 


surviving, and thus lead to the development of a new 
species, genus, or higher group of man. On the other 
hand, we know that far greater changes of conditions 
and of his entire environment have been undergone by 
man, than any other highly organized animal could 
survive unchanged, and have been]'met by mental, not 
corporeal adaptation. The difference of habits, of food, 
clothing, weapons, and enemies, between savage and 
civilized man, is enormous. Difference in bodily form 
and structure there is practically none, except a slightly 
increased size of brain, corresponding to his higher 
mental development. 

We have every reason to believe, then, that man 
may have existed and may continue to exist, through 
a series of geological periods which shall see all other 
forms of animal life again and again changed ; while he 
himself remains unchanged, except in the two parti- 
culars already specified the head and face, as imme- 
diately connected with the organ of the mind and as 
being the medium of expressing the most refined emo- 
tions of his nature, and to a slight extent in colour, 
hair, and proportions, so far as they are correlated with 
constitutional resistance to disease. 


Briefly to recapitulate the argument ; in two dis- 
tinct ways has man escaped the influence of those 
laws which have produced unceasing change in the 
animal world. 1. By his superior intellect he is ena- 
bled to provide himself with clothing and weapons, and 


by cultivating the soil to obtain a constant supply of 
congenial food. This renders it unnecessary for his 
body, like those of the lower animals, to be modified 
in accordance Avith changing conditions to gain a 
warmer natural covering, to acquire more powerful 
teeth or claws, or to become adapted to obtain and 
digest new kinds of food, as circumstances may re- 
quire. 2. By his superior sympathetic and moral 
feelings, he becomes fitted for the social state ; he 
ceases to plunder the weak and helpless of his tribe ; 
he shares the game which he has caught with less 
active or less fortunate hunters, or exchanges it for 
weapons which even the weak or the deformed can 
fashion ; he saves the sick and wounded from death ; 
and thus the power which leads to the rigid destruc- 
tion of all animals who cannot in .every respect help 
themselves, is prevented from acting on him. 

This power is "natural selection;" and, as by no 
other means can it be shown, that individual varia- 
tions can ever become accumulated and rendered per- 
manent so as to form well-marked races, it follows 
that the differences which now separate mankind from 
other animals, must have been produced before he be- 
came possessed of a human intellect or human sympa- 
thies. This view also renders possible, or even requires, 
the existence of man at a comparatively remote geo- 
logical epoch. For, during the long periods in which 
other animals have been undergoing modification in 
their whole structure, to such an amount as to con- 
stitute distinct genera and families, man's body will 


have remained generically, or even specifically, the 
same, while his head and brain alone will have un- 
dergone modification equal to theirs. We can thus 
understand how it is that, judging from the head 
and brain, Professor Owen places man in a distinct 
sub -class of mammalia, while as regards the bony 
structure of his body, there is the closest anatomical 
resemblance to the anthropoid apes, " every tooth, every 
bone, strictly homologous which makes the determi- 
nation of the difference between Homo and Pithecus 
the anatomist's difficulty." The present theory fully 
recognises and accounts for these facts ; and we may 
perhaps claim as corroborative of its truth, that it 
neither requires us to depreciate the intellectual chasm 
which separates man from the apes, nor refuses full 
recognition of the striking resemblances to them, which 
exist in other parts of his structure. 


In concluding this brief sketch of a great subject, 
I would point out its bearing upon the future of the 
human race. If my conclusions are just, it must in- 
evitably follow that the higher the more intellectual 
and moral must displace the lower and more de- 
graded races ; and the power of " natural selection," 
still acting on his mental organization, must ever lead 
to the more perfect adaptation of man's higher facul- 
ties to the conditions of surrounding nature, and to 
the exigencies of the social state. While his external 
form will probably ever remain unchanged, except in 


the development of that perfect beauty which results 
from a healthy and well organized body, refined and 
ennobled by the highest intellectual faculties and sym- 
pathetic emotions, his mental constitution may con- 
tinue to advance and improve, till the world is again 
inhabited by a single nearly homogeneous race, no 
individual of which will be inferior to the noblest 
specimens of existing humanity. 

Our progress towards such a result is very slow, but 
it still seems to be a progress. We are just now living 
at an abnormal period of the world's history, owing to 
the marvellous developments and vast practical results 
of science, having been given to societies too low 
morally and intellectually, to know how to make the 
best use of them, and to whom they have consequently 
been curses as well as blessings. Among civilized na- 
tions at the present day, it does not seem possible for 
natural selection to act in any way, so as to secure the 
permanent advancement of morality and intelligence ; 
for it is indisputably the mediocre, if not the low, both 
as regards morality and intelligence, who succeed best 
in life and multiply fastest. Yet there is undoubtedly 
an advance on the whole a steady and a permanent 
one both in the influence on public opinion of a high 
morality, and in the general desire for intellectual ele- 
vation ; and as I cannot impute this in any way to 
"survival of the fittest," I am forced to conclude that 
it is due, to the inherent progressive power of those 
glorious qualities which raise us so immeasurably above 
our fellow animals, and at the same time afford us the 


surest proof that there are other and higher existences 
than ourselves, from whom these qualities may have 
been derived, and towards whom we may be ever 




THROUGHOUT this volume I have endeavoured to show, 
that the known laws of variation, multiplication, and 
heredity, resulting in a "struggle for existence" and 
the " survival of the fittest," have probably sufficed to 
produce all the varieties of structure, all the wonderful 
adaptations, all the beauty of form and of colour, that 
we see in the animal and vegetable kingdoms. To the 
best of my ability I have answered the most obvious 
and the most often repeated objections to this theory, 
and have, I hope, added to its general strength, by 
showing how colour one of the strongholds of the 
advocates of special creation may be, in almost all its 
modifications, accounted for by the combined influence 
of sexual selection and the need of protection. I have 
also endeavoured to show, how the same power which 
has modified animals has acted on man; and have, I 
believe, proved that, as soon as the human intellect 
became developed above a certain low stage, man's 
body would cease to be materially affected by natural 
selection, because the development of his mental facul- 
ties would render important modifications of its form 
and structure unnecessary. It will, therefore, probably 


excite some surprise among my readers, to find that 
I do not consider that all nature can be explained on 
the principles of which I am so ardent an advocate ; 
and that I am now myself going to state objections, 
and to place limits, to the power of " natural selection." 
I believe, however, that there are such limits ; and that 
just as surely as we can trace the action of natural 
laws in the development of organic forms, and can 
clearly conceive that fuller knowledge would enable 
us to follow step by step the whole process of that 
development, so surely can we trace the action of 
some unknown higher law, beyond and independent 
of all those laws of which we have any knowledge. 
We can trace this action more or less distinctly in 
many phenomena, the two most important of which 
are the origin of sensation or consciousness, and the 
development of man from the lower animals. I shall 
first consider the latter difficulty as more immediately 
connected with the subjects discussed in this volume. 

What Natural Selection can Not do. 

In considering the question of the development of 
man by known natural laws, we must ever bear in 
mind the first principle of " natural selection," no less 
than of the general theory of evolution, that all changes 
of form or structure, all increase in the size of an 
organ or in its complexity, all greater specialization or 
physiological division of labour, can only be brought 
about, in as much as it is for the good of the being 
so modified. Mr. Darwin himself has taken care to 


impress upon us, that "natural selection" has no power 
to produce absolute perfection but only relative perfec- 
tion, no power to advance any being much beyond 
his fellow beings, but only just so much beyond them 
as to enable it to survive them in the struggle for 
existence. Still less has it any power to produce 
modifications which are in any degree injurious to its 
possessor, and Mr. Darwin frequently uses the strong 
expression, that a single case of this kind would be 
fatal to his theory. If, therefore, we find in man any 
characters, which all the evidence we can obtain goes 
to show would have been actually injurious to him on 
their first appearance, they could not possibly have 
been produced by natural selection. ' Neither could 
any specially developed organ have been so produced 
if it had been merely useless to him, or if its use were 
not proportionate to its degree of development. Such 
cases as these would prove, that some other law, or 
some other power, than " natural selection " had been 
at work. But if, further, we could see that these 
very modifications, though hurtful or useless at the 
time when they first appeared, became in the highest 
degree useful at a much later period, and are now 
essential to the full moral and intellectual development 
of human nature, we should then infer the action of 
mind, foreseeing the future and preparing for it, just 
as surely as we do, when we see the breeder set himself 
to work with the determination to produce a definite 
improvement in some cultivated plant or domestic 
animal. I would further remark that this enquiry is 


as thoroughly scientific and legitimate as that into the 
origin of species itself. It is an attempt to solve the 
inverse problem, to deduce the existence of a new 
power of a definite character, in order to account for 
facts which according to the theory of natural selection 
ought not to happen. Such problems are well known 
to science, and the search after their solution has often 
led to the most brilliant results. In the case of man, 
there are facts of the nature above alluded to, and in 
calling attention to them, and in inferring a cause for 
them, I believe that I am as strictly within the bounds 
of scientific investigation as I have been in any other 
portion of my work. 

The Brain of the Savage shoivn to be Larger than he 
Needs it to be. 

Size of Brain an important Element of Mental 
Power. The brain is universally admitted to be the 
organ of the mind ; and it is almost as universally 
admitted, that size of brain is one of the most impor- 
tant of the elements which determine mental power 
or capacity. There seems to be no doubt that brains 
differ considerably in quality, as indicated by greater 
or less complexity of the convolutions, quantity of grey 
matter, and perhaps unknown peculiarities of organiza- 
tion ; but this difference of quality seems merely to 
increase or diminish the influence of quantity, not to 
neutralize it. Thus, all the most eminent modern 
writers see an intimate connection between the di- 
minished size of the brain in the lower races of man- 


kind, and their intellectual inferiority. The collections 
of Dr. J. B. Davis and Dr. Morton give the following 
as the average internal capacity of the cranium in the 
chief races : Teutonic family, 94 cubic inches ; Esqui- 
maux, 91 cubic inches ; Negroes, 85 cubic inches ; 
Australians and Tasmanians, 82 cubic inches; Bush- 
men, 77 cubic inches. These last numbers, however, 
are deduced from comparatively few specimens, and 
may be below the average, just as a small number of 
Finns and Cossacks give 98 cubic inches, or con- 
siderably more than that of the German races. It is 
evident, therefore, that the absolute bulk of the brain 
is not necessarily much less in savage than in civilised 
man, for Esquimaux skulls are known with a capacity 
of 113 inches, or hardly less than the largest among 
Europeans. But what is still more extraordinary, the 
few remains yet known of pre-historic man do not 
indicate any material diminution in the size of the 
brain case. A Swiss skull of the stone age, found 
in the lake dwelling of Meilen, corresponded exactly 
to that of a Swiss youth of the present day. The 
celebrated Neanderthal skull had a larger circumfer- 
ence than the average, and its capacity, indicating 
actual mass of brain, is estimated to have been not less 
than 75 cubic inches, or nearly the average of exist- 
ing Australian crania. The Engis skull, perhaps the 
oldest known, and which, according to Sir John 
Lubbock, a there seems no doubt was really contem- 
porary with the mammoth and the cave bear," is yet, 
according to Professor Huxley, "a fair average skull, 


which might have belonged to a philosopher, or might 
have contained the thoughtless brains of a savage. " 

" O 

Of the cave men of Les Eyzies, who were undoubtedly 
contemporary with the reindeer in the South of France, 
Professor Paul Broca says (in a paper read before 
the Congress of Pre-historic Archaeology in 1868) 
" The great capacity of the brain, the development of 
the frontal region, the fine elliptical form of the anterior 
part of the profile of the skull, are incontestible char- 
acteristics of superiority, such as we are accustomed to 
meet with in civilised races ; " yet the great breadth of 
the face, the enormous development of the ascending 
ramus of the lower jaw, the extent and roughness of 
the surfaces for the attachment of the muscles, espe- 
cially of the masticators, and the extraordinary de- 
velopment of the ridge of the femur, indicate enormous 
muscular power, and the habits of a savage and 
brutal race. 

These facts might almost make us doubt whether 
the size of the brain is in any direct way an index of 
mental power, had we not the most conclusive evidence 
that it is so, in the fact that, whenever an adult male 
European has a skull less than nineteen inches in cir- 
cumference, or has less than sixty-five cubic inches of 
brain, he is invariably idiotic. When we join with this 
the equally undisputed fact, that great men those who 
combine acute perception with great reflective power, 
strong passions, and general energy of character, such 
as Napoleon, Cuvier, and O'Connell, have always heads 
far above the average size, we must feel satisfied that 



volume of brain is one, and perhaps the most impor- 
tant, measure of intellect ; and this being the case, we 
cannot fail to be struck with the apparent anomaly, 
that many of the lowest savages should have as much 
brains as average Europeans. The idea is suggested 
of a surplusage of power ; of an instrument beyond the 
needs of its possessor. 

Comparison of the Brains of Man and of Anthropoid 
Apes. In order to discover if there is any foundation 
for this notion, let us compare the brain of man with 
that of animals. The adult male Orang-utan is quite as 
bulky as a small sized man, while the Gorilla is consi- 
derably above the average size of man, as estimated by 
bulk and weight ; yet the former has a brain of only 
28 cubic inches, the latter, one of 30, or, in the largest 
specimen yet known, of 34J cubic inches. We have 
seen that the average cranial capacity of the lowest 
savages is probably not less than Jive-sixths of that of 
the highest civilized races, while the brain of the 
anthropoid apes scarcely amounts to one-third of that 
of man, in both cases taking the average; or the 
proportions may be more clearly represented by the 
following figures anthropoid apes, 10 ; savages, 26 ; 
civilized man, 32. But do these figures at all approxi- 
mately represent the relative intellect of the three 
groups ? Is the savage really no further removed from 
.the philosopher, and so much removed from the ape, 
as these figures would indicate ? In considering this 
question, we must not forget that the heads of savages 
vary in size, almost as much as those of civilized 


Europeans. Thus, while the largest Teutonic skull 
in Dr. Davis' collection is 112'4 cubic inches, there is 
an Araucanian of 115*5, an Esquimaux of 113*1, a 
Marquesan of 110*6, a Negro of 105*8, and even an 
Australian of 104*5 cubic inches. We may, there- 
fore, fairly compare the savage with the highest 
European on the one side, and with the Orang, Chim- 
panzee, or Gorilla, on the other, and see whether 
there is any relative proportion between brain and 

Range of intellectual power in Man. First, let us 
consider what this wonderful instrument, the brain, is 
capable of in its higher developments. In Mr. Galton's 
interesting work on " Hereditary Genius," he remarks 
on the enormous difference between the intellectual 
power and grasp of the well-trained mathematician 
or man of science, and the average Englishman. The 
number of marks obtained by high wranglers, is often 
more than thirty times as great as that of the men 
at the bottom of the honour list, who are still of fair 
mathematical ability ; and it is the opinion of skilled 
examiners, that even this does not represent the full 
difference of intellectual power. If, now, we descend 
to those savage tribes who only count to three or five, 
and who find it impossible to comprehend the addition 
of two and three without having the objects actually 
before them, we feel that the chasm between them and 
the good mathematician is so vast, that a thousand to 
one will probably not fully express it. Yet we know 
that the mass of brain might be nearly the same in 

z 2 


both, or might not differ in a greater proportion than 
as 5 to 6 ; whence we may fairly infer that the savage 
possesses a brain capable, if cultivated and developed, 
of performing work of a kind and degree far beyond 
what he ever requires it to do. 

Again, let us consider the power of the higher or 
even the average civilized man, of forming abstract 
ideas, and carrying on more or less complex trains 
of reasoning. Our languages are full of terms to 
express abstract conceptions. Our business and our 
pleasures involve the continual foresight of many con- 
tingencies. Our law, our government, and our science, 
continually require us to reason through a variety of 
complicated phenomena to the expected result. Even 
our games, such as chess, compel us to exercise all 
these faculties in a remarkable degree. Compare this 
with the savage languages, which contain no words 
for abstract conceptions ; the utter want of foresight 
of the savage man beyond his simplest necessities ; his 
inability to combine, or to compare, or to reason on 
any general subject that does not immediately appeal 
to his senses. So, in his moral and aesthetic faculties, 
the savage has none of those wide sympathies with all 
nature, those conceptions of the infinite, of the good, 
of the sublime and beautiful, which are so largely 
developed in civilized man. Any considerable develop- 
ment of these would, in fact, be useless or even hurtful 
to him, since they would to some extent interfere with 
the supremacy of those perceptive and animal faculties 
on which his very existence often depends, in the 


severe struggle he has to carry on against nature and 
his fellow-man. Yet the rudiments of all these powers 
and feelings undoubtedly exist in him, since one or 
other of them frequently manifest themselves in ex- 
ceptional cases, or when some specia.1 circumstances 
call them forth. Some tribes, such as the Santals, 
are remarkable for as pure a love of truth as the most 
moral among civilized men. The Hindoo and the 
Polynesian have a high artistic feeling, the first traces 
of which are clearly visible in the rude drawings of 
the palaeolithic men who were the contemporaries in 
France of the Reindeer and the Mammoth. Instances 
of unselfish love, of true gratitude, and of deep reli- 
gious feeling, sometimes occur among most savage 

On the whole, then, we may conclude, that the general 
moral and intellectual development of the savage, is 
not less removed from that of civilized man than has 
been shown to be the case in the one department 
of mathematics ; and from the fact that all the moral 
and intellectual faculties do occasionally manifest them- 
selves, we may fairly conclude that they are always 
latent, and that the large brain of the savage man is 
much beyond his actual requirements in the savage 

Intellect of Savages and of Animals compared. Let 
us now compare the intellectual wants of the savage, 
and the actual amount of intellect he exhibits, with 
those of the higher animals. Such races as the 
Andaman Islanders, the Australians, and the Tasma- 


nians, the Digger Indians of North America, or the 
natives of Fuegia, pass their lives so as to require 
the exercise of few faculties not possessed in an equal 
degree by many animals. In the mode of capture of 
game or fish, they by no means surpass the ingenuity 
or forethought of the jaguar, who drops saliva into 
the water, and seizes the fish as they come to eat it; 
or of wolves and jackals, who hunt in packs; or of 
the fox, who buries his surplus food till he requires 
it. The sentinels placed by antelopes and by monkeys, 
and the various modes of building adopted by field 
mice and beavers, as well as the sleeping place of the 
orang-utan, and the tree-shelter of some of the Afri- 
can anthropoid apes, may well be compared with the 
amount of care and forethought bestowed by many 
savages in similar circumstances. His possession of 
free and perfect hands, not required for locomotion, 
enable man to form and use weapons and implements 
which are beyond the physical powers of brutes ; but 
having done this, he certainly does not exhibit more 
mind in using them than do many lower animals. 
What is there in the life of the savage, but the satisfy- 
ing of the cravings of appetite in the simplest and 
easiest way ? What thoughts, ideas, or actions are 
there, that raise him many grades above the elephant 
or the ape ? Yet he possesses, as we have seen, a 
brain vastly superior to theirs in size and complexity; 
and this brain gives him, in an undeveloped state, 
faculties which he never requires to use. And if this 
is true of existing savages, how much more true must 


it have been of the men whose sole weapons were 
rudely chipped flints, and some of whom, we may 
fairly conclude, were lower than any existing race ; 
while the only evidence yet in our possession shows 
them to have had brains fully as capacious as those 
of the average of the lower savage races. 

We see, then, that whether we compare the savage 
with the higher developments of man, or with the 
brutes around him, we are alike driven to the con- 
clusion that in his large and well-developed brain 
he possesses an organ quite disproportionate to his 
actual requirements an organ that seems prepared in 
advance, only to be fully utilized as he progresses in 
civilization. A brain slightly larger than that of the 
gorilla would, according to the evidence before us, 
fully have sufficed for the limited mental development 
of the savage; and we must therefore admit, that the 
large brain he actually possesses could never have 
been solely developed by any of those laws of evolu- 
tion, whose essence is, that they lead to a degree of 
organization exactly proportionate to the wants of 
each species, never beyond those wants that no pre- 
paration can be made for the future development of 
the race that one part of the body can never increase 
in size or complexity, except in strict co-ordination to 
the pressing wants of the whole. The brain of pre- 
historic and of savage man seems to me to prove 
the existence of some power, distinct from that which 
has guided the development of the lower animals 
through their ever- varying forms of being. 


The Use of the Hairy Covering of Mammalia. 

Let us now consider another point in man's organi- 
zation, the bearing of which has been almost entirely 
overlooked by writers on both sides of this question. 
One of the most general external characters of the 
terrestrial mammalia is the hairy covering of the body, 
which, whenever the skin is flexible, soft, and sensitive, 
forms a natural protection against the severities of cli- 
mate, and particularly against rain. That this is its 
most important function, is well shown by the manner 
in which the hairs are disposed so as to carry off the 
water, by being invariably directed downwards from 
the most elevated parts of the body. Thus, on the under 
surface the hair is always less plentiful, and, in many 
cases, the belly is almost bare. The hair lies down- 
wards, on the limbs of all walking mammals, from the 
shoulder to the toes, but in the orang-utan it is directed 
from the shoulder to the elbow, and again from the 
wrist to the elbow, in a reverse direction. This corre- 
sponds to the habits of the animal, which, when resting, 
holds its long arms upwards over its head, or clasping 
a branch above it, so that the rain would flow down 
both the arm and fore-arm to the long hair which meets 
at the elbow. In accordance with this principle, the 
hair is always longer or more dense along the spine 
or middle of the back from the nape to the tail, often 
rising into a crest of hair or bristles on the ridge of the 
back. This character prevails through the entire series 
of the mammalia, from the marsupials to the quadru- 


mana, and by this long persistence it must have ac- 
quired such a powerful hereditary tendency, that we 
should expect it to reappear continually even after it 
had been abolished by ages of the most rigid selection ; 
and we may feel sure that it never could have been 
completely abolished under the law of natural selec- 
tion, unless it had become so positively injurious as to 
lead to the almost invariable extinction of individuals 
possessing it. 

The constant absence of Hair from certain parts of 
Man's Body a remarkable Phenomenon. 

In man the hairy covering of the body has almost 
totally disappeared, and, what is very remarkable, it 
has disappeared more completely from the back than 
from any other part of the body. Bearded and beard- 
less races alike have the back smooth, and even when 
a considerable quantity of hair appears on the limbs 
and breast, the back, and especially the spinal region, 
is absolutely free, thus completely reversing the charac- 
teristics of all other mammalia. The Ainos of the Kurile 
Islands and Japan are said to be a hairy race ; but Mr. 
Bickmore, who saw some of them, and described them 
in a paper read before the Ethnological Society, gives 
no details as to where the hair was most abundant, 
merely stating generally, that " their chief peculiarity 
is their great abundance of hair, not only on the head 
and face, but over the whole body." This might very 
well be said of any man who had hairy limbs and 
breast, unless it was specially stated that his back was 


hairy, which is not clone in this case. The hairy family 
in Birmah have, indeed, hair on the back rather longer 
than on the breast, thus reproducing the true mam- 
malian character, but they have still longer hair on the 
face, forehead, and inside the ears, which is quite ab- 
normal ; and the fact that their teeth are all very im- 
perfect, shows that this is a case of monstrosity rather 
than one of true reversion to the ancestral type of man 
before he lost his hairy covering. 

Savage Man feels the Want of this Hairy Covering. 

We must now enquire if we have any evidence to 
show, or any reason to believe, that a hairy covering to 
the back would be in any degree hurtful to savage 
man, or to man in any stage of his progress from his 
lower animal form ; and if it were merely useless, could 
it have been so entirely and completely removed as not 
to be continually reappearing in mixed races ? Let 
us look to savage man for some light on these points. 
One of the most common habits of savages is to use 
some covering for the back and shoulders, even when 
they have none on any other part of the body. The 
early voyagers observed with surprise, that the Tas- 
manians, both men and women, wore the kangaroo- 
skin, which was their only covering, not from any 
feeling of modesty, but over the shoulders to keep the 
back dry and warm. A cloth over the shoulders was 
also the national dress of the Maories. The Patago- 
nians wear a cloak or mantle over the shoulders, and 
the Fuegians often wear a small piece of skin on the 


back, laced on. and shifted from side to side as the 
wind blows. The Hottentots also wore a somewhat 
similar skin over the back, which they never removed, 
and in which they were buried. Even in the tropics 
most savages take precautions to keep their backs dry. 
The natives of Timor use the leaf of a fan palm, care- 
fully stitched up and folded, which they always carry 
with them, and which, held over the back, forms an 
admirable protection from the rain. Almost all the 
Malay races, as well as the Indians of South America, 
make great palm-leaf hats, four feet or more across, 
which they use during their canoe voyages to protect 
their bodies from heavy showers of rain; and they 
use smaller hats of the same kind when travelling 
by land. 

"We find, then, that so far from there being any 
reason to believe that a hairy covering to the back 
could have been hurtful or even useless to pre-historic 
man, the habits of modern savages indicate exactly the 
opposite view, as they evidently feel the want of it, and 
are obliged to provide substitutes of various kinds. 
The perfectly erect posture of man, may be supposed to 
have something to do with the disappearance of the 
hair from his body, while it remains on his head ; but 
when walking, exposed to rain and wind, a man natur- 
ally stoops forwards, and thus exposes his back ; and the 
undoubted fact, that most savages'feel the effects of cold 
and wet most severely in that part of the body, suffi- 
ciently demonstrates that the hair could not have ceased 
to grow there merely because it was useless, even if it 


were likely that a character so long persistent in the 
entire order of mammalia, could have so completely dis- 
appeared, under the influence of so weak a selective 
power as a diminished usefulness. 

Marts Naked Skin could not have been produced by 
Natural Selection. 

It seems to me, then, to be absolutely certain, that 
a Natural Selection " could not have produced man's 
hairless body by the accumulation of variations from a 
hairy ancestor. The evidence all goes to show that 
such variations could not have been useful, but must, 
on the contrary, have been to some extent hurtful. If 
even, owing to an unknown correlation with other 
hurtful qualities, it had been abolished in the ancestral 
tropical man, we cannot conceive that, as man spread 
into colder climates, it should not have returned under 
the powerful influence of reversion to such a long per- 
sistent ancestral type. But the very foundation of 
such a supposition as this is untenable ; for we cannot 
suppose that a character which, like hairiness, exists 
throughout the whole of the mammalia, can have be- 
come, in one form only, so constantly correlated with 
an injurious character, as to lead to its permanent 
suppression a suppression so complete and effectual 
that it never, or scarcely ever, reappears in mongrels 
of the most widely different races of man. 

Two characters could hardly be wider apart, than 
the size and development of man's brain, and the dis- 
tribution of hair upon the surface of his body ; yet 


they both lead us to the same conclusion that some 
other power than Natural Selection has been engaged 
in his production. 

Feet and Hands of Man, considered as Difficulties on 
the Theory of Natural Selection. 

There are a few other physical characteristics of 
man, that may just be mentioned as offering similar 
difficulties, though I do not attach the same importance 
to them as to those I have already dwelt on. The 
specialization and perfection of the hands and feet of 
man seems difficult to account for. Throughout the 
whole of the quadrumana the foot is prehensile ; and a 
very rigid selection must therefore have been needed 
to bring about that arrangement of the bones and 
muscles, which has converted the thumb into a great 
toe, so completely, that the power of opposability is 
totally lost in every race, whatever some travellers 
may vaguely assert to the contrary. It is difficult to 
see why the prehensile power should have been taken 
away. It must certainly have been useful in climb- 
ing, and the case of the baboons shows that it is quite 
compatible with terrestrial locomotion. It may not 
be compatible with perfectly easy erect locomotion; 
but, then, how can we conceive that early man, as an 
animal, gained anything by purely erect locomotion ? 
Again, the hand of man contains latent capacities 
and powers which are unused by savages, and must 
have been even less used by palaeolithic man and his 
still ruder predecessors. It has all the appearance of 


an organ prepared for the use of civilized man, and 
one which was required to render civilization possi- 
ble. Apes make little use of their separate fingers 
and opposable thumbs. They grasp objects rudely 
and clumsily, and look as if a much less specialized 
extremity would have served their purpose as well. 
I do not lay much stress on this, but, if it be proved 
that some intelligent power has guided or determined 
the development of man, then we may see indications 
of that power, in facts which, by themselves, would 
not serve to prove its existence. 

Tlie voice of man. The same remark will apply 
to another peculiarly human character, the wonder- 
ful power, range, flexibility, and sweetness, of the 
musical sounds producible by the human larynx, 
especially in the female sex. The habits of savages 
give no indication of how this faculty could have 
been developed by natural selection; because it is 
never required or used by them. The singing of 
savages is a more or less monotonous howling, and 
the females seldom sing at all. Savages certainly 
never choose their wives for fine voices, but for rude 
health, and strength, and physical beauty. Sexual 
selection could not therefore have developed this won- 
derful power, which only comes into play among 
civilized people. It seems as if the organ had been 
prepared in anticipation of the future progress of man, 
since it contains latent capacities which are useless 
to him in his earlier condition. The delicate correla- 
tions of structure that give it such marvellous powers, 


could not therefore have been acquired by means of 
natural selection. 

The Origin of some of Man's Mental Faculties, by the 
preservation of Useful Variations, not possible. 

Turning to the mind of man, we meet with mariy 
difficulties in attempting to understand, how those 
mental faculties, which are especially human, could 
have been acquired by the preservation of useful 
variations. At first sight, it would seem that such 
feelings as those of abstract justice and benevolence 
could never have been so acquired, because they are 
incompatible with the law of the strongest, which is 
the essence of natural selection. But this is, I think, 
an erroneous view, because we must look, not to indi- 
viduals but to societies ; and justice and benevolence, 
exercised towards members of the same tribe, would 
certainly tend to strengthen that tribe, and give it 
a superiority over another in which the right of the 
strongest prevailed, and where consequently the weak 
and the sickly were left to perish, and the few strong 
ruthlessly destroyed the many who were weaker. 

But there is another class of human faculties that 
do not regard our fellow men, and which cannot, 
therefore, be thus accounted for. Such are the capa- 
city to form ideal conceptions of space and time, of 
eternity and infinity the capacity for intense artistic 
feelings of pleasure, in form, colour, and composition 
and for those abstract notions of form and number 
which render geometry and arithmetic possible. How 


were all or any of these faculties first developed, when 
they could have been of no possible use to man in 
his early stages of barbarism ? How could " natural 
selection," or survival of the fittest in the struggle 
for existence, at all favour the development of mental 
powers so entirely removed from the material neces- 
sities of savage men, and which even now, with our 
comparatively high civilization, are, in their farthest 
developments, in advance of the age, and appear to 
have relation rather to the future of the race than 
to its actual status? 

Difficulty as to the Origin of the Moral Sense. 

Exactly the same difficulty arises, when we endeavour 
to account for the development of the moral sense or 
conscience in savage man ; for although the practice of 
benevolence, honesty, or truth, may have been useful 
to the tribe possessing these virtues, that does not at 
all account for the peculiar sanctity, attached to actions 
which each tribe considers right and moral, as con- 
trasted with the very different feelings with which 
they regard what is merely useful. The utilitarian 
hypothesis (which is the theory of natural selection 
applied to the mind) seems inadequate to account for 
the development of the moral sense. This subject has 
been recently much discussed, and I will here only 
give one example to illustrate my argument. The 
utilitarian sanction for truthfulness is by no means 
very powerful or universal. Few laws enforce it. ISTo 
very severe reprobation follows untruthfulness. In all 


ages and countries, falsehood has been thought allow- 
able in love, and laudable in war ; while, at the present 
day, it is held to be venial by the majority of mankind, 
in trade, commerce, and speculation. A certain amount 
of untruthfulness is a necessary part of politeness in 
the east and west alike, while even severe moralists 
have held a lie justifiable, to elude an enemy or prevent 
a crime. Such being the difficulties with which this 
virtue has had to struggle, with so many exceptions 
to its practice, with so many instances in which it 
brought ruin or death to its too ardent devotee, how 
can we believe that considerations of utility could 
ever invest it with the mysterious sanctity of the 
highest virtue, could ever induce men to value 
truth for its own sake, and practice it regardless of 
consequences ? 

Yet, it is a fact, that such a mystical sense of wrong 
does attach to untruthfulness, not only among the 
higher classes of civilized people, but among whole 
tribes of utter savages. Sir Walter Elliott tells us 
(in his paper " On the Characteristics of the Popula- 
tion of Central and Southern India," published in 
the Journal of the Ethnological Society of London, 
vol. i., p. 107) that the Kurubars and Santals, barbar- 
ous hill-tribes of Central India, are noted for veracity. 
It is a common saying that " a Kurubar always speaks 
the truth; " and Major Jervis says, " the Santals are 
the most truthful men I ever met with." As a re- 
markable instance of this quality the following fact is 
given. A number of prisoners, taken during the 

2 A 


Santal insurrection, were allowed to go free on parole, 
to work at a certain spot for wages. After some 
time cholera attacked them and they were obliged to 
leave, but every man of them returned and gave up 
his earnings to the guard. Two hundred savages 
with money in their girdles, walked thirty miles back 
to prison rather than break their word ! My own 
experience among savages has furnished me with 
similar, although less severely tested, instances; and 
we cannot avoid asking, how is it, that in these few 
cases " experiences of utility " have left such an over- 
whelming impression, while in so many others they 
have left none ? The experiences of savage men as 
regards the utility of truth, must, in the long run, 
be pretty nearly equal. How is it, then, that in some 
cases the result is a sanctity which overrides all con- 
siderations of personal advantage, while in others there 
is hardly a rudiment of such a feeling ? 

The intuitional theory, which I am now advocating, 
explains this by the supposition, that there is a feeling 
a sense of right and wrong in our nature, antecedent 
to and independent of experiences of utility. Where 
free play is allowed to the relations between man and 
man, this feeling attaches itself to those acts of uni- 
versal utility or self-sacrifice, which are the products 
of our affections and sympathies, and which we .term 
moral ; while it may be, and often is, perverted, to 
give the same sanction to acts of narrow and con- 
ventional utility which are really immoral, as when 
the Hindoo will tell a lie, but will sooner starve than 


eat unclean food ; and looks upon the marriage of 
adult females as gross immorality. 

The strength of the moral feeling will depend upon 
individual or racial constitution, and on education 
and habit; the acts to which its sanctions are applied, 
will depend upon how far the simple feelings and affec- 
tions of our nature, have been modified by custom, 
by law, or by religion. 

It is difficult to conceive that such an intense and 
mystical feeling of right and wrong, (so intense as 
to overcome all ideas of personal advantage or utility), 
could have been developed out of accumulated ancestral 
experiences of utility ; and still more difficult to under- 
stand, how feelings developed by one set of utilities, 
could be transferred to acts of which the utility was 
partial, imaginary, or altogether absent. But if a 
moral sense is an essential part of our nature, it is 
easy to see, that its sanction may often be given to 
acts which are useless or immoral ; just as the natural 
appetite for drink, is perverted by the drunkard into 
the means of his destruction. 

Summary of the Argument as to the Insufficiency of 
Natural Selection to account for the Development of 

Briefly to resume my argument I have shown that 
the brain of the lowest savages, and, as far as we yet 
know, of the pre-historic races, is little inferior in size 
to that of the highest types of man, and immensely 
superior to that of the higher animals ; while it is. 

2 A 2 


universally admitted that quantity of brain is one of 
the most important, and probably the most essential, of 
the elements which determine mental power. Yet the 
mental requirements of savages, and the faculties ac- 
tually exercised by them, are very little above those of 
animals. The higher feelings of pure morality and re- 
fined emotion, and the power of abstract reasoning and 
ideal conception, are useless to them, are rarely if ever 
manifested, and have no important relations to their 
habits, wants, desires, or well-being. They possess a 
mental organ beyond their needs. Natural Selection 
could only have endowed savage man with a brain a 
little superior to that of an ape, whereas he actually 
possesses one very little inferior to that of a philo- 

The soft, naked, sensitive skin of man, entirely free 
from that hairy covering which is so universal among 
other mammalia, cannot be explained on the theory of 
natural selection. The habits of savages show that 
they feel the want of this covering, which is most com- 
pletely absent in man exactly where it is thickest in 
other animals. We have no reason whatever to be- 
lieve, that it could have been hurtful, or even useless to 
primitive man ; and, under these circumstances, its com- 
plete abolition, shown by its never reverting in mixed 
breeds, is a demonstration of the agency of some other 
power than the law of the survival of the fittest, in the 
development of man from the lower animals. 

Other characters show difficulties of a similar kind, 
though not perhaps in an equal degree. The structure 


of the human foot and hand seem unnecessarily perfect 
for the needs of savage man, in whom they are as 
completely and as humanly developed as in the highest 
races. The structure of the human larynx, giving the 
power of speech and of producing musical sounds, and 
especially its extreme development in the female sex, 
are shown to be beyond the needs of savages, and from 
their known habits, impossible to have been acquired 
either by sexual selection, or by survival of the fittest. 

The mind of man offers arguments in the same direc- 
tion, hardly less strong than those derived from his 
bodily structure. A number of his mental faculties 
have no relation to his fellow men, or to his material 
progress. The power of conceiving eternity and in- 
finity, and all those purely abstract notions of form, 
number, and harmony, which play so large a part in 
the life of civilised races, are entirely outside of the 
world of thought of the savage, and have no influence 
on his individual existence or on that of his tribe. 
They could not, therefore, have been developed by any 
preservation of useful forms of thought ; yet we find 
occasional traces of them amidst a low civilization, and 
at a time when they could have had no practical effect 
on the success of the individual, the family, or the 
race ; and the development of a moral sense or con- 
science by similar means is equally inconceivable. 

But, on the other hand, we find that every one of 
these characteristics is necessary for the full develop- 
ment of human nature. The rapid progress of civi- 
lization under favourable conditions, would not be 


possible, were not the organ of the mind of man pre- 
pared in advance, fully developed as regards size, 
structure, and proportions, and only needing a few 
generations of use and habit to co-ordinate its com- 
plex functions. The] naked and sensitive skin, by 
necessitating clothing and houses, would lead to the 
more rapid development of man's inventive and con- 
structive faculties ; and, by leading to a more refined 
feeling of personal modesty, may have influenced, to a 
considerable extent, his moral nature. The erect form 
of man, by freeing the hands from all locomptive uses, 
has been necessary for his intellectual advancement; 
and the extreme perfection of his hands, has alone 
rendered possible that excellence in all the arts of civili- 
zation which raises him so far above the savage, and 
is perhaps but the forerunner of a higher intellectual 
and moral advancement. The perfection of his vocal 
organs has first led to the formation of articulate 
speech, and then to the development of those exqui- 
sitely toned sounds, which are only appreciated by the 
higher races, and which are probably destined for more 
elevated uses and more refined enjoyment, in a higher 
condition than we have yet attained to. So, those 
faculties which enable us to transcend time and space, 
and to realize the wonderful conceptions of mathe- 
matics and philosophy, or which give us an intense 
yearning for abstract truth, (all of which were occasion- 
ally manifested at such an early period of human his- 
tory as to be far in advance of any of the few practical 
applications which have since grown out of them), are- 


evidently essential to the perfect development of man 
as a spiritual being, but are utterly inconceivable as 
having been produced through the action of a law 
which looks only, and can look only, to the immediate 
material welfare of the individual or the race. 

The inference I would draw from this class of phe- 
nomena is, that a superior intelligence has guided the 
development of man in a definite direction, and for a 
special purpose, just as man guides the development of 
many animal and vegetable forms. The laws of evolu- 
tion alone would, perhaps, never have produced a grain 
so well adapted to man's use as wheat and maize ; such 
fruits as the seedless banana and bread-fruit ; or such 
animals as the Guernsey milch cow, or the London 
dray-horse. Yet these so closely resemble the unaided 
productions of nature, that we may well imagine a 
being who had mastered the laws of development of or- 
ganic forms through past ages, refusing to believe that 
any new power had been concerned in their produc- 
tion, and scornfully rejecting the theory (as my theory 
will be rejected by many who agree with me on other 
points), that in these few cases a ^controlling intelli- 
gence had directed the action of the laws of variation, 
multiplication, and survival, for his own purposes. "We 
know, however, that this has been done ; and we must 
therefore admit the possibility that, if we are not the 
highest intelligences in the universe, some higher intel- 
ligence may have directed the process by which the 
human race was developed, by means of more subtle 
agencies than we are acquainted with. At the same 


time I must confess, that this theory has the disadvan- 
tage of requiring the intervention of some distinct indi- 
vidual intelligence, to aid in the production of what we 
can hardly avoid considering as the ultimate aim and 
outcome of all organized existence intellectual, ever- 
advancing, spiritual man. It therefore implies, that 
the great laws which govern the material universe were 
insufficient for his production, unless we consider (as 
we may fairly do) that the controlling action of such 
higher intelligences is a necessary part of those laws, 
just as the action of all surrounding organisms is one of 
the agencies in organic development. But even if my 
particular view should not be the true one, the difficul- 
ties I have put forward remain, and I think prove, that 
some more general and more fundamental law under- 
lies that of " natural selection." The law of u uncon- 
scious intelligence" pervading all organic nature, put 
forth by Dr. Laycock and adopted by Mr. Murphy, is 
such a law ; but to my mind it has the double disad- 
vantage of being both unintelligible and incapable of 
any kind of proof. It is more probable, that the true 
law lies too deep for us to discover it ; but there seems 
to me, to be ample indications that such a law does 
exist, and is probably connected with the absolute ori- 
gin of life and organization. 

TJie Origin of Consciousness. 

The question of the origin of sensation and of thought 
can be but briefly discussed in this place, since it is a 
subject wide enough to require a separate volume for 


its proper treatment. No physiologist or philosopher 
has yet ventured to propound an intelligible theory, of 
how sensation may possibly be a product of organiza- 
tion ; while many have declared the passage from mat- 
ter to mind to be inconceivable. In his presidential 
address to the Physical Section of the British Associa- 
tion at Norwich, in 1868, Professor Tyndall expressed 
himself as follows : 

" The passage from the physics of the brain to the 
corresponding facts of consciousness is unthinkable. 
Granted that a definite thought, and a definite mole- 
cular action in the brain occur simultaneously, we do 
not possess the intellectual organ, nor apparently any 
rudiment of the organ, which would enable us to pass 
by a process of reasoning from the one phenomenon 
to the other. They appear together, but we do not 
know why. Were our minds and senses so expanded, 
strengthened, and illuminated as to enable us to see and 
feel the very molecules of the brain ; were we capable 
of following all their motions, all their groupings, all 
their electric discharges, if such there be, and were we 
intimately acquainted with the corresponding states of 
thought and feeling, we should be as far as ever from 
the solution of the problem, ' How are these physical 
processes connected with the facts of consciousness ? ' 
The chasm between the two classes of phenomena would 
still remain intellectually impassable." 

In his latest work (" An Introduction to the Classifica- 
tion of Animals,") published in 1859, Professor Huxley 
unhesitatingly adopts the "well founded doctrine, that 


life is the cause and not the consequence of organiza- 
tion." In his celebrated article " On the Physical 
Basis of Life," however, he maintains, that life is a 
property of protoplasm, and that protoplasm owes its 
properties to the nature and disposition of its molecules. 
Hence he terms it " the matter of life," and believes 
that all the physical properties of organized beings are 
due to the physical properties of protoplasm. So far 
we might, perhaps, follow him, but he does not stop 
here. He proceeds to bridge over that chasm which 
Professor Tyndall has declared to be " intellectually 
impassable," and, by means which he states to be 
logical, arrives at the conclusion, that our " thoughts 
are the expression of molecular changes in -that matter 
of life which is the source of our other vital phenomena." 
Not having been able to find any clue in Professor 
Huxley's writings, to the steps by which he p'asses from 
those vital phenomena, which consist only, in their 
last analysis, of movements of particles of matter, to 
those other phenomena which we term thought,, sensa- 
tion, or consciousness ; but, knowing that so positive an 
expression of opinion from him will have great weight 
with many persons, I shall endeavour to show, with as 
much brevity as is compatible with clearness, that this 
theory is not only incapable of proof, but is also, as it 
appears to me, inconsistent with accurate conceptions of 
molecular physics. To do this, and in order further to 
develop my views, I shall have to give a brief sketch 
of the most recent speculations and discoveries, as ta 
the ultimate nature and constitution of matter. 


The Nature of Matter. 

It has been long seen by the best thinkers on the 
subject, that atoms, considered as minute solid bodies 
from which emanate the attractive and repulsive forces 
which give what we term matter its properties, could 
serve no purpose whatever ; since it is universally 
admitted that the supposed atoms never touch each 
other, and it cannot be conceived that these homo- 
geneous, indivisible, solid units, are themselves the 
ultimate cause of the forces that emanate from their 
centres. As, therefore, none of the properties of matter 
can be due to the atoms themselves, but only to the 
forces which emanate from the points in space indi- 
cated by the atomic centres, it is logical continually 
to diminish their size till they vanish, leaving only 
localized 'centres of force to represent them. Of the 
various attempts that have been made to show how 
.the properties of matter may be due to such modified 
atoms (considered as mere centres of force), the most 
successful, because the simplest and the most logical, is 
that of Mr. Bayma, who, in his "Molecular Mechanics,' * 
has demonstrated how, from the simple assumption of 
such centres having attractive and repulsive forces 
(both varying according to the same law of the in- 
verse squares as gravitation), and by grouping them in 
symmetrical figures, consisting of a repulsive centre, an 
attractive nucleus, and one or more repulsive envelopes, 
we may explain all the general properties of matter; 
and, by more and more complex arrangements, even 


the special chemical, electrical, and magnetic properties 
of special forms of matter.* Each chemical element 
will thus consist of a molecule formed of simple atoms, 
(or as Mr. Bay ma terms them to avoid confusion, 
" material elements") in greater or less number and 
of more or less complex arrangement ; which molecule 
is in stable equilibrium, but liable to be changed in 
form by the attractive or repulsive influences of differ- 
ently constituted molecules, constituting the phenomena 
of chemical combination, and resulting in new forms 
of molecule of greater complexity and more or less 

Those organic compounds of which organized beings 
are built up, consist, as is well known, of matter of an 
extreme complexity and great instability; whence re- 
sult the changes of form to which it is continually 
subject. This view enables us to comprehend the possi- 
bility, of the phenomena of vegetative life being due to 

* Mr. Bayma's work, entitled " The Elements of Molecular 
Mechanics," was published in 1866, and has received less 
attention than it deserves. It is characterised by great 
lucidity, by logical arrangement, and by comparatively simple 
geometrical and algebraical demonstrations, so that it may 
be understood and appreciated with a very moderate know- 
ledge of mathematics. It consists of a series of Propositions, 
deduced from the known properties of matter; from these 
are derived a number of Theorems, by whose help the more 
complicated Problems are solved. Nothing is taken for 
granted throughout the work, and the only valid mode of 
escaping from its conclusions is, by either disproving the 
fundamental Propositions, or by detecting fallacies in the 
subsequent reasoning. 


an almost infinite complexity of molecular combinations, 
subject to definite changes under the stimuli of heat, 
moisture, light, electricity, and probably some unknown 
forces. But this greater and greater complexity, even 
if carried to an infinite extent, cannot, of itself, have 
the slightest tendency to originate consciousness in such 
molecules or groups of molecules. If a material ele- r 
ment* or a combination of a thousand material elements 
in a molecule, are alike unconscious, it is impossible 
for us to believe, that the mere addition of one, two, 
or a thousand other material elements to form a more 
complex molecule, could in any way tend to produce 
a self-conscious existence. The things are radically 
distinct. To say that mind is a product or function 
of protoplasm, or of its molecular changes, is to use 
words to which we can attach no clear conception. 
You cannot have, in the whole, what does not exist 
in any of the parts ; and those who argue thus should 
put forth a definite conception of matter, with clearly 
enunciated properties, and show, that the necessary 
result of a certain complex arrangement of the ele- 
ments or atoms of that matter, will be the production 
of self-consciousness. There is no escape from this 
dilemma, either all matter is conscious, or conscious- 
ness is something distinct from matter, and in the 
latter case, its presence in material forms is a proof 
of the existence of conscious beings, outside of, and 
independent of, what we term matter. 

Matter is force. The foregoing considerations lead 
us to the very important conclusion, that matter is 


essentially force, and nothing but force; that matter, 
as popularly understood, does not exist, and is, in fact, 
philosophically inconceivable. When we touch matter, 
we only really experience sensations of resistance, im- 
plying repulsive force; and no other sense can give us 
such apparently solid proofs of the reality of matter, as 
touch does. This conclusion, if kept constantly present 
in the mind, will be found to have a most important 
bearing on almost every high scientific and philoso- 
phical problem, and especially on such as relate to our 
own conscious existence. 

All Force is probably Will-Force. If we are satis- 
fied that force or forces are all that exist in the ma- 
terial universe, we are next led to enquire what is 
force ? We are acquainted with two radically distinct 
or apparently distinct kinds of force the first consists 
of the primary forces of nature, such as gravitation, 
cohesion, repulsion, heat, electricity, &c. ; the second is 
our own will-force. Many persons will at once deny 
that the latter exists. It will be said, that it is a mere 
transformation of the primary forces before alluded to ; 
that the correlation of forces includes those of animal 
life, and that will itself is but the result of molecular 
change in the brain. I think, however, that it can 
be shown, that this latter assertion has neither been 
proved, nor even been proved to be possible; and 
that in making it, a great leap in the dark has 
been taken from the known to the unknown. It 
may be at once admitted that the muscular force 
of animals and men, is merely the transformed energy 


derived from the primary forces of nature. So much 
has been, if not rigidly proved, yet rendered highly 
probable, and it is in perfect accordance with all 
our knowledge of natural forces and natural laws. 
But it cannot be contended that the physiological 
balance-sheet has ever been so accurately struck, that 
we are entitled to say, not one-thousandth part of a 
grain more of force has been exerted by any organized 
body or in any part of it, than has been derived from 
the known primary forces of the material world. If 
that were so, it would absolutely negative the existence 
of will ; for if will is anything, it is a power that directs 
the action of the forces stored up in the body, and it 
is not conceivable that this direction can take place, 
without the exercise of some force in some part of the 
organism. However delicately a machine may be con- 
structed, with the most exquisitely contrived detents 
to release a weight or spring by the exertion of the 
smallest possible amount of force, some external force 
will always be required ; so, in the animal machine, how- 
ever minute may be the changes required in the cells or 
fibres of the brain, to set in motion the nerve currents 
which loosen or excite the pent up forces of certain 
muscles, some force must be required to effect those 
changes. If it is said, " those changes are automatic, 
and are set in motion by external causes," then one 
essential part of our consciousness, a certain amount 
of freedom in willing, is annihilated ; and it is incon- 
ceivable how or why there should have arisen any 
consciousness or any apparent will, in such purely 


automatic organisms. If this were so, our apparent 
WILL would be a delusion, and Professor Huxley's be- 
lief " that our volition counts for something as a con- 
dition of the course of events," would be fallacious, 
since our volition would then be but one link in the 
chain of events, counting for neither more nor less 
than any other link whatever. 

If, therefore, we have traced one force, however mi- 
nute, to an origin in our own WILL, while we have no 
knowledge of any other primary cause of force, it does 
not seem an improbable conclusion that all force may 
be will-force ; and thus, that the whole universe, is not 
merely dependent on, but actually is, the WILL of higher 
intelligences or of one Supreme Intelligence. It has 
been often said that the true poet is a seer : and in the 
noble verse of an American poetess, we find expressed, 
what may prove to be the highest fact of science, the 
noblest truth of philosophy : 

God of the Granite and the Rose ! 

Soul of the Sparrow and the Bee ! 
The mighty tide of Being flows 

Through countless channels, Lord, from thee. 
It leaps to life in grass and flowers, 

Through every grade of being runs, 
While from Creation's radiant towers 

Its glory flames in Stars and Suns. 


These speculations are usually held to be far beyond 
the bounds of science ; but they appear to me to be 
more legitimate deductions from the facts of science, 


than those which consist in reducing the whole universe, 
not merely to matter, but to matter conceived and 
defined so as to be philosophically inconceivable. It 
is surely a great step in advance, to get rid of the 
notion that matter is a thing of itself, which can exist 
per se, and must have been eternal, since it is supposed 
to be indestructible and uncreated, that force, or the 
forces of nature, are another thing, given or added to 
matter, or else its necessary properties, and that 
mind is yet another thing, either a product of this 
matter and its supposed inherent forces, or distinct 
from and co-existent with it ; and to be able to sub- 
stitute for this complicated theory, which leads to 
endless dilemmas and contradictions, the far simpler 
and more consistent belief, that matter, as an entity 
distinct from force, does not exist ; and that FORCE 
is a product of MIND. Philosophy had long demon- 
strated our incapacity to prove the existence of matter, 
as usually conceived ; while it admitted the demon- 
stration to each of us of our own self-conscious, ideal 
existence. Science has now worked its way up to 
the same result, and this agreement between them 

' O 

should give us some confidence in their combined 

The view we have now arrived at seems to me 
more grand and sublime, as well as far simpler, than 
any other. It exhibits the universe, as a universe 
of intelligence and will-power ; and by enabling us to 
rid ourselves of the impossibility of thinking of mind, 
but as connected with our old notions of matter, 

2 B 


opens up infinite possibilities of existence, connected 
with infinitely varied manifestations of force, totally 
distinct from, yet as real as, what we term matter. 

The grand law of continuity which we see pervading 
our universe, would lead us to infer infinite gradations 

/ o 

of existence, and to people all space with intelligence 
and will-power ; and, if so, we have no difficulty in 
believing that for so noble a purpose as the progressive 
development of higher and higher intelligences, those 
primal and general will-forces, which have sufficed 
for the production of the lower animals, should have 
been guided into new channels and made to converge 
in definite directions. And if, as seems to me probable, 
this has been done, I cannot admit that it in any 
degree affects the truth or generality of Mr. Darwin's 
great discovery. It merely shows, that the laws of 
organic development have been occasionally used for 
a special end, just as man uses them for his special 
ends ; and, I do not see that the law of " natural 
selection " can be said to be disproved, if it can be 
shown that man does not owe his entire physical and 
mental development to its unaided action, any more 
than it is disproved by the existence of the poodle 
or the pouter pigeon, the production of which may 
have been equally beyond its undirected power. 

The objections which in this essay 1 have taken, to 
the view, that the same law which appears to have 
sufficed for the development of animals, has been alone 
the cause of man's superior physical and mental nature, 
will, I have no doubt, be over-ruled and explained 



away. But I venture to think they will nevertheless 
maintain their ground, and that they can only be 
met by the discovery of new facts or new laws, of 
a nature very different from any yet known to us. 
I can only hope that my treatment of the subject, 
though necessarily very meagre, has been clear and 
intelligible ; and that it may prove suggestive, both 
to the opponents and to the upholders of the theory 
of Natural Selection. 

2 B 2 



AEEAXAS grossulariata, 119. 

Acanthotritus dorsalis, 94. 

Accipitcr pileatus, 107. 

ACR^EID.E, the subjects of mimicry, 
85, 86. 

Acronycta psi, protective colouring 
of, 62. 

ADAPTATION brought about by gene- 
ral laws, 276 ; looks like design, 

^EGERIID.E mimic Hymenoptera, 

AGASSIZ, or embryonic character of 
ancient animals, 301. 

Agnia fasciata, mimics another 
Longicorn, 95. 

Agriopis aprilina, protective colour- 
ing of, 62. 

ALCEDINID.E, sexual colouring and 
nidification of, 240. 

AMADIXA, sexual colouring and ni- 
dification of, 243. 

AMPELID.E, sexual colouring and 
nidification of, 243. 



Angr&cum sesquipedule, 272 ; its 

fertilization by a large moth, 

ANIMALS, senses and faculties of, 

127 ; intellect of, compared with 

that of savages, 341. 
AXOA, 196. 


ANTHRIBID.E, mimicry of, 94; di- 
morphism in, 155. 

Anthrocera filipendulce, 120. 

ANTHROPOLOGISTS, wide difference 
of opinion among, as to origin 
of human races, 304; conflict- 
ing views of, harmonized, 321. 

ANTIQUITY of man, 303, 322. 


APPARENT exceptions to law of co- 
lour and nidification, 253. 

AQUATIC birds, why abundant, 32. 

Araschnia prorsa, 154. 



ARCHITECTURE of most nations de- 
rivative, 228; Grecian, false in 
principle, 226. 

ARCTIC animals, white colour of, 
50, 51. 

ARGYLL, Duke of, on colours of 
Woodcock, 53 ; on mind in na- 
ture, 265; criticism on Darwin's 
works, 2G9 ; on humming birds 
282; on creation by birth, 287. 

ASILUS, 97. 

ASPECTS of nature as influencing 
man's development, 317. 

BALANCE in nature, 42. 
BARRINGTON, Hon. Daines, on song 
of bird?, 220. 




BATES, Mr., first adopted the word 
" mimicry," 75 ; his observations 
on Leptalis and Heliconidse, 82 ; 
his paper explaining the theory 
of mimicry, 83 ; objections to 
his theory, 108 ; on variation, 
165 ; on recent immigration of 
Amazonian Indians, 214. 

BAYMA, Mr., on "Molecular Me- 
chanics," 363, 364. 

BEAUTY in nature, 282; not uni- 
versal, 284 ; of flowers u c ef ul to 
them, 285; not given for its own 
sake, 285. 

BIRDS, possible rapid increase of, 
29 ; numbers that die annually, 
30 ; mimicry among, 103 ; dull 
colour of females, 114; nidi- 
fication as affecting colour of 
females, 116 ; refusing the 
gooseberry caterpillar, 119 ; the 
highest in rank and organiza. 
tion, 137 ; dimorphism in, 155 ; 
why peculiar nest built by each 
species, 215-219; build more per- 
fect nests as they grow older, 
224, 227; alter and improve 
their nests, 226; sexual differ- 
ences of colour in, 239. 

Bombus hortorurn, 90. 

Bombjcila garrula, colours and 
nidification of, 255. 


BRAIN of the savage but slightly 
less than that of civilized man, 
336 ; size of, an important ele- 
ment of mental power, 335 ; of 
savage races larger than their 
needs require, 338, 343 ; of man 

and of anthropoid apes com- 
pared, 338. 

BROCA, Professor Paul, on the fine 
crania of the cave men, 337. 

Bryophila glandijera and B. perl a 
protectively coloured, 63. 

BUCEROTIDJE, sexual colouring and 
nidification of, 241. 

BUCCOXID.E, sexual colouring and 
nidification of, 241. 

BUFF-TIP moth, resembles a broken 
stick, 62. 

BUILDINGS of various races do not 
change, 213. 

BUPRESTID.E, resembling bird'* 
dung, 57 ; similar colours in 
two sexes, 114. 

BUTTERFLIES, value of, in studying 
" natural selection," 131 ; varie- 
ties of, in Sardinia and Isle of 
Man, 178. 

CACIA anthriboules, 94. 

Callizona acesta. protective colour- 
ing of, 59. 


CAPITONID.E, sexual colouring and 
nidification of, 241. 

Capnolymma stygium, 94. 

CARABID.E, special protection 
among, 72 ; similar colouring 
of two sexes, 114. 

CASSID.E, resemble dew drops, 58. 

CATERPILLARS, mimicking a poi- 
sonous snake, 99 ; gaudy co- 
lours of, 117 ; various modes of 
protection of, 118; gooseberry 
caterpillar, 119 ; Mr. Jenner 
Weir's observations on, 119; 
Mr. A. G. Butler's observations 
on, 121. 


CELEBES, local modifications of 
form in, 170 ; probable cause of 
these, 176; remarkable zoolo- 
gical peculiarities of, 195-199. 

CENTROPUS, sexual colouring and 
nidification of, 242. 

Ccphalodonta spinipes, 92. 

Ceroxylus laceratus, imitates a 
moss covered stick, 64. 

CERTHIOLA, sexual colouring and 
nidification of, 244. 

Cethosia (sole, 172 ; biblis, 172. 

CETONIAD.E, how protected, 73; 
similar colours of two sexes, 


Charis melipona, 96. 

CIIEMATOBIA, wintry colours of this 
genus, 62. 

Chlamys pilula, resembles dung of 
caterpillars, 58. 

CIIRYSIDID.E, how protected, 72. 

CHRYSOMELID.E, similar colouring 
of two sexes, 1 14. 

CICINDELA, adaptive colour of va- 
rious species of, 57. 

Cilix compressa, resembles bird's 
dung, 63. 

CLADOBATES, mimicking squirrels, 

CLASSIFICATION, form of true, 6; 
circular, inadmissible, 8 ; quina- 
rian and circular, of Swainson, 
46; argument from, against 
Mr., 295. 

CLIMACTERIS, sexual colouring and 
nidification of, 243. 

COCCINELLID^E, how protected, 72; 
similar colouring of sexes, 114. 

COEXISTING varieties, 159. 

Colly r odes lacordairei, 95. 

COLOUR, in animals, popular theo- 
ries of, 47 ; frequent variations 
of, in domesticated animals, 48; 
influenced by need of conceal- 
ment, 49 ; in deserts, 49, 50 ; 
in Arctic regions, 50, 51 ; noc- 
turnal, 51 ; tropical, 52 ; special 
modifications of, 52 ; different 
distribution of, in butterflies 
and moths, 58 ; of autumnal 
and winter, moths, 62 ; white, 
generally dangerous and there- 
fore eliminated, 66 ; why it 
exists so abundantly although 
often injurious, 69 ; influenced 
by need of protection, 113; of 
female birds, 114; in relation to 
nidification of birds, 116 ; gaudy 
colours of many caterpillars, 
117; in nature, general causes 
of, 126 ; local variations of, 
173 ; sexual differences of, in 
birds, 239 ; in female birds, how 
connected with their nidifica- 
tion, 240, 246; more variable 
than structure or habits, and 
therefore more easily modified, 
249 ; of flowers, as explained by 
Mr. Darwin, 262 ; often corre- 
lated with disease, 316. 


Condylodera tricondyloides, 97. 

CONSCIOUSNESS, origin of, 360; 
Professor Tyndall on, 361 ; not 
a product of complex organiza- 
tion, 365. 

CORRELATION of growth, 310. 

Corynomalus sp., 92. 

COTINGID.E, sexual colouring and 
nidification of, 244. 

CRATOSOMUS, a hard weevil, 94. 



CRICKETS mimicking sand wasps, 


Oucullia verbasci, 120. 

CURCULIONID.E, often protected by 
hard covering, 71 ; similar co- 
lours of two sexes, 114. 

Cuviera squamata, 258. 

Cyclopeplus batesii, 92. 


Cynthia arsinoe, 172. 

DANAID.H, the subjects of mimi- 
cry, 85, 80. 

Danais erippus, 88; cfirysippus, 
112; sobrina, 179; aglaia, 179; 
tytia, 180. 

DARWIN, Mr., his principle of uti- 
lity, 47 ; on cause of colour in 
flowers, 127, 262 ; on colours of 
caterpillars, 118; on sexual co- 
louration, 260; his metaphors 
liable to misconception, 269 ; 
criticism of, in North British 
Review, 291. 

DESERT animals, colours of, 49, 50. 

DIADEMA, species of, mimic Danai- 
dre, 86, 87 : female with male 
colouration, 112. 

Diudema misippits, 112; D. ano- 
mala, 113. 

Diaphora mendica, 89. 



Diloba cxruleoccphala, 120. 

DIMORPHISM, 145 ; in beetles, 155 ; 

in birds, 155 ; illustrated, 157. 
DIPTERA mimicking wasps and 

bees, 97. 

ionLls*, 91. 

DOMESTICATED animals, their essen- 
tial difference from wild one?, 


DRUSILLA, mimicked by three ge- 
nera, 181. 

Drusilla bioculata, 180. 
DVTISCUS, dimorphism in, 155. 

EGYPTIAN architecture, intro- 
duced, 225. 

Elapsfulvius, E. corcdlinus, E. lem- 
niscatus, 101 ; E. mipartitus, E. 
lemniscatus, E. hemiprichii, 102. 

ENODES, 196. 

EXNOMUS, autumnal colours of this 
genus, 62. 

Eosfuscata, dimorphism of, 155. 

EQUUS, 299. 

Eronia tritcea, 172; Valeria, 172. 

Eroschema poweri, 93. 

ERYCINID.E mimic Heliconidag, 84. 

Erythroplatis corallifer, 92. 

ESTRELDA, sexual colouring and 
nidification of, 243. 

EUCNEMID.E, mimicking a Malaco- 
derm, 93. 

Eudroniias morinellus, 251. 

Euglossa dimidiata, 98. 

EUMORPHID,E, a protected group, 
72 ; imitated by Longicorns, 92. 

EUPLOSA, local modifications of co- 
lour in, 173. 

Euploea midamus, 87-113, 179 ; 
E. rhadamantkus, 87, 179. 

Eurhinia megalonice, 172; poly- 
nice, 17:\ 

EURYL.EMID.E, sexual colouring and 
nidification of, 243. 

EXTINCT animala, intermediate 
forms of, 298. 



EXTINCTION of lower races, 318. 

FEMALE birds, colours of, 114; 
sometimes connected with their 
mode of nidification, 240 ; more 
exposed to enemies than the 
males, 248. 

FEMALE butterflies generally dull- 
coloured, 259. 

FEMALE insects, mimicry by, 110, 
259; colours of, 113. 

FEMALE sex, has no incapacity for 
as brilliant colouration as the 
male, 247 ; in some groups re- 
quires more protection than the 
male, 258. 

FISHES, protective colouring of, 55. 

FISSIROSTRAL birds, nests of, 238. 

FLOWERS, causes of colour in, 127. 

FLYCATCHERS, genera of, absent 
from Celebes, 177. 

FORBES, EDWARD, objections to his 
theory of Polarity, 17-23. 

FORCE is probably all Will-force, 


GALTOX, Mr., on range of intellec- 
tual power, 339. 


GastropacJia qucrci, protective co- 
lour and form of, 6:?. 

GAUDRV, M., on fossil mammals of 
Greece, 299. 

GEOGRAPHICAL distribution, de- 
pendent on geologic changes, 1 ; 
its agreement with law of in- 
troduction of new species, 9 ; 
of allied species and groups, 12. 

GEOLOGICAL distribution analogous 
to geographical, 13. 

GEOLOGY, facts proved by, 2-5. 

GIRAFFE, how it acquired its long 
neck, 42. 

GL.EA, autumnal colours of this 
genus, 62. 

GOULD, Mr., on sexual plumage of 
Gray Phalarope, 115; on incu- 
bation by male Dotterell, 115. 

Grallina ausindis, 254. 

GREEN birds almost confined to 
the tropics, 52. 

G-ymnocerus cratosomoides, 94. 

Gymnocerous capucinus, 96. 

Gymnocerous dulcissimus, 97. 

GUNTIIER, Dr., on arboreal snakes, 
55 ; on colouring of snakes, 102. 

G-ynecia dirce, 59. 

HABITS, often persistent when 
use of them has ceased, 234 ; of 
children and savages analogous 
to those of animals, 235 ; if 
persistent and imitative may be 
termed hereditary, 235, 236. 

HAIRY covering of Mammalia, use 
of, 344 ; absence of, in man re- 
markable, 345; the want of it 
felt by savages, 346 ; could not 
have been abolished by natural 
selection, 348. 

Harpagus diodon, 107. 

HEILIPLUS, a hard genus of Cur- 
culionidae, 94. 

HELICON ID.E, the objects of mimi- 
cry, 77 ; their secretions, 88 ; 
not attacked by birds, 79; some- 
times mimicked by other Heli- 
conidjE, 85. 


HEMIPTERA, protected by bad 
odour, 72. 



HERBERT, Rev. W., on song of 

birds, 221. 
HESPERID.E, probable means of 

protection of, 176. 
HESTIIESLS, longicorns resembling 

ants, 96. 

Hestia leuconoe, 180. 
HEWITSON, Mr., 131. 


HISPID.E, imitated by Longicorns, 


Homalocranium semicinctum, 101. 
HOOKER, Dr., on the value of the 

" specific term," 165. 
HOUSES of American and Malay 

races contrasted, 213. 
HUXLEY, Professor, on " Physical 

Basis of Life," 362 ; on volition, 


HYBERNIA, wintry colours of this 

genus, 62. 
HYMENOPTERA, large number of, 

peculiar to Celebes, 196. 

ICTERID JE, sexual colouring and 
nidification of, 244. 


Ideopsis daos, 180. 

IMITATION, the effects of, in man's 
works, 212. 

INDIANS, how they travel through 
trackless forests, 207. 

INSECTS, protective colouring of, 
56 : mimicking species of other 
orders, 97 ; senses of, perhaps 
different from ours, 202, 203. 

INSTINCT, how it may be best stu- 
died, 201 ; definition of, 203 ; 

in many cases assumed without 
proof, 205 ; if possessed by man, 
206 ; supposed, of Indians, 207 ; 
supposed to be shown in the 
construction of birds' nests, 211. 

INTELLECT of savages compared 
with that of animals, 341. 

INTELLECTUAL power, range of, in 
man, 339. 

Iphias glaucippe, 172. 

ITHOMIA, mimicked by Leptalis, 83. 

Ithomia ilerdina, mimicked by four 
groups of Lepidoptera, 84. 

JAVA, relations of, to Sumatra 

and Borneo, 193. 
JAMAICA swift altering position of 

nest, 228. 
JERDON, Mr., on incubation by 

males in Turnix, 115. 

KALLIMA inavhis and Kallima 
paraleJcta, wonderful resem- 
blance of, to leaves, 59-61. 


LAKES as cases of imperfect adapt- 
ation, 278. 

LANIAD.E, sexual colouring and ni- 
dification of, 245. 

LAMARCK'S hypothesis very dif- 
ferent from the author's, 41. 

Larentia tripunctaria, 63. 

LAW which has regulated the in- 
troduction of new species, 5 ; 
confirmed by geographical dis- 
tribution, 9 ; high organization 
of ancient animals consistent 
with, 14; of multiplication in 
geometrical progression, 265 ; 



of limited populations, 265 ; of 
heredity, 266 ; of variation, 
266 ; of change of physical con- 
ditions, 266 ; of the equilibrium 
of nature, 266 ; as opposed to 
continual interference, 268. 

LAY COCK, Dr., on law of " uncon- 
scious intelligence," 360. 

LEAP BUTTERFLY, appearance and 
habits of, 59-61. 

LEPIDOPTEUA, especially subject to 
variation, 132. 

LEPTALIS, species of mimic Ileli- 
conidte, 82 ; gain a protection 
thereby, 259. 

LESTER, Mr. J. M., on wood-dove 
and robin, 53. 

LEVAILLANT, on formation of a 
nest, 224. 

Limenltis archippus, 88. 

Limenitis limire, 172 ; procris, 172. 

LIZARDS refusing certain moths 
and caterpillars, 121 ; devour- 
ing bees, 121. 


LOCAL variation of form, 169 ; of 
colour, 173 ; general remarks 
on, 174 ; in Celebesian butter- 
flies, probable use of, 175. 

LOCUSTID.E, adaptive colouring of, 

LUMIXOUSNESS of some insects a 
protection, 71. 

LYC.EXID.E, probable means of pro- 
tection of, 176. 

MAMMALS, mimicry among, 107. 

MAX, does he build by reason or 
imitation, 212; his works mainly 
imitative, 225 ; antiquity of, 303, 
322 ; difference of opinion as to 

his origin, 304 ; unity or plural- 
ity of species, 305 ; persistence 
of type of, 306 ; importance of 
mental and moral characters, 
312; his dignity and supremacy, 
324 ; his influence on nature, 
326; his future development, 
326; range of intellectual power 
in, 339; rudiments of all the 
higher faculties in savage, 341 ; 
his feet and hands, difficulties 
on the theory of natural selec- 
tion, 349: his voice, 350; his 
mental faculties, 351 ; difficulty 
as to the origin of the moral 
sense in, 352 ; development of, 
probably directed by a superior 
intelligence, 359. 

MANTID.E, adaptive colouring of, 
64 ; mimicking white ants, 98. 

MALACODEKMS, a protected group, 


MATTER, the nature of, 363 ; Mr. 
Bayma on, 363 ; is force, 365. 

MECHANITIS and Methona, mi- 
micked by Leptalis, 83. 

MECOCERUS, dimorphism of, 155. 

Mecocerus gazella, 94. 


MEGAPODID.E, sexual colouring and 
nidification of, 246. 


Midas dives, 97. 

MIMETA, mimicking Tropidorhyn- 
chus, 104. 

MIMICRY, meaning of the word, 
74 ; theory of, 76 ; among Lepi- 
doptera, 77 ; how it acts as a 
protection, 80, 81 ; of other in- 
sects by Lepidoptera, 89; among 



beetles, 91 ; of other insects b'y 
beetles, 95 ; of insects by species 
of other orders, 97 ; among the 
vertebrate,, 99; among snake?, 
101 ; among tree frogs, 103 ; 
among birds, 103; among mam- 
mals, 107 ; objections to the 
theory of, 108 ; by female in- 
sects, 110; among Papilionida^ 
179; never occurs in the male 
only, 2; 0. 

MOMOTID.E, sexual colouring and 
nidification of, 241. 

MONTROUZIER, M., on butterflies 
of Woodlark Island, 152. 

MORAL sense, difficulty as to the 
origin of, 352. 

MORPIIOS, how protected, 73. 

MURRAY, Mr. Andrew, objections 
to theory of mimicry, 108. 

MUSCICAPID.E, sexual colouring 
and nidification of, 245. 

MUSOPIIAGID.E, sexual colouring 
and nidification of, 242. 

NAPEOGENES, all the species 

\ are miraickers, 85. 

NATURAL selection, the principle 
stated, 41-43; general accept- 
ance of the theory of, 46 ; 
tabular demonstration of, 302 ; 
outline of theory of, 307 ; its 
effects on man and animals dif- 
ferent, 311 ; hardly acts among 
civilized societies, 330 ; what it 
can not do, 333 ; cannot pro- 
duce injurious or useless modi- 
fications, 334. 


NECYDALIDJJ, mimic Hymenop- 
tera, 96. 

Nemophas grayi, a Longicorn mi- 
micked by a Longicorn, 95. 

NESTS of Birds, why different, 
215 ; of young birds, how built, 
219; construction of, described 
by Levaillant, 224; imperfec- 
tions in, 229 ; influenced by 
changed conditions and per- 
sistent habits, 232 ; classification 
of, according to function, 237. 

NEW FORMS, how produced by 
variation and selection, 286. 

NEW GUINEA, relation of the seve- 
ral Papuan islands to, 194. 

NOCTURNAL animals, colours of, 

NOMADA, 98. 

OBEREA, species resemble Ten- 
thredinidae, 96. 

Odontocera odyneroides, 96. 


Odynerus sinuatus, 90. 

Onthophilus sulcatus, like a seed, 

Onychocerus scorpio, resembles 
bark, 56. 

ORANGE TIP butterfly, protective 
colouring of, 59. 

ORCHIS, structure of an, explained 
by natural selection, 271. 

Orgyia antiqua and 0. gonoatigma, 
autumnal colours of, 62. 


Ornithoptera priamus, 145, 173 ; 
0. kelcna, 173. 

Oxyrhopus petolarius, 0. trigemi- 
nus, 0. formosus, 102. 

CWEX, Professor, on more gene- 
ralized structure of extinct ani- 
mals, 298. 



PA CHYO TRIS fabricii, 96. 

PACHYRIIYXCIII, weevils mimicked 
by Longicorns, 95. 



PAPILIO, black and red group imi- 
tated, 84. 

Papilio achates, 147 ; P. adaman- 
tius, 111 ; P. (Enigma, 87 ; P. 
agamernnon, 141, 158, 170, 171 ; 
P. agestor, 180 ; P. alpkenor, 
148, 169 ; P. amanga, 151 ; P. 
androcles, 171 ; P. androgeus, 88, 
147, 180, 183; P. antiphates, 
141, 171 ; P. antiphus, 87, 150, 
170, 180, 183 ; P. aristaws. 171 ; 
P. arjuna, 141 ; P. ascalaphits, 
171 ; P. autolycus, 160 ; P. bathy- 
clcs, 141 ; P. blumei, 171 ; P. 
brama, 171 ; P. caunus, 87, 179 ; 
P. corfrws, 160, 171 ; P. cow?, 88, 
146, 180, 182 ; P. deiphobus, 140 ; 
P. deiphontes, 171 ; P. delessertii, 
180 ; P. demotion, 171 ; P. c%Ai- 
foa, 87, 170, 180, 183 ; P. double- 
day i, 88, 180; P. elyros, 148 ; P. 
encelades, 171 ; P. erect heiis, 151 ; 
P. euripilus, 160; P. evcmon, 
159 ; P. gigon, 171 ; P. glaucus, 
152; P. focfor, 87, 150, 180, 183; 
P. Menus, 160, 171 ; P. hospi- 
ton, 178; P. idaoides, 180; P. 
;Vwo, 159, 171 ; P. ledebouria, 
148 ; P. lettcotkoe, 171 ; P. ?eorfa- 
mas, 170 ; P. Kris, 87, 1< Q ,0, 184 ; 
P. macareus, 179; P. mackaon, 
178 ; P. melanides, 148, 150 ; P. 
memnon, 88, 140, 146, 117, 152, 
180, 183; P. wztfow, 171; P. ne . 
jjhelus, 140; P, meaner, 170; P 
cenomaus, 88, 180, 184; P.onesi- 

mus, 151 ; P. ormcnus, 150, 152, 
182; P.pammon, 147, 152, 170, 
180; P. pamphylus, 171; P. 
pandion, 152, 180; P. paradoxa, 
87, 179 ; P. peranthus, 160, 171 ; 
P. pcrtinctXj 145 ; P. philoxenus, 
182 ; P. polydorus, 88, 170, 182 ; 
P. polytes, 147, 148 ; P. rfosus, 
171 ; P. romulus, 87, 143, 15'J, 
183 ; P. sarpedon, 141, 158, 171 ; 
P. sataspes, 171 ; P. sevcnts, 
140, 144; P. f&wews, 87, 148, 
150, 169, 170, 171, 180, 183 : P. 
fAwfe, 179; P. torquatus, 156; 
P. turnus, 152; P. ulysses, 140, 
160, 173; P.varuna, 88. 

PAPILIONID.E, the question of their 
rank, 133 ; peculiar characters 
possessed by, 134; peculiarly 
diurnal, 136; compared with 
groups of mammalia, 138 ; dis- 
tribution of, 140 ; large forms 
of Celebes and Moluccas, 168; 
large forms of Amboyna, 169; 
local variation of form, 139; 
arrangement of, 186 ; geogra- 
phical distribution of, 189 ; of 
Indo-Malay and Austro-Malay 
regions, 192; of Java, Suma- 
tra, and Borneo, 193. 

PARID.E, sexual colouring and nidi- 
fication of, 243. 

PASSENGER pigeon, cause of its 
great numbers, 308. 

PATENT inventions, as illustrating 
classification, 295. 

Phacellocsra bates ii, mimics one of 
the Anthribklas. 

Phalaropusfulicarius, 115, 251., imitate sticks and 



twig?, 64 ; females resembling 
leaves, 112. 

PIIYLLIUM, wonderful protective 
colour and form of, 64. 


PIERID.E, local modification of 
form in, 172. 

PIEKIS, females only imitating 
Heliconidse, 112. 

Pier is coronis, 172; eperia, 172. 

Pieris pyrrha, 113. 

PICID.E, sexual colouring and nidi- 
fication of, 242. 

PIPRID.E, sexual colouring and 
nidification of, 245. 

PITTID^, 253. 

Pliocerus egualis, 101 ; P. elapoides, 
P. euryzonus. 102. 

Pfsciloderma terminate, 93. 

POLARITY, Forbes' theory of, 17, 

POLYMORPHISM, 145; illustration 
of, 157. 

POPULATION of species, law of, 28 ; 
does not permanently increase, 
29; not determined by abun- 
dance of offspring, 29; checks 
to, 30 ; difference in the case of 
cats and rabbits explained, 32. 

PREVISION, a case of, 122. 


PROTECTION, various modes in 
which animals obtain it, 69-71, 
258 ; greater need of, in female 
insects and bird?, 113. 

PROTECTIVE colouring, theory of, 

PSITTACI (Parrots), sexual colour- 
ing and nidification of, 42. 



EACES, or subspecies, 160; of 
man, origin of, 319. 

EEDBREAST and woodpigeon, pro- 
tective colouring of, 53, 54. 

EEPRESENTATIVE groups, 9; of Tro- 
gons, butterflies, &c., 12. 

EEPTILES, protective colouring of, 

EIIAMPHASTID.E, sexual colouring 
and nidification of, 242. 


EIVER system, as illustrating self- 
adaptation, 276. 

EOSES, Mr. Baker on varieties of, 

EUDIMENTARY organs, 23. 

SALVIN, Mr. Osbert, on a case of 
bird mimicry, 107. 

Saturn ia pavonia-minor, protective 
colouring of larva of, 63. 

SATYRLD.E, probable means of pro- 
tection of, 176. 


SAVAGES, why they become extinct, 
319 ; undeveloped intellect of, 
339, 341 ; intellect of, compared 
with that of animals, 341, 343; 
protect their backs from rain, 

SCANSORIAL birds, nests of, 238. 



SCOPULIPEDES, brush-legged bees, 

ScuDDER,Mr.,on fossil insects, 301. 

SCUTELLERID.E, mimicked by Long- 
icorns, 96. 

Sesia bombiliformis, 90. 

SESUD.E, mimic Hymenoptera, 90. 

SEXES, comparative importance of, 



in different classes of animals, 
111; diverse habits of, 156. 

SEXUAL SELECTION, 156; its nor- 
mal action to develop colour in 
both sexes, 247; among birds, 

SIDGWICK, Mr. A., on protective 
colouring of moths, 62. 


SITTA, sexual colouring and nidi- 
fication of, 243. 

SITTELLA, sexual colouring and 
nidification of, 243. 

SNAKES, mimicry among, 101. 

SONG of birds, instinctive or imita- 
tive, 220. 

SPECIES, law of population of, 28 ; 
abundance or rarity of, depend- 
ent on the adaptation to condi- 
tions, 33; definition of, 141, 
161 ; the range and constancy 
of, 143; extreme variation in, 
163, 164. 

SPEED of animals, limits of, 292. 

Sphecia craboniforme, 90. 

Sphecomorpha chalybea, 96. 

SPIIEGID.E, mimicked by flies, 97. 

SPIDERS, which minac ants, 98 ; 
and flower buds, 99. 

Spilosoma menthastri, 88. 

STAINTON, Mr., on moths rejected 
by turkeys, 78, 88. 

STALACIITIS, a genus of Erycinida?, 
the object of mimicry, 84. 

STINGING insects generally conspi- 
cuously coloured, 72. 


STUKNID.E, sexual colouring and 
nidification of, 244. 


ST. HELENA, 10. 

Streptolabis hispoides, 93. 

STRUGGLE for existence, 28, 33. 

SURVIVAL of the fittest, law of, 
stated, 33 ; its action in deter- 
mining colour, 67. 

SWAINSON'S circular and quinarian 
theory, 45. 

SYLVIAD.E, sexual colouring and 
nidification of, 245. 

SYNAPTA, 258. 

TACHORNIS pJuenicobea, 228. 
Tachyris hombronii, 172; it home, 

172 ; lycaste, 172 ; lyncida, 172 ; 

nephele, 172; nero, 172; zarinda, 

TANAGRID/E, sexual colouring and 

nidification of, 245. 
TAPIR, 299. 
TELEPHORI, similar colouring of 

two sexes, 114. 

TEMPERATE and cold climates fa- 
vourable to civilization, 318. 
TIIEUATES, mimicked by Hetero- 

mera, 95. 
Thyca descombesi, 172 ; Jiyparete, 

172; rosenbergii, 172; zebudn, 


TIGER, adaptive colouring of, 52. 
TIMES newspaper on Natural Selec- 
tion, 296. 
TOOLS, importance of, to man, 

TREE FROGS, probable mimicry by, 


TRIMEX, Mr., on rank of the Papi- 

lionidw, 136. 
TRISTRAM, Kev. II., on colours of 

desert animals, 50, 



TrcchUium tipuliforme, 90. 

TROGONID.E, sexual colouring and 

. nidification of, 241. 

TROPICAL birds often green, 52. 

TROPICS, most favourable to pro- 
duction of perfect adaptation 
among animals, 68 ; not favour- 
able to growth of civilization, 
318. ' 

orioles, 104. 

TRUTHFULNESS of some savages, 
353 ; not to be explained on 
utilitarian hypothesis, 354. 

TURDID.E, sexual colouring and 
nidification of, 245. 

TURNIX, 115, 251. 

TYNDALL, Professor, on origin of 
consciousness, 361. 

TJPUPID^E, sexual colouring and 
nidification of. 241. 

USEFUL and useless variations, 34. 

UTILITY, importance of the prin- 
ciple of, 47, 127. 

VARIABILITY, simple, 144. 

VARIATIONS, useful and useless, 34; 
laws of, 143, 266; as influenced 
by locality, 166 ; of size, 168 ; 
universality of, 287-291 ; are 
there limits to, 291 ; of domestic 
dogs, 293 ; of pigeons, 293. 

VARIETIES, instability of, supposed 
to prove the permanent dis- 
tinctness of species, 26; if su- 
perior will extirpate original 
species, 36; its reversion then 
impossible, 37 ; of domesticated 
animals may partially revert, 

38, 40; inconvenience of u<ing 

the term, 161. 

VERTEBRATA, mimicry among, 99. 
VOICE of man, not explained by 

natural selection, 350. 
VOLUCELLA, species of mimic bees, 

75, 98. 

WALSH. Mr., on dimorphism, of 
Papilio turnus, 153. 

WEAPONS and tools, how they 
affect man's progress, 314. 

WEEVILS often resemble small 
lumps of earth, 58. 

WEIR, Mr. Jenner, on a moth 
refused by birds, 89 ; on beetles 
refused by birds, 93 ; on cater- 
pillars eaten and rejected by 
birds, 119. 

WESTWOOD, Professor, objections 
to theory of mimicry, 108. 

WHITE colour in domesticated and 
wild animals, 66. 

WILD and domesticated animals, 
essential differences of, 38-41. 

WILL really exerts force, 357 ; 
probably the primary source of 
force, 368. 

WOOD, Mr. T. W., on orange-tip 
butterfly, 59. 

WOODCOCKS and Snipes, protective 
colouring of, 5'3. 

WOODPECKERS, why scarce in Eng- 
land, 32. 

XANTHIA, autumnal colours of 
these moths, 62. 

ZEBRAS, 299.