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Full text of "The structure of animal life : Six lectures delivered at the Brooklyn Academy of Music in January and February, 1862"

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QforncU Ittioeraitg ffiibrarg 







Cornell University Library 
QL 799.A26 

The structure of animal life.SIx lecture 

3 1924 004 974 782 

The original of tiiis book is in 
tine Cornell University Library. 

There are no known copyright restrictions in 
the United States on the use of the text. 















Entered according toSict of vonCTfi^, in th,e year 1865, ty 


President of the Brooklyn Institute, 

in the Clerk's Office of the District Court of the United States for the SouCharn 

District of New York. 





I. Four Different Plans of Stkuctuee among 

Animals 1-24 

II. Relative Standing oe Gradation of the 

Animal Kingdom 25-46 

III. Remote Antiqthtt of Animal Life as shown 


IV". Physical History op the Earth. — Man 

THE Ultimate Object .... 69-89 

V. Triple Coincidence in the Succession, Gra- 
dation, AND Growth of Animals . . 90-110 
VI. Evidence of an Intelligent and constant- 
ly Creative Mind in the Plans and "Ma- 
RiATioNS OP Structure .... 111-128 


In bequeathing to the Brooklyn Institute a 
fund the interest of which was to be applied to 
the purchase of pictures by the best American 
artists, Mr. Graham, no doubt, proposed to him- 
self gradually to build up a gallery in Brooklyn 
which should show to future generations the state 
of the arts in the past. So also, in these lectures, 
which we have denominated the " Graham Lec- 
tures," he designed to supply a series of lectures 
by men of the highest hterature and science, 
which, by being published, should furnish a series 
of authors that would evince to future ages the 
progress of thought and talent among their ances- 
tors, and become a valuable part of the literature 
of our country. 

For these lectures he designed that the proofs 
of the "Power, Wisdom, and Goodness of God" 
should be drawn directly from His works, as they 
exist in, and in fact constitute nature. The obvious 
teaching of the creg,tion can hardly be questioned. 
Every man is, in some measure, an admirer of the 
works of God. From the moment when, as a child, 


the flowers attract his attention, to mature years. 
Nature is presented to him, in her various forms, 
harmonies, and adaptations, and becomes a subject 
of study and admiration, " especially to one who," 
as Saint Pierre remarks, "stops at every step, 
transported by the beauty and sublimity of her 
divine works." 

Students and men of science acquire a more 
minute knowledge, and learn those interior facts 
which escape the common observer. The man of 
science, therefore, wiU trace the hand of God, His 
skill, goodness, and wisdom, at every step of prog- 
ress in his studies. He will discover more minutely 
that sublime wisdom which has made the wonder- 
ful organisms of plants and animals, and arranged 
the immensity of nature. 

. Modern science has very much extended the 
fields of study by its discoveries, and has greatly 
enlarged our knowledge of the extent and variety 
of creation. 

Not only does the profound thinker observe the 
harmonies and adaptations of God's works in the 
visible creation, but he is led to study the no less 
wonderful harmonies to be found in the intellect, 
the morals, and the affections of men. All become 
to him the subjects of study and admiration. 
Nature, in the largest sense of the word, may 
be considered to include all created things, with 
their habits, and the laws by which they are gov- 


erned, and by whicli they operate. Thus all that 
we call art is but the effect of the natural laws 
which the Creator has given to his creature man, 
and which He has stamped upon his nature. Thus 
the works of man, as well as those works with 
which he has no power to interfere, are but a part 
of God's design. The works which grow out of 
man's skill are derived from the nature and capa- 
city bestowed upon man by his Creator. The artis- 
tic dwelling, and the steamship, no less than the 
house and dam of the beaver, the ant-hill, and the 
bird's-nest, are, in this consideration, a part of 
Nature's works. They grow out of that nature, 
and the laws by which it operates and by which 
it is developed. Thus the languages, the archi- 
tecture, cities, the codes of laws, the systems of 
religion, the fashions of men, their institutions and 
civilizations, their progressions in arts, wisdom, 
and virtue, considered in the largest sense, no less 
than those works over which man has no control, 
— ^^the rising and setting sun, the flowing tides, the, 
seasons, the rolling earth, — are but one great Na- 
ture; all are but the artistic design and work of 
God, in the creation of this and of all other worlds. 
Thus it will be seen that the field chosen by Mr. 
Graham for these lectures is sufficiently ample, 
and the subjects indicated may be considered as 

The works of God appear to be- the proper study 


of mankind. By this they learn the character and 
attributes of the Creator; they harmonize their 
lives thereby ; they learn skill and wisdom to fulfil 
their duties over such of God's works as are, either 
in whole or in part, under their control, and which 
constitute their art, and make up the sum of their 
work on earth ; enabling them, in their degree, to 
fulfil that sublime precept " be ye perfect, even as 
your Father which is in heaven is perfect." 

It is to the profound thinkers, to men of sci- 
ence, that we must principally look for these lec- 
tures. Such we are proud to know abound in our 
country, who have extended their studies in vari- 
ous directions far into the domain of Nature. 

It is with great satisfaction we lay before the 

public this course of lectures by Professor Agassiz. 

They have been somewhat delayed, owing, no 

doubt, to his various scientific engagements and 

the complexity of his researches. 

PETER G. TAYLOR, President. 

OLIVER HULL, Vice-Pebsidbnt. 

THOMAS ROWE, Treasuker. 

JOHN W. PRAY, Secretary. ' 





CHARLES H. BAXTER, L Directors. 









Ladies and Gentlemen : — You are aware that in 
conformity with, the foundation of this course of 
Lectures, of which mine are to form a part, a spe- 
cial object is assigned to them ; and considering the 
position in which I have been reported to stand 
with reference to my opinions in matters of sci- 
ence, I feel bound in frankness to explain to you, 
before I proceed to my subject, in what light I 
view the study of nature, and in what way it may 
promote the object that these lectures are espe- 
cially intended to further. 

The study of nature has one great object which 
fairly comes within the scope of the foundation of 
this course of lectures,; it is to trace the connec- 
tion between all created beings, to discover, if pos- 
sible, the plan according to which they have been 
created, and to search out their relation to the 
great Author. 


But if science is to contribute its share to the 
recognition of the existence of God, — if it is to 
lead the way to Him, from the study of His works, 
that study must be independent of every other 
influence; and he who undertakes to state what 
science has developed with reference to this ques- 
tion must not allow other and antecedent consid- 
erations or convictions to interfere. Hence the 
necessity I feel of presenting to you the results of 
science in this unbiased spirit. 

I know that I have been considered by many 
persons an infidel, because I have not taken for 
my guidance in the study of science the dictum 
of certain creeds. But science cannot submit to 
dictation, it must buUd up what it seeks upon the 
premises which it finds. Let us be content if the 
results lead to the same conclusion ; we shall 
stand then in the position of one who, having been 
brought up in the religion of his parents, and 
having been led astray by doubts, has at length, 
under the influence of a better frame of mind 
and of sober thought, come to reconsider the basis 
of his doubts, and by laborious investigation has 
returned to the faith he had forsaken. 

Such is the position of science. It is the ques- 
tioning, the doubting element in human progress ; 
and when that has gone far enough, it begins the 
work of reconstruction in such a way as will never 
harm true religion, or cause any reasonable appre- 
hension to the real and sincere Christian. Such 
is my conviction ; and while I am considered on 
one side as an infidel, and decried on the other, in 


scientific circles, as a J)igot, as one who . follows 
the lead of a creed rather than that of science, I 
feel bound to say that I am neither ; and that, if 
you will receive these lectures ih the simplicity 
with which I offer them, you will find I have not 
deceived you. 

I shall of necessity limit my remarks to the 
consideration of the animfil kingdom, because it is 
the branch of Natural History with which I am 
most familiar, and respecting which I can present 
views which are the result of my own investiga- 
tion, during a lifetime devoted to the contempla- 
tion of nature. The importance of the study of 
the animal kingdom with reference to ,its manifes- 
tation of the power, wisdom,- and goodness of God;' 
is very great. But this is shown only as we ad- 
vance in the knowledge of the phenomena pre- 
sented by the animal kingdom. 

At this moment natural history can show not 
only that there is a plan in the creation of the 
animal kingdom, but that the plan has been pre- 
conceived, has been laid out in the course of time, 
and executed with the definite object of introduc- 
ing man upon the earth. When naturalists first 
approached the study of the animal world, they 
could hardly recognize any system among animals, 
or ascertain the vaguest relation between them, on 
account of their extraordinary diversity and their 
diffusion over the whole surface of the earth, which 
rendered it extremely difficult to get access to all 
the different representatives of the animal king- 
dom. Hence, as a natural consequence, their first 


study was directed to external appearances. They 
endeavored to classify animals according to their 
most obvious resemblances and differences. They 
put all the aquatic animals in one division under 
the name of Fish, and arranged all the terrestrial 
animals under a few classes. Those without legs 
they called Reptiles; those with wings, Birds; those 
that walked on all-fours. Quadrupeds; and those 
who walked on two feet. Bipeds. Next, further 
distinctions were recognized, as bringing fortlji liv- 
ing young or laying eggs, breathing through gills 
or through lungs, and such most obvious feat- 
ures. But such classifications brought together a 
variety of beings which did not belong together, 
showing that the method of classification was ilot 
natural. - 

Then followed, in the further study, a survey of 
the structure of animals. This was a better guide 
for classification, and anatomy became the founda- 
tion of the systems of Zoology. Animals were 
arranged according to their structure, and the mo- 
ment that key-note was struck an immense prog- 
ress began. Very soon it appeared that internal 
structure brought animals much more closely 
together, according to their real afl&nity, than 
features in their external appearance; and fol- 
lowing the lead of Cuvier, since the beginning of 
this century, we have made such progress that 
we may safely say that at this moment the gen- 
eral affinities or relations among the greater num- 
ber of animals are satisfactorily known, and that 
the whole animal kingdom is now classified in 


a manner not likely to undergo any great modi- 
fication, except in the details. 

But yet one thought lingered in these classi- 
fications which was not true to nature. Those 
who presented them to the world supposed that 
they exhibited systems devised by themselves, 
methods of their own ingenuity; and hence they 
were put forth as the system of this or that 

But while comparing the difierent systems with 
one another, it became apparent to those who 
sought to trace the source of their resemblances, 
that, however ingenious, they all agreed in certain 
respects, and that the discrepancies between the 
different systems tended more and more to agree- 
ment, leading to the conclusion, that, after all, 
these systems might not be the inventions of 
their supposed authors, but only their difierent 
readings of the systems really existing in nature, 
and that all the classifications might perhaps be 
only difierent translations of one great system. 
And the moment this suggested itself it became 
self-evident that the work of naturalists, instead 
of consisting of ingenious devices for classifica- 
tion, was henceforth to consist only in an attempt 
to read more and more accurately a work in 
which they had no part, a work which displayed 
the thought of a mind more comprehensive than 
their own, which called into existence the various 
beings that we see around us, and established their 
classification. It is now, therefore, the task of 
the naturaliftt to read the thoughts of that mind 


as expressed in the living realities that surround 
us ; and the more we give up our own conceit in 
this work, the less selfish we become, the more 
we shall discern, the deeper we shall read, and 
the nearer shall we come to nature. It is to this 
attempt at presenting a translation, made con- 
scientiously after reading this plan, that I ask 
your attention at this time. I shall , endeavor 
to show you, that there is really a plan — a 
thoughtful plan — a plan which may be read — 
in the relations which you and I, and all living 
beings scattered over the surface of our earth, 
hold to one another. 

In another lecture I shall attempt to prove 
that the animal world which now exists on the 
globe is not the same that existed in earlier 
times, and I shall endeavor to point out their 
relations to each other, to show you when these 
animals were first called into existence, how they 
have followed one another, and what has been 
the thought running through the succession of 
creations, from the beginning, down to the time 
when, as the crowning act of the Creator, man was 
placed on the earth at the head of creation. 

It was Cuvier who first recognized the fact that 
the animal kingdom is constructed upon a plan, 
though that plan did not necessarily imply, ac- 
cording to Cuvier, a conception by an intelligent 
author. Cuvier only recognized certain structural 
complications among animals, which brought them 
together in accordance with the resemblance of 
their combinations. He recognized four such 


plans, and showed that all animals, however di- 
versified, are built upon these four plans ; and all 
investigation since that time has only confirmed 
his discovery. It is true, some naturalists have 
attempted to show that there are more than four 
. plans, some maintaining that there are five or six, 
others, even as many as seven or eight; but I 
think we shall find that they have confounded two 
distinct ideas, — that of plan with complication of 
structure ; in other words, that, as the same plan is 
susceptible of several modes of execution, it is 
therefore possible to confound the mode of execu- 
tion with the plan ; and this is the mistake into 
which I think these naturalists have fallen. 

In the present lecture I propose to lay before 
you the facts of the case, and not merely to speak 
of my own views with reference to them ; I shall 
begin therefore by explaining to you these four 
plans of structure, according to which all animals 
have been created. They correspond to the four 
great divisions of animals, known under the name 
of Eadiates, MoUusks, Articulates, and Vertebrates. 
These four great divisions have been classified into 
certain species, according to their general resem- 
blance. For more than twenty centuries, ever 
since the time of Aristotle, all animals having a 
backbone have been included under the name 
of Vertebrates. Quadrupeds, Birds, Keptiles, and 
Fishes all have a solid internal frame known as 
the vertebral column, or in common parlance, the 
backbone, surrounded by flesh, within which are 
cavities containing all their organs, and are, there- 


fore, called Yeftebrates. This natural division in 
the animal kingdom was long known, before it 
was understood that they were all built upon the 
same plan ; and it requires no small amount of 
anatomical knowledge to demonstrate this fact. 
It requires as much practical knowledge, in dealing 
with facts of anatomy, to trace the relations of 
one family with another, as it does in mathe- 
matics to deal with intricate problems. The anat- 
omist, unless he be very skilful, will fail to fur- 
nish the demonstration that the Fish is built on 
the same plan as the Snake, the Snake on the 
same plan as the Bird, the Bird on the same plan 
as the Cat, the Cat on the same plan as Man, 
and that between all these animals there is no 
difference as regards the general plan of structure. 
To furnish that demonstration conclusively is now 
the aim of anatomical science. The demonstration 
is possible, and even easy, in its general outline. 

Another of the four plans embraces the ani- 
mals known as Articulates. To this division we 
refer all the host of Insects, from Beetles, Bugs, 
Butterflies, Flies, and the great variety of winged 
animals with six legs, to Crabs, Lobsters, kc, which 
have a larger number of locomotive appendages, 
and even down to Worms. All these belong to 
one and the same division, and are easUy recog- 
nized by their general appearance ; they have 
rings on the surface of the body, movable one 
upon the other, and jointed legs, projecting from 
the sides of these rings. Their relation to one 
another is thus made very plain by a few general 


features. But in order to demonstrate that the 
Crab, the Lobster, the Butterfly, and the Worm 
are all built on the same plan, it is necessary to 
show a form of structure capable of transforma- 
tion into another, and requires great anatomical 

The third group or division is that known by 
the name of Mollusks. In it are included those 
soft>bodied animals, which, like the Oyster, Clam, 
Snail, and Slug, have a body capable of great 
expansion and contraction, generally covered with 
a shelly envelope, or outer coating, of hard sub- 
stance. Between these animals we find as great a 
diversity as in the Insect world or among Verte- 
brates ; and yet they are all buUt. upon one and 
the same plan, and each structure may be trans- 
formed into the other without altering in any de- 
gree the structural elements. 

The last group is called Eadiates ; the name 
suggests that they are animals whose parts di- 
verge like rays from a common centre; to this 
group belong Star-fishes, Sea-urchins, Jelly-fishes, 
oi Sun-fishes, also Corals and animals of that 
character; and they are built, as we shall see, 
upon a plan totally distinct and different from 
that of the other three. 

If there be anything which can satisfy us of 
the working of an stU-powerful and comprehensive 
mind, it is the faculty Of expressing one and the 
same thought in the most diversified forms, and 
varying the forms of expression in a multitude 
of ways, so that the thought may be made familiar. 


TMs we have in the animal kingdom, to a degree 
that challenges our powers of expression, and baf- 
fles our most comprehensive modes of thought. 
Conceive for a moment the whole animal king- 
dom, consisting of hundreds of thousands of dif- 
ferent kinds of beings, constructed only on four 
different plans. Each one of these plans must 
therefore necessarily be expressed in thousands 
of different ways, and it has cost all the thought 
bestowed by men upon the study of nature till 
now, to reach the idea that animals are all built 
upon these four plans. 

I proceed, in presenting the characteristics of 
these plans, to consider the Radiates as the sim- 
plest and most easily appreciated. 

The Star-fish has its mouth in 
the centre, from which radiate 
five arms in different directions. 
All the organs are arranged like 
rays in the direction of the arms. 
The organs of locomotion project 
from five furrows, on the lower surface of the 
arms, with suckers at their extremity, with which 
the animal attaches itself to the 
rocks, or moves about. At the 
end of each ray, there is an eye. 
In the centre there is a large cir- 
cular stomach, projecting into the 
arms. A nervous ring encircles 
the mouth, from which rise fine threads, extending 
to the extremity of the rays and reaching the eyes. 
This structure, so far as the plan is concerned, 


is common to all radiate animals; but so far as 
relates to the mode of execution, it is different in 
each class. If we examine, for instance, the Sear 
anemone, we find that the body is like a sac, 
from the upper edge of which project feelers in 
every direction ; in the centre we have an open- 
ing, leading into an internal 
cavity, and from that open- 
ing hangs another sac inter- 
nally, which is the digestive 
cavity. This second sac has 
an opening in the bottom, 
which leads into the main 
cavity of the body, and the main cavity itself is 
divided by vertical partitions into a number of 
chambers. On the edge of these chambers, we 
have bunches of eggs, which in the Star-fish are 
placed on the sides of the rays. 

In the Sea-anemone the main cavity, formed 
by the outer sac, is divided by partitions into 
chambers, so that you may compare 
the internal structure to a circular 
room, divided up into stalls by ver- 
tical walls or partitions, leaving, 
however, free communication in the 
centre. From each of these cham- 
bers projects one of the feelers or arms, which are 
hollow and communicate with the chamber. In 
the Sea-anemone, therefore, the idea of radiation, 
as a plan, is just as obvious as in the Star-fish; 
but you see at once that the mode of execution 
is totally different. 


Now let us takie the Jelly-fish. Seen in profile 
it is like a hemispherical body of gelatinous sub- 
stance, from the margin of which hang a number 
of feelers. In the centre there is 
a cavity from which project nar- 
row tubes extending to the edge, 
and from that central cavity other 
appendages hang. Looking at the 
animal from above, we find that the gelatinous 
substance occupies -the whole of this disc. But 
there is a central cavity hollowed or scooped out 
of this mass of narrow channels extending to the 
periphery. They may be small or 
they may be ramified before reach- 
ing the periphery, according to the 
variety of these animals. From 
the periphery hang these feelers ; 
if there are only four radiating 
channels there may be but four 
of these threads ; if there are many there will be 
a corresponding number of feelers. Here instead 
of an animal which is, as it were, all hollow, with 
only a thin wall outside and thin partitions divid- 
ing the main cavity into a number of chambers, 
we have an animal which is all substance. The 
Jelly-fish has only a small excavation in the cen- 
tre, with very small tubes extending to the periph- 
ery. Yet you see that the general arrangement 
is the same. 

Here, then, is an exhibition of thought in 
the mode of execution ; the differences in struc- 
ture are only different expressions of the same 


thought of radiation pervading this group of ani- 

You will see at once that each mode of execu- 
tion leads into the others. Suppose instead of a 
thin partition there had been a thick 
one ; by increasing the thickness of 
the partitions, there "will be left only 
a narrow channel between them ; and 
if we fold them above and below, there 
will be only a narrow tube left. So that, after all, 
the structure is upon the same plan, but in one 
case broad walls have been made, leaving only 
thin tubes between them, while in another case 
thin walls have been made, dividing the cavity 
into wide chambers. Only a thinking power could 
devise such a plan ; it is not the result of chance. 
Such close relations under the same circumstances 
show a power to overcome physical and local influ- 
ences. For these animals live side by side on the 
same rock. You cannot visit a single coral reef 
without finding on its surface thousands of Star- 
fishes, hundreds of Jelly-fishes, almost as soft as 
the water, Polyps and Corals innumerable, all in 
the same element and locality, and therefore under 
the same influences. How can they exist there 
side by side, except by a higher power .than the 
forces which are active in the sheet of water ? Is 
there not some other cause for their diversity than 
the influence of heat, light, moisture, and soil com- 
bined ? One combination certainly cannot pro- 
duce such diverse results, such different structures 
upon the same plan. It must be mind acting among 


these elements, making them subservient to its 
purpose, and not the elements themselves working 
out higher combinations of structure. 

The next plan of structure is that expressed in 
the organization of animals like the Oyster, Snail, 
Cuttle-fish, and the like. Let us take, as an ex- 
ample, the Oyster. If we remove one of the valves, 
we see the whole surface of the animal protected 
by a living skin ; that skin is attached to the shell. 
The edge of the shell is provided aU around with 
innumerable little fringes, which are in unceasing 
action, and are the means by which a constant 
renewal of water ,takes place around the animal. 
In the middle region there is ■ a circular speck of 
a somewhat tougher substance, which is commonly 
called the eye of the oyster. It is a bundle of flesh 
extending between the two valves. ^ In a view of 
the oyster edgewise, we see that the eye, so called, 
is a bundle of flesh, the fibres of which are at 
tached to the inner surface of the two walls. These 
fibres by contraction shut the oyster. There is be- 
tween the hinge, or at the place where the two 
valves are united, an elastic ligament. When the 
two valves are brought together, this elastic liga- 
ment is .compressed, and the nioment the muscular 
fibres relax, its elasticity forces the two valves apart, 
and so the oyster gapes. This antagonism is an ac- 
tive means of locomotion. The oyster itself is not 
capable of changing its place except by means of 
the fringes around its skin or mantle. The fleshy 
bundle which extends across the two valves passes 
through the skin. Below that, there is a fringe 


which extends all around in parallel lines, beyond 
which, when examined carefully, are found to 
exist the parallel blood-yessels which form the 
gills. This fringe is nothing but a respiratory 
organ. Of these there are two, one parallel with 
the other, and they exist chiefly in the lower part 
of the animal, within the mantle, extending to the 
cross muscle. These fold around the mouth, from 
which rises a canal, terminating, after sharp con- 
volutions, at the other end of the body ; and all 
this is surrounded by a large mass of liver, which 
is the green spot you find in the blunt end of 
the oyster. A ring of nerve extends around the 
alimentary canal, with a swelUng above, and one 
below, from which sensitive parts go to every 
organ of the body. 

What is particularly striking in this structure, 
and entirely different from the plan of the Radi- 
ates, is, that everything is symmetrical on the two 
sides of the body along the longitudinal axis, at 
one end of which is the mouth. In neither the 
Sea-anemone, the Jelly-fish, nor the Star-fish, do we 
find anything of the kind. These have a mouth 
in the centre, from which all parts tadiate. There 
is nothing that can be considered as j)assing 
through the animal longitudinally, dividing it into 
equal parts ; but in the oyster we have symmet- 
rical parts arranged on the two sides of the axis, 
with the mouth at ane end. It is particularly 
characteristic of this MoUusk, that the weight of 
structure, *as it were, is thrown on the sides, so 
much so, that, if you would examine it to advan- 


tage, you should place it on its side. You must 
lay the oyster flat to see all its characteristic 
features, and not look at it in profile. You take 
oflf one valve and raise one of the hanging cur- 
tains or membranes, and thus expose the whole 
side of the body with all the organs. The load of 
life is thrown on the sides, though the arrange- 
ment of parts is bilateral and symmetrical along 
the longitudinal axis. That is a peculiarity of this 
plan of structure. 

These animals, moreover, have a soft body, capa- 
ble of great contraction and expansion, and hence 
the very appropriate name of MoUusks. 

It would be easy to show that between the 
Oyster and the Snail there is the closest resem- 
blance, and that between the Snail and the Oyster 
there is no difference in the plan of structure, but 
only in the proportion and prominence of certain 
parts. The same may be shown of the Cuttle-fish, 
or any other animal belonging to the division of 

The third group of animals is that of the Articu- 
lates, the most prominent representatives of which, 
as I have already stated, are Insects, Beetles, 
Crabs, ^ Lobsters, and Worms. Let me take for 
illustration the Insect : the body is divided into 
three distinct regions, separated by transverse 
folds into a number of rings movable one upon 
the other, forming an articulated cylinder. These 
rings are so combined as to differ slightly in shape, 
some being more movable than others, 'so that the 
anterior portion, called the head, moves readily 


on the middle region, and the middle region on 
the posterior part. And yet all the rings are mov- 
able one upon the other. This articulated cylinder 
has only one cavity, in which are embraced all the 
organs of life. But these organs are singularly 
arranged. The breathing organs are always on 
the side ; there is no trace of a breathing organ in 
what is called the head. Each ring has a breath- 
ing-hole on the side, so that if we cut the body 
longitudinally, we find the lateral holes commu- 
nicating with a tube, with branches through the 
whole cavity, filling it with ramifications. The 
great similarity of Insects is due to the extreme 
development of their respiratory organs, of which 
there is one pair to each ring all the way along 
the body, with ramifications throughout the whole 

In addition, they have an alimentary canal, ex- 
tending through t];ie centre of the cylinder like a 
tube. Then there is the heart in the upper part 
of the body, and the nervous system, which con- 
sists of one or more swellings in the chest, and one 
for each ring, along the whole region, so that the 
nervous system is in the under part of the body 
between the legs and just above the part where 
the legs join the side. You see what a singular 
combination of parts is presented, — the heart on 
the dorsal part, the nervous system on the ventral, 
the respiratory organs on the side, and the limbs, 
when they are only legs, on the lower side of the 
body, and wings, if there are any, on the upper 
side. It is a totally different plan of structure 



from that of the MoUusks or Eadiates. It is true 
these animals are symmetrical ; their parts are 
arranged in pairs on the two sides of the longitu^ 
dinal axis as in MoUusks; but see the difiFerence. 
In MoUusks the whole body is one mass, capable 
of expansion and contraction without a sign of 
a joint or articulation ; while the essential charac- 
teristic of Articulates is, that the body is jointed, 
that every region is movable on the next region, 
and that there are numerous jointed appendages 
to some of the rings. 

The Crab and Lobster have the same structure, 
only the wings are wanting, and they have respir- 
atory gUls instead of breathing -holes. But the 
gUls are in the same position ; they are con- 
nected with the sides of these movable lateral 
cylinders, and therefore the plan of structure is 
the same. 

And so it is with the Worm. It has an articu- 
lated cylinder, and if it differs from the Insect, it 
is only in this, that the riijgs ' are all of the same 
dimensions and proportions, and none of them are 
connected more closely than others. So that it is 
only a slight difference in the mode of execution. 
The locomotive appendages are of a rudimentary 
character, being reduced to stiff bristles. The re- 
spiratory organs are on the side, the organs of cir- 
culation along the back, and the nervous system 
on the lower side. There is no doubt, therefore, 
that Worms belong to the same type and are built 
on the same plan as the Crab, the Lobster, the 
Insect, and all the Crustacea. And to see that this 


is so, we need only look at the growth of some of 
these animals. What is the caterpillar ? It is a 
young butterfly ; it is an animal hatched from the 
egg of the butterfly. At first it has the worm-like 
structure; in the next stage of development it 
casts its skin, shortens and widens its dimensions, 
opens its joints, which were at first uniform, and 
forms two regions, like the crab or lobster. Then 
it remains immovable for some time, takes no food, 
and passes into what is called the chrysalis state. 
But it is the same animal in its various stages of 
progress or growth. In the chrysalis state, it has 
all the essential features of the lobster, and yet it 
is a middle-aged butterfly. Then in its final trans- 
formation it casts ofi" that skin, the legs and wings 
are developed, and it becomes a perfect insect. 
What more positive demonstration could you have 
tihat all these animals are built upon one and the 
same plan ? 

So we must admit, that, however different in 
appearance these various animals may be, it is 
only a difference in the mode of execution, and 
that they are all formed on one and the same plan, 
which is different from that of the Mollusks or 

Let us now pass to the fourth plan, that of the 
Vertebrates, embracing Fishes, Reptiles, Birds, and 
Mammals, the latter including Man, at the head 
of the animal kingdom. The essential peculiarity 
of these animals is that they have a backbone ; 
but what is more important, they have a double 
structure, — a double symmetry, — all their parts 


being represented above and below upon the body. 
Take, for example, the Fish. The body consists 
of a backbone, made up of a number of solid 
pieces. Above each piece rises an arch, 
which terminates in a spine along the 
middle hne of the back. That arch en- 
closes a cavity. Then below is a similar 
arch enclosing another cavity. We call 
these arches the ribs, and we call the 
spines the backbone. You see that there is a 
double structure, — one arch above enclosing a 
cavity, and another below enclosing another 
cavity, around which are masses of flesh with a 
bony frame, and over the whole is stretched the 

The upper cavity contains only one set of or- 
gans, and not all the organs, as we find them con- 
tained in the cavity of the Articulates, MoUusks, 
and Radiates. In the upper cavity are contained 
only the sensitive organs, which establish the re- 
lations between the body and the surrounding 
world, and through which impressions from the 
surrounding world reach the animal. That is to 
say, we have in this cavity the centre of the 
nervous system, — in the head, the brain ; and 
along the backbone, the spinal marrow. To the 
brain are attached the organs of sense, and to the 
spinal marrow the nerves. 

In the other cavity, on the contrary, are con- 
tained all the organs through which life is main- 
tained, the organs which only go to sustain the 
animal in its normal condition, namely, digestion, 


respiration, and circulation, which have nothing 
to do with the activity proper of the animal. 
This double symmetry or division of parts is the 
same in all vertebrate animals, from the Fish up 
to Man.'. 

As time will not permit me to go into a full 
explanation of the similarity of structure in this 
group of animals, I will take, as an extreme illus- 
tration, the arm of a man and the fin of a fish. I 
win endeavor to show you that they are not only 
built upon the same plan, but the parts are com- 
bined together in the same way and almost in the 
same number. The difference between these ani- 
mals is essentially this : The head may be more 
or less isolated from the body by a contraction 
behind the skull, and the tail may be reduced to 
a mere tapering point ; the extremities may be 
more projecting, and so jointed as to terminate 
in the shape of limbs. The covering also may be 
different ; in the fish it may be scales, in the bird 
feathers, and in the quadruped hair. If you ex- 
amine the early growth of the scales in the young 
fish, of the feathers in the young bird, and of the 
hair in the young quadruped, you will see scarcely 
any difference. In the penguin, for instance, the 
feathers in their early growth are so similar to the 
scales of fishes, that it is difficult to detect the 
difference. It is only when we view things in 
their extremes, that we are struck with their dif- 
ferences. We give them certain names, and think 
that there is no relation between them, when in 
reality, if we trace them in a series, we find the 


closest resemblance, as in the case of the arm of 
Man and the fin of a Pish, which I will now ex- 
plain to you. 

The limb of any quadruped, the arm of man, in 
particular, consists first of a broad triangular bone 
which is called the shoulder-blade, from which pro- 
jects another bone called the collar-bone. Then 
we have the upper arm-bone, which extends to the 
elbow. Then there are two parallel bones, extend- 
ing from the elbow to the wrist. Then eight 
bones which form the wrist ; then five which form 
the palm. Then we have the thumb with two 
joints, and the fingers with three joints each. I^ 
without attempting to imitate the human hand, we 
represent the bones only by dots, the resemblance 
to the foot of an animal is apparent. Of course 
the resemblance is not great. It is only when 
forms are minutely copied in detail, that you obtain 
the human hand ; the moment you fail to produce 
a detailed outline, and make only a general one, 
the resemblance to the foot and arm of the quad- 
ruped is readily seen. But in the Fish the diflfer- 
ence is more striking. There we have the fore- 
arm, composed of two bones, one of which is 
broader than the other. On that are articu- 
lated four little parallel bones, and to these we 
have attached a large fin, consisting of a num- 
ber of bones united by a web, and each of these 
bones presenting - a number of articulations. But 
let us examine these ramifications. All animals 
have not five fingers, some have four, some three, 
and others two. The horse walks on tiptoe, — on 


one finger, — owing to the peculiar structure of 
the foot. But there are other animals in which 
the number of fingers is much larger. Among 
Reptiles, instead of three joints of the finger, there 
is a larger number, and instead of five, there are six 
fingers. Occasionally in the human family there 
have been individuals with six fingers. Among 
animals this is frequent. In Fishes it goes on in- 
creasing from six to twenty. So that all these small 
bones are only so many fingers, each divided into a 
great number of joints. But after all it is only the 
spreading hand in which all the joints are united 
by a web; if we go a step beyond, we find the 
four bones corresponding to the wrist, then two 
broad bones which correspond to the forearm; 
then a very short upper arm - bone ; then close 
to the shoulder a collar-bone and shoulder-blade, 
exactly as in man. So that the correspondence is 
complete ; it is only another mode of execution, 
— a modification by the all-skilful Architect of the 
same plan. 

We can therefore say, assuming that mere com- 
parisons like those I have presented to you can be 
made, that, however diversified the animal king- 
dom may be, the beings are aU constructed upon 
four plans only.' There are none on the earth 
that we cannot easily refer to one of those four 

In my next lecture I shall attempt to show you 
the classes into which these animals are divided, 
according to the various modes of execution, and 


what is the relative standing of the classes to 
one another, in order that we may be a:ble to 
examine the question how far the animal kingdcan 
forms one single series from the lowest to the 



Ladies and Gentlemen : — I propose to-night to 
lay before you the subject of the relative standing 
or gradation of the animal kingdom. It is one 
vphich has long engaged the attention of natural- 
ists. The favorite idea has been that all living 
beings form an unbroken natural chain from the 
lowest to the highest, or, as the phrase has been, 
" froml the Monad to Man." This view has been 
greatly modified in the progress of investigation. 
It was, as it were, a theoretical view in the begin- 
ning, started by general impression, and not at 
once submitted to the severe scrutiny of a care- 
ful investigation ; and when that was made, this 
idea was found not to be true in the form in 
which it had been stated. And yet the investiga- 
tion has led to some interesting results ; as, for 
instance, the discovery of the limits within which 
there is a gradation or relative rank, and beyond 
which there is not. 

This view of an unbroken continuity of the ani- 
mal kingdom from the Monad to Man, was started 
before it became known that aU animals are con- 


structed upon four different plans, so that the 
differences of structure with reference to these 
plans was no obstacle to the formation of a sup- 
posed series or chain. The discovery of the four 
plans has in a great measure checked that the- 
ory, though at this moment it is reviving in con- 
nection with questions which I shall hereafter con- 
sider, especially with reference to the question now 
so extensively discussed among scientific men and 
philosophers, of the origin of species, of which I 
shall have something to say presently. 

But before considering that question, we should 
become familiar with the broad, comprehensive 
principles lying at the foundation of all natural 
science. I have already shown you that there 
are four great plans upon which all animals are 
buUt, and that those plans are essentially different, 
so much so that it is difl&cult to conceive how a 
transition from one to the other could be made. 
But before this knowledge was reached so that it 
could be demonstrated to ordinary minds, there 
was a general and vague impression of a gradation 
in the animal kingdom. It was evident that man 
was superior to the rest of the animal creation. 
His structure presented greater complication, and 
there was a remarkable superiority in some of the 
most essential organs, especially in the develop- 
ment of the brain. It was already shown by 
Kasmpfer, that among all the animals the Monkey, 
especially the Orang-outang, came nearest to man, 
and it appeared as if from man there was a gradual 
descent to the lowest animal creation. From air- 


breathing, aquatic animals there appeared to be 
a transition to whales, which in those days were 
erroneously supposed to be fishes, and thence to 
gill-breathing fishes. With reference to the lower 
orders of creation, it seemed hardly worth while to 
consider them, as the series was so plain among 
the higher beings ; and as it was supposed that 
sooner or later the same gradation would be dis- 
covered among the inferior animals, the principle 
was taken for granted. The bulk of those lower 
animals were according to this view reduced to a 
few types. Worms were thought to form a sort 
of connecting link with snails, eels, and the elonr 
gated Vertebrates. - With the Worms were asso- 
ciated shell-fishes and the like, and the class was 
extended so as to include some animals which were 
supposed to be more simple. The microscope not 
having applied its severe test of scrutiny to the 
structure of the so-called animalcules, they were 
considered as mere animal globules, capable of mov- 
ing, of feeding, and sustaining existence. Hence 
it seemed a legitiniate conclusion that there was a 
single uniform' series, beginning with the lowest 
beings, called Monads, and rising to the highest, 
which was Man. 

But when, by a deeper and deeper study of the 
structure of a larger and larger number of animals, 
it was attempted to complete the links in the 
series, or to test more accurately their relative 
rank, difl&culties began to arise, and doubts to be 
entertained as to the real existence of such a series, 
until at length the conviction became prevalent, 


that, instead of such a single series, there were 
many series ; and the question now is, within what 
limits do these series obtain, and where do we fail 
to find them in steady progression ? 

I will in this discourse consider the facts bearing 
upon this question. An insight into this subject 
is absolutely necessary, before we proceed to con- 
sider the order in which living beings have been 
introduced upon the earth. For, of the two theo- 
ries which are generally entertained now, namely, 
either that all animal species have been developed 
from the lowest to the highest, one from the other, 
or that they have been created as they exist, one 
or the other must be false. And if we have no 
single series of progression from the lower to the 
higher, then the first of these views becomes less 
probable than it otherwise would appear. 

But the consideration of this question involves 
the necessity of a further examination of the clas- 
sification of animals. And I will begin by showing 
you in what way the Vertebrates — that type 
being more universally known, and being also the 
highest of the four primary divisions — are subdi- 
vided into classes. 

But I may, perhaps, be able to make more clear 
the nature of this investigation, if, instead of pro- 
ceeding at once to the subject, I introduce a com- 
parison from the study of languages. This I may 
be pardoned for doing at this time, inasmuch as 
there is hardly any one who does not know some 
language besides his mother-tongue. Now, if I can 
show you first what philologists have been aiming 


at, I shall be able to stow you more readily what 
naturalists have been aiming at. 

Take the common word " father." In the Latin 
and Greek it is " pater," in the French " p^re," in 
the Italian "padre," and in the German "vater." 
At first it may perhaps seem that there is not a 
very close connection of sound between these 
words. But it is found that there is a law pre- 
vailing, which the ■ philologists in Germany, and 
especially^ the Messrs. Grimm, have detected, in 
the, gradual transformation of letters, which is as 
unerring in the progress of human development as 
any other law of nature. It is found that the 
hard letters are the older, and that they have 
gradually softened in the course of time. Thus 
b, p, and ph, which are equal to / or f in pronunci- 
ation, have succeeded each other very much in the 
same manner as d, t, and th, or as 'g, Jc, and ch ; and 
all the words in which these letters occur among 
the ancient, and especially the Southern languages, 
have at later periods been transformed into other 
languages. Thus the Latin and Greek "pater" 
becomes in the Gothic " phthar," in the German, 
"vater," in the Italian "padre," in the French 
(leaving off the " pa ") "pfere," and in , the English 
"father." All these words are therefore so inti- 
mately allied that it is impossible to mistake their 
genetic connection ; and if you have occasionally 
heard people speak two languages, you will see 
how natural it is for them to pass from one to the 
other. The German does not pronounce the " th " 
as we do, who have learned to pronounce it a little 


better than Europeans. There are others who 
pronounce p like h. All that is the natural result 
of local association. 

If I were to dwell upon this subject, I might go 
a step farther, and show you that the Hebrew 
word " bar6 " (to create, to make, to prepare) is the 
same as the word " bear " (to bring forth) ; and 
that here again we have the root of the word 
" pater " (the originator, or father) ; and still 
further, that a host ojF derivatives, such as "par- 
ent," &c., are brought into this association, merely 
undergoing a slight change of outer form or into- 
nation, showing the genetic connection of all these 

Now transfer this idea to the study of the struc- 
ture of animals. Conceive a primary idea at the 
foundation of all the animal structures, according 
to which they have been called into existence. If 
we can obtain an insight into their various struc- 
tures, we shall be able to detect the affinities among 
animals, just as the etymologist discovers the inter- 
nal relations among words. It is a kind of etjono- 
logical study of the structure of the animal king- 
dom. It is going back beyond the mere external 
appearance, and seeking for the origin of things. 
And we may perhaps be able to see how far that 
goes, when, besides the analysis of these structures, 
we proceed to consider the question of the first 
introduction of animals upon the surface of the 
earth in early geological epochs, to which I shall 
advert in my next and following lectures. 

Among Vertebrates we have, as they are gener- 


ally described, four classes, namely, Fishes, Reptiles, 
Birds, and Mammals. On the average they stand 
one above the other in the order in which I have 
named them. Fishes being the lowest and Mam- 
mals the highest. This rank is readily conceded 
to the latter. It is also readily perceived that 
Birds must stand above Eeptiles, a class of animals 
in which there is a simpler circulation ; and there 
is no reason why we should not place Fishes the 
lowest, when we remember that they are aquatic 
animals, -breathing through gUls, destitute of the 
power of coming on land, and in every respect of 
structure inferior to the other three classes. For a 
century past, no naturalist has doubted the relative 
rank of the four classes in the order in which I 
have given them. 

But when the question is asked, whethei', begin- 
ning with the lowest species of Fishes and ascend- 
ing to the highest, we can thence make a transition 
to the loWest Reptile, in an ascending series, and 
then, rising to the highest Reptile, pass to the lowest 
Bird, thence to the highest, and then again pass 
from the highest Bird to the lowest Mammal, and 
so on up to Man, we are placed in the same embar- 
rassing position in which naturalists were when 
they attempted to arrange all animals in one .single 
series, before the discovery of the four distinct 
divisions. We cannot make the passage from one 
group to the other, without doing violence to the 
internal arrangement of those several groups. For 
though it may be acknowledged that Fishes as a 
class are the lowest, Reptiles next. Birds next, and 


Mammals highest, it does not follow that we can 
string them together so as to place Eeptiles entirely 
as a class above Fishes, Birds entirely above Rep- 
tiles, and Mammals entirely above Birds. When we 
come to consider Fishes among themselves, it ap- 
pears difl&cult to determine which species is lowest 
and which is highest. Anatomy seems to have 
settled the fact pretty nearly that Sharks and 
Skates are superior to the other species. Their 
limbs are more develpped, and their anterior 
region has acquired a preponderance not noticed 
among ordinary bony and scaly fishes. If we ac- 
knowledge this position to be correct, then we 
must place the common fishes, and among them 
the Lamper-eel, which is very simple in its struc- 
ture, at the opposite end. Then we have a 
series beginning with the Lamper-eel, next would 
come the ordinary bony fishes, then those singu- 
lar fishes of our Western waters, the Gar-pikes, 
which bear a strange resemblance to Eeptiles, 
and lastly Sharks and Skates at the head of the 
series. This would seem to be the best arrange- 
ment that can be proposed, according to our pres- 
ent knowledge of these animals. But a closer 
scrutiny will show that such an arrangement can- 
not be maintained, though it is as nearly in ac- 
cordance with their rank as we can make it. 

We next pass to Eeptiles. This group embraces 
Tortoises, Crocodiles, Lizards, Salamanders, Ser- 
pents, Frogs, Toads, and the like. If we examine 
into their structure, it is at once apparent that 
there are two classes of Reptiles, which differ 


widely from one another. One is essentially 
aquatic; the aniinals are hatched from eggs, and 
in the form of tadpoles live like fish in the water, 
and undergo a succession of very striking changes. 
They are not born in the form of the adult animal; 
every Prog or Toad is at first a Tadpole, which 
has gills like a Fish instead of lungs. Gradually, 
however, it loses its tail, puts forth legs, develops 
lungs instead of gills, and assumes the character- 
istics of an air-breathing animal. The other class, 
embracing Snakes, Lizards, (not Salamanders, 
which are erroneously called Lizards, but which 
belong to the Frog tribe,) the CrocodUe, the Alli- 
gator, the Tortoise, all have a very different mode 
of development. Their eggs are like Birds' eggs, 
and their young when hatched have the form of 
the adult, with no further change except in growth. 
They breathe through lungs at birth, like the adult 
Keptile. You see~at once, that there is reason for 
placing these fish-like Reptiles lowest in the scale, 
in consequence of their resemblance to Fishes, and 
the air-breathing R,eptiles highest, because in that 
respect they resemble Birds and Mammals. 

This is then the order of Reptiles : Salamanders 
(commonly called, in the Northern States, Water- 
dogs) lowest, then terrestrial Salamanders, then 
Frogs and Toads ; and from these we pass at once 
to the scaly Reptiles. • If we attempt to establish 
an order among the scaly Reptiles, we find that 
Serpents, on account of the absence of locomotive 
organs, and on many other accounts, (I have not 
time to go into the anatomical details,) rank the 


lowest; then we have Lizards with rudimentary 
legs, then the true Lizards with limbs very fully 
developed, then Alligators and Crocodiles, and 
lastly Tortoises, which are the highest. 

And now what series would we have ? Sala- 
manders lowest among the aquatic Eeptiles, and 
Frogs the highest. Then :0:om Frogs we would 
pass to Serpents, which are the lowest among the 
Bcaly Eeptiles, and from them to Tortoises. So 
then, if we attempt to arrange our series in con- 
nection with Fishes, we have first, Lamper-eels, 
the lowest of the Fishes, then bony Fishes, next 
Gar-pikes, and then Sharks or Skates, the highest. 
From- these, attempting to pass to the lowest Eep- 
tiles, we should come to Salamanders, then to Frogs, 
then to Serpents, and lastly to Tortoises. And now 
we come to Birds. But whatever kind of Bird 
you select to connect with the Eeptiles, you see 
at once what an awkward transition you make 
from Turtles to Birds. And yet unquestionably 
Tortoises are not only the highest -among Eeptiles, 
but they come nearest, of the Eeptile class, to 
Birds. And this is a fair example of the violation 
of natural relations which we commit whien we 
attempt to arrange the whole animal kingdom in 
a single series. ' 

But let us proceed with this attempted arrange- 
ment higher up. Even if we entertain this idea 
of a passage between Tortoises and Birds, we must 
take the water Birds as the lowest. If we take 
those that are hardly able to fly, such as the 
Penguins, and bring them by the side of the Tor- 


toises, what species of the latter do they resemble 
most? The sea-Turtles. But it is demonstrated 
that the land-Turtles are higher than the sea-Tur- 
tles. And yet if we attempt the comparison be- 
tween aquatic Birds and Tortoises, we must make 
it not with the highest Tortoises, which are land- 
Turtles, but with the inferior, or sea-Turtles. But 
having started with the water Birds, which are the 
lowest, and progressing through the wading, the 
running, the gallinaceous, the climbing, and the 
singing Birds, we reach the Birds of prey, which 
are generally considered the highest. Suppose this 
to be the true order, or any other ; — some have 
supposed that Parrots stood at the head of Birds, 
others have placed the singing Birds at the head, 
others, Ostriches, on account of their size ; but I 
will not discuss these questions ; it is enough that 
through some one species we should attempt to 
make the transition to the Mammals j — whichever 
species we select, the transition will be awkward, 
quite as much so as from the highest Reptile 
to the lowest Bird. There is no possibility of 
passing from one class to the other. 

And when we attempt to arrange the Mammals 
among themselves, the awkwardness of such an 
attempt to establish a single series is still more 
apparent. The lowest among them are the Whales. 
Whales are not Fishes ; they have lungs, a double 
circulation, and warm blood ; they bring forth liv- 
ing young, and nurse them with milk, like Quad- 
rupeds. They belong to the same class of animals 
to which we belong, only they are the lowest. 


Their structure is more nearly like ours than it is 
like that of Fishes, to which they bear such a 
striking external resemblance. These, then, being 
the lowest of the class of Mammals, if we attempt 
to connect them with Birds, see what follows. 
From Whales, Porpoises, or Grampuses, or Black- 
fish, all of which belong to the same order, we 
must pass downward either to Birds of prey, sing- 
ing Birds, Parrots, or Ostriches. Is such a transi- 
tion possible ? 

But there is, nevertheless, something true in 
the idea of gradation, only it is not so simple a 
matter as those who first propounded it conceived 
it to be. Instead of a single series, a uniform 
gradation, we have complicated relations, all em- 
braced, however, by a comprehensive idea. The 
truth is, that whUe the Mammals are imquestion- 
ably the highest group, they are not in every 
respect superior to Birds, and while Birds are 
on the whole superior to Eeptiles, there are some 
Birds, that are inferior to some Eeptiles. And 
the same is true of Reptiles and Fishes. On the 
whole. Fishes are inferior to Eeptiles, Eeptiles 
to Birds, and Birds to Mammals. But 
they do not stand in an unbroken 
series, one above the other ; 
they may be repre 
sented thus: 



Within each of these classes, there are several 
parallel series, more or less closely linked together, 
and which, when compared, present strange corre- 
spondences. I will take one example for illustra- 


tion. I have described purposely in some detail 
two classes of Reptiles, for the sake of introducing 
this point. There are *fish-like Reptiles that dur- 
ing the early stage of life have gills; they lay a 
large number of eggs ; and undergo successive 
transformations. They are considered by some as 
forming a class under the name of Amphibians. 
The lowest of this type is called the Conger-eel, 
and is found in the Southern States. It has very 
rudimentary- limbs and large gills, and is known 
by the nam6 of Syren among naturalists. Then 
we have the Salamander, in which the limbs are 
more fully developed, and gills exist only in the 
early stages. Then we have those animals, such 
as Frogs and Toads, which, in passing from the 
Tadpole state lose their tail, acquire limbs, and 
develop lungs instead of gills. Now among the 
scaly Reptiles, called Reptiles proper, we have a 
similar gradation. First, we have the Serpents, 
the lowest,' next the Lizards, and lastly the Tor- 
toises. If you compare these animals, you will 
find that the, Syrens resemble the Serpents, the 
Salamanders resemble the Lizards, and the Frogs 
(especially the large tropical animals provided 
with a shell over their heads) are allied to Tor- 
toises. So we have here two classes, which are 
strictly parallel in their gradations, having the 
same features with certain modifications of struc- 
ture. And such a parallel series you find every- 
where among these animals. So that the truth as 
regards series is' this : that instead of one grand 
uniform succession from lowest to highest, there 


are certain broken series within the minor groups, 
in which it is possible to trace more closely and 
intimately links of subordinate series. 

Something of the same kind obtains among the 
Articulates. The best arrangemeijt of this group 
reduces the number of classes to three, namely, 
Worms, Crustacea, and Insects, the latter being 
{he highest. The relative standing of each of 
these classes is determined by the nature of the 
complication of their rings. In Insects they are 
combined in three regions, in Crustacea (Crabs 
and Lobsters) in two, and in Worms in one. In In- 
sects the posterior region is generally made up 
of nine joints, the middle region of three, and 
the anterior region of one ; there are limbs at- 
tached to the middle region below,. wings above, 
and appendages attached to the head. These 
animals are superior to Crabs and Worms in con- 
sequence of this peculiar arrangement of the 

In the Crustacea you have only two regions. 
The posterior part consists of movable rings, and 
the ant^erior part of rings that are not movable. 
But the anterior part contains long locomotive 
appendages, called legs, then a number of other 
appendages in the shape of mouth - pieces, and 
then long feelers. But the essential characteristic 
of Crustacea is the division into two regions. 

In Worms the essential characteristic is one uni- 
form cylinder. All the rings are of nearly the 
same size. That fact alone is sufficient to indicate 
their rank as the lowest of the Articulates, and all 


further study of their internal structure justifies 
and coiifirms that position. 

But yet we have a certain number of Insects 
which are Worm-like in form. Centipedes, for 
instance, have a body divided by a number of 
nearly equal joints. But if you ask, why then not 
refer them to the class of Worms ? I answer, for 
the very obvious reason that their essential organs 
are those of Insects. They are a lower form of a 
higher class, but from their external appearance 
they seem to belong to a lower class. 

Again, we have Spiders, which are divided into 
two regions ; the head is not separated from the 
chest, as it is in Insects generally. But what 
shows that you cannot refer the Spider to the 
class of Crabs, nor the Centipede to the class of 
Worms, is, that all Insects are air-breathing ani- 
mals, having air- tubes opening upon either side, 
one pair to ^ach ring, ramifying in the body ; and 
their other anatomical features bind them in the 
same class together, though the outward form of 
the Centipede is more uniform than in Insects 
generally, more like the Worm, arid the Spider 
is externally like the Crab. The Centipede stands 
in the same relation to Insects as the Whale 
does to Mammals. The head and chest are not 
divided by a contraction between them, the limbs 
are not protruding and free, but are packed to- 
gether. So we have first. Centipedes, which are 
lowest among Insects, next Spiders, and then In- 
sects proper, which are the highest. 

Hence though we are justified in placing Worms 


lowest, we have some Insects which are Worm- 
like ; and though we are justified in placing Crus- 
tacea next,, we have Spiders which resemble Crus- 
tacea externally, but which must be ranked among 
Insects. Thus the classes are interwoven as it 
were. "When you take the essential features of 
structure you bring them together; when you 
consider the external form only, you have yet 
recognized relations which escape in the other 
combination. There is, therefore, no more possi- 
bility of arranging one continuous series of these 
animals than of the Vertebrates. For from the 
highest Worms we should pass to the Crustacea, 
from the highest Crustacea (the Lobster) to the 
lowest Insect (the Centipede), from the Centipede 
to the Spider, and from the Spider to the winged 
Insect. It is only in the minor divisions that we 
find a natural gradation — not in the arrange- 
ment of the whole group. The classes are supe- 
rior or inferior to one another on the average, but 
•not by such an arrangement as would place them 
in one serial order. 

If now we proceed to the group of MoUusks, we 
have the same facts. MoUusks are divided into 
three classes, namely, Acephala (embracing Clams, 
Oysters, and- the like). Gasteropoda (embracing 
Snails, Slugs, Periwinkles, and the like). Cephalo- 
poda (embracing Cuttle-fishes, Squids, Nautilae, and 
the like) ; and their relative, standing is. Squids and 
Cuttle-fishes highest. Snails and Slugs next, Clams 
and Oysters lowest. One single fact of their struc- 
ture win at once show you their relative standing. 


In the Clam we have a proboscis made out 
of two tubes through 
which water is - intro- 
duced into the shell. 
We have gills on the 
sides, and other inte- 
rior organs, an^ pro- 
truding appendages hardly capable' of moving. 
But when we come to the Snail we have the 
anterior parts more 
highly developed, and 
marked by a striking 
prominence of these appendages. Passing to the 
Slugs we find the head marked out by a con- 
traction of the body, large eyes, and a number 
of large appendages arranged around the head, 
commonly called arms, eight in number. The 
head is made prominent, 
while in the Snail it is 
only slightly indicated, 
and in the Clam it is entirely wanting. The name' 
Acephala (headless animal) has really a reference 
to the total absence of specialization in the ante- 
rior region of the body, which should be the head. 
You see, therefore, that the marking out or defining 
of that anterior portioii indicates the position we 
should assign to, these classes. 

Again, if we attempt an arrangement of all 
these classes in a single series, we find that there 
are some Acephala which are superior in endow- 
ment to certain Gasteropoda; and we find certain 
Snails and Slugs which are superior to certain 


Cephalopoda. So that here we find the same 
difficulty again in attempting to fiarm a single 
series, while the minor serial arrangement is ap- 

As regards Radiates, the relative position of the 
classes is most curious. Eadiates are divided into 
three classes, namely, Echinoderms (the.highest, em- 
bracing Star-fishes and Sea-urchins), Acalephs (the 
next, embracing JeUy-fishes and the like). Polyps 
(the lowest, embracing Corals and the hke). This 
is their natural order, as I explained in the first 
lecture. But any attempt at a general serial ar- 
rangement among them leads to the . same diffi- 
culty as heretofore. There are in all these classes 
some animals that are inferior to certain animals 
of the dass below ; so that it is only the average 
bulk or weight of the class which assigns to it its 
relative position. 

A few facts respecting their mode of develop- 
ment will show you how strikingly their features of 
growth agree with the fact of their relative stand- 
ing. You know what Jelly-fishes are. Animals 
of a very soft nature^ with a hemispherical form, 
from the margin of which hang innumerable 
fringes, and from the centre of which hang long 
appendages which surround an opening leading to 
the internal cavity ; thence tubes radiate to the 
periphery. There is nothing like a Polyp here, 
— no body like a sac with fingers or tentacles 
around the upper margin, and a central sac lead- 
ing into a digestive sac below. The structure is 
quite different ; and yet the egg of the Jelly-fish, 


when hatched, (and I have raised too many of them 
not to know exactly how they are developed,) pro- 
duces a young animal which is at first a free swim- 
ming creature in this form, covered all 
over with fringes, by which it is set 
in motion. It has no cavity, but is a 
homogeneous mass of cells, as closely 
packed in the interior as at the surface. 
Now the first change indicated in this little animal 
is a depression of form at one end, and as that 
depression is enlarged, the cells, or substance of 
the animal within, are gradually loosened ; the 
interior becomes less and less solid, and at length 
entirely liquefied. As soon as that is completed, a 
cpmmunication between this depression and the 
interior is effected, and the animal has 
now a main digestive cavity and a 
mouth. But it still moves freely about. 
Could you imagine it was anything but 
a free animal ? But that is a mistake. 
The next step is, the animal attaches itself to the 
surface of the rock, the point by which it attaches 
itself flattens and spreads, the upper part of the 
body widens, and from the corners of that opening 
begin to protrude four short tubercules, which in a 
short time lengthen into four 
long tentacles ; then between 
these four more, opening and 
leading into the main cavity ; 
so that the young Jelly-fish 
is now a Polyp-like creature, 
so much so that it has always 



been described as a species of Polyp, until by 
direct observation, by raising it from the eggs, 
it was found to be the progeny of the Jelly- 

There are two ways in which the Jelly-fishes are 
developed. First, in the Polyp-Uke 
form, until they appear like a long 
stem with a head at the end and 
tentacles on the summit, or scat- 
tered over the head. Then in 
course of time certain buds grow 
out at the side and become gradu- 
ally more and more prominent, pre- 
senting at the same time marked 
changes. Here are buds which 
after a certain time drop ofl^ and 
then the animal has this form, with 
only a few tentacles. But it is a genuine Jelly-fish 
developed from the body of the 
Polyp-like animal, born from the 
egg. In the other case this little 
Polyp-like body grows, becomes a 
long stem surrounded by tentacles, and has a 
mouth. Presently several contractions 
arise, from six to fifteen or twenty in 
number, which grow deeper and deeper 
until the whole stem is transformed 
into what looks like a pile of saucers. 
Through the whole stem there is a cen- 
tral cavity. After these contractions 
have become very deep, and the discs 
in the pile have become free along the edge, the 

N I I 111 


hole is widened to a considerable extent, and the 
top of the pile drops off and dies. 
Each disc then separates and as- 
sumes this outline. From the cen- 
tral cavity eight tubes arise, and ■ 
extend to the margin of - eight 
leaves. Presently fringes project from these, and 
then you have a little Jelly-fish 5 the resemblance 
is apparent in every respect, and the animal only ' 
requires to grow in order to become a perfect 
Jelly-fish. Each one of these discs drops off to the 
number often, fifteen, twenty, or more, and becomes 
a Jelly-fish ; so that from one egg is born a Polyp- 
like animal, which divides up into many animals of 
an apparently different species. Here the idea of 
the Jelly-fish is so combined with the idea of the 
Polyp, that the structure of the latter is made the 
. pattern of growth of the former. If this does not 
show that the same thought existed in the founda- 
tion of the law of this growth, then it does not 
demonstrate anything. And we have the addi- 
tional extraordinary feature, that out of one egg 
are born a large number of individuals. These 
facts seem almost like fables, and yet they may 
be tested every day. Yesterday I witnessed the 
birth of one of these Jelly-fishes. And if you wiU 
at the proper season gather the eggs of these ani- 
mals, often stranded on the beach, and take care of 
them during the winter, (and they are easily kept,) 
you will have an opportunity of obtaining an 
insight into this complicated relation among Jelly- 


Knowmgj then, the general classification of the 
animal kingdom, built up as it is upon four plans, 
in the order I have described, you will at once see 
that to attempt to place these four great divisions 
one above the other, we should have to make the 
transition in this way.* Beginning with Star-fishes 
and Sea-urchins, which are the highest Eadiates, 
we pass , to the lowest Mollusk, represented by 
the Oyster ; then rising to the Squids and Cuttle- 
fishes, at the head of MoUusks, we make a transi- 
tion to the lowest of the Articulates, represented 
by the Worms ; thien rising to the winged Insects, 
the Butterfly, for example, we pass to the lowest 
of the Fishes. So that the moment we have 
established, by a better insight into the minor 
afl&nities of animals, their true order and relative 
position, the impossibility of establishing a single 
series becomes evident. 

With these facts before you, I shall be able to 
proceed in my next lecture to discuss more satis- 
factorily the question, when and in what order of 
succession have animals been introduced upon the 
earth ? 



Ladies and Gentlemen : — I propose this evening 
to consider a question, which has long attracted 
the attention of the world, and led to some angry 
discussions, but which we must nevertheless face, 
like all other questions of the day, and meet openly 
and frankly. The question is simply this : When 
have the animals inhabiting the surface of the 
globe been called into existence? There is an- 
other question intimately connected with this, 
which I will take up in my next lecture, namely : 
In what order have those animals been called into 
existence ? 

You see at once that this question involves also 
the question of the age of the world. For a long 
time it has been believed that we knew exactly 
how old the world is, and that there could be no 
question as to its comparatively recent origin. 
But this impression has resulted from the fact that 
the chronology of the world has been confounded 
, with that of the human race. The traditions of 
the relative existence of man on earth, and the 
history of the development of nations, have been 
taken as the chronology by which to measure the 


age of the universe. Students of nature, however, 
have found that the standard of human history 
does not apply to the history of the physical world. 
There are facts showing that our earth is much 
older than the existence of man on its surface. I 
propose, therefore, to consider those facts, as based 
upon observations of nature. 

And while at the outset I set aside all tradition 
with reference to this question, let me not be un- 
derstood as supposing that there is any conflict 
between the narrative of Genesis and the results 
of scientific investigation. "In the beginning God. 
created the heaven and the earth." When that 
beginning was, Genesis does not say. That begin- 
ning is so far remote from the period when man 
was called into existence, that the question of the 
age of man, and of the animals and plants now ex- 
isting on earth, we may fairly say, has nothing 
whatever to do with the question of the age of the 

But to approach the subject under considera- 
tion, it is interesting to gather the evidence at 
hand respecting the time which has elapsed since 
the animals now existing were created, and also 
respecting the changes which they may have un- 
dergone, in order to obtain light upon the question 
of the successive introduction of all the varieties of 
animals now known to exist on earth. 

Our domestic animals have always followed man 
in the progress of civilization. Wherever the 
traces of civilization are found, there are found 
also traces of the presence of animals, not only 


domesticated, but also wild. No civilization has 
left us more interesting traces in this respect than 
that of Egypt ; on the Egyptian monuments are 
represented in sculptures and drawings, and in the 
catacombs are preserved in the shape of mummies, 
animals, which lived many thousand years ago. 
Some of those relics, which have come down to us, 
are unquestionably nearly five thousand years old. 
They form a very interesting basis, by which to 
ascertain to what extent animals may change 
under the different circumstances in which they 
live. The most careful comparison which has been 
made between the skeletons of the animals pre- 
served in mummies, and those recently killed in 
the valley of the NUe, has not shown the slight- 
est difference between them. We have here, there- 
fore, direct and positive evidence that a period 
of five thousand years does not change the appear- 
ance, character, or structiire of any living being. 

But there is something more to be considered 
in regard to domestic animals. They are con- 
stantly modified under the fostering care of man, 
and in a way that is peculiar, — very different 
from what we- observe among the wild animals. 
This feature should be kept in mind whenever the 
question of the diversity which we observe in 
nature is under consideration, — especially since 
thfere are those who believe that the varieties 
we find among our domesticated animals, may 
afford the clue by which to explain the diver- 
sity which exists among wild animals. It is an 
undoubted fact that the differences among do- 



mestic animals, which we designate by the term 
"breeds," are of comparatively recent date. The 
time when many of them were first introduced is 
known, the variations are the work of man, — 
the result of human care, of artificial means. But 
these differences are not of the same kind as the 
differences we observe among wild animals. 

Let us compare some groups of wild animals 
with the domestic animals to which they evidently 
belong. There is roving in the Western prairies 
a wild kind of bull called the Buffalo. It is a 
distinct species of that family, not yet domesti- 
cated. There are different kinds of wild bulls 
in Africa ; on the northernmost part of this conti- 
nent there is still another kind called the Musk- 
ox ; there is also another kind on the Table-Lands 
of Asia. All these wUd bulls differ from one an- 
other in certain ways : either by the character 
of the hair, the form of the horns, tbeir propor- 
tions, size, or color. But all those of one kind 
are so similar among themselves, that he who has 
sefen one of a herd of Buffalo has seen them all. 
And the same is the case with the Musk-ox, the 
Aurochs of Europe, and the Yak of Asia. The ani- 
mals of each species have a great uniformity among 
themselves, though they differ widely from those 
of the other species. 

Now examine different breeds. One of the first 
results of domestication is to introduce an extraor- 
dinary diversity among the different individual 
heads. There are no two heads alike in a herd of 
domesticated animals. They differ, not only in color 


and size, but also in the form or twist of the horns. 
And these differences are only constant as the ani- 
mals are kept under the same influences. Breeders 
of cattle know, that, unless they take care of their 
herds, all the improvements which domestication 
has introduced will disappear. 

Here, then, we have the evidence that these dif- 
ferences are the work of man, the result of arti- 
ficial means applied for the purpose of rendering 
the animals subservient to him ; while on the 
other hand, the differences existing among wild 
animals are the result of a creative power over 
which the mind of man has no control. Domesti- 
.cated animals show us only the amplitude of the 
pliability of structure in each animal, and in no 
way the method by which the diversity exist- 
ing among wild animals can be supposed to have 
been introduced. Domestication never produces 
forms which are self-perpetuating, and is there- 
fore an no way an index of the process by which 
species are produced. 

Thus we have two important facts, namely : 1. 
That a long period of time does not cause differ- 
ences among animals that are left in their natural 
condition of existence. 2. That the mind of man 
alone is capable of producing the extreme differ- 
ences we observe among the breeds of animals. 
* Let us now consider the data which are af- 
forded us respecting the age of the animals which 
now inhabit this globe. There is no field of ob- 
servation so rich for this purpose as the coral 
reefs, and among them perhaps none are so in- 


structive as those which skirt the southern ex- 
treraity of our own country. I will therefore lay 
before you to-night what I know of the history 
of the coral reefs of Flo-rida, of their origin and 

And in order that I may be well understood, it 
will be necessary to recapitulate some statements 
respecting the nature of the animals which build 
those reefs. Coral reefs are banks or walls of 
hard material, growing from a definite depth to 
near the surface of the water. They are entirely 
the work of marine animals, commonly known by 
the name of Corals, and belonging to the class 
which naturalists designate under the name of 
Polyps. The prevalent idea that corals are the 
work of a kind of insect, has arisen from a mistaken 
impression derived from the sight of corals, many 
of which look very much like a honey -comb, 
suggesting therefore the idea that an animal some- 
what resembling the Bee has produced them. It 
is not so. Corals are a part of th^ body of an 
animal, as much so as our bones are a part of our 
frame. The corals we see are the solid portion 
of that animal when alive. In earlier times, when 
the classification of the atnimal kingdom was not 
based upon difference of plan of structure, all ani- 
mals belonging to the lower classes were referred 
to two groups, Insects and Worms. In those 
days these animals were called Worms by some, 
Insects by others. They are neither. They ^re 
buUt upon the plan of radiation ; they consist of a 
number of equal parts, diverging from a vertical 



axis, and arranged in a perfectly symmetrical way. 
They have a central mouth, and a number of feel- 
ers surrounding the upper part of the body, which 
receive the food. They are identical with our Sea- 
anemones, differing only in this, that they are the 
hard parts of that animal. I will explain to you 
presently how these animals, having- such hard 
parts, are at the same time readily movable, and 
can conceal themselves altogether within those 
hard parts. 

The Sea-anem- 
one is an ani- 
mal of this char- 
acter. In the 
centre it has a 
mouth with feel- 
ers all around. 
This mouth opens into a sac, which is the diges- 
tive cavity. At the bottom of this cavity is a hole, 
through which the digested food is carried into 
the main cavity of the body. This main cavity is 
divided by radiating partitions into a number of 
• chambers communicating with one another at 
the centre. The partitions are not united at the 
centre, and therefore the different chambers com- 
municate with the digestive cavity. Such an ani- 
mal, when soft, is called a Searanemone. But let 
the walls be loaded with limestone and become 
stiff, then we have a coral. Thus, not only the 
side-walls become stiff and hard, but each par- 
tition also, so that the radiating divisions of 
the cavity remain visible when the soft parts are 


decomposed. If you examine a coral attentive- 
ly, you will perceive that 
each piece on the surface 
presents the appearance of a 
little star, owing to the- ra- 
diating partitions projecting 
from the outer hard walls 
towards the interior. But 
now the upper part of the 
animal remains soft and mov- 
able, capable of expansion and contraction to such 
an extent, that, in its fully expanded state, the 
upper portion may be two, three, or four times 
higher than that portion which has solid walls ; and 
yet, if the animal is disturbed by the approach of 
anything, and is apprehensive of danger, it draws 
in its feelers, contracts itself, and coils up so that 
the whole of it may be hidden in the slight de- 
pression in the centre between these radiating 
partitions and the outer wall, and there remains 
nothing visible at the surface but, a cup-shaped, 
hard body. The whole of the soft parts of. the 
animal in that way disappear from sight, and are 
only discoverable upon careful inspection. 

Another fact in regard to these animals. In- 
stead of being single, like the Sea-anemone, Corals 
are generally compound; that is, they multiply 
without dividing. The successive generations do 
not become separated from the parent stock, but 
go on growing attached thereto. We are so 
familiar with this phenomenon in plants that we 
hardly notice it. But when we refer to it as a 


fact occurring among animals, it strikes us with 
wonder. The little plant, germinating after throw- 
ing out a few leaves for the first year, comes to a 
stand. It is a little stem with one bud. What is 
it but an individual grown to that size ? The lit- 
tle bud at the head is the next individual, which 
grows upon the plant the next year. And so dn, 
bud after bud, each of which is an individual grow- 
ing upon the parent stock, until finally we may 
have a large tree producing thousands and thou- 
sands of buds, no one of which wiU separate and 
form a new tree until we cut it ofi" and ingraft it 
on another plant, which gives us evidence that it 
is an independent individual. But yet the whole 
tree is not a single individual, but a community 
of individuals, growing in close connection and 
never separating spontaneously. So corals are 
communities, masses of individuals, growing up 
in the same way, budding side by side, or dividing 
in another way, and while dividing or budding 
or multiplying^ -remain united together so as to 
form a larger and larger mass. Around the small 
body of a Polyp will grow first one 
bud here, another there, then three or 
four on this and on the other side, 
until they form a nest around the 
parent. Then others will form in the 
intervals when the first have grown further apart, 
and will in their turn acquire the same size, until 
we have a multitude of individuals all united in 
one mass. 

The buds are so arranged that the end has the 


form of a hemispherical body. You must have 
seen some of these masses of coral as they are fre- 
quently exhibited in the windows of drug stores, 
showing a rounded form. But there are others 
which are like branches divided and subdivided, 
and presenting the most beautiful ramifications. 
All this is owing to the manner in which the new 
individuals unite with one another. We find the 
same among trees. The buds of the oak are dif- 
ferent from the buds of the maple, the willoTV, or 
the poplar; so much so that we are enabled to 
detect, from the mode of ramification, the differ- 
ent kinds of trees even when they are destitute 
of leaves. So each species of Polyp has its own 
pecuHar mode of budding, branching, and rami- 
fying, giving it a different external .appearance; 
and what we know as leaf corals, brain corals, 
finger corals, and all the intermediate forms, are 
only the result of different modes of multipli- 
cation or budding. The number of these dit 
ferent species is very great; there are as many 
different kinds of corals in the seas as there are 
of fishes or shells, only our attention not being 
turned so much to the corals, the common ver- 
nacular has not supplied us with their different 
appellations. Naturalists, however, have distin- 
guished many different kinds. They all have 
peculiar habits and features, and require different 
positions in the sea. There are tho^e which arfe 
only found in shallow waters ; others never grow 
to a height above two fathoms ; others are never 
found in waters which are less than five or six 


fathoms deep ; others grow only in waters at least 
ten fathoms deep. And these peculiarities are as , 
constant as the differences we observe in the dis- 
tribution of plants and trees on mountain-slopes, 
or in the distribution of animals. There is. only 
this difference: that while plants and animals have 
a range more or less extended, the limits within 
which corals will grow are very narrow, and the 
fact of the water being more or less clear is 
enough either to foster their growth or cause their 

You wUl see what striking conditions come to 
bear upon them when you consider that at the level 
of the water there is one atmosphere pressing upon 
them ; at the depth of thirty-two feet the weight of 
another atmosphere is added ; and at the depth of 
sixty-four feet there is a pressure equal to three 
atmospheres. An animal made of such soft and 
tender materials must be very nicely and evenly 
adjusted in its structure to be able to bear the 
pressure of a particular depth and no other. Each 
kind is as marked in its level as the range of trees, 
and more so. Whoever has liv6d at the foot of a 
mountain-range and has seen vegetation progress- 
ing in the spring, may have noticed that certain 
tregs will form horizontal lines along the base of the 
mountain when spring sets in, resulting from the 
earlier budding of some plants, and as the season 
advances these lines of vegetation will rise against 
the sides of the mountain-slopes. Now if this dif- 
ference of range exists among trees, how much 
more definite must be the different degrees of 


pressure upon animals in the ocean, inhabiting 
dififerent depths. 

We have then two conditions relative to these 
animals which will bear upon the question of the 
formation of coral reefs, namely, 1. That these ani- 
mals are influenced to a great degree by the con- 
ditions in which they grow, and are extremely lim- 
ited in the range they occupy. 2. That they are 
very different in their structure, one from the other, 
so much so that one species cannot be mistaken 
for another. 

A coral reef is a structure built up from a defi- 
nite depth successively and gradually, not by one 
kind of coral, but by a great variety of kinds, 
combining together and forming by their joint 
work a wall, which, from a given depth, may end 
in reaching the surface of the water. And while it 
is growing, this wall is all the time changing its 
builders. It is not one kind that commences and 
completes the structure to the summit. One kind 
does a part of the work and then ceases ; another 
kind comes in and continues the work for a while , 
and ceases in its turn ; and so on till it is completed. 

Here we have a slanting shore. Suppose at six 

hundred feet distance from the shore the depth is 
ten or twelve fathoms ; it will be a favorable l^vel 
for the formation of a succession of reefs, for the 
animals which begin the work live at that depth. 


They commence building a wall in that form, — 
steep towards the ocean, slanting gently towards 
the shore, rising in the end to the level of the 
water. The steepness of the outward wall and the 
gentle sloping towards the land are the result of 
those fostering influences which accelerate the 
growth of the reef under conditions which are most 
favorable to the development of different corals. 
On the one hand the effect of muddy water, occa- 
sioned by storms and tides raising the sand and 
mud at the shore, is to destroy the corals near the 
shore and pi-event the building of the reef On the 
other hand where there is a somewhat steeply slantr 
ing shore and the water is pure and plentiful, the 
conditions are most favorable to the animals. Con- 
sequently, on the side towards the sea the favorable 
conditions are increased, while towards the land 
they are diminished. The wall therefore towards 
the sea will be built up almost vertically, and wiU 
grow more rapidly than that towards the land. 
Hence you see that there will be a gentle slope 
towards the land, as here represented. 

But one thing must be remembered. The Ra- 
diates which begin the reef after building, it up to 
a certain height necessarily create conditions that 
are unfavorable to their growth. The condition of 
the water inside, towards the land, is so altered that 
the first set of corals can no longer prosper there. 
The space inside becomes almost an inland pool, 
even though the water washes over the top of 
the wall. And now another kind of coral sets in 
and begins to build. The work goes on, but not so 


rapidly, perhaps, as before. The first set stops at a 
certain height ; the second set carries it up higher 
towards the surface. The second set are more hardy, 
and require less of the immediate action of the sea 
to sustain their growth. But there are stUl other 
kinds which never build the reef itself j namely, 
those which grow under its shelter., They may be 
compared to the underbrush of the forest, which 
does not begin till the forest-trees have reached 
a certain height. So . we have the reef-builders 
and the underbrush. And then still a third set of 
reef-builders may come in and bring it up to the 
level of the water; and after they have grown, 
the underbrush fills up the bottom towards the 

Now comes a question which, for a length of 
time, was one of the most perplexing in the study 
of these animals. Having ascertained that different 
portions of the reef, at different depths, are built by 
different species, and that all these Corals are im- 
movably attached together, the question arises, 
Whence did these new Corals come which have 
built up the later portions of the reef? 

On examining these animals we find, along the 
partitions which divide the internar cavity, bunches 
of eggs. They have been long known as such. 
But what was not known is the fact that the 
young which are hatched from these eggs are 
free and swim in the water. They are little pear- 
shaped bodies surrounded with innumerable fringes 
which keep them revolving in the water. They 
move about at wUl until they find a proper rest- 


ing-place, where they fix themselves and grow. 
Whenever there is a reef which has grown up to 
the level, say, of six fathoms, where the second set 
of Corals come in, there will be found these little 
floating animals, which subsequently attach them- 
selves to the reef at their proper level, and grow. 
Then another set wiU come in, in the same way, 
find their proper resting-place, and so build up the 

The succession of these different species of ani- 
mals is now readily explained. Each one of these 
little young animals undergoes a transformation 
from a free swimming body to a Polyp. The 
method of that transformation has already been 
explained in a preceding lecture. 

The next question is, how long does it take a 
Coral reef to grow from its base to the. level of the 
sea ? They begin, as I have said, at the depth of 
ten or twelve fathoms, so that the height of one of 
these reefs is from sixty to seventy-two feet. 

Now, here I will make a statement which those 
who have read the' voyages of Captain Cook will 
perhaps discredit. Captain Cook, or rather Mr. Fos- 
ter, who was his scientific companion, brought, from 
the depth of two thousand feet in the Pacific Ocean 
fragments of Coral ; and from that time it has been 
generally, if not universally believed, that Coral may 
grow at that depth. And yet I say that there is no 
evidence whatever that Coral reefs grow at the 
depth -of more than twelve fathoms. Now I do not 
* deny the fact that Mr. Foster did bring up Corals 
from the depth of two thousand feet. But they were 


dead Corals ! Living Coral reefs are never found 
below twelve fathoms. And since we know that in 
our own day the Pacific Ocean is subsiding, and 
even in what direction that subsidence takes place, 
is there any reason to marvel at the fact of finding 
remains of Coral reefs at the depth of two thou- 
sand feet ? They are Corals which have long been 
dead, and since the period of their death they. have 
subsided with the land to that great depth. 

The rate of growth is an important item in the 
solution of the present problem; and it is the more 
important that it should be accurately determined, 
since it must form the basis of the estimate of the 
age of these reefs. It would be trying your patience 
for me to attempt to give the full evidence upon 
this subject. I wUl mention only a portion of it. 

There are on the southern coast of Florida several 
Coral formations of great magnitude, the foundations 
of which were, at a date which is recorded in books, 
laid under the level of. the water. From those rec- 
ords I have ascertained that within fourteen years 
(the period which has elapsed since I made an ex- 
amination of the foundations of Fort Taylor at 
Key West, and Fort Jefferson at Tortugas Islands) 
the addition in the way of a crust of Corals formed 
upon those new artificial structures does not exceed 
an inch. Therefore less than a foot would grow in 
a century. But branching Corals do not occupy 
the whole of the ground over which they spread, 
any more than trees. And if I should make al- 
lowance for the addition that is due to the accumu- 
lated material of the Coral, — as the wood of a 


forest, for example, if reduced to powder, would 
add considerably to the thickness of the soil, — it 
would perhaps reduce my estimate one half or 
thereabouts. But that there may be no cavil at my 
data, I will say that an inch in fourteen years, or, to 
make it easier, a foot in a. century, is the amount 
which the Coral reef is likely to add to the thick- 
ness of the soil on which it grows. And by so 
doing I have certainly overrated it more than twice. 
How. long will it take, at that rate, for a reef sixty 
feet. high to grow? Six thousand years. That, 
then, is the age we may, ascribe to one reef And 
if my standard is too large by double, as it probably 
is, then it would take twelve thousand years. But 
we. will put it at. six thousand. 

Now let us see how these reefs are arranged 
around the extremity of Florida. Here is a map 
of that end of the ^y 

peninsula. Outside 
of the main land is 
a series of islands, 
known under the 
name of Keys, the 
westernmost of which ^ "^v^^ 
is Key West. Out- 
side of these Keys is 

a succession of very xSii N^^J^ rl^'f^' 
small islands, very FLORIDA '^'^ 

much scattered, but all resting up~on what is known 
as the Florida Eeef They rise just above the 
summit of that reef, the whole of which is made up 
of living Corals, — not only the crest, but the sides. 


The reef has just grown to such a height that the 
crest begins to emerge above the surface of the 
water. This outer row of islands^ therefore, must 
have required six thousand years to form. We will 
put that down as the first item in our estimate of 
the age of that region of country. 

Now let me give you a few geographical details 
respecting that country, so that you may more 
readily take in the facts of history. The reef is 
separated from the Keys by a shallow channel rang- 
ing from two or three fathoms on the right, to six 
on the left. Then we have a series of Keys separ 
rated one from the other by shallow cuts, and, from 
the peninsula by mud flats in which there is rarely 
more than a few fathoms of water. Indeed, some- 
times large tracts of these mud flats are uncovered 
at low water. The shore of the peninsula is made 
up of bluffs rarely more than ten feet in height. 
The highest peak on the shore is thirteen feet, and 
the highest of any of these islands not more than 
that. We have such crests all along the shore. 
But north of the shore we have what are known 
as the hunting-grounds pf the Indians, — low, flat, 
marshy grounds, hardly above the level of the sea. 
Still further in the interior we find what are known 
as hummocks, — ; httle hilly tracts of land, from five 
to ten feet above the level of the sea, strangely ar- 
ranged in a row. 

When I examined these Keys under the direc- 
tion of the Superintendent of the Coast Survey, 
who always takes a pride in making scientific in- 
vestigations, I found that they were reef and noth- 


ing else, and that they diflfered-in no way from 
the reef which is growing at present, except that 
they were cut at their summit as by loose material 
breaking off from an old reef j in fact, that they 
were an old reef altogether dead, the materials of 
which had partly been broken off at the top by the 
action of the tides and storms. 

Now the question is, How could that reef have 
grown inside of the other,' when the evidence is that 
not even single Corals will grow inside of a reef 
already grown ? On examining and comparing the 
outer reef with this row of Keys, I very soon came 
to the conclusion that when these Keys were grow- 
ing, there was no outer reef at all ; that the inner 
reef had all the conditions favorable to growth 
which the outer one has now ; that it was formed 
in the same way ; that it rose from its foundation 
to the surface of the water, then died, and then at 
the distance of some three or five miles, the con- 
ditions favorable to the formation of another rejef 
having been laid, the reef which is now nearly 
completed began to be built. 

•But there have been soundings made in that reef 
It is as thick as the other ; it has come up from the 
same depth, and it must have taken as long to grow 
as the outer reef We have therefore evidence here 
that six thousand years before the outer reef began 
to grow there was another reef beginning to grow 
nearer the shore, which must have taken as much 
time to complete as the outer reef, and which now 
forms the series of islands called Keys. This is the 
second item in our calculation. 


Upon examining the mud flats inside, and com- 
paring them with the mud flats accumulating out- 
side of the reef, we find that they are exactly the 
same. In some places the depth is from two to 
six fathoms, while in others the channel which 
separates the shore from the Keys has been filled 
with mud, so as almost to connect them with the 
main land. 

Having satisfied myself of the fact that these Keys 
were nothing but a Coral reef which had ceased to 
grow, I became exceedingly interested in ascertain- 
ing the nature and character of the main land, and 
accordingly extended my explorations to the shore. 
So closely connected are scientific investigations 
that to carry them out immediately for a present 
practical purpose is impossible ; and the sooner the 
community understand this, the sooner will they 
get rid of pretenders and false researches. A care- 
ful examination of the geology of the shore led me 
to the conviction that here again we have nothing 
but a reef identical in structure with the Keys, just 
as the Keys are identical with the outer reef How 
could that reef have grown with a dry barrier out- 
side of it ? It could only have grown when the 
Keys did not exist, when the most favorable con- 
ditions prevailed for a reef to, grow along the shore 
of the continent. And this formation on the shore 
has been measured, and found to have an average 
thickness of the Keys; therefore it must have 
taken as great a length of time to form, that is, six 
thousand years at least. So then we have a third 
item of six thousand years to add to our chro- 


But within these shore bluffs and the Indian 
hunting-grounds are hummocks, and these hum- 
mocks — not to extend this demonstration further 
in detail — are another Coral reef, concentric with 
that on the shore. They have been built by the 
same animal and have the same structure. I have 
collected all the species which are alive at present 
on the reef, and compared them with those which 
formed these hummocks, and they are the same. 
So that, if there is any accuracy in these two lead- 
ing facts, namely, that the rate of growth is less than 
^a foot in a century, and that the existence of an out- 
side reef precludes the formation of a reef inside, 
we have the evidence, in the existence of these 
four concentric reefs, that twenty -four thousand 
years ago there was a sea washing the place where 
these hummocks are, and that no reef had then 
formed beneath them. 

And yet this is not all. AU these animals are 
of the same kind as those that live now, and what 
I have described to you is only a narrow tract of 
only some fifteen or sixteen miles. More than 
sixty miles in the interior is Lake Okeechobee, and 
though I have not myself penetrated as far as that, 
intelligent officers of the United States army, who 
travelled over the whole of that country during 
the Seminole War, have told me that the whole 
country to Lake Okeechobee is made up of similar 
hummocks in concentric lines. Now if we take into 
account the fact that at Tallahassee and Augustine 
we have the same Coral formation, we have more 
reason to assume that this has not been growing at 


another rate than that at which the extremity of 
the peninsula is growing. Taking, therefore, the 
distance of sixty miles upon this basis, you see it 
opens a prospect of chronology for which we are 
hardly prepared. We shrink even from the evi- 
dence that it has required twenty-four thousand 
years to build this narrow strip of land ; how shall 
we shrink from the assumption that" hundreds of 
thousands of years must have been required to build 
that prolongation of the peninsula of Florida which 
is entirely made up of Coral reefs ! And yet what 
is that compared to the age of the world ? It is 
to-day ! It is modern time ! It is the period 
which geologists call the present, for it is a period 
within which the species of animals which now live 
began to exist on the earth ! 

I shall show you hereafter that geology has 
established a chronology which is still less within 
the limits of our comprehension, demonstrating 
more conclusively than by anything I have been 
able to bring before you to-night, that it is indis- 
pensably necessary to separate the chronology re- 
lating to human events from that which relates to 
events in the physical world, and that to identify 
the age of mankind with that of the world, or even 
of our earth, is, to confound things which have 
hardly any relation to one another. 




Ladies and Gentlemen : — I attempted in my last 
lecture to satisfy you that the phenomena of na- 
ture, and especially those relating to the existence 
of animals upon earth, must be measured by a 
chronology different from that by which human 
events are recorded. Man has passed through a 
short history upon this home of his, while we know 
from observation of animals that their existence 
must be counted by hundreds of thousands of 
years, showing that the standard of measurement 
of their existence is very different from that by 
which we measure events in which the human 
famOy is interested. 

There are other phenomena which would afford 
similar evidences, but which I must pass by as they 
are not necessary to show that these views are 
capable of demonstration. I wiU only allude to 
one or two facts. The manner in which the Niag- 
ara River has worn a channel below the Ealls affords 
undoubted proof of the long period that it has 
taken the river to produce that result. And we 
should arrive at similar conclusions if we exam- 
ined the loose materials which have been accumu- 


lating at the mouths of. the great rivers of the 
world. The delta of the Nile, which has been solid 
land since the dawn of human history, is the work 
of that river, and shows that it was flowing when 
there were no men on earth. Our own Mississippi 
tells the same history. We have no tradition 
which accounts for the accumulation around those 
prominent forks of the river which project below 
New Orleans; and yet what is that space com- 
pared with the whole distance from St. Louis to 
the Gulf of Mexico, all of which has become dry 
land by the deposit of mud brought down by that 
river ? For there is geological evidence that the 
Gulf of Mexico once extended even to the upper 
bend of the Missouri. With such data before us, 
we are at a loss to appreciate the duration of the 
periods which are embraced in that modern epoch 
which, geologically speaking, constitutes the pres- 
ent of our earth ; for all these phenomena are 
contemporary with the animals and plants which 
now exist. We find in these accumulations of 
mud the remains of the same plants which grow on 
the adjacent hills, the same shells, and the bones 
of the same fishes that now exist, just as we find 
the same corals in the reefs inside of the Florida 
coast and those outside. 

But there is one feature in the growth of coral 
reefs to which I have not alluded, and to which I 
beg leave to call your attention for a moment. 
Simple as the structure of these animals is, there 
is yet a difference in their respective standing. 
Some, by the complication of their structure, rank 


higher than others, so that there is a possibility of 
establishing between them a gradation from the 
lower to the higher ; and we shall see hereafter 
that that same gradation may be traced also in 
the order in which animals have been introduced 
upon the surface of the earth. Now this gradation 
in corals is simply this : Those which a,re more 
compact in form are inferior to those which divide 
or radiate in elegant branches. Thus in the suc- 
cessive complications of structure there is thought 
manifested of successive improvements. And that 
same gradation we observe in the various levels 
at which the corals grow. Those which are found 
deepest are lowest in gradation or structure, while 
those which grow at the level of low-water mark 
are the highest in structure. So completely is 
nature imbued with this plan, — with the thought 
of successive gradation, — that even in these walls, 
built up by corals in the depths of the sea, we read 
the mind of the Creator, as well as in those higher 
developments which characterize the structure of 
animals and assign to each class its respective 
standing, and also in the order in which they have 
been introduced upon earth from the earliest pe- 
riods to the present time. 

But the evidence of the long period necessary 
for the introduction of all these beings would be 
incomplete, were I not now to give you a short 
account of the physical history of our earth as far 
back as it can be traced, calling to assistance the 
evidence furnished by astronomy on "one hand 
and geology on the other. Within the limits of 


our own solar system we have a few hints re- 
specting the earlier condition of planetary bodies 
and the mode of formation of our whole solar 
system. The existence of Saturn's rings is a phe- 
nomenon easily explained by the experiments of 
Plateau, which show that masses revolving upon 
a common axis are gradually spread at the equator, 
and finally divide and form separate bodies. Let 
me give a brief explanation of his experiments. 
Plateau, by combining alcohol and water, formed 
a liquid of a speqific gravity equal to oil. Of 
course oil being poured in would no longer float 
on the surface, but would form a cluster or globe 
in the centre and remain balanced. Introducing 
a rod into the vessel and setting it rotating, 
the mass of oil was gradually brought to r'evolve 
with the rod. As the rotation increased, the mass 
of oil became projecting at the equator and flat- 
tened at the poles. Accelerating the motion still 
more, the portions at the equator had a tendency 
to fly oflF, until at last, by increasing the velocity, 
the extreme portions separated entirely and formed 
a ring, like Saturn's ; these, after rotating a short 
time around the mass, were again attracted to the 
centre. And as this ring lost its rotation, the 
tendency was to flow together in a spherical form, 
constituting a body revolving around the central 
mass. Thus was exemplified, no doubt, the way 
in which our whole solar system has been formed, 
if we start with the generally received hypothesis 
of La Place, that the solar system was once a 
nebula similar to those which we see in space, and 


which, by the highest telescopic power, cannot be 
resolved into distinct bodies. Such a mass set re- 
volving would necessarily assume an ellipsoid form. 
Portions of the periphery would be thrown off 
first, then others, then others, which would revolve 
around the central body, so that, finally, a greater 
or less number of these isolated portions would 
form planets. Then, if one of these planets should 
repeat the same phenomena, we would have sat- 

But there is no means of- ascertaining what 
lapse of time it has required for this process, and 
yet we have to take this part of the history into 
account in the chronology of the physical world. 
The earth being once set off from its primary has 
thenceforth a history of its own, and the question 
is, what is that history from that time to the pres- 
ent ? ' There remains here a field of investigation 
to be explored. The history as presented by the 
astronomer is not yet taken up by the geologist 
and followed up. There is a middle ground which 
requires both astronomical and geological knowl- 
edge ; and owing to the deficiency of our means 
of investigation, and to the fact that there are no 
scientific minds prepared for that kind of inves- 
tigation, we must wait till another generation of 
scientific men is educated for that purpose. 

When geologists take up the subject it is with 
our earth as a distinct body, already solidified at its 
surface, presenting two kinds of rocks of different 
origin. These two classes of rocks we trace every- 
where as forming the crest of our globe, namely, 


first, those rocks in which we see no regular 
divisions, only unbroken masses ; and second, 
those rocks which are divided into layers, one 
above the other. These two classes have unques- 
Ijonably been formed in diflferent ways. Those 
which occur in layers have been deposited by the 
agency of water; for ever3rwhere we see that loose 
materials, when dropped in water, form such lay- 
ers at the bottom. On the other hand, the other 
kinds of rocks present such a similarity in their 
structure to the lavas which flow from volcanoes, 
that it has been demonstrated that they must 
have had an igneous origin, — that they were first 
in a state of fusion, and afterwards became solid. 
Such are aU the granites, the syenites, the por- 
phyries, the serpentines, and the like. Nowhere 
do they present regular divisions into beds and 
layers, as we observe among the rocks which 
consist of grains of sand, or particles of lime or 

One of the most direct evidences that the strati- 
fied rocks have been deposited by water is derived 
from the fact that in all of those rocks we find re- 
mains of animals and plants in as varied a condi- 
tion as they are now found in the alluvium along 
our coast. They form an integral part of the rock 
itself, and their position in the rock shows that 
the beds must have been deposited in horizontal 

This is an important point, because, if it can be 
demonstrated, consequences of great magnitude 
follow with reference to the changes which these 


beds have undergone. I will therefore present that 
evidence so far as it is necessary. 

Heavy materials falling to the bottom of the 
water always fall on their broadest surfaces. Throw 
an oyster shell into the water and it will reach the 
bottom on its side. Karely will it be planted in the 
mud upon its edge. Now, remains of shells are 
found in all stratified rocks, and everywhere are 
they found lying parallel to the surface of strati- 
fication. You may remove layer after layer, and 
find the uniform position of the shell to be with its 
broad surface parallel to the surface of the rock. 
And yet we find stratified rocks in very different 
positions, which leads to the conclusion that when- 
ever they are found in a slanting position they 
must ■ have assumed it after their formation ; and 
that if they had remained in a plastic state, foreign 
bodies deposited in them would have resumed a 
position in accordance with their weight, their 
greatest surface being parallel to the horizon. 

As regards the Unstratified rocks we never find 
in them any traces of organic remains. And upon 
this broad evidence, which the limits of the present 
leicture will not allow mei to present more fully, it 
is generally admitted by geologists that these two 
classes of rocks have been formed in diflFerent ways, 
— that the massive or Plutonic rocks were once in 
a state of fusion, and that the stratified rocks are 
the result of the accumulation and deposit of loose 
materials at the bottom of the water. 

Now the point where geology takes up the his- 
tory of our earth is when the whole of this globe 


was in all probability a mass of melted material. 
How it came to assume that state is not under- 
stood ; but tbe evidence, that the material forming 
the interior of the earth must be in that condition, 
is derived from the fact, that, as we penetrate 
through the stratified layers and reach the rocks 
below, they present no stratification. Here for in- 
stance we have a mountain. The interior is a mass 

of granite. On the sides are planted beds of strati- 
fied rocks, sloping in opposite directions on the two 
sides. It is evident that the mass of granite is in- 
ferior to the beds on the sides, though it rises 
higher ; for these beds can easily be ascertained to 
correspond to one another, the lowest on one side 
corresponding to the lowest on the other, and so on 
through the successive beds to the highest. Such 
demonstration in mountain regions is very easy. 
The Jura and the Alps in Switzerland present for 
geological investigation diagrams from nature on a 
grand scale in which these facts can be shown just 
as I present them on the black-board. The nucleus 
of the mountain is made of masses of unstratified 
rock, and the slopes are made up of beds slanting 
in opposite directions ; and frequently the lower 
beds resting upon this mass can be seen to close 
over the top. It is a matter of demonstration that 


the want of continuity is the result of breaks which 
have taken place when these beds were removed 
from their primitive horizontal position into that 
which they now occupy, in consequence of an up- 
heaval or pressure from below, causing a protrusion 
of the masses beneath through the stratified layers. 
Thus we have mountain chains the centre of which 
consists of masses upheaved from below, flanked by 
the superficial strata thus displaced. And when this 
evidence is connected with the fact that in all these 
beds oyster-shells and other remains of animals and 
plants are found in the slanting position assumed 
by the beds themselves, and that on the opposite 
sides are found the same kinds of remains in the 
same relative position and order, the evidence is 
overwhelming that those beds must have been 
origin'ally formed in a horizontal position, where 
they remained until they hardened into rock. 

Whatever be the age of these beds, we find 
everywhere below them unstratified masses, show- 
ing that rocks of igneous origin are the foundation 
crust of our earth. 

Let us connect with this another fact ; to wit, 
that these beds must have been deposited one 
after the other, the lowest first and the uppermost 
last; and if everywhere we find below the lowest 
beds unstratified masses, we must come to the con- 
clusion that there must have been a time when 
there was nothing at all above the unstratified 
masses, and when the material out of which the un- 
stratified beds were formed was all there was that 
constituted the solid portion of our earth. 


That this material must have been in a state 
of igneous fluidity is demonstrable by geological 
evidence. For it is found everywhere that at the 
point of contact between the unstratified and the 
stratified masses, the stratified rocks are altered in 
the same manner that heat would alter them. If 
you throw limestone in the fire, you make quick- 
lime of it. If you throw sandstone in the fur- 
nace, you make coarse glass of it. You alter 
those substances in the same manner that heat 
would have altered these stratified beds. Wher- 
ever the stratified beds are found in contact with 
the unstratified rocks, they present alterations which 
are identical with those produced by heat, thus 
affording undoubted evidence that the unstratified 
rocks were once in a state of fusion. And this is 
farther demonstrated by the fact that in most of 
the great mountain chains cavities are found where 
these unstratified masses have flowed in, filling 
them up with solid material. The sides of the 
cavities are actually soldered together in this way. 
There is therefore no escape from the conclusion 
that the stratified rocks were deposited, the lowest 
first and the uppermost last, and that the unstrat- 
ified rocks are the oldest. 

But even these unstratified rocks are not all of 
one age ; the eruptions of the igneous mass have 
not aU taken place at one time. The largest volca- 
noes in our day are pouring forth melted material; 
so there have been such eruptions at all times. 
The diflSiculty is in a given case to trace the rela- 
tive age of the unstratified and the stratified masses. 


That geologists are now doing, and they have ac- 
complished it to a great extent. 

I will therefore proceed to show you, 1st, In 
what order the stratified beds have been deposited. 
2d, In what order organized beings — animals 
and plants — have been introduced upon earth. 
3d, That in this order of succession we recognize 
a plan, the ultimate object of which was the intro- 
duction of man on earth. For though creation has 
been carried on so long, it is a matter suscep- 
tible of demonstration that at the very outset, when 
the first animals and plants were called into exist- 
ence, they were so constructed as to show that 
they involved the plan of the creation of man. 

The unstratified rocks, as I have shown, are the 
oldest. They contain no traces of the remains of 
either animals or plants, and therefore furnish evi- 
dence that there was a time when the earth was 
not inhabited ; for there are hardly any animals so 
soft that none of their parts could be preserved. 
The solid parts of animals, when once deposited in 
sand or mud and covered, are there preserved and 
treasured up for all future time in the solid rock that 
is formed out of the deposit. In exploring the strata 
of our earth and examining their contents, geolo- 
gists have become acquainted with the various ani- 
mals and plants that have inhabited our globe in 
the early periods ; and their number is so great that 
the conclusion is inevitable that at all times, since 
the stratified rocks have been forming, the earth 
has teemed with inhabitaints as various and diver- 
sified as they are now. Within the Hmits of this 


state there are beds of rock so full of remains of 
animals and plants that the mass of strata consists 
of almost nothing else. Indeed, along our sea- 
shores we do not find such quantities of dead shells 
as we find in some of the limestone rocks in the 
western part of the State of New York. And yet 
these rocks are among the oldest of the stratified 
beds on the surface of the earth. But below these 
are found masses of rock in which no trace of or- 
ganic remains are found. 

Having now the first appearance of these re- 
mains upon earth in the earlier stratified rocks, we 
can begin to trace the gradual succession of the 
stratification, and so form a complete history of the 
development and progress of life from the begin- 
ning to the present day. We may consider these 
beds or layers as the leaves of a great book, in 
which , is recorded the history of all the various 
plants and animals that have existed since crea- 
tion, and the order of their succession. The abil- 
ity to read this book is not very difl&cult. It is 
only necessary to study living animals and plants 
to such an extent as to be able to recognize them 
when they are not quite perfect. Now as a skilful 
surgeon is able to recognize every bone in the 
human body when presented singly and separately, 
so it is possible for the naturalist to recognize each 
tooth of any common animal, and to assign it its 
proper place in the mouth. So different are the 
teeth of the various animals, — the horse, the cow, 
the dog, the cat, — that he who has studied them 
minutely can recognize at once to which animal any 


single tooth belongs. And this study may be ex- 
tended so far that it will not be difficult to dis- 
tinguish any separate bone of an animal and tell to 
what species it belongs. So also may the different 
scales of fishes be recognized and distinguished 
even when separately presented. In fact there are 
those who can not only recognize any fish from a 
single scale, but can tell to what place on the body 
it belongs. And so with a dead shell ; a fragment 
wiU indicate the particular kind of animal that it is 
part of. Now when you have acquired sufficient 
familiarity with the anatomy of the various living 
animals, you may apply that knowledge to animals 
which no longer live on earth, — to remains of 
those which have existed in former ages ; and when 
even fragments of those animals are found in the 
rocks, a comparison between them and animals now 
living will be sufficient to ascertain how far they are 
related to one another, and whether they belong to 
the same or to different species. To such an ex- 
tent has this study been carried that geologists are 
able to refer these remains at once to their different 
natural groups. And the result of their investiga- 
tion is ♦this, that all the animals which live now 
upon the earth, to whatever class they may belong, 
differ from all the animals which have existed 
before ; and those animals which have existed in 
the earher periods are liot the same at different 
depths of the earth's crust, but each successive bed 
contains remains entirely different from those above 
it. So that we may consider the whole stratified 
crust of our earth as an immense cemetery made 



up of large leaves or sheets of rocks, within which 
are buried all the varieties of inhabitants which 
have lived on the globe, and to such an extent 
preserved that their true character can be identified. 
And in this work of restoration of the earlier in- 
habitants of our globe naturalists have already pro- 
ceeded so far that it is no exaggeration to say that 
the remains of some of the animals of those periods 
are better known to us now than some that exist 
at the present time which have not been brought 
within the range of civilization ; as for instance, 
certain animals inhabiting the interior of Austra- 
lia, or of Africa, or even our own contipent. This 
is owing to the fact that fossil remains are in cer- 
tain localities to be found in immense quantities, 
so that we may make collections as complete as we 
can of butterflies in summer. 

' Knowing now the level at which the first ani- 
mals and plants were called into existence, as we 
proceed with the examination of the successive 
beds of rocks, we find that there are certain breaks 
or interruptions of the order of succession, indi- 
cating great commotions on the globe. It is well 
known, that, at the beginning of the Christian era, 
Monte Nuovo, in the Bay of Naples, rose above 
the level of the sea about four hundred feet, where 
it has remained ever since. In that upheaval the 
water was so shaken that fishes died in immense 
numbers ; and for a great distance in the surround- 
ing region the bottom of the sea was elevated, 
causing innumerable marine animals to perish. 
Before that eruption everything was going on 


quietly in those waters : the sea was beating the 
shore, animals were dying in the course of nature 
and sinking in the mud in regular order. But 
when this mountain rose those beds were disturbed 
in the same manner, probably, as in former ages, 
though on not so grand a scale, when immense por- 
tions of the garth's strata were upheaved and 
erected into mountain chains. It is those gigantic 
upheavals, no doubt, which have changed the con- 
figuration of the earth's surface, and produced 
those interruptions in the regular order of suc- 
cession which we observe in the strata of rocks. 

Now if. we take advantage of these breaks to 
separate and classify the beds which form the bulk 
of the earth's crust, we find that they may be di- 
vided into some twelve different systems, which 
geologists have named as follows : — 

The lowest, or those which contain no animal 
remains, are called Azoic. Upon them are depos- 
ited the lowest formations which contain animal 
remains. These are subdivided, but the name of 
the general system is Silurian. Next we have the 
Devonian ; then the Carboniferous, the Permian, 
the Tiiassic, the Jm-asic, the Cretaceous, the Eocene, 
Miocene, and Pliocene ; and, lastly, those beds of 
Alluvium which form the present system in which 
deposits are stUl going on. 

Now these different sets of beds mark as many 
different epochs in the history of our globe. Each 
is characterized by peculiar animal and vegetable 
remains; in none bf them do we find identical 


There has been recently entertained by some a 
favorite idea that all animals began by a few rep- 
resentatives, which have been gradually improving 
and changing until all the diversity which now 
exists was produced. I have already alluded to ' 
the domestic animals as furnishing no evidence 
whatever of any such theory. And I introduced 
the subject of corals with a view of showing that 
we had positive evidence that, outside of the di- 
rect, fostering care of man, animals do not change 
during immensely long periods. And now geology 
furnishes us the most direct evidence upon the 
same point. It shows that there has been no such 
gradual transformation, but on the contrary that 
there has been the same diversity, which we ob- 
serve now, in all times. 

We find that all the different types of animals 
existed in the most ancient times. Representa- 
tives of the four great divisions — Eadiates, Mol- 
lusks, Articulates, and Vertebrates — have always 
existed side by side. These, therefore, could not 
have been derived from one another, for con- 
temporaries cannot be each other's descendants. 
On the lowest layer on which remains of animals 
have been found, we discover various kinds of Ra- 
diates, Mollusks, and Articulates. And though we 
do not find Mammals, Birds, or Reptiles, yet we do 
find Fishes there also, so that at least the type of 
the Vertebrates is represented, showing that there 
was an intention of introducing these classes in 
such a manner as to indicate their relation to the 
highest being on earth, — Man. 


Again, while all these types have been repre- 
sented from the beginning, at each successive 
period they' have been represented by different 
kinds. The Eadiates that are found in the lowest 
beds are not the same as those found in the Devo- 
nian system, while those found in the Carboniferous 
system are still different, and so of the Permian, 
the Triassic, the Jurassic, the Cretaceous, the 
Eocene, the Miocene, / and the Pliocene. They 
differ, as found in aU these systems, from one 
another, as well as from those which are now liv- 
ing. And this is also true of the MoUusks, the 
Articulates, and the Vertebrates ; and though of the 
latter we have oAly Fishes first, at a later period we 
find Keptiles, still later Birds, still later Mammals, 
and during the last period Man. 

The character of this succession I shall explain 
in a future lecture. I will only lay before you 
now the evidence that all the principal divisions 
of the animal kingdom have had a common start ; 
that they originated at the same time, and that 
therefore whatever ideas are involved in the plan 
of creation, the whole plan dates back from the 
beginning, and involves all the combinations which 
are presented in time. The earliest of them show 
that they are intimately linked to all those of a 
later period ; but to that I shall devote my next 

Biit there is one point I want to mention to- 
night, in order that I may not have to interrupt 
the demonstration in the next lecture ; it is the 
nature of the evidence that these animals have 


discontinued their existence ; that there are breaks 
or interruptions at which the inhabitants of the 
earlier periods ceased to exist, and were replaced 
by the representatives of another period. When- 
ever we examine the slopes of mountains we find 
that the beds which have been raised by upheavals 
do not present everywhere the same relation to 
one another. In the Jura, for instance, the lowest 

beds have a certain slant; upon these are deposited 
other beds that slant at a different angle, and upon 
these we have still other beds which are perfectly 
horizontal. Here we have the evidence of the up- 
heaval of that moimtain at successive times. It is 
perfectly plain that when these lower beds were 
raised to their present position, the upper beds did 
not exist. We must assume that the second set 
of strata were deposited after . the first were up- 
heaved, and were deposited in a horizontal position 
against them, and that after they had lain so for an 
unknown length of time, they were themselves 
raised into their present position, and the upper- 
most beds were deposited upon them afterwards. 

And now if we can ascertain that the first set of 
beds is Jurassic, the second Cretaceous, and the 
third Miocene, we know that that mountain chain 


was raised earlier than the Cretaceous period, and 
that before the Miocene period the Jura underwent 
a second elevation. It is by such facts that 
geologists have been able to determine the rela- 
tive age of all the mountain chains on the globe. 
And the conclusion of this investigation is this, — 
that the higher mountains are younger than the 
lower ; that all the highest mountain chains have 
been upheaved in the most recent period, prior, of 
course, to the present epoch, for the phenomenon 
is one that has never been witnessed by man. 

If we exdmine -the Alps we find that there 
have been upheavals not only of Jurassic and 
Cretaceous beds, but also of Miocene, showing that 
the Alps were raised subsequent to the Jura. The 
Jura, therefore^ is the older mountain chain. And 
we find similar facts in regard to mountains in 
other parts of the globe, all proving that moun- 
tain chains are older in proportion as they are 
lower, or younger in proportion as they are higher. 
, And this you wUl see is a natural conclusion, 
and one which we should have expected if we had 
reasoned on a sound basis. The lofty mountains 
were once considered as the backbone of the earth, 
around which the waves of the ocean had been 
heaping up loose materials. But if the internal 
structure of the earth had been known as it no'w 
is, it would at once have appeared, that, before any 
of the stratified beds had beeur deposited, the crust 
of the earth. being thinner than it now is, whenever 
an upheaval took place, there being no great resist- 
ance by the earth's crust, only small hills would be 


formed. It is only where the resistance is greai 
that the result is gigantic. When the crust of the 
earth became thicker, the internal movements of 
the melted material became active for a long time 
before they could overcome this resistance ; but 
when at length they did overcome it, the result 
was the upheaval of gigantic mountains. So we 
find all the geological facts to be in accordance 
with this result. Let us take for example the 
Eocky Mountains of this continent, and compare 
them with the Apalachian chain along the Atlantic 
seaboard. Here we find the sandstone of the 
Connecticut Valley is slanting everywhere, while 
the Cretaceous beds, and more recent sand and loam 
deposits which form the low lands along the shore, 
are horizontal. Go to the region of the Eocky 
Mountains, and there you see even the most recent 
deposits to be found on this continent following the 
mountain slopes, showing that those mountains are 
younger than those on the seashore. Thus it 
also appears that the oldest 'chain on this continent 
is that which follows the great Canada lakes, for 
there we have only the very oldest beds raised so 
as to follow the undulations of the land, while even 
the oldest fossU-bearing rocks are at the foot of 
the hiUs and do* not rise to their sujnmit. 

Now, interruptions resulting from the successive 
depositions of these beds in consequence of such 
upheavals, mark the 'limits of these great successive 
geological periods. During the intervals between 
those great commotions, the earth has remained 
quiet as it is now ; animals jp,nd plants have gone 


on multiplying, and their remains have become 
buried ia the strata, until another commotion pro- 
duced another change, another configuration, an- 
other disturbance of land and sea, and all the 
concomitant results. And in each of these sets of 
beds, as I have stated, we find peculiar combina- 
tions of animals, but through all ages consisting 
of representatives of all the great divisions of the 
animal kingdom, — at first Polyps, Acalephs, and 
Echinoderms, associated with Bivalves, Univalves, 
and Chambered shells, also with Worms, Crustacea, 
and Fishes, then very soon with Insects, Reptiles, 
Birds, and Mammals, and at last with Man. And 
now the order of succession in detail I shall present 
to you in my next lecture. 



Ladies and Gentlemen : — Thus far the train of my 
argument has been mainly to show that there is 
order in nature; that the animal kingdom espe- 
cially has been constructed upon a plan which pre- 
supposes the existence of an intelligent being as its 
Author. But there is one phase of this question far 
more important in a moral point of view than any I 
have presented, and to the consideration of which 
I propose to devote this and the closing lecture. 
It is that phase which involves, the question of the 
existence of Providence in nature, or in other 
words, the recognition, on scientific grounds, of the 
working of a Providence in the world. If nature, 
as we see it manifested in the facts I have pre- 
sented, is the result of the working of mind, of in- 
telligence, the result may have been accomplished 
by one of two methods, namely, 1st, By established 
laws ; or 2d, by direct action. An intelligent 
Creator may have devised laws as the means by 
which these results are indirectly obtained ; or they 
may be the direct or immediate work of his hand. 
A comparison of the works of nature with those of 
art will at once illustrate my meaning. We recog- 


nize intelligence in the construction of a machine 
because we know that it could not operate in the 
manner it dofes were it not the device of an intelli- 
gent artisan. But then the work that the machine 
does is not intellectual work ; it is work delegated 
to it by intelligence,, and from that time intelligence 
has nothing more to do; the machine does the 
work. Now the question with reference to the ex- 
istence of living beings, whether they are the 
products or results of laws working in nature, es- 
tablished by the Almighty, or whether they are the 
work of the Creator directly, — this is the point I 
propose to examine on the basis of scientific facts ; 
not on the moral ground upon which we trust in 
Divine Providence, but upon scientific evidence, 
for science must deal with facts on its own ground, 
without reference to preconceived opinions or con- 
victions, and we should welcome what science has 
to say upon the subject of an overruling Provi- 

I have already adverted in my last lecture to a 
series of facts bearing upon this question. I showed 
that there had been interruptions in the sequences 
of organized beings which have existed upon our 
globe ; that the first set of animals had gone on 
multiplying up to a certain period, or to a certain 
level, beginning at the lowest formation, and then 
disappeared to make room for another set of ani- 
mals, and so in their turn each set of new-comers 
had vanished to give place to others. But nOt in 
the way in which one generation makes room for 
another. At each period there have existed dif- 


ferent kinds of living, beings with their successive 
generations, which, having had a certain duration, 
have given place to other kinds with their successive 
generations. So that the earth has been again and 
again inhabited by different successive generations 
of different kinds of animals, with interruptions 
between them, indicating great disturbances in the 
natural course of events and extensive changes in 
the prevailing conditions through whicti the earth 
has passed, accompanied by successive renewals of 
its inhabitants. 

If we were to credit a certain theory which is 
very well received at this time, which has lately 
been propounded by some very learned, but, I ven- 
ture to say, rather fanciful scientific men, it would 
appear that in the beginning animals were few in 
number, and that as they became more and more 
numerous they became more and more different 
from one another, as if all the diversity which 
exists on earth at the present moment had grown 
out of a comparatively simple and small beginning. 
This is an impression which prevails so generally 
that before I take another step in my demonstra- 
tion I will endeavor to show the fallacy of it. 

From the position of the lower strata of the crust 
of the earth it is apparent that they are not so 
easily accessible as the superficial ones. The upper- 
most sheet in a pile is that which we get at most 
easily, and with greater and greater difficulty do 
we reach those at the bottom. Now our informa- 
tion respecting the inhabitants which have existed 
on the surface of our globe at different times is 


entirely derived from the remains of animals buried 
in these beds. We know their number and charac- 
teristics only in proportion as we can exhume them, 
.and this process is difl&cult in proportion as they 
are buried deeper. So you see at once that we are 
likely to know less of the animails that existed in 
the most ancient times, even though they may have 
been as numerous as in later periods. 

Then there is another difficulty which has been 
entirely overlooked. The animals which live at 
the present time we meet with everywhere. We 
are impressed with the extraordinary abundance of 
living beings. The forest teems with trees, the 
meadow with grass and non-herbaceous plants, and 
there are living animals in profusion all around us. 
But fossils, or the remains of animals of past ages, 
are few. The moment we seek for the inhabitants 
of the earlier periods, we are restricted in our re- 
searches. We are quite familiar with the living 
animals of Africa and Australia, but what informa- 
tion have we respecting the remains of animals 
buried in the strata of those continents ? Not only 
Africa and Australia, but the greater part of Asia 
and South America are sealed books in that respect. 
It is chiefly in certain parts of Europe and North 
America that we are enabled to compare the re- 
mains of past ages with the animals now living on 
the whole surface of the globe. In order to make 
a fair comparison, we should institute it between 
tracts of the earth's surface of equal extent to those 
in which we have surveyed animals of past ages in 
this fossil condition. Let us do so. Let us take as 


the measur/e of the variety which has existed in 
past ages, such tracts of the earth's crust as are 
accessible to us, in which we can collect the fossils 
and compare them with the living animals. 

The number of species of fishes which inhabit the 
Mediterranean is only a few hundred ; those that 
inhabit the German Ocean only about one hundred 
and eighty or two hundred ; those on the Atlantic 
coast of France not more than two hundred and 
fifty J and yet the sum total of the different kinds 
of fish known in all parts of the world is nearly ten 
thousand. If we were to compare the fossil fishes 
found thus far in the strata of the globe with those 
of the whole world as they now exist, we should 
make the same mistake as in estimating the inhabi- 
tants of one region as those of the whole world. 

The fossU fishes which have been found, and 
which I have had an opportunity of examining in 
certain circumscribed regions, form a very favorable 
basis for comparison and estimate. At Mount Vul- 
can, near Verona, is a celebrated quarry, not many 
miles in extent, from which alone have been taken 
over one hundred different kinds of fossil fishes. 
The Adriatic in its whole extent does not furnish 
as many dififerent species as are found in this 
quarry. I have examined the fossil fishes of the 
neighborhood of Riga on the Baltic, and they are 
more numerous than the present living species of 
the Baltic and German Ocean. 

Here, then, we have direct evidence that in 
former periods, within similar areas, there was as 
great a diversity of animals as now exists. 


But not to confine the comparison ^to fishes, let 
us take shells. The number of shells of different 
kinds in the Mediterranean does not amount to five 
hundred ; in the Eed Sea there are not more, nor 
in any region of the eartl^ of one hundred square 
miles can there be found more than that number. 
And yet the whple number of species known at 
this moment exceeds fifteen thousand. Now, in 
one single region in the neighborhood of Paris, a 
single naturalist, Lamarck, after ten years' research;, 
described several hundred different kinds of fossil 
shells, all of which, of course, are different from 
any that now exist. The geological survey of 
the State of New York ordered by the legislature 
has disclosed in each of the successive sets of beds 
within the area of this State as numerous a variety 
of shells as the sum total of all the species now 
living along the whole Atlantic coast of this con- 
tinent. What better evidence do we want that at 
all times the world has been inhabited by as great 
a diversity of animals as exists now, and that, at 
each period they have been different from those of 
every other period ? 

This is a very important, fact, because it is a most 
powerful blow at that theory which would make us 
believe that all the animals have been derived from 
a few original beings, which have become diver- 
sified and varied in course bf time. 

I will now proceed to enumerate the animals of 
the different periods, and then to illustrate their 
charac,ter. I will represent the different systems 
of rocks in their order "by a diagram, dividing them 



by horizontal lines ; and I will indicate by vertical 
lines the divisions of the animal kingdom. 






































Now, upon examining the lowest of these beds 
in which remains of animals are found, we find at 
once representatives of Eadiates, MoUusks, Articu- 


lates, and Vertebrates. And not only the repre- 
sentatives of those four great primary divisions of 
the animal kingdom, but all the diflFerent classes 
of the first two of those great (Jivisions. Of the 
Eadiates we have Polyps, Aealephs, and Echino- 
derms from the beginning. Of the MoUusks, we 
have Acephala, Gasteropoda, and Cephalopoda from 
the beginning. Of the Articulates, we have Worms 
and Crustacea in the lowest strata, but no Insects. 
The latter only begin to appear in the Carbonifer- 
ous period. Of the Vertebrates, the only repre- 
sentatives we have in the lowest strata are Fishes. 
Reptiles are only to be found as we reach the Car- 
boniferous period. Birds not earlier than the Trias- 
sic, (if they are found there at all,) and Mammals 
at a still later epoch, while no trace of Man is 
found untU Ve reach the present period. Thus 
we have nine classes of the animal kingdom exist- 
ing from the first dawn of life ; then by a singu- 
lar coincidence Insects and Reptiles are introduced 
together at a later period ; then at a' still later 
period we find Birds, still later. Mammals, and 
lastly, Man. 

Let us now proceed to examine the character of 
this succession. So striking are the differences be- 
tween the various classes of animals at different 
periods that geologists are able to recognize almost 
at first sight the coral of the Carboniferous period 
as readily as a shell from the Gulf of Mexico, the 
Red Sea, or Ailstralia. Animals are distributed on 
the surface of the globe according to definite laws, 
and with remarkable regularity. There is no dis- 


order in their distribution, only it requires long 
study before we can grasp their diversity to such 
an extent as to be able to understand how they are 
combined on the surface of the globe. You know 
very well that if you wish to see a Palm you must 
travel to the south, and if you would see a Pine 
forest without any deciduous leaves you must go 
very far north, — for in our own latitude we have 
a mixture of permanent with deciduous leaves. 
Now this study may be carried so far as to show 
that each species of plants and animals has its 
definite home, and the power with which animals 
are endowed of locomotion is used by them iiot 
to wander at random over the surface of the glolse, 
but to roam within genial regions. 

Now in the order of succession we find something 
quite similar. It does not require many years' 
study of fossils to recognize at a glance a cham- 
bered shell as belonging to this, that, or the other 
geological period. Their characteristics are as 
distinct and as easily recognized as the pine is 
distinguished from the palm. And with these dif- 
ferences is very soon associated the idea of an 
earlier or later existence, just as you associate the 
idea of a warm climate with the palm and a cold 
climate with the pine. And not only is there 
order in this succession, but there is an order 
which shows at all times consecutive thought, which 
at the outset perceives the end. This is some- 
thing which is never put by mind into machinery ; 
it is something that the architect retains to him- 
self only while he is superintending the work. In 


the combinations which are observable among the 
representatives of the earlier period we can dis- 
cover that relation to one another which at the 
very beginning implies that the end is perceived. 

In presenting this argument, in the brief limits 
that are allowed me, I will select for illustration 
the class of Echinoderms. Of these there are a 
great variety of representatives living all over the 
surface of the globe, and they differ among them- 
selves in the complication of their structure to such 
an extent that they have been classified in several 
orders. One of those orders embraces Star-fishes, 
which have a star-shaped form ; another embraces 
Sea-urchins, which have more or less a hemispheri- 
cal form ; and a third order is called B^che-de-mer, 
having a cylindrical form. There is common to aU 
these animals, whether star-shaped, spheroidal, or 
cylindrical, a mouth in the centre from which aU 
parts radiate in every direction ; for the ribs which 
extend from pole to pole in the cylindrical animal 
correspond to the rows which we see on the hemi- 
spherical body of the Sea-urchin and to the rays of 
the Star-fish. 

But this is not all ; the upper and lower side of 
the body are made up of different elements. There 
are Star-fishes in which those elements are closely 
packed together and form a sort of calyx, which 
may be attached to the ground by a solid stem, 
while from the upper portion only branches radiate. 
Such animals are attached to the ground, and in- 
capable of locomotion. They have received the 
name of Crinoids, while Star-fishes proper are called 




Asterians, and then there is another group called 
Ophurians, — animals with a sort of disc in the 
centre from which arms radiate very abruptly. 

Now you perceive at once that there 
is a gradation in these animals. First 
and lowest we have Star-fishes with a 
stem attached to the ground ; next those 
which radiate equally in every direc- 
tion; then animals with a central disc 
and radiating arms ; then those which 
have a hemispherical form with certain 
anatomical complications, which, with- 
out entering into the details, require us 
to assign them to the fourth position; 
and lastly, we have the cylindrical- 
formed animal which is the high- 
est in structure, being the most 
comphcated of all. 

As to the frequency of the 

types of these different animals, 

we find only one single kind of 

the description of No. 1 now 

known to exist ; that is foimd 

in the West Indies, about Porto 

Eico, and is called Pentacrinus ; 

while of the kind of No. 2 there 

are more, of No. 3 still more, and 

so on. Those occupying a higher 

position are very numerous, while 

those occupying the lowest places 

are exceedingly few. 

But let us inquire in regard to 


the Seartirchins of past ages and 
those of the present. "We need 
only go to Lockport Or any 
part of "yy^estem New York to 
find in the lowest beds an in- 
numerable C[uantity of Echi- 
noderms. But they are all of 
the kind of No. 1, — nothing 
but Crinoids. In one locality at Lockpbrt there 
are as many different kinds of Echinoderms of that 
family as exist of all living species along the whole 
coast of the United States. Beginning, then, at 
the lowest of these beds, we follow up through the 
limestone of Pennsylvania, which is superior in 
position to that of New York, and so on through 
the carboniferous rock. Here we find quite as 
great a variety of Star -fishes as iii the strata of 
New York, but of dijSerent kinds, not a single one 
like those t)f the lower strata. Then a little higher 
up we find genuine Star-fishes, and still higher gen- 
uine Sea-urchins. Then as we rise higher these, 
animals are very numerous, but we have not a sin- 
gle one of No. 5 in the early geological periods ; 
they all live at the present time. 

So what here strikes the observer is the fact 
that the order in which these animals have been 
introduced on earth in the course of time, from the 
most atident period up to the present time, presents 
a similar series to that which we observe in the 
gradation of the structure of the present living 
species of the same animals. We have two series 
which coincide in their result : one an order of 


succession in time, aiid the other an order of grada- 
tion of structure. It is a coincidence of result ob- 
tained by different methods or different ideas. 

But this is not all. Let us examine the manner 
in which these animals grow. The little Star-fish, 
when it is forming within the egg and when it is 
hatched, is not the same free animal that it is in the 
adult state. It is a little being attached to 
a stem or prong, with branches above, form- 
ing a kind of cup. It resembles those 
Echinoderms first born on the surface of the 
earth, the type of which has become ex- 
tinct with the single exception of that one 
which lives in the Gulf of Mexico. After 
having lived for some time in that form, 
it casts off the stem ; just as we find in 
the course of time a period when Star-fishes with 
stems no longer exist in great numbers, but are suc- 
ceeded by those that have no stem. So this little 
animal casts off its stem, becomes free, and assumes 
the form of its parent. 

Now what is there to bring about this coincidence 
if it is not the mind that has devised the order in 
which animals should appear on earth, — the mind 
that has assigned to the lowest in structure the 
same degree of complication that was given to the 
oldest in the order of time, — the mind that has 
established the order of growth of the young ani- 
mal after the same pattern and upon the same 
idea that is presented in the order of time and in 
the gradation of structure ? 

We have here, then, three different ideas in no 


way necessarily connected with one another : 1. 
The plan upon which animals shall vary in their 
structure in course of time. 2. The order of gra- 
dation of structure of living beings. 3. The order 
of the growth of the young animal from the, egg. 
And yet in their results those three ideas are the 

Here, then, we have the w'ork of mind, but not 
of a mind which acts by necessity, but with the 
freedom of omnipotence. We have it here directly, 
and we can demonstrate it the more fully as we 
trace the facts thus presented more in detail. 

It is not in the class to which I have adverted 
alone that we find these results, but in every class, 
so far as our researches have gone. Unfortunately 
we are not so well acquainted with the representa- 
tives of every class in past ages as to be able to 
trace them through the different periods. It is not 
every class that we can arrange according to com- 
plication of structure with unerring certainty. It 
is not every class in which we have traced the 
growth of the young from its first formation in the 
egg through the different stages of its develop- 
ment. But in order to satisfy you that this triple 
coincidence is not an accidental thing, I will take 
another class of animals. 

The class of Crustacea, among Articulates, em- 
braces Crabs, Lobsters, Shrimps, and the like. 
The great difference between Crabs and Lobsters 
consists in this : that while Crabs have a short tail, 
which is bent under the body and almost con- 
cealed, in Lobsters the tail is nearly as bulky as 



the anterior part. The Crab and the Lobster have 
similar Hmbs placed in the same position, the same 
jaws performing the same functions, and the same 
feelers projecting from the head. But there is a 
third group of Crustacea, known as Sand-flies or 
Shrimps, which have very minute limbs, like hooks; 
otherwise their main features are the same. Now 
it requires not much insight into their structure to 
perceive that these are the lowest, while Lobsters 
occupy the middle position, and Crabs the highest. 
In Crabs there is a concentration of parts. The 
longitudinal nervous swellings become united in 
the Crab so as to form a centre of sensation more 
dense than in any other of the Crustacea. There- 
fore we place Crabs the highest in structure. 

Now let us take the Crustacea of past ages. At 
Trenton, N. Y., are found immense quantities of 
Trilobites, and any one who has ever seen one of 
them cannot have failed to notice that they have 
two distinct regions, one in front and one behind, 
each diflFerent from the middle region, which is 

divided by a num- 
ber of rings trans- 
versely, and then 
by a few longitudi- 
nal marks. These 
Trilobites are 
found in the low- 
est fossiliferous strata. There may be such differ- 
ences as a prong on the side of the shield or a 
greater prominence given to the eye ; but all these 
are subordinate differences. The prominent char- 


acteristic is a body in which the head and tail are 
hardly distinct, being of the same width as the rest 
of the body, with uniform transverse divisions of 
the whole animal, such as we find in the Shrimps 
of the present day. 

Now what do we find in the middle geological 
ages, — in the Carboniferous, the Permian, and es- 
pecially the Triassic period ? Nothing but Lobster- 
like Crustacea. In the lithographic quarries of 
Bavaria they are as numerous as Tfilobites at 
* Trenton. But Trenton belongs to the period of 
the earliest Crustacea, while the quarries of Bava- 
ria belong to the middle geological period. But 
when you come to Mount Vulcan, to which I have 
alluded, or to the sandstone which forms the greater 
part of Switzerland, there you find Crabs, and 
scarcely anything else. Lobsters are less numer- 
ous, and of Trilobites there are none. 

How many kinds of Lobsters have you on the 
coast of the United States ? Only a few. Crabs, 
however, are innumerable. They are the last in 
order, and are now the dominant tribes on the 
earth. They stand highest in order of time. Lob- 
sters next, and Shrimps lowest. 

Let us see how they grow, and take the young 
of the Crab ; when examined in the egg, long be- 
fore it is hatched, you find a Httle oval disc which 
when it first shows signs of distinct parts pre- 
sents a shield in front and behind and transverse 
ribs just like a Trilobite, and so striking is the 
resemblance that it is not too much to say that 
the figure of the various kinds of Crustacea in 


the egg is a diminutive diagram of the Trilobite 
of the earher ages. 

But when the little Trilobite -like embryo is 
hatched it does not come out a Crab, but a long- 
bodied animal, with prominent feelers, and a long 
tail, just like the Lobster. 

So here again we have the same thought mani- 
fested as among Echinoderms. The pattern of 
growth, the order of introduction in time, and the 
gradation of structure, are coincident. If we fol- 
low the course of rocks from the oldest to the pres- 
ent time, we trace the same idea. And if natu- 
ralists would study the embryology of Crabs, they 
may do it as well by resorting to the quarries 
where the oldest Crustacea' are found, as to the 
eggs of the living animal. 

But there is something somewhat different in one 
of the types of animals to which I will now call 
your attention. While examining the relation of 
Polyps, Acalephs, and Echinoderms, we cannot fail 
to perceive that these three classes are not absd- 
lutely higher, one than the other, but 
that they stand relatively about 
in this position. But 



among Vertebrates there 
is something quite striking. The Pish is unques- 
tionably lower than the Reptile ; the Reptile is su- 
perior in every respect to the Fish, the Bird is in 
every respect superior to the Reptile, and among 
Mammals .there are none which we should feel 
inclined to place below Birds. This gradation we 
see at once, upon examination of their structure, is 


a marked feature among them. In the circulation 
of their blood we find a dijQFerence. It is simple 
a,mong Pishes. Their mode of breathing is through 
gills ; their blood is cold; they lay a large number of 
eggs, with a very few exceptions taking no care of 
th«m whatever. Then we have the clangs of Reptiles, 
in which the circulation is more complicated, whose 
mode of respiration is aerial, and though they lay 
eggs, those eggs are fewer in number, and there is 
a more close relation of parent and offspring than 
among Fishes. Coming to Birds, we have warm 
blood, a more complicg,ted circulation, fewer eggs, 
and though in some dases the young when hatched 
are sufficiently developed to take care of them- 
selves, as among hens and ducks, there are others 
in which the young are so imperfectly developed 
that they require the nursing care of the parent. 
Then, as we come to Mammals, we find a new fea- 
ture introduced, — the dependence of the young 
upon the mother, the nourishing of thfe young by 
the mother from her own body. And this depend- 
ence is proportioned to the standing of the young. 
There is not so helpless a being born as the human 
infant, and yet he occupies the highest position 
according to his organization. 

So these four classes are so linked together that 
from the Fish to Man we have an unbroken succes- 
sion. The plan of Man's organization begins with 
the Fish. And we can trace it through the succes- 
sive geological formations in the same way. In 
the lowest fossiliferous strata we find Fishes, subse- 
quently we find Eeptiles, then Birds, then Mammals, 


and lastly Man. So here in the order of succession 
we have a coincidence with their gradation accord- 
ing to structure. And let us see if this coincidence 
does not exist in their mode of development. Ta,ke 
the egg of a Bird, and examine the growth of the 
young animal. At first it has all the features of a 
Fish J the structure coincides very closely. So here 
again we have the same thought in the mode of 

Is it, then, too much to say, that, when the first 
Vertebrate was called into existence, in the shape 
of a Fish, it was part of the plan of that framework 
into which its life was moulded, that it should end 
with Man, the last and highest in the order of suc- 
cession? We find evidence of this fact in the 
comparison of the attitude in which he stands 
with that of the Fish, and also in the comparison 
of the brain. 

, Let us examine these relations for a moment. In 
the Fish the brain is only a slight swelhng, scarcely 
raised above the level of the spinal marrow, which 
extends through the whole backbone, and the pos- 
terior division of the brain is the highest. In the 
Keptile the posterior, middle, and anterior portiohs 
are of the same height, and the whole brain is 
slightly raised above the level of the spine, for 
the Tortoise, Lizard, and Snake all raise their heads. 
In Birds we find the anterior portion the largest, 
and the posterior portion the smallest, and we have 
a slanting position of the spine. In quadrupeds we 
have still further progress. Coming to the noble 
form of Man we find the brain so organized that 


the anterior portion covers and protects all the 
rest so completely that nothing is seen outside, and 
the brain stands vertically p'oised on the summit of 
the backbone. Beyond this there is no further 
progress, showing that man has reached the highest 
development of the plan upon which, his structure 
was laid. 

But trace this progress also in another aspect. 
The Fish swims horizontally. His body is all one 
cylindrical mass, the head does not rise above the 
rest of the body, and there is no contraction be- 
hind it to mark a neck. The Reptile has a slight 
contraction behind the head ; for even the Serpent 
is not so uniform that you cannot perceive where 
the body ends and the neck begins, even though 
there are no limbs to raise that body. But the 
next step is in the Lizard, where jrudimentary legs 
appear, sometimes capable of raising the body 
slightly ; but even yet, like the Snake, the animal 
moves mainly by means of the undulation of the 
backbone instead of its limbs. Then we come to 
Birds, in which the tendency is to an upright posi- 
tion ; the Bird stands on its hind limbs, but yet it 
has not entirely, reached that position. It requires 
one further step, by which one pair of limbs alone 
are made to perform the function of locomotion, 
while the other pair become subservient to the 
mind. The hand of Man is no longer an organ of 
locomotion, and it is no longer a paw ; it is the 
organ with which we express our deepest feeling ; 
it is the limb with which we grasp our fellow-being 
in cordial recognition. The brain of Man occupies 


not merely the foremost, but the uppermost posi- 
tion. It is not merely forward, but upward: for- 
ward in the direction of all progress in intellectual 
culture ; upward iu the direction of all moral excel- 
lency : forward and upward towards that Mind ac- 
cording to whose image man is made. 



Ladies and Gentlemen •' — In presenting in my 
last lecture the order of succession of animals in 
past ages, my object was chiefly to show that there 
exists such a connection between them as bespeaks 
thought, plan, and deliberation, and that in their 
combination at different periods is clearly seen the 
interveintion of an intelligent Creator. I propose 
to-night to complete the argument by showing that 
the nature of the intelligences is the same whether 
it be human or divine, finite or infinite. In order 
to bring this argument near to the comprehension 
of those who have not studied natural history 
closely, I will select for this demonstration a class 
of animab in which the complication of structure 
is not great. 

Nowhere is the evidence of plan more plain, 
without, the deeper study of anatomy, than in the 
radiated animals. As the basis of their structure 
we may take the sphere, in which all the points 
are equally distant from the centre. For though 
the plan of radiation as exhibited in these- animals 
is not a mathematical sphere, it is nevertheless an 
organic sj)here ; it is a sphere loaded with life ; it 


is a sphere in which there is as much differentiar 
tion as can well be introduced upon the idea of 
radiation. And the first difiference which we, no- 
tice is this : that instead of the outer structure 
bearing a relation to a central point, it bears a 
relation to an axis which extends from pole to pole. 
The living sphere, as shown in the radiate animal, 
comes nearer to a revolving sphere which has an 
axis of revolution, and which, in consequence of 
that movement, has two poles and an equator. 
This axis is surrounded by parts which are iden- 
tical in their nature, and which bear among them- 
selves the same relation to one another and to the 
central axis. But the two poles are essentially 

If we take the problem of radiation in a 
mathematical point of view, if we -present to the 
mathematician the question involved in the plan 
of radiation, it will be this : How to execute, 
with the elements given, — with- a vertical axis, 
around which are arranged parts of equal value, — 
all the possible variations involved in that plan. 
This question is not a mere fiction. I have pre- 
sented it to one of our great mathematicians. I 
requested him to solve the problem, how to devise 
structures variously .executed, the elements being 
given^ without introducing any new elements. His 
answer was readily given, and it was this : That 
the simplest way would be to represent the whole 
sphere as a series of wedges placed side by side 
with one another. 

And to make this demonstration as clear as I 


can, I will take for illustration the melon, the ribs 
on the outside of which will give the idea of 
wedges combining to form a spheroidal body. The 
orange which I hold in my hand would give us the 
same idea, with one additional element which I will 
consider presently. Let me take first the inside 
of the orange. You all know it is divided into a 
number of parts which are all equal. They are 
what mathematicians call spherical wedges, the 
edges of which correspond to the axis, the spheri- 
cal surfaces of which are segments of a sphere, and 
the sides of which are the surfaces dividing those 
segments one from the other. , 

Now in executing any structure upon the idea 
of radiation, the simplest way would be to bring 
together around the axis a number of these spher- 
ical wedges until the whole space is occupied by 
them. There would be a larger or smaller number, 
according to the angle of the sides of the wedges. 
If they are thin there will be many, if thick there 
wiU be few. So we could introduce at once a var 
riety among them by changing the numbers and 
perhaps the relative dimensions of them, increasing 
the thickness of the partition, and modifying the 
surface which encloses them aU. 

The substance of the orange is surrounded by a 
bark. That bark is not however primitively so 
distinct from the pulp as when it is ripe. When 
forming, the orange is composed of a number of 
spherical wedges not yet separate from the bark, 
which has as yet no special consistency or color. 
The bark or rind is the result of growth. 


These modifications in structure can be further 
extended by changing the thickness of the wedge 
near the equator. Also by having each of the 
wedges hollow, and surrounded by thin walls. 
Then by making the walls thicker and reducing 
the cavities. Again, by isolating the surrounding 
elements, freeing the cavities in the interior and 
giving them distinct walls ; for this is complicating 
their structure in such manner that they would 
form independent orders. These are what mathe- 
maticians, conversant with all the powers of mathe- 
matical combinations, present as the various possi- 
bilities of these structural elements. 

And now when we come to examine the dif- 
ferent classes of Radiates, we find that there are 
three, that differ one from the other in exactly the 
manner in which a mathematician conceives that 
these' elements may be combined with one another. 
In the class of Polyps we have a 
cavity divided by radiating parti- 
tions. In Acalephs, on the contrary, 
we have tubes leading from the cen- 
tral cavity, surrounded by a solid 
gelatinous substance. 
In Echinoderms we 
have an outer solid 
wall, and these tubes 
transformed into in- 
dependent organs, 
which wend their 
course in various 
ways in the interior, 
forming a compli- 



bated structure. So we have a plan 
in the construction of these animals 
similar to that which a mathemati- 
cian would conceive. The mathe- 
matician to whom I appealed for the 
solution of the problem was entirely ignorant of 
natural history, and could not therefore have ob- 
tained his knowledge from the animal structures ; 
and yet he at once devised these three as the only 
essential plans which could be framed upon the 
idea of a radiated structure around a vertical axis. 
But now let us see what freedom and richness 
there is in the execution of that plan as represented 
in nature. In the first place, instead of a mo- 
notonous sphere in the living radiated animal we 
have a striking contrast between the two poles, one 
being essentially the base of attachment while the 
other is essentially a pole of expansion. The 
means of connection with the ground is composed 
of a different element from that by which the ani- 
mal displays its activity. These two elements 
may be best shown in a profile view. The base of 
attachment presents a simple 
radiation ; the sides of the 
spherical wedges are shown 
in the vertical lines upon the 
cylindrical body, while the 
upper end displays the radi- 
ation in the form of rays 
which communicate with the central opening. How 
much richer that is than the mere mathematical 
idea of a sphere ! And yet you see how these ele- 
ments are reducible to that very mathematical form. 



We need only shorten these feelers and contract the 
upper part to reduce the whole upper region to a 
hemisphere. We need only lessen the height of the 
animal and reduce the base of attachment to a point, 
and we transform the whole body into a sphere. 

Take now the Acaleph, or Jelly-fish. Here we 
have the same elements, only instead of preponder- 
ating cavities they are reduced to mere tubes, the- 
intervals between them being composed of a solid 
mass. In addition to that we have elongated ap- 
pendages or feelers. These can be 
better represented in a profile 
view. Around the margin of the 
bottom project a number of arms 
downwards. There is another set 
of appendages, which are only ornamental, intro- 
duced at the opening of the mouth. The marginal 
appendages may be more numerous than the rest, 
and there may be intermediate appendages ; all 
these are\similar parts, more or less numerous, with 
no new elements. Then again the diversity is in- 
creased by the tubes 
which radiate from 
the centre, instead of 
being straight, being 
variously complicated. 
For instance, ip the 
common white Jelly- 
fish, we have simple 
tubes radiating in four 
directions, . alternat- 
ing with other tubes 


which enlarge into a cavity, from which cavity 
proceed other small tubes radiating to the surface. 

Let any one study the different varieties of Jelly- 
fishes, and he will find in their forms all possible di- 
versities of combination with the very few elements 
they contain. We have, for instance, long feelers 
and short ones between ; then again long ones 
'corresponding to the small tubes ; and so on. 

It is therefore evident that we have something 
similar to what may perhaps be better understood 
if I use the very familiar illustration of a musician 
who, taking a simple, familiar tune, plays an endless 
number of variations upon it, in each of which tne 
fundamental theme may be recognized. So this 
idea of radiation, with its simple elements, is played 
upon by the Almighty artist, and made into a mul- 
titude of living realities, to fill the world with 
variety. And the more we penetrate into the dif- 
ferences among these animals, the more do we 
see that between all there is an intellectual link 
which brings them into close relation and shows 
them to be but variations of an idea, and not the 
result of diverse circumstances and influences oper- 
ating upon them. They were made what they are 
by an intellectual process which connects them all 
and combines them under one original plan. They 
are not the product of accident or of chance ; and 
the evidence of the fact that they are the work of 
intellect may be derived from the facility with 
which our mind can grasp the idea which lies , at 
the foundation of their structure, and generalize it. 
Let it once be understood that all radiate animals 


are built upon the plan of radiation, and let the 
elements of that radiation be discovered, and we at 
once perceive the intellectual thought that unites 
and combines them all. 

But there are problems of still greater interest 
presented as we study these animals more in detail. 
You have been accustomed in these lectures to the 
presentation of no considerable details. I trust you 
will allow me this evening to enter into such details 
as will make it perfectly evident that when we 
analyze these structures we disclose the mental 
operations of the Creator at every step. - 

There is a third class of Radiates, more compli- 
cated in structure than either Polyps or Acalephs. 
It is the Echinoderms, including Star-fishes, Sea- 
urchins, and the like. I will select this class for 
illustrating the subject in the details. 

In their external appearance they present three 
very marked modifications of form. Those known as 

rrj;,^ Beche-de-mer 
— ^ have a cylin- 
drical form, 


and in moving rest on one side. Their radiating 
organs are essentially developed at one end, of the 
body, but continued by vertical rows which extend 
from one pole to the other. Naturalists call them 
Holothurians. Next to them we have those which 

have a more spherical form ; 

these are called Sea-urchins. 

Then we have a third class, 

of a star-like form, called 
Star-fishes, or Asterians. 



Suppose the problem were 
presented thus: "With the 
same structural elements to 

build a cylindrical, a spheri- ^^I^-t^^P --^ 

oal, and a star-shaped body. \ / 

Ask an architect to build, with \J 

the same number of pieces connected in the same 
way, a circular tower, an arched dome, and a pentag- 
onal edifice ! It will be a problem not easy to 
solve, especially if there is required the further 
condition that each structure shall be closed at the 
two ends. 

When we examine the structure of these ani- 
mals, the problem, instead of being so difficult as 
when presented in that form to the architect, be- 
comes very simple. Indeed, the solution becomes 
at once apparent when we examine their structure, 
so much so, that, like the egg of Columbus, we are 
surprised that we did not know it before. 

Let me, in entering into these details, give you all 
the representatives of this class, and then select the 
two extremes, namely, the spheroidal and the star- 
shaped, — the Searurchin and the Star-fish. It will 
be necessary to represent the Sea-urchin from three 

AboTe. In profile. Below. 

sides, above, in profile, and below. Below we have 


an opening which is the mouth. It is armed with 
five jaws. Above we have a number of little plates, 
five of which are larger than the rest, each traversed 
by a hole. Then the interior is occupied by a number 
of very small plates. Now each one of these small 
plates on the upper side corresponds to an interval 
between the two jaws of the lower side. From the 
centre extend five rows to the periphery, both in 
the upper and lower part. These rows are built of 
a number' of small plates, all of which are perforated 
with holes, and through these holes proceed tubes, 
by which the animal moves. The wider intervals 
between them are occupied by broader plates, and 
therefore fewer. 

What are all these parts ? 'The little plates at 
the summit are occupied by eyes ; we have there- 
fore five eyes. The broad plates which cover the 
surface of the Sea-urchin contain the soft parts, 
which come out through the rows, and by which 
the anirnal is enabled to move. 

With these few very simple materials, how 
shall we build a Star-fish ? Let us see how the 
Star-fish is constructed. Seen from above it pre- 
sents a net-work of very minute plates, and there 
is no alternation of larger plates at all. They 
extend all over the surface. There is one point 
at which there is a large dot, and that is a sort of 
seam through which the water penetrates into the 
interior. There seems to be nothing like these parts 
in the Sea-urchin at first sight. But when we ex- 
amine the Star-fish on the lower side, we find a very 
different structure. 'Here are five deep furrows. 


Under those furrows project long tubes in every 
direction, being the organs with which the animal 
crawls about. They are evidently, so far as use is 
concerned, the same organs as those which project 
from the Sea-urchin. But in the Sea-urchin we 
have them all united, while in the Star-fish they 
are found only on the lower side. 

Let us see what this furrow is made of, and 
how these tubes are connected with it. Each 
furrow is made up of a number of large, pieces 
alternating with one another, and between them 
there are holes through which come the tubes by 
which the animal moves. Then, on the side of 
these broad tubes are smaller plates. Now these 
plates gradually ta|)er in size until the whole is 
transformed into an angular furrow having the 
same structure all the way through. At the end 
of each ray in the Star-fish there is an eye. We 
have, therefore, everything on the lower surface in 
the Star-fish which we find over the whole body 
of the Sea-urchin, with the single exception of 
the small circle on the summit of the latter which 
is occupied by other plates. 

If now we proceed to 
compare these arrange- 
ments, we cannot fail to 
see a certain analogy be- 
tween them. Suppose I 
should split an orange into 
five parts and stretch those 
parts in every direction 
thus, forming a pentagonal figure. The sphere 


is transformed into a star. Now the point on the 
upper side of the Sea-urchin occupied by those 
small plates becomes divided and transferred, in the 
transformation to the Star-fish, to the five extremi- 
ties of the rays ; and the five eyes which I de-^ 
scribed in the Sea-urchin, occupying the apex, are 
now distributed to the five extremities of the rays 
of the Star-fish. So that, though at first sight they 
seem to be in a different position, they are in the 
same position. There is nothing changed except 
that the little circle, occupying the summit of the 
sphere, has been stretched, and its parts so multi- 
plied, that it extends over the whole upper surface 
of the animal. 

Now it becomes very apparent that this problem 
was easy ; that it required only an increase of 
the elements in one direction to build up the Star- 
fish instead of the Sea-urchin. 

Facts like this, I think, show the immediate 
working of mind in the construction of the ani- 
mal kingdom. It is not a kind of work which is 
delegated to secondary agencies ; it is not like that 
which is delegated to a law working its way uni- 
formly 5 but is that kind of work which the engineer 
retains when he superintends and controls his ma- 
chine while it is working. It is evidence of the 
existence of a Creator, constantly and thoughtfully 
working among the complicated structures that He 
has made. 

In every class of animals we see the same thing. 
Let us take a familiar example, in order to show 
that what I have done with two animals, or two 


orders in the same class, or a great variety of mem- 
bers of the same class, may be done in the different 
parts of one and the same animal. I am prepared 
to demonstrate that such an animal as the Lobster, 
for instance, is built of the same elements from 
head to tail, only more or less modified according 
to the region they occupy; that the head, chest, 
claws, jaws, fins, and tail are all one and the same 
thing, only diversified according to the position and 
use of those parts. 

As a starting-point let us examine the Worm. 
It is a cylindrical animal divided into a number of 
uniform joints, to which, among the higher fami- 
lies, are attached little paddles or oars for locomo- 
tion. In some there are a few bristles, perhaps 
three to each paddle, and they may be a little 
Ipnger or shorter ; but after all you perceive that 
every ring has its locomotive appendages, slightly 
modified according to the position of the body, but 
presenting great uniformity in all the parts, which 
are not bound together in two distinct regions. 

It is, however, very different in the Lobster. 
There we have an anterior region which is very 
distinct from the posterior region. In the posterior 
region of the body the division into rings is at once 
\exj obvious. There are on the sides of the tail 
fin-like appendages, and under the tail other simi- 
lar little appendages, which are all very different 
from those at the end of the tail. Then under the 
body are other appendages of greater length, with 
joints, and terminating in a little hook. There are 
five pairs of these, the front pair of which has a 


remarkable peculiarity, terminating in a large claw 
with two nippers, which may be moved one against 
the other with great force. Then in the head are 
several jaws which move one against the other ; 
and in the extreme front two pairs of long feelers, 
the foremost of which contain a pair of eyes sup- 
ported on a peduncle. 

Let us examine the resemblance between these 
various parts. In the first place', whether one 
of these appendages has a larger or smaller num- 
ber of joints is a matter of no consequence,, be- 
cause we find among Crustacea those in which' 
the number of joints to a limb is greater or less. 
Whether the appendage terminates in a sharp claw, 
or whether the last joint is flattened, is also of no 
great consequence, because we find among Crus- 
tacea those in which one pair of legs is flattened 
in the shape of an oar, and others in which the end 
is shaped like a claw. And when we examine the 
diflFerent kinds of Shrimps which iiihabit our coast, 
and compare them with one another, we find that 
there are those which, instead of flat oars, have, 
like the Crab, a slender branch at the side of the 
appendage ; and still others which, instead of one 
oar, may have two. Therefore, between the leg 
and one of these oars under the tail of the Lobster 
there is only a diflference in form, or in mode of 
execution; nothing diflFerent in their nature, be- 
cause there is at the end of the tail a large pair of 
appendages which constitute a most powerful organ 
of locomotion, and that terminal pair differs from 
those under the tail only in size and power, not 


in structure. "We are, therefore, as far as this, pre- 
pared to say that the large fins at the end of the 
tail, and the small fin-like appendages under the 
tail, and those slender ones under the main body 
and the legs, are all one and the same thing. 

But here is the claw, which seems to be some- 
thing entirely different in structure from the other 
appendages. Let us examine it more closely, and 
we shall see that it is not so different as it first 
appears. The leg is composed of a series of joints, 
three or four in number, and then a last joint taper- 
ing to a point The last joint has a little hook at 
the side. We find the same thing in some Shrimps. 
Now let this hook be very much enlarged and you 
• have -the claw of the Lobster. ' And this last joint 
is made to play against the prong of the last joint 
but one, and m.akes a nipper. It is therefore iden- 
tical in structure with all the other appendages ; 
we have nothing new in the structure of the claw, 
only a modification of parts. Passing now to the 
jaws, we find little appendages armed with teeth, 
which, when brought one against the other, enable 
the animal to seize and crush its prey. These ap- 
pendages are arranged on opposite sides and curved 
inwards, the inner margin being serried or variously 
armed. And what is peculiar to all Articulates, 
these appendages move horizontally towards one 
another, instead of perpendicularly. These jaws 
you perceive are nothing but legs made subservient 
to the use of seizing prey and crushing it and then 
pushing it into the aUmentary canal. There are 
as many as six pairs of these jaws, one behind the 


other, all essentially of the same character as the 
claw, the leg, or the fin. 

But what are these feelers ? They come near 
the simplicity of structure of those appendages 
which we find in Worms, thread-like, and divided 
into a large number of close articulations. This 
organ is now made to subserve the purpose of 
touching or feeling. But it bears to the body the 
same identical relation as all the other parts. 

If we examine how these appendages are con- 
nected with the rings of which the body is com- 
posed, we find them everywhere in the same posi- 
tion. The body is made up of rings from which 
arise lateral appendages in the shape of tubes; 
these tubes are jointed, and when highly compli- 
cated they assume the form of a claw, when flat- 
tened, the shape of an oar, when divided into a 
number of joints, feelers, and when made to move 
laterally, one set against another set, jaws. And the 
eye is attached to one of these feelers at the end. 
It is a feeler made extremely sensitive at its ex- 
tremity, and especially sensitive to one kind of 
impression. But because it receives impression of 
light it is not therefore an eye like ours, having a 
close connection with the brain ; it is only a foot- 
like or claw-like organ placed on the summit of the 
appendage made sufficiently sensitive to receive 
an impression of light. 

So, then, from one end of the body to the other, 
whatever be the function of these organs, we have 
only a different expression of one and the same 


And that this is the true view of the case we have 
evidence whenever we compare different animals of 
this class with one another. Take, for instance, the 
Crab and the Lobster. Take that singular animal 
called the Horseshoe crab which is found along 
our shore, and compare its rings with those of the 
Lobster. In the Lobster we have six pairs of jaws, 
six pairs of legs, six pairs of fins, a pair of eyes, a 
pair of feelers, and a broad terminal fin at the end 
of the tail. In the Horseshoe crab we find around 
the mouth six pairs of legs, no feelers, no jaws 
proper ; but such is the complete demonstration of 
the identity of all these parts, that, while the tips of 
these legs are the feet with which the animal moves, 
the elbows of the same appendages are the surfaces 
which crush and bring the food to the mouth. The 
same appendage is, in other words, both a locomo- 
tive and a chewing organ, and they are placed in 
the same position as in the Lobster or Crab. 

Nothing, therefore, could be plainer than that 
these various parts which are made subservient to 
such diverse purposes are essentially the same in 
structure, only differing in the execution. It is 
something akin to the device of man, to do as 
much work as possible with the smallest and sim- 
plest apparatus ; and when the largest amount and 
greatest variety of work is produced by a particu- 
lar invention, we consider the result as indicative 
of superiority of genius or inventive capacity. Here 
in the animal kingdom we see it illustrated to an 
extent which the best-trained mind can hardly fol- 
low, showing how far beyond our comprehension 


are the wonderful works of nature. Even though 
we can make ourselves conscious that they are 
built by mind, and that it has pleased the Maker of 
all things to give us a spark of that life which 
makes us to be His children, formed in His image, 
that evidence is nowhere stronger than in the fact 
that our mind is capable of studying those works 
to a limit which approaches to a comprehension 
of their wonderful relation to one another.