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Full text of "On the nature of limbs"

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THE NATURE OF LIMBS. 



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A DISCOURSE 



DELIVERED ON FRIDAY, FEBRUARY 9, AT AN EVENING 



MEETING OF THE 



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ROYAL INSTITUTION OF GREAT BRITAIN 



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BY 



RICHARD OWEN, F.R.S. 



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LONDON: 

JOHN VAN VOORST, PATERNOSTER ROW 

MDCCCXLIX. 



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ON 



THE NATURE OF LIMBS 



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The chief difficulty that I have encountered in the endea- 
vour to fulfil the request with which I have been honoured 
by the Managers of this Institution, is one which the 
able Secretary will be surprised to hear I owe to him: 
it has been the attempt to give a plain answer to Mr. 

Barlow's question, ' By what title shall I announce your 
Lecture?' 

It w^as not until I had written and erased two or three 
which first suggested themselves that I became fully con- 
scious how foreign to our English philosophy were those 
ideas or trains of thought concerned in the discovery of 
the anatomical truths, one of which I propose to explain 

on the present occasion in reference to the Hmbs or loco- 
motive extremities. 

A German anatomist, addressing an audience of his 
countrymen, would feel none of the difficulty which I ex- 
perienced. His language, rich in the precise expressions 
of philosophic abstractions, would instantly supply him 
with the word for the idea he meant to convey ; and that 
w^ord would be ' Bedeutung.' It is the ' Bedeutung ' of 
the limbs which is my present subject^ and the literal 
translation of the word is ' signification.' 



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I had written at firsts ^ On the Signification of the Limbs 
of Man and Animals ;' when it occurred to me that a prac- 
tical audience might deem that there was small need of a 
learned lecture to prove that matter^ and might be disposed 
to think that any old Pensioner at Greenwich or Chelsea 

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could certify better than a Professor^ that ^ arms and legs ^ 
signified a good deal. 

Our word ^meaning/ as applied to what I shall en- 
deavour to prove, in regard to those useful appendages, 
would convey as false or feeble an idea of my meaning. 

^ On the idea of the limbs ^ might be understood only 
by those who knew that the word was used in the sense it 
bears in the Platonic philosophy. 

^ Homology^ seems now to be accepted as the name of 
that study or doctrine the subject of which is the relations 
of the parts of animal bodies understood by the German 
word ' Bedeutung ;^ and in the technical language of ana- 
tomical science I should define the present lecture as 
being : ^^ On the General and Serial Homologies of the 
Locomotive Extremities.^^ But such a title would have 
been comprehended only by anatomists, and I knew that 
your Secretary had in view the information of a more 
general audience, to whom such technical phraseology 
would be less intelligible perhaps than the literal trans- 
lation of the German term. 

The ^ Bedeutung/ or signification of a part in an animal 
body, may be explained as the essential nature of such 
part — as being that essentiality which it retains under 



1. 



every modification o f size and f orm, and for whatever office 
such modifications may adapt it. I have used therefore 
the word ' Nature ' in the sense of the German ' Bedeu- 
tung/ as signifying that essential character of a part which 
belongs to it in its relation to a predetermined pattern, 
answering to the ' idea ' of the Archetypal World in the 
Platonic cosmogony, which archetype or primal pattern is 
the basis supporting all the modifications of such part for 



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specific powers and actions in all animals possessing it, 
and to which archetypal form we come^ in the course of 
our comparison of those modifications^ finally to reduce 
their subject. 

The ^ limbs ^ to which the limits of the present Dis- 
course confine its appHcation^ are those of the Vertebrate 
Series of animals ; they are the parts called the ^ arms ' 
and ^legs^ in Man; the ^fore-^ and ^^ hind-legs^ of Beasts; 
the ^wings' and '^legs^ of Bats and Birds; the ^pectoral 
fins' and Central fins^ of Fishes. I take for granted that 
it is generally known^ as it is universally admitted by 
competent anatomists and naturalists^ that these limbs or 
locomotive members^ which^ according to their speciality 
of form^ have received the above special names^ are an- 
swerable or ^homologous' parts : that the arm of the Man 
is the fore-leg of the Beast^ the wing of the Bird^ and the 
pectoral fin of the Fish. This speci al hom ology has been 
long discerned and accepted; but the general homology 
of the parts or their relation to the vertebrate Archetype, 
in short their ^Bedeutung' or essential nature, is not ge- 
nerally known. Some of the keenest wdts and deepest 
thinkers amongst the anatomists of the German Philoso- 
phical School have endeavoured to penetrate the mystery, 
and have propounded the views which have resulted from 
such their attempts. But those views have never received 
the sanction of even partial assent ; and, if the conclusion 
to which I have arrived be the correct one, such assent 
has not been unreasonably withheld. 

It must be owned, however, that the non-acceptance 
of these generalizations has been due more to indifference 
and to the non-appreciation of the value of the inquiries. 



than to a rigorous 



merits 



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few of the exact conclusions as to the general homology 
of parts of the skeleton of animals have been admitted with 
thorough comprehension and fruition of the discovery by 
the actual cultivators of Natural History in this country ; 

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so that I can scarcely appeal to an example in illustration 
of my meaning with any hope that it will prove such to 
more than a very small portion of my hearers. 

Some however may understand and assent to the pro- 
position that ^'^ the basilar part or process of the occipital 
bone in human anatomy is the ^ centrum^ or body of a 
cranial vertebra/^ Now^ by virtue of this truths mark 
what the human anatomist comprehends ! Firsts that the 
'^pars basilaris ^ is not a process in the proper signification 
of the term, but a self-subsistent, independent element of 
the skull ; whereby he is prepared for its primitive appear- 
ance as a distinct part in the embryo, and as a persistent 
distinct ^bone^ in all the cold-blooded Vertebrata. He 
further recognises it to be a member of the same series of 
bones as the flat bodies of the cervical vertebrae, the thick 
bodies of the dorsal and lumbar vertebrae, and the broad 
bodies of the sacral vertebrae ; and he understands whv 
it differs from the other ^ processes of the occipital bone ^ 
by its primitive relation to the embryonic ^chorda dor- 

salisJ* All this, and much more comfortable knowledge 
of the ^processus seu pars bas'ilaris ossis occipitalis/ is im- 
plied by the definition of its general homology, i. e. of its 
essential nature, signification, or ^Bedeutung^; and it is 
precisely the same kind of knowledge which I imply by 
the w^ord ^ nature ^ in reference to the limbs. 



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The parts to which 1 here refer, and to which alone the 
reasoning will apply that leads to the desired conclusion in 
the present lecture, are those in the Vertebrated animals, 
serving chiefly for locomotion, but sometimes adapted to 
other offices. Many and multiform parts answering these 
purposes are present in the Invertebrated animals; but 
their framework is formed out of a distinct system of hard 
parts from those employed in the Vertebrata. Here it is 
the internal or endo-skeleton : in the Invertebrata it is the 
hardened skin, the dermo- or exo-skeleton. 



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The hard parts of the leg of a Crab or an Insect may 
be * analogous ' to the bones of the limb of a Quadruped, 
but they are not 'homologous^ with them; and where 
there is no special homology^ there can be no relations of 
a higher or more general homology between the parts^. 

The Vertebrated animals enjoy as extensive and diversi- 
fied a sphere of active existence as the Invertebrated. They 
people the seas^ and can move swiftly both beneath and 
upon the surface of water: they can course over the dry 
land^ and traverse the substance of the earth : they can 

rise above that surface and soar in the lofty regions of 
aerial space. 



The instruments for effecting: these different kinds of 




locomotion — diving and swimmings burrowing and run- 
ning, climbing and flying — are accordingly very different 



in their configuration and proportions. The simplest form 

Fig. 1. 




External form and skeleton of the pectoral fin of the Dugong 

{Halicore indicus), 

of the locomotive member is that of the fin. The marine 
mammal called Dugong here offers us an example of such 
(fig. 1). It is a strongs stiff, shorty broad^ flat^ and ob- 

* The parts termed ^ femur/ ^ tibia/ * tarsus/ &c. in Entomology 



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tusely pointed paddle or oar ; M'ithout other apparent joint 
than that which unites it to the body it has to propel : a 
joint permitting that degree of rotation with the oblique 
stroke that makes the movement of the oar most effective. 
The instrument for burrowing^ such as the Mole pre- 
sents (fig. 2)y is not very different in form and character 

Fig. 2. 




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External form and skeleton of the fore-limb of the Mole {Talpa 

Europcea), 

from the fin ; but being destined to displace a denser ele- 
ment than water^ it is shorter in proportion to its breadth^ 
and much stronger : it resembles the fin in consisting, seem- 
ingly, of but one segment or joint^ and being moveable as 

a w^hole only where it is set on to the trunk. The free 
border^ however^ instead of being smooth and thin, is 
notched, and armed with a row of hard, tooth-like, horny 



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were so denominated from a loose appreciation of this analogy, and 
convenience obviously suggests their retention in an arbitrary sense. 
To attempt to change the application of these names from a supposed 
more accurate appreciation of the analogical resemblance, argues either 
a mind more subservient to nomenclature than zealous for the advance- 
ment of the science of Nature ; or an ignorance of the distinct systems 
to which the skeletons of the limbs of Articulates and Vertebrates owe 
their origin. 



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points, adapted for scraping and throwing back the soil. 
With such rapidity does the mole effect this purpose*, that 
it may literally be said to ^ swim through the earth.' 

The third form of limb or locomotive member here ex- 
hibited (fig. 3), offers a striking contrast to the burrowing 

Fig. 3. 




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External form and skeleton of the whig of the Bat. 

trowel we were last contemplating. It is a thin^ vastly 
expanded sheet of membrane, sustained, like an umbrella, 
by slender rays, and flapped by means of these to and fro 



* Prof. Bell, History of British Quadrupeds, p. 96, 8vo, Van Voorst 






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in the air; and with such force and rapidity, as, combined 
with its extensive surface, to make it react upon the atte- 
nuated element more powerfully than gravitation can 
attract the weight to which the hmb is attached, and con- 
sequently the body is raised aloft and moved swiftly 
through the air ; in brief, the animal flies, and these instru- 
ments of its aerial course are called ^ wings/ 

When a quadruped has to move swiftly along the surface 
of the earth by reacting upon the hard ground, its Hmbs 
are as remarkable for their length and slenderness as those 
of the burrower or swimmer are for their shortness and 
breadth. In the racer the instruments of its rapid course 
are four long tapering columns, with joints permitting 

Fig. 4. 





Skeleton of the fore- and hind-leg of a Horse. 

them to bend in opposite directions, and of the form repre- 
sented in the diagram (fig. 4) and familiar to all : each 
column rests upon a slightly expanded base encased by the 
hard horny sheath which we call the ^ hoof.^ 

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able appendages or digits^ one of which can be opposed 
to the others and retain the object of their mutual press- 
ure. Each of the four extremities is so organized in the 
ape and monkey, M^hich are thus especially adapted for 
climbing and living in trees. 

In Man the principle of special adaptation goes further ; 
and, whilst one pair of limbs is expressly organized for 
locomotion and standing in the erect position, the other 
pair is left free to execute the manifold behests of his ra- 
tional and inventive Will, and is exquisitely organized for 
delicate touch and prehension, emphatically called *' mani- 
pulation.' 

Such are some of the more striking amongst the count- 
less purposes to which the parts of animals called ^ limbs ' 
are adapted, and such the consequent diversity of their 

outward shapes and proportions. We cannot be surprised 
at this ; it could not be otherwise : the instrument must 
be equal to its office. And consider the various devices 
that human ingenuity has conceived and human skill and 
perseverance have put into practice in order to obtain 

corresponding results ! 

To break his ocean-bounds the islander fabricates his 
craft, and glides over the water by means of the oar, the sail, 
or the paddle-wheel. To quit the dull earth Man inflates 
the balloon, and soars aloft, and, perhaps, endeavours to 
steer or guide his course by the action of broad expanded 
sheets, hke wings. With the arched shield and the spade 
or pick he bores the tunnel : and his modes of accelerating 
his speed in moving over the surface of the ground are 
many and various. But by whatever means or instruments 
Man aids, or supersedes, his natural locomotive organs, 
such instruments are adapted expressly and immediately 
to the end proposed. He does not fetter himself by 
the trammels of any common type of locomotive instru- 
ment, and increase his pains by having to adjust the parts 
and compensate their proportions, so as best to perform 



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the end required without deviating from the pattern pre- 
viously laid down for all. There is no community of plan 
or structure between the boat and the balloon^ between 
Stephenson^s locomotive engine and Brunei's tunnelling 
machinery : a very remote analogy, if any, can be traced 
between the instruments devised by man to travel in the 
air and on the sea, through the earth or along its surface. 

Nor should we anticipate, if animated in our researches 
by the quest of final causes in the belief that they M^ere the 
sole governing principle of organization, a much greater 
amount of conformity in the construction of the natural 
instruments by means of which those different elements 
are traversed by different animals. The teleologist would 
rather expect to find the same direct and purposive adapta- 
tion of the limb to its office as in the machine. A deep and 
pregnant principle in philosophy, therefore, is concerned 
in the issue of such dissections, and to these, therefore, I 
now pass, premising that the end in view will be attained 
without extending the comparison beyond the framework 
of the limbs, or the leverage of the bones and joints. 

The human anatomist is of course familiar with this 
part of the skeleton in man. The arm is suspended from 
a broad bone called ^ scapula ' (Frontispiece, and Plate I. 
fig. 6, 51), and the shoulder-joint is strengthened by a 
slender bone called ^ clavicle ' (58), which abuts against the 
top of the ^ sternum ' (69), forming with its fellow an in- 
verted arch, called in Comparative Anatomy the ^ scapular 
arch.' The arm proper is appended to this arch : its first 
joint or segment is formed by a single long bone, the 
^ humerus ' (53) ; its second joint, by a pair of shorter and 
more slender bones, the ^ radius (55) and ulna' (54) ; and 
the hand or third segment is formed by a group of little 
thick bones, the ^ carpals ' (66), and by five rays or digits ; 
one (i) consisting of three segments, the rest (ii— v) of 
four segments each; the five bones joining the carpus 
being called ^ metacarpals,' and the others the ^ phalanges.' 



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the corresponding limb of the horse^ ox, or other hoofed 
animal, the simphfication of structure seems not to be m 
the ratio of the loss of function : almost all that the hoof 
can be made to do is to rest upon or beat against the 
ground ; and yet we find in the solidungulate hmb (fig. 4) 
the broad scapula (51), the long humerus (53), the radius 
(55) and ulna (64), the carpus (56), the metacarpus (67) and 
the digital phalanges. There is a diminution and simpli- 
fication of accessory parts, but the essentials are main- 
tained : it is obvious that the same type has governed the 
formation of the two limbs compared. The most 
distinction is the total absence of the clavicle in the hoofed 
quadruped : the shoulder-joint did not need to be made 
the fixed point upon which the fore-limb might rotate in 
a variety of directions ; on the contrary, the movements of 
the humerus in the horse, though restricted almost to one 
plane, are extensive, and the scapula must play backwards 
and forwards to some extent with the limb ; M^hich move- 
ments would have been impeded had it been bound by a 
brittle bony bar to the sternum. 

In like manner, since the hand had no need in the horse 
or ox to be turned, now prone now supine,.in subserviency to 
manipulation, the accessory joints that allow the radius to 
rotate on the ulna are abohshed, and the ulna is retained 
only in so fiir as it is required to strengthen the radius, 
make the joint of the elbow more secure, and give advan- 
tageous attachment to certain muscles. Here, however, 
we plainly see the same bone, with its olecranon (Frontis- 
piece and fig. 4, 54), although it is anchylosed to the 

radius (55) and forms what, in Human anatomy, would 
be called a process of that bone. 

The carpal series of small bones answers almost exactly, 
bone for bone, to that in man* : the hand of the horse, 



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lettered in the human skeleton, PL L fig. 6, 56. 




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though to outward view reduced to a single digit, yet 
shows the rudiments of two others (fig. 6, ii and v) 
when anatomized; these are called * splint-bones' by the 
Veterinarians; but we shall presently demonstrate the 
very fingers in the human hand to which they answer. 

If we had httle a-priori ground to expect so much con- 
formity between the skeleton of the arm of m.an and that 
of the fore-limb of the horse, still less have we to antici- 
pate such between these and the bony frame of the wide- 
spread wing of the bat. Yet you perceive (fig. 3) that 
the essential similarity of its composition to that of the 
human arm (Frontispiece) is greater, the difference de- 
pending more on the proportion than on the change or 

suppression of parts. 

Besides the scapula (51) we have the clavicle (58), which 
reappears in its perfect state ; strong, long and^ curved, 
rendering the shoulder-joint a firm ' point d'appui ' to the 
vigorous strokes of the wing that centre in the head of the 
humerus. This bone (53) is proportionally as long as in 
man, but the bones of the fore-arm are much longer, at 
least the radius (55) ; for, rotatory movement of the wrist 
being here as little needed as in the horse, the ulna (54) is 
similarly atrophied and reduced to its olecranon and prox- 
imal half which is anchylosed to the radius. The small bones 
of the wrist or carpus (56) again succeed the radius, and 
here they support the same number of fingers as in man, 
of which, also, the first or innermost (i) is distinguished 

v) by its shortness and difference of 
direction, and by its inferior number of phalanges. The 
chief modification of the bones of the fore-limb in the bat 
consists in the extreme elongation and attenuation of the 
four ordinary fingers ; two or more of which consist, as in 
man, of the metacarpal bone and of three phalanges, proxi- 
mal, middle and distal ; but the last phalanx tapers to a 
point and is without a nail. 

To skim the air and to burrow in the earth would seem 



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to require instruments as different in construction as in 
size and shape ; but observe how closely the skeleton of 
the mole's trowel (fig. 2) conforms in the number and rela- 
tive position of the parts to that of the bat's wing! The 
chief change is in this^ — whatever is elongated and attenu- 
ated in the bat is shortened and thickened in the mole. With 
regard to one bone, indeed, the statement may be reversed, 
for the scapula (fig. 2, 51) now appears as a long, straight, 
prismatic column, and is the centre of a most powerful 
mass of muscle in the recent limb. The clavicle (68) on 
the other hand, though perfect, is a short thick cube : the 

humerus (53) must be classed by its shape amongst the 
broad bones, the ordinary form of this bone and the sca- 
pula being reversed in the mole. The radius (55) and 
ulna (54) are both completely developed, and enjoy all the 
accessory rotatory movements as in man ; but are rela- 

tively much more powerful bones, especially the ulna, 
which has an enormous olecranon as the fulcrum of 
powerful muscular forces. Then follow, as usual, the 
double series of little carpal bones (56), supporting five 
digits (i— v), which, notwithstanding they are buried up 
to the claws in a sheath of tough skin, have precisely the 
same number of bones and joints as in the prehensile hand 
of man ; only that every bone, save the last in each digit, 
is as broad and thick as it is long. The chief deviation 
from the human type is by redundancy instead of defi- 
ciency, and is exemplified by one or two supernumerary 
carpal ossicles, the most remarkable of which is sabre- 
shaped (56'), and strengthens the digging or scraping edge 
of the broad palm. 

If the dissector were little prepared on teleological 
grounds to meet with the full number of joints or seg- 
ments in the short and seemingly simple trowel of the 
mole, he could still less expect to find them hidden be- 
neath the common undivided sheath of the fin of the du- 
;ong or whale. Yet the bones of this simple form of limb 



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offer perhaps the most striking and suggestive instance of 
an adherence to type, necessitated as it would seem, not- 
withstanding the absence of all those movements and ap- 
phances of the Umb that explain the presence of the seve- 
ral segments, on the principle of final causes, in the horse 

and man. 

First we have the blade-bone or scapula (fig. 1, 51), now 
again broad and flat ; next the single arm-bone (63), this 
united by an elbow-joint to a radius (65) and ulna (54) ; the 
latter complete with its elbow-prominence or olecranon : 
the two antibrachial bones are followed by the ossicles of 
the carpus (56) in their normal double series, and these 
support the five digits (i-v), with the first distinguished 
from the rest by its inferior number of phalanges. 

In descending to an inferior aquatic species and exami- 
ning the corresponding (pectoral) fin of a fish (PL I. fig. 2), 
we find indeed one segment (53) of the Hmb abrogated, and 
its framework attached to the scapular arch (51, 52) by the 
two bones answering to radius (55) and ulna (54) ; these, 
however, are followed by the constant carpals (56), which 
support a variable number of digits (57, a) in the form of 
slender pointed rays, like those in the bat, but usually 
more numerous, often bifurcated, and always divided into 
a greater number of segments. We clearly recognise, how- 
ever the hand, the wrist and the fore-arm in this fish's fin. 
The number of digital rays in some fishes falls short of 
the typical 5, and in the Lepidosiren (PI. 1. fig. 7) they 
are reduced to 1, which is partially divided into many seg- 
ments, and in which all distinction of arm, fore-arm and 

In the Murcena and Anguis the scapular 
arch alone remains, the appended hmb being lost ; and 
lastly, in ordinary Serpents and Cyclostomous fishes (Lam- 
preys) all trace of both arch and appendage has vanished. 
On glancing back over the great classes of animals re- 
presented by the examples that have been adduced, we 
perceive M'ithin what narrow limits of the Vertebrate series 



hand is lost. 



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the type of the anterior or pectoral member^ as shown in 
man^ ceases to be recognizable ; and then^ not by a change A 
but by a fading away of the pattern^ as the limb rapidly ^ 
disappears at the extreme of the series. It is by the 
study of these transitory or rudimental manifestations of 
the limbs that we gain the deepest and truest insight into 
theu" essential nature. But before proceeding to this part 
of my inquii-y^ I shall advert to another class of corre- 
spondences or evidences of unity of type which give ad- 
ditional impulse to the pursuit of the higher generalization 
that may reveal the meaning of those evidences. 

The bilateral symmetry of the body and the consequent 

answerableness or parallelism of the parts or organs of one 
side to those of another^ are too obvious facts to need more 
than a passing reference. They have been universally re- 
cognized^ were scientifically enunciated by the Father of 

Natural History ^^ and in all languages the parts are de- 
signated by the same names^ and distinguished only by the 
epithets ^ right^ and ^ left/ Thus we have a right arm and a 
left arm^ a right leg and a left leg^ and so with respect to 
their several segments and the subdivisions of these^down 
to the right thumb and the left thumbs the right great-toe 
and the left great-toe^ &c. The identity of structure in this 
transverse direction is complete. The great Newton was so 
much struck by the contemplation of this law of symmetry^ 



that he breaks out into the following emphatic and beauti 



r 



ful anticipation of the aim and general result of Philosophi- 
cal Anatomy: — *^^Tammiram uniformitatem in planetarum 
systemate, necessario fatendum est inteUigentia et consilio 

fuisse effectam ! Idemque dici possit de uniformitate ilia 
quae est in corporibus animalium. Habent videlicet ani- 
malia pleraque omnia^ bina latera^, dextrum et sinistrum^ 

* " Habet autem liomo partes superas et inferas ; anteriores et pos- 
tei-iores ; dextras et sinistras. Dextrse igitur atque sinistra; partes omnes 
inter se similes fere et esedem, pra^terquam quod sinistrae imbecilliores/' 
Schneider's Aristotelis de Animal. Hist. Lib. 11. , torn, ii. p. 30. 




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forma coasimili : et in lateribus illis, a posteriore quidem 
corporis sui parte, pedes binos ; ab anteriori autem parte, 
binos armos, vel pedes, vel alas, humeris affixos : interque 
hurneros collum in spinam excurrens, cui affixum est ca- 
put -, in eoque capita binas aures, binos oculos, nasum, os 
et linguam ; similiter posita omnia, in omnibus fere ani- 



malibus/'— iVewifow, Optices, 1719 



Aristotle, also. 



saw that, besides the lateral symmetry, the inferior parts 
corresponded in a certain proportion to the superior parts. 
The most superficial comparison of the limbs of our 
own species must impress the observer with the resem- 
blance between the arm and the leg in their general form 
and character, notwithstanding the marked contrast of 
their powers and 



offices 



characterizes the human 



species 



Every one may see that the thigh answers to 
the arm proper, the leg to the fore-arm, the ankle to the 
wrist, the five-toed foot to the five-fingered hand, in which 
also the thick thumb may be recognized as answering to 
the great-toe, and the little finger to the little toe, and so 



of the rest. 
. When w 



A 



two limbs, the correspondence becomes more striking, 
broad and flat bone, the haunch-bone or ^ ilium' (Frontis- 
piece and PI. I. fig. 6, 62), with its base towards the spine 
and its apex forming the hip-joint, plainly repeats the sca- 
pula (61), and the inverted arch is completed by the meet- 
ing of two broad and perforated plates below (63 & 64), 
which in a general way correspond with the clavicles. The 
single bone of the thigh (65) more decidedly repeats the 
single bone of the arm (53) * ; the two bones of the leg 

* It will, of course, be obvious tbat the humerus is not ' the same 
bone' as the femur of the same individual in the same sense in which 
the humerus of one individud^or species is said to be ' the same bone ' 
as the humerus of another individual or species. In the mstance of se- 
rial homology above-cited, the femur, though repeating in its segment 
the humerus in the more advanced segment, is not its namesake or 



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17 



(tibia, 56, and fibula, 57) repeat the two bones of the fore- 
arm (radius, 55, and ulna, 54) ; the small thick bones of the 
tarsus (68) those of the carpus (56) ; the five metatarsals 



the five metacarpals : and, if proof were wanting of the 



serial homology, as I have termed these relations, between 
the thumb (i) and great toe (^), we find it in the skeleton, 
Mhich shows that both have only two phalanges, whilst the 
remaining four toes, notwithstanding most of them are 
shorter than the great- toe, have the same superior number 
of phalanges, viz. three, as the four fingers have on the 
hand. The bones that are developed in tendons, which 
glide over joints, in order to remove them from the centre 
of motion, are the least regular or subject to type : they are 
called ^sesamoids,' and the largest and most conspicuous 
of these is that of the knee-pan or ^patella' {66'), to which 
there is no corresponding ossification in the homotypal 
tendon of the arm. 

In comparing the bones of the hind-leg (fig. 4, B) with 
those of the fore-leg (fig. 4, A) of the horse, we find that the 
modifications by which the latter depart from the type of 
the skeleton of the human arm are repeated both in kind 
and degree in the hind-leg. The foot is similarly simplified, 
attenuated and elongated : it consists chiefly of a single 
toe {Hi), with the same number of joints as that of the fore- 
foot, and touches the ground by a single hoof: rudiments 
of two other toes {ii and iv, fig. 19, PI. I.) are similarly re- 
presented by the splint-bones : there is a group of tarsal 
bones (fig. 4, 68) answering to the carpal ones {ib. 56). The 
segment of the leg is formed chiefly by a single bone {66), 

Hke the corresponding segment of the fore-limb (53) ; the 



' homologue.' I have proposed, therefore, to call the bones so related 
serially in the same skeleton ' homotypes,' and to restrict the term 
' homologue ' to the corresponding bones in different individuals or 
species, which bones bear, or ought to bear, the same names. See 
' On the Archetype and Homologies of the Vertebrate Skeleton.' Svo, 
V.Voorst, 1848. 



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fibula (67) being reduced to a rudiment of its upper end, as 
the ulna (64) is in the antibrachium. The short oblique 
femur (65) repeats the short oblique humerus (53), only the 
obhquity is in the opposite sense; but the modification of 
the end of the bone which produces this change is feeble in 
comparison to that of the entire femur in different species : 
compare e. g. the femur in man and the megatherium. The 
long and narrow ilium (62) departs from the human type 
of that bone just as the long and narrow scapula (51) does 



man 



be noticed is, that, whereas the coracoid (52) is rudimental 
and the clavicle nil in the fore-limb, their homotypes the 



com 
When 



iscmum \oo) auu puui.3 \yj-i:) u.,.^ ^--v 1 

plete the arch to which the hind-limb is attached, 
we remember that the hind-limbs are the chief instruments 
in propelling the body, we shall see the necessity for the 
firm and unyielding condition of the part that immediately 



from 



to the trunk. 



The scapular arch is the seat of more variety in regard 
to its closed or open state in the class Mammalia than m 
the lower Vertebrata, which depart less from the type in re- 
taining its complete or closed state. But what chiefly con- 
cerns us in the present parallehsm between the fore and 
hind Umbs is the fact that the pelvic arch is subject in cer- 
tain mammals to the same variety by defect as the scapular 
arch is. Thus, in the skeleton of the bat (fig. 3), m which 
we saw the scapular arch completed by the extension of the 
strong clavicles (58) to the sternum, the pelvic arch remains 
open below, the pubis (64) and ischium (63) being rudimen- 
tal and forming mere ' processes' of the ilium (62), as the co- 
racoid does of the scapula. Here, therefore, the supporting 
arches of the fore- and hind-hmbs present the reverse con- 
ditions to those in the horse in regard to their complete- 
ness, and the final cause is obvious. In the bat the fore- 
limbs are the locomotive instruments, the hind-hmbs 



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19 

merely the supporting members from which the animal 
suspends itself, head downwards. 

But if we find that the correspondence between the sca- 
pular and pelvic arches is interrupted in the bat to the 
same extent as in the horse^ though contrariwise, the pel- 
vis being open and the scapular arch closed, in relation 
to the different values of their respective hmbs in loco- 
motion; yet the parallehsm between the fore- and hind- 
Hmbs themselves is equally complete as to their composi- 
tion. The single femur (65) answers to the humerus (53), 
and the tibia (66) alone is fully developed in the leg, as the 
radius (55) is in the fore-arm : whilst the fibula {67) exhi- 
bits an equally rudimental and incomplete state to that 
presented by the ulna (54) ; only in the leg the lower half 
of the bone is retained, whilst in the arm it is the upper 
half: and we may observe a similar contrast in the Camel- 
tribe. The tarsus (68) in the bat again parallels the carpus 
(56), and the digits are developed in the same typical number 
in the foot as in the hand, only that they retain their more 
normal form and unguiculate character. 

There is one item of conformity of structure between 
the fore- and hind-limbs of certain bats not usually met 
With in other animals, viz. the development of a sesamoid 
m the tendon of the biceps bracMi in front of the elbow- 
joint, which is the true homotype of the patella in the leg. 
There is also a second sesamoid above the olecranon (54) of 
the bat, which has been thought to represent the patella ; 
but I shall presently advert to the true homotype of the 
ulnar sesamoid in the hind-limb. 

The comparison between the fore- and hind-limbs in the 
mole may be briefly discussed, as they differ in their pro- 
portions, not in their composition. 

The pelvic arch is reduced in its transverse dimensions 
to the ordinary size of the haemal arches in the tail, and 
surrounds only the pelvic continuation of the aortic arte- 
rial trunk; but the ilium, resembles the scapula in its 

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length and slenderness : the femur— the homotype of the 
humerus— is followed by a complete tibia and fibula, an- 
s\vering to the complete radius and ulna in the fore-limb : 
there is a tarsal segment of small ossicles answering to the 
carpal series, and five toes with the same number of joints 
as those of the fore-foot, the first or innermost of each 

having but two phalanges. 

We cannot pursue this paralleHsm in respect of the 
limbs that have been adduced as examples of the fin or 
organ of swimming (fig. 1), because all the whale-tribe are 
characterized by the absence of the ventral fins or repre- 



& 



Muraena 



In the 



that traces of their sustaining arch still exist, 
whale the ischium or inferior member of the arch is pre- 
sent : in the dugong there is both a rudimental ischium 

and ilium. 

The Reptihan sea-turtle {Chelone) is an instance m 

which both fore- and hind-limbs are modified to serve as 
fins ; but I have selected in illustration of this comparison 
an extinct form of Reptile, which of all the ancient Sea- 
lizards {Enaliosauria) w^as most nearly alhed to the Che- 
Ionia. The skeleton of the Plesiosaurus (PI. II.) shows the 
unity of type closely preserved between the fore- and 

hind-limbs. 

The scapula (51) is a long, narrow, almost vertical bone, 
both in shape and position like a rib : the arch is com- 
pleted below by a broad coracoid (52) and a clavicle (58) . 
The ihum (62) in like manner retains much of its proper 
pleurapophysial or rib-like character, and the pelvic arch 
is completed below by a broad ischium (63) and pubis (64) . 
The flattened femur (65) closely parallels the flattened hu- 
merus (53). In the two short bones of the next segment, 
the stronger and straighter one in the pectoral fin (55) ob- 
viously represents the radius, and its homotype the tibia 
(66) has the same shape in the ventral fin. The ulna (54) 



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21 

is shorter than the radius^ is curved and projects back- 
vA'ards ; the fibula (67) repeats the same character : there 
is a carpal group of ossicles (56) and a tarsal group of ossi- 
cles (68) ; a row of five metacarpals (57), and a row of five 
metatarsals (69) ; and the number of the digits, as well as 
the number of their joints respectively, is almost identical 
in both fore- and hind-paddles. 

The conformity is the more striking here, because it is 
not broken by the opposite flexures that characterise the 
corresponding segments of the fore- and hind-limbs in the 
terrestrial mammalia; and it is the more interesting and 
significative as being manifested by an animal which lived 
and died at a period so remote as the existence of that 
ocean from Avhich the lias of Somersetshire was precipi- 
tated. 

Vicq-d^Azyr seems to have been the first anatomist 
whose attention was so much awakened by the perception 
of these serial correspondences, at least in the human 
frame, as to have led him to pursue them in detail. He 
communicated the result of his comparisons to the Parisian 
Academy, in whose celebrated ^ Memoires^ it appears in 
the year 1774, under the title " Parallele des Os que com- 
posent les Extremites.^^ The philosophic Condorcet, at that 
time Perpetual Secretary to the Academy, was so much 
struck by the grand views of animal structures which this 
mode of inquiry promised to disclose, that in his Re- 
port on the Memoir he characterises it as ^a new kind of 
Comparative Anatomy.' It seldom happens, however, in 
such early excursions into a foreign territory, that success 
is complete ; and Vicq-d^Azyr, though right in respect of 
the scapula, humerus^ and bones of the hand, was led 
astray by the different proportions of the ulna and fibula 
in the human skeleton in his comparison of those bones. 

Preconceptions from modifications of form can only be 
corrected by an extended survey of such variable morpho- 
logical characters. Vicq-d'Azyr conceived that the ante- 



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rlor extremity was not paralleled or repeated by the poste- 
rior one of its own side, but by that of the opposite side ; 
the right arm by the left leg, and vice versa -, and Cuvier 
adopted this notion of a dextro-sinistral conformity*. 

Vicq-d'Azyr also supposed that the ulna in the fore- 
arm was the correspondent of the tibia in the leg, with the 
patella as the detached olecranon, and that the radius 
answered to the fibula ; a mistake which he could scarcely 
have fallen into had he extended his comparisons to the 



lower Mammal! 



shall 



from the Marsupial 



So tardily however have the exact generahzations of 
Philosophic Anatomy been appreciated in France, that, in 
one of the latest and most elaborate ' Manuals of Descrip- 
tive Anatomy /—a w^ork of considerable repute for its 

accuracy of detail, — it is laid down, that " the up- 



minute 



per end of the tibia is represented by the upper half of the 
ulna, and the lower half of the tibia by the lower half of 
the radius; whilst the fibula is represented by the upper 



t 

Nature, however, when rightly interrogated and propi- 
tiated by due observant service, extricates us from these 
complex involutions and alternations of serial homology, 
and makes the simple truth plain. The extensive know- 
ledge of Comparative Anatomy possessed by my revered 
preceptor in Anatomy, Dr. Barclay, enabled him truly 
to interpret the parallehsm of the bones of the fore-arm 
and of the leg-proper. He showed how the ulna and its 
homotype the fibula exhibited the same ^variety and un- 
steadiness of character, sometimes large, sometimes small. 



* Legons d'Anat. Comp. t. i. 1836, p. 342. 

t " L'extremite superieure du tibia est representee par la moitie su- 
perieure du cubitus, et la moitie inferieure du tibia par la moitie infe- 
rieure du radius ; tandis que le perone est represente par la moitie 
supeneure du radius et par la moitie inferieure du cubitus."— Crz/t?e/- 
Ider, Anatomie Descriptive, t. i. p. 315. 



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and sometimes merely a process^ of the more constant 
bone of their respective segments^. 

Some anatomists may still be biased by the cause of 
Vicq-d'Azyr^s mistake, viz. the great development of the 
olecranon or upper end of the ulna: but it needs only m- 
stances in which the fibula manifests a similar develop- 
ment to satisfy the most sceptical as to the soundness 



of the 



grounds 



on which the 



illustrated in Plate I. 



figs. 



Homological conclusions 
15 and 16 are based. The 



marsupial and monotrematous animals are fertile in this 
parallel instance of excessive development. The head of 
the fibula in the ornithorhynchus extends far beyond the 
knee-joint, and is expanded like the olecranon in the 
mole^s ulna. Many of the marsupial quadrupeds have a 
rotatory motion of the hind-foot analogous to the prona- 
tion and supination of the hand: in the opossums and 
phalangers the great-toe is an opposable thumb, whilst its 
homotype in the hand remains parallel with the other 
fingers, and the location of the foot and hand is thus the 
reverse of that in the human subject: whence naturalists 
have styled these marsupial animals ^ Pedimana ^ — foot- 
handed. One might expect that the modifications of the 



* 



M. Flourens had probably never seen Dr. Barclay's ' Explanations 
of MitcheFs Plates of the Bones/ 4to, 1824, when he wrote, "II a 
ete plus difficile de rapporter individuellement chaque os d'un membre 
a chaque os de Tautre. Chose etrange, on ne sait pas encore s'il faut 
comparer ensemble Vliumerus et le femur du meme cote o\\ Vhumerus 
d'un coteet \q femur de 1' autre; on ne sait pas quel est celui des deux 
OS de Vavant-bras, le radius ou le cubitus, qu'il faut comparer a tel ou 
tel des deux os de la jambe, le tibia ou \q perone.^' He supports his 
reproduction of Barclay's proposition regarding the serial homology of 
the bones of the fore-arm and leg by similar remarks drawn from Com- 
parative Anatomy. ''Deja/' writes M. Flourens, " dans les Chauve- 
souris, dans les Galeopitheques, le cubitus n'est plus qu'un filet tres 
grele; ce meme cubitus ne se montre plus qu' en vestige dans les Rumi- 
nans, dans les SoUpedes; le 2:)erone, deja tres grele dans les Chauve- 
souris, deja simple rudiment stylo'ide dansle Cheval, manque a-peu-pres 



tout-a-fait dans plusieurs Ruminans. 
relies, 1838, pp.35, 3?. 



?? 



Annales des Sciences Natu- 



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bones of the leg, in subserviency to those transferred 
powers of prehension^ would resemble the characters that 
disguise the serial homology of the bones of the fore-arm 
in man ; and accordingly we find that, whilst the co-adapted 
joints between the tibia and fibula in the Pedimana are 
such as to permit their reciprocal rotation, the proximal 
end of the fibula is developed to afford the requisite advan- 
tage to the muscles acting upon the foot. 

In illustration of this instructive parallelism I have se- 
lected the leg-bones of the wombat [Phascolomys^ PL L 
figs. 15 and 16), because in them not only does the fibula 
{&"]) show the broad, flat and high process from its proximal 
end, but also a superadded sesamoid {&f) which parallels 
the peculiarity observable in the olecranon of the bat 
(fig. 3, 54), viz. the separate superincumbent ossicle, which 
at first sight might have been deemed confirmatory of 
V.-d^Azyr^s idea of the patella being a detached olecranon. 

In instituting the same kind of comparison between the 
little bones of the carpus and tarsus, I have been forcibly 
struck with the perspicacity with which V.-d^Azyr detected 
their true homologies in the human skeleton, notwith- 
standing their difference in form and number. He com- 
pares the Vscaphoides^ {sc) of the vsTist (PI. I. fig. 6, 56) with 
the ^scaphoides' or ^naviculare^ {s) of the ankle [ib. 68), 
the ^ lunare ^ (/) with the ^ astragalus ^ (a), the ' cuneiforme ^ 
{en) and ^pisiforme^ {p)y together, with the ^calcaneum^ 
\cl^ cT) ; and, in the second row, the ' trapezium ' [t) with 
the ^ entocuneiforme ^ (d), the ^ trapezoides ' [z) with the 

im) with the 



magnum 



^mesocuneiforme ^ (cm), the '^os 

^ ectocuneiforme ^ [ce)^ and the ^unciforme^ [u) with the 

^cuboides^ (6). 

To some anthropotomists, viewing the different position 
of the scaphoid in the wrist [sc) and ankle {s) of the human 
skeleton (PL I . fig. 6), these comparisons may still seem forced 
and fanciful : and since tlie calcaneum {cl, cl) is actually 
developed from a single ossific centre, they may regard its 
division as purely arbitrary, in order to form the homotypes 



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25 

of the two outer bones of the proximal row of carpal bones. 
And these objections can only be explained and removed 
by reference to an enlarged survey of all the modifications 
of the bones in question. 

_■ 

As M. Flourens^ in adopting the determinations of Vlcq- 
d^Azyr^ has not met these obvious and seemingly natural 
objections^ by reference to Comparative Anatomy^ I shall 
adduce some of those instances which illustrate the true 
character of the carpal and tarsal bones^ especially in re- 
gard to the classification of the bones of the skeleton into 
^ simple ^ and ^ compound"^/ 

Without looking further than the human skeleton^ it 
will be obvious that the distal row of the tarsal bones is 

w 

undisturbed (PL I. fig. 6^ ci^ crn^ ce^ b)^ and in the same 
relation to the metatarsals as the distal row of the carpals 
[ty Zy m^ u) is to the metacarpals : the cuboid [b) for exam- 
ple supports the two outer toes^ as the unciforme [u) sup- 
ports the two outer fingers. But the same order does not 
prevail in the arrangement of the other bones of the tarsus : 
the scaphoid [s) is so displaced as to represent part of an 
intermediate row. M. Flourens explains this modification 
by reference to the necessity of the greater length required 
by the inner digit of the foot for the functions of that 
member^ which elongation he affirms to be exclusively 
caused by this displacement of the scaphoid f. A glance, 
however^ at the relations of the advanced scaphoid in the 
human skeleton {s in fig. 6^ PI. L) will show that it ought 
equally to aflfect the length of the toes attached to the 

* ' On the Archetype and Homologies of the Skeleton/ 8vo, pp. 103- 
105. 

t " Or^ supposez le semilunaire grandi a la main, comme Vastragale 
I'est an pied, il repoussera necessairement le scaphdide, il le portera 
en avant; et, ce qui le prouve, e'est Fallongement du pouce du pied, 
compare au pouce de la main, allongement qui n'a, en effet, d' autre 
cause que le deplacement du scaphdide, son transport en avant, et sa 
position sur la meme ligne que les autres os du pouce." — Annates des 
Sciences Natwelles, t. x. p. 39, 1838. 



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mesocuneiform (cm) and ectocuneiform {ce) bones; and 

that the elongation of the e;reat-toe is due rather to the 



disproportionate length of the entocuneiform (ci) or homo- 
type of the little trapezium {t) of the wrist. The true ex- 
planation^ therefore^ of the difference in question must be 
sought for in other and wider considerations. 

I have elsewhere remarked^ that^ ^^Inmammahan qua- 
drupeds generally the fore-limb takes the greater share in 
the support^ the hind-limb in the propulsion of the body. 
The manus is accordingly commonly shorter and broader 
than the j965; this may be seen in the terminal segment of 
even the monodactyle hand and foot of the horse. Conse- 



quently the transverse direction prevails in the arrange- 



ment of the carpal bones and the longitudinal in that of 
the tarsal bones. The difference is least in the carpus and 
tarsus of the long and slender fore- and hind-hands of the 
duadruraana. If the carpus of the chimpanzee^ for ex- 



man 



which presents itself is the comparatively small proportion 
of the scaphoid which articulates with the radius^ as com- 
pared with that in man^ in whom the distal articulation of 
the radius (PL I. fig. 6^ 55) is equally divided between the 
scaphoides {sc) and lunare (/) which are on the same par- 
allel transverse series. In the orang (PL I. fig. 13)^ the 
divided scaphoid {s^ s^) extends^ almost as much from the 
lunare as from the radius, along the radial side of the 

carpus, to reach the trapezium {t) and trapezoides [z] ; it 
is in great part interposed between the lunare (/) of the 
proximal row and the trapezium and trapezoid of the dis- 
tal row of the carpal bones. The similarity of its connec- 
tions, therefore, in the carpus with those of the scaphoid 
in the tarsus (PL I. fig. 14, s) is so close that the serial 
homology of the two bones is unmistakeable. The astra- 
galus {ib. a), then, in the foot, repeats the os lunare (/) in 
the hand, but usurps the whole of the articular surface of 

* 'On the Archetype and Homologies of the Skeleton/ p. 167. 









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27 

the tibia, and presents a larger proportional size, especially 
in man, whose erect position required such exaggerated 
development of the astragalus, or homotype of the lunare. 
The prominent part of the calcaneum (PI. I. figs. 6 and 
14, cV) obviously repeats the prominent pisiforme (figs. 6 
and 13,^), and the body of the calcaneum (figs. 6 and 14, 
cl) articulates with the fibula, as the cuneiforme (figs. 6 
and 13, cu) articulates with the ulna. The strain upon 
the homotype of the pisiforme {cl') to produce the required 
effect in raising the back-part of the foot with its superin- 
cumbent weight upon the resisting ends of the toes, re- 
quired its fii^m coalescence with the homotype of the cunei- 
forme." The calcaneum, therefore, is essentially a ' com- 
pound bone '; that is, it answers to two bones, and includes 
them ideally, though they be connate*. We might infer 
the same in respect to the unciform {v) in the hand and 
the cuboid (b) in the foot, seeing that they each support 
two digits, Avhilst the other ossicles of their series re- 
spectively support a single digit. 

The test of the truth of this idea will be the result of a 
comparative survey of the carpal and tarsal bones in the 
Vertebrate series : and, accordingly, in descending to the 
cold-blooded animals that are more obedient to the arche- 
typal law, and where more of the primitive ossific centres 
continue distinct, we find in the Chelonian reptiles for 
example (PI. I. fig. 12) the unciform bone represented by 
two bones {u, u'), and each of the five metacarpals is sup- 
ported by its own carpal ossicle. This structure naturally 
suggests that the normal or typical number of carpal bones 
is ten, viz. five in each row, corresponding with the typical 
number of the digits. But we should search in vain the 



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* This term is used in the definite sense explained in my work on the 
'Archetype of the Vertebrate Skeleton' (8vo, V, Voorst, p. 49), as sig- 
nifying those essentially different parts which are not physically distinct 
at any stage of development ; and in contradistinction to the term 
fluent/ which applies to those united parts M'hich were originally distinct. 



con- 



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23 



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human carpus to find any characters that would justify our 
choice of the compound or essentially double bone in the 
proximal series, like those that indicate the compound bone 
in the distal series. Comparative Anatomy, however, affords 
the key to this problem and directs our choice. The same 
instance (PL I. fig. 12) which gives the typical bipartite con- 
dition of the unciforme [u, u) also presents it in the ' sca- 
phoides ' {s, s') : and we become assured that the second 
ossicle {s) is no mere accidental and exceptional supernu- 
merary from the frequent repetition of the divided '^sca- 
phoid ' in higher classes : it reappears, for example, in the 
Quadrumana, and the typical character of the bone is even 
retained in the species which approaches so near to man 
as the orang-utan (PI. I. fig. 13, s, s'). The only differ- 
ence from the tortoise being, that whereas in that reptile 
the two scaphoids in the wrist articulate with the three 
carpal bones of the second row, answering to the three 
cuneiform bones of the ankle, and thus repeat the con- 
nections of the undivided tarsal ' scaphoid '—in the orang 
the divided carpal ' scaphoid ' supports only the trapezium 
and trapezoides, answering to the inner and middle cunei- 
form bones, the os magnum (m) being so elongated as di- 
rectly to articulate with the lunare (l) . In both the tor- 
toise and orang, however, we perceive that the arrange- 
ment of the five bones of the proximal row of the carpus 
is irregular, and parallels that of the corresponding bones 

of the tarsus ; the two bones represented by the scaphoid 
intervening between the distal row and those bones that 
"remain in the proximal row. 



With 



human anatomist 



view the little ossicles of the carpus and tarsus when their 
homologies have been thus determined 1 It must be evi- 
dent to him that their true nature could never have been 
understood by the study of them in the human skeleton 
alone, however minutely scrutinized there. But by the 
light reflected from Comparative Anatomy he is now en- 



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29 



abled both to discern their homotypal relations and their 
natural classification. In the carpus, the lunare^ cuneiforme^ 
plslformcj trapezium^ trapezoides, and os magnum rank 
with the ^ simple^ bones; and the scaphoides and unci- 
forme with the ^ compound^ bones. And so likewise in 
the tarsus, the calcaneum and cuboides are the compound 
bones, the others are simple bones. Connation or blend- 
ing together of two essentially distinct bones is by no 
means however confined to the scaphoid and unciforme in 
the wi-Ist, or to the calcaneum and cuboid in the anlde. 

In many ferine, rodent^ and marsupial quadrupeds the 
scaphoid unites with the lunare ; examples of such scapho- 
lunar bone are shown In PI. I. figs. 5 and 15, sc^ L In 
the sloth and megatherium the trapezium blends with the 
scaphoid. In the tarsus of the ruminants the cuboid is 
anchylosed to the scaphoid : an example of this scapho- 
cuboid bone is given in the hind-foot of the ox (5, 5, 



m 



Those that have been adduced may serve, however, to re- 
mind the hesitating or sceptical anatomist, that the same 
reasons which prevailed with Cuvier to recognise the com- 
pound character of the scapho-lunar bone of the lion, the 
scapho-trapezial bone of the sloth, and the scapho-cuboid 
bone of the ox^ have led me to the same conclusion with 
regard to the unciforme in the carpus, the calcaneum in 
the tarsus, and the bone called scaphoid in both those 
segments of the limbs of man. 

Another important and instructive result of the fore- 
going comparisons is the constancy of the relations of the 
distal series of carpal and tarsal bones, whether simple or 
compound, with the five digits with which they essentially 
correspond In number : for by this constancy of connexion 
we are able to determine the precise digits that are lost 
and retained when their number falls below the typical 5 ; 
to point out, for example^ the finger in the hand of 
man that answers to the fore-foot of the horse, and the 



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30 



toe that corresponds to its hind-foot; nay, the very nail 
in the hand or foot which becomes by excess of deve- 

Were anything 

wanting to impress the thinking mind with the conviction 
of the unity of type which pervades animal structures, it 



lopment the great hoof of the horse. 



might be such a fact as this. 



The small styliform ossicle which is attached to the tra- 
pezium in the wrist of the spider-monkey {Ateles) or the 
hyaina, is plainly shown by that connexion, besides its re- 
lations to the other digits, to be a remnant of the thumb— 
the first digit of the hand that disappears in the process 
of reduction. The similar ossicle that is attached to the 
diminished unciforme of the marsupial bandicoot, in like 
manner is shown by that connexion to be the rudiment of 
the little finger ; the three remaining digits also retaining 
respectively their normal connexions with the trapezoides, 
the magnum, and the unciforme. 

In the tridactyle rhinoceros a mere rudiment of the 
trapezium lingers in the wrist, but the homologue of the 
thumb is lost ; and the part of the compound unciforme 
supporting the little finger has disappeared with every 

trace of that digit. 

In the ox we find a rudiment of the fifth digit (fig. 5, v) 
attached to the outer part of the carpal bone {u) articu- 
lating with the outer half of the cannon-bone (iv) ; and 
thus we recognize the os unciforme supporting, besides 
that rudiment (v), the metacarpal of the fourth digit (iv), 
which has coalesced with that of the third digit (iii) : the 
inner half of the cannon-bone, representing the third or 
middle metacarpal, articulates, in fact, with a distinct carpal^ 
ossicle {m), which, by its relations to the unciforme (w) ex- 
ternally and to the lunare {I) and scaphoides {s) above, is 
plainly the homologue of the os magnum (m). A rudi- 
ment of the second metacarpal (ii) is retained on the inner 
side of the base of the cannon-bone, and a trapezoid is di- 
stinct in the carpus of the camels and the diminutive 



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chevrotains [Tragulus) ; but it 



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coalesced with the 



magnum in the ox^ and both trapezium and thumb have 
disappeared in all Ruminants. Thus we learn that the 
fully developed digits that support the cloven hoof of the 
Ruminants answer in the fore-foot to the middle and 
fingers of our hand^ and that the cannon-bone consists of 
the coalesced metacarpals of those two fingers. 



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Fig. 5. 



Fig. 6. 






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Bones of the fore-foot of the 

Bos Urus. 



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Bones of the fore-foot 
of the Horse. 



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When we examine the bones of the fore-foot of the 
horse (fig. 6)^ we find the cannon-bone (in) articulated to 
a single bone of the carpus (m), which^ from its relations 
to the scaphoid {s) and lunare (/)j is the homologue of the 
OS magnum in the 0x3 but it is relatively of larger size^ 
having increased to the dimensions required for its appli- 
cation to the whole of the proximal surface of the great 
metacarpal (in). This is not^ however^ the equivalent of 





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32 

the two united bones (fig. 5, in and iv) so placed in the 
ruminant, for the unciforme (fig. 6, w) exists external to it, 
but reduced in size in conformity with the reduction of the 
rudimental metacarpal (iv) which it now supports. The 
carpus of the horse, in fact, resembles that of the rhinoceros 
more than that of the ox ; and the readiest key to the nature 
and homologies of the bones of the horse's foot is afforded 
by comparison with that of the ponderous three-toed Pa- 
chyderm. The rudiment of the trapezium has disappeared 
in the horse, but the three other bones remain, and the 
middle one is the largest, as in the rhinoceros. The extinct 
Palffiotheriura offers a connecting link in the transition to 
the apparently monodactyle foot. The trapezoides [z) and 
unciforme {u) are however still more reduced in size, in the 
horse, corresponding with the reduction of the toes, which 
they support, to mere styliform remnants of their meta- 
carpal bones ; and the os magnum and its metacarpal bone 

are proportionally increased in bulk. 

Thus not only are the first and fifth digits wanting in 
the horse, but the second and fourth are rudimental, and 
only the third is retained complete, and it constitutes 
almost the entire foot. 



The cannon-bone of the horse 
is not therefore composed, like that of the ox, of two 
metacarpals confluent, but is essentially as well as actually 
a single bone ; and accordingly it supports a single toe of 
three phalanges, which, in the special language of the 
Hippotomist, are the 'great pastern-bone' (1), the 'small 



coffin 



moid behind the last joint being called the ' navicular 



or 



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^nut^ bone^. 

* The common term ' cloven-hoof/ applied to the foot of the Rumi- 
nants, indicates the idea that it was the sohdungulous foot split up ; 
and the converse in respect of the horse's foot has been taught by 
high and justly esteemed authorities. Sir Charles Bell, in his 'Bridge- 
water Treatise/ 8vo, 1833, states, p. 82, " In the horse, the cannon- 
bone may be shown to consist of two metacarpal bones." But he does 
not give the demonstration. He refers (p, 85) to a comparison which 
led him to view the phalanges as still more compounded. " In lookmg 



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A perfect and beautiful parallelism reigns in the order 
m which the toes successively disappear in the hind-foot 
with that in the fore-foot. The ' hallux ' or inner toe, an- 
swering to the great-toe in man, is the first to fade away : 
e- g. m the dog (PI. I. fig. 5), where its rudiment may be 
tound {% 1, m) with a slender entocuneiform (c i) : in the 
hippopotamus both the digit and its tarsal bone are want- 
ing. The outer or fifth toe, answering to the httle toe in 
man, is reduced to a rudiment in the alactaga, and totally 



r 



shows the middle toe in its normal relation with the' ecto- 
cuneiform, the second toe with the mesocuneiform 



now 



the internal bone, and the fourth toe with the reduced 
cuboides. Fig. 18 shows that the toe which next disap- 
pears, e.g. in the hind-foot of the Ruminant, is the second, 
as in the fore-foot ; the third and fourth being retained to 
support the ' cloven^hoof ' ; the one articulating with the 
ectocuneiform (c e), the other with the cuboid (5), here con- 
fluent with the scaphoid. The rudiments of the second [ii) 
and fifth iv) digits appear externally as the 'spurious hoofs,' 
which dangl^ or project behind the normal one. These 
howeyer, are n^^vithkit their use : when the elk or bison 
treads in swampy ground, the hoofs expand, the false hoofs 
are pushed out, and the resisting surface is increased as the 

to this sketch and comparing it with that of the hand on page 7.9, we 
see that m the horse's leg the five bones of the first digital phalanx 
are consolidated into the large pastern-bone; those of the second pha- 
lanx mto the lesser pastern or coronet ; and those of the last phalanx 
into the coffin-bone.' The learned Professor of Comparative Anatomy in 
Lniversity College, London, describing the bones of the horse's foot 
also says, : " We observe that the phalanges, three in number in each 
toe, of the anterior and posterior extremities, are composed each of two 
bones anchylosed together, so that only one toe appears to touch the 
ground, which is covered with a large undivided hoof, from which thev 
are called ' Solidungula '." And again : " The anchylosis seen in the 
cannon-bone of the Ruminantia has here proceeded downwards throueh 
toe whole extent of the feet."— Dr. Grant's Lectures, ' Lancet; No. 550, 



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34 

foot sinks ; but when it is lifted up the small hoofs collapse 
to the sides of the large ones^ which contract^ and by this 
diminution of the size of the foot the act of withdrawal is 
facilitated*. 

In the Ruminants confined to arid deserts we should 
hardly expect to meet with the mechanism which seems 
expressly adapted to the marsh and the swamp ; and in 
fact every trace of the second and fourth digits has disap- 
peared from the feet of the camel and dromedary. The 
comparison of the bones of the extremities is replete with 
these beautiful evidences of design ; but our present pur- 
pose is to gather the indications of that which has been 
sometimes^ but wrongly^ regarded as the antithetical prin- 
ciple^ viz. the unity of plan which lies at the bottom of all 
the adaptive modifications. 

In the hind-foot of the horse you will perceive that 
the homologue of our small external cuneiform bone (ce^ 
fig. 6y PL I.) has attained an excessive size in fig. 19^ ce^ 
and that the toe {Hi) which that bone supports through- 
out the MammaHan series is correspondingly developed; 
whilst the mesocuneiform {m) and the cuboid {b) are in 
an equal degree reduced^ and^ like their carpal homotypes 
the trapezoid and unciform^ they support only rudiments 

of the second and fourth metatarsals in the form of the 
accessory splint-bones {ii and iv). 

To sum up^ then^ the modifications of the digits : they 
never exceed five in number on each foot in any existing 
vertebrate animal above the rank of Fishes; and in the 
class Mammalia^ the Cetacea excepted^ the number of pha- 
langes is limited to two in the first digit and to three in 
each of the other digits^ in both fore- and hind-feet. In the 
cuts and in each figure of PL I. they are numbered from 
the innermost^ i, ii;» iii^ iv^ v, in the fore-foot^ and % ii^ iiiy 
iVy Vy in the hind-foot : these are their symbols^ and are 

Sir Charles Bell has well shown the advantage of the cloven hoof 
over the undivided hoof in this respect, op. cit, p. 89. 



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applied arbitrarily to their objects ; thus the digit (i«) in 
the rhinoceros is the innermost or first of its series, and the 
digit {iv) is the third ; but the notation signifies in this and 
all the figures that the digits ii, Hi, or iv, are those answering 
to the second, third and fourth in the fully-developed foot. 
The first or innermost digit, as a general rule, is the first 
to disappear; In the hind-foot of the orang (fig. 14) com- 
monly, and in that of the wombat (fig. 16) constantl^its 
sh^rt metatarsal supports but one phalanx ; in the dog 
c^" (fig.^), the inner digit is usually wanting in the hind-foot, 
and IS always very diminutive in the fore-foot. The first 
digit of the hand is reduced to a short metacarpal in the 
spider-monkeys [Ateles). 

The outer digit v and v is the next to disappear. In th. 
tapir it is wanting in the hind-foot ; and in the rhinoceros 
(fig. ] 7) in both hind- and fore-feet. 

In the bisulcate quadrupeds the development of the se- 
cond digit [ii) is arrested in addition to the outermost one 
(v), and the functions of support and progression are com- 
mitted to the equally and symmetrically developed digits 
Hi and iv : rudiments of the second and fifth digits are 
retained In most Ruminantia (as at ii and v, fig. 18) ; but 
in the camel-tribe they have entirely disappeared, together 
with the first digit, i and i. 

In the horse (fig. 1 9) the fourth digit Is the additional 
subject of arrested development, and the median one in 
both fore- and hind-feet, in and Hi, is the last and sole 
digit which retains its full and functional perfection, thus 
manifesting its character as the most constant and essen- 
tial of the terminal ramifications of the primitive ray which 
we saw in the lepidosiren. 

Whilst the number of toes is thus seen to fall short 
progressively, of five, the typical character of that number 
IS still indicated by the power of determining the particular 
toe or toes of the five in man, which are retained in the 
tetradactyle, tridactyle, didactyle and monodactyle feet re- 



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36 

spectlvely of the lower mammals. But although the number 
* five ' thus governs the development of digits, properly so 
called, in all existing air-breathing Vertebrata, the tendency 
to multiplication of terminal rays in the diverging ap- 
pendages modified for locomotion may be seen to manifest 
itself in the sexual ' spurs ' of the Galhnaceous birds and 
Monotremes ; in the hereditary supernumerary toes in cer- 
tain varieties of the common fowl, and even in some indivi- 
duals of the human race. But the single spur of the tetra- 
dactyle cock is not more a homologue of a normal digit in a 
pentadactyle reptile or mammal, than is the spur of the 
Platypus, or either of the spurs in the Pavo bicalcaratus*. 

So long as the digits are developed as simple rays they 
are not subordinated to the typical number, but usually 
much exceed it, as we find in most fishes. In the skate 
{Raid), indeed, the pectoral members far surpass in bulk 
and seeming complexity their homologues in man: but 
their development is of a lower kind : it consists of a vege- 
tative repetition, — division, bifurcation and segmentation 
of mere rays, of a multiphcation of essentially similar parts, 
without power of reciprocal action and reaction on one an- 
other ; all being bound up in one common fold of integu- 
ment for one simple kind of flapping motion— the only one 
required for an animal so low in the scale, but perfectly 
provided for by the form of fin in question. At first sight 
the pectoral fin of the skate with its hundred digits seems 
a more complex deviation from the primordial single ray, 
as shown in the lepidosiren (PL I. fig. 7)? than the penta- 
dactyle upper extremity (fig. 6, 53 — 57) of man; but this is 
far from being the case : true complexity is not shown in 
the number, but in the variety and coordination of parts. 

The high characteristics of the human arm and hand are 
manifested by the subordination of each part to a harmo- 
nious combination of function with another, by the de- 

* These horny appendages of the metatarsus appear rather to be 
homotypes of the strong quills attached to the metacarpus in birds. 



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37 

parture of every element of the appendage from the form 
of the simple ray^ and each by a special modification of its 
own ; so that every single bone is distinguishable from an- 
other: each digit has its own peculiar character and name, 
and the ^ thumb/ w^hich is the least constant and important 
of the five divisions of the appendage in the rest of the class, 
becomes in man the most important element of the terminal 

segment, and that which makes it a *^hand^ properly so 
called. 

In the pelvic, as in the scapular extremity, the same 
digit (i), w^hich is the first to be rejected in the mammalian 
series, becomes, as it were, ^ the chief stone of the corner,^ 
and is termed ^par excellence/ the ^great-toe :^ and this is 
more peculiarly characteristic of the genus Homo than even 
its homotype the thumb ; for the monkey has a kind of 
pollex on the hand, but no brute mammal presents that 
development of the hallux^ on which the erect posture 
and gait of man mainly depend. 

We perceive, however, that although the first toe (PI. L 
fig. 6, i) is the longest as well as the largest, it retains its 
characteristic inferior number of phalanges ; its bulk de- 
pending, like the larger toe in the didactyle ostrich (fig. 11, 
m), on the superior size instead of an increased number of 
bones ; w^hilst the fifth or little toe {v) still retains with 
diminished proportions its full complement of phalanges. 
The teleologist will discern that the requisite strength of the 
toe, which is the chief fulcrum when the w^hole body is raised 
by the power acting on the heel, as in stepping forward, 
has been regarded in the diminished number of its joints; 
but the same final cause w^ould not appear to have governed 
the different number of joints of the equally-sized first and 
fifth of the five toes inclosed in the massive hoof of the 
elephant or the webbed hind- paddle of the seal: and whe- 
ther the hallux be the shortest of the five or the longest, it 
has always the same number of phalanges whenever it is 

present, provided it supports a nail, a hoof or a claw, in 
the mammalian series. 



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The satisfaction felt by the rightly constituted mind 
must ever be great in recognising the fitness of parts for 
their appropriate functions ; but when this fitness is gained^ 
as in the great-toe of the foot of man and the ostrich^ by a 
structure which at the same time betokens harmonious 
concord with a common type^ the prescient operation of 
the One Cause of all organization becomes strikingly ma- 
nifested to our limited intelligence. 

It is interesting to perceive both in the human hand and 
foot that the digits that have been most modified either by 
excess or defect of development are precisely those that are 
the least constant in the mammalian series — the two^ for 
example^ that form the extremes of the series ; whilst the 
three intermediate digits are more conformably and equably 
developed. In the hand^ the ^ digitus medius^ — the most 
constant of all in the vertebrate series^ and most entitled 
to be viewed as the persistent representative of the terminal 
segments of the primitive elementary ray, — still shows a 
slight superiority of size 3 though few would be led thereby 
to suspect that the bones forming the three joints of this 
finger answer to those called ^ great pastern-bone/ ^ little 
pastern-bone/ and ' coffin-bone ^ in the horse^ and that the 
nail of this finger represents the hoof in the horse. 

In the human foot the three more constant toes, ii^ iii^ 
iVy maintain more equality of size than their homotypes in 
the hand : the middle toe here also is the representative of 
the chief part of the hind-foot of the horse : but the fourth 
toe answers to that which^ by excess of growth^ becomes 
the chief member of the long and strong hind-foot of the 
kangaroo. These and the like relations to the Vertebrate 
archetype, which, together with the principle of the fitness 
of things, govern the forms and proportions of parts of the 
human frame, cannot but be both interesting and useful to 
the artist, as being calculated to call his attention to differ- 
ential characters, which, though constant, may be so slight 

as to escape attention until their true significance is made 
known. 




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unmutilated 



the ancient Greek sculptors show^ indeed^ how truly their 
just observation of nature supplied the insight into the 
archetypal law^ and guided them to an exact and beautiful 
indication of the affinities of the three middle toes as con- 
trasted with the first and fifths the distinctive characters of 
the last being as truly given as those of the great-toe *. 



If we pause to take a retrospect of the ground over 
which we have been travelling, and consider the nume- 
rous and beautiful evidences of unity of plan which the 
structures of the locomotive members have disclosedy 
evidences so little to be expected^ a priori^ seeing the dif- 
ferent shapes and sizes of instruments adapted to such 

r 

diversity of functions ; — when also we find that besides the 
^-eneral conformity of structure in the limbs of diiferent 
species^ a more special parallelism could be traced between 
the fore- and hind-limbs of the same species^ no matter to 
w^hat diversity of office they might be severally adapted — a 
parallelism or ^ serial homology^ demonstrable even to each 
little carpal and tarsal bone, from man down to the mono- 
dactyle horse^— the thinking mind cannot but be forcibly 
struck by such facts^ and be impelled with the desire to 
penetrate further^ and ascend if possible to the higher law 
or generalization from which those harmonies flow. 

I think it will be obvious that the principle of final adap- 
tation fails to satisfy all the conditions of the problem. 
That every segment and almost every bone which is pre- 
sent in the human hand and arm should exist in the fin of 

* I have elsewhere cited examples from some great painters in which 
these characters have been overlooked^ and the toes drawn " small by 
degrees and beautifully less '^ from the second to the fifth : the natural 
proportions given to the feet of the dead Saviour by the truthful and 
severe Francia, and by Sebastian del Piombo to those of the figures 
in the " Raising of Lazarus/' contrast favourably with the conventional 
feet in some of the paintings by Correggio and Guido in our National 

Gallery. 



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40 

■ ^ 

the whale^ solely because it is assumed that they were re- 
quired in such number and collocation for the support and 
movements of that undivided and inflexible paddle^ squares 
as little with our idea of the simplest mode of effecting the 
purpose^ as the reason which niight be assigned for the 

^^ r 

great number of bones in the cranium of the chick, viz. to 
allow of the safe compression of the brain-case during the 
act of exclusion, squares with the requirements of that act. 
Such a final purpose is indeed readily perceived and ad- 
mitted in regard to the multiphed points of ossification of 
the skull of the human foetus, and their relation to safe 

^ 

parturition. But when we find that the same ossific cen- 
tres are established, and in similar order, in the skull of the 
embryo kangaroo, which is born when an inch in length, 
and in that of the callow bird that breaks the brittle egg, 
we feel the truth of Bacon^s comparison of '^ final causes' 
to the Vestal Virgins, and perceive that they would be 
barren and unproductive of the fruits we are labouring to 
attain, and would yield us no clue to the comprehension of 
that law of conformity of which we are in quest. And so, 
again, with regard to the structural correspondences ma- 
nifested in the locomotive members ; if the principle of 
special adaptation fails to explain them, and we reject the 
idea that these correspondences are manifestations of some 
archetypal exemplar on which it has pleased the Creator 
to frame certain of his living creatures, there remains only 
the alternative that the organic atoms have concurred for- 
tuitously to produce such harmony*. 



But from this Epicurean slough 



of 



despond everv 



healthy mind naturally recoils : and reverting therefore to 
the hypothesis of the dependence of special and serial ho- 
mologies upon some wider principle of conformity, we have 
next to inquire, what is the archetype or essential nature 
of the limbs ? 

* 'Atto twv drofMov uajxiiTrnv airpomrjTov Kol Tvxaiav exovrav rrjv kI- 

urjtTiv. — Epicurus. 



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41 



Cuvier seems to have regarded the science of Compara- 
tive Anatomy to be not sufficiently advanced to enter upon 
this analysis with any prospect of success. 

Oken's idea of the essential nature of the arms and legs 
IS, that they are no other than * liberated ribs'; "Freye 



Bewegungsorgane konnen nichts anderes als frey gewor- 
dene Rippen seyn*/' 



Cams, in his ingenious endeavours to gain a view of the 



primary homologies of the locomotive members, sees in 
their several joints repetitions of vertebral bodies [tertiar- 
wirbel)—yertehYse of the third degree t — a result of an ul- 
timate analysis of a skeleton pushed to the extent of the 
term ^vertebra' being made to signify little more than what 
an ordinary anatomist would call a '^ bone/ But these 
transcendental analyses sublime all differences, and defiuite 

knowledge of a part evaporates in an unwarrantable ex- 
tension of the meaning of terms. 

I believe, however, that I have satisfactorily demonstrated 
that a vertebra is a natural group of bones, that it may be 
recognised as a primary division or segment of the endo- 
skeleton, and that the parts of that group are definable 
and recognizable under all their teleological modifications, 
their essential relations and characters appearing through 
every adaptive mask J. 

Subjoined is a view of such a natural segment as it ex- 
ists in the thorax of a bird, c is the ' centrum,' which 
was originally a separate element : n, one of the walls of 
the canal for the ' spinal marrow' (myelon or trunk-portion 
of the neural axis) ; it was originally distinct from the cen- 
trum and from its fellow of the opposite sidej it is the 
* neurapophysis' : pi indicates another pair of elements 
the ^ pleurapophyses,' which here maintain their primitive 

* Lehrbuch der Natur-Pliilosophie, p. 330, 8vo, 1843. 

t Urtheilen des Knochen und Schalengeriistes, fol. 1828. 

t ' On the Archetype of the Vertebrate Skeleton,' 8vo, 1848, pp, 80 



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distinctness^ and grow long in order to aid in encompass- 
ing the dilated canal or cavity for the great vascular cen- 
tres: so modified, these elements are called ^ribs^ or ver- 
tebral ribs. The elements more constantly related to the 

Fig. 7. 



ns 



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Natural skeleton-segment, 'osteocomma' or * vertebra/ Thorax of 

Bird. 

■ 

protection of the vascular or haemal axis are those marked 
hy the ^ haemapophyses/ here displaced from the centrum 
by the development of the heart and hings and other or- 
gans of the embryonic vascular layer : they then get the 
special name of ^ sternal ribs/ or that of ^ costal cartilages^ 
when their ossification is arrested. The haemal arch is 
here completed by an unusually expanded ^ haemal spine/ 
hs^, which coalesces with those of contiguous segments^ and 
they are then collectively denominated the ^ sternum/ The 



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a ^ cranium^ 



43 

neural arch is completed by an answerable piece above^ n s, 
which here retains its normal size and form as a ^ neural 
spine/ Butj where the neural canal is expanded for great 
developments of the nervous centres^ the brain^ e.ff.y analo- 

r 

gous to the development of the vascular centres in the ^ tho- 
rax/ the neural canal is correspondingly expanded and forms 

; other elements besides the ^ neurapophyses^ 
enter into the formation of its walls^ and the ^ neural spine' 
is expanded horizontally^ often retains its individuality^ 
and, like the '^sternum' in the thorax of the bird, receives 
a special name, e. ff. ^parietaP or ^frontal/ Two other 
distinct elements, «, a, in fig. 7^ are attached at one end 
to the haemal arch, and project backwards, overlapping, in 
the bird, the succeeding arch. Less constant, secondary 
or derivative processes more or less complicate the typical 
segment, but are not essential to it : of these are shown 
in fig. 7^ ^^ the ^ zygapophyses,' pp the ^ parapophyses,' 
dd the ^ diapophyses,' and y^ the ^ hyp apophysis.' 

As the expanded nervous centres contract to a column 
or trunk of moderate and pretty uniform diameter, so also 
do the vascular centres ; and where the vascular axis is re- 
duced to the dimensions of the nervous axis above, the 



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Fig. 8. 




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zygapopJiysis.'^^^^ 



diapophysis. '"--,_ 



par apophysis. 



zyg apophysis. 




neural spine. 



neurapophysis. 



--pleurapophysis. 



'-. hsemapophysis 



-■ heemal spine. 



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Ideal typical vertebra. 



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44 

vertebra resumes a more symmetrical character, by the 
corresponding reduction of the hsemal arch : in the croco- 
dile, e. g. this is formed by the haemapophyses which 
ascend to contact with the centrum ; the pleurapophyses 
being shortened, projecting outwards, and anchylosed as 
processes : but such a vertebra, when analysed as it is de- 
veloped, resolves itself very nearly into the ideal type given 

in the diagram fig. 8. 

n is the neural axis or myelon, and h the haemal axis or 
aorta, protected by their respective arches. The Roman 
type is used for the ^ autogenous elements,^ or those usually 
developed from distinct centres of ossification ; and the 
italics denote the parts more properly called ^ processes^ 
which shoot out from the preceding elements. 

On comparing this form of the segment with the fore- 
going one, it will be seen that they differ by altered pro- 
portions with changed positions of certain elements ; but 
it is important to our present inquiry to notice that in 
figure 7 there is an additional bone marked a which pro- 
jects as an appendage from each side of the haemal arch. 

As we find such appendages in the thoracic segments of 
the crocodile (PI. I. fig. 3, a, a), and in the corresponding 
abdominal segments of the skeleton of most bony fishes 
{ib. fig. 2, a, a),, where they are usually longer, and extend 
through the flesh to the skin, we may regard them also 
as parts of the primitive segment or vertebra, though less 
constant than the arches that support them. 

The attempt to decipher the essential nature of limbs 
will lead us in the first place to their comparison with one 
or other of the elements of the typical segment. And, 
having arrived at the demonstration of such segment, and 
proved that every modification of the axis of the skeleton 
has its seat in one or other of the segmental or ^vertebral' 
elements, w^e may enter upon this track of inquiry with 
hopeful confidence in the results. 

I have already observed that Oken selected the rib as 



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the seat of those developments from which the varied forms 
of the limbs of animals result : the truth of this idea will be 
tested by tracing the progressive simplification of the limb 
in the Vertebrate series. 

We already find it in the Mammalian series reduced al- 
most to one long jointed ray in the horse (fig. 4)^ tW'O other 
terminal forks being feebly indicated by the little splint- 
bones. In the lower Reptilia we find the limbs progres- 
sively diminish in relative bulk to the body and to their 
sustaining arch. In the amphiuma (PI. L fig. 8) each limb 
is a jointed appendage^ consisting first of a single segment 
(63) J then of a bifid segment (54 & 55), lastly of a bifid (57) 
or a trifid segment {A. tridactylmn) \ in these segments 



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w^e have the homologues respectively of the humerus or i^ 



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femur^ of the two bones of the fore-arm or leg^ and of the 



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three middle and most constant toes. In the proteus t ^^JU^^ 



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(fig. 10) the terminal forks are diminished to two on the 
hind-limb^ and in the Amphiuma didactyhim to two digits 
on both fore- and hind-limbs. In the apteryx (fig. 9) the 
second segment of the stunted fore-limb is bifid, but the 
last segment is simple or monodactyle. One other step 
in the series^ and, in the lep idoslr gn, w^e find the limb 
reduced to an unbranched ray, modified only by a vege- 
tatively multiplied succession of simple segments (PI. I. 

figs. 7 &9). 

But in none of these instances do the limbs diverge, like 
the free or false ribs in the parachute of the little flying 
dragon, from the vertebral centrums or neural arches. 

of structure the limbs exist^ 



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Under whatever 



grade 



they are supported by inverted arches, the anterior 
being the ^ scapular arch,^ the posterior the ^pelvic arch^ : 
and these arches remain when every trace of limb has 
disappeared ; as for example^ the scapular arch in the 
Anguis and Mur(Ena^ and a rudiment of the pelvic arch in 
the Cetacca. 

The question, therefore, which w^e have now to determine 







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is^ what is the nature or general homology of these arches r 



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and first of the scapular arch r 

Of the special homology of its parts^ to the extent that 
we have traced them^ there exists I believe no difference of 
opinion amongst anatomists. 

The scapula is usually as broad and flat in mammals as 
the first rib of the whale is ; it becomes narrow and ver- 
tical in the ornithorhynchus; continues long and slender 
in birds and saurians ; is a columnar rib-like bone in the 
Chelonia, where it is as straight as the first rib in the ox ; 
and it retains the same form in the amphiuma (PL L 
fig, 85 51) and lepidosiren (ib. fig. 7^ 51). 

The scapula is the upper element or pier of an inverted 
arch^ completed^ with a few exceptions^ by a second elon- 
gated bone^ converging towards its fellow on the opposite 
side, and joining it either directly or through the medium 
of a single interposed key -bone, called ^ sternum/ w hich 
bone answers below to the key-bone or ^ spine ^ of the 
neural arch above. The special name of the second bone 

is the ^coracoid/ The crocodile (PI. I. fig. 3) affords a 
good example of the proper scapular arch so composed, 
L e. consisting of a pair of scapulae (51), a pair of coracoids 
(52), and the sternum or episternum (52'). 

In all reptiles and in all birds the arch is thus com- 
pleted: in fishes the coracoids meet without the inter- 
position of a sternum (PI. I. figs. 2 & 7j 52). In most 
oviparous vertebrates the arch is complicated by a second 
inferior element, parallel or nearly so with the coracoid ; 
behind it in fishes (fig. 2, 58), before it in reptiles, birds 
(fig. 4, 58) and monotremes : this accessory bone is the 
^ clavicle ' : when it unites below with its fellow, as in birds, 
it is called the ^ merry-thought^ [as furcatorium) ; but it is 
wholly wanting in some species, as in certain ground par- 
rots and the apteryx (fig. 9). The clavicle is wanting alto- 
gether in entire groups of Mammalia, e. g. in the Cetacea, 
and in all the Hoofed orders. But the coracoid is always 



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47 

present^ although its complete development, which is the 
rule in the lower classes of Vertebrata^ becomes the excep- 
tion in Mammalia^ M^here it reaches the sternum only in 
the ovoviviparous ornithorhynchus and echidna. In the 
rest of the class the coracoid projects as a longer or shorter 
process from the scapula^ but differs from the other ^ pro- 
cesses ^ of that bone in having a separate centre of ossifi- 
cation ; it is^ in short, an autogenous element, whilst the 
^ spine ' and ^ acromion ^ are merely exogenous growths. 

Fig. 9. 



».T 




Part of the thorax with the scapular arch and appendage, Apteryx 



australis. 



Mammalia 



of the fully-developed coracoid of the Ovipara, and com- 
pletes the scapular arch by extending from the acromion 
to the sternum, as e.g. in our own skeleton (Frontispiece 
and PI. I. fig. 6, 58*). But it will be readily understood by 
what has been stated with regard to the relative constancy, 
both as to connexion and existence, of the coracoid, that 
this is the true inferior element of the scapular arch, and 

* A front view of the human scapular arch is given at p. 46 of Sir 
C. Bell's ' Bridgewater Treatise.' 



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that its place is^ so to speak^ usurped by the clavicle in 
man, just as the chain of suborbital bones in the skull of 
the fish takes the place of the true zygomatic arch of higher 
Vertebrates'^. 

r ^^ 

Leaving, however, for the present the discussion of the 
general homology of the clavicle, and returning to that of 
the scapular arch, as it exists in its integrity and simplicity, 
in the apteryx or crocodile, the question before us is, with 
what part of the typical segment of the vertebral skeleton 
can it best be compared? The answer is at once suggested 
by the haemal arch, as it exists in the thoracic region of 
any air-breathing vertebrate, in which the parallel parts 
are obviously presented in similar connexion wdth each 



other. 



7 



7 



to the haemapophysis or sternal rib (A), and the scapular arch 
is completed in most vertebrates by a bone of the sternum 
or haemal spine (PI. I. fig. 3, 52'). In harmony with this 
determination is the interesting correspondence in the range 
of its diversities of form and proportion which the scapula 
presents with that w^hich may be traced in the thoracic 
pleurapophyses or ^vertebral ribs. ^ I have already cited 
the whale, e.g. as manifesting such a ^ rib ^ with proportions 
as broad and flat as any mammalian scapula; and nume- 
rous instances will occur to the anatomist of ^ribs^ that 
are as long, narrow, compressed and gently curved as is 

the scapula in the bird ; or that are straight and columnar 

like the scapula in the tortoise. 

Any difficulty of appreciating or hesitation in accepting 
such general homological views by the anthropotomist 
arises, he may be assured, from his habitual and exclusive 
contemplation of the vertebral element in question under 
one only of its morphological phases, and that usually an 
extreme and an exceptional one. Even the steps in the 
progressive degradation of the true scapular arch which we 

* On the Archetype of the Vertebrate Skeleton, p. 62. 



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49 



witness in the mammalian class are closely paralleled by 
the ordinary costal arches : thus the twelfth vertebral rib 
in man, with its sternal rib or cartilage curtailed and ap- 
pended to its free extremity, as a process, repeats the 
condition of the scapula with its shortened coracoid ap- 
pended and anchylosed to it, as a process, in man also, and 
m most mammals. 

The posterior costal arch in the bird's thorax, to the 
sternal rib (ha^mapophysis) of which may be attached the 
same element of a contiguous arch, unconnected with its 
proper vertebral rib, as seen in the aptervx (fig. 9, h, h'), 
parallels that condition of the scapular arch where it is 
comphcatedby an appended clavic]e,-the ha^mapophysis 
of a second inverted arch. 

The scapula, however, differs, in most of the higher 
Vertebrata, from the thoracic ribs in being more or less 
turned from the perpendicular to the horizontal direc- 
tion : this is particularly the case in birds, where it lies 
almost at right angles across those ribs, as in „^. 

Its progressive assumption, however, of the\er- 
tical position, or one more or less parallel with that of 
the ordinary ribs, as the species descend in the scale, would 
have much weight, in forming a judgment as to the essen- 
tial nature of the scapula, with the physiologist who ap- 
preciated the law that the Archetype is progressively de- 
parted from as the organization is more and more modified 
m adaptation to higher and more varied powers and actions. 
But what is still more significative of the nature of the 
scapula IS the discovery that its vertical position in reptiles 
and fishes is a retention of that position which the bone 
manifests on its first appearance in all Vertebrata. The ro- 
tation of the scapula from its primitive verticallty to what- 
ever approach to the horizontal line, or axis of the ver^ 
tebral bodies, the exigencies of the full-grown animal may 
require, its primitive appearance close to the occiput and 
Its longer retention of a place anterior to the first thoracic 



PI. I. 



fig. 4, 



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ribj are developmental phaenomena which cease to be mere 
empmcal facts "^^ but receive their explanation and become 
intelligible by the recognition of the general homology of 
the scapula v^^hich I am now attempting to illustrate. 

Sufficient^ I trusty has been adduced to show that^ of 
all the elements of the typical vertebra or primary seg- 
ment, the scapula can be compared only with the ^ pleur- 
apophysis/ arid the coracoid only with the ^haemapophysis/ 
But it may be objected^ that the ordinary costal or heemal 
arch has been detached from its centrum for the purpose 
of this comparison. True ! And the scapular arch in 
mammals^ birds and reptiles is a haemal arch so dislo* 
cated, — a statement which I do not hesitate to make under 
a pledge to demonstrate the proper centrum and the rest 
of the segment or vertebra to which it belongs. 

In the first place I may remark^ that the dislocation of 
parts of admitted costal or haemal arches is no new thing. 
Why does the human anatomist refer the fourth costal arch 
to the fourth dorsal vertebra and not to the fifth, to the cen- 
trum and neurapophyses of which it is equally connected ? 
The head of the rib is applied half to one centrum half to 
the other : the upper border of the neck of the rib, viewed 
in the upright skeleton, articulates with the upper neural 
arch, the tubercle of the rib with the diapophysis of the 
lower neural arch : the human anatomist, in restoring this 
displaced haemal arch to its proper segment, has availed 
himself of the same kind of inquiry and comparison f which 
has been instituted in order to detect the segment from 
which the scapular arch has strayed. The same kind of 
comparison was equally requisite in order to determine 




* 

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L 

* See Rathke, 'Ueber die Entwickelung der Schildkroten/ 4to, 1848, 
pp. 182, 183. The diiferent position of the scapula in fig. 9, 51, from 
that in the typical Bird's skeleton (PI. I. fig. 4, 53), is due to a retention 



of an embryonic phase in the apteryx. 



t 
119. 



Ai'chetyp 



Skeleton/ pp. 118, 



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51 



the true segments to which the displaced neural arches in 
the sacrum of the bird belonged*. 

But here let us examine how far down the vertebrate 
scale the scapular arch continues to manifest itself as a 
haemal arch displaced : and let us ascertain whether Na- 
ture affords us any instance of such a retention of the ideal 
type as would be exemphfied by the connection of that 
haemal arch with its proper centrum and neural arch? 
The object we are in quest of is soon attained. 

The desired instance is mostly clearly and satisfactorily 
afforded by the eel-like fish to which I have already re- 
ferred as affording the most simple type of locomotive ex- 
tremity, I mean the lepidosiren. We see that the upper 
element of the arch is now articulated to the neural arch 
of the occipital vertebra : and if we remove this segment of 
the skull and take a full view of it, as in fig. 7, PI. I., we 
have a vertebra which closely conforms to the typical'one 
illustrated by the thoracic segment of the bird, p. 42, fig. 7. 
In both figures, c is the centrum, n the neurapophyses, s 
the neural spine, pi the pleurapophyses, and h the hsem- 
apophyses : the haemal spine alone is wanting to complete 
the parallel : and we know that it is not more essential to 
the composition of the haemal arch, than the neural spine 
is to the completion of the neural arch. 

There can be no doubt that the bone which represents 
the rib or hasmapophysis in the occipital segment of the 



7) 



We 



It under all its modifications down to the low batrachian 

reptile (PI. I. fig. 8), in which its special homology was 
clearly recognised by Cuvier; and between the straight 
columnar upper element (51) of the inverted arch which 
supports the simple pectoral limb of the amphiuma, and 
the upper element (51) of the inverted arch which supports 
the still more simple Hmb in the lepidosiren, the resem- 

* 'On the Archetype of the Vertebrate Skeleton/ pp. ]18, I59. 



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The sole fact lending 



52 

blance is much closer than that between the scapula of 
man and the scapula of the mole, or between this and the 

r 

scapula of the ornithorhynchus. 

Since also comparative anatomists have arrived at one 
conclusion in respect to the homology of the stunted cora- 
coid in man with the coracoid element that stretches from 
scapula to sternum in the ornithorhynchus and all air- 
breathing Ovipara, it would be captious to deny the same 
relationship between the coracoid of the amphiuma {h 52) 
and that of the lepidosiren {h 62) . 

colour to such negation is the slight difference in the place 
of attachment of the diverging appendage, which is wholly 
in the coracoid in the lepidosiren, instead of partially, as in 
the amphiuma,— a difference which, with that in the upper 

connections of the scapula, is characteristic of their respec- 
tive classes. 

The main fact, then, is estabhshed, viz. that the inverted 
arch (51, 52,%. 7, PI. I.) which supports the pectoral ray in 
the lepidosiren is the scapular arch, and Nature here shows 
us its attachment to the occiput (c 1, n 2, s 3) in the rela- 
tion of the haemal arch of the occipital vertebra. 

Nor is the lepidosiren an exceptional instance of this 
connection and relation. It forms but one of a vast class 
of Vertebrata — by far the most numerous and widely-di- 
spersed class — which manifest the same attachment of the 
scapular arch. The pectoral fin (PI. I. fig. 2, 54-57, a) 
which consists, in most fishes, of amultiphcationof jointed 
rays like that of the lepidosiren, is supported by an in- 
verted bony arch, attached to the neural arch of the occiput, 
and completing that segment of the skeleton by forming its 
haemal arch*. Whatever be the size, form or function of 
the pectoral limb, its supporting arch maintains this posi- 
tion and connection in all osseous and some cartilaginous 
(Chim^roids, Sturionidae) fishes : and here, also, we find 



* < 



Archetype of the Vertebrate Skeleton/ p. 107. 




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trace of its appendage, the pectoral fin, has disappeared. 

How then is this connection of the scapular arch to be 
interpreted ? If we were prepossessed by the habitual con- 
templation of its detached state in man and the higher Ver- 
tebrata, we might deem such occipital connection an ano- 
maly, an ^ instantia devians,^ and so in fact it has hitherto 
been viewed by those anatomists who have entered into the 
study of the higher generahzations of their science. Geof- 
froy St. Hilaire, one of the boldest speculators in the mine 
of transcendental ideas, calls it in his ' Anatomic Philoso- 
phique' (p. 481) ^une amalgame inattendue:^ and in one 
of his Memoirs speaks of it as « Disposition veritablement 
tres singuhere, et que le manque absolu de cou, et une 
combinaison des pieces du sternum avee celles de la t^te 
pouvoient seuls rendre possible *.^^ 

We no longer, however, believe that the vertebra of the 
neck are absolutely wanting in fishes ; but recognize them 
with their pleurapophjses more normally or typically de- 
veloped than in the corresponding region of the crocodile. 



H 



are doubtless 



present in the head of fishes, as in that of other Verte- 
brates, where they are exemplified by the basihyal (see 41, 
figs. 2 to 6, PI. I.) ; but it is not requisite to conclude that 
the median bones (41, 42, 43, fig. 2) of the hyoid arch, or 
the analogous ossicles of the transitory splanchnic branchial 
arches, in fishes, are the homologues of 59 and 60 in figs. 3 
to 6, PI. I., in order to arrive at the comprehension of the 
connection of the scapular arch with the occipital vertebra 
in the lepidosiren and the majority of its class. 

Viewing that vertebra, like the other natural segments of 
the skeleton, to be conformable to the type as illustrated by 
fig. 7? p. 42, it would be incomplete without the haemal arch 
formed by the scapula and coracoid. And further, there 



* 



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is no other arch which could so complete the occipital ver- 
tebra. There are three neural arches in advance of the 
occipital one^ in fig. 2^ viz. the parietal (5^ 6^ 7^ 8)^ the frontal 
(9, 9', 10^ 11, 12), and the nasal (13, 14, 16) ; and there are 
three haemal arches, viz. the maxillary (20^ 21, 22), the 
mandibular (28, 29, 32), and the hyoid (38, 39, 40, 41). With 
the exception of the hyoid arch, which is slightly de- 
pressed, each of these haemal arches is directly connected 
with its respective neural arch, just as the scapular arch is 
connected with the occipital : there is no other arch to 
supply the place of the h£emal one of the occipital seg- 
ment, if the scapular arch be removed. 

Are w^e then to view the instances of its detachment 
from its piscine connections as exemplifying the normal 
or typical conditions of such arch? Surely not; as well 
might we consider the displaced haemal arches of the 
human thorax to manifest their typical positions and 

^ 

connections, and regard their direct and exclusive connec- 
tions with their proper centrums in reptiles and fishes as 
the exception and the anomaly. But that which has hap- 
pened to the crocodile in the restoration of the ribs, ho- 
mologous to the second and tenth inclusive of man, each 
from the interspaces of two vertebrae to the body and neural 
arch of one vertebra, i. e. to the connections which the 
first, eleventh and twelfth ribs retain in the Human skele- 
ton, has lik<*vvise taken place in fishes in regard to the mo- 
dified rib forming the scapula. So true is the Baconian 
aphorism regarding the power of interpretation consequent 
upon the knowledge of the archetype or ^ via Naturae!^ 
'^ Inter pr^rogativas instantiarum ponemus loco octavo in- 
stantias deviantes ; errores scilicet naturae, et vaga ac mon- 
stra : ubi natura declinat et deflectit a cursu ordinario. 
Difierunt enim errores naturae ab instantiis monodicis in 
hoc, quod monodicae sint miracula specierum, at errores sint 

+ 

miracula individuorum. Similis autem fere sunt usus ; quia 
rectificant intellectum adversus consueta; et revelant formas 





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55 

communes. Neque enim in his etiam desistendum ab inqui- 
sitione^ donee inveniatur causa hujusmodi declinationis. 
Veruntamen causa ilia non exsurgit ad formam aliquam 
proprie^ sed tantum ad latentem processum ad formam. 
Qui enim vias naturae noverit^ is deviationes etiam facilius 
observabit. At rursus^ qui deviationes noverit is accuratius 
vias describet^/^ 

Most of the mistakes in the attempts to ascertain the 
typical or essential nature of parts of the skeleton^ and 
almost all the impediments and opposition to the prosecu- 
tion of this main end of anatomical science^ have arisen 
from its study being confined to that by-path in which it 
is usually commenced, viz. where the course of develop- 
ment has reached the highest form of animal life, in which 
modification of each part in mutual subserviency to an- 
other is greatest, and the deviation from the archetype is 
in the same degree. The rectification of the mistakes and 
the acquisition of a more cathoHc feeling towards the study 
are gained by pursuing the broader high-road of organic 
nature, where those forms are offered to our contempla- 
tion in which vegetative uniformity most prevails, and the 
archetype is least obscured by purposive adaptations. 

If therefore we find in that class which best displays the 
conditions for solving the problem immediately before us, 
that the connections of the scapular arch are such as to 
complete a typical segment, which otherwise would be ab- 
normal by defect, we must conclude that the type is here 
adhered to ; and that, although these connections are abro- 
gated in all the other Vertebrate classes, they, nevertheless, 
are the ^instantiae deviantes,^ and are exceptions in reo-ard 



to the rule of the archetype, notwithstanding the actual 
numerical superiority of the instances. 

And the latter fact leads us to another consideration. 
This superiority was not always such as it now is. Time 




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was when fishes were the sole representatives of the Verte- 
brate subkingdom in this planet. During the long periods 
antecedent to the formation of the coal-measures, the verte- 
brate type was exclusively manifested by forms in the great 
majority of which the scapular arch was articulated to the 
occiput. Subsequent changes in our planet have height- 
ened and varied the conditions of animal existence;, but the 
primitive pattern of the skeleton may be discerned beneath 
all the superinduced modifications. 

We perceive a r eturn to it , as it were, in the early phases 
of development oftlieliighest organized of the actually ex- 
isting species, or we ought rather to say, that development 
start s^ from the o ld point; and thus, in regard to the sca- 
I pula, we can explain the constancy of its first appearance 
close to the head, whether in the human embryo or in that 
of the swan, and also its vertical position to the axis of the 
spinal column, by its general homology as the rib or ' pleur- 
apophysis ' of the occipital vertebra. 

We observe, as might naturally be expected, that its 
degree of displacement is least in those air-breathing Ver- 
tebrata that make the nearest approach to fishes : whether 
in general structure, as e. g, the siren and amphiuma, or 
in outward form, as e. g. the Cetacea. In comparing the 
crocodile's skeleton (fig. 3. PL I.) with that of the fish, the 

chief modification that distinguishes the occipital segment 
from its homologue in the fish, is the absence of its at- 
tached haemal arch. We recognise, however, the special 
homologues of the chief piscine constituents of that arch in 

51 and 52; but the upper or suprascapular piece (50) re- 
tains, in connection with the loss of its proximal or cranial 
articulations, its cartilaginous state, and is not shown in 
fig. 3: the scapula (51) is ossified, as is likewise the cora- 
coid (52), the lower end of which is separated from its fel- 
low by the interposition of a median, symmetrical, partially 
ossified piece called ' episternum ' [hs). The power of re- 
cognising the special homologies of 50, 51, and 52 in the 





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57 



crocodile^, with the similarly numbered constituents of the 
arch H i in fishes (fig. 2)^ though masked not only by mo- 
difications of form and proportion but even of very sub- 
stance^ as in the case of 50, depends upon the circumstance 
of these bones constituting the same essential element of 
the archetypal skeleton : for although in the present in- 
stance there is superadded to the adaptive modifications 
above-cited the rarer one of altered connections^ Cuvier 
does not hesitate to give the same names (suprascapulaire) 
to 50 and (scapulaire) to 51, in both fish and crocodile : but 
he did not perceive or admit that the narrower relations of 
special homology were a result of, and necessarily included 
in^ the wider law of general homology. According to the 
view which I am attempting to establish and illustrate^ m'o 
discern in 50 and 51 a teleologically compound pleurapO'- 
physis^ in 52 a h^mapophy sis ^ and in hs the hmmal spine^ 
completing the hccmal arch. 

The general relations of the scapulo-coracoid arch to a 
haemal or costal one was recognised^ as I have already ob- 
served, by Oken. This philosopher, having observed the 
free cervical ribs in a specimen of the Lacerta apoda {Pseu- 
dopus)y deemed them representatives of the scapula, and 
this bone to be, in other animals, the coalesced homo- 
logues of the cervical pleurapophyses^. In no animal are 
the conditions for testing this question so favourable and 
obvious as in the crocodile (fig. 3. PI. I.): not only do 
cervical ribs coexist with the scapulo-coracoid arch, but 
they are of unusual length and are developed from the atlas 
as well as from each succeeding cervical vertebra : we can 

"Audi die Scapula nicht ein Knochen^ sondern wenigstens eine 
aus fiinf Halsrippen zusammengeflossene Platte ist/' — Programm uber 
die Bedeuhmg der Schddelknochen, 4to, 1807, p. 16, He reproduces 
the same idea of the generaF homology of the scapula in the ^ Lehr- 
buch der Natur-philosophie/ 1843, p. 331, % 2381. Carus also regards 
the scapulo-coracoid arch as the reunion of several (at least three) proto- 
vertebral arches of the trunk- segments. ^ Urtheilen des Knochen und 
Schalen gerustes/ fol. 1828. 



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58 



also trace them beyond the thorax to the sacrum^ and 
throughout a great part of the caudal region^ as the sutures 
of the apparently long transverse processes of the coccygeal 
vertebrae demonstrate in the young animal; the lumbar 
pleurapophyses being manifested at the same period as 
cartilaginous appendages to the ends of the long diapo- 

physes. 

The scapulo-coracoid arch (61^ 52)^ both elements of which 
retain the form of strong and thick vertebral and sternal ribs 
in the crocodile^ is applied in the skeleton of that animal 
over the anterior thoracic haemal arches. Viewed as a more 
robust hsemal arch^ it is obviously out of place in reference 



to the rest of its vertebral segment. If we seek to deter- 




mine that segment by the mode in which we restore to their 
centrums the less displaced neural arches in the sacrum of 

F 

thebird (fig. 105^1-^4)^ we proceed to examine the vertebrae 

before and behind the displaced arch wdth the view to dis- 
cover the one which needs it in order to be made typically 
complete. Finding no centrum and neural arch without 
its pleurapophyses from the scapula to the pelvis^ we give 
up our search in that direction 3 and in the opposite direc- 
tion we find no vertebra without its ribs until we reach the 
occiput : there we have centrum and neural arch^ with coa- 
lesced parapophyses — the elements answering to those in- 
cluded in the arch fig. 7^ c, n^p^ ns, but without the inverted 
arch ply hy hs ; which arch can only be supplied^ without de- 
stroying the typical completeness of antecedent cranial seg- 
ments^ by a restoration of the bones 51-52^ fig. 3^ PL Lto the 
place which they naturally occupy in the skeleton of the fish 
(fig. 2). And since anatomists are generally agreed to regard 
the bones 51-52 in the crocodile (PI. I. fig. 3) as specially 
homologous with those so numbered in the fish {ib.fig.2)y we 
must conclude that they are likewise homologous in a higher 
sense ; that in fig. 2 the scapulo-coracoid arch is in its natural 
or typical position^ whereas in the crocodile it has been dis- 
placed for a special purpose. Thus^ agreeably with a general 



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59 

principle, we perceive that as the lower vertebrate animal il- 
lustrates the closer adhesion to the archetype by the natural 
articulation of the scapulo-coracoid arch to the occiput, so 
the higher vertebrate manifests the superior influence of 
the antagonising power of adaptive modification by the re- 
moval of that arch from its proper segment. 

The scapula retains the more common cylindrical long 
and slender rib-hke form of the pleurapophysis in the che- 
lonian reptiles, where, from the greater length of the neck, 
it has retrograded further than in the crocodile from its 
proper centrum, and is placed not upon, but within, an 
anterior thoracic haemal arch, by virtue of the great expan- 
sion to which the pleurapophysis of that arch has been 
subject. Here the rib has become a broad and flat bone^, 
whilst the scapula has retained its primitive rib-like shape. 

If the arguments founded upon the relations of the sca- 
pulo-coracoid arch to the segments of the skeleton in osse- 
ous fishes and crocodilians be admitted to sustain the con- 



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elusion here drawn from them, that arch must be held to ^^ UJ^A 



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form the haemal complement of the occipital vertebra in all 

animals. 

Bojanus, in illustrating his vertebral theory of the skull 
by the osteology of the Emys Europcea^ thus defines the 

"Vertebra occipitalis, sive capitis prima. 

" Basis occipitis, sen corpus hujus vertebrae, 
" Pars lateralis occipitis, sive arcus, 

" Crista occipitalis, processus spinosi loco, 
Cornu majus hyoidis, costte vertehrm occipitalis compa- 



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randumf.^^ 

He adds a dotted outline of the hyoid arch to complete 
the vertebra occipitalis^ in tab. xii. fig. 32, B. 1 of his 
beautiful Monograph. 






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By what process this metamorphosis is effected I have explained 



in a Memoir read before the Royal Society, January 18th, 1849, 
t Anatome Testudinis Europsese, fol. 1819, p. 44. 




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60 

Supposing the special homology of the middle cornua of 
the hyoid of the chelonian, so represented and compared 
to ribs by Bojanus^ with the stylo-^ epi- and cerato-hyals 
of the fish (PI. L fig. 2, 38, 39, 40) to have been correct, which 
the metamorphoses of the hyoid and branchial arches in 
the batrachians disprove^ the singular and highly interest- 
ing change of position as well as shape of the true cerato- 
hyals^ during the same metamorphosis^ prepares us to ex- 
pect a retrogradation of the hyoid arch in respect to its 
proper centrum, in the skulls of the air-breathing verte- 
brates. In the young tadpole the thick cartilaginous hyoi- 
dean arch^ is suspended, as in fishes^ from the tympanic 
pedicle : the slender hyoidean arch of the mature frog is 
suspended from the petrosal capsule f. The mandibular 
arch has, also^ receded ; and the scapular arch, which, at its 
first appearance, was in close connection with the occiput, 
further retrogrades in the progress of the metamorphosis to 

the place where we find it in the skeleton of the adult fro 

The argument, therefore^ may be summed up as follows. 
The position of the pleurapophyses in the human thorax 
and that of most mammals ^ and the position of the neur- 
apophyses in the dorsal vertebrae of chelonians and in the 
sacral vertebrae of dinosaurians and birds^ show that a 
change of relative position in respect of other elements of 
the same vertebra may be one of the adaptive modifica- 
tions to w^hich even the most constant and important of 

those elements are subject. Instead of viewing such shifted 
arches as primary and independent constituents of the 
skeleton^ we recognise them as secondary and derivative 
parts of a natural segment or whole, and we trace their 
relation to the stationary elements — the centrums of the 
primary vertebral segments, 

* Cuvier, Ossem, Foss. v. pt. ii. pi. 24, fig. 23 a. 

f lb, fig. 2/ a : — an intermediate stage is shown at fig. 25. Duges 
and Reichert confirm and further illustrate this change of position of 
the hyoidean arch. 





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61 



Thus, commencing, for example, with the anterior of the 
sacral vertebrae of the ostrich, A in fig. 10, we observe that. 

Fig. 10. 




Seven sacral vertebrae of a young ostrich (Sfruthio camelus). 

besides supporting its own neural arch ^, it bears a small 
portion of that of the next vertebra : the third neural arch 
[n 1) has encroached further upon the centrum of the 
vertebra in advance; and thus, in respect to the neural 
arch (^2), if it were view^ed with the centrums, c2 and cl, 
upon which it equally rests, apart from the rest of the 
sacrum, it w^ould appear to appertain equally to either, 

and be referable to the one in preference to the other 
quite gratuitously, to all appearance. Nevertheless >^2 is 

proved, by the intermediate changes in antecedent neural 
arches, to belong actually, and in no merely ideal or tran- 
scendental sense, to c2 altogether, and not to the segment 
of which cl is the centrum ; and in tracing the modifica- 
tions of those sacral vertebrae which follow c 2, we find n 4 
to have regained nearly the whole of its centrum, 6' 4, and 
the normal relations of the elements are quite restored in 
the succeeding vertebra. 

Now let us suppose the habits of the species to have re-, 
quired a more extensive displacement of the arch {n 2) and 
its appendages : if its formal characters as a neural arch 
M^ere still retained beneath the adaptive development super- 
added to the adaptive dislocation, and if the segments be- 




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fore and behind the centrum c 2 were found complete^ and 
that centrum alone wanting its neural arch; would the 
mere degree of modification in respect of relative position 
nullify the conclusion that the shifted arch appertained to 
such incomplete segment^ and forbid that restoration to the 
typical condition^ w^hich no anatomist^ it is presumed^ will 
dispute in the case of /^2^ c2^ fig. 10 ? 

The anthropotomist^ by his mode of counting and de- 
fining the dorsal vertebrae and ribs^ admits^ unconsciously 
perhaps^ the important principle in general homology for 
which w^e are contending, and which, pursued to its legi- 
timate consequences and further applied, demonstrates 
that the scapula is the modified rib of that centrum and 
neural arch which he calls the ^ occipital bone^^ and that the 
change of place which chiefly masks that relation (for a 
very elementary acquaintance with comparative anatomy 

shows how little mere form and proportion affect the ho- 
mological characters of bones) diifers only in extent and 
not in kind from the modification which makes a minor 

amount of comparative observation requisite in order to 

determine the relation of the shifted dorsal rib to its proper 

centrum. 

With reference,, therefore, to the occipital vertebra of 
the crocodile, if the comparatively well-developed and per- 
manently distinct ribs of all the cervical vertebrae prove 
the scapular arch to belong to none of those segments, and, 

if it be wanting to complete the occipital segment, which 
it actually does complete in fishes, then the same conclu- 
sion must apply to the same arch in other animals, and we 
must regard the occipital vertebra of the tortoise as com- 
pleted below by its scapulo-coracoid arch, and not, as Bo- 
janus supposed, by its hyoidean arch *. 

* Geoffroy St. Hilaire selected the opercular and subopercular bones 
to form the inverted arch of his seventh (occipital) cranial vertebra 
('Tableau de la Composition de la Tete osseuse de I'Homme et des 
Animaux/ cited in Cuvier's ' Histoire de Poissons/ torn, i, p. 230. See 



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63 

The facts and arguments that determine the nature of 
the haemal arch of the occipital vertebra in reptiles equally 
apply to that in the bird (see fig, 4, 51, 52, PL L). The 
extent of its displacement, it is true, has been greater : 
not seven only, but seven and tvv^enty vertebrae may inter- 
vene between its actual position and that of the rest of its 
proper segment. But this difference of extent of displace- 
ment ought no more to hide the true relationship of the 
scapulo-coracoid arch to its proper position and typical 
segment in the skeleton, than the jugular position of the 
ventral fins of a fish (PL I. fig. 2, v^') prevents the ichthyo- 
logist from determining their nature and consequently their 
proper position in relation to the archetype skeleton. 

In Mammalia we find the scapula retaining its primitive 
vertical position and much of its elongated narrow form in 
the low ovoviviparous monotremes ; and the arch in them is 
completed by the coracoid. We observe the scapula long 
and slender in the mole (fig. 2, 51); but in most of the class 
it is developed into a broad quadrate or triangular plate, 
with outstanding exogenous processes called ^ spine ^ and 

The hsemapophysial element is also reduced 
to an appendage, as in the false ribs at the back part of the 
thorax, and coalesces as a process (PL I. fig. 4, 52) with 
the pleurapophysis (51). In many mammals and in man, 
the arch is completed by the pair of bones called clavicles 
(PL I. fig. 6, 58) which coexist with the coracoids in 
most birds and reptiles. I have elsewhere adduced the 
facts and arguments which show that the bone 58, figs. 4, 
5 & 6, PL I,, is the special homologue of the bone 58 
in the fish (fig. 2, 51 & 52)^ : and its anterior position to 
the coracoid in the air-breathing Vertebrata is no valid 



' acromion/ 



also the Table IIL and note 11 in my Work ' On the Archetype/ &c. 
p. 172), and took no account of the instructive natural connections and 
relative position of the hyoidean and scapular arches in fishes. 

* *^ On the Archetype and Homologies of the Vertebrate Skeleton/ 
pp. 19, 99, 133. 




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64 

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argument against the determination^ since in these we 
have shown that the true scapular arch is displaced back- 
wards. The parallelism of the clavicles with the coracoids, 
and their inferior convergence^ indicate their serial homo- 
logy with the coracoids^ and consequently their general 
homology as ^ haemapophyses ^ ; and I regard the clavicle 
in its relations to the vertebrate archetype (PL I. fig. 1)^ 
as the displaced haemapophysial element of the atlas, to 
which segment its true relative position is shown in the 
same low organized class (fig. 2^ 58) in which the typical 
position of the scapular arch is likewise retained. 

Having thus traced out and determined the nature^ 
^bedeutung^ or general homology of the scapular arch^ 
the next step, in regard to the limb appended to it, is 
plain and easy. We saw that the typical segment of the 
vertebrate skeleton (p. 42, fig. 7) was occasionally comph- 
cated by an appendage {a) developed from each side of the 
haemal arch, serving to attach that arch to the next in suc- 
cession in the thorax of birds {a, p) ; but diverging into 

the flesh and adding to the leverage of the locomotive 
powers in the abdomen of fishes (PI. I. fig. 2, a, a). The 
pectoral extremities exhibit varied developments of this 
appendage ; but, if our determination of their general ho- 
mology be the true one, we ought to trace them under 
progressive stages of reduction and simplification to their 
primitive or archetypal character. 

Already, in the class of Birds, we find the diverging 
appendages of the scapulo-coracoid arch of the apteryx 
(fig. 9, 63-57, a) reduced in bulk nearly to the dimensions 
of those of the thoracic-costal arches (a, a), but projecting 
into the flesh like the costal appendages of fishes ; and, 
beino* a longer ray, protruding its extremity beyond the 
teo-umentary surface, but to so short an extent that the 
whole of this monodactyle limb or rudimental wing is con- 
cealed by the plumage. 

The proportion of the fore-limb to the supporting arch 



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in the proteus and amphiuma (PI. I. %• 8, 53-67, a) is 
hardly greater than that of the ray-hke appendage to the 
abdominal rib in many fishes. 

In the lepidosiren (jb. fig. 7, 53-67, a) we actually find 
the diverging appendage of the scapular arch retaining its 
elementary form of the ray, and differing only by its seg- 
mentation and relative length from its serial homoloo-ues 
{ib. fig. 2, a a) in the succeeding segments of the skeleton 
of better ossified fishes. But by virtue of its elongation 
it extends beyond the surface of the body, and carries with 
it a sheath of the integument. 

In the view of the Archetype skeleton (PI. I. fig. 1), 
the pectoral Hmb (53-57, a) is represented under this form 
as the diverging appendage of the fourth or occipital 
haemal arch (50, 51, 52, 52'), and its serial homology with the 
shorter appendages (a, a) of the succeeding arches is un- 
mistakeable. 

If then the diverging rays or appendages of the thoracic 
and abdominal vertebrae of fishes (fig. 2, a, a), of reptiles 
(fig. 3, a, a), and of birds (fig. 4, a, a), be serial repetitions 
of the more developed appendage of the scapulo-coracoid 
arch, they must be * rudimental limbs,^ future possible or 
potential arms, legs, wings or feet. 

To become recognised specially as a ' Hmb,^ it needs 
only that the diverging appendage carry out beyond the 
surface a fold or sheath of the integument, which it may 
be able by its muscles to move and make react upon the 
ambient medium or supporting surface. Hence the simple 
filamentary ventral appendages of the lepidosiren and the 

blenny are acknowledged by Naturalists as hinder limbs. 
In Zoology, however, not more than two pairs of hmbs are 
recognised in the Vertebrate series. But with our present 
knowledge of the nature of limbs, we are stimulated to 
inquire w^hether there be no other diverging appendages 
of haemal arches similarly developed and deserving that 
name ? 



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If we examine the segments of the skeleton in ad- 
vance of the occipital one, which are represented by their 
inferior or haemal arches in the lepidosiren ^j W'e shall 
find that each of them developes its pair of appendages 
(23, 34, 37) : that (37) from the hyoid (parieto-haemal) arch 
projects freely outwards as a simple osseous unsegmented 
ray : that (34) from the tympano-maxillary (fronto-haemal) 
arch has a like form and condition. The diverging append- 
age of the maxillary (naso-hasmal arch) is anchylosed as a 
(pterygoid) process, and repeats the function of the costal 
appendages in birds by attaching the arch from which it 
diverges to the next in succession. The free moveable 
appendages of the tympanic and hyoid arches carry out 
with them a fold of integument; but, like the ventral and 
pectoral fins of the lump-fish {Cy clop t ems) ^ they combine 
to support the same fold or rudimental fin, w^hich is deno- 
minated the ^ operculum ^ ; but this is essentially a limb, 
or rather two cephalic limbs conjoined, w^hich, in fact, are 
specially distinguished in ichthyology as the ^ opercular^ 

and ^ branchiostegal ^ flaps. 

An osseous fish, therefore, of the type of that the ske- 
leton of which is represented in PL I. fig. 2, is an ^octo- 
pod,^ and six of its limbs belong to the head. With 
regard to the third pair, which are more especially orga- 
nized for locomotion, whatever be their ultimate develop- 
ment and destination, they always first appear in the 

simple form in which they are permanently arrested in 
the lepidosiren, viz. as an unbranched ray. Development 
simply augments itslengthand the number of its segments 
in the lepidosiren: in other fishes the jointed ray is mul- 
tiplied : sometimes a segment is modified between the 
terminal rays and the supporting arch, which may be re- 
cognised as a carpus {Lophiusf): sometimes a second seg- 

r 

Lectures on the Comparative Anatomy and Physiology of the Ver- 
tebrate Animals, 8vo, 1846, p. 79, fig. 27, 19, 32, 40. 
t lb. p. 121, fig. 40, 56. 



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ment is interposed between the ' carpus ' and the arch, 
which may be recognised as the ^ antibrachium ' (PL I. 



fig. 



1 

2; 54^ 55) : but the development of definite segments 
in the longitudinal direction of the limb does not go be- 



yond this point in fishes. Far otherwise, however, is it in 
respect of development in breadth ; multiplication of di- 
gital rays is the characteristic type of the pectoral extre- 
mity in the piscine class^ and reaches its maximum in the 
species which have accordingly received the emphatic de- 
nomination of ' Ray-fishes' {Raiidm). And this mode of 
complication of the pectoral member by vegetative repeti- 
tion of like parts^ is a striking and instructive instance of 
the special divergence of the piscine branch from the 
common Vertebrate stem. 

In order to follow the development of the diverging ap- 
pendage of the occipital haemal arch through other rami- 
fications of that stem, w^e must retrace our steps to the 
species in which it retains its embryonic state and repre- 
sents its archetypal character. The first step in develop- 
ment from the primitive type of the pectoral ray of the lepi- 
dosiren is made by the Amphiuma didactylum (PL I. fig. 8). 
The haemal arch is detached from the neural arch, and 
slightly displaced backwards; but the pleurapophysis {pl^ 
51) retains its simple rib-like form and position, slightly 
inclining outwards below from the vertical line. The haem- 

apophyses (^, 52) do not pass beyond the state of gristle, 
but are much expanded : they resemble in their histologi- 
cal condition their homotypes, called ^ cartilages of the 
ribs,' in the thorax of man. If the study of the essential 
nature of the detached inverted arch so formed had been 
begun at this point and compared with that of the Verte- 
brates lower in the scale, no doubt, I apprehend, would 
have been entertained as to the detachment of such h^mal 
arch in the amphiuma being a deviation from type, and its 
attachment to the rest of its segment in the iepidosiren 
and osseous fishes as being a retention of the typical struc- 

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68 

ture : this condition would have been in point of fact the 
rule, and the other the exception. 

So likewise with respect to the diverging appendages, 
a a^ of the occipito-haemal arch of the amphiuma : if the 
anatomist had observed them wdth a previous knowledge 
only of the lepidosiren and other fishes, the bones 54, 55 
and 57 would doubtless have been regarded and described 



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only as bifid segments of the primitive simple ray. But 
the parts having been originally studied from a higher 
point in the animal series, where the homologues of those 
segments by virtue of their special developments in adap- 
tation to special functions had obtained special names, 

those names were naturally transferred to their simplified 
homologues in the appendage recognised as the anterior 
limb or extremity of the amphiuma : the proximal single 
segment 53 w^as described as ' humerus,^ the ossified di- 
visions of the next segment as ^radius' and ^ulna^ (54 and 
55), the terminal bifurcation (57) as the ^digits/ This ex- 
treme instance of the exemplification from ^special homo- 
logy^ of the unity of the plan upon which the limbs of the 
vertebrate animals have been constructed is a perfectly 

true one. 

Cuvier has most accurately assigned their special names 
to each of the parts of the fore-limb of the amphiuma in 
his celebrated memoir^. All that I would ask of the most 
devoted disciple of the school of ^positive facts^ is to reci- 
procate ; to grant the inference as to the signification of 
the parts arrived at by their study in the ascending route 
of inquiry, which the homologist is ready to give to the 
determinations of the special character of the parts which 
have been obtained by comparisons pursued descensively 
from man : in other words, to admit that the whole (53-57) 

Dans ces deux figures a est Vomoplate^ h les plaques sternales car- 
tilagineuses formees probablement des os coracoidiens i c VhumeruSy 
suivi du cubitus et du radius qui portent un carpe cartilagineux et deux 
OS metacarpiens tt phalangiens osseux," Memoire ki a I'Academie des 
Sciences, le 13 Novembre 1826, p. 15. 



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in the amphiuma (fig, 7) 
(53-57) in the lepiclosiren (fig. 6) ; that this may answer to 
the ray (53-57 a) in the fourth segment of the archetype 
(fig. 1) ; and that such ray is repeated in the diverging ap- 
pendages^ a a, of the succeeding segments of the skeleton : 
whereby he will be led to the recognition of the essential 
nature of the hmbs as developed diverging appendages of the 
haemal arches of vertebrae^ and the fore-limbs as being such 
appendages of the occipital vertebra^. The facts are not 
less ^ positive ^ than they wete before^ only they cease to be 
empirical and become intelligible. 

1 need not trespass further on the time of this distin- 
guished audience^, by adding instances of the complication 
and concomitant powers of these appendages to those that 
have already been illustrated at the commencement of the 
present discourse ; 1 will only repeat^ that the adaptive deve- 
lopments of the radiated appendage of the occipital haemal 
arch reach their maximum in man^ and the distal segment 
of the appendage constitutes in him an organ which the 
greatest of ancient philosophers has defined as the 
instrument of the rational soul;^^ and which an eminent 
modern physiologist has described ^^'as belonging exclu- 
sively to man — as the part to which the whole frame must 
conform f.^^ And these expressions give no exaggerated 

* The want of connection of a peripheral piece^ at its peripheral end 
or border, appears to be one condition of its greater extent of variety of 
form and proportion than in the more central pieces of a natural seg- 
ment. There is nothing to restrain its luxuriant development from a 
simple spine to a plate^, to a divided plate with intercalations, &c., or 
to a lengthened segmented ray bifurcating into additional segments 

with indefinite modifications of these. Always, however, it is to be re- 
membered that the polarising forces which tend to shoot out particle 
upon particle after the pattern of dendritic corals, lichens or crystals, 
are so controlled by the antagonising principle of adaptation, that the 
radiating growth is always checked at that stage and guided to that 
form which is best suited to the needs and habits and sphere of life of 
the species. 



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t Sir Charles Bell, Bridgewater Treatise, 1833, pp. 16, 18. 

a\ ojU^tSe^fcov ylyverac rS)V aXk(OV (d)(OV civdpcoTros 



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70 



idea of the exquisite mechanism and adjustment of its 
parts. 

It is no mere transcendental dream, but true knowledge 
and legitimate fruit of inductive research, that clear insio-ht 
into the essential nature of the organ, which is acquired 
by tracing it step by step from the unbranched pectoral 
ray of the lepidosiren to the equally small and slender but 
bifid pectoral ray of the amphiuma, thence to the similar 
but trifid ray of the proteus, and through the progressively 
superadded structures and perfections in higher reptiles 
and in mammals. If the special homology of each part of 
the diverging appendage and its supporting arch are re- 
cognisable from Man to the fish, shall we close the mind's 
eye to the evidences of that higher law of archetypal con- 
formity on which the very power of tracing the lower and 
more special correspondences depend ? 

Until the alleged facts (pp. 50, 53) are disproved, demon- 
strating change of position to be one of the modifications 
by which parts of a natural and recognisable endoskeletal 

segment are adapted to special offices, and until the con- 
clusions (pp. 54, 68) deduced from those facts are shown to 
be fallacious, I must retain the conviction that, in their 
relation to the vertebrate archetype, the human hands and 
arms are parts of the head - diverging appendages of the 
costal or haemal arch of the occipital segment of the skull*. 

* As another example of the new light and interest which a know- 
k^dge of general homology gives to the facts of abnormal anatomy in 
the human species, I may cite the remarkable case described by Sir C. 
Bell (op. cit. p. 52), of the boy 'born without arms/— 'but who had 
clavicles and scapula;.' Here development was arrested at the point at 
which it is normal in the Anguis, Pseudopus, and some other limbless 
and snake-like lizards. The usual predominating development of the 
scapular appendage has bred so prevalent an idea of the subordinate 
character of the supporting arch, that the existence of the arch minus 
the appendage, is adverted to not without a note of surprise in the 
above-cited and other excellent works. General homology, however, 
teaches that a vertebral arch is a more constant and important part 
than its appendages ; and, that, being anterior in the order of develop- 



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71 

Having thus arrived at a solution of the question mooted 
at the outset of the present Discourse, viz. the signification, 
' bedeutung^ or general homology of locomotive members, 
and of the pectoral pair in particular, little needs to be 
added in respect of the pelvic pair of limbs. 

When a bone in the skeleton of a dog, a horse, a mole, 
and a platypus, is proved to be the same or answerable 
bone to the one called ^ scapula^ in man, and is called by 
the same name; and M^hen the answerable bone can be 
traced through birds, reptiles and fishes, where it is simi- 
larly recognised and indicated, — determined, in short, to 

be the namesake or ^homologue^ of the human scapula; it 
follows, that, whatever other or higher proposition respect- 
ing the nature of that bone and its relations to the funda- 
mental pattern of the vertebrate skeleton can be demon- 
strated by the sum of its characters in all applies indi- 
vidually to every form of the bone : and whatever element 
of the typical segment of the skeleton it may be recognised 
to be in an instance where the typical characters are best 
retained, such conclusion equally applies to the instances 
in which it is most metamorphosed. In other words, 
when the general homology of a bone is determined in any 
one species, the same is proved of its special homoiogues 
in every other species. If the scapula of the lepidosiren is 
the rib of the occipital vertebra, every other scapula must 
be the same element. 



ment, it may be expected, in cases where development is arrested, 
whether normally in accordance with the nature of the species, or ab- 
normally as an individual defect, to be present when the diverging ap- 
pendages are absent. Sir Charles Bell, well recognising the primary 
function of the modified occipital rib in relation to breathing, observes, 
in reference to the above-cited case, '^ We w^ould do well to remember 
this dovible office of the scapula and its muscles, that, whilst it is the 
very foundation of the bones of the upper extremity, and never want- 
ing in any animal that has the most remote resemblance to an arm, it 
is the centre and point d'appui of the muscles of respiration, and acts 
in that capacity where there are no extremities at all !'' — P. 52, 






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72 

So^ likewise, when a bone in a given natural segment of 
the skeleton is demonstrated to be answerable to another 
bone in another natural segment of the same skeleton, 
whatever higher homological proposition may be demon- 
strated of the one must apply to the other and to all its 
serial homologues, i. e. to all the bones that have been 
shown to stand in the same relations to their respective 
segments. The comprehension of these propositions wall 
be facilitated by tracing the bones that have the same kind 

of marking, from segment to segment, in the diagrams of 
the skeletons in PL L 

No anatomist, I presume, could doubt or would con- 
travene so plain a proposition as that the frontal bone or 
bones in their part of the skull repeat the general relations 
of the parietal bone or bones in their part, and those of the 
supraoccipital bone in its part of the skull ; or that the 
basioccipital in its segment repeated the essential charac- 
ters of the basisphenoid in the next segment. 

Whatever element, therefore, of the typical s( 
supraoccipital is demonstrated to be, the same must be 
true, not only of the supraoccipital in all other animals, 
but of the parietals and irontals in the succeeding segments 

r 

of the same animal. And whatever element the basiocci- 
pital is demonstrated to be in its segment, the basisphenoid 
must be that element in the succeeding segment. In 
other w^ords, when parts are demonstrated to be ^ homo- 
types ^ or serial homologues, a general homology proved of 
one applies to all^, 

A due appreciation of these rigorous deductions will 
leave no diflSculty in dealing with the general homology of 
the hinder or pelvic limbs. 

Anatomists with one consent admit that the ilium is the 

* The terms 'general/ 'special/ and 'serial homology/ are ex- 
plained and exemphfied in my " Lectures on the Comparative Anatomv 

4/' 

and Physiology of the Vertebrata/' p. 48, and ' On the Archetype of 
the Vertebrate Skeleton/ p. 7. 








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homotype of the scapula ; in other words, is the answer- 
able bone in the series of segments of the same skeleton : 
few^ if any, doubt, and none with reason, that the ischium 
is the homotype of the coracoid, and the pubis of the cla- 
vicle. The ilium must therefore be, like the scapula, a 
^ pleurapophysis,^ and the ischium and pubis, like the cora- 
coid and clavicle, must be ^haemapophyses' ; for whether 
the serial homology just enunciated in regard to the latter 

bones be accepted or inverted, and the pubis be viewed as 
the homotype of the clavicle or coracoid, matters not ; 
they are the same elements of the haemal arch in the abs- 
tract; their general homology is^ therefore^ the same. 

The serial homology of the pectoral and pelvic extremi- 
ties has been so fully discussed, that no more need be 
added on that head to prove their general homology. If the 
pectoral members have been demonstrated to be develop- 
ments of the diverging appendages of the haemal arch^ the 
pelvic members must necessarily be the same elements of 
the typical vertebra. 

This conclusion as to the general homology of the hind- 
limbs would, however, have been arrived at if the study of 
the Nature of Limbs had been commenced with them, and 
had been illustrated by their morphological and develop- 
mental characters, independently of the light reflected from 
serial homology. But as it may serve to establish con- 
fidence in the truth of the evidence by which such genera- 
lizations are arrived at, I will briefly adduce some of the 
more striking facts or links in that independent chain of 
reasoning. 

The most simple and elementary condition of the com- 
plete and normally connected pelvic arch and appendages 
is found in the lowest forms of crawhng reptiles, viz. the 
perennibranchiate Batrachia. Here is a side vicAV of the 
parts in the Menopoma (fig. 11), and fig. 10 in PI. I. gives 
a direct front-view of them in the Proteus. In fig, 11 the 
three anterior vertebrae which answer in position to the 



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Mumbar' vertebrae in PI. 1. fig. 3, differ chiefly in having 
pleurapophyses (p/) articulated and not anchylosed to the 

Fig. 11. 




Pelvic vertebra and appendage with contiguous vertebra; (Menopome). 

ends of the diapophyses (d) ; but the ribs are rudimental, 
and the archetypal segment is departed from by defect of 
the hsemal arch. In the next vertebra the diapophysis 
(d') is thickened, and the pleurapophysis (p/) elongated 

and divided into two parts hke the occipital pleurapophysis 
in the fish (PI. I. fig. 2, 50, 51) : and the second rib-like 
piece (62, fig. 11) is joined by its lower end to a broad 
partially ossified cartilage (64), the heemapophysis, which 
meets and joins its fellow, completing a haemal arch and 
restoring the vertebra in question to the typical character. 
A radiated appendage, a, moreover, diverges on each side 
from the articulation between 62 and 64, and forms the 



hind-limb. 



limb 



the undivided filamentary appendage similarly situated in 
the lepidosiren (PI. I. fig. 9) and with the ventral fins of 
fishes, in the descending series, and with the hind-limb of 
other reptiles, of birds and of mammals in the ascending 
series, is unmistakeable, and, I believe, is generally ad- 
mitted : so that comparative anatomists have not hesitated 
to call the rib-like bone (62) ' ilium,' and the cartilage (64) 
'ischium' or 'pubis' in the menopome. 



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- The correspondence of the segment of the endoskeleton 
in the menopome d^, vP^ h, a, with the typical vertebra^ as 
ilhistrated by fig. 7, p. 42, is such, that any other explana- 
tion of its essential nature than as a representative or repeti- 
tion of such fully-developed segment or vertebra, would be 
plainly contrary to nature. The chief modification has its seat 
in the most peripheral part, viz, the appendage a, as com- 
pared with its simple homologue in the thoracic segment 
of the bird (fig. 7^ ct)* If 62 and 64, fig. 11, are to be regarded 
as strangei's to the vertebral system, new parts introduced 
for special purposes, and not as normal elements modified 
for special purposes, I am at a loss to know on what prin- 
ciples, or by what series of comparisons we can ever hope 
to attain to the higher generahzations of anatomy, or dis- 
cover the pattern after which the vertebrate forms have 
been constructed. 

It may be said that the arch which they constitute per- 
forms a new function, inasmuch as it sustains a locomo- 
tive limb which reacts upon the ground. But this new 
function arises in the menopome, rather out of the modifi- 
cations of the appendage than of the arch itself. In so far 
as the mere support of the appendage is concerned, the in- 
verted or haemal arch (p/', h) performs no new function, 
but one which is common to such arches in the thorax of 
birds, and to the less completely ossified homologous arches 
in the abdomen of fishes, where moreover the simple di- 
verging appendages (PL 1. fig. 2, a, a) do give attachment 
to the muscles of locomotion. 

Comparing, then, the haemal arch in question with that 
of the typical vertebra (fig. 7^ p* 42), we find that, hke the 
scapulo-coracoid arch in fishes (PI. I. fig. 2, and fig. 7^ 50, 
51, 52), its parts are open to two interpretations. The upper 
piece of p/' may be the whole pleurapophysis, the lower (62) 
the haemapophysis, and the part. 64, the half of an expand- 
ed and bifid haemal spine : or p/' with 62 may be two por- 
tions of a teleologically compound pleurapophysis, and 64 



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verges 



the hgemapophysis, which would join with its fellow with- 
out, or with a mere rudiment of, a haemal spine intervening. 
From the analogy of the scapulo-coracoid arch in fishes, 
which is proved by its modifications in higher animals to 
want the h;emal spine, we might infer that such was the 
condition and true interpretation of the correspondingly 
simple pelvic arch under consideration, and the inference 
is confirmed by the undivided condition of the pleurapo- 
physis or Milium' in the proteus (PL I. fig. 10, 62), as well 
as by the position from which the appendage or limb di- 

But the general relation of this arch to the haemal 
one'of the typical segment is not affected by the alternative. 
In ascending from the proteus and menopome to the 
crocodile (PI. I. fig. 3), we find the homologue of 62 
broader than it is long, and articulated to the thickened 
proximal portions of the pleurapophyses of two vertebrae ; 
and we observe, likewise, the pelvic arch completed below 
by two pairs of heemapophyses : for the anterior pair the 
name of ' ossa pubis ' is retained ; for the posterior pair 

that of ^ischia.' In general homology these bones com- 
plete, as haemapophyses, the two vertebral segments modi- 
fied to form the sacrum of the crocodile ; and the inter- 
mediate connecting piece (ilium) might be Interpreted, as 
either the confluent distal portions of the pleurapophyses 
of both vertebrse, or as an expansion of one such portion, 
answering to 62 in the menopome, and intruding itself be- 
tween the stunted pleurapophysis and distant haemapo- 
physls of the other sacral vertebra In the crocodile. 

The doubt thus left in the prosecution of the Inquiry by 
the successive steps of special homology is resolved by the 
light of serial homology. The ilium is the homotype of the 
scapula ; it parallels the scapula in the nature and extent 
of Its morphological modifications ; and, since the scapula 
under Its extremest expansion is proved to be the deve- 
lopment of one and the same element, viz. the lower por- 
tion of the divided occipital pleurapophysis in the fish, so 



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likewise must the broadest ilium be considered to be the 
development of the same portion of one pelvic pleurapo- 
physis. Its broad expanded modification is its common 
morphological character in Mammalia; and its position 
becomes less vertical than in reptiles, and more oblique ; 
and in both these particulars it resembles the scapula. In 
Plate I. 62 shows its common form in quadrupeds, fig. 5, 
and 62 in fig. 6 its still broader proportions in man, in re- 
lation to the extent of surface required by the muscles that 
sustain the upright trunk upon the diverging appendage 
of the arch. 

The second sacral vertebra in man is complete : but its 
pleurapophysis is in two pieces, as in the menopome : the 
proximal piece coalesces with the neural arch and forms 
the so-called ' transverse process ' of the vertebra ; the dis- 
tal or lower portion is expanded to form the so-called 
^ ilium' (62). The haemapophysis (63) coalesces with that 
of the preceding vertebra (64), and with its own pleurapo- 
physis (62). 

The first sacral vertebra has its haemapophysis (64, called 
« pubis ') ossified, but separated from its proper pleurapo- 
physis by the expanded (iliac) portion of that of the suc- 



ceeding vertebra (62), with which it coalesces, as well as 
with the succeeding haemapophysis (63, ' ischium'). The 
short and thick pleurapophyses of the third sacral vertebra 
also articulate, in the adult, with the expanded distal por- 
tion of those of the second sacral vertebra ; but these (iliac 
bones) are restricted in infancy and early childhood to 
their connections w ith the first and second sacral vertebrae, 

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which connections are permanent in most reptiles. 

In the bird the modification of the vertebral segments 
at the posterior region of the trunk in relation to the trans- 
ference of the whole weight of the body and fore-limbs 
(wings) upon the hind-hmbs, is greater and more extensive 
than in man, and the essential nature of the pelvic arch 
is still more masked. By the extreme expansion of the 



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element 62, fig. 4, PI. I.^ it is brought into connection with 
the homologous stunted or proximal ends of pleurapo- 
physes of several contiguous segments, besides its own 
proximal piece, in the manner indicated by the dotted line 
in the menopome (fig. 11, p. 74). 

Now, if the ilium, so expanded, were interpreted as the 
coalesced complementary portions of all the short pleur- 
apophyses with which it articulates, its nature would be 
very similar to that which Oken has attributed to the sca- 
pula. But its ossification radiates, as in the simple rib- 
like ilium of the menopome, from a common centre: there 
are no corresponding multiplications of hasmapophyses be- 
low ; these are restricted in the pelvis of all animals to the 
number which they present in the crocodile. And since 
the scapula has been proved to be, under its most ex- 
panded form, the homologue of a single pleurapophysis, so 
also its homotype, the ilium, must be regarded as maintain- 
ing, under every variety of form and proportion, the same 
fundamental singleness of character which it presents on 

its first appearance in the perennibranchiate batrachian. 

The rudimental hind-limb in serpents is suspended in 
the flesh and attached only indirectly by one of its simple 

muscles to the bifurcate and shortened rib of the anterior 
caudal vertebra: that pleurapophysis, therefore, is but little 
more modified than the one which represents the ilium in 
the proteus, and the diverging appendage is as simple as in 
the lepidosiren, consisting of fewer joints, even where best 
developed as in the boa, and being reduced to a single 

osseous style in the slow- worm. 

In the air-breathing Vertebrata the typical character of 

the pelvic arch is progressively disguised by excess of de- 
velopment as we ascend from the low point at which w^e 
commenced its analysis ; and, in descending below the 
same low point to the water-breathing class, we find the 
pelvic arch deviating from its typical character by defective 
development. And for this indeed we might have been 



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prepared by the consideratioG of the close relation which 
this arch and its appendages bear to locomotion and sup- 
port of the body on dry land. 

In fishes (PI. L fig. 2) we find the fin-like homologue of 
the hind-limbs (v) radiating from a bone (63) which con- 
verges to its fellow at the median line^ and which is recog- 
nised by some anatomists as the ^ pubis'; by others^ and 
with better reason^ as the ^ ischium '; but which is evidently 
the same abstract vertebral element^ viz. a ^ ha^mapophysis/ 
The ilium, if it be developed, retains its character as a short, 
free, or false rib, like 62, its development not proceeding so 
far as to effect the normal junction with the ha^mapophysis. 
This lower element therefore of the arch being liberated 
from its typical connections, has no fixed position in the 
class of Fishes, but in some existing species and all the pri- 
meeval forms of fishes, keeps near its proper segment, as at 
V, fig- 2. PI. L ; and that this is its true position in relation 
to the archetype, is significantly indicated by the fact that 
all the fishes in the geological formations anterior to the 
chalk are ^ abdominal/ In certain species of the actual 
creation the ventral fins advance to the place marked v' in 
fig. 2, the ischium elongating to join the coracoid, just as 
one detached costal cartilage is suspended from another at 
the back of the thorax in certain birds. By the shortening 
of the attached ischium, the ventral fins, in other existing 
fishesj are brought forwards to v'^ 



In PI. I. fia'. 9, the elementary condition of the hind 




limbs in the vertebrata is shown in nature in a back view 
of the pelvic vertebra of the Protopterus or lepidosiren. 
The letters signify the general and the figures the special 
homologies of the parts. The apical elements (haemapo- 
physes or ischia, 63) of the inverted arch are detached 
from the basal ones (pleurapophyses or ' iha,' 62) and from 
the rest of their segment, and carry with them the diverging 
appendages (65-69), as in all other fishes. 

The true meaning and nature of this piscine condition 






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80 

is beautifully illustrated if we now return, by one step in 
advance to the point from which we commenced the ana- 
lysis of the pelvic arch and limbs. 

In fis. 10. PI. I. e.p. the haemal arch retains its natural 
connections with the rest of its vertebra, and henceforth 
preserves them, with a few exceptions [Enaliosauria and 
Cetacea), in all the air-breathing classes, up to and in- 
cluding man- 
In respect of the modification by displacement, the nu- 
merical examples of adhesion to and of departure from type 
are reversed in the pelvic segment, as compared with the 
occipital one. Mammals, birds and reptiles show the rule 
of connection, and fishes the exception, typically as well as 
numerically. There has been, therefore, no difficulty or 
discrepancy of opinion in regard to the homology of the 
detached haemal arch and its appendages in fishes. Cuvier 
saw in 63, fig. 2, the representative of the 'os innomlnatum* 
^ OS du bassin ;' and, notwithstanding the degree of dis- 
placement to which such rudiment of a pelvis, with its 

pelvic members, were subject in fishes, Linnasus had as 
little hesitation in recognizing in the ventral fins the ho- 
mologues of hind-limbs wherever they were placed. 

in their normal position, as at v, fig. 2, they characterized 
the 'abdominal' fishes; w^hen advanced to beneath the 
pectoral fins, as at v', they characterized the ' thoracic ' 

fishes ; when still more advanced, as at v", they charac- 
terized the 'jugular' fishes. The species in which the 
ventral fins were absent were ' apodal,' in the philosophic 
language of the immortal Swede. He knew them to be 
hind-feet under their webbed disguise. 

Now all that is here required, in regard to the determi- 
nation of the locomotive members, is, that no more value 
be given to the character of detachment and change of 
place in regard to the scapular arch and its appendages 
than Linneeus allowed in the case of the pelvic arch and 
its appendages. 



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The arms are shifted to and fro in the bodies of the air- 
breathing vertebrates, the legs in those of the water- 
breathing vertebrates : the arch supporting the arms is 
fixed in its true place in fishes, and the arch supporting 
the legs retains its true place in the higher classes ; only it 
is often necessary that it should be so developed as to be 
applied to many segments besides the one to which it pro- 



perly belongs. In the proteus (fig. 10), however, the ilium 



(62) retains its simple primitive rib-like form, just as the 
scapula (51) does in fig. 8; and it is connected, as we saw 
likewise in the menopome (p. 74, fig. 11), to its own ver- 
tebra exclusively. 

Wherever either arch with its appendages may be situ- 
ated, it is in its best possible place in relation to the exi- 
gences and sphere of life of the species. It is only when 
we consider its relations to the ideal exemplar that we 
are compelled to use the terms expressive of rule and de- 
viation. 

When a truth is arrived at, the conception of it is clear, 
and it can be expressed plainly and intelhgibly. When the 
inquirer stops short of, or goes astray from, his aim, yet 
thinks he has gained it, he can only have a distant and cloudy 
notion of it, and his definitions must partake of the obscu- 
rity of his conceptions. When Oken, after recognising 
in the scapula an aggregate of cervical ribs, afterwards de- 
fined the limbs as ' liberated ribs,' we perceive that neither 
his notion of ribs, or of the scapular arch, or of Hmbs, could 
be clear. When Carus explains the nature of limbs by 
caUing them ' tertiary vertebra^,' we discern the same ob- 
scurity in his idea of the primary segments of the ske- 
leton. 

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According to my definition of a vertebra^ we recognise 
in it the centrum^ the neural arch^ the haemal arch^ and 
the appendages diverging or radiating from the haemal arch. 
The centrum^ though the basis^ is not less a part of a ver- 
tebra than are the neurapophyses^ haemapophyses; pleur- 

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4 

apophyses, &c. ; and each of these parts is a different part 
from the other : to call all these parts ^ vertebra' is in effect 
to deny their differential and subordinate characters, and 
to voluntarily abdicate the power of appreciating and ex- 
pressing them. The terms * secondary' or ' tertiary verte- 
brae' cannot, therefore, be correctly apphed to the parts or 
appendages of that natural segment of the endoskeleton to 
the whole of which segment the term ' vertebra' ought to 

be restricted. 

So likewise the term ' rib' may be given to each moiety 
of the hcfimal arch of a vertebra ; although I would con- 
fine such special appellation to the pleurapophyses when 
they present that long and slender form characteristic of 
the thoracic abdominal region, viz. that part of such mo- 
dified hcfimal or costal arch to which the term ^vertebral 
rib' is applied in anatomy and the term « pars ossea costae' 
in anthropotomy : but, admitting the wider application of 
the term * rib ' to the whole haemal arch under every mo- 
dification, yet the bony diverging and backward projecting 
appendage of such rib or arch is something diff"erent from 

the part supporting it. 

Arms and legs, therefore, are developments of 

They are not ribs that have 
become free : although liberated ribs may perform analo- 
gous functions, as in the serpents and the Draco volans. 

Having thus attained the end proposed as the subject 
of the present discourse, let us finally apply the few minutes 
that remain of the allotted time to the contemplation of the 
abstract Archetype skeleton, as illustrated in fig. 1, PL I. 

The pectoral and ventral limbs are there exhibited as 
the appendages of the fourth and twenty-sixth segments : 
the occipital segment is always the fourth, the pelvic seg- 
ment has no fixed place or numerical symbol. The lepi- 
dosiren realizes, very closely, the primitive condition of the 
limbs, -as exemplified in the ideal archetype. 



COSTAL APPENDAGES. 



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We 



mals as being characterized by the hmitation of their 
limbs to two pairs, and it is true that no more diverging 
appendages are developed for station, locomotion and ma- 
nipulation. But the rudiments of many more pairs are 
present in many species. And though they may never be 
developed as such in this planet, it is quite conceivable 
that certain of them may be so developed, if the Vertebrate 
type should be that on which any of the inhabitants of 
other planets of our system are organized. 

The conceivable modifications of the vertebrate arche- 
type are very far from being exhausted by any of the forms 
that now inhabit the earth, or that are known to have ex- 
isted here at any period. 

The naturalist and anatomist, in digesting the knowledge 
M^hich the astronomer has been able to furnish regarding the 
planets and the mechanism of the satellites for illuminating 
the night-season of the distant orbs that revolve round 
our common sun, can hardly avoid speculating on the 
organic mechanism that may exist to profit by such sources 
of light, and which must exist, if the only conceivable 
purpose of those beneficent arrangements is to be fulfilled. 
But the laws of light, as of gravitation, being the same in 
Jupiter as here, the eyes of such creatures as may disport 
in the soft reflected beams of its moons will probably be 
organized on the same dioptric principles as those of the 

aninials of a like grade of organization on this earth. And 
the inference as to the possibility of the vertebrate type 
being the basis of the organization of some of the inha- 
bitants of other planets will not appear so hazardous, when 
it is remembered that the orbits or protective cavities of the ' 
eyes of the Vertebrata of this planet are constructed of mo- 
dified vertebrae. Our thoughts are free to soar as far as 
any legitimate analogy may seem to guide them rightly in 
the boundless ocean of unknown truth. And if censure 
be merited for here indulging, even for a moment, in pure 

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may 



that the discovery of the vertebrate archetype could not 
fail to suggest to the Anatomist many possible modifica- 
tions of it beyond those that we knov^ to have been realized 

in this little orb of ours. 

The inspired Writer^ the Poet and the Artist alone have 

been privileged to depict such. 

Something also I would fain add with a view to remove 
or allay the scruples of those who may feel offended at any 
expressions that seem to imply that any part or particle of 
a created being could be made in vain. 

Those physiologists who admit no other principle to 
have governed the construction of living beings than the 
exclusive and absolute adaptation of every part to its func- 
tion^ are apt to object to such remarks as have been offered 
regarding the composition of the skeleton of the whale's 
fin and of the chick's head, that '^ nothing is made in vain f 
and they deem that adage a sufficient refutation of the 
idea that so many apparently superfluous bones and joints 

should exist in their particular order and collocation in 
subordination to another principle; conceiving, quite gra- 
tuitously in my opinion, the idea of conformity to type to 
be opposed to the idea of design. 

But let us consider the meaning which in such dis- 
cussions is commonly attached to the phrase ^made in 



vam. 



Wer 




principle governing organization, he would, perhaps, find 
it to mean, that so far as he can conceive of mechanism 

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directly adapted to a special end, he deems every organic 
mechanism to have been so conceived and adapted. In 

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a majority of instances he finds the adaptation of the 
organ to its function square with his notions of the per- 
fection of a machine constructed for such an end ; and 
in the exceptional cases, where the relation of the 
ascertained structure of an organ is not so to be un- 
derstood, he is disposed to believe that that structure may 




^ 






85 



be, nevertheless, as directly needed to perform the function, 
although he perceives that function to be a simple mecha- 
nical action, and might conceive a more simple mechanism 
for performing it. The fallacy perhaps lies in judging of 
created organs by the analogy of made machines; but it is 
certain that in the instances where that analogy fails to 
explain the structure of an organ, such structure does not 
exist ' in vain ' if its truer comprehension lead rational and 
responsible beings to a better conception of their own ori- 
gin and Creator*. Our philosophic poet felt that 

" 'Tis the sublime of Man, 
Our noontide maj esty, to know ourselves 
Parts and proportions of a wondrous \Yhole."— Coleridge. 

Nor could the ignorance of this truth be without its be- 
numbing and bewildering influence on the human mind. 
The learned Cudworth tells us that — " The Democritick 



World 



Mind 



then there must needs be an ^Idaja' and ^Exemplar' of 

the w^hole world before it was made, and consequently 

actual knowledge, both in order of Time and Nature, before 
Things." 



But these Democritans arguing of knowledge as it is 



got by our finite minds, and ignorant of any evidence of an 
ideal Archetype for the world or any part of it, concluded 
that there could be no knowledge or mind before the 

world, as its cause. And in the same spirit Lucretius asks : 

•' Exemplum porro gignundis rebus et ipsa 



Notities hominum Divis unde insita primiim. 
Quid vellent facere ut scirent animoque viderent ? 



33 



No\^ 



the Vertebrated animals proves that the knowledge of such 

* '' L'ensemble de tous les ordres de perfections relatives, compose 
la perfection absolue de ce tout. L'Unit6 du dessein nous conduit a 

Tunite de rintelligence qui Ta confu/' — Bonnet, Contemplations de la 
Nature, 







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86 

a being as Man must have existed before Man appeared. 
For the Divine mind which planned the Archetype also 
foreknew all its modifications. 

The Archetypal idea was manifested in the fleshy under 
divers such modifications, upon this planet, long prior to the 
existence of those animal species that actually exemplify it. 

To what natural laws or secondary causes the orderly 
succession and progression of such organic phaenomena 



i may have been committed we as yet are ignorant. But if, 
without derogation of the Divine powxr, we may conceive 
the existence of such ministers, and personify them by the 
term ^ Nature/ we learn from the past history of our globe 

r 

that she has advanced with slow and stately steps, guided 
by the archetypal light, amidst the wreck of worlds, from 
the first embodiment of the Vertebrate idea under its old 
Ichthyic vestment, until it became arrayed in the glorious 
arb of the Human form. 






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DESCRIPTION OF PLATE I.^ 



This Plate includes diagrams of the ideal pattern or archetype of 
the vertebrate endoskeleton, and of the modifications of it charac- 
teristic of the four great divisions of the vertebrate subkingdom, 
viz. fishes^ reptiles, birds, and mammals, and also of man. 

In each figure the parts or ' elements' of the four anterior seg- 
ments — the seat of the chief modifications in relation to the lods-e- 
nient of the brain, the action of the jaws and tongue, and the in- 
terposition of the sense-organs— are numbered as in the column 
of No mm a in the Plate. 

As the four anterior segments of the neural axis are called col- 
lectively ' brain' {encephalon)^ so the four corresponding segments 
of the vertebral axis are called collectively ^ skulF (cranium). The 
head therefore is not otherwise a repetition of the rest of the body, 
than insofar as each segment of the skull is a repetition or *^ homo- 
type' of every other segment of the body ; each being subject to 
modifications which give it its individual character^ without 
obliterating its typical features. So neither are the ^ arms' and 
' legs' repeated in the head in any other sense than as the cranial 
segments may retain their diverging appendages. The ^fore- 
limbs' are actually such appendages of the occipital vertebra, 

which undergo modifications closely analogous to those of the 
appendages of the pelvic segment or ' hind-limbs.' And inasmuch 

as in one class the pelvic appendages, with their supporting 
haemal arch, are detached from the rest of their segments, and 
subject to changes of position (fig. 2, V, V, V'% so also in other 
classes the appendages of the occipital segment are liable to be 
detached with their sustaining hsemal arch, and to be transported 
to various distances from their proper centrum and neural arch. 

* The Plate and the description are taken from my work * On the Arche- 
type and Homologies of the Vertebrate Skeleton/ 8vo, Van Voorst, 1848. 



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88 

The head therefore is not a virtual equivalent of the trunk but 
is only a portion, i. e. certain modified segments, of the whole 
body. 

The jaws are the modified hsemal arches of the first two seg- 
ments ; they are not 'limbs' of the head'''. 

The different elements of the primary segments are distinguished 
by peculiar markings : 



the neurapophyses by diagonal lines, thus : 

the diapophyses by vertical lines : 
the parapophyses by horizontal lines : 




the centrum by decussating horizontal and vertical lines : 




the pleurapophyses by diagonal lines 



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the hsemapophyses by dots : 



by the ini- 
1, and the 



the appendages by interrupted lines : — — =: — r-n^,^ 
the neural spines and haemal spines are left blank. 

In certain segments the elements are also specified 
tials of their names, as in the third segment in fig. 

fourth in fig. 2, fov example : 

ns is the neural spine. 
n is the neurapophysis. 

plis the pleurapophysis. 
c is the centrum. 

h is the hsemapophysis. 

hs is the heemal spine. 
a is the appendage. 

Fig. 1 . Ideal pattern or archetype of the vertebrate endoske- 
leton, as shown in a side-view of the series of typical segments, 
osteocommata, or Vertebrae' of which it is composed, the ex- 

* These are counter-propositions to Oken's '' Der Kopf ist der ganze Rumpf 
mit alien seinen Systemen/' &c., ' Lehrbuch der Natur-philosophie/ 8vo, 
p. 300, 1843. See the Translation of this Work published by the Ray So- 
ciety. ** The head is the whole trunk with all its systems, the brain is the 
spinal marrow, the skull the vertebral column, the mouth intestine and abdo- 
men, the nose lung and thorax, the jaws are members or limbs." — P. 364 
Prop. 2072, ' ' 



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treme ones indicating the commencement of those modifications, 
which, according to their kind and extent, impress class-characters 
upon the type. 

The four anterior neurapophyses, 14, 10, e, 2, give issue to the 
nerves, the terminal modifications of which constitute the organs 
of special sense. 

The first or foremost of these is the organ of smell (is, 19), 
always situated immediately in advance of its proper segment, 
which becomes variously and extensively modified to inclose and 
protect it. 

The second is the organ of sight (17), lodged in a cavity or 
' orbit' between its own and the nasal segment, but here drawn 
above that interspace. 

The third is the organ of taste, the nerve of which (gustatory 
portion of the trigeminal) perforates the neurapophysis (e) of its 
proper segment (vertebra parietalis seu gustatorid)^ or passes by 
a notch between this and the frontal vertebra, to expand in the 
organ which is always lodged below in the cavity called ' mouth,' 
and is supported by the hsemal spine (41, 42) of its owii vertebra. 

The fourth is the organ of hearing (le), indicated above 
the interspace between the neurapophysis of its own (occipital) 
and that of the antecedent (parietal) vertebra, in which interspace 
it is always lodged ; the surrou.nding vertebral elements being 
modified to form the cavity for its reception^ called ^ otocrane.' 

The mouth opens at the interspace between the haemal arches 
of the anterior and second segment ; the position of the vent varies 
(in fishes), but always opens behind the pelvic arch (Pv) when 
this is ossified. 

Outlines of the chief developments of the dermoskeleton, in 
different vertebrates, which are usually more or less ossified, are 

added to the endoskeletal archetype ; as, e, g. the median horn 
supported by the nasal spine (15) in the rhinoceros; the pair of 
lateral horns developed from the frontal spine (ix) in most rumi- 
nants 3 the median folds (Di, Dii) above the neural spines, one or 
more in number, constituting the ^ dorsal ' fin or fins in fishes and 
cetaceans, and the dorsal hump or humps in the buffaloes and 
camels ; similar folds are sometimes developed at the end of the 
tail, forming a ^caudal' fin, C, and beneath the hsemal spines, 
constituting the ' anal ' fin or fins. A, of fishes, or the subcaudal 
dermo-adipose tumour of the Cape-sheep. 

Fig. 2. Typical skeleton of a fish (class Pisces). The plane of 



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the anterior haemal arch (20, 21, 22) is here raised to parallel with 
the axis of the trunk, and its apex or spine (22) is modified and de- 
veloped so as to articulate with the neural spine (15) of the same 
segment, which thus becomes closed anteriorly ; both 22 and the 
hsemapophysis 21 are developed downwards and backwards in re- 
lation to the protractile and retractile motions of the arch ; and, for 
the purpose of associating these motions with corresponding ones 
of the succeeding hsemal arch, the diverging appendage is subdi- 
vided (23 and 24) and developed so as to articulate with the pleur- 
apophysis (28) of the next arch ; a rudiment of an appendage (23) 
IS attached m some fishes to the heemapophysis (21) of th? nasal 
segment, but it will be observed that no new element is added to 
the hsemal arch ; and, although the Lepidosteus offers an excep- 
tional instance of subdivision of the pleurapophysis (21), that kind 
of modification is usually restricted to the diverging appendage. 

In the next segment the haemal arch has been the seat of un- 
usual growth, but retains more of its normal position and attach- 
ments. Its weight and that of the appendages it supports have 
required an extension of the proximal articulation of its pleurapo- 
physis (28 a) from its proper parapophysis (12) backwards to 
the next parapophysis (8) ; and the pleurapophysis itself is sub- 
divided into two, three, or four overlapping pieces for the final 

. '" ' "On the Archetype," &c. p. 112; 
but it is evident that no new element has been introduced, because 
the extremities of the subdivided pleurapophysis (23 a and 28 d) re- 
tain their normal connections, the one with the parapophysis (12), 
the other with the hsemapophysis (29, 30) . This element is also 
subdivided, for the same final purpose as the pleurapophysis ; and 
its squamous union with the hsemal spine (32) is retained. ' Yet 
the connections of 29 with the condyle of the pleurapophysis and 
of 32 with its fellow, forming the free apex of the inverted arch of 
the second segment, show that the complexity is the result of 
adaptive subdivision, and that no new part has been added to the 
typical elements as exhibited in the archetype (fig. 1, 29-32) ; 
every anatomist has recognised the bones so numbered in the fish 
as the homologue of the single (undivided or anchylosed) bone 
forming the lower jaw (29-32) of the mammal (fig. 5) and of man 
(fig. 6). In addition, therefore, to change of shape and propor- 
tion, the parts of the archetype may be modified by division and 
subdivision. And in this respect the pleurapophyses (2s) and 
haimapophyses (29, so, 31) of the fish deviate further from the 



Work 









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91 

archetype than the same parts do in the warm-hlooded vertebrates. 
Herein is manifested the early divergence to a special form for the 
lowest class^ which the higher classes do not assume in passing 
towards their own types. The diverging appendages are the seat 
of such excess of subdivision with special development of the di- 
vided parts, as best to countenance the idea of a superaddition of 
new parts to the typical element ; yet the most essential character 
of the diverging appendage is retained under its extremest modifi- 
cation, as where it forms the wing of the bird or the arm of man ; 
viz. its connection by one extremity to a haemal arch^ and the free 
projection of the opposite subdivided extremity, carrying out with 



it a fold of integument. 



With 



^^^m- ^^^m- ^m-^^ ^^^^b ^^^^^r 

of the haemal arch of the second segment, its modifications are 
arrested at different stages of departure from the simple archetypal 
form (34-37, fig. 1), as explained at pp. 66 and 112 of my Work 
"On the Archetype," &c. The most common modification in 
bony fishes is that shown in fig. 2, where it is divided into two 
segments, and the second segment into three pieces (35, 36, 37), 
usually broad and flat, for the office explained at p. 112 of the 
same Work. 

The parietal segment, or third counting backwards, has the 
haemal arch (33-41) detached from its proper supporting parapo- 
physis (s) by the backward development of 28 a of the preceding 
segment. This is the first example of another modification, viz. 
that of dislocation, sometimes accompanied by great change of 
place, which has tended most to obscure the essential nature of 
parts, and their true relations to the archetype. The principle 
of subdivision still manifests itself in the elements of the haemal 
arch, especially in its spine, 41-43 ; and in a greater degree by a 
vegetative repetition of the ^ appendage ' (44), without departure 
from its primitive ray-like form. 

The pleurapophysis of the occipital segment (50, 51) is divided 
into two, and its proximal end is usually bifurcate in fishes, arti- 
culating like the normal ribs of higher animals, by a 'head' and 
a 'tubercle' to two points of the neural arch of its segment. 

Almost every stage of development and departure from the 
primitive type is manifested by the diverging appendage (54-57) up 
to the extent of modification attained by the typical osseous fish. 
The proximal segment is divided into two pieces (54 and 55), the 
next seament into four or more (so), and the last segment into 






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a greater but variable number of pieces^ retaining the elementary 

form of rays. 

The Lepidosiren (fig. 7) is eminently instructive by the reten- 
tion in the occipital vertebra of the primitive condition of the ap- 
pendage, as shown in the archetype (fig. 1, 53-57) modified only 
by segmentation of the ray. The pleurapophysis of the arch (51) 
likewise retains its simple cylindrical form^ and is articulated to 
its centrum, like the other ribs of the Lepidosiren, by an undi- 
vided head. 

The haemal arch of the fifth segment (first of the trunk) is 
commonly detached from its centrum and neural arch in fishes 
without being displaced backwards. The pleurapophysis (pi) is 
short and simple, sometimes expanded ; the hsemapophysis (ss, h) 
is simple, long and slender. When this arch supports an ap- 
pendage it is a simple diverging ray. 

All the succeeding abdominal segments of the fish have their 
haemal arches incomplete by bone ; the heemapophyses and spines 
retaining the primitive fibrous condition. The pleurapophyses of 

most support diverging appendages in the form of simple undi- 
vided bony rays. 

A part of the haemal arch of a post-abdominal (pelvic) segment 
is ossified (es), and supports a more complex appendage (59) in the 

form of one, two or more jointed rays, which project beyond the 
surface and are enveloped by a fold of skin forming the "^ ventral' 
fin, V, making a pair with the one on the opposite side. This 
partially ossified haemapophysis articulates with its fellow by its 
anterior apex, forming a ^symphysis ischii' sen 'pubis'; and, in 
some fishes called * abdominal,' it is connected to its proper pleur- 
apophysis (62) by an aponeurosis representing its unossified con- 
tinuation. 

The remarkable degree to which one and the same part may be 
subject to the modification of change of position, is strikingly 
exemplified in this lower portion of the pelvic arch with its ap- 
pendages in fishes. It may be moved forwards, so that the sym- 
physis of the pelvic arch is brought into connection with that of 
the scapular arch ; when, according to the length of the ossified 
parts of the pelvic haemapophyses, the species is either ^ thoracic,' 
as when the ventral fins are at V, or ^jugular,' when they are 
advanced to V". The universally acknowledged and long recog- 
nised special homology of the haemal arch and appendages of the 



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pelvic vertebra, as the ^ ventral fins' of fishes, under these changes 
of position, prepare us for the recognition of an analogous modifi- 
cation of the htemal arch and appendages of the occipital vertebra 
in the higher classes of Vertebrata. 

Beyond the abdomen the osseous and aponeurotic parts of the 
hsemal arches rapidly contract ; the progressively elongated par- 
apophyses usually bend down and complete the inverted arch by 
their apical coalescence ; sometimes distinct pleurapophyses con- 
tinue to form these arches ; sometimes these elements may be 
traced, anchylosed with their fellows of the opposite side, and with 
the coalesced extremities of the parapophyses. The bodies of a 
certain number of the terminal segments coalesce together in the 
typical osseous fishes, and suj)port several neural and heemal 
arches and spines, usually more or less expanded, and forming the 
basis of the caudal fin, C 

The ossified parts of the dermal median and symmetrical folds, 
constituting the dorsal (Di, Dii), the anal (A), and caudal (C) 
fins, are added to the endoskeleton in fig. 2 ; in are the inter- 
neural spines ; dn the dermoneural spines ; ih the interhsemal 
spines ; dh the dermohsemal spines ; these form no part of the 
true vertebral skeleton, and are peculiar to fishes. 
of the modified cranial segments is not complicated by the outlines 
of the sense-capsules or mucodermal bones. 

Thus, compared with the archetypal figure, the endoskeleton of 
the fish deviates by excess of development, manifested chiefly in 
the diverging appendages of the four anterior or cranial segments, 
and by arrest of development in most of the other segments ; but 
the principle of polaric or vegetative repetition greatly prevails, 
and more of the segments resemble one another than in any of the 
higher classes. 



The diagram 



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Fig. 3. The Crocodile is here taken as the type of the class 
Reptilia. 

The hsemal arch of the anterior segment is now firmly fixed by 
excessive development, chiefly of its heemapophyses (21), which 
have extended their attachments to all the elongated elements 
(13, 14 and 15) of their own neural arch. The diverging appendage 
(24) from the pleurapophysis (20) fixes the arch extensively to the 
centrums of the second and third segments : the appendage from 
the hsemapophysis (21) bifurcates; one branch, divided into two 



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pieces (26 and 27), connects the arch with the plenrapophysis (as) 
of the next segment ; the other branch (25) extends the attach- 
ment to the parapophysis (12) of the same segment, and also to 



own 



The plenrapophysis (23) of the frontal segment is nndivided ; it 
is represented as displaced and depressed ; bnt in natnre it still 
retains a small part of its connection with its proper plenrapo- 
physis (12), although it is developed backwards so as chiefly to 
articulate with that (s) of the following segment : it supports no 
diverging appendage. The heemapophysis (29-31) is more sub- 
divided than in fishes, in relation to functions explained in my 
Work " On the Archetype/' &c., pp. 122, 123. 

The excess of development of the hsemal arch of the frontal 
vertebra is compensated by the defect of development of that of 
the parietal one (40, 4i) ; and this constitutes the next great addi- 
tional step in the deviation from the archetype. Only the hsem- 
apophyses (40) are ossified : the haemal spine, though much ex- 
panded and flattened, remains cartilaginous, and the plenrapo- 
physis is represented by a feeble ligament. The whole arch is 
detached and displaced backwards, and its diverging appendages 
cease to be developed. 

The tendency to retrogradation manifested by the preceding 

haemal arches is carried out to a striking extent in that (51, 52) of 
the occipital segment (the fourth counting backwards) : it overlaps 
the homotypal arches of the 8th to the 11th segments of the 
trunk : the ossified portions of both its constituent elements, 51 and 
52, are simple ; the hsemal spine, 52', is prolonged backwards. The 
diverging appendage manifests, in comparison with that in the fish, 
an additional segment (53), which is single ; the segment of two 
pieces (54 and 55) is now the second. The rays of the distal seg- 
ment are reduced to five in number, which is never afterwards 
exceeded in the vertebrate subkingdom. The dislocation and re- 
trogradation of the posterior hsemal segment of the skull form the 
second chief additional feature of departure from the archetype, 
as compared with the skeleton of fishes. The third well-marked 
modification is the development of an inferior (cortical) portion of 
the body of the atlas (ca, x), distinct from the main part of that 
centrum (ca), which coalesces with that of the axis, and is com- 
monly called its 'adontoid' process. 

The nine segments that succeed the head resemble those of 



i 





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95 

fishes in the non-ossification of the haemapophyses and heemal 
spines, but deviate further from the archetype by the minor deve- 
lopment of the pleurapophyses. These progressively elongate to 
the 1 2th vertebra, where the haemal arch is completed by a hsem- 
apophysis and hsemal spines. 

The haemapophyses are not so completely ossified as the pleur- 
apophyses, and they are divided from these by the interposition of 
cartilaginous pieces, a, a ; these pieces may be regarded either as 
dismemberments of the hsemapophyses, or as unossified parts of 
the pleurapophyses. The diverging appendages {a, a) are usually 
cartilaginous. 

Beyond the 21st segment of the trunk ^ the pleurapophyses 
usually cease to be represented either by bone or cartilage : but 
the partially ossified h^mapophyses are continued to those of the 
pelvic segments, 64 and 63, h. In these segments the pleurapo- 
physes reappear, and are divided into two parts, like those in the 



thorax 



vi) 



distal portions have either coalesced into one broad and thick 
plate (62 pV), or the distal portion of one pleurapophysis is still 
more remarkably developed and takes the place of two : this 
question is discussed at pp. 75 and 1^. The two haemapophyses 
(63, 64) are distinct and well-ossified. The diverging appendage 
(65-69) has been subject to the same kind and amount of develop- 
ment as that of the scapular arch (53-57) . The first steps in the 

* According to Cuvier, the pleurapophyses cease to appear after the 20th 
trunk- vertebra in Crocodilus biporcatus, and after the 19th in Alligator 
lucius. I allude to these differences for the purpose of remarking that the 
conformity of organization is greater than would appear at first sight from the 
formulae of the vertebrae of the different species of crocodile cited in the Table 
at p. 220, tome i. Lemons d'Anatomie Comparee, 1835. The number of ver- 
tebrae from the atlas inclusive to the sacrum is the same in each species, as 
will be seen by the following extract : 



Crocodile a deux aretes 


Cervical, 

7 


Dorsal. 

13 


Lumbar. 
4 


Crocodile du Gauge 


7 


14 


3 



Caiman a mus. de brochet 7 



12 



5 



24 
24 
24 



The difference in the dorsal and lumbar series depends merely on the ossifi- 
cation or otherwise of the pleurapophysial tendons or fibrous bases attached to 
the diapophyses of the 20th, 21st and 22nd vertebrae. 

A slight change in the form and size of the pleurapophysis is all that di- 
stinguishes the first dorsal from the last cervical vertebra in the Cuvierian 
Table. 



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progression of this metamorpliosis from the primitive type is shown 
in the Lepidosiren (fig. 9), and the Froteits (fig. 10). The mo- 
dification of the pelvic segments and their appendages in the rep- 
tile forms another prominent feature of deviation from the arche- 
type. Thepleurapophyses are continued, progressively shortening, 
attached to the diapophyses of a certain numher of the vertebrse 
that succeed the sacrum : the hsemapophyses are no longer at- 
tached to their extremities, but are directly articulated to the cen- 
tral elements, with 9 slight degree of displacement, whereby they 
articulate to another segment as well as to their own. The mode 
and degree of departure from the archetype are how such that 
different series of vertebral segments may be classed into groups, 
with distinctive characters and names : — 

The first four segments, by the fixed union of their neural 
arches, as cranial (Cr), under the collective name of ^ skull/ 

The next nine segments, moveably articulated, and with free or 
' floating' pleurapophys^s, as cervical^ C, forming collectively the 



region called 



neck/ 



The 



succeeding nine segments with ossified and moveable 



pleurapophyses and hsemapophyses, as dorsal, D, forming the 
' back,' ' thorax' or ^ chest/ 



The 



three following moveable vertebrse, without free 



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bony 
pleurapophyses, as lumbar, L, forming the ^ loins/ 

The next two vertebrse, immoveably united, and with modified 
and much-developed hsemal arches and appendages, are called 

sacral, and collectively 'pelvis and hind-limbs/ 

All the other segments are "^ caudaV and constitute the 'tail/ 
The haemal arch (si, 52) with the developed appendages (53-57^) 

detached from the occipital vertebra, may require to be specially 

noticed in this summary of tbe parts of the endoskeleton, as from 
the circumstance of its commonly remote position from its proper 
segment, it may not have been thought of as a part included in 
the first class of vertebrse constituting the skull. 

Many striking and extreme deviations from the archetype are 
manifested in the skeleton of the more aberrant forms of the rep- 
tilia. 

minimum in the BatracJiia {e.g. 7 in Pipa), and increased to the 
maximum in the Ophidia (422 in Python). At first view the 
principle of vegetative repetition seems to have exhausted itself in 
the long succession of incomplete vertebrse which support the 



The number of moveable trunk-segments is reduced to the 



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trunk of the great constrictors : but by the endless combinations 
and adjustments of the inflections of their long spine, the absence 
of locomotive extremities is so compensated that the degraded 
and mutilated serpent can overreach and overcome animals of far 
higher organization than itself : it can outswim the fish, outrun 
the rat, outclimb the monkey, and outwrestle the tiger ; crushing 
the carcase of the great carnivore in the embrace of its'redoubled 
coils, and proving the simple vertebral column to be more effectual 
in the struggle than the most strongly developed fore-limbs with 
all their exqmsite rotatory mechanism for the effective and varied 
apphcation of the heavy and formidably-armed paws. And whilst 
the vertebral column of the ophidian order exhibits the extreme 
of flexibility that of the chelonia manifests the opposite extreme 

of rigidity : back, loins and pelvis constitute one vast sacrum or 
rather abdommal skull, but a skull subordinated chiefly to the 
lodgement and defence of a much-developed haemal system, and in 
which the pleurapophyses, hsemapophyses and their spines' appear 
to repeat the same modification of great expansion and fixed union 
by marginal sutures, which the neurapophyses and spines undergo 
in the cranium of the higher vertebrates. This formation of the 
' carapace ' is actually due, however, to the connation of dermal 
bones with the above-named vertebral elements, but in which it is 
worthy of note that the neurapophyses exhibit the modification of 
change of position, like that which has been described in the sacrum 
of the bird ; being shifted from their own centrum over one half of 
the next centrum, thus adding to the strength and elasticity of 
the whole osseous vault. The plastron is formed by the conna- 
tion of dermal plates with the sternum and abdominal ribs. The 
confluence of the neurapophysis (14) with its own moiety of the 
neural spine (15) is characteristic of the anterior segment of the 
cephalic skull of most Chelonia. I may here add, that the typical 
condition of the haemal (maxillary) arch of the same segment is 
well shown in the Um^js expansa. The pleurapophyses (palatines) 
meet at the base of the cartilaginous vomer, above and behind the 
posterior nares, sweep outwards and downwards, give attachment 
to the hsemapophyses (maxiUaries) which advance and converge, 
and the arch is closed below the nasal passage by the h^mal spine 
/ maxillary). Cut through the junction of the hEemapophyses 



(pre 



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pendages (malars), and the inverted arch is then suspended by its 
proper piers^ the pleurapophyses or palatines. 

In the connation or coalescence of the neurapophyses and spines 
forming the parietal and frontal neural arches in the ophidian and 
some chelonian reptiles, we perceive a return to the common con- 
stitution of those arches in the vertebrae of the trunk, in which 
the permanent separation of the neural spine from the neurapo- 
physes occurs as a rare exception. 

In the class-skeleton (Aves) represented in fig. 4, the archetype 
is further departed from than in the typical Reptilia ; and when 
the general form of this diagram is contrasted with that of the 
first figure, the power of demonstrating the fundamental agreement 
which reigns throughout, and which is equally manifested in the 
comparison of figure 4 with those of the piscine and reptihan ske- 
letons, affords a most striking proof of the unity of plan which 
pervades the whole series. 

As compared with the crocodile (fig. 3), the proportions of the 
hsemapophysis (21) and spine (22) of the anterior segment are re- 
versed ; there is a return towards the condition of the parts in 
fishes (fig. 2) ; the strength of the arch being chiefly due to the 
great development and extensive connections of 22, which usually 

sends a process upwards and backwards between the divided neural 
spine (15) of its own to that (11) of the next segment. The pleur- 
apophysis (20) has often a slender rib-like form, and the append- 
ages retain the form of bony rays. That (24) from the pleurapo- 
physis is simple ; that (26, 27) from the haemapophysis is divided 
in the embryo-bird : both concur in attaching the heemal arch of 
the anterior segment to the pleurapophysis of the second segment. 

The neurapophyses of the anterior segment coalesce and form a 
single vertical bone, slightly expanded above and sometimes ap- 
pearing anterior to the frontal. 

The inferior or cortical part of the centrum, 9, of the second or 
frontal vertebra is connate, as in the fish (fig. 2, 9), with that of 
the third, 5 ; and the superior dismemberment of the second cen- 
trum., answering to 9' in fig. 2, is connate with the'coalesced neur- 
apophyses, 10. 

The haemal arch of the second segment is detached from its 
neural arch ; and, although its proper parapophysis (12) some- 




\ 



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99 



times joins the next one (s), yet this exclusively supports, in birds, 
the pleurapophysis (23) of the frontal segment. The haimapo- 
physis is developed, as in the reptile, from several centres (29, 29', 
30', 31), but these coalesce with each other and with the hEemal 
spine, 32, to form the single bone called lower jaw in most birds. 

The haemal arch (40-46) properly appertaining to s— the par- 
apophysis of the parietal segment—is detached from it, and freely 
suspended, somewhat retrograded in position beneath the next 
segment : its development has suffered as marked an arrest as in 
the crocodile. 

The haemal arch, with its appendages of the hindmost segment 
of the skull, IS displaced backwards to a greater extent than in the 
reptile * . 

The pleurapophysis (51) retains the form of along, flat, slightly- 
arched rib : the haemapophysis (52) is straighter and stronger 
There are birds {Apteryx, e. g., fig. 9, p. 47) in which this arch is 
arrested at almost as early a stage of growth as is the antecedent 
(hyoid) arch of the skull. The elements of the neural arches of the 
skull, 1-15, early anchylose together in most birds, with the excep- 
tion of the centrum (13) of the foremost segment, which more com- 
monly coalesces with the pleurapophyses (20) of its hsemal arch. 

The size of the brain now demands a modification of the neural 
arches superadded to those which they present in the cold-blooded 

vertebrates, and occasions a marked difference in the form of the 
skull : it is important to note how this is obtained. The nature 
of the modification is well shown in the young of those large birds 

which are devoid of the powers of flight. No new bone is intro- 
duced to increase the cranial walls and give the cavity its due 

* The process of retrogradation is associated with the difference of time in 
the order of development of different segments of the endoskeleton. The 
typical vertebraj are usually the first to be completed, e. g. those of the thorax 
and head ; the intervening ones are later developments, and the head is re- 
moved from the chest to an extent corresponding with their number or size 
But the haemal arch of the last cranial vertebra being detached in air-breathing 
Vertebrates from the rest of its segment, follows the heart, which it was pri- 
marily developed to support and protect, and consequently maintains its pri- 
mitive contigmty with the thorax. The original relation of its ha^mapophyses 
—the coracoids— to the pericardium is most instructively maintained in the 
Chelonia. In the higher air-breathing animals the proper thoracic hcemal 
arches take this function, and leave the scapular arch to subserve the offices of 
its greatly and variously developed appendages. 

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100 

capacity ; this is gained by excess of growth of common and con- 
stant elements ; and those (3, r, 11) furthest from the centrums are 
the chief seat of such excess. With regard to the neural spines 
of the frontal and parietal vertehrEe, it is accompanied by a tempo- 
rary bipartition, the ossification commencing from two lateral cen- 
tres in each ; but the halves soon coalesce with each other and with 
their sustaining neurapophyses (2, 6, 10) • 

In those segments which, from the brevity and free termination 
of the pleurapophyses, may be called ' cervical/ the elements of 
the neural arch and also the pleurapophyses early anchylose 
together in each segment, converting it into the single bone, called 
in comparative osteology a 'vertebra/ and these vertebrse are re- 
markable for their great number in most birds ; and consequently 
the neck is as remarkable for its great length and flexibility. The 
detached hsemapophyses (ss) of one of these vertebrse, (which 
vertebra, by the analogy of the fish (fig. 2, ss), should be the 
atlas,) commonly coalesced together at their distal ends forming 
a bony arch, hke a slender edentulous loAver jaw, have followed 
the hsemal arch of the occipital vertebra (51, 55) in its retrograde 
course, though not quite to the same extent. These mutually 
anchylosed hsemapophyses (53) forming the bone, called ' furcu- 
lum ' in ornithotomy, are generally the only pair of ossified cervical 

hsemapophyses. If, however, we define the cervical vertebr£e, as 
in the crocodile, by their mobility and the free termination of their 
pleurapophyses, we may then recognise in some birds the detached 
hsemapophyses of the last cervical vertebra attached, as at h, to 
those of the succeeding segment : this structure may be observed 
in the common goose (Anser palustris) , The pleurapophyses of 
the posterior cervical vertebrse are free, and rapidly elongate. 

The hsemapophyses of the segments with complete haemal arches 
are bony, and are commonly defined as ' sternal ribs,' their pleur- 
apophyses being called 'vertebral ribs,' agreeably with the re- 
stricted anthropotomical meaning of the term 'vertebra.' These 
pleurapophyses support bony appendages (a a), which serve, hke 
those of the foremost haemal arch of the skull, to connect their 



own 



& 



* These appendages are not the result, as has been supposed, of a bifurca- 
tion of the vertebral rib : they are independent pieces originally in all birds 
and retain their individuality in some, e, g, apteryx, penguin, with proper 
muscles for their elevation and depression — potential homotypes of the flexors 
and extensors of more developed limbs. 



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101 

After six or seven segments with these typical hamal arches come 
others with shorter pleurapophyses terminating freely, not reach- 
ing their hsemapophyses, one of which, ossified, is shown in the 
diagram at A', adhering by its distal end to the preceding hsem- 
apophysis and terminating freely above. These ' floating sternal 
ribs ' are more numerous in the crocodile (fig. 3, h'). The heemal 
spines of the dorsal segments with complete heemal arches become 
the seat of the most extensive and characteristic modifications of 
the avian type of skeleton. They are greatly extended in breadth, 
and, like the correspondingly expanded neural spines of the cranial 
vertebrae, are developed from two lateral moieties ; but the in- 
dividual spines, indicated by dotted lines in the diagram (go), are 
not ossified from separate centres, but continuously, so that the 
haemal spines of six or eight vertebree are at first represented by a 
pair of osseous plates. A cartilage is usually extended vertically 
from their median junction, which, when ossified, forms a strong 
crest or ' keel ' (so') . The heemal spine of the scapular arch (52') 
is sometimes ossified from a proper centre ; as is also a piece pro- 
longing the series posteriorly : but all soon coalesce into one bone 
called ' sternum.' The anterior portion, 52', has received the name 
of ' episternum,' the median keel, so', that of ' entosternum,' the 
posterior piece, which sometimes remains cartilaginous, that of 
' xiphisternum.' In the terrestrial birds incapable of flight, the 
keel or ' entosternum ' is not developed : in the rest of the class 
the extent of this part and of the ossified portion of the body of 
the sternum bears a direct ratio to their power of flight ; the pecu- 
har modification of these extreme elements of the dorsal segments 
being governed by the size of the muscles moving the wings. 

^ The next great deviation from the typical standard, peculiar to 
birds, is the great extent of the vertebral axis which is embraced 
by the enormously developed pelvic pleurapophyses, 62, and the 
unusual number of segments which, being thus deprived of reci- 
procal motion, grow together and form, according to this cha- 
racter, the bone or region called ' sacrum.' In investigating the 
structure of this part of the endoskeleton in the embryo-bird, 
the neural arches are found to manifest a change of position ana- 
logous to, though less extensive than, that of certain of the heemal 
arches of more anterior segments (51-52, e. g.) : the results of 
this analysis are detailed at p. 61. Most of the pleurapophyses 
of the sacral vertebree are stunted in their growth, which may 



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literally be said to be stopped by the pressure upon their extremi- 
ties of the overgrown distal portion of one of their homotypes 
forming the bone called ' ilium ' (62, pi) . But one or two of the 
pleurapophyses at the anterior part of the series (jjl) escape from 
beneath the 'ilium' to terminate freely at some distance below it: 
these are usually bifurcate at their proximal ends, and moYeably 
articulated to their anchylosed centrums and diapophyses : the 
shorter anchylosed sacral pleurapophyses have simple proximal 
ends and articulate in the embryo to the interspace between their 
own and the adjoining centrum, as shown in fig. 10, pi, p. 61, to 
which they soon become anchylosed. 

The contemplation of the modifications of the different natural 
segments in the trunk of the bird, particularly the freedom of 
some elements and the fixation of others, strongly impresses on 
the mmd the purely artificial character of the regions of the spine 
which have been transferred from anthropotomy into the anatomy 
of the vertebrate animals. Thus Cuvier declares, " II n'y a point 
de vertebres lombaires proprement dites *." And a later author • 

cc "ni;_ ■\T7' 11 n -,-• .__-__ 



Wirbel 



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scheiden." 



Cuvier' s negation in 1799 of proper lumbar vertebra in birds is 
reproduced in succeeding systems and handbooks of comparative 
anatomy down to the latest by Siebold and Stannius, e. g. of 1846. 
But the student of anatomy in its wider acceptation will under- 
stand that the segments homologous with those included under 

L in fig. 3 are by no means wanting in fig. 4, but only otherwise 
modified. 

It may be regarded as highly probable at least, from the striking 
pomts of agreement which are observable in the organization ol" 
the crocodile and of the bird, that, counting backwards from the 
first 'dorsal' in figs. 3 and 4, the next twenty segments are ho- 
mologous m both. But, in the bird, those that answer to the 
three or four last dorsal vertebrae in the crocodile are anchylosed 
together, and the last of these had its pleurapophyses modified to 
form abutments against the elongated ilia. The next three seg- 
ments, answering to the lumbar in the crocodile, are modified as 
m the last ' dorsal.' The two following segments similarly modi- 

* Cuvier, Lefons d'Anatomie Comparee, i. (Ed. 1799, p. 170; Ed. 1836, 






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103 






fied will answer then to the two sacral vertebrse of the crocodile, 
and anchylosis extends backwards so as to include two or three 
vertebrse homologous with the anterior caudals in the crocodile. 
This appears to be the true interpretation of the enormous ' sa- 
crum' of the bird ; it is not merely ^ himbo-sacral' but ' dorso- 
lumbo-sacro-caudal/ including as it does representatives of each 

■t 

of those classes of vertebrse in the crocodile^ but which have lost 
the artificial characters that distinguished them in that nearest 
allied existing vertebrate. The special homologies are indicated 
bv the letters D. L and S. 

The characters of the regions of the vertebrate skeleton are, as 
already remarked in reference to the crocodile, artificial, and are 
used for the sake of convenience in describing and comparing the 
vertebrse of different species. Those, therefore, are the best which 

I 

are the most constant and most readily applicable in any given 
class. Proceeding to assign such to the bird, as in the crocodile, un- 
biased by anthropotomical characters of the vertebral regions, all 
those may be called ^ cervical' in the bird that extend from the skull 
to the first vertebra with the hsemal arch complete, and those dorsal 
that extend from that vertebra inclusive, to the first vertebra em- 

r 

braced by, and anchylosed to, the iliac bones. One usually finds 
in the falcons, the gallinaceous birds and in some waders, five or six 
of the centrums and neural arches of the dorsal vertebrse anchy- 
losed into one mass, a single free centi^um usually intervening be- 
tween this mass and the true sacrum. Some comparative anato- 
mists call that cervical vertebra the ^ first dorsal' in which the 
pleur apophyses retain, or begin to regain, their moveable articu- 
lations : but this character varies in different individuals of the 
same species. I have even found the pleurapophysis of the last 
cervical vertebra anchylosed on one side and not on the other. 

The retention by the pleurapophyses of moveable articulations 
with the centrum, might also seem a good character of dorsal ver- 
tebrse at the hinder end of the series ; but it is inconstant : I have 
found those elements anchylosed in one individual and free in 

another of the same species, in the anterior vertebrse, which are 
sacral by coalescence. All those vertebrse may be called for con- 
venience ^ sacral' in the bird, which are confluent by both centrums 
and neural arches with each other and with the iliac bones; and this 
confluence is so complete that it usually requires a vertical section 
d reference to the nerve-outlets in order to determine their 



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104 



number. The free vertebrae tliat succeed these are the caudal, of 
which the last, as in most osseous fishes, is a coalesced congeries 
of several, though for convenience counted as one, and called in 
ornithotomy the plough-share bone (c, n, h). Although so many 
segments of the bird's skeleton are modified to transfer the weio-ht 
of the horizontal trunk upon the ilia (m), the ' pelvis ' as in the 
crocodile has but two haemapophyses, 63, oi, below : il is charac- 
teristic of birds, however, that these are not united at their distal 
ends to their fellows of the opposite side, either with or without 
the intervention of a haemal spine. The exception which the 
ostrich offers in regard to the anterior pair (pnbic bone, e,) and 
that which the rhea presents in respect to the posterior pair 
(ischia, 63), serve to prove the rule of "the inferiorly open pelvis 
m birds. 

In regard to the diverging appendages of the two haemal arches 
(scapular and pelvic) which have been selected for development 
into locomotive organs in all classes of vertebrata, the corresponding 
segments (carpal, so, and tarsal, es) agree in the paucity of their 



divisions, two bones in each, in all bird 



s 



and the succeeding seg- 



ments (metacarpal and metatarsal) in consisting of three coalesced 
bones in both wing and leg, supporting digits answering to those 
marked ii, m and iv, ii, in, iv, in the crocodile. Such at least 
is their general character, the minor differences being the follow- 
ing :— In the hand-segment of the wing the anchylosed metacarpal 
of digit II is very short, represented as it seems only by its proxi- 
mal end ; those of the digits numbered iii and iv attain their 
normal length, and are anchylosed together at the extremities only, 
with an interspace between their shafts. 

The wing of the bird is chiefly formed by the quill-feathers 

developments of the hard, insensible epidermal system : and this 
expanse forms a striking contrast with the dehcately organized and 
highly sensitive web which is stretched over the long and slender 

Its period of activity in the hours of 
gloom necessitated the accessory sense of fine touch in aid of vision 
to safely guide its flight. 

In the metatarsus of the bird the three bones coalesce through- 
out their length, except in the penguin, where interspaces tre 
left between their shafts or middle parts. But they also coalesce 
proximally with the two primitively distinct tarsal bones (es), whilst 
the metacarpals coalesce proximally with only part of the carpal 



finger-bones of the bat. 






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105 

series, if at all. And to the metatarsus there is usually superadded 
a rudimental, but unanchjdosed, metatarsal bone of the digit an- 
swering to no. 1 in the crocodile ; but directed backwards, except 
in the swift. The numbers of the phalanges of the toes, i, it and 
in in birds, correspond with those of their homologues in the 
crocodile : the toe iv has an additional phalanx, and the regular 
progression of the increase from two to five phalanges, with one or 
two exceptions, is constant in the class, and serves to determine the 
toes in those birds in which they are reduced to three or two in num- 
ber. Thus in the ostrich (fig. 11), the shorter of the two toes is de- 
termined by its greater number of phalanges, 5, to be the homologue 
of the fourth in tetradactyle birds ; and it is interesting to observe 
that the toe in, notwithstanding its much greater length, has the 
usual smaller number of phalanges. But whilst unity of design is 
thus manifested, the wisdom of the Designer is displayed by the 
greater strength which results from the minor degree of subdivision 
of the part which takes the largest share in the support and pro- 
pulsion of the body. The toe v is never present in birds ; there 
is not even the rudiment of its metatarsal bone. The toe i is 
equally absent. (See paragraph at p. 36, on the spurs of the 
Gallinacea.) 



Fig. 4 is the diagram of the skeleton of a typical mammahan 

quadruped ; e. g. the dog (genus Canii) . The modifications of 
the haemal arch of the anterior segment resume the characters of 
those in the crocodile; the heemapophysis (21) being the chief 
seat of development, and for the same purpose of extending its 
attachments, and adding to the firmness and strength of the hence- 
forth immoveable maxillary arch. The diverging appendage from 
the pleurapophysis (20) is a single bone on each side (24), and in 
most mammals becomes confluent with the part of the posterior 
segment (5) against which it abuts. 

The neurapophyses (14) of the anterior segment have coalesced 
together, as in birds, but are complicated and their nature further 
obscured by anchylosis with ossified portions of the olfactory cap- 
sules, often extremely complex and extensive in the class Mam- 
maha, in which the organ of smell attains its maximum of de- 
velopment. The neural spine (15), sometimes single, more fre- 
quently bifid, enjoys, agreeably with its extreme position in the 
series, a vast range of variety in its forms and proportions. In 
the rhinoceros it supports a dermal spine or ' horn.' 



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106 

The second (frontal) segment presents unexpectedly a return to 
the archetypal character in a particular, in the absence of which 
all the lower classes of vertehrata depart from it, viz. the primitive 
independence of its centrum (o) from that (5) of the succeedins; 
segment. The spine (u) of this, as well as those (7, 3) of the two 
following segments, continue, as in birds, to be the chief seat of 
the expansion requisite for the protection of the progressively de- 
veloping brain. But in most mammals an additional element in 
the cranial walls is gained by the expansion of the distal end of 
the diverging appendage from the heemopophysis (21) of the an- 
terior segment. This appendage consists, as in birds and reptiles, 
of two pieces, and it is the second or most remote piece (27) which 
is the seat of the principal varieties, and especially of that squa- 
mous development which enables it not only to extend the points 
of fixation of the maxillary arch, but at the same time to subserve 
the requirements of cranial space consequent on the large size of 
the cerebrum. The dismemberment called ' interparietale,' x, of 
the spine 3, has a less constant relation to the increased capacity 
of the cranium - 

The pleur apophysis (2s) of the second segment becomes, in the 
present class, still further displaced from its typical connections, 
and is even superseded in its typical functions by the intervention 
and development of 27. It is consequently much reduced in size 
and strangely distorted in form, in subserviency to the almost sole 
office that now remains to it, viz. the support of the tympanic 
membrane. 

The frontal hsemapophyses and spine (29-32) have coalesced into 
a single bony arch, articulated by its extremities to the under part 
of the appendage 27. 

The pleurapophysis (33) of the hyoid or third h^mal arch re- 
sumes in many mammals its typical connections with the parapo- 
physis (s) of its proper segment ; but its development is usually 
more or less restricted. 

The articulation of the fourth (occipital) segment with the 
succeeding one called ' atlas,' is chiefly by means of zygapophyses 
(condyles) developed from the neurapophyses (2) ; the parapo- 
physes (4) are likewise exogenous processes of the same ele- 
ments. 

The haemal arch of the occiput (51, 52), though in close proxi- 
mity with its praper neural arch in some mammals, and in all 
mammals at the earlier period of development, is not directly 






M , J ,i 












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107 

articulated thereto, and sometimes recedes far from the rest of 
the stulL 

The hsemapophysis (52) of the arch is ossified throughout its 
entire extent and articulated with the hsemal spine 52', below, 
in only one small exceptional order of the class (Monotremata). 
It becomes anchylosed with the pleurapophysis in all, and ap- 
pears in the majority therefore as a mere process of si. 

The single pair of cervical hsemapophyses (ss) are more vari- 
able, both as to their extent of ossification and even existence. 

The body of the atlas continues subject to the same modifica- 
tion of development from two centres with coalescence of one por- 
tion with the next centrum, which characterises it in all the other 
vertebrates above Batrachians"^. 

The confluence of the centrum with the neural arch takes place 
in every vertebra of the tnmk ; and the pleurapophyses, which 
are very short in the seven segments that succeed the skull, here 
also commonly coalesce with the other elemxcnts, circumscribing 
the lateral foramina for the 'vertebral' arteries. With the ex- 
ception of the detached bones ss, they are the only ossified parts 
of the hsemal arches of those segments* 

The constancy of the number, seven, of the segments so modi- 
fied, is truly remarkable and characteristic of the class Mammalia. 
It is true that the number is established at a very early stage of 
development, when the neck is alike short in all ; and its law must 
be sought for in the circumstances, such as the existence of a 
complete diaphragm in the mammalia, which determined the 
number and distribution of the pairs of cervical nerves, upon 
which the development of the cervical vertebree more immediately 
depends. The exceptions to the number seven, viz. sio) in the 

manatee, and eiffht or nine in the three-toed sloths, serve to esta- 
blish the rule. 

The eighth segment of the trunk in mammalia, like the tenth 
in the crocodile, has a complete haemal arch, and here therefore 
the ' dorsal ' series begins ; but the hsemapophysial elements are 
rarely ossified in the present warm-blooded class. 

The pleurapophyses (pi ) of these arches are not only move- 
able, but are subject to a slight displacement, and their articula- 
tions, like those of the neurapophyses in the bird's sacrum, extend 
over the interspace of their own and a contiguous centrum. 

* See Taylor's Annals and Magazine of Natural History, vol. xx. p. 217. 



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108 

The haemal spines (eo, ei, ^5) commonly remain distinct, and 
form a chain of ossicles corresponding in number with the com- 
plete hsemal arches, hut they coalesce with each other in some of 
the higher mammalia, and are called collectively ' sternum.' 

As the segments recede the pleurapophyses become shorter, 
return to their proper vertebra, and usually become appended to 
its diapophyses ; the hsemapophyses also become shorter, and ter- 
minate^ at first by abutting against their antecedents, and finally 
by projecting freely. 

These segments are followed by others (L) in which only the 
pleurapophysial parts (pi) of the haemal arch are ossified, and 
these parts coalesce with the diapophyses (d) . 

Then come the segments (S), which, hke those of the skull, are 
the seat of the modification by anchylosis, and of great and pecu- 
liar development of two of the haemal arches in connection with 
them; the nature of the deviations from the typical standard 
which characterise the province of the endoskeleton called 'sacrum' 
and 'pelvis,' has been explained at pp. 61 & 73. In most mam- 
mals a greater number of segments is involved in this metamor- 
phosis than in reptiles ; in none are so many the seat of it as in 
birds . In the cetacea the modification by anchylosis is transferred 
to segments at the fore-part of the trunk ; their ' sacrum ' may be 
said to be in the neck ; none of the post-abdominal vertebrae are 
subject to confluence any more than in serpents, fishes, or the ex- 
tinct marine reptiles {EnaMosauria) . 

Great diversity of form, of number and of development pre- 
vails in the vertebrae that succeed the sacrum in mammaha. Short 
pleurapophyses are developed at the extremities of the diapo- 
physes of the anterior ones and coalesce with them. The hsem- 
apophyses, when present or ossified, are articulated, as in reptiles, 
to the centrum directly, and alone form the haemal arch. The 
terminal vertebrae are reduced to the central element, and rarelv 
anchylose together. 

The ^interior anchylosed and expanded vertebrae are the cra- 
nial, Cr. 

Those usually free vertebrae with short pleurapophyses, anchy- 
losed to both their centrum and neural arch, are called ' cervical,' 
C. In some whales and armadilloes all or some of these vertebrae 
coalesce into one mass. 

The series with moveable and usually longer pleurapophyses is 
called 'dorsal,' D. 







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109 

Those with pleurapophyses confluent or connate with the ex- 
tremities of the diapophyses are called Mumbar/ L. 

The succeeding vertebrae which anchylose together are called 
'sacral/ S, 

The rest are ' caudal/ Cd. 

The modifications of the diverging appendages of the scapular 
and pelvic arches are numerous in kind and extreme in degree : 
with the exception of the cetacea, in which the hinder pair is ab- 
sent — the cheiroptera, in which the fore-pair is specially developed 
for the actions of flight — and some burrowers, as the mole — a close 
analogy is commonly kept up between the two pairs : both, for 
example, are reduced to the same degree of simplicity in the solid- 
ungulous horse ; both arrive at almost the highest stage of de- 
velopment, in the special adaptation of one of the digits to react 
upon the rest as an opposable thumb in both the fore- and hind- 
feet of the Quadrumana. 

Fig. 15, bones of the fore-limb, and fig. 16, bones of the hind- 



Wombat 

^ - ^ 

bones, explained at pp. 23 & 24. 



homology of those 



53, 'humerus,' is the homotype of 65, 'femur.' 

54, ^ulna,' is the homotype of er, 'fibula.' 

0, 'its olecranon,' is the homotype of 67', 'fabella,' or the sesa- 
moid bone articulated to the produced and expanded head of 
the fibula. 

55, * radius,' is the homotype of 66, ' tibia ' ^. 

sCy scaphoid portion of ' os scapholunare,' is the homotype of 
sCy 'scaphoides.' 

/, lunar portion of 'os scapholunare,' do. of a, ' astragalus.' 

cUj cuneiform portion of 'os scapholunare,' do. of cl, articular 

part of ' calcaneum.' 
p^ 'pisiforme,' is the homotype of cl', fulcral part of 'calca- 



neum, 



t, 'trapezium' 
^, ' trapezoides ' 
m, 'magnum' 
M, ' unciforme ' 



do. 
do. 
do. 
do. 



of ci, inner cuneiform. 

of cm, middle cuneiform. 

of ce, outer cuneiform. 

of 5, cuboides ; both of these 



representing two distinct carpals coalesced, as the scapholunar 

* The tendon of the triceps femoris is not ossified in this species, whez'e it 
passes over the knee-joint at 66' ; it resembles in this respect its homotype, 
the tendon of the biceps brachii, in the fore-Hmb. 



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110 



in the carpus represents the astragalus and scaphoid in the 
tarsus, and the calcaneum reciprocally the cuneiform and 
pisiform bones. 
The serial homologies of the carpals and tarsals are better illus- 
trated in the hand (fig. 13) and foot (fig. 14) of the orang, as has 
been before explained. 

Having thus noticed some of the chief varieties of the mamma- 
han modification of the vertebrate archetype, there remains to add 
only a few words in explanation of fig. 6,— the diagram of the 
human skeleton. 



As this is that which the anatomist has been accustomed to 
hear described most frequently and exclusively by the special 
terms, and according to the special views and ends of anthropo- 
tomy, the language in which its deviations from the common 
archetype have now to be noticed will probably appear strange and 
bizarre. The comprehension of the explanation will be facilitated 
by reference to the special name of the bone through its num.eral 
in the column of names whenever such bone is alluded to under 
its general or archetypal name. 

In the first and, notwithstanding the upright posture, the most 
anterior of the cranial segments, by reason of their forward curva- 
ture, the hsemapophysis (21) coalesces early with its own moiety 
of the divided spine (22), and the same thing happens to the next 
haemal arch (29) with subsequent obliteration of the symphysis 
between the halves of its spine (32) . 

The pleurapophysis (20) of the first arch remains a distinct bone : 
its diverging appendage (24) coalesces with and becomes a '^pro- 
cess ' of the centrum (5) of the parietal vertebra. 

he neurapophyses (14) of the anterior segment are modified as 
in other mammalia, i. e, become confluent together and with the 
olfactory capsules ; but appear externally below the orbital pro- 
cess of the frontal. 

The spine (15) is small, but bifid. 

That of the second segment (n) attains its maximum of de- 
velopment, as do also the spines of the two following vertebrte 
(7 and 3). The bifid spine of the parietal segment is truly enor- 
mous as compared with that of the fish (fig. 2, 7) or the reptile 
(fig. 3, 7), in which latter animal the spine, being undivided, ad- 
heres closer to the archetype. 



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11 



111 

The diverging appendage (26, 27) from the haemapophysis (21) 
is divided into two pieces^ as in most mammals and reptiles ; both 
are broad and flat : the first (26) serves to fix the arch to the 
parapophysis (12) of the second segment, from which it is here 
dislocated ; the portion (27), which becomes enormously expanded, 
covers a large vacuity between the third and fourth neural arches, 
and overlaps by a squamous suture part of the expanded spines of 
both those vertebrae • It also anchyloses below with the pleur- 
apophysis (23) of the second segment, with the parapophysis (s) 
and the pleurapophysis (as) of the third segment, as well as with 
the bony capsule of the organ of hearing (le), forming with those 
parts the most singularly complex ' cranial bone '—the ' os tern- 
poris' of anthropotomy. 

The centnnns (5, 9) andneurapophyses (e, 10) of the second and 
third segments coalesce with each other, and with the first pair of 
diverging appendages (24) of the anterior heemal arch (20, 21, 22), 
forming the complex 'sphenoid' bone of anthropotomy. 

The centrum (i), neurapophyses (2), and neural spine (3) of the 
fourth segment speedily anchylose together, and their centrum 
afterwards coalesces with that (5) of the parietal vertebra, forming 
the still more complex cranial bone called 'os spheno-occipitale ' 
by Soemmering, 

The hsemapophyses of the third much-reduced haemal arch (40) 
are ossified only at the extremity which joins the spine (41) : the 
remainder of the haemapophysis is continued in a ligamentous 
state to their anchylosed pleurapophyses (ss), forming the 'styloid 

processes of the temporal bone/ 

The detached and displaced pleurapophyses (51) of the occipital 
vertebra attain considerable breadth : their haemapophyses (52) are 
ossified only at the extremity which joins the pleurapophysis, and 

with which it coalesces. The diverging appendage (53-57) here 

attains its maximum of adaptive development ; as in the skate-fish 
(Baia) it exhibits the extreme of vegetative or polaric growth. 
But the progressive steps by which it departs from the primitive 
or archetypal simplicity, shown in figures 7 and 8, are so gradual, 
that the special homology of the arm and hand of man with the 
bifid-jointed appendage of the scapular arch in the amphiuma, and 
with the simple jointed ray of that of the scapular arch of the 
lepidosiren, has never been doubted or called in question. In 
ascending, therefore, to the higher generalization of the significa- 



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tion, or relation to the archetype, of such simple, or bifid, jointed 
or more complicated appendage of such scapular arch, we are 
compelled by the truth, as it exists in nature, to admit that the 
scapular arch in the lepidosiren and other fishes forms the inferior 
costal or hsemal arch of the occipital segment or vertebra • and 
by reference to the archetype, to see in the diverging appendage 
of such arch, a repetition of similarly simple diverging appendages 
of succeeding segments. These, indeed, retain their primitive 
simplicity, as shown in the trunk-vertebrse of the fish (fig. 2, a a) 
and of the bird (fig, 4, ad); and that simplicity is very gradually 
departed from in the case of the appendages of the occipital ver- 
tebra, by the stages recognisable in figs. 7 and 8. If, then, it be 
admitted that the upper limb (arm and hand) of man is the homo- 
logue of the fore-limb of the amphiume, of the pectoral fin of the 
fish and of the pectoral ray of the lepidosiren ; it follows, that, like 
the latter, it must also be the ' diverging appendage ' of the arch 
called ' scapular,' which is the h^mal arch of the occipital verte- 
bra ; and, therefore, however strange or paradoxical the proposition 
may sound, that the scapular arch and its appendages, down to 

the last phalanx of the little finger, are truly and essentially bones 
of the skulh 

The centrum of the first segment of the neck is subject to the 
same modification as in the ordinary mammalia, the major part 
(c a) remaining anchylosed to the centrum of the succeeding seo-- 
ment (c d), of which it forms the ' odontoid process ' in human 
anatomy. The inferior cortical part (c, a, x), or ' hypapophysis,' 
is that which is usually called the 'body' of the atlas : it is con- 
nected by aponeurosis to the corresponding part of the centrum 
of the occipital vertebra : the articulation of the head with the 
neck is chiefly by means of zygapophyses developed in the form 
of convex condyles from the neurapophyses (2), and received by 
the concave zygapophyses of the neural arch of the atlas. In the 
other cervical segments, the autogenous elements of which they 
are composed are represented diagrammatically in fig. 6 as distinct, 
viz. the centrum, neurapophysis, neural spine, and pleurapophysis ; 
the latter element in the seventh vertebra sometimes attains a 
length nearly equal to that of the first dorsal. The h^mapo- 
physes of the atlas (ss : see also fig. 2, ss) are wholly ossified and 
well-developed. 

In the seven vertebrae which succeed the cervicals the pleur- 



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113 



apophyses (pi) are progressively elongated ; they are shifted frona 
their proper centrum to the interspace between it and the next seg- 
ment above, or in advance, and retain their moveable joints. The 
hsemapophyses (h) are cartilaginous and articulate with the ends 
of the pleurapophyses and with the haemal spines (hs), which are 
flattened, shghtly expanded, and ultimately blended into one bone 



called ^sternum.' 



gment 



remains longest distinct : it receives, also, the extremities of the 
displaced hsemapophyses (53), and has been called 'manubrium 
sterni/ The haemal spine of the seventh segment commonly con- 
tinues longer distinct, and is later in becoming ossified, whence it 
is called ' ensiform cartilage ' : it probably includes the rudiments 
of some succeeding hsemal spines. In the four succeeding seg- 
ments the pleurapophyses become progressively shorter, and the 
hsemapophyses, still cartilaginous, are severally attached by their 
lower attenuated ends to the pair in advance ; leaving the heemal 
arch incomplete below. In the next vertebra (19th from the 
skull) the still shorter pleurapophyses resume the exclusive arti- 
culation with their proper centrum ; and the correspondingly short 
and pointed hsemapophyses are appended to their extremities and 
terminate freely. 

Those pleurapophyses and hsemapophyses which directly arti- 
culate with hsemal spines (sternum) are called collectively ' true 
ribs' (costse verse), the proximal element being 'the bony part 
of the rib ' (pars ossea costse), the distal one * the cartilage of 
the rib.' The rest of the hsemal arches which are incomplete 
through the absence of the hsemal spine, are called ' false ribs ' 
(costse spurise) ; and the last, which terminates freely in the origin 
of the diaphragm, is a 'floating rib/ The centrum, neurapo- 
physes, and neural spine of each segment with freely articulated 
pleurapophyses coalesce into one bone, called 'dorsal vertebra' in 
anthropotomy : these vertebrae are twelve in number. Each of 
the five succeeding segments is represented by the same elements 
(centrum and neural arch) coalesced that constitute the so-called 
dorsal vertebrse : they are called ' lumbar vertebrse ' : they have no 
distinct ossified pleurapophyses, but rudiments of such are connate 
with and lengthen out the diapophyses. The hsemal arches in the 
abdominal region retain their aponeurotic texture : the anchylosed 
and stunted pleurapophyses are continued by the tendinous origins 
of the ' transversus abdominis ' j the hsemapophyses are the ' in- 

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114 

scriptiones tendinese recti abdominis ;' and the basis of the hsemal 
spines is tlie ^linea alba/ . Certain elements of the five succeeding 
segments coalescing together in the progress of growth form the 
bone called ^sacrum/ and are described individually as sacral 
vertebree. The first four of these each combine the same elements, 
coalesced, as in the neck; viz. centrum, neurapophyses, neural 
spine, and short but thick pleurapophyses'*'. One typical segment, 
the second, is completed by the meeting of the broad sides of the 
inverted arch (62, 63, 64) at the ' ischio-pubic symphysis ' forming 
the ^pelvis' of anthropotomy. 

The first sacral vertebra has its hsemapophysis (64, pubis) 
ossified, but separated from its proper pleurapophysis by the ex- 
panded (iliac) portion of that of the succeeding vertebra, with 
which it coalesces, as well as with the hsemapophysis (ischium) of 
the same vertebra. 

The second sacral vertebra has its pleurapophysis divided, and 
the lower portion expanded to form the so-called ^ ilium ^ (62). 
The liHEmapophysis (03) coalesces with that of the preceding ver- 
tebra (gi), and with its own pleurapophysis (02, fig. 6). 

The short and thick pleurapophyses of the third sacral vertebra 
also articulate in the adult with the expanded distal portions of 
those of the second sacral vertebra : but these (iliac bones) are re- 
stricted in infancy and early childhood to their connections with 
the first and second sacral vertebrae, which connections are perma- 
nent in most reptiles (fig. 3). 

The fourth sacral vertebra consists of centrum, neurapophyses^ 
and rudimental pleurapophyses ; the fifth sacral vertebra of cen- 
trum and rudimental neurapophyses, which rarely meet above the 
neural canal. 

In each sacral vertebra the elements of the neural arch and 

rudimental ribs first coalesce together ; and afterwards the ver- 
tebrse unite with each other and form the anthropotomical bone 
called ^ sacrum.' 

The first coccygeal vertebra in man consists of a centrum and 
of stunted exogenous neurapophyses f wide apart above, but deve- 

* J. Muller notices the rudimental ribs in the first and second sacral ver- 
tebrae of the hiiman foetus in his 'Anatomic der Myxinoiden/ heft i. 1834, 
p. 240. Mr. Carlile has described (Heport of British Association, 1837, p. 112), 
and Dr. Knox has figured (Lancet, 1839, p. 191), these ribs and their homo- 
types in the third and fourth sacral vertebras. 

t ** Shoulders of the os coccygis.''— Monro, I. c. p. 142, 



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115 

loping zygapophyses, which join those of the last sacral vertebra, 
and diapophyses which extend outwards further than those of the 
same vertebra. The neurapophyses are represented by exogenous 
tubercles of bone in the second coccygeal vertebra ; and the third 
and fourth vertebrae are reduced to the centrums only. 

The cartilaginous deposits in the primitive blastema of this ex- 
tremity of the trunk indicate a greater number of caudal vertebrse, 
and the rudimental tail is proportionally longer in the embryo 
than in the adult. It is shortened, however, by absorption prior 
to the commencement of ossification, and but fonr segments are 
indicated by depositions of the earthy salts in the situations proper 
to the above-specified elements of a typical vertebra : these finally 
coalesce into a single bone " of a crooked pyramidal figure/' which 
got its name of ' os coccygis ' from its supposed resemblance to a 
cuckoo's beak*. 

The early recognition of these and other specialities arising out 
of the various ad^^ptive modifications of the typical segments of the 
human skeleton found its expression, necessarily, in special terms, 
the convenience of which will ensure their permanence ; but the 
progress of anatomical science having unfolded the primary form 
which is the basis of those modifications, there arises the same 
necessity for giving utterance to ideas of the generic character of 
the parts by general terms. 

Inasmuch, however, as the different segments of the human 
skeleton deviate in various degrees from the common archetype, 
and as the different elements of such segments differ in their 
modifiabihty, anthropotomy has at no period wanted also its 
' general terms ' expressive of the recognised extent of such con- 
formity : such terms also, indicating, obscurely indeed, so much 
perception of the pre-existing model as could be obtained from the 
study of one form, at a period when that form — the human frame 

was viewed as something not only above, but distinct from, if 
not antithetical to the structures of the brute creation, and when 
it was Httle suspected that all the parts and organs of man had 
been sketched out, in anticipation, so to speak, in the inferior 
animals. Thus the word ' vertebra ' shows, by the number of the 
segments or parts of segments to which it is appHed in anthro- 
potomy, a recognition of the degree in which the principle of re- 
petition of similar parts more obviously prevails in the construc- 



* Monro, L c. p. 141. 



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116 

tion of the liuman endoskeleton. And, Inasmuch as in some 
regions (the cervical, e, ff.) the ' vertebra ' includes all the elements 
of the typical segment, there developed, it has been retained in 
homological anatomy, but, with a more consistent and definite 
meaning, as the technical term of the primary segment of the 
endoskeleton in all vertebrate animals. 

The ^truevertebree' of anthropotomy are those segments which 
retain the power of moving upon each other ; and the term is 
applied in a peculiar and empirical sense very different from the 
meaning which the anatomist attaches to a true or typical vertebra. 
The ' false vertebrse ' of anthropotomy are those segments or parts 
of segments forming the lower or hinder extreme of the endo- 
skeleton, and which do not admit of reciprocal motion at their 
joints. And Monro, admitting that the condition of even the human 
OS coccygis sometimes militates against the definition, meets the 
objection by arguing for the speciality of that bone, and with as 
good or better reason than those who have subsequently contended 
against admitting the cranial segments into the category of ver- 
tebrae. " From the description of this bone '' (os coccygis), ^^ we 
see how little it resembles vertebrce ; since it seldom has processes, 
never has any cavity for the spinal marrow, nor holes for the 
passage of nerves'^." 

Embryology has since demonstrated that the parts of the os 
coccygis are originally in vertebral relation with the neural axis ; 
and that this is subsequently shortened by a concentrative move- 
ment, which in like manner withdraws it from the terminal seg- 
ment at the opposite extreme of the endoskeleton. The homology 
of the divisions of the sacrum with the true vertebrae is admitted 
by Monro, because of the perforations for the nerves : and this 

character is still retained in the nasal vertebra in the form of the 
cribriform foramina, although its neurapophyses, like those of the 
sacrum, have lost their primitive relation to the neural axis. 

Homological anatomy, therefore, teaches, that the term ^ ver- 
tebra ' should not only be applied to the segments of the human 
skeleton in the technical and definite sense illustrated by figs. 7 
and 8, pp. 42 & 43, but be extended to those modified and recipro- 
cally immoveable segments which terminate the endoskeleton supe- 
riorly, in Man, and are called collectively ^ skull/ (figs. 1 to 6, Cr.) 

The term ' head,' then, indicates a region of specially modified 

* Monro, /. c. p. 143. 






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117 

vertebrae, like the terms ^neck;' ' chest/ ' loins/ &c. ; and amongst 
the groups of the primary segments characterized by specific modi- 
fications, the ' cranial ' vertebrse must be added to the ' cervical/ 
* thoracic or dorsal/ Humbar/ ^sacral/ and ^ coccygeal or caudal.' 

Such, with reference to the ' general ' term ' vertebra/ seems to 
be the advance of which anthropotomical science is susceptible/ in 
order to keep pace and be in harmony with anatomy. 

As to the elements of the typical vertebra, anthropotomy has 
also its general phrases (see Table II. column vi. 'Soemmering/ 



"Work 



some 



of which are equivalent to the clearly-defined technical 
terms of such elements in anatomy properly so called. 

The serial homology of the centrum (corpus vertehrce) has 
been recognised in all the so-called ' true vertebrEc,' and in some of 
the ' false vertebrae' : thus Monro says, "The fore-part of the os 
sacrum, analogous to the bodies of the true vertebrae, is smooth 
and flat^''." But their smooth and flat homotypes in the skull 
have only the special names of 'basilar' and 'cuneiform' pro- 
cesses ; of 'processus azygos' and 'vomer.' The 'neurapo- 
physes ' are recognised as repetitions of the same part under the 
definitions of ' a bony bridge produced backwards from each side 
of the body of the vertebra,' of ' arcus posterior vertebrce,' of 
Vertebral laminae' or 'pedicles.' Monro describes these rudi- 
mental elements in the last sacral vertebra, where they are 'exo- 
genous,' as "^ knobs,' and in the first coccygeal vertebra as its 
'shoulders.' In the skull they receive the special definitions of 
" the pieces of the occipital bone situated on each side of the 
great foramen ; from which nearly the whole condyles are pro- 
ducedf" {partes laterales seu condyloideccy Soem.) ; 'great' or 
'temporal wings of the sphenoidal bone' J ; ' orbitar wings ' or 
' processes of the sphenoidal bone;' 'nasal' or 'vertical plate' 

and ' crista galli' of the ethmoid {^pars media ossis cethmoidei,' 
Soem.). 

The neural spines are called generally ' spinal processes' in 
every segment of the trunk' : in the head they are known only by 
the special names of ' occipital plate,' ' parietal bones,' ' frontal 
bone,' 'nasal bones.' 

The pleurapophyses, when free, long, and slender, are called 
'ribs/ ' vertebral ribs,' or ' bony parts of the ribs ' ; when short 



* Monro, Lc, p. 138. 



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and anchylosed, they are called, in the neck, 'Hhe second trans- 
verse processes that come out from the sides of the hody of each 
vertebra*;" (radix prior processus transversi vertehrce^ Soem. ;) 
in the sacrum, ' transverse processes ' and ' ilium ' ; in the skull, 
^scapula,' 'styloid process of the temporal bone,' 'external 
auditory or tympanic process of the same bone ;' ' palatine bone.' 

In like manner the serial homology of the hsemapophyses is 
recognised in the thoracic region by the general term ^ cartilages 

3S of the sternum ' "f there applied to the 
same elements of twelve successive segments. "When ossified in 
other vertebrae they have received the special names of ' ischium,' 
'pubis,' ' coracoid process of the scapula,' 'clavicle/ 'appendix 
or lesser cornua of the hyoid bone,' (' crura superiora^ ' os lin- 
guale siiperiusy Soem.), 'lower jaw' or mandibular 'upper jaw' 
or maxilla. 

The exigences of descriptive anthropotomy and its highly im- 
portant applications to Medicine and Surgery necessitate such 
special nomenclature, and the reform which that nomenclature 
chiefly requires is the substitution of names in the place of phrases 
for the parts of the human body. 

But the retention and use of specific names for specially modi- 
fied elements in the different segments by no means preclude the 
entertainment of general ideas and the necessity of expressing 
them by generic names for the homologous elements in the entire 
series of vertebrse. 

If anthropotomy is to make corresponding progress with ana- 
tomy, and to derive the same light from the generalizations of 
zootomical science which medical botany has derived from, general 
botanical science, its nomenclature must expand to receive those 
generic terms which express the essential nature of the parts, here- 
tofore named and known only according to the results of parti- 

* Monro^ /. c. p. 126. 

f Laurentius, in describing the human thoracic pleurapophyses, says, 
'•Earum duplex est articulatio, altera cum spondylis dorsi, altera cum sterni 
cartilaginibus " (Anatomica Humani Corporis, Fol. 1600, p. 94). The percep- 
tion of the essential distinctness of the vertebral ribs had not then been 
blunted by the constant repetition of the conventional idea of their forming 
an ossified part of a whole, i. e. a rib, completed by the hsemapophysis under 
the name of the * cartilage costse/ In birds it is not uncommon to find the 
hsemapophyses not only ossified, but some of them attached to the sternum, 
and detached from the pleurapophyses. 



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119 

cular and insulated observation. A term which truly expresses 
the general homology of a part enunciates the most important and 
constant characters of such part throughout the whole animal 
series, and implies therefore a knowledge of such characters in that 
part of the human body, when used and understood by the human 
anatomist. Before the cuneiform process of the occipital bone 
could be defined as the ' occipital centrum/ the modifications and 
relations of the homologous part in all classes of vertebrate animals 
had to be accurately determined. The generic homological term 
expresses the sum or result of such comparisons, and the use of 
such terms by the anthropotomist implies his knowledge of the 
' idea ' or primal pattern of the human frame supporting the modi- 
fications that raise it to an eminence so far above those of all other 
vertebrate animals. 

In no species, however, is each segment of the endoskeleton 
so plainly impressed with its own individual characters, as in 
Man ; the practised anthropotomist, for example, will at once 
select and name any given vertebra from either the cervical, 
the dorsal, or the lumbar series. During that brilliant period of 
human anatomy which was illuminated by a Fabricius, an Eusta- 
chius, a Fallopius, and a Laurentius, the terms expressive of the 
recognition of such specific characters were more numerous and 
often more precise than in our modern compilations. Pleurapo- 
physes were individuahzed in the thorax as well as in the head : 
the 'antistrophoi,' *^stereai' and ' sternitides,' for example, were 
distinguished from the other ^pleurai gnesiai '^, 

General anatomical science reveals the unity which pervades the 
diversity, and demonstrates the whole skeleton of man to be the 
harmonized sum of a series of essentially similar segments, although 
each segment diifers from the other, and all vary from their 

archetype. 

* Anatomica Humani Corporis, &c., multis controversiis et observationibus 
novis illustrata, Andr. Laurentio, fol. 1600, p. 95. 



1 




THE END. 



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London, June, 1848 



BOOKS PUBLISHED BY MR. YM VOORST. 



The Illmtrations to the Worls enumerated in this Catalogue have been designed or 
dra-ivn and engraved expressly for tlm Worls they respectively embellish^ and 
tliey are never used for other Works. 



X 



^ L 



\ 



Illustrated Reprints. 



WATTS' DIVINE AND MORAL SONGS. With 
W. Cope, A.R.A. ; engraved by John Thompson. 
or 21s. in morocco. 



30 Illustrations by C 
Square Svc, 75. Qd, 



Uniform with the above, 

THE VICAR OF WAKEFIELD. With 32 Illustrations by William Mcil- 
READY, R.A.: engraved by John Thompson. IL Is. square Svo, or 36s. in 
morocco. 



V 



Uniform 



SHAKSPEARE^S SEVEN AGES OF MAN. Illustrated by William 
MuLREADY, R.A. ; J. Constable, R.A. ; Sir David 'Wilkie, R.A. ; W 
Collins, R.A.; A. E. Chalon, R.A. ; A. Cooper, R.A. ; Sir A. "W. Call- 
coTT, R.A.; Edwin Landseer, R.A.; W. Hilton, R.A. 6s. 
A few copies of the First Edition in 4to. remain for sale. 

THE FARMER'S BOY AND OTHER RURAL TALES AND POEMS. 
By RoEKRT Bloomfield. With Thirteen Illustrations by Sidney Cooper. 
R.A., Horsley, Frederick Tayler, and Thomas Webster, R.A.* 
A few copies on large paper, of a size to correspond with the above, price 15s! 
(Small Paper copies, 7s. M.) 

GRAY'S ELEGY IN A COUNTRY CHURCH- YARD. Each stanza Il- 
lustrated with an Engraving, from 33 original drawings by the most eminent 
Artists. Post 8vo., price ds, cloth. A Polyglot Edition of this Volume- with 
inter-paged Translations in the Greek, Latin, German, Italian, and French 
Languages. Price 12s. And of uniform size. 

THE BARD. By Gray. With Illustrations by the Hon. Mrs. John 
Talbot, Post 8vo. 7s. 

A CABINET EDITION OF THE HOLY BIBLE ; The Authorized Ver- 
sion. With 24 highly-fniished Steel Engravings, In embossed binding, 
] Os. M, And uniform, 

THE BOOK OF COMMON PRAYER. With 10 Engravings. In 
embossed binding, 4s. 

A CABINET EDITION OF THE ECONOMY OF HUMAN LIFE. In 

Twelve Books. By R. Dodsley. With 12 Plates engraved on steel, from 
original designs, 18mo. 5s, 

AIKIN'S CALENDAR OF NATURE ; or, Natural History of each Month 
of the Year. With additions, by a Fellow of the Linneean and Zoological 
Societies, and 18 designs by Cattermole. Small 8yo., 2s. Qd. 



I 

i 



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Architecture, 

r 

ARCHITECTURAL PARALLELS ; or, The Progress of Ecclesiastical Archi- 
tecture in England, through the Twelfth and Thirteenth Centuries, exhibited 
in a Series of Parallel Examples selected from Abbey Churches. By Edmund 
Sharpe, M.A. 121 Plates in tinted outline, each 18 in, by 12 in., half mor. 
13Z. 135.5 or large paper, 161, 10s. 

INSTRUMENTA ECCLESIASTICA : a Series of Seventy-two designs for 
the Furniture, Fittings, and Decorations of Churches and their Precincts. 
Edited by the Ecclesiological, late Cambridge Camden Society. 4to, IZ, lis, 6d, 

A MANUAL OF GOTHIC MOLDINGS. A Practical Treatise on their 
Formation, Gradual Development, Combinations, and Varieties ; with full 
Directions for copying them, and for determining their Dates. By F. A. 
Paley, M.A, Second Edition, Illustrated by nearly 600 Examples. 8vo. 7s. 6d. 

Other Works by Mr. Paley. 

THE CHURCH RESTORERS ; A Tale, Treating of Ancient and 
Modern Architecture and Church Decorations. With a Frontispiece. 
Foolscap 8vo. 4s. 6d, 

A MANUAL OF GOTHIC ARCHITECTURE. With a full Account 
of Monumental Brasses and Ecclesiastical Costume. Foolscap 8vo., with 
70 Illustrations, 6s, 6d, 

BAPTISMAL FONTS. A Series of 125 Engravings, Examples of the 
different Periods, accompanied with Descriptions ; and with an Introduc- 
tory Essay. In 8vo. IZ. Is. 

DECORATED WINDOWS. By Edmqnd Sharpe, M.A., Architect. Each 
Part, price 2s. 6d.^ will contain Eight Examples selected from the Parish 
Churches of England, engraved on Steel, with accompanying Descriptions ; 
the concluding part will be Introductory, and Illustrated by Woodcuts, &c. 

PERRAN-ZABULOE ; with an Account of the Past and Present State of 
the Oratory of St. Piran-in-the-Sands, and Remarks on its Antiquity- By 
the Rev. Wm. Haslam, B.A., Resident Curate. Foolscap 8vo., with se- 
veral Illustrations, 4s. 6d. 



HERALDRY OF FISH. By Thomas Moule. The Engravings, 205 in 

number, are from Stained Glass, Tombs, Sculpture, and Carving, Medals and 
Coins, Rolls of Arms, and Pedigrees. 8VO.5 price 21s. A few on large paper 
(royal 8vo,) for colouring, price 2Z. 2s. 

Natural History. 

THE ISLE OF MAN ; its History, Physical, Ecclesiastical, Civil, and 
Legendary. By the Rev. J. G. Gumming, M.A,, F.G.S., Vice-Principal of 
King William's College, Castletown. Post Svo., with Illustrations, 12s. 6i. 

PROFESSOR OWEN ON THE ARCHETYPE AND HOMOLOGIES 
OF THE VERTEBRATE SKELETON. 8vo. 10s, 

A SYSTEMATIC CATALOGUE OF THE EGGS OF BRITISH BIRDS, 

arranged with a View to supersede the use of Labels for Eggs. By the Rev, 
S. C. Malan, M.A., M.A.S, On writing-paper, 8vo. 8s. 6d, 

RARE AND REMARKABLE ANIMALS OF SCOTLAND, Represented 
from Living Subjects : with Practical Observations on their Nature. By Sir 
John Graham Dalyell, Bart. Vol. First, 53 Coloured Plates, 4to., '^l, Bs. 



.^ 



JOHN VAN VOORST, 1, PATERNOSTER ROW. 




the Botanv School 



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• ITt-* 




Natm^al History continued. 

GEOLOGY : Intro due tory. Descriptive, and Practical. By David Thomas 
Ansted, M.A., F.R.S. ; Fellow of Jesus College, Cambridge ; Professor of 
Geology in King's College, London. 2 Vols. Svo., with numerous Illustrative 

Engravings, price 2L 2s, .. ■ ^ 

THE BIRDS OF JAMAICA. By P. H. Go sse. Author of the "Canadian 
Naturalist," &c. Post 8vo., price lOs. 

ILLUSTRATIONS to this Work of the Species not heretofore figured;- 
Imperial 8vo., to be completed in about 15 PartS; at 2,?. Qd, Each Part 
will contain Four Birds Coloured. 

OBSERVATIONS IN NATURAL HISTORY ; with a Calendar of Pe- 
riodic Phenomena. By the Rev. Leonard Jenyns, M.A.^ F.L.S, Post 
8vo, lOs. 6(Z. 

ILLUSTRATIONS OF INSTINCT, deduced from the Habits of British 
Animals. By Jonathan Couch, F.L.S., Member of the Royal Geological 

Society and of the Royal Institution of Cornwall, &c. Post 8vo. 85. Qd, 

THE ANCIENT WORLD ; or, Picturesque Sketches of Creation. By D. T. 
Ansted, M.A., F.R.S. , F.G.S., Professor of Geology in King's College, Lon- 
don, &c. &c. A New Edition, Post 8vo., with 149 Illustrations, 10s. 6d. 

OUTLINES OF STRUCTURAL AND PHYSIOLOGICAL BOTANY. 
By Arthur Henfrey, F.L.S., Lecturer on Botany at the Middlesex Hospi- 
tal ; late Botanist to the Geological Survey of the United Kingdom. "With 
18 Plates, Foolscap 8vo. IO5. 6c^. 

A MANUAL OF BRITISH BOTANY ; containing the Flowering Plants 
and Ferns, arranged according to the Natural Orders. By Charles C. 
Babington, M.A., F.L.S.5 F.Z.S., &c. Second Edition, 12mo. IO5. 

THE NATURAL HISTORY OF ANIMALS ; By T. Rymer Jones, F.R.S., 
F.Z.S. Professor of Comparative Anatomy in King's College, London. 
Post 8vo., Vol. L, with 105 Illustrations, price 125. 

FIRST STEPS TO ANATOMY. By James L. Drummond, M.D., Professor 
of Anatomy and Physiology in the Belfast Royal Institution. With 12 Illus- 
trative Plates. 12mo. bs, 

TRAVELS IN LYCIA, MILYAS, AND THE CIBYRATIS, in company 

with the late Rev. E. T. Daniell. By Lieut. Spratt, R.N. and Pro- 
fessor Edward Forbes. With numerous Illustrations, including Views of 
the Scenery ; Plans of Ancient Cities and Buildings ; Plates of Coins and 
Inscriptions ; Cuts of Rock Tombs, Fossils, and Geological Sections, and an 
original Map of Lycia. 2 Vols. 8vo., 36s. 

THE NATURAL HISTORY OF STAFFORDSHIRE, comprising its Geo- 
logy, Zoology, Botany, and Meteorology ; also its Antiquities, Topography, 
Manufactures, &c. By Robert Garner, F.L.S. Illustrated, 8vo. \l. I5. 

THE HONEY BEE ; its Natural History, Physiology, aud Management. By 
Edward Bevan, M.D. A new Edition, 12mo., with Illustrations, IO5. Qd. 

ON THE GROWTH OF PLANTS IN CLOSELY-GLAZED CASES. By 
N. B. Ward, F.L.S. 8vo., Bs. 

A FAMILIAR INTRODUCTION TO THE HISTORY OF INSECTS. 



By Edward Newman, F.L.S., F.Z.S., &c. 
tions, price 125. 



8vo. with nearly 100 Illustra- 



WHITE'S NATURAL HISTORY OF SELBORNE. A new edition, with 
Notes, by the Rev. L. Jenyns^ M.A., F.L.S. Fcp. 8vo,, illustrated, 7s. 6^^, 



f 



i 



JOHN VAN VOORST, 1, PATERNOSTER ROW. 








i- 



\ 



I 

I 



. \ . 



* , ™?'"PK™F°°"'^'froN TO THE STUDY OF POLARIZED 

LIGHT ; with a Description of, a„d tatroctions for U»V, ihe Table and 
, t,on to the Dse of the Microscope, to. B, AlfbIo T^ik MRCS 2/5" 



77?^ NATURAL HISTORY OF GREAT BRITAIN. This Series of 

Works IS Illustrated hj many Hundred Engravings ; every Species has been 
Drav,n and Engraved under tU immediate inspeeUon of tj' aSZ tLZ 
Artists have been employed, and no care or expense has been spared. A few comes 
on larger paper , royal ^vo. i-- ^. a jew copies 

THE QUADRUPEDS, by Professor Bell. M. 8s. 

THE BIRDS, By Mr. Yarrell. Second Ed., 3 vols. U. Ms. 6d. 

COLOURED ILLUSTRATIONS OF THE EGGS OF BTRDc; 
By Mr. Hewitson. 2 vols. 41. 10s. ^^ ^^^^^' 

THE REPTILES, By Professor Bell. Second Edition, shortly. 
THE FISHES, By Mr. Yarrell. Second Edition, 2 vols. 3/.* 

THE CROSTACEA, By Professor Bell. Now in Course of 
Publication, m Parts at 2s. 6d. 

THE STARFISHES, By Professor Edward Forbes. 

THE ZOOPHYTES, By Dr. Johnston. Second Ed., 2 vols., 21. 2s. 

THE MOLLUSCOUS ANIMALS AND THEIR SHELLS Br 
Professor Ed. Forbes, and Mr. Hanlet. Now in Course of 

Coloured ° S's. '"^ ''' '' ^'^ ^^^ ' °' ^'''^' ^''^''' ^''^ '^' P^^tes 
THE FOREST-TREES, By Mr. Selby. 28s. 
THE FERNS AND ALLIED PLANTS, By Mr. Newman. 25s 



1 5s. 



™UU 6?"^ MAMMALS AND BIRDS, By Processor Owen. 



A GENERAL OUTLINE OF THE ANIMAL KINGDOM Bv 
Pkofessor T. Rymer Jones. 8vo. U. I8s. ' ^ 



m 






JOHN VAN VOORST, 1, PATERNOSTER ROW. 




Tfin^^-ii^tfe 



the Botany 






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