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2 REMARKS ON THE FIGURES OF PLATE XVII. 
form, hold series with fig. A’ and A”, 
pieces marked 1 in all these forms are still holding their 
The exogenous 
own serial order, and the costal pieces marked a in these 
forms are likewise standing in: series, and proving them- 
selves as being only various to each other by the rule of 
plus rendered minus. That rule which proportions the 
several figures of the skeleton axis, is also seen to per- 
form the like variations upon the lumbar vertebra C, and 
the cervical yertebra B, for their autogenous or costal 
element @ occasionally traverses towards the median point 
c, thus imitating figs. A” and A’. 
Now it is to be observed of the serial quantities of fig. 
A’ that, as sterno-costo-vertebral forms, they are still 
presided over by the law of symmetry. The median line 
bisects at the same time their sternal pieces ¢, ¢,c, ante- 
riorly, and their vertebral quantities posteriorly. At both 
sides of this median cleavage result homologous moieties 
of the complete circle. And it is also to be noticed that 
there exists for the forms of fig. A’ not only a lateral 
homology of structure but also a serial homology. Thus 
half of the first costo-vertebral circle not only represents 
its opposite side, but even the corresponding and opposite 
side of the next succeeding costo-vertebral circle. Further- 
more, when we proportion them at the points 4, d, e, pro- 
vided we do so symmetrically in reference to the sternal 
median line ¢, still this line will bisect each proportional 
quantity equally as to its sides. But as we see them to be 
unequal as to quantity, the first having been metamor- 
phosed at the point 0, the second at d, and the third at e, 
so are they now rendered serial unequals. However, it is 
sufficient that we know how the three forms had once 
actually met at the sternal median line, and consequently 
they are now to be regarded as various to each other 
only by our having proportioned them unequally from 
uniform plus equals. In what other respect, therefore, 
are we to account the series of fig. A” to be different to 
the series of fig. A’, except as minus quantities metamor- 
phosed from such plus forms as fig. A’? If we say that 
the sternal pieces exist for fig. A’ and not for fig. A”, what 
else can the difference be except that of plus and minus, 
creation and increation? If the median line bisects the 
sternal pieces c of fig. A’, does it not also bisect the linea 
alba of fig. A”? If we regard fig. A’ as plus and fig. A” 
as minus quantities, who then shall define genus or species 
by any other fact of skeleton formation than this of plus 
quantity being subtracted from? If all the plus anomalies 
of fig. A” are but as. the approaches towards the median 
line ¢, does not this very occurrence seem a natural rule of 
fig. A” equating itself with fig. A’, the archetype of 
series ? 
What is species? Let us first understand what is the 
law of form. If it be true that the laws of species are 
centred in the laws of form, then it is reasonable to expect 
that the revelation of the laws of form will best expose to 
Are the vertebrated skeletons 
Are the serial homologues of 
the one skeleton axis uniform as to quantity? Neither 
skeleton figures of animals nor serial osseous quantities 
the root the laws of species. 
uniform as to quantity? 
within the one animal being as absolutely uniform quan- 
tities, what then is the source of their difformities and 
their analogies? Are the skeleton figures produced as 
things of one species? Are even the serial figures of the 
one animal produced as things of one species? The 
answer being in the negative for both questions, let us 
then inquire whether the source of their structural dif- 
formities be the cause of their varieties in species. 
What is the law of forms in variety? Is it the law of 
metamorphosis? If it be so, what then is the archetype 
figure or quantity which suffers metamorphosis? Should 
it not be to the recognition of this archetype that all the 
science of comparison ought to lead? And until it be 
discovered, what can we know of the transcendent walk of 
Nature and design, of her creations of forms in variety, 
and of her species, which are those varieties ? 
the differences between figs. B and C compared to fig. A”, 
and this compared to fig. A’, but proportional differences ? 
Does not the one common median line bisect them one 
and all, such as they are in series ; and does not the serial 
order bind them together as one continuous entity? Is 
not the quantity of fig. B or C to be found in any of the 
asternal costo-vertebral quantities of fig. A”, and are not 
these latter to be found im the sternal costo-vertebral 
quantities of the archetype series fig. A’? Is it not within 
the limits of possible operation to metamorphose from fig. 
A’ quantities equal to those of fig. A”, and hence to those 
represented in figs. B and C? Can we not reasonably . 
conceive that the plus originals of figs. B, C, or A” were 
equal to those of fig. A’, and that these originals in series 
represented the prime model of uniformity? May we not 
state thus much of figs. B, C, A”, and A’ without asserting 
ad impossibile that all these forms are now existing as 
If we here assert that they are the 
several proportionals of a uniform plus series, and that as 
such they are only various to each other—specifically dif- 
uniform quantities ? 
ferent as proportional unequal quantities of a plus uniform 
series, will this interpretation sin either against the law of 
Nature or the law of reason? Or, supposing that we read 
them as examples of an absolutely different species, can we 
at the same time cast aside all ideas of their relationary 
character, and conjure up to ourselves such vivid impres- 
sions of hiatus and dissimilarity between figs. A’, A”, B, and 
C, as we may recognise between the leaf of a tulip, the 
proboscis of an elephant, a crystal of sulphate of lime, and 
a chemist’s blow-pipe? If between these things we grant 
a specific difference in many other respects, beside the fact 
of their not being as the proportionals of each other, 
certainly the same specific variety cannot be asserted of 
the opposite’ figures, which are proportional osseous 
structures, and only diverse as serial plus and minus 
forms. 
Still holding, therefore, to the examination of the word 
species, as applied to characterise difference between skele- 
ton quantities, and still believing that a precise definition 
of this word, as descriptive of the difformity existing 
between two or more organic products, to be the ultimate 
aim of comparative science, we shall yenture to assert thus 
What are ° 
