9 REMARKS ON THE FIGURES OF PLATE VIII. 
absolutely annihilated, and that the different remaining 
elements of these three vertebre were sufficient to fashion 
one complete figure; this figure would then be no other 
than the original archetype. If, for example, we add 
the pieces a and 1 of fig. A” to the pieces 2 and 8 of fig. 
A’, we would then create the very archetype quantity to 
which the pieces a and 1 of fig A” refer. 
Whatever be the elemental parts which are understood 
to be metamorphosed from the figure of the vertebral arch- 
etype, still we invariably find that the persistent elements 
happen in their own proper place, and holding serial order 
with their own homologous elements. [If all pieces of the 
vertebral quantity be metamorphosed except the centrum, 
this element holds series with all the other centrums. If 
it be the spinous process which alone persists, this process 
still holds serial order with the like parts and with no 
others. 
The degradation of form, by the natural process of 
metamorphosis or subtraction of quantity, is that theme 
which comparative science has always had before its contem- 
plation. Even when it appears to have mistaken or forgot- 
ten its prime regard of this theme, still, all its reasonings 
have been instinctively based and generated upon it, and 
have tended to no other end than the acknowledgment of it. 
The unity under metamorphosis is a subject long since 
openly avowed; and we shall find, even if it have not 
been understood, that unity, like a whole quantity, is that 
which has undergone subtraction for the creation of things 
proportionally various to itself; still, that the observation 
and chronicle of every isolated anatomical fact, now consti- 
tuting a multitudinous mass, indicates to-day, that some- 
thing which is called unity is presented to the observation 
in a broken and disjomted shape. Comparative osteology 
is an amassment of observances of separated things which 
admit of readjustment, for the creation of the figure of 
unity; but it is not by a continuance in the description 
of any of the separate parts of this thing of unity or 
entirety that we can ever hope to advance beyond the 
science of the following sentence :—“ Farther still, they 
also differ in multitude and paucity, in magnitude and 
parvitude, and, in short, in excess and defect.” * In this 
observation is contained the whole subject of comparative 
osteology. 
Things which differ only in multitude compared to 
paucity, in magnitude compared to parvitude, and in 
excess compared to defect, speak the truth, that the sub- 
traction from multitude leaves behind paucity, that the 
subtraction from magnitude leaves parvitude, and that the 
subtraction from excess leaves behind defect: hence, if we 
must come to the conclusion, that one skeleton quantity 
differs from another only as excess differs from defect, it is 
also evident, that, as we cannot demonstrate the quantity of 
excess in the quantity characterised by defect, so must we 
turn the rule of comparison to teach us how much quantity 
is lost to the thing of defect, and this we can plainly de- 
monstrate by comparing it with the thing of excess. Thus, 
as a—6, compared to a+4, tells that b is the quantity 
lost to the former, so will fig. A’ minus the parts 3, 2, a, 
teach us, (when we compare it with a cervical vertebra, 
which is plus 3, 2, a,) that 8, 2, a, is the lost quantity. 
And the knowledge of how much quantity is lost to any 
figure, is as real as the knowledge of that same quantity 
seen to exist in another figure. 
Now, from this it follows, that if natural subtraction of 
parts from unity or.the whole quantity is that process by 
which Nature varies uniformity to itself, and also, that if 
it be possible to imitate the natural process by one of 
our own mechanical acts of withdrawing quantity from 
plus and rendering it minus or various, then the opinion 
arises that variety is equal to nothing, that is to say, variety 
is consequent upon subtracted or annihilated quantity ; 
whereas, on the contrary, uniformity is an ens, which, 
whether it remain in full condition or only in part, still 
finds something in series like itself. Thus, if fig. A’ 
persists complete im all its parts, it is repeated by the 
homologue fig. A” through series, or even if fig. A’ be 
metamorphosed to the part marked 1, its centrum, still 
this part is again represented in fig. A”, or the homo- 
logues of A” throughout series. We have shown that a 
cervical, dorsal, lumbar, and sacral vertebra are equals, 
and homologous to each other, and also, that even a 
caudal centrum and a cervical centrum reciprocally repre- 
sent each other, hence causing us to interpret that Nature 
has metamorphosed the former from a quantity similar 
to that of a cervical form, which we ourselves might me- 
chanically metamorphose to a caudal proportional, for 
it is evident that fig. A’ minus 3, 2, a, would then equal a 
caudal nodule; ergo, this latter quantity, plus 3, 2, a, would 
equal, &c., &c. . Such is the inference to be drawn from 
a comparison of plus and minus quantities in series. 
* Aristotle, History of Animals, Book 1., p. 4. 
