2 REMARKS ON THE FIGURES OF PLATE XXI. 
Fig. F’1, the last caudal nodule, holds series with figs. 
E’D’C’B’ and A’; so therefore, as it is easy to understand 
how metamorphosis could degrade any of these forms to 
the centrums marked ] in each, and thereby render them 
equal to fig. F’, we have equated F’ with themselves, and 
drawn around it all the proportionals of the serial spinal 
axis. 
The common median line which would pass through 
the figs. A’B C’D’ and EH’ would, when cleaving the centres 
of those several forms, divide, in the body of each of them, 
a proportional similar to that of the last caudal bone F’, 
and it is for this reason we say how that the median 
line which cleaves the archetype B’ in one part of series, 
cleaves likewise the ideal homologue of such an archetype 
when it passes through the centre of F’ at the extremity 
For we here interpret F’ to be the 
proportional of suchas B’. 
of the same series. 
Now this comparison of fig. F with fig. B’, is like a 
comparison held between the fractional of an integer and 
that integer itself, and granting this to be a rational 
comparison, it must be also granted that all conclusions 
or inductions which shall perform, as it were, their orbits 
around a central reason, may be held to partake of its 
own quality. For though fig. F be the vanishing point of 
series consequent upon the law of metamorphosis, and 
though the presence of fig. F in contrast to fig. B’ shall 
be actually a contrast of extremes, still we say that if we 
interpret fig. F as a creation resulting from metamorphosis, 
then must we inquire the character of the thing meta- 
morphosed. If anatomy already grants that fig. F is a 
metamorphosed vertebra, then, we ask, what are the pro- 
portions of the form which anatomy names vertebra? If 
it be answered that it can be seen in the region of the 
cervix, the lois, or the sacrum, then may it be asked, 
why not also in the region of the thorax? As fig. F 
_ differs from fig. E only by the subtraction of quantity, and 
from figs. D’C’ or A’ only by the like process and with 
the same result, so, for the like reasons, we may infer that 
fig. F, and all the other proportionals of the same series, 
differ from fig. B by the same law of metamorphosis. 
From this very contemplation of a graduated or pro- 
portional series (interpreted as having been created under 
the operation of a law of metamorphosis), springs, as it 
were, the genesis of the idea of uniformity together with 
the law of species or variety. For in the present condi- 
tion of fig. F we read all the history of its past changes, 
the proof of which changes may be drawn from the fact, 
‘that if the whole quantity fig. B were now subjected to 
the same process of subtraction, it would yield the special 
proportional fig. F; and hence we infer that the whole 
quantity or original of fig. F equals fig. B, which equation 
then yields the idea of original uniformity as by a mode of 
abstraction. It is true, therefore, that fig. F, such as it 
stands, refers itself first to the whole quantity fig. B, and 
thence to its own lost quantity, which equalled fig. B ; 
and this is a comparison of Nature with herself, to which 
mode of comparison she herself invites by the creation of 
her proportional series, whose several members differ. from 
each other in no other respect than by quantity. The 
cervical, thoracic, lumbar, sacral, aud terminal figures 
vary only by quantity, as we have already seen; and, 
further than this, we have understood that even the ab- 
normal productions of figs. A’ C’D” E” F” are still 
only minus quantities compared to fig. B’” the thoracic 
archetype. 
Thus then it appears that fig. F in its minus character, 
discourses of its own past changes from plus and the 
archetype, to its present existing state; and also, that so 
long as it shall be viewed in the same series with fig. B, 
it is to be known as indicator of the differential quantity 
existing between B as plus, and itself as minus.* Thus, 
as the hand upon the serial dial still and for ever records 
the march of time, and points to the visible present 
symbol whieh divides the past from the future ; so fig. F, 
the vanishing point of the converging serial line, tells, 
like an index, the differential quantity between itself and 
fig. B, as also between itself and total increation. 
We say, therefore, that between plus quantity and its 
proportionals resides the immateriality of species, and we 
call it immaterial, because it depends upon the mere 
negation of quantity. For as ab is a species compared 
to a+6 so (as by the addition of the quantity 6 to the 
former, or by the subtraction of 4 from the latter, we can 
render them in either case equal and identical) we then 
assert that species is consequent upon the presence or 
absence of the thing 4, and like its shadow follows -it, or 
like the shadow, is nonexistent when the thing @ is anni- 
hilated. 
To search for the ens of species would therefore be as 
vain as to seek for the ens of nihil, for species is nothing 
more than the state, subtraction, absence, void, or darkness, 
each of which is a state of mere negation, and when we 
give it the symbol 0, it implies the absence of some thing 
or quality of a thing which when present, invariably 
opposes. itself to species, and by re-establishing the 
presence of a whole quantity or unity renders the nega- 
tive or species as a state extinct, by the same mode that the 
presence of matter becomes the absence of vacuum or void. 
* We apply to the graduated serial line of the skeleton quantities, the same opinion which has been entertained of a serial graduated line 
or chain of animal quantities. “ Parmi les considerations qui intéressent la Philosophie Zoologique, ’une des plus importantes est celle qui 
concerne la dégradation et la simplification que l’on observe dans V’organization des animaux, en parcourant d’une extremité 4 Vautrela chaine 
animale depuis les animaux les plus parfaits jusqu’A ceux qui sont les plus simplement organisés.”—Lamarck, Philosophie Zoolog., chap. vi, 
p- 130, degrad. de Porganisation. 
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