bo 
REMARKS ON THE FIGURES OF PLATE XXVI. 
We have before seen that the number of lumbar | what we may lay hands upon, dissect, and reason about. 
vertebra, as well as the number of thoracic quantities, 
depended upon the condition of development of the last 
thoracic form or of the first lumbar unit. In one spinal 
series, that unit which presented as the last thoracic form 
was, in another spinal series, fashioned to the character of 
a lumbar vertebra. The plus quantity had been reduced 
to minus, and, consequent upon this, the number of forms 
in either thorax or lumbar spine varied. 
The number of vertebre in the lumbar spine may 
also vary according to that unit of series which shall 
present in the character of a first sacral vertebra; hence 
we have figs. A and B presenting the units marked 12 da, 
as terminating the thoracic series, consisting of the usual 
number of 12 costo-vertebral figures, whilst, nevertheless, 
the lumbar spine of fig. A holds 5 vertebra, although 
that of fig. B contains only 4. There can be no other 
reason given for this variety than such as follows—viz., 
the unit marked 5 of fig. A takes on the sacral form 
marked 5 in fig. B or C. 
The number of vertebree proper to a sacrum is not fixed, 
neither is the number of vertebre proper to a caudal 
series fixed. The number of either class of vertebre is 
dependent upon the serial or numerical position of that 
unit which shall be rendered of sacral character, or reduced 
to a still smaller proportional, when it then becomes of 
caudal stamp. ‘The variation of character follows the 
law of proportioning. 
In the figs. D, E, F, G, H, and I, the homologous units 
are similarly lettered, and they will (viewed comparatively) 
indicate the law by which both sacral and caudal series 
are developed. The plus is reduced to minus, and this is 
all the difference between them. 
The last caudal nodule is the smallest proportional of 
the archetype of series, and when we reckon the serial 
units of the human spine from occiput to the last caudal 
nodule, we then discover that the same units do not 
terminate the several regions of series in all human skeleton 
axes. The figures prove this, and the law under whose 
operation the facts are occurring, must be interpreted 
according to those facts. | 
Now in all themes which occupy human inquiry, as 
well as this one of comparative osteology, it will be plainly 
apparent that it is the nomenclature, and not the facts of 
nature, which excites disputation as to whether the ens is 
or is not thus. For when we designate by a name of one 
signification two things which have diverse quantities, or 
when we apply different names to characterise two entities 
as bemg various at the same time that they exist in 
nature as analogous, then it is that we envelope in a fume 
and cloud of sounding phrase of speech, the actuality and 
entity of natural fact, and would hence be led by nomen- 
clature to conclude that nothing is but what is not, only 
that we may readily experience the corrective matter of 
presential nature, and know therefrom that nothing is but 
according to analogy. 
The several regions of the mammal serial axis are fettered 
with the bonds of a nomenclature, with which (despite 
the observation that Nature herself is continually emanci- 
pating her person from it, and passing free) we still are 
pursuing her footsteps, and vainly endeavouring to interpret 
her person, not according to what she is, but to what we 
falsely conceive to be her condition. We name her cerviz to 
consist of seven vertebral units, invariably ; but still the fact 
isnot thus. We name her thoracic series to consist of twelve 
costo-vertebral units, invariably ; but still she transcends 
that rule. We name her lumbar, sacral, and caudal regions — 
to be developed of fixed numbers of vertebral units, but 
still she overreaches our rules. We say that each unit of 
series is produced of fiwed osseous quantity, but still the 
rule is void. We give to one form the name of vertebra, 
but yet we do not know of the form thus suitably named. 
We say that her regions of series severally commence and 
severally terminate at such and such a numerical unit, but 
still we cannot name the fixed serial situation of those 
units; and still we indulge in nomenclature, regardless of 
the facts that the transition serial quantities between the 
several regions of cervix, thorax, loms, and sacrum may be 
and are from time to time of either cervical, thoracic, lumbar, 
or sacral character ; still we endeavour to define species as 
a fixed character of any quantity, compared to other quan- 
tities standing in the same serial order, and still we find 
that any one of those serial quantities may assume any 
character of species. 
Finding these to be the actual facts of development 
produced in the mammalian serial axis, need we pass from 
these further into the subject of an animal kingdom for 
discovering the law of an ever-moving metamorphosis, 
which not only varies two or more entities amongst them- 
selves, but which moreover actually causes a third ens to 
assume the special character of either ; and it is this which 
reads the lesson, that as there is nothing fixed in nature 
but her law, consequently there cannot be any other fixed 
knowledge than that which concerns her law, and this is 
one of metamorphosing special proportionals from whole 
quantities, and in this process is contained the long ac- 
count of species. For while we discover that the twentieth 
spinal unit is (in one mammalian skeleton axis) the first 
lumbar figure, and that this same twentieth unit is (in 
another mammal axis) the thirteenth thoracic form; then 
we say, that by reading them as the variable proportionals 
of a whole quantity, we may arrive at a clearer under- 
standing of a law than if we continue for ever to rack 
ourselves between the counter-arguments for unity and 
for species.* 
The differential method pursued for the isolation of 
species, (as it commences from nihil and ends in the same) 
may itself be called the visionary and the abortive. For 
species having its location in subtracted quantity, may be 
* “Tl est aisé de voir que le grand défaut de tout ceci est uné errewr de métaphysique dans le principe méme des méthodes—erreur qui 
consiste 4 vouloir juger d’un tout par une séule des ses parties.” —Buffon, tom. i, page 20. 
