REMARKS ON THE FIGURES OF PLATE XXVII. 
oo 
THE CERVICAL AND LUMBAR REGIONS OF SERIES ARE MINUS, COMPARED TO THE THORACIC REGION WHICH IS 
PLUS. 
NALOGY exists amongst the several osseous quantities of the mammalian serial axis, notwithstanding 
the fact that those quantities vary to each other by plus and minus proportioning. If a cervical series 
cannot be said to give example of the plus quantities constituting a thoracic series, still the former is 
| referrible to some proportionals of the latter. If a lumbar, sacral, or even a caudal series, does not instance 
the same plus condition visible in thoracic series ; yet it is quite true that the former do still point to their 
counterpart proportionals in the latter, and consequently the thoracic series being plus, is only in this 
respect different to the cervical, lumbar, sacral, and caudal series, which are minus. Now, as it is on the 
one hand possible to abduct quantity from the plus thoracic series, so as to render them in a condition equal 
to a minus cervical or lumbar series, so is it possible to add quantity to a cervical or lumbar series in order 
to equate them with the plus quantities of a thorax. And acting upon these premises, we produce certain 
consequences which are the actual imitations of natural operation. For we find that the subtraction 
of costal quantity from a thoracic series is attended with a lengthening of the cervix and loins, whereas 
the addition of costal quantity to a cervix or loins, causes in an equal ratio an extension of the thoracic 
series, and a shortening of the cervical and lumbar regions. ~The progress of Nature herself may be 
tracked through this wake of evidence ; for while in one anneal series she terminates the cervix at 
the seventh unit, and commences the lumbar region at the twentieth ; she also may be seen to have created 
another mammal series, whose seventh and twentieth units produce the coste, thus rendering the cervix and 
loins each minus a vertebra, by no other cause than that the thorax remains plus two costo-vertebral figures 
or archetypes. 
The serial spinal axis is one of graduation and propor- | 
tioning. The complete thoracic costo-vertebral quantity 
is that which we name the archetype of the series. The 
last caudal bone is that which we name the smallest pro- 
portional of such another archetype quantity. This is our 
interpretation of the law of formation respecting the mam- 
malian serial axis, and we believe that it would be as 
impossible to find reasonable grounds for denying the 
truth of that interpretation as it would be to deny that 
a—b=c, or that the integer 100 minus 99 equals 1. 
Now we have already seen that no one region of even 
the human spine can be mentioned as commencing or ter- 
minating invariably at the same numerical units of series. 
The cervical region cannot be said to terminate invariably 
at the seventh spinal unit, for we have examples of the sixth 
and seventh cervical vertebrz producing costal forms; and, 
consequent upon this.fact, neither can the thoracic region 
be said to commence at the eighth unit of series, for we 
see that it sometimes begins at the sixth cervical costal 
quantity. : 
Furthermore, we also observe that the thoracic region 
does not always terminate at the nineteenth serial unit, for 
we have examples of where it terminates at the eighteenth, 
and so lengthens the lumbar spine by a vertebra; and 
also of where it is continued to the twentieth, or even 
the twenty-first, thus encroaching upon the lumbar region, 
and diminishing it by the quantity of two vertebrz. 
The like remarks apply to the sacral and caudal regions 
of series, for these do not commence or. terminate at the 
same numerical units invariably. Neither does the human 
spinal axis terminate at the same unit; for we see that, 
numbering all the serial units from the occiput to the 
a~al) aa 
