REMARKS 
ON THE FIGURES 
OF PLATE XVI. 
THE COSTO-VERTEBRAL THORACIC FIGURE IS THE ARCHETYPE OF SERIES. 
JNITY, or the archetype, is a name which may be applied to characterise that whole structure which 
is capable of undergoing metamorphosis or subtraction through all degrees of quantity severally equal 
to all those proportional forms which stand im series with itself. And this name archetype will still more 
fittingly apply to this whole quantity when we shall find that it contains not only proportionals equal to the 
normal condition of minus serial forms, but equal also to the abnormal varieties, whether of plus or minus, 
in which we occasionally find those minus serial quantities to be produced. 
A thoracic costo-vertebral 
figure is a natural symbol expressive of an integer, and when we view it in connexion with all the other 
serial quantities of the mammalian spinal axis, we discover that it contains proportionals equal to any minus 
form of the same series ; just as when we write the integer 9, we know it to hold quantities equal any one 
of decreasing series 9, 8, 7, 6, 5, 4, 3, 2, 1. 
It is quite possible to imitate Nature in her simple law 
of metamorphosis from plus to minus quantity. The Rule 
a—b=c, or c+ 6=a, affords a symbolic illustration of that 
law by which nature designs the mammalian skeleton axis 
from the series of plus archetype quantities. 
In fig. A’ we see the costo-vertebral archetype holding 
the exogenous piece 1, called transverse process, which 
never exceeds these set dimensions, whereas the autogenous 
piece ais part of the fuller quantity ranging from a to ec. 
The entire structure is such as we find in the thoracic 
region of the serial skeleton axis; so, therefore, it must be 
clear that when we break off the costal forms at the point 
a, we then produce a structure, terminating at a, as a pro- 
portional of the once complete structure’ whose coste 
were fully produced to the point c. Hence, therefore, it 
becomes totally impossible for us to regard fig. A as 
broken off at the point a, without knowing it to be minus 
something. 
Fig. A”, which has the elemental piece a produced from 
this point to J, is consequently to be understood as the 
plus archetype of fig. A’ broken off at the point a. 
Fig. A”, therefore, which has the piece a produced from 
this point still further to the sternal element at the median 
point c, must be mterpreted as the plus archetype of figs. 
A’ and A”. When, therefore, we compare the fig. A’ 
broken off at the point a, to the fig. A” produced to the 
point c, we then reasonably interpret fig. A’ to be a pro- 
portional minus the quantity proper to the archetype A’, 
and so the comparison of the proportional fig. A’ with the 
archetype plus fig. A” will cause us reasonably to infer 
that fig. A’ is 
and c¢. 
Now, therefore, as figs. B’ or B”, and figs. C’ or C”, are 
minus the quantity ranging between a 
the homologues of the proportional A’ broken off at the 
point a, so the remainder of the subject may be plainly 
inferred. 
It is an undeniable fact that fig. B’, the cervical 
vertebra, is rendered anomalous to itself by the occasional 
production of the piece a beyond its usual proportions, and 
also that this piece a traverses the line from a to c of fig. B’. 
It is also a fact that fig. C’, the lumbar vertebra, is now 
and then anomalous to itself, by the production of the 
piece a towards the mid point ¢ of fig. C’, and therefrom 
we infer that figs. B” and C” are minus proportionals of 
some plus quantity which is archetype——What, then, is 
the form of this archetype? It may be known by the 
following remark. 
If figs. B” and C” contain elements equal to fig. A’ 
metamorphosed at the point a; if, furthermore, we readily 
understand fig. A’ to be a proportional of the known 
quantity fig. A”, and that we discover how the anomalies 
of figs. B” and C” are solely owing to the fact that the 
pieces a now and then imitate the costa ac of fig. A”, so 
therefore, &c. 
When we compare the minus quantity with the plus 
quantity, we are invited to equate the former to the figure 
and dimensions of the latter, and by this process of rea- 
soning we are enabled to track the rule by which Nature 
metamorphoses plus to minus, and fashions the design of 
‘fitting proportions. 
We at once acknowledge to the fact that fig. A”, con- 
sidered as a whole quantity, contams within its own 
dimensions proportionals severally equal to figs. A” and 
A’, for it is true that fig. A’ may be metamorphosed at 
those points of itself which correspond to the points 4 and 
a of figs. A” and A’. Now, the idea must also occur that 
