oy) REMARKS ON THE FIGURES OF PLATE XXXII. 
metrical homology. The perpendicular median line, if 
carried through the centres of all those circles, would 
cleave the whole series into a double line of semicircles, 
thus proving the fact of symmetry, and as we see that 
every circle of the same series is the repetition of that 
which precedes and succeeds itself, so are they, one and 
all, plus serial homologues. 
It is also true of fig. A, that whatever be the degree 
of metamorphosis practised upon each circle of the series, 
provided this metamorphosis takes place equally at both 
sides of the median line, this line will still divide the 
series symmetrically. Thus the median line equally 
divides the segment of the metamorphosed circle 3, and 
the semicircle of the metamorphosed circle 14. Even 
when we proportion various segmental quantities from 
circles, as seen at numbers 16, 17, and 18 of the series, 
still, provided such segments be cut in reference to 
median cleavage, the same median line will render all the 
quantities, circles, segments, and semicircles, all equally 
bipartite so far as regards bilateral symmetry. ’Tis true 
that the symmetrical quantity of the segment will not 
equal that of the symmetrical semicircle, but ’tis- also 
true that, whatever be the variety as to quantity, the 
law of symmetry still prevails. The reason of this is, 
that every proportional quantity of the series is the pro- 
portional of the circle, and the circles are all plus homo- 
logues, both in quantity and every other character. 
Again, in fig. B we likewise see that the law of serial 
and symmetrical homology prevails. The entire series is 
cleavable at the common median line from the vertex 
downwards, through the cervical quantities, through the 
thoracic archetypes, through the lumbar quantities, and 
through those of sacral and caudal character. Even the 
last caudal nodule is cleft symmetrically by this common 
median line, and the reason is, that it bears the same pro- 
portional relation to the thoracic archetype quantity of its 
own series as the segment of the circle, 18, fig. A, bears 
to its archetype circle, described in dotted line. Even as 
the inverted triangle proportions varying quantities from 
the circles 16, 17, and 18, of fig. A, so does the law of 
proportioning fashion, from out of archetype skeleton 
quantities in serial order, the graduated units of a sacral 
and caudal series for fig. B or C. 
By the law of serial homology we are enabled to fill up 
space where quantity is lost. If we omit the rib between 
two other ribs in series, these latter, whilst left standing 
as nature produced them, will inform us of the lost costal 
quantity between them. In fig. B, we take three thoracic 
quantities, such as 12, 13, and 14, we metamorphose the 
rib of 13 at the point a, right side, but if we again would 
create the idea of that lost quantity we are then enabled 
to do so by drawing analogy with the rib of the unit 12 
above and that of the unit 14 below, or even its place 
might be fulfilled by re-creating it after the plan of its 
fellow of the opposite side. So, unit 13, minus the left 
costa, may have this quantity re-established according 
to the serial costa above and below on the same 
side, or according to the symmetrical costa opposite 
to it, and this law prevails for all units of the thoracic 
series. 
Now the law of serial and symmetrical homology may 
likewise extend our ideas so as to fill up lost quantity 
either in the cervix or loins, as well as in that hiatus 
occasioned in thoracic series by the omission of a costa 
between two others. . 
On one side of fig. B we omit alternate cost from the 
thoracic series. The units marked 9, 11, 18, 15, 17, and 
19, show that their coste on the right are metamorphosed 
at the points a, a, a, &c. (The dotted forms here and else- 
where, it should be remembered, indicate lost quantity.) 
So we say, that if we happen to have presented to us a 
skeleton whose alternate costz were thus metamorphosed, 
and that we were required to re-establish the costal forms 
according to their original normal type, this might be 
performed with unerring rule according to serial and 
symmetrical law, even if we were in want of another com- 
plete skeleton form to imitate. For, although the right 
costz be lost from the units 9, 11, 13, 15, 17, and 19, still 
their analogues are existing at the same side on the 
units 8, 10, 12, 14, 16, and 18, and their analogues are 
also standing in complete series on the opposite side ; 
hence, we say, that an observation of the law of serial and 
symmetrical homology, aids the mind in recreating lost 
quantity, whereby we re-establish plus serial uniformity ; 
for, taking any unit of thoracic series which may have 
been rendered minus a costal form, (the unit 13 for 
example,) we then interpret that unit 13 is minus the right 
costa from the point a, and this lost form was, without 
doubt, the homologue of the right cost of units 12 and 
14, or of its fellow at the left side; thus the rule of 
analogy becomes a creator of ideas regarding lost form. 
The form which is lost at the cervical, lumbar, sacral, 
and caudal regions of series, can also be filled up according 
to this same law of serial and symmetrical homology. 
Fig. B presents to us, on the left side, (the right and 
left side of series is spoken of in reference to ourselves,) a 
serial order of articulating coste from unit 7 to unit 21, 
thus abnormally extending into the cervical region, and 
into the lumbar region of series; but on the right side the 
costal series of fig. B terminates at the normal points, 
Now 
we venture to assert, that any one who would contemplate 
this condition of development in fig. B, cannot refrain 
commencing at unit 8, and ending at unit 19. 
from coming to this conclusion concerning it, namely, 
that unit 7 in the cervix, which has a left costa, must have 
lost the analogue of the right; and also that since units 
19, 20, and 21, of the lumbar spine possess the left costz, 
so must they also have lost their analogues of the opposite 
Thus it is, that, by symmetrical law, we give costal 
forms to the cervical and lumbar regions. And the same 
may be done by the law of serial homology as follows :— 
In fig. B, unit 8 bears symmetrical ribs lke unit 9, 
below. But above the unit 8 we see that unit 7 bears 
only one rib, having lost the opposite homologue, no element 
of which remains excepting the autogenous piece a. Again, 
unit 6 has lost both costz, the autogenous pieces, aa, of 
side. 
