9 REMARKS ON THE FIGURES OF PLATE XXIX. 
works bore an unmistakable similitude to that of an orang- 
utan, a chimpanzee, a mandril, and a baboon. The paragon 
of the human MOP®H was confessed by them to stand 
beside its anthropomorphous satire; but it was by the very 
acknowledgment of this fact, and the recognition of a law 
in Nature, that they themselves described the well-marked 
line which separates the human intelligence from that of 
mere brute instinct. The motive marks the difference. 
For if a list of all the transcendent secrets of anatomical 
philosophy were inclosed within the compass of a cocoa- 
nut, and rolled, like the apple of contention, in amidst the 
assembly, consisting of these eight personages, we can 
very easily guess the motive which would actuate the 
quadrumanous species on the one hand, and the biped 
species on the other, to break open the concealed contents. 
But however distinctive these beings in this psychical par- 
ticular, still we cannot deny that fig. A has been cast after 
the same mould as the type human, and presents itself as 
a created illustration of the fact that between species and 
species, as between the sublime and the ridiculous, there is 
a point of fluxion which masks the differential line. 
Fig. A represents the skeleton axis of the orang-utan 
(simia satyrus), and if there be any truth in the foregoing 
interpretation of the units of the human spine, the same 
interpretation applies here also. 
Fig. B is the front view of the skeleton axis of the 
sloth (bradypus tridactylus), a mammalian skeleton, in 
which we find that the nine first units have been rendered ° 
minus for the cervical region, a fact which, however un- 
usual its occurrence in the class mammalia, may bear of 
interpretation according to foregoing remarks. 
Fig. C shows the skeleton axis of the chimpanzee (simia 
troglodytes), and we at once discover it to be a form 
fashioned after the same type as that of the human osseous 
framework. 
Fig. B differs in the cervical region of the serial axis 
from figs. A and C by the plus amount of two vertebra. 
But we already understand that the vertebral body is a 
proportional of the costo-vertebral quantity, and hence 
all that requires to be said of this singularity of form 
in the cervical region of the sloth’s skeleton is, that 
nine costo-vertebral units of series, instead of seven, have 
undergone the rule of minus proportioning. 
In figs. A and C the cervical region of the serial axis 
consists of seven vertebral quantities, but it may be rea- 
sonably supposed that even these quadrumanous species 
are subject to the occurrence of cervical ribs, thus occa- 
sionally shortening the cervical spine, as in the human 
form. In fig. C the unit 7 a a, shows something of this 
sort. 
The thoracic region of series in figs. A, B, and C is seen 
to develope variable quantities. Fig. Ais developed accor- 
ding to that numerical plan usually found in the human 
skeleton. Its thoracic series of archetypes commences 
at the eighth unit and terminates at the nineteenth. Its 
lumbar spine commences at the twentieth and ends at 
the twenty-fourth. But the twentieth unit of series, 
which is of lumbar proportion, in fig. A, is seen to pro- 
duce the coste in fig. C; however, since in fig. A the 
unit 20, is a proportional of the unit 19, so is the unit 20, 
of fig. A the proportional of the unit 20, in figs. C and B. 
In these figs. A, B, and C, the same units of series bear 
the same letters or numbers, and a comparison of the units 
of either figure will express the law of proportioning, meta- 
morphosis or modification. 
In these three figs. A, B, and C we find that the spinal 
series is developed in unequal numbers of units, but since 
whatever be the numerical position of any unit of series, or 
whatever be its modification, it still may be regarded as a 
proportional of such a form as 20 a, fig. B, we then under- 
stand how series may be terminated at any unit which the 
law of form shall metamorphose to caudal quantity or 
minus condition. 
Each region of the skeleton series terminates by the 
same process which gives the entire finite serial line its 
special length. The caudal quantities we herewegard to 
be the smallest proportionals of the costo-vertebral arche- 
type series, and hence the length of every skeleton axis is 
determined by the extreme degree of metamorphosis to 
which the archetype is subjected. When we say that 
9—8=1, we apply this fact to the interpretation of that 
law of design which produces fig. A, or B, or C, having an 
archetype quantity in the thoracic region of series, and 
the smallest proportional of such an archetype in the 
caudal region of the same series ; and hence we infer that 
the thoracic quantity 15a, of fig. A, B, or C, mmus a cer- 
tain quantity, will equal the ultimate caudal bone of either 
fig. A, B, or C. But as we find that this extreme degree 
of subtraction does not take place upon the same numeri- 
cal unit, destined to become an ultimate caudal ossicle, so 
do we discover that the serial spimal lengths vary accord- 
ingly. For the finity of the serial axis fig. A is marked at 
the 31 numerical unit, whereas im fig. B it is reckoned at 
44, and in fig, C at 32. 
Now we have already observed that even the human 
serial axis terminates at numerically various units, as well 
for its regions as for its entire length. We cannot assert 
of the human cervix that it invariably ends at the seventh 
unit, nor of the human thoracic series that it constantly 
ends at the nineteenth. Neither can we say that the 
human lumbar region terminates at the twenty-fourth 
unit, and it is also true that the terminal caudal ossicle of 
the human spinal series is a numerically different unit in 
several human skeleton figures. We doubt not that the like 
numerical variations as to regional lengths might be also 
observed through the species of fig. A as well as through 
that of fig. B or C. And it is a certain fact that the com- 
parison of these three forms, A, B, and C, with each other, 
reveals the very same differential law whereby they are 
yaried to one another, simply according to the numerical 
position of that plus costo-vertebral unit which has under- 
gone cervical,lumbar, sacral, or caudal modification. 
As we find that the proportionals of one series or 
skeleton axis admit of comparison, and the interpretation 
that the lesser unit is a quantity metamorphosed from 
such as the greater, so shall we meet with further proof of 
