SKELETON. 



631 



the lumbar "transverse process" or costa ; 

 and this serial order clearly indicates that 

 these are of the same original, but created 

 specifically diverse by undergoing metamor 

 pliosis quantitatively. The originals, there- 

 fore, of the lumbar vertebrae must have been 

 such as the sternal costo-vertebral circles, 

 and I have drawn this original quantity in 

 dotted outline for fig. 452., for it is true 



Fig. 452. 



The last caudal bone, equal to the centrum (5, 

 fig. 45.3.), being a spinal centrum itself, is the 

 vanishing point of the series. The next degree 

 of subtraction is annihilation of all quantity 

 proper to the costo-vertebral original whole 

 quantity, the complement of which I have 

 drawn as the parts marked 1, 2, 3, 4, 6 

 around 5, fig. 452., thereby equating it with 

 the plus thoracic form. 



PROP. XV. The seven cervical verlebrce 

 are projwrlionak degraded from seven sterno- 



costo-vertcbraf whole quantities. The same 

 elemental quantity which is proper to a 

 lumbar vertebra is to be found in a cervical 

 vertebra. In both (\\defigs. 445. and 447.) we 

 distinguish the centrum (5), the neural arch 

 (2), the spinous (1), and transverse pro- 

 cesses (3), and the costal rudiments (4). In 

 both we find that the difference which they 

 manifest on comparison with the costo-ver- 

 tebral thoracic archetypes is simply a differ- 

 ence in costal quantity ; and hence the same 

 reasons which have been here advanced for 

 regarding the lumbar segments as propor- 

 tionals of sterno-costo-vertebral circles, may 

 be also applied as proof of the truth of the 

 interpretation that cervical vertebrae (such as 

 fig. 454.), are also proportionals of the like 



Fig. 454. 



that the presential proportional condition of 

 lumbar vertebras, consisting of the elements I, 

 2, 3, 4, 5, fig. 452.), manifests no other variety 

 or species to the archetypal quantity 1, 2, 3, 

 4, 5, 6, 7, elsewhere persisting, than a simple 

 quantitative variety. 



PROP. XIV. The sacro-cocci/geal series of 

 vertebrce are proportionals degraded from sfer~ 

 nal costo-vertebral circles. That which is true 

 of lumbar vertebra?, compared with thoracic 

 segments, must be true of sacral vertebra; com- 

 pared with the same. For as it seems that 

 lumbar vertebrae are the proportionals of ster- 

 nal costo-vertebral circles, so must sacral ver- 

 tebrae, which are developed of elements iden- 

 tical in all respects with those of lumbar ver- 

 tebrae, be proportionals of the like whole quan- 

 tities or originals. And this is what I affirm 

 of both sacral and coccygeal spinal segments. 



Fig. 453. 



whole originals, and therefore I have equated 

 it with the thoracic whole quantity. 



PROP. XVI. The mammalian spinal axis 

 consists of a series ofsegmental quantities, whose 

 only variety or specific distinction depends upon 

 proportioning from whole thoracic quantities. 

 The truth of this proposition has been 

 established by the foregoing remarks. All 

 the spinal segments of those regions of 

 fig. 455., named cervical, thoracic, lumbar, 

 sacral, and caudal, are not uniform, because 

 they are not equal quantities. A cervical 

 uniformity throughout the spinal axis would 

 require that all the serial segments stood in 

 cervical quantity. A lumbar uniformity would 

 require all the serial segments to be of lumbar 

 quantity. The same with respect to sacral 

 uniformity; and the same of caudal uni- 

 formity. A thoracic uniformity would also 

 require the spinal axis to be of thoracic 

 sterno-costo -vertebral quantity from cranium 

 to the other extreme of the same linear 

 series, such as is represented in fig. 455., 

 where the ribs are indicated in dotted out- 

 line in the neck from 1 to 7, and in the 

 loins from 20 to 24. Tn neither of these con- 

 ditions is the mammal spinal axis developed; 

 and therefore it is that the original plus uni- 

 formity of all the segments from 1 to 25 is 

 interrupted, the serial quantities being now 

 developed of thoracic or plus, and of minus or 

 cervical and lumbar, &c. proportions. Now 

 as to the just interpretation of the natural 

 law which creates t\\\s figure 455., thus com- 

 posed of spinal segments in plus and minus 

 variety, T apprehend that it is more rational to 

 regard nature as being an artificer who, after 

 creating a prime-model of whole or entire 

 dimensions (such as fig. 455.), with the ribs 



884 



