SKELETON. 



643 



Where this original or archetypal thoracic 

 structure suffers metamorphosis, as at the 

 neck, there the hyoid apparatus appears as 

 part of the original thoracic quantity, and 

 hence it is that the hyoid apparatus, as such, 

 bears an analogy with the thoracic apparatus 

 as such, because the original of the former is 

 thoracic quantity. When this original thora- 

 cic quantity undergoes metamorphosis imme- 

 diately after the occiput, then the vertebral 

 cervix is formed, and also the hyoid apparatus 

 below it. As both these have come by the 

 metamorphosis of costo- vertebral quantity, so 

 do we find them bearing analogy to those seg- 

 ments, next succeeding them in spinal series, 

 those segments, namely, which persist as whole 

 archetypes, and constitute the thorax.* 



Fig. 464. 



PROP. XXXIII. The Ventral Apparatus oc- 

 curs opposite to the lumbar spinal region, where 

 we understand that costal quantity is lost. The 

 ventral apparatus refers to the lumbar vertebrae, 

 and consists of their ribs metamorphosed. With 

 the mere change of name from hyoid to ven- 

 tral apparatus, I may apply the foregoing 

 remarks, which prove that the hyoid appa- 

 ratus has come of the metamorphosis of the 

 ribs of cervical vertebrae, to demonstrate, also, 

 that the ventral apparatus ( 1, 2, 3, 4, 5, 6, 7, Jiff. 

 464.) has come of the metamorphosis of ribs 

 proper to the lumbar vertebrae. As the origi- 

 nal or whole archetypal quantities from which 

 the hyoid apparatus and the cervical vertebra? 

 have been metamorphosed are of thoracic or 

 costo-vertebral proportions, so, in like manner, 



The lumbar spine and ventral apparatus of the Crocodile, 



Showing that the venlral ribs (1 to 7) are the proper continuations of the lumbar costal pieces, 

 b, c, d, e,f, g, h, with which they correspond numerically. 



I believe that the original or whole archetypal 

 quantities, from which the ventral apparatus 

 (1 to 8, /#.464.) and lumbar vertebrae (b to h, 

 X^.464.) have been metamorphosed, are also of 

 thoracic costo-vertebral proportions. In the 

 ophidian thoracic skeleton, I find that that 

 region of the spinal axis which corresponds 

 numerically to the cervical region of the mam- 

 mal spinal axis presents in thoracic costo- 

 vertebral proportions ; and therefore I say, 

 that the true interpretation of the law of for- 

 mation, which strikes the skeletal neck of the 

 mammal specifically different to the skeletal 

 neck of the ophidian, must be this, viz , that 

 the costo-vertebral original of the mammal neck 

 is equal and homologous to the persisting 

 figure of the ophidian neck ; but that meta- 

 morphosis has modified the original quantity of 

 the mammal neck (jty.455.) to its existing appa- 

 ratus of hyoid arcs a b and cervical vertebras, 

 whereas the original quantity of the ophidian 

 neck still persists. In the latter we therefore 

 find the cervix in thoracic costo-vertebral 

 quantity, having appended to it, in front, the 



* Professor Owen considers the first circle of the 

 fishes' throat apparatus as the only part of it which 

 is homologous to that of other animals, and ac- 

 counts all the succeeding arches (three or more in 

 number, and all similar to the first, however,) as 

 " appertaining to the system of the splanchno- 

 skeleton, or to that category of bones to which the 

 heart-bone of the ruminants, and the hard jaw-like 

 pieces supporting the teeth of the stomach of the 

 lobster, belong." See HOMOLOGIES, &c. 



simple hyoid apparatus metamorphosed of the 

 sternal elements. In the former we find the 

 cervix consisting of vertebrae with stunted 

 ribs, which are occasionally produced to more 

 imposing proportions, being then called " cer- 

 vical ribs" and still having appended to them, 

 in front, the hyoid apparatus. The same in- 

 terpretation will apply, also, to the mammal 

 lumbar spine (Jig. 455.), viewed in connec- 

 tion with the fibrous bands named " linece 

 transversae" (20 to 24) and "lineaalba" (d to 

 e). And still more evidently will the same 

 interpretation apply to the saurian lumbar 

 region (b to h,fg. 464.), arid the ventral appa- 

 ratus (I to 7) ; for this latter structure is 

 evidently composed of sternal and costal ele- 

 ments. What the hyoid apparatus is to the 

 cervical vertebrae, namely parts of the thoracic 

 original whole quantities, just in the same re- 

 lation stands the ventral apparatus of jig. 464. 

 to the lumbar vertebrae ; for I regard both 

 these latter structures to be parts, likewise, of 

 the thoracic whole quantities. The hyoid ap- 

 paratus refers to the cervical vertebrae, there- 

 fore, just as the costo-sternal structures of the 

 thorax refer to the dorsal vertebrae ; and in 

 the same relation does the ventral apparatus 

 of fiy. 464. refer to the lumbar vertebrae. If 

 we seek a proof still further that the original 

 quantities of the cervical and lumbar regions 

 of the spinal axis of any animal are thoracic 

 costo-vertebral quantities, equal to those of 

 the thoracic region of the same animal, we 

 have this proof in the fact, that all the spinal 

 T T 2 



