SKELETON. 



633 



of uniformity throughout the serial line of 

 spinal segments such as they are, we must 

 submit them to a mental process of com- 

 parison which is to tell us what they once 

 were. For as it is evident that these seg- 

 ments are only proportionally various, so is 

 it equally evident that their plus originals 

 must be uniform and absolutely similar. When 

 I compare a caudal, a lumbar, or a cervical 

 segment with a sternal costo-vertebral seg- 

 ment, I must acknowledge to a specific dif- 

 ference existing between these bodies ; but 

 then I also have every reason to believe that 

 this specific difference is only a proportional 

 difference.* If, then, the cervical, lumbar, or 

 caudal segment shall severally prove to be 

 parts or proportionals when they are com- 

 pared with a sternal costo-vertebral segment 

 standing at the thorax, it cannot be errone- 

 ous to read them as having been meta- 

 morphosed from their own originals, such as 

 those of the thorax, and hence 1 conclude that 

 uniformity alone characterises the series of 

 such originals. -f- 



PROP. XVIII. Every spinal segment which 

 is lesser, refers to every spinnl segment which is 

 greater ; and all lesser segments refer to that 

 which is greatest. If it be easy to conceive that 

 the last caudal bone (i, t y%.444.) is a lesser quan- 

 tity metamorphosed from such another quantity 

 as the penultimate caudal bone (H, fig. 444.), 

 where can be the difficulty in rationally inter- 

 preting both to be as quantities metamor- 

 phosed or proportioned from such quantities 

 as lumbar vertebrae (E, fig. 444.), and hence 

 from such segmental quantities as sternal 

 costo-vertebral plus forms (such as^/fg. 453.). 

 I could not entertain this idea of a caudal 

 bone, if I found that it were an ens holding 

 within its dimensions any elemental part 

 which may not also be found to be contained 

 in the plus form of fig. 450. ; or if it were 

 not the fact that the archetype (fig. 450. 

 or 453.) could undergo a simple graduated 

 metamorphosis of its parts (1,2, 3, 4, 6), so 

 us to simulate any other segment of the spinal 

 axis lesser than itself.^ A caudal ossicle, 



* The number of proportionals capable of being 

 struck from a Avhole quantity being of infinite 

 amount, it will be also seen that the number of 

 species which those proportionals themselves repre- 

 sent are likeAvise infinite. " Species autem ilia ab- 

 scissio infinite recte vocari possit." Bacon, Nov. 

 Organon Scientiarum, Aph. 2G. 



f The series of the archetypal sterno-costo-verte- 

 bral circles constitutes absolute uniformity ;and when 

 we contrast with this quantitative uniform line this 

 other line of graduated proportional serial quantities, 

 such as the present state of the mammal skeletal 

 axis exhibits them, we are enabled to estimate the 

 law which has created the line of proportional quan- 

 tities such as we find it. When the special or pro- 

 portional thing is contrasted with the uniform whole 

 or complete quantity, the contrast gives the inter- 

 pretation. If species arise from the infinite sub- 

 division of the line of whole quantities, then this 

 latter, as perfect quantitative uniformity, may be 

 defined as follows : " Unitas (uniformitas) est sine 

 commissura (sine hiatu) continuatio." Seneca, Na- 

 tur. Qusest. lib. xi. 



J " The great advantage of this idea of a whole 

 is, that a greater quantity of truth may be said to be 



such as the centrum (Jig. 453. 5), reminds 

 me as strongly of its original whole quantity, 

 viz. Jig. 453., from which it has been meta- 

 morphosed as a dorsal spinous process (I, 

 Jig. 450.), separated from that thoracic seg- 

 ment, reminds me of the whole of such seg- 

 ment. If it be true that I could never thus 

 interpret the caudal ossicle, if I had not seen 

 the thoracic archetype, this can be no argu- 

 ment to show the error of my interpretation ; 

 for it is equally true, that I could never know 

 of what whole figure the dorsal spinous pro- 

 cess was a part, if I had not seen the thoracic 

 segment named costo-vertebral.* 



PROP. XIX. Structural uniformity cannot 

 characterise such spinal segments as are pro- 

 portionally or quantitatively various. A cer- 

 vical segment differs from a thoracic seg- 

 ment by existing quantity ; and the like dif- 

 ference prevails between all other segments 

 of the spinal series, therefore those segments 

 cannot be termed uniform. But though these 

 segments are not uniform by reason of their 

 bemg unequal things, still it is most true, that 

 they are only diversified by reason of their 

 quantitative inequality. In fig. 455. all the 

 spinal segments are rendered plus and equal, 

 by supplying in idea the osseous quantities 

 lost at neck and loins. 



PROP. XX. Specific variety is none other 

 than proportional variety. A cervical, a lum- 

 bar, a sacral, or a caudal spinal segment is 

 various to a thoracic segment, forasmuch 

 only as the former fall short of those parts 

 which are proper to the latter figure, and 

 therefore I say that specific variety is none 

 other than proportional difference. For when, 

 asinJZg. 455 , we equate those segments which 

 are proportionally different, we re-establish 

 uniform series. 



PROP. XXI. The knowledge of the differ- 

 ential quantity between all spinal segments 

 renders them exactly uniform in idea. Upon 

 holding comparison between one spinal seg- 

 ment and another, when I find that certain 

 persistent parts of the segment of greater 

 dimensions, viz. that of the thorax (fig. 455.), 

 are those which are subtracted from the 

 segment of lesser dimensions, viz. that of the 

 neck or loins (fig. 455.), this is tantamount to 

 the knowledge that the lesser segment has 

 lost those parts which are persistent for the 

 greater. And therefore 1 say, that in the 

 knowledge of those parts which are wanting 



contained and expressed in it." Sir Joshua Rey- 

 nolds' Discourses, Discourse xi. 



* The self-evident truth which attends the geo- 

 metrical axiom, that the whole is greater than its parts, 

 needs no comment to sustain it ; but that the part 

 standing alone per se still refers to the whole quan- 

 tity of which it is the part, requires to be insisted 

 upon much oftener, for at first sight we are apt, 

 without reflection, to regard it as it is in the light of 

 a perfect figure. How many anatomists are there 

 who never waken to the idea', that every lesser seg- 

 ment of the spinal axis refers to the greater whole 

 quantity ; and yet in this interpretation the law of 

 formation enshrines itself. "L'ensemble de tous les 

 ordres de perfections relatives, compose la perfec- 

 tion absolue de ce tout." Bonnet, Contenip. de la 

 Nature, part i. chap. iii. 



