SKELETON. 



635 



contains seven. The human cervix (B, fig. 

 457.) occasionally develops only five or six. I 

 have seen some species of the monkey tribe 



wherein the cervix counted only five or six ; 

 and I have no doubt, that if we dissected 

 other mammalian bodies as frequently as we 



A, the neck of the sloth (Bradypus didactylus), representing the costo-sternal quantities lost to 

 the seven cervical vertebras ; B, the neck of another species of sloth {B. tridactylus), exhibiting the 

 loss of costo-sternal quantity, from nine cervical vertebrae. In both figures it is shown how 

 the numerical diiference of vertebrae of the cervix depends upon the number of metamorphosed 

 archetypes. 



do the human subject, we should find also in 

 them many exceptions to the rule which we 

 now call general. 



But these exceptions will be called " ano- 

 malies " by the special anatomist. To this I 

 answer, that if we understood fairly the true 

 interpretation of the universal law, we should 

 forthwith blot out the word anomaly from 

 anatomical nomenclature ; for there can be 

 no anomalies any more than there can be 

 exceptions to the universal law. Anomalies, 

 such as they appear upon the bodies of one 

 species, as, for instance, the cervical ribs (a, b) 

 of the cervical vertebrae (6, 7 of B, fig. 457.), 

 are, in reality, not more remarkable to the 

 normal condition of that species than the 

 figure and proportions of one species (\,fig. 

 456.) are to those of another and different 

 species (p,fig. 456.). The same law presides 

 over ail conditions of formation. * 



PROP. XXIV. The number of cervical 

 vertebrcB in the mammal cervix depends 

 upon the number of archetypal costo-vertebral 

 figures which have suffered metamorphosis. 

 Even if it were true that the mammal 

 cervix invariably contains the fixed number 

 of seven vertebrae, still there would appear no 

 reason why we should not interpret the fact 

 in the following mode, namely, that the seven 

 cervical vertebrae of fig. 455. are those pro- 

 portional osseous quantities left standing after 

 the metamorphosis of the ribs (1, 2, 3, 4, 5, 

 6, 7) of seven costo-vertebral archetypes. 

 For it is evident that cervical vertebrae do, 



* " Tout phe'nomene dans la nature est lie a 1'ea- 

 semble ; et, quoique nos observations nous semblent 

 isolees, quoique les experiences ne soient pour nous 

 que des faits individuels, il n'en resulte pas qu'elles 

 le soient reellement ; il s'agit seulement de savoir 

 comment nous trouverons le lien qui unit ces faits ou 

 ces evenements entre eux." Gcethe,(Euv. d'HistNat. 

 Introd. p. xi. traduits par Martins. 



like the thoracic figures, contain costal ap- 

 pendages, although in rudimental propor- 

 tions. In the cervical vertebra? the costal 

 pieces are liable to a plus condition (a b, of B, 

 fig. 457.). In the thoracic vertebrae the costae 

 are fully produced. 



Fig. 457. 



A, the human cervix, numbering only five cervical 

 vertebrae of normal quantity, owing to the pre- 

 sence of a, b, the cervical ribs persistent on the 

 6th and 7th vertebrae ; B, the cervix of the sloth 

 (B. tridactylus ), which numbers as many as nine 

 cervical vertebrae, in consequence of the metamor- 

 phosis of nine costo-sternal quantities. 



If it were possible to raise a rational objec- 

 tion to the above mentioned interpretation of 

 the cervical spinal region, I would then re- 

 mark that "cervical ribs" do still further 

 prove the truth of what I advance concerning 

 this region of the spinal axis. For is it not 

 true that when the sixth or seventh cervical 



