LIMBS OF THE CROCODILE. 117 



sense ; that in tlie fish the scapiila-coracoid arch is in its 

 natural or typical position, whereas in the crocodile it 

 has been displaced for a special purpose. Thus, agree- 

 ably with a general principle, we perceive that, as the 

 lower vertebrate animal illustrates the closer adhesion to 

 the archetype by the natural articulation of the scapulo- 

 coracoid arch to the occiput, so the higher vertebrate 

 manifests the superior influence of the antagonizing 

 power of adaptive modification by the removal of that 

 arch from its proper segment. 



The anthropotomist, by this mode of counting and de- 

 fining the dorsal vertebrae and ribs, admits, unconsciously 

 perhaps, the important principle in general homology 

 which is here exemplified; and which, pursued to its 

 legitimate consequences, and further applied, demon- 

 strates that the scapula is the modified rib of that 

 centrum and neural arch, which he calls the " occipital 

 bone ;" and that the change of place which chiefly masks 

 that relation (for a very elementary acquaintance with 

 comparative anatomy shows how little mere form and 

 proportion affect the homological characters of bones), 

 differs only in extent, and not in kind, from the modifica- 

 tion which makes a minor amount of comparative obser- 

 vation requisite, in order to determine the relation of the 

 shifted dorsal rib to its proper centrum in the human 

 skeleton. 



With reference, therefore, to the occipital vertebra of 

 the crocodile, if the comparatively well-developed and 

 permanently-distinct ribs of all the cervical vertebrae 

 prove the scapular arch to belong to none of those seg- 

 ments, and if that haemal arch be required to complete 

 the occipital segment, which it actually does complete in 



