64 Traces of Unity in the 



On Icfoking into the matter more particularly there 

 is found to be a tendency to the formation of arti- 

 cular processes by which contiguous vertebra:; are con- 

 nected together at those parts where limbs or appen- 

 dages of various sorts spring from the vertebrae. The 

 skeleton of the fish is especially significant in this 

 respect. At the parts where the sternal and dorsal fins 

 are given off (provided these fins be well developed) 

 there is a chain of osseous bodies formed by the de- 

 velopment and articulation with each other of the 

 bases of the fin-rays, and thus is formed, as it were, an 

 additional spinal column in the median line above and 

 below the true spinal column. In animals higher in the 

 scale of being than the fish, the development of limbs 

 from the median regions is no longer manifest, but a 

 tendency to it may be detected still in cases where the 

 ridge of the sternum and the spinal processes of the 

 vertebrae are especially developed. In the chelonian, 

 moreover, the bases of these latter processes in the 

 region of the carapace are developed into perfect arti- 

 cular processes, by the union of which a quasi-spinal 

 column of a rudimentary character is formed behind the 

 neural axis. In the majority of vertebrate animals, 

 behind the bodies of the vertebrae there is also a double 

 chain of lateral connecting surfaces the oblique or 

 articular processes which would seem to have a close 

 relation to limbs or organs. At any rate, in connection 

 with them are osseous projections which, though more 

 rudimentary than other processes belonging to the same 

 vertebrae, are yet now and then (especially in marsupial 

 animals and birds) developed to such a degree as to 

 make it impossible to overlook them. In the animals 

 which have just been named, indeed, the outwardly pro- 

 jecting portion of the oblique processes are so highly 



