CHAPTER VII. 



THE SPIKAL COLUMN OF REPTILES. 



Leaving the birds, the various reptile tribes 

 next demand our notice. The difference in 

 form and habits between the numerous groups 

 into which the reptiles are divided is very- 

 great. Some have four limbs, some only two, 

 and some none. Some are clad in strong 

 armour, some are clad with scales, and some 

 are naked. Some are terrestrial, some aquatic, 

 and some arboreal. Some dart along with 

 wonderful rapidity, others are sluggish and 

 heavy in their movements. Many are capable 

 of writhing and twisting their forms into various 

 curves or flexures; others have no movements 

 excepting those of the head and limbs. Under 

 all these circumstances great modifications in 

 the character of the spine may be expected, 

 and nothing affords a more decided contrast 

 than that of the tortoise compared with that of 

 the serpent. 



