96 



STRUCTURE OF SERPENTS. 



their ribs are also very numerous ; and they are able to crawl 

 upon the points of these, using them almost as Centipedes do 

 their legs (fig. 42). But in general the movement of their 



Fig. 34. ANATOMY OF A COLUBER 



bodies is accomplished by their being drawn-up into folds, 

 and then straightened so as to project the head. The pro- 

 longed form of the body in Serpents occasions a curious 

 variation in the arrangement of the principal organs, which 

 is shown in the accompanying figure. The oesophagus or 



