16 BRITISH LIZARDS 



pared for examination by allowing the bones which 

 have been partially stripped of muscles, to soak in 

 water for some time. The soft parts which are left 

 will soon decay, and can then readily be stripped off, 

 leaving the bones clean. A quicker method is to boil 

 the specimen for a quarter of an hour, which renders 

 the soft parts easily detachable. 



Having, in one or other way, prepared a clean 

 skeleton, observe first the vertebral column. Eight 

 vertebrae are found in the cervical or neck region, 

 then follow twenty-two in the trunk region ; behind 

 these, two vertebrae in the sacral region to which the 

 pelvis is joined ; and, lastly, a number of vertebrae 

 in the tail, the number of which vary in different 

 specimens. 



The ribs arise in pairs from the vertebrae, but not 

 from all. They are largest in the front part of the 

 chest, where they are joined to the sternum or breast- 

 bone, smaller in front of this, and become gradually 

 smaller as we trace them backwards from the chest to 

 the sacral region. 



Note particularly the shape of the large vertebrae. 

 They are concave in front, convex behind, the type of 

 vertebrae called procoelous. They thus form a series 

 of cup-and-ball joints, which are admirably adapted 

 for flexibility and general ease of motion. Five ribs 

 will be found to articulate with the sternum, the 

 hinder ribs of the thorax do not reach it. In the 

 neck region ribs will be found arising from the last 



