CHAPTER XI 



THE FKAGILITY OF THE TAIL IN LIZARDS 



It is a matter of very common knowledge and ob- 

 servation that in some families and species of lizards, 

 the tail is extremely fragile. The European slow- 

 worm {Anguis fragilis) takes its specific name from 

 this circumstance. This anomalous reptile if startled 

 or taken hold of at once stiffens its tail into a rigid 

 condition, and very slight violence is then sufficient to 

 cause a fracture of the tail, either complete or partial. 

 If complete, the portion of tail broken off remains 

 in the grasp while the lizard escapes ; if partial, the 

 fracture appears on the ventral aspect of the tail as a 

 transverse crack, but remains attached along the dorsal 

 aspect. When the lizard thus makes the tail rigid, a 

 very slight blow is enough to cause part of the tail to 

 come away, and the reptile is apparently none the 

 worse for the loss of a portion of its anatomy. 



Ophiologists have accounted for this remarkable 

 phenomenon by the peculiarity of structure exhibited 

 by some families of Lacertilia in the caudal vertebrae. 

 Thus Professor Cope in his monumental work on The 



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