THE LIZARD AND ITS ALLIES 



271 



ous yellowish punctations (Fig. 253). It is nocturnal in 

 its habits and its bite is very poisonous, although not often 

 fatal to man. 



The family Anguidae, or slow-worms, includes the famous 

 glass-snake or joint-snake of the South. * This snake-like 

 lizard has no legs, or only rudiments of the hinder pair. 

 It is noted for the ease with which 'it breaks in two when 



FIG. 253. Heloderma, the Gila monster. About two-fifths nat. size. 

 From Brehm. 



struck or lifted by the tail. This result is due to the fact 

 that, as in certain other lizards, the vertebriB of the tail are 

 unossified along the middle plane, so that they separate 

 at this point upon the slightest blow. The muscles of this 

 species seem also to be arranged so as to facilitate sepa- 

 ration. In Europe there is a lizard of this family, the 

 so-called " blind- worm " (having, however, well-developed 



