338 



UTILITARIAN ZOOLOGY 



Mention may here be made of the fact that two species of 

 poisonous Lizards exist, both native to North America. One 

 \Helodcr7na Iwrridmn, fig. 1236) is a Mexican form, while the 

 other, commonly known as the "Gila Monster" {H. szispectum), 

 inhabits New Mexico and Arizona. The sharp curved teeth of 

 these creatures are grooved in front and behind for the purpose of 

 conducting the poison, which is secreted by a series of small glands 

 opening along the edge of the lower jaw. Of the Gila Monster, 



Fig. 1236. — Mexican Poisonous Lizard [Heloderiiza hcryidiDn) 



Gaclow states (in The Cambridge Nattiral History): — " Frogs are 

 probably paralysed or killed by the bite, which, although not so 

 dangerous as that of poisonous snakes, is effective enough to 

 produce severe symptoms even on man, and a few cases of death 

 of people who had been bitten are on record ". 



Poisonous Snakes are among the most formidable personal 

 enemies of man, and are justly dreaded in the countries they in- 

 habit, which embrace all but the coldest parts of the globe. There 

 is also reason to think that at least one of the larger non-poisonous 

 snakes, i.e. the Anaconda or Water-Boa [Eiineces nmrinns) of 

 northern South America, may now and then crush and devour 



