OVOVIVIPARITY 



it is not so frequently seen as the more active common 

 lizard Lacerta agilis, on account of its retiring habits. 

 Unfortunately for itself the slow-worm does not dislike, 

 indeed it seems to prefer, the neighbourhood of human 

 habitations ; this is unfortunate, for the animal has 

 succeeded in gaining a most terrific reputation for 

 poisonous properties, of which it has not the slightest 

 hint. It has thus suffered much persecution by hob- 

 nailed boots. It is true that the slow-worm will bite 

 at times, especially during the breeding season, which 

 seems to be productive of irascibility in the animal 

 world generally. But its tiny teeth will not scratch, 

 let alone bite, the human skin to any purpose. It has 

 been pointed out, however, that this reptile has some 

 of its teeth grooved. Now that is a character of the 

 only known poisonous lizard Heloderma, and of certain 

 snakes known as venomous colubrines. But there is no 

 developed salivary gland in association with these 

 grooved fangs, which are, however, sufficient to retain 

 a hold of slugs, which the slow- worm particularly affects 

 as food. Anguis fragilis occurs nearly all over Europe, 

 avoiding the colder northern regions ; like most other 

 reptiles it is not to be found in Ireland. It brings forth 

 its young alive like many lizards, but this process 

 must not be confounded with the mammalian method 

 of gestation. For in the snake the eggs are merely 

 retained in the oviduct until they are hatched ; there 

 is not any connexion by growth with the parent as 

 in the mammalian foetus. The family to which Anguis 

 fragilis belongs, the anguidse, contains a number of 

 other forms of which some are legless, and others possess 

 the normal complement of three appendages. The 

 large grass snake of Russia and Morocco, often to be 

 seen at the Zoo, grows to three feet or so in length and 

 is much like an enlarged edition of the slow-worm ; 

 but it has, which the slow- worm has not, a deep groove 



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