VIVIPAROUS LIZARD. 35 



not found in Italy, nor, I believe, in France, and is very 

 probably confined in a great measure to our own latitude. 

 Its movements are beautifully gracile as well as rapid ; it 

 comes out of its hiding-place during the warm parts of the 

 day from the early spring till autumn has far advanced, 

 basking in the sun, and turning its head with a sudden mo- 

 tion the instant that an insect comes within its view, and 

 darting like lightning upon its prey, it seizes it with its little 

 sharp teeth and speedily swallows it. Thus it will often 

 take a great number of the smaller insects, preferring those 

 of the dipterous order ; though it will not refuse many of the 

 coleoptera or orthoptera, if they be not too large. 



Instead of depositing her eggs in the sand to be hatched 

 by the warmth of the sun, as is the case with the former, 

 the female of the present species retains the eggs within the 

 oviduct until the young are ready to leave them, and they are 

 produced alive. As in all the ovo-viviparous reptiles, the 

 covering of the egg is very thin, and merely membranous. 

 In this respect they differ from those which deposit their eggs 

 before the embryo is formed. In the latter case a more 

 efficient protection is necessary, and the covering is either 

 calcareous, as in the Tortoises and Crocodiles, or of a sub- 

 stance resembling parchment, as those of the Snakes and 

 most Lizards. In the Viper, which also produces its young 

 alive, the covering, as in the present animal, is extremely 

 thin and very easily torn ; and there is reason to believe that 

 the laceration of this membrane and the emancipation of the 

 young take place in and are occasioned by the very act of 

 parturition. 



As the young ones are occasionally found with the mother, 

 there is some reason to believe that these little animals are 

 not wholly devoid of the instinct of parental care and tend- 

 ance ; but it is scarcely probable that the exercise of this 

 feeling is ever very powerful, or that it endures for any con- 



