NATURAL HISTORY 



helpless young down her throat on sudden surprises, 

 just as the female opossum does her brood into the 

 pouch under her belly, upon the like emergencies ; and 

 yet the London viper-catchers insist on it, to Mr. Bar- 

 rington, that no such thing ever happens 10 . The serpent 

 kind eat, I believe, but once in a year ; or, rather, but 

 only just at one season of the year 11 . Country people 

 talk much of a water-snake, but, I am pretty sure, 

 without any reason ; for the common snake (Coluber 

 Natrix) delights much to sport in the water, perhaps 

 with a view to procure frogs and other food. 



I cannot well guess how you are to make out your 

 twelve species of reptiles, unless it be by the various 

 species, or rather varieties, of our Lacertce, of which 

 Ray enumerates five. I have not had opportunity of 

 ascertaining these ; but remember well to have seen, 

 formerly, several beautiful green Lacertce on the sunny 

 sandbanks near Farnham, in Surrey 12 ; and Ray admits 

 there are such in Ireland. 



10 I have been assured by a very honest and worthy gardener in Dor- 

 setshire, that he had seen the young vipers enter the mouth of the mother 

 when alarmed. I have never been able to obtain further evidence of the 

 fact, though I have made the most extensive inquiries in my power. If 

 it be untrue, the popular error may have arisen from the circumstance of 

 fully formed young having been found in the abdomen of the mother, 

 ready to be excluded. The actions of the young which were emancipated 

 from the oviduct by White on a subsequent occasion (see Letter XXXI. 

 to Daines Harrington) do not appear necessarily to bear upon the question, 

 as there are many instances of the young of animals manifesting the 

 habits and instincts of their species immediately on coming into the world 

 as in the case of young ducks seeking the water, &c. T. B. 



II The slow power of digestion possessed by serpents renders them 

 capable of remaining long without food. If a snake swallows a frog, 

 or a viper a mouse, it is several weeks before it is digested. It is 

 probable, accordingly, that they do not eat above three or four times in 

 the course of a summer, and in winter not at all. During the summer of 

 1830, I kept both a slow worm ( Anguis fragilis) and a snake (Coluber 

 Natrix) for several months, during which time they refused every sort of 

 food I could offer them. When taken in the autumn, M. Bory St. Vincent 

 says they will endure abstinence for an incredible period ; but this will 

 not be the case if they are taken in spring. RENNIE. 



12 [See Letter XXII.] 



