582 SNAKES. 



bird was struggling violently. Not getting good hold, the 

 snake put it down and began again, so that the poor little 

 sparrow was twenty minutes in being swallowed, gasping to 

 the last, and evidently only very feebly poisoned. One of the 

 Najas bit his companion, and held on for about ten minutes, 

 and for no reason whatever that one could discern. In no 

 other venomous snakes have I seen such prolonged suffer- 

 ing caused by such stupidity or bungling as in those young 

 African ' Ring Hals.' Their fangs are, however, exceedingly 

 short, as I found on examining a dead one, and this may 

 account for the slow effect of them. 



Three other heads were often seen in a row peeping out, 

 but belonging to harmless 'glass snakes,' and there was 

 intelligence in their looks ; for they recognised the keeper, 

 and advanced to the glass whenever he passed, asking 

 for their dinner as plainly as little snakes could ask. A 

 Heterodon exhibited equal intelligence when it was dinner- 

 time, and sprang at the glass when he saw the keeper 

 coming. Some of the pythons display intelligence too, on 

 feeding days, but of quite an epicure form. One day 

 in May 1876, on remarking that the pythons were disin- 

 clined to eat, Holland said ' they were waiting for young 

 ducks,' only elderly birds being in their cage at the time. 

 Even in summer they don't eat the old ducks so eagerly, 

 because the large, hard quills annoy them. A bunch of these 

 quills passes undigested. Hair or feathers in a desiccated 

 mass pass through the snakes, and occasionally, when they 

 are not in health, digestible but undigested substances too, 

 also the beaks of the ducks. 



Vegetable substances have been found in snakes, from 



