92 SNAKES. 



Mr. Mann confirmed all these facts in his own ophidian 

 pets, and going to see these interesting individuals, we felt 

 no doubt about it when a saucer of water was in the way. 



But I do feel inclined to doubt whether the use of the 

 tongue in 'lapping,' as it has been called, is not rather to 

 moisten that organ than to quench the thirst. We shall see 

 in the following chapter what it does for its owner, and we 

 shall see the necessity for this delicate organ to be well 

 lubricated. Both it and its sheath require to be constantly 

 moistened ; how else could it glide in and out with that 

 wonderful activity ? how in a dry and parched condition could 

 it retain its exceeding flexibility and delicacy of perception ? 



Unfortunately, the position of the tanks in the cages at 

 the London Zoological Gardens, and the stone ledge in 

 front of them, prevent the visitors from watching the actions 

 of the snakes in the water, either when swimming or drinking. 

 Occasionally one of the inmates of the larger cages may be 

 seen in a pan of water, though their motions are necessarily 

 restricted there. One day, however, the yellow Jamaica 

 boa, when drinking from the pan, afforded an excellent 

 opportunity for observation. And he was a long time 

 imbibing. There was no perceptible action of the lips, 

 which were barely parted. The snake kept its mouth 

 just below the level of the water, and the only action or 

 movement seen was at the back of the head, or on each 

 side of the neck, like a pulsation, as the water passed down 

 in short gulps. This is the * suction ' which writers describe, 

 a drawing in of the liquid ; but the lips do not take part in 

 the act. When, therefore, we read that snakes drink both 

 by lapping and also by suction, we may surmise that the former 



