112 



ANIMAL SKETCHES. 



CHAP. 



ballast to keep them down, without which they could not 

 dive to catch fish. I have opened them at this time, and 

 found in a pouch they have inside upwards of twenty-five 

 pounds of stones, some as large as a goose-egg. As they 

 get thin they have the power of throwing up these stones, 

 retaining only a sufficient quantity to keep them from 



CAUGHT ! 



coming up too freely to the surface." It is probable how- 

 ever that the primary object of swallowing the stones is 

 to aid in the preparation of the food (which is not masti- 

 cated in the mouth) for digestion ; but at the same time 

 it is not impossible that on this primary digestive purpose 

 a secondary ballasting purpose has been engrafted. The 

 captain of a small sailing vessel at the Cape assured me 



