92 THE FOOD OF ANIMALS 



below the skin, and which possesses the unpleasant property of 

 secreting enormous quantities of slime by means of the glandular 

 skin. This creature is able actually to bore into the bodies of 

 other fishes, though the common idea that a cod can swim about 

 with a hag-fish half-imbedded in it rests on slender foundation. 

 The fact appears to be that when cod are caught on deep-sea lines 

 they are often attacked by the hag, which bores some distance into 

 them before they are pulled up. 



PRIMITIVE VERTEBRATES 



The lowly Vertebrates, or more properly speaking Chordates, 

 wnich are inferior in the scale to Fishes, feed to a large extent on 

 animal matter, but as their diet is also in part of plant nature it 

 will be best to leave them till omnivorous forms are described. 



