THE TEETH OF FISHES. 225 



means of these largest teeth ; then, after holding it thus for 

 a time, and so maimed it and lessened its power of escape, it 

 swallows it, generally head foremost. The tenacity of the 

 pike's hold is often illustrated when it takes a bait, and 

 retains it so firmly that when the angler " strikes " the 

 hooks do not get driven into the fish's mouth; but after 

 tugging at the bait for a time the pike releases it, and the 

 angler finds that it has never been hooked at all. 



The margin of the upper jaw is not bordered by teeth, 

 save at the front, where the intermaxillary bones carry a 

 few teeth of insignificant dimensions ; indeed, it is rather 

 exceptional for the true maxillary bones to carry teeth in 

 osseous fish. The roof of the mouth presents three wide 

 parallel bands of teeth, those in the median band (on the 

 vomer) being directed backwards, those upon the lateral 

 bands (on the palatine bones) backwards and inwards. 

 Some of the latter teeth are very large, but not quite so 

 large as those at the sides of the lower jaw. 



The marginal teeth are firmly anchylosed, but the teeth 

 upon the palate are all hinged, and in such a manner that 

 they can only bend exactly in one direction. Those of the 

 vomerine band which lie in the middle line, will bend back- 

 wards only ; those upon the outer margins of this band 

 backwards, with an inclination outwards. Those of the 

 lateral or palatine bands bend obliquely backwards and 

 inwards, about at an angle of 45 with the median line of 

 the mouthj or somewhat more directly backwards. To a 

 body sliding over them in one direction they offer no 

 resistance, bending down as it passes, and springing up as 

 the pressure is removed from them, but to anything moving" 

 in any other direction they are rigidly fixed sharp curved 

 stakes impeding its further progress. 



An elongated body of some size, such as a living fish, 

 can only be swallowed by the pike when it is arranged 

 lengthwise in the mouth; crosswise it cannot possibly enter 



Q 



