Chap. XII.] 



FISHES. 



believes, is permanent and best marked in the older males* 

 which have previously ascended the rivers. In these old 

 males the jaws become developed into immense hook-like 



Fig. 27.— Head of female salmon. 



projections, and the teeth grow into regular fangs, often 

 more than half an inch in length. With the European 

 salmon, according to Mr. Lloyd, 8 the temporary hook-like 

 structure serves to strengthen and protect the jaws, when 



8 ' Scandinavian Adventures,' vol. i. 1854, pp. 101, 104. 



