378 THE DESCENT OF MAN. 



half an inch in length. With the European salmon, 

 according to Mr. Lloyd,* the temporary hook-like structure 



Fig. iff. Head of male common salmon (Salmo solar) during the breeding- 

 season. 



[This drawing, as well as all the others in the present chapter, have been exe- 

 outed by the well-known artist, Mr. G. Ford, from specimens in the British 

 Museum, under the kind superintendence of Dr. Qunther.] 



serves to strengthen and protect the jaws, when one male 

 charges another with wonderful violence; hut the greatly 

 developed teeth of the male American salmon may be com- 



" Scandinavian Adventures, " vol.. j, 1854, pp. 100, 104 



