135 



lengcth or number of the gill-rakers has much to do with the abundance 

 of Entomostraca and other minute animal forms in the food of the 

 fish, while the presence or absence of the terminal hook or the 

 masticatory surface to the pharyngeal teeth is not thus far shown 

 to have any sensible influence upon the general average of the 

 food. Finally, a species may depart widely in food characters 

 from those more nearly allied to it in structure, if its favorite 

 haunts are peculiar. 



