THE COD FAMILY . 99 



The ling lias a very elaborate dentition, as is well shown in the 

 drawing. TJiere is a broad band of small teeth, throe deep extending 

 fmther back than in the cod and witliin this on the vomer is a 

 raised horse-shoe shaped area bearing four teeth on either side, 

 and a single median tooth ; these are conical in form, strong, and 

 sharp. The dentition of the pollack is simpler ; there is a band of 

 small teeth in two rows, but mesially in four rows ; there is a V- 

 shaped area on the vomer with small sharp curved teeth in two 

 rows. Both the dentary formula of ling and pollack point to a well- 

 marked predatory habit of feeding. The dentition of the hake will 

 be described later in the chapter devoted to this interesting fish. 



Reviewing the above descriptions it is clear that the haddock, 

 cod, whiting, and pollack have teeth suitable to their diet, and we 

 note a more or less gradual change in type as the crustacean and 

 shell-fish diet gives place to a purely fish diet. The ling has a unique 

 dentition and this is most evident in the vomerine teeth. It may be 

 that this dentition is of some particular value in its nocturnal 

 habits of hunting, but what precise use the conical teeth are to the 

 fish and why they have been evolved is difficult to imagine. 



In the descriptive letterpress to the drawings of gadoid brains, 

 there is given a short summary of the chet of each fish. We propose 

 to amplify the facts there stated, as there has been a vast amount 

 of research on the stomach contents in recent years by the naturalists 

 of the Ministry of Agriculture and Fisheries. These reports we 

 shall quote and also make free use of the textbooks of Cunningham 

 and Travers Jenkins. Starting with the haddock, it is found that 

 crustaceans and molluscs are found most frequently. The actual 

 percentages vary, but if we pool the observations of all the observers 

 they are present in about equal jDroportions. Polychaete worms and 

 echinoderms are also found, but fishes rarely, and never more than 

 three to five per cent, of the contents. Herring spawn may occur, 

 whence the name, " spawny haddocks," apphed to the fish at certain 

 periods. The haddock is, therefore, with reason, called by the 

 Germans " the shell-fish." 



The cod, gadus morrhua, is the next in the series and is found 

 to be not only a feeder on the bottom fauna, but is also predacious 

 and hunts other fish. Like the fishermen who go to sea in a drifter- 

 trawler, when herring are about, the pursuit of fish is the means of 

 livelihood, and at other times the bottom of the sea provides the 

 harvest. But further complications arise in the feeding habits of 

 the cod, as with advancing size the diet of this fish changes, it 

 might almost be said becomes reversed. The cod is a voracious 

 feeder on other fish and also has a marked appetite for Crustacea. 



