CODS. 



4g:) 



tliey soinetiiiics cIkjoso to cuter fresh water". Striclly 

 speaking, we can hanlK call tliciii deeiJ-sea fishes; hut 

 some species descend to a depth of at h'ast ')•)() or (iOO 

 metres. Tlieir ]iroiiouiiced gregarious habits and their 

 voracity make them an easy prey; and as the flesh of 

 most of them is well-i<nown lor its wholesome (pialities 

 and good flavour, main- of them are the ol)jects of most 

 productive fisheries. 



The difference between the species of the genus is 

 so slight that to divide it into subgenera, for which end 

 several systems h-.wc been suggested, has hitherto proved 

 almost impracticable. Still, the species compose sevei'al 

 form-series, \\hicli, when we take into account the clian- 

 ges of growth, apjjear to be stages of development, more 

 or less advanced in difterent respects, and issuing from 

 a starting-point that has probably been common to this 

 genus and the following one. The first series contains 

 one species in the Scandinavian fauna, Gadiis pontassoK, 

 which is without pyloric appendages, anfl tims comes 

 nearest the Hake {Mcrlurius mcrluccius), which has oidy 

 one appendage to the intestine. The Poutassou is also 

 remarkable for the gi-eat length of tlie base of the fii'st 

 anal fin; and the historv of development brings to light 

 in the true Cods the general rule that the relative length 

 of this fin decreases during the growth of the iish. In 

 some of the species, however, the Coalfishes and Whithigs 

 for example, the length of the first anal fin is persist- 

 ently at least more than half the distance between this 

 fin and the tip of the snout; -wliile in others the first 

 anal fin invariably measures less than half tiiis distance, 

 this last group containing the true Coch. In two re- 

 spects, which are indicated bv different changes of groAvth 

 of fair constancy, the Coalfishes and Whitings differ so 

 greatly from each other that they may well be regarded 

 as representatives of distinct gi'oups in the system. The 

 relative length of the snout increases wdth age, but that 

 of the lower jaw decreases. In these respects the Coal- 

 fishes occupy a lower rank in the scale of development 

 than the Whitings. Again, the Coalfishes and their allies 

 arc distinguished from the true Cods \)\ tiie greater 

 length of the lower ja\v (a relatively shorter snout) in 

 the former; and tlie Haddock, which in this respect 

 (with the relatively longest snout) stands highest in 



ment, thus claims a group for it- 



the generic develop 

 self in our fauna. 



These series of forms mu\\ be arranged according 

 to the following characlci's: 



I: Ijcngth of tlio liase of the iiist anal I'm 



less than hull' the distance between tliis 



fin and the tip of tlie snout: 



A: Least depth of the tail at least about 



half (iriore than 411 %) of the length of 



the lower jaw Gadus a'c/lejinus. 



B: Least dc])th of the tail distinctly less 

 tliiui half (less than 4(> %) of the length 

 of the lower jaw: 



a: Jjcast depth of the tail move than 

 ' ^ I if the length of the pectoral fins 

 or than 30 % of the lengtli of the 

 lower jaw: 



a; Lengtli of the head more than 

 V4 of that of the body: 

 aa: Least breadth of the inter- 

 orbital space more than :^S 'i 

 of the length of the head.. GcuUts oi/uc. 

 (i(i: Least breadth of the inter- 

 orbital space less than 2>S % 

 of the Icnjrth of the head.. OcuIuk callaria.f. 

 fi: Length of the head less than 

 24 % of that of the body: 

 aa: Length of the snout less 

 than -, .J of the postorbital 

 length of the head; least 

 depth of the tail more than 

 41 % of the lengtli of the 



lower jaw. Gadus gracilis. 



/V;S; Length of the snout more 

 than (58 ', of the postorbital 

 length of the head; least 

 depth of the tail less than 

 40 "o of the length of the 



lower jaw Gadus lutvaga. 



b: Least depth of the tail less than 

 23 °o of the length of the pectoral 

 tins or than 29 % of the length of 



the lower jaw Gadus saidu. 



Lenffth of the base of the first anal fin 

 more than half the distance between this 

 fin and the tip of the snout: 

 1 : Length of the base of the first dorsal 

 fin more than 30 % of that of the base 

 of the first anal fin, and the length of 

 the base of tlie second dorsal fin more 

 than 5(1 \ of the latter: 

 A: L pper jaw projecting beyond the 

 lower jaw (length of the snout and 

 the upper jaw-bone — distance be- 

 tween the tip of the snout and the 



II: 



" III Bi:ouN-GtiODE {Fisheries and Fishery Industries of the United States, sect. I. pp. 202 and 223) we find instances given of the 

 presence in North American rivers both of the Cod and the Tonicod ; ftnd according to Malm the Cod makes its wiiy up tlie River Gotlia as 

 far as Rising Bridge, and is laisen not so seldom off the Public Iron Stores of Gothenburg, where it keeps to the salt water at the bottom 

 of the river. In Uav (1. c, p. 271) the Earl cf DLClli gives some personal observations on this point from Norway. He says that the 

 Pollack occurs in Midluiigen and, tojrctlier with the Cod and Green Cod, in Siirejde Fjord — like Midhingen a salt-water tarn with fresh water 

 at the surface — and that at k'usl the I'l.llack ventured up into the fresh water to bite. 



Scanttinttfinti Fishts. 5"' 



