268 THE COD FAMILY. 



On hatching, the larvae (Plate X, fig. 4) float about helpleasly 

 with the yolk-sac uppermost. The fact that the pigment is slight 

 and scattered distinguishes the larval green cod from the same 

 stage in the cod, and the entire absence of yellow pigment in 

 this and the later periods of incubation separates this form 

 from the whiting. 



About the 6th day after hatching, the chromatophores show 

 a tendency to group themselves into dorsal and ventral masses, 

 simulating, to some extent, the arrangement met with in the 

 larval cod. There are also conspicuous groups of stellate black 

 spots upon the back of the head, over the abdomen, and over 

 the pectoral fins. The uyes have small black specks and are 

 silvery. 



Fig. 5, Plate X, is a larval green cod of eight days, showing 

 the distribution of pigment above referred to and also the 

 embryonic rays in the tail-fin ; at the age of 14 days little 

 more advance is made except in diminution of the yolk, the 

 surface of the sac enveloping which now presents a distinct 

 reticulation, and the more general scattering of black spots, 

 which however still appear in a ventral view to lie in two 

 longitudinal lines. 



The green cod therefore, as surmised before identification, 

 closely resembles the cod in its development. 



The post-larval stages are still in need of investigation ; 

 they are probably very similar to those of the cod, but perhaps 

 are more darkly pigmented. Fig. 6, Plate X, represents a 

 post-larval fish of about ^ inch in length, which is probably a 

 young green cod. The belly is brightly coloured by crustacean 

 food, the eyes are bluish-silvery, and larger in proportion than 

 those of the cod, probably because the snout and the lower jaw 

 are shorter in the green cod. Black pigment is found on the 

 head and the belly. The increase and prominence of this black 

 pigment is probably diagnostic of the later stages, but little of 

 these is at present known, though figs. 7 and 8 (Plate X) in 

 our opinion represent an older stage after the fins are differen- 

 tiated. 



The young green cod of about 1^ inch are found in great 

 abundance in the tidal rock-pools of St Andrews Bay in May 



