280 THE COD FAMILY. 



This is a small post-larval form (Plate XI, fig. 6) about ^ of 

 an inch in length. Its gadoid affinities are at once shown by its 

 large blue eyes, so like those of the whiting, and the two well- 

 marked transverse black bars, extending across the trunk. The 

 black pigment on the head is also very similar to that of the 

 post-larval cod, as are the massive head and lower jaw. The 

 peculiar structure of the paired fins, however, not only distin- 

 guishes this little fish from the gadoids but from any other 

 known species. The pectorals have short fleshy bases which 

 bear the fan-like expansions of the fin-rays. The ventrals are 

 enormously elongated ; at this stage it is seen that they are 

 nearly half as long as the whole fish, the rays being of a yellow 

 colour with black specks upon the membrane. This hyper- 

 trophy of the ventral fins is found to some extent in the rockling 

 and tadpole-fish, fishes very closely allied to the ling. In each 

 case it is strictly confined to the post-larval stages, neither the 

 adult ling nor the adult rockling being conspicuous for large 

 ventral fins. The large pectoral fins of the post-larval gurnard 

 and bull-head present a feature somewhat analogous to this. 

 The marginal fin is still continuous, and the tail is peculiar for 

 an early development of the upper caudal rays. 



Little post-larval ling of -J inch in length were caught in 

 the 3rd week of July in the mid-water net at about 22 fathoms 

 south-east of the Island of May. Except in size, these closely 

 resembled the earlier stage described. At the end of August 

 the ling had increased to a length of nearly 1 inch (Plate XI, 

 fig. 7). A pale greenish tint is spread over the dorsal surface, 

 and the black pigment is more diffused than formerly. The 

 bands remain only on the dorsal half of the trunk, and there are 

 a few changes, readily observed, in the arrangement of the black 

 marks on the head. The ventrals are still very long, though not 

 so elongated in proportion to the length of the body as in 

 the former stage. It may also be noted that the dorsal, anal 

 and caudal fins have assumed an appearance closely like that 

 of the adult. 



From this stage, at the end of the post-larval period, to the 

 next described there is the gap which is so common in the history 

 of many of the food-fishes. In the case of the ling, however, 



