THE COD FAMILY. 279 



towards the end of Aprils Pigment first appears upon the 

 larva at about the 7th day, in the shape of black stellate spots 

 upon the back of the trunk. These spots increase and shortly 

 after arrange themselves in two longitudinal rows, and a few 

 spots appear on the yolk. About the middle of the 8th day, a 

 number of fine greenish yellow pigment-spots appear, mostly 

 on the ventral surface and on the marginal fin. The ling 

 therefore, along with the whiting and the poor-cod, can readily 

 be distinguished in the egg from the cod or haddock by the 

 presence of coloured pigment before hatching. 



The young larva on escaping measures about ^th of an 

 inch. Its appearance upon the second day after hatching is 

 shown in Plate XI, fig. 4. The large and conspicuous oil- 

 globule usually rests at the posterior border of the yolk. The 

 yellow pigment is generally distributed, the black on the con- 

 trary being most conspicuous about the trunk and tail, and a few 

 spots are seen scattered over the yolk-sac. These latter increase 

 rapidly in size, and 2 days after this stage extend over the whole 

 surface of the yolk. By that time (4 days after hatching) the 

 yellow pigment has increased and the envelope of the oil-globule 

 shows black chromatophores. The tail has now become very 

 long in comparison with the rest of the body. 



A week after hatching, the larval ling is very characteristic 

 (Plate XI, fig. 5). About 'IS inch in length, it is thickly dotted 

 over with oval yellow chromatophores, the black ones being 

 finely branched and also conspicuous, though not so numerous 

 as the former. They are grouped principally in dorsal and in 

 ventral rows, with a mass collected at the posterior end of these 

 rows just anterior to the tail, and another small mass at the 

 back of the neck. The eye is of a metallic bluish colour. 

 Amongst other structural features, we note that the vent has 

 reached the outer edge of the marginal fin, and that there 

 is a considerable space between the former and the posterior 

 border of the yolk-sac. This is the latest stage reared in 

 captivity and the next appears from the open sea, captured 

 in the tow-nets at the end of August. 



1 For fertilized eggs of the ling one of us was indebted to a typical liner 

 of the east coast, a race as industrious as daring, and as simple as contented. 



