1889.] on the Life-Mstory of a Marine Food-fisli, 399 



rocky coast like that of Aberdeenshire, south of Girdleness, as well 

 as on the hooks of the liners on rough ground. Sj)ecial trips, indeed 

 were, and perhaps are, made by the liners for the capture of these 

 young cod (termed codling), and thus their numbers are kept in 

 check. 



So far as present observations go, therefore, the young cod in a 

 free condition reach the length of from 4 to 10 inches the first year, 

 while in the second they attain from 10 to 20 inches or more. It 

 probably takes 3 or 4 years (and this is the original opinion of Sars) 

 or more to reach full maturity and a length of 3 feet or upwards ; 

 though he mentions having seen young cod a foot in length, with 

 mature roe and milt, in the fish-market of Christiania. These, how- 

 ever, were probably abnormal examples. 



Let us now glance at the condition in the whiting. Its earlier 

 post-larval stages immediately following those observed in the tanks 

 at the laboratory (for we failed to rear them) are even now somewhat 

 obscure, but they probably approach those of allied forms, such as the 

 cod and haddock. The characteristic nature of the larval pigment, 

 however, would lead to the belief that perhaps in the brighter tints 

 (e, g. yellow), differences may occur. Such, however, are lost before 

 they come under observation ; for all these delicate and minute forms 

 are dead before reaching the deck, and indeed considerably altered. 

 The pressure to which they are subjected in the large mid-water net 

 by the crowds of hydromedusas, and ctenophores alone w^ould suffice 

 for this, and the handling of the heavily laden net increases the 

 dangers to forms so fragile. One about 12 mm. shows in spirit the 

 dorsal and anal fins outlined though not separated from each other, 

 and permanent rays occur in them and in the caudal. Minute 

 ventral s are present, while the pectorals form large mobile fans. 

 Groups of black pigment-corpuscles are distributed along the base of 

 the dorsal and anal fins and over the brain, and a similar series occurs 

 along the ventral median line of the abdomen. The sides have these 

 blackish pigment-corpuscles more generally distributed than in the 

 cod. No barbel is noticeable. When a little longer (15 mm.), the 

 species is distinguished from the young cod by a more abundant 

 distribution of black pigment-specks along the sides of the body and 

 on the fins, and by the greater length and diminished depth of the 

 first anal iin. The median line of pigment still runs along the ventral 

 surface of the abdomen. At 20 mm. the characters that distinguish 

 it from the cod of the same size are better marked, viz., the distribu- 

 tion of dense blackish pigment along the base of the dorsal fins ; and 

 it soon spreads downward over the sides. The first anal fin assumes 

 the character of the adult, and a minute papilla indicates a barbel. 

 Between the stage just mentioned and a length of 28 mm. a decided 

 change in the dense dorsal jDigment takes place, viz., a tendency to 

 form separate groups or touches (Fig. 16). These differ from the cod 

 in being confined to the dorsal region, though a few bars occur at the 

 base of the tail. The fish is also now minutely flecked, all over the 



