276 THE COD FAMILY. 



embryo. At a slightly later stage the pigment has increased 

 and is more generally distributed, and the oil-globule, in par- 

 ticular, has a few black chromatophores. 



The larva upon hatching (Plate X, fig. 9), is elongated and 

 has a yolk-sac extended backwards, the somewhat large oil- 

 globule being situated at the extreme posterior end of the 

 yolk-sac, a feature which if constant would be diagnostic. The 

 median fin is continuous and well-developed, and the vent, some 

 distance behind the oil-globule, opens at this stage about half 

 way towards the edge of the fin. The black pigment is abundant 

 round the eyes, below the brain and above the visceral cavity, and 

 forms two lateral transverse bands in the region of the tail. This 

 arrangement resembles that found in some of the typical gadoids, 

 the tail-bands recalling those of the cod, and the pigment at 

 the front part of the body that of the haddock, and especially 

 of the rocklings. Raffaele refers also to yellowish pigment 

 scattered over the body but his plate is unfortunately not 

 coloured. If we may take his lighter shading to indicate the 

 yellow pigment, then, as is readily seen, its distribution is closely 

 similar to that of the black : in his synoptic table he speaks of 

 the oil-globule having black pigment above and yellow beneath. 

 He does not state the order of appearance in the embryo of 

 the two pigments and, on the whole, more details are much 

 needed. Beyond this early stage, nothing is yet known of the 

 development of the hake. 



Mr Holt in the survey of the fishing grounds on the west 

 coast of Ireland procured young examples 1^ to 1^ inches long, in 

 80 fathoms in August, these being the young of the season. In 

 March, examples of 6 and 7-| inches were taken respectively at 

 115 and 40 fathoms, and two of 8 inches in 53 fathoms in May. 

 The latter may be taken to represent the average growth during 

 the first year. A specimen of 15 inches, again, was captured 

 off Aberdeen on the 6th June, and presumably is in its second 

 year. All these were taken in trawls. On the whole it would 

 seem that the hake, like the haddock, keeps to the deep water 

 in its early stages, roaming after prey nearer shore when 

 attaining the length of the last-mentioned example (15 inches) 

 and upwards. 



