A FISH FROM A PELAGIC EGG. 61 



occur. No example indeed was procured in the trawling 

 expeditions for the Commission under Lord Dalhousie. The 

 hooks of the liners are too large for the mouth at this 

 stage, and hence they escape capture. Their small size and 

 translncency also seem to afford protection in the case of 

 predatory fishes of their own or other kinds, for they are rare, 

 so far as present observation goes, in the stomach of any fish. 

 Their great numbers are doubtless kept in check by some 

 means, and we know that even jelly-fishes (e.g. Pleurobrachice, 

 Fig. 11) and sparrows are very fond of post-larval fishes. It is 

 only when they become somewhat larger that they are preyed on 

 by their own and other species, and are swept up in thousands 

 by the destructive shrimp-nets on our sandy shores. 



While the little food-fishes are assuming the change of hue 

 indicated in the preceding pages, they in many cases seek the 

 inshore waters ; at least, systematic use of the mid-water and 

 other nets prove that at certain seasons they are met with in 

 large numbers at the entrance to bays or off-shore, and that a 

 little later, in the case of the cod from the first of June 

 onwards, they are visible from the rocky margins. The colora- 

 tion in this species (cod) is now beautifully tessellated (Fig. 5), 

 and they swim in groups, often in company with the young 

 green cod, at the margin of the rocks at low water, and in the 

 little tidal bays connected with rock-pools. The latter are 

 often richly clothed with tangles, bladder-weed, red and green 

 seaweeds, and the green Ulva amidst the mazes of which the 

 young fishes find both food and shelter, capturing the little 

 crustaceans (Copepods, Ostracods, and others) swimming there, 

 and snatching the young mussels and minute univalve mollusks 

 from the blades of the seaweeds. To the zoologist few sights 

 are more interesting than to watch the little cod in these fairy 

 lakes, as they swim in shoals against the current, balancing 

 themselves gracefully in the various eddies by aid of their 

 breast-fins. In a mixed company, the young cod are easily 

 recognised by their coloration, and the reddish hue of the 

 occiput, for the blood-vessels there shine through the tissues, 

 which generally are more translucent than in the green cod. 



Prof. G. O, Sars considered that about this stage there was 



