of the Fishery Board for Scotland. 



233 



place, nature seems to succeed better in fertilising the small eggs of the 

 sea fish than the large eggs of the salmon. Again, the fry are usually 

 hatched, in a few days (3 to 20) in the sea fish referred to, while in the 

 Salmonidse hatching is delayed for several mouths ; and further, while from 

 pollutions and other causes food for the salmon and trout fry may no 

 longer exist in the rivers, there is little if any chance of the young cod 

 and herring fry suffering for want of food in the open sea. 



Thus far the two cases are not quite parallel. But, further, in the case 

 of salmon and trout we are pretty certain of our results. If, other condi- 

 tions being the same, the numbers of fish increase in any given river or 

 lake into which known quantities of fry have been set free, it may be taken 

 for granted that the increase is the direct result of man's interference. On 

 the other hand, in the case of sea fish which are either more migratory or 

 less true to their original birthplace than trout and salmon, it is next to 

 impossible to say, should there be an increase where hatching has been 

 carried on, whether the increase is accidental or due to the formation of a 

 local race sprung from the artificially hatched fry. 



It maybe taken for granted that the most sanguine pisciculturist would 

 scarce dare propose to increase the number of the more migratory fish 

 that live in the open sea. It has been suggested that by hatching fish 

 inshore local races might be formed, but this is taking for granted that 

 during the process of incubation the fish are brought under some remark- 

 able spell which arrests their strongly inherited instincts, and leads them 

 to settle down for life in the vicinity of their birthplace, instead of roam- 

 ing about to see the world like their free-born cousins. 



I have elsewhere pointed out that, although haddocks may abound in 

 the Forth during summer, they seem to desert it almost completely in the 

 autumn, and that the cod only visits the Firth in any force when there is 

 an abundance of herring or herring spawn. It seems, therefore, too much 

 to expect cod and haddock and other wanderers to remain always about 

 our doors because they happened to see the light under artificial instead of 

 natural conditions. But though fish hatching may not be able to influence 

 much if at all the number of fish in the open sea, and though it may not 

 be able to establish local races or shoals, it may still be of great service. 



In the first place, it may be the means of introducing fish which have 

 the migratory instinct fairly well developed, into waters where they prac- 

 tically did not previously exist. For example, by instituting hatcheries 

 in the upper reaches of some of the long fjords in Norwaj 7 , a large school 

 of haddocks or other round fish might be readily created which might 

 find all the conditions necessary to their existence without wandering into 

 the open sea ; and, in fact, the same results might follow the hatching on 

 a large scale of round fish in some of our own firths and bays. 



Again, as in America, it might be possible to produce shoals of fish, such 

 as the shad, which, by wandering along the coast or living in the estuaries, 

 would be the means of attracting large and more valuable forms to the 

 inshore grounds. Fish, in fact, which would act the part of the herring, 

 but be a more constant source of attraction — remaining in the firths for 

 several months at a time. 



Lastly, fish culture may have a great future before it in hatching flat 

 fish, which have the double advantage of being extremely valuable, while 

 they are often very limited in their migrations. 



The culture of sea fish is still, however, only passing through the initial 

 stages, and we have much to learn before we can hope to hatch by millions 

 some of our best flat fishes, — the hatching of the sole e.g., presenting this 

 one great difficulty, that males are rarely ever captured, or at least, if 

 captured, are seldom identified. 

 2 G 



