of the Fishery Board for Scotland. 



231 



genealogy of which is not a little hard, without the aid of an ancestral tree 

 to fully comprehend. 



Complete success having been gained, it may now be asked, Why the 

 necessity of interfering with nature in the production of trout and salmon 1 ? 

 Why not leave her unaided, believing that, as in olden times, she main- 

 tained an abundant supply of fish in our rivers and lakes, she will continue 

 to do this in the future 1 



There are two pregnant reasons why great good may result from a 

 judicious use of our power to hatch and rear trout and salmon. 



The first and most obvious is, that the demand for salmon is infinitely 

 greater than it was a generation ago. 



The second and more important is that the character of the spawning 

 grounds has in many instances been greatly altered by the necessities of 

 civilisation. 



Nature provided for enormous losses" during the development of the 

 salmon and most other fish ; in fact, so wide is the margin, that were half of 

 the eggs produced to hatch, and half the young to develop into adult fish, 

 even the boundless sea in a few years would be overcrowded — be almost 

 solid from the presence of fish, and our rivers would contain more fish 

 than water. But although this is true, nature has not blundered ; she has 

 not been prodigal with the material at her command without the best 

 possible reasons. 



In the higher animals, not only are the eggs protected, but even the 

 young are hedged in with the greatest care, in most cases, until they are 

 able to care for themselves, and fight their own battles in the struggle for 

 existence. 



In most fish, on the other hand, the eggs as soon as they are ripe 

 escape into the world of waters, to enter an unequal struggle from which, 

 at the best, few can escape. And even when the eggs succeed in bringing 

 forth their precious harvest of fry, the dangers are not over — in many 

 cases they are only beginning — for the fry may not only have to run the 

 risk of a thousand enemies, they may even fall a prey to the hungry 

 members of their own family. That the dangers are many and great will 

 be sufficiently evident, when it is remembered that in the case of the cod 

 and some other fish, nature, in order to preserve the species from extinction, 

 has found it necessary to produce every year several millions of eggs. 

 But there are other and less apparent dangers. From observations made 

 in the case of both fresh water and sea fish, it is evident that a very large 

 number of the eggs never have a chance of producing fry, because they 

 have never been fertilised, and even the fertilised eggs may soon succumb 

 owing to unfavourable surroundings — impure water, rapid changes of 

 temperature, &c. And further, the fry may be hatched too weakly to 

 survive, or in water where there is an entire, or almost entire absence of 

 the food on which, during their fryhood, they must depend. For all these 

 ordinary losses, nature has, however, sufficiently provided, as soon appears 

 when the natural conditions are restored. But for the difficulties which 

 arise from the construction of impassable dams, and the still worse pollu- 

 tions from factories, she has not been able to cope, and as far as we can 

 judge, she never will. It is at this stage intelligence steps in, either to 

 break down the obstructions or provide the necessary conditions for the 

 early stages of development and growth, no longer found in the rivers and 

 streams. 



Because of the wide margin nature has allowed for the destruction of 

 her offspring by natural causes, this interference is not only possible, but 

 when judiciously rendered, better results are obtained than even nature 

 herself anticipated. 



