240 The Life Story of the Fish 



now know to be a nest-digging movement was part of the act 

 of egg-deposition, and that the ensuing approach of the male 

 which we now know to be courtship behavior was the act of 

 fertilization. Under the circumstances it is not surprising that 

 one fish-cultural authority made the statement in print that 

 only two out of every thousand naturally spawned eggs were 

 able to complete their development. 



In contrast, it was known that with proper handling over 

 ninety per cent fertilization resulted from artificial spawning. 

 Man could do far better than nature. So he proceeded to build 

 hatcheries, and to take every spawning trout that he could 

 lay hands on, strip it of its eggs or its milt, hatch the eggs in 

 his troughs, hold the offspring until they had absorbed the 

 yolk-sac, and then place these tiny creatures back in the 

 natural waters from which he had taken their parents. Only, 

 since this work was so much more efficient, it was not neces- 

 sary to replace them all in those same waters; he could place 

 a part of them there — ^perhaps only a small part — and use 

 the rest to stock other waters. The trout fisherman could be 

 happy. His sport was assured forever; in fact, he could look 

 forward to expanding into new waters, and having more fish 

 than ever before. 



How long it took people to begin to see the fallacy in this 

 program is not exactly known. As the results failed to meet 

 expectations, efforts were made to raise the fry to larger 

 size before releasing them on the theory that this increased 

 their survival. But it also cost more for fish food and 

 handling, and more of the fingerlings died in the troughs — 

 partly because the longer period gave time for more deaths 

 to occur, and partly because it gave time for disease to take 

 hold in epidemic form. Sometimes, in spite of almost per- 

 fect fertilization, the number of young fish planted was less 

 than ten per cent of the number of eggs taken. Thoughtful 

 fish culturists wondered whether the extra money and labor 



