110 Thirtieth Annual Meeting 



them to the yearling age, for the mere hatching of millions of 

 trout and retaining them during the yolk sac period only, is a 

 small achievement compared with the raising of one-tenth of the 

 number to a 3'ear old. 



DISCUSSIOX OF MR. AVOOD's PAPER. 



Mr. Titcoml) : I wish to bring up one subject in connection 

 with the pajjer for the consideration of the members, with the 

 possibility that if it does not bring out discussion here, it may 

 develop something in the form of a paj^er another year. 



I have been experimenting with the eggs of the domesticated 

 trout and the eggs of the wild trout. The eggs of the domestic 

 trout are ke])t in spring water at these commercial hatcheries at 

 a temperature of about 4G degrees, and the parent fish are kept 

 in what you might call spring water in those drive-well hatch- 

 eries. In taking them to my hatchery and subjecting them to a 

 temperature during the winter sometimes as low as 34 degrees, 

 yes, even down to less than 33 degrees, (you can see the frost 

 sparkling in the water) the eggs of the domesticated fish seem 

 to be affected, while the eggs of the wild fish do not. Xow I do 

 not consider a water supply for a hatchery good which goes down 

 to that extreme low temperature, but the question arises 'in my 

 mind whether the domesticated trout reared in spring water will 

 produce an i^gg which can l^e hatched as well in the cold water as 

 the Qgg of the wild fish which is subjected to all temperatures of 

 cold water, you might say. There is a point there that I have 

 not lieen able to settle in my own mind, but I have suspected 

 that trout which have been kept for a long time, or in different 

 generations, in the warmer water throughout the winter, are not 

 so well al)le to exist in the lower temperatures as the wild trout. 



Mr. ("lark : T take it from Mr. Wood's paper that it turns 

 more upon the ki]id and quality of water. Of course, as you are 

 aware, I have liad considerable experience in trout culture and 

 fish hatching for quite a number of years. Now I just want to 

 give you my ideal of water for a hatchery: It is to have two 

 kinds of water, as we have spring water, and either creek or lake 

 water. In having the two, which range during the hatching sea- 

 son from 32 1-3 to -16 or 4<S degrees, we are enabled by mixing 

 the water to control and regulate the temperature, determining 



