Fish-Hatching in a Current of Water. 105 



a much, lower temperature in dull, sluggish 

 running water would be dangerous, and the 

 young fry have perished at once, when suddenly 

 placed in water at 80 deg. 



My hatching apparatus was erected at a 

 small spring, trickling down an oozy hollow, 

 and rising out of the side of a volcanic hill. 

 To collect the water and protect it from the 

 sun, and from pollution by cattle, I formed a 

 stone drain about three feet in depth down the 

 channel, and collected the water in a small 

 dam, which was filled with loose stones and 

 turfed over. The water comes through the 

 dam in a galvanized-iron pipe, and is not ex- 

 posed to the sun or to the open air until it 

 reaches the hatching-boxes. It is perfectly 

 pure and free from sediment. The tempera- 

 ture when I first tested it was constant for 

 some months at 53 deg., which was very 

 suitable for fish-hatching. From some un- 

 known cause, which, as the spring rises 

 from the side of an extinct crater, is probably 

 due to volcanic action, it has risen to 

 62 deg. in summer, or 60 deg. in winter, but 

 the heat is now lessening. The supply is only 

 five pints per minute in summer. 



