15 



others in w^ter of a lower temperature have remained one 

 hundred and forty days before they hatched. 



From the careful experiments made by Mr. John Shaw in 

 Great Britain, about thirty years ago, it is found that the 

 eggs of salmon will hatch in one hundred and fourteen days 

 when the water has a temperature of thirty-six degrees ; one 

 hundred and one days with a temperature of forty-three, and 

 ninety days with a temperature of forty-five degrees. 



The spawn when first deposited are quite translucent. If 

 properly impregnated, a milky speck will appear in the egg, 

 which will gradually expand into a whitish line — the germ of 

 the spine. At one end of this two black specks appear that 

 mark the spots for the eyfes. These continue to grow till 

 the embryo fish breaks from the shell, when the eyes appear 

 disproportionately large. As the young fry emerges from the 

 shell it is nearly transparent, its fins but imperfectly formed, 

 and it is able to swim but little in consequence of the um- 

 bilical bladder that is attached to it just back of the gills. 

 This bladder is nearly as large as the egg which contained it, 

 and from it the young fry derives its entire support during 

 the first month of its existence. It is when the fish are in 

 the embryo state — just after the black spots that mark the 

 eyes appear — ^that they can safely be transported and intro- 

 duced into streams far distant from the one in which their 

 progenitors lived. All that is required to insure their safe 

 removal seems to be an uniform temperature, and a sufiicient 

 amount of aerated water to keep them wet. If they are placed 

 in water it should be often changed, or air should be driven 

 through it with a bellows or syringe. Moss from swamps is 

 like a sponge and not only retains the water but also seems 

 to impart oxygen to it. Spawn carefully - packed in wet 

 sphagnum moss can be safely transported to a considerable 

 'distance. 



Soon after the umbilical bladder is absorbed the young fry 

 seek food, and are very sprightly in their motions. They are 



