MR. BFIST'S OBSERVATIONS. 99 



ing the shell daily. In consequence of the 

 fine open winter, the eggs have hatched in our 

 ponds in 115 days, and have done so corre- 

 sponding to the days on which the eggs were 

 deposited. Thus the eggs on the 13th of 

 November have hatched on the 8th of March, 

 and have continued doing so in the corre- 

 sponding days. In former seasons they have 

 taken from 130 to 140 days, according to 

 the temperature of the water. In spring 

 water flowing from the rock in winter, where 

 the temperature is always equal, I have 

 known them to hatch in about sixty days." 



Not only does temperature affect the eggs, 

 but also the young fish, for in the second 

 week in February the sun's rays fell at mid- 

 day almost direct upon my boxes, causing 

 the temperature of the water to rise nearly 



H 2 



