SPAWNING OF BLACK BASS 39 



fry proceed much more slowly than in the case 

 of the smallmoTith. 



During the sac stage the fry of the small- 

 mouth huddle close among the stones in the 

 nest, a quivering and almost solid black mass. 

 In this period they cling so closely to the stones 

 that it is impossible to remove them without in- 

 juring and killing large numbers. As the fish 

 approach the advanced-fry stage they begin 

 slowly to rise. When the metamorphosis is 

 completed they approach close to the surface, 

 provided the water-temperature is right. If 

 when they are rising the temperature falls the 

 little fish will drop at once to the bottom. The 

 ascent from the nest to the surface is not sud- 

 den but gradual, and by a series of upward and 

 downward movements, covering a period of 

 about three days. A rise of a few inches is 

 the limit for the first day, and about a foot or 

 more the second, if the water-Conditions are 

 favourable, or if there is that much depth. The 

 shallower the water the more rapid wiU be the 

 ascent, which means of course, a more rapid de- 

 velopment of the fry, on account of a higher 

 water-temperature. The third rise is usually 



