Zalsman. — Experiments in Fish Culture 163 



Fry hatched prematurely are not good. Care should 

 be taken in transferring eyed eggs that the temperature 

 does not get any warmer than the water from which 

 the eggs were taken. Also the water feeding a hatchery 

 should be kept at as constant a temperature as possible. 

 A sudden rise or fall at hatching time will cause a prem- 

 ature hatch. These fry will live until they have out- 

 grown their yolk sac and sometimes a week or two 

 longer, but they do not seem to be able to feed and finally 

 die. 



(Many similar experiments in hybridization were made at Caledonia, 

 N. Y., by Seth Green forty years ago. Hybrids between a large-scaled 

 species, such as the rainbow and brook trout or other small-scaled 

 species are sterile. T. H. Bean.) 



