Report U. S. F. C. 1898. (To face page LXXII.) 



Plate XIII. 



1 . Unfertilized whitefish egg 24 hours old. 



2. Fertilized whitefish egg 6 hours old, geminal discs form- 

 ing, no segmentation having taken place. 



3. Whitefish, 12 hours, showing first cleavage. Water 38° 



Whitefish eggs, 18th hour. Water 38°, showing second 

 segmentation, four cells formed 



5 Whitefish egg 24 hours. Water 38°. 6. Whitefish egg 48 hours. Water 38° 



DEVELOPMENT OF THE WHITEFISH EMBRYO 



y 



