FIG. i. A normal two-cell stage of Fundulus egg drawn to same scale as other 

 cleavages. 



FIG. 2. A normal four-cell stage. 



FIG. 3. An aberrant cleavage occurring five hours after fertilization from egg 

 treated with five per cent, alcohol in sea water prior to fertilization with norma 

 sperm. 



FIG. 4. An abnormal cleavage of an egg which was fertilized by sperm treated 

 with ten per cent, alcohol in sea water. 



FIG. 5. An irregular cleavage occurring three hours after fertilization in an 

 egg which was treated with three per cent, alcohol in sea water for fifteen minutes 

 prior to fertilization with normal sperm. 



FIG. 6. An imperfect cleavage occurring four hours and a half after fertilization 

 in an egg which was treated with two per cent, alcohol in sea water for fifteen 

 minutes prior to fertilization with normal sperm. 



FIG. 7. A normal eight-cell cleavage stage. 



FIG. 8. An abnormal cleavage occurring two and a half hours after fertiliza- 

 tion in an egg treated with two per cent, alcohol in sea water prior to fertilization 

 with normal sperm. 



FIG. 9. An aberrent cleavage occurring four hours after fertilization in an egg 

 treated with five per cent, alcohol for twenty minutes prior to fertilization with 

 normal sperm. 



