THE DUALITY OF INHERITANCE 



products of the ori2:inal cell contain in each case 

 two chromosomes, half the original number. 



Fig. 5. — Diagrams showing the essential facts of chromosome 

 reduction in the development of the spenn-cells. (After 

 Wilson.) 



These chromosomes make up the bulk of the 

 head of the sperm which forms from each of 



17 



