MENDEL'S TWO LAWS 71 



Thus the independent assortment of the mem])ers 

 of the two pairs of elements in the hybrid accounts 

 for the kinds of individuals that appear in the next 

 generation and also the proportion in which they 

 occur. 



Another illustration of Mendel's second law — ■ 

 one from the animal kingdom — is given in figure 27, 

 for the vinegar fly. xVn ebony colored fly (e) with 

 long wings (F) is crossed to a gray colored fly 

 (E) with vestigial wings (v) . The offspring (F^) 

 are gray flies with long wings, EeVv. If two of 

 these hybrids (jPi's) are mated they f)roduce 9 gray- 

 long: 3 ebony-long: 3 gray-vestigial : 1 ebony-vesti- 

 gial. The explanation (fig. 28) is the same as in the 



^ggs VE Ve vE ve 



Fig. 38. — Diagram to show the composition of the IG 

 clashes of individuals represented in F^ of fi(/. 27. 



