9^ EVOLUTION AND GENETICS 



In the second figure ( b ) the wings turn up at the 

 end. The mutant is called jaunty. 



In the third figure (c) the wing is long and nar- 

 row and sometimes bent back on itself, as shown 

 here. In several respects the wing resembles strap 

 (d) but seems to be due to another factor, called 

 antlered. 



In the fourth figure (d) the wings are long and 

 narrow and several of the veins are unrepresented. 

 This character, "strap," is very variable. On the 

 thorax there is a deep black mark called trefoil. In the 



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"■^^^'ft-- 1 



r¥K 



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fB 



Fig. 41. — Some of the characters of the second chromo- 

 some of Drosophila melanogaster. See text. 



