SECONDARY SEXUAL CHARACTERS 127 



species have been dubbed the hector form and the 

 aristolochia form. 



Wallace, and those who adhere to the same view, 

 beUeve that the resemblance of the model and the 

 mimic has come about through the accumulation of 

 minute variations which have survived as a result of 

 their advantages. In a word, the process of natural 

 selection is assumed to have gradually brought about 

 the evolution of these two new types of females. 



This case has been recently examined by Punnett. 



Punnett says that while in cabinet specimens the 

 resemblance between the model and the mimic is re- 

 markably close, yet in the hving animals, with their 

 wings spread out, the resemblance is less marked, espe- 

 cially the resemblance between the hector model and 

 the polytes mimic. At a distance of a few yards the 

 difference between the two is easily seen. 



When flying the differences are very apparent. ^ ^ The 

 mode of flight of P. polytes is similar for all three forms, 

 and is totally distinct from that of P. hector and P. 

 aristolochia.'^ In flight the latter pursue an even 

 course, while the polytes form follow a lumbering 

 up and down course. Punnett thinks these differ- 

 ences are so distinct that they are '^unhkely to be 

 confounded by an enemy with any appreciation of 

 color or form." 



Moreover, in Ceylon at least, the distribution of the 

 model and its mimic is very different from what is 

 expected on the theory of mimicry. He concludes that 

 the facts relative to their distribution ''are far from 

 lending support to the view that the polymorphic 

 females of P. polytes owe their origin to natural selec- 



