SPECIES NOT 



CHAPTER VIII. 



DIVERSIFIED habit next engages Mr. Darwin's 

 attention. He expresses his opinion in the fol- 

 lowing extraordinary passage: "But it is diffi- 

 cult to tell, and immaterial for us, whether habits 

 generally change first, and structure afterwards; 

 or whether slight modifications of structure lead 

 to changed habits; both probably often change 

 almost simultaneously." (Page 183.) 



In what Mr. Darwin calls "diversified and 

 changed habits," he is singularly unfortunate. A 

 British insect is made to feed upon exotic plants 

 nothing certainly wonderful, considering the 

 general similarity of all vegetable tissues; a tyrant 

 flycatcher hovers like a kestrel at one time, and 

 at another dives like a kingfisher. 



Nuttall gives a very different explanation of 

 this diving: "Occasionally he (the tyrant fly- 

 catcher) is seen hovering over the field with 

 beating wing, almost like a hawk, surveying the 

 ground for grasshoppers, which are a favourite 

 diet. At other times they may be observed in 

 small companies, flickering over still waters in 

 the same employment the gratification of appetite. 

 Xow and then, during the heat of summer, they 

 are seen to dip and bathe in the watery mirror, 

 and with this washing, drying, and pluming, they 

 appear to be both gratified and amused." (Manual, 

 vol. i., p. 269.) 



