tf2 FOOD AND HABITS. 



mainJy an attack surely an ungallant one- 

 made by these upon two females of the same 

 species that were sucking at the same bush. 

 These were certainly in the skirmish, but the evo- 

 lutions were too rapid to be certain how the bat- 

 tle went. 



" The whirring made by the vibrating wings 

 of the male Polytmus is a shriller sound than 

 that produced by the female, and indicates its 

 proximity before the eye has detected it. The 

 male almost constantly utters a monotonous 

 quick chirp, both while resting on a twig or 

 while sucking from flower to flower. They do 

 not invariably probe flowers on the wing ; one 

 may frequently observe them thus engaged when 

 alighted and sitting with closed wings; and 

 often they partially sustain themselves, by cling- 

 ing by the feet to a leaf while sucking, the 

 wings being expanded and vibrating." 



The clinging power of the feet of Humming- 

 birds is very remarkable ; and, indeed, according 

 to Bullock, they frequently while sleeping sus- 

 pend themselves by the feet with the head down- 

 wards, in the manner of some parrots, as, for 

 example, the Love-birds (Psittacula) of Africa. 

 In the Swift this clinging power of the foot is 

 very great ; but here the four toes are all directed 

 forwards. Mr Grosse says that the Humming- 

 birds, as a general rule, sleep (he alludes to 

 those of Jamaica) with the head not behind the 

 wing, but slightly drawn back on the shoulders. 



