2l6 OUR SUMMER MIGRANTS. 



add, Coursers, have a pectinated claw upon the 

 middle toe, and yet do not take insects upon 

 the wing, or even seize their prey with their feet. 



It has been ingeniously suggested that perhaps 

 the serrated claw may be used for brushing 

 away the broken wings and other fragments of 

 struggling insects which doubtless adhere oc- 

 casionally to the basirostral bristles with which 

 the mouth of this bird is furnished. This is 

 very possible ; at the same time it may be 

 observed that Hawks, Parrots, and other birds 

 habitually cleanse the bill and sides of the gape 

 with their feet, and yet have no pectination of 

 the middle claw. 



A theory advanced by Mr. Sterland,^ and 

 endorsed by Mr. Robert Gray,* is that since the 

 Nightjar sits lengthwise and not crosswise upon 

 a bough, the serrated claw gives a secure foot- 

 hold, which in so unusual a position could not be 

 obtained by grasping. But to this theory the 

 objection above made also applies, namely, that 

 many birds, such as Coursers and Thick-knees, 



1 " The Birds of Sherwood Forest," p. 172. 

 * "The Birds of the West of Scotland," p. 212. 



