THE INDIAN DARTER. 



329 



it. Arrived within striking-distance, the Darter suddenly transfixes, in 

 fact bayonets, the fish on the tip of its beak with marvellous dexterity, 

 and then immediately comes to the surface, where the fish is shaken off 

 the beak by jerking of the head and neck (repeated till successful), 

 thrown upwards, and swallowed, usually head first. 



A study of the neck in the recently dead bird leaves little doubt as to 



Fig. 1. 



B' 



B 



Fig-. 2. 



a 





Diagram to show the mechanism of the " kink " of the neck in the Darters. 



a, head and anterior moiety of neck (1st to 7th cervical vertebrae) ; p, posteriorjmoiety 

 of neck (from the 9th cervical vertebra to thorax) ; 8, 8th cervical vertebra ; D, 

 "Donitz's bridge," on the 9th cervical ; /, the two flexor muscles (vide text) ; e, the 

 extensor muscle (the longus colli anterior}. In fig. 1 the flexor muscles are sup- 

 posed to be acting, bending back the anterior part of the neck on the 8th cervical ; 

 in fig. 2 the extensor muscle has opened out the anterior genu formed by the 8th 

 cervical, thereby protruding the apex of the beak (marked B in fig. 1) to B'. 



the mechanism by which this peculiar impaling of the prey is effected. 

 The 8th cervical vertebra is articulated, as has already been described, 

 with the 7th in such a way that the two cannot naturally be got to lie 

 in the same line, but form an angle, open forwards, of about 145, when 

 the two bones are stretched as far as is possible in that direction. 

 Behind, its articulation with the 9th cervical is such as to permit it to be 

 bent back at an angle a little greater than 90 with that vertebra, beyond 

 which extent, however, no further flexion is possible. The 8th vertebra 

 is thus so articulated with the 7th anteriorly and the 9th posteriorly as 

 to allow it, when the neck is flexed, to be nearly at right angles to the 

 rest of the neck, the two portions of which, though parallel, are then at 



P. Z. S. 1882, 

 p. 212. 



