B 1 1 D. 



463 



This agrees well with the habit of the bird, great 

 part of whose food consists of small fishes captured 

 when on the wing : and thus the bird has not only to 

 resist the contact of the water with the fore-part of 

 its body, but also to regain the sky with little or no 

 assistance from the feet, while the line of the wings is 

 nearly touching the surface. This is a position from 

 which hardly any bird besides the kingfisher has to 

 recover its flight ; for other fishing birds, if we except 

 the eagles and hawks which have that habit, derive 

 assistance either from the bottom, as in the case of 

 the wading birds ; or from the water, as in the case 

 of the gannets, darters, and other birds of that tribe. 

 Even the fishing eagles derive advantage from the 

 water in regaining the sky after their stoop. The 

 points of their wings, and especially their broad arid 

 firm tail feathers, assist them in working themselves so 

 far out of the water as that they have it under their 

 wings, and thus are able to use these for flight. Tin; 

 twitch which the common kingfisher makes downward 

 upon its prey is performed so rapidly as not to be 

 easily seen , but it is probable that not only the long 

 bill, but also the head and neck, are plunged into the 

 the water, and they are again recovered with equal 

 swiftness, and without materially disturbing the sur- 

 face ; so that this bird requires a very peculiar action 

 of the wing, though it is an action very difficult of 

 explanation. The following figure represents the 

 sternum of the common kingfisher of the natural size. 



Kingfisher. 



It is found, by examining it in plan, that this 

 sternum is much wider posteriorly than toward the" 

 front ; but that it is much weakened there, in conse- 

 quence of the two notches upon each side, the ex- 

 ternal ones of which divide it to nearly a third part 

 of its length. The difference between this sternum 

 and that of a bird of nearly similar haunt and some 

 similarity of habit, will appear by contrasting the 

 preceding figure with the following one, which re- 

 presents, of the size of nature, the sternum of the 

 common bee-eater. 



This sternum, as will be seen, has some resemblance 

 in shape to that of the swift, only the posterior part 

 of it is rendered much weaker than in that bird by the 

 two very deep notches on each side ; the processes 

 that separate which are, with the exception of the 

 middle one which is strengthened by the keel, thin 

 and hVxiblc, though they are widened at their ter- 

 minations so as to make the posterior line of the ster- 

 uum nearly a continued curve. The keel is very 

 large, extending the whole length of the sternum, 

 long as it is, and very much curved, both on its ridge, 



and at its junction to ihe rest of the sternum. It is, 

 indeed, an exceedingly strong bone, and at the same 

 time a very light one ; and if the profile is examined, 

 it will be found that the power of supporting musrles 

 of flight is not diminished by the notches in the sides ; 

 for if a straight line is drawn from the anterior pro- 

 cess at the insertion of the coracoid to the posterior 

 termination of the keel, it will be seen that this line 

 passes entirely over the solid bone, and that the two 

 processes formed laterally by the notches are not very 

 dissimilar in their situation to false ribs only inserted 

 on the sternum, and not on the spinal column. 



Bee- eater. 



The other parts are equally well fitted for powerful 

 and long-continued nights. The coracoids are long 

 and strongly formed, with their heads much enlarged ; 

 the furcal bone is a perfect arch, placed, like that of 

 the falcons, in the position of greatest strength and 

 strongly united to the coracoids. The scapulars also 

 are large and sithe-shaped. The furcal bone is not 

 united to the anterior part of the sternum, though 

 there is a bifurcated process there, neither has it any 

 tubercle or other indication of a junction of two 

 branches at the middle, but consists of one unbroken 

 curve of nearly uniform strength throughout. 



This sternum is very beautifully adapted to the 

 habits of its owner. It combines great flying power : 

 length for the support of a body habitually on the 

 wing, and flexibility in the posterior angles, by means 

 of which the bird can better thread its way among 

 obstacles. And the birds of this and the analogous 

 genera are all powerful and long-continued in their 

 flight, although none of them are lofty fliers. Feed- 

 ing chiefly upon winged insects, by the banks of 

 rivers or over other humid surfaces in warm climates 

 where vegetation is luxuriant, they have to pursue 

 their prey among twigs and branches, the pendent 

 festoons of climbing plants, and the tall steins and 

 large leaves of aquatic ones, so that while they pursue 

 on a swift and smooth forward flight, it is also neces- 

 sary that they should be able to glide and turn in 

 all directions with the utmost freedom. This facility 

 in turning is very necessary to birds which feed upon 

 insects, many of which are themselves carnivorous, 

 and hawk for their prey in the bushes or on the 

 leaves, and others are to be sought for in the corollas 

 of plants, into which they have plunged for the sake 

 of the sweet juices which accumulate there. 



Birds of this family bring us to the margin and 

 surface of the waters, with those races whose habit 

 it is to prey on the wing ; but there are still those 

 tribes which feed chiefly by perching on the stems 

 or the twigs of trees, or walking on the ground ; and 

 we shall find that, though there are great differences 



