BIRD. 



419 



of matter, occupying a definite space ; and to that 

 quantity and that space all the productions of the 

 earth must be capable of accommodating- themselves, 

 otherwise the system would be imperfect. 



The earth itself is, perhaps, at once.^he best index 

 t.o the system of the earth's productions, and the best 

 illustration of the mode in which that system works. 

 It careers round the sun, altering its distance from 

 that luminary, and the rate of its motion, every mo- 

 ment, aud differently affected as its own attendant 

 moon, or any other body in the solar system, is dif- 

 ferently situated with respect to it. But though 

 altered it is not disturbed ; the balance is never de- 

 ranged, and we are so far from feeling the inequalities 

 of its motions, that it is only after the most profound 

 investigation that we become aware of their taking 

 place. The law which God has given it is a perfect 

 law ; and no case can arise to which it does not 

 apply with the same ease and perfection. If the 

 motion requires to be accelerated or retarded, in order 

 to keep up the perfect balance, the very necessity for 

 the change is, in itself, the cause of that change ; and, 

 be the aberration ever so much, there is always a 

 principle inseparably connected with it, which, in due 

 time, produces a return. 



Just so with the growing and living productions of 

 nature ; if the general circumstances are such as to 

 harmonise with an increase, there is no waiting for 

 that increase as man must wait in his workings, and 

 no toil as he must toil to bring it about. The neces- 

 sity and the supply come so simultaneously, that the 

 one cannot be called the cause and the other the 

 effect. They at once prove their origin from the 

 same cause ; and that that cause is no part of the 

 system of nature, although intimately familiar with it 

 all in extent and in duration. * 



The preservation of the whole system of nature 

 requires that, at certain pauses, and those not very 

 wide of each other, the races which, among their 

 other uses, put the birds in motion, must be as " the 

 dry bones in the valley of death ;" but the Author ol 

 nature has so ordered that, when their activity 

 becomes necessary, there is "a spirit'' breathed by 

 them into the system, which can, unseen, and in an 

 instant, pass over them and 'seal them to life and 

 activity. Thus the cold winter of the polar climes, 

 and the withering drought of the equator, are alike 

 necessary for preserving the energy and the^ beauty 

 of the world. 



All preyers, and birds in an especial manner, as 

 being the most discursive rangers, are highly valuable. 

 They give play to the energy of life generally in that 

 which they individually destroy ; and but for them 

 the earth would become rank and foul with the car- 

 casses of those tribes which must perish and be 

 renewed in the different seasons. 



In the performance of these labours, many species 

 )f birds have to prey upon animals, the immediate 

 contact of which with the body of the bird would be 

 attended with fatal consequences ; and in other cases 

 the prey is in places which the bird cannot, with 

 safety, approach too closely. The parts of birds 

 which are naked of feathers, whether they are co- 

 vered with horn or with skin, contain few museles or 

 blood-vessels, so that they are not easily wounded or 

 otherwise injured in such a manner as to affect the 

 general economy and action of the bird. This is the 

 more necessary on account of some of the creatures 

 upon which the birds feed being capable of inflicting 



joisoned wounds, all of which would be painful in 

 he fleshy parts of the bird, and some of them very 

 speedily fatal. It does not appear that the animal 

 joisons, known by the general name of venom, are 

 deadly, or wen in the least injurious, if they are not 

 taken into the circulating blood. Whether they 

 must be so taken by direct introduction into a blood- 

 vessel, in order to produce their fatal effects, or" 

 whether the poison may be carried into the circu- 

 .ation by the lymphatics, which pour what they 

 collect into the veins through the thoracic duct, is 

 not clearly ascertained; but as the effect of those 

 poisons always shows itself locally, near the place of 

 the wound, before it injures the system generally, 

 it is probable that a direct mixture of the'venomous 

 fluid with the blood is necessary, in order that it may 

 produce its destructive effects ; and this is rendered 

 the more probable from the fact that the same fluid 

 may be taken into the stomach without the. smallest 

 injury, by animals to which it would prove fatal in a 

 very short time if taken into the blood. 



Many birds feed upon creatures provided with 

 poisoning apparatus, as the bee-eaters and other 

 species feed upon many insects that have poisoned 

 stings ; and various species of birds feed upon ser- 

 pents which have poison fangs. Now, all those birds 

 are so constructed, that those parts of their bodies 

 which could be seriously injured by the sting or the 

 fangs, are kept out of the way. If, like the bee-eaters, 

 they capture stinging insects on the wing, the bill is 

 long, and the tongue either short or indurated, so 

 that no part of them which comes in contact with 

 the insect, is liable to be hurt by its puncture or its 

 venom. In those species which eat poisonous 

 snakes, the bill is long, and the tarsi also, so that all 

 those parts of the bird which are vulnerable by the 

 reptile, are elevated above its reach after it is once 

 pressed to the earth by the feet, when it is not at 

 once killed by the stroke of these on the head, which 

 is a very common habit with birds in the case of 

 such prey. If food which is thus dangerous is taken 

 by the bird on the wing, as is the case with wasps 

 and other venomous insects, the bill is long, and the 

 tongue either short, or callous towards the tip, so as 

 not to be very liable to injury, if the snap of the bill, 

 which however is seldom the case, should fail in 

 despatching the insect. 



If the food is in itself harmless, and not liable to 

 escape rapidly, so as to require a quick dart of the 

 bill, that organ is short, and any inconvenience which 

 may arise from the distance at which it is below the 

 level of the body, or from the difficulty of the surface 

 on which it is found, is usually got the better of by 

 the length and flexibility of the neck ; but as a long 

 and flexible neek is neither so steady nor so quick in 

 its motions as a shorter one, the bill and neck are 

 seldom both long unless in those species which take 

 their food from the water, by darting rapidly on it 

 by an aim taken when the eye and head are above 

 the surface. Birds of this structure usually find their 

 food on the margin of the water, or in the shallows ; 

 and there is hardly any instance of a bird which 

 feeds on the wing, having both a long bill and a 

 long neck. 



The same observation applies to birds which seek 

 their food while launched on the waters. Swans, 

 geese, and those ducks which never get wholly below 

 the surface, though they get with the head perpen- 

 dicularly under them, and hang, as it were, upon the 

 L L2 



