The instances of this kind are numerous. There is a curious resemblance between the stomach of a hen and a corn-mill; the crop answering to the hopper, and the gizzard to the stones which crush the corn. But the most interesting point of resemblance is this: to prevent too much corn from going into the stones at once, a receiver is placed between them and the hopper, so that it may be dribbled out just as fast as is required. The same process takes place in the hen, for though the crop may be filled, its food only enters the gizzard gradually, and as fast as that is able to digest it.
Another instance of obvious fitness and adaptation of one part to another, is furnished in birds of prey. Owls, hawks, eagles, &c., by their talons and beaks, are qualified to seize and devour other birds and quadrupeds; and accordingly the gastric juice in the stomach of these birds will act upon or digest flesh, but it will not digest seeds or grasses, or vegetables of any kind. On the other hand, the mouth of the ox and sheep is suited to the cropping of herbage; and accordingly we find the gastric juices of their stomachs will digest vegetable food, and not flesh!
There is another instance of fitness in a provision of nature, which marks the intelligence of the Creator, and that is, that the eyes of all animals are placed in front, in the direction in which the legs move, and the hands work; and therefore where they are most useful. How awkward would it be for us if our eyes were in the back of the head! How comparatively useless would the eyes of quadrupeds be, if placed behind!
Nature is full of such instances as these, all setting forth the intelligence and wisdom of the Creator; and not only displaying the marks of a designing and intelligent Mind, but intelligence in contriving and power in executing, which know no bounds. No obstacle seems to be presented that is not surmounted, and no contrivance to accomplish an object seems to be adopted, that is not, all things considered, the best that could be devised.
Another fertile and interesting source of evidence of the wisdom of God is found in the contrivances resorted to by the Creator to compensate his creatures for certain defects in their organization. Thus the short neck of the elephant is compensated by the admirable device of a proboscis, one of the most complicated and ingenious, but successful expedients of nature.
The bat has a clumsy foot and leg, but to compensate for this, he is supplied with a hook on his wing, by which he suspends himself to a beam, or to the sides of rocks, and in this way he usually obtains his sleep. The crane, the heron, the bittern are destined to live upon fish, yet they cannot swim. To make up for this deficiency they are provided with long legs for wading, or long bills for groping, and sometimes with both.
The common parrot would have an inconvenience in the very hooked shape of its upper jaw, or mandible, if like that of other birds it was stationary, for in this case it could hardly open its mouth to take its food. But this hook being wanted by the parrot to climb and suspend itself with, to remedy the evil above mentioned, this upper mandible is capable of being elevated or depressed at pleasure.
There is a grub called the glowworm, that gives out a phosphoric light in the darkness. Why is this? That her mate may find her; for while she is a worm he is a fly; while she is on the earth he is in the air. They would not be likely to meet therefore, if some extraordinary means of uniting them was not resorted to; but this, Nature has foreseen and provided for.
The spider’s web is a compensating contrivance, of a very ingenious character. This creature is made to feed on flies; yet how was it to catch them, for it had no wings? This might seem to be a case of difficulty, but the web is a net, and the spider is not only taught how to weave it, but his body furnishes the thread! How ingenious, how wonderful, how multiplied, are the resources of the God of Nature!
In many species of insects, the eye is fixed, and cannot be turned in its socket. To supply this great defect, the eye is a multiplying glass, with a lens looking in every direction, and showing every object that may be near. Thus, what seemed at first a privation, by this curious and interesting expedient is made to be an advantage, as an eye thus constructed, seems better adapted to the wants of these creatures than any other. The common fly is said to have four thousand lenses in each eye, and the butterfly thirty thousand!