Simple as it is, however, as a mechanical structure, the life and growth of the sponge is as mysterious as that of the most highly organized animal or even the soul of man. We can study out the structure of a plant or animal; we can analyze it and tell what are the elements of which it is composed; we can describe the mechanical operations that are carried on and the chemical combinations that take place, but no man has ever yet solved the mystery of life, even in the lowest form—whether animal or vegetable.
The sponge, whether considered as a single or compound animal, has the power to reproduce itself, and here the mystery of life is as much hidden as it is in God's highest creation. It has been stated that every sponge contains a large number of separate cells which carry on the operation of circulation and respiration, and may be likened to the heart and lungs of an animal of a higher creation. Zoölogists claim that each one of these cells represents a separate animal, living in a common structure. However this may be, it is an interesting fact that the sponge has the power of secreting ova that grow in large numbers in little sacks until they have reached a certain stage of progress, when they are expelled from the mother sponge and turned adrift in the great ocean to struggle for their own existence. These eggs do not differ much in their structure and composition from an ordinary hen's egg, except that there is no shell, only a skin provided with little fibers called cilia, that project from it, and by the movement of these the embryo sponge is able to propel itself through the water. It thus lives until it has reached a certain stage of development, when it seeks out a pebble or rock, to which it attaches itself at one end—preparation for which has been made by its peculiar structure during its life when it was free to float around through the water. It is now a prisoner and chained to the rock it has selected for the foundation of its home. Having no longer any use for the little cilia, which enabled it to swim through the water, it now loses them. Here is a beautiful illustration of how nature provides for the necessities of the smallest things, and how when the necessity that demanded a certain condition passes by the condition passes with it. The embryo begins to show a fibrous development, which is the beginning of the framework of a new sponge. Evolution goes on, every step of which is as mysterious as a miracle, until the growing thing is a full-grown sponge, equipped with the means for respiration, circulation, feeding, digestion, and reproduction.
Sponges grow in the bottom of the sea at different depths. They are obtained by divers who make a business of gathering them. The best sponges are called the Turkish sponge, which are very soft and velvety, and may be bleached until they are nearly white by subjecting them to the action of certain acids. The divers become very expert, but they do not have the modern equipments of a diving suit. The Syrian divers in the Mediterranean go down naked with a rope attached to their waists and a stone attached to the rope to cause them to sink, together with a bag for carrying the sponges. They have trained themselves until they can remain under water from a minute to a minute and a half, and in that time can gather from one to three dozen sponges. The ordinary depth to which they descend is from eight to twelve fathoms. But a very expert diver will go down as far as forty fathoms. The better class of sponges are said to grow in the deeper waters. The coarse inferior sponges are called the Bahama sponge. This sponge is of a peculiar shape, growing more like a brush, with long bristly fiber.
The trade in sponges is quite large. The consumption in Great Britain alone amounts to about $1,000,000 per annum.
The sponge as an animal possesses many advantages over his more aristocratic neighbor, man. He breathes but he has no lungs, and therefore cannot have pneumonia. He digests his food, but he has no stomach, and therefore never has dyspepsia, gastritis, or any of the many ailments that belong to that much abused organ. He has no intestines, and therefore cannot have appendicitis or Asiatic cholera or any of the long train of diseases incident to those complicated organs. He has no nervous system—oh, happy sponge!—therefore he cannot have nervous prostration, hysteria, or epilepsy. He has no use for doctors, and therefore has no unpleasant discussions with his neighbors about the relative merits of the different schools of medicine. If he has any predilections in the way of "pathies" we should say that he is a hydropath. While he is a great drinker, he is not at all convivial—he drinks only water, and takes that in solitary silence. He sows all his wild oats when he is very young, while he has the freedom to roam at will. He soon tires of this, however, for he selects the rock that is to be the foundation of his future home and there settles down for life, "wrapt in the solitude of his own originality." He is not troubled with wars or rumors of wars. His eyes are never startled or his nerves shaken by the scare headlines of yellow journalism. The one sensation of his life, if sensation he ever has, is when a great ugly creature of some Oriental clime comes down to his home and tears him away from his native rock, carries him to the surface, and there literally "squeezes the life out of him." He finally dies of the "grip," and here he sinks to the level of his more aristocratic neighbor.
But there is another side to our philosophy. If the sponge is exempt from all these ills that we have enumerated it is because he is incapable of suffering and is therefore incapable of enjoyment. Those beings that have the ability to suffer most have also the ability to enjoy most. The higher the type of civilization the greater possibilities it offers for real enjoyment—also for real misery. This being true, it should be the aim of highly civilized people to eliminate as far as possible those things that make for misery, and cultivate those things that make for happiness in the highest and best sense.