Though one transparent vacancy it seem,
Void of their unseen people. These, concealed
By the kind art of forming Heaven, escape
The grosser eye of man: for, if the worlds
In worlds inclosed should on his senses burst,
From cates ambrosial and the nectared bowl,
He would abhorrent turn; and in dead night,
When silence sleeps o’er all, be stunned with noise.”
Leewenhoeck calculates, that a thousand millions of animalcules, which may be discovered in common water, are not altogether so large as a common grain of sand! Eminent naturalists have discovered not less than 30,000 in a single drop of water! What a display is this of the manifold wisdom of God! While he makes some of the aquatic tribes so large, that they seem to require almost a whole sea to float in, he forms others so astonishingly minute, that several thousands will adhere to the point of a needle.[147]
Every animalcule being an organized body, how delicate and subtile must the parts be that are necessary to constitute it, and to preserve its vital actions! How inconceivably small must it be, and yet a perfect animal. In animalcules, we discover the same multiplication of parts, diversity of figures, and variety of motions, as in the largest animals. How amazingly curious must be the internal structure of these creatures! how minute the bones, joints, muscles, tendons! how exquisitely delicate the veins, arteries, nerves! What a number of vessels and different circulations must be contained in one of these little creatures, and yet all have sufficient room for the performance of their several functions, without interfering with each other! It is difficult to conceive how in so narrow a compass, there should be contained a heart as the fountain of life propelling the circulating fluid, veins and arteries as the conductors of the blood, a brain to supply nerves in every part of the minute structure, muscles necessary to its motions, glands for the secretion of its fluids, stomach, and bowels to digest its food, eyes to direct its progress, a mouth to take in its nourishment, and organs of generation to propagate its kind!