little fellows are those to whom they belong, that it is impossible to conceive a more animated scene than that presented to the eye of the microscopic observer in the examination of a drop of water.
The waters of the earth teem with these minute forms of existence; but as their presence was first detected in certain infusions of vegetable matter, they were named Infusoria—a term which they have been allowed to retain, though it is now known that their sphere of existence embraces all the aqueous portions of the globe. We have said that their quaint forms baffle description; but we will endeavour to give the reader some idea, however inadequate, of one or two individuals of the infusorial race.
The smallest and the most active members of this immense family are the Monads, which so thickly populate the invisible world, that Ehrenberg has declared that a selected drop of water may actually contain as many as there are human beings upon the surface of the great globe itself! These minute creatures are always in motion, and may be seen bustling about in every part of the drop—to them a mighty sea—as though their health and happiness depended on constant exercise.
The little creatures, or rather the congeries of creatures, called the Volvox, and formerly known as the globe animalcule, is not the least remarkable of this group. It consists of a number of monads, invested by a common envelope, each individual maintaining
