If a garden wall can lead our vagabond thoughts into such speculations as these, surely it may also furnish us with matter for our Studies in Animal Life? Those patches of moss must be colonies. Suppose we examine them? I pull away a small bit, which is so dry that the dust crumbles at a touch; this may be wrapped in a piece of paper—dirt and all—and carried home. Get the microscope ready, and now attend. I moisten a fragment of this moss with distilled water. Any water will do as well, but the use of distilled water prevents your supposing that the animals you are about to watch were brought in it, and were not already in the moss. I now squeeze the bit between my fingers, and a drop of the contained water—somewhat turbid with dirt—falls on the glass slide, which we may now put on the microscope stage. A rapid survey assures us that there is no animal visible. The moss is squeezed again; and this time little yellowish bodies of an irregular oval are noticeable among the particles of dust and moss. Watch one of these, and presently you will observe a slow bulging at one end, and then a bulging at the other end. The oval has elongated itself into a form not unlike that of a fat caterpillar, except that there is a tapering at one end. Now a forked tail is visible; this fixes on to the glass, while the body sways to and fro. Now the head is drawn in—as if it were swallowed—and, suddenly, in its place are unfolded two broad membranes, having each a circle of waving _cilia_. The lifeless oval has become a living animal! You have assisted at a resuscitation, not from death by drowning, but by drying: the animal has been drowned into life! The unfolded membranes, with their cilia, have so much the appearance of wheels that the name of “Wheel-bearer” (_Rotifera_) or “Wheel Animalcule” has been given to the animal. The Rotifera (also—and more correctly—called _Rotatoria_) form an interesting study. Let us glance at their organization:— [Illustration: Fig. 16. ROTIFER VULGARIS. A, with the wheels drawn in (at _c_). B, with wheels expanded; _b_, eye spots; _c_, jaws and teeth; _f_, alimentary canal; _g_, embryo; _h_, embryo further developed; _i_, water-vascular system; _k_, vent.]