borrowed from the kitchen, filled with the water from the stream. By the side of the globe I place another jar, empty. Taking the shorter tube, I place one end in the aquarium and give a quick draw with my lips, slipping the end instantly into the empty jar. As soon as I see that the water is flowing through the siphon I repeat the operation with the full jar, and, as the leg of the siphon is sufficiently long, the water runs from the jar into the bottom of the globe. Thus a current is set up in which the plants wave back and forth, and from the liveliness of
Fig. 1.—Hydra Vulgaris.
the living creatures it is evident that they enjoy the sensation. When I see that the upper jar is nearly empty, I remove the siphon from the lower one, and the replenishing of my "tank" is at an end.
Few can tell how much pleasure is obtained from this apparently trifling "hobby," but it really is intense. Close at hand is the microscope, and on the table, ready for use, lie a piece of glass tubing for a pipette, a zoöphyte trough, a pair of forceps, and an ordinary pocket magnifier. It is easy, when anything is
