re much the largest. The animal shows only the upper part of its
body, and I can see with my pocket lens that it is somewhat
transparent and whitish. But my lens has not sufficient magnifying
power to reveal more, so I must tell you what I have seen of Melicerta
under my compound microscope. Each of these four leaf-like lobes or
expansions is surrounded with very minute hairs, which can move with
great rapidity in all directions; these you will remember are called
"cilia," from the resemblance to _eyelashes_, for which cilia is the
Latin word. The motion caused by these numerous cilia lashing the
water brings currents containing particles of food for the Melicerta,
and materials for his house. Mr. Melicerta "is at once brick-maker,
mason, and architect, and fabricates as pretty a tower as it is easy
to conceive." The mouth is situated between the two large leaflets,
and leads to a narrow throat, in which are the curious jaws and teeth
of the animal. Below the jaws are the stomach and intestine; so you
see the Melicerta, though so minute a creature, has a complex
structure. "You said, papa," remarked May, "that the little creature
makes its own tube; how does it do that?" Upon the upper part of the
head there is a small hollow cup, which is lined with cilia, and
probably also secretes some sticky fluid to make the pellets of clay
adhere together; the particles of clay and mud, having been brought to
the space between the leaflets by the action of the cilia, are
conveyed to this little cup-shaped cavity, and are then worked about
by the cilia within, till a round pellet is formed which completely
fits the cavity. The little creature then bends itself down upon the
tube and deposits the pellet upon it, then it raises itself up again
and proceeds to form another brick, its jaws working all the time. "I
wonder," said Jack, "how the little creature manages to set apart and
put in its proper place the particles required for food and those
required for brick-making; it would be funny if it sometimes made a
mistake and put the clay in its stomach and the food in the brick
machine!" It is curious, indeed, to know how the materials are put in
the proper place; I suppose the Melicerta has the power to change the
direction of the currents and thus to place the particles in their
proper place. By rubbing a little paint, such as carmine or indigo, in
some water and placing a drop upon the glass slide with the Melicerta,
these currents