rs spread out on each side of the stem, and the
tree is covered with moving beings. These tentacles are feelers, which
lash food into a mouth and stomach in each cup, where it is digested
and passed, through a hole in the bottom, along a jelly thread which
runs down the stem and joins all the mouths together. In this way the
food is distributed all over the tree, which is, in fact, one animal
with many feeding-cups. Some day I will show you one of these cups
with the tentacles stretched out and mounted on a slide, so that you
can examine a tentacle with a very strong magnifying power. You will
then see that it is dotted over with cells, in which are coiled fine
threads. The animal uses these threads to paralyze the creatures on
which it feeds, for at the base of each thread there is a poison
gland.

In the larger Sertularia the whole branched tree is connected by jelly
threads, running through the stem, and all the thousands of mouths are
spread out in the water. One large form called _Sertularia cupressina_
grows sometimes three feet high and bears as many as a hundred
thousand cups, with living mouths, on its branches.

The next of my minute friends I can only show to the class in a
diagram, but you will see it under the fourth microscope by and by. I
had great trouble in finding it yesterday, though I know its haunts
upon the green weed, for it is so minute and transparent that even
when the weed is in a trough a magnifying-glass will scarcely detect
it. And I must warn you that if you want to know any of the minute
creatures we are studying, you must visit one place constantly. You
may in a casual way find many of them on seaweed, or in the damp ooze
and mud, but it will be by chance only; to look for them with any
certainty you must take trouble in making their acquaintance.

[Illustration: FIG. 6. _Thuricolla folliculata_ and _Chilomonas
amygdalum_. (_Saville Kent_.)

1, _Thuricolla_ erect. 2, Retracted. 3, Dividing. 4, _Chilomonas
amygdalum. hc,_ Horny carapace, _cv_, Contractile vesicle. _v_ Closing
valves.]

Turning then to the diagram (Fig. 6) I will describe it as I hope you
will see it under the microscope--a curious, tiny, perfectly
transparent open-mouthed vase standing upright on the weed, and having
an equally transparent being rising up in it and waving its tiny
lashes in the water. This is really all one animal, the vase _hc_
being the horny covering or carapace of the body, which last stands up