This little animal belongs to the family of snails, class Heteropoda,
is about an inch long, and is devoid of any shell or covering
whatever. It is flat, and so absolutely transparent that a person
can read through its body. It is provided with a pair of feelers. The
little animal is very luminous if placed in fresh water or disturbed,
but this phenomenon is most beautiful when an ammonia solution is
poured over the animal. It will shine with a vivid blue light, which
extinguishes with life. But even after death the nerve cells, which
are directly below the skin and produce the light, can be irritated
sufficiently to become luminous. It is a singular fact that
electricity has no effect upon these nerve cells.
[Illustration: PHYLLIRHOE BUCEPHALA--AS SEEN IN THE LIGHT.
_a b_, ganglion; _c_, intestines; _d_, liver; _f_, kidneys; _g_,
generative organs.]
[Illustration: PHYLLIRHOE BUCEPHALA--SHOWING IN THE DARK THE LUMINOUS
SPOTS.]
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