m their signs. Thus this light is the vibration of that
ethereal matter, and from this vibration we infer the existence of ether.

MAN AND EVOLUTION

Certain European philosophers agree that the species grows and develops,
and that even change and alteration are also possible. One of the proofs
that they give for this theory is that through the attentive study and
verification of the science of geology it has become clear that the
existence of the vegetable preceded that of the animal, and that of the
animal preceded that of man. They admit that both the vegetable and the
animal species have changed, for in some of the strata of the earth they
have discovered plants which existed in the past and are now extinct; they
have progressed, grown in strength, their form and appearance have
changed, and so the species have altered. In the same way, in the strata
of the earth there are some species of animals which have changed and are
transformed. One of these animals is the serpent. There are indications
that the serpent once had feet; but through the lapse of time those
members have disappeared. In the same way, in the vertebral column of man
there is an indication which amounts to a proof that, like other animals,
he once had a tail. At one time that member was useful, but when man
developed it was no longer of use, and therefore it gradually disappeared.
As the serpent took refuge under the ground, and became a creeping animal,
it was no longer in need of feet, so they disappeared; but their traces
survive. The principal argument is this: that the existence of traces of
members proves that they once existed; and as now they are no longer of
service, they have gradually disappeared. Therefore while the perfect and
necessary members have remained, those which are unnecessary have
gradually disappeared by the modification of the species, but the traces
of them continue.

The first answer to this argument is the fact that the animal having
preceded man is not a proof of the evolution, change, and alteration of
the species, nor that man was raised from the animal world to the human
world. For while the individual appearance of these different beings is
certain, it is possible that man came into existence after the animal. So
when we examine the vegetable kingdom, we see that the fruits of the
different trees do not arrive at maturity at one time; on the contrary,
some come first and others afterwards. This priority does