om what do we affirm these
existences? From their signs. Thus this light is the vibration of that
ethereal matter, and from this vibration we infer the existence of ether.

49: THE GROWTH AND DEVELOPMENT OF THE HUMAN RACE

Question.--What do you say with regard to the theories held by some
European philosophers on the growth and development of beings?

Answer.--This subject was spoken of the other day, but we will speak of it
again. Briefly, this question will be decided by determining whether
species are original or not--that is to say, has the species of man been
established from its origin, or was it afterward derived from the animals?

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