race, arose by a special intervention that modified a Specific life - force already in existence.

Speculative.

Conception is the incarnation of life, and we may surmise that the modification of an existing Specific life-force to produce a new type was effected at conception by the same Power that first incarnated life.

It may be that, in the higher organisms, the fecundated ovum of an existing type was in some unknown manner again fecundated with a new force, and the old and new forces thus incorporated evolved the new type. Further, if the womb of the antecessor was utilised to foster the embryo, a new race was evolved by a single direct intervention of the same Power that called the first simple forms of life into existence. Was not the mammal evolved from the fish through the amphibia?

The first evidence of a new life is the growth of the germ-plasm. We cannot penetrate deeper in our search for the origin of life, but yet the question will suggest itself, Whence comes the inexhaustible supply of force to animate the count

less millions of beings that every hour come into existence?

Judging by our experience of force in inanimate nature, a definite quantity of Specific life-force cannot, within itself, multiply or increase, and if Specific life-force comes from the progenitors, the first parents must have been endowed, not only with a sufficiency of vitality for themselves, but also for all their descendants.

But this would be at variance with Nature's parsimony in the use of means.

Again, if the Specific life - force of the individual is only sufficient for its own existence, whence comes the Specific lifeforce of its successor?

We know nothing of the forces that cause conception, or bring the embryo from the germ-cell, or develop the mature animal from the foetus.

The ignorance of the untutored savage in a great factory, where machines, driven by invisible electric energy, automatically produce cunning designs, is not more profound than that of the most highly gifted of our race in Nature's workshop.

But may not the great factory with its invisible motive force suggest, that the world of life is continuously sustained and

renewed by invisible but all - pervading energy, from a source that is inexhaustible, and that every individual life, to all seeming independent, is in reality but a motor, actuated invisibly to discharge its appointed functions, until the connection with the vitalising energy is sundered?

It may not be unnecessary to observe, that our theory deals only with the life which is common to all animals.

CHAPTER X.

PHASES OF THE EMBRYO AND FRAG-
MENTARY ORGANS.

LET us now test our theory by its explanation of, perhaps, the most mysterious and at the same time most significant phenomena in evolution - the similarity of an embryo to that of an antecessor more or less remote, and the presence in many races of what we call fragmentary (not rudimentary) organs.

The embryo of every mammal presents in its growth phases similar to what may be seen in that of its antecessor, and there may, in some cases, be observed the transformation of certain partially formed organs of the antecessor into others, different in appearance, but performing similar functions, in the successor.

Again, in the bodies of many mammals are found fragments of organs once perfect in the antecessor, but now apparently superfluous to their present owner.

These footprints of evolution seem to present a clue to the method of its progress; and to explain these phenomena satisfactorily, is an important test of any theory of evolution.

According to our theory, the phases in the growth of an embryo should resemble the corresponding phases in the embryo of its antecessor, up to the stage when the Specific life-force of the successor begins to differentiate the new type. When the differentiation between the old type and the new is slight, as in the case of what are called varieties of the same species, the modification of the pre-existing Specific lifeforce is slight, and the embryos are consequently similar up to an advanced stage in their growth.

In cases where the differentiation between two types arises only after birth, the mature fœtus of the one is not distinguishable from that of the other. But when the differentiation is important and extends to several organs, the co-operation of the old and the new Specific life-forces becomes more complicated. The sequence of the growth in the embryo of the organs of the old type and of the new is not always the same, and in such cases two forces seem for a time to be in