rd, when those changes
are interposed between two radio-active transformations which can
be followed, show that spontaneous transmutation is possible without
measureable radio-activity. And, indeed, any theory of disintegration,
such as Thomson's corpuscular hypothesis, would suggest that atomic
rearrangements are of much more general occurrence than would be
apparent to one who could observe them only by the effect of the
projectiles, which, in special cases, owing to some peculiarity of
atomic configuration, happened to be shot out with the enormous velocity
needed to ionize the surrounding gas. No evidence for such ray-less
changes in ordinary elements is yet known, perhaps none may ever be
obtained; but the possibility should not be forgotten.

In the strict sense of the word, the process of atomic disintegration
revealed to us by the new science of radio-activity can hardly be called
evolution. In each case radio-active change involves the breaking up of
a heavier, more complex atom into lighter and simpler fragments. Are
we to regard this process as characteristic of the tendencies in accord
with which the universe has reached its present state, and is passing
to its unknown future? Or have we chanced upon an eddy in a backwater,
opposed to the main stream of advance? In the chaos from which the
present universe developed, was matter composed of large highly complex
atoms, which have formed the simpler elements by radio-active or
ray-less disintegration? Or did the primaeval substance consist
of isolated electrons, which have slowly come together to form the
elements, and yet have left here and there an anomaly such as that
illustrated by the unstable family of uranium and radium, or by some
such course are returning to their state of primaeval simplicity?

INDEX.

Abraxas grossulariata.

Acquired characters, transmission of.

Acraea johnstoni.

Adaptation.

Adloff.

Adlumia cirrhosa.

Agassiz, A.

Agassiz, L.

Alexander.

Allen, C.A.

Alternation of generations.

Ameghino.

Ammon, O., Works of.

Ammonites, Descent of.

Amphidesmus analis.

Anaea divina.

Andrews, C.W.

Angiosperms, evolution of.

Anglicus, Bartholomaeus.

Ankyroderma.

Anomma.

Antedon rosacea.

Antennularia antennina.

Anthropops.

Ants, modifications of.

Arber, E.A.N.,--and J. Parkin, on the origin of Angiosperms.

Archaeopteryx.

Arctic regions, velocity of development of life in.

Ardig