of the mneme and adapts it to
the surrounding local circumstances.

_De Vries_ has objected that the variations produced by artificial and
natural selections are mutable, while sudden mutations have a much
more stable character. But we have just seen that these mutations
themselves are evidently only the delayed ecphoria of a long ancestral
engraphia accumulated.

On the other hand, the variations obtained by selection are themselves
only due to more rapid ecphorias, derived from repeated conjugations
in a certain direction. _Plate_ and others have shown that they may
become more and more fixed, if they are well adapted, and thus become
more tenacious. There is, therefore, no contradiction between the
fundamental facts, and all is simply and naturally explained by the
combination of hereditary mnemic engraphia with selection.

Recent study on the transformations of living beings have shown that
they do not take place in a regularly progressive manner, as _Darwin_
at first believed, but that periods of relatively rapid transformation
alternate with periods of relative arrest, both in a general way and
for each particular species. We see certain species remaining almost
stationary for an immense time and tending rather to disappear, while
others vary enormously, showing actual transformation. The
transplantation of one species to a new environment, for instance to a
new continent, provokes, as has been proved, a relatively rapid
transformation. It is evident that mnemic engraphia transforms
organisms the more rapidly as it changes in nature itself, which is
the case in the migrations we have just mentioned, and which also
changes the factors of selection.

Other facts show clearly that the fauna and flora of the present world
find themselves in a period of recoil with regard to their
modification. In the tertiary period the fauna and flora of the world
were richer than to-day; many more older species have disappeared than
new ones have arisen. This fundamental fact seems due to the extremely
slow cooling of the earth, and appears to be indicated by the powerful
growth in tropical climates, the fauna and flora of which resemble
those of the tertiary period, and, on the other hand by the relative
poverty and slowness of growth in cold countries.

=Conclusions.=--What are the principal conclusions to which we are led
by this short study of the ancestral history or phylogeny of man?

(1). The transformation or evolutio