icta
of scientific men, and more particularly against his own dicta, though
he made no claim to be a scientist. If his reader _must_ believe in
something, "let him believe in the music of Handel, the painting of
Giovanni Bellini, and in the thirteenth chapter of St. Paul's first
Epistle to the Corinthians." And he exclaims: "Let us have no more 'Lo,
here!' with the professor; he very rarely knows what he says he knows;
no sooner has he misled the world for a sufficient time with a great
flourish of trumpets than he is toppled over by one more plausible than
himself." That is a somewhat unkind way of putting it; but undoubtedly
theory after theory is put forward, and often claimed to be final, only
to disappear when another explanation takes its place. Thus at the
moment we are in the full flood of the chemical theory which is employed
to explain inheritance. That heredity exists we all know, but so far we
know nothing about its mechanism. Darwin, with "Pangenesis," and others,
using other titles, argued in favour of a "particulate" explanation, but
the number of particles which would be necessary to account for the
phenomena involved, this and other difficulties, have practically put
this explanation out of court. Then we had the Mnemic theory of Hering,
Butler, and others, by which the unconscious memory of the embryo--even
the germ--is the explanation. Quite lately the mnemic theory has been
claimed by Rignano in his _Scientific Synthesis_ as a complete
explanation, in forgetfulness of the fact that even the all-powerful
protozoon can only remember what has passed and could certainly not
_remember_ that it was some day going to breed a man. At the moment,
things are explained on a chemical basis, though that basis is far from
firm; is of a shifting nature, and a little hazy in details. Some time
ago, colloids were the cry. A President of the British Association
almost led one to imagine that "the homunculus in the retort" might be
expected in a few weeks. But the chemists would have none of this, and
denied that the colloids, about which they ought to know more than do
the biologists, had that promise in them which had been claimed. We had
Leduc and his "fairy flowers," as now we have Loeb and others with their
metabolites and hormones. As to these last, there seems to be no kind of
doubt that the internal secretions of many organs and structures have
effects which were, even a few years ago, quite unsuspected. Those of