rithing.
Such a worm has the general plan of the body of the higher forms
fairly well, though rudely, sketched. Many improvements will come,
and details be added. But the rudiments of the trunk of even our own
bodies are already visible. Head, in any proper sense of the term,
and skeleton are still lacking; they remain to be developed.

And yet, taking the most hopeful view possible concerning the animal
kingdom, its prospects of attaining anything very lofty seem at this
point poor. Its highest representative is a headless trunk, without
skeleton or legs. It has no brain in any proper sense of the word,
its sense-organs are feeble; it moves by writhing. Its life is
devoted to digestion and reproduction. Whatever higher organs it has
are subsidiary to these lower functions. And yet it has taken ages
on ages to develop this much. If _this_ is the highest visible
result of ages on ages of development, what hope is there for the
future? Can such a thing be the ancestor of a thinking, moral,
religious person, like man? "That is not first which is spiritual,
but that which is natural (animal, sensuous); and afterward that
which is spiritual." First, in order of time, must come the body,
and then the mind and spirit shall be enthroned in it. The little
knot of nervous material which forms the supra-oesophageal
ganglion is so small that it might easily escape our notice; but it
is the promise of an infinite future. The atom of nervous power
shall increase until it subdues and dominates the whole mass.

CHAPTER III

WORMS TO VERTEBRATES: SKELETON AND HEAD

In tracing the genealogy of any American family it is often
difficult or impossible to say whether a certain branch is descended
from John Oldworthy or his cousin or second cousin. In the latter
cases to find the common ancestor we must go back to the grandfather
or great-grandfather. The same difficulty, but greatly enhanced,
meets us when we try to make a genealogical tree of the animal
kingdom. Thus it seems altogether probable that all higher forms are
descended from an ancestor of the same general structure and grade
of organization as the turbellaria, although probably free swimming,
and hence with somewhat different form and development, especially
of the muscular system. It seems to me altogether probable that all,
except possibly Mollusca, are descended from a common ancestor
closely resembling the schematic worm last described. Some would,
however, mai