486 Science and the Bible. [July,
sexual
relations, and a superior surface differing from an inferior in its
functions and forms. It adds to the above variables (as to form,
texture, structure, color, kind of symmetry) many new variables: as, to
a mouth, whether with teeth or with none, etc.; as to the form of the
teeth and their modes of movement, etc.; as to the stomach and its
appendages, and all their variations ; as to the liver (if any) and its
variations; as to the system of reproduction; as to means of movement,
taking food, etc. ; as to senses, or none, etc.
11.
Let, again, the number of rays, instead of five, be a multiple of five
; or let it be four, or a multiple of four ; or six, or a multiple of
six; or let the number be indefinite.
12.
Let the radiate structure be not strictly the rays of one or more
mathematical planes, but of a spiral approximately circular, and this,
like the above, a result of systematic evolution — a fact of all
apparent circles in plants and animals.
We have passed these steps in review, in order to give some idea of the Radiate type in the animal kingdom, the simplest of its four grand
divisions or sub-kingdoms. With mere animality in its lowest forms, and
no senses but touch and sight (the latter usually wanting, and at the
best imperfect), the type-idea includes a radiate arrangement of the
organs externally and internally, and a symmetry between the two halves
either side of the medial line. These are the constants, and
the true basis of our notion of the type. It is to be observed, again,
that these constants are not constants as to form, proportions, size,
color, or texture, those qualities which are necessary, at least, in
part, in all mental images. There are limits to each system of
variation; and, in this respect, the variables become constants, but
in no other. Again, it should be borne in mind, that all the variations
are so harmonized, that a change in one part involves others throughout
a structure. From the abstract notion of the type, the mind obtains a
conception of the whole system under it, as far as it can, by flashing
along the systems of variables ; and whenever it rests for an instant,
it has lit on
