an armor, while others still are naked. Those having shells
secrete the material for their construction from the water. Some of
them are fixed to rocks, etc., while others roam at will. Strange as it
may appear at first sight, some of the higher forms of the mollusca
show signs of a rudimentary vertebra, and science has hazarded the
opinion that the sea-squirts and similar creatures were descended from
some ancestor from whom also descended the vertebrate animals, of which
man is the highest form known today on this planet. We shall mention
this connection in our next lesson, where we will take up the story of
"The Ascent of Man" from the lowly vertebrate forms.

And now, in closing this lesson, we must remind the reader that we are
_not_ teaching Evolution as it is conceived by modern science. We are
viewing it from the opposite viewpoint of the Yogi Teaching. Modern
Science teaches that Mind is a by-product of the evolving material
forms--while the Yogi Teachings hold that there was Mind _involved_ in
the lowest form, and that that Mind constantly pressing forward for
unfoldment _compelled_ the gradual evolution, or unfoldment of the
slowly advancing degrees of organization and function. Science teaches
that "function precedes organization," that is, that a form performs
certain functions, imperfectly and crudely, before it evolves the
organs suitable for the functioning. For instance the lower forms
digested food before they evolved stomachs--the latter coming to meet
the need. But the Yogi Teachings go further and claim that "desire
precedes function," that is, that the lowly life form "desires" to have
digestive apparatus, in order to proceed in the evolutionary scale,
before it begins the functioning that brings about the more complex
organism. There is ever the "urge" of the Mind which craves unfoldment,
and which the creature feels as a dim desire, which grows stronger and
stronger as time goes on. Some yield more readily to the urge, and such
become the parents of possible higher forms. "Many are called, but few
are chosen," and so matters move along slowly from generation to
generation, a few forms serving to carry on the evolutionary urge to
their descendants. But is always the Evolutionary Urge of the
imprisoned Mind striving to cast aside its sheaths and to have more
perfect machinery with which, and through which, to manifest and
express itself? This is the difference between the "Evolution" of
Modern Sci