ntussusception.

No one would look in his writings for an idea or suggestion of the
principle of differentiation of parts or organs as we now understand it,
or for the idea of the physiological division of labor; these were
reserved for the later periods of embryology and morphology.

_Origin of the First Vital Function._--We will now return to the germ.
After it had begun spontaneous existence, Lamarck proceeds to say:

"Before the containable fluids absorbed by the small, jelly-like
mass in question have been expelled by the new portions of the same
fluids which reach there, they can then deposit certain of the
contained fluids they carry along, and the movements of the
contained fluids may apply these substances to the containing parts
of the newly organized microscopic being. In this way originates the
first of the vital functions which becomes established in the
simplest organism, _i.e._, nutrition. The environing containable
fluids are, then, for the living body of very great simplicity, a
veritable chyle entirely prepared by nature.

"Mutilation cannot operate without gradually increasing the
consistence of the parts contained within the minute new organism
and without extending its dimensions. Hence soon arose the second of
the vital functions, _growth or internal development_."

_First Faculty of Animal Nature._--Then gradually as the continuity of
this state of things within the same minute living mass in question
increases the consistence of its parts enclosed within and extends its
dimensions, a vital orgasm, at first very feeble, but becoming
progressively more intense, is formed in these enclosed parts and
renders them susceptible of _reaction_ against the slight impression of
the fluids in motion which they contain, and at the same time renders
them capable of contraction and of distention. Hence the origin of
_animal irritability_ and the basis of feeling, which is developed
wherever a nervous fluid, susceptible of locating the effects in one of
several special centres, can be formed.

"Scarcely will the living corpuscle, newly animalized, have received
any increase in consistence and in dimensions of the parts
contained, when, as the result of the organic movement which it
enjoys, it will be subjected to successive changes and losses of its
substance.

"It will then be obliged to take nourishment not only to obtain any
development whatever, but also to p