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PRINCIPLES OF PHYSIOLOGY. 75
all the most complicated end beautiful organs of the
human body.
But before a cell can be formed, there must be mat
ter suitable to its formation. We have here again the
principles necessary to form a universe. There must
be matter and the intelligent forming spirit. This mat
ter, out of which cells are formed, is called blastema.
It is essentially albuminous, and the egg of the common
fowl, out of which is formed all the parts of the chicken,
is the type of all blastema.
It is not to be understood that all forms of organic mat
ter originate in the kind of cell growth above described.
These are investigations surrounded with difficulties;
but there is reason to believe that the blastema may take
on the forms of simple
fibrous tissue and basement
membrane, without passing through the cellular trans
formation. These parts are less vital than others, and
less subject to decay ; while the whole cellular substance
of the system, and by this I mean all parts generated by
cell growth, is in a constant process of —of change dis
solution and reproduction. Each of the myriad cells
that goes to make up the human seems to body, have
its own birth, life, and death; it dissolves, is carried
away, and another cell takes its place. All vital pro
cesses, even those of thought, have to be accompanied
by the destruction and reproduction of cells; and hence
the necessity for constant nutrition and constant excre
tion—the perpetual supply of new materials, and the
conveying away of the waste matter.
Thus it is in the human ns body, in the human race.
The individual cell dies, and another takes its place, but
the body lives on. The individual mau dies, the life of