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such period as actual decomposition of the tissues sets in ; 
but assuredly we do not know this as a matter of fact, and any 
reasoning based upon an assumption that this is the case 
must be regarded as being, in the meanwhile, open to doubt. 
Whatever may be thought as to the validity of the above 
argument in relation to the chemical properties of protoplasm, 
no hesitation at all can be entertained as to its force so far as 
the so-called “ vital ” properties of this substance are con- 
cerned. These properties — as their very name implies — are 
not, and never can be, known, except as manifested by living 
protoplasm. I do not say that it may not be ultimately proved 
that they are “ properties ” of protoplasm, as protoplasm pure 
and simple, whatever its state may be, and that in the one 
case they are simply dormant or potential properties, while in 
the other they are active and visible ones. I do not say that 
we may not ultimately have sufficient proof to establish the 
thesis that dead protoplasm and living protoplasm are one and 
the same substance, with no other difference than that dead 
protoplasm is in a statical, and living protoplasm in a 
dynamical condition. I do say, however, that we have not at 
present a shadow of actual proof to support such a thesis, and 
that it is begging the entire question at issue to speak of the 
“ vital properties ” of protoplasm at all. If there be — as for 
all that science has yet proved there may be — any truth, or 
kernel of truth, at the bottom of the old vitalistic theories, 
then, however modified a shape these theories may assume, it 
will remain true that the so-called vital properties 33 of 
protoplasm are properties which belong to it in virtue of its 
being alive , and not in virtue of its having the physical and 
chemical properties of the substance known under this name. 
I shall return to the point here alluded to again, and we 
may pass on now to briefly consider what the so-called “ vital 
properties ” of protoplasm actually are. In other words, what 
are the essential phenomena manifested by a living mass of 
protoplasm ; and in what respects do these phenomena differ 
from those exhibited by all known aggregates of purely 
inorganic matter, or by dead bodies in general ? In order 
to arrive at clear ideas upon this subject, we may with 
advantage briefly glance at the phenomena exhibited by a 
“ cytode,” by an independent cell,” and by any complex 
organism, whether animal or vegetable. 
What is known as a (< cytode 33 is a minute microscopic 
mass of protoplasm, which is not bounded by a definite or 
rigid outer envelope or “ wall,” and which does not possess 
in its interior the structure known as a “ nucleus.” It is in 
the form of a cytode, or a simple mass of indifferentiated and 
