A Criticism of the Cell-Theory; being an Answer to Mr. Sedgwick's ...

A CRITICISM OF THE CELL-THEORY. 153
essentially similar process, a continuous sheet of protoplasm
containing many nuclei is formed as a tissue-constituent of a
multicellular animal or plant, we do not call the whole multinuclear
tract a single cell—we call it a syncytium, or take
some roundabout way of describing it. Such a case is the
formation of the endosperm in the embryo-sac of Phanerogams.
By repeated mitotic division of the nucleus and growth
of the surrounding cytoplasm, a tract of continuous protoplasm
is formed, containing many nuclei. At a later stage
partitions are formed and the mass is divided up into cells, but
for a period the endosperm has a structure which recalls that
of the Coeloblastse. Can we say that the condition in the
endosperm is to be regarded as multicellular because it is not
permanent, and that the condition in the Coeloblastse is to be
regarded as unicellular because it is permanent ? If this is
allowed the consequences are far-reaching, for it follows that
the multinuclear phase in Actinosphserium and other Protozoa
is also multicellular, because not permanent.
Take, again, the case of the Mycetozoa. The plasmodium of
Badharaia or Fuligo is not unicellular, for it is formed by the
union of many cells: it is not called multicellular, because
there are no cell divisions : yet we draw, rightly enough, a
distinction between the plasmodium, where cell bodies fuse but
the nuclei do not unite, and the single cell resulting from, conjugation,
where the nuclei do unite.
A survey of the facts must lead to the conclusion that there
is an intermediate phase between the unicellular and the multicellular
condition, which is the multinucleate but non-cellular
condition, 1 and that there is no fundamental distinction
1 The term non-cellular does not exactly represent the condition which it
is intended to describe. Yet, if one adheres to existing nomenclature, it is
difficult to find a substitute. The term "cell," though founded on an
erroneous conception, is so firmly established in biological language that it
would probably be impossible to eject it. Yet if one were to make general
use of the Greek equivalent KVTIS (literally a little box), which has already
come into such favour as to have respectable claims on our attention, ons
might adopt much more exact expressions. Thus the uninucleate Protozoa
might be said to exhibit a monocjtial condition, multicellular organisms a