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283
rous growth zones and observed scores of pear-shaped bodies;
however, I have not found any trace of the development described,
but invariably only the mature structure, even in the very apex of
the stem or branches (fis. 3 a, b). There is no initial which has
not got a tail. It has no thick »mucilage coat», but a very thick
cellulose wall, by which it differs from all other cells. There is
never any sign of a cell row with walls so thick. I cannot find
any resorplion of cross walls. In some cases the nucleus is quite
distinct; the protoplasm sometimes forms portions or exhibils trans-
verse stripes, probably mistaken for a resorption of walls. The
posilion of the mature »initial» is not quite regular; sometimes the
head is well within the young cortex, sometimes raised above it,
even leaving a considerable part of the tail outside the cortex, but
the shape of the body is always the same and certainly does not
result from pressure, as the wall is thick and strong while the
growing lissue is rather loose. As my figures show, the theory of
pressure seems quile out of place.
Besides, there must be a conneclion belween the pear-shaped
body and one of the cortical cells, at least in the younger slages.
Now, there are no younger stages in the sense of Ror, but even the
bodies in the very apex are loose, possibly with the tail pressed
against a lower cell, but not connecled. The connections showed
in figures of MITCHELL, WHITTING and Ror are not at all satisfac-
tory. Ror does not seem to have observed any connection between
her »mature structure» and a cortical cell; I suppose she thinks it
carried along by the growing cortex and thus torn loose, but I fail
to see how this could be effected.
In a microtome section the thick-walled head of one of the pear-
shaped bodies may be mistaken for one of Ror’s initials, but I
always found the tail on the next seclion. In other cases I expect
that her rows are only basal parts of hairs. It is evident that she
has not been able to make a proper distinclion between a young
hair and an initial row. And her illustralions do not at all prove
that the various stages have anything to do vith each other.
The question: »what are the pear-shaped bodies?» thus remains
unanswered. I believe that they have nothing to do with Splach-
nidium but represent a separate organism, growing in the cortex.
The reasons for this opinion are several. These bodies have no
connection with olher cells. Their shape is quite peculiar. Their
wall is much thicker than in all other cells. Though they gene-
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