transparent. A bent stem was immersed for 30 m. in a solution of one
part of carbonate of ammonia to 109 of water, and two or three of the
uppermost cells in the pedicels now contained granular or aggregated
matter; the glands having become of a bright yellowish-green. The
glands of this species therefore absorb the carbonate much more quickly
than do those of Saxifraga umbrosa, and the upper cells of the pedicels
are likewise affected much more quickly. Pieces of the stem were cut
off and immersed in the same solution; and now the process of
aggregation travelled up the hairs in a reversed direction; the cells
close to the cut surfaces being first affected.
Primula sinensis. The flower-stems, the upper and lower surfaces of the
leaves and their footstalks, are all clothed with a multitude of longer
and shorter hairs. The pedicels of the longer hairs are divided by
transverse partitions into eight or nine cells. The enlarged terminal
cell is globular, forming a gland which secretes a variable amount of
thick, slightly viscid, not acid, brownish-yellow matter.
A piece of a young flower-stem was first immersed in distilled water
for 2 hrs. 30 m., and the glandular hairs were not at all affected.
Another piece, bearing twenty-five short and nine long hairs, was
carefully examined. The glands of the latter contained no solid or
semi-solid matter; and those of only two [page 349] of the twenty-five
short hairs contained some globules. This piece was then immersed for 2
hrs. in a solution of one part of carbonate of ammonia to 109 of water,
and now the glands of the twenty-five shorter hairs, with two or three
exceptions, contained either one large or from two to five smaller
spherical masses of semi-solid matter. Three of the glands of the nine
long hairs likewise included similar masses. In a few hairs there were
also globules in the cells immediately beneath the glands. Looking to
all thirty-four hairs, there could be no doubt that the glands had
absorbed some of the carbonate. Another piece was left for only 1 hr.
in the same solution, and aggregated matter appeared in all the glands.
My son Francis examined some glands of the longer hairs, which
contained little masses of matter, before they were immersed in any
solution; and these masses slowly changed their forms, so that no doubt
they consisted of protoplasm. He then irrigated these hairs for 1 hr.
15 m., whilst under the microscope, with a solution of one part of the
carbonate to 218 of water; the glands were not perceptibly affected,
nor could this have been expected, as their contents were already
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