DROSERA ROTUNDIFOLIA. [Cuar. II. 
CHAPTER III. 
AGGREGATION OF THE PROTOPLASM WITHIN THE CELLS OF THE 
TENTACLES. 
Nature of the contents of the cells before aggregation—Various causes which 
excite aggregation—The process commences within the glands and travels 
down the tentacles—Description of the aggregated masses and of their 
spontaneous movements—Currents of protoplasm along the walls of the 
cells—Action of carbonate of ammonia—The granules in the protoplasm 
which flows along the walls coalesce with the central masses—Minuteness 
of the quantity of carbonate of ammonia causing aggregation—<Action of 
other salts of ammonia—Of other substances, organic fluids, &c.—Of 
water—Of heat—Redissolution of the aggregated masses—Proximate 
causes of the aggregation of the protoplasm—Summary and concluding 
remarks—Supplementary observations on aggregation in the roots of 
plants. 
I wit here interrupt my account of the movements of the 
leaves, and describe the phenomenon of aggregation, to which 
subject I have already alluded. 
If the tentacles of a young, 
yet fully matured leaf, that has never been excited or become 
inflected, be examined, the cells forming the pedicels are seen 
to be filled with homogeneous, purple fluid.* 
The walls are 
lined by a layer of colourless, circulating protoplasm ;f but 
this can be seen with much 
greater distinctness after the 
* [The statement as to the absence 
of a nucleus in the stalk-cells of 
Drosera (Francis Darwin, ‘ Quarterly 
Journal of Microscopical Science,’ 
1876) has been shown by Pfeffer to 
be quite erroneous (‘ Osmotische 
Untersuchungen,’ 1877, p. 197).— 
F. Ds) 
t (Mr. W. Gardiner (Proc. R. Soc., 
No. 240, 1886) has described a re- 
markable body named by him the 
“ rhabdoid,” which exists within the 
epidermic cells of the stalk of the 
tentacles. This body was discovered 
in Drosera dichotoma, but exists also 
in D. rotundifolia; in the former 
species, in which it has been more 
especially studied by its discoverer, 
it is a more or less spindle-shaped 
mass, stretching diagonally across 
the cell, the two ends being embedded 
in the cell-protoplasm. “It is 
present in all the epidermic cells of 
the leaf except the gland cells and 
the cells immediately beneath the 
same.” Further reference to the 
rhabdoid will be found at p. 35.— 
E D) 
