38 DROSERA ROTUNDIFOLIA. Cuap. IIL 
CHAPTER ITI. 
ASGREGATION OF THE PRoTorLasM WITHIN THE CELLS OF THE 
TENTACLES. 
Nutuce 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 wii here interrupt my account of the movements 
of the leaves, and describe the phenomenon of aggre- 
gation, 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 ex- 
amined, 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 ; 
but this can be seen with much greater distinctness 
after the process of aggregation has been partly 
effected than before. The purple fluid which exudes 
from a crushed tentacle is somewhat coherent, and 
does not mingle with the surrounding water; it con- 
tains much flocculent or granular matter. But this 
matter may have been generated by the cells having 
been crushed; some degree of aggregation having 
been thus almost instantly caused. 
