Page:Insectivorous Plants, Darwin, 1899.djvu/53

 CHAPTER III. AGGREGATION OF THE PROTOPLASM WITHIN THE CELLS OF THE TENTACLES.

I 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, circultfting 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 contains much flocculent or granular matter. But this matter may have been generated by the cells having been