CHANGES IN CELL-ORGANS OF DROSERA ROTUNDIFOLIA. 403 
The cytoplasm in this specimen has retracted from all the 
walls equally. 
It is very difficult to distinguish in colour between the 
cytoplasmic granulation and its matrix. The general tone is 
of a deep-blue purple, and the matrix seems to be paler than 
the granulation. Fully half the cell is occupied by very large 
vacuoles filled with a fluid which stains pale blue. The walls 
of the vacuoles are lined, to a great extent, with deep blue 
granules which show no trace of purple or red. The vacuoles 
are largest in the upper third of the cell, but usually one or two 
large ones lie also near the base. The cytoplasmic granulation 
is extremely dense round the nucleus, and stretches between 
the vacuoles in radiating ameba-like processes. 
Characteristic of this stage is the presence in the cyto- 
plasm of one (occasionally two) very apparent blue “ corpus- 
cles,” about twice the size of the nucleolus, and having a dark 
blue granular periphery. The explanation I should like to 
offer for this appearance is as follows :—In the unstimulated 
cell some substance is freely distributed, which helps to give 
rise to the affinity for the blue stain. On stimulation this 
substance is withdrawn from the cytoplasm (which now takes 
a purplish stain), and is collected in vacuoles of various sizes. 
By mordanting the cytoplasm surrounding the vacuoles an 
affinity for the blue dye is established, and the deeply stained 
cytoplasm will give rise to the appearance of a distinct wall to 
the vacuole. The smaller vacuoles, because seen in their 
entirety, appear of a deeper colour than the large ones which 
are seen in section, and could easily be mistaken for definite 
corpuscles. The substance acting as a mordant is in this case 
probably tannic acid. 
The Nucleus maintains its normal position in the cell, its 
normal size, shape, and outline. There is no sign of a collapse, 
it being still plump and well filled out. It stains exactly the 
same depth and tint as the cytoplasm, but is distinctly marked 
off from it by its dark blue periphery. 
The Nuclear Chromosomes are in no way different from 
those of unfed specimens. 
VOL. 39, PART 4.—NEW SER. FE 
