CTTOLOGICAL CHANGES PEODUCED IN DROSERA. 207 



the sections of material used in this experiment. The changes 

 in the apical gland cells are as follows : 



Five Seconds after the Application of a 10 per 

 cent. Solution (fig. 4). — A precipitate (?) resembling minute 

 blue droplets covers the interior of the cell walls, especially the 

 lateral ones. 



The cell walls stain very faintly blue, or show no colour. 



The cell plasm stains much more deeply blue than in 

 controls. It appears more dense and homogeneous, being 

 apparently almost free from vacuoles. The reticular arrange- 

 ment seen in controls has given place to what appears like a 

 thick, evenly distributed granular mass. Thus instead of 

 vacuolation there is found a direct increase in bulk. At the 

 periphery of the plasmic body are seen dark blue droplets or 

 granules resembling those on the walls. 



The nucleus is normal as to position, size, shape, and clear- 

 ness of definition. 



The nuclear plasm is often also bluer than in controls, 

 though it frequently stains normally. Its arrangement is 

 unaffected. 



The nuclear chromosomes are unchanged. 



The nucleolus is normal as to size^ and also as to colour in 

 those nuclei in which the plasm stains normally. In the 

 bluer nuclei it stains more of a purple. Frommann's zone 

 remains clear. 



The nuclei of the third layer remain unchanged. 



Ten to Thirty Seconds. — The above description holds 

 good. I have, however, observed a slight shortening of the 

 nuclei of the third layer of gland cells in leaves fed for thirty 

 seconds. 



Specimens fed for one minute require no separate detailed 

 description, as they resemble the bluer types about to be 

 described. 



Five Minutes after Feeding (fig. 5). — The precipitates 

 appear as in earlier stages. The cell walls stain blue with 

 extreme faintness. The cytoplasm remains as shown in fig. 

 4:, or is more vacuolated^ and stains less deeply (fig. 5). The 



VOL. 42, PART 2. — NEW SERIES. 



