16 



were iiiipei'fectly colored, and had many small green specks 

 on the petals. When these specks, or diminutive spots, 

 were brushed across for a few moments they disappeared, 

 being lost in the general blue color, and blue veins a}y3eared 

 in the whitish area at the base. 



Similar effects were produced on the white specks in 

 sweet william, and on the white halos surrounding the 

 purple dots of foxglove. 



One of the maroon spots on a yellow pansy was brushed 

 lightly for 10 or 15 minutes, when numerous fine purple 

 veins ai)peared at the outer border, while in the interme- 

 diate space few were seen, they being more deeply imbedded 

 in the cellular tissue. A white pansy with blue honey 

 guides gave lietter results. A white variety of Martha 

 Washington geranium, with dark maroon honey guides on 

 the two upper petals, when treated in the same manner, 

 became covered with a network of dark red lines, while the 

 parenchyma itself was largely tinged with the same color. 

 The dilute coloring matter must have been conveyed by 

 ca})illarity through the vascular bundles, and diffused 

 through the cellular tissue by osmosis, as no pressure was 

 brought to bear beyond the area of the honey guide. When 

 two different colors meet, as the basal color of a petal with 

 the honey guide, an intermediate color is sometimes pro- 

 duced naturally, by the blending of the two as in water 

 colors, which would also seem to imply that there was a 

 diffusion and commingling of the contents of the contiguous 

 cells. 



An experiment was made to ascertain if the color of a 

 flower could ))e changed or in any way modified by mechan- 

 ical irritation on the surface of its petals. The writer 

 noticing that Primida Sinensis was apt to change color 

 with age, selected several varieties of the flower and pro- 

 ceeded to manipulate them w'ith a camel's-hair brush. A 

 deep crimson variety with a green eye was chosen for the 

 experiment. Holding a flower while still attached to the 



