Box.— Vol. II.] PEIRCE— SEQUOIA SEMPERVIRENS. 95 



In this connection I may state that the white redwood 

 taken from near Gihoy and planted in my garden had at 

 least one leaf which, after the little tree was transplanted 

 and before it died, became pale green over half its surface 

 on either side of the midrib. I have made no attempt as 

 yet either to transplant, or to disconnect from their parents 

 without transplanting, the white redwoods growing on the 

 summit near the La Honda road. This I shall do presently. 

 Obviously the white redwoods must turn green if they are 

 to survive after being severed from the parent. Some white 

 redwoods can do this more readily than others, the condi- 

 tion of the chromatophores being one of the factors con- 

 trolling this change. Why there should be these differences 

 in the rudimentary condition of the chromatophores of white 

 redwoods we can understand only after determining the 

 reason for the production of any white leaves at all. 



Comparing white redwoods with cedars, which, in culti- 

 vation and in nature, not infrequently produce white leaves 

 or green leaves striped or otherwise variegated with white, 

 we find the cell-structure as well as the general conditions 

 for the nutrition of the plants quite unlike. The mesophyll 

 cells in the white parts of green variegated leaves, and of 

 white leaves, contain less protoplasm (Frank, 1896) than do 

 normal green cells, the cytoplasm forming a comparatively 

 thin layer lining the cell-wall, the greater part of the cell- 

 cavity being filled with the more than usually abundant 

 cell-sap. Chromatophores, if visible at all, are colorless, 

 small, and scarcely denser than the cytoplasm, or otherwise 

 distinguishable from it, but they vary in this respect with 

 the degree of whiteness of the leaves. The white redwoods 

 are similar, the cells of the whitest containing no structures 

 recognizable as chromatophores, while those leaves which 

 contain visible chromatophores are not perfectly white. 

 But between the unorganized though abundant protoplasm 

 in the mesophyll cells of the white redwood, and the meagre 

 but very definitely situated protoplasm of the white meso- 

 phyll cells of cedar and similar plants, there is a great dif- 

 ference. This we may perhaps account for thus. 



