94 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



At the edges, as well as elsewhere throughout the palisade 

 and mesophyll tissues of the green leaves, starch-grains 

 occur in considerable numbers in all the cells. The amount 

 of starch present undoubtedly varies at different seasons of 

 the year; but since these green leaves were collected at the 

 same time as the white ones, and near them, comparison of 

 the starch content is justified. 



Figure 9 represents under higher magnification the part 

 of fig. 2 cut off by the dotted line. As this shows, scleren- 

 chyma cells are found at the edges of the white leaves, but 

 they are not so firm as in the green leaves. The resin-tube 

 is decidedly smaller and bounded by cells evidently less 

 active than the glandular cells of the resin-tubes in the 

 green leaves. There is no starch in any mesophyll cells of 

 the white leaves. The cytoplasm and nucleus are not easily 

 distinguishable from one another in most of the mesophyll 

 cells. The cytoplasm presents a thoroughly disorganized 

 or, as one may more truthfully say, a by no means organ- 

 ized, appearance, neither vacuoles nor plastids being dis- 

 cernible in most cells. The vacuoles occur in few cells 

 only and are unlike those of green mesophyll cells. 



The plastids are variable. In sections of white redwood 

 leaves from the summit near where the Redwood City-La 

 Honda stage road crosses the first ridge between here and 

 the sea, I have entirely failed to detect even rudiments of 

 plastids or chromatophores. There are granules and gran- 

 ular aggregations in the cells, as fig. 9 shows, but material 

 carefully fixed in Flemming's weaker mixture of chrom- 

 osmic-acetic acids and stained by two-tenths per cent, acid 

 fuchsine in distilled water* failed to exhibit any structures 

 which I could positively identify as even rudimentary chro- 

 matophores. On the other hand, the material from near 

 Gilroy, treated in exactly the same way, contained chro- 

 matophores which ranged in size from those about half as 

 large as the average chloroplastids in the normal green 

 leaves down to indistinguishable rudiments. 



* See Zimmermann-Humphrey, Botanical Microtechnique, pp. 196, 202, etc. 



