132 BOTANICAL GAZETTE [FEBRUARY 
irregular to be used for making radial sections. Phloem from large 
branches did not show much callus, specimens usually presenting 
in radial section but two or three rows of sieve tubes with callus. 
The material used was cubes about a centimeter each way, 
which included the cambium as well as the phloem. These were 
killed, fixed, and softened, and then imbedded in celloidin. For 
general study the sections were double stained with hematoxylin- 
safranin and mounted in balsam. Russow’s callus reagent was 
used to demonstrate the callus. 
It will be appropriate to consider first the figures which accom- 
pany this paper. Figs. 1 and 2 show the topography of the phloem 
of Carya alba under lower power. The sections used for these were 
stained with hematoxylin-safranin. Fig. 3 is a higher-power mag- 
nification of a part of fig. 2. Figs. 4-6 are views of sections of 
Carya glabra that were recently treated with Russow’s callus reagent. 
Fig. 1 is a radial longitudinal section. At the left side of this 
section are seen two rows of sieve tubes with portions of end walls 
showing sieve plates in face view, and along the right side lateral 
sieve plates are shown in cross-section. The long, narrow, thick- 
walled cells are bast fibers. These usually occur in groups of three 
to six as seen in radial view. 
The larger phloem parenchyma cells contain prismatic crystals 
which have elongated, nucleus-like spots in the center. The rays 
are made up of short parenchyma cells that have several simple 
pits where they come in contact with phloem parenchyma. A 
portion of a ray is shown in the left side of this section. No crystals 
have been observed in the ray parenchyma cells of any of the 
Juglandaceae studied. 
Fig. 2 is a tangential section. Many crystal-bearing phloem 
parenchyma cells are seen in this view also. The large cells with 
oblique end walls are sieve tubes. They show the lateral sieve 
plates very strikingly in face view, and cross-sections of termina 
sieve plates on the slanting end walls. This section shows but 
few bast fibers. The phloem parenchyma cells toward the lower 
right side of this figure, wherever their starch content is not t0° 
dark, may be seen to have densely pitted radial walls. The rays 
vary from uniseriate to multiseriate. 
