Internal Phloem in Gelsemium sempervirens, Att. 53 
6. The continued disintegration of the pith and growth of 
the internal phloem results in the filling up of the pith cavity 
with the latter. 
7. The internal phloem, which runs into the petiole, consti- 
tutes there at first a bicollateral bundle system, but at the base 
of the petiole, it descends through the xylem as two strands, 
and from this point upward the primitive collateral bundle 
system prevails. 
8. No internal phloem is present in the root. 
g. A copious fungoid growth is found in the cortex of the 
root. Absorption of starch usually results in cells inhabited 
by the fungus. 
10. No internal phloem is present in the lower portion of 
the hypocotyl, nor in the cotyledons. 
11. Two of the internal phloem patches of the stem arise 
just below the cotyledonary node, the other two just below the 
node bearing the first pair of leaves. 
12. Internal phloem is an acquired characteristic of the 
plant, and has probably been developed in these long and at 
times twisted stems, to supplement the external phloem. 
EXPLANATION OF PLATE IX. 
Fig. 1. Transverse section of one year old stem. > 35°. 
Fig. 2. Transverse section of portion of ten year old stem, showing the internal 
phloem divided into eight patches. > 50°. 
Fig. 3. Transverse section of young root. XX 50°, cu, cuticle; ep, epider- 
mis; co, cortex; end, endodermis; phl, phloem, prx, protoxylem. 
Fig. 4. Transverse section of young hypocotyl. > 50°. 
