17 
the long axes of the cells lying parallel to a tangent drawn to the near¬ 
est point of the original stem. Each was completely filled with mate¬ 
rial for growth. Passing farther out this form gradually changes first 
to that represented in Fig. 16, then to a form like those in Fig. 17, then 
to smaller cells again, and covering all the epidermal cells, as shown in 
Fig. 18. The cells described above all had thin walls, without pits or 
openings. In most of them the nucleii were very large and conspicu¬ 
ous, especially in those represented in Fig. 18. Abnormal fibro-vascular 
bundles ran through the tissue, and adjacent to them the cells of the 
ground tissue were elongated in the direction of the length of the 
bundle. 
In Fig. 19 a bundle is represented in which the distortion has not 
been carried very far. It has become a little broader by cell-multipli¬ 
cation, anc the xylem parenchyma and tracheides as well as all of the 
phloem have become very thin-walled, and give the reaction tor cellu¬ 
lose with Schultze’s Solution. In the normal structure the two former 
were composed of liquefied elements. Large nucleii were observed in 
a great many of the cells of the xylem parenchyma and in one or two 
cases in the sieve tubes. The cells of the bundle sheath have multi¬ 
plied at both ends of the bundle, and in a more distorted bundle than 
the one represented were seen to also have become thin-walled. In 
stages a little farther on, cells which looked like those of the ground 
tissue, and which were filled or partially so with starch, had grown in, 
and separated the bundle into little groups or bundles of thin-walled 
cells. These branches passed out into the abnormal growth, and these 
branched again, forming altogether a sort of tree-like organ for the 
support and nourishment of the delicate tissue through which it runs. 
Figs. 20 a and 21 show longitudinal sections of the bundles as they 
appear in this tissue. They are composed of short, narrow, thin-walled 
cylindrical cells, arranged end to end. Nucleii are conspicuous in most 
of them, and all are filled with a finely granular substance which colors 
yellow with Schultze’s Solution. In Fig. 21 the bundle has thrown off 
a slender branch at a. The walls of these cells had no markings, and the 
cells themselves appeared very much like cambiform cells, except that 
they were shorter, and contained conspicuous nucleii. In the normal tis¬ 
sue nucleii were not observed in either sieve tubes or cambiform cells. 
In some of the bundles similar to those figured in 20 and 21 there were 
one or two layers of cells at each edge of the bundle which were 
small and thin-walled, but showed reticulated and pitted markings. 
In Fig. 22 a cross section of one of these bundles is represented. In 
them the elements are so changed that phloem can not be distinguished 
from xylem, and there are no large elements. Where the large pitted 
ducts run into the abnormal tissue, which usually they do not, they take 
a course separate from the bundles and have very grotesques forms, 
changing direction constantly. 
The observations made upon the fungus which causes these changes 
20414—No. 1-2 
