534 TRANSACTIONS OF THE CANADIAN INSTITUTE. [Vor. VIII. 
ILLUSTRATIONS. 
1. Transverse section of stem of seedling of Osmunda cunnamomea above the third 
node. 
2. Transverse section of stem above the fifth node showing depression in stele. 
3. Transverse section of stem above the eighth node, showing closure of gap to 
form a ‘‘stelar’’ pith. The cylinder of xylem is unusually thin. At the lower right 
the associated fungus may be seen in the cortex. 
4. A transverse section of the stem of a seedling showing the first appearance of 
the internal endodermis. It is the dark spot in the pith at the entrance to the last 
formed leaf-trace. 
5. A longitudinal section of the cortex of a seedling showing a line of cells occupied 
by the fungus. The surrounding celis are heavily-laden with starch. 
6 A section of a seedling showing the winged petioles. 
7. A section of an adult stem that has become much reduced in size. Most of 
the medullary rays are closed on the pith side. 
8. An enlarged view of the stele of a section a short distance above the one repre- 
sented in Figure 7. 
g. A part of the stele abutting on the pith. The long row of dark cells is a portion 
of the internal endodermis. An isolated group of endodermal cells occupies a paren- 
chyma pocket. 
10. A much reduced adult stem in which an internal phloem is well-developed 
11. A normal adult stem showing a leaf-gap through which internal and external 
endodermes, pith and cortex communicate. In the cortex is the corresponding leaf- 
trace, and to the right a root-trace. 
12. A portion of the stele in the neighbourhood of a fork showing internal phloem 
and isolated strands of xylem. 
13. Transverse section of the stele and endodermis at the second node. 
14. Transverse section of the stele and a leaf-trace just above twelfth node. 
15. Three sections in the neighbourhood of the eighth node, (a) below the node, (b) 
at the node, (c) above the node. (p. pericycle.) 
16. Transverse section of stele and endodermis at about the sixteenth node. 
17. Transverse section of stem several nodes higher up. 
18. A segment of the cortex of a seedling, some of the cells of which are occupied 
by a fungus. ‘The rounded dark bodies shown in several of the cells are nuclei. Three 
of the infected cells contain irregular masses of dark-staining substance intermixed 
with closely-packed hyphe. 
19. A segment of a section of the stele not far from the one represented in Fig. 10, 
(e.e., external endodermis ; ph., external phloem ; 7. p.h., internal phloem ; 2.e., inter- 
nal endodermis.) 
