188] PYROLA APHYLLA: A MORPHOLOGICAL STUDY 249 
showing the well-known elements of normally developed tissues. 
There is a wrinkled cuticle covering the thick-walled epidermis, 
inside of which follows a heavy layer of cork parenchyma of 
rather closely packed polyhedric cells, which border on a thin- 
walled endodermis. This endodermis encircles the leptome and 
tadrome, the last of which has distinctly lignified cell walls, 
while an ordinary pith occupies the innermost part of the cen- 
tl cylinder. Tannin was observed in abundance in the cells of 
the bark and epidermis. 
In comparing the structure with that of the aerial flower- 
ing stem, we notice only a few divergencies. The bark 
contains chlorophyll, and a closed ring of stereome is developed 
wound the central cylinder, of which the pith occupies the 
‘ager part. In combining these anatomical features of the 
aves, the aerial and subterranean stem, there is so far no 
indication of our plant being a parasite or saprophyte or in any 
other way differing from the other species of Pyrola. 
_ The last organ of the plant, which is not to be overlooked, 
the toot, the main and the adventitious. Only a part of the 
2 foot Was preserved in our specimens (¥ in jig. 7), and it 
No means certain whether this dark colored and slightly 
; thed root is the main root or merely a branch. It is from 
. 3a however, that the subterranean shoots have developed 
We oe root-shoots, a fact that is readily observed in fig. 7- 
ae only observe that the two long underground branches 
Proceed directly from this root, but also the development of 
oM ag Clusters of shoots with more or less curved apices, all 
stems, are beginning to develop into underground creeping 
» like the two larger ones described above (o* and hol & 
ay then a strongly pronounced vegetative aire 
th a. perhaps has reached a higher development in this 
also y other Species of Pyrola. Adventitious roots were 
“singe 
Nght or left of the axillary buds. 
