126 BOTANICAL GAZETTE [FEBRUARY 
The xylem in Burmannia candida Engl. (16) is represented by 
but two spirally thickened cells in the central cylinder; occasionally 
there is only one, seldom three. In addition, there are parenchyma 
cells and phloem. B. Championii (16), in contrast to this, has 
a central cylinder largely made up of xylem elements, with no 
phloem evident. B. coelestis (19), a chlorophyll-containing form, 
shows a similar simple situation as to root anatomy. 
In all the forms investigated, the floral axis has well developed 
collateral bundles. The vascular cylinder is sometimes surrounded 
by a ring of sclerenchyma tissue, as in Burmannia candida and 
B. Championii. The endodermis is usually distinct. Some of 
the cortical cells contain raphides. In Burmannia candida some of 
the surface cells are much like stomata in form, with pores always - 
open. In B. coelestis, a chlorophyllous form, there are normal 
functioning stomata, in contrast to the usual lack in saprophytic 
forms. . 
In Thismia americana, superficial examination of the under- 
ground structures shows a relatively large number of buds in all 
stages of development. These occur not only on the main struc- 
ture, which would appear to be a rhizome, but also on the structures 
which are very evidently roots appearing at the base of the floral 
axis. On examination of prepared sections, it appears that the 
histology of the main structure and of these secondary roots is 
identical, even to the appearance of a cap at the tip. Because of 
this fact, these structures, whether primary or secondary, will be 
referred to as roots. It would appear in field material that roots 
originally secondary might later appear primary by the dying away 
of a portion which thus severs the connection with the mother 
plant. 
In the older part of a root of Thismia, there is evident a very 
conspicuous epidermis (figs. 7, 14). This consists of large cells, 
more or less protuberant, but not developed into hairs in any 
region. The epidermal cells, in contrast with the cortical cells 
below the surface, are hyaline. The layer of cells immediately 
below the epidermis is packed with the thick-walled, branching 
mycelium of a coarse fungus. In fresh material the mycelium 
