382 Cooke and Schively on Observations on the 
rather small, spherical thin-walled cells, showing no inter- 
cellular spaces. All of these cells are well filled with deeply 
stained protoplasm, and have a very large and dense nucleus 
and nucleolus. Starch grains are present in considerable 
quantity. 
This nectary may probably be regarded as the remaining 
trace of the fifth stamen that should be present to preserve 
agreement of number throughout the flower. The presence 
of this nectary is also evidence that this plant was once a 
typically insect-pollinated form. It is rather remarkable 
that it should be so well developed in the cleistogamic flow- 
ers of the present time, where it is entirely useless. This 
persistence of the nectary, and also the production of the 
primitive chasmogamic flowers, seem to indicate that para- 
sitism in this plant must perhaps not have been of so very 
ancient date. At any rate, modifications due to parasitism 
are still occurring, and the plant is at present in a somewhat 
transitional state. This is especially indicated by the pro- 
duction or non-production of chasmogamic flowers, by the 
variable development of roots and by the evolution of two 
types of floral structure that are united by intermediate 
stages. 
The style and stigma are identical structures in the two 
flowers, except for differences in size. The style is elliptical 
in section. Two vascular bundles traverse its length. These 
are well developed, and show phloem cells, also numerous 
spiral trachee. Toward the stigma these elements loosen 
and spread apart noticeably. Simple two-celled stomata 
are numerous along the entire length of the style, but are 
present in greatest number midway between the ends. 
The stigmatic surface has the aspect of a broad convex 
cap set on the end of the style. It is thickly covered with 
short, round swollen unicellular hairs. 
There is a marked horizontal division through the style. 
In all cases there is evident a thinned-out, broken region 
across the style midway between the two bundles. In the 
