Polygala polygama and P. paucifiora. 127 
These aérial cleistogamic flowers bring forth fruit with the 
same rapidity as do the underground ones, and unlike those 
of the chasmogamic, their fruits generally mature properly. 
It may be here stated in advance that the structural char- 
acteristics of these green cleistogamic flowers are strikingly 
intermediate between those of the other two types. Every 
transition stage from one to the other has been obtained. 
Series of forms connecting the green and underground cleis- 
togamics are easy to find. On the other hand, it is not infre- 
quent to find transition types between the green cleistogamics 
and those having the fully developed perianth. In this 
respect our plant calls to mind very strikingly the series 
of transitions already described for Amphicarpea by Dr. 
Schively. 
CoMPARATIVE MoRPHOLOGY OF THE CHASMOGAMIC, AERIAL 
CLEISTOGAMIC AND SUBTERRANEAN CLEISTOGAMIC FLOWERS. 
We will now pass to a detailed consideration of the mor- 
phology of the various types of flower. This may best be 
done by taking up points of structure successively, and com- 
paring them in the three forms of flower. 
Inflorescence Axis ——In order to describe the rachis we 
refer for a moment to the structure of the vegetative stem. 
This has, exteriorly, several winglike angles. The wood 
appears at an early period as a zone. In an ordinary shoot 
it is difficult to find traces of separate vascular bundles, since 
the wood and bast early become continuous rings. The 
phloem ring is provided with numerous indurated cells. 
Without is a layer of cortical parenchym six or eight cells 
thick, limited by a strong cuticle. Incidentally it was noticed 
that for some reason, when stem sections were treated with 
iodine, the woody portion presently showed a strong red col- 
oration. This seemed to suggest the presence of sugar. The 
reaction took place in various specimens, differently preserved. 
