traces come to lie closer soon after separation and seem 
to fuse with one another and then proceed upwards in the 
gynostemium. I) illustrates the climax of this tendency. 
The origin itself of both the staminal members is carried 
higher to a point where the adjacent marginal traces fuse 
and thus their distinctness becomes totally obliterated. 
Further, the marginal traces of the respective perianth 
au 
a , 
a. +A3 az+As 
m™ 
A B Cc O 
Ne ° ° Py eé 
Fig. 8. A to D. Diagrams to illustrate the evolution of © compound”’ 
staminal traces, a2-+A3. 
member are also separated from the same point. Thus 
the nature of the staminal trace in this instance becomes 
“compound” by the adnation of a lateral stamen of the 
inner whorl with that of a lateral stamen of the outer 
whorl, and as a consequence such traces have been here 
interpreted and represented as al + A 2 or a2+ A38, as the 
case may be. 
The degree of expression of adnation is often seen to 
vary in one and the same species. Geodorum densiflorum 
may be taken as a good example to exhibit this phenome- 
non; furthermore, this orchid also throws some light on 
the fundamental nature of the androecium of the family. 
Normally in this species, in addition to A1, the lateral 
stamens of the two whorls are also represented by ‘‘com- 
pound’’ traces, al+A2 and a2+A8 (Fig. 9 A and B). 
[ 80 | 
