significance, the position of the anthers in relation to the 
stigmas. Both Apostasioideae and Cypripedioideae have 
been distinguished from the monandrous orchids by the 
adnation of the anthers to the style at a level below the 
stigma. This criterion, however, may not be applied as 
an absolute rule, as it has been in the past, because, in 
addition to these groups, an extensive number of genera 
(ca. 50) in the Neottioideae, as well as the whole Satyrium- 
complex of the Ophrydoideae, exhibit a position of sub- 
stigmatic insertion of the anthers. Therefore, the criterion 
of the occurrence of such an insertion, which was also 
applied to justify the removal of 4 postasioideae from the 
Orchid family, is invalidated. 
The striking structural similarity of the column in both 
Satyrium and Cypripedium points to the convergent na- 
ture of the respective branches of the main lines of Ophry- 
doideae and Cypripedioideae. Satyrium itself represents 
a departure from the general monandrous orchid type in 
having two distinct anthers developed in the outer whorl 
of stamens (PI. VIII, fig. 5). The fact that it is referred 
constantly to the monandrous orchids is, however, due 
to the nature of its pollinia. 
Rostellum. One of the most significant features in the 
organogenesis of the column is the formation of a new or 
modified structure, the rostellum. The theoretical ex- 
planation of the origin of this organ, as postulated by 
Brown and Darwin, is widely discussed in various text- 
books; therefore, it is sufficient if we merely state that 
the median stigma during the reorganization of the flow- 
er has evolved into a new organ, the rostellum, with a 
specific function. It is the controlling and ensuring de- 
vice for fertilization, since its position is located between 
the anther and the remaining stigmas; the pollinia are 
attached by a viscid secretion to the tip of this structure. 
Although this general situation is observable in the great 
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