From a consideration of these facts, the only reasonable 
conclusion that can be arrived at is that the labellum is 
not a compound structure as was supposed by Brown 
and Darwin. It may also be noted here that those in- 
stances in which the marginal traces of the labellum were 
not in evidence or exhibited abnormal behavior when 
present offered difficulties of interpretation to Darwin 
himself. For he writes: ‘‘This anomaly is so far of im- 
portance, as it throws some doubt on the view that the 
labellum is always an organ compounded of one petal and 
two petaloid stamens. ”’ 
Spur. This structure, as has been explained already, 
is a basal outgrowth from the labellum in the form of a 
pouch, sac or narrow tube. Where the spur is single, 
the median trace of the labellum continues into it and 
then recurves upwards in conformity with the curvature 
of the spur to constitute the median trace of the same 
petal. When the spur is double, the median trace of the 
labellum does not enter the spur but each marginal trace 
enters into the spur of the corresponding side. In pass- 
ing, it may be mentioned that Darwin thought the traces 
that traverse the double spurs were staminal (A2 and 
A8). That Darwin’s views are untenable has already been 
made clear. 
GYNOSTEMIUM. This is a structure peculiar to the or- 
chid flower. Its exact nature has, until now, been little 
understood. Chiefly the works of Oliver (1895), Rendle 
(1930) and Willis (1936) have propagated the idea that 
this structure is an extension of the floral axis and that 
on this account it isto be looked upon as being axial. 
It may be recalled that such a distinct structure is not 
clearly evidenced in Cypripedium, Habenaria, ete. In 
the former, it is incipient if it is present at all; serial 
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