157 
in Orchis purpurea , Huds. 
which Orchids make, especially in the androecial and gynaecial whorls. 
A question that specially interested the earlier workers was whether all the 
stamens in a more or less complete state of development are confluent with 
the column, or whether the two lateral members of the outer whorl are 
incorporated with the labellum. Brown ( 5 ) advances the view that the 
small auricles of Orchis are essentially the same structures as the leaf-like 
staminodes in Diuris, and therefore form the complement As, A3, of the 
outer whorl of stamens. But to this view Brown did not permanently 
hold. At first he believed the stamens as, A3, were combined with the 
labellum. Cruger (6) contends that the labellum is a simple organ and 
not the union of one petal with two petaloid stamens. According to 
Fig. 4. Transverse section through bud of normal flower where the staminodes are free from the 
column, s. staminode ; V.B. vascular bundle. 
Darwin ( 7 ), whose views are based on the course of the vascular bundles 
in the flower, the labellum is a complex structure representing the fusion 
of the odd petal with the pair of outer stamens. This hypothesis has 
lost favour in view of the more recent study of floral development by 
Pfitzer (8). The number and distribution of the vascular bundles in the 
labellum are a physiological problem, and cannot always be accepted as 
morphological evidence. In Orchis Darwin found no trace of bundles 
in the auricles which he believed to represent the stamens of the inner 
whorl. Nor have I succeeded in tracing vessels to these structures in cases 
where the flower is normal. They are small and need no special system 
apart from the large bundle which supplies the column. But when they 
develop into stamens in such abnormal flowers as have been described, then 
I find that each is supplied with a vascular strand. As stamens their 
demand for nutrition is greater than when they remain as staminodes. The 
