PLATE VI. 



Dendrobmm Dalhousieanum Paxt. — Three semi-diagrammatic sections through 

 the column and base of lip, slightly to one side of the median line. 



Fig. 1. — Normal position of parts: a, vascular bundle of column ; b, base 

 of dorsal sepal removed ; c, fold of filament ; d, filament 

 e, anther ; /, pollen-cell ; g, rostellum ; h, stigma ; i, passage 

 k, ridge on lip ; I, callus on lip ; m, base of sepal ; n, nectary 

 o, stigmatic canal. 



Fig. 2. — Anther after dislocation, thrown forwards and downwards, by the 

 elasticity of the filament. The anther should be a little 

 lower. 



Fig. 3. — Position into which the anther is shoved if a bee attempts to 

 enter a flower for a second time. The anther is adhering to 

 the stigma. 



Dendrobmm secundum Lindl. 



Fig. 4. — Longitudinal median section through the flower : p, petal. The 

 rest of the lettering as in Fig. 1. 



Fig. 5. — Column and portion of sac of a young flower showing narrow 



stigma. 

 Fig. 6. — Column and portion of sac of an older flower with the stigma 

 widened out; the anther has gone. 



