OF THE ROSTELLUM OF LISTER A OVATA. 
263 
PLATE I. 
Fig. 1. Flower of Listera nvata with the perianth removed, before the protrusion of 
the gland, a, termination of column; b, anther-case; c, pollen-masses ; 
d, rostellum ; e, stigma; f, base of the labellum. 
Figs. 2 and 3. Vertical sections of two other flowers of Listera ovata, fig. 2 before, 
and fig. 3 after, the protrusion of the gland, which is shown at d of fig. 3. 
The other letters indicate the same organs as in fig. 1. 
Fig. 4. Rostellum seen from above; (a) the discoloured spots where the glandular 
masses are protruded. 
Fig. 5. Vertical section of anterior portion of column, through the rostellum (a), 
showing one loculus and its contents ( b ), and stigma (c). 
Fig. 6. Transverse section of rostellum. a , loculi ; b, their contents in situ as 
coagulated by alcohol. 
Fig. 7- Half the rostellum with the striated wall removed, a, the contents of the 
loculi (as coagulated by alcohol) ; b, the broken septa of the loculi. 
Fig. 8. Very highly magnified view of the loculi, showing the band of transverse 
striae (a) bordering the lines indicating the position of the septa. 
Fig. 9. Contents of the loculi. 
Fig. 10. Upper portion of one of the same, in a very immature state, showing the 
areolation of its surface. 
Fig. 11. Very highly magnified view of the substance of the gland on its first 
expulsion. 
Fig. 12. Pollen-grains. 
