of Masdevallia muscosa , Rchb . f 253 
Fig. 7 b. Labellum in position of contraction. 
Fig. 8. Front view of column, a anther, b.c. base of column, r. rostellum. 
j. stigmatic surface. 
Figs. 9 a and 9 b. Views from side and above of anther a. p. pollinia. 
Fig. 10. Diagrammatic view of flower from above, a anther. c dorsal side 
of column, e aperture by which the insect escapes, b.l. labellum. l.p. lateral 
petal. Labellum is in position of contraction. 
Fig. 11. Series of diagrammatic transverse sections corresponding to dotted lines 
a, b, c, &c. in Fig. 12. 1 1 a. through distal part of blade ; 1 1 b. through beginning of 
crest ; 11 c. through middle of crest ; nd. through region where blade passes into 
neck ; lie. through the neck at point of bending ; nf. through the neck below 
point where emergence is given off; shows the emergence, e, in its natural relation 
to the neck ; 11 g. through foot just above insertion of emergence. 
Fig. 12. Key to Fig. 11! showing points at which a, b, c, &c. have been 
taken. 
Fig. 13. Transverse section through the central vascular bundle from Fig. 11c. 
ph. phloem, sh. tannin- containing sheath, tr. tracheides. 
Fig. 14. Shows continuity of protoplasm from a transverse section of the crest 
treated with hydric sulphate and Hoffmann’s blue. 
Fig. 15. Pterostylis Woolsii. Lateral view of column and labellum, showing 
relative positions in the extended and contracted state. The labellum is dotted in 
the latter, a anther, bl'. bl" . blade of labellum in extended and contracted states 
respectively, c column, e. e . emergence in the two positions, ft. foot. h. 
neck of labellum. ov. ovary, w. wing of upper part of column (after Fitzgerald). 
Fig. 16. Pterostylis curta. Similar view showing fimbriated emergence e. 
The labellum is in the contracted state (after Fitzgerald). 
Fig. 17. Longitudinal section through the emergence of Masdevallia muscosa. 
Fig. 18. Diagram illustrating nature of experiments made. A, position of cut 
in experiment 1, afterwards continued through the vascular bundles (dotted line). 
B, cut in experiment 3, cutting the bundles from below. X, point stimulated. 
