245 
of Masdevallia muscosa , Rchb. f 
In order to avoid this, contraction is slow at first, be- 
ginning at the point where the blade runs into the neck, 
i. e. where the crest has given place to the groove. The 
blade is thus raised through a small angle, and the emergence 
satisfactorily circumvented (Fig. 7 a). The tip of the emer- 
gence now touches the groove, and would seem to be used as a 
sort of fulcrum, round which the blade continues its move- 
ment. The momentary check, recorded above, occurs at this 
period. There is now no hindrance to the completion of the 
movement, and the contraction has meanwhile extended 
further along the neck. The result is that the neck is raised 
slightly so as to be in contact with the under side of the 
emergence, the latter also being deflected a trifle downwards 
(from the pressure of the upfolding blade on its tip) to meet 
it. The final position is shown in Fig. 7 b ; the emergence is 
now in contact with the proximal part of the crest above, and 
with the neck below. 
Function of emergence . — The chief part played by the 
emergence is that of preventing the blade from overstepping 
its proper limit in contraction. Fig. 7 b shows how it is 
impossible for it to be approximated any nearer to the 
column. The emergence brings it to a dead stop. 
If the emergence be removed by a transverse cut near 
its point of insertion (which can be effected from above 
with a sharp scalpel without injuring any other part of 
the flower), it is found that, on stimulation, the blade is 
often carried beyond its previous limit and tends to be- 
come jammed by the distal ends of the two lateral petals 
where they pass in front of the apex of the column. This 
overstepping and jamming is especially found to occur if 
the flower operated on be still young and the contraction 
rapid. 
It may be that the emergence also assists the blade in 
its relaxation ; for, being highly elastic (cf. page 242) and 
in the position of contraction somewhat diverted downwards, 
it will exert a certain continued pressure at the edge of the 
crest where it is in contact with it. I have, however, no 
