92 



A NATURALISTS WANDEEINGS 



its anther erect on the posterior part of the column. Underneath 

 is the stigma, of a roughly square shape, its upper rim standing 

 erect in front of the poUinia, rising to about one third of their 

 height as a triangular eminence, which corresponds with the front 

 margin of the rostellar platform. It is not in every flower that 

 the shape of the stigma can be seen Avell, for the stage presently 

 to be described begins very soon, often before the flower is 

 expanded ; and only by the examination of a very large series 

 have I been able to follow the modifications that have 

 occurred, • '' ^ 



Concurrent with or even before the commencement of 

 the rotation of the anther into its normal position some in- 



Z> 



Fio. 20. 



arundixa spe(uosa, showing 

 a section of column orexed fkom 

 behind; c, top of tppkb mar- 

 gin OF STIGMA (CORUESrONDING TO 



Kcs r ellum) ; c-, pot.tion of stigma; 



G, STYLAliY CANAL. 



FIG. 21. 



ahi:ndi>\v spectosa, bud show- 

 ing THE IPPER BIM OF STIGMA 

 ALREADY INVERTED DOWN THE 

 STYLAT'.Y canal; LETTERS AS IX 

 FIG. 17. 



fluence — which I do not know— causes the npper margin of the 

 stigma to become inveitcd close down the posterior wall of the 

 stylary canal, as seen in Fig. 17, and in longitudinal section 

 opened from hehhid in Fig. 20, where the rostellum is seen hang- 

 ing down the canal as a narrow^ band. Fig. 21 represents a very 

 young bud, in which, though the pollinia had scarcely begun 

 to rotate, the stigma had become already much modified, and is 

 in ^-aiting for the rotation of the pollinia. Along with this in- 

 vagination of the upper margin of the stigma (the rostellum) its 

 lower lip is in consequence dragged (?) upwards. Dissections 

 of the column showed that the rostellum goes on elongatinjr 



down the stylary canal, as in Fig. 20, while the pollinia, slowly 



finally precipitate them- 

 selves into the stigma, ^^hose flap-like margins embrace the 



continuing to rotate downwards. 



