90 



A NATUBALIST'S WANDEBINGS 



the longitudinal section, Fif^, 10. 



^, ^., The stigma is triangular, 

 with its apex do^vn wards. There is no nectary. The stigmatic 



substance becomes viscid even in the 

 young bud ; and as soon as the anther has 

 rotated into its normal position, it begins to 

 increase in quantity— the increase is often 

 so great that it bulges out in front of the 

 rim of the stigma — and, swelling up, flows 

 over into the anther by the canals (seen in 

 Fig. 15), between the column and the edge 

 of the rostellum. Even before the opening 

 of the flower I have found the external 

 pollen masses on each side bathed with 

 the stigmatic fluid, and already exserting 

 their tubes. These descend by the grooves 

 I have mentioned on both sides to the 

 stylary canal. Concomitant with the flood- 

 ing of the anther there has been taking place a slow approxi- 

 mation of the under side of the rostellimi to the lower lip of 

 the stigma, till its lobes finally embrace the rostellum, bind- 

 ing down the whole anther (Figs. 10, 12), so that when the 



FIG. 13. — SPATHOGLOTTIS 



^ PLtCATA SAME AS FIG. 12, 



«VT WITH A"NTHEU-CAP 



nEMOVED ; B, C, G, AS IX 



FIG. 12. 



FIG. 



i^.— SPATHOGI.OTTIS rUCATA(FRONT 

 view) DIAGUAMMATIC, fiHOWTNG 

 ROCTE TO THE STYLARY CANAL 

 TAKEN BY TOLLEX TUliES, B- ; A, B, 

 C, F, AS IN FIG. 10. 



-I 



PIG. 15 



SP.\THOGLOTTIS PLICATA ; THE 

 APEX OF THE COLUiJN, WITH THE 

 POLI.IMA REMOVED; SHOWING THE 

 MARGINAL CANALS BETWEEN THE 

 C0LU3IX-WALL AND THE FLOOH, T, OP 

 THE ANTHEU; H, THE ROSTELLUM. 





act of fertilisation has been completed the st 

 obliterated, leaving no room for any foreign "pollen to be 

 applied to its surfoce. The direction taken by the pollen 

 tubes is shown somewhat diagrammatically in Fig. 14. The 

 pollen grains of the caudicles of the poUinia remain as a rule 

 unaffected, but, not being at all viscid^ they are not easily 



