452 NOTES ON PLANTS INDIGENOUS TO SYDNEY. 



is also prevented from contact with them, by the indusium 

 completely covering it ; and separated, too, from them, by the 

 corolla. The mouth of the indusium now opens widely and the 

 dense margin of cilia on its edges becomes more erect, forming a 

 stiff brush, likely to sweep the pollen from any insect bearing it. 

 It sometimes happens however, that although the mouth of the 

 indusium is presented to the opening of the corolla, it may not 

 have quite entered it when the stigma is ready to receive pollen ; 

 the slightest touch however of the corolla lobe, from the inside, 

 opens the division, leaving the open indusium and stigma exposed 

 from within, and in such a position, that an insect could not enter 

 the corolla without coming into contact with them. The indusium 

 will often be found in this position, (like that of a person standing 

 in the open door-way of a room, but not actually in the room) open 

 and full of pollen covering the stigma ; and which could only have 

 been placed on it from the inside of the corolla. 



As to the fertilization of this plant ; I think there can be little 

 doubt, when we consider the construction of the flower, that it 

 must be cross-fertilized. Either each flower must be fertilized by 

 its own pollen while shut up in the bud ; or by the pollen of some 

 other flower, after the relative positions of the stigma and anthers 

 are so changed, that contact between them is impossible. The 

 first is unlikely, since neither pollen or stigma is mature ; and in 

 all the flowers I have examined in the bud, either cpiite closed or 

 partly open, I have found the anthers unbroken and the open 

 indusium free from pollen. Of course, it is quite possible, that an 

 insect may alight on the anthers, load itself with pollen, and then 

 go directly to the stigma of the same flower ; and there is also a 

 chance of its leaving pollen on one flower which it had gathered 

 from another on the same plant ; but there can be little doubt that 

 the species to which I have referred (and perhaps the whole genus) 

 are entirely dependent upon insects for their fertilization. 





