156 



To rupture the capsule of the disk artificially, a light 

 but appreciable force is required. An attempt to produce 

 rupture by 15 minutes' exposure to chloroform vapour, as 

 in Darwin's experiment, was unsuccessful. Tlie facility Avith 

 which the whole pollinarium may be removed is strongly sug- 

 gestive of an insect-pollinated plant, yet the examination of 

 large numbers of plants revealed the pollinia still in situ and 

 in only one instance was pollen found adhering to the stigma. 

 No difficulty was experienced in removing the pollinia from 

 fully expanded flowers, although R. D. Fitzgerald states that 

 this is impossible. This botanist writes: — "I could discover 

 no trace of a rostellum or disc of any kind. In this flower 

 the persistence with which the pollinia remained behind the 

 stigma, though left naked by the shrinking back of the anther, 

 is very peculiar. No transfer of the substance of the stigma 

 on the point of a pin or a bristle induces them after opening 

 of the flower to come forth for the chance fertilization of 

 another flower. It even requires some violence to break them 

 as the more friable portions turn towards the anther" (Aus- 

 tralian Orchids, vol. i.). 



In the numerous specimens which I have examined from 

 South Australia, Victoria, and Queensland, the "split 

 rostellum," the "boat-formed disk," the "easily-removable 

 pollinia" of Darwin were all present. In fact, Darwin's 

 description of these structures in S. autumnalis may be 

 accepted as a most accurate description of the same structures 

 in the Australian species. The capsule of the disk does not 

 appear to split so readily as in the European species. In no 

 other respect does it appear necessary to modify the great 

 observer's classical description. 



It can hardly be doubted that Fitzgerald's observations 

 were conducted on a species with which Australian botanists 

 are unfamiliar, a species which, so far as is known to the 

 writer, is unrepresented in our national collections. 



Whether Spiranthes australis is self-pollinated or other- 

 wise is a matter which cannot yet be. regarded as settled. 

 Undoubtedly a large number of seed capsules are frequently 

 to be found on some spikes, whereas spikes from other locali- 

 ties display comparatively few. 



Calochilus paludosus, R. Br. Victoria: Bayswater; 

 Mrs. Edith Coleman. 23/10/21. 



Thelymitra megcalyptra, Fitzg. Victona: Grampian 

 Mountains;- J. W. Audas. 31/10/20. 



T. Macmillani, F. v. M. This speeies, which is usually 

 salmon coloured, has been collected by Mr. E. E. Pescott at 

 Bannockburn, Victoria, of a deep rose or crimson colour. 



