52 



iDetter seen in fig. 3, which shows the column from the back. 

 They are attached to the sides of the anther-case at its base. 

 The blunt point of the anther (fig. 3, a) is incurved over the 

 rostellum, and if it be examined at this stage it vi\\\ be found 

 that dehiscence has already commenced, as indicated by an 

 . oblique slit in the anterior surface of each chamber, through 

 which the pollen can be seen. This is moderately friable and 

 inaccessible, unless the anther is forcibly disturbed from its 

 natural position. The pollen-masses are guarded by the 

 anther-case behind, the stigma in front, and the lateral 

 appendages at the sides. 



2. The flower has just expanded. The labellum has 

 descended, and the lateral sepals are almost horizontal. 

 Dehiscence of the anther is complete. The rostellum has bent 

 a little forward (fig. 4, r), and it can be seen that the pollinia 

 are still retained loosely within the anther-case. They are 

 united at their upper ends and are simply hung like saddle- 

 bags on each side of the septum, which divides the case into 

 two loculi. There is no connection whatever between them 

 and the rostellum. They are not at all sticky, and when 

 removed present the appearance shown in fig. 7, where their 

 anterior surface is uppermost. 



3. At slightly more advanced stage the stigma is still 

 glistening and moist-looking. The anther-tip has retracted 

 slightly and the rostellum continued to bend forward. At this 

 stage the pollen-masses, still attached at their upper narrow 

 ends, drop accurately from their loculi, one on each side of the 

 little mesial ridge already referred to on the back of the 

 stigma. This ridge now exactly occupies the anterior groove 

 between the pollinia, and helps to retain them in position. 

 This position is further secured by the lateral appendages of 

 the column, which prevent the masses from being shifted to 

 either side. 



4. Shortly after the pollen-masses have fallen from their 

 loculi they become adherent to the back of the stigma. The 

 late R. D. Fitzgerald noticed and recorded this interesting fact 

 some years ago, and thought that the subsequent pollination 

 was effected by an erosion of the anterior wall of the stigma 

 until the pollen gains access to that surface. I have not been 

 able to verify this observation. Nor is there any curling back 

 of the stigmatic margins, so as to bring the anterior surface 

 into contact with the pollen, such as occurs in some of the 

 Thelymitras. 



What does happen is that about the time adhesion is going 

 to take place there is a general softening of the stigmatic plate 

 and some of the pollen grains germinate. The actuating cause 

 of their germination is still obscure. So far as I am aware, 



