60 



masses is hastened and assisted by numerous minute crawling 

 insects which, seem to frequent these flowers in great numbers. 



Thelymitra venosa, Br. PI. ix.B. 



This pretty swamp form with its dainty blue flowers would, 

 one would think, prove sufficiently attractive to induce many 

 insects to visit it. Nevertheless, its mechanism is adapted 

 entirely for self-pollination, which, as in the case of T. luteo- 

 cilium, is accomplished in the very early bud long before there 

 is any possibility of expansion of the flower. It blooms in 

 December, and the flowers open freely in the sunshine. 



The column is winged, its lateral appendages erect, rather 

 blunt, spirally twisted, not pencillate. These appendages are 

 connected to each other and to the back of the anther towards 

 its base by an inconspicuous crest. They do not reach the level 

 of the anther-point when dehiscence takes place,, but may sub- 

 sequently much exceed it, owing to alterations in the position 

 of the anther itself. 



The anther is attached close to the top of the column, and 

 even in the very early bud it will be found that only a small 

 portion of its base lies below the level of the upper border of 

 the stigma and that its bifid point is already carried well 

 forward, so as to cause the pollen-cases to overhang the stig- 

 matic surface. The pollen-cases are very protruberant, and 

 there is no caudicle and no connection of any kind between the 

 pollen masses and the rostellum. 



The stigma is placed in a plane making an angle of about 

 45° with the vertical column, its upper margin is bicusped, and 

 the wings of the column unite, so as to form a sort of cup 

 at its base. 



The pollen is very friable, and, as already stated, dehis- 

 cence of the anther takes place in the early bud (figs. 1 and \a). 

 The pollinia cannot be removed by touching the rostellum. 



Just before expansion of the flower the anther assumes an 

 angle of about 45° with the column (figs. 2 and 2a), thus bring- 

 ing its point to a lower level than that of the lateral append- 

 ages. There is thus an angle of about 90° between anther and 

 stigma, and the granular pollen falls plentifully upon the latter 

 (figs. 3 and Za). Loss is guarded against by the retracting 

 anther-cases above and the cup-like depression at the base of 

 the stigma below. 



By the time the flower has become fully expanded (figs. 

 4 and 4ca) the anther is almost horizontal, and the stigma has 

 lost its glistening appearance ; it has become tumid, and has 

 swollen up to a level with the edges of the column cup. 



