57 



and completed the tilting movement of the lower ends of the 

 pollen-cases. The pollinia are now divergent and quite 

 horizontal, and may be easily removed by a touch on the ros- 

 tellum. Their position behind the stigma renders self- 

 pollination impossible. The rough and prominent anther- 

 point affords an excellent landing place for an insect. The 

 reddish-brown lateral appendages not only attract the attention 

 of a visitor to this platform, but likewise prevent it from travel- 

 ling towards the back, rather than towards the front of the 

 column. 



ThELYMITRA MACMILLANI, F. V. M. 



Unlike Thelymitra antennifera^ T. macmillani is a rare 

 orchid. Structurally it approximates closely to the former, 

 and its mechanism of pollination appears to be the same. The 

 flower is a salmon-red ; the lateral appendages are tall, nar- 

 row, yellow structures ; and the rough, yellow anther-point is 

 longer, narrower, and more prominent than in the case of its 

 ally. 



Thelymitra luteocilium, Fitz. PI. viii.B. 



As T. anteiiiufera typifies the mechanism of cross- 

 pollination in the genus Thehjmtfia, so T. luteocilium typifies 

 the mechanism of self-pollination. The flowers of this species 

 cannot be said never to open, but they open very rarely, and 

 then only on hot days. They are, however, fertilized in the 

 bud long before expansion is possible, and before the full size 

 of the mature flower has been attained. One has indeed to 

 search diligently to find a bud young enough to show the con- 

 dition of the parts prior to dehiscence of the anther. 



In such a bud (fig. 1) the middle lobe of the column is 

 cristate and forms an incomplete hood. The lateral lobes are 

 yellow, pencillate, and vertical, rising to about the same level 

 as the middle lobe. The anther is attached to the front of 

 the column near the top. Its rather blunt triangular point 

 is situated between the lateral appendages. The pollen-cases 

 form two long convex somewhat triangular bodies, with a deep 

 sulcus in the middle line between them. Their lower borders 

 rest on the two cusps which represent the upper margin of the 

 stigma, and between them, where the two cusps join, is situated 

 the rostellum. The stigma itself is placed obliquely from above 

 downwards and forwards, and the wings of the column pass 

 forward and unite in front of its lower border, so as to form 

 a cup-like depression. 



At a rather more advanced stage (fig. 2), but long before 

 the flower is capable of expanding, the pollen-cases dehisce in 

 a valvular way along their internal and lower borders, ex- 

 posing the very granular pollen within them. There is no 



