228 CTPEIPEDE^. Chap. VHI 



polished internally ; and this is of much importance, 

 as it prevents insects which have once entered the 

 labellum from escaping through the great opening in 

 the upper surface. In the position in which the flower 

 grows, as here represented, the dorsal surface of the 

 column is uppermost. The stigmatic surface is slightly 

 protuberant, and is not adhesive; it stands nearly 

 parallel to the lower surface of the labellum. With a 

 flower in its natural state, the margin of the dorsal 

 Surface of the stigma can be barely distinguished be- 

 tween the edges of the labellum and through the 

 notch in the rudimentary, shield-like anther («') ; but 

 in the drawing (s, fig. A) the margin of the stigma has 

 been brought outside the edges of the depressed la- 

 bellum, and the toe is a little bent downwards, so that 

 the flower is represented as rather more open than it 

 really is. The edges of the pollen-masses of the two 

 ■ lateral anthers (a) can be seen through the two small 

 orifices or open spaces in the labellum (fig. A) on 

 each side, close to the column. These two orifices are 

 essential for the fertilisation of the flower. 



The grains of pollen are coated by and immersed in 

 viscid fluid, which is so glutinous that it can be drawn 

 out into short threads. As the two anthers stand be- 

 hind and above the lower convex surface (see fig. B) of 

 the stigma, it is impossible that the glutinous pollen 

 can without some mechanical aid get on to this, the 

 efScient surface of the stigma. The economy here 

 shown by Nature in her manner of gaining the same 

 end is surprising. In all the other Orchids seen by 

 me, the stigma is viscid and more or less concave, by 

 which means the dry pollen, transported by means of 

 the viscid matter secreted by the rostellum or niodified 

 stigma, is retained. In Cypripedium the pollen is 

 glutinous, and assumes the function of viscidity, which 



