228 THE ORCHIDACEiE OF THE 



Other and the shape of the mass of pollen-grains are variable. 

 The caudicles of the pollinia are remarkably long, thin, and 

 flexible, instead of being, as in the other Ophryece, rigid enough to 

 stand upright. They are necessarily curved forward at their upper 

 ends, owing to the shape of the anther-cells, and the pear-shaped 

 masses of pollen lie embedded high above and directly over the 

 stigma. The anther-cells naturally open soon after the flower is 

 fully expanded, and the thick ends of the pollinia fall out, the 

 viscid discs still remaining in their pouches. Slight as is the 

 weight of the pollen, yet the caudicle is so thin, and soon 

 becomes so flexible, that, in the course of a few hours, they sink 

 down until they hang freely in the air (see lower pollen mass in 

 Fig. 11,//^*, exactly opposite to, and in front of, the stigmatic 

 surface. When in this position a breath of air, acting on the 

 expanded petals, sets the flexible and elastic caudicles vibrating, 

 and they almost immediately strike the viscid stigma, and, being 

 thus secured, impregnation is efl'ected. To make sure that no 

 other aid was requisite, though the experiment was superfluous, I 

 covered up a plant under a net, so that some wind but no insects 

 could pass in, and in a few days the pollinia had become attached 

 to the stigmas ; but the pollinia of a spike kept in water in a still 

 room remained free, suspended in front of the stigma. Robert 

 Brown* first observed that the structure of the Bee Ophrys is 

 adapted for self-fertilisation. When we consider the unusual and 

 perfectly-adapted length, as well as the remarkable thinness, of 

 the caudicles of the pollinia : when we see that the anther-cells 

 naturally open, and that the masses of pollen from their weight 

 slowly fall down to the level of the stigmatic surface, and are there 

 made to vibrate to and fro by the slightest breath of wind till the 

 stigma is struck : it is impossible to doubt that these points of 

 structure and function, which occur in no other British Orchid, 

 are specially adapted for self-fertilisation. The result is what 

 might have been anticipated. 



" I have often noticed that the spikes of the Bee Ophrys appar- 

 ently produced as many capsules as flowers. NearTorquay I carefufly 

 examined many dozen plants, some time after the flowering season, 

 and on all I found from one to four and occasionafly five capsules, 



=^ Trans. Lin. Society, Vol. XVI., p. 740. 



