ORCHIDS 159 



night. Though the flowers are not otherwise faded, 

 the lip on the oldest flower, which stood so stiff and 

 erect, will now droop forward, and its gay beard 

 will hide its colours upon the upturned stigma. 

 You will find the same to be true of the lips of older 

 flowers as they grow in the fields. Here, then, is 

 a distinct mechanism, planned to accomplish some 

 purpose in the direction of cross-fertilisation. The 

 change in the lip has modified the flower com- 

 pletely, as seen in the two sketches. A bee ap- 

 proaching the upper blossom will naturally make 

 for the bright spot on the erect lip, and cling fast to 

 the roughened, hairy surface. But where the lip 

 has shut down, the heart of the flower will seem 

 closed, and the bee will alight on the petal which 

 hangs down in the middle, a landing-stage directly 

 under the pollen-sacs. 



Here, then, is my explanation of the action of 

 the flower : A bee comes to a mature blossom whose 

 lip is depressed, alights upon the lower petal, which 

 serves as a lip or door-step in this new position, and 

 thrusting his head in under the column where nectar 

 ought to be, he casually knocks off the cap from 

 the pollen-cells and receives a charge of pollen. 



He probably goes away from this visit disap- 

 pointed as to nectar, but seeks a more hospitable 

 flower elsewhere, whose lip is erect. Now, with the 

 pollen upon his back, how can he deposit it on the 



