Chap. VIII. OYPEIPEDIUM. 231 



orifices, always coTered with pollen. I repeated tke 

 operation five times, always with the same result. I 

 afterwards cut away the labellum, so as to examine the 

 stigma, and found its whole surface covered with pollen. 

 It should be noticed that an insect in making its escape 

 must first brush past the stigma and afterwards one of 

 the anthers, so that it cannot leave pollen on the 

 stigma, until being already smeared with pollen from 

 one flower it enters another ; and thus there will be a 

 good chance of cross-fertilisation between two distinct 

 plants. Delpino* with much sagacity foresaw that 

 some insect would be discovered to act in this manner ; 

 for he argued that if an insect were to insert its pro- 

 boscis, as I had supposed, from the outside through 

 one of the small orifices close to one of the anthers, the 

 stigma would be liable to be fertilised by the plant's 

 own pollen : and in this he did not believe, from 

 having confidence in what I have often insisted on — 

 namely, that all the contrivances for fertilisation are 

 arranged so that the stigma shall receive pollen from 

 a distinct flower or plant. But these speculations are 

 now all superfluous; for, owing to the admirable ob- 

 servations of Dr. H. Miiller, t we know that Cypri- 

 pedium caleeolus in a state of nature is fertilised in the 

 manner just described by bees belonging to five species 

 of Andrena. 



Thus the use of all the parts of the flower, — namely, 

 the inflected edges, or the polished inner sides of the 

 labellum, — the two orifices and their position close to 

 the aipithers and stigma, — the large size of the medial 

 rudimentary stamen, — are rendered intelligible. An 



♦ ' Feoondazione nelle Piante xxv. III. Folge, v. Bd. p. 1 : see 



Antnoarpee,' 1867, p. 20. also 'Befruohtung der Blumen,' 



t ' Verb. d. Nat. Ver. fur Pr. 1873, p. 76. 

 Eheinland und Weetfal.' Jahrg. 



