39 



ORCHIS MASCULA. 



PAKT II. 



Fig. 73. Orchis mascula : Front view 

 of flower, with sepals and petals re- 

 moved ; a, anther ; 

 stigma ; 7, labellum. 



extraordinary forms. It is called the labellum, or lower 

 lip ; it secretes nectar, a sweet juice, to attract in- 

 sects, and is often produced 

 into a long, hollow, spur-like 

 nectary, as in fig. 72 n. On 

 that side of the spur which 

 is opposite to the labellum, 

 the organs of reproduction 

 are so placed, that an insect 

 alighting upon the labellum 

 cannot insert its proboscis 

 into the nectary tube to eat 

 the honey, without touching 

 them. 



Mr. Darwin, in his admi- 

 rable work on the ' Fertiliza- 

 tioii of Orchids,' assumes the 

 Orchis mascula as a type for 

 explaining the mechanism of the reproductive organs 

 of the Orchidacese generally. Fig. 73 represents a front 

 view of the flower with -all the sepals and petals cut off, 

 except the labellum, or lip ; and fig. 72 is a side view of 

 the same, with the near half of the labellum cut away, 

 as well as the upper portion of the near side of the 

 nectary, or spur. 



In all common Orchids there is only one stamen, which 

 is confluent with the three pistils, to form what is called 

 the column. The edges of the labellum are attached to 

 the sides of the column, leaving a space known as the 

 chamber or mouth of the nectary, and thus the mouth 

 has the column on one side, and the labellum on the 

 other. Although the three pistils are united into one, the 

 three stigmas are not; for the stigma of the upper pistil 

 is transformed into a pouch-shaped viscous mass (r, fig. 

 73), called the rostelluin, bearing no resemblance what- 

 ever to a stigma, while the other two stigmas form a bi- 



