SENSITIVE PLANTS. 235 



Similar movements may be observed in the rose- 

 bay willow herb (Epilobium angustifolium). The 

 pistil in the centre of the flower has a four-lobed 

 stigma, supported on an erect style, which is rather 

 longer than the filaments of the stamens. When the 

 flower first opens, the lobes are closely applied to 

 each other, and the style and stamens hang down (a). 

 As the anthers become mature the style becomes 

 erect, and the stamens begin to elevate themselves (&). 

 By the time the anthers are fully matured the 

 lobes of the stigma divide and curl outwards and 

 downwards in a circinate manner, so that they may 

 be reached by the anthers ; the filaments become 

 erect, and the pollen is discharged upon the lobes of 

 the stigma (c). After discharging the contents of 

 their anthers the stamens droop and become pendu- 

 lous again, whilst the style remains erect (d). 



Peculiar movements have been observed in other 

 parts of flowers, and in some orchids, as in Mega- 

 cliniumfalcatum, the lip, or labellum, is said to exhibit 

 spontaneous movement. Alluding to these remark- 

 able plants, Dr. Lindley says, 1 " Among many other 

 remarkable peculiarities the irritability of the labellum 

 must not be passed over in silence. This is extremely 

 striking in some species. 3 In Caleana nigrita the 



1 "Vegetable Kingdom," p. 179. 



2 As in various species of Pterostylis, in the genus Mega- 

 clinium, and in Bolbophyllum barbigerum and Careyanum. 



